Pest Control Company Located in Florida

Bioremediation of Pesticides Using Petrox®  to Meet Part per Trillion
Remediation Goals

Summary

Petrox  bioremediation successfully reduced pesticide contaminant concentrations in ground water at a pest control company in Florida. Dieldrin and heptachlor epoxide were found in ground water at concentrations exceeding state drinking water standards, which were measured in parts per trillion. After three applications of Petrox, the pesticide concentrations decreased more than 99% in three source area monitoring wells.

Geology and Hydrogeology

The site is set in the Florida Panhandle where thick coastal sediments characterize the shallow geology. The sediments underlying the site were fine-grained sand and silt more than 60 feet thick. The depth to the water table was approximately 45 feet.

Contamination

Pesticides were found in shallow soil and ground water at the property. Pesticides had also migrated off the source property in the ground water. The pesticide concentrations in the ground water were relatively low, but exceeded state regulatory standards by orders of magnitude. Prior to remediation, the maximum concentration of dieldrin in ground water was 9.8 µg/L, while the remediation goal was 0.002 µg/L. Heptachlor epoxide was present in the source area ground water at 0.68 µg/L, with a remediation goal of 0.200 µg/L. The remediation challenge was to reduce the contamination levels from the very low initial concentrations to meet even lower remediation goals.

Remediation Design

Petrox bioremediation was direct injected into the ground water in three applications approximately 30 feet apart. During each injection 275 gallons of hydrated Petrox were injected into the three locations over a 15 foot thick interval. Monitoring wells in the treatment area were sampled to assess the progress of the remediation. Three injections were completed on 60 day intervals. The following charts show the contaminant concentration trends in the monitoring wells. The vertical red line shows the initiation of bioremediation.

Results

Despite the low initial concentration and dispersed contamination, Petrox bioremediation significantly reduced the contaminant concentrations over the full treatment area.  The heptachlor epoxide concentrations met the remediation goals in all monitoring wells in the treatment area. The maximum dieldrin concentration was reduced from 9.8 µg/L to 0.22 µg/L. After three treatments and less than 9 months, the dieldrin and heptachlor epoxide concentrations were reduced by more than 99%. The product cost for treatment was less than $15,000. Petrox provided an efficient, cost-effective remediation solution for the site.