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Simple & Effective Gravity-fed Greywater Harvesting Systems Legalized in Utah

—and How You Can Help Make Such Change Where You Are

By Brad Lancaster

Utah has recently revised its rules for greywater harvesting systems to allow for residential households to permit, install, and use simple, affordable, and effective branched drain gravity-fed systems discharging to naturally-filtering mulched and vegetated basins in the landscape.

This should greatly benefit Utah, which is the second driest state in the U.S., and has the second highest water-use-per-person rate in the county.1

While advocating for the greywater rule change, Utah activists Ros Brain McCann and Jeffrey Adams pointed out in numerous presentations to state and county health officials that if every household in Utah were to harvest all its greywater (to offset other on-site irrigation uses of water) the greywater could potentially create a “new” water source (in the form of the harvested greywater) in the state equaling 68,000 to 98,500 acre-feet of water per year.

An acre-foot is the amount of water it takes to cover an acre of land with a one-foot depth of water. One acre-foot = 325,851 gallons2


The math:
The average household of 3 people generates 25,000 – 36,600 gallons of greywater per year+

This represents 1 acre-foot of “new” water supply per every 9-13 households using greywater (assuming they use all greywater to offset other on-site irrigation uses)

With 866,770 households* = 68,000 – 98,500 AF of potential!


+Ludwig – Creating an Oasis with Greywater



Greywater, dark greywater, and blackwater
Greywater is lightly used water going down the drains of household showers, bathtubs, laundry, and bathroom sinks, which can be redirected to your landscape and reused, thereby transforming that “waste” water into a free “resource” for irrigating your landscape.

Kitchen sink drain water is considered either dark greywater or blackwater (classification changes depending on the entity classifying the water) due to the presence of food scraps, oils, and grease and the resulting bacteria which necessitate different strategies for reuse than greywater. For a kitchen sink drain water reuse system legal in Arizona, see “Sizing and Implementing a Kitchen Resource Drain (KRD) in Arizona, Code Clarification, and Recommended Changes to the Code” in Appendix 3 of Rainwater Harvesting for Drylands and Beyond, Volume 2, 2nd Edition.

Toilet drain water is coined blackwater due to human waste, and high amounts of resulting bacteria such as E. coli which makes it much more challenging to treat than greywater.


Comparing Utah’s old rules to the new rules
Under Utah’s old rules, the greywater permit cost $350, and you were required to install a system with a minimum 250-gallon surge tank and pump. This storage of the greywater in tanks is problematic, because when you do so—the greywater goes septic, bacteria populations soar, and the tanked greywater becomes blackwater—which smells horrible and is more difficult to safely treat and reuse than the much more benign greywater. Tanks and pumps also significantly increase the cost, maintenance, and potential failure of the system.

Under Utah’s new rules, the Tier 1 greywater in southeast Utah costs $100 for a gravity-fed branched-drain greywater system discharging into mulched and vegetated basins in the landscape (cost may vary depending on health department district in Utah). No tank or pump required.

But the new rules do NOT, as of yet, allow the Laundry to Landscape (L2L) system.

For a description of the rule change see Utah State University Extension Sustainability’s Graywater Systems

KZMU radio story on revising the greywater laws in Utah:

Utah Center for Water Efficient Landscaping, Youtube power point presentation:
Greywater in Utah – Roslynn McCann and Jeff Adams, June 2020


How a few people led the way for state-wide change

After taking a 2014 Watershed Management Group water harvesting certification course in Albuquerque, NM taught by Brad Lancaster, Catlow Shipek, and Jeffrey Adams—Ros Brain McCann, Sustainable Communities Specialist at Utah State University, returned home determined to set up a greywater harvesting system in the straw bale house she was building in Moab, Utah. 

But she was soon frustrated by the Utah greywater rules at that time, which were dysfunctional and prohibitive to the point that not a single residence in the state had ever applied for a permit. The rules did not allow for affordable, easy-to-use and easy-to-maintain gravity-fed branched drain greywater systems (which were legal in Arizona and New Mexico) that she had learned about in the water harvesting course.

