Soil Remediation

Client: Northeast Natural Energy

The objective of the soil remediation was to excavate soils impacted with drilling fluid via signs of stressed vegetation and the measuring of soil electrical conductivity (EC). Remedial activities consisted of excavating impacted soil for off-site disposal and restoration of excavated areas. NGE provided technical assistance in identifying sample locations for the collection of soil samples for on-site field screening and off-site laboratory analysis and the field labor/equipment to remediate impacted areas.

NGE used the stressed vegetation at this job site as an initial indicator of the horizontal extent. Pre-excavation EC measurements were then taken to accurately determine the horizontal extent of soils impacted by the drilling fluid. The following areas were identified as areas of remediation:

1. Remote Area A
2. Access Road/Sump
3. Remote Area B; and
4. Gas Line Area

Remedial activities began in August 2016 at the Remote Area A. Typically these materials once assessed would be excavated and loaded directly into tri-axles for off-site disposal following landfill approval, but due to the limited access to Remote Area A, Remote Area B and the Access Road/Sump Area and the lower portion of the Gas Line Area, excavated material was hauled via a track-dump to the pad area and staged on plastic until agency approval for disposal was received. Post-excavation EC measurements were the main driver for the remedial cleanup and confirmed by collecting post-excavation confirmation soil samples. Approximately 770 tons of impacted soil was transported off-site to an approved disposal facility.

Once EC measurements and the confirmation soil sample results were within the cleanup criteria the areas were restored. Restoration of all areas consisted of grading the area with surrounding soils, seeding with an orchard grass, red clover and rye seed mixture and covering the areas with a single-sided straw matting. Restoration of all areas was completed in September 2016.