REMOVAL_1998 - Laserfiche WebLink

Home Browse Search

TANK REMOVAL PROTOCOL 1.0 Tank Removal and Disposal Upon determination to remove a particular underground tank, the necessary permits for such removal will be obtained. The tank will then be scheduled for removal and disposal in accordance with the local regulatory requirements. 1.1 Utilities Clearance An environmental specialist reviews all available tank data including tank material, age of installation, cover(asphalt, concrete, earth) piping, depth of tank, direction of tank, and any as-built drawings. Any underground piping/conduit will be located with the use of an underground pipe locator, and marked on the ground surface. If appropriate, Underground Service Alert will be requested to assist in determining location of ' underground utilities and provide clearance information. Fire extinguishers, no smoking signs, and barricades are situated on the site. All sources of possible ignition at the tank site are eliminated. The tank is rendered inert by removing all product, triple rinsing the tank, inserting 20-pounds of solid carbon dioxide for each 1,000-gallons of tank volume and allowing a minimum of one hour for oxygen displacement which is checked using a lower explosive limit (LEL) meter and oxygen meter. All appropriate regulatory agencies are notified 48-hours in advance of the actual tank removal. 1.2 Excavation Asphalt or concrete pavement coverings are removed with the most cost efficient method available, using either a concrete-cutter or jack-hammer/air compressor. The debris is stockpiled in an isolated area for later removal. Of primary concern to the excavation team is to not disturb the existing tank/piping installation with the backhoe. The laborer will probe and hand-excavate near and around all external product piping and vent lines. Backfill is removed along one side of the tank and two ends of the tank, to a depth of the tank bottom and a width of 24-inches. Periodic examination continues through the excavation process for any possibility of contaminated soil. In the event of encountering soil contamination, the soil is isolated on a sheet of 10 mil visquene. A determination as to disposal of contaminated soil will be negotiated with the appropriate regulators. 1.3 Tank Removal The tank is disconnected at appropriate fittings, with existing lines capped and tank plugged. One plug is vented, to allow for vapor dispersal. Installation lift lugs are located, and chains are secured to lugs (nylon rope for fiberglass tanks) and to lifting equipment. The lifting equipment is checked for proper capacity before moving the tank. Prior to the tank being lifted from the excavation, the oxygen content shall be less than 5% and lower explosive limitless than 10%.