Section 2643 - Non-Visual Monitoring/Quantitative Release Detection Methods(a) Non-visual quantitative release detection methods shall comply with the requirements of this section. Subdivision (b) contains monitoring requirements for underground storage tanks; subdivision (c) for pressurized piping; subdivision (d) for suction piping; and subdivision (e) for gravity-flow piping. Examples of release detection methods that may be used to meet the requirements of this section are in Appendix III.(b) Quantitative release detection methods used to monitor underground storage tanks shall be conducted according to one of the methods listed in paragraphs (1) through (4) below. These quantitative monitoring methods shall meet the requirements of section 2643(f) and shall be capable of detecting release rates specified in this section with at least a 95 percent probability of detection and not more than a five percent probability of false alarm. (1) Automatic tank gauge -- The automatic tank gauge shall test the tank at least once every 30 days after product delivery or when the tank is filled to within 10 percent of the highest operating level during the previous 30 days and shall be capable of detecting a release of 0.2 gallons per hour. The automatic tank gauge shall generate a hard copy of all data reported including time and date, tank identification, fuel depth, water depth, temperature, liquid volume, and the duration of the test. Automatic tank gauge systems installed on or after January 1, 1995, shall also generate a hard copy of the calculated leak rate and leak threshold.
(2) Statistical inventory reconciliation plus tank integrity testing -- Statistical inventory reconciliation shall be conducted at least once every 30 days in accordance with section 2646.1 and shall be capable of detecting a release of 0.2 gallons per hour. In addition, a tank integrity test shall be conducted at least once every 24 months in accordance with section 2643.1. On and after October 1, 2018, statistical inventory reconciliation shall report a quantitative leak rate using a threshold value that does not exceed one-half the minimum detectible leak rate at least once every 30 days.
(3) Continuous in-tank leak detection -- On and after October 1, 2018, continuous in-tank leak detection shall be capable of detecting an unauthorized release of 0.2 gallons per hour. Continuous in-tank leak detection shall operate on an uninterrupted basis or within a process that allows the system to gather incremental measurements to determine the leak status of the tank at least once every 30 days.
(4) Other test methods -- Other equivalent test methods may be used following review by the State Water Board for compliance with this subdivision and subdivision (f) below.
(c) Piping that conveys hazardous substances under pressure shall be monitored in accordance with paragraph (1), and either paragraph (2) or (3) below. (1) Monitoring shall be conducted at least hourly at any pressure. The monitoring method shall be capable of detecting a release equivalent to 3.0 gallons per hour defined at 10 pounds per square inch pressure within one hour of its occurrence with at least a 95 percent probability of detection and not more than a five percent probability of false alarm. The leak detection method shall restrict or shut off the flow of product through the piping or trigger a visual and audible alarm if an unauthorized release occurs. If the use of piping is intermittent, leak detection monitoring is required only at the beginning or end of the period during which the piping is under pressure, but in any event there shall not be more than one hour between the time the equipment initiates the test and detection of an unauthorized release; and(2) Monitoring shall be conducted at least once every 30 days at any pressure. The monitoring method shall be capable of detecting a minimum release equivalent to 0.2 gallons per hour defined at normal operating pressure; or(3) Monitoring shall be conducted at least once every 12 months at a pressure designated by the equipment manufacturer. The monitoring method shall be capable of detecting a minimum release equivalent to 0.1 gallons per hour defined at 150 percent (one and one half times) the normal operating pressure.(d) Piping that conveys hazardous substances under less than atmospheric pressure (suction piping) shall be tested at least once every 36 months at a pressure designated by the test equipment manufacturer. The test method shall be capable of detecting a minimum release equivalent to 0.1 gallons per hour defined at a minimum of 40 pounds per square inch with at least a 95 percent probability of detection and not more than a five percent probability of false alarm. If the piping cannot be isolated from the tank for testing purposes, the piping shall be tested using an overfilled volumetric tank integrity test or other test method meeting the requirements of section 2643(f) if approved by the local agency. Daily monitoring shall be performed as described in Appendix II except for emergency generator systems, which may be monitored less often, but at least once every 30 days. Written records describing the results of the monitoring shall be maintained in accordance with section 2712(b).