Leak Detection for Underground Storage Tanks

gas line testingThe Environmental Protection Agency (EPA) requires that all underground storage tanks have leak detection. This regulation is to ensure that leaks are discovered as quickly as possible before they can cause irreparable environmental damage.

Leak Detection Requirements

There are four basic requirements the leak detection on your underground storage tank must meet:

  • The leak must be detectible from any portion of the tank that holds fuel.
  • The leak detection technology must be properly installed and maintained in compliance with the manufacturer’s instructions.
  • The leak detection technology must be regularly maintained and tested the way the manufacturer’s instructions state.
  • The leak detection technology must be one of the seven federal regulation methods.

Federal Regulation Methods

The seven federally regulated methods are all designed to detect leaks. However, even these federally regulated methods can miss a leak if used individually. It is strongly recommended to implement not just one single method but multiple methods.

The seven federally regulated methods include:

  • Automatic Tank Gauging: An automatic tank gauging (ATG) system tracks the delivery and dispensing of inventory to detect when leaks are present. This method requires ATG equipment and optional software.
  • Monitoring for Vapor in the Soil: Vapor monitoring technology can detect leaks through sensing fumes in the soil and around underground storage tanks. It requires vapor monitoring sensors and an automatic tank gauge. This method is not recommended to be used alone as contamination has to have already occurred for the leak to be detected.
  • Monitoring for Contamination in Groundwater: Groundwater monitoring uses monitoring wells that are close to the underground storage tank. These wells are then checked every month for groundwater contamination. This method requires monitoring wells and groundwater sensors. Just like vapor monitoring, this is not a good method to use alone because the contamination has to have already occurred to be detected.
  • Interstitial Monitoring: Interstitial monitoring involves creating a barrier around the underground storage tank, so that any leaks are trapped within this secondary contaminant.  This method can be complex because it requires so many different pieces of equipment to ensure the leak stays put and does not contaminate the ground.
  • Statistical Inventory Reconciliation: Statistical Inventory Reconciliation (SIR) involves the use of software and technology to track, analyze, and report inventory data collected from 30 to 60 days to determine if the underground storage tank is leaking. This method does come with frequent, recurring costs as it is a vendor-supplied service, and it does not collect inventory data. It only tracks and analyzes what it receives.
  • Weekly Manual Tank Gauging: Manual tank gauging is simply measuring the underground storage tank once at the beginning of the week and a second time at the end of the week to measure its supply for leaks. This method does mean the tank will be out of service for a few hours each week to take measurements.
  • Annual Tank Tightness Testing: This method is a combination of testing tank tightness and inventory control. Tank tightness testing must be done by a vendor who can install special equipment, and inventory must be calculated monthly for this method to work.


If these regulations seem overwhelming, why not recruit help? At American Petroleum, we offer a comprehensive and legally compliant leak detection service. Get in touch with our team today to find out what we can do for you.