MERCERSBURG, PA. — SKIERS at the new Whitetail Ski Resort in Mercersburg, Pa., plowed through snow as clean and pure as a mountain stream this winter.
But some of that snow didn't come from the sky - or from a stream. It came from the kitchen sink and the shower drain.
The project here is part of an environmental trend in the United States called waste-water reuse. Instead of treating waste water and discharging it into a river or lake, many communities are building systems that recycle the water and use it in creative ways. Treated waste water irrigates golf courses, fertilizes crops, makes snow, and can even be recycled into drinking water.
"You can't keep throwing away resources [like water] and spending huge amounts of money to treat it," says Jack Sheaffer, president of the environmental planning and engineering firm that designed the ski resort's snowmaking system. "We should be recycling and reusing it."
Since the ski resort's system went in two months ago, the borough of Mercersburg has moved closer to building a municipal water-reuse system. In all, Mr. Sheaffer's suburban Chicago firm has been involved in more than 50 such systems since 1976. Many water experts are predicting that waste-water reuse will grow.
"The main driving force is going to be availability of water resources," says Charles White, spokesman for the Phoenix Water and Wastewater Department in Arizona. "Where water is a scarce commodity, it [reuse] will be coming more and more to the forefront."
Water scarcity is the reason the arid city of Phoenix has begun studying a water-reuse project that would provide drinking water. The city's newest source of water, which brings water from the Colorado River 100 miles away, can meet the city's needs only until about 2000, Mr. White says. Water reuse could be one new source.
"You will see more and more emphasis on reuse," adds Ken Kirk, executive director of the Association of Municipal Sewerage Agencies. But "it really depends on where you are." The idea won't take off in water-rich areas, he says. That is why the projects here in Mercersburg, where water is abundant, are so surprising.
"We care about streams. We care about open spaces," says Fran Wolfe, owner of the Mercersburg Inn and an early advocate of the water-reuse project.
The idea of recycling water came about because state officials had ordered Mercersburg to upgrade its traditional waste-treatment plant. Upgrade plans were already under way when Ms. Wolfe approached the borough council with the idea of water reuse. Nice idea, she was told, but too late to change direction.
Wolfe eventually got the council to agree to listen to Sheaffer, the water-reuse engineer. After his talk, the council put off voting on the traditional system, and the momentum began to swing the other way.
"I didn't think there was a chance," says John Mohr, another supporter of the project. "It's just really amazing, on the eve of decision when no one really cares, what a little talk can do."
The council finally voted to use Sheaffer's water-reuse system. The city has paid a local group of investors to have the system built and guarantee the project's success. The investors says the project's construction cost will be $1.7 to $1.9 million, less than the $2.2 million estimated for the traditional waste-treatment system.
If all goes according to plan, the water-reuse project will go into operation later this year.
At present, Mercersburg draws its water from the Buck Run Reservoir, four miles northwest of town, and from two groundwater wells within the borough. The water runs through sinks and toilets and gets collected at a treatment plant, which treats it with chemicals, then discharges it into Johnston's Run creek. The sludge left behind is spread on nearby fields.
Under the new system, the waste water will be pumped to a treatment lagoon southeast of the community, where it will be aerated intensively for 14 days. The aeration causes the solids in the water to settle to the bottom and decompose biologically. This process will cut by 90 percent the amount of sludge Mercersburg currently produces, says J. Craig Rockwell, president of Future Water of Pennsylvania Inc., the local investors group that formed a public-private partnership with Mercersburg to build the ne w system.
The water will then flow to a storage reservoir, where it will be further aerated and held until it can be sprayed on two adjacent fields. The nutrient-rich water will fertilize and irrigate the crops in careful doses. The crops will take up some of the water, and the rest will sink slowly through the soil, further purifying itself and eventually recharging the groundwater.
IN a true closed-loop system, the groundwater would be reused, starting the cycle again. In this modified loop, the groundwater will be used by residents around the fields, who rely on wells.
This process is a far cry from traditional systems that take used water, treat it, and then discharge it into a stream or body of water. Also, unlike traditional systems, the water-reuse projects at Mercersburg and the ski resort rely more on natural processes than on chemicals to treat the waste.
The ski resort, for example, collects the waste water from its lodge and pumps it to a similar system of aerated treatment lagoons. By holding the water for days instead of only hours, as traditional systems do, the system allows biological processes to do their work. Eventually, the treated water is mixed with water from a nearby reservoir and flows to the resort's snowmaking machines. Only 10 percent of the water used can be treated waste water, according to state regulations.
Bill Brick, the system's certified operator, says he believes the treated water is at least as pure as that coming from the reservoir.
But the resort has had to cut down on its use of cleaning compounds, Mr. Brick says. A sudsy foam is still visible at the center of the second pond. And some neighbors around the farm to be irrigated with Mercersburg's treated waste water worry about the effect on their land.
"The whole idea sickens me," says Annabel Fries, who lives adjacent to the field. She and her husband worry that the water will be sprayed on their land, over-saturate the ground, and flow into the creek at the back of the field.
The opponents still hope they can stop the project. They plan to meet with the Pennsylvania Department of Environmental Resources to air their concerns.
The department says it has thoroughly tested the site and is satisfied that it will work. The system's storage lagoons are big enough to hold the treated waste water when the fields are too wet. As for water in the creek, the current waste-treatment system now discharges directly into the creek.
"I think this is an idea whose time has come," says Mr. Rockwell. If the project succeeds in Mercersburg, he hopes to encourage others to follow the example. Already, half a dozen nearby communities are looking into the water-reuse system as a result of the projects here.