laboratory flasks with clear liquid

​Water Quality Laboratory

The city of Thornton Water Quality laboratory is charged with ensuring that the city's drinking water meets all state and federal drinking water regulations. Thornton has a qualified staff of water utility professionals that understand the importance a water supply plays in the overall quality of life for its community. They are dedicated to providing customers with the best quality of water that is possible. The water quality laboratory provides water sampling, monitoring and testing using approved procedures and methods in accordance with all regulatory requirements.

Laboratory AnalystTreated water is collected and analyzed weekly at both Wes Brown and Thornton Treatment Plants and in the city of Thornton water distribution system. Raw water sources are also sampled and closely monitored to protect the quality of Thornton's drinking water. In addition to providing safe drinking water for Thornton's customers, the laboratory prepares and distributes an annual Water Quality Consumer Confidence Report and investigates water complaints.

Coronavirus (Update 4/28/2020): Water Quality strongly recommends that all closed businesses flush their water systems before reopening to clear out old, stagnant water. While the city continues to produce safe drinking water, water that has sat idle in consumers' lines during the prolonged shutdown may have degraded resulting in loss of disinfectant, increased lead and copper, water discoloration, and other issues. Flushing each point of use (hot and cold taps) for at least five minutes will help clear the stagnant water and ensure the customer is receiving the freshest drinking water. Please see CDC guidance for additional information and other helpful tips at:

If you have any questions or concerns about your tap water, please email or call the Water Quality Line at 303-255-7770.