Conserving water meant designing and installing a new plumbing system. Before the renovation, the outdated faucets, toilets, showerheads and appliances wasted water. Outside the house, the landscape required gallons of water to stay healthy and green.
The new plumbing system uses new insulated copper pipes, supplies hot water on demand, and is gray-water ready. The new fixtures and appliances use low-flow technology to perform well with less water.
Indoor Water Conservation
The water in the house has five main points of use: the dishwasher, the washing machine, faucets, showers and baths, and toilets.
Recurve (formerly Sustainable Spaces) installed remote-controlled recirculation pumps. 30 seconds after the remotes are pressed, the cooled water in the water line is flushed to the domestic hot water tank to be re-heated. Hot water from the tank refills the line and flows from the shower heads and faucets. This reduces the wait time for hot water as well as conserves water by sending it back to the tank instead of down the drain.
Timeline Design installed a low-flow Energy Star dishwasher and washing machine. The Energy Star dishwasher heats its own water, which is more energy efficient than drawing hot water from the hot water storage tank.
The Energy Star washing machine has a front-loading horizontally-mounted drum that uses less water and energy than top-loading models. The design extracts more water from the clothes, reducing drying time.
Low-flow faucets and showerheads were installed in the kitchen and bathrooms. The low-flow fixtures use aerator filters that add air to maintain the water pressure while reducing the flow volume.
Toilets consumed more water than any other fixture. The 3.5-gallon-per-flush toilets were removed and dual-flush low-flow toilets were installed. The dual-flush toilets use 1.6 gallons of water to flush solid waste and 0.8 gallons to flush liquid waste.
Outdoor Water Conservation
The back yard was “de-lawned” and Project Manager Lynn Kingsbury planted a garden that supplies vegetables and herbs for the house including lettuce, tomatoes, peppers and squash.
The new plumbing system is designed to separate the home’s gray water (from kitchen and laundry appliances, bathroom faucets, showers) and the black water (from the toilets and kitchen sink.)
When the garden is complete, the gray water will run through PVC pipes to a subterranean drip system that drains the gray water into a constructed wetland garden designed by Zeterre Landscape Architecture. Plants in the garden thrive on the nutrient-rich gray water. Within the constructed wetland, physical, chemical and biological processes treat the waste water as it passes through the wetland medium. Aerobic and anaerobic micro-organisms help decompose organic material. Solids are filtered out as they settle in the water column or are physically filtered out by the wetland medium. Bacteria and viruses filter out of the water beneath ground level.
Black water from the toilets and kitchen sink flows into the City of Palo Alto’s waste water sewage system. By separating the two types of water and treating the gray water in the home’s constructed wetlands, the amount of waste water that is
polluted and requiring treatment is greatly reduced.