MGP-impacted soils are secured within the “burrito bag” truck liner prior to departure from the site

Sevenson Environmental, National Grid’s Remediation Contractor, completed the reconnection of the air handling unit and other ancillary equipment and began excavation within the fifth temporary fabric structure (TFS) location on Wednesday, April 1. In addition, Sevenson conducted an “open air” excavation (outside of the TFS) of northwestern portion of the site, southwest of the intersection of Long Island Avenue and Bridge Street. 4,201.24 tons of MGP-impacted soils were removed and transported from the site to a thermal treatment facility in Southeast Pennsylvania. The total amount of soil removed from the site to date is 29,971.14 tons.

Sevenson’s dewatering subcontractor, Griffin, connected the header piping to the previously installed dewatering wellpoints and began dewatering operations on Tuesday, March 31. 1,188,421 gallons of water were treated this week, bringing the total amount of treated water discharged from the site to 13,396,810 gallons.

Conducting the “open air” excavation of MGP-impacted soils along the northwest portion of the site

Two-Week Outlook

The excavation and transport of MGP-impacted soils within the fifth excavation location is scheduled to be completed by the middle of next week. Backfilling, confirmation survey of the final excavation depth and the disconnection of the air handling unit and other ancillary equipment will continue through the remainder of the week. The final move of the TFS to the sixth excavation location will occur late next week or the beginning of the following week, followed by reconnection of the air handling and carbon filtration units and other ancillary equipment. Excavation activities at the sixth and final TFS location are anticipated to begin mid-week. Access road re-alignment for on-site truck traffic, site grading, and site maintenance activities will continue in preparation for excavation of the sixth location. Backfill material will continue to be delivered to the site on an as-needed basis.

Sevenson’s dewatering subcontractor will reconnect the headers to the wellpoints installed at TFS position 5 and remove the wellpoints installed at the fourth TFS location. Dewatering will begin prior to the commencement of excavation activities at the sixth excavation location. Groundwater removed from the excavation footprint will be pumped to the water treatment plant and discharge.

Roadwork Construction continues work to tie-in the businesses located along Long Island Avenue to the new 12-inch water main and complete the retirement of the old water mains. The water main work along Long Island Avenue will continue to be conducted during the general site operation hours, with work scheduled to be completed Tuesday, April 7. Again, one lane of Long Island Avenue from Main Street to Bridge Street will be closed with traffic controls in place to support 2-way traffic flow on Long Island Avenue.

Utility crews continue to work on the temporary re-location of overhead and buried utility lines on northern Bridge Street to Long Island Avenue in preparation for the excavation of soils beneath Bridge Street. The line re-location work is anticipated to be completed Monday, April 6.

General hours of operation will continue to be Monday through Friday, 7:00 AM to 5:00 PM, and Saturdays, between 8:00 AM and 6:00 PM.