Centennial, Colorado’s Home for Water Softeners, Water Filters,
& Water Delivery

Yes. Centennial’s drinking water meets federal and state drinking water standards. The city completes required testing for regulated contaminants, and results are reviewed to confirm compliance with Safe Drinking Water Act requirements.

Yes. Centennial’s tap water is considered moderately hard, with average hardness levels of approximately 113 parts per million (ppm) as calcium carbonate, and reported ranges from about 56 to 154 ppm. Water in this hardness range can contribute to scale buildup on fixtures, appliances, and plumbing, reduce soap efficiency, and leave residue on glassware and surfaces.

Recent sampling for Centennial, Colorado drinking water detected the presence of PFAS chemicals. The EPA is in the process of setting new maximum contaminant levels (MCLs), which range from 4 to 10 parts per trillion, equal to 0.00000000004 for PFOA and PFOS individually, and up to 0.0000000001 for PFNA, PFHxS, and HFPO-DA (GenX chemicals). As you can see in the water quality report, many samples do not meet these standards. Click here to learn more about our whole house PFAS filtration systems.

Yes. Fluoride is present in Centennial tap water at an average level of approximately 1.0 ppm, which is below the EPA maximum contaminant level of 4.0 ppm. Fluoride enters the water through natural erosion of mineral deposits and is monitored regularly as part of routine water quality testing.

Centennial’s drinking water is supplied by a combination of groundwater and regional water sources, including shallow and deep aquifers in the Denver Basin, along with water treated at the Joint Water Purification Plant (JWPP) through partnerships with neighboring water districts. Source water originates from groundwater wells, alluvial aquifers near Cherry Creek, and imported supplies, providing a diversified and resilient supply system for the region.

Centennial’s drinking water is treated using multi-step treatment processes that include coagulation, sedimentation, filtration, and disinfection. Treatment is performed through regional purification facilities, including the Joint Water Purification Plant (JWPP), which provides advanced treatment designed to remove sediment, organic material, pathogens, and chemical contaminants before water is disinfected and distributed to homes and businesses.

Many Centennial homeowners choose water treatment systems due to moderately hard water levels (56–154 ppm), which can contribute to scale buildup in plumbing, appliances, and fixtures. Additional filtration is also commonly used to address taste, odor, sediment, and trace contaminants, including disinfection byproducts and emerging contaminants such as PFAS.

Centennial’s water providers operate an extensive monitoring program that includes routine sampling throughout the distribution system, covering disinfectants, metals, inorganic contaminants, radionuclides, organic compounds, and unregulated contaminants. Hundreds of samples are collected annually and analyzed at state-certified laboratories, ensuring compliance with the Safe Drinking Water Act and early detection of potential water quality issues.

You can access the most recent Centennial’s Tap Water Quality Report here.