The Andover Health Division said "untreated or partially" wastewater from the Lowell Wastewater Treatment Facility leaked into the Merrimack between 3:20 a.m. and 6:18 p.m. on Monday, Sept. 5, the division said on Facebook.
As a response, people should stay away from the river and its surrounding areas for at least 48 hours to avoid potential health risks.
The Merrimack Runs for 117 miles through several New Hampshire and Massachusetts cities including Lawrence, Lowell, Haverhill and Newburyport.
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