[Federal Register Volume 67, Number 15 (Wednesday, January 23, 2002)]
[Rules and Regulations]
[Pages 3370-3410]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-106]
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Part III
Environmental Protection Agency
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40 CFR Parts 9 and 434
Coal Mining Point Source Category; Amendments to Effluent Limitations
Guidelines and New Source Performance Standards; Final Rule
Federal Register / Vol. 67, No. 15 / Wednesday, January 23, 2002 /
Rules and Regulations
[[Page 3370]]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Parts 9 and 434
[FRL-7125-4]
RIN 2040-AD24
Coal Mining Point Source Category; Amendments to Effluent
Limitations Guidelines and New Source Performance Standards
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
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SUMMARY: EPA is amending the current regulations for the Coal Mining
Point Source Category by adding two new subcategories to the existing
regulation. EPA is establishing a Coal Remining Subcategory that will
address pre-existing discharges at coal remining operations. EPA also
is establishing a Western Alkaline Coal Mining Subcategory that will
address drainage from coal mining reclamation and non-process areas in
the arid and semiarid western United States. These amendments do not
otherwise change the existing regulations.
The establishment of new subcategories has the potential to create
significant environmental benefits at little or no additional cost to
the industry. Establishing the Coal Remining Subcategory will encourage
remining activities and will reduce hazards associated with abandoned
mine lands. The new subcategory has the potential to significantly
improve water quality by reducing the discharge of acidity, iron,
manganese, and sulfate from abandoned mine lands. EPA projects total
monetized annual benefits of $0.7 million to $1.2 million due to
remining. Additionally, EPA expects that this regulation will result in
significant ecological and public safety benefits that could not be
quantified and/or monetized. EPA projects that the annual compliance
cost for this new subcategory will be $0.33 million to $0.76 million.
EPA estimates that the Western Alkaline Coal Mining Subcategory
will result in a net cost savings to affected surface mine operators.
The monetized and non-monetized benefits for this subcategory are a
result of adopting alternative sediment control technologies for
reclamation and non-process areas in the arid west. These technologies
are projected to increase the volume of storm water drainage to arid
watersheds and avoid the disturbance of approximately 600 acres per
year, thus reducing severe erosion, sedimentation, hydrologic
imbalance, and water loss. EPA projects that the subcategory will
result in annualized monetized benefits of $0.04 to $0.75 million.
DATES: This regulation is effective February 22, 2002.
ADDRESSES: A copy of the supporting documents cited in this document
are available for review at EPA's Water Docket; Room EB57, 401 M
Street, SW, Washington, DC 20460. A copy of the record supporting the
development of the Western Alkaline Coal Mining Subcategory is also
available for review at the Office of Surface Mining Library, 1999
Broadway, 34th Floor, Denver, CO. The public record for this rulemaking
has been established under docket number W-99-13, and includes
supporting documentation. The public record supporting this rule does
not include any information claimed as Confidential Business
Information (CBI). For access to EPA docket materials, please call
(202) 260-3027 between 9 a.m. and 3:30 p.m Eastern Standard Time,
Monday through Friday, excluding Federal holidays, to schedule an
appointment. For access to docket materials at the Office of Surface
Mining Library, please call (303) 844-1436 between 8 a.m. and 4 p.m.
Mountain Standard Time to schedule an appointment.
FOR FURTHER INFORMATION CONTACT: For additional technical information
contact William Telliard at (202) 260-7134 or
``[email protected]''. For additional economic information
contact Kristen Strellec at (202) 260-6036 or
``[email protected]''.
SUPPLEMENTARY INFORMATION: Regulated Entities: Entities potentially
regulated by this action include:
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Examples of
Category regulated SIC codes NAICS codes
entities
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Industry..................... Operations 1221 212111
engaged in the 1222 212112
remining of 1231 212113
abandoned
surface and
underground
coal mines and
coal refuse
piles for
remaining coal
reserves in
areas
containing
discharges
defined as
``pre-
existing''
Operations
engaged in
coal mine
reclamation
activities in
the arid and
semiarid
western coal
region..
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This table is not intended to be exhaustive, but rather provides a
guide for readers regarding entities likely to be regulated by this
action. This table lists the types of entities that EPA is now aware
could potentially be regulated by this action. Other types of entities
not listed in the table could also be regulated. To determine whether
your facility is regulated by this action, you should carefully examine
the applicability criteria in 40 CFR part 434. If you have questions
regarding the applicability of this action to a particular entity,
consult the person listed for technical information in the preceding
FOR FURTHER INFORMATION CONTACT section.
Judicial Review
In accordance with 40 CFR 23.2, this rule will be considered
promulgated for purposes of judicial review at 1 p.m. Eastern Standard
Time on February 6, 2002. Under section 509(b)(1) of the Clean Water
Act, judicial review of this regulation can be obtained only by filing
a petition for review in the United States Court of Appeals within 120
days after the regulation is considered promulgated for purposes of
judicial review. Under section 509(b)(2) of the Clean Water Act, the
requirements in this regulation may not be challenged later in civil or
criminal proceedings brought by EPA to enforce these requirements.
Compliance Dates
Existing direct dischargers must comply with limitations based on
the Best Practicable Control Technology Currently Available (BPT), Best
Conventional Pollutant Control Technology (BCT), and Best Available
Technology Economically Achievable (BAT) as soon as their National
Pollutant Discharge Elimination System (NPDES) permits include such
limitations. The compliance date for New Source Performance Standards
(NSPS) is the date the new source commences discharging.
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Supporting Documentation
The regulations are supported by several key documents:
1. ``Coal Remining Best Management Practices Guidance Manual'' (EPA
821-B-01-010). This document describes abandoned mine land conditions
and the performance of Best Management Practices (BMPs) that have been
implemented at remining operations. The BMP Guidance Manual is a
technical reference document that presents research and data concerning
the prediction and prevention of acid mine drainage to the waters of
the United States. There have been minimal changes to the BMP manual
since proposal.
2. ``Coal Remining Statistical Support Document'' (EPA 821-B-01-
011). This document describes the statistical methodology for
establishing and monitoring baseline conditions and setting discharge
limits at remining sites.
3. ``Development Document for Final Effluent Limitations Guidelines
and Standards for the Western Alkaline Coal Mining Subcategory'' (EPA
821-B-01-012): This document presents EPA's technical conclusions
concerning the Western Alkaline Coal Mining Subcategory.
4. ``Economic and Environmental Impact Assessment of Effluent
Limitations Guidelines and Standards for the Coal Mining Industry:
Remining and Western Alkaline Subcategories'' (EPA-821-B-01-013): This
document presents the methodology employed to assess economic and
environmental impacts of the final rule and the results of the
analysis.
5. Statistical Analysis of Abandoned Mine Drainage in the
Assessment of Pollution Load. (EPA 821-B-01-014) This document
describes pollutant characteristics of pre-existing discharges at
abandoned mine lands.
How To Obtain Supporting Documents
All documents are available from the National Service Center for
Environmental Publications, 11029 Kenwood Road, Cincinnati, OH 45242,
(800) 490-9198, http://www.epa.gov/ncepi. Several of these documents
can also be obtained on the Internet, located at http://www.epa.gov/OST/guide/coal. This website also links to an electronic version of
today's notice.
Table of Contents
I. Legal Authority
II. Background
A. Statutory Authorities
1. Clean Water Act
2. Pollution Prevention Act
B. Regulation of the Coal Mining Point Source Category
1. EPA Regulations at 40 CFR Part 434
2. Surface Mining Control and Reclamation Act
3. Rahall Amendment
C. Proposed Rule
III. Summary of Significant Changes to Proposed Rule
A. Coal Remining Subcategory
B. Western Alkaline Coal Mining Subcategory
IV. Scope of Final Regulation
A. Coal Remining Subcategory
B. Western Alkaline Coal Mining Subcategory
V. Development of Final Effluent Limitations Guidelines
A. Coal Remining Subcategory
1. Background
2. Scope of Final Regulation
3. Pollution Abatement Plan
4. Pollution Abatement Plan and Passive Treatment
5. Commingling of Waste Streams
6. Relocation of Pre-Existing Discharges
7. BMP-Only Permits
8. Water Quality Variances
9. BAT for the Coal Remining Subcategory
10. BPT for the Coal Remining Subcategory
11. BCT for the Coal Remining Subcategory
12. NSPS for the Coal Remining Subcategory
B. Western Alkaline Coal Mining Subcategory
1. Background
2. Inspection and Maintenance of BMPs
3. Affected Areas
4. SMCRA Requirements
5. Bond Release
6. Definition of Alkaline Mine Drainage
7. BPT for the Western Alkaline Coal Mining Subcategory
8. BCT for the Western Alkaline Coal Mining Subcategory
9. BAT for the Western Alkaline Coal Mining Subcategory
10. NSPS for the Western Alkaline Coal Mining Subcategory
VI. Statistical and Monitoring Procedures for the Coal Remining
Subcategory
A. Statistical Procedures for the Coal Remining Subcategory
B. Evaluation of Statistical Triggers
C. Sample Collection to Establish Baseline Conditions and to Monitor
Compliance for the Coal Remining Subcategory
D. Regulated Pollutant Parameters in Pre-Existing Discharges
1. Acidity
2. Sulfate
3. Solids
VII. Non-Water Quality Environmental Impacts of Final Regulations
VIII. Environmental Benefits Analysis
A. Coal Remining Subcategory
B. Western Alkaline Coal Mining Subcategory
IX. Economic Analysis
A. Introduction, Overview, and Sources of Data
B. Method for Estimating Compliance Costs
1. Coal Remining Subcategory
2. Western Alkaline Coal Mining Subcategory
C. Costs and Cost Savings of the Final Rule
1. Coal Remining Subcategory
2. Western Alkaline Coal Mining Subcategory
D. Economic Impacts of the Final Rule
1. Economic Impacts for the Coal Remining Subcategory
2. Economic Impacts for the Western Alkaline Coal Mining
Subcategory
E. Additional Impacts
1. Costs to the NPDES Permitting Authority
2. Community Impacts
3. Foreign Trade Impacts
F. Cost Effectiveness Analysis
G. Cost Benefit Analysis
X. Regulatory Requirements
A. Executive Order 12866: Regulatory Planning and Review
B. Regulatory Flexibility Act (RFA), as amended by the Small
Business Regulatory Enforcement Fairness Act of 1996 (SBREFA)
C. Congressional Review Act
D. Paperwork Reduction Act
E. Unfunded Mandates Reform Act
F. Executive Order 13175: Consultation and Coordination with Indian
Tribal Governments
G. Executive Order 13132: Federalism
H. National Technology Transfer and Advancement Act
I. Executive Order 13045: Protection of Children from Environmental
Health Risks and Safety Risks
J. Executive Order 13211: Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use
XI. Regulatory Implementation
A. Upset and Bypass Provisions
B. Variances and Modifications
1. Fundamentally Different Factors Variances
2. Permit Modifications
C. Relationship of Effluent Limitations to NPDES Permits and
Monitoring Requirements
D. Analytical Methods
XII. Summary of EPA Responses to Significant Comments on Proposal
A. Coal Remining Subcategory
B. Western Alkaline Coal Mining Subcategory
Appendix A: Definitions, Acronyms, and Abbreviations Used in This
Document
I. Legal Authority
These regulations are promulgated under the authority of sections
301, 304, 306, 308, 402, 501, and 502 of the Clean Water Act, 33 U.S.C.
1311, 1314, 1316, 1318, 1342, 1361, and 1362.
II. Background
A. Statutory Authorities
1. Clean Water Act
Congress adopted the Clean Water Act (CWA) to ``restore and
maintain the
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chemical, physical, and biological integrity of the Nation's waters'
(section 101(a), 33 U.S.C. 1251(a)). To achieve this goal, the CWA
prohibits the discharge of pollutants into navigable waters except in
compliance with the statute. The CWA confronts the problem of water
pollution on a number of different fronts. Its primary reliance,
however, is in establishing restrictions on the types and amounts of
pollutants discharged from various industrial, commercial and public
sources of wastewater.
Direct dischargers must comply with effluent limitations in
National Pollutant Discharge Elimination System (``NPDES'') permits;
indirect dischargers must comply with pretreatment standards. These
limitations and standards are established by regulation for categories
of industrial dischargers and are based on the degree of control that
can be achieved using various levels of pollution control technology.
a. Best Practicable Control Technology Currently Available (BPT)--
section 304(b)(1) of the CWA. Effluent limitations guidelines based on
BPT apply to discharges of conventional, toxic, and non-conventional
pollutants from existing sources. BPT guidelines are generally based on
the average of the best existing performance in terms of pollution
control by plants in a particular industrial category or subcategory.
In establishing BPT, EPA considers the cost of achieving pollution
reductions in relation to the pollution reduction benefits, the age of
equipment and facilities, the processes employed, process changes
required, engineering aspects of the control technologies, non-water
quality environmental impacts (including energy requirements), and
other factors the Administrator deems appropriate. Where the pollution
control performance of existing sources for a category or subcategory
is uniformly inadequate, EPA may set BPT by transferring technology
used in a different subcategory or category.
b. Best Available Technology Economically Achievable (BAT)--section
304(b)(2) of the CWA. In general, BAT effluent limitations guidelines
are based on the degree of pollution control achievable by applying the
best available technology economically achievable for facilities in the
industrial subcategory or category. The CWA requires BAT for
controlling the direct discharge of toxic and non-conventional
pollutants. The factors considered in determining BAT for a category or
subcategory include the age of the equipment and facilities involved,
the process employed, potential process changes, engineering aspects of
the control technologies, non-water quality environmental impacts
(including energy requirements), and other factors the Administrator
deems appropriate. EPA retains considerable discretion in assigning the
weight to be accorded these factors. Generally, economic achievability
is determined on the basis of total costs to the industrial subcategory
and their effect on the overall industry's (or subcategory's) financial
health. As with BPT, where existing performance is uniformly
inadequate, BAT may be transferred from a different subcategory or
category. BAT may be based upon process changes or internal controls,
such as product substitution, even when these technologies are not
common industry practice. The CWA does not require cost-benefit
comparison in establishing BAT.
c. Best Conventional Pollutant Control Technology (BCT)--section
304(b)(4) of the CWA. The 1977 amendments to the CWA established BCT as
an additional level of control for discharges of conventional
pollutants from point sources other than publicly owned treatment
works. In addition to other factors specified in section 304(b)(4)(B),
the CWA requires that BCT limitations be established in light of a two
part ``cost-reasonableness'' test. EPA published a methodology for the
development of BCT limitations which became effective August 22, 1986
(51 FR 24974, July 9, 1986).
Section 304(a)(4) designates the following as conventional
pollutants: biochemical oxygen demanding pollutants (measured as
BOD5), total suspended solids (TSS), fecal coliform, pH, and
any additional pollutants defined by the Administrator as conventional.
The Administrator designated oil and grease as an additional
conventional pollutant on July 30, 1979 (44 FR 44501).
d. New Source Performance Standards (NSPS)--section 306 of the CWA.
NSPS reflect effluent reductions that are achievable based on the best
available demonstrated control technology. New facilities have the
opportunity to install the best and most efficient production processes
and wastewater treatment technologies. As a result, NSPS should
represent the most stringent controls attainable through the
application of the best available control technology for all pollutants
(i.e., conventional, nonconventional, and priority pollutants). In
establishing NSPS, EPA is directed to take into consideration the cost
of achieving the effluent reduction and any non-water quality
environmental impacts and energy requirements.
e. Pretreatment Standards for Existing Sources (PSES)--section
307(b) of the CWA--and Pretreatment Standards for New Sources (PSNS)--
section 307(b) of the CWA.
Pretreatment standards are designed to prevent the discharge of
pollutants to a publicly-owned treatment works (POTW) which pass
through, interfere, or are otherwise incompatible with the operation of
the POTW. Since none of the facilities to which this rule applies
discharge to a POTW, pretreatment standards are not part of this
rulemaking.
f. CWA section 304(m) Requirements. Section 304(m) of the CWA,
added by the Water Quality Act of 1987, requires EPA to establish
schedules for (1) reviewing and revising existing effluent limitations
guidelines and standards and (2) promulgating new effluent guidelines.
On January 2, 1990 (55 FR 80), EPA published an Effluent Guidelines
Plan, which established schedules for developing new and revised
effluent guidelines for several industry categories. The Natural
Resources Defense Council, Inc., challenged the Effluent Guidelines
Plan in a suit filed in the U.S. District Court for the District of
Columbia (NRDC v. Browner, Civ. No. 89-2980). On January 31, 1992, the
Court entered a consent decree (the ``304(m) Decree''), which
established schedules for EPA's proposal of and final action on
effluent guidelines for a number of point source categories. The
Effluent Guidelines Plan published in the Federal Register on September
4, 1998 (63 FR 47285) required, among other things, that EPA propose
the Coal Mining Effluent Guidelines by December 1999 and take final
action on the Guidelines by December 2001. On November 19, 1999, the
Court modified the decree revising the deadline for proposal to March
31, 2000. The deadline of December 2001 for taking final action on
these guidelines was not modified.
2. Pollution Prevention Act
The Pollution Prevention Act of 1990 (PPA) (42 U.S.C. 13101 et
seq., Public Law 101-508, November 5, 1990) ``declares it to be the
national policy of the United States that pollution should be prevented
or reduced whenever feasible; pollution that cannot be prevented should
be recycled in an environmentally safe manner, whenever feasible;
pollution that cannot be prevented or recycled should be treated in an
environmentally safe manner whenever feasible; and disposal or release
into the environment should be employed only as a last resort * * *''
(Sec. 6602; 42 U.S.C. 13101 (b)). In
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short, preventing pollution before it is created is preferable to
trying to manage, treat or dispose of it after it is created.
The PPA directs EPA to, among other things, ``review regulations of
the EPA prior and subsequent to their proposal to determine their
effect on source reduction'' (Sec. 6604; 42 U.S.C. 13103(b)(2)). Source
reduction reduces the generation and release of hazardous substances,
pollutants, wastes, contaminants, or residuals at the source, usually
within a process. The term source reduction ``includes equipment or
technology modifications, process or procedure modifications,
reformulation or redesign of products, substitution of raw materials,
and improvements in housekeeping, maintenance, training or inventory
control. * * * The term source `reduction' does not include any
practice which alters the physical, chemical, or biological
characteristics or the volume of a hazardous substance, pollutant, or
contaminant through a process or activity which itself is not integral
to or necessary for the production of a product or the providing of a
service'' (42 U.S.C. 13102(5)). In effect, source reduction means
reducing the amount of a pollutant that enters a waste stream or that
is otherwise released into the environment prior to out-of-process
recycling, treatment, or disposal.
In today's rule, EPA encourages pollution prevention by requiring
the use of site-specific Best Management Practices (BMPs) that are
integral to remining operations in abandoned mine lands and to
reclamation activities in the arid and semiarid western coal regions.
These BMPs, under each subcategory, are designed and implemented to
improve existing conditions and to reduce pollutant discharges at the
source, thereby reducing the need for treatment.
B. Regulation of the Coal Mining Point Source Category
1. EPA Regulations at 40 CFR Part 434
On October 9, 1985 (50 FR 41296), EPA promulgated effluent
limitations guidelines and standards that are in effect today under 40
CFR part 434. Prior to today's rule, there were four subcategories:
Coal Preparation Plants and Coal Preparation Plant Associated Areas;
Acid or Ferruginous Mine Drainage; Alkaline Mine Drainage; and Post-
Mining Areas. Additionally, there is a subpart for Miscellaneous
Provisions. The subcategories include BPT, BAT, and NSPS limitations
for TSS, pH, iron, manganese, and/or settleable solids (SS).
2. Surface Mining Control and Reclamation Act
In 1977, Congress enacted the Surface Mining Control and
Reclamation Act (SMCRA), 30 U.S.C. 1201 et seq, to address the
environmental problems associated with coal mining on a nationwide
basis. SMCRA created the Office of Surface Mining Reclamation and
Enforcement (OSMRE) within the Department of Interior, which is
responsible for preparing regulations and assisting the States
financially and technically to carry out regulatory activities.
Title V of the statute gives OSMRE broad authority to regulate
specific management practices before, during, and after mining
operations. OSMRE has promulgated comprehensive regulations to control
both surface coal mining and the surface effects of underground coal
mining (30 CFR parts 700 et seq). Implementation of these requirements
has significantly improved mining practices, control of water
pollution, and protection of other resources. Title IV of SMCRA
addresses the problem of presently abandoned coal mines by authorizing
and funding abandoned mine reclamation projects.
All mining operations subject to today's regulation must also
comply with SMCRA requirements. EPA has worked extensively with OSMRE
in the preparation of this rule in order to ensure that today's
requirements are consistent with OSMRE requirements.
3. Rahall Amendment
As part of the 1987 amendments to the CWA, Congress added Section
301(p), often called the Rahall Amendment, to provide incentives for
remining abandoned mine lands that pre-date the passage of SMCRA in
1977. Section 301(p) provides an exemption for remining operations from
the BAT effluent limits for iron, manganese, and pH for pre-existing
discharges from abandoned mine lands. Instead, a permit writer may set
site-specific, numerical BAT limits for pre-existing discharges based
on Best Professional Judgement (BPJ). The effluent limits may not allow
discharges to exceed pre-existing ``baseline'' levels of iron,
manganese, and pH. In addition, the permit applicant must demonstrate
that the remining operation ``will result in the potential for improved
water quality from the remining operation.'' The Rahall Amendment
defines remining as a coal mining operation which began after February
4, 1987 at a site on which coal mining was conducted before August 3,
1977, which was the effective date of SMCRA. Thus, the Rahall Amendment
attempted to encourage remining by no longer requiring operators to
treat degraded pre-existing discharges to the BAT levels established in
Subpart C of 40 CFR part 434.
Despite the statutory authority provided by the Rahall Amendment,
coal mining companies remained hesitant to pursue remining without
formal EPA approval and guidelines. Today's regulation establishes
requirements for determining baseline pollutant loadings in pre-
existing discharges. It also specifies how to determine site-specific
BAT requirements for remining operations and how to demonstrate the
potential for environmental improvement from a remining operation. EPA
is today promulgating a regulation that is consistent with, but not
identical to, the Rahall Amendment.
C. Proposed Rule
On April 11, 2000 (65 FR 19440), EPA published proposed amendments
to effluent limitations guidelines and new source performance standards
for the coal mining point source category. EPA proposed adding two new
subparts to the existing regulations at 40 CFR part 434 applicable to
Coal Remining (subpart G) and Western Alkaline Coal Mining (subpart H).
In the proposal, EPA solicited comment on 18 specific areas
identified by the Agency, in addition to a general comment solicitation
on all aspects of the proposed regulation. During the comment period,
EPA held public meetings in three locations in the western coal mining
region (Denver, CO; Gillette, WY; and Flagstaff, AZ) and three public
meetings in areas affected by remining (Nitro, WV; Frankfort, KY; and
Zanesville, OH) to explain the proposal and to solicit comment.
On July 30, 2001 (66 FR 39300), EPA published a Notice of Data
Availability (NODA) to provide a discussion of options relating to two
issues raised by commenters on the Coal Remining Subcategory that were
not presented in the proposal. EPA presented these comments, data
collected since the proposal, and options being considered for the
final rulemaking in the notice and solicited comment on: (1) The
expansion of applicability of the Coal Remining Subcategory to sites
abandoned after 1977, and (2) alternative effluent limits for solids in
pre-existing discharges. The majority of comments received supported
these proposed changes. In Section XII of this document, EPA presents a
summary of the significant comments received on the proposal and NODA
and a summary of the Agency's responses. The complete
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set of comments and EPA's detailed responses can be found in the
``Comment Response Document for the Coal Remining and Western Alkaline
Coal Mining Subcategories'' (DCN 3056).
III. Summary of Significant Changes to Proposed Rule
Based on comments received, EPA has made several changes to the
proposed subcategory applicability, regulated parameters, and
statistical methodology presented in the April 11, 2000 Federal
Register notice. EPA has summarized these changes below, and is
presenting its rationale for these changes in Sections V and VI of this
document.
A. Coal Remining Subcategory
At proposal, EPA defined a remining operation as a coal
mining operation at a site on which coal mining was conducted prior to
August 3, 1977. EPA has modified the definition of ``remining'' to
include coal mining operations on sites where coal mining was
previously conducted and where the site was abandoned or the
performance bond forfeited after August 3, 1977. The rationale for
these changes is provided in Section V of this document.
EPA proposed to establish alternative effluent limitations
for pH, iron, and manganese. EPA has modified the pollutants to be
regulated by setting limits for net acidity instead of pH, and by
establishing alternative limitations for sediment such that solids
loads cannot be increased over baseline during remining and reclamation
activities, but must meet standards for post-mining areas prior to bond
release. The rationale for this decision is described in Section VI.D
of this document.
For pre-existing discharges where it is infeasible to
determine baseline conditions for discharge monitoring, EPA is
providing an exclusion from numeric standards. In these cases, the coal
mining operator will be required to implement a pollutant abatement
plan. The rationale for this decision is described in Section V of this
document.
For the calculation and monitoring of numeric limitations
in pre-existing discharges, EPA has made several changes to the
statistical methodology. Further information on the statistical
procedures is described in sections VI.A and VI.B of this document and
in Appendix B of the final regulation.
B. Western Alkaline Coal Mining Subcategory
In the proposal, EPA limited the application of the
Western Alkaline Coal Mining Subcategory requirements to ``reclamation
areas'' but solicited comment on the possibility of expanding the scope
of coverage to include other areas. EPA received significant comment on
the use of alternative sediment controls for non-process runoff at mine
sites subject to the Western Alkaline Coal Mining Subcategory. Based on
comments received, EPA has revised the applicability of the subcategory
to allow the use of alternative sediment controls on runoff from some
non-process areas of western coal mines. This allowance is discussed in
Section V.B of this document.
At proposal, EPA calculated the costs and benefits based
on a model mine run for conditions present in the desert southwest.
This model represented the ``worst case'' scenario (in that runoff in
the desert southwest contains the highest sediment loadings in the
western alkaline coal regions) in order to demonstrate that alternative
sediment controls can be used effectively to control sediment to below
pre-mined, undisturbed conditions in the arid west. For the final
regulation, EPA incorporated the results for two additional model mines
representing the ``intermountain'' and ``northern plains'' regions. The
changes in EPA's estimates of cost savings and benefits are the result
of using three different model mines to represent three different types
of conditions present in the arid west. The results of these changes
are presented in Sections VIII and IX of this document.
IV. Scope of Final Regulation
Today, EPA is promulgating effluent limitations and performance
standards for the Coal Remining Subcategory and for the Western
Alkaline Coal Mining Subcategory. The new subcategories will be added
to the existing regulations for the Coal Mining Point Source Category
found at 40 CFR part 434. The new subcategories will create a set of
standards and requirements for the specific waste streams defined in
the final regulation. The new subcategories will not otherwise change
the existing regulations.
A. Coal Remining Subcategory
The effluent limitations and standards for the Coal Remining
Subcategory apply to pre-existing discharges that are located within,
or that are hydrologically connected to, pollution abatement areas of a
coal remining operation.
EPA proposed to define coal remining as the mining of surface mine
lands, underground mine lands, and coal refuse piles that were
abandoned prior to the enactment of the Surface Mining Reclamation and
Control Act (August 3, 1977), consistent with the language of the
Rahall Amendment to the Clean Water Act. However, due to the
anticipated benefits of the remining subcategory, EPA received comment
on the proposal requesting that EPA extend the applicability of the
Remining Subcategory to mine lands that have been abandoned since
August 3, 1977. In response to this comment, EPA published a Notice of
Data Availability (NODA) to solicit further comment on the issue,
including whether to limit applicability to mine lands abandoned before
the effective date of today's rule. As described in the NODA, it is
estimated that there are currently 260 bond forfeiture sites producing
acid mine drainage.
EPA concluded that remining of abandoned mine lands (AML) has many
potential benefits, and has decided to extend the applicability of the
subcategory to mine lands that are abandoned after August 3, 1977. EPA
also concluded that there is no basis for precluding applicability of
today's rule to AML abandoned after the effective date of today's rule.
Based on comments received from regulatory authorities, EPA does not
believe that this change will create an incentive for future bond
forfeitures. As noted by commenters, once a coal operator has abandoned
an active permit and forfeited the performance bond, there are
safeguards that prevent the operator from being allowed to mine in the
future. Upon forfeiture of the bond, no portion of the bond would be
returned until the site meets all the standards of the operator's
permit, including the applicable effluent limitations. Secondly, SMCRA
provides an avenue to pursue additional monies and to place additional
liabilities upon an operator if the bond is insufficient to complete
total reclamation. This includes barring the operator from receiving
any other SMCRA permits until reclamation is completed, penalties are
paid, and any outstanding liabilities are resolved.
