2026 Haverhill Sewer Main Break
On Friday, June 26, a sewer main break occurred in Haverhill.
As of Monday (June 29), the break was expected to take a minimum of 4 days to repair and possibly longer. Until the break is repaired, the overwhelming majority of Haverhill’s sewage is being discharged directly into the Merrimack River at an estimated rate of 7-10 million gallons a day. The pipe involved was a 50-year old 42” concrete main. As initial evaluation work was done on the site, a second break in the line was discovered several hundred feet up from the first break.
MRWC recommends that people do not engage with the Merrimack River downstream of Haverhill, including Newburyport Harbor, until testing can validate that it is safe to do so. Unsafe conditions will likely extend through the July 4th Weekend.
MRWC is currently testing for bacteria downstream of the break from Haverhill to Plum Island every day beginning Monday June 29 and posting the results below. We are also curating updates from the impacted municipalities at the bottom of this page as they become available to us.
Putting This Event Into Context:
Haverhill has an average of 35 combined sewer overflow (CSO) events in a year. A median Haverhill CSO discharges roughly 60,000 gallons. However, a large Haverhill CSO (top 2%, or roughly once every 2 years) can discharge approximately 10 million gallons. Typical Haverhill CSOs impact an area immediately downstream for roughly 3 days. These typical CSOs do not significantly impact the bacteria levels beyond the Artichoke River in West Newbury.
Post-event Testing
Our Test Sites
The map above shows each of our test sites downstream of Haverhill. We will be testing each of these sites throughout the week and providing information on our test results in the table below. Please note that there is a 24-hour waiting period for each test to allow the bacteria to incubate to a measurable level. The most recent result in the table below will always be from at least 24 hours ago.
Results in the table below are for bacteria only. A reading of ‘safe’ indicates a fecal coliform level below the recreational limit of 235 colony-forming units per 100 milliliters for E. coli or 104 colony-forming units per 100 milliliters for Enterococcus.
E. coli measurements are taken at Haverhill and West Newbury, while Enterococcus measurements are taken from sites downstream.
Test results take 24 hours to incubate so the results in the table below should not be interperted as current information. Defer to public health officials when making the decision to recreate in the river.
| 6/29/2026 | |
| Route 113 Bridge | Safe |
| Ferry Park | >40x limit |
| Deer Island | Safe |
| Route 1 Bridge | 4 – 5x limit |
| Newburyport Harbor Master | 1 – 2x limit |
| Salisbury Beach River Side | Safe |
| Plum Island Light | Safe |
Municipal and State Response
What is your town or city saying about the impact of this event?
Keep posted for the most recent updates from each municipality, including official recreation recommendations.
A response from Massachusetts Department of Conservation and Recreation (DCR) is also included.
Haverhill
Haverhill has already begun installing a temporary bypass pipe from the pumping station at the site of the break to the wastewater treatment plant, but as of 6/29 the break is not yet repaired.
Haverhill has warned the public to avoid contact with the river both in Haverhill and downstream.
Read more from the City of Haverhill here. (6/29/26)
The Merrimack River Watershed Council will post test results from the Route 113 Bridge above as they become available.
Groveland
Groveland has not yet issued an official statement on the situation . As all of Groveland’s riverfront is located across the water from Haverhill, residents and visitors should continue to check Haverhill’s daily updates here.
West Newbury
West Newbury has not yet issued an official statement on the situation . Residents and visitors should continue to check Haverhill’s daily updates here, and refer to our test results from Ferry Park as they become available.
Merrimac
West Newbury has not yet issued an official statement on the situation . Residents and visitors should continue to check Haverhill’s daily updates here.
Amesbury
Residents and recreational users are advised to continue avoiding contact with the Merrimack River in the vicinity of Haverhill and downstream until further notice due to the potential presence of elevated bacteria and other pollutants.
Newburyport
“Out of an abundance of caution, the City of Newburyport has closed Plum Island Beach to swimming until further notice. The closure will remain in effect until the discharge has stopped, repairs have been completed, and water quality testing confirms that conditions are safe for the public.”
“Residents are urged to avoid contact with the Merrimack River until further notice, consistent with public health guidance. The City will continue to provide updates as new information becomes available and will reopen Plum Island Beach for swimming as soon as testing confirms it is safe to do so.”
Salisbury
“The State Department of Conservation and Recreation has issued the following precautionary posting for Plum Island and Salisbury Beaches: Swimming at these beaches is not advised at the present time due to potential exposure to bacteria associated with a sanitary sewer overflow in Haverhill, which was caused by the rupture of a force sewer drain.”
https://www.facebook.com/109687914116386?ref=embed_page (6/29/2026)
Massachusetts
“Swimming at Salisbury Beach State Reservation Main Beach & North Beach DCR has issued a precautionary posting in response to the recent CSO event in Haverhill affecting the Merrimack River which lets out to the Atlantic Ocean adjacent to Salisbury State Reservation. Swimming is not advised due to potential exposure to bacteria associated with the accidental wastewater release. Please check back for updates.”