Water Quality

To protect public health, the United States Environmental Protection Agency (EPA) and the Washington State Department of Health (DOH) set the standards for public drinking water quality.  These standards require specific action, including public notification, if levels of certain contaminants are exceeded.


To ensure safe drinking water for the public, the water supply is chlorinated.  North Perry Avenue Water District’s Wellhead Protection Plan helps protect our groundwater supplies from contamination and ensures a safe drinking water supply for our customers.


NPW also has a Cross Connection Control Program, which requires customers with potential backflow from their private system into the public water system to install backflow prevention assemblies (required by state law), and to have the backflow assembly checked annually by a certified tester.


Each month, NPW draws over twenty water samples from key locations throughout our service area, and tests them for the presence of coliform bacteria.  Regularly scheduled testing is also done for inorganics, volatile organics, synthetic organic chemical, radionuclides, and disinfectant byproducts, along with other tests as required.  Testing is performed by state certified labs, and test results are routinely sent to DOH, which monitors NPW’s compliance with the many regulatory standards and testing protocols required to assure safe drinking water.  A Consumer Confidence Report is sent to customers annually to inform them about their drinking water.