Water treatment in Denver, CO

Denver Water meets every federal and state standard — surface supply from the South Platte and Colorado River headwaters, treated and disinfected with chlorine. But chlorine residual is on by design, disinfection byproducts form in the main overnight, and the older in-fill neighborhoods — Capitol Hill, Five Points, Park Hill, Washington Park, Highland, and Baker — carry pre-1986 copper with lead solder and brass that pick up trace metals. A real on-site test is the only way to know.

Denver Water's supply runs moderately hard out of the plant — about 97 mg/L — and climbs higher inside older homes from mineral pickup in service lines. The contaminants the city's reports surface most often are haloacetic acids (HAA5), total trihalomethanes, chloroform, lead (from solder and brass in older homes, not the source), and naturally occurring radium in the South Platte headwaters granite. The 2016 E. coli boil-water advisory proved distribution events happen. On rare well-driven properties on the city edges, iron, manganese, occasional arsenic, and coliform after heavy rain round out the list.

For homes on the Denver Water supply, test at least yearly for hardness, chlorine residual, pH, total dissolved solids, lead and copper (especially if your home was built before 1986), and any radium you want confirmed against the city's number. For rare well-driven properties on the city edges, test annually for coliform, nitrates, iron, and manganese, plus an arsenic check where the alluvium runs that way. Retest after a major storm, after a boil-water advisory, after work on the well or plumbing, and after remodeling in a pre-1980 home where you disturbed solder.

Most do. Denver Water's finished supply comes out of the plant at about 97.3 mg/L (5.7 gpg) — moderately hard on the USGS scale. Inside many homes the working hardness climbs higher from mineral pickup in older service lines and the long runs to the in-fill neighborhoods. You'll see it as scale on faucets and shower glass, spotting on glassware, and wear on water heaters, dishwashers, washing machines, and ice makers. A properly sized ion-exchange water softener removes the calcium and magnesium that drive the damage. Salt-free conditioners help with scale control but do not pull the hardness minerals out.

Yes. Our Denver Metro office at (303) 248-3390 covers Denver and the inner-ring communities — Lakewood, Wheat Ridge, Englewood, Arvada, Westminster, Thornton, Commerce City, Aurora, and Centennial — with techs running scheduled routes along the I-25, I-70, and I-76 corridors year-round. On-site testing, softener and reverse osmosis installs, and filtration work on older in-fill homes with pre-1986 plumbing are routine, and well-edge properties see regular service. Statewide dispatch out of four regional offices covers anything further out.

For most Denver homes, yes. Denver Water meets standards at the plant, but chlorine residual, disinfection byproducts, trace metals from older plumbing, and naturally occurring radium are still present at the tap to some degree. A reverse osmosis system pulls those down to drinking-water levels at the one tap your family drinks from. An under-sink RO unit with a carbon stage ahead of the membrane is the standard setup for Denver Water supply homes. For outer-well properties on the city edges, RO also handles nitrates and any arsenic the well delivers.