Section 434.11 - General definitions(a) The term "acid or ferruginous mine 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.(b) The term "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.(c) The term "alkaline, mine drainage" means mine drainage which, before any treatment, has a pH equal to or greater than 6.0 and total iron concentration of less than 10 mg/l.(d) The term "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.(e) The term "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.(f) The term "coal preparation plant associated areas" means the coal preparation plant yards, immediate access roads, coal refuse piles and coal storage piles and facilities.(g) The term "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 is coal preparation processes within a coal preparation plant.(h) The term "mine drainage" means any drainage, and any water pumped or siphoned, from an active mining area or a post-mining area.(i) The abbreviation "ml/l" means milliliters per liter.(j)(1) Notwithstanding any other provision of this Chapter, subject to paragraph (j)(2) of this section the term "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 re-mined. (i) The construction of which is commenced after May 4, 1984; or(ii) Which is determined by the EPA Regional Administrator to constitute a "major alteration". In making this determination, the Regional 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 NPDES permit is being considered:(A) Extraction of a coal seam not previously extracted by that mine;(B) Discharge into a drainage area not previously affected by wastewater discharge from the mine;(C) Extensive new surface disruption at the mining operation;(D) A construction of a new shaft, slope, or drift; and(E) Such other factors as the Regional Administrator deems relevant.(2) No provision in this part shall be deemed to affect the classification as a new source of a facility which was classified as a new source coal mine under previous EPA regulations, but would not be classified as a new source under this section, as modified. Nor shall any provision in this part be deemed to affect the standards applicable to such facilities, except as provided in § 434.65 of this chapter.(k) The term "post-mining area" means:(1) A reclamation area or(2) 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.(l) The term "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.(m) The term "settleable solids" is that matter measured by the volumetric method specified in § 434.64 .(n) The terms "1-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, two, and ten years respectively as defined by the National Weather Service and Technical Paper No. 40, "Rainfall Frequency Altas of the U.S.," May 1961, or equivalent regional or rainfall probability information developed therefrom.(o) The terms "treatment facility" and "treatment system" mean all structures which contain, convey, and as necessay, chemically or physically treat coal rine 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.(p) The term "coal refuse disposal pile" means any coal refuse deposited on the earth and intended as permanent dispoal 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.(q) The term "controlled surface mine drainage" means any surface mine drainage that is pumped or siphoned from the active mining area.(r) The term "abandoned mine" means a mine where mining operations have occurred in the past and(1) The applicable reclamation bond or financial assurance has been released or forfeited or(2) If no reclamation bond or other financial assurance has been posted, no mining operations have occurred for five years or more.(s) The term "1-year, 24-hour precipitation event" means the maximum 24-hour precipitation event with a probable recurrence interval of once in one year as defined by the National Weather Service and Technical Paper No. 40, "Rainfall Frequency Atlas of the U.S.," May 1961, or equivalent regional or rainfall probability information developed therefrom.(t) The Term "2-year, 24-hour precipitation event" means the maximum 24-hour precipitation event with a probable recurrence interval of once in two years as defined by the National Weather Service and Technical Paper No. 40, "Rainfall Frequency Atlas of the U.S., "May 1961, or equivalent regional or rainfall probability information developed therefrom.