General: Single-family detached, single-story, 2,300-square-foot home.
Foundation: Slab-on-grade with 24-inch-deep stem walls.
Walls: 2 by 6 wood-framed walls spaced 24 inches on-center, insulated with R-19 fiberglass batt.
Roof: Standing seam metal roof.
Exterior Finish: Traditional stucco.
Mechanical Systems: Natural gas boiler with radiant floor heating.
A separate greywater PVC drain system was installed in the home to serve bathroom sinks, showers, and bathtubs flowing to a commercially-available greywater reuse system. The reuse system filters the greywater and discharges it to an irrigation area serving an orchard of six trees.
Greywater System Layout
Six-tree orchard, irrigated by gray water, is thriving even during extreme drought conditions.
A 600-gallon underground storage tank was originally installed to collect rainwater from gutters. Later, this tank was replaced with a 1,200-gallon tank. A pump discharges the water to a spray irrigation system for front and rear gardens.
Front courtyard irrigated from rainwater system
A data logger collected water data including flow rate and quantity of water provided at the discharge of the greywater reuse system, and whole-house water consumption was measured with a flow meter. Soil samples were taken from the orchard irrigation area at 6-inch and 24-inch depth and at 20 feet from the irrigation area. Samples were tested for nitrates, various nutrients, trace elements, salts, and other pollutants.
A water meter was placed on the outlet of the rainwater collection tank and on the tap water inlet to the tank. A separate meter measured total household consumption. An on-site weather station was installed to monitor rainfall and other weather data.
Air Admittance Valves:
An AAV was placed in the attic area in lieu of a plumbing vent stack penetrating the standing seam metal roof.
- June and July 2000: Installation of PATH technologies
- August 2000: Home construction complete
- Summer 2002: Retrofit of systems completed
- Summer 2002 through September 2003: Monitoring period
- October 2004: Final report