Merrimack River still contaminated as rain brings new concern – NBC Boston

Tuesday’s rain could complicate cleanup efforts on the Merrimack River.

New testing from the Merrimack Watershed Council revealed some areas are still contaminated after a massive sewage spill in Haverhill last month.

The water is being tested every day between Haverhill and the mouth of the river.

Another concern was that the rain could trigger a combined sewer overflow, adding even more bacteria to the water before the river has a chance to recover.

“Rain, in and of itself, can introduce bacteria into the river just from stormwater runoff. But it can also put a lot of bacteria in the river, as well, from a CSO, or a combined sewer overflow,” said Curt Rodgers of the Merrimack River Watershed Council. “Haverhill does release CSOs when its system becomes overwhelmed.”

NBC10 Boston reached out to the office of Haverhill Mayor Melinda Barrett to see if there had been a CSO release during the storm, but has not heard back.