Construction Progress at the Former Hempstead Manufactured Gas Plant Week Ending 10/10/2008
National Grid’s contractor (Entact Environmental Services) started assembling the temporary enclosure in the area of IRM Excavation Areas B & C (refer to the August 2008 Hempstead Fact Sheet for the location of Areas B & C).
Some additional test pit excavations were performed to better understand the orientation of underground piping located near IRM excavation Area B.
Contaminated soil excavation started near the eastern property line of the former MGP site, adjacent to adjoining Long Island Railroad property. Limited excavation work is being performed in this area without the temporary structure because nearby overhead electrical power lines on the Long Island Railroad property are too close to permit safe working conditions with the enclosure installed in this area. Odor controlling foam was used as necessary during this excavation to reduce odors from this work.
On and off site drilling and sampling activities continued. This work is being performed to support the design of remedies for off site contaminated groundwater and for deeper tar impacted soils.
Community air monitoring was conducted during all intrusive activities to ensure that the activities did not produce airborne contaminant levels above regulatory standards. Monitoring alarms were set at levels below the regulatory standards to ensure that corrective actions could be taken before the standards were exceeded.
Two week Outlook:
Assembly of the temporary enclosure will be completed and a vapor treatment system will be attached to the enclosure. Removal of MGP-impacted soil adjacent to the Long Island Railroad property will continue and the excavation will be backfilled with clean fill. Contaminated soil from interior portions of the site will be excavated beneath the temporary enclosure and taken off-site for treatment and disposal. All excavated areas will be backfilled with clean fill.
Drilling and sampling activities will continue on site and off site.