Water Treatment Process

Renewable water
The Town has set a goal of using 75 percent renewable water by the time the Town reaches build-out population of about 100,000 residents. Several projects are currently underway, or planned, to help meet that goal.

Plum Creek project

Plum Creek Water Purification Facility is a Legacy Water Project. It opened in 2013 to treat renewable water from East Plum Creek for the Town’s use. The Town began preparing to use this renewable water in fall 2012. This change means a necessary switch from chlorine to chloramine for the Town’s water distribution system.

Purification process

Currently, all of Castle Rock’s water comes from nonrenewable wells - some as deep as 2,000 feet. Because the water comes from such depths, chlorine is enough to disinfect the water. Renewable water sources that are either surface waters or connect with surface waters (e.g. shallow groundwater along Plum Creek), however, contain natural organic matter that can cause the formation of disinfection byproducts when disinfected with chlorine. Using chloramine in place of chlorine reduces these environmental impacts.

While this process is new to Castle Rock customers, many municipal and private water providers across the United States and Canada have used this safe, effective disinfectant for more than 90 years. Denver and surrounding communities, for example, have been using chloramine to treat water since 1917, because they have renewable water systems that require this process. We are working toward the same goal - to secure long-term renewable water resources.

The chloramine disinfectant offers numerous benefits, including:

  • Decreased production of harmful byproducts that could be present when treating renewable water with chlorine
  • Enhanced water taste and smell
  • Prolonged residual strength (meaning the disinfectant lasts longer in the system, protecting your water from the time it leaves the water plant to when it enters your home)
Like chlorine, chloramine can impact kidney dialysis treatment, aquatic life, and business and industries that rely heavily on highly processed water. In addition, older homes with lead plumbing may experience a lead increase in drinking water for a short time period. For more specific information, visit the Environmental Protection Agency's Chloramines


Call 720-733-6000 or email us if you have any questions or comments.