One hundred percent of the grey and black water generated by the School is reclaimed. The wastewater is first digested, then filtered, chlorinated, and dechlorinated. It is then sent to a holding tank under the parking lot near the Sprague Gymnasium. The treated water is mixed with potable water and used for irrigation on campus. The wastewater treatment plant saves 265,000 gallons of water a year that would otherwise be lost.
The Emmett Horowitz Aquatic Center, which opened in 2010 uses a microturbine to heat its water. Rather than use natural gas to heat the pool, the gas is used to power a turbine, which generates electricity. The fugitive heat from that process is what heats the competition pool, the recreation pool, the locker room showers, and the space heating in the building. The microturbine generates one-third of the electricity on campus for about two-thirds the price using the utility. When the center opened, the savings were estimated at around $30,000 a year.
The Emmett Horowitz Aquatic Center is LEED Gold certified.
Solar panels on the Sprague Gymnasium have a 72 kW capacity. Twenty-one and a half kW of power comes from panels on faculty homes. That combined production covers around 20% of the electricity usage on campus. Another 72 kW system is planned for Cate’s new dining commons.
Emmett Horowitz Aquatic Center: LEED Gold
Class of 1985 House (Admission): LEED Platinum
Cate Mesa Road Faculty Residences (5): LEED Platinum
Currently, 3000-4000 of gallons of pool water are wasted each week. The filtering process requires an excess amount of water, which is typically dechlorinated with sodium metabisulfite. The resulting water is toxic to aquatic life if it reaches waterways or the ocean.
A planned system approved by the School will use vitamin C to dechlorinate the water. Then the dissolved solids will be settled out and the treated water will be mixed with condensate from the proposed dining commons. The mixture of the two will generate 4700 to 5000 gallons of water, which will be used for an interactive water feature on the Kirby Quad. Excess water will overflow to a 72,000-gallon cistern, where it can be mixed with rainwater and used for irrigation.
Wrapping around the Kirby Quad and spanned by a footbridge, Cate’s bioswale is designed to disperse and collect sediment normally carried into waterways. Layers of angled rock embedded into the bioswale prevent sand, dirt, and debris from flowing freely toward streams and to the ocean.
The Mesa is planted with centuries-old coast live oaks and Italian stone pines, which are drought tolerant. Other landscaped areas include many native California plants which require very little irrigation. Because of California’s drought, the School is mindful of its water use and is constantly seeking new ways to reduce water use.