New rules on stormwater ordered

Developers building everything from homes to shopping centers could soon be forced to take extensive steps to keep polluted stormwater out of streams and Puget Sound.

Picture housing developments built to soak up rainwater with special gardens, roofs covered with plants, narrower streets paved with asphalt that absorbs water, or foundations that leave topsoils undisturbed.

A ruling released Friday by the state Pollution Control Hearings Board means the Ecology Department must rewrite regulations governing stormwater control in the biggest cities and counties in Western Washington.

Ecology has been simply encouraging counties and cities to try new, rain-absorbing techniques, known as low-impact development or LID. Such techniques aim to filter stormwater runoff through the soil, thereby stripping out pollution and keeping it from rivers, lakes and streams and the Sound.

The decision by the three-person board, which acts like a court for appeals of state environmental regulations, says Ecology must require LID techniques for all new development where feasible.

Just how big a difference the ruling will make in local neighborhoods or in the health of Puget Sound is an open question. Local governments, builders, environmentalists and the state Department of Ecology will likely wrestle over the implementation.

And the ruling can be appealed, either to Superior Court, an appeals court, or directly to the state Supreme Court.

"A sea change"

Still, environmentalists were pleased.

"We're talking about a sea change," said Jan Hasselman, an attorney with Earthjustice, an environmental law firm representing several groups in the case.

Friday's decision could also make Western Washington one of the only places in the nation requiring these new approaches to stormwater runoff, one of the largest and thorniest pollution problems facing the region.

The decision could wind up affecting dozens of cities and counties in Western Washington. It applies only to some of the most populous places, including Seattle, Tacoma and Pierce, King, Snohomish and Clark counties. But the board is considering a related case for smaller cities and counties.

Permit issue

Under the federal Clean Water Act, many cities and counties that manage stormwater systems must have a permit from the state Department of Ecology. The permit sets standards for how strict local regulations must be when it comes to telling developers how to control stormwater runoff.

Environmentalists challenged a version of the permit issued in 2007, arguing in part that it was too wedded to failed, old-fashioned approaches that use underground pipes and man-made ponds to funnel runoff to nearby streams.

Ecology had shied away from requiring LID on grounds that it was still experimental, and risked going beyond the permit's legal authority.

The Pollution Control Hearings Board, however, ruled that low-impact development has proved workable, and could be more effective in reducing environmental damage. Under state and federal law, Ecology has to require it where it's feasible, the board said in its decision.

New direction

Kathy Fletcher, executive director of the environmental group People for Puget Sound, said the ruling marks a major shift in direction for the region's approach to stormwater.

Stormwater runoff is a major problem facing the Sound, and one that could grow as population increases here. When rain hits pavement and rooftops, it feeds gushes of stormwater that erode stream channels, and wash millions of gallons of oil and toxic chemicals into the Sound every year.

Fletcher said the ruling should push leaders of the Puget Sound Partnership, a new agency created to help revive the Sound, to tackle the issue.

"I hope that will signal to the Partnership that they can afford to be a little bit bold here," said Fletcher, whose group challenged the Ecology permit.

Local builders have shown some interest in low-impact development, but the industry has resisted making it mandatory.

"LID doesn't work everywhere," said Allison Butcher of the Master Builders Association of King and Snohomish Counties.

That could determine how sweeping an effect the board's ruling has. It stated that runoff should be avoided on a development "where feasible."

"There are lots of folks that are going to say it's always feasible," said Bill Moore of the Ecology Department. "There's going to be other folks that say there's only limited circumstances and here's why."

Warren Cornwall: 206-464-2311 or wcornwall@seattletimes.com