Resource: Greywater Reuse Systems
Title: Greywater Reuse Systems
Resource type: Product
Topics: Individual Choices, Water
Keywords: grey water, graywater, gray water, water efficiency, resource efficiency, water hierarchy
Audience: All
Region: Northeast, Twin Cities, Minnesota Statewide, Outside Minnesota
Summary: Water from showers, sinks and washing machines can be reclaimed for reuse - where potable water isn't necessary - in irrigating landscapes and in supplying water for toilets.
Content: Wastewater can be broken down into two types - blackwater and graywater. As the name suggests, blackwater is the dirtier of the two and consists of effluent from toilets, which can be composted using a number of proven systems (for use in cabins and elsewhere) including one from Equaris Corp. in Afton, MN (see http://www.nextstep.state.mn.us/res_detail.cfm?id=285). Greywater is everything else: water from showers, sinks and washing machines. In households, greywater can account for 60% of total wastewater volume.

Greywater systems for residential and commercial (offices, apartments, hotels) use range in sophistication and cost, but a suitable and practical one can cost under $1,500 and pay for itself in water and sewer cost savings. These systems run used water through small filters and treat it with small amounts of chlorine or an alternative.

Benefits flow not just to system owners, but to local governments, as greywater systems decrease demands on drinking water and sewer systems, decreasing volumes and system energy use. See, for example, systems made by the Canadian company Brac Systems (http://www.bracsystems.com - the Minnesota representative is Sun Energy-CMC in Mora: 320/679-0877). Oasis Design's website - http://www.oasisdesign.net - is a good resource for learning about benefits and also the complexities of a greywater system. Also see this site for resources on rainwater catchment (rainwater harvesting, rainwater collection from roofs) and storage (in cisterns. In 2008 a 10,000 gallon cistern was installed in the Minneapolis City Hall as part of a greenroof system).

See also Evaluating the Feasibility and Developing Design Requirements and Tools for Large-scale Rainwater Harvesting in Ontario (Canada Mortgage and Housing Corporation: 2009) at http://www.cmhc.ca/odpub/pdf/66602.pdf

With areas of Minnesota facing more frequent drought, use of greywater is getting a renewed look. Systems have been approved on a case-by-case basis at the city and county level, and information on home kits and installation is readily available. See, for example, the SymBioSystem of Round River Alternatives in Finland, MN (http://www.nextstep.state.mn.us/res_detail.cfm?id=1049). Also read about a greywater greenhouse north of Duluth at http://www.nextstep.state.mn.us/res_detail.cfm?id=256

Greywater Action at http://greywateraction.org/ has many do-it-yourself system designs and pictures, collected by a collaborative group of educators, designers, builders and artists who educate and empower people to build sustainable water culture and infrastructure.

Suggested by: Philip Fuller
Added: 10/28/08
Updated: 08/30/12