Approximately 87 percent of Renton's water is supplied by the Cedar Valley Aquifer, with the rest coming from Springbrook Springs - a source located in south Renton. As Renton's primary water source, the Cedar Valley Aquifer has been designated a "sole source" by the U.S. Environmental Protection Agency. This means that no federal financial assistance can be given to a project which might contaminate the aquifer and create a public health hazard.
The aquifer is an underground layer of sand and gravel running 3 1/2 miles long, and furnishing Renton residents with an average of 7.3 million gallons of water each day. At some points, the groundwater contained in our aquifer is only 23 feet below ground, making it very sensitive to pollutants.
Fed by rain and snow falling on the aquifer and higher adjacent ground, the aquifer is also replenished by groundwater flow from the Cedar Valley. It is highly permeable, and contaminants reaching these recharge areas could potentially find their way into our drinking water.