Zone 1 Wellhead Protection Areas

Overview This Feature Service presents the designated Zone I areas around public water supply wells and wellfields within Massachusetts. As stated in 310 CMR 22.02, Zone I means the protective radius required around a public water supply well or wellfield. For public water system wells with approved yields of 100,000 gpd or greater, the protective radius is 400 feet. Tubular wellfields require a 250-foot protective radius. Protective radii for all other public water system wells are determined by the following equation: Zone I radius in feet = (150 x log of pumping rate in gpd) - 350. This equation is equivalent to the chart in the Guidelines and Policies for Public Water Systems. A default Zone I radius or a Zone I radius otherwise computed and determined by the Department shall be applied to transient non-community (TNC) and non-transient non-community (NTNC) wells when there is no metered rate of withdrawal or no approved pumping rate. In no case shall the Zone I radius be less than 100 feet. Feature Layer DEPApprovedZoneI: This layer delineates Zone I boundaries applied to public water supply wells based on their approved pumping rates and well configurations. Protective radii vary from a minimum of 100 feet up to 400 feet, with specific criteria established by 310 CMR 22.02 regulations. The layer incorporates data about well types, approved water withdrawal rates, and associated public water system identifiers. Geographic Coverage The service covers the Town of Yarmouth, Massachusetts, focusing on areas around public water supply wells regulated by MassDEP.