See full Data Guide here. Aquifer Protection Areas Set is a 1:24,000-scale, polygon feature-based layer that includes all Preliminary (Level B) and Final (Level A) Aquifer Protection Areas approved by the Connecticut Department of Energy and Environmental Protection (DEEP). These areas represent the land area contributing ground water to active public water supply wells or well fields that serve more than 1000 people that are set in sand and gravel aquifers (stratified drift deposits). These areas are commonly referred to as wellhead protection areas. The Aquifer Protection Areas were delineated by the individual water utilities owning the well fields and submitted to the DEEP for approval. The preliminary mapping provides a general estimate of the area contributing ground water to the well field. The final mapping is based on extensive, site-specific, detailed modeling of the ground water flow system. As the final mapping is completed it replaces the preliminary mapping. The layer is based on information collected and compiled from 1991 to the present. The layer depicts current conditions. Attribute information is comprised of codes to uniquely identify individual features, encode the aquifer protection area type and status, and cartographically represent area features on a map. Data is compiled at 1:24,000 scale. This data is updated as final mapping becomes available.