Castle Rock, Colorado, USA – Operating Raw Water Augmentation with plans for direct potable reuse
Reuse water in Castle Rock, Colorado, USA.
Changes in population and climate are affecting water supply and demand throughout Colorado requiring the Town of Castle Rock to secure additional water supply sources. Castle Rock is one of the fastest growing communities in the nation and its 2022 population of 85,000 and is expecting to reach more than 120,000 by 2050.
In 2006, Castle Rock Water began planning for and implementing projects to secure a strong water future. Supplementing the deep aquifer groundwater supply, Castle Rock Water began using the local Plum Creek in 2013 and importing WISE water from other areas in 2018 (Water Infrastructure and Supply Efficiency (WISE) is a partnership between Denver Water, Aurora Water and 10 South Metro water providers to provide a sustainable water supply).
In 2020, Castle Rock Water began utilising reuse water. Reuse water will constitute about 1/3 of the entire supply for the community and is one of the most economical, sustainable and environmentally-sound options available to the Town.
Currently, Castle Rock’s reuse water is indirect as it is released from the wastewater treatment plant into Plum Creek before being pumped out and back to the drinking water purification facility. With the investment of $40 million for the Advanced Treatment addition to the purification facility, indirect and direct potable reuse were not delineated to the public. In 2022, Colorado instituted Direct Potable Reuse regulations, of which Castle Rock Water provided input. Plans are currently being drafted for direct potable reuse in which the direct pipe will simply be identified as an improvement to the reuse system.
The Advanced Treatment processes added in 2020 include a raw water blending tank, ozonation, granular activated carbon, ultraviolet radiation and biologically active carbon filtration. These were added to the existing treatment of aeration, flocculation and sedimentation, microfiltration and chlorine contact. Open house events and tours of Plum Creek Water Purification Facility are available to the public.
Related resources:
Castle Rock Water provided extensive outreach that was focused on the need for a diversified water supply, one of which was reuse water. Along with open houses and tours of Plum Creek Water Purification Facility, mailers, social media and billing newsletters provided education over the course of several years. A webpage, Reuse Water | Castle Rock, CO – Official Website (crgov.com), provides updated information along with a series of videos explaining the need, benefits and safety of reuse water.
What is reuse water (Fact sheet)
Why is purified reuse great for Castle Rock?
How safe is reuse water? (video)