Wyoming Administrative Code › Agency 020 - Environmental Quality, Dept. of › Sub-Agency 0011 - Water Quality › Chapter 2 - DISCHARGES, PERMIT REGS › Appendix J - Additional Requirements Applicable to Coal Mining Operations

Current through July 13, 2024
(a) General definitions applicable to Appendix J.
(i) "Abandoned mine" means a mine where mining operations
				  have occurred in the past and:
(A) The applicable reclamation bond or financial assurance
				  has been released or forfeited; or
(B) If no reclamation bond or other financial assurance has
				  been posted, no mining operations have occurred for five years or more.
(ii) "Acid or ferruginousmine drainage" 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.
(iii) "Active mining area" means 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.
(iv) "Alkaline, mine drainage" means mine drainage which,
				  before any treatment, either has a pH of greater than 6.0 or a total iron
				  concentration less than 10 mg/l.
(v) "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.
(vi) "Coal preparation plant" means a facility where coal is
				  subjected to cleaning, concentrating, or other processing or preparation in
				  order to separate coal from its impurities and then is loaded for transit to a
				  consuming facility.
(vii) "Coal preparation plant associated areas" means the
				  coal preparation plant yards, immediate access roads, coal refuse piles, and
				  coal storage piles and facilities.
(viii) "Coal preparation plant water circuit" means all
				  pipes, channels, basins, tanks, and all other structures and equipment that
				  convey, contain, treat, or process any water that is used in coal preparation
				  processes within a coal preparation plant.
(ix) "Coal refuse disposal pile" means any coal refuse
				  deposited on the earth and intended as permanent disposal or long-term storage
				  (greater than 180 days) of such material, but does not include coal refuse
				  deposited within the active mining area or coal refuse never removed from the
				  active mining area.
(x) "Controlled surface mine drainage" means any surface mine
				  drainage that is pumped or siphoned from the active mining area.
(xi) "Mine drainage" means any drainage, and any water pumped
				  or siphoned, from any active mining area or a post mining area.
(xii) "ml/l" means milliliters per liter.
(xiii) "New source coal mine" means a coal mine (excluding
				  coal preparation plants and coal preparation plant associated areas) including
				  an abandoned mine which is being reminded:
(A) The construction of which is commenced after May 4, 1984;
				  or
(B) Which is determined by the administrator to constitute a
				  "major alteration." In making this determination, the administrator shall take
				  into account whether one or more of the following events resulting in a new,
				  altered or increased discharge of pollutants has occurred after May 4, 1984 in
				  connection with the mine for which the WYPDES permit is being
				  considered:
(I) Extraction of a coal seam not previously extracted at the
				  mine;
(II) Discharge into a drainage area not previously affected
				  by wastewater discharge from the mine;
(III) Extensive new surface disruption at the mining
				  operation;
(IV) A construction of a new shaft, lope, or drift;
				  and
(V) Such other factors as the administrator deems
				  relevant.
(xiv) "One year, 2-year, and 10-year, 24-hour precipitation
				  events" means the maximum 24-hour precipitation event with a probable
				  recurrence interval of once in one (1), two (2), and ten (10) years
				  respectively as defined by the National Weather Service Technical Paper No. 40,
				  "Rainfall Frequency Atlas of the U.S." May 1961, or equivalent regional or
				  rainfall probability information developed therefrom.
(xv) "Post-mining area" means:
(A) A reclamation area; or
(B) The underground workings of an underground coal mine
				  after the extraction, removal, or recovery of coal from its natural deposit has
				  ceased and prior to bond release.
(xvi) "Reclamation area" means 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.
(xvii) "Settleable solids" is that matter measured by the
				  volumetric method specified in Appendix J (f).
(xvii) "Treatment facility" and "treatment system" mean all
				  structures which contain, convey, and as necessary, chemically or physically
				  treat coal fine drainage, coal preparation plant process wastewater, or
				  drainage from coal preparation plant associated areas, which remove pollutants
				  regulated by this part from such waters. This includes all pipes, channels,
				  ponds, basins, tanks, and all other equipment serving such structures.
(b) Application requirements specific to discharges from coal
				  mines must provide the following information, in addition to that described in
				  Section
				  5(a)
				  (v), and where applicable the information
				  described in Appendix B, Appendix C, and/or Appendix D, to the administrator,
				  using an application form provided by the administrator.
