Southgate Water and Sanitation District

Where does your water originate? Denver's municipal water comes from rivers, lakes, streams, and reservoirs fed by pristine mountain snow melt. Denver Water's supply is 100% surface water that originates from watersheds encompassing 4,000 square miles on both sides of the Continental Divide.

Mountain Water Resources
Denver Water's primary sources include the South Platte River and its tributaries, streams feeding Dillon Reservoir, and waterways above the Fraser River. The utility stores water in five mountain reservoirs: Antero, Eleven Mile Canyon, Cheesman, Dillon and Gross. From these collection points, water travels to one of three treatment facilities via an intricate network of streams, canals and pipelines.

After processing, drinking water flows through both gravity systems and pumps to underground clean-water reservoirs before reaching homes and businesses. The distribution network spans over 3,000 miles of pipeline throughout the service area.

Source Water Assessment
Colorado's health department has completed a source water assessment examining potential contaminants reaching Denver Water's three terminal reservoirs at Strontia Springs, Marston and Ralston. Possible contamination sources include: EPA Areas of Concern, Permitted Wastewater Discharge Sites, Storage Tank Sites (Above/Underground/Leaking), Solid Waste Facilities, Mining Operations, Commercial/Industrial/Transportation facilities, Residential Areas, Recreational Lands, Quarries, Agricultural Activities, Forests, Septic Systems, Oil/Gas Wells and Roadways.

For additional information about this assessment, please contact the Colorado Department of Public Health and Environment at 303-692-2000.

Water Quality Commitment
Denver Water proudly serves high-quality water to 1.4 million residents in Denver and many surrounding communities. Since 1918, we've expertly planned and operated a sophisticated system delivering clean, safe, great-tasting water. Our program operates as a public enterprise funded through water rates, tap fees and hydropower sales—not taxes.

As Colorado's oldest and largest water utility, Denver Water manages a service area exceeding 360 square miles. We provide 25% of the state's population with less than 2% of all water consumed statewide. We protect our natural environment by promoting water conservation.

Water quality remains our highest priority. Last year, we collected over 35,000 samples and conducted more than 68,000 tests ensuring water safety and cleanliness. Denver Water vigilantly protects mountain water supplies, with careful treatment before delivery to your tap.

The Treatment Process
Our water undergoes five critical steps:

1. COAGULATION/FLOCCULATION: Raw water from reservoirs enters mixing basins where we add alum and polymer, causing small particles to combine into larger particles.
2. SEDIMENTATION: These larger particles become heavy enough to settle at the basin bottom for removal.
3. FILTRATION: Water passes through layers of fine materials (sand or sand/coal combinations) removing smaller suspended particles and reducing turbidity.
4. DISINFECTION: To protect against remaining microorganisms, disinfectant is added before water flows into underground reservoirs and throughout the distribution system.
5. CORROSION CONTROL: pH is adjusted with alkaline substances to minimize corrosion in distribution pipes and household plumbing.

All drinking water, including bottled varieties, may reasonably contain small amounts of some contaminants. Their presence doesn't necessarily indicate a health risk. For more information about contaminants and potential health effects, contact the EPA's Safe Drinking Water Hotline (800-426-4791).

Special Health Considerations
Some individuals may be more vulnerable to water contaminants than the general population. Immunocompromised persons—including cancer patients undergoing chemotherapy, organ transplant recipients, people with HIV/AIDS, some elderly individuals, and infants—may face increased infection risks. These individuals should seek advice about drinking water from their healthcare providers. EPA/CDC guidelines on reducing Cryptosporidium and other microbial contaminant risks are available from the Safe Drinking Water Hotline (800-426-4791).

Lead in Drinking Water
Since 1992, Denver Water has tested water in homes throughout its distribution system considered at risk for lead and copper contamination, following EPA protocols. Denver Water's source water, treated water, and distribution system water contain no detectable lead and only trace copper levels.

Lead can enter water through lead-containing household plumbing. Softened water more aggressively affects household pipes. Homes built before 1951 may have lead service lines connecting the water main to the house. Pre-1987 homes may contain lead solder in their plumbing (banned in 1986). Newer homes generally have lower lead contamination risk.

Lead exposure can cause serious health problems, especially for pregnant women and young children. While Denver Water provides quality drinking water, we cannot control materials used in plumbing components. After water sits for several hours, minimize lead exposure by flushing your tap for up to three minutes before using water for drinking or cooking. If concerned about lead, consider water testing. Information about lead in drinking water, testing methods, and exposure reduction is available from the Safe Drinking Water Hotline or at epa.gov/safewater/lead and denverwater.org/Lead.

Cryptosporidium and Giardia Testing
Denver Water has monitored for Cryptosporidium and Giardia in both raw and treated water since the 1980s. We have never detected viable organisms in the treated drinking water. These microscopic organisms can cause gastrointestinal symptoms (diarrhea, cramps, fever) when ingested, though they typically spread through means other than drinking water.

These organisms appear in many Colorado waterways due to animal waste in watersheds. Our treatment facilities remove Cryptosporidium through effective filtration, while both filtration and disinfection eliminate Giardia.

Municipal Water Sources
Sources include rivers, lakes, streams, ponds, reservoirs, springs, and wells. As water travels over land or underground, it dissolves naturally occurring minerals and sometimes radioactive material, while potentially picking up substances from human activity and animal presence. Potential contaminants include:

• Microbial contaminants – viruses, bacteria and microbes from sewage treatment, septic systems, agricultural operations, and wildlife
• Inorganic contaminants – salts and metals (naturally occurring or from urban runoff, wastewater discharges, oil/gas production, mining, farming)
• Pesticides and herbicides – chemicals from agricultural runoff, urban stormwater, and residential usage
• Organic chemical contaminants – synthetic and volatile compounds from industrial processes, petroleum production, gas stations, urban runoff, and septic systems
• Radioactive contaminants – naturally occurring substances or byproducts of oil/gas production and mining activities

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