June 06--ANDOVER -- Flame retardant used to douse a burning plane at Hanscom Field in Bedford on Saturday night has floated down the Shawsheen River and appeared at the Ballardvale dam, where huge piles of light, white, fluffy foam formed over the rocks and floated into the air Tuesday and Wednesday.
Yesterday afternoon, pockets of it remained and small pieces continued to float into the air around the dam, located just north of the Andover Street bridge. Smaller pockets of foam were reported at the Stevens Street dam in Andover.
Environmental officials say the flame retardant used at the crash site floated down the river as "residuals" which aren't visible unless the water gets stirred up, which is what happened due to the turbulence of the water at the base of the dams. However, it presents no environmental or health threat, they said.
But it certainly created a curiosity.
Charlie MacNeil, co-owner of Andover Hardware, an industrial supply company with an office on the river, said he saw it Wednesday afternoon and assumed it was created by dish soap thrown into the river.
"It was like someone had a bubble-maker," he said. "It was floating up into the air."
He said a fisherman who had waded into the river was enveloped by the foam as he cast his line.
"He was surrounded by it," he said. "It was interesting to see."
The fire-retardant foam was used to douse the flames Saturday night in a plane crash that killed seven people. At 9:40 p.m., the Gulfstream IV aircraft was attempting to take off from Hanscom but apparently never left the ground. Instead, it hurtled off the runway, across a field and into a ravine where it exploded into flames. Federal officials are continuing to investigate the cause of the crash.
The point where the plane crashed and burned is also where the Shawsheen River begins. According to the Shawsheen River Watershed Association, the river starts at Hanscom Field and runs 25 miles through a half-dozen cities and towns before dumping into the Merrimack River near the I-495 overpass in Lawrence.
The dam in Ballardvale is the first dam on the river after the headwaters.
In Bedford, town officials shut down the wells it uses to pump drinking water from the Shawsheen on account of the crash. Environmental cleanup crews installed booms and other devices to soak up the oil and fuel that spilled as a result of the crash.
The booms did not, however, contain the fire-retardant foam.
For a short time, the origin of the foam at the Ballardvale dam was something of a mystery, said Bob Douglas, the agent for the Andover Conservation Commission.
He said he was at the regular, monthly Commission meeting Tuesday night when someone showed him pictures of the foam, which was building up at the base of the Ballardvale dam, blowing around in the breeze and floating down the river.
Conservation volunteer Andy Menezes of 3 Waverly Drive, Andover, was also at the commission meeting and he saw the photos and became extremely curious about where the foam came from.
"I live down there, so after the meeting I went down there at about 10:30 that night and stood on the wall," he said. "I could see some pieces of it floating around. It didn't smell, and to the touch it was very dry. I figured it was some kind of chemical dispersant from some kind of spill. But that's usually slimy. This was dry."
At daylight Wednesday morning, he said, he went out and took a closer look and noticed that it was bright white, so it couldn't have been organic. He said organic foam is usually slightly brown.
He then went home and did some research about the cleanup of the plane crash. He saw photos and read accounts of fire-retardant foam being used. He wrote up a memo and sent it to Douglas.
"Most of the stuff is supposed to be non-toxic," Menezes said. "I think it's benign, but they used a lot of it. The headwaters of the Shawsheen are right at the end of the runway. I thought about those poor people who died, then I thought about the river."