Ground Water Standards

(1) Except as otherwise provided in 314 CMR 5.11(2), or unless the Department determines that the ground water is not an underground source of drinking water as provided in 314 CMR 5.10(9)(c), all ground waters of the Commonwealth are designated as a source of potable water supply and the minimum criteria applicable to all ground waters of the Commonwealth shall be the effluent limitations set forth in 314 CMR 5.10(3)(a) and (b). (2) The ground waters classified as Class III Ground Waters prior to March 20, 2009 are designated for uses other than a source of potable water supply. At a minimum, the most sensitive use of these ground waters shall be as a source of non-potable water which may come in contact with, but is not ingested by humans. The minimum criteria applicable to such ground waters shall be the effluent limitations set forth in 314 CMR 5.10(3)(a) and (b) as modified by 314 CMR 5.10(3)(c). (3) To prevent the ground waters classified as Class III Ground Waters prior to March 20, 2009 from being further degraded, the Department may require that any discharge to such ground waters not authorized by a permit issued by the Department prior to March 20, 2009, and any increase in the volume or amount of pollutants above that authorized by a permit issued by the Department prior to March 20, 2009 to such waters, meet the more stringent of the water quality based effluent limitations and the technology based effluent limitations set forth in 314 CMR 5.10(3)(a) and (b), and (4). Alternatively, the Department may require the discharge to meet the special effluent limitations set forth in 314 CMR 5.10(9), if the permittee requests such limitations and makes the required demonstrations.