(i) Construction application requirements. A permit
				  application, which may include an approved sedimentation structure control
				  plan, in accordance with the provisions outlined in Wyoming Water Quality Rules
				  and Regulations, Chapter 3, is required for the construction of any
				  sedimentation ponds or runoff control facilities associated with surface coal
				  mining operations. By agreement between the Land Quality Division and the Water
				  Quality Division, this may take the form of one consolidated application for
				  surface coal mining operations.
(ii) Minimum design standards for sedimentation control
				  facilities. The minimum design standards for runoff control facilities of
				  surface coal mining operations are set forth in this subparagraph. The
				  department reserves the right to impose more stringent design requirements to
				  ensure compliance with the effluent limitations contained in Section
				  5(c)
				  (iii) of these regulations.
(A) Scope. These standards pertain only to permits for
				  surface coal mining sedimentation control facilities required pursuant to
				  Wyoming Water Quality Rules and Regulations, Chapter 3.
(B) Sedimentation ponds and sedimentation control structures.
				  (I) Design.
(1.) Inlet ditches or structures shall be designed to
				  minimize erosion, disturbance of the pond bottom, and resuspension of silts or
				  colloidal soil particles.
(2.) Outlet structures, if used, shall have an overflow
				  device, minimize short-circuiting, minimize floating solids from discharging
				  and shall not erode or disturb the dike. All pipe protruding through a dike
				  shall have adequate seepage control. The point of discharge into a channel
				  shall be protected against erosion and erosion control devices shall be
				  designed based on flow velocities.
(3.) The design, construction and maintenance of a
				  sedimentation pond or other sediment control measures shall not relieve the
				  person from compliance with applicable effluent limitations.
(4.) Computations showing the facility volume to include
				  runoff from a 10-year 24-hour precipitation event shall be provided. The pond
				  treatment or containment volume shall be in addition to sediment storage
				  required by Land Quality Division regulations. A lesser design event may be
				  approved by the administrator based on terrain, climate, other site-specific
				  conditions and on a demonstration by the applicant that the effluent
				  limitations of Section
				  5(c)
				  (iii) will be met. The design for the runoff
				  control facilities shall contain all supportive documentation, calculations and
				  drawings necessary to determine compliance with the effluent limitations of
				  Section
				  5(c)
				  (iii) of these regulations.
(5.) Each person who conducts surface mining activities shall
				  design, construct and maintain sedimentation ponds to minimize short-circuiting
				  where the facility is not designed to contain the 10-year 24-hour precipitation
				  runoff.
(II) Construction. This paragraph pertains only to
				  impoundments not defined as major impoundments by the State Engineer's
				  regulations. Below grade sedimentation ponds may be exempted provided site
				  specific contours indicate a slope that will provide wall structure stability
				  and minimize seepage.
(1.) Where pond bottoms and sidewalls are made of fill
				  material, the soils used shall be relatively incompressible, have a low
				  permeability, and be free from organic material and trash. The soil shall be
				  compacted at a water content that will ensure structural stability, minimize
				  hydraulic seepage, and minimize settling.
Fill material containing rocks larger than six (6) inches in
				  the longest dimension shall not be placed within five (5) feet of the interior
				  slope surface of any pond embankment. Material containing by volume less than
				  25 percent of rock larger than six (6) inches and less than 12 inch in the
				  longest dimension may be placed in the remainder of the embankment.
(2.) Outer dike slopes shall not be steeper than one vertical
				  to two (2) horizontal. Flatter slopes may be required to maintain slope
				  stability. Inner dike slopes shall be sloped one vertical to three horizontal
				  or flatter.
(3.) The minimum top dike width shall be sufficient to
				  provide structural stability.
(4.) The application shall contain an evaluation of the need
				  for riprap. This evaluation shall address site specific conditions such as
				  surrounding topography, predominant wind directions, highest predicted peak
				  wind velocity, calculation of predicted wave heights, data on windy months
				  versus potential of water and water depths in the impoundment, impoundment life
				  or any other relevant parameters. If necessary, riprap or other acceptable
				  erosion control shall be installed on the inner dike slopes at all anticipated
				  levels of water. Sedimentation control structures shall be exempted from
				  requirements of this appendix.
