Stormwater Called The "Single Largest Contributor To Urban Pollution
Human beings are really good at paving stuff. Such as parking lots and roads. Our development patterns have very real effects on water quality.
With the Clean Water Act turning 40 years old Thursday EarthFix reporter Ashley Ahearn takes a look at stormwater runoff. It’s been called the single largest contributor to urban pollution.
You might think of paved streets and gutters as liquid raceways – channeling rainwater away from development and into the nearest waterbody.
But anyone who’s gone puddle jumping in a city knows that rainwater picks up a lot of gunk as it flows toward the nearest storm drain – everything from our lawn care chemicals to particles from our car exhaust.
That’s when we start calling it stormwater runoff and that’s when it becomes an environmental problem.
Jen McIntyre studies that gunk and what it does to fish. She’s an aquatic ecotoxicologist at Washington State University.
We walk down a long row of tanks in her lab. After a recent rainfall McIntyre and her team collected almost 100 gallons of water flowing off one of Seattle’s major freeways and took it here.
They poured some of the water through plastic columns filled with soil and plants to filter pollutants out of the road runoff. Then they added juvenile coho salmon.
McIntyre: “I don’t know if we’re going to be able to see but yeah, there are fish swimming around in the bottom of these treatments.”
These fish are lucky. They were put in a tank of filtered water. Some of the other fish were not.
McIntyre: “Over on the other side, behind door number two, we have some of the runoff water and as you can see it’s not very clean and I couldn’t even see the fish in here when they were in here.”
The fish weren’t in here for long. The strait cocktail of petroleum hydrocarbons, dirt, heavy metals, particles of tires and brake pads – and other pollutants that show up in storm-water all over the country – made short work of those fish.
McIntyre: “It is a very stark result. Right away, within the first day of this experiment, we saw that the fish in the straight runoff all died and the fish in the water that had been put through these soil columns are still alive.”
Scientists have known for some time that urban stormwater runoff is bad for fish. The pollutants in it can affect fish development and cause cardiovascular problems and brain hemorrhaging.
But the undiluted water McIntyre collected strait from the freeway is even more toxic than your average urban creek. She’s putting the water through several different filtering combinations. Some contain compost, some have plants, some don’t.
McIntyre: “At the end of the day the winner takes all and when we find the most effective treatment then we can start applying that out in the real world and that’s what we’re very hopeful for.”
By comparing the different filtration combinations she and her team hope to come up with solid advice for everyone from city planners to the average homeowner who’s thinking about installing a rain garden on their property.
The goal is to make all our stormwater runoff less toxic to fish by the time it makes its way from city streets into nearby waterways.
The Department of Ecology shares that goal.
It has instituted new state-wide stormwater regulations that will require Low Impact Development techniques – like rain gardens and porous pavement – to be used wherever possible. Oregon and some parts of Idaho are adopting similar requirements.
The Washington regulations will also require cities and towns to do more street sweeping, monitoring and storm drain cleaning - among other things.
And the state is getting some push back on the local level.
Kerry Ritland: “I’m Kerry Ritland at the city of Issaquah Public Works. We’re going to a location where our maintenance crew is doing the storm drain cleaning.”
We get out of Ritland’s truck in a nice neighborhood of Issaquah, about 20 miles east of Seattle.
A crew from the Department of Public Works has funneled a long tube out of the back of a truck and down into what’s called a catch basin. It looks like your typical manhole. It collects the water that flows off the lawns and streets of the surrounding neighborhood.
The bottom is clogged with oily wet leaves and mud.
All that stuff is about to get sucked up the tube. Ritland says this is one good way to keep pollution out of waterways.
Ritland: “The fact is that most of our city the only thing keeping pollutants from getting to our streams, rivers and lakes are these catch basins so that’s what they’re designed to do is intercept those pollutants.”
But here’s the problem:
Ritland: “Well the city has upwards of 6000 or more of these catch basins.”
And cleaning all these catch basins costs money.
Ritland says right now city workers clean each catch basin once every five years. Under the new regulations they’d have to clean them twice as often. This and other maintenance requirements will translate into more work for people like Kerry Ritland and higher utility fees for residents.
Issaquah has joined almost 20 cities and towns in Washington to appeal the new regulations.
Josh Baldi is special assistant to the director of the Department of Ecology. He’s not surprised the regulations are being appealed but he says the new rules are necessary.
Ecology has channeled than 180 million dollars of state and federal money to help. The money is being used to support local governments’ stormwater management and ease the transition to the new regulations.
But Baldi acknowledges that amount won’t cover the full cost of dealing with stormwater.
Baldi: “It’s going to cost more money and actually paying through utility fees is probably an appropriate fund source given that we all contribute to the problem. Our hope is that as we learn to implement these programs more efficiently that the cost will go down.”
Baldi says the first step is to see the landscape differently. Instead of funneling water away, new development and management strategies should imitate nature and look for ways to absorb the water on site.
Baldi: “In many ways stormwater pollution is a land use challenge in terms of the way we develop the landscape and the way we live on the landscape.”
There’s no quick or cheap solution to the stormwater problem – and finger pointing is impossible. The pollutants from our daily lives – our lawn care, our cars, our household goods – even the materials we use to build our homes – all contribute to the problem.
And unlike the flaming rivers or raw sewage outflows of the past – polluted stormwater runoff is largely invisible. It’s an environmental threat that the creators of the Clean Water Act may not have envisioned, but is rapidly emerging as one of the greatest challenges to urban waterways in the country.
Copyright 2012 Northwest Public Radio