NEWBURYPORT — With boating and beach season fast approaching, Mayor Donna D. Holaday wishes to provide an update on the combined sewer overflow (CSO) early alert system for Newburyport.
The City of Newburyport is working to certify a new online early alert system to help better inform the public about potential risks from pollutants and effluent following combined sewer overflow events.
This predictive tool was designed by consultants Brown and Caldwell. It uses river flow data provided by stream gauges and data shared by regional sewage treatment plants to predict and evaluate when storm-triggered sewage discharges may result in potential risks to recreational river users.
To help validate this system, the Merrimack River Watershed Council (MRWC) is conducting water sampling in the Merrimack River during the spring and summer.
Due to drought conditions throughout the season, flow levels in the river remained low and bacteria from CSO discharges did not reach Newburyport. The early alert tool successfully predicted this low potential risk.
Further sampling is needed at higher river flows to fully validate the tool. If CSOs are not observed during higher river flows, the project team will consider alternative methods to confirm the early alert tool’s accuracy in order to allow for its use this summer.
Development of this tool was made possible through cooperation from the regional wastewater utilities, including Greater Lawrence, Haverhill, Lowell, Manchester, New Hampshire and Nashua, New Hampshire. This new collaborative approach was also made possible through the formation of the Merrimack River District Commission which represents key stakeholders along the river.
“The partnership of the MRWC, Merrimack Valley Planning Commission and Brown and Caldwell has been invaluable in the extensive analysis of data and creation of the early alert tool,” said Mayor Holaday. “This is a major step forward in the notification to all users of the river when bacteria levels are elevated and there may be risks associated with CSO discharges.”
Additionally, the recent passage of CSO notification legislation in Massachusetts will result in better data transparency which will help advance the science that informs the tool.
A formal launch date for the system will be announced in the near future.