The long-awaited Fawn Lake dredging project is scheduled to start in the following days, the Town of Bedford, Massachusetts, said in their latest announcement.
The Town has contracted with Dredgit Corp. to dredge the pond and to reconstruct the outlet dam at Springs Road.
The work includes hydraulic wet dredging of the bottom sediments to restore the lake to approximately 8-feet deep. The material is pumped from the dredge barge to a dewatering system.
Once the material is dried, it will be transported to a residuals holding area and then hauled off-site to a nearby compost facility for eventual reuse as loam.
Dredgit will utilize a small, portable dredge to hydraulically remove material from Fawn Lake.
The slurry from the lake will be pumped to a parallel array of multiple, high-capacity, big-bowl centrifuges for dewatering. The paint-filter-dry material will then be trucked to a local disposal facility.
The dam restoration and rehabilitation activities will proceed concurrently with the dredging and dewatering operations.
Phase I Mobilization – Initial Site Prep
Commencing on Tuesday, July 21, approximately four days (based on working 12-hours/day, 7-days/week) to prepare the material laydown holding area, including:
- Installation of approximately 60 CY of gravel to level out the area
- Installation of wood mats
Phase II Mobilization – Equipment Set-up
Approximately four days to receive, install, and set up the dredging, dewatering, and material handling equipment, including:
- The centrifuge array and automated polymer injection system—together with their attendant tanks, manifolds, pumps, and piping
- Connecting the 500 kW power plant
- A 6-inch hydraulic dredge and aquatic weed harvester placed in Fawn Lake
- A 6-inch HDPE dredge effluent pipeline installed from Fawn Lake to the dewatering area
- A second 6-inch HDPE return water pipeline installed and routed from the dewatering area back to Fawn Lake
- Installation of a silt curtain in Fawn Lake to control TSS
- Installation of approximately 700’ of temporary chain link security fencing
Phase III Mobilization – Final Site Prep
Approximately four days to finish the material laydown holding area, including:
- Installation of concrete blocks around the laydown area to contain the dewatered material
- Installation of approximately 300’ of silt fence
- Placement of traffic barriers and pedestrian crossing