Distribution Letter

January 25, 2003

To: Local Agencies and Other Interested Parties

This letter transmits Local Guidance Letter LG 113-16, which contains an updated list of leak detection equipment and test methods (hereafter referred to as "equipment") for use in California. LG 113-16 supersedes and replaces all other versions of LG 113. This LG contains the following information:

Enclosure 1

  1. List of Leak Detection Evaluations User Survey
  2. Work Group Members
  3. Work Group Teams
  4. Leak Detection Equipment Review - Document List
  5. Work Group Policy Memoranda

Enclosure 2

  1. Disclaimer
  2. table of Contents
  3. Part I - Leak Detection Test Methods and Equipment/Systems
  4. Part II - Leak Detection Equipment/Systems Specifications
  5. Part III - Newly Listed Equipment and Methods
  6. Part IV - Acceptable Test Protocols
  7. Part V - Monitoring System Certification Forms
  8. Appendix - Glossary of Terms

The LG 113 and Its Uses

To assist local agencies in reviewing and approving monitoring plans, the State Water Resources Control Board (SWRCB) has published updated versions of LG 113 since December 13, 1990. In March 1993, an independent "National Work Group on Leak Detection Evaluations" (hereafter referred to as "Work Group") was formed. Ms. Shahla Farahnak, Senior Engineer with the SWRCB is a member of this Work Group, which reviews all third-party evaluated equipment for placement on the Work Group's list. This version (LG 113-16) is based on the November 2001 Work Group list with some changes (indicated in bold type) to make it current and consistent with California regulations. These changes reflect the following points:

  1. Tanks must be at least 65% full for a valid Volumetric Tank Tightness Test.
  2. Automatic Tank Gauges must meet California's minimum regulatory product level requirement.
  3. Statistical Inventory Reconciliation methods have additional requirements for leak rate and leak threshold reporting.
  4. Mechanical and electronic line leak detectors must be checked annually for capability of detecting a line leak of 3.0 gallons per hour (gph).
  5. Sensors that are not reusable do not meet California's requirements.
  6. Vadose zone vapor monitoring and interstitial monitoring must be continuous. Intermittent monitoring does not satisfy California regulations.
  7. Installation of discriminating sensors at new installations is currently discouraged. (see Enclosure 2, Part I, page 12)

Limitations of the LG 113

Publication of the LG 113 should eliminate the need for local agencies to review third-party evaluations of equipment for compliance with state and federal requirements. However, it has inherent limitations. It is based on one-time evaluations, often conducted in a lab setting according to protocols that do not test all aspects of the equipment. Therefore, appearance on the LG 113 does not mean that the equipment will work or comply with regulations at every site.

Some agencies may prohibit the use of some types of equipment listed in this document based on their own review, poor field performance, or other site-specific issues. For these reasons, the LG 113 cannot be the final word; regulatory decisions should be based on all available sources of information. Furthermore, appearance on his list is not to be construed as an endorsement by the SWRCB or any other regulatory agency, nor is it any guarantee of the performance of the method or equipment. Equipment should be installed and operated in accordance with all applicable laws and regulations.

Equipment Not on the LG 113

  1. A listing of new equipment reviewed by the Work Group after November 2001 will be updated regularly on the State Water Resources Control Board website at: http://www.swrcb.ca.gov/cwphome/ust/docs/lgs/lg113/lg113-16.html under Newly Listed Equipment and Methods. Adobe Acrobat Reader is required to access this file. Please note that equipment specification sheets, for those listed in this section, will not be available until the next version of the Work Group list is published.
  2. Certain equipment listed in the older versions of the LG 113 may not be included in this version if the Work Group was unable to obtain all necessary information from the vendor to complete the review.

User Survey and Other Information

  • The LG 113 includes a user survey (see Enclosure 1). After familiarizing yourself with the LG 113, please take a moment to provide your feedback. We rely on your feedback to continually improve this document and make it more useful.
  • The LG 113 also includes a separate listing of protocols under which listed evaluations were performed (see Enclosure 2, Part IV).
  • The "Monitoring System Certification Forms" have been added (see Enclosure 2, Part V).

Adding Equipment to the LG 113

If you have an evaluation to submit or if you have comments about a particular listing, see the enclosed list of Work Group members for the various types of leak detection equipment and contact the appropriate person. To enable the Work Group to properly review the third-party evaluations, please send one (1) copy of all applicable information indicated in the enclosed "Leak Detection Equipment Review - Document List" to the appropriate team leader and each team member. Comments and new information are welcome. (For more details on the Work Group policies and general procedures, please see enclosed Work Group Policy Memoranda 1, 2, and 3.)