Pressure washing costs in Dayton

Dayton drinks groundwater. The city pumps from the region's buried valley aquifer, a layer of sand and gravel saturated with water, through about 110 production wells in two well fields, the Mad River field and one other. Those wells serve about 400,000 people in Montgomery County and part of Greene County, and the aquifer as a whole supplies an estimated 1.5 million people in southwest Ohio. The U.S. EPA named it a sole-source aquifer in 1988.

It's also easy to reach from above. In its 2017 assessment, Ohio EPA rated the aquifer under Dayton's well fields as highly susceptible to contamination. Among its reasons: surface water recharges it, the protective clay layer on top is thin, and the aquifer is shallow.

That's worth keeping in mind with what goes in the sprayer. Plain water and a mild cleaner are one thing. A strong degreaser for an oil-stained driveway, or a bleach mix for siding, is another, and the three reasons above all come down to how easily water from the surface gets in.

The city has run a Source Water Protection Program since 1988, with zoning controls on land use, chemical inventory reports and business inspections, together with Huber Heights, Riverside, Vandalia and Harrison Township. If fuel or a cleaning chemical spills during a job, the program keeps a line for spill reports.