Topping Off, for the Environment

As in many older cities, the District's storm and sanitary sewers run together. When they overflow, raw sewage can get into the local drinking water supply, increasing purification costs.

Years of runoff from suburban development, officials said, have forced the Washington Suburban Sanitary Commission to consider spending more than $20 million to install new pipes in the Potomac to obtain cleaner water farther from the Maryland shoreline. Excess runoff containing silt and other pollutants has clogged the shore near the pipes that draw drinking water from the Potomac.

In the Chesapeake Bay, storm water runoff is widely viewed as the fastest-growing source of excessive nitrogen and phosphorous levels that harm aquatic life and the food they rely on to survive.

Pete Johnson, who is managing seven green roof projects in the District for the Chesapeake Bay Foundation, said the potential benefits to builders are huge.

"If you are building a 10-story office building in downtown Washington, sometimes putting on a green roof is the easiest thing to do," he said. "A green roof is a self-maintenance system. You don't have to do much of anything once it gets established."

The American Society of Landscape Architects, which installed a green roof on its building on I Street in Chinatown 18 months ago, has found that the roof is an excellent insulator. "It got so cold in the summer that some staff members were using space heaters," said spokesman Jim Lapides. Preliminary findings also suggest the roof gets rid of some impurities in rainwater, he said.

But persuading officials to take such steps has been difficult, said Diane Cameron, a water quality consultant. Cameron, a member of Stormwater Partners, a Maryland coalition, is trying to encourage state and local governments to draw up tougher standards.

Among the ideas the group is promoting are green roofs, "rain gardens" with certain types of plants that soak up and filter rainwater, porous pavement for roads and sidewalks to filter water, and more green space in new developments.

The federal storm water permits for Montgomery and Frederick counties are up for renewal, and coalition officials hope to use the review process to win changes.

The group is also waiting for the Maryland Department of the Environment to issue regulations that stem from a new law calling for more environmentally friendly construction standards.

Like many in the building industry, Mondell would be happier if the government allowed him to try out new systems voluntarily.

"We realized that if we did a green roof and worked with the county, we were almost positive it was going to cost us more money," he said. "But we also knew it wasn't going to send us to the poorhouse."

The extra cost turned out to be about $350,000, he said.

Johnson said setting up government-sponsored incentives can help boost the use of green technology. But only widespread use, he said, will benefit the region's air and water quality.

"You need to do it on a large scale. You can't just do one building here and one building there and expect it to have a big effect."