Section 27.07 - Exemption(1)Aquifer. The Department may exempt an aquifer from being an underground source of drinking water if, after notice and an opportunity for a public hearing the Department determines, subject to the approval of the U. S. Environmental Protection Agency, that the aquifer: (a) currently does not serve as a source of public drinking water; and,(b) cannot now and will not in the future serve as a source of public drinking water because: 1. it is used to produce mineral, hydrocarbon or geothermal energy;2. it is so contaminated that it would be economically or technologically impractical to render the water fit for human consumption; or3. it contains more than 3000 mg/l Total Dissolved Solids and it is not reasonably expected to be used as a source of public drinking water.(2)Registration. The following Class V injection wells are exempt from the registration requirements of 310 CMR 27.08: (a) on-site subsurface sewage disposal systems used solely for the disposal of sanitary sewage and regulated under 310 CMR 15.000: The State Environmental Code, Title 5: Standard Requirements for the Siting, Construction, Inspection, Upgrade and Expansion of On-site Sewage Treatment and Disposal Systems and for the Transport and Disposal of Septage;(b) Class V injection wells permitted under 314 CMR 5.00: Ground Water Discharge Permit Program; and(c) Class V injection wells on properties that are only used for one single-family residential unit, and that are only used for one or more of the following types of discharges: 2. water purification backwash;3. wastewater from the recovery of geothermal energy for heating, or water used for cooling;4. groundwater infiltration; and5. swimming pool drainage.Amended by Mass Register Issue 1322, eff. 9/23/2016.