Current through Register Vol. 54, No. 44, November 2, 2024
Section 88.92 - Hydrologic balance: effluent standards(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.The provisions of this §88.92 adopted December 19, 1980, 10 Pa.B. 4789, effective 7/31/1982, 12 Pa.B. 2382; amended March 30, 1984, 14 Pa.B. 1143, effective 8/10/1985, 15 Pa.B. 2872; amended June 15, 1990, 20 Pa.B. 3383, effective 7/27/1991, 21 Pa.B. 3316; amended December 15, 1995, effective 12/16/1995, 25 Pa.B. 5821; amended November 14, 1997, effective 11/15/1997, 27 Pa.B. 6041; amended May 8, 1998, effective 5/9/1998, 28 Pa.B. 2227; amended March 13, 2020, effective 3/14/2020, 50 Pa.B. 1508.The provisions of this §88.92 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); section 1920-A of The Administrative Code of 1929 (71 P.S. § 510-20); section 3.2 of the Coal Refuse Disposal Control Act (52 P.S. § 30.53b); and section 7(b) of The Bituminous Mine Subsidence and Land Conservation Act (52 P.S. § 1406.7(b)).
This section cited in 25 Pa. Code § 86.1 (relating to definitions); 25 Pa. Code § 86.159 (relating to self-bonding); 25 Pa. Code § 86.283 (relating to procedures); 25 Pa. Code § 86.294 (relating to uses and limitations); 25 Pa. Code § 88.91 (relating to hydrologic balance: general requirements); 25 Pa. Code § 88.93 (relating to hydrologic balance: precipitation event exemption); 25 Pa. Code § 88.96 (relating to hydrologic balance: sediment control measures); 25 Pa. Code § 88.97 (relating to hydrologic balance: treatment facilities); 25 Pa. Code § 88.98 (relating to hydrologic balance: sedimentation ponds); 25 Pa. Code § 88.100 (relating to hydrologic balance: acid-forming and toxic-forming spoil); 25 Pa. Code § 88.101 (relating to hydrologic balance: permanent impoundments); 25 Pa. Code § 88.138 (relating to haul roads and access roads: general); 25 Pa. Code § 88.381 (relating to general requirements); 25 Pa. Code § 88.507 (relating to treatment of discharges); 25 Pa. Code § 88.510 (relating to effluent limitations); and 25 Pa. Code § 88.511 (relating to baseline determination and compliance monitoring for pre-existing discharges at remining operations).