2016 NGWA Groundwater Summit

Passive Removal of Chlorinated Volatile Organic Compounds from Contaminated Groundwater

Monday, April 25, 2016: 11:00 a.m.
Confluence Ballroom A (The Westin Denver Downtown)
Brian LaFlamme , Nationwide Environmental Services, Inc., Golden, CO

The Hardage-Criner Superfund Site in central Oklahoma operated as a permitted disposal site from 1972-1980 and received over 20 million gallons of waste from industries in Texas and Oklahoma. A remedy component captures contaminated groundwater behind an interceptor trench using six recovery sumps.

A water treatment plant (WTP) using conventional air stripping technology and carbon polishing to remove chlorinated volatile organic compounds (CVOCs) before discharging the treated groundwater was in operation for over 12 years. The WTP was efficient at treating CVOCs to regulatory levels. However, rising operation and maintenance (O&M) costs, e.g., chemicals, electricity, and labor, necessitated an alternative for treating groundwater contaminated with CVOCs. The alternative had to remove CVOCs to below detection limits (BDL) for incorporation into the Monitored Natural Attenuation (MNA) remedy component, decrease O&M costs, and meet regulatory approval.

A series of field pilot tests, based on air stripping/carbon polishing technology, were designed to evaluate a Passive Aeration System (PAS) to demonstrate that CVOCs could be successfully removed to BDL. Based on the successful pilot tests, a full-scale test was implemented and demonstrated that the PAS could consistently remove CVOCS to BDL at flows up to 10 gallons per minute

Removal efficiencies and CVOC speciation from the pilot tests indicated that the PAS technology was a viable alternative to the conventional WTP. Analytical results from the full-scale test showed consistent analytical results of CVOCS that were BDL. The PAS was approved by the U.S. EPA and the Oklahoma Department of Environmental Quality as a permanent remedy modification to replace the conventional WTP.

The electricity savings alone using the PAS amount to more than $20,000 per year.  The PAS also employs air stripping and polishing steps but utilizes the sun and wind to remove the CVOCs without electricity or chemicals and with minimal O&M costs.

Brian LaFlamme, Nationwide Environmental Services, Inc., Golden, CO
Brian LaFlamme is an environmental consultant with Nationwide Environmental Services, Inc. in Golden, Colorado. LaFlamme obtained his Master’s in Chemical Oceanography at the University of Washington in 1985. He was involved in studying water-rock interactions and videoing ‘black smokers’ off the Juan de Fuca Ridge before joining a national environmental consulting firm in 1988. LaFlamme has evaluated geochemical data to assess the natural background concentration of metals for active mine sites; interpreted radioisotope data to delineate multiple aquifers at complex sites; managed the design of software programs to streamline the review on an environmental database, enhance the quality and usability of the environmental database, and provide real-time tools for interpretation; conducted numerous fate and transport modeling efforts; and managed multi-million dollar Superfund projects through the RI/FS and RD/RA process. LaFlamme currently manages the long-term remediation operation and maintenance at Superfund sites and provides technical and regulatory strategy to avoid and limit environmental liability.