Leaking Underground Storage Tank (UST) Free Product Recovery

The North Carolina Department of Correction (DOC) operates a laundry facility at the former Craggy Prison location on NC Highway 251 near Woodfin in Buncombe County, North Carolina.  Formerly, the laundry facility had a 15,000-gallon underground storage tank (UST).  In 1990, subsurface assessment confirmed a release from the UST.  In 2004, Altamont was contracted by the DOC to evaluate the condition of site groundwater wells and separate phase hydrocarbon recovery sumps.  In 2005, four recovery sumps were replaced under Altamont’s supervision.  The existing four-inch diameter polyvinyl chloride (PVC) sump casing was overdrilled and removed.  It was then replaced with six-inch diameter schedule 40 PVC screen with 0.02-inch slots and blank casing. 

In 2005, following repair of the recovery sumps, Altamont performed hydrocarbon removal at the site by hand bailing free product from monitoring wells and recovery sumps.  Subsequent hydrocarbon recovery events were performed in August and November 2005, January and December 2006, June and December 2007, and June and December 2008.  Letter reports were submitted to the North Carolina Department of Environment and Natural Resources (DENR) Underground Storage Tank (UST) Section following each event.  In June 2009, in response to a Notice of Regulatory Requirement (NORR) issued by the UST Section, Altamont completed a Preliminary Evaluation of Free Product and submitted a report entitled Free Product Recovery Report.  The report included an evaluation of Free Product Removal Actions.  The evaluation included a cost comparison worksheet on a unit-cost-per-gallon recovered basis over a period of five years for three separate, accepted methods of hydrocarbon recovery.  In December 2010, Altamont performed a free product recovery event and submitted a Free Product Recovery Report.  In February 2011, the DOC was required to implement an approved free product recovery plan by the UST Section.  In May 2011, on behalf of the DOC, Altamont submitted a free product removal plan utilizing Aggressive Fluid Vapor Recovery (AFVR).