Clearing the Grey

The average American Citizen uses 80-100 gallons of water a day and the average African Citizen uses 5 gallons of water a day. ^[1] The reason for the disparity, technology. This is why I have decided that my first project will be to build a graywater system and to reuse the water for the landscape and for the toilet. The primary resource for the design I plan to build is from Oasis.

Once I have built the greywater design from Oasis, I plan to create a wetland to further filter the water. Wetlands have been used purposefully, to filter water since the 1970s.  Numerous case studies have proven that wetlands significantly reduce many graywater contaminants including pathogens, biochemical oxygen demands, solids, nitrogen and phosphorus species and heavy metals.  

Filtering wastewater from the washing machine is necessary because it has been shown that toxins present in laundry wastewater are harming the Puget Sound.  A study, conducted by the Seattle-based nonprofit, Washington Toxics Coalition, concluded that residential washing machines send about 2,110 pounds of phthalates to wastewater treatment plants each year from household dust, about 17.5 percent of the total annual load.^[2]   

 The problem with Phthalates is that they accumulate in marine sediments and interfere with reproductive activity in marine creatures.^[2]  With experimentation, it is my hope that the wetland I create filters out these toxins. 

Eventually, I would like to reuse all of the greywater to minimize my water usage.  John Todds, developer of the Living Machine has successfully integrated ecological systems to filter wastewater to this degree. One successful example was a Living Machine  designed to treat wastewater of 80,000 gallons per day in Vermont. Here is a good article on some of the advantages and disadvantages on Living Machines.