Final report of Bioremediation of contaminated soil at a gas station in VA PC # 97-4045

Final closure report for the pollution complaint PC # 97-4045.

A Corrective Action Plan (CAP) was implemented, which was conducted in two phases.

  1. Remediation of petroleum saturated soil with AgroRemed and
  2. Monitoring and recovery of free product in the groundwater.

In March, 2012, AgroRemed was injected in the two sites showing values of TPH above saturation point or more than 3000 ppm of Gasoline Range Organics). At the next sampling event in June, the samples of soil from these two sites showed below detect values of TPH. The soil end point as per CAP was met in June, 2012 after single application of AgroRemed. However, the monitoring and recovery of free product trapped in the vadose zone was continued. The three quarterly sampling events of groundwater did not show any free product water and VA DEQ was requested to issue a closure of the CAP. Some free product was detected in two of the wells after the treatment; therefore, monitoring of the wells for the presence of free product and product recovery continues. It was observed that there is a small amount of mobile (but not migrating) free product trapped in lower portion of the vadose zone in the former tank field, which seeps into well Recovery Well -1 when the water table is high. Based on the monitoring of groundwater in the first three quarters of 2014, no free product was recorded and it was recommended to DEQ for closure and DEQ has given the closure letter in November, 2014.