Members of the www.pmihome.orgPlumbing Manufacturers Institute discovered at their spring meeting that this whole green building thing might be more complicated than advertised.
First, manufacturers have to deal with the multitude of green building standards issued by different groups. Then they have to figure out which products are genuinely green, and which ones are “greenwash.” Finally are the technology issues that have to be resolved in systems that contribute to sustainable buildings such as graywater and rainwater harvesting.
“There are 60 green rating systems in the United States,” environmental consultant Paul Shahriari told PMI members April 1 during the meeting in Newport Beach, Calif. “In the last 10 years, going green hasn’t gotten easier.”
Earlier in the meeting, PMI Technical Director Shawn Martin noted: “It’s the Wild West out there. We as an industry should encourage harmonization and consolidation of water-efficiency standards. Everyone seems to be out for themselves.”
To address this situation, PMI approved two action items:
- 1. PMI will
monitor the water-efficiency efforts by all the groups that have issued
standards or guidelines.
2. PMI will organize an industry forum to get all the groups on the same page.
“There’s a huge amount of greenwash,” Shahriari said. “Some greenwash is more based in Madison Avenue than in reality.”
Perhaps most troubling, however, are the technology questions that must be answered in systems that contribute to sustainable construction. Graywater and rainwater harvesting systems can benefit the environment only if they are designed, installed and maintained properly.
Graywater is household wastewater that does not come from toilets, kitchen sinks or dishwashers but rather from showers, bathtubs, bathroom and laundry sinks and washing machines. A person can produce 40 gallons of graywater per day, said Eddie Wilcut, conservation department manager for the San Antonio (TX) Water System.
Using graywater has both benefits and risks, he told PMI members. Benefits include: reduced potable water use; lower water and sewer bills; reduced impact on septic systems and wastewater treatment plants; and reclamation of nutrients that can help the soil and plants. Among potential risks are: health risks; reduced water quality; backflow contamination; and sodium buildup in water.
Overall, the benefits of a properly designed, installed and maintained graywater system outweigh the risks, he said. Cost can be another issue, though.
“In San Antonio, if you build a new home equipped for graywater, it will cost about $200 or $300,” Wilcut said. “After the house is built, it will cost thousands. The industry should promote plumbing of new homes for graywater.”
Rainwater harvesting and reuse can be as expensive too. Such a system can be more costly than desalinating ocean water due to the storage that’s required, he said.
“Rainwater needs disinfectant as does graywater because of biogrowth in storage tanks,” Wilcut said. “Rainwater falling from the sky may be pure, but there are contaminants on the roof, and maybe asbestos. A roof-washing system may be needed.”
Another consideration is whether a system can capture all the rain if it comes all at once, he said. Conveying the rainwater requires gutters, downspouts and piping, in which mold, squirrel feces and leaves may accumulate.
Aesthetics may figure into selecting the system’s storage tank, which can be installed below or aboveground. Some neighborhood covenants won’t allow homeowners to install aboveground cisterns.
Owners also have to decide whether the tank is made from fiberglass, plastic, wood, steel drums or polyethylene. Galvanized steel tanks must be lined if they’re to be used for drinking water, Wilcut said.
A number of these complications can be resolved if people involved in different aspects of sustainable construction do a better job of talking with one another, he said. In concluding his presentation, Shahriari noted the winners of the next phase of the green revolution would be the companies that make being green easier for people.
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