Plattsburgh, New York
The project site is located on Saranac Street in the City of Plattsburgh, NY. An electricity generating plant was constructed on a portion of the site in 1891, and a coal tar lagoon was used to store waste generated by the facility. By 1949, the plant had expanded to include three gasholders. The electricity generating plant was converted to a utility garage and repair shop, and commercial businesses were established in several other site buildings. MGP operations ceased around 1960, and the site was used as a NYSEG service center until 1980. The site has been vacant since 1980. Sediments in the Saranac River are contaminated with MGP-related material, including coal tar, sheens, and odors from earlier operations. As a result, elevated levels of VOCs and PAHs were documented.
Sevenson participated in various constructability reviews for this project where we provided an analysis of multiple remediation methodologies and their respective impacts and costs. Once the remedial design was finalized, Sevenson performed the mechanical dredging of 48,648 CY of impacted river sediment and designed and implemented a major river diversion system. Crews performed the characterization, stabilization, transportation, and disposal of 36,000 CY of impacted sediment. Sevenson constructed, operated, and maintained a 1,000 GPM WWTP which ran 24 hours per day, seven days per week, and treated and discharged >2.2M gallons of water. Sevenson was the recipient of the Iberdrola 2016 Supplier of the Year Award (Finalist) and the Avangrid 2016 Sustainability & Corporate Social Responsibility Award for this project.