The provisions of this new subpart apply only to pre-existing
discharges and do not apply to discharges produced or generated in
active mining areas, which include the active mining areas of remining
operations. Section 434.11(b) defines active mining area as ``the area,
on and beneath land, used or disturbed in activity related to the
[[Page 3375]]
extraction, removal, or recovery of coal from its natural deposits.
This term excludes coal preparation plants, coal preparation plant
associated areas and post-mining areas.'' Wastewater discharges
produced or generated by active coal mining operations will remain
subject to the effluent limitations already established in part 434,
Subpart C--Acid or Ferruginous Mine Drainage or Subpart D--Alkaline
Mine Drainage.
Additionally, in accordance with Sec. 434.61, any waste stream
subject to this rule that is commingled for treatment or discharge with
a waste stream subject to another subpart of part 434 will be required
to meet the most stringent limitations applicable to any component of
the combined waste stream. However, EPA would like to further clarify
this statement of applicability for the Coal Remining Subcategory. For
the reasons discussed in the proposal, a waste stream that is
intercepted and/or commingled with active mining wastewater during
remining is subject to the provisions of Sec. 434.61. However,
Sec. 434.61 applies to the commingled waste stream only during the time
when the pre-existing discharge is intercepted by active mining or is
combined with active mine wastewater for treatment or discharge. After
commingling has ceased, the pre-existing discharge remains subject to
the provisions established by the Coal Remining Subcategory.
B. Western Alkaline Coal Mining Subcategory
Today's rule establishes effluent limitations and performance
standards for the Western Alkaline Coal Mining Subcategory applicable
to alkaline mine drainage from reclamation areas, brushing and grubbing
areas, topsoil stockpiling areas, and regraded areas at western coal
mining operations. ``Western coal mining operation'' is defined as a
surface or underground coal mining operation located in the interior
western United States, west of the 100th meridian west longitude, in an
arid or semiarid environment with an average annual precipitation of
26.0 inches or less. ``Alkaline mine drainage'' is defined as ``mine
drainage which, before any treatment, has a pH equal to or greater than
6.0 and total iron concentration of less than 10 mg/L.'' The Western
Alkaline Coal Mining Subcategory may also apply to drainage where the
total iron concentration is greater than 10 mg/L, provided that the
discharge, before any treatment, has a pH equal to or greater than 6.0,
and a dissolved iron concentration less than 10 mg/L; and a net
alkalinity greater than zero.
The regulation applies to the following areas:
``Reclamation area'' is the surface area of a coal mine
which has been returned to required contour and on which revegetation
(specifically, seeding or planting) work has commenced.
``Brushing and grubbing area'' is the area where woody
plant materials that would interfere with soil salvage operations have
been removed or incorporated into the soil that is being salvaged.
``Topsoil stockpiling area'' is the area outside the
mined-out area where topsoil is temporarily stored for use in
reclamation, including containment berms.
``Regraded area'' is the surface area of a coal mine which
has been returned to required contour.
The provisions in Subpart D--Alkaline Mine Drainage will continue
to apply to discharges produced or generated in active mining areas.
Section 434.11(b) defines active mining area as ``the area, on and
beneath land, used or disturbed in activity related to the extraction,
removal, or recovery of coal from its natural deposits. This term
excludes coal preparation plants, coal preparation plant associated
areas and post-mining areas.'' Wastewater discharges produced or
generated by active coal mining operations will not be affected by this
regulation and will remain subject to the effluent limitations already
established in part 434.
Additionally, in accordance with Sec. 434.61, any waste stream
subject to this rule that is commingled with a waste stream subject to
another subpart of part 434 will be required to meet the most stringent
limitations applicable to any component of the combined waste stream.
Today's new rule simply maintains this regulatory approach.
V. Development of Final Effluent Limitations Guidelines
In this section, EPA describes the rationale for the development of
the final limitations and guidelines being promulgated today. For more
detailed information on the profile of the industry, please see section
IV, ``Industry profile,'' in the April 11, 2000 proposal. For more
detailed information on the data gathering efforts used to support this
regulation, please see section V, ``Summary of data gathering
efforts,'' in the proposal.
A. Coal Remining Subcategory
1. Background
Coal remining is the mining of surface mine lands, underground mine
lands, and coal refuse piles that have been previously mined. Acid mine
drainage from abandoned coal mines is damaging a significant number of
waterways in the Appalachian and mid-continent coal regions of the
eastern United States. Information gathered from the Interstate Mining
Compact Commission (IMCC) and the Office of Surface Mining and
Regulatory Enforcement (OSMRE) Abandoned Mine Land Inventory System
indicates that there are over 1.1 million acres of abandoned coal mine
lands and over 9,709 miles of streams polluted by acid mine drainage in
Appalachia alone. As discussed in the proposal, EPA recognizes that one
of the most successful means for improvement of abandoned mine land is
for coal mining companies to remine abandoned areas and extract the
coal reserves that remain. EPA also recognizes that if abandoned mine
lands are ignored during mining of adjacent areas, a time-critical
opportunity for reclaiming the abandoned mine land is lost. Once coal
mining operations have ceased on the adjacent areas, there is little
incentive for operators to return.
During remining operations, acid-forming materials are removed with
the extraction of the coal, pollution abatement Best Management
Practices (BMPs) are implemented to control acid-forming materials and
sediment, and the abandoned mine land is reclaimed. During remining,
many of the problems associated with abandoned mine land, such as
dangerous highwalls, vertical openings, and abandoned coal refuse piles
can be corrected without using public funds from OSMRE's Abandoned Mine
Land Program. Furthermore, implementation of appropriate BMPs during
remining operations can be effective at improving the water quality of
pre-existing discharges. For example, implementation of appropriate
BMPs during 112 remining operations in Pennsylvania has been effective
in improving or eliminating acidity loading in 45 percent of the pre-
existing discharges, total iron loading in 44 percent of the
discharges, and total manganese in 42 percent of the discharges. This
improvement has resulted in reduced annual pollutant loadings of up to
5.8 million pounds of acidity, 189,000 pounds of iron, 11,400 pounds of
manganese, and 4.8 million pounds of sulfate. The environmental
benefits associated with reclamation of abandoned mine lands are
discussed further in Section VIII of this document.
[[Page 3376]]
The current regulations at 40 CFR part 434 create a disincentive
for remining because of their high compliance costs. Moreover, the
potential of the statutory exemption contained in the Rahall Amendment
to overcome this disincentive and derive the maximum environmental
benefits from remining operations has not been fully realized in the
absence of implementing regulations. If mining companies face
substantial potential liability or economic loss from remining, they
will continue to focus on mining virgin areas and ignore abandoned mine
lands that may contain significant coal resources. Based on information
collected in support of this regulation, EPA believes that remining
operations are environmentally preferable to ignoring the coal
resources in abandoned mine lands.
As described in Section II of this document, Congress attempted to
address the problems associated with discharges from abandoned mine
lands by passing the Rahall Amendment to provide incentives to
encourage coal remining. The Rahall Amendment (CWA section 301(p))
allows permitting authorities to issue NPDES permits for remining sites
with different requirements than those in the existing regulations for
some pollutant limits. Specifically, section 301(p) allows permit
writers to use best professional judgement (BPJ) to set site-specific
BAT limits determined for pre-existing discharges. These limits may not
exceed baseline levels of iron, manganese, and pH. The operator must
also demonstrate that the remining operation will result in the
potential for improved water quality. The statute does not specify how
to determine site-specific BAT, baseline pollutant discharge levels, or
the potential for improved water quality and has left these up to each
permitting authority to determine.
Between 1987 (date of enactment of Rahall Amendment) and 1999,
seven States established formal remining programs that issued
approximately 330 Rahall permits with numeric limits for pre-existing
discharges that are less stringent than those in the existing
regulations. Of these 330 Rahall remining permits, 300 were issued by
the Commonwealth of Pennsylvania. The remaining thirty Rahall permits
were issued by Alabama, West Virginia, Kentucky, Virginia, Ohio, and
Maryland. Under these Rahall permits, remining operations must meet the
alternate baseline numeric limits specified in the permits and must
implement site-specific BMPs. These BMPs include special handling of
acid-producing materials, daylighting of abandoned underground mines,
control of surface water and ground water, control of sediment,
addition of alkaline material, and passive treatment. Remining
operations currently underway have proven to be a viable means of
remediating the environmental conditions associated with abandoned mine
lands without imposing a significant cost burden on industry (Skousen,
Water Quality Changes and Costs of Remining in Pennsylvania and West
Virginia, 1997).
A discussion paper released by IMCC, EPA and OSMRE in February 1998
(Discussion Paper on Water Quality Issues Related to Remining)
presented an alternative BMP-based remining permit approach where
implementation of BMPs would be the central focus of permitting. This
alternative would not impose any numeric limits for pre-existing
discharges, but would require implementation of selected BMPs. The IMCC
Remining Task Force believes that BMPs can result in improved water
quality and, in certain cases, can qualify as BAT for achieving
standards required by the Clean Water Act. EPA has considered
conditions under which remining permits based solely on BMP
implementation in lieu of numeric effluent limits may be appropriate.
In addition, EPA recently accepted a Coal Remining and Reclamation
Project XL agreement from the Pennsylvania Department of Environmental
Protection. Once completed, this pilot project is expected to provide a
substantial amount of data about remining BMPs in eight different
watersheds throughout Pennsylvania.
2. Scope of Final Regulation
EPA is today promulgating a new remining subcategory with effluent
limitations guidelines based on a combination of numeric limits and
non-numeric BMP requirements. EPA is also allowing effluent limits
based on BMP only requirements where numeric monitoring of a baseline
pre-existing discharge is infeasible. EPA is establishing a
standardized procedure for determining pollutant loadings for baseline
and for compliance monitoring. This procedure is described in Appendix
B of the regulation and in chapter 3 of the Coal Remining Statistical
Support Document. Example calculations using these procedures and
further discussion of EPA's determination of these procedures are
provided in the support document. EPA intends these regulations to
control pre-existing discharges at remining operations in a manner
consistent with, but not identical to, requirements under the Rahall
Amendment. These requirements are effluent limitations guidelines
authorized under section 304(b) of the CWA, but are also in effect
implementing regulations for section 301(p), providing EPA's
interpretation of of the intent of that provision. Section 301(p)
requires the permit authority to establish BAT on a case-by-case basis,
using best professional judgment to set specific numeric effluent
limitations for pH, iron, and manganese in each permit. Section 301(p)
requires the operator to demonstrate that the coal remining operation
will result in the potential for improved water quality, and in no
event may pH, iron, or manganese discharges exceed the levels
discharged prior to the remining operation.
Under the final regulations, the permit will contain specific
numeric and non-numeric requirements, constituting BPT, BCT, BAT and
NSPS. The numeric requirements will be established on a case-by-case
basis in compliance with standardized requirements for statistical
procedures to establish and monitor baseline. The numeric effluent
limitations set at baseline levels will ensure that the pollutant
discharges do not exceed the pollutant levels in the discharges prior
to remining consistent with section 301(p)(2).
The extent of the non-numeric permit provisions will be established
using best professional judgement to evaluate the adequacy of the
selected BMPs contained in a pollution abatement plan to improve
conditions of the abandoned mine lands. The pollution abatement plan
must demonstrate that the remining operation has the potential to
improve water quality, consistent with section 301(p)(2). Together, the
numeric and non-numeric requirements constitute BPT, BCT, BAT and NSPS.
3. Pollution Abatement Plan
In the regulatory text, EPA has included a qualitative description
of the pollutant abatement plan that must be developed. The regulation
requires an operator to prepare a pollution abatement plan that
identifies the characteristics of the remining area and the pre-
existing discharges at the site, identifies design specifications for
selected BMPs, and includes periodic inspection and maintenance
schedules. The pollution abatement plan must demonstrate that there is
a potential for water quality improvement. These requirements are
intended to help the permitting authority evaluate the efficacy of the
plan in relation to the conditions existing at the site. EPA has
provided a support document, the Coal Remining BMP Guidance Manual, to
assist industry and permitting
[[Page 3377]]
authorities in the development and implementation of the pollution
abatement plan. EPA and OSMRE plan to sponsor guidance workshops for
the States and Tribes on implementation issues and approaches to
maximize efficiency and eliminate possible duplication with respect to
requirements in the final rule and SMCRA permitting requirements. Upon
review of the permit application, it is within the discretion of the
regulatory authority to determine whether additional or more intensive
BMPs than those identified in an applicant's proposed plan are
required.
The SMCRA permit application process requires a coal mining
operator to submit an extensive operation and reclamation plan,
documentation, and analysis to OSMRE or the primacy permitting
authority for approval. The requirements for the operation and
reclamation plan are specified in 30 CFR part 780 for surface mining
permit applications and part 784 for underground mining permit
applications. In brief summary, some of the OSMRE requirements that
directly relate to this CWA regulation include requirements for coal
mining operators to provide: a description of coal mining operations; a
plan for reclaiming mined lands; a plan for revegetating mined lands;
geologic information; hydrologic information including: a description
of baseline ground water and surface water characteristics under
seasonal conditions; and an analysis of the hydrologic impacts caused
by the mining activity. Specifically, the plan must include a
``probable hydrologic consequences (PHC)'' determination to determine
the impacts of the mining on existing hydrologic conditions and a
hydrologic reclamation plan to show measures for reducing impacts and
to meet water quality laws and regulations. Furthermore, the coal
mining regulatory authority is required to conduct a cumulative
hydrologic impact analysis of the proposed operation and all
anticipated mining on surface water and ground water systems.
EPA believes that many requirements for the pollution abatement
plan will be contained in the operations and reclamation sections of an
approved SMCRA permit. However, EPA or the State NPDES permitting
authority will retain the authority to require additional or expanded
BMPs as necessary to ensure that implementation of the identified BMPs
is consistent with Clean Water Act requirements. The permitting
authority will evaluate the adequacy of the plan as part of its
evaluation of whether the permit application is complete, pursuant to
40 CFR 124.3(c).
EPA is also requiring that this pollution abatement plan be
developed to the extent practicable for the entire ``pollution
abatement area,'' defined as the area that is causing or contributing
to the baseline pollution load of the pre-existing discharge. The
pollution abatement area shall include the part of the permit area that
is causing or contributing to the baseline pollution load of pre-
existing discharges. The pollution abatement area must include, to the
extent practicable, areas adjacent to and nearby the remining operation
that also must be affected to reduce the pollution load of the pre-
existing discharges and may include the immediate location of the pre-
existing discharges.
Commenters suggested that the definition of pollution abatement
area be modified to include ``adjacent and nearby areas that must be
affected to reduce pollution load.'' EPA agrees with commenters that
the additional flexibility afforded by today's rule is needed to
identify the entire pollution abatement area within which BMPs can
affect improvement in water quality. EPA believes that this will
further the intent of today's regulation by focusing on those areas
that must be affected to achieve improved water quality. In this
manner, the regulatory authority may require a different or larger
permit boundary in order to demonstrate the potential for improvement
in water quality, or to develop a holistic approach for water quality
improvement in the context of related SMCRA programs such as the Acid
Mine Drainage Treatment and Abatement Fund or the Title IV Abandoned
Mine Reclamation Program. This definition reflects the often complex
hydrologic relationships between discharges within or emanating from a
permit area and those which originate on adjacent or nearby sites but
which may affect pollution loadings on the permit site. This is also
consistent with the definition in Pennsylvania's remining program (25
Pa. Code section 87.202).
EPA has defined a pre-existing discharge as ``any discharge
resulting from mining activities that have been abandoned prior to the
time of a remining permit application.'' EPA has modified the
definition of pre-existing discharge from the proposal to address
issues raised by commenters.
4. Pollution Abatement Plan and Passive Treatment
EPA received comments from stakeholders concerned that coal mining
operators may be held perpetually liable for maintaining certain
passive treatment technologies installed during the remining process.
As discussed in section 4.0 of the Coal Remining BMP Guidance Manual,
passive treatment encompasses a series of engineered treatment
practices that require very little or no maintenance once constructed
and operational. Passive water treatment generally involves natural
physical, biochemical, and geochemical actions and reactions, such as
calcium carbonate dissolution, sulfate/iron reduction, bicarbonate
alkalinity generation, metals oxidation and hydrolysis, and metals
precipitation. The systems are commonly powered by existing water
pressure created by differences in elevation between the discharge
point and the treatment facilities. Passive treatment technologies
discussed in the Coal Remining BMP Guidance Manual include: limestone
drains, constructed wetlands, successive alkalinity-producing systems,
open limestone channels, Pyrolusite systems, and alkalinity-
producing diversion wells.
However, passive treatment may not meet the standard definition of
a BMP. In general, BMPs consist of abatement, remediation, and/or
prevention techniques that are conducted within the mining area during
active remining operations.
Passive treatment, by its nature, is commonly accepted as an end-
of-the-pipe solution to an existing source of acid mine drainage (AMD).
A passive treatment system is designed to be a self-sustaining system
that relies on chemical or biological processes that should require no
external reagents, maintenance, or support to treat AMD. BMPs, on the
other hand, may be performed as part of the mining or reclamation
process to eliminate or prevent the formation of AMD. For example, EPA
considers the application of lime to the overburden to be a BMP and not
passive treatment.
Stakeholders expressed concern that the language concerning bond
release in Sec. 434.71 for remining operations could be debilitating if
the language is interpreted to mean that any time passive treatment is
incorporated into the pollution abatement plan, the operator will be
perpetually liable for the operation and maintenance of the treatment
facility. EPA recognizes that passive treatment technologies can be
used as part of the overall abatement plan to reduce pollution loads
discharging from remining sites and that there are situations where
passive treatment may be employed to improve water quality above what
was
[[Page 3378]]
acceptable through the use of BMPs alone.
Therefore, EPA clarifies that for those remining operations that
include passive treatment as an inherent portion of an approved
Pollution Abatement Plan, the passive treatment operation shall be
treated as part of the Pollution Abatement Plan. Today's regulation
requires that the Pollution Abatement Plan is incorporated into the
permit as an effluent limitation and applies until the appropriate
SMCRA authority has authorized bond release. In this manner, passive
treatment technologies also can be incorporated into the Pollution
Abatement Plan along with more traditional BMPs in order to further
improve water quality. Therefore, coal mining operators are responsible
for maintaining passive treatment technologies in accordance with the
Pollution Abatement Plan until the appropriate SMCRA authority has
authorized bond release.
5. Commingling of Waste Streams
Today's rule makes it clear that the requirements of this
subcategory apply only to pre-existing discharges that are not
commingled with waste streams from active mining areas and that are not
intercepted by active mining. It is not the intention of this rule or
of the Rahall Amendment to provide alternative standards for active
discharges that are generated by mining and remining operations.
Any pre-existing discharge that is commingled with active mining
wastewater for treatment or discharge is subject to the most stringent
limitations applicable to any component of the waste stream. This
maintains the current regulatory approach at Sec. 434.61 for
``commingling of waste streams,'' which states that where waste streams
that are subject to two different effluent limits are commingled for
treatment or discharge, the combined discharge is subject to the more
stringent limitation.
EPA also recognizes that during remining, it may be necessary or
even preferable for an operator to intercept and/or commingle a pre-
existing discharge with active mining wastewater. Unless the active
wastewater has been previously treated and discharged, this combined
wastewater would be required to meet the more stringent applicable
limitations for active coal mining operations and would not be covered
by the conditions of the Coal Remining Subcategory. However, in cases
where a pre-existing discharge is not eliminated by the remining
activity and remains after remining has been completed, the pre-
existing discharge would no longer be commingled with active mining
wastewater. A discharge that is no longer commingled with active
wastewater becomes subject to the Coal Remining Subcategory
requirements which bar an increase in pollutant loadings from baseline
conditions.
In today's rule, a pre-existing discharge that has been intercepted
by, or commingled with, an active discharge is not required to continue
to meet the more stringent effluent limitations once commingling has
ceased. If EPA were to require that these commingled discharges remain
subject to effluent limitations designed for active mining operations
once interception or commingling has ceased, EPA believes it would
create a significant disincentive for remining activities. Based on
anecdotal and historical evidence of current mining activities, mining
companies may try to avoid intercepting pre-existing discharges because
they do not want to assume the liability for future treatment of
discharges that were not the result of their mining operations. This
can result in a ``donut hole'' in the permitted area, to which BMPs are
not applied and from which pre-existing degraded mine drainage
continues to be discharged. In many cases, EPA believes that the most
environmentally beneficial approach would be for the coal operation to
physically intercept this pre-existing discharge, treat the discharge
to the more stringent standards during active mining and reclamation,
implement BMPs, and then allow the pre-existing discharge to continue
discharging at or below baseline pollutant levels. This approach is
consistent with the approach Pennsylvania has been using to implement
the Rahall provisions. Another option for a remining operator would be
to divert the discharge stream away from the active mining area. In
this case, the pre-existing discharge that has been diverted would be
subject to the Coal Remining Subcategory effluent limitations, and the
mine operator would have to implement appropriate BMPs and demonstrate
that the pollutant loadings of the diverted pre-existing discharge
stream have not been increased.
6. Relocation of Pre-Existing Discharges
EPA recognizes that the implementation of certain BMPs,
particularly hydrologic and sediment control BMPs (e.g., daylighting,
regrading, revegetation, spoil pile reclamation, and diversion ditches)
within the pollution abatement area is often intended to redirect
runoff and infiltration water. In these cases, BMP implementation may
result in relocation or dispersion of the pre-existing discharges and
of the infiltration water that contributes to these pre-existing
discharges. It is the intention of the pollution abatement plan to
improve both the pollution loading from pre-existing discharges and the
overall environmental conditions. For this reason, today's regulations
are also applicable to those pre-existing discharges that have been
relocated as a result of the implementation of the best management
practices contained in the Pollution Abatement Plan, and that are not
commingled with discharges from active mining operations.
7. BMP-Only Permits
As explained in the preamble to the proposed rule (65 FR 19451),
EPA interprets the definition of ``effluent limitation'' in section 502
of the CWA to include non-numeric effluent limitations where it is not
feasible to establish numeric effluent limitations. This longstanding
interpretation is implemented in 40 CFR 122.44(k), which provides that
permits may include BMPs to supplement, or in lieu of, numeric effluent
limitations when ``numeric effluent limitations are infeasible.''
In Section VI.A of the preamble to the proposal (65 FR 19449), EPA
discussed the issue of BMP-only permits for the Coal Remining
Subcategory. After considering comment on this approach, EPA included a
limited provision in the final rule for ``BMP-only'' effluent
limitations where numeric limitations are infeasible. EPA believes that
in specific and limited cases, permit requirements may be based on
implementation of an approved BMP plan in lieu of numeric limitations
based on baseline pollutant levels. EPA has determined that in certain
specific cases, it is infeasible to calculate and monitor baseline
pollutant levels in pre-existing discharges. These limited
circumstances include: a pre-existing discharge that exists as diffuse
groundwater flow or as base flow to a receiving stream and is therefore
inaccessible; a pre-existing discharge that is inaccessible due to
steep or hazardous slopes; a pre-existing discharge that is too large
to adequately assess via sample collection; or, a number of pre-
existing discharges so extensive that monitoring of individual
discharges is infeasible.
In today's final rule, EPA has included a provision for ``BMP-
only'' permits for those cases in which determination and monitoring of
baseline pollutant loading is infeasible and for which remining will
result in
[[Page 3379]]
significant improvement that would not otherwise occur.
EPA considered requiring that the mine operator monitor the
receiving stream to assess the impact the remining operation is having
on the receiving stream when there are no numeric limitations on the
pre-existing discharge. Pennsylvania's approved Coal Remining and
Reclamation Project XL agreement that uses the BMP-based remining
permit approach requires the operator to monitor the receiving stream.
While EPA strongly supports and encourages monitoring the receiving
stream as part of a BMP-based permit, EPA acknowledges that receiving
stream monitoring may not be appropriate in all cases (such as a small
AML discharge into a very large river), and EPA has not included a
requirement for in-stream monitoring. EPA recommends that the
regulatory authority review the site-specific factors of the discharge
site and include in-stream monitoring wherever appropriate and useful.
8. Water Quality Variances
Section 303(d) of the Clean Water Act provides that States are to
list waters for which point source technology-based limits do not
ensure attainment of water quality standards, identify the pollutants
causing a violation of the standards, and establish total maximum daily
loads (TMDLs) that will meet water quality standards for each listed
water. Generally, a TMDL identifies what must be done to meet water
quality standards in a particular water or watershed. In recent years,
EPA and the States have increased their emphasis on TMDL activities.
When water quality impairments are identified and TMDLs are
established, pollution allocations are determined and implemented. TMDL
analyses have identified drainage emanating from abandoned mine land as
the source of pollutants inhibiting attainment of water quality
standards for thousands of stream miles.
EPA received comments requesting EPA to categorically allow water
quality variances for pre-existing discharges at coal remining
operations. Water quality variances under the Clean Water Act are a
form of State water quality standards developed on a case-by-case
basis. Effluent limitations guidelines are national technology-based
regulations that establish restrictions on the discharge of pollutants
to surface waters or to publicly owned treatment works by specific
categories of industries. The requirements are developed by EPA based
on the application of process or treatment technologies to control
pollutant discharges. The effluent limitations guidelines promulgated
under part 434 establish minimum national technology-based effluent
standards for the coal mining industry. Therefore, EPA has not included
potential variances on water quality standards in this guideline. Of
course, a State may submit a proposed variance to EPA under the
applicable provisions of 40 CFR part 131.
9. BAT for the Coal Remining Subcategory
Today, EPA promulgates BAT effluent limitations for the Coal
Remining Subcategory to control identified toxic and non-conventional
pollutants. EPA is defining BAT for the Coal Remining Subcategory
through a combination of numeric and non-numeric limitations.
Specifically, EPA is establishing that the best available technology
economically achievable for remining operations is implementation of a
pollution abatement plan that incorporates BMPs designed to improve pH
(as acidity) and reduce pollutant loadings of iron, manganese and
sediment, and a requirement that such pollutant levels do not increase
over baseline conditions. This is essentially the level of treatment
that is currently required under permits issued in accordance with the
Rahall Amendment (with the exception of sediment), and that has been
demonstrated to be currently available by remining facilities included
in EPA's Coal Remining database (Record section 3.5.1), the Coal
Remining BMP Guidance Manual and in Pennsylvania's study of 112 closed
remining sites (Record section 3.5.3). These data support EPA's
conclusion that site-specific pollution abatement plans have potential
for significant removals of pollutant loadings compared to pre-existing
discharge conditions. Based on these data, EPA determined that design
and implementation of a pollution abatement plan should, in most cases,
achieve reductions below baseline discharge levels.
In order to evaluate available technologies to determine BAT, EPA
relied on data from 41 remining operations in Pennsylvania. These data
are contained in section 3.2.4 of the regulatory record. All of these
facilities used abatement plans implementing various combinations of
BMPs as their pollutant control technology. Section 301(p) allows
permit writers to use best professional judgment (BPJ) to set site-
specific BAT limits determined for pre-existing discharges.
Pennsylvania completed this BAT determination for 40 of the 41 remining
operations. These 40 remining permit modules indicated that the only
more stringent technology available (other than BMPs) included
treatment (chemical addition, precipitation, and settling). In all 40
cases, remining was considered not economically feasible if treatment
of pre-existing discharges to part 434 subpart C effluent limits was
required. In the same 40 cases, remining was economically feasible if
the abatement plan was implemented. Thus, the Pennsylvania remining
permits issued under Rahall were issued as BAT permits. Congress
recognized that remining was not being conducted on abandoned mine
lands because of the cost and liability of requiring treatment to meet
existing regulations and authorized less stringent requirements for
remining operations. Therefore, EPA has determined that the
implementation of a pollution abatement plan represents the BAT level
of control.
The problem with setting numeric effluent limitations representing
the reductions achieved through implementation of a pollution abatement
plan is that it is difficult to project the results, in terms of
measured improvements in pre-existing pollutant discharges, that will
be produced through the application of any given BMP or group of BMPs
at a particular site. EPA believes that the Coal Remining BMP Guidance
Manual compiles the best information available on appropriate
implementation and projected performance of all currently identified
BMPs applicable to coal remining operations. However, the Coal Remining
BMP Guidance Manual provides only reasonable estimates of projected
performance and efficiency. There are numerous variables associated
with the design, implementation, and effectiveness of a particular BMP
or group of BMPs at a particular site. Additionally, application of
these estimates is subject to substantial, site-specific uncertainties.
In some cases, despite appropriate design and implementation of a BMP
plan, there is the potential for little improvement over baseline
discharges. For these reasons, it is not feasible to project the
expected numeric improvements that will occur for a specific pre-
existing discharge through application of a particular BMP plan. As a
consequence, EPA is establishing a case-by-case non-numeric requirement
to implement a pollution abatement plan incorporating BMPs designed to
reduce the pollutant levels of acidity, iron, manganese, and solids
(TSS or SS) in pre-existing discharges.
