A few home builders in central Florda are recycling ''gray water'' from sink and tub drains into the ground instead of discharging it into local sewer lines, thus reducing the outgoing sewage from a house by as much as 65 percent.
In addition to easing pressure on the city's sewerage system and treatment facilities, the method helps conserve the state's already overtaxed aquifer.
Although considered innovative in modern home-building techniques, the gray-water discharge program is simply another form of the age-old septic tank -- a treatment method rendered nearly archaic with the growth of mandatory sewer-line connections.
David Chacey, Longwood, Fla., city manager who gave his full support to the idea after hearing of its isolated use elsewhere in the US, explains: ''You just run a line of two-inch PVC pipe from the bathrooms to outside. It's just like throwing bath water out in the backyard.''
Despite its simplicity, however, the concept was prohibited by a state health law, which required that all homes be connected to a public sewer system whenever one is available. Mr. Chacey, along with members of the Florida Home Builders Association, took their argument to the state capital in Tallahassee to bargain with the health officials.
The result was a compromise of the state law allowing the on-site discharge of the gray water from the sinks if the ''black water'' from toilets and garbage disposals went into the sewer lines.
In early December Mr. Chacey issued a building permit to builder Cathy Peatross for the installation of the state's first gray-water system in an upper-middle-class subdivision in Longwood.
''It's an energy feature for the buyer in that it's saving water and passing along a cheaper sewer bill,'' says Ms. Peatross.
''But the main thing it's doing,'' she adds, ''is helping to restore the water table which is in real bad shape.''
To make sure that there are no substantial discharges of grease or suspended solids, state health officials do require the use of a holding tank outside the home. The 225-gallon fiberglass tank, imbedded in the ground, then passes the water out into a septic-tank drain field. The drain field, which is a perforated pipe running over a rock base, distributes the water throughout the backyard.
By the time the gray water percolates 20 or 30 feet into the soil it is already clean enough to drink because of the filtering action of the earth, Mr. Chacey says.
Meanwhile, he hopes he can persuade the state officials to rescind their holding-tank requirement by the end of the year if he can show that the tanks are free of pollutants.
To create an interest on the part of potential home buyers, the City of Longwood has decreased the normal charge for sewer-system hookup by $100 and knocked 20 percent off the monthly sewer bill -- a discount Mr. Chacey would like to increase to at least 50 percent.
In addition, it allows the city to double the number of new houses that can be connected to Longwood's nearly full sewage treatment plants since it reduces incoming sewage from those new connections by more than half.
One builder plans to install the system in some 130 new houses once the state streamlines its requirements.