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|State Police #||11-06603|
|Pollutant||Duration||Point Source||Greenhouse Gas||Criteria Pollutant||Ozone forming chemical||Amount of Release|
|Hydrocarbon||No information given||Tank 68||NO||NO||YES||7,229.0 pounds|
|Benzene||No information given||Line leak at Tank 68||NO||NO||YES||9,204.0 pounds|
|Oil||No information given||Line leak and Tank 68||NO||NO||NO||1,932.0 gallons|
Accident Classified As: Reportable Quantity
Oil was initially discovered in the area of Tank 68 (Alkylate storage)on October 20, 2011. The amount released to the environment was initially estimated to be less that reportable quantities, so no immediate notifications were required. A sample was collected in order to determine the root cause of the leak. On the morning of October 21, liquid was again observed coming from the bottom of the tank, and the lab sample results concurrently confirmed the oil to be alkylate. At approximately 0935 hours on October 21, 2011 a separate incident occurred when a retired line in a ground level piperack in the Treating Area was found to be leaking. The initial amount observed was approximately fourteen gallons of undetermined hydrocarbon, and both emissions and the amount in soil were determined to be less than the reportable quantities. Foam was also applied to the leak areas in order to mitigate odors and emissions. On October 21, 2011, at approximately 1400 hours, oil began accumulating at an increased rate at Tank 68, and it was determined that considering the two releases together, reportable quantities were potentially exceeded for volatile organic compounds (VOC) and benzene, and notifications were made. Several inches of water were introduced into Tank 68 on October 22 to displace the hydrocarbon layer on the tank floor. This ended the hydrocarbon release in excess of a reportable quantity. Additionally, line isolation efforts on the retired line in the Treating Area were performed on October 24, 2011, ending the release in excess of a reportable quantity. Visual observation and monitoring confirmed no ongoing leak to the environment at that time. Cleanup of the area was completed at 1600 hours on Tuesday, November 1, 2011.
Root cause investigation into the corrosion mechanism for the tank floor is under review. Results of the investigation will be provided in the next 60-day follow-up report. The line leak in the ground level piperack was later reported under incident number 11-06761, for which a 60 day report will follow under separate cover.
Vacuum trucks were used to remove the oil and water from Tank 68, containing the release to the smallest area possible. Mitigation efforts to reduce amount to the environment emissions at Tank 68 also included the introduction of water into the tank to successfully displace the hydrocarbon from the leak interface on Saturday, October 22. The tank was emptied and removed from service on November 7, 2011, ending the release. Cleanup of the area is ongoing. Foam was applied to the area of the line leak, to reduce the emissions from the event. Vacuum trucks were used to recover the hydrocarbon and water, and the line was isolated October 24, ending the reportable release. United States Environmental Services also arrived Monday, October 24 to assist with cleanup of the ares, which was completed November 1, 2011. Tank 68 was cleaned, and initial inspection was performed on December 7, 2011. A repair scope is currently under development, which will implement corrective actions to mitigate corrosion potential for the tank floor.