A notice from the Merrimack River Watershed Council (reprinted by permission.)

NEWBURYPORT — Join the Merrimack River Watershed Council on Thursday, Oct. 18 in Newburyport City Hall at 7 p.m. for an informative discussion on an environmental issue that has gained much public attention — the frequent release of sewage into the Merrimack River by municipal wastewater treatment plants.

Brown foam, scum and detritus litter a public landing in Newburyport a few days after sewage was released into the Merrimack River.

The sewage releases often occur after heavy rainstorms, fouling the river for days and causing potential health risks to humans and animals. A 2015 health study found that Merrimack Valley hospitals experience a significant increase in emergency room admissions for intestinal disorders in the days following sewage releases. The releases often lead to harmful conditions for fish such as striped bass, and dog owners in the Newburyport area have reported severe illnesses contracted by dogs after swimming in the river.

The MRWC has gathered a substantial amount of data on these sewage releases, known as Combined Sewage Overflow events or CSOs, and has also been active in an effort to require sewer plants to alert the public whenever CSO events occur. Thursday’s talk will give a detailed look at the data and trends, the status of legislation, potential solutions, and ways that the public can help bring about change.

About 400 to 600 million gallons of polluted CSO wastewater is released into the Merrimack every year by the plants that serve Haverhill, greater Lawrence, greater Lowell, Nashua and Manchester. The sewage releases had been trending downward from 2015-2017 largely due to a three-year drought, but 2018 has seen a significant increase in rainfall and CSO events.

The current trend is likely an indicator of the future. The federal Environmental Protection Agency predicts that climate change will cause heavier and more frequent rainstorms, further increasing the quantity of CSO events.

The plants are permitted by the EPA to release raw sewage into the Merrimack. However, they are also operating under enforcement agreements that require them to end their CSO events over the course of the next 20 or more years.

The event is free and open to the public. This is the first in a series of public events that the MRWC will host in the Merrimack Valley regarding the CSO issue. For more information on CSOs and the Merrimack River Watershed Council, visit www.merrimack.org.

Founded in 1976, Merrimack River Watershed Council (MRWC) is dedicated to promoting a clean and accessible Merrimack River and watershed. As “the voice of the Merrimack,” the Council’s mission is to protect, improve, and conserve the Merrimack River watershed for people and wildlife through education, recreation, advocacy, and science.