All Underground Storage Tanks (USTs) are required to be tested on a regular basis. The regulations vary from facility to facility and Golars can provide comprehensive testing which include the following:
Line Tightness and Leak Detector
Line tightness and leak detector tests are required to be performed every year. There are two types of Leak Detectors.
Automatic Line Leak Detector (ALLD)
ALLD is an electronic/mechanical device designed to detect a catastrophic leak from pressurized piping. When a leak is detected, automatic LLDs must shut off the product flow, restrict the product flow, or trigger an audible or visual alarm
Mechanical Line Leak Detectors (MLLDs)
MLLDs are installed on submersible turbine pump (STP) head and has no wiring connections. The pump must start against a closed valve to allow pressure to build in the line sufficiently to allow the line leak detector to open and flow. If pressure does not build in the line properly (due to leaking product), then the mechanical line leak detector trips and restricts the pump flow Line Tightness Testing USTs with pressurized piping with MLLD installed must conduct the test at least annually USTs with non-safe – suction with foot valve/in-line check valve must conduct a line tightness test every three years (American Suction) If you have safe suction piping with a check valve immediately below the dispensing unit, no tightness testing is required (European Suction)
Interstitial monitoring is a method of leak detection to check for the presence of liquid between the two walls of double walled tank or piping systems.
Tank tightness testing (also known as precision testing or integrity testing) is an analytical method that determines if a tank leaks in quantities at least as small as 0.1 gallons per hour (gph).
Generally, technicians come on-site to conduct this test with mobile equipment, although some automatic tank gauges have been certified to perform tightness tests.
Cathodic Protection (CP) which is also known as corrosion protection applies to steel tank systems and steel piping. Without cathodic protection, underground metal tank/pipe systems will corrode (create small holes) and may allow the product to leak into the environment. Also, the UST components made from metal that are in contact with the ground (and routinely contain regulated substances) must have corrosion protection.
One way to protect underground storage tank system components from corrosion is to make them with non-metallic/non-corrodible materials such as USTs that are made of clad steel/jacketed steel/fiberglass reinforced plastic.
Tank Internal Lining
Internal Lining is a thick layer of non-corrodible material lined inside the tank for corrosion protection and must have passed an internal lining inspection within 10 years of installation of the internal lining and every five years after that to make sure that the lining is sound.
Automatic Tank Gauge
An automatic tank gauge (ATG) system consists of a probe permanently installed in a tank and wired to a monitor to provide information on product level and temperature. ATG system automatically calculates the changes in product volume that can indicate a leaking tank. It also prints out the results of the test, usually “pass” or “fail”.
Owners/Operators are required to inspect and test the release detection system every year in accordance with the manufacturer’s requirements. At a minimum, test the alarm, battery back-up, and verify the system configuration.
For probes and sensors, you must inspect for residual build-up, ensure floats move freely, ensure the shaft is not damaged, ensure accessible cables are free of kinks and breaks, and test alarm operability and communication with controller.
Spill Prevention Equipment
Spill Prevention devices are used at fill pipes to prevent small drips/spills from entering the environment. The most common spill prevention device is a spill bucket.
Spill Bucket/Catchment Basin is a liquid tight container that surrounds the fill pipes to prevent small drips/spills from delivery hose that may occur during a delivery. Any tank filled with 25 gallons or more at one time must have spill prevention.
Overfill protection are devices that either shut off product flow, restrict product flow or alert the delivery operator with an alarm when the tank is close to being full. These devices are installed inside the tank and activate if the product in the UST reaches a certain level in the tank
The three most common types of overfill protection devices are automatic shutoff devices, overfill alarms, and Ball float valves/Float vent valve. Ball float valves cannot be installed or replaced for use as overfill protection after September 1, 2017.
Containment sumps have sides and a bottom, are designed to be liquid tight, and may have a special cover designed to keep out water.
Submersible Turbine Sumps (STP) are designed to provide access to the turbine area above the tank. The turbine area may house the submersible turbine pump head, piping, line leak detectors, interstitial monitoring devices, wiring, and other equipment.
Under-Dispenser Containment Sumps (UDCs) are usually made of fiberglass, steel/HDPE (plastic). Dispenser sumps are designed to provide access to piping, flex connectors, shear valves, and other equipment located beneath the dispenser. They are found directly under dispensers and are designed to contain any leaks from the dispenser piping.