One of the great ironies of building in chronically water short California is that “grey water” (water from sinks and showers and washing machines) and “black water” (water from toilets) are both dumped into the sewers because you are not allowed to do anything else with your grey water. Never mind that it could be reclaimed for irrigation, or re-used as water in your toilet tank so that you aren’t filling your toilet with what was potable water before you dumped it in the bowl… in theory, grey water could be re-used, but the code requirements for permitting are so difficult, that for all intents and purposes, grey water systems can’t be built. There are all kinds of groups like grey water guerrillas who are flying under the radar, but nothing “legit” until the group at the Ecology Center in Berkeley actually designed and built a permitted residential greywater system in 2007 – with that precedent, we are also going to try.
We will be plumbing our house with parallel sewer systems, and bringing our greywater to the edge of the house near the future stream. Until we get the permit, the greywater goes into the regular sewer like any normal plumbing, but the plan is to build the leach field underneath the stream bed, and have it terminate in a constructed grey water wetlands at the bottom of the stream, and once we have the permit (and we’ve built the leach field), we turn the diverter valve and start watering the wetlands. We expect that the permitting process will be long, so we are pursuing it separately from the house building, because the wetlands can be built long after the house is done if we have to.