Although it is not feasible to establish numeric limits based on
predicting pollutant removal efficiencies, it is possible to calculate
baseline pollutant
[[Page 3380]]
levels in pre-existing discharges at most remining sites. Moreover, the
record indicates that application of appropriately designed BMPs should
be able to prevent any increase in these pollutant loadings. Today, EPA
promulgates numeric effluent limitations that require that the
pollutant levels for net acidity, iron, manganese, and solids do not
exceed baseline levels. EPA is promulgating a uniform methodology to
use for determining and monitoring these levels. Baseline level
determination and monitoring procedures are presented in Appendix B of
the regulation and in the Coal Remining Statistical Support Document.
EPA expects that these limitations and standards will apply
primarily to new remining operations. In cases of existing remining
operations with Rahall-type permits and established BPJ limitations,
EPA believes that it may not be feasible for a remining operator to re-
establish baseline pollutant levels during active remining because the
BMPs implemented may have already affected the pre-existing discharge.
In this case, it would be impossible to require additional baseline
sampling after the baseline time window has passed. In situations where
coal remining operations seek reissuance of an existing remining
permit, the regulatory authority may determine that it is not feasible
for a remining operator to re-establish baseline pollutant levels in
accordance with the statistical procedures contained in today's
rulemaking. Therefore, pre-existing discharges at existing remining
operations would remain subject to baseline pollutant levels
established during the original permit application.
In its determination of BAT, EPA also performs a cost analysis on
the level of treatment required by the regulation. The cost methodology
for this assessment was described in Section X.B of the proposal, and
EPA has made no changes to the cost methodology for this final action.
EPA projects that the annual compliance cost for this new subcategory
will be approximately $330,000 to $759,000.
10. BPT for the Coal Remining Subcategory
As discussed above, EPA concluded that the requirement to design
and implement a pollution abatement plan represents BAT and that there
are no more stringent technologies that are economically achievable.
Furthermore, EPA is aware that permits containing these BMPs are
currently in place and are being implemented by a large number of
operators. Thus, EPA determined that pollution abatement plans also
represent the average of the best technology currently available. The
pollution abatement plan is required to be designed to control
conventional, toxic and non-conventional pollutants, and the plan must
reflect levels of control consistent with BPT for conventional
pollutants. The Coal Remining BMP Guidance Manual should be consulted
to determine the adequacy of the plan. As discussed above, EPA
concluded that it is infeasible to express BAT as a single numeric
limit. Therefore, EPA has established a combination of site-specific
numeric and non-numeric effluent limitation guidelines for BPT
identical to the BAT limitations for net acidity, iron, manganese, and
TSS.
11. BCT for the Coal Remining Subcategory
In July 1986, EPA promulgated a methodology for establishing BCT
effluent limitations. EPA evaluates the reasonableness of BCT candidate
technologies--those that are technologically feasible--by applying a
two-part cost test: (1) A POTW test; and (2) an industry cost-
effectiveness test.
EPA first calculates the cost per pound of conventional pollutant
removed by industrial dischargers in upgrading from BPT to a BCT
candidate technology and then compares this cost to the cost per pound
of conventional pollutants removed in upgrading POTWs from secondary
treatment. The upgrade cost to industry must be less than the POTW
benchmark of $0.25 per pound (in 1976 dollars).
In the industry cost-effectiveness test, the ratio of the
incremental BPT to BCT cost divided by the BPT cost for the industry
must be less than 1.29 (i.e., the cost increase must be less than 29
percent).
In today's notice, EPA is establishing BCT effluent limitations
guidelines for TSS equivalent to the BPT guidelines for the Coal
Remining Subcategory. In developing BCT limits, EPA considered whether
there are technologies that achieve greater removals of conventional
pollutants than established for BPT, and whether those technologies are
cost-reasonable according to the BCT Cost Test. EPA identified no
technologies that can achieve greater removals of conventional
pollutants than established for BPT that are also cost-reasonable under
the BCT Cost Test, and accordingly EPA is establishing BCT effluent
limitations equal to the established BPT effluent limitations
guidelines.
12. NSPS for the Coal Remining Subcategory
In the proposal, EPA did not consider any regulatory options for
new sources for the Coal Remining Subcategory because pre-existing
discharges at abandoned mine lands covered by the proposed regulation
would be by definition in existence prior to permit application.
Therefore, at proposal EPA defined all pre-existing discharges as
existing sources. However, as described earlier, EPA requested comment
in the NODA on applying the effluent limitations for the Remining
Subcategory to coal mining operations conducted and abandoned after
August 3, 1977. Based on comments received on the NODA, EPA has
modified the definition of ``remining'' to include coal mining
operations on sites where coal mining is conducted and abandoned after
August 3, 1977. Therefore, despite SMCRA requirements and disincentives
to bond forfeiture, it is possible that in the future there will be as-
yet unmined sites that will be mined and abandoned for which remining
permits will be sought. Pre-existing discharges from remining areas
where active mining commenced after the effective date of today's rule
and which are subsequently abandoned will be subject to new source
performance standards. EPA is establishing NSPS equivalent to BPT, BCT,
and BAT because EPA has not identified any economically achievable
technology more stringent that BAT.
B. Western Alkaline Coal Mining Subcategory
1. Background
The effluent limitations and performance standards for the Western
Alkaline Coal Mining Subcategory apply to alkaline mine drainage from
reclamation areas, brushing and grubbing areas, topsoil stockpiling
areas, and regraded areas. This new subcategory is being created
primarily because of negative impacts caused by the predominant use of
sedimentation ponds necessary to meet the guidelines for Subpart D--
Alkaline Mine Drainage. Additional information on the rationale for the
new subcategory are explained in Section VI.B of the proposal.
Today's final regulation requires that a western coal mine operator
develop and implement a site-specific sediment control plan for
applicable areas. The sediment control plan must identify sediment
control BMPs and present their design, construction, maintenance
specifications, and their expected effectiveness. The final regulations
require the operator to demonstrate, using watershed models accepted by
the
[[Page 3381]]
permitting authority, that implementation of the selected BMPs will not
increase sediment loads over pre-mined, undisturbed condition sediment
levels. The permit must then incorporate the site-specific sediment
control plan and require the operator to implement the plan.
Sediment control BMPs for the coal mining industry are well known
and established and include regrading, revegetation, mulching, check
dams, vegetated channels, straw bales, dikes, silt fences, small sumps
and berms, contour terracing, sedimentation ponds, and other
construction practices (e.g., grass filters, serpentines, leaking
berms, etc). In order to maintain pre-mined, undisturbed conditions on
reclamation and associated areas, EPA is promulgating non-numeric
effluent limits based on the design, implementation, and maintenance of
these BMPs.
As noted in the proposal, EPA has determined that the predominant
use of sedimentation ponds in order to meet the Subpart E numeric
standards for settleable solids have caused negative impacts in arid
and semiarid environments. This is predominantly due to the large land
areas and volume of runoff that must be controlled through ponds in
order to meet a sediment limit that is not appropriate for runoff in
the arid and semiarid regions of the western United States. EPA notes
that sedimentation ponds are considered an effective BMP for
controlling sediment, and that sedimentation ponds may be used in
conjunction with other BMPs in order to control sediment loads. EPA
also recognizes that sedimentation ponds do not necessarily cause
negative environmental impacts in all cases. EPA believes that ponds
may be necessary in certain circumstances to ensure that sediment
levels are not increased over pre-mined levels, or may be necessary to
meet SMCRA requirements or to protect water quality. In certain cases,
it may also be necessary for the regulatory authority to establish
numeric limits to protect water quality. EPA notes that ponds are one
in a suite of BMPs that a mine operator may install in order to meet
reclamation standards. However, ponds may not be necessary in all
circumstances and the use of other BMPs such as check dams, vegetation,
silt fences, and other construction practices can be equally protective
of the environment. Advantages of using other BMPs in lieu of, or in
addition to, ponds is that less land is disturbed than for pond
construction and removal and more water is available to maintain the
hydrologic balance. EPA believes that the regulation promulgated today
allows permitting authorities and mining operators sufficient
flexibility to use the appropriate BMPs necessary to control sediment
and protect water quality in these regions. EPA has provided
information on the range and implementation of available BMPs in the
Development Document for Final Effluent Limitations Guidelines and
Standards for the Western Alkaline Coal Mining Subcategory.
Under today's regulation, EPA is establishing a requirement to
develop and implement site-specific sediment control plans that apply
in lieu of numeric limits. EPA is requiring that a mine operator
develop a site-specific sediment control plan for these areas.
EPA is establishing requirements for site-specific sediment control
plans based on computer modeling in lieu of nationally applicable
numeric effluent limitations. As discussed above in section V.A.7, such
requirements are authorized at 40 CFR 122.4(k) as non-numeric effluent
limitations where it is infeasible to establish numeric effluent
limitations.
EPA believes that determining compliance for settleable solids
based on a single numeric standard for runoff from BMPs is infeasible
at western coal mines due to the environmental conditions present.
Precipitation events are often localized, high-intensity, short-
duration thunderstorms and watersheds often cover vast and isolated
areas. Rain may fall in one area of a watershed while other areas
remain dry, making it extremely difficult to evaluate overall
performance of the BMPs. These factors combine to take it burdensome
for a permitting authority or mining operator to extract periodic,
meaningful samples on a timely basis to determine if a facility is
meeting effluent limitations for settleable solids. The difficulty of
sample collection is described in the Phase I Report: Technical
Information Package provided by the Western Coal Mining Work Group
(Record Section 3.3.1).
Because it is infeasible in such areas to determine compliance and
performance of the BMPs in numeric terms, EPA believes that
establishment of non-numeric effluent limitations for sediment for this
subcategory is authorized under, and is necessary to carry out the
purposes and intent, of the CWA.
2. Inspection and Maintenance of BMPs
EPA believes a key factor in using BMPs is the opportunity for
continual inspection and maintenance by permitting authorities and coal
mine personnel to ensure that sediment control measures will continue
to function as designed. EPA concludes that requirements based on site-
specific control plans will ease the implementation burden of the rule
and allow a permit authority to determine compliance on a regular
basis. A permit authority will be able to visit the site and determine
if BMPs have been implemented according to the site's sediment control
plan. The permit authority would not have to wait for a significant
precipitation event to determine compliance.
EPA believes that regular operation and maintenance inspections of
BMPs are necessary to ensure compliance with the sediment control plan.
EPA also recognizes that SMCRA establishes inspection and monitoring
requirements for both surface coal mining and reclamation operations.
These requirements include partial inspections at least once per month
and complete inspections at least once per quarter. The monitoring
requirements include maintenance of records and monitoring equipment,
monthly reports to the permitting authority, and provision of other
information as the permitting authority deems appropriate.
EPA received several comments on appropriate inspection frequencies
and monitoring requirements. The State of New Mexico envisions monthly
inspections during the first three years a watershed is in reclamation
status and quarterly inspections thereafter. New Mexico believes that
field notes or forms maintained on file in mine records and available
for inspection is appropriate documentation of these inspections. Other
States and mine operators have suggested that self inspections be
conducted quarterly and after significant precipitation events.
EPA is not specifying a frequency or procedure for BMP inspections
because EPA believes that these decisions should be left to discretion
of the permitting authority and be made on a site-specific basis, in
accordance with SMCRA and CWA requirements (40 CFR 122.41(i), 122.43,
122.48).
3. Affected Areas
In the proposal, EPA described that the Agency also was considering
the use of alternative sediment controls for non-process areas in
addition to reclamation areas. Such non-process areas include areas
that are not directly in contact with the excavation and processing of
coal materials. EPA received numerous comments on the issue in support
of expanding the applicability of the final regulation to include these
additional non-process areas. EPA also received additional data from
the National
[[Page 3382]]
Mining Association, in a report entitled ``Western Alkaline Coal Mining
Subcategory Modeling of Pre-mining Activities Supporting Reclamation
and Performance Cost-Benefit Analysis.''
As described in the proposal, EPA determined that alternative
sediment controls were appropriate for reclamation areas for several
reasons. These reasons included: sediment is a natural component of
runoff in arid watersheds; sediment is typically the only parameter of
concern in runoff from western alkaline reclamation areas; BMPs are
proven to be effective at controlling sediment; and computer modeling
procedures are able to accurately predict sediment runoff conditions.
Due to comments received in support of expanding the application of
alternative sediment controls, EPA evaluated non-process areas in
addition to reclamation areas under the same set of circumstances.
Based on this rationale, in addition to comments and data received on
the proposal, EPA determined that similar circumstances exist for
runoff from some, but not all, non-process mine areas. Namely, that
sediment is typically the only parameter of concern; BMPs can be
implemented to maintain sediment levels below baseline; and modeling
procedures are accurate for these areas. Therefore, EPA has expanded
the Western Alkaline Subcategory to include ``brushing and grubbing
areas,'' ``topsoil stockpiling areas,'' and ``regraded areas.''
``Brushing and grubbing area'' is defined to mean ``the
area where woody plant materials that would interfere with soil salvage
operations have been removed or incorporated into the soil that is
being salvaged.'' BMPs modeled and/or utilized for sediment control of
this area include infiltration berms, silt fences, porous rock check
dams, and woody plant chipping/rotoclearing surface treatments.
``Topsoil stockpiling area'' is defined to mean ``the area
outside the mined-out area where topsoil is temporarily stored for use
in reclamation, including containment berms.'' BMPs modeled and/or
utilized for sediment control of this area include establishing
vegetation, infiltration berms, and silt fences.
``Regraded areas'' are defined to mean ``the surface area
of a coal mine that has been returned to required contour.'' BMPs
modeled and/or utilized for sediment control of this area include
contour furrowing, establishing timely vegetation, silt fences, porous
rock check dams, and woody plant chipping/rotoclearing surface
treatments.
EPA concluded that these areas may be sufficiently consistent in
slope, vegetative cover, and soil stability such that BMPs can be
modeled and implemented to maintain sediment levels below pre-mined,
undisturbed conditions. Due to lack of exposure to potential acid
forming or toxic materials, EPA does not believe that runoff from these
areas will cause degredation of water quality. Therefore, EPA believes
that alternative sediment controls can be effectively used on disturbed
areas where sediment is typically the only pollutant of concern in
order to avoid additional land disturbance.
However, EPA does not believe that alternative sediment controls
should be applicable to spoil piles. Spoil piles are areas where
overburden is placed prior to regrading and revegetating. Overburden is
the material that lies on top of the coal that is removed to gain
access to the coal seam. First, EPA does not believe that computer
modeling programs are sufficient to accurately model runoff from a
highly erodible, unconsolidated land form with steep slopes, such as
spoil piles. Second, in terms of BMPs that would be available to
sufficiently control runoff from these areas, EPA notes that many of
the traditional BMPs, including regrading, revegetating, mulching,
check dams, vegetated channels, straw bales, dikes, silt fences, small
sumps and berms, and contour terracing could not be implemented or
adequate on unconsolidated steep slopes or highly erodible areas. EPA
notes that the most likely form of sediment control for runoff from
these areas would be site containment by means of temporary berms,
ponds, diversion into pit area, and/or commingling with process waters.
In contrast, the non-process areas where the Agency is allowing
alternative sediment control structures are amenable to utilization of
BMPs due to their level surfaces or more stable environment.
EPA generally considers spoil piles as part of the active mine due
to the disturbed nature of the materials and the potential for toxic or
acid forming materials to be present. Additionally, EPA believes there
exists the potential for exposure to toxic or acid forming materials in
runoff from spoil piles. EPA notes that, as part of SMCRA requirements,
the mine operator must conduct an analysis of the potential toxic or
acid forming materials present in the overburden and take appropriate
action to prevent the discharge of these materials to surface waters.
However, the appropriate action (such as covering material) may be
concurrent with deposition of overburden, and EPA does not believe that
the Agency has been presented with sufficient evidence that toxic or
acid forming materials are guaranteed not to be present in runoff from
spoil piles.
EPA believes that the exclusion of spoil pile areas from the
Western Alkaline Subcategory will not significantly detract from the
benefits of this new subcategory. OSMRE regulations restrict the size
of the overburden salvaging area and require timely regrading and
revegetation (SMCRA, Pub. L. 95-87 sections 508 and 515). In a report
submitted in comments by the National Mining Association, the salvaging
area was estimated to be 750 feet wide and 5,083 feet long. Although
the spoil pile area has a fairly large footprint, EPA notes that the
area generating runoff that EPA considered for inclusion of the Western
Alkaline Subcategory is limited. EPA notes that the runoff from the
spoil piles adjacent to the active mine pit will drain directly into
the mine pit and will be treated as active mine water, regardless of
EPA's decision. The only area that would be affected by EPA's decision
is the area containing runoff from the outslope of the last spoil pile,
and this area is relatively limited. Based on the decision not to
include spoil piles in the Western Alkaline Coal Mining Subcategory,
EPA envisions that the runoff from spoil pile areas will be rerouted
back into the mine pit through temporary berms and dikes and will not
likely involve construction of additional sedimentation ponds. Such
spoil piles continue to be covered by existing regulations at subpart
D--Alkaline Mine Drainage.
4. SMCRA Requirements
The SMCRA permit application process requires a coal mining
operator to submit an extensive operation and reclamation plan,
documentation, and analysis to OSMRE or the primacy permitting
authority for approval. The requirements for the operation and
reclamation plan are specified in 30 CFR part 780 for surface mining
permit applications and part 784 for underground mining permit
applications. In brief summary, some of the OSMRE requirements that
directly relate to this CWA regulation include requirements for coal
mining operators to provide: a description of coal mining operations; a
plan for reclaiming mined lands; a plan for revegetating mined lands;
geologic information; hydrologic information including: a description
of baseline ground water and surface water characteristics under
seasonal conditions; and an analysis of the
[[Page 3383]]
hydrologic and geologic impacts caused by the reclamation activity.
Specifically, the plan requires a ``probable hydrologic consequences
(PHC)'' determination to determine the impacts of the mining on
existing hydrologic conditions and a hydrologic reclamation plan to
show measures for reducing impacts and to meet water quality laws and
regulations. Furthermore, the coal mining regulatory authority is
required to conduct a cumulative hydrologic impact analysis of the
proposed operation and all anticipated mining on surface water and
ground water systems.
Additionally, SMCRA requires a chemical analysis of potentially
acid or toxic forming sections of the overburden and chemical analysis
of the stratum lying immediately underneath the coal (Section 507
(b)(15)). The mine operator must provide for avoiding acid or other
toxic mine drainage by such measures as, but not limited to: preventing
or removing water from contact with toxic producing deposits; treating
drainage to reduce toxic content which adversely affects downstream
water upon being released to water courses; and keeping acid or other
toxic drainage from entering ground and surface waters (Section 515 (b)
(10)). This analysis is required for the determination that the mine
produces alkaline mine drainage and will be covered by the Alkaline
Mine Drainage Subcategory. Based on the applicability of this
regulation which restricts the Western Alkaline Coal Mining Subcategory
to areas producing alkaline drainage in arid and semi arid areas, EPA
does not believe that toxic or acid forming materials will be present
in the runoff from non-process areas of alkaline coal mines. However,
EPA acknowledges that SMCRA requirements are an additional measure of
protection to ensure that any acid forming or toxic forming pockets
will be identified and addressed as necessary to prevent the release of
these materials in stormwater runoff.
EPA concluded that sediment control plans developed to comply with
SMCRA requirements will usually fulfill the requirements in today's
regulation. In general, the sediment control plan will largely consist
of materials generated as part of the SMCRA permit application. The
requirement to use modeling techniques also is not inconsistent with
SMCRA permit application requirements, as mining facilities already
submit a watershed model as part of their SMCRA reclamation plan.
EPA proposed and is finalizing the following language regarding
acceptable computer models: ``The operator must use the same watershed
model that was, or will be, used to acquire the SMCRA permit.'' EPA
intends this to mean that a mine can use the upgraded version of a
computer model that was used in the original application. For example,
if the mine used SEDCAD 4.0 in their SMCRA permit application, then the
mine operator can use SEDCAD 5.0 in subsequent modeling procedures for
its CWA permit application. EPA believes that this language provides
the necessary flexibility to use the most recent and appropriate
modeling procedure. A guidance manual entitled ``Guidelines for the Use
of the Revised Universal Soil Loss Equation (RUSLE) Version 1.06 on
Mined Lands, Construction Sites, and Reclaimed Lands'' published by
OSMRE in August, 1998 describes the use of RUSLE for sediment modeling
and should be consulted for modeling approaches.
5. Bond Release
The new subpart for Western Alkaline Coal Mining includes the
following language: ``The effluent limitations in this subpart apply
until the appropriate SMCRA authority has authorized bond release.''
This language is consistent with the language in other subparts to part
434. As defined in Sec. 434.11(d) General definitions: ``The term `bond
release' means the time at which the appropriate regulatory authority
returns a reclamation or performance bond based upon its determination
that reclamation work (including, in the case of underground mines,
mine sealing and abandonment procedures) has been satisfactorily
completed.'' EPA notes that this language does not necessarily mean
``final'' bond release (which may be applicable to an entire mining
operation) and that reclamation work may be satisfactorily completed on
a watershed or a specific part of a disturbed area before the entire
mine site has been reclaimed (or even mined), i.e., ``partial bond
release.'' Therefore, EPA intends this current definition to allow a
facility to terminate NPDES discharge points when ``partial'' bond
release is obtained.
6. Definition of Alkaline Mine Drainage
EPA received comment that the proposed definition for alkaline mine
drainage imposes limitations for iron concentrations without regard to
the form of the iron. The commenter noted that the primary mineral
responsible for high total iron readings in certain western areas is
magnetite. Magnetite (Fe3O4) is a naturally
occurring iron mineral, which is in a form not typically associated
with coal mining operations and acid mine drainage. In natural
undisturbed conditions, the commenter cited that surface water samples
register values for total iron as high as 40,000 mg/L (or 4%), due to
the sediment, which is collected as part of the water sample. The
commenter argued that the form of iron was not considered in the
original mining regulations, and the commenter requested that EPA
modify the definition of the Western Coal Mining Subcategory to include
areas that have naturally-occurring high concentrations of iron due to
magnetite.
Although EPA has not revised either the definition of alkaline mine
drainage or western coal mining operations, EPA acknowledges the
concern regarding the high levels of total iron that may be found in
natural discharges from western alkaline coal regions. EPA recognizes
that the geochemistry of the western arid and semiarid coal regions,
which is predominated by sandstone and limestone, differs from that of
the eastern coal regions. As a result, the production of acid mine
drainage is much less typical due to the inherent buffering capacity.
In addition, EPA recognizes that there is a low occurrence of pyrite in
the west, which is the common culprit of acid mine drainage generation.
Instead, iron often occurs in the form of magnetite
(Fe3O4), an inert iron oxide that has no acid
forming potential.
EPA evaluated the processes that produce acid mine drainage and the
geologic conditions typical of the western alkaline coal regions to
determine the most appropriate parameters for indicating alkaline mine
drainage. In summary, EPA concluded that pyrite is generally uncommon
in this coal region and that, if it does occur at a significant level,
it can be identified by the presence of dissolved iron. For this
reason, it is also appropriate to measure dissolved iron, in lieu of
total iron, for surface runoff from the areas affected by the Western
Alkaline Coal Mining Subcategory. Additionally, acid mine drainage in
the western region is often prevented by the presence of carbonate
minerals. Therefore, to ensure that acid-forming potential is not
inherent to a particular discharge, EPA believes that an assessment of
net alkalinity should be made. Determination of net alkalinity takes
into account the effects of non-ferrous metals (e.g., Al, Mn),
carbonates, and other substances, and, as such, negative values of net
alkalinity are a true indication of potential acidity of drainage
waters.
For these reasons, EPA has revised the applicability of the Western
Alkaline Coal Mining Subcategory as follows: ``This subpart applies to
drainage at western coal mining operations from
[[Page 3384]]
reclamation areas, brushing and grubbing areas, topsoil stockpiling
areas, and regraded areas where the discharge, before any treatment,
meets all the following requirements: (1) pH is equal to or greater
than 6; (2) dissolved iron concentration is less than 10 mg/L; and (3)
net alkalinity is greater than zero.'' EPA believes that this will
enable certain mines to use alternative sediment controls while
maintaining the intent of the regulation that this subcategory does not
apply to mines that produce acid mine drainage.
7. BPT for the Western Alkaline Coal Mining Subcategory
EPA is today promulgating BPT effluent limitations for the Western
Alkaline Coal Mining Subcategory to control sediment in discharges from
reclamation areas, brushing and grubbing areas, topsoil stockpiling
areas, and regraded areas. For further information on the basis for the
limitations and technologies selected see the Development Document for
Effluent Limitations Guidelines and Standards for the Western Alkaline
Coal Mining Subcategory.
EPA determined that BPT for the Western Coal Mining Subcategory
consists of designing and implementing BMPs to maintain the average
annual sediment yield equal to or below pre-mined, undisturbed
conditions. EPA has developed this new subcategory primarily to
addresss the negative environmental impacts created by the previous
requirements.
Requirements for reclamation areas (40 CFR part 434, subpart E)
establish BPT, BAT, and NSPS based on the use of sedimentation pond
technology, and set effluent limitations for settleable solids and pH.
The Subpart E guidelines apply to all reclamation areas throughout the
United States, regardless of climate, topography, or type of mine
drainage (i.e., acid or alkaline).
Subpart E establishes controls on the amount of settleable solids
that can be discharged into waterways from reclamation areas. Although
sedimentation ponds are proven to be effective at reducing sediment
discharge, EPA believes that there are numerous non-water quality
impacts that may harm the environment when construction of large
sedimentation ponds in arid and semi arid regions are necessary to meet
current effluent limits. The negative non-water quality impacts
associated with existing regulations include: disturbing the natural
hydrologic balance of arid and semiarid western drainage areas;
accelerating erosion; reducing groundwater recharge; reducing water
availability; and impacting large areas of land for sedimentation pond
construction. A further discussion of these impacts can be found in
Section VIII of this document and in the Development Document for the
Western Alkaline Coal Mining Subcategory.
EPA has concluded that the current numeric requirements at subpart
E are not appropriate for arid and semiarid western reclamation areas
because of the negative non-water quality impacts associated with the
predominant use of sedimentation ponds to meet these limits, as
discussed above. The appropriate goal for reclamation and discharges
from post-mined lands should be to mimic conditions that were present
prior to mining activities. In order to do this, it is necessary to
maintain the hydrologic balance and sediment loadings of pre-mining,
undisturbed conditions on post-mined lands. EPA believes that use of
BMPs, including sedimentation ponds where appropriate, to control
discharges is the most effective control technology. Therefore, EPA is
establishing BPT that consists of designing and implementing BMPs that
are projected to maintain the average annual sediment yield equal to or
below pre-mined, undisturbed conditions. This would ensure that
undisturbed conditions are maintained. In order to achieve these
results, EPA requires that the coal mining operator develop a sediment
control plan and demonstrate the effectiveness of the sediment controls
through computer modeling. These requirements are detailed in the
regulatory text.
EPA also evaluated the costs of BPT. As discussed in Section IX of
this document, EPA estimates that today's regulation will result in a
net cost savings to all affected surface mine operators, and will be at
worst cost-neutral for affected underground operators (although EPA
believes that most will also incur cost savings). Therefore,
implementing these standards will result in no facility closures or
negative economic impact to the industry. EPA projects that the new
subcategory will result in cost savings of $12.8 million to $13.2
million annually.
8. BCT for the Western Alkaline Coal Mining Subcategory
EPA is establishing BPT and BAT to control conventional, toxic, and
non-conventional pollutants based on a sediment control plan. EPA is
not establishing numeric effluent limitations for any conventional
pollutant and EPA is not promulgating BCT limitations for this
subcategory at this time.
9. BAT for the Western Alkaline Coal Mining Subcategory
EPA has not identified any more stringent treatment technology that
could represent BAT level of control for maintaining discharge levels
of solids consistent with pre-mined conditions on post-mined land in
the western alkaline coal region. EPA is therefore establishing that
BAT standards be equivalent to BPT. Further, as discussed in Section IX
of this document, EPA estimates that today's regulation will result in
a net cost savings to all affected surface mine operators, and will be
at worst cost-neutral for affected underground operators. Therefore,
implementing BAT standards will result in no facility closures or
negative economic impact to the industry.
10. NSPS for the Western Alkaline Coal Mining Subcategory
As discussed for BAT, EPA has not identified any more stringent
treatment technology option that it considers to represent NSPS level
of control. Further, EPA estimates that today's regulation will result
in a net cost savings to all affected surface mine operators, and will
be at worst cost-neutral to affected underground operators. Therefore,
implementing NSPS standards will result in no barrier to entry based
upon the establishment of this level of control for new sources. EPA
has therefore determined that NSPS standards be established equivalent
to BAT.
