Neilson Research Corporation chemists analyze soil, sludge, and water taken from underground and aboveground storage tanks (USTs). To meet the regulations of various state and federal agencies we test for solvent content and to identify petroleum hydrocarbons. Analyses of underlying soils determine tank leakage, and soil gas investigations pinpoint the extent of contamination. Staff trained in all aspects of petroleum hydrocarbon forensics oversee testing procedures and are available to provide technical consulting and litigation support services.
Why be concerned about USTs?
Underground storage tanks installed before 1980 were made of untreated steel, which eventually corrodes and leaks its contents into the environment. In addition to leaks, faulty installation or poor maintenance practices can contaminate groundwater, cause fire, or explosion.
Technical requirements for USTs
Regulations for USTs are designed to reduce leakage, detect leaks and spills when they do occur, and secure a prompt cleanup. UST owners and operators are responsible for reporting and cleaning up any releases.
How are leaks detected?
Owners and operators of petroleum USTs must use at least one of the leak detection methods approved by their state agency. Secondary containment and interstitial monitoring involves placing a barrier between the UST and the environment, and can be a vault, liner, or the outer wall of a double-walled structure. Other leak detection methods include:
• Automatic tank gauging (ATG) systems use monitors permanently installed in the tank to provide information on product level and temperature.
• Vapor monitoring measures product vapor in the soil around the tank and piping to determine the presence of a leak.
• Groundwater monitoring senses the presence of liquid product floating on the groundwater.
• Statistical inventory reconciliation (SIR) conducts a statistical analysis of inventory, delivery, and dispensing data collected over a period of time.
• Manual tank gauging can be used on tanks 2,000 gallons or smaller. The tank is taken out of service for at least 36 hours each week to measure its contents.
In 1984, Congress expanded groundwater protection by adding to the Resource Conservation and Recovery Act (RCRA). The EPA was tasked to develop a comprehensive regulatory program for USTs storing petroleum or other hazardous substances.