Why Is Stormwater Runoff a Major New Threat?

In the1960s, water pollution assaulted our senses. Ohio’s Cuyahoga River was so loaded with toxins that it caught on fire. The Potomac River near Washington was so coated with slimy sewage that officials posted health warnings. Armed with the Clean Water Act of 1972, the EPA fought the most obvious pollution – pollution spilling from drainage pipes at industrial and waste treatment plants. The worst got cleaned up.

Today, a new pollution threat has emerged – stormwater runoff. Stormwater is the rain showers that hit rooftops, streets, sidewalks, driveways, parking lots, hard surfaces and that wash man-made chemicals into nature: oil, gas, tiny bits of ground metals from cars and trucks, herbicides, pesticides, PCBs and industrial toxins. Stormwater carries this deadly mix into storm drains or into neighborhood streams and then out into major rivers, lakes and coastal bays.

What makes stormwater runoff so hard to control is that doesn’t look dangerous. It accumulates a toxic load from millions of home lawns, highways and farm fields. It’s everywhere, but it’s hard to see. Take Puget Sound, for example - its waves glisten at sunset. But dive below with scuba diver Mike Racine and you see another world: underwater pipes spewing filthy clouds of stormwater runoff from Seattle. “This is sick,” says Racine. “Doesn’t look sick, but it is sick.”

“We put in about 150,000 pounds a day of untreated toxics into Puget Sound,” Says Governor Chris Gregoire of Washington State. Add up just the oil spill and in two years, says Jay Manning, Director of Washington’s Department of Ecology, “the volume of oil that is carried into Puget Sound by stormwater runoff is equal to the Exxon Valdez spill.”

That constant flow of chemical pollutants is going on all over the nation, a major cause for the increased closing of park beaches, for health warnings from state and local governments telling people to limit consumption of local fish, and for new dangers that scientists have spotted in our drinking water systems.

As one way to cope with stormwater runoff, experts have developed several strategies. One is called Low Impact Development (LID). The basic idea is to let more rain water sink into the ground where it falls. The High Point area of West Seattle is a showcase for LID.

In place of standard impervious concrete or asphalt surfaces, High Point’s designers used porous surfaces for sidewalks and gravel for driveways. Downspouts from condo buildings spill into beds of stones that allow rainwater to sink in. Neighborhood streets are sloped toward one side, with gaps in curbing to let street water run into grassy swales beside sidewalks, instead of gushing down the curb-line. To handle really heavy rains, High Point community has built a large retention pond, which serves as the centerpiece of a park with walking trails, wildlife and a children’s playground.

Background Essay Written by Hedrick Smith.

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