(a)
Groups of effluent
criteria. A person may not allow a discharge of water from an area
disturbed by mining activities which exceeds the following groups of effluent
criteria. The effluent limitations shall be applied under subsection (b).
Group A
Parameter
|
30-day Average
|
Daily
Maximum
|
Instantaneous Maximum
|
iron (total) |
3.0 mg/l |
6.0 mg/l
|
7.0 mg/l |
manganese (total) |
2.0 mg/l |
4.0
mg/l |
5.0 mg/l |
suspended solids |
35 mg/l |
70
mg/l |
90 mg/l |
pH
1
|
greater than 6.0; less than 9.0 |
alkalinity greater than acidity
1 |
1 The
parameter is applicable at all times. |
Group B
Parameter
|
Instantaneous Maximum
|
iron (total) |
7.0 mg/l |
settleable solids |
0.5 ml/l
|
pH |
greater than 6.0; less
than 9.0 |
alkalinity greater than acidity |
Group C
Parameter
|
Instantaneous Maximum
|
pH |
greater than 6.0; less
than 9.0 |
alkalinity greater than acidity |
(b)
Effluent limitations and
precipitation exemptions. Effluent limitations and precipitation
exemptions are as follows:
(1) The discharges
specified in this subsection shall comply with the effluent limitations set
forth as follows:
Type of Discharge
|
Precipitation Event
|
Effluent
Limitations
|
Pit Water |
all |
Group A |
Surface runoff from active
area |
dry weather |
Group A |
less than or equal to 10yr-24hr |
Group
B |
greater than 10yr-24hr |
Group C |
Surface runoff from area where Stage
2 standards achieved |
dry weather |
Group A |
less than or equal to 10yr-24hr |
Group
B |
greater than 10yr-24hr |
Group C |
All other discharges |
dry
weather |
Group A |
less than or equal to 10yr-24hr |
Group B
|
greater than 10yr-24hr |
Group C |
(2) To be entitled to the effluent
limitations in Group B or Group C, the permittee shall comply with §
88.93 (relating to hydrologic
balance: precipitation event exemption).
(c)
Exceptions to effluent
limitations. Exemptions to effluent limitations are as follows:
(1) The pH of discharges shall be maintained
between 6.0 and 9.0 except in the following circumstances:
(i) Where the wastes are discharged to an
acid stream, in which cases the pH may be greater than 9.0.
(ii) When the discharger affirmatively
demonstrates to the Department that the wastewater treatment process being used
by the discharger requires the pH to be raised above 9.0, that the elevated pH
will not cause a safety hazard at the outfall and that the elevated pH will not
result in a violation of applicable water quality standards in Chapter 93
(relating to water quality standards) or of the applicable treatment
requirements and effluent limitations to which a discharge is subject under the
Clean Water Act (33 U.S.C.A.
§§
1251-
1376), the Department
may grant a variance from this limitation.
(2) When a discharge without chemical or
biological treatment has a pH greater than 6.0 and a total iron concentration
of less than 10.0 mg/1, the manganese limitation does not apply.
(d)
Single facilities used
for sediment and erosion control. If a single facility is used for
sediment and erosion control facilities and treatment facilities covered by
this section, the concentration of each pollutant in the combined discharge may
not exceed the most stringent limitations for that pollutant applicable to a
component waste stream of the discharge.
(e)
Postmining pollutional
discharges.
(1) If a postmining
pollutional discharge occurs, the discharger shall immediately provide interim
treatment to comply with the Group A effluent requirements in subsection (a),
including any modifications authorized or required under subsection (c), (d) or
(f). The discharger shall also take whatever measures are necessary and
available to abate the discharge, including modifying the operation and
reclamation plan for the mining activity.
(2) If the discharge continues to exist,
after implementation of the abatement measures required under paragraph (1),
the discharger shall make provisions for sound future treatment of the
discharge to achieve the Group A effluent requirements in subsection (a),
including modifications authorized or required under subsection (c) or (f). If
the untreated discharge can be adequately treated using a passive treatment
system, paragraph (3) applies in lieu of the Group A effluent requirements of
subsection (a). Discharges which can be adequately treated using a passive
treatment system include, but are not limited to:
(i) Discharges with a pH which is always
greater than 6.0 and an alkalinity which always exceeds the acidity.
(ii) Discharges with an acidity which is
always less than 100 milligrams per liter, an iron content which is always less
than 10 milligrams per liter, a manganese content which is always less than 18
milligrams per liter and a flow rate which is always less than 3 gallons per
minute.
(iii) Discharges with a net
acidity always less than 300 milligrams per liter which is calculated by
subtracting the alkalinity of the discharge from its acidity.
(3) A passive treatment system
authorized under paragraph (2) shall comply with the following effluent
requirements:
(i) The system shall reduce the
iron concentration by at least 90% or by that percentage necessary to achieve
the Group A effluent requirements in subsection (a), whichever percentage is
less.
(ii) The system shall produce
an effluent alkalinity which exceeds effluent acidity.
(4) In addition to achieving the effluent
requirements of paragraphs (2) and (3), the passive treatment system shall be
designed and constructed to accomplish the following:
(i) Prevent discharge of mine drainage into
the groundwater.
(ii) Prevent
extraneous sources of groundwater and surface water runoff from entering the
treatment system.
(iii)
Hydraulically handle the highest average monthly flow rate which occurs during
a 12-month period.
(iv) Have inlet
and outlet structures which will allow for flow measurement and water
sampling.
(v) Prevent to the
maximum extent practicable physical damage, and associated loss of
effectiveness, due to wildlife and vandalism.
(vi) Be of a capacity so that it will operate
effectively and achieve the required effluent quality for 15 to 25 years before
needing to be replaced.
(5) The passive treatment system shall be
designed by, and constructed under the supervision of, a qualified professional
knowledgeable in the subject of passive treatment of mine drainage.
(f) In addition to the
requirements of subsections (a)-(e), the discharge of water from areas
disturbed by mining activities shall comply with Chapters 91-93, 95, 96, 97
(reserved) and 102.