So, Ros approached Orion Rogers of the Southeast Utah Health Department and shared with him the simpler, safer, less expensive, and more effective systems she’d just learned about in the water harvesting course. Orion was intrigued, as the gravity-fed greywater systems looked simpler to him, and they’d be affordable to the many low-income households of Grand county; whereas the costly and complex systems permitable at the time in Utah were not affordable.3

Orion asked Ros to present her idea at a 2015 conference of the Utah Environmental Health Association where all Utah’s health departments would be represented. But just before the meeting Ros had complications with a failed pregnancy and asked Jeffrey Adams—one of the instructors from Ros’ water-harvesting course and owner of the ecological design company TerraSophia LLC,—to take her place for the presentation. The presentation intrigued many of the health department officials and they allowed Ros to apply for an experimental greywater harvesting permit so her house could become a pilot project, which was followed a few years later by another low-income straw bale house being built by Community Rebuilds in Moab. (After I taught a 2013 water-harvesting course for Community Rebuilds, they have been installing greywater-harvesting stubouts in their homes since 2014 waiting for the day affordable greywater harvesting would be legalized.

Jeffrey Adams designed Ros’s greywater-harvesting system and designed and built the second permitted system being sure to properly size both for each site’s soil type and percolation rate, the expected household output of greywater, and the residents’ projected irrigation needs.

Jeff also excavated the greywater-harvesting basins and did some of the basin bank-stabilizing rockwork for Ros’ system. Ros and her husband Dan installed the plumbing, planting, and the rest of the rockwork.

The system is beautiful and productive—an outstanding example for the community and the state—as it is well stewarded by Ros and Dan (see figures 1 and 2).


Figure 1. Passive rainwater and greywater-irrigated (from shower and laundry) fruit trees and understory plants in the north-side landscape of Roslynn Brain McCann’s family home, Moab, Utah. Photo credit: Roslynn Brain McCann


Figure 12. Passive rainwater and greywater-irrigated (from shower and laundry) fruit trees and understory plants in the north-side landscape of Roslynn Brain McCann’s family home, Moab, Utah. Photo credit: Roslynn Brain McCann


Ros’ site has had a big impact. She enthusiastically gives tours when Orion and many others ask. Through first-hand observation, health officials immediately understood the simplicity and effectiveness of her greywater system. And health officials from all of Utah’s counties toured Ros’ system just before voting to approve the greywater rule change that went into effect January 1, 2020.

Now that the plants of Ros’ greywater harvesting basins are well established, she does not need to apply supplemental irrigation. Passively harvested rainwater and household greywater take care of all the plants’ water needs, and those plants are now providing a cherished food source for her household, ranging from cherries to currants. No virgin drinking water straight from the municipal water supply is used to irrigate her system.

She has also found it possible to continue running her greywater system throughout winter and hard freezes (household greywater leaves the house at the home’s interior temperature – well above freezing).

This is a great example of the power of a few striving for positive change. Ros had no experience or comfort in changing policy when all this began in 2014. But since the state policy did not allow her to better manage water on her site in an affordable way that would also benefit the larger community, she decided the policy had to be changed. And this process has taught her that anyone can make such change when you pull the right team of people together.

Though Orion adds, “It will likely take longer than you think. It took three years longer than I expected. But you just keep picking away at it. Have persistence. Things happen, such as staffing turn overs that put things on hold. It’s not so much changing minds, but getting through all the committees and reviews, clarifying language in the rules, sharing information, and clarifying language in the rules, sharing information, and getting everyone on same page. And in this case, it wasn’t just writing in rules for the branched drain system, but reworking the entire greywater rule.”4

Orion then pointed out that there are still others to thank, for example, Orion’supervisor first took the branched drain greywater system to the appropriate committee, then Orion took over when his supervisor retired and Orion got promoted.


The change is spreading

The folks behind the Arroyo Crossing housing development in Moab were inspired by Ros’ system, toured it, and are now requiring greywater-harvesting stubouts in all the development’s homes, and are giving preference to builders that include fully functional greywater systems in the homes they build.

