By Jenn Danko
When it comes to installing greywater recycling systems for residential or commercial clients, the economics may prove to be a grey area in their own right. According to Nancy Harrington, president of Let's Go Green, Inc., an online retailer of composting toilets and garden composters based in Calgary, Alberta, the current health, legal and financial risks outweigh the benefits greywater recycling can provide its users-especially in a climate such as that of the western coast of Canada.
"Greywater can only be used for toilet flushing if its treated, and irrigation; but in Western Canada, the irrigation season is only about three to five months, which makes it hard to justify the cost of a greywater system," she explains. "In many other parts of the country there is enough rain that greywater is not needed for irrigation."
So when is the right time to install a greywater recycling system in a home or business? And when does it make sense from a cost-effective standpoint?
Clients should first decide why they need the recycled water-or if they need it at all, says Harrington. A good place to start, she says, is by defining the basics.
Greywater is wastewater that is not contaminated with sewage waste and has been used for household matters-including laundering clothes or bathing-which are its two main sources. Although the definition of greywater is somewhat subjective, Harrington says it generally does not include kitchen sink water, which can be more heavily contaminated with grease or food particles.
Because the use of greywater is so site-specific, it is important to assess how a client will use it before agreeing to install a system. Such assessment will relieve aggravation for both the contractor and the client in the long run.
"There is actually not much value in greywater in most of North America, as water is generally not expensive and greywater recycling systems are," Harrington says. "The economics change in an area of extended drought where water might be expensive, unavailable or the recycled water is needed for irrigation for food production."
When clients decide that a greywater recycling system meets their needs, they must also decide if it meets their budgets. Installing a system can be quite a costly process, especially in older homes, where retrofits are required.
"You need to run pipes from the source-be it a washer, shower or bathroom sink-to the holding tank, and then to the outlet," Harrington says. "There should be a pipe to the sewer or septic system as well, with a shut-off valve so that wastewater can bypass the greywater recycling system in the event it malfunctions or requires maintenance."
The most optimal way to install such a system is during the new construction project phase when purple pipes-which are the standard color of pipe adopted by the international utility industry to distributed reclaimed water-can be fitted at a small incremental cost.
"Rainwater harvesting makes a lot more sense as the bacteria and health risks are minimal by comparison," Harrington says.
When it comes to indoor, household use, greywater must be filtered extensively before reentering the indoor system because it carries a lot of suspended solids, such as soap scum, grease, hair and lint that can clog other pipes. If it is simply being used for irrigation, it does not require pre-filtering, Harrington explains.
"In the latter case, there should be a subsurface discharge into the topsoil layer, or at least under a bed of mulch," she adds.
Most importantly, both Harrington encourages contractors working with eco-eager clients to consult with local legislation before agreeing to the project.
"Many jurisdictions-such as the Province of Alberta-do not recognize greywater at all and consider any household wastewater as blackwater," Harrington says. "This makes it illegal to put greywater anywhere except into an approved sewer or septic system."
So what are the benefits to such water recycling systems in Canada as a whole? Right now, not much. Harrington says that currently, rainwater harvesting is a better way to recycle water, and although clear guidelines do not exist against greywater systems, the practice does not offer people many benefits.
Greywater recycling is not economically feasible nor can the high costs be justified since greywater systems can pose health concerns and require more maintenance from owners, she adds. Unless a homeowner or business resides in an area of extreme or extended drought, there is little advantage to using the system.
"I think there might be some beneficial installation scenarios, like a gym where there are lots of showers and toilets," Harrington says. "Also some industrial situations might save enough water to justify the cost of the system-but I don't think the average family in Canada benefits."
Will perceptions change in the coming years? The matter remains grey, to say the least.