VI. Statistical and Monitoring Procedures for the Coal Remining
Subcategory
A. Statistical Procedures for the Coal Remining Subcategory
EPA's statistical procedures are presented in Appendix B of the
regulation and described in detail in the Coal Remining Statistical
Support Document. The procedures in Appendix B apply to the Coal
Remining Subcategory.
The regulatory text requires that calculations described in
Appendix B be applied to pollutant loadings. Pollutant loadings are
calculated as the product of a flow measurement and a pollutant
concentration. As described in the proposal, EPA has interpreted the
Rahall amendment's requirement not to exceed a pollutant baseline
``level'' as a requirement not to exceed a pollutant baseline loading.
EPA's record demonstrates that BMPs applied during remining act
principally by reducing discharge flow and pollutant loading. In fact,
pollutant concentration may actually increase in some cases where the
pollutant quantity (loading) is
[[Page 3385]]
reduced substantially. Setting limits based on concentrations would
very likely inhibit beneficial remining projects and would be counter-
productive and ineffective. To achieve pollutant reductions from
remining, EPA concluded that it is essential to set limits for
pollutant loadings rather than concentrations.
The objective of these statistical procedures is to provide a
method for deciding when the pollutant levels of a discharge exceed
baseline pollutant levels. These procedures are intended to detect a
substantial, continuing state of exceedance, while reducing the
likelihood of a ``false alarm.'' To do this, it is essential to a have
an adequate duration and frequency of sample collection to determine
baseline levels and to determine compliance with these levels.
In developing these procedures, EPA considered the statistical
distribution and characteristics of discharge loadings data from pre-
existing discharges, the suitability of parametric and non-parametric
statistical procedures for such data, the number of samples required
for these procedures to perform adequately and reliably, and the
balance between false positive and false negative decision error rates.
EPA also considered the cost involved with sample collection as well as
delays in permit approval during the establishment of baseline, and
considered the potential that increased sampling could discourage
remining. In order to sufficiently characterize pollutant levels during
baseline determination and during each annual monitoring period, EPA is
requiring that the results of at least one sample be obtained per month
for a period of 12 months.
EPA evaluated the statistical properties of eastern coal mine
discharge data (EPA's Coal Remining Database, DCN 1335 and the
Statistical Analysis of Abandoned Mine Drainage in the Assessment of
Pollution Load, EPA (821-B-01-014). EPA verified its findings as
discussed in the proposal on relative variability of pollutant
loadings. EPA also characterized the serial correlation of loadings and
flow. EPA found that (a) to a first approximation, loadings might
reasonably be described by a first-order autoregressive model, and (b)
the coefficient of serial correlation for loadings at a one-month time
lag typically ranged from 0.35 to 0.65, with the median near 0.50.
EPA evaluated the proposed statistical procedures and a variety of
parametric and non-parametric alternative procedures to determine their
decision error rates, their suitability for serially correlated data,
and their ability to accommodate zero loadings and negative loadings.
As a result of these evaluations, EPA modified the proposed statistical
procedures so as to achieve the objective stated in the preamble to the
proposed rule: to have a power of at least 0.75 for detecting an
increase of one standard deviation in the average for loadings, while
minimizing the chance of `false alarms' in the event that the average
loading decreases or remains unchanged.
Zero loadings are expected to occur, at least for some remining
sites, after regrading and contouring when discharge flows may be
reduced greatly; zero flows have been observed after remining at some
mine sites (EPA's Coal Remining Database, DCN 1335 and the Coal
Remining BMP Guidance Manual). Negative values of loadings are possible
and have been observed for net acidity at some mine sites.
Serial correlation has a profound influence over the power of
statistical procedures. The statistical procedures, as proposed, were
more suitable for uncorrelated data than for serially correlated data.
EPA modified the procedures so that they have the intended power when
applied to serially correlated loadings data of the sort typical of
remining sites in the eastern U.S. (Record section 11.1). The
modifications consisted of (a) increasing the number of times in
succession that the baseline trigger value must be exceeded for
additional sampling or treatment to be required, (b) changing numeric
constants used in the calculation of baseline trigger values, and (c)
under proposed Procedure B, dropping the parametric statistical methods
and providing a nonparametric calculation for the single-observation
trigger.
In the preamble to the proposed rule, EPA discussed the potential
problem of unrepresentative baseline years and optional measures that
could mitigate the uncertainty of characterizing the baseline loadings.
It is possible that one year of sampling may not accurately
characterize baseline levels, because discharge flows can vary among
years in response to inter-year variations in rainfall and ground water
flow. There is some risk that the particular year chosen to
characterize baseline flows and loadings will be a year of atypically
high or low flow or loadings. There may be a need to evaluate
differences among baseline years in loadings and flows. Therefore, EPA
investigated optional procedures that could be used to account for the
uncertainty in characterizing baseline from a one-year sample duration,
or that could be used to account for the unrepresentative character of
a baseline sampling year. EPA evaluated correlations between discharge
flow and various parameters of existing mine discharge data and indices
for which data spanning over many years are available to the public
(i.e., Palmer Indices, Standardized Precipitation Index, Crop Moisture
Index, Surface Water Supply Index, and USGS Current and Historical
Daily Streamflow). EPA concluded that historical stream flow data from
a USGS gage station associated with a discharge could be used to test
whether the given baseline year was significantly different from the
previous years. This would be done by comparing the mean stream flow
for the baseline year to the 2.5th and 97.5th percentiles of annual
mean stream flows prior to the baseline year. If the mean stream flow
for the baseline year falls below the 2.5th percentile or above the
97.5th percentile, corrective action can be taken on the baseline data,
and EPA recommends that the operator or permitting authority conduct
additional monitoring to establish a meaningful baseline. However, due
to the site-specific nature of discharges and the variability of
streamflow compared to discharge data, EPA was unable to establish any
optional procedure that could incorporate existing data from public
sources into a meaningful baseline calculation.
Stakeholders have commented that, occasionally, a pre-existing
discharge may contain iron or manganese concentrations that are lower
than the current subpart E effluent limitations established for active
mine wastewater. In these circumstances, the baseline standards may be
a disincentive for remining because the operator may have to treat a
discharge to levels below those currently required by BAT for active
mine discharges. This may be a disincentive for remining operations.
Therefore, EPA has incorporated a methodology in the statistical
procedure for determining baseline so that the BAT concentration limit
is substituted for certain baseline measurements when a measured
concentration is below the BAT limit.
B. Evaluation of Statistical Triggers
EPA evaluated the power of the statistical triggers in Section VIII
of the proposed rule. Power can be defined in plain language as the
frequency with which a statistical decision procedure will declare that
remining loadings exceed baseline loadings when the remining loadings
truly are greater than baseline loadings.
The ideal statistical procedure would always declare ``not larger''
when
[[Page 3386]]
remining pollutant loadings are less than or equal to baseline
loadings, and would always signal ``larger'' when remining loadings
exceeded baseline. No such ideal procedure exists. Instead, the rate of
signaling ``larger'' will increase as the average difference between
baseline and remining loadings increases in magnitude. Statistical
triggers may be ``tuned'' by choosing their numeric constants so that a
compromise is achieved between false alarms (that is, signaling
``larger'' when remining loadings are not larger than baseline
loadings) and correct alarms (when remining loadings truly are
greater).
Power of the statistical triggers was evaluated by simulating a 60-
month monitoring program for 5000 discharges, and recording the
frequency with which the triggers indicated that the remining loadings
exceeded baseline. The evaluations of power led to a choice of numeric
constants that achieve a reasonable balance between false alarms and
correct alarms.
This reasonable balance was considered to be achieved when a
trigger produced the following results:
(1) When there was no change in loadings from the baseline to
remining time period, the power (``false alarm rate''; type-I error
rate) was not larger than that for the triggers used by Pennsylvania's
successful remining program;
(2) When there was a decrease of 0.5 standard deviations in the
mean loading after the baseline period, the power (``false alarm
rate,'' in this case the probability of concluding that loadings
increased during remining when they actually decreased) was smaller
than 5%;
(3) When the mean loading increased by 1 to 2 standard deviations
after the baseline period, the power (``correct alarm rate'') was
maximized.
EPA reached several conclusions about the proposed statistical
triggers based on these evaluations.
(1) The proposed Cumulative Sum Control Chart (CUSUM) method under
Procedure B did not add value to the simpler monthly and annual
comparisons. Accordingly, the CUSUM method is omitted from Appendix B
to the final rule.
(2) The magnitude of serial correlation has a substantial effect on
power. Statistical triggers that have reasonable power when there is no
serial correlation could be unreasonable when there is substantial
serial correlation, because they could then have very high rates of
type I errors (false alarms). It was necessary to select numeric
constants for the statistical triggers that are appropriate to data
having autocorrelation. For evaluating and comparing statistical
methods and triggers, EPA relied primarily upon the power in
simulations for which the first-order autocorrelation coefficient took
the value of 0.5.
(3) The Single Observation Trigger of the proposed Procedure A had
a high rate of declaring loadings to be larger than baseline when they
were not. The Single Observation Trigger was therefore modified to
agree with the method that has long been used successfully in the State
of Pennsylvania. The statistical modification was to change the Single
Observation Trigger at Step 5 from ``If any two observations exceed L
during weekly monitoring, * * *'' to the following: ``If all four
weekly observations exceed L during weekly monitoring, * * *''
(4) Proposed Procedure B, ``E. Annual Comparisons,'' also had a
high rate of declaring loadings to be larger than baseline when they
were not. This part of proposed Procedure B was modified to require use
of Tables for the 99.9% level (alpha = 0.001) rather than the 95% level
(alpha = 0.05) for the Wilcoxon-Mann-Whitney Test.
(5) The Single Observation Limit of the proposed Procedure B was
changed from a parametric to a nonparametric method which has similar
power. The nonparametric method accommodates zero flows (which may
occur during remining) and negatively-valued loading data (which may
occur for net acidity) without requiring additional or complex
modifications (as the proposed parametric method would).
(6) The annual (subtle trigger) and single-observation (quick
trigger) triggers long used in Pennsylvania were included in the
simulations. EPA believes that the error rates and power of these
triggers were acceptable in practice because BMPs reduced discharge
loadings substantially. Hawkins (1994) reviewed the application of
these triggers to remining operations in Pennsylvania, and concluded
that the rates of triggering were low because remining almost always
reduced loadings substantially. EPA's Coal Remining Best Management
Practices Guidance Manual includes an extensive analysis of remining
discharges that supports this conclusion. EPA concluded that the
statistical triggers that Pennsylvania uses in its remining program are
acceptable and effective. Method 1 of the Final Rule follows the
Pennsylvania triggers exactly except that a different constant (1.815 =
1.96 * 1.25 / 1.35) is used in the formula for the Annual Procedure in
order to decrease the likelihood of obtaining false positives.
Pennsylvania uses a more stringent number (1.58 = 1.7 * 1.25 / 1.35).
For a complete discussion of EPA's rationale and selection of
statistical methodology, see the Coal Mining Statistical Support
Document.
(7) The evaluation of power applies to a worst-case situation. In
particular, the rate of declaring loadings to be larger than baseline
when they are not is over-stated by the results. It is evaluated in
terms of the percentage of mines that would experience at least one
finding that loadings exceed the baseline level over a period of five
years (60 months), when in fact there has been no change from baseline.
In practice, the area contributing to a discharge should be remined and
regraded in less time, after which the discharge flow and loading will
be substantially reduced. Thus, the time period during which one can
expect loadings at the baseline level typically will be shorter than
five years. This in turn will mean lower percentages than reported in
Table 1 for the condition of no change from baseline loadings.
(8) The procedures as proposed had unreasonably high ``false alarm
rates'' because they were designed for uncorrelated data. The modified
procedures provided for the final regulation have reasonable
performance when applied to serially-correlated, lognormally-
distributed data typical of coal mine discharge loadings.
The power of statistical triggers for the final regulation is shown
in Table VI.B.1. The results show that Method 1 and Method 2 have
comparable power. The main difference stems from the Monthly Procedure,
which has higher power when Method 1 is used. Note that the Annual
Procedure used without the Monthly Procedure would not have a high rate
of detecting an increase of one standard deviation above baseline. Used
in combination, the monthly and annual triggers provide power over 90%
to detect substantial increases above baseline at least once during
five years, although in practice the power will be smaller for reasons
discussed above under (7).
[[Page 3387]]
Table VI.B.1.--Statistical Triggers as Modified for Final Regulation: Percentage of Mines Declared to Exceed
Baseline Level (at least once during 5 years of simulated monthly monitoring) \1\
----------------------------------------------------------------------------------------------------------------
Shift from baseline to remining period \2\
Annual trigger \3\ Monthly trigger \4\ ---------------------------------------------------
-0.5 0 +1 2
----------------------------------------------------------------------------------------------------------------
None................................ Method 1.............. 10 33 89 99
Method 1 (a=1.96)................... none.................. 3 11 59 94
Method 1 (a=1.96)................... Method 1.............. 12 39 93 100
Method 1 (a=1.96)................... Method 2.............. 7 29 91 100
----------------------------------------------------------------------------------------------------------------
None................................ Method 2.............. 5 22 86 100
Method 2 (=0.001).......... none.................. 2 11 65 97
Method 2 (=0.001).......... Method 2.............. 7 28 91 100
Method 2 (=0.001).......... Method 1.............. 12 38 93 100
----------------------------------------------------------------------------------------------------------------
\1\ Assumes monthly serial correlation of 0.5 for log(x), with x distributed lognormally. Percentages were
rounded to the nearest 1%.
\2\ The shift was scaled in terms of standard deviation units (sigma symbol = standard deviation)
\3\ Annual procedures: Method 1 of the final regulation is the Subtle Trigger under Procedure A of the proposed
regulation, with the leading constant changed from 1.58 to 1.96. Method 2 of the final regulation is the
Wilcoxon-Mann-Whitney Test under Procedure B (E. Annual Comparisons) of the proposed regulation, with the
significance level changed from 0.05 to 0.001.
\4\ Monthly procedures: Method 1 of the final regulation is the Single-Observation Trigger under Procedure A of
the proposed regulation. Method 2 of the final regulation is a nonparametric replacement for the parametric
Single-Observation Trigger under Procedure A of the proposed regulation.
C. Sample Collection To Establish Baseline Conditions and To Monitor
Compliance for the Coal Remining Subcategory
EPA evaluated the duration and frequency of sampling necessary to
apply the statistical procedures. Those procedures are used to compare
the levels of baseline loadings to the levels of loadings during
remining or the period when the discharge is permitted. Without an
adequate duration and frequency of sampling, the statistical procedures
would often fail to detect genuine exceedance of baseline conditions or
could establish baseline levels that are established as either too low
or too high.
Based on the considerations described below, EPA proposed that the
smallest acceptable number and frequency of samples is 12 monthly
samples, taken consecutively over the course of one year. In the
proposal, EPA raised the possibility that seasonal stratification might
have the potential to provide a basis for more precise estimates of
baseline characteristics, if the sampling plan is designed and executed
correctly and if results are calculated using appropriate statistical
estimators, and that there may be alternative plans that could be based
upon subdivision of the year into distinct time periods. These time
periods might be sampled with different intensities, or could be based
on other types of stratified sampling plans that attempt to account for
seasonal variations. EPA received several comments stating that a
baseline sampling period of less than 12 months may be appropriate.
EPA considers an adequate number of samples to be that number that
would allow an appropriate statistical procedure to detect an increase
of one standard deviation in the mean or median loading between a
baseline year and a monitoring year with a probability (power) of at
least 0.75.
The power analysis used in the proposed statistical procedures was
based on a two-sample t-test. The t-test can be an appropriate
statistical procedure for a yearly comparison because loadings from
mine discharges appear to be approximately distributed log-normally,
and thus logarithms of loadings are expected to be approximately
distributed normally. The (non-parametric) Wilcoxon-Mann-Whitney test
is also appropriate for yearly comparisons and has a power nearly equal
to that of the t-test when applied to normally distributed data. EPA
determined that annual comparisons of baseline to remining years based
upon 12 samples in each year were expected to have a power 0.75 to
detect a difference of one standard deviation. While the t-test was
dropped as a statistical procedure for assessing baseline in the Final
Rule, the analyses defined in Appendix B, including the Wilcoxon-Mann-
Whitney test, were designed to have similar power if 12 baseline
samples were collected. If significant autocorrelation is present
between samples (as discussed in section VI.B), the estimated power is
likely to be less than 0.75; therefore, 12 samples should be considered
the minimum acceptable for determining baseline.
An increase of one standard deviation can represent a large
increase in loading, given the large variability of flows and loadings
observed in mine discharges. The coefficient of variation (CV) is the
ratio of the standard deviation to the mean of the observations. Sample
CVs for iron loadings range approximately from 0.25 to 4.00, and
commonly exceed 1.00. Sample CVs for manganese loadings range
approximately from 0.24 to 5.00. When the CV equals 1.00, an increase
of the average loading by one standard deviation above baseline implies
a doubling of the loading.
The duration, frequency, and seasonal distribution of sampling are
important aspects of a sampling plan, and can affect the precision and
accuracy of statistical estimates as much as can the number of samples.
To avoid systematic bias, sampling, during and after baseline
determination, should systematically cover all periods of the year
during which substantially high or low discharge flows can be expected.
Unequal sampling of months could bias the baseline mean or median
toward high or low loadings by over-sampling of high-flow or low-flow
months. However, unequal sampling of different time periods can be
accounted for using statistical estimation procedures appropriate to
stratified sampling. Stratified seasonal sampling, possibly with
unequal sampling of different time periods, is a suitable alternative
to regular monthly sampling, provided that correct statistical
estimation procedures for stratified sampling are applied to estimate
the mean, median, variance, interquartile range, and other quantities
used in the statistical procedures, and provided that at least one
sample be taken per month over the course of 1 year.
In conclusion, EPA is promulgating a statistical procedure that
requires a minimum of 12 monthly samples, taken
[[Page 3388]]
consecutively over the course of one year to determine baseline.
D. Regulated Pollutant Parameters in Pre-Existing Discharges
EPA proposed to regulate iron, manganese, and pH, which are the
parameters addressed by the Rahall Amendment and are a subset of the
parameters directly regulated in 40 CFR part 434. Additionally, EPA
solicited comment in the proposal and NODA on regulating acidity
instead of pH, on establishing alternative limits for sediment, and on
establishing limitations or monitoring requirements for additional
parameters such as sulfate. Based on comments received and on further
data evaluation, EPA is establishing limitations for iron, manganese,
net acidity, and solids. These issues are addressed below.
1. Acidity
The Rahall Amendment provides an exemption for remining operations
from BAT effluent limitations for the pH level in pre-existing
discharges. In the proposed rule, EPA solicited comment on the use of
acidity instead of pH for pre-existing discharges. In very dilute or
pure water, pH can be considered a measurement of acidity. In drainage
from abandoned coal mines, however, pH is an indication of the
instantaneous hydrogen ion concentration, and does not measure the
potential of the solution to produce additional hydrogen from metals or
carbon dioxide during neutralization or further oxidation. Because
hydrogen ions are only one component of the acidity that can occur in
acid mine drainage, there can be instances where, although the pH is
nearly neutral, acidity exceeds alkalinity. Therefore, EPA concluded
that the reduction of pollutant loadings can best be achieved by
evaluating acidity, which includes pH.
In the final rule, pollutant loading is used to define baseline
conditions for remining operations because loading captures both
pollutant concentration and discharge flow. Although it is possible to
determine a pH load (i.e., load of H+ ions), it is not very
meaningful because pH load does not account for the latent acidity that
is present in the form of dissolved metals or carbon dioxide.
Additionally, in cases where treatment of discharges is required, the
amount of treatment is based on acidity or net alkalinity rather than
on pH. For this reason, acidity data already are typically submitted
with remining permit applications and reporting. Pollutant loading is
also used to determine mass balances and the effects of a discharge on
a receiving waterbody. Such a determination is possible for acidity,
net acidity, or alkalinity, but is not likely to be meaningful for pH
because mixing can result in precipitation or dissolution of ions.
EPA notes that commenters were unanimous in their support for the
use of acidity instead of pH. For these reasons, EPA has modified the
limitations in the final rule to require compliance with baseline net
acidity determinations.
2. Sulfate
EPA also solicited comments and data regarding the merits of using
sulfate as a parameter for assessment of pollution loading from pre-
existing discharges. Commenters agreed that this is a useful parameter
for determining whether or not a pre-existing discharge is affected by
mine drainage, and how remining BMPs have affected the discharge.
However, commenters noted that it should be assessed as part of the
baseline and for the potential effects of remining, but should not be
included as a baseline effluent limit.
EPA concluded that sulfate is a useful parameter for evaluating the
effectiveness of BMPs implemented under a Pollution Abatement Plan, and
is aware that current State remining programs request that sulfate data
are submitted during permit application and periodic reporting. EPA
encourages this practice, but EPA agrees with commenters that effluent
limitations for sulfate are unnecessary to determine that pre-existing
discharge loadings are not increased over baseline.
3. Solids
EPA did not initially propose alternative limits for solids.
However, due to comments received on the proposal, EPA issued a Notice
of Data Availability (NODA) presenting commenters' concerns and new
data submitted to EPA regarding solids levels in pre-existing
discharges. EPA received numerous comments on the NODA which supported
EPA's decision to adopt alternative limits for solids.
Based on the existing conditions of sediment present at some AML,
EPA concluded that the benefits of remining may be severely limited if
EPA does not address sediment in the final rule. Consistent with the
intent of the Rahall Amendment, which seeks to encourage remining while
ensuring that the remining activity will potentially improve and
reclaim AML, EPA is establishing alternative limits for TSS such that
the sediment load of the pre-existing discharge cannot be increased
over baseline during remining and reclamation activities.
EPA believes that the final regulation is consistent with SMCRA
which mandates the prevention of additional contribution of suspended
solids to streamflow to the extent possible using the best technology
currently available. EPA has adopted what is essentially a compliance
schedule so that, during remining and reclamation activities, the
operator cannot contribute sediment levels beyond the baseline
discharge loading. After remining and reclamation has been completed,
the operator must meet the standards for TSS and SS contained in
subpart E--Post Mining areas prior to bond release. EPA concluded that
the implementation of successful sediment control BMPs should, in most
cases, be able to meet the BPT standards contained in subpart E--Post
Mining areas regardless of whether the area has been disturbed due to
remining or virgin mining.
Based on comments provided, however, EPA believes that there may be
some exceptions where the post-mining sediment standards may not be
economically feasible and may be detrimental for remining areas.
Therefore, EPA has provided an exclusion from the post-mining sediment
standards for ``steep-slope'' areas and other areas where the
permitting authority determines it is infeasible or impractical based
on the site-specific conditions of soil, climate, topography, or
baseline conditions. In these instances, the pre-existing discharge
must still meet the alternative baseline standards.
An example of when it would be impractical to establish subpart E
numeric standards would be a tract of AML in the pollution abatement
area that is not disturbed by remining. In this case, voluntary
vegetative growth may have already been established and sediment runoff
may be minimal. In this case, however, the AML area may not support
100% plant coverage and the discharge may contain a moderate amount of
sediment that does not meet the subpart E numeric standards. In this
case, the NPDES permitting authority may decide that it would be
excessively costly and may even be more harmful to disturb the area,
reclaim the land, revegetate the area and incorporate BMPs to meet the
subpart E standards. EPA believes that this exclusion establishes
necessary flexibility to permit authorities to adopt the most
environmentally beneficial and cost-effective approach to reclamation.
During remining, the alternative limits for TSS are to be
established in a manner consistent with the alternative
[[Page 3389]]
limits established for acidity, iron, and manganese (i.e., based on the
statistical methodology provided in Appendix B of the final
regulation). The statistical procedures are described in Section VI.A
above. This protocol requires a minimum of 12 monthly samples to
establish baseline. EPA recommends that baseline sediment sampling
include precipitation events in order to adequately characterize the
baseline where runoff contributes directly to the sediment load.
VII. Non-Water Quality Environmental Impacts of Final Regulations
The elimination or reduction of pollution has the potential to
aggravate non water quality environmental problems. Under sections
304(b) and 306 of the CWA, EPA is required to consider these non-water
quality environmental impacts (including energy requirements) in
developing effluent limitations guidelines and NSPS. In compliance with
these provisions, EPA has evaluated the effect of this regulation on
air pollution, solid waste generation, energy consumption, and safety.
Today's rule does not require the implementation of treatment
technologies that result in any increase in air emissions, in solid
waste generation or in energy consumption over present industry
activities.
Non-water quality environmental impacts are a major consideration
for this rule because the rule is intended to improve or eliminate a
number of existing non-water quality environmental and safety problems.
Remining operations have improved or eliminated adverse non-water
quality environmental conditions such as abandoned and dangerous
highwalls, dangerous spoil piles and embankments, dangerous
impoundments, subsidence, mine openings, and clogged streams that pose
a threat to health, safety, and the general welfare of people. EPA
projects that remining has the potential to eliminate nearly three
million feet of dangerous highwall in the Appalachian and mid-Continent
coal regions.
EPA also does not expect today's rule to have an adverse impact on
health, safety, and the general welfare of people in the arid and
semiarid western coal region. The intent of the rule is to allow runoff
to flow naturally from disturbed and reclaimed areas. EPA believes
that, in most cases, this is preferable to retention in sedimentation
ponds that is accompanied by periodic releases of runoff containing
sediment imbalances potentially disruptive to land stability. Alternate
sediment control technologies in these regions address and alleviate
adverse non-water quality environmental conditions such as: quickly
eroding stream banks, water loss through evaporation, soil and slope
instability, and lack of vegetation.
Based on this evaluation, EPA concluded that the regulations being
promulgated today under these new subcategories will improve existing
AML conditions in the eastern United States and will improve the
hydrologic imbalances produced by application of current regulations in
the western arid and semiarid United States.
VIII. Environmental Benefits Analysis
EPA presented estimates of the environmental benefits of today's
regulation in Section IX of the proposal. The benefits assessment for
the Coal Remining Subcategory is identical to the assessment performed
at proposal. For the Western Alkaline Coal Mining Subcategory, the
methodology for the assessment is identical to that performed at
proposal. However, the calculations have changed due to the
incorporation of additional data provided by two model mine studies
submitted during the comment period.
EPA's complete benefits assessment can be found in Benefits
Assessment of Effluent Limitations Guidelines and Standards for the
Coal Mining Industry: Remining and Western Alkaline Subcategories
(hereafter referred to as the ``Benefits Assessment''). A detailed
summary is also contained in Chapter 8 of Economic and Environmental
Impact Analysis of Effluent Limitations Guidelines and Standards for
the Coal Mining Industry: Remining and Western Alkaline Subcategories
(hereafter referred to as the ``EA'').
A. Coal Remining Subcategory
The water quality improvements associated with today's rule for
remining depend on (1) changes in annual permitting rates for remining;
(2) characteristics of sites selected for remining; and (3) the type
and magnitude of the environmental improvements expected from remining.
Remining permits in Pennsylvania increased by an estimated factor of
three to eight following State implementation of a regulation that is
similar to today's remining rule. EPA believes that implementing
today's rule is likely to have a similar effect on other States with
remineable coal reserves and similar abandoned mine drainage problems.
The type and magnitude of site-specific water quality improvements
under the final rule are not expected to be dramatically different than
those that have occurred under existing requirements in Pennsylvania.
Of approximately 9,500 miles of acid mine drainage impacted streams
in States where coal mining has previously occurred (Record Section
3.2.2), EPA estimates that remining operations have the potential to
improve 2,900 to 4,800 miles of impacted streams, and that 1,100 to
2,100 miles of these streams may demonstrate significant improvement.
EPA estimates that one to six miles of stream may see improvement for
every 1,000 acres of abandoned mine land reclaimed. Based on an average
of 38 acres of AML reclamation per permit, EPA estimates approximately
0.04 to 0.2 miles of stream improvement per remining project. EPA
estimates that AML sites affected by the rule have an average of 70
highwall feet per acre. EPA also estimates that an additional 216,000
to 307,000 feet of highwall (41 to 58 miles) will be targeted for
removal each year as a result of today's rule.
EPA assessed the potential impacts of remining BMPs on water
quality using pollutant loadings data from pre-existing discharges at
13 mines included in EPA's Coal Remining Database (Record Section
3.5.1). Approximately 58 percent of the post-baseline observations
showed a decrease in mean pollutant loadings. Approximately half of
these sites (27 percent of the post-baseline observations) showed a
statistically significant decrease in loadings. The 13 mines examined
by EPA are active remining operations; decreases in pollutant loads are
expected to become more significant with time. In comparison,
Pennsylvania's Remining Site Study of 112 closed remining sites (Record
Section 3.5.3) found that the Pennsylvania program for these sites was
effective in improving or eliminating acidity loading in 45 percent of
the pre-existing discharges, total iron loading in 44 percent of the
discharges, and total manganese in 42 percent of the discharges. The
Pennsylvania Remining Site Study focused on sites reclaimed to at least
Stage II bond release standards, so that the mitigating impacts of BMPs
had ample time to take effect.