(e) Piping that conveys hazardous substances by the force of gravity (excluding vertical drops) shall be monitored at least once every 24 months at a pressure designated by the test equipment manufacturer. The method shall be capable of detecting a minimum release equivalent to 0.1 gallons per hour defined at 40 pounds per square inch. If the piping cannot be isolated from the tank for testing purposes, the piping shall be tested using an overfilled volumetric tank integrity test or other test method meeting the requirements of section 2643(f) if approved by the local agency.(f) Each quantitative release detection method, with the exception of manual inventory reconciliation and manual tank gauging, shall be certified to comply with the performance standard(s) specified in this section and shall be subject to limitations specified in the certification. This certification shall be obtained by the equipment manufacturer following one of the evaluation procedures in paragraphs (1) through (3) below: (1) An independent third party testing laboratory shall evaluate and approve the method using the appropriate "EPA Standard Test Procedure" for leak detection equipment in Appendix IV;(2) An independent third party testing laboratory shall evaluate and approve the method using a voluntary consensus standard that is intended for the method being evaluated;(3) An independent third party testing laboratory shall evaluate and approve the method using a procedure deemed equivalent to an EPA procedure. Any resultant certification shall include a statement by the association or laboratory that the conditions under which the test was conducted were at least as rigorous as those used in the EPA standard test procedure. This certification shall include statements that: (A) The method was tested under various conditions that simulate interferences likely to be encountered in actual field conditions (no fewer nor less rigorous than the environmental conditions used in the corresponding EPA test procedure);(B) Each condition under which the method was tested was varied over a range expected to be encountered in 75 percent of the normal test cases;(C) All portions of the equipment or method evaluated received the same evaluation;(D) The amount of data collected and the statistical analysis are at least as extensive and rigorous as the data collected and statistical analysis used in the corresponding EPA test procedure and are sufficient to draw reasonable conclusions about the equipment or method being evaluated;(E) The full-sized version of the leak detection equipment was physically tested; and(F) The experimental conditions under which the evaluation was performed and the conditions under which the method was recommended for use have been fully disclosed and that the evaluation was not based solely on theory or calculation.(4) The evaluation results referred to in paragraphs (2) and (3) shall contain the same information and shall be reported following the same general format as the EPA standard results sheet as any corresponding EPA test procedure.(g) The underground storage tank owner or operator shall notify the local agency 48 hours before conducting a tank or piping integrity test. Within 30 days of completion of an underground storage tank or piping integrity test, the tank owner or operator shall submit a report to the local agency through the California Environmental Reporting System or a local reporting portal. The results of any underground storage tank tests, other than those required by this article, performed on the underground storage tank or piping to detect an unauthorized release shall be submitted by the owner or operator to the local agency through the California Environmental Reporting System or a local reporting portal within 30 days of completion of the test. The report shall be presented in written format, as appropriate, and shall be at a level of detail appropriate for the release detection method used.Cal. Code Regs. Tit. 23, § 2643
1. Repealer and new section filed 8-9-91 as an emergency; operative 8-9-91. Text remains in effect uninterrupted pursuant to Health and Safety Code section 25299.7 (Register 92, No. 14).
2. Editorial correction of printing errors in HISTORY 1 (Register 92, No. 43).
3. Amendment filed 4-5-94; operative 5-5-94 (Register 94, No. 14).
4. Editorial correction renumbering HISTORIES (Register 99, No. 7).
5. Amendment of subsections (a)-(b), (b)(2), (b)(5), (c), (d), (f), (f)(4) and (g) and amendment of NOTE filed 10-13-2016; operative 1-1-2017 (Register 2016, No. 42).
6. Amendment filed 8-27-2018; operative 10-1-2018 (Register 2018, No. 35). Note: Authority cited: Sections 25299.3 and 25299.7, Health and Safety Code. Reference: Sections 25292 and 25404, Health and Safety Code; and 40 CFR §§ 280.40, 280.41, 280.42, 280.43, 280.44 and 280.45.
1. Repealer and new section filed 8-9-91 as an emergency; operative 8-9-91. Text remains in effect uninterrupted pursuant to Health and Safety Code section 25299.7 (Register 92, No. 14).
2. Editorial correction of printing errors in History 1 (Register 92, No. 43).
3. Amendment filed 4-5-94; operative 5-5-94 (Register 94, No. 14).
4. Editorial correction renumbering Histories (Register 99, No. 7).
5. Amendment of subsections (a)-(b), (b)(2), (b)(5), (c), (d), (f), (f)(4) and (g) and amendment of Note filed 10-13-2016; operative 1/1/2017 (Register 2016, No. 42).
6. Amendment filed 8-27-2018; operative 10/1/2018 (Register 2018, No. 35).