Okla. Admin. Code § 165:26-3-20.1
Current through Vol. 42, No. 4, November 1, 2024
Section 165:26-3-20.1 - Monitoring requirements for aboveground tanks and aboveground pipingOne of the following methods must be used:
(1)Visual Monitoring.(A) Visual inspection of the aboveground storage tank systems to identify cracks or other defects in the secondary containment area and product transfer area.(B) Visual inspection of the exterior surface of the tanks, piping, valves, pumps and other equipment for cracks, corrosion, releases and maintenance deficiencies; and identify poor maintenance, operating practices or malfunctioning equipment.(C) Visual inspection of elevated tanks or tanks on concrete slabs.(D) Visual inspection of the area between the tank's outer shell or the tank's floor and containment area or a vapor monitoring of the soil directly under the tank bottom or perimeter and the water table, unless the tank containment has a sound concrete floor.(E) Visual inspections are not adequate where due to the nature of the aboveground storage tank and/or its secondary containment it cannot be determined whether a leak has occurred. A good example would be a vertical tank that is not raised off the ground, making it impossible to visually inspect its bottom, and is not sitting on a sound concrete slab within sound secondary containment.(F) An annual line tightness test performed by a licensed tester may be used in lieu of thirty (30) day visual monitoring for aboveground product piping.(2)Inventory Reconciliation. Product inventory control (or another test of equivalent performance) must be conducted at least every thirty (30) days to detect a release of at least one percent (1.0%) of flow-through plus 130 gallons on a thirty (30) day basis in the following manner:(A) Inventory volume measurements for regulated substance inputs, withdrawals, and the amount remaining in the tank are recorded each operating day.(B) The equipment used is capable of measuring the level of product over the full range of the tank's height to the nearest one-eighth inch (1/8").(C) The regulated substance inputs are reconciled with delivery receipts by measurement of the tank inventory volume before and after delivery.(D) Product dispensing is metered and recorded within an accuracy of six (6) cubic inches for every five (5) gallons of product withdrawn.(E) The measurement of any water level in the bottom of the tank is made to the nearest one-eighth inch (1/8") at least once every thirty (30) days.(F) Use of the PSTD Inventory Reconciliation Form or an electronic equivalent is required.(3)Interstitial Monitoring. Interstitial monitoring must be used for double walled aboveground storage tank systems. The sampling or testing method must detect a release at least every thirty (30) days in accordance with the manufacturer instructions through the inner wall in any portion of the tank that routinely contains product.(4)Automatic tank gauging systems.(A) Automatic tank gauging systems (ATGs) that test for the loss of product must conduct an automatic product level monitor test at a minimum frequency of once every thirty (30) days and be capable of detecting at least a 0.2 gallon per hour leak rate with a probability of detection of 0.95 and a probability of false alarm of 0.05.(B) Automatic tank gauging systems (ATG's) must be third party certified for the size and quantity of the tank. Only third party certifications that have been reviewed and approved by the National Work Group on Leak Detection Evaluations (NWGLDE), as evidenced by their posting on the NWGLDE Web Site, will be accepted (nwglde.org).Okla. Admin. Code § 165:26-3-20.1
Amended and renumbered from 165:26-2-134 at 23 Ok Reg 2297, eff 7-1-06; Amended at 25 Ok Reg 2187, eff 7-11-08; Amended at 26 Ok Reg 1831, eff 7-1-09Amended by Oklahome Register, Volume 33, Issue 23, August 15, 2016, eff. 8/25/2016Amended by Oklahoma Register, Volume 35, Issue 24, September 4, 2018, eff. 10/1/2018Amended by Oklahoma Register, Volume 41, Issue 23, August 15, 2024, eff. 10/1/2024