What Can I Do With My Recycled Greywater?
In California, the answer to that question is easy, with a couple exceptions. By state law, you can install a simple, laundry to landscape system which uses your washing machine’s water pump to deliver wash and rinse cycle greywater to a series of underground “mulch basins”. These can’t be too far from the machine, nor can they be much above grade. Push either of these variables and soon enough you’ll be on the phone with the appliance shop, getting quotes for replacement of your washing machine pump.
If you want your greywater to become a primary irrigation water source, you’ll need to consult with your local health and building departments to determine what guidelines are followed for greywater use. You will have to modify your plumbing to isolate the greywater drains from the blackwater drains. In San Francisco, for example, greywater needs to be treated to a level approaching that of drinking water. The thinking is that coming into contact with untreated wastewater is dangerous. There are indeed nasty bugs (bacteria and viruses) which could spread via standing greywater. So even if water is treated to a high degree, it still must be delivered at least 2” below the surface of the soil, to minimize human/animal contact. Greywater Recycling Systems manufactures a unit which safely produces and delivers water suitable for subsurface irrigation.
Another complication is storage. Nearly every code limits untreated greywater storage to no more than 24 hours. After that, the water will turn “septic”, which means it will begin to smell bad and present a danger to those unlucky enough to come in contact with it. So if you want to reclaim all your greywater, you need to treat it as soon as you generate it. And have landscaping in place which will soak it up during your irrigation cycles.
The gold standard for reclaiming greywater revolves around an arduous test developed by the National Sanitary Foundation. It’s called NSF350. Very few systems have achieved this certification. The bar was set high, which makes sense. Some of us Californians recall having fluorescent lighting jammed into our homes by state government. It’s not that we didn’t want to save energy, it’s that our homes looked terrible under harsh, nasty neon tubes. There were no standards for light quality, so high efficiency lighting was adopted, literally by hook and by crook. Now we have LED lighting, but before our overlords forced us to switch, they made as a price of admission to California, that manufacturers produce light that was warm and pleasing to the eye.
The NSF350 test is a demanding process treating 10,000 gallons of greywater over a 6 month period. No maintenance is allowed for the duration. This makes sense, as the best systems will operate “out of sight, out of mind.” Word of successful systems will spread fast enough, but installed-system failures will give the doubters enough ammo to keep the technology stalled and not mainstreamed. To date there are only a few manufacturers in the market with a system that is NSF350 compliant. Grey Water Recycling Systems will be submitting a unit for certification this winter.
This treated water can be used outside the home, for any purpose except bathing or drinking. Your plumber will install specially labeled hose bibbs. This greywater can even be used inside your home, to replace drinking water used for flushing toilets. Imagine living a life of verdant lawns and landscaping, clean cars, and long showers, guilt free.
John Yates-Sales Vice President for Greenergy Group