Once lost in the shadow of other energy-efficient techniques and designs, greywater is now having its moment in the sun, if not in the company of a client’s garden. A former renegade movement, the system’s steady rise to prominence has much to do with a concerted look at water preservation. With record droughts in recent years, suggesting greywater retrofits to your clients could not come at a better time.
Despite being an economical approach to water conservation, installing greywater retrofits are not right for everyone, and bad planning can cause unforeseen challenges for plumbers working with existing pipes in a client’s home.
“Greywater systems can be achieved very simply from a plumbing perspective,” says Greg Bullock, proprietor of Bang for Your Green Buck. “But you have to be cautious not to over-engineer. The product can fail overtime and may not be a sustainable solution.”
According to Bullock, the key to a successful greywater system is to obey the rules of gravity. For many drain systems that use a three-way valve diverter, it’s integral that the direction of the pipe allows the recycled water to flow freely and avoid blockage. This system is useful when intercepting water from showers, bathroom sinks or the laundry. The water continues through the pipe and, as the valve’s name suggests, is diverted to the sewer line or to an irrigation destination. Gravity assures there is no need for a pump to disperse water throughout a client’s yard. So, strategic line placement is important to maximize the sustainable nature of the system.
“Years of greywater use has found that filters or pumps can lead to problems,” Bullock says. “If you use this [drain] system, it can last forever and never let you down.”
Location is another major factor in greywater design. Some of the biggest challenges plumbers face when installing this kind of retrofit is accessing plumbing covered in sheet rock, under flooring or concrete. Accessing the pipes to redirect the lines can prove to be more trouble than it’s worth, and the layout can cause the product to fail overtime, says Bullock.
Proximity and environmental elements are huge factors in ensuring the utility of greywater systems. Uphill landscapes will require electricity to pump and irrigate, and therefore are not as environmentally friendly.
The Right System
It’s important to examine a client’s potential for ROI when choosing the right greywater retrofit. Unsurprisingly, many systems range in price and effectiveness. When opting for a system with pumps and filters — sun filtration and sub-service emitters — a lot of mechanical effort is expended to irrigate a yard.
“Focus more on areas of conservation first,” says Bruce Broderick, CEO of Being Water, LLC. “You can use simple systems attached to a shower or washing machine, and there is no high infrastructure cost.”
A simple, and often permit-free, popular retrofit is the laundry-to-landscape system. In an elevated setting, it can work without harming the washing machine’s pump. Water is directed to different zones around a yard and placed directly into basins for irrigation. To align with code requirements, greywater cannot be exposed so outdoor basins must be covered with mulch.
A pricier option is the automated sun filtration to sub-surface emitters system. This includes filters and pumps within a main surge tank. Water is filtered through small emitters and pumped out through drip irrigation. If cost is not an issue, and there is plenty of land to irrigate, this is a more suitable program.
Broderick says there are some off-the-shelf products to purchase for a client’s retrofit, but he cautions plumbers against opting for those kinds of systems. To assure the right water treatment precautions are taken against the spread of pathogens and other potential health hazards, site-specific examinations are necessary to pick the right system for clients.
Another challenge many plumbers face is controlling backflow. Once the correct system is selected, it’s important to take the proper precautions to protect against cross-contamination. The swing check valve, a one-way valve that prevents the flow of water in the opposite direction, and the vacuum break, an anti-siphon device that stops water from being sucked back into the system, are good additions that break the forceful flows that can lead to contamination.
In California, backflow preventers must be inspected yearly, Broderick says. Also, designating a proper air gap, a free flowing area where there is no possibility of water flowing back where it came from, is an important step plumbers should not forget.
But cross-contamination doesn’t have to pertain to water flow. It can come from the client. Plumbers “need a commitment from whoever owns the system to use plant-friendly detergents,” Bullock says. Cleaning products with bleach and dishwasher soaps with salt can be very harmful to the environment and cancel out all a client’s greywater good will.
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