DIY Grey Water System for an Off-Grid Homestead
Build Your Own Off-Grid Water System
Reading Time: 6 minutes
This simple DIY grey water system is such a great way to recycle precious water while saving lots of money! When I moved into my partner’s owner-built, off-grid homestead in the woods, it had an outhouse, a deep well with a hand pump, and a kitchen sink with no running water and a five-gallon bucket under the open drain. We soon decided to create an off-grid water system by adding solar panels and installing a solar pump in the deep well that would get water into the house. We added a pressure tank and indoor pipes that ran through the wood stove in winter and an instant hot water heater in summer. We had hot and cold running water in the kitchen and bathroom sinks and shower.
Our new indoor aquatic luxury meant we had to plan how to dispose of this “gently used water” by building a simple DIY grey water system. When we checked with the building inspector, he looked blank and said there were no state or local grey water regulations.
We decided the first step was our decision had to be to be frugal — no everyday showers, dishes washed by hand in plastic tubs, a sawdust bucket toilet that saves us one and a half gallons per flush, and doing our laundry at the local laundromat. Those who have washing machines will want to use only natural organic soap and consider a DIY grey water system with a larger farm pond from which they can recycle the water on plants, trees, yard, or garden. I have even seen super simple systems that use a hose attached to the washer that runs out the window directly to the plants.
Regulations for grey water disposal, or reuse systems separate from sewage, are beginning to evolve now that more homes have composting toilets and reuse of grey water for irrigation is seen as desirable, especially in dry states, such as California, Texas, and the Southwest. Some of these states even offer a certain amount of reimbursement.
Integrating a DIY grey water system into a farm pond design is a perfect match. Some regulation barriers still exist. Eighteen states allow grey water reuse. Some of them have regulations; the rest have no regulations but only a few do not allow grey water systems or reuse. The tendency is toward better, friendlier codes, so if necessary contact and convert your local building inspector. Those who are rural and own a decent sized piece of homesteading land will most likely have few problems, but be sure to assess the height of your water table and that there will be no run off onto someone else’s property.
Our neighbor owned a bulldozer, so we hired him to come over and dig us a four-foot deep trench in the backyard. It ran from inside the basement (our house actually sits on four foot pilings) where the insulated plumbing pipes from kitchen and bathroom converge, through the slight downslope of the grassy backyard, turning to run to a place where the slope slants more sharply into the woods. He dug out a small shallow downhill pond to catch any overflow at the end of the pipe. If we are having a particularly wet year and a houseful of super clean guests, the pond will fill up with crystal clear water.
We decided to go with a French drain system. This meant some work shoveling half a foot of large size gravel into the bottom of the 40-foot long trench, laying and connecting four inch plastic plumbing pipe with spaced holes on top of that, then filling in gravel around and above the pipe, followed by some back breaking labor filling up the trench and mounding the dirt we’d dug out to settle. Later we planted grass on our leveled backyard and now there’s no trace of the pipe that runs under the lawn.
From the insulated basement juncture under the bathroom about 10 feet out into the yard, we laid a four inch regular plumbing pipe (no holes) at a depth of 12 inches. At this point, we got overly ambitious and made our first large mistake! We ordered a five-foot high, round plastic 300-gallon sewage settlement tank with an inlet and outlet near the top. When the bulldozer tried to dig a hole deep enough to place it underground 10 feet from the house, sparks flew and we encountered what is all too common here in New England — granite ledge. Lots of it, too near the surface!
And no, the big yellow monster we nicknamed Sputnik, could not be returned. After days of despair, we came up with a brilliant idea. We built a platform four-feet high attached to the back of the house and lifted Sputnik to a place of honor upon it. We connected pipes from the roof gutters to the intake/outflow holes at the top and made a small hole in the bottom to which we connected an on/off handle, faucet, and hose that now allows us to water the gardens. Not a summer goes by that we haven’t complimented ourselves on this odd but perfect irrigation system!
So the chastened but intrepid homesteaders returned to the simple DIY grey water system and a less ambitious plan two. We found a sturdy second hand 55-gallon plastic barrel with a removable screw top, made two holes on either side of it, one-foot down for the inflow and outflow pipes, and set it upright 10 feet from the basement door with the top at ground level.
We cut an entry hole 12-inches from the top for the pipe from the basement that lets in grey water from the house, and an exit hole opposite for water to flow out when the barrel gets full. Water flows in and spends enough time in the barrel that any tiny particles of solids that have gotten through the drain strainers drop down to the bottom, just as in a septic system.
Since we had solved our garden watering with Sputnik, we decided not to worry about actively recycling our grey water. So here comes the homesteady, slightly yucky part, but we end up laughing over it. Once a year in the late spring, we buck up our courage and open the top of the 55-gallon plastic drum. My partner drops a five-gallon bucket on a rope down in, lets it fill with water and I have the job of lugging the bucket over to the woods and dumping the water out. As the barrel is emptied, the liquid left gets more and more odiferous and that’s when the laughing and funny faces begin. At the very bottom of the barrel are some particularly pungent semi-solids that the trees in the woods seem to love having poured on their roots, even if I have to hold my breath and rush away. And that half-hour job is our total maintenance for the year.
We could streamline this process and save our noses by using a pump and a long hose down into the woods, but doing things by hand around here is a habit we often enjoy.
Another necessary part of this DIY grey water system are metal strainers that fit in the sink and shower drains and catch a great deal of the food and hair that would ordinarily go down the drain. It gets dumped in the compost bucket.
For frost insurance, every late fall we lay panels of four-inch roofing insulation from the basement to the barrel which stays on until the spring. We cover it with a tarp, though our New England snow is also a good insulator.
The Approximate Cost of Our DIY Grey Water System:
4 hours to dig a 40’ long x 4’ deep trench $300
55-gallon second hand plastic barrel $20
Plastic 4’x10’ pipe, glue and couplings $80
Small load of large size gravel delivered $200
We’ve used this DIY grey water system for almost 10 years with nary a problem. We do use biodegradable natural soap, dishwashing liquid, and shampoo that we’ve learned to make ourselves, since certain commercial biodegradable soaps have sodium which is bad for plants.
I ask you, when compared to the $10-$20,000 cost of a septic system, doesn’t a composting toilet and do-it-yourself grey water disposal system seem like the sensible homesteading way to go?