This indicator tracks the number of households in Jersey that use private water supplies such as boreholes, wells and surface water for drinking water.

Mains water supplied by Jersey Water meets national compliance standards, but not all households in Jersey are connected to this public water supply. Testing in 2019 confirmed previous findings that approximately half of households supplied by private water systems have supplies with nitrate levels exceeding the EU and local drinking water limits. Several of the private water supplies tested also contained traces of pesticides and other chemicals. Some were over the prescribed legal limit of 0.1ug/l (a precautionary level based on the limit of detection).