Zone 2 Wellhead Protection Areas

Overview This feature service provides spatial data on Zone II wellhead protection areas approved by the Massachusetts Department of Environmental Protection (MassDEP). As stated in 310 CMR 22.02, a Zone II is: "That area of an aquifer which contributes water to a well under the most severe pumping and recharge conditions that can be realistically anticipated (180 days of pumping at safe yield, with no recharge from precipitation). It is bounded by the groundwater divides which result from pumping the well and by the contact of the aquifer with less permeable materials such as till or bedrock. In some cases, streams or lakes may act as recharge boundaries. In all cases, Zone IIs shall extend up gradient to its point of intersection with prevailing hydrogeologic boundaries (a groundwater flow divide, a contact with till or bedorck , or a recharge boundary)." Feature Layers Zone II (DEP Approved): This polygon feature layer represents Zone II boundaries as defined by the Massachusetts regulation 310 CMR 22.02. These zones identify regions around public wells where groundwater contributes to supply wells during severe pumping conditions (up to 180 days at safe yield without recharge). The boundaries are formed by groundwater divides resulting from pumping and geologic contacts with less permeable materials such as till or bedrock. Additional recharge boundaries may include streams or lakes. Geographic Coverage The data geographically covers the area of Yarmouth, Massachusetts where public water supply wells exist and Zone II areas have been delineated according to MassDEP standards. Data Source and Licensing The service covers the Town of Yarmouth, Massachusetts, focusing on areas around public water supply areas regulated by MassDEP.## 概览 本要素服务提供经马萨诸塞州环境保护厅（Massachusetts Department of Environmental Protection, MassDEP）批准的II类井口保护区空间数据。根据310 CMR 22.02的规定，II类区域定义为："在可预见的最严苛抽水与补给条件下（以安全产水量连续抽水180天且无降水补给），向水井供水的含水层区域。其边界由抽水形成的地下水分水岭以及含水层与弱透水物质（如冰碛物或基岩）的接触带构成。在部分场景中，溪流或湖泊可作为补给边界。无论何种情况，II类区域均应沿上游延伸至与主要水文地质边界（地下水流分水岭、与冰碛物或基岩的接触带，或补给边界）的交汇点。" ## 要素图层 II类区域（环境保护厅批准）：该面要素图层代表马萨诸塞州监管标准310 CMR 22.02所定义的II类区域边界。此类区域标识公共水井周边的区域，在严苛抽水条件下（以安全产水量连续抽水180天且无补给），地下水将向供水井提供水源。其边界由抽水形成的地下水分水岭以及与冰碛物、基岩等弱透水物质的地质接触带构成，额外的补给边界可包括溪流或湖泊。 ## 地理覆盖范围 本数据的地理覆盖范围为马萨诸塞州雅茅斯镇内存在公共供水水井且已按照MassDEP标准划定II类区域的区域。 ## 数据来源与授权 本服务覆盖马萨诸塞州雅茅斯镇，聚焦于受MassDEP监管的公共供水区域周边范围。