AS/SVE System Installation, Soil Excavation, + Operations + Maintenance

In order to remove soil and dissolved-phase groundwater contamination present at the site from a former underground storage tank (UST) an Air Sparge/Soil Vapor Extraction (AS/SVE) system was recommended and designed.  Additionally, two small pockets of soil contamination were present at the site that required excavation and removal as extending the AS/SVE system to these two locations was not cost effective.  The Rhea team was tasked with the soil excavation and removal, as well as with the installation and operations and maintenance (O&M) of the proposed AS/SVE system.

 Rhea prepared a Work Plan (WP) and Health and Safety Plan (HASP) for the safe soil excavation and AS/SVE system installation.  Following approval of the WP and HASP, Rhea’s subcontractor mobilized to the site and excavated soil from the two pockets of soil contamination present outside the radius of influence of the proposed AS/SVE system.

The areas of soil contamination were excavated to a depth at which groundwater was encountered.  The horizontal extent of the excavation was determined by field screening with a photoionization detector (PID).  Rhea collected confirmatory samples from each of the four sides of each excavation to verify that all of the impacted soil had been removed.  A total of approximately 66 tons of soil was removed from the excavated areas. Excavated areas in the grass were backfilled by Rhea’s subcontractor with clean fill material in 12-inch thick lifts, compacted, and seeded. 

For the proposed AS/SVE system, Rhea installed 11 AS wells within the core of the existing plume of groundwater contamination. Steel well vaults encased in concrete were installed around each AS well to protect the integrity of the well. Following system installation and startup, Rhea began and has continued to date O&M activities and associated groundwater monitoring, and reporting at the site.

Rhea’s knowledge with and efficiency at managing the installation of AS/SVE systems allowed for a $20,000 cost savings for the system installation.

Services: Field Monitoring + Management

Industries: Federal Government