Connecting Land portion of pipeline to harbor portion

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 14 trucks were utilized to transport and dispose of 341 tons of the soil mix wall spoils to a thermal facility in New Jersey. Sevenson installed the land portion of the discharge line from the waste water treatment plant to the harbor. The waste water treatment plant initiated discharging to the harbor on Saturday.

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 10 soil mix wall columns were installed.

Welding discharge pipeline

Soil mix wall activities were shutdown from Tuesday to Friday due to standing water onsite. An unmarked water service was severed on Monday while installing the soil mix wall. Suffolk County Water Authority located and shut off service late Wednesday evening.

Sevenson’s dewatering subcontractor, Griffin, continued the installation of the excavation dewatering system this week. The well points will be used to pump groundwater from the excavation to the waste water treatment plant.

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. Winterization and heat tracing of the water treatment plant 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. Transportation and the erection of the temporary fabric structure are also scheduled to begin within the next two weeks. Griffin will continue installing well points.

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.