PITTSFIELD -- It's been the site of two significant oil spills. It's had garbage, sewage and PCBs dumped into it. It even caught fire in 1923.
But the 26-acre Silver Lake, historically one of the city's most polluted water bodies, is about to enter a new and unexpected chapter as a recreational area that supports activities like catch-and-release fishing, boating and ice skating.
Workers capped major PCB contamination in the lake bottom last fall. That procedure was one of the final tasks in the 16-year-old consent decree that required General Electric to clean up PCB contamination in Pittsfield.
The city will dedicate a pedestrian walkway along Silver Lake's eastern and northern shorelines on Friday, May 23, but the lake is available for recreational uses now, said Parks and Open Space Manager James McGrath.
"It's been successfully cleaned up and restored," said David Dickerson, the EPA's project manager for Silver Lake. "All the monitoring and data that we have since the restoration and capping were done shows that PCB levels are very low. They're not detectable in water."
Silver Lake contains sunfish, carp and largemouth bass among other species, but Dickerson said the EPA doesn't believe the fish are safe enough to eat due to the level of PCBs in their bodies.
"Because PCBs build up in the food chain, they tend to have a fair amount of PCBs in their tissues," Dickerson said. "Until sometime down the road when we see those levels fall below the safe level, we'll have a catch-and-release policy."
The remaining PCBs, which Dickerson said have been found only in sediment since the lake bottom was capped, do not pose a risk to swimming in Silver Lake. However, swimming is "discouraged" due to the lake's location in an urban area, McGrath said, citing language in an agreement between the city and the EPA that outlines Silver Lake's future recreational uses.
The bottom of Silver Lake is capped with a combination of sand and top soil that was mixed with water to create a slurry, Dickerson said. The top soil contains organic carbon, which Dickerson described as a "magnet" for attracting any PCBs that enter the water. The mixture was then spread along the bottom of the lake through pipes hooked to a barge that moved back and forth on the surface.
The mixture was spread at a minimum of 14 inches deep along the lake bed, but is deeper than that at "most locations," he said.
While growing up in Pittsfield, Mayor Daniel L. Bianchi remembers Silver Lake not freezing in the winter, changing colors from time to time, and sometimes being "steamy" in the fall and winter.
"My recollection is that it was a pretty surly place," he said.
He never thought the lake would be in the condition that it is in now.
"I think it's absolutely wonderful to have a nice lake in the middle of the city," Bianchi said.
Not everyone sees Silver Lake as a safe recreational site.
Jane Winn, the executive director of the Pittsfield-based Berkshire Environmental Action Team, doesn't believe capping the bottom of Silver Lake will be effective.
"I don't believe this cap will work," Winn said.
That scenario is supposed to prevent animals from burrowing into the lake bottom, she said.
"I'd be worried that it [the cap] won't last," Winn said. "But they will be monitoring water coming out of the lake, so hopefully we will know if there are still PCBs."
Dickerson said that so far testing reveals that the cap is working.
"I've worked on big PCB dredging projects and big PCB capping projects," Dickerson said. "There's no one-size-fits-all remedy. We're cautiously pleased with the results we've seen so far.
"Time will tell," he continued. "We'll continue to monitor. Right now everything is in the right place. We hope that will continue."
Winn was asked if she would go boating on Silver Lake.
"Gee, I'd probably go boating on it," Winn said. "But I grew up playing on the east branch of the Housatonic River where you could put a stick in there, wiggle it around, and get oil fumes coming up."
She wouldn't recommend boating on Silver Lake to other people.
"I would not want my children doing that," she said.
To reach Tony Dobrowolski:
or (413) 496-6224.