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Water quality standards for Washington's groundwater

The Water Quality Standards for Groundwaters of the State of Washington, Chapter 173-200 Washington Administrative Code (WAC), sets standards to maintain the highest quality of groundwater.

What are the groundwater standards?

Our goal is to protect existing and future beneficial uses of groundwater by reducing or eliminating pollution. Chapter 173-200 WAC establishes groundwater quality standards to help us meet that goal. The standards apply to any activity that has potential to contaminate groundwater quality.

Together with the state's technology-based treatment requirements, the standards protect the environment, human health, and existing and future beneficial uses of groundwater.

Implementation guidance

We developed implementation guidance for groundwater quality standards. The guidance explains and interprets the standards, providing clear direction to promote consistent statewide implementation for activities that have a potential to degrade groundwater quality.