Historical Produced Water Release Chemical Oxidation Remediation Project – Colorado

In-situ Chemical Oxidation Remediation Project

HRL personnel were hired to oversee a chemical oxidation application to remediate approximately 110 bbls of oil that was released below a leaking secondary containment. The release resulted in the impact of 4,450 cubic yards of soil. HRL observed hydrocarbon impacts in six of twelve boreholes drilled at the site. HRL field screen results indicated that the majority of the impacted area was directly beneath the containment to a depth of approximately 45-50 feet bgs. No groundwater was encountered during the site characterization. HRL field screen results also indicate that the contamination moved laterally in a westerly direction.PID readings

In-situ chemical oxidation treatment process over the course of two weeks. Sixty-one treatment points were completed in the impacted area. An AMS 9620 Geo Probe was used to inject the oxidative solution into the impacted area from five feet below ground surface to a depth of 45 feet below the ground surface. Approximately 510 gallons was injected into each treatment point and of 31,110 gallons were injected throughout the impacted area. Seven gallons of oxidation solution was used for every cubic yard of impacted soil.

During the injection process, oxidative reactions at the surface were used to help delineate the extent of the impacted soil. Visual observations confirmed that the impacted area was isolated beneath the containment ring as was determined during the site characterization. Twenty-two of the sixty-one injection points showed evidence of hydrocarbon impacts during the injection process. The project has since received a second treatment procedure to address hydrocarbon located under the storage tanks on site. The tanks were removed and the soil was treated using oxidation chemicals. HRL monitored this project while conducting sample and remediation activities.