By Tim Stelloh
Staff Writer

September 22, 2007

NORWALK - A stormwater filter system designed to keep harmful pollutants out of Long Island Sound will be installed in East Norwalk next week, according to Soundkeeper, a Norwalk environmental group.

Fifteen filters will be placed in catch basins along Second Street, New Street and Cove Avenue, said Terry Backer, Soundkeeper's executive director.

The system is part of a two-year pilot project funded by the federal Environmental Protection Agency. The filters contain a sponge that captures oil, grease, garbage and contaminated sediment. The sponges are treated with material that also kills bacteria, Backer said.

The first part of the project - which included the installation of 275 filters in South Norwalk - has been successful, Backer said.

The filters have killed 80 percent to 90 percent of the bacteria that would have entered the Sound, he said.

"Bacteria is why they close beaches. Bacteria is what concentrates in shellfish," he said. "When you start looking at bacterias like E. coli, that limits the public's interaction with water."

The filters have picked up loads of garbage - "we've found potato chip wrappers, booze bottles, socks, shoes, you can find it all," Backer said - and captured the equivalent of a 1,200-gallon oil spill.

But the filters do not capture metals such as chromium and lead, he said.

Once the project's two years are up in November, it is up to municipalities to begin using the technology, Backer said.

"We'll compile data from tests, have someone look over the data and vet it," he said. "Then we'll work up a price-versus-value ratio for public works departments. If you can open up swimming areas you couldn't open up before, that's a big deal."

The filters cost $600 to $1,000 each and must be replaced every four to five years, Backer said. More than a third of the filters' cost is for a stainless steel collar that attaches the filter to the catch basin and has a lifespan of 20 to 30 years, he said.

Unlike sewage treatment plants - which have come under greater scrutiny in the last 20 years - Backer called stormwater runoff "the last great unregulated pollutant."

Cleanup of the Sound has been stalled because of a lack of stormwater management, he said.

"Our stormwater regulations are laughable," he said. "You have to sweep the streets once or twice a year and clean the catch basins once a year."

An EPA report earlier this year gave the Sound some of the worst ratings in the United States. Though its water quality was given a fair rating, fish and sediment were found to be contaminated with industrial pollutants.

Mark Tedesco, head of the EPA's Long Island Sound Study, said it's too early to tell how effective the stormwater filters are at stemming pollution in the Sound. Though the project has a lot of potential, using filters to curb runoff is just one solution, he said.

"The filter project is the end of the line, it's that last-ditch effort where its your last chance to catch (pollution) before it goes into local water," he said. "We're also interested in how we can minimize future increases in stormwater pollution through better management decisions and growth patterns."

Low-impact development and collecting stormwater runoff from roofs and parking lots for landscaping irrigation are also important tools, he said.

Copyright © 2007, Southern Connecticut Newspapers, Inc.