Applying foam to control odors from soil mix wall installation

Sevenson Environmental, National Grid’s Remediation Contractor, is continuing pre-trenching activities this week. Debris that is removed during pre-trenching is placed inside the designated storage pad, sprayed with long duration foam and covered with a plastic liner to mitigate potential odors until the debris is removed from the site for disposal. Last week 49 trucks were utilized to transport and dispose of 1,180 tons of the soil mix wall spoils to a thermal facility in New Jersey.

Sevenson’s soil mix wall subcontractor, Geocon, continued the construction of the soil mix wall along the perimeter of the site parallel to Bridge Street. A total of 57 soil mix wall columns were installed.

National Grid’s pipeline contractor is continuing the installation of the pipeline that will be used for the Waste Water Treatment Plant discharge. The harbor portion of the pipeline is complete and work on the land portion of the pipeline will start in the next two weeks.

National Grid determined that grout from site operations have impacted sanitary sewer flow in Long Island Avenue, adjacent to the Post Office, and is continuing work to remedy the problem. National Grid contractors have been using trucks to bypass and transport sanitary water directly to the Village treatment facility.

Two-Week Outlook

Sevenson is expected to continue the mobilization of equipment, materials, and construction of temporary facilities. Set-up of the water treatment plant for the dewatering operation will be ongoing for the next several weeks. Sevenson and Geocon are also expected to continue pre-trenching activities and the construction of the soil mix wall along the perimeter of the work area. Mobilization of the temporary fabric structure is also scheduled to begin within the next two weeks. Sevenson’s dewatering subcontractor, Griffin, will be installing well points used to pump groundwater from the excavation to the waste water treatment plant.

National Grid contractors will continue working in Long Island Avenue to address sewer line issues.

General hours of operation will continue to be Monday through Friday, 7:00 AM to 5:00 PM.