Remining generates human health benefits by reducing the risk of
injury at AML sites and reducing discharge of acid mine drainage to
waterways. However, the human health benefits associated with
consumption of water and organisms are not likely to be significant
because (1) acid mine drainage constituents are not bioaccumulative,
and adverse health effects associated with fish consumption are
therefore not expected; and (2) public drinking water sources are
[[Page 3390]]
treated for most acid mine drainage constituents associated with
adverse health effects. Eliminating safety hazards by closing abandoned
mine openings, eliminating highwalls, stabilizing unstable spoils, and
removing hazardous waterbodies potentially prevents injuries and saves
lives.
EPA evaluated the potential impacts to human and aquatic life by
comparing the number of water quality criteria exceedances in receiving
waterbodies in the baseline (pre-remining) and post-baseline sampling
periods for 11 remining sites in the Coal Remining Database for which
relevant data exist. Exceedances of the human health criterion for pH
(water plus organism consumption, field pH) were eliminated at two
sites while exceedances of chronic aquatic life criteria were
eliminated for pH (field pH) and iron at two sites. Exceedances of the
acute aquatic life criterion for manganese also were eliminated at two
sites. Although surface water quality data examined indicate changes in
the number of water quality exceedances due to remining, nine of the 11
sites consist of active remining operations where the full
environmental impacts of BMPs have yet to be realized. Correlations
between pre-existing discharge loads and pollutant concentrations in
receiving water can be used to determine the extent to which remining
BMPs are responsible for changes in surface water quality. However, the
lack of sufficient data on relevant sources of acid mine drainage
upstream from pre-existing discharges at the selected mine sites made
it difficult to estimate these correlations.
Remining and the associated reclamation of AML is expected to
generate ecological and recreational benefits by (1) improving
terrestrial wildlife habitat, (2) reducing pollutant concentrations
below levels that adversely affect aquatic biota, and (3) improving the
aesthetic quality of land and water resources. EPA was able to quantify
and monetize some of the benefits expected from increased remining
using a benefits transfer approach. The benefits transfer approach
relies on information from existing benefit studies applicable to
assessing the benefits of improved environmental conditions at remining
sites. Benefits are estimated by multiplying relevant values from the
literature by the additional acreage reclaimed under the remining
subcategory.
EPA used the following assumptions to estimate annual benefit
values for ecological improvements: (1) 3,100 to 4,400 acres will be
permitted annually under the subcategory; (2) 57 percent of the acres
permitted will actually be reclaimed (1,800 to 2,500 acres) ; (3) 38
percent to 44 percent of acres reclaimed per year are expected to be
associated with significant decreases in acid mine drainage (AMD)
pollutant loads to surface water bodies; and (4) annualized benefits
from remining begin to occur five years after permit issuance and are
calculated for a five year period. EPA assumed that 57 percent of the
acres permitted would actually be reclaimed based on a study of 105
remining permits in Pennsylvania (Hawkins, 1995, Characterization and
Effectiveness of Remining Abandoned Coal Mines in Pennsylvania). The
study found that on average, a remining site had 67 AML acres, of which
38 acres (or 57 percent) were actually reclaimed. The assumption that
38 to 44 percent of acres reclaimed would be associated with
significant decreases in AMD pollutant loads was based on the results
of Pennsylvania's study of 112 closed remining sites. A detailed
explanation of all assumptions is provided in the Benefits Assessment
document for the proposed rule.
EPA estimated water-related ecological benefits using the benefits
transfer approach with values taken from a benefit-cost study of
surface mine reclamation in central Appalachia by Randall et al. (1978,
Reclaiming Coal Surface Mines in Central Appalachia: A Case Study of
the Benefits and Costs). EPA's analysis is based on two values from the
study: (1) Degradation of life-support systems for aquatic and
terrestrial wildlife and recreation resources, valued at $37 per acre
per year (1998$); and (2) aesthetic damages, valued at $140 per acre
per year (1998$). EPA estimated nonuse benefits using a widely accepted
approach developed by Fisher and Raucher (1984, Intrinsic Benefits of
Improved Water Quality: Conceptual and Empirical Perspectives), where
nonuse benefits are estimated as one-half of the estimated water-
related recreational use benefits. The estimated water-related benefits
range from $0.53 to $0.89 million per year.
Reclaiming the surface area at AML sites will enhance the sites'
appearance and improve wildlife habitats, positively affecting
populations of various wildlife species, including game birds. This is
likely to have a positive effect on wildlife-oriented recreation,
including hunting and wildlife viewing. EPA estimated land-related
ecological benefits using the benefits transfer approach with values
taken from a study of improved opportunities for hunting and wildlife
viewing resulting from open space preservation by Feather et al. (1999,
Economic Valuation of Environmental Benefits and the Targeting
Conservation Programs). EPA's analysis is based on two values from the
study: (1) The average wildlife viewing value of $21 per acre per year;
and (2) the improved pheasant hunting value of $7 per acre per year.
Based on an aggregate value of $28 per acre per year, EPA estimates
land-related benefits of $0.20 to $0.29 million per year.
The sum of the estimated monetary values of the different benefit
categories results in total annual benefits of $0.73 to $1.17 million
from implementing the remining subcategory. This estimate does not
include benefit categories that EPA was unable to quantify and/or
monetize, which include human health and safety impacts. EPA examined a
number of data sources to determine the annual rate of accidents
associated with exposed highwall and other hazardous features of AML in
order to estimate the benefits attributable to the decreased risk
resulting from remining safety improvements. EPA contacted State and
Federal agencies responsible for AML statistics as well as agencies
responsible for maintaining public health statistics and concluded that
the necessary information was not available to support such an
analysis.
B. Western Alkaline Coal Mining Subcategory
Only a small percentage of potentially affected western coal mines
discharge to permanent or perennial water bodies. Information about
receiving waters is available for 39 of the existing surface coal mines
affected by this rule, and 30 of these discharge to intermittent or
ephemeral creeks, washes, or arroyos. Only two of these mines list a
permanent water body as the primary receiving water. It is therefore
difficult to describe the benefits of the Western Alkaline Coal Mining
Subcategory in terms of the use designations referenced in the section
101(a) goals of the Clean Water Act.
The environmental conditions and naturally high sediment yields in
arid and semiarid coal regions were discussed in Section IV of the
proposal. The potential impacts of the predominant use of sedimentation
ponds to control settleable solids in these regions include reduced
sediment loads to natural drainage features, reduced downstream flood
peaks and runoff volumes, and downstream channel bed and bank changes.
The environmental and water quality effects of these hydrologic impacts
include: (1) Reducing ground water recharge, (2)
[[Page 3391]]
shrinking biological communities consisting of and reliant upon
riparian and hydrophytic vegetation, (3) degrading downstream channel
beds by cleaner waters, resulting from retention of water and sediment
runoff, and (4) accelerating erosion. Because of the depletion of
runoff associated with such ponds, the potential impact to endangered
fish species exists in some watersheds in the West. Therefore,
construction of sedimentation ponds in Utah, Colorado or Southern
Wyoming that results in an additional water depletion to the upper
Colorado or Platte River system triggers formal Section 7 Endangered
Species Act consultation with the U.S. Fish and Wildlife Service.
Site-specific alternative sediment control plans incorporating BMPs
designed and implemented to control sediment and erosion have the
potential to provide both land and water-related benefits. Land-related
benefits include decreased surface area disturbance, increased soil
conservation, and improved vegetation. Surface disturbance is estimated
to decrease by approximately 600 acres per year across all existing
potentially affected surface mine sites in the western region.
Vegetative cover may increase by five percent when BMPs are used.
EPA was only able to monetize land-related benefits associated with
decreased surface area disturbance. Hunting benefits from increased
availability of undisturbed open space were estimated to be between
$0.37 and $2.46 per acre per year based on Feather et al. (1999) and
Scott (Scott, M., G.R. Bilyard, S.O. Link, C.A. Ulibarri, H.
Westerdahl, P.F. Ricci, and H.E. Seely. 1998. Valuation of Ecological
Resources and Functions. Environmental Management, Vol. 22, No 1:49-
68). Annual land-related benefits of the subcategory range from $2,000
to $13,000 per year, based on the value of enhanced hunting
opportunities. However, this estimate does not account for a number of
benefit categories, including nonuse ecological benefits that may
account for the major portion of land-related benefits in relatively
unpopulated areas such as those affected by this rule.
Water-related benefits include improved hydrologic and fluvial
stability in the watersheds affected by western mining operations.
These benefits will be site-specific and depend upon the nature of
environmental quality changes; the current in-stream water uses, if
any, and; the population expected to benefit from increased water
quantity. EPA estimated water-related benefits using the estimated mean
``willingness to pay'' (WTP) values for preservation of perennial
stream flows adequate to support abundant stream side plants, animals
and fish from Crandall et al. (1992, Valuing Riparian Areas: A
Southwestern Case Study). The WTP value is applied to water-based
recreation consumers residing in counties affected by western mining
operations discharging to, or affecting, water bodies with perennial
flow. EPA identified seven perennial streams located in six counties
that are likely to be affected by today's rule. The estimated monetary
value of recreational water-related benefits for these streams ranges
from $25,000 to $488,000. As noted above, EPA estimates that nonuse
benefits are equal to one-half of the water-related recreational
benefits, or $12,500 to $244,000 per year.
Total estimated annualized benefits for the subcategory range from
$39,500 to $745,000. This estimate does not include benefit categories
that EPA was unable to quantify and/or monetize, which include
increased vegetative cover and some additional recreational and nonuse
benefits associated with western alkaline coal mine reclamation areas.
A more detailed discussion of the benefits analysis is contained in the
EA.
IX. Economic Analysis
A. Introduction, Overview, and Sources of Data
This section presents EPA's estimates of the economic impacts
attributed to the final regulation. The economic impacts are evaluated
for each subcategory for BPT, BCT, BAT, and NSPS as applicable. A
description of the regulatory requirements for each subcategory is
given in Section V of today's document. EPA's detailed economic impact
assessment can be found in Economic and Environmental Impact Analysis
of Final Effluent Limitations Guidelines and Standards for the Coal
Mining Industry: Remining and Western Alkaline Subcategories (referred
to as the ``EA''). Additional information can be found in Coal Remining
and Western Alkaline Mining: Economic and Environmental Profile, which
EPA prepared in support of the proposed rulemaking.
This section of today's document describes the segment of the coal
industry that would be impacted by the final rule (i.e., the number of
firms and number of mines that would incur costs or realize savings
under the final rule), the financial condition of the potentially
affected firms, the aggregate cost or cost savings to that segment, and
the economic impacts attributed to the final rule. The section also
discusses impacts on small entities and presents a cost-benefit
analysis. This discussion will form the basis for EPA's findings on
regulatory flexibility, presented in Section X.B. All costs are
reported in 1998 dollars unless otherwise noted.
EPA developed this regulation using an expedited rulemaking
procedure. Therefore, EPA's economic analysis relied on industry
profile information voluntarily provided by stakeholders, on data
compiled from individual mining permits, and on data from publicly
available sources. For the Coal Remining Subcategory, EPA obtained
information on abandoned mine lands from the Abandoned Mine Lands
Information System (AMLIS) maintained by the Office of Surface Mining
(Record Section 3.5.2), the National Abandoned Lands Inventory System
(NALIS) database maintained by the Pennsylvania Department of
Environmental Protection (Record Section 3.5.5), and a survey of States
conducted by the Interstate Mining Compact Commission (Record Section
3.2.2). For the Western Alkaline Coal Mining Subcategory, EPA relied on
industry profile data developed and submitted to EPA by the Western
Coal Mining Work Group as described in Section V of the proposal.
Specifically, the work group provided data on coal mine operators, mine
locations, annual production, reclamation permit numbers, acres of land
reclaimed, and reclamation bond amounts. This information is included
in Section 3.3 of the Record.
Data on the coal industry as a whole, including coal production,
employment, and prices, as well as information on individual western
alkaline underground mines, were obtained from various Energy
Information Administration sources, including the 1997 Coal Industry
Annual, the 1998 Annual Energy Outlook, and the 1992 Census of Mineral
Industries. EPA used the Security and Exchange Commission's Edgar
database, which provides access to various filings by publicly held
firms, such as 8Ks and 10Ks, for financial data and information on
corporate structures. EPA also used a database maintained by Dun &
Bradstreet, which provides estimates of employment and revenue for many
privately held firms, and obtained industry financial performance data
from Leo Troy's Almanac of Business and Industrial Financial Ratios.
B. Method for Estimating Compliance Costs
The costs and savings of the final regulation are associated with
BMP
[[Page 3392]]
implementation, baseline monitoring, and performance monitoring. For
each subcategory, EPA estimated economic baseline conditions based on
existing State and Federal regulations and current industry practices.
For remining, EPA assumed as economic baseline conditions remining
under a Rahall permit, pursuant to section 301(p).
1. Coal Remining Subcategory
As discussed in the proposal, EPA projected costs for each remining
site by calculating the cost of monitoring requirements for determining
baseline, the cost of potential increases in reclamation permit
numbers, acres of land reclaimed, and reclamation bond amounts. This
information is included in Section 3.3 of the Record.
Data on the coal industry as a whole, including coal production,
employment, and prices, as well as information on individual western
alkaline underground mines, were obtained from various Energy
Information Administration sources, including the 1997 Coal Industry
Annual, the 1998 Annual Energy Outlook, and the 1992 Census of Mineral
Industries. EPA used the Security and Exchange Commission's Edgar
database, which provides access to various filings by publicly held
firms, such as 8Ks and 10Ks, for financial data and information on
corporate structures. EPA also used a database maintained by Dun &
Bradstreet, which provides estimates of employment and revenue for many
privately held firms, and obtained industry financial performance data
from Leo Troy's Almanac of Business and Industrial Financial Ratios.
B. Method for Estimating Compliance Costs
The costs and savings of the final regulation are associated with
BMP implementation, baseline monitoring, and performance monitoring.
For each subcategory, EPA estimated economic baseline conditions based
on existing State and Federal regulations and current industry
practices. For remining, EPA assumed as economic baseline conditions
remining under a Rahall permit, pursuant to section 301(p).
1. Coal Remining Subcategory
As discussed in the proposal, EPA projected costs for each remining
site by calculating the cost of monitoring requirements for determining
baseline, the cost of potential increases in compliance monitoring
requirements, and the potential costs associated with implementing the
required pollution abatement plan. To assess the increased baseline
determination and monitoring requirements of the rule, EPA evaluated
current State requirements for operations permitted under the Rahall
provision and calculated the costs under this final regulation that
exceed the current State requirements. Current State sample collection
requirements for determining and monitoring baseline are included in
the Record at Section 3.4.
Although EPA estimated that the Coal Remining Subcategory would be
applicable to 64 to 91 remining sites and 3,810 to 5,400 acres
annually, EPA projects that fewer sites would realize costs or benefits
from this proposal. As noted throughout the proposal, the Commonwealth
of Pennsylvania has an advanced remining program and EPA does not
believe that the rule will have a measurable impact on Pennsylvania's
remining activities. Therefore, EPA did not include Pennsylvania's
remining sites in the estimation of costs or benefits. EPA's cost and
benefit analysis were calculated for a total of 43 to 61 sites
representing 3,100 to 4,400 permitted acres each year. EPA estimates
that approximately 1,800 to 2,500 of these acres would actually be
reclaimed each year. Table IX. B.1 shows the various estimates EPA used
in the estimation of costs and benefits (these are the same estimates
used in the proposal).
Table IX. B.1: Annual Estimates of Affected Remining Sites Used in the Economic Analyses
----------------------------------------------------------------------------------------------------------------
Number of
Additional sites permitted sites Acres Used in analysis of
----------------------------------------------------------------------------------------------------------------
All types, all States (initial estimate)....... 64-91 3,812-5,401
All types, excluding PA........................ 43-61 3,111-4,407 Monitoring costs for selected
States; NPDES permitting
authority costs.
10% of surface & underground sites only (no 3.9-5.6 309-438 Costs of additional BMPs.
coal refuse piles), excluding PA.
Additional acres reclaimed: (57% of acres ............ 1,773-2,512 Benefits from recreational use of
permitted, all types excluding PA). reclaimed land.
Additional acres reclaimed expected to have ............ 667-1,115 Benefits from recreational use of
significant decreases in AMD pollutant loads improved water bodies; Aesthetic
(37.6-44.4% of additional reclaimed acres). improvements in water bodies;
Nonuse benefits.
----------------------------------------------------------------------------------------------------------------
2. Western Alkaline Coal Mining Subcategory
EPA's Coal Remining and Western Alkaline Mining: Economic and
Environmental Profile prepared for proposal provides profile
information on the 47 surface coal mines and 24 underground coal mines
initially believed to be in scope of the subcategory. As discussed in
the proposal, EPA determined that one of the surface mines profiled was
already in the final reclamation stage and would not be affected by the
rule. EPA also determined that any savings to underground producers
were likely to be small given the limited acreage and lack of
complexity associated with these reclamation areas, and did not
calculate these benefits. The remainder of this section considers only
the 46 active existing surface mines in its discussion.
In the proposal, the only incremental cost attributed to the
subcategory was associated with the watershed modeling requirements.
Although information provided by OSMRE during the comment period
(Record Section 7.2) indicates that all coal mine operators already
perform modeling (to support their SMCRA permit applications) that is
sufficient for purposes of this rulemaking, EPA has chosen to maintain
the proposed costing approach that conservatively allows for some
additional modeling costs due to this regulation.
C. Costs and Cost Savings of the Final Rule
1. Coal Remining Subcategory
Under the final rule, EPA is requiring operators to conduct one
year of monthly sampling to determine the baseline pollutant levels for
net acidity, iron (total), TSS, and manganese (total) (see part 434
Appendix B). Although most States with remining activities
[[Page 3393]]
have similar requirements, remining sites in Alabama and Kentucky will
be required to add six samples annually. EPA did not have data for
Illinois, Indiana, or Tennessee because the remining operations that
occur in these States do not incorporate Rahall provisions for pre-
existing discharges. EPA has conservatively assumed sample collection
costs for 12 additional samples annually for these States. Information
representing current state sampling requirements is included in the
Record at Section 5.
EPA has generated compliance costs based on monthly monitoring.
Most States already have similar requirements, with the exception of
Ohio, which currently requires quarterly modeling. Again, EPA did not
have data for Illinois, Indiana, or Tennessee because these States do
not incorporate Rahall provisions in their remining permits. For these
States, EPA has conservatively assumed that an additional 12 compliance
monitoring samples per year would be required for five years.
Because each remining site will typically have more than one pre-
existing discharge, EPA reviewed Pennsylvania remining sites to
estimate the average number of pre-existing discharges per site. EPA
used this calculated average of four pre-existing discharges per site
for estimating baseline determination and compliance monitoring costs
(Record Section 3.3.1). Additionally, EPA assumed that remining
operators would have to purchase and install flow weirs to comply with
the baseline monitoring requirements in the States that do not
currently incorporate Rahall provisions in their remining permits.
These assumptions result in an upper-bound estimate of additional
monitoring costs for the 43 to 61 potentially affected sites per year.
EPA estimates the total annual incremental monitoring costs to be
in the range of $133,500 to $193,500. Of this, between $83,000 and
$120,000 is associated with incremental baseline monitoring
requirements and between $50,500 and $73,500 results from incremental
compliance monitoring during the five-year mining period. Detailed
assumptions and calculations are presented in the EA.
In addition to baseline determination and compliance monitoring,
remining operators must develop and implement a site-specific pollution
abatement plan for each remining site. In many cases, EPA believes that
the requirements for the pollution abatement plan will be satisfied by
an approved SMCRA plan. However, EPA recognizes that some operators may
be required to implement additional or more intensive BMPs under the
rule beyond what is included in a SMCRA-approved pollution abatement
plan.
EPA developed a general estimate of the potential costs of
additional BMPs based on review of the existing remining permits
contained in the Coal Remining Database (Record Section 3.5.1) , and on
information provided in the Coal Remining BMP Guidance Manual. EPA
determined that the most likely additional BMP that NPDES permit
writers might require would be a one-time increase in the amount of
alkaline material used as a soil amendment to prevent or ameliorate the
formation of acid mine drainage. EPA assumed that an average mine
facility requiring additional BMPs would need to increase its alkaline
addition by a rate of 50 to 100 tons per acre to meet the additional
NPDES permit review requirements. EPA estimated an average cost for
alkaline addition of $12.90/ton, and assumed that 10 percent of surface
and underground remining sites would be required to incur these
additional BMP costs. Because the typical BMP for coal refuse piles is
simply removal of the pile, no incremental BMP costs would be incurred
for these sites. Based on EPA's estimate that between 309 and 438 acres
could be required to implement additional or more intensive BMPs each
year, the estimated annual cost of additional BMP requirements would
range from $199,500 to $565,000.
Based on the above assumptions, the total estimated incremental
costs associated with the final rule range from $333,000 to $758,500
per year for the Coal Remining Subcategory. These costs are based on
EPA's estimates of what is likely to happen in the future, and they
would be incurred by new remining operations. Table IX. C.1 summarizes
the incremental costs associated with the subcategory. These are the
same estimates presented in the proposal.
Table IX. C.1.--Annual Costs for the Remining Subcategory
[1998$]
------------------------------------------------------------------------
------------------------------------------------------------------------
Monitoring Costs................................... $133,500-$193,500
Additional BMPs.................................... $199,500-$565,000
Total Compliance Costs......................... $333,000-$758,500
------------------------------------------------------------------------
2. Western Alkaline Coal Mining Subcategory
The cost impacts of the subcategory will vary, depending on site-
specific conditions at each eligible coal mine. However, based on
available data and information, EPA believes that the costs of
reclamation under today's rule will be less than or equal to
reclamation costs for Subpart E for each individual operator, and thus
for the subcategory as a whole.
EPA expects that the sediment control plan will consist entirely of
materials generated as part of the SMCRA permit application. The SMCRA
permit application process requires that a coal mining operator submit
an extensive reclamation plan, documentation and analysis to OSMRE or
the permitting authority for approval. Based on these requirements, EPA
believes that plans developed to comply with SMCRA requirements will
fulfill the EPA requirements for sediment control plans. The
requirement to use watershed modeling techniques is not inconsistent
SMCRA permit application requirements. As discussed in the proposal,
EPA believes that none of the coal mine operators will incur
incremental modeling costs. However, because modeling requirements for
this regulation may differ in some circumstances from SMCRA
requirements, EPA has conservatively assumed that each surface mine
operator will incur $50,000 in watershed modeling costs in the economic
impact analysis. Total incremental modeling costs (annualized at seven
percent over ten years) for the 46 surface mines are estimated to be
$327,000 based on this assumption.
EPA projects that cost savings for this subcategory would result
from lower capital and operating costs associated with implementing the
BMP plans, and from an expected reduction in the reclamation bonding
period. The cost savings for controls based on BMPs were calculated for
three representative model mines differentiated by geographic region:
Desert Southwest (DSW), Intermountain (IM), and Northern Plains (NP).
The cost models were submitted by the Western Coal
[[Page 3394]]
Mining Work Group (WCMWG, 1999a, 2001). The cost models are discussed
in detail in the Development Document for Final Effluent Limitations
Guidelines and Standards for the Western Alkaline Coal Mining
Subcategory and are included in the Record at Section 3.3.2. The cost
estimates for each model mine relied on data taken from case study mine
permit applications, mine records, technical resources and industry
experience. The models estimated capital costs (design, construction
and removal of ponds and implementation of BMPs) and operating costs
(inspection, maintenance, and operation) over the anticipated bonding
period.
EPA classified each mine by region within the subcategory (DSW, IM,
or NP). Cost savings for reclamation at each mine were calculated by
extrapolating the cost savings per disturbed acre calculated for the
appropriate model mine. Costs are discounted at a seven percent real
rate over a ten-year period. Although individual input data changed
with the addition of the two new representative model mine types, EPA's
methodology did not change from proposal. The present value of cost
savings for the DSW model mine was calculated to be $672,000 ($1,760
per acre). For the IM model mine, the present value of expected cost
savings is $199,000 ($522 per acre). Finally, the NP model mine is
expected to achieve a present value of cost savings of $235,000 ($617
per acre) under the new subcategory.
EPA used the projected disturbance acreage divided by the remaining
mine life to estimate the annual acres reclaimed at each existing mine
site. This information was available for 26 mines: two DSW mines, one
IM mine, and 23 NP mines. The 20 mines without data available on
expected mine life and disturbance acres are located in the NP (18
mines) and IM (two mines) regions. EPA used the average annual acres
reclaimed for mines with available data in these two regions (305 acres
per year) to estimate reclamation cost savings. For each mine site,
annual acres reclaimed were multiplied by the present value of savings
per acre for the appropriate regional model mine and totaled. Estimated
annual reclamation cost savings total $12.7 million for the 46
producing surface mines in the subcategory, significantly smaller than
the estimate for proposed rulemaking of $30.8 million. The decrease in
total estimated annual reclamation savings is primarily due to the
lower savings per acre at IM and NP mines which comprise the majority
of the subcategory. A detailed analysis of this difference as it
relates to the additional model mines that account for different
geographical features is contained in the EA.
EPA has also calculated cost savings that may result from earlier
Phase II bond release. The OSMRE hydrology requirement to release
performance bonds at Phase II, requires compliance with the previously
applicable 0.5
ml/L effluent standard for SS (30 CFR part 800.40(c)(1)). The Western
Coal Mining Work Group, in its draft Mine Modeling and Performance Cost
Report (Record Section 3.3.2) estimates that the typical post-mining
Phase II bonding period can be ten years or more under the previous
effluent guidelines. Reclamation areas must achieve considerable
maturity before they are capable of meeting this standard. The BMP-
based approach in today's rule uses the inspection of BMP design,
construction, operation and maintenance to demonstrate compliance
instead of the current sampling and analysis of surface water drainage
for reclamation success evaluations. The report estimates that the BMP-
based approach would reduce the time it takes reclaimed lands to
qualify for Phase II bond release by about five years. 3
EPA used the following assumptions to estimate cost savings due to
earlier Phase II bond release: (1) A post-mining Phase II bonding
period of ten years under the numeric effluent guidelines and five
years under the new subcategory; (2) twenty-five percent of the
reported bond amount would be released at the end of Phase II; and (3)
surety bonds were used, with annual fees between $3.75 and $5.50 per
thousand. Twenty-six mines provided information necessary to calculate
associated bond savings. The total estimated savings for these mines
range from $0.2 to $0.3 million when annualized at seven percent over
the five-year permit period. EPA assumes that the remaining 20 mines
for which savings could not be calculated would achieve the average
savings per mine ($7,200 to $10,600) resulting in total annualized
savings between $0.1 and $0.2 million. Detailed assumptions and
calculations are contained in the EA. Projected bond savings for the
entire subcategory thus total from $0.3 to $0.5 million. These
estimated bond savings are about 2 percent less than the estimated bond
savings presented at proposal. The difference in the two estimates is
entirely attributable to lower expected disturbance acres per permit
period in IM and NP mines.
The estimated net savings in compliance costs associated with the
subcategory, considering the savings to mining operations in sediment
control and bonding costs, is estimated to be approximately $12.8
million, as shown in Table IX. C.2.
Table IX. C.2.--Annual Cost Savings for the Western Alkaline Coal Mining
Subcategory
[$1998]
------------------------------------------------------------------------
------------------------------------------------------------------------
Modeling Costs............................. ($ 327,000)
Sediment Control Cost Savings.............. $12,721,000
Earlier Phase 2 Bond Release Savings....... $341,900-$501,400
Total Compliance Cost Savings.............. $12,735,900-$12,895,400
------------------------------------------------------------------------
D. Economic Impacts of the Final Rule
1. Economic Impacts for the Coal Remining Subcategory
As discussed in Section V, EPA is promulgating BPT, BCT, BAT, and
NSPS that have the same technical basis. EPA believes that the final
rule will not impact existing remining permits. For new permits,
remining operators will have the ability to choose among potential
remining sites, and will only select sites that they believe are
economically achievable to remine. Furthermore, any additional BMPs
required by the NPDES authority under the final rule will be site-
specific. Today's requirements will not create any barriers to entry in
coal remining, but instead are specifically designed to encourage new
remining operations. Hence, the Agency finds no significant negative
impacts to the industry associated with the subcategory.
The implementation of a pollution abatement plan containing BMPs
may impose additional costs beyond what is included in a SMCRA-approved
pollution abatement plan. At the same time, the profits may increase at
remining sites because the new regulations provide an incentive to mine
coal from abandoned mine land areas
[[Page 3395]]
that may have been avoided in the absence of implementing regulations.
