A water quality report for the city of Redmond has been released and shows that there was no significant contamination in the system during 2017.
The city of Redmond delivers water to more than 16,000 households and 3,500 small businesses and conducts more than 1,200 water quality tests each year. Water comes from the Tolt watershed for residents living west of the Sammamish River, as well as Redmond Ridge and Trilogy. The rest of the city is served by the city’s shallow aquifer, which is supplemented with water from the Tolt watershed. Because the aquifer is so close to the surface it is considered vulnerable to contamination.
The Tolt reservoir and watershed is located roughly 15 miles east of Redmond in the Cascade Mountains. Water is filtered and treated before traveling through pipelines to Redmond, other Eastside cities and ultimately Seattle, which owns the watershed. Redmond is a member of the Cascade Water Alliance, which buys water for use in the city.
Common sources of water contaminants include pesticides, germs and organic materials. However, the Tolt watershed and aquifer tested well below levels which pose a risk to humans. A range of contaminants were tested for, including arsenic, chlorine, barium and chromium.
The city treats its water with fluoride to promote dental health as well as chlorine to keep harmful bacteria from thriving. Additionally, Redmond has been treating water to minimize corrosion in household plumbing since 1983 to head off potential lead risks. Lead used to be a common material for home plumbing and can lead to serious health problems. Lead testing is conducted every three years, with the last one in 2015 showing there was no lead in the water supply. The next test will be conducted this year.
Redmond’s leakage was also low, sitting at seven percent in 2017, lower than the 10 percent maximum allowed under state law.
Earlier this year, the Redmond City Council put a moratorium on using reclaimed water in parts of the city to protect the shallow aquifer, which at some points is only five feet beneath the ground. City staff recommended the moratorium largely due to a lack of scientific data showing that reclaimed water, once it entered the city aquifer, would be safe to drink.
Residents can help ensure water stays clean by properly maintaining their vehicles to prevent fluid leakage, limiting the use of fertilizers and pesticides and properly disposing of hazardous products like antifreeze and vehicle fuels and oil.