(III) Dewatering. The storage resulting from inflow shall be
				  removed by a nonclogging dewatering device or a spillway as soon as possible
				  but not prior to the time that the discharge will comply with the effluent
				  standards of these regulations. The application shall contain documentation
				  that equipment or outlet structures are available for draining the pond.
(C) Discharge structures. Outfall structures and related
				  equipment which is sufficient to meet the self-monitoring requirements of the
				  WYPDES permit shall be properly installed, maintained, operated, and shall be
				  removed when no longer required.
(c) Permit condition. Identification of outfalls. Point
				  source discharges which consist of process wastewater or a combination of
				  process wastewater and water from affected lands shall be identified as
				  specific points of discharge in the discharge permit for each mine. Point
				  source discharges which consist of water discharged from affected lands only
				  may not be required to be identified as specific points of discharge in the
				  discharge permit for each mine. Even if a discharge is not designated as a
				  specific point of discharge, such discharges shall be required to meet the
				  applicable self-monitoring and effluent requirements of the permit.
(d) Effluent limitations.
(i) The following types of mine discharges are subject to the
				  effluent limitations of Appendix J (d) (ii):
(A) Coal preparation plants and coal preparation plant
				  associated areas, as indicated, including discharges which are pumped,
				  siphoned or drained from the coal
				  preparation plant water circuit and coal storage, refuse storage and ancillary areas related to the cleaning or
				  beneficiation of coal of any rank including, but not limited to, bituminous,
				  lignite, and anthracite.
(B) Acid or ferruginous mine drainage from an active mining
				  area resulting from the mining of coal of any rank including, but not limited
				  to, bituminous, lignite, and anthracite.
(C) Alkaline mine drainage from an active mining area
				  resulting from the mining of coal of any rank including, but not limited to,
				  bituminous, lignite, and anthracite.
(D) Post-mining underground mine drainage from the
				  underground workings of underground mines until Surface Mining Control and
				  Reclamation Act (SMCRA) bond release.
(ii) All point source mine discharges, as described in
				  Appendix J (d) (i), which enter or will directly affect surface waters of the
				  state shall meet the following effluent limitations except during a
				  precipitation event of any duration within any 24-hour period which results in
				  a rainfall depth greater than the 10-year, 24-hour precipitation amount (or
				  snowmelt of equivalent volume). During such precipitation events only the
				  limitation on pH shall apply:
Effluent
							 Characteristic
30 Day Average
Daily Maximum
Instantaneous Maximum
Total Suspended Solids (mg/l)
35
70
90
Total Iron (mg/l)
3.0
6.0
9.0
Total Manganese* (mg/l)
2.0
4.0
6.0
pH (standard units)
N/A
N/A
6.0 to 9.0
*Applicable only when pH of the discharge, prior to any
				  treatment, is less than 6.0 standard units.
(iii) Post-Mining Areas. The provisions of this paragraph are
				  applicable to discharges from post mining areas, except as provided in Appendix
				  J (h).
(A) Reclamation Areas. The following limitations apply to
				  discharges from reclamation areas until the performance bond issued to the
				  facility by the appropriate SMCRA authority has been released. The following
				  limitations establish the concentration or quality of pollutants which may be
				  discharged.
Pollutant or Pollutant Property
Limitations
Settleable Solids
0.5 ml/l maximum not to be exceeded
pH
Within the range of 6.0 and 9.0 at all times
(iv) Co-mingling of waste streams. Where waste streams from
				  any facility covered by this appendix are combined for treatment or discharge
				  with waste streams from another facility covered by this part, the
				  concentration of each pollutant in the combined discharge may not exceed the
				  most stringent limitations for that pollutant applicable to any component waste
				  stream of the discharge.
(v) Alternate effluent limitation for pH. Where the
				  application of neutralization and sedimentation treatment technology results in
				  inability to comply with the otherwise applicable manganese limitations, the
				  permit issuer may allow the pH level in the final effluent to exceed 9.0 to a
				  small extent in order that the manganese limitations can be achieved, provided
				  that the pH of the receiving surface water of the state does not exceed water
				  quality standards of Wyoming Water Quality Rules and Regulations Chapter 1,
				  Wyoming Surface Water Quality Standards.
(e) Effluent limitations for precipitation events.