The subcategory will also affect the relative profitability of remining
different types of sites, with the potential to encourage remining of
the sites with the worst environmental impacts. An analysis by the
Department of Energy (DOE) of potential remining sites estimated an
average coal recovery of between 2,300 and 3,300 tons per acre of
remined land (1993, Coal Remining: Overview and Analysis). At these
coal recovery rates, the estimated steady state annual increase in
acres being remined would produce between 7.1 and 14.5 million tons of
coal per year. This represents only 1.5 to 3.1 percent of total 1997
Appalachian coal production of 468 million tons. The same DOE report
noted that, given the general excess capacity in the coal market, it is
likely that coal produced from new remining sites will simply displace
coal produced elsewhere, with no net increase in production overall.
The Coal Remining Subcategory is therefore not expected to have a
significant impact on overall coal production or prices.
2. Economic Impacts for the Western Alkaline Coal Mining Subcategory
As discussed in Section V, EPA is promulgating BPT, BAT, and NSPS
limitations that have the same technical basis. EPA concludes that all
economic impacts are positive, that compliance will result in a cost
savings to the industry, and that the rule is economically achievable.
Because reclamation costs under today's rule will be less than or equal
to those previously incurred by all individual operators, and thus, to
the subcategory as a whole, no facility closures or direct job losses
associated with post-compliance closure are expected. However, EPA did
estimate potential changes in labor requirements attributable to the
rule caused by changes in labor hours associated with the types of
erosion and sediment control structures used.
EPA based its estimates of changes in labor requirements on the
detailed cost estimates developed for the three model mines submitted
by the WCMWG (1999, 2001). Dividing the full time equivalent (FTE)
reduction for each model mine by the 10 year project life results in an
estimated annual reduction of 0.22 FTE at the DSW model mine, 0.11 FTE
at the NP model mine, and 0.09 FTE at the IM model mine. Applying these
reductions in FTE to each mine in the appropriate region results in an
estimated annual reduction of 5.2 FTEs per year. This represents less
than 0.1 percent of the total 1997 coal mine employment (6,862 FTEs) in
the western alkaline region States.
The cost savings associated with the subcategory are not expected
to have a substantial impact on the industry average cost of mining per
ton of coal, and therefore are not expected to have major impacts on
coal prices. While the savings are substantial in the aggregate (and
for some individual mine operators), on average they represent a small
portion of the total value of coal produced from the affected mines. As
described in the EA, the overall estimated cost savings are, on
average, 3 cents per ton or about 0.4 percent of the value of
production. In addition, the value of production reflects the value of
coal at the minehead. Transportation costs of coal, especially from the
western alkaline region to the Midwestern utilities and other
consumers, are significant and the estimated savings as a percent of
delivered price will be smaller than 0.4 percent. Thus, as with the
Coal Remining Subcategory, the Western Alkaline Coal Mining Subcategory
is not expected to result in significant industry-level changes in coal
production or prices.
EPA is promulgating NSPS equivalent to the limitations for BPT and
BAT for the Western Alkaline Coal Mining Subcategory. In general, EPA
believes that new sources will be able to comply at costs that are
similar to or less than the costs for existing sources, because new
sources can apply control technologies more efficiently than sources
that need to retrofit for those technologies. Specifically, to the
extent that existing sources have already incurred costs associated
with installing sedimentation ponds, new sources would be able to avoid
such costs. There is nothing about today's rule that would give
existing operators a cost advantage over new mine operators; therefore,
NSPS limitations will not present a barrier to entry for new
facilities.
E. Additional Impacts
1. Costs to the NPDES Permitting Authority
Additional costs will be incurred by the NPDES permitting authority
to review new permit applications and issue revised permits based on
the rule. Under the final rule, NPDES permitting authorities will
review baseline pollutant levels and pollution abatement plans for the
Coal Remining Subcategory and watershed modeling results and sediment
control plans for the Western Alkaline Coal Mining Subcategory.
EPA estimates that permit review will require an average of 35
hours of a permit writer's time per site and that permit writers
receive an hourly wage of $31.68. Based on these assumptions, total
annual costs to the NPDES permitting authorities range from $47,500 to
$67,500 for the 43 to 61 additional sites that can be expected to be
permitted under the Coal Remining Subcategory. An upper-bound estimate
of costs associated with implementing the western subcategory assumes
that all 46 existing surface mine permits are renewed. The total
incremental annual cost would be $12,500 when annualized over a 5-year
permit (using a seven percent discount rate). Total additional permit
review costs for the rule are therefore estimated to be between $60,000
and $80,000 per year. A detailed analysis is contained in the EA.
2. Community Impacts
EPA considered whether the rule would significantly alter the
competitive position of coal produced in different regions of the
country, or lead to growth or reductions in employment in different
regions and communities. EPA concluded that the final rule would not
have a significant impact on relative coal production in the West
versus the East. The annualized cost savings estimates for Western
Alkaline surface mines affected by today's regulation average about
$0.033 per ton, or only 0.4 percent of the value of coal production
from these mines. Data from the Department of Energy indicate that the
average cost of rail transportation for coal from western to midwestern
States is approximately $0.00912 per ton-mile. Therefore, the potential
cost savings that would be realized by this rule in western mines would
not affect the price competitiveness of coal because Western Alkaline
mines would be able to ship their coal about 4 additional miles while
maintaining the same delivered price. The coal from western mines
appears to compete directly with eastern coal in about eight States,
where the $0.033 savings per ton comprises only 0.13 percent of the
average delivered price (the average delivered price of coal was about
$25.51 per ton in 1998). Therefore, EPA concluded that the cost savings
generated for Western Alkaline Coal Mines as a result of today's rule
will have minimal impact on coal production in the West versus the East
coal regions.
For the Coal Remining Subcategory, it is likely that production and
employment will shift toward eligible abandoned mine lands, but will
not to increase national coal production and
[[Page 3396]]
employment or affect coal prices significantly overall.
EPA projects that impacts of the Western Alkaline Coal Mine
Subcategory on mine employment will also be minor. As discussed above,
EPA estimated a reduction in labor requirements of 5.2 FTEs per year by
extrapolating from the model mine results for each region. This
represents less than 0.1 percent of the total 1997 coal mine employment
in the western alkaline region States. The estimated annual 5.2 FTE
direct mine job losses would result in an additional 8.7 FTE indirect
job losses based on RIMSII regional employment multipliers (U.S. Bureau
of Economic Analysis, Regional Input-Output Modeling Systems,
``RIMSII''). Therefore, the total impact on employment, direct and
indirect, that may result from the Western Alkaline Coal Mining
Subcategory is a reduction of approximately 13.9 FTEs per year. This
reduction in employment might be offset if lower costs under the
subcategory encourage growth in coal mining in the western alkaline
region.
3. Foreign Trade Impacts
EPA does not project any foreign trade impacts as a result of the
final effluent limitations guidelines and standards. U.S. coal exports
consist primarily of Appalachian bituminous coal, especially from West
Virginia, Virginia and Kentucky (U.S. DOE/EIA, Coal Data: A Reference;
U.S. DOE/EIA Coal Industry Annual 1997). Coal imports to the U.S. are
insignificant. Impacts are difficult to predict, since coal exports are
determined by economic conditions in foreign markets and changes in the
international exchange rate for the U.S. dollar. However, no foreign
trade impacts are expected given the relatively small projected
increase in production and projected lack of impact on costs of
production or prices.
F. Cost Effectiveness Analysis
Cost-effectiveness calculations are used during the development of
effluent limitations guidelines and standards to compare the efficiency
of regulatory options in removing toxic and non-conventional
pollutants. Cost-effectiveness is calculated as the incremental annual
cost of a pollution control option per incremental pollutant removal.
The results for an option are considered relative to another option or
to a benchmark, such as existing treatment. In EPA's cost-effectiveness
analysis for effluent guidelines, pollutant removals are measured in
toxicity normalized units called ``pounds-equivalent.'' The cost-
effectiveness value, therefore, represents the unit cost of removing an
additional pound-equivalent of pollutants. In general, the lower the
cost-effectiveness value, the more cost-efficient the technology will
be in removing pollutants, taking into account their toxicity. While
not required by the CWA, cost-effectiveness analysis is a useful tool
for evaluating regulatory options for the removal of toxic pollutants.
While cost-effectiveness results are usually reported in the Notice
of Final Rulemaking for effluent guidelines, such results are not
presented in today's document because of the nature of the two
subcategories. For the Coal Remining Subcategory, EPA is unable to
predict pollutant reductions that would be achieved at future remining
operations. As described in Section V, it is difficult to project the
results, in terms of measured improvements in pollutant discharges,
that will be produced through the application of any given BMP or group
of BMPs at a particular site. EPA is therefore unable to calculate
cost-effectiveness. For the Western Alkaline Coal Mining Subcategory,
cost-effectiveness was not calculated because there are no incremental
costs attributed to the rule.
G. Cost Benefit Analysis
EPA estimated and compared the costs and benefits for each of the
subcategories. Both subcategories have the potential to create
significant environmental benefits at little or no additional cost to
the industry. The monetized annual benefit estimates for the Coal
Remining Subcategory ($734,000 to $1,175,500) substantially outweigh
the projected annual costs ($380,500 to $826,000).
In addition to the monetized benefits, the increase in remining is
projected to result in the removal of some 216,000 to 307,000 feet of
highwall each year. As described in the EA, EPA was not able to find
reliable data to evaluate the decreased risk of serious injury or death
resulting from remining safety improvement. It is clear that AMLs are
dangerous sites and that implementation of the Coal Remining
Subcategory will result in benefits by making these sites less
hazardous. The increase in remining also has the potential to recover
an estimated 7.1 to 14.5 million tons of coal per year that might
otherwise remain unrecovered, with a value of approximately $188.5 to
$385.0 million (based on an average 1997 value per ton of coal in
Appalachia of $26.55).
The Western Alkaline Coal Mining Subcategory is projected to result
in net cost savings while increasing environmental benefits. The
industry compliance cost savings associated with the final rule arise
from reduced costs for sediment control and earlier Phase II bond
release. Total annual cost savings to society are expected to be
approximately $13 million. Annual environmental benefits are valued
between $39,500 and $745,000--with the majority of benefits resulting
from recreational use of waters with improved water flow. Table IX.G.1
summarizes the total social costs/cost savings and benefits attributed
to today's rulemaking.
Table IX.G.1.--Total Annual Social Costs/(Cost Savings) and Benefits of
the Rule
[$1998]
------------------------------------------------------------------------
------------------------------------------------------------------------
Social Costs/Cost Savings:
Total Social Costs--Remining........... $380,500-$826,000
Total Social Cost Savings--Western ($12,723,500-$12,882,500)
Alkaline..............................
Total Social Cost Savings.......... ($12,343,000-$12,056,500)
Monetized Social Benefits:
Total Monetized Benefits--Remining..... $734,000-$1,175,500
Total Monetized Benefits--Western $39,500-$745,000
Alkaline..............................
Total Monetized Benefits........... $773,500-$1,920,500
------------------------------------------------------------------------
[[Page 3397]]
X. Regulatory Requirements
A. Executive Order 12866: Regulatory Planning and Review
Under Executive Order 12866 (58 FR 51735 (October 4, 1993)), the
Agency must determine whether the regulatory action is ``significant''
and therefore subject to OMB review and the requirements of the
Executive Order. The Order defines ``significant regulatory action'' as
one that is likely to result in a rule that may:
(1) Have an annual effect on the economy of $100 million or more or
adversely affect in a material way the economy, a sector of the
economy, productivity, competition, jobs, the environment, public
health or safety, or State, local, or Tribal governments or
communities;
(2) Create a serious inconsistency or otherwise interfere with an
action taken or planned by another agency;
(3) Materially alter the budgetary impact of entitlements, grants,
user fees, or loan programs or the rights and obligations of recipients
thereof; or
(4) Raise novel legal or policy issues arising out of legal
mandates, the President's priorities, or the principles set forth in
the Executive Order.
It has been determined that this rule is not a ``significant
regulatory action'' under the terms of Executive Order 12866 and is
therefore not subject to OMB review.
B. Regulatory Flexibility Act (RFA), as amended by the Small Business
Regulatory Enforcement Fairness Act of 1996 (SBREFA)
The Regulatory Flexibility Act generally requires an agency to
prepare a regulatory flexibility analysis for any rule subject to
notice and comment rulemaking requirements under the Administrative
Procedure Act or any other statute unless the agency certifies that the
rule will not have a significant economic impact on a substantial
number of small entities. Small entities include small businesses,
small organizations, and small governmental jurisdictions.
For purposes of assessing the impacts of today's rule on small
entities, small entity is defined as: (1) A small business that has 500
or fewer employees (based on SBA size standards); (2) a small
governmental jurisdiction that is a government of a city, county, town,
school district or special district with a population of less than
50,000; and (3) a small organization that is any not-for-profit
enterprise which is independently owned and operated and is not
dominant in its field.
After considering the economic impact of today's final rule on
small entities, I certify that this action will not have significant
economic impact on a substantial number of small entities. In
determining whether a rule has significant economic impact on a
substantial number of small entities, the impact of concern is any
significant adverse economic impact on small entities, since the
primary purpose of the regulatory flexibility analysis is to identify
and address regulatory alternatives ``which minimize any significant
economic impact of the rule on small entities.'' 5 U.S.C. 603 and 604.
Thus, an agency may certify that a rule will not have a significant
economic impact on a substantial number of small entities if the rule
relieves regulatory burden, or otherwise has a positive economic effect
on all of the small entities subject to the rule.
EPA projects that the new subcategory for western alkaline mines
results in cost savings for all small surface mine operators. For all
small underground mine operators, EPA projects no incremental costs,
and the Agency believes that many are likely to experience some cost
savings. Section IX of this document discusses the likely cost savings
associated with the subcategory in more detail. As described in Section
V of this document, the previous regulations at 40 CFR part 434 create
a disincentive for remining by imposing limitations on pre-existing
discharges for which compliance is cost prohibitive. Despite the
statutory authority for exemptions from these limitations provided by
the Rahall Amendment, coal mining companies and States remain hesitant
to pursue remining without formal EPA guidelines. The remining
subcategory provides standardized procedures for developing effluent
limits for pre-existing discharges, thereby eliminating the uncertainty
involved in interpreting and implementing current Rahall requirements.
This subcategory is intended to remove barriers to the permitting of
remining sites with pre-existing discharges, and is therefore expected
to encourage remining activities by small entities. Thus, we have
concluded that today's final rule will relieve regulatory burden for
all small entities.
C. Congressional Review Act
The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the
Small Business Regulatory Enforcement Fairness Act of 1996, generally
provides that before a rule may take effect, the agency promulgating
the rule must submit a rule report, which includes a copy of the rule,
to each House of the Congress and to the Comptroller General of the
United States. EPA will submit a report containing this rule and other
required information to the U.S. Senate, the U.S. House of
Representatives, and the Comptroller General of the United States prior
to publication of the rule in the Federal Register. A major rule cannot
take effect until 60 days after it is published in the Federal
Register. This action is not a ``major rule'' as defined by 5 U.S.C.
804(2). This rule will be effective February 22, 2002.
D. Paperwork Reduction Act
The Office of Management and Budget (OMB) has approved the
information collection requirements contained in this rule under the
provisions of the Paperwork Reduction Act, 44 U.S.C. 3501 et seq. and
has assigned OMB control number 2040-0239.
Today's rule requires an applicant to submit baseline monitoring
and a pollution abatement plan for coal mining operations involved in
remediation of abandoned mine lands and the associated acid mine
drainage during extraction of remaining coal resources. In addition,
today's rule requires an applicant involved in reclamation of coal
mining areas in arid regions to submit a sediment control plan for
sediment control activities. Information collection is needed to
determine whether these plans will achieve the reclamation and
environmental protection pursuant to the Surface Mining Control and
Reclamation Act and the Clean Water Act. Without this information,
Federal and State regulatory authorities cannot review and approve
permit application requests. Data collection and reporting requirements
associated with these activities are substantively covered by the
``Surface Mining Permit Applications--Minimum Requirements for
Reclamation and Operation Plan--30 CFR part 780'' ICR, OMB Control
Number 1029-0036. Data collection and reporting requirements from
today's rule that may not be included in the 30 CFR part 780 ICR are:
some incremental baseline and annual monitoring and some sediment yield
modeling.
The initial burden for coal mining and remining sites under the
rule is estimated at 1,890 hours and $314,538 for baseline
determination monitoring at coal remining sites. The initial burden
associated with preparation of a site's pollution abatement plan or
sediment control plan is already covered by an applicable SMCRA ICR.
The annual burden for coal mining and remining sites under the rule is
estimated at 3,024 hours per year and $189,302 per year for
[[Page 3398]]
annual monitoring at coal remining sites.
The initial burden for NPDES control authorities is estimated at
9,800 hours and $310,464 for review of SMCRA remining and reclamation
plans (which include BMPs) and preparation of the NPDES permit. The
annual burden for NPDES control authorities is estimated at 2,340 hours
per year and $74,131 per year for review of annual monitoring data at
coal remining sites.
For the Coal Remining Subcategory, the reporting burden is
estimated to average 15.6 hours per respondent per year ((1,890 hours/3
years + 3,024 hours/year)/234 coal remining sites). This estimate
includes time for collecting and submitting baseline and annual
monitoring results. For the Western Alkaline Coal Mining Subcategory,
there is projected to be no additional reporting burden.
Burden means the total time, effort, or financial resources
expended by persons to generate, maintain, retain, or disclose or
provide information to or for a Federal agency. This includes the time
needed to review instructions; develop, acquire, install, and utilize
technology and systems for the purposes of collecting, validating, and
verifying information, processing and maintaining information, and
disclosing and providing information; adjust the existing ways to
comply with any previously applicable instructions and requirements;
train personnel to be able to respond to a collection of information;
search data sources; complete and review the collection of information;
and transmit or otherwise disclose the information.
An Agency may not conduct or sponsor, and a person is not required
to respond to a collection of information unless it displays a
currently valid OMB control number. The OMB control numbers for EPA's
regulations are listed in 40 CFR part 9 and 48 CFR chapter 15. EPA is
amending the table in 40 CFR part 9 of currently approved ICR control
numbers issued by OMB for various regulations to list the information
requirements contained in this final rule.
E. Unfunded Mandates Reform Act
Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), Public
Law 104-4, establishes requirements for Federal agencies to assess the
effects of their regulatory actions on State, local, and Tribal
governments and the private sector. Under section 202 of the UMRA, EPA
generally must prepare a written statement, including a cost-benefit
analysis, for proposed and final rules with ``Federal mandates'' that
may result in expenditures to State, local, and Tribal governments, in
the aggregate, or to the private sector, of $100 million or more in any
one year. Before promulgating an EPA rule for which a written statement
is needed, Section 205 of the UMRA generally requires EPA to identify
and consider a reasonable number of regulatory alternatives and adopt
the least costly, most cost-effective or least burdensome alternative
that achieves the objectives of the rule. The provisions of section 205
do not apply when they are inconsistent with applicable law. Moreover,
section 205 allows EPA to adopt an alternative other than the least
costly, most cost-effective or least burdensome alternative if the
Administrator publishes with the final rule an explanation why that
alternative was not adopted. Before EPA establishes any regulatory
requirements that may significantly or uniquely affect small
governments, including Tribal governments, it must have developed under
section 203 of the UMRA a small government agency plan. The plan must
provide for notifying potentially affected small governments, enabling
officials of affected small governments to have meaningful and timely
input in the development of EPA regulatory proposals with significant
Federal intergovernmental mandates, and informing, educating, and
advising small governments on compliance with the regulatory
requirements.
EPA has determined that this final rule does not contain a Federal
mandate that may result in expenditures of $100 million or more for
State, local and Tribal governments, in the aggregate, or the private
sector in any one year. Although the rule will impose some permit
review and approval requirements on regulatory authorities, EPA has
determined that this cost burden will be less than $80,000 annually.
Accordingly, today's regulation is not subject to the requirements of
sections 202 and 205 of UMRA. EPA has determined that this regulation
contains no regulatory requirements that might significantly or
uniquely affect small governments. Thus, it is not subject to the
requirements of Section 203 of the UMRA. The regulation does not
establish requirements that apply to small governments.
F. Executive Order 13175: Consultation and Coordination with Indian
Tribal Governments
Executive Order 13175, entitled ``Consultation and Coordination
with Indian Tribal Governments'' (65 FR 67249, November 6, 2000),
requires EPA to develop an accountable process to ensure ``meaningful
and timely input by Tribal officials in the development of regulatory
policies that have tribal implications.'' ``Policies that have tribal
implications'' is defined in the Executive Order to include regulations
that have ``substantial direct effects on one or more Indian Tribes, on
the relationship between the Federal government and the Indian Tribes,
or on the distribution of power and responsibilities between the
Federal government and Indian Tribes.''
This final rule does not have tribal implications. It will not have
substantial direct effects on Tribal governments, on the relationship
between the Federal government and Indian Tribes, or on the
distribution of power and responsibilities between the Federal
government and Indian Tribes, as specified in Executive Order 13175.
Although EPA has identified sites in the western United States with
existing coal mining operations that are located on Tribal lands, EPA
projects that this regulation will generate a net cost savings for
these mine sites. Thus, Executive Order 13175 does not apply to this
rule.
Nevertheless, EPA consulted with representatives of tribal
governments. EPA has identified sites in the western United States with
existing coal mining operations that are located on Tribal lands. With
assistance from its American Indian Environmental Office, EPA has
identified five Tribes as having lands in the western U.S. with, or
having an interest in, coal mining activities. The Tribes are the
Navajo Nation, the Hopi Tribe, the Crow Tribe, the Southern Ute Indian
Tribe, and the Northern Cheyenne Tribe. EPA representatives met with
Tribal officials from the Navajo Nation during coal mine site visits in
New Mexico and Arizona in August 1998 to review environmental
conditions and the applicability of the proposed regulation. In
December 1999, EPA sent meeting invitations to Tribal Chairmen,
Directors of Tribal Environmental Departments, and other
representatives of the five Tribes with existing or potential interest
in coal mining, and met with Tribal representatives from the Navajo
Nation and Hopi Tribes in Albuquerque, NM on December 16, 1999 to
consult on the proposed amendments to the existing effluent limitations
guidelines, and to discuss plans for involvement at public meetings in
western locations. As a result of this consultation, EPA agreed to an
initial comment period on the proposal of 90 days. EPA later granted an
extension to the comment period of 60 days. EPA provided a copy of the
[[Page 3399]]
relevant portions of the Rulemaking Record at the western location
identified in the ADDRESSES section of this document to be available
for Tribal representatives. During the comment period, EPA held public
meetings in three locations that were convenient for attendance by
Tribal representatives. No significant issues were raised by the
Tribes. In response to the proposed rule, EPA received written comments
from the Navajo EPA, which indicated general support for the Western
Alkaline Coal Mining Subcategory.
G. Executive Order 13132: Federalism
Executive Order 13132, entitled ``Federalism'' (64 FR 43255, August
10, 1999) requires EPA to develop an accountable process to ensure
``meaningful and timely input by State and local officials in the
development of regulatory policies that have federalism implications.''
``Policies that have federalism implications'' is defined in the
Executive Order to include regulations that have ``substantial direct
effects on the States, on the relationship between the national
government and the States, or on the distribution of power and
responsibilities among the various levels of government.''
This final rule does not have federalism implications. It will not
have substantial direct effects on the States, on the relationship
between the national government and the States, or on the distribution
of power and responsibilities among the various levels of government,
as specified in Executive Order 13132. The rule will not impose
substantial costs on States and localities. The rule establishes
effluent limitations imposing requirements that apply to coal mining
facilities. The rule does not apply directly to States and localities
and will only affect State and local governments when they are
administering CWA permitting programs. The rule, at most, imposes
minimal administrative costs on States that have an authorized NPDES
program. (These States must incorporate the new limitations and
standards in new and reissued NPDES permits). Thus, Executive Order
13132 does not apply to this rule. Although Executive Order 13132 does
not apply to this rule, EPA did consult with representatives of State
governments throughout this regulatory development. State authorities
raised numerous issues which are discussed in Section XII of this
document. In the spirit of Executive Order 13132, and consistent with
EPA policy to promote communications between EPA and State and local
governments, EPA specifically solicited comment on the proposed rule
from State and local officials.
H. National Technology Transfer and Advancement Act
As noted in the proposed rule, section 12(d) of the National
Technology Transfer and Advancement Act (NTTAA) of 1995, Public Law No.
104-113 section 12(d) (15 U.S.C. 272 note) directs EPA to use voluntary
consensus standards in its regulatory activities unless to do so would
be inconsistent with applicable law or otherwise impractical. Voluntary
consensus standards are technical standards (e.g., materials
specifications, test methods, sampling procedures, business practices,
etc.) that are developed or adopted by voluntary consensus standard
bodies. The NTTAA directs EPA to provide Congress, through the Office
of Management and Budget (OMB), explanations when the Agency decides
not to use available and applicable voluntary consensus standards.
Today's rule does not establish any technical standards, thus,
NTTAA does not apply to this rule. It should be noted, however, that
today's rule requires dischargers to monitor for total suspended solids
(TSS), settleable solids (SS), manganese, iron, and acidity. Facilities
monitoring for these analytes need to use previously-approved technical
standards already specified in the tables at 40 CFR 136.3.
I. Executive Order 13045: Protection of Children From Environmental
Health Risks and Safety Risks
The Executive Order ``Protection of Children from Environmental
Health Risks and Safety Risks'' (62 FR 19885, April 23, 1997) applies
to any rule that: (1) Is determined to be ``economically significant''
as defined under Executive Order 12866, and (2) concerns an
environmental health or safety risk that EPA has reason to believe may
have a disproportionate effect on children. If the regulatory action
meets both criteria, the Agency must evaluate the environmental health
or safety effects of the planned rule on children; and explain why the
planned regulation is preferable to other potentially effective and
reasonably feasible alternatives considered by the Agency. This rule is
not subject to Executive Order 13045 because it is neither
``economically significant'' as defined under Executive Order 12866,
nor does it concern an environmental health or safety risk that EPA has
reason to believe may have a disproportionate effect on children.
J. Executive Order 13211: Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use
This rule is not subject to Executive Order 13211, ``Actions
Concerning Regulations That Significantly Affect Energy Supply,
Distribution, or Use'' (66 FR 28355 (May 22, 2001)) because it is not a
significant regulatory action under Executive Order 12866.
XI. Regulatory Implementation
Upon promulgation of these regulations, the effluent limitations
for the appropriate subcategory must be applied in all Federal and
State NPDES permits issued to affected facilities in the Western
Alkaline Coal Mining Subcategory and Coal Remining Subcategory. This
section discusses upset and bypass provisions, variances and
modifications, and monitoring requirements.
A. Upset and Bypass Provisions
A ``bypass'' is an intentional diversion of waste streams from any
portion of a treatment facility. An ``upset'' is an exceptional
incident in which there is unintentional and temporary noncompliance
with technology-based permit effluent limitations because of factors
beyond the reasonable control of the permittee. EPA's regulations
concerning bypasses and upsets are set forth at 40 CFR 122.41(m) and
(n), and 40 CFR 403.16 (upset) and 403.17 (bypass).
B. Variances and Modifications
The CWA requires application of the effluent limitations
established pursuant to section 301 or the pretreatment standards of
section 307 to all direct and indirect dischargers. However, the
statute provides for the modification of these national requirements in
a limited number of circumstances. Moreover, the Agency has established
administrative mechanisms to provide an opportunity for relief from the
application of national effluent limitations guidelines and
pretreatment standards for categories of existing sources for priority,
conventional and non-conventional pollutants.
1. Fundamentally Different Factors Variances
EPA will develop effluent limitations guidelines or standards
different from the otherwise applicable requirements if an individual
existing discharging facility is fundamentally different with respect
to factors considered in establishing the guidelines or standards
applicable to the individual facility. Such a modification is known as
a
[[Page 3400]]
``fundamentally different factors'' (FDF) variance.
Early on, EPA, by regulation, provided for FDF modifications from
BPT effluent limitations, BAT limitations for priority and non-
conventional pollutants and BCT limitation for conventional pollutants
for direct dischargers. FDF variances for priority pollutants were
challenged judicially and ultimately sustained by the Supreme Court.
(Chemical Manufacturers Ass'n v. NRDC, 479 U.S. 116 (1985)).
Subsequently, in the Water Quality Act of 1987, Congress added
section 301(n) explicitly to authorize modification of the otherwise
applicable BAT effluent limitations or categorical pretreatment
standards for existing sources if a facility is fundamentally different
with respect to the factors specified in section 304 (other than costs)
from those considered by EPA in establishing the effluent limitations
or pretreatment standards. Section 301(n) also defined the conditions
under which EPA may establish alternative requirements. Under section
301(n), an application for approval of an FDF variance must be based
solely on (1) information submitted during the rulemaking raising the
factors that are fundamentally different or (2) information the
applicant did not have an opportunity to submit. The alternate
limitation or standard must be no less stringent than justified by the
difference and must not result in markedly more adverse non-water
quality environmental impacts than the national limitation or standard.
