Case studies       The Conyers Residence   Located about an hour north of Seattle this house, featured in HGTV's Extreme Homes series, utilizes the first permitted graywater system in the State of Washington. MORE>>       C.K. Choi Institute of Asian Research on the West Mall at University of British Columbia, Vancouver. Matsuzaki Wright Architects, and Landscape Architect Cornelia Oberlander.   The gray water system uses a subsurface constructed wetland to filter and clean water. The gray water comes from the "compost tea" from the composting toilets and from the sinks in the building. Rainwater is collected in a cistern and used for irrigation in the summer. See http://www.greenbuildingsbc.com for more information.       Leslie Science Center, Ann Arbor, MI   Greywater irrigated south-facing planter bed in the public facility owned by the city. Greywater is purified in the Leslie Science Center 's MichCon Nature House. Planter beds are used for symbiotic irrigation and treatment in many public facilities around the USA and Canada.       Private Residence, Cambridge,MA   This example demonstrates greywater use in a masonary soil bed on the floor of a basement living room.       Indiana County, Pennsylvania   This facility is a lakeside meeting center with flower beds; greywater irrigation systems are located in the greenhouse. Flower beds are an ideal use of the greywater irrigation and purification planters.       King Street Center   Located in the heart of Seattle's International District, the King Street Center demonstrates the effective use of greywater recycling in an urban context.       Massachusetts Audobon   A no discharge grey water system was created for the Massachusetts Audobon Society.       Thorpe Wood Conference Center   Located in the Catoctin Mountains of central Maryland, this completely self-contained facility reuses water, including both greywater and blackwater. This is especially important since the site is located in an area where sewage disposal is at a premium