Marin Municipal Water District looks to update grey water rules
Installing drought-tolerant landscaping or using recycled water for irrigation could become substitutes for grey water systems under a proposal from the Marin Municipal Water District.
The district’s communications and water efficiency committee has endorsed a proposal that will overhaul the grey water ordinance that was adopted in 2016. Grey water is wastewater from bathtubs, showers, bathroom sinks and clothes washers.
The existing ordinance states that applicants seeking new water service, and projects requesting expanded water service for large residential or commercial remodels, must install a grey water recycling system for landscape irrigation.
However, the district allowed customers to self-certify whether a grey water system was feasible, resulting in many owners of eligible sites exempting their properties, staff said.
“What staff is proposing here is to maintain the applicability of the current grey water ordinance,” said Carrie Pollard, the district’s water efficiency manager. “What that means is the threshold that would require someone to comply with the ordinance would be new construction and a substantial remodel.”
“But the real change that we’re looking at here is adding options, so not just saying you have to do grey water,” Pollard said.
A customer could choose to install drought-tolerant plants in all new or rehabilitated planting areas that total at least 500 square feet and use no- or low-volume irrigation.
A customer could install a grey water system or irrigate the site with recycled water, which is required where recycled water is available.
MMWD offers the laundry-to-landscape grey water program to customers to reduce the overall reliance on drinking water for irrigation. The district is working with the Urban Farmer store to offer a $125 discount for customers who purchase a grey water kit.
From 2020 to 2023, 59 grey water kits were incentivized for customers through the partnership.
Depending on system complexity, costs range from $1,500 for a laundry-to-landscape system to over $16,000 for a comprehensive, full-home system, according to the district.
Water savings from grey water systems range from 4,400 to 29,200 gallons per year, depending on the type of system, the district reported.
The change is part of a suite of proposed water efficiency incentives and policy updates in the district’s draft 2024 water efficiency master plan that is under development.
The committee’s endorsement also applies to a plan to sunset the high-efficiency toilet rebate and high-efficiency clothes washer programs. It’s proposed those programs would be replaced by a custom rebate program for commercial, industrial, institutional, irrigation and multifamily home customers.
The rebate of the new program would be a 50% cost share or an amount calculated based on water savings, which ever is lower.
The plan also proposes updating fixture standards to align with the CALGreen standards for interior plumbing.
Jed Smith, a water district board member, said he is concerned about the value of the ordinance. Smith said he is more interested in turf replacement and increased investment in irrigation efficiencies.
“To me those are the best bang for the buck by far and focusing on customers who use the most in those areas would be extraordinarily important,” Smith said.
“We’re trying to make these improvements as they make sense,” Pollard said. “As far as the policy piece and the overall savings, we’re moving the marker with these new constructions installing low-water-use landscaping, and I think that’s where you’re going to see the majority of folks comply with this program.”
Ben Horenstein, the district’s general manager, said the updates are about efficiency of resources and effectiveness in driving down consumption.
“It’s modifying a policy that hasn’t really worked,” Horenstein said.
The updates are expected to be presented to the board at a future meeting.