U.S. Water News Online
SEATTLE -- So it's been raining for 27 days. Where does all
that water go?
The rain falls on rooftops and sidewalks and streets, on fields,
golf courses and lawns, on park lands and play fields, on forests and
industrial sites. It mixes with oil, pesticides and any number of
other nasty substances.
Then much of the water finds its way into area lakes and streams
-- many of them salmon-bearing -- and eventually into Puget Sound.
"Stormwater is a source of pollution, because there are pollutants
in our environment that the stormwater picks up and conveys through
the system," state Ecology Department spokesman Larry Altose said.
Recently, Seattle had its 27th consecutive rainy day here -- six days
away from the 33-day record set in 1953. "That's why you're starting
to see stormwater controls become part of our municipal
Industry, septic tanks and manure-rich dairies are not the only
polluters putting salmon runs and killer whales at risk.
Look in the mirror for the source of "non-point pollution." Cars
leak fluids and spew brake-shoe and tire residue onto the street.
Homeowners using pesticides to ensure a velvety lawns. Pet owners
walk the dog and leave the droppings where they fall.
"It's everybody's turn," said Fred Felleman of Ocean Advocates.
"It's about caring for your car so it doesn't leak oil, using organic
alternatives in the garden."
Runoff used to be an issue primarily for lakes and other smaller
bodies of water, he noted. Now larger bodies -- Hood Canal and Puget
Sound -- are at risk as the area's population booms.
"We each, in our very small ways -- multiplied by the millions of
us -- are contributing to the overall pollution of our waters,"
There's also persistent pollution from way back. PCBs, or
polychlorinated biphenyls, once used in electrical transmitters and
banned since the 1970s, still show up in top-of-the-food-chain
critters such as killer whales -- and humans.
"There are compounds used in everyday life that we might not be
aware of -- elements of plastics that we use are found in stormwater
sediments, for example -- that are finding their way into our bodies
of water and ... into us and other creatures," Altose said.
Cities are making headway in the struggle to cope with heavy
But during heavy rains, combined sewage and stormwater flows still
gush into Puget Sound and the Duwamish River from the greater Seattle
area. Improved systems help reduce overflows of raw sewage, Altose
said, eliminating a certain "ambiance" that used to be an inevitable
byproduct of heavy rain.
Most of the sewage has undergone at least basic treatment before
"There's raw sewage in there but it's really diluted," said King
County wastewater-treatment spokesman Gary Larson. At the same time,
"we don't recommend swimming in any of these areas."
Relentless drizzle can cause other problems, as well. Sewer pipes
always leak, Altose says -- and when the ground is saturated,
sometimes the stormwater seeps into the pipes, increasing the load
for treatment plants.
Cities and builders are exploring more natural systems that allow
stormwater to pool and filter through dirt, giving sediments in road
runoff to settle out.
Seattle has a couple natural-drainage-system projects, said
project coordinator Jim Johnson.
There's a completed system of planted cascades and stairsteps near
Carkeek Park called a Street Edge Alternative, with no sidewalks. In
West Seattle's High Point neighborhood -- a 120-acre Seattle Housing
Authority project that combined low-income rental properties with
private ownership -- there are plans for a system that includes
sidewalks with 2-foot-wide "curb cuts" every 25 feet or so to let the
water into shallow swales of mowed grass.
"We're infiltrating runoff back into the water table, keeping
pollutants out of the urban streams and holding the runoff back,"
In heavy rains, the swales still fill up and overflow goes into
area streams. But it's an improvement over the old days, when water
flowed off the road into a ditch directly into a creek.
"This is holding it back, reducing volumes and velocity in the
creek and reducing pollutants -- both of which are important to the
health of the sound," Johnson said.
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