off the grid ~ gray water disposal ?
Filed in Conserving energy on Feb.16, 2009
Christina H asked:
does anyone know of an easy, cheap way to dispose of gray water.
does anyone know of an easy, cheap way to dispose of gray water.
were leaving the grid and will only have gray water (composting toilet) we have no desire to reuse the water (since filtration systems come with a hefty price tag)
but I’m not sure what laws there are regarding disposal in upstate NY



February 17th, 2009 at 10:42 am
An orchard is typically the best reuse choice for greywater; a small fruit tree can easily uptake fifteen plus gallons per day. Even a small system can easily dispose and/or reuse well over 200 gallons of greywater per day. You should go to your local building department for required building codes.
February 20th, 2009 at 6:58 am
Can you make a sand bed leading to a garden pond? You can grow transition zone plants like reeds in the sandy bed and water plants in the pond, flow the waste water through there, as well as circulate the pond water through the bed and the plants will extract the organics and the sand will filter out the particulates, bacteria seeded into the sand bed will break down the more complex compounds down into something the plants can use.
Use solar power to run the pumps so that the circulation rate is greatest during the day in order to discourage algae growth on the remaining organics in the water.
You can harvest the plant material for a biomass gasifier to produce syngas (aka wood gas, aka town gas) which you could use as stove or lighting fuel or if you want to get fancy, feed a Fischer Tropsch reactor (a chamber filled with iron pipes and some cooling pipes to control temperature) to produce gasoline and or diesel. Depending on how well you can control the pressure, temperature and H2 to CO ratio of the syngas, you may wind up with a wide range of hydrocarbon products that would require additional refinement so it’s probably best to keep the pressure relatively low at just over 10 bar and the temperature high at about 330 C so that you make mostly gasoline and methane which you could feed back into the gasifier for more syngas (FEMA publishes plans for an emergency use gasifier made from trash cans that you can use as a starting point). Home built FT reactors tend to make what amounts to crude due to low temperatures and poor regulation and would require cracking to make something useful so you may just have to sell the FT products to a small refinery. It might be easier to just run a generator, yard gas lamps or a pump on the syngas.
If you have a really big yard, expand the pond by adding a swimming hole region hence resulting in a natural swimming pool where the water is kept clean by biological processes. Remember that with any biological ecosystem based system, the bigger the better.