N.M. Admin. Code § 20.5.108.808

Current through Register Vol. 35, No. 23, December 10, 2024

Section 20.5.108.808 - INTERSTITIAL MONITORING REQUIREMENTS FOR USTS

A. Owners and operators of underground storage tanks may use interstitial monitoring between the UST and a secondary barrier immediately around and underneath the tank, but only if the system is designed, constructed and installed to detect a leak from any portion of the storage tank system that routinely contains any regulated substance and also meets one of the following requirements:

(1) For double-walled UST systems, the sampling or testing method can detect a release through the inner wall in any portion of the tank that routinely contains a regulated substance, and the sampling or testing method complies with the requirements of the current edition of an industry code or standard approved in advance by the department; Steel Tank InstituteStandard F841, "Standard for Dual Wall Underground Storage Tanks" may be used to meet this requirement.

(2) For UST systems with a secondary barrier within the excavation zone, the sampling or testing method used can detect a release between the UST system and the secondary barrier; the monitoring system shall meet all of the following requirements:

(a) The secondary barrier around or beneath the UST system consists of artificially constructed material that is sufficiently thick and impermeable (at least one X 10(-6)) centimeters per second for the regulated substance stored) to direct a release to the monitoring point and permit its detection.

(b) The barrier is compatible with the regulated substance stored so that a release from the UST system will not cause a deterioration of the barrier allowing a release to pass through undetected.

(c) For cathodically protected USTs, the secondary barrier shall be installed so that it does not interfere with the proper operation of the cathodic protection system.

(d) The groundwater, soil moisture, or rainfall will not render the testing or sampling method used inoperative so that a release could go undetected for more than thirty days.

(e) The site is assessed to ensure that the secondary barrier is always above the groundwater and not in a 25-year flood plain, unless the barrier and monitoring designs are for use under such conditions.

(f) Monitoring wells are clearly marked and secured to avoid unauthorized access and tampering, or

(3) For USTs with an internally fitted liner, an automated device can detect a release between the inner wall of the UST and the liner, and the liner is compatible with the regulated substance stored.

B. For all interstitially monitored USTs, owners and operators shall have all sensors tested by a qualified tester at least annually to ensure proper operation and functionality, including for alarm operability and communication with controller or monitoring equipment, and sensors shall be verified as set to the proper height, placement, and location in accordance with Subsection A of 20.5.108.800 NMAC and 20.5.107 NMAC. At a minimum, these tests shall follow either:

(1) liquid sensor functionality testing procedures described in Petroleum Equipment InstitutePublication RP 1200,"Recommended Practices for the Testingand Verification of Spill, Overfill,Leak Detection andSecondaryContainmentEquipment at UST Facilities"; or

(2) the equipment manufacturer's published testing procedures.

C. Owners and operators shall ensure the requirements in 20.5.108.800 NMAC are met prior to implementing interstitial monitoring.

D. Owners and operators shall maintain and provide the department reports relating to the requirements of this section in accordance with 20.5.108.815 NMAC and 20.5.108.816 NMAC.

N.M. Admin. Code § 20.5.108.808

Adopted by New Mexico Register, Volume XXIX, Issue 14, July 24, 2018, eff. 7/24/2018