UST Program - Local Guidance (LG) 151-3

November 23, 1998

To: Local Agencies

The purpose of this revision to LG 151 is to update the list of monitoring options for BFCUSTs (includes two additional options 9 and 10).  As the technology of leak detection for BFCUSTs improves, it is important to add these new options for the purpose of encouraging tank owners to install more sensitive leak detection systems.

Enclosure 1 includes the list of monitoring options for BFCUSTs. These monitoring options were developed in accordance with the provisions of Section 2643(b)(5) of the UST regulations.  Enclosure 2 includes the list of monitoring options for bulk piping when compliance with Section 2643(c) requirements is not feasible and practical. These monitoring options were developed in accordance with the Section 25292(d) of Health & Safety Code authorities.

We will review test equipment or methods as they are certified and submitted for approval and include them as updates to the Local Guidance Letter 113 (LG 113) document. For third-party certified equipment or test methods that meet the performance criteria for the monitoring options, refer to LG 113 updates.  For the latest additions to this list, check our web site (www.waterboards.ca.gov).

If you have any questions regarding this letter, please call Ms. Shahla Farahnak of the Division of Clean Water Programs at (916) 227-4350.

Sincerely,
 
 [Original signed by:]
Allan Patton, Manager
Underground Storage Tank Program

Enclosures

1. Monthly monitoring using a third-party certified electronic device (for example, automatic tank gauging system) that is capable of detecting release rates of 0.2 gallons per hour (gph) with at least a 95% probability of detection and not more than a 5% false alarm.

2. Monthly monitoring using a third-party certified equipment/test method that is capable of detecting release rates of 1-2 gph (inclusive) with at least a 95% probability of detection and not more than a 5% false alarm.  In addition to monthly monitoring, a tank tightness test that is capable of detecting release rates of 0.1 gph with at least a 95% probability of detection and not more than a 5% false alarm must be performed every other year.

3. Monthly monitoring using a third-party certified equipment/test method that is capable of detecting release rates of larger than 2 gph but equal to or less than 3 gph with at least a 95% probability of detection and not more than a 5% false alarm.  In addition to monthly monitoring, a tank tightness test that is capable of detecting release rates of 0.1 gph with at least a 95% probability of detection and not more than a 5% false alarm must be performed annually.

4. Monthly monitoring using a third-party certified equipment that is capable of detecting release rates of larger than 2 gph but equal to or less than 3 gph with at least a 95% probability of detection and not more than a 5% false alarm.  In addition to monthly monitoring, groundwater monitoring performed monthly in accordance with Section 2648, as approved by the local agency, must also be performed.

5. A third-party certified continuous vapor monitoring or monthly ground water monitoring in accordance with Section 2647 or 2648, and an annual tank tightness test that is capable of detecting release rates of 0.1 gph with at least a 95% probability of detection and not more than a 5% false alarm annually.

6. Quarterly monitoring using a third-party certified test method that is capable of  detecting release rates of 0.2 gph with at least a 95% probability of detection and not more than a 5% false alarm.  Monthly groundwater monitoring in accordance with Section 2648 and as approved by the local agency must also be performed.

7. Monthly monitoring using a third-party certified equipment/test method that is capable of detecting release rates of 1-2 gph (inclusive) with at least a 95% probability of detection and not more than a 5% false alarm.  In addition to monthly monitoring, a test method that is capable of detecting release rate of 0.2 gph with at least a 95%  probability of detection and not more than a 5% false alarm must be performed semi-annually.

8. Monthly monitoring using a third-party certified equipment/test method that is capable of detecting release rates of 1-2 gph (inclusive) with at least a 95% probability of detection and not more than a 5% false alarm.  In addition to monthly monitoring, continuous vadose zone monitoring, in accordance with Section 2647, must also be performed
 

9. Monthly monitoring using a third-party certified equipment/test method that is capable of detecting release rates of larger than 0.3 gph but less than 1 gph with at least a 95% probability of detection and not more than a 5% false alarm.  In addition to monthly monitoring, a tank tightness test that is capable of detecting release rates of 0.1 gph with at least a 95% probability of detection and not more than a 5% false alarm musts be performed every three years.

10. Monthly monitoring using a third-party certified equipment/test method that is capable of detecting release rates of larger than 0.3 gph but less than 1 gph with at least a 95% probability of detection and not more than a 5% false alarm.  In addition to monthly monitoring, a test method that is capable of detecting release rates of 0.2 gph with at least a 95% probability of detection and not more than a 5% false alarm must be performed annually.

For list of third-party certified equipment meeting the above criteria, refer to the LG 113 list.

Monitoring Options for Single-wall Bulk Piping

All the test methods and equipment used for any of the following options must have been third-party certified and meet the requirements of Section 2643(f), Title 23.

• Monitoring in accordance with Section 2643(c) Title 23.
• Monitoring using a qualitative continuous vapor monitoring method that relies on detection of hydrocarbon vapors or an inert tracer compound outside the piping system in accordance with Section 2647 Title 23.
• Quarterly monitoring using a piping monitoring method that is third-party certified to detect a minimum release equivalent to 0.1 gph defined at 150 percent the normal operating pressure.  Please note that the testing may be performed at a test pressure designated by the equipment manufacturer.