§ 46-13.1-4. Groundwater classification. (a) For the purpose of protecting existing, proposed, or potential drinking water supplies, the director shall conduct a survey of all groundwater sources and related groundwater aquifers, watersheds, and deep flow recharge areas. Upon completion of the survey, the director shall designate the groundwater sources under one of the following classifications:

(1) GAA - groundwater sources suitable for public drinking water use without treatment;

(2) GA - groundwater sources which may be suitable for public or private drinking water without treatment;

(3) GB - groundwater sources which may not be suitable for public or private drinking water without treatment due to known or presumed degradation;

(4) GC - groundwater sources which may be suitable for certain waste disposal practices because past or present land use or hydrogeologic conditions render the groundwaters more suitable for receiving permitted discharges than for development as public or private water supply.

(b) The director shall develop water quality standards for each classification which specify maximum contaminant levels for each classification. The approach for establishing the water quality standards shall include appropriate criteria established by the United States Environmental Protection Agency to protect the uses of groundwater as designated by the director. Water quality standards shall be used to promote restoration of groundwater to drinking water quality without treatment except where the groundwater is:

(1) In a zone of discharge otherwise permitted by the provisions of the general laws;

(2) Classified as GB and there exists no demonstrated present or future need to upgrade to GA; or

(3) Classified as GC.

(c) The director shall also develop a preventive action limit for each maximum contaminant level for each classification. In determining the percentage of the maximum contaminant level to be used as a preventive action limit for each contaminant, the director shall take into account whether the contaminant is a toxic pollutant and, if so, whether it has carcinogenic, mutagenic, or teratogenic properties or interactive effects. The director shall promulgate rules setting forth the range of responses that he or she may take, or that he or she may require the person, corporation, or other entity controlling a facility, activity, or practice that is a source of the contaminant to take, if the preventive action limit is attained or exceeded. The responses shall be designed to:

(1) Minimize the concentration of the contaminant in the groundwater where technically and economically feasible;

(2) Regain and maintain compliance with the preventive action limit, unless the director determines that the preventive action limit is either not technically or not economically feasible, in which case he or she shall achieve compliance with the lowest possible concentration that is technically and economically feasible; and

(3) Ensure that the maximum contaminant level is not attained or exceeded.

(d) The director shall complete duties assigned under this section on or before February 28, 1989.

History of Section. (P.L. 1985, ch. 494, § 1; P.L. 1986, ch. 298, § 1.)