Carus

Treatment Train for Remediation of NAPL and BTEX in Shallow, Silty Clay Soil

The Site in Davenport, IA is a petroleum fueling facility. Previous investigations of the site revealed that shallow groundwater (4 to 15 ft below ground) in a silty clay aquifer contained BTEX above the Iowa DNR regulatory standards for soil and groundwater. This presentation will introduce Site remediation efforts completed to date and present the benefits realized by evaluating and implementing a treatment train of technologies at the site: free product recovery, hydrogen peroxide injection, air sparge/soil vapor extraction, Oxygen BioChem (OBC™) injection, and vacuum-enhanced recovery.

Groundwater analytical results indicated that the OBC™ injection remedy is working, but rapid BTEX reductions will be hard to achieve based on the low permeability of the aquifer and limited to no preferential pathways. However, given the aquifer conditions, mass removal through sulfate-enhanced anaerobic reductive biodegradation is possibly higher than any other in-situ technology would be able to achieve.

Presenter: Brian D. Symons, P.E., Senior Technology Manager, Foth Infrastructure & Environment LLC