UPDATE: Water samples taken yesterday, August 29, detected manganese levels between 0.025 and 0.035 milligrams per liter (parts per million), below the regulatory standards of 0.05 milligrams per liter.
August 30, 2017 The City has been receiving calls about discolored water. Water Quality Analysts have collected samples and determined the discoloration is being caused by manganese, a mineral that is naturally present in most Colorado lakes and streams.
The water is safe to drink. Manganese does not cause adverse health effects and therefore is not regulated as a chemical that might cause illness. It is only regulated for the aesthetic impact it has on drinking water, such as discoloration and staining. Water samples taken yesterday, August 29, detected manganese levels between 0.025 and 0.035 milligrams per liter (parts per million), below the regulatory standards of 0.05 milligrams per liter.
Manganese and other elements ‘settle’ during the winter months and are often 'flushed out' when higher volumes of water pass through the distribution system. The current discoloration in the water is most likely due to the higher volume of water passing through the distribution system due to our higher temperatures.
The City of Arvada is currently working to eliminate the discoloration by better matching the chemistry of water leaving our treatment plants, as well as flushing discolored water from some areas to eliminate it from the system. Residents can rid any remaining discoloration in their homes by opening the COLD water faucet and allowing cold water to run for several minutes to clear it out. If water discoloration persists for an extended period of time, call Water Quality at 720-898-7802 or Water Treatment at 720-898-7820.
For information on the maintenance of water mains, visit arvada.org/flushing-water-mains.