Coast Guard, Mass DEP respond to dielectric oil leak in Mystic River
by U.S. Coast Guard 1st District Northeast 21 Apr 2018 11:29 UTC

A boat crew from Clean Harbor is working to locate the source of the dielectric oil sheen on Friday, April 20, 2018. The unified command is overseeing dive and freeze pit operations to try and pin point the location of the mineral oil leak © Petty Officer 3rd Class Nicole J. Groll
The unified command is overseeing dive crews and freeze operations this weekend as crews work to locate the source of the dielectric fluid leak in the Mystic River near the Alford St. bridge.
Crews from the unified command will be freezing sections of the pipeline and using pressure to identify the location of the leak.
"During the pressure test, we will freeze the product inside the pipe in two places," said Doug Foley, Eversource's vice president of electric operations. "We'll then test for any pressure loss in the section of pipe between the freeze locations. If there is a loss of pressure in that section, we can focus our efforts along that area of cable to determine if there's a leak."
Dive crews will be using remote operated vehicles and thermal imaging cameras to scan the pipeline in 100-foot intervals.
Once the source of the leak is identified, plans will be put in place to evacuate the pipeline and make the necessary repairs.