More support also comes in the form of Ros’ husband, Dan, who is a builder/craftsman and home designer who works for an architectural firm designing for Arroyo Crossing, as he too can share his experience of what works.


Though change has also been slowed by Covid-19

Each health department district must opt in to administer the new greywater rule, but as they are all also currently dealing with the response to Covid-19, adoption is going slower than it otherwise would. Nonetheless, so far, three have done so in SE Utah, five in Central Utah, and two in NE Utah—which means the majority of the health department districts in state have now opted in to administer the new greywater rule as of this writing.4

Note that the revised greywater rules have not yet been updated on Utah’s Department of Environmental Quality website because they are building a new one. Thus the new rules are not easily googled…


Are greywater harvesting rules in your state prohibitive?

If so, use the precedent of other states to improve your state’s rules
The state of Arizona helped set some of the groundwork for Utah’s change by, in 2001, being the first state in the nation to allow tank-less, gravity-fed greywater-harvesting systems directing the greywater to mulched and vegetated basins in the landscape. Arizona then improved, simplified, and clarified the regulations with additional revisions adopted January 1, 2018.

For the full story, see the section “How Safe, Effective, and Accessible Greywater Harvesting Was Legalized and Incentivized in Arizona” in Chapter 12 of Rainwater Harvesting for Drylands and Beyond, Volume 2, 2nd Edition by Brad Lancaster.

Utah has made tremendous progress with its recent rule revisions, and I would argue that there is still room to make it significantly easier and less expensive for residents to safely harvest household greywater, such as what Arizona has done with a no cost permit that it is automatically granted without inspection if you follow the state’s 13 common sense guidelines.

What’s more, Arizona also allows the harvest of kitchen sink dark greywater (but for this you apply, and pay, for a permit)—for that story and how-to info see “Sizing and Implementing a Kitchen Resource Drain (KRD) in Arizona, Code Clarification, and Recommended Changes to the Code” in Appendix 3 of Rainwater Harvesting for Drylands and Beyond, Volume 2, 2nd Edition.

Greywater is also more accessible in Arizona because the state allows for the homeowner to design their own system, whereas Utah only allows those who have both a Level 1 certification for Soil Evaluation and Percolation Testing and a Level 2 certification for Design, Operation, Inspection, and Maintenance of Conventional On-Site Wastewater Treatment Systems to design a greywater system.

Though information or methods on how to design a greywater harvesting system for irrigation purposes—so the greywater output is in balance with the water needs of associated plantings—is not currently part of the certification curriculum.4,5 Depending on who you speak to, some may say the primary focus of the Utah code is safe disposal and treatment of greywater, while others may say it’s the safe reuse and treatment of greywater.

Info on how to design your greywater system’s plantings and their water needs in balance with your estimated greywater output is available in:

• The greywater harvesting chapter of Rainwater Harvesting for Drylands and Beyond, Volume 2, 2nd Edition
How to Create an Oasis with Greywater by Art Ludwig
The Water-Wise Home by Laura Allen

One way of educating and incentivizing the public and designers on simpler and more effective greywater systems can include providing free courses on the topic. These are required for those applying for the $1,000 greywater harvesting rebate from Tucson Water in the city of Tucson, AZ.


Nothing is perfect, but we get closer as we keep striving to improve

Arizona’s rule revisions along with those in Utah, New Mexico, California, west Texas, and more can all be inspirations and guides for other states to do likewise or even better. Arizona and New Mexico rules are very similar, while California’s are somewhat more restrictive. Such diverse examples, can help mitigate other states’ policy makers’ fears and lack of knowledge.

When you approach local policy makers to inquire on how to evolve current rules, contact policy makers at both the state, county, and municipal level in multiple departments to see who is receptive, then work with those who are receptive to forge a plan to address the concerns of those who are not currently receptive.





2. Greywater presentation by Jeffrey Adams of Terrasophia LLC and Dr. Rosylnn Brain McCann, Sustainable Communities Specialist Utah State University

3. Personal communication with Roslynn Brain McCann on 11-8-2019

4. Personal communication with Orion Rogers on 8-17-20

5. Personal communication with Jeff Adams on 8-13-20.



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