The Connecticut Department of Energy and Environmental Protection has announced their monthly project update for the cleanup of lead impacted sediment by hydraulic dredging in the Mill River.
“We are currently in the process of dredging, dewatering the sediment, treating the filtrate water from the dewatering process, and discharging treated water back to the Mill River,” CDEEP stated.
All of the sediment dewatering and water treatment work is occurring at the newly‐constructed facility on Exide’s property at 2190 Post Road in Fairfield. TRC is the firm conducting the cleanup work for Exide.
Activities in November:
– Dredging continued in Area V ‐ the portion of the Mill River near the Mill Hollow Park;
– The turbidity meters (yellow buoys with solar panels), turbidity curtains (floating yellow items), and the large orange pipeline (that conveys sediment to Exide’s property) were moved periodically, as dredging progressed in Area V;
– Area V was divided into seven dredge cells. A dredge cell is an area within Area V with turbidity curtains installed as active dredging is occurring;
– By the end of November, six of the seven dredge cells were successfully remediated;
– Dewatering of sediment and treatment of filtrate at Exide’s property is ongoing;
– Monitoring and sampling, as required by CT DEEP is being conducted;
– Additional operating protocols were implemented that are mitigating intermittent odors.
What to Expect in December:
– Dredging in Area V will be completed in December;
– Dewatering of sediment and treatment of filtrate will continue at Exide’s property;
– Monitoring and sampling will continue, as required by CT DEEP;
– Winter demobilization, consisting of the following:
• The dredge and support equipment will be secured for the winter. This will involve rolling up the turbidity curtains and securing them along the east bank of Area II by Exide’s property. The dredge and support vessels will be removed from the river and stored on Exide’s property;
• The water treatment plant will be “winterized”, this involves a combination of flushing lines, draining pipes and equipment, and securing equipment;
• CDEEP will demobilize staff. However, security will be present at the site during the off season;
– CDEEP will periodically perform inspections of Exide’s property during the winter shut‐down;
– The expectations are to return to the site about mid‐March, weather depending, to begin dredging for 2015.