Irrigation: Dual Piping For New Construction
CHULA VISTA , A Chula Vista company is cresting the wave of the future of water conservation in San Diego County.
ReWater Systems, Inc. has formed partnerships with the cities of Chula Vista and San Diego to begin construction on a new graywater irrigation system.
The system promises to save water, reduce homeowners’ water costs, cut water damage to homes and improve the health of plants in homeowners’ gardens , all while reducing water pollution and saving the cities a fortune in wastewater treatment costs.
The ReWater irrigation system would accomplish all this by relying on graywater, or water that goes down the drain of showers, tubs, bathroom sinks, and in the laundry. Instead of going into the waste stream, the water would first be filtered, then diverted into an underground irrigation system in the garden.
Blackwater, or toilet water and water from the kitchen, can not be used. Instead, that wastewater would go into the sewer system for conventional treatment.
There are several advantages to installing graywater systems, said Stephen Bilson, chief executive officer of ReWater.
“All the end users end up saving money on their water bill, the wastewater people end up receiving much less wastewater, so they don’t have to treat that, and the bay gets better because you don’t have all this irrigation runoff,” he said.
Bilson described graywater as a water conservation device, irrigation system, wastewater reduction system and pollution prevention system all in one. That should make it easier to get federal and state and other money to help build the system, since the government has funding for these priorities, he said.
Chula Vista is close to getting the funding, and San Diego is not far behind. Chula Vista would initially hook up 650 homes to a graywater system, while San Diego hopes to construct 1,000 homes with a graywater system, he said.
Both programs would be similar and would involve the city using federal and state funding to install graywater systems in new homes. Depending on how much funding is available, the contractors might not incur any additional costs, Bilson said.
John Lippitt, director of public works for the city of Chula Vista, described how far along the city is toward putting such a system in place. The project is only in the preliminary stages, he said.
Seeking Money, Volunteers
The city has applied to the state and federal government for grant money and loans for a demonstration project. The city has also asked for contractors to volunteer to participate, but none have yet signed on, Lippitt said.
So far, the city has approved a 25 percent reduction in sewer connection fees if they have a proper graywater system installed, but that’s the only financial assistance they’ve obtained so far, Lippitt said.
Another possibility is to require new homes to be built with dual plumbing. That way, if the homeowners decide to install a graywater system at a later date, the infrastructure already is in place, Lippitt said.
At this stage, it’s unlikely the city would get up to the stated total 650 homes unless a developer signed on or a funding source came through, he said.
Only new homes would be built with the graywater system. The cost of going back and retrofitting an existing home with an additional plumbing system would be prohibitively expensive, Bilson said.
However, as more and more homes get hooked up, the unit cost will go down, and it could become more feasible to upgrade the plumbing of older homes, he said.
John Wiedmann, senior resource specialist with the Metropolitan Water District, was familiar with graywater and with drip irrigation systems. They both have a number of benefits, he said.
Since it drips water only where the roots are, it saves money on water that would otherwise be wasted. It has made growing avocados feasible in San Diego County, he said.
“They’re growing on steep hillsides. You couldn’t water those with a conventional irrigation system; the water would just run downhill on the surface,” he said. “But the drip system applies the water very slowly, a drip at a time, and it’s very effective in those types of situations,” Wiedmann said.
Although drip irrigation isn’t widely used yet in homes, Wiedmann can foresee a time when it becomes more popular.