(i) The alternate limitations specified in Appendix J (e)
				  (ii) apply with respect to:
(A) All discharges of alkaline mine drainage except
				  discharges from underground workings of underground mines that are not
				  commingled with other discharges eligible for these alternate
				  limitations;
(B) All discharges from steep slope areas, (as defined in
				  Section 515(d) (4) of the SMCRA of 1977, as amended), and form mountaintop
				  removal operations (conducted pursuant to Section 515(c) of SMCRA);
(C) Discharges from coal preparation plants and preparation
				  plant associated areas (excluding acid or ferruginous mine drainage from coal
				  refuse disposal piles).
(ii) Any discharge or increase in the volume of a discharge
				  caused by precipitation within any 24-hour period less than or equal to the
				  10-year, 24-hour precipitation event (or snowmelt of equivalent volume) may
				  comply with the following limitations instead of the otherwise applicable
				  limitations:
Pollutant or Pollutant Property
Limitations
Settleable Solids
0.5 ml/l maximum not to be exceeded
pH
Within the range 6.0 to 9.0 at all times
iii) The following alternate limitations apply with respect
				  to acid or ferruginous drainage from coal refuse disposal piles: Any discharge
				  or increase in the volume of a discharge caused by precipitation within any
				  24-hour period greater than the 1-year, 24-hour precipitation event, but less
				  than or equal to the 10-year, 24-hour precipitation event (or snowmelt of
				  equivalent volume) may comply with the following limitations instead of the
				  otherwise applicable limitations:
Pollutant or Pollutant Property
Limitations
Settleable Solids
0.5 ml/l maximum not to be exceeded
pH
Within the range 6.0 to 9.0 at all times
(iv) The following alternate limitations apply with respect
				  to acid or ferruginous mine drainage, except for discharges addressed in:
				  Appendix J (e) (i) (B) (mountaintop removal and steep slope areas) and Appendix
				  J (e) (vii) (discharges from underground workings of underground mines):
(A) Any discharge or increase in the volume of a discharge
				  caused by precipitations within any 24-hour period or less or equal to the
				  2-year, 24-hour precipitation event (or snowmelt of equivalent volume) may
				  comply with the following limitations instead of the otherwise applicable
				  limitations:
Pollutant or Pollutant Property
Limitations
Total Iron
7.0 mg/l maximum for any one day
Settleable Solids
0.5 ml/l maximum not to exceed
pH
Within the range 6.0 to 9.0 at all times
(B) Any discharge or increase in the volume of a discharge
				  caused by precipitation within any 24-hour period greater than the 2-year,
				  24-hour precipitation event, but less than or equal to the 10-year, 24-hour
				  precipitations event (or snowmelt of equivalent volume) may comply with the
				  following limitations instead of the otherwise applicable limitations:
Pollutant or Pollutant Property
Limitations
Settleable Solids
0.5 ml/l maximum not to be exceeded
pH
Within the range 6.0 to 9.0 at all times
(v) Any discharge which occurs during a precipitation event
				  of any duration within any 24-hour period which results in a rainfall depth
				  greater than the 10- year, 24-hour precipitation amount (or snowmelt of
				  equivalent volume) shall be required to meet an instantaneous maximum pH
				  limitation of 6.0 - 9.0 only.
(vi) The operator shall have the burden of proof that the
				  discharge or increase in discharge was caused by the applicable precipitation
				  event described Appendix J (e) (ii), (iii), (iv) and (v).
(vii) Discharges of mine drainage from underground workings
				  or underground mines which are not commingled with discharges eligible for
				  alternate limitations set forth in Appendix J (e) shall in no event be eligible
				  for the alternate limitations set forth in Appendix J (e).
(f) If effluent limitations more stringent than those given
				  in paragraph (c) (i) or (ii) of this appendix are necessary to assure
				  compliance with Wyoming Water Quality Rules and Regulations, Chapter 1, such
				  limitations shall be established in accordance with Section
				  5(c) (iii)
				  (C).
(g) Procedure and method detection limit for measurement of
				  settleable solids. For the purposes of this appendix, the following procedure
				  shall be used to determine settleable solids: Fill an Imhoff cone to the
				  one-liter mark with a thoroughly mixed sample. Allow to settle undisturbed for
				  45 minutes. Gently stir along the inside surface of the cone with a stirring
				  rod. Allow to settle undisturbed for 15 minutes longer. Record the volume of
				  settled material in the cone as milliliters per liter. Where a separation of
				  settleable and floating materials occurs, do not include the floating material
				  in the reading. Notwithstanding any provision of 40 CFR Part 136, the method
				  detection limit for measuring settleable solids under this part shall be 0.4
				  ml/l.
