Appearance on this list is not to be construed as an endorsement by any regulatory agency nor is it any guarantee of the performance or the method or equipment. Equipment should be installed and operated in accordance with all applicable laws and regulations.

This list of Leak Detection Evaluations was prepared by a work group consisting of State and EPA members and is limited to evaluations of leak detection equipment and procedures, or systems conducted by an “independent third-party evaluator” (see the Glossary page) and reviewed by the work group. This list includes evaluations conducted in accordance with either EPA Standard Test Procedures for Evaluating Leak Detection Methods (EPA/530/UST-90/004 through 010) or other test procedures accepted by the NWGLDE as equivalent to the EPA standard test procedures (see the Protocols page).

The National Work Group on Leak Detection Evaluations (NWGLDE) does not guarantee the performance of any leak detection method or equipment appearing on this List, nor does it warrant the results obtained through the use of such methods or equipment.


  • The NWGLDE does not evaluate methods or equipment and appearance on this List does not mean they are automatically acceptable for use in any particular state or local jurisdiction.
  • The NWGLDE List is not an EPA List, nor does appearance on this list constitute endorsement or approval by the NWGLDE or EPA. Anyone claiming that a device or method is “EPA approved” because it appears on this list is making a false claim.
  • The NWGLDE makes no representations concerning the safe operation of any method or equipment.  All users of any method or equipment appearing on this List must assume full responsibility for the proper and safe operation of said equipment and assume any and all risks associated with its use.
  • On each data sheet, this List reports parameters and data values for methods, equipment, and software that are specific to the most current third-party evaluation submitted to the NWGLDE.  Subsequent modifications or changes to the method, equipment, or software may produce parameters and data values that are significantly different than the listed third-party evaluation parameters and data values.  It is the responsibility of the local implementing agency to accept or reject those modifications or changes.
  • NWGLDE Listings apply to leak detection functionality only and not material compatibility. Since long term material compatibility with the product stored is not addressed in test procedures and evaluations, the NWGLDE makes no representations as to the compatibility of leak detection equipment with the product stored.
  • Unless specifically indicated on the individual data sheets, performance with alternative fuels has not been demonstrated with the following exception:
    • Biodiesel B6 through B20 meeting ASTM D7467 and biodiesel B100 meeting ASTM D6751 may be used with all equipment listed for diesel whether or not these alternative fuels are included on individual data sheets.  This exception DOES NOT APPLY to leak detection test methods using Out-Of Tank Product Detection (Vapor Phase) for B6-B20, and Out-Of Tank Product Detection (Liquid and Vapor Phase) and any tracer-based test methods for B100.  For these methods, individual data sheets will have to be referenced to determine applicability.
  • Measurements derived for minimum detectable water level and minimum water level change for automatic tank gauge method, continuous automatic tank gauge method, and certain non-volumetric tank tightness test method listings were calculated in 100% hydrocarbon fuels, unless otherwise noted.
  • NWGLDE listed leak detection equipment may be applicable for use with additional liquids after consultation with the manufacturer and/or third party evaluator and subject to approval by the implementing agency.
  • The work group will only review evaluations of leak detection systems that monitor tanks or piping systems in accordance with methods described in 40 CFR 280 or API 334. Systems that detect leaks in tanks or piping systems utilizing a method described in a construction or repair standard; such as PEI RP-100, PEI RP-200, API 653 or API 1631, will not be reviewed. This includes testing performed as part of the internal inspection and recertification of ASTs and USTs, and pre/mid/post installation testing such as soap testing or helium testing.

If you have any questions about the NWGLDE Listing Content Disclaimer, Privacy Policies, or have suggestions on how these policies can be improved, please feel free to email us at NWGLDE Questions.