Oct 08, 2007

At Luxury Housing, Recycled Rain Is a Perk

The luxury housing development going up near a corner of Weston's Highland Street and Boston Post Road boasts the usual high-end features—Sub-Zero refrigerators and Wolf stoves, options for basement saunas and wine rooms—and something else that is not so common, even to such tony projects: top-of-the-line technology for those less-savory elements of modern life, waste-water and storm-water treatment.

Highland Meadows is envisioned as a development for suburban denizens 55 and older who want low-maintenance, condo-style living with all the perks. When the project is finished, it will include 69 condominium units, seven of which will be set aside as affordable housing. Most market-rate units will be priced between $1.6 million and $2 million. Its host community will be spared the rainwater runoff and sewage that comes when land is first developed, because the developer, Highland Real Estate Development, has installed innovative, eco-friendly technology.

A network of underground pipes and tanks collects and stores up to 120,000 gallons of rainwater so that it can be used to irrigate the property's landscaping. Mark Romanowicz, vice president of development for the project, said that during a dry season, it can be supplemented with water from on-site wells. Waste water from sinks, bathtubs, showers and toilets is routed into an on-site treatment system that leaves the water potable - although at Highland Meadows, the water will be routed into a leaching field and back into the environment.

The waste-water treatment system employs a membrane bioreactor to filter out particles of matter and germs. Microorganisms eat the waste material in the water. Ultraviolet light disinfects the water before it is discharged into the leaching field on the property.

The runoff collection system has two parts, said Sasaki Associates engineer John Hollywood, who helped design it. The first collects rainwater from the roofs, which is considered cleaner than runoff from lawns or paved surfaces like driveways because it's less likely to have contaminants such as fertilizer or motor oil. The roof water flows into pipes that lead to underground storage tanks, where it can be pumped out and used for irrigation. The second component collects runoff from the driveways, sidewalks, and streets, and channels it toward a sloped, grassy area with special vegetation that filters out both silt and some man-made pollutants. The water then flows into tanks with packed earth or stones at the bottom, which act as filters before the water is put back into the natural water table. This prevents flooding.

Putting the runoff system underground costs about 12 percent more than a standard system, but Romanowicz said the expense is worth it. Residents get a nicer view, and fewer trees in the surrounding "buffer zone" of vegetation have to be sacrificed. Weston's permitting authorities were also more friendly toward a proposal that minimized disruption to the land and prevented runoff from flooding natural areas and neighbors' yards.

"Above-ground open basins would be much less expensive. But it was a challenge between saving trees in the buffer and storing and infiltrating underground," said Romanowicz.