Testing, Treatment & Taste


Our labs are responsible for testing monitoring wells, production wells, packed tower aeration systems, combined well water, water plant process water, water plant "finished" water, and distribution system water.

The lab also tests calcium oxide (used for water softening) samples, NPDES sites, water main break samples, new water main samples, and conducts research, regulatory and other special project sampling and testing.

Testing Performed:

  • Calcium Oxide Quality Control
  • Chlorine
  • Fluoride
  • Metals (Arsenic-Zinc, including Lead)
  • Microbiological (including bacteria)
  • Nitrates
  • Total organic carbon
  • Volatile organic compounds
  • Water Plant sand filter evaluations
  • Wet chemistry parameters (Hardness, Alkalinity, etc.)
  • Etc.


  • Bacteria Testing
  • Emergency Response
  • Method 1623 Sampling
  • Sand Filter Evaluations
  • Water Quality Laboratory
  • Water Sampling


Employees of the City of Dayton Division of Water Supply and Treatment treat and pump drinking water to over 400,000 people in Montgomery County. Water is supplied by wells in the Miami and Mad River Well Fields. Wells pump water to the Ottawa Water Treatment Plant and the Miami Water Treatment Plant. Each plant has a rated capacity of 96 million gallons per day. Lime (calcium oxide), fluoride and chlorine are used for water treatment. Rapid sand filtration is the final step in the treatment process. In 2010,  23.7 billion gallons of treated drinking water was pumped to the distribution system. Approximately 750 miles of water main serve customers inside the city of Dayton.

Dayton has 16 treated water storage facilities with a total capacity of 88 million gallons. The Water Department also controls two main pumping stations and 10 booster pumping stations. A Lime Recovery Facility reclaims calcium carbonate from the lime softening residuals of both water treatment plants and produces more lime for softening. This process, recalcination, produced 36,533 tons of lime in 2021.

The City of Dayton's Source Water Protection Program includes land use control zoning, groundwater remediation and emergency preparedness. An early warning, network of approximately 320 monitoring wells surrounds both well fields. Monitoring wells and 110 production wells are sampled and tested for water quality. Eighteen packed tower, air stripping systems were constructed to treat contaminated groundwater. Dayton's Source Water Protection Program is internationally recognized and was the first program approved by the Ohio Environmental Protection Agency. In 1998, the American Water Works Association presented its large system, Source Water Protection Program Award to the City of Dayton. Dayton has also been designated as a Groundwater Guardian community by the Groundwater Foundation.

Diagram of treatment process


Dayton's water supply meets or exceeds all state and federal drinking water standards. Adding chlorine during the water-treatment process helps protect the water supply. However, chlorine's taste may not appeal to you. Use these tips to help improve the flavor of your tap water.
  • Put a pitcher of tap water in the refrigerator.  This allows the chlorine to dissipate. After just a few hours, you'll notice an improvement in flavor.
  • Add a lemon or orange slice. You'll add zest and overcome the chlorine taste simply by overpowering it.
  • Filter your water.
There are hundreds of filter options at varying costs, but an inexpensive activated carbon filter, like those found in carafe systems, can improve taste and odor perceptions associated with chlorine. These filters do not remove hardness, minerals, sodium or fluoride.