Remediation Resource by ReRem

An agricultural / hardware chain was operating on a former retail petroleum site.  During its first winter, employees noted gasoline odors in the storage and retail areas.  Little or no vapor was noted in other months. Over the second winter an industrial hygienist identified BTEX as an IAQ issue and recommended removal of all automotive products from the structure.  The vapor issue continued.

A local environmental contractor was retained for a subsurface investigation which found high soil-vapor concentrations adjacent the structures and under the slab.  A floor sealing program was completed and the vapor issue continued.

Subsequent investigations identified the source-area, plume concentrations and areal extent.  Insurance companies placed blame and the business threatened to move as the vapor issue continued.

I know the property owner.  He was distraught over the contamination and the loss of a leasing tenant.  He did not believe the insurance, nor consultants, would come to a solution any time soon.  I proposed a simple solution: sub-slab depressurization.

The structure had been built with a footer-drain system draining to a parking lot dry well.  ReRem provided a soil vapor extraction skid to apply a stepped vacuum to the footer grains while others monitored the airspace VOC’s and pressure beneath the slab.  The four-week trial was a success!  A moderate vacuum at the drain was sufficient to induce a vacuum across the slab.  Our stepped-testing program optimized vacuum and flow, providing design data for a long-term remedy.

The owner bought and now operates the depressurization system, the tenant is no longer threatening to vacate.  The insurance companies still bicker and attempt to assign blame.