On site decommissioning of an underground storage tank in OR
A residence in Portland, OR, reported a release of heating oil from a 675 gallon underground Heating Oil Tank and Xavier Environmental Inc was contracted to complete the cleanup and remediation. The location of the tank was such that removal was not possible without damaging some of the structures and it was decided to decommission the tank at the site itself. The residual fuel was transferred into an Above ground Storage Tank and the sludge was sent for disposal as per the regulations. The top of the tank was cut open and infiltration galleries were set up. The impacted soil was proposed to be remediated following the protocol of Risk Based Cleanup and use of bioremediation product was agreed. 20 gallons of VaporRemed was introduced into the soil through the infiltration galleries and some VaporRemed was also sprayed in the bottom of the tank. There was 68% reduction in the values of VOC in the soil and the there was a significant reduction in the vapor phase concentrations of VOC. Results of the soil and vapor concentrations showed values that were less than the values stipulated for RBS cleanup, the tank was decommissioned with clean gravel at the site.