A Monday storm at approximately 8 p.m. – which included 20 minutes of intense rainfall – triggered a combined sewer overflow event during which a high volume of storm water flooded into the system, and a mixture of storm water and sewage was diverted and released into the harbor.
Pavilion Beach was closed pending test results for bacteria levels in the water, which were expected back Wednesday.
Max Schenk, manager of environmental health services for the Gloucester Health Department, said that in some older sections, the catch basins are connected to the sewer systems, with all of the water flowing to the waste-water treatment plant.
In a combined sewer overflow event, “the system becomes inundated, and automatic release points keep it from backing up into homes and coming to the surface,” explained Michael Lane, director of public works.
Under state and federal environmental mandates, the city has been addressing the issue of combined sewer overflow with a $40 million project aimed at expanding the system’s capacity, said Lane. The project, which began in 2005, is expected to be completed in November. But Lane said the city would continue to review its needs and could determine that more work is needed.
Combined overflow events have become much less common. “It wasn’t many years ago that for each rain event we’d have, Pavilion Beach closed,” Lane said. “Now it’s once every 18 to 24 months.”
In the past, Lane said, the beach has usually been reopened after a day, when the test results have returned, a testament to the tidal flush cleaning the water.
It was the second time a city beach has been closed this year. Earlier in June, Plum Cove Beach was closed when a high bacteria count was detected by the Health Department’s routine testing.
Updates are available at the city’s website, www.gloucester-ma.gov, or call the Gloucester Department of Public Works at 978-281-9785.