(a) In addition to NFPA 52 §7.3.2, and NFPA 55 §§4.11 and 7.1.9, equipment related to a compression, storage, or dispensing installation, shall be protected from tampering and damage in accordance with subsections (b) and (c) of this section. These protections shall be maintained in good condition at all times.
(b) Fencing at CNG stationary installations shall comply with the following.
  (1) Fencing material shall be chain link type with wire at least 12‑1/2 American wire gauge in size.
  (2) Fencing shall be at least six feet in height at all points. Fencing may be five feet in height when topped with at least three strands of barbed wire, with the strands four inches apart.
  (3) Uprights, braces, and cornerposts of the fence shall be composed of noncombustible material.
  (4) Uprights, braces, and cornerposts of the fence shall be anchored in concrete a minimum of 12 inches below the ground.
  (5) All fenced enclosures shall have at least one gate suitable for ingress and egress. All gates shall be locked whenever the area enclosed is unattended.
  (6) A minimum clearance of two feet shall be maintained between the fencing and the compression equipment, cylinder cascade(s), or container(s), and the entire dispensing system(s).
  (7) Fencing which is located more than 25 feet from any point of a CNG dispensing system(s), container(s), or compression equipment is designated as perimeter fencing. If a CNG dispensing system(s), cylinder cascade(s), or compression equipment is located inside perimeter fencing and is subject to vehicular traffic, it shall be protected against damage according to the specifications set forth in subsection (c) of this section.
  (8) The storage and compression area must be completely enclosed by fencing.
  (9) Where fencing is not used to protect the installation, then valve locks, a means of locking the electric control for the compressors, or other suitable means shall be provided to prevent unauthorized withdrawal of CNG.
(c) Guardrails at CNG stationary installations shall comply with the following:
  (1) Vertical supports for guardrails shall be at least three‑inch Schedule 40 steel pipe, or other material with equal or greater strength. The vertical supports shall be capped on the top or otherwise protected to prevent the entrance of water or debris into the guardpost, anchored in concrete at least 18 inches below the ground, and rise at least 30 inches above the ground. Supports shall be spaced four feet apart or less.
  (2) The top of the horizontal guardrailing shall be secured to the vertical supports at least 30 inches above the ground. The horizontal guardrailing shall be at least three‑inch Schedule 40 steel pipe, or other material with equal or greater strength. The horizontal guardrailing shall be capped on the ends or otherwise protected to prevent the entrance of water or debris into the guardpost, and welded or bolted to the vertical supports with bolts of sufficient size and strength to prevent damage to the protected equipment under normal conditions, including the nature of the traffic to which the protected equipment is subjected.
  (3) Openings in horizontal guardrailing shall not exceed 36 inches. Only one opening is allowed on each side of the guardrailing. A means of temporarily removing the horizontal guardrailing and/or vertical supports to facilitate the handling of heavy equipment may be incorporated into the horizontal guardrailing and vertical supports. In no case shall the protection provided by the horizontal guardrailing and vertical supports be decreased.
  (4) A minimum clearance of 24 inches shall be maintained between the railing and any part of the CNG compression equipment, cylinder cascade(s), container(s), or dispensing equipment.
  (5) The operating end of the container(s) and any part of the CNG compression equipment, piping, or cylinder cascade(s) which is exposed to collision damage or vehicular traffic shall be protected from this type of damage.
(d) Dispenser protection. Each dispenser shall be secured to a concrete island a minimum of six inches above the normal grade and two inches above the grade of any other fuel dispenser(s). Each dispenser shall be protected against collision damage. Support columns or other such protection installed at the approach end(s) of the concrete island shall prevent collision with the dispenser. If such protection cannot be provided, then the requirements of subsection (c) of this section shall apply.
(e) The provisions of this section notwithstanding, AFS may require an installation to be protected in accordance with this section when evidence exists that because of exceptional circumstances, added safeguards are needed to adequately protect the health, safety, and welfare of the general public. If a person owning or operating such an installation disagrees with the determination of AFS made under this subsection, then that person may request a public hearing on the matter. However, until a determination is issued subsequent to a hearing on the matter, the subject automatic dispenser(s) shall be either protected in the manner described by AFS or removed from CNG service and/or all of the product withdrawn from it.
(f) At least two monitoring sensors shall be installed at all stationary installations where methane can be trapped to detect hazardous levels of methane. Sensors shall activate prior to the methane level exceeding 25% of the lower flammability limit (LFL). If the level exceeds 25% of the LFL, the sensor shall either shut the system down or activate an audible and visual alarm. The number of sensors to be installed shall comply with the area of coverage for each sensor and the size of the installation. The sensors shall be installed and maintained in accordance with the manufacturer's instructions.
(g) In addition to NFPA 52 §§7.4.3.11, 7.11.5.2, and 7.14.12 and NFPA 55 §§4.10 and 7.1.8.3, all CNG storage installations, and installations protected by guardrails only, must comply with the sign and/or lettering requirements of Table 1 of this section.
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Source Note: The provisions of this §13.93 adopted to be effective November 15, 1990, 15 TexReg 5941; amended to be effective June 1, 1994, 19 TexReg 3170; amended to be effective June 5, 2006, 31 TexReg 4604; amended to be effective December 24, 2012, 37 TexReg 9917; amended to be effective February 15, 2021, 46 TexReg 1035; amended to be effective February 7, 2023, 48 TexReg 507