EPA regulations at 40 CFR part 125, subpart D, authorizing the
Regional Administrators to establish alternative guidelines and
standards, further detail the substantive criteria used to evaluate FDF
variance requests for existing direct dischargers. Thus, 40 CFR
125.31(d) identifies six factors (e.g., volume of process wastewater,
age and size of a discharger's facility) that may be considered in
determining if a facility is fundamentally different. The Agency must
determine whether, on the basis of one or more of these factors, the
facility in question is fundamentally different from the facilities and
factors considered by EPA in developing the nationally applicable
effluent guidelines. The regulation also lists four other factors
(e.g., infeasibility of installation within the time allowed or a
discharger's ability to pay) that may not provide a basis for an FDF
variance. In addition, under 40 CFR 125.31(b)(3), a request for
limitations less stringent than the national limitation may be approved
only if compliance with the national limitations would result in either
(a) a removal cost wholly out of proportion to the removal cost
considered during development of the national limitations, or (b) a
non-water quality environmental impact (including energy requirements)
fundamentally more adverse than the impact considered during
development of the national limits. EPA regulations provide for an FDF
variance for existing indirect dischargers at 40 CFR 403.13. The
conditions for approval of a request to modify applicable pretreatment
standards and factors considered are the same as those for direct
dischargers.
The legislative history of section 301(n) underscores the necessity
for the FDF variance applicant to establish eligibility for the
variance. EPA's regulations at 40 CFR 125.32(b)(1) are explicit in
imposing this burden upon the applicant. The applicant must show that
the factors relating to the discharge controlled by the applicant's
NPDES permit which are claimed to be fundamentally different are, in
fact, fundamentally different from those factors considered by EPA in
establishing the applicable guidelines. FDF variance requests with all
supporting information and data must be received by the permitting
authority within 180 days of publication of the final effluent
limitations guideline. The specific regulations covering the
requirements for and the administration of FDF variances are found at
40 CFR 122.21(m)(1), and 40 CFR 125 Subpart D. FDF variances are not
available for new sources.
2. Permit Modifications
Even after EPA (or an authorized State) has issued a final NPDES
permit to a direct discharger, the permit may still be modified under
certain conditions. (When a permit modification is under consideration,
however, all other permit conditions remain in effect.) A permit
modification may be triggered in several circumstances. These could
include a regulatory inspection or information submitted by the
permittee that reveals the need for modification. There are two
classifications of modifications: major and minor. From a procedural
standpoint, they differ primarily with respect to the public notice
requirements. Major modifications require public notice while minor
modifications do not. Virtually any modification that results in less
stringent conditions is treated as a major modification, with
provisions for public notice and comment. Conditions that would
necessitate a major modification of a permit are described in 40 CFR
122.62. Minor modifications are generally non-substantive changes. The
conditions for minor modifications are described in 40 CFR 122.63.
C. Relationship of Effluent Limitations to NPDES Permits and Monitoring
Requirements
Effluent limitations act as a primary mechanism to control the
discharges of pollutants to waters of the United States. These
limitations are applied to individual facilities through NPDES permits
issued by EPA or authorized States under section 402 of the Act.
The Agency has developed the limitations for this regulation to
cover the discharge of pollutants for these industrial categories. In
specific cases, the NPDES permitting authority may elect to establish
technology-based permit limits for pollutants not covered by this
regulation. In addition, if State water quality standards or other
provisions of State or Federal law require limits on pollutants not
covered by this regulation (or require more stringent limits on covered
pollutants), the permitting authority must apply those limitations.
All mining operations subject to today's regulation must also
comply with SMCRA requirements. EPA has worked extensively with OSMRE
in the preparation of this rule in order to ensure that today's
requirements are consistent with OSMRE requirements. EPA believes that,
in most cases, CWA requirements for a pollution abatement plan and
sediment control plan will be satisfied by the requirements contained
in an approved SMCRA permit.
EPA believes that compliance determinations under today's rule will
encourage coordination and cooperation between SMCRA and NPDES
authorities. EPA believes that, in some cases, the NPDES permit
authority may not have the mining expertise or resources to adequately
review pollution abatement plans, sediment control plans and associated
modeling efforts and recognizes that the requirements for permit
application provided under SMCRA, section 507, reclamation plans under
SMCRA section 508, and inspections and monitoring provided under SMCRA
section 517 are, in most cases, substantial and adequate. EPA envisions
that approval by OSMRE or the delegated authority on the modeling
effort and sediment control plan will often be sufficient review to
satisfy the NPDES permitting authority. The coordination of regulatory
agencies may require a memorandum of understanding to be developed
between regulatory agencies or other
[[Page 3401]]
mechanisms in order to implement alternative sediment control standards
efficiently.
D. Analytical Methods
Section 304(h) of the Clean Water Act directs EPA to promulgate
guidelines establishing test methods for the analysis of pollutants.
Facilities use these methods to determine the presence and
concentration of pollutants in wastewater, and EPA, State and local
control authorities use them for compliance monitoring and for filing
applications for the NPDES program under 40 CFR 122.21, 122.41, 122.44
and 123.25.
The final rule requires facilities in the Coal Remining Subcategory
to monitor for net acidity, TSS, SS, iron, and manganese. EPA has
previously approved test methods for all these pollutants at 40 CFR
136.3.
XII. Summary of EPA Responses to Significant Comments on Proposal
The following section summarizes significant comments received on
the proposed rule and the NODA, and a summary of EPA's response.
Thirty-two stakeholders provided comments on the April 11, 2000
proposal addressing over 40 separate issues, and ten stakeholders
provided comment on the NODA.
The complete comment summary and response document can be found in
the public record for this final rule (DCN 3056). In selecting comments
and responses for summary, the Agency selected those major and
controversial issues that received considerable comment. Alternatively,
comments and responses on other less controversial issues and issues
where EPA essentially agrees with the commenters are not included
below.
A. Coal Remining Subcategory
Comment: The implications of the language concerning bond release
for remining operations could be debilitating if the language is
interpreted to mean that any time passive treatment is incorporated
into the pollution abatement plan, the operator will be perpetually
liable for the operation and maintenance of the treatment facility. The
ultimate result could be that the operator is never able to achieve
complete bond release due to the existence of a passive treatment
system.
Response: EPA understands the concern regarding perpetual liability
for remining operations implementing passive treatment operations. EPA
clarifies that for those remining operations that include passive
treatment as an inherent portion of an approved Pollution Abatement
Plan, the passive treatment operation should be considered a BMP and
treated as part of implementing the Pollution Abatement Plan. See
section V.A.4 of this document.
Comment: The requirements for baseline data collection for remining
sites with pre-existing discharges should be no more stringent than
baseline data collection requirements for permit applications that do
not include remining. If existing water quality and seasonal variation
requirements are more stringent, burdensome, and expensive for remining
applicants, this will present another barrier for remining.
Response: There are no baseline data collection requirement for
NPDES permit applications. However, EPA is aware that baseline data
collection requirements for coal mining permits under SMCRA that do not
include remining may be less stringent than those for remining permits.
For mining permits that do not include remining operations, baseline
information is typically collected from undisturbed areas and is used
for a number of purposes. These purposes include: indicating overburden
quality; predicting post-mining water quality; establishing background
conditions for affected and unaffected groundwater (for permit decision
making); providing background data for water supplies; and establishing
circumstances for which a mining operation resulted in environmental
improvement or degradation. The baseline data collected for these
mining permits is not used to establish effluent limitations, and the
collection of baseline data is not required for establishing effluent
limitations.
Part 434 does not require baseline data collection for mines not
involved in remining. The differing baseline sampling requirements
reflect the different purpose and use of the baseline data in each
circumstance. In the case of remining, baseline pollutant discharge
samples are collected for the establishment of baseline conditions
which are then used to establish site-specific effluent limitations for
the pre-existing discharge. The effluent limitations based on this data
collection are incorporated into the NPDES permit. Therefore, EPA
believes that an adequate baseline sampling program must be used in
order to accurately characterize baseline conditions that are used to
establish effluent limitations. Therefore, EPA believes that the
baseline data collection for Coal Remining Subcategory, while more
stringent than that associated with non-remining permits, is necessary
due to the site-specific nature of the Coal Remining Subcategory NPDES
effluent limitations.
Comment: Where incentives are offered to encourage remining, those
incentives should not include a lowering of environmental protection
standards, but rather should focus on financial incentives that
encourage remining without compromising the post-remining environmental
quality of the area. Predictably, the resulting proposed rule is skewed
towards assisting coal operators to cut costs in remining previously
disturbed areas, while sacrificing the ability to achieve meaningful
improvements in baseline conditions from previously mined areas.
Response: EPA agrees that coal operators should be provided
financial incentives that encourage remining without compromising the
post-remining environmental water quality. However, EPA does not agree
that it has lowered environmental standards in order to achieve this
goal. The issue with AML is that there is no responsible party for
cleaning abandoned mine land, and discharges from abandoned mine lands
continue to be a very serious problem affecting many areas of the
Appalachian coal region. As noted in the proposal, there are over 1.1
million acres of abandoned coal mine lands in the United States which
have produced over 9,709 miles of streams polluted by acid mine
drainage.
Under SMCRA, a fund was established to pay for damage associated
with abandoned mine lands. Expenditures from this fund are authorized
through the regular congressional budgetary and appropriations process.
Additionally, the funds are prioritized to fix problems that pose
immediate health and safety risks, such as highwalls and open mine
shafts. In 1999, $2.5 billion of the $3.6 billion of high priority coal
related AML problems in OSMRE's AML inventory had yet to be funded and
reclaimed. Due to the vast expense of reclaiming all AML, EPA believes
that remining is a timely and cost-efficient means of reclaiming AML.
EPA does not agree that the remining regulations are sacrificing
the ability to achieve meaningful environmental improvements. As noted
in comments submitted by the Commonwealth of Pennsylvania, over 100
sites containing over 200 pollution discharges and 34,000 acres have
been successfully reclaimed as a result of remining. This has been done
at no expense to the taxpayer and has resulted in the reduction of
discharge of acid loading by 15,918 pounds/day. A detailed
[[Page 3402]]
assessment of the water quality improvements and BMP implementation at
these sites was provided in EPA's proposed rulemaking record and in
Chapter 6 of EPA's Coal Remining BMP Guidance Manual.
Comment: The rule should include provision for BMP-based permit
requirements in lieu of specific loading-based effluent limits for
remining sites because remining is virtually certain to result in
improvement.
Response: The goal of this rule is to improve water quality. EPA
agrees that in most cases, remining operations will result in improved
water quality. In fact, EPA's record on the rule contains data that
overwhelmingly demonstrate improvement in water quality and
environmental conditions resulting from remining operations. At these
remining operations, most pre-existing discharges demonstrated a
significant improvement in water quality. However, numerous pre-
existing discharges demonstrated no change in water quality, and a
small number demonstrated a decrease in water quality. At these sites,
other non-water quality benefits may have been achieved. Therefore, EPA
concluded that implementing BMPs is not a guarantee of success, and EPA
concluded that numeric monitoring is necessary in most cases to ensure
that a mine operator is not contributing additional quantities of
pollutant loads to the nation's waterways. While EPA believes that
there is a high likelihood of improvement in pre-existing discharges
due to remining, EPA also acknowledges that improper or inadequate BMPs
may increase pollutant loadings. EPA concluded that it is necessary for
mine operators to adequately demonstrate that they are not increasing
pollutant loadings over baseline, as required by the Rahall amendment.
EPA does not believe that monitoring poses an undue burden on the
mine operator. EPA notes that monitoring costs are less than $3000 per
year per discharge. If BMPs are appropriately incorporated into the
plan and implemented accordingly, then the mine operator should be able
to comply with the baseline numeric limits established in this
regulation without incurring additional cost. Therefore, EPA has
concluded that numeric limits, in addition to a pollution abatement
plan, is the Best Available Technology for the Coal Remining
Subcategory.
EPA has included a provision in the final rule for BMP-based
effluent limitations where numeric limitations are infeasible. EPA
believes this provision will allow improvement of AML that otherwise
would continue to remain unreclaimed. EPA has determined that in
certain specific cases, it is infeasible to calculate and monitor
baseline pollutant levels in pre-existing discharges.
Comment: Under the current language in the law the States have some
flexibility on how they would approach their respective remining
programs. This enables a State program to develop rules and policies in
concert with their State water quality authority that work for their
specific region. A one-size-fits-all approach as contained in this rule
does not necessarily work for all of the States' mining areas.
Response: In this final rule, EPA is balancing the need to provide
guidance and clarification of the provisions of the Rahall Amendment
with a recognition of the authority and flexibility given States to
allow alternative requirements for remining permits. EPA is specifying
the minimum requirements necessary for determining baseline. The permit
authority then has the discretion to determine appropriate remining
standards (which can be set at baseline or better) and site-specific
BMPs. EPA is providing guidance on appropriate BMPs, but is not
specifying the actual selection of BMPs. Thus, the final rule assumes
that the coal remining expertise available from State and regional
agencies will be used heavily in the review and approval of appropriate
BMPs for each remining site's Pollution Abatement Plan.
Comment: A twelve-month sampling program to determine baseline
pollution loads is a significant disincentive to remining due to the
cost and time involved.
Response: The comment asserts that the monitoring requirements of a
minimum of 12 monthly samples is too restrictive and will serve as
disincentives to remining. EPA disagrees with this assertion. EPA has
considered the findings by R.D. Zande & Associates and the Ohio Coal
Development Office, which included responses to a questionnaire given
to mine operators. While the responses did identify the number of
samples as a disincentive to remining, responses also expressed concern
over ``the risk operators take that the information they are getting
from the sampling will not give an accurate picture of how the remining
will affect the effluent for the NPDES discharge,'' which is precisely
the reason EPA has established the requirement for at least 12
representative baseline samples. Although EPA agrees there are likely
to be some circumstances where the requirements for baseline sample
collection may discourage remining, there are clearly other
disincentives for remining that this rule will reduce. Namely, this
regulation will establish formal EPA procedures for remining procedures
based on standardized statistical procedures and the use of BMPs.
Moreover, EPA does not agree with the commenter's assertion that
the requirement for 12 monthly baseline samples is a significant
deterrent to obtaining a mining permit because this would cause an
unreasonable delay in getting a permit. This has not been the
experience of Ohio's neighbor, Pennsylvania, which has required 12
monthly samples since 1986. As explained in one of the documents
supporting the proposed rule (i.e., Coal Remining Statistical Support
Document (EPA 821-R-00-011)), since 1985, PADEP has issued
approximately 300 remining permits, with a 98 percent success rate.
This document defines a successful remining site as one that has been
mined without incurring treatment liability as the result of exceeding
the baseline pollution load of the pre-existing discharges. The comment
does not explain why the requirement for 12 monthly samples would act
as disincentives in Ohio when Pennsylvania has demonstrated its
success.
EPA further notes that planning, collecting data, completing the
paperwork, and processing SMRCA mine permits is a time-consuming
process of about a year during which the baseline samples can be
collected. In particular, meeting the SMCRA requirements before
preparing and submitting a permit application will require several
months, during which a mine operator has the opportunity to begin
baseline sampling. For example, the PA DEP requires at least three
samples to have been collected prior to submission of a remining permit
application. In theory, this can be accomplished within 60 days (by
sampling on days 1, 30 and 60). EPA also believes, optimistically, that
it will take at least 2 months for an operator to prepare a permit
application due to the necessity of complying with SMCRA, and a minimum
of 6 months for permit review and approval. Thus, if the permit were
approved in an unusually short time, a mine operator would need to
obtain an additional 2 or 3 monthly samples in order to accumulate 12
months of baseline data, and more likely, a 12-month sampling program
could be completed before permit approval. Thus, because of the SMCRA
requirements and Pennsylvania's success, EPA does not believe that
requiring 12 monthly samples places an
[[Page 3403]]
undue burden on mine operators, and EPA believes it is more likely that
a mine operator will be able to obtain 12 samples during the permitting
process if the operator identifies and plans for baseline sampling
early in the remining process.
In addition, EPA notes that the baseline sample collection
requirements of this rule protect both the remining operator and the
environment. If baseline characterization of pre-existing pollutant
discharges is inadequate (for example, if it is based on too few
samples), there is a chance that an operator could consistently face
noncompliance by discharging pollutant loadings above an underestimated
baseline that did not adequately incorporate natural variation in
pollutant loading. In addition, there is the chance that environmental
improvement could be jeopardized by allowing for pollutant loading
discharges at high levels that still fall below an overestimated
baseline.
Finally, as discussed in the Coal Remining Statistical Support
Document (EPA-821-B-01-011), and in Statistical Analysis of Abandoned
Mine Drainage in the Assessment of Pollution Load (EPA-821-B-01-014),
EPA believes that 12 monthly samples are the minimum to derive a
statistically sound estimate of baseline.
Comment: EPA should consider expanding the rule to allow for
alternative remining limits for other parameters, including suspended
solids and settleable solids. The same rationale justifying alternative
limits for acid mine drainage should apply to all existing water
quality problems from abandoned mine lands. For instance, in Virginia,
the State's 1998 303(d) list identifies fifteen streams in the
coalfields impaired by resource extraction. Only two of those streams
are identified as impaired by AMD and only one by active coal mining.
The majority of the impaired streams have been impacted by discharges
from abandoned underground mines or drainage from unreclaimed surface
mines containing high levels of dissolved, settleable, and suspended
solids. Coal companies will continue to be discouraged from assuming
these significant drainage and discharge liabilities without some
alternative effluent limitations.
Response: Based on the baseline conditions of sediment present at
some AML, EPA believes that the benefits of remining may be severely
limited if EPA does not address sediment in the final rule. In
accordance with the intent of the Rahall Amendment, which seeks to
encourage remining while ensuring that the remining activity will
potentially improve and reclaim AML, and due to comments received on
the NODA, EPA is establishing alternative limits for sediment in pre-
existing discharges.
Comment: EPA does not have the authority to promulgate alternative
standards for sediment because this is inconsistent with the Rahall
amendment.
Response: The authority for today's rule is section 304(b) of the
Clean Water Act, which requires the Agency to adopt and revise
regulations providing guidelines for effluent limitations as
appropriate. The Rahall Amendment, section 301(p) of the Act, provided
specific authority for modified, less stringent effluent limitations
for specified coal remining operations. Because the effluent
limitations guidelines for the Coal Mining Point Source Category did
not provide any different requirements for coal remining operations,
the Rahall Amendment provided the only basis for issuing permits
containing modified requirements to remining operations. In
promulgating today's regulations adopting effluent limitation
guidelines for the coal remining subcategory, EPA is adopting
requirements that are consistent with, but not necessarily identical
to, the provisions of the Rahall Amendment. The applicability of these
effluent limitation guidelines to remining operations in AML abandoned
after the enactment of SMCRA is within EPA's discretion under section
304(b).
B. Western Alkaline Coal Mining Subcategory
Comment: EPA documents related to the rule assume that the proposed
Western Alkaline Coal Mining Subcategory would have no ``significant
impacts on relative coal production in the West versus the East'' but
fail to detail the basis for this assumption.
Response: EPA further examined the potential impact of the proposed
guidelines on the competitiveness of coal production in the East
relative to coal production in the West. This analysis supported EPA's
conclusions that the rule would have no significant impact on
competitiveness. The revised estimated cost savings comprise an average
of about $0.033 saved per ton of coal produced in western alkaline
surface mines or about 0.4 percent of the value of coal production.
This relatively small percentage decrease in delivered price, combined
with the effect of transportation costs, suggest that the impact of the
savings on the relative competitiveness of eastern and western coal
should be very small. A detailed analysis of this issue is presented in
the economic analysis, included in the rulemaking record.
Comment: The commenter believes that if modeling can demonstrate
compliance it does not matter where the runoff originates. The
commenter supports the expansion of the Western Alkaline Coal Mining
Subcategory to include drainage from active mining areas.
Response: The Agency has considered the use of alternative sediment
controls for non-process areas in addition to reclamation areas. EPA
determined that alternative sediment controls were appropriate for
reclamation areas for several reasons. These reasons included that
sediment is a natural component of runoff in arid watersheds, that
sediment is typically the only parameter of concern in runoff from
western alkaline reclamation areas, that BMPs are proven to be
effective at controlling sediment, and that computer modeling
procedures are able to accurately predict sediment runoff conditions.
Due to comments received in support of expanding the area of
alternative sediment controls, EPA evaluated additional non-process
areas under the same set of circumstances. Based on this rationale, in
addition to comments and data received on the proposal, EPA determined
that similar circumstances exist for runoff from some non-process mine
areas including brushing and grubbing areas, topsoil stockpiling areas,
and regraded areas. In each of these areas, sediment is typically the
only parameter of concern, BMPs can be implemented to maintain sediment
levels below baseline, and modeling procedures are appropriate.
Therefore, EPA has expanded the Western Alkaline Coal Mining
Subcategory to include these areas in addition to the mining
reclamation area. However, EPA decided not to include spoil piles in
the Western Alkaline Coal Mining Subcategory due to the lack of
applicable BMPs, the lack of adequate modeling procedures for an
unconsolidated land area, and the potential for contamination of the
runoff. See section V.B.3 for further explanation.
Comment: If indeed there are serious negative impacts to retaining
sedimentation ponds after active mining has ceased, then EPA has chosen
the wrong solution. The obvious remedy is to enforce the existing
regulations, not change them to accommodate these negative impacts that
violate Federal and State mining laws.
Response: EPA notes that it has received comments from other
stakeholders which have both agreed and disagreed with EPA's assertion
that
[[Page 3404]]
sedimentation ponds may be causing negative environmental impacts. EPA
believes that sedimentation ponds, when constructed to meet numeric
discharge standards, may cause negative environmental impacts in
certain circumstances. EPA listed the potential impacts in the proposal
which include loss of water due to evaporation, additional land
disturbance, accelerated erosion, and upset of the natural hydrologic
balance. While in many cases sedimentation ponds are not causing
negative impacts, EPA also believes that there are instances where
sedimentation ponds are causing upsets to the natural hydrologic
balance. As discussed in the preamble, EPA believes that the most
environmentally responsible goal is to maintain sediment loads at pre-
disturbed conditions.
The negative impacts caused by the exclusive use of sedimentation
ponds cannot necessarily be remedied by enforcing existing regulations.
For example, water loss from a sedimentation pond cannot reasonably be
controlled. Additionally, land must be disturbed during the
construction, maintenance, and removal of the sedimentation ponds.
Although this land must eventually be reclaimed in order to meet
existing regulations, EPA estimates that 600 acres per year will not be
disturbed due to implementation of the sediment control plan required
by the Western Alkaline Coal Mining Subcategory.
OSMRE regulations require that mine operators ``minimize the
disturbances to the prevailing hydrologic balance at the mine-site and
in associated offsite areas and to the quality and quantity of water in
surface and ground water systems both during and after surface coal
mining operations and during reclamation * * *'' (SMCRA section
515(b)(10)). While existing EPA regulations at 40 CFR part 434, subpart
E Post-Mining Areas require that wastewater discharges from reclamation
areas contain less than 0.5 ml/L settleable solids, EPA has concluded
that background sediment concentrations in the arid and semiarid west
are significantly higher than the 0.5 ml/L standard. EPA has recognized
this discrepancy by adopting the Western Alkaline Subcategory.
Comment: In Colorado, all of the coal mines rely extensively on
approved and permitted sedimentation ponds to ensure compliance with
applicable discharge standards, to control sediment and to protect
downstream water quality. Colorado's topography and hydrologic regime
generally dictate the need for sedimentation ponds to achieve this
compliance and protection. The proposed alternative standards and
practices may also be applicable in some cases and such options should
be allowed. However, we recommend that the rules clearly include a
``grandfather clause'' which states that mines can continue to utilize,
now and in the future, sedimentation ponds with numeric standard
methods.
Response: EPA notes that in many cases, sedimentation ponds may be
necessary to meet water quality standards or to protect receiving
streams and has concluded that the use of sedimentation ponds should be
determined on a site by site basis in accordance with computer
modeling, NPDES permit authorities and SMCRA permit authorities. EPA
does not believe that a ``grandfather clause'' is necessary to address
the commenter's concerns. EPA has clearly stated in the proposed and
final preamble that sedimentation ponds are considered a BMP which may
be necessary in certain circumstances to protect water quality. EPA
also believes that numeric limitations may be necessary in certain
circumstances to protect water quality, and recognizes that the NPDES
authority can impose numeric effluent limits on point source discharges
from reclamation areas where necessary to meet water quality standards.
Comment: A commenter would like further clarification regarding the
use of the term ``natural'' in reference to sediment loading,
background levels and undisturbed conditions. In New Mexico most land
cannot be considered ``natural'' since it has been disturbed some way.
There is nothing that could be considered ``natural''.
Response: EPA agrees with the commenter that ``natural'' conditions
are not the same as ``background'' conditions because much of the
applicable land has been disturbed in some way by activities such as
grazing or development. EPA erroneously used these two terms
interchangeably in the proposal. EPA has revised its language in the
final preamble and rule to correct this error by using the term ``pre-
mined, undisturbed'' to indicate the level of sediment present prior to
disturbance by surface coal mining.
Comment: The successful enforcement of both SMCRA and Clean Water
Act requirements on the coal industry is, at best, a tenuous situation.
EPA proposes to eliminate numeric effluent limitations in the western
alkaline coal mining subcategory and instead place its trust in control
plans based on computer modeling. This rather subjective standard would
be difficult to enforce.
Response: As documented by comments submitted by the Office of
Surface Mining, State and Tribal regulatory authorities, and mine
operators, EPA does not agree that enforcement of both SMCRA and CWA
requirements will be difficult. In fact, EPA believes that the new
subcategory requirements will be much easier to enforce than numeric
limits. As described in the proposal, implementation of a sediment
control plan based on computer modeling will allow inspectors to
determine compliance at any time, regardless of whether or not
precipitation has occurred. Additionally, EPA does not agree that
computer modeling produces a ``subjective'' standard. The RUSLE and
SEDCAD models are well documented models based on many years of
experience. As documented by comments submitted, these models are
commonly used by regulatory authorities to determine sediment loadings.
Comment: The requirements for the proposed western alkaline coal
mining subcategory have the potential to duplicate many permitting,
inspection, and enforcement provisions of SMCRA.
Response: EPA does not intend for the new subcategory requirements
to result in a duplication of work. Rather, EPA believes that
compliance determinations under today's rule will encourage
coordination and cooperation between SMCRA and NPDES authorities. EPA
believes that, in many cases, the NPDES permit authority may not have
the expertise or resources to adequately review mining related sediment
control plans and associated modeling efforts. EPA recognizes that the
requirements for permit application provided under SMCRA section 507,
reclamation plans provided under SMCRA section 508, and inspections and
monitoring provided under SMCRA section 517 are, in most cases,
substantial and adequate. EPA envisions that approval by OSMRE or the
delegated authority on the modeling effort and sediment control plan
will often be sufficient to satisfy the NPDES permitting authority. As
stated in Section XI.2.C of this document, this may require a
Memorandum of Understanding to be developed to further the cooperation
between regulatory agencies.
Comment: Some experience with sedimentation ponds in the arid and
semiarid West is that downstream erosion caused by ``clear water
discharge,'' while theoretically possible, is not generally a problem
because storm runoff at most western mines is stored and rarely
discharges from these ponds. Water is mostly lost to
[[Page 3405]]
evaporation and seepage. Also, in northwest Colorado, coal mine
operators may also discharge into streams that, by contrast, are shrub
lined, stable and not subject to additional erosion or scouring. Thus,
sedimentation ponds produce environmental benefits and are generally
used by coal mine operators in the Uinta Basin to meet applicable
discharge requirements.
Response: EPA thanks the commenter for clarification that ``clear
water discharge'' may not typically be a problem. Comment on this issue
has been varied. Some commenters have supported the claim that
sedimentation ponds disturb downstream hydrologic balances and the
``clear water'' discharge from such ponds can cause erosion to
receiving streams. Other commenters have noted that they have not found
this to be the case.
EPA agrees that sedimentation ponds do not necessarily result in
adverse environmental impacts. EPA believes that ponds may be necessary
in certain circumstances to ensure that sediment levels are maintained
below pre-mine levels. EPA notes that ponds are one of a suite of BMPs
that a mine may install in order to meet reclamation standards.
However, ponds may not be necessary in all circumstances and the use of
other BMPs such as check dams, vegetation, silt fences, and other
construction practices may be equally protective of the environment.
One advantage of using BMPs in lieu of, or in addition to, ponds is
that less land is disturbed for pond construction and removal.
EPA also acknowledges there are differences in background
conditions among sites in the West. For this reason, EPA has
established a regulatory structure for the Western Alkaline Coal Mining
Subcategory that allows mine sites to design site-specific sediment
control plans that demonstrate that the discharge of sediment will not
be greater than pre-mined, undisturbed conditions. Therefore, the
sediment control plan and discharge limitations for a mine in northwest
Colorado will likely be different from a mine site in New Mexico.
