a. General. External release detection devices (RDDs) consist of slotted (screened) piping installed within the excavation zone to permit either the testing or monitoring of vapors or the testing or monitoring for liquids on the water table. All RDDs mustshall meet the following requirements. i. All RDDs mustshall have a 4-inch inside diameter and be constructed of either polyvinyl chloride (PVC), polytetrafluoroethylene (PTFE), or stainless steel, and mustshall be chemically compatible with the stored product. The screened interval mustshall be commercially fabricated, slotted, or continuously wound. Screen size mustshall be 0.01 inches. No solvents, glues, epoxies, thermal processes, or rivets shall be used. ii. The screened interval mustshall extend from 1 foot beneath the ground surface through the entire excavation zone. iii. Each RDD mustshall be sealed from the ground surface to a depth of 1 foot and provided with a locking cap. Each RDD mustshall be installed in such a fashion as to preclude the introduction of surface contaminants into the RDD. iv. No RDD be installed within or penetrate native soils unless the hydraulic conductivity of the native soil is no less than 0.01 centimeters per second. v. If only one UST system is located within the excavation zone, at two RDDs mustshall be installed. For excavation zones containing between two and four UST systems, at least four RDDs mustshall be installed. If more than four UST systems are situated within a common excavation zone, additional RDDs shall be installed as appropriate to ensure adequate coverage for release detection. If, prior to the implementation of these regulations, fewer RDDs than required in this Clause were installed at a specific location, the
a. General. External release detection devices (RDDs) consist of slotted (screened) piping installed within the excavation zone to permit either the testing or monitoring of vapors or the testing or monitoring for liquids on the water table. All RDDs mustshall meet the following requirements. i. All RDDs mustshall have a 4-inch inside diameter and be constructed of either polyvinyl chloride (PVC), polytetrafluoroethylene (PTFE), or stainless steel, and mustshall be chemically compatible with the stored product. The screened interval mustshall be commercially fabricated, slotted, or continuously wound. Screen size mustshall be 0.01 inches. No solvents, glues, epoxies, thermal processes, or rivets shall be used. ii. The screened interval mustshall extend from 1 foot beneath the ground surface through the entire excavation zone. iii. Each RDD mustshall be sealed from the ground surface to a depth of 1 foot and provided with a locking cap. Each RDD mustshall be installed in such a fashion as to preclude the introduction of surface contaminants into the RDD. iv. No RDD be installed within or penetrate native soils unless the hydraulic conductivity of the native soil is no less than 0.01 centimeters per second. v. If only one UST system is located within the excavation zone, at two RDDs mustshall be installed. For excavation zones containing between two and four UST systems, at least four RDDs mustshall be installed. If more than four UST systems are situated within a common excavation zone, additional RDDs shall be installed as appropriate to ensure adequate coverage for release detection. If, prior to the implementation of these regulations, fewer RDDs than required in this Clause were installed at a specific location, the
UT018fin.docx