Current through Register Vol. 35, No. 11, June 11, 2024
Section 20.6.7.23 - REQUIREMENTS FOR NEW PIPELINES AND TANKSA.Engineering design requirements. At a minimum, the following requirements shall be met in designing new pipeline or tank systems at copper mine facilities that contain process water or impacted stormwater unless the applicant or permittee can demonstrate that an alternate design will provide an equal or greater level of containment.(1)New Pipelines. New pipelines shall: (a) be constructed of impermeable materials that are compatible with the particular contents that are contained and carried in the pipeline and are resistant to degradation by ultraviolet light if they will be exposed to sunlight;(b) for pipelines located outside of the open pit surface drainage area and outside an area authorized for discharge of process water, impacted stormwater or tailings, incorporate a mechanism for monitoring the integrity of the pipeline system including visual inspections, pressure change sensors, or other appropriate means; and(c) for pipelines located outside of the open pit surface drainage area and outside an area authorized for discharge of process water, impacted stormwater or tailings, incorporate a mechanism of secondary containment to contain and control leaks and spills including berms, placement within or drainage toward areas authorized for discharge of the conveyed fluids, and impoundments that are constructed consistent with the requirements of Subsection D of 20.6.7.17.D NMAC.(2)Tanks. New tank systems shall meet the following requirements. (a) Tanks shall be designed and constructed of steel, concrete or impermeable materials that are compatible with the particular contents that are contained within the tank and resistant to degradation by ultraviolet light where exposed to sunlight.(b) A tank system shall have a constructed foundation consisting of a stable, level base free of rocks, debris, sharp edges or irregularities that could puncture, crack or indent the tank materials.(c) A tank system shall be designed to prevent overflow and the collection of surface water run-on.(d) An above-ground tank system shall be bermed to contain 110 percent of the volume of the largest tank within the system or the largest interconnected tanks.(e) A below-grade tank system shall either be placed in such a manner that the side walls are open for visual inspection or the tank shall be designed with a secondary containment and leak detection system.B.Construction.(1)New pipeline and tank units. Construction of a new pipeline or tank system shall be performed in accordance with the applicable requirements of Subsection A of 20.6.7.23 NMAC and 20.6.7.17 NMAC.(2)Existing pipeline and tank units. A pipeline or tank system in existence on the effective date of the copper mine rule is not required to meet the design requirements of Subsection A of 20.6.7.23 NMAC and may continue to operate as previously permitted under a discharge permit provided that, for a tank in contact with the ground surface and located outside an open pit surface drainage area, it is inspected and tested at least once every ten years for integrity pursuant to Subsection C of 20.6.7.23 NMAC. If an existing tank or pipeline system cannot maintain integrity it shall be replaced in accordance with the engineering requirements of Subsection A of 20.6.7.23 NMAC and 20.6.7.17 NMAC as applicable. A permit issued for such an existing tank or pipeline system after the effective date of the copper mine rule may include the conditions of the existing discharge permit, which shall not be considered to be "additional conditions" under Subsection I of 20.6.7 NMAC.C.Operational requirements. A permittee operating a pipeline or tank system shall operate the system pursuant to the following requirements, as applicable. (1) Pipelines and tanks shall remain within the area identified in the discharge permit.(2) Pipelines, tanks and secondary containment systems shall be inspected on a monthly basis.(3) The permittee shall maintain and operate a below-grade tank(s) to prevent overtopping of the tank(s).(4) Any evidence of leaks or spills of fluids, process water or tailings from a pipeline or tank system outside of permitted secondary containment systems or outside an area permitted for discharge shall be recorded, reported and corrected pursuant to Subsection G of 20.6.7.30 NMAC.(5) Any evidence of leaks or spills of fluids, process water or tailings from a pipeline or tank system inside of permitted secondary containment systems or inside an area permitted for discharge shall be recorded and reported to the department in the semiannual reports submitted pursuant to Subsection A of 20.6.7.29 NMAC.(6) Existing pipelines that do not meet the engineering requirements of Subsection A of 20.6.7.23 NMAC shall be evaluated for integrity at least once every five years. A pipeline evaluation plan for such pipelines shall be included in an application for renewal of a discharge permit for a copper mine facility.(7) Existing below-grade tanks that do not meet the engineering requirements of Subsection A of 20.6.7.23 NMAC shall be emptied and visually inspected for integrity at least once every five years.(8) A written record of all pipeline and tank system inspections and integrity testing shall be maintained by the permittee for a period of at least five years.(9) Any wastes generated from the cleaning of pipeline or tank systems shall be disposed of offsite in accordance with applicable laws or onsite in a manner approved by the department.20.6.7.23 NMAC - N, 12/1/13