Frequently Asked Questions
About Denver Water's
Recycled Water Project
Recycling wastewater to a high standard for commercial, industrial and irrigation purposes is a proven technology. Federal legislation enacted in the 1950s established wastewater guidelines, and treatment programs spread across the nation. Denver Water’s new recycling system joins more than a dozen others already operating in Colorado. The water from our treatment plant in Commerce City doesn’t meet drinking water standards, but it is suitable for irrigation, commercial applications, lakes and wildlife refuges. At full capacity, the plant can produce about 19,000 acre feet of recycled water. By satisfying the part of Denver's water needs with recycled water, the plant will free up drinkable water to serve 40,000 households each year.
Here are some answers to frequently asked questions about recycled water:
What is recycled water?
Recycled water is wastewater treated to a standard suitable for uses other than drinking. It satisfies Colorado Department of Public Health and Environment guidelines for specific, non-potable uses, usually industrial applications and outdoor irrigation.
Why reclaim wastewater?
Denver Water owns rights to a significant amount of water that the Metro Wastewater Reclamation Plant treats and discharges into the South Platte River. Before the Recycled Water System, this water was lost downriver. The water recycling plant treats our share of the water released by Metro Wastewater and provides it to customers for non-potable uses. The Colorado Department of Public Health and Environment enforces state regulations governing the recycling process just as it does the regulations governing the treatment of drinking water. Water from Denver Water's recycled water treatment plant exceeds government standards for irrigation use.
Where is the plant?
The treatment plant is located in Commerce City, a stone’s throw from its source, Metro Wastewater, and a key customer, Xcel Energy. Operations began early in 2004.
Who gets the water?
The system serves customers along a corridor extending from the plant to the south-central portions of the city. Xcel Energy’s Cherokee power plant uses recycled water for cooling purposes. Other destinations are Swansea, Dunham and Schafer parks, Bruce Randolph Middle School, the Denver Zoo, and the Park Hill and City Park golf courses. City Ditch carries the recycled water back north, channeling it to the the Denver Country Club and lakes in Washington Park and City Park.
Later, the system will be expanded to include more customers, notably the Stapleton and Lowry development sites and the Rocky Mountain Arsenal National Wildlife Refuge. Additional pump stations and a storage reservoir are being constructed to extend the system's reach east.
Why not build a dam instead?
Recycling water extends Denver’s current water supplies farther into the future. Building a recycling treatment plant is less expensive and has fewer environmental impacts. At full capacity, our new treatment plant will save about the same amount of water that a small dam and reservoir would hold.
How safe is recycled water?
Although there are no known cases of people getting sick from ingesting it, recycled water doesn't meet drinking water standards and shouldn't be consumed. The water is treated to a quality higher than required by state regulations for body contact. Pets also won't suffer ill effects from occasional contact or ingestion.
How is recycled water different than drinking water?
It's treated essentially the same – coagulation, sedimentation, filtration and disinfection – but to a lesser degree. The recycled water is treated to make it non-corrosive before it is sent to commercial customers, and water headed for park lakes is de-chlorinated to protect aquatic life. However, some contaminants absent in drinking water might persist in recycled water, and concentrations of disinfection byproducts and nitrates are likely to be higher.
How will I know if water I see sprinkling parks and other outdoor spaces is drinkable water or recycled water?
Places using recycled water will be clearly marked with irrigation signs identifying the water as recycled. Valve boxes and some sprinkler heads will be colored purple.
How much will recycled water cost and how will it be paid for?
The rates for recycled water are lower than rates for treated water.
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The Purple Pipes |
Can recycled water get mixed up in the drinking water system?
Denver Water has taken great care during the design and installation of the recycled water system to ensure that recycled water and drinking water are kept separate. Recycled water is carried in new, separate pipes that are distinctly purple. Pipes for recycled water are installed lower than drinking water pipes, so that recycled water cannot leak into the other system. There will be no direct interconnections or cross connections between the two systems. Air-gap connections will allow potable water to be injected into the recycled system in emergencies. The air gap makes it impossible for recycled water to enter the drinking water system.
Still have questions?
Call Joe Sloan at 303.628.6320.
