This UST system upgrade project was provided for the New World Gas Station in Merrimack, NH. The underground storage tank (UST) system upgrade consisted of installing 2 new Containment Solutions fiberglass double-wall storage tanks (one dual compartment 10,000-gallon and one 14,000-gallon), new double-wall piping, and new containment sumps. CommTank is an ICC certified UST installer in New Hampshire. All equipment was installed in accordance with the manufacturer’s instructions. To prevent the intrusion of groundwater and surface runoff all piping, dispenser sumps, and conduit entries utilize water-resistant gaskets and entry boots. The concrete mix used in the construction of the UST pad has a design strength of 4,000 PSI and utilizes #4 reinforcing steel installed at 12” on center. This design prevents any loads from trucking to be transmitted to the tanks or piping. All control joints in the dispensing pad were sealed to reduce exposure to spills. Prior to the UST system being placed in service, CommTank performed tank testing on the installed tanks and submitted the results to NHDES per ENV-OR 407.08. Tank sumps, spill containers, and dispensers were tested hydrostatically before the UST was backfilled. Line leak detectors were tested in accordance with the manufacturer’s requirements. The primary, secondary, and vent piping were also tested for a 24-hour period before they were backfilled. The canopy was also upgraded as part of this project. The existing canopy footings were demolished and removed, new steel-reinforced footings were poured and electrical conduits were installed for the lighting and fire suppression. New underground drains were installed as required by NHDES. Fire suppression was installed according to NFPA 17 and State codes. The fire suppression system was installed under the canopy at a height of 15’ above the driving mat along with fire suppression cylinders. The fire suppression system included the following: (12) Pyro-Chem ATD-80 Fire Suppression Cylinders (12) Cylinder Brackets (13) Cylinder Actuators (72) Nozzles Pull Station Electric Control Head w/ Solenoid Monitor (5) Heat Sensors Actuation Cylinder Pipe / Fittings. CommTank reprogrammed and certified the existing Veeder-Root ™ TLS 350 System, which measures liquid in the interstitial space (between the inner tank and outer containment). It also measures the amount of fuel or water (if any) inside the tanks. It will also trigger an alarm in case the tanks exceed their filling capacity. The system is able to detect any leaks that may develop in the underground fuel lines. A photo of the completed gas station construction project. After placing gasoline and diesel into the three compartments, satisfactory operation of the monitoring system was ensured before the system was placed into operation. Satisfactory operation of the secondary containment system, overfill prevention devices and line leak detectors were also tested.