Aboveground/Underground Storage Tanks
Aboveground Storage Tanks (AST) are an alternative storage container for various liquids. Aboveground tanks offer full view of the tank and any problems that may arise with the tank, including product leakage. Any problems can then be dealt with quickly which decreases the risk of contamination due to unknown leaks.
dse offers removal, repair, and remediation of damaged Underground Storage Tanks (UST), decreasing the chance of stored product leakage and soil and/or groundwater contamination.
Federal Emergency Management Administration (FEMA), Region 6
dse provided project management and oversight of the in-place closure of part of the UST system at the FEMA Region VI Site. TCEQ considered the site to have three separate source areas: a pipechase, a fuel dispenser island and the tankhold. The system consisted of a fuel island with two dispensers, two day tanks ASTs, four USTs in a common tankhold and associated below ground piping. The four USTs included two 20,000-gallon diesel USTs, which dse closed in-place. One 20,000-gallon water tank and one 5,000-gallon hydro-pneumatic tank were to remain in use. The two day tanks, located within Site buildings and their associated above ground piping were also removed. dse conducted document review, correspondence and submitted various closure, registration and permit documents with the TCEQ.
dse personnel coordinated with FEMA and collected a groundwater sample from the previously installed tankhold observation well prior to the UST closure in order to provide a baseline. Fourteen soil samples along the pipechases and one soil sample beneath each dispenser island were collected and analyzed to close the fuel lines in-place and close out the dispenser islands. In order to close the two diesel USTs in-place, a series of soil samples were collected from the native soils outside the tankhold perimeter. One sampling point was converted to a monitor well, which was developed, purged and sampled using low-flow methods. Both diesel USTs were emptied, triple rinsed, purged, and then filled with a flowable fill material consisting of a lightweight concrete and sand mix. Emergency generator equipment, ASTs, associated piping and monitoring equipment were removed from three equipment rooms at the Site and the piping was capped. All samples were analyzed for BTEX/MTBE and TPH with PAH analyses for the sample with the highest detectable concentration.
United States Post Office (USPS)
North Central Texas
dse furnished all material, labor and equipment for the removal of in-ground hydraulic vehicle lifts and/or USTs at seven locations in Northwest Texas. All vehicle lifts and equipment were disposed of and all oil from the lifts, lines and tanks were recycled. Soil samples were taken from the lift pit floors and analyzed. In some cases, correspondence with the TCEQ was required due to levels of impact in the soils. The holes were then filled in, concreted and new electrical circuits installed to accommodate the new lifts. In some instances new transformers and panels were required to also accommodate the new equipment.
TY Equity Group (Cooper Medlin)
Three USTs were removed from the site and three new 8000 gallon USTs were installed in 1984. These activities were performed before removal of USTs was regulated by the TCEQ. The TCEQ required remediation of the hydrocarbons detected in soil and groundwater samples which were believed to be the result of improper removal of the USTs. dse provided project management, well drilling, quarterly groundwater sampling events, TCEQ required reports, and closure activities.
dse removed a 265-gallon capacity tank used for storing kerosene and waste oils as well as the accessible associated piping. A total of 147 gallons of liquid was removed from the tank. After confirming that the vapors in the UST were below the explosive limit, the UST was removed from the pit, loaded and transported for final destruction. The tank had been out of service for several months and no evidence of product leakage was observed or suspected based on the physical inspection of the UST, surrounding soils and laboratory analysis.
Silverking Productions Inc., KHSX TV-49
Cedar Hill, Texas
dse was hired to remove, relocate and re-install an existing 2000 gallon diesel-containing AST, emergency generator and underground piping. The Potential environmental impacts from the AST on the former and new tank locations were also identified. dse visually observed no evidence of previous leakage or spills in the vicinity of the AST on either site. No fuel spillage or leakage occurred at either site during emptying, removal, re-installation and refilling of the tank. dse reviewed site history records, tank closure report and acquired all required registrations and permits to complete the work. The field efforts included trenching, installation and pressure testing the new piping system.