30 CFR 817.41 - Under what conditions may I discharge water and other materials into an underground mine?
(a) You may not discharge any water or other materials from your operation into an underground mine unless the regulatory authority specifically approves the discharge in writing, based upon a demonstration that -
(1) The discharge will be made in a manner that -
(ii) Prevents material damage to the hydrologic balance outside the permit area, including the hydrologic balance of the area in which the underground mine receiving the discharge is located;
(iii) Does not adversely impact the biology of perennial or intermittent streams; and
(iv) Otherwise eliminates public hazards resulting from surface mining activities.
(2) The discharge will not cause or contribute to a violation of applicable state or tribal water quality standards or effluent limitations, including, but not limited to, water quality standards established under the authority of section 303(c) of the Clean Water Act, 33 U.S.C. 1313(c), and effluent limitations established in any National Pollutant Discharge Elimination System permit issued for the operation under section 402 of the Clean Water Act, 33 U.S.C. 1342, or its state or tribal counterpart.
(i) The discharge will be at a known rate and of a quality that will meet the effluent limitations for pH and total suspended solids in 40 CFR part 434.
(ii) The regulatory authority may approve discharges of water that exceed the effluent limitations for pH and total suspended solids in 40 CFR part 434 if the available evidence indicates that there is no direct hydrologic connection between the underground mine and other waters and that those exceedances will not be inconsistent with paragraph (a)(1) of this section.
(5) The Mine Safety and Health Administration has approved the discharge.
(6) You have obtained written permission from the owner of the mine into which the discharge is to be made and you have provided a copy of that authorization to the regulatory authority.
(b) Discharges are limited to the following materials:
(3) Fly ash from a coal-fired facility.
(4) Sludge from an acid-mine-drainage treatment facility.
(5) Flue-gas desulfurization sludge.
(6) Inert materials used for stabilizing underground mines.
(7) Underground mine development waste.