Protecting our groundwater

Tacoma Water operates several wells within the South Tacoma Groundwater Protection District; however, 95+% of the drinking water for Tacoma and our surrounding communities comes from an abundant supply in the Green River Watershed. The water we provide our customers is filtered at the Green River Watershed before traveling through more than 1,400 miles of well-maintained water main systems to provide more than 6.5 billion gallons per year to approximately 110,000 taps in the metro area.

The wells in South Tacoma are supplied from an aquifer that extends as far south as the Roy and Fredrickson area. These wells are used primarily as a backup water source for the Green River supply during drier summer months when demand is at its highest. In a normal weather year, these groundwater wells currently supply only 5% of Tacoma Water’s total annual water requirements.

We’ve recently received questions from customers about a planned development project located in the South Tacoma Groundwater Protection District. While this project is located near our property, it is a project led by an independent private company that is working directly with the City’s Planning and Development Services in the permitting process, which includes evaluating potential environmental impacts. As a public utility, TPU has a responsibility to supply water service to all customers in our service area regardless of business or customer type including both public and private. Any decision-making about the project is not within the authority of TPU or its operating divisions.

Tacoma Water protects these groundwater wells by carefully monitoring activities in the areas that drain into them. We partner with the Tacoma Pierce County Health Department to perform periodic inspections of businesses to ensure safe handling and storage of potential contaminants. We also conduct regular sampling of monitoring wells to check for early signs of potential contaminants before they reach our wells.

For more information about the independent project and the City of Tacoma’s permitting process, including environment impact studies, go to

To learn more about Tacoma Water’s water source and supply, including our long-term Water System Plan, go to

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