Coast Guard, Mass DEP respond to dielectric oil leak in Mystic River

Eversource identified the location of the dielectric fluid leak Sunday, after gas was released into the pipe to help identify the leak during the freeze test, USCG said in a media release.

An electrical pipe running underground, under the I-93 bypass in Somerville, was identified as being the source of the product. After excavation, it was discovered that a crack in the line allowed the oil to enter the soil. The product leaked into the storm drain system and then into the Mystic River.

A temporary clamp was fitted around the crack to stop the leak. Crews are scheduled to weld a permanent seal on Wednesday.

Due to the the location of the leak, the unified command, consisting of Eversource, Mass DEP, and the Coast Guard, requested the Coast Guard National Strike Force to deploy and assist with the incident. The Coast Guard Atlantic Strike Team arrived on scene Sunday. The National Strike Force (NSF) provides highly trained, experienced personnel and specialized equipment to Coast Guard and other federal agencies to facilitate preparedness for and response to oil and hazardous substance pollution incidents in order to protect public health and the environment.

The unified command is discussing a long-term environmental clean-up plan for the impacted soil, storm drain system, and the Mystic River. The public is urged to be aware of clean-up operations in the area and avoid contact with any oil. Pollution recovery teams and containment boom remain in place around the Mystic River near the Amelia Earhart Dam.