Produced Water Release Bioremediation Project Colorado

In-situ & Ex-situ Bioremediation Project

HRL conducted an initial investigation of a produced water tank release at a well pad located in Garfield County, Colorado. A rock from the hillside above and adjacent to the well pad scaled from the hillside and broke through the steel secondary containment. The rock then ricocheted off the condensate tank and struck a flow line to the partially buried produced water tank. This resulted in a release of produced water into an unlined secondary steel containment. TPH levels in the soil were in excess of 6,000 ppm.

Approximately 760 cubic yards of soil was impacted with light end oil produced water. In-situ bioremediation was the preferred option to remediate the impacted soil. In July 2011 HRL personnel were onsite to install a series of slotted PVC pipes (treatment ports) to a depth of approximately 30-feet bgs.

Three in-situ bioremediation treatment events were conducted. Based on analytical and field screen data, approximately 50% of the site was remediated to below COGCC allowable concentration levels (500 ppm total TPH) suring the first phase of treatment. The top ten (10) feet of the impacted soil had not yet been treated.

The client decided to remove the partially buried tank from the tank battery location and the top ten (10) feet of soil was excavated and stored in four separate land treatment units for bioremediation landfarming activities. The four land treatment units were positioned on site and were treated weekly. The remediation of the soil in the land treatment units was completed in six months. Soil in two of the land treatment units were clean within four (4) months, while two other Land treatment units required additional months to complete because of non-homogeneity. TPH levels in all four cells were remediated to below COGCC Table 910.1 TPH values.