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Seneca Companies’ Environmental Services and Waste Solutions divisions were hired as subcontractors to remove 11 remaining fuel oil tanks from a decommissioned army base according to Illinois EPA and Illinois Office of State Fire Marshal (OSFM) regulations. The project lasted approximately 2.5 months in the field, followed by submittal of OSFM Site Assessment documents and select IEPA 20-day and 45-day reports.
The Savanna Army Depot was in the process of being decommissioned for return to the private sector and to the Illinois Department of Natural Resources. As part of this process, the Army Core of Engineers requested a bid to evacuate the remaining fuel oil and heating oil from the last 11 USTs at the site. Five USTs were 6,000 gallons or less in capacity. However, the remaining six USTs were situated in two separate tank pits comprised of three 30,000-gallon double walled steel tanks. On top of that, the large USTs each had several thousand gallons of 20-year-old fuel oil number 5 and 6, which is roughly equivalent to tar and asphalt in consistency.
Seneca Waste Solutions provided CSE-certified tank cleaners, vacuum trucks and frac tank management. Seneca Environmental provided Illinois-licensed UST decommissioner oversight, sample collection, permitting and reporting, and managed the excavation, hauling and backfill elements of the project. Seneca worked under the direct oversight of army personnel. UST cleaning and removal activities are considered permitted work, so all work was done under the direct oversight of an OSFM inspector.
Five small USTs were removed, cleaned and shipped off-site three days after the project was initiated. The remaining six 30,000-gallon tanks took three weeks to clean and remove. The USTs were cleaned by Waste Solutions personnel equipped with air tanks. Typical cleaning shifts lasted for 15-20 minutes, at which point Waste Solutions personnel would emerge from the UST into 90-degree heat, covered head to toe in opaque black sludge and boots filled with cups of perspiration.
Once field activities were done, the project shifted over to reporting mode. Seneca submitted all required OSFM Site Assessment documentation and sample results. Four of the UST sites exhibited small exceedances of Illinois Tier 1 remediation objectives. Seneca prepared and submitted 20-day and 45-day reports, which resulted in closure statuses.
Nature was already hard at work reclaiming the decommissioned army base, as evidenced by abundant prickly pear cactus, migratory birds and signs of massive deer. Seneca played a part in restoring this beautiful landscape back to the people of Illinois.
This project was a great example of two Seneca divisions coming together to complete a complex project resulting in a very satisfied customer.