Clemson Pond Cleaning and Inspection
In March 2025, voters approved Warrant Article 9, authorizing the use of excess bond proceeds for Clemson Pond cleaning and inspection. This project includes evaluating the Combined Sewer Overflow (CSO) infrastructure at Clemson Pond, as well as the two 36-inch CSO siphons that extend from Swasey Parkway, run beneath the Squamscott River, and discharge into Clemson Pond.
For public safety, portions of the walking trail surrounding Clemson Pond will be temporarily closed. Heavy equipment and truck traffic will be present throughout construction, making the trail unsafe for pedestrian use.
We appreciate your patience and cooperation while this important work is completed.
Status Updates
3/13/2026: Cleaning of the two 36” CSO Siphons that carries water from Swasey Parkway to Clemson Pond is underway. Each siphon is fed from a different location. The southernmost siphon receives its flow from Water Street at the bottom of Spring Street. The northernmost siphon receives it’s flow from Water Street in the general area between Dewey Street and Park Street.
The southern siphon has been successfully dewatered, cleaned, and inspected. The contractor began the dewatering portion of the job on the northern siphon at the end of last week, on March 5, 2026. Shortly after work began, it was discovered that the water that was being removed had a noticeable odor, and work was temporarily halted.
Following further investigation, it was determined that residual contaminated material from the decommissioned Manufactured Natural Gas Plant -now owned by Unitil- had migrated into the northern siphon due to its proximity to the contaminated area.
AECOM is currently under contract with Unitil to mitigate issues related to this contamination. AECOM was contacted by the Town last week and they have responded by mobilizing frac tanks to treat the liquid and containers to collect the contaminated material that is being removed during the siphon cleaning. These services are being provided at no cost to the Town.
Work is expected to resume on March 16, 2026. This portion of the project is anticipated to be completed by March 27, 2026.
1/16/2026: Work will resume on Monday, January 26th, to allow for two consecutive 5-day work weeks to complete the cleaning and inspection.
12/5/2025: Due to the past snow and cold weather, this work has been postponed to Monday, December 8th.
11/25/2025: Beginning December 1, a crew from GVC Construction will be on site at Clemson Pond to begin clearing and dredging operations. Work is expected to continue for 3-4 weeks, weather permitting.