On Nov. 14, the state’s Water Quality Control Commission (WQCC) members gave final approval to regulations that pave the way for treated wastewater from sanitation districts to be used as drinking water. The measure had won unanimous provisional approval by the commissioners at its October meeting. The WQCC is the administrative agency under the Colorado Department of Public Health & Environment that is “responsible for developing specific water quality policy” in the state.
The process is known as direct potable reuse (DPR), where wastewater that has been treated in the conventional way at a sanitation plant is subjected to further purification and filtering that brings the effluent up to potable (drinking-quality) level. It can then be recirculated into municipal water systems.
The standard process for handling wastewater in Colorado is that, after an appropriate level of treatment, it is returned to a river, stream or reservoir or is injected into the ground. In that way, the discharge mixes with “raw” surface water or groundwater, which then acts as an environmental buffer. Downstream from those discharge sources, the combined flow can become a source for drinking water after it is suitably treated at a municipal waterworks, a process called indirect potable reuse (IPR).
The sanitary districts of each of the three main communities along the Roaring Fork River — Carbondale, Basalt and Aspen — all discharge treated wastewater into the river. None uses water directly from the Roaring Fork in its water supply, but the water systems of Basalt and Carbondale obtain part of their water from wells driven into the Roaring Fork alluvium (accumulated sediments along the river bed).
The process leading up to WQCC’s approval of the new rule on DPR was several years in the making. Tyson Ingels, the lead drinking water engineer on staff at the WQCC, told The Sopris Sun that the final decision came from a 2021 informal stakeholder process that was “built on four to five years of earlier work” by highly skilled experts in the field. He continued, “I’m really proud of the amount of collaboration and good will from stakeholders and professionals … we really relied on a lot of expertise from them.”
Laura Belanger, a water reuse specialist and policy advisor at Western Resource Advocates who was involved in the WQCC’s process, echoed Ingels’ sentiments. She told The Sun that it was a “well-crafted regulation” and “a super collaborative effort” that was “very transparent and included a lot of one-on-one with affected communities.” She continued, “We’re really excited about this new regulation,” which will “help meet the gap between supply and demand,” especially on the Front Range.
Ingels elaborated on the process to finalize the regulation. Now that it has been formally adopted by the WQCC, it is being sent to the Secretary of State’s office, which will then publish it. Following a 20-day period after publication, the regulation will become official. Ingels did note that the new rules are completely optional for a city or town and are in place to guide the process for adopting a DPR system. He mentioned that the agency has not yet received any applications.
It seems likely that the development of any early DPR systems will be in the densely populated Front Range urban corridor, where economies of scale will be an important factor for the considerable investment required. Mark O’Meara, utilities director in Carbondale, told The Sun that DPR was an “ongoing debate,” but that, “We don’t have anything in the pipeline … the infrastructure to do [DPR] would be significant.”
In an email to The Sun, Nathan Nelson, treatment manager at the Aspen Consolidated Sanitation District, stated that DPR was “the future of wastewater treatment.” He went on, “I can see it happening in Aspen if the never-ending drought and dwindling snowpack forces us to reuse wastewater and treat it to potable standards.”
And then there is the “ick” factor, the notion that one may be drinking water derived from sewage. Belanger emphasized the importance of reaching out early to the community (including non-English speakers), and making it clear that the use of DPR is really no different from the growing number of IPR systems in use throughout Colorado.