Section 485-C:5 - Classes of GroundwaterI.All groundwater shall be classified for the purpose of prescribing protections and management practices. These classifications do not necessarily reflect existing water quality. For purposes of classification, all groundwater shall be assigned to one of 4 classes as follows:(a) Class GAA groundwater shall be the most protected class. Groundwater in this class is within the wellhead protection area for wells which presently are used or well sites which have been identified for future use as drinking water supply for public water systems. An inventory of potential contamination sources in the wellhead protection area shall be conducted, and a management program shall be implemented as provided under RSA 485-C:8.(b) Class GA1 shall be assigned to groundwater in a defined zone of high value for present or future drinking water supply. An inventory of potential contamination sources in the contributing area of this class shall be conducted, and a management program shall be implemented as provided under RSA 485-C:8.(c) Class GA2 shall be assigned to groundwater within aquifers identified as highly productive for potential use as a public water supply by the U.S. Geological Survey regional groundwater studies, or other regional studies. Zones of stratified drift with a saturated thickness greater than 20 feet, and a transmissivity greater than 1,000 feet squared per day shall be designated as class GA2. Zones of bedrock with average well yields greater than 50 gallons per minute shall also be designated as class GA2.(d) Class GB shall be assigned to all groundwater not assigned to a higher class.II.The land area vertically above shall be assigned to the highest class of groundwater beneath it, for purposes of managing potential contamination sources. 1991, 344:1, eff. June 28, 1991.