Instead of letting all that water in your washing machine drain to the sewer, why not redirect it to irrigate your lawn and flower beds?

Reuse of household gray water to stretch limited water supplies is seen as one tool to handle drought and a drier climate. But you need a permit, so to speak.

Colorado has set up regulations to allow for a variety of water reuse opportunities, and La Plata County is considering adopting the one that taps into your laundry room.

“As water supplies get tighter, we need to look for more ways to use the supply more efficiently, whether it is conservation, increased efficiency or reusing the water,” said Peter Butler a water expert and moderator of the Southwestern Water Conservation District annual seminar March 31 at the Sky Ute Casino in Ignacio.

The conference, attended by 270 people, featured a panel that took a deep dive into the world of treating wastewater and using it again.

Brandi Honeycutt, environmental specialist with Colorado Department of Health and Environment’s Water Control Division, provided a crash course on water reuse regulations.

“Water reuse is a broad term to talk about reusing water more than once for beneficial purposes, such as nonpotable purposes like agriculture irrigation, landscape irrigation, cooling towers and toilet flushing,” she said.

Converting wastewater into potable use for drinking, bathing and cooking also is possible and safe, she said.

Water reuse generally fits into two broad categories: potable and nonpotable.

Potable reuse of wastewater is tightly regulated and requires treatment to remove pathogens and contaminates to protect the environment and public health.

Gray water is a form of nonpotable reclaimed water that does not have as many organic contaminates; for example, water from showers, bathroom sinks, washing machines and sinks.

The CDPHE Water Quality Control Commission has three main regulations for water reuse.

Regulation 84 is for reclaimed water, Regulation 86 is for gray water and Regulation 11 maintains Colorado’s primary drinking water regulations, including the new Direct Potable Reuse Rule, which went into effect in January.

Gray water systems have to be locally enforced, so governments have to adopt an ordinance that complies with Regulation 86, Honeycutt said.

Molly Morris, Home H2O Program Manager at Four Corners Office for Resource Efficiency, explained a project in partnership with La Plata County to adopt a portion of Regulation 86 for a “laundry to landscape” gray water system in the unincorporated county.

4CORE was awarded funding from the Colorado Water Conservation Board to support a new gray water regulation, which has support from the La Plata County Commission, Morris said.

A draft regulation is under review by the county manager. If passed, Durango, Bayfield and Ignacio could opt in on the regulation specific to redirecting washing machine water toward landscaping irrigation, rather than down the drain.

“This is the first step. Unincorporated La Plata County then work with towns to develop (a memorandum of understanding) to opt in,” Morris said. “We are going with the most easily implemented category, simple laundry to landscape.”

There is potential the new regulation could add reuse of laundry sink water for landscaping, but whether that will be included is to be determined.

The project will create a design manual for operations and maintenance of laundry to landscape systems in residential settings.

A pilot project installation is planned to demonstrate the system and to provide education about gray water systems and regulations.

The system is relatively straightforward. The washing machine drain would be reconfigured to redirect the wastewater into the yard. Use of environmentally safe soaps and detergents are part of the process.

The planned system calls for the untreated gray water to be released into mulch basins and not holding tanks.

“We’re excited and (if passed) it would be one of a handful of Colorado communities to do this,” Morris said.

According to the Southwest Basin Implementation Plan, the region uses 198 gallons of water per capita per day, higher than the statewide average of 164 gallons per capita per day.

“This shows we have some room for conservation and efficiency in our area,” Morris said.

In addition to support from La Plata County and CWCB, the project is also supported by San Juan Basin Public Health, and Western Water Resources Advocates.

The topic of water reuse has led to questions about its potential impact for downstream water rights, Butler said.

Under Colorado prior appropriation doctrine, water users have a right to divert a certain amount of water for consumptive use. Some of that water becomes return flow that is relied on by the next downstream water user.

“Reusing some of the return flow increases consumptive use, and of course the downstream user is depending on that water, so there may be some conflict on being able to utilize a water right more consumptively,” Butler said.

Morris said the county laundry to landscape project has worked with the Division of Water Resources regarding possible impacts on water rights, and it appears most rural providers are within their rights to participate.

jmimiaga@the-journal.com