Section 90.102. Hydrologic balance: water quality standards, effluent limitations and best management practices

(a) A person may not allow a discharge of water from an area disturbed by coal refuse disposal activities, including areas disturbed by mineral preparation, processing or handling facilities which exceeds the following groups of effluent criteria. The effluent imitations are to be applied under subsection (b).

Group A

	30-day	Daily	Instantaneous
Parameter	Average	Maximum	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

	Instantaneous
Parameter	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

	Instantaneous
Parameter	Maximum
pH	greater than 6.0; less than 9.0
alkalinity greater than acidity

(b) 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:

	Precipitation	Effluent
Type Discharge	Event	Limitations
Drainage from coal refuse disposal piles	dry weather and less than or equal to 1yr-24hr greater than 1yr-24hr, to less than or equal to 10yr-24hr greater than 10yr-24hr	Group A Group B Group C
Surface runoff from active areas disturbed by coal refuse disposal activities	dry weather less than or equal to 10yr-24hr greater than 10yr-24hr	Group A Group B Group C
Surface runoff from area where Stage 2 standards achieved	dry weather less than or equal to 10yr-24hr greater than 10yr-24hr	Group A Group B Group C
All other discharges	dry weather less than or equal to 10yr-24hr greater than 10yr-24hr	Group A Group B Group C

(2) To be entitled to the effluent limitations in Group B or Group C, the permittee shall comply with the procedures in § 90.103 (relating to precipitation event exemption).

(c) Exceptions to effluent limitations are as follows:

(1) The pH of discharges of water shall be maintained between 6.0 and 9.0, except in the following circumstances:

(i) The discharger can show the water is discharged to an acid stream, in which case the pH may be greater than 9.0.

(ii) The discharger affirmatively demonstrates, in writing, to the Department that biological respiration in the wastewater treatment system will cause the discharge to exceed the limits set forth in this section and that exceeding these limits will not result in 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 of 1977, the act of December 27, 1977 (Pub. L. No. 95-217, 91 Stat. 1566-1609), in which case the Department may grant a variance, in writing, from the limitations in this section.

(iii) 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 or of the applicable treatment requirements and effluent limitations to which a discharge is subject under the Clean Water Act, 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 mg/l, the manganese limitation does not apply.

(d) 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 any 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 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) Additional requirements. In addition to the requirements of subsections (a)—(e), the discharge of water from coal refuse disposal activities shall comply with this title, including Chapters 91—93, 95, 97 (reserved) and 102.

(g) Abatement plan. If water from a coal refuse disposal area is discharged into a mine for treatment with the drainage from the mine, that mine may not be closed or sealed until an approval for the abatement of the discharges from the coal refuse disposal area is granted by the Department. The abatement plan, including necessary permit applications, shall be submitted to the Department at least 18 months prior to the anticipated closure date of the mine to assure that necessary facilities and measures will be implemented prior to the mine closure or sealing.

The provisions of this § 90.102 adopted December 19, 1980, 10 Pa.B. 4789, effective July 31, 1982, 12 Pa.B. 2382; amended July 30, 1982, 12 Pa.B. 2473, effective July 31, 1982, 12 Pa.B. 2382; amended June 15, 1990, 20 Pa.B. 3383, effective July 27, 1991, 21 Pa.B. 3316; corrected August 16, 1991, effective July 27, 1991, 21 Pa.B. 3697; amended December 15, 1995, effective December 16, 1995, 25 Pa.B. 5821; amended November 14, 1997, effective November 15, 1997, 27 Pa.B. 6041; amended May 8, 1998, effective May 9, 1998, 28 Pa.B. 2227. Immediately preceding text appears at serial pages (237209) to (237213).

Notation

Authority

The provisions of this § 90.102 amended under the Surface Mining Conservation and Reclamation Act (52 P. S. § § 1396.1—1396.19a); The Clean Streams Law (35 P. S. § § 691.1—691.1001); and section 1920-A of The Administrative Code of 1929 (71 P. S. § 510-20).

Cross References

This section cited in 25 Pa. Code § 86.1 (relating to definitions); 25 Pa. Code § 86.283 (relating to procedures); 25 Pa. Code § 86.294 (relating to uses and limitations); 25 Pa. Code § 90.35 (relating to protection of the hydrologic balance); 25 Pa. Code § 90.101 (relating to hydrologic balance: general requirements); 25 Pa. Code § 90.103 (relating to precipitation event exemption); 25 Pa. Code § 90.106 (relating to hydrologic balance: erosion and sedimentation control); 25 Pa. Code § 90.107 (relating to hydrologic balance: treatment facilities); 25 Pa. Code § 90.108 (relating to hydrologic balance: sedimentation ponds); 25 Pa. Code § 90.111 (relating to hydrologic balance: impoundments); 25 Pa. Code § 90.122 (relating to coal refuse disposal); 25 Pa. Code § 90.134 (relating to haul roads and access roads: general); and 25 Pa. Code § 90.307 (relating to treatment of discharges).