The Merrimack River Watershed Council has reported a large sewage release by Lawrence, MA.  See the article here.  In addition to Lawrence, the MRWC will try to report on releases from Lowell, MA; Haverhill, MA; and Manchester, NH.  As noted in the cited link, only Nashua, NH is required by law to make timely notifications to the public of sewage releases.

Please be aware of limiting contact of people and pets to Merrimack River water over the next several days.  See the cited article for more details.