Comment: Models are constantly in a state of upgrade, thus model
predictions written into an operator's permit application package can
become outdated. New models may be released that better predict
sediment yield for reclaimed areas than one used for the original
reclamation and hydrologic analysis. The commenter recommends that EPA
stipulate in the final regulation flexibility with regard to models
that OSMRE validates for developing sediment yield standards.
Response: EPA proposed and finalized the following language
regarding acceptable computer models: ``The operator must use the same
watershed model that was or will be used to acquire the SMCRA permit
.'' EPA intends this to mean that a mine can use the upgraded version
of a computer model that was used in the original application. For
example, if the mine used SEDCAD 4.0 in their application, then the
mine operator could use SEDCAD 5.0 in subsequent modeling procedures.
This does not mean that the operator could switch to an entirely new
model that was not approved in the original mine permit. EPA believes
that this language provides the necessary flexibility that the
commenter desires to use the most recent and appropriate modeling
procedure.
Appendix A: Definitions, Acronyms, and Abbreviations Used in This
Document
Act--Clean Water Act
Agency--U.S. Environmental Protection Agency
Alkaline mine drainage--mine drainage which, before any treatment,
has a pH equal to or greater than 6.0 and total iron concentration
of less than 10 mg/l.
AMD--Acid mine drainage, which means mine drainage which, before any
treatment, either has a pH of less than 6.0 or a total iron
concentration equal to or greater than 10 mg/l.
AML--Abandoned mine land
BAT--The best available technology economically achievable, under
section 304(b)(2)(B) of the Clean Water Act
BCT--Best conventional pollutant control technology under section
304(b)(4)(B) of the Clean Water Act
BMP--Best management practice
BPT--Best practicable control technology currently available, under
section 304(b)(1) of the Clean Water Act
Brushing and grubbing area--The area where woody plant materials
that would interfere with soil salvage operations have been removed
or incorporated into the soil that is being salvaged.
CFR--Code of Federal Regulations
Clean Water Act--Federal Water Pollution Control Act Amendments (33
U.S.C. 1251 et seq.)
Conventional pollutants--Constituents of wastewater as determined by
Section 304(a)(4) of the Clean Water Act, including pollutants
classified as biochemical oxygen demanding, suspended solids, oil
and grease, fecal coliform, and pH
CWA--Clean Water Act
EPA--U.S. Environmental Protection Agency
FTE--Full-time employees
ICR--Information Collection Request
NAICS--North American Industry Classification System
NPDES--National Pollutant Discharge Elimination System
NSPS--New source performance standards under Section 306 of the
Clean Water Act
OMB--Office of Management and Budget
OSMRE --Office of Surface Mining, Reclamation and Enforcement
Pollution abatement area--The part of the permit area that is
causing or contributing to the baseline pollution load of pre-
existing discharges. The pollution abatement area must include, to
the extent practicable, areas adjacent to and nearby the remining
operation that also must be affected to reduce the pollution load of
the pre-existing discharges and may include the immediate location
of the pre-existing discharges.
POTW--Publicly-owned treatment works
PPA--Pollution Prevention Act of 1990
Pre-existing discharge--Any discharge resulting from mining
activities that have been abandoned prior to the time of the
remining permit application.
Pre-mined, undisturbed--The conditions present at the time of a
mining permit application.
PSNS--Pretreatment standards for new sources
Reclamation area--the surface area of a coal mine that has been
returned to required contour and on which revegetation
(specifically, seeding or planting) work has been commenced.
Regraded area--The surface area of a coal mine which has been
returned to required contour.
Remining--Coal remining refers to a coal mining operation at a site
on which coal mining was previously conducted and where the site has
been abandoned or the performance bond has been forfeited.
RFA--Regulatory Flexibility Act
RUSLE--Revised Universal Soil Loss Equation
SBA--Small Business Administration
SBREFA--Small Business Regulatory Enforcement Fairness Act
Sediment--All undissolved organic and inorganic material transported
or deposited by water.
Sediment Yield--The sum of the soil losses from a surface minus
deposition in macro-topographic depressions, at the toe of the
hillslope, along field boundaries, or in terraces and channels
sculpted into the hillslope.
SIC--Standard Industrial Classifications
SMCRA--Surface Mining Control and Reclamation Act
SS--Settleable Solids
Topsoil stockpiling area--The area outside the mined-out area where
topsoil is temporarily stored for use in reclamation, including
containment berms.
Toxic Pollutants--The pollutants designated by EPA as toxic in 40
CFR 401.15.
TSS--Total Suspended Solids
UMRA--Unfunded Mandates Reform Act
U.S.C.--United States Code
WTP--Willingness to pay
List of Subjects
40 CFR Part 9
Reporting and recordkeeping requirements.
[[Page 3406]]
40 CFR Part 434
Environmental protection, Mines, Reporting and recordkeeping
requirements, Waste treatment and disposal, Water pollution control.
Dated: December 27, 2001.
Christine Todd Whitman,
Administrator.
For the reasons set forth in the preamble, 40 CFR Parts 9 and 434
are amended as follows:
PART 9--[AMENDED]
1. The authority citation for part 9 continues to read as follows:
Authority: 7 U.S.C. 135 et seq., 136-136y; 15 U.S.C. 2001, 2003,
2005, 2006, 2601-2671; 21 U.S.C. 331j, 346a, 348; 31 U.S.C. 9701; 33
U.S.C. 1251 et seq., 1311, 1313d, 1314, 1318, 1321, 1326, 1330,
1342, 1344, 1345 (d) and (e), 1361; E.O. 11735, 38 FR 21243, 3 CFR,
1971-1975 Comp. p. 973; 42 U.S.C. 241, 242b, 243, 246, 300f, 300g,
300g-1, 300g-2, 300g-3, 300g-4, 300g-5, 300g-6, 300j-1, 300j-2,
300j-3, 300j-4, 300j-9, 1857 et seq., 6901-6992k, 7401-7671q, 7542,
9601-9657, 11023, 11048.
2. In Sec. 9.1 the table is amended by adding a new heading with
entries in numerical order to read as follows:
Sec. 9.1 OMB approvals under the Paperwork Reduction Act.
* * * * *
------------------------------------------------------------------------
OMB control
40 CFR citation No.
------------------------------------------------------------------------
* * * * *
Coal Mining Point Source Category
------------------------------------------------------------------------
434.72-434.75.............................................. 2040-0239
434.82-434.83.............................................. 2040-0239
434.85..................................................... 2040-0239
Appendix B................................................. 2040-0239
* * * * *
------------------------------------------------------------------------
PART 434--[AMENDED]
2. The authority citation for part 434 continues to read as
follows:
Authority: 33 U.S.C. 1311, 1314(b), (c), (e), and (g), 1316(b)
and (c), 1317(b) and (c), and 1361.
3. Revise Sec. 434.50 to read as follows:
Sec. 434.50 Applicability.
The provisions of this subpart are applicable to discharges from
post-mining areas, except as provided in subpart H--Western Alkaline
Coal Mining of this part.
4. Revise Sec. 434.60 to read as follows:
Sec. 434.60 Applicability.
The provisions of this subpart F apply to this part 434 as
specified in subparts B, C, D, E and G of this part.
5. Add subpart G, consisting of Secs. 434.70 through 434.75, to
read as follows:
Subpart G--Coal Remining
Sec.
434.70 Specialized definitions.
434.71 Applicability.
434.72 Effluent limitations attainable by the application of the
best practicable control technology currently available (BPT).
434.73 Effluent limitations attainable by application of the best
available technology economically achievable (BAT).
434.74 Effluent limitations attainable by application of the best
conventional pollutant control technology (BCT).
434.75 New source performance standards (NSPS).
Subpart G--Coal Remining
Sec. 434.70 Specialized definitions.
(a) The term coal remining operation means a coal mining operation
at a site on which coal mining was previously conducted and where the
site has been abandoned or the performance bond has been forfeited.
(b) The term pollution abatement area means the part of the permit
area that is causing or contributing to the baseline pollution load of
pre-existing discharges. The pollution abatement area must include, to
the extent practicable, areas adjacent to and nearby the remining
operation that also must be affected to reduce the pollution load of
the pre-existing discharges and may include the immediate location of
the pre-existing discharges.
(c) The term pre-existing discharge means any discharge resulting
from mining activities that have been abandoned prior to the time of a
remining permit application. This term shall include a pre-existing
discharge that is relocated as a result of the implementation of best
management practices (BMPs) contained in the Pollution Abatement Plan.
(d) The term steep slope means any slope above twenty degrees or
such lesser slope as may be defined by the regulatory authority after
consideration of soil, climate, and other characteristics of a region
or State. This term does not apply to those situations in which an
operator is mining on flat or gently rolling terrain, on which an
occasional steep slope is encountered and through which the mining
operation is to proceed, leaving a plain or predominantly flat area.
(e) The term new source remining operation means a remining
operation at a coal mine where mining first commences after February
22, 2002 and subsequently becomes an abandoned mine.
Sec. 434.71 Applicability.
(a) This subpart applies to pre-existing discharges that are
located within or are hydrologically connected to pollution abatement
areas of a coal remining operation.
(b) A pre-existing discharge that is intercepted by active mining
or that is commingled with waste streams from active mining areas for
treatment is subject to the provisions of Sec. 434.61 Commingling of
waste streams. For the purposes of this subpart, Sec. 434.61 requires
compliance with applicable BPT, BAT, BCT, and NSPS effluent limitations
in subparts C, D, and F of this part. Section 434.61 applies to the
commingled waste stream only during the time when the pre-existing
discharge is intercepted by active mining or is commingled with active
mine wastewater for treatment or discharge. After commingling has
ceased, the pre-existing discharge is subject to the provisions of this
part.
(c) In situations where coal remining operations seek reissuance of
an existing remining permit with BPJ limitations and the regulatory
authority determines that it is not feasible for a remining operator to
re-establish baseline pollutant levels in accordance with the
statistical procedures contained in Appendix B of this part, pre-
existing discharge limitations at existing remining operations shall
remain subject to baseline pollutant levels established during the
original permit application.
(d) The effluent limitations in this subpart apply to pre-existing
discharges until the appropriate SMCRA authority has authorized bond
release.
Sec. 434.72 Effluent limitations attainable by the application of the
best practicable control technology currently available (BPT).
(a) The operator must submit a site-specific Pollution Abatement
Plan to the permitting authority for the pollution abatement area. The
plan must be approved by the permitting authority and incorporated into
the permit as an effluent limitation. The Pollution Abatement Plan must
identify characteristics of the pollution abatement area and the pre-
existing discharges. The Pollution Abatement Plan must be designed to
reduce the pollution load from pre-existing discharges and must
identify the
[[Page 3407]]
selected best management practices (BMPs) to be used. The plan must
describe the design specifications, construction specifications,
maintenance schedules, criteria for monitoring and inspection, and
expected performance of the BMPs. The BMPs must be implemented as
specified in the plan.
(b) (1) Except as provided in 40 CFR 125.30 through 125.32 and
paragraph (b)(2) of this section, the following effluent limits apply
to pre-existing discharges:
Effluent Limitations
------------------------------------------------------------------------
Pollutant Requirement
------------------------------------------------------------------------
(i) Iron, total........................ May not exceed baseline
loadings (as defined by
Appendix B of this part).
(ii) Manganese, total.................. May not exceed baseline
loadings (as defined by
Appendix B of this part).
(iii) Acidity, net..................... May not exceed baseline
loadings (as defined by
Appendix B of this part).
(iv) TSS............................... During remining and
reclamation, may not exceed
baseline loadings (as defined
by Appendix B of this part).
Prior to bond release, the pre-
existing discharge must meet
the applicable standards for
TSS or SS contained in Subpart
E.\1\
------------------------------------------------------------------------
\1\ A pre-existing discharge is exempt from meeting standards in Subpart
E of this part for TSS and SS when the permitting authority determines
that Subpart E standards are infeasible or impractical based on the
site-specific conditions of soil, climate, topography, steep slopes,
or other baseline conditions provided that the operator demonstrates
that significant reductions of TSS and SS will be achieved through the
incorporation of sediment control BMPs into the Pollution Abatement
Plan as required by paragraph (a) of this section.
(2) If the permitting authority determines that it is infeasible to
collect samples for establishing the baseline pollutant levels pursuant
to paragraph (b)(1) of this section, and that remining will result in
significant improvement that would not otherwise occur, then the
numeric effluent limitations in paragraph (b)(1) of this section do not
apply. Pre-existing discharges for which it is infeasible to collect
samples for determination of baseline pollutant levels include, but are
not limited to, discharges that exist as a diffuse groundwater flow
that cannot be assessed via sample collection; a base flow to a
receiving stream that cannot be monitored separate from the receiving
stream; a discharge on a steep or hazardous slope that is inaccessible
for sample collection; or, a number of pre-existing discharges so
extensive that monitoring of individual discharges is infeasible.
Sec. 434.73 Effluent limitations attainable by application of the best
available technology economically achievable (BAT).
Except as provided in 40 CFR 125.30 through 125.32 and
434.72(b)(2), a pre-existing discharge must comply with the effluent
limitations listed in Sec. 434.72(b) for net acidity, iron and
manganese. The operator must also submit and implement a Pollution
Abatement Plan as required in Sec. 434.72(a) .
Sec. 434.74 Effluent limitations attainable by application of the best
conventional pollutant control technology (BCT).
Except as provided in 40 CFR 125.30 through 125.32 and
434.72(b)(2), a pre-existing discharge must comply with the effluent
limitations listed in Sec. 434.72(b) for total suspended solids. The
operator must also submit and implement a Pollution Abatement Plan as
required in Sec. 434.72(a).
Sec. 434.75 New source performance standards (NSPS).
Except as provided in Sec. 434.72(b)(2), a pre-existing discharge
from a new source remining operation must comply with the effluent
limitations listed in Sec. 434.72(b) for iron, manganese, acidity and
total suspended solids. The operator must also submit and implement a
Pollution Abatement Plan as required in Sec. 434.72(a).
6. Add subpart H, consisting of Secs. 434.80 through 434.85, to
read as follows:
Subpart H--Western Alkaline Coal Mining
Sec.
434.80 Specialized definitions.
434.81 Applicability.
434.82 Effluent limitations attainable by the application of the
best practicable control technology currently available (BPT).
434.83 Effluent limitations attainable by application of the best
available technology economically achievable (BAT).
434.84 Effluent limitations attainable by application of the best
conventional pollutant control technology (BCT). [Reserved]
434.85 New source performance standards (NSPS).
Subpart H--Western Alkaline Coal Mining
Sec. 434.80 Specialized definitions.
(a) The term brushing and grubbing area means the area where woody
plant materials that would interfere with soil salvage operations have
been removed or incorporated into the soil that is being salvaged.
(b) The term regraded area means the surface area of a coal mine
that has been returned to required contour.
(c) The term sediment means undissolved organic and inorganic
material transported or deposited by water.
(d) The term sediment yield means the sum of the soil losses from a
surface minus deposition in macro-topographic depressions, at the toe
of the hillslope, along field boundaries, or in terraces and channels
sculpted into the hillslope.
(e) The term topsoil stockpiling area means the area outside the
mined-out area where topsoil is temporarily stored for use in
reclamation, including containment berms.
(f) The term western coal mining operation means a surface or
underground coal mining operation located in the interior western
United States, west of the 100th meridian west longitude, in an arid or
semiarid environment with an average annual precipitation of 26.0
inches or less.
Sec. 434.81 Applicability.
(a) This subpart applies to alkaline mine drainage at western coal
mining operations from reclamation areas, brushing and grubbing areas,
topsoil stockpiling areas, and regraded areas.
(b) This subpart applies to drainage at western coal mining
operations from reclamation areas, brushing and grubbing areas, topsoil
stockpiling areas, and regraded areas where the discharge, before any
treatment, meets all the following requirements:
(1) pH is equal to or greater than 6.0;
[[Page 3408]]
(2) Dissolved iron concentration is less than 10 mg/L; and
(3) Net alkalinity is greater than zero.
(c) The effluent limitations in this subpart apply until the
appropriate SMCRA authority has authorized bond release.
Sec. 434.82 Effluent limitations attainable by the application of the
best practicable control technology currently available (BPT).
Except as provided in 40 CFR 125.30 through 125.32, the following
effluent limitations apply to mine drainage from applicable areas of
western coal mining operations:
(a) The operator must submit a site-specific Sediment Control Plan
to the permitting authority that is designed to prevent an increase in
the average annual sediment yield from pre-mined, undisturbed
conditions. The Sediment Control Plan must be approved by the
permitting authority and be incorporated into the permit as an effluent
limitation. The Sediment Control Plan must identify best management
practices (BMPs) and also must describe design specifications,
construction specifications, maintenance schedules, criteria for
inspection, as well as expected performance and longevity of the best
management practices.
(b) Using watershed models, the operator must demonstrate that
implementation of the Sediment Control Plan will result in average
annual sediment yields that will not be greater than the sediment yield
levels from pre-mined, undisturbed conditions. The operator must use
the same watershed model that was, or will be, used to acquire the
SMCRA permit.
(c) The operator must design, implement, and maintain BMPs in the
manner specified in the Sediment Control Plan.
Sec. 434.83 Effluent limitations attainable by application of the best
available technology economically achievable (BAT).
Except as provided in 40 CFR 125.30 through 125.32, any existing
western coal mining operation with drainage subject to this subpart
must meet the effluent limitations in Sec. 434.82.
Sec. 434.84 Effluent limitations attainable by application of the best
conventional pollutant control technology (BCT). [Reserved]
Sec. 434.85 New source performance standards (NSPS).
Any new source western coal mining operation with drainage subject
to this subpart must meet the effluent limitations in Sec. 434.82.
6. Part 434 is amended by adding appendix B to part 434 as follows:
Appendix B to Part 434--Baseline Determination and Compliance
Monitoring for Pre-existing Discharges at Remining Operations
I. General Procedure Requirements
a. This appendix presents the procedures to be used for
establishing effluent limitations for pre-existing discharges at
coal remining operations, in accordance with the requirements set
forth in Subpart G; Coal Remining. The requirements specify that
pollutant loadings of total iron, total manganese, total suspended
solids, and net acidity in pre-existing discharges shall not exceed
baseline pollutant loadings. The procedures described in this
appendix shall be used for determining site-specific, baseline
pollutant loadings, and for determining whether discharge loadings
during coal remining operations have exceeded the baseline loading.
Both a monthly (single-observation) procedure and an annual
procedure shall be applied, as described below.
b. In order to sufficiently characterize pollutant loadings
during baseline determination and during each annual monitoring
period, it is required that at least one sample result be obtained
per month for a period of 12 months.
c. Calculations described in this appendix must be applied to
pollutant loadings. Each loading value is calculated as the product
of a flow measurement and pollutant concentration taken on the same
date at the same discharge sampling point, using standard units of
flow and concentration (to be determined by the permitting
authority). For example, flow may be measured in cubic feet per
second, concentration in milligrams per liter, and the pollutant
loading could be calculated in pounds per year.
d. Accommodating Data Below the Maximum Daily Limit at subpart C
of this part. In the event that a pollutant concentration in the
data used to determine baseline is lower than the daily maximum
limitation established in subpart C of this part for active mine
wastewater, the statistical procedures should not establish a
baseline more stringent than the BPT and BAT effluent standards
established in subpart C of this part. Therefore, if the total iron
concentration in a baseline sample is below 7.0 mg/L, or the total
manganese concentration is below 4.0 mg/L, the baseline sample
concentration may be replaced with 7.0 mg/L and 4.0 mg/L,
respectively, for the purposes of some of the statistical
calculations in this Appendix B. The substituted values should be
used for all methods in this Appendix B with the exception of the
calculation of the interquartile range (R) in Method 1 for the
annual trigger (Step 3), and in Method 2 for the single observation
trigger (Step 3). The interquartile range (R) is the difference
between the quartiles M-1 and M1; these values
should be calculated using actual loadings (based on measured
concentrations) when they are used to calculate R. This should be
done in order to account for the full range of variability in the
data.
II. Procedure for Calculating and Applying a Single-Observation
(Monthly) Trigger
Two alternative methods are provided for calculating a single-
observation trigger. One method must be selected and applied by the
permitting authority for any given remining permit.
A. Method 1 for Calculating a Single Observation Trigger (L)
(1) Count the number of baseline observations taken for the
pollutant of interest. Label this number n. In order to sufficiently
characterize pollutant loadings during baseline determination and
during each annual monitoring period, it is required that at least
one sample result be obtained per month for a period of 12 months.
(2) Order all baseline loading observations from lowest to
highest. Let the lowest number (minimum) be x(1), the
next lowest be x(2), and so forth until the highest
number (maximum) is x(n).
(3) If fewer than 17 baseline observations were obtained, then
the single observation trigger (L) will equal the maximum of the
baseline observations (x(n)).
(4) If at least 17 baseline observations were obtained,
calculate the median (M) of all baseline observations:
Instructions for calculation of a median of n observations:
If n is odd, then M equals x(n/2+1/2).
For example, if there are 17 observations, then M =
X(17/2+1/2) = x(9), the 9th highest
observation.
If n is even, then M equals 0.5 * (x(n/2) +
x(n/2+1)).
For example, if there are 18 observations, then M equals 0.5
multiplied by the sum of the 9th and 10th highest observations.
(a) Next, calculate M1 as the median of the subset of
observations that range from the calculated M to the maximum
x(n); that is, calculate the median of all x larger than
or equal to M.
(b) Next, calculate M2 as the median of the subset of
observations that range from the calculated M1 to
x(n) ; that is, calculate the median of all x larger than
or equal to M1.
(c) Next, calculate M3 as the median of the subset of
observations that range from the calculated M2 to
x(n) ; that is, calculate the median of all x larger than
or equal to M2.
(d) Finally, calculate the single observation trigger (L) as the
median of the subset of observations that range from the calculated
M3 to x(n).
Note: When subsetting the data for each of steps 3a-3d, the
subset should include all observations greater than or equal to the
median calculated in the previous step. If the median calculated in
the previous step is not an actual observation, it is not included
in the new subset of observations. The new median value will then be
calculated using the median procedure, based on whether the number
of points in the subset is odd or even.
(5) Method for applying the single observation trigger (L) to
determine when the baseline level has been exceeded
If two successive monthly monitoring observations both exceed L,
immediately begin weekly monitoring for four weeks (four weekly
samples).
[[Page 3409]]
(a) If three or fewer of the weekly observations exceed L,
resume monthly monitoring
(b) If all four weekly observations exceed L, the baseline
pollution loading has been exceeded.
B. Method 2 for Calculating a Single Observation Trigger (L)
(1) Follow Method 1 above to obtain M1 (the third
quartile, that is, the 75th percentile).
(2) Calculate M-1 as the median of the baseline data
which are less than or equal to the sample median M.
(3) Calculate interquartile range, R = (M1 -
M-1).
(4) Calculate the single observation trigger L as
L = M1 + 3 * R
(5) If two successive monthly monitoring observations both
exceed L, immediately begin weekly monitoring for four weeks (four
weekly samples).
(a) If three or fewer of the weekly observations exceed L,
resume monthly monitoring
(b) If all four weekly observations exceed L, the baseline
pollution loading has been exceeded.
III. Procedure for Calculating and Applying an Annual Trigger
A. Method 1 for Calculating and Applying an Annual Trigger (T)
(1) Calculate M and M1 of the baseline loading data
as described above under Method 1 for the single observation
trigger.
(2) Calculate M-1 as the median of the baseline data
which are less than or equal to the sample median M.
(3) Calculate the interquartile range, R = (M1 -
M-1).
(4) The annual trigger for baseline (Tb) is calculated as:
[GRAPHIC] [TIFF OMITTED] TR23JA02.002
where n is the number of baseline loading observations.
(5) To compare baseline loading data to observations from the
annual monitoring period, repeat steps 1-3 for the set of monitoring
observations. Label the results of the calculations M' and R'. Let m
be the number of monitoring observations.
(6) The subtle trigger (Tm) of the monitoring data is calculated
as:
[GRAPHIC] [TIFF OMITTED] TR23JA02.003
(7) If Tm > Tb, the median loading of the monitoring
observations has exceeded the baseline loading.
B. Method 2 for Calculating and Applying an Annual Trigger (T)
Method 2 applies the Wilcoxon-Mann-Whitney test to determine
whether the median loading of the monitoring observations has
exceeded the baseline median. No baseline value T is calculated.
(1) Steps for Conducting the Wilcoxon-Mann-Whitney Test
(a) Let n be the number of baseline loading observations taken,
and let m be the number of monitoring loading observations taken. In
order to sufficiently characterize pollutant loadings during
baseline determination and during each annual monitoring period, it
is required that at least one sample result be obtained per month
for a period of 12 months.
(b) Order the combined baseline and monitoring observations from
smallest to largest.
(c) Assign a rank to each observation based on the assigned
order: the smallest observation will have rank 1, the next smallest
will have rank 2, and so forth, up to the highest observation, which
will have rank n + m.
(1) If two or more observations are tied (have the same value),
then the average rank for those observations should be used. For
example, suppose the following four values are being ranked:
3, 4, 6, 4
Since 3 is the lowest of the four numbers, it would be assigned a
rank of 1. The highest of the four numbers is 6, and would be
assigned a rank of 4. The other two numbers are both 4. Rather than
assign one a rank of 2 and the other a rank of 3, the average of 2
and 3 (i.e., 2.5) is given to both numbers.
(d) Sum all the assigned ranks of the n baseline observations,
and let this sum be Sn.
(e) Obtain the critical value (C) from Table 1. When 12 monthly
data are available for both baseline and monitoring (i.e., n = 12
and m = 12), the critical value C is 99.
(f) Compare C to Sn. If Sn is less than C,
then the monitoring loadings have exceeded the baseline loadings.
(2) Example Calculations for the Wilcoxon-Mann-Whitney Test
BASELINE DATA
--------------------------------------------------------------------------------------------------------------------------------------------------------
8.0 9.0 9.0 10.0 12.0 15.0 17.0 18.0 21.0 23.0 28.0 30.0
--------------------------------------------------------------------------------------------------------------------------------------------------------
MONITORING DATA
--------------------------------------------------------------------------------------------------------------------------------------------------------
9.0 10.0 11.0 12.0 13.0 14.0 16.0 18.0 20.0 24.0 29.0 31.0
--------------------------------------------------------------------------------------------------------------------------------------------------------
BASELINE RANKS
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1.0 3.0 3.0 5.5 8.5 12.0 14.0 15.5 18.0 19.0 21.0 23.0
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MONITORING RANKS
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3.0 5.5 7.0 8.5 10.0 11.0 13.0 15.5 17.0 20.0 22.0 24.0
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Sum of Ranks for Baseline is Sn = 143.5, critical value is Cn,m = 99.
(3) Critical Values for the Wilcoxon-Mann-Whitney Test
(a) When n and m are less than 21, use Table 1.
In order to find the appropriate critical value, match column
with correct n (number of baseline observations) to row with correct
m (number of monitoring observations)\*\.
[[Page 3410]]
Table 1.--Critical Values (C) of the Wilcoxon-Mann-Whitney Test
(for a one-sided test at the 0.001 significance level)
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n m 10 11 12 13 14 15 16 17 18 19 20
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10............................. 66 79 93 109 125 142 160 179 199 220 243
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11............................. 68 82 96 112 128 145 164 183 204 225 248
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12............................. 70 84 99 115 131 149 168 188 209 231 253
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13............................. 73 87 102 118 135 153 172 192 214 236 259
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14............................. 75 89 104 121 138 157 176 197 218 241 265
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15............................. 77 91 107 124 142 161 180 201 223 246 270
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16............................. 79 94 110 127 145 164 185 206 228 251 276
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17............................. 81 96 113 130 149 168 189 211 233 257 281
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18............................. 83 99 116 134 152 172 193 215 238 262 287
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19............................. 85 101 119 137 156 176 197 220 243 268 293
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20............................. 88 104 121 140 160 180 202 224 248 273 299
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(b) When n or m is greater than 20 and there are few ties,
calculate an approximate critical value using the following formula
and round the result to the next larger integer. Let N = n + m.
[GRAPHIC] [TIFF OMITTED] TR23JA02.004
For example, this calculation provides a result of 295.76 for n
= m = 20, and a result of 96.476 for n = m = 12. Rounding up
produces approximate critical values of 296 and 97.
(c) When n or m is greater than 20 and there are many ties,
calculate an approximate critical value using the following formula
and round the result to the next larger integer. Let S be the sum of
the squares of the ranks or average ranks of all N observations. Let
N = n + m.
[GRAPHIC] [TIFF OMITTED] TR23JA02.005
In the preceding formula, calculate V using
[GRAPHIC] [TIFF OMITTED] TR23JA02.006
[FR Doc. 02-106 Filed 1-22-02; 8:45 am]
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