The ultraviolet (UV) pilot program at King’s Beach wrapped up on Monday, and all equipment—except for the UV trailer—is expected to be dismantled by Friday, according to interim Town Administrator Gino Cresta.

Water quality issues at King’s Beach date back nearly a century, when Stacey’s Brook, which flows into the beach, was converted into a combined sewer and stormwater system serving both Lynn and Swampscott. In 2023, King’s Beach failed nearly half of its water quality tests, according to data on the City of Lynn’s website. The project, fully installed on June 2, uses UV light to kill bacteria in stormwater before it reaches the ocean, aiming to create a cleaner beach for residents of Swampscott and Lynn.

“We ended the pilot program as a mutual agreement between all of the parties – myself, the mayor of Lynn, and Kleinfelder,” Cresta said. “We felt that we got as much information as we possibly could get from it, with the exception of this entire time we never got that one big storm we were hoping to get to see how effective it would be in a one-inch, two-inch rain storm.”

Cresta said there’s no guarantee of a large rainstorm in the next two weeks, so the decision to end the program early was made because “we’re starting to override the cost of this…plus the added (benefit) of stopping the noise.”

A group of residents from Swampscott and Lynn issued a legal notice over noise generated by the two-town UV treatment project. The group alleges the pilot program violated noise limits, citing a commissioned study that recorded noise levels between 61 and 65 dB, “far in excess of the allowance of 10 dB above” ambient noise, as permitted by the Department of Environmental Protection.

Since June 20, water treated through the UV system has consistently tested at or below 10 colony-forming units per 100 milliliters (cfu/100 ml), except on June 28, July 24, and July 26. The Massachusetts Department of Public Health specifies that safe waters have at or under 104 bacterial organisms cfu/100 ml.

Meanwhile, untreated water flowing from the Stacey’s Brook culverts in Lynn and Swampscott have often been above 104 cfu. Majority of the Massachusetts Department of Health’s weekly testing has shown the water quality as acceptable throughout the summer.

On Tuesday, Cresta said the barriers and fencing were starting to be removed. 

“The only thing that could be left is the UV tank itself…because that has to go back up to Canada, and we have to coordinate a crane, trailer and shipping it back up to Canada,” Cresta said. “All (costs) covered.”

In September, engineering consultant Kleinfelder will analyze the data, and Cresta said follow-up meetings will be held to discuss the findings. Lynn Communications and Strategic Initiatives Manager Valerie Vong told the Swampscott Tides that the analysis will help inform another potential program in 2026. 

Beachgoers are able to check the bacteria levels at the Department of Public Health’s interactive website. The data is on a 24-hour lag, however. 

As of publication, the site lists King’s Beach as open in both towns.

Updated August 20 with additional information on water testing data