(h) Western alkaline coal mining.
(i) Applicable to alkaline mine 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 of the following requirements:
(A) pH is equal to or greater than 6.0,
(B) Dissolved iron concentration is less than 10 mg/l,
				  and
(C) Net alkalinity is greater than zero.
(ii) Special definitions.
(A) "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) "Regraded area" means the surface area of a coal mine
				  that has been returned to required contour.
(C) "Sediment" means undissolved organic and inorganic
				  material transported or deposited by water.
(D) "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) "Topsoil stockpiling area" means the area outside the
				  mined-out area where topsoil is temporarily stored for use in reclamation,
				  including containment berms.
(F) "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
				  inches or less.
(iii) The effluent limitations of Appendix J (h) (iv) apply
				  until the appropriate SMCRA authority has authorized bond release.
(iv) Effluent limitations.
(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 administrator 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.
(I) Coal remining. Applicable to pre-existing discharges that
				  are located within or are hydrologically connected to pollution abatement areas
				  of a coal mining operation.
(i) Specialized definitions.
(A) "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) "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) "Pre-existing discharge" means any discharge resulting
				  from mining activities that have been abandoned prior tot the time of a
				  remining permit application. The term shall include a pre-existing discharge
				  that is relocated as a result of the implementation of BMPs contained in the
				  Pollution Abatement Plan.
(D) "Steep slope" means any slope above 20 degrees or such
				  lesser slope as may be defined by the administrator after consideration of
				  soil, climate, and other characteristics of the State. The 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) "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.
(ii) 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 Appendix J (d) (iv) of these
				  regulations 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 Appendix J (i) of these regulations.
(iii) In situations where coal remining operations seek
				  reissuance of an existing remining permit with BPJ limitations and the
				  administrator determines that it is not feasible for a remining operator to
				  re-establish baseline pollutant levels in accordance with the statistical
				  procedures contained in 40 CFR Part 434 Appendix B pre-existing discharge
				  limitations at existing remining operations shall remain subject to baseline
				  pollutant levels established during the original permit application.
(iv) The effluent limitations of Appendix J (i) apply to
				  pre-existing discharges until the appropriate SMCRA authority has authorized
				  bond release.
(v) Effluent limitations applicable to coal remining.
(A) The operator must submit a site-specific pollution
				  abatement plan to the administrator for the pollution abatement area. The plan
				  must be approved by the administrator 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 pollution load from pre-existing
				  discharges and must identify the selected 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) Except as provided in Appendix J (h) (v) (C) of these
				  regulations, the following effluent limits shall apply to pre-existing
				  discharges:
(I) Total iron may not exceed baseline loadings (as defined
				  40 CFR Part 434 Appendix B).
(II) Total manganese may not exceed baseline loadings (as
				  defined 40 CFR Part 434 Appendix B).
(III) Net acidity may not exceed baseline loadings (as
				  defined 40 CFR Part 434 Appendix B).
(IV) TSS, during remining and reclamation, may not exceed
				  baseline loadings (as defined 40 CFR Part 434 Appendix B).
(V) Prior to bond release, the pre-existing discharge must
				  meet the applicable standards for TSS or SS contained in Appendix J (d)
				  (iii).
(VI) A pre-existing discharge is exempt from meeting
				  standards in Subpart E for TSS and SS when the administrator 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 Appendix J (i) (v) of
				  these regulations.
(C) If the administrator determines that it is infeasible to
				  collect samples for establishing the baseline pollutant levels pursuant to
				  Appendix J (i) (v) (B) of these regulations and that remining will result in
				  significant improvement that would not otherwise occur, the numeric effluent
				  limitations in Appendix J (i) (v) (B) of these regulations do not apply.
(D) Pre-existing discharges for which it is infeasible to
				  collect samples for determination of baseline pollutant levels include, but are
				  not limited to:
(I) Discharges that exist as a diffuse groundwater flow that
				  cannot be assessed via sample collection;
(II) A base flow to a receiving surface water of the state
				  that can not be monitored separate from the receiving surface waters of the
				  state;
(III) A discharge on a steep or hazardous slope that is
				  inaccessible for sample collection; or
(IV) A number of pre-existing discharges so extensive that
				  monitoring of individual discharges is infeasible.