Systems that separate toilet wastes (blackwater) from household wastes (greywater) need a provision for greywater disposal.
Greywater contains many chemicals, bacteria and nutrients, and is technically still “sewage;” therefore, it must be treated and dispersed properly. It is illegal to discharge greywater into the river. The requirements for disposition depend on the volume; therefore, the use of water-saving devices is important.
There are two methods of greywater disposal that can be used in the 1000 Islands region:
Greywater Treatment Tank and Sand Filter
This is one of the best and most feasible alternatives for treatment of greywater. The greywater flows through a two-chambered tank much like a septic tank. The first chamber settles out solids. The second chamber contains rocks one to two inches in diameter that remove grease and allow for bacteria growth to aid in waste breakdown. From there, wastes go through a sand filter, such as that described on page 30. Engineered systems (special design) such as just described, may be commercially available, but require a waiver from the Department of Health.
These systems clean the impurities from greywater using reverse osmosis (see glossary) through a semi-permeable membrance. Silver- coated charcoal is then used to filter impurities. This equipment involves computer technology and has many parts that can break down. The cost is relatively high.
In collaboration with:
Eric E. Murdock, P.E.