Commercial Point — Dredging
Client: Private Client
Location: Dorchester, MA
Project Description: T Ford Co. Inc. performed near shore and offshore dredging of contaminated sediment at a former MGP site on Boston Harbor. The site is currently an active marina. Near shore dredging was performed outboard of a 100 year old granite block seawall and required development of a staged dredging plan and seawall protection plan. The near shore dredging was performed in small cells within steel sheet pile cofferdams adjacent to the seawall. Each cell was dredged to remove the contaminated sediment and backfilled with a lean concrete mix.
Off shore dredging work consisted of both contaminated sediment and maintenance dredging of non-contaminated sediments. Maintenance dredging spoils were disposed of at the Massachusetts Bay Disposal Area as per the US Army Corps of Engineers permit. Contaminated sediments were offloaded to land at the site and trucked to the soil processing area (SPA).
Contaminated sediments were stabilized at the SPA prior to off-site disposal. Initially the sediments were dumped in a containment pit where excess water was collected and pumped into Frac tanks for offsite disposal. The sediments were then stabilized by blending Portland Cement into the sediment and allowing the mixture to cure in a stockpile. After sufficient curing the stabilized sediments were loaded on trucks for hauling to the offsite Thermal treatment facility.