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Protecting rivers and streams

Protecting rivers and streams

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    Left: John White (center), Streamwood's director of public works, points out some of the features of a new stormwater cleaning unit during installation in Streamwood, III. Greg Sterchi (left) of CDS Technologies and Trudy Buehler of Mackie Consultants in Rosemont, III., look on. Right: The view from the top of a unit reveals the diversion chamber where debris and suspended solids settle out of the incoming stormwater. The unit is designed with a sump that typically has to be cleaned only one or two times per year. Photo: Bob Mead

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    The CDS unit relies on water hydraulics and gravity. Stormwater enters the diversion chamber where a weir guides the flow into the unit's separation chamber. A vortex is formed that spins all floatables and most suspended solids to the center of the separation chamber. The trash and suspended solids settle into a sump where they remain until they are removed. The water passes through a self-cleaning screen with the cleaned water then being discharged. Source: CDS

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    Teacher Deb Perryman (left) and public works director John White work with a crew to clean up Poplar Creek and the Fox River. Photo: Bob Mead

Like a train leaving the station, the impact of the Federal Water Pollution Control Act of 1972 has gradually gained momentum over the years. After more than a quarter-century the effects of the Clean Water Act, as it is often called, are undeniable: America's surface waters are cleaner than they have been in three decades.

There was a time when the Clean Water Act was not vigorously enforced. A few years ago, the U.S. Environmental Protection Agency turned up the heat on enforcement, with particular attention to rules governing point source pollution control and erosion control. The National Pollutant Discharge Elimination System (NPDES) is the portion of the Clean Water Act dealing with point source pollution control. The NPDES states that facilities such as businesses and housing developments that discharge pollutants from any point source into America's waterways must have a permit.

“The NPDES definitely has more bite these days. There is much greater enforcement and fines are being levied for noncompliance,” said Trudy Buehler, P.E., with Mackie Consultants in Rosemont, Ill.

The growing emphasis on point source pollution control has focused increasing attention on stormwater runoff. As a result, public works directors all over the country are now addressing the issue, some more eagerly than others. One of the most ardent clean water proponents in northern Illinois is John White, P.E., director of public works for the village of Streamwood, Ill. (population 36,500), a fast-growing suburb about 30 miles northwest of downtown Chicago. In addition to his duties for Streamwood, White serves on the Poplar Creek Watershed Planning Committee, a group that is the prototype for other regional watershed management organizations in the state. For the past several years, White has been actively involved in researching and designing a new residential stormwater system for his community that will incorporate some of the best new pollution control technologies available.

“It's too early to see the results in our local waters, but we're confident that the steps we've taken in designing this system will clean our stormwater runoff and protect the surface water in the area,” said White.

Which Way To Go?

Streamwood's newest stormwater system was designed to transfer rainwater runoff from an upscale residential housing development to nearby Poplar Creek and then further downstream to the Fox River. The new development covers 120 acres and has almost 325 dwellings. Part of the acreage will be left as wetlands or detention ponds, meaning that some of the stormwater will not leave the site but instead percolate into the groundwater.

When considering this new subdivision, one of the first questions White had to answer was, “which stormwater pollution treatment technology was best for this application?” A studious and careful planner, White was not going to make a snap decision based on any one factor. “I started doing research into the different stormwater treatment systems on the Internet and in various publications,” said White. “I went to the annual Water Environment Federation conference and spent a couple of days going to each manufacturer's booth to get specific information about each technology. I tried to be very thorough because this was an important decision for us. My goal is to use the same technology throughout all of Streamwood's storm sewer systems, for the sake of continuity and so that we only have to train our personnel to work on one type of device.”

White said that several of the systems he examined do a good job of cleaning stormwater runoff and most are generally in the same price range, but that does not mean that all technologies are created equal.

“Ease of operation is always a consideration. I found that a lot of the systems are very difficult to clean. I don't want something that requires an enormous effort to maintain. We have two Vactor trucks already, so we felt it was important to find a technology that could be cleaned using those machines,” he said. “We wanted to avoid buying new equipment or getting into a complicated maintenance program.”

After considering several options, White zeroed in on CDS Technologies Inc., Morgan Hill, Calif., makers of a continuous deflective separation unit that removes solid wastes and floatables from stormwater. According to White, the technology was not only easy to maintain, it was an effective device for removing debris and contaminants from stormwater.