The lack of familiarity of officials was consequential at Berea College, where Hellmuth + Bicknese (H+B) of St. Louis, Mo., is designing a 120-bed dormitory. The discharge collected from the project’s proposed composting toilets would qualify as on-site treatment, and also would offset the Kentucky institution’s fertilizer expense for its agricultural land, says Dan Hellmuth, H+B principal. But after meeting local, county, and state officials, the project team had to present before the state plumbing review committee.

When the committee tried to compare composting toilets to conventional plumbing—which is like “comparing apples to oranges,” Hellmuth says—red flags were raised. In the end, the committee did not approve the graywater or blackwater treatment systems.

Distributing reclaimed graywater for nonpotable uses, such as underground or drip irrigation or flush water in toilets, is a more manageable process. Design requirements include increased signage, restricting access to water supply, dying reclaimed water, and integrating an infrastructure system with approved backflow devices.

Many more restrictions come into play if projects want to supply potable water. “In Oregon, a building owner or entity would have to become a licensed water district,” Gray says. “You fall underneath all the administrative, testing, and reporting requirements because you become a public-water supplier.”

As a result, health and public-safety officials can mandate weekly or even daily water testing by a licensed technician—an expense that some projects cannot shoulder. Even the method of potable water treatment comes under scrutiny. The LBC does not permit the chemical treatment of water, such as chlorination, preferring instead ozone or UV treatment, reverse osmosis, or microfiltration. But because these latter methods leave no traceable residual in the water, health department officials cannot easily measure water quality. Installing redundant, non-chemical treatment systems is one way to seek a variance, Muñoz says, but the approval process may take six to 18 months with no guaranteed outcome.

Because every jurisdiction differs, navigating the regulatory matrix is challenging even for net-zero-water veterans. To start, Worthen recommends researching the local infrastructure and policies. Teams should gather information on reclamation and treatment systems as well as sizing and maintenance data. For the Phipps CSL, Minnerly says, “We had to demonstrate what it means to meet the net-zero balance. You want to make sure you don’t overcharge your system, and understand what happens if the system breaks down.”

Collaborating with consultants and regulatory officials very early in the design process is essential. “Your biggest asset is your skill to negotiate with and understand code officials, their requirements, and how they’re going to apply their local laws and statutes,” Gray says. Muñoz recommends “communicating the goals of the project and giving the regulator the opportunity to help you achieve those goals.”

Despite the mountain of regulations, change is in the air. Some local codes now reference packaged water-treatment systems on the market, and the International Plumbing Code lists two composting toilet products as approved fixtures, Muñoz says. Officials may sanction these preapproved systems and fixtures quicker than other products, though site-specific treatment systems such as constructed wetlands don’t yet qualify.

“My job gets easier every day because more design professionals and clients push for changing the laws,” Muñoz says. As more net-zero-water projects come online, officials have more case studies to assure them that nature’s waste and wastewater treatment systems in commercial settings can, in fact, work.