The city of Bangor is still working to clean up a contaminated part of the Penobscot River more than 50 years after the closure of a gas plant that polluted it with coal tar.
Bangor has been under a state consent decree since April 2007 to clean up a part of the Penobscot River near the Maine Savings Amphitheater that is contaminated with large amounts of coal tar deposits. It’s one of several ongoing federal and state efforts to rehabilitate the Penobscot River along the Bangor waterfront.
Bangor Gas Works operated a manufactured gas plant from 1850 to 1963 on land that is now the site of Shaw’s supermarket on nearby Main Street, and dumped coal tar, which is a byproduct of gas manufacturing, into that part of the river, where some of it hardened into sediment.
While a court found that Citizens Communications Co., the company that owned Bangor Gas Works, was responsible for financing most of the cleanup, the city has been on the hook for the rest because it provided the sewer line that Bangor Gas Works used to dump the coal tar into the river, city engineer John Theriault told the city council’s infrastructure committee earlier this week.
“At real low tide, there was so much gas, [the river] looked like it was boiling,” Theriault said of when the city began its cleanup efforts.
The infrastructure committee agreed at its Monday meeting to adopt Theriault’s recommendation that the city pay $98,000 to Burns and McDonnell, an engineering firm that has contracted with the city for the past two decades, to continue efforts to remove 10 acres of hardened tar deposits that have settled on the river bottom, where they’re visible at low tide.
Some of those deposits lie in the river’s navigational channel, where boats travel down the river, though they haven’t had an impact on the cruise ships that have docked in Bangor this summer, Theriault said.
The city previously dredged the river in 2009 to remove tar deposits and capped other parts using crushed stone, clay and boulders in order to prevent the coal tar deposits from migrating to the surface, according to a city summary of the project.
