Statutes, codes, and regulations
Wyoming Administrative Code
Agency 020 - Environmental Quality, Dept. ofSubagency 0014 - Storage TanksChapter 1 - STORAGE TANKS
Part I - AST SYSTEMS
Section 1-35 - Construction Requirements for AST Systems

020-1 Wyo. Code R. § 1-35

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Current through April 27, 2019
Section 1-35 - Construction Requirements for AST Systems

(a) Tanks. All tanks regulated by this Part, whether existing or new, shall be welded steel tanks. Bolted or riveted steel tanks or tanks made of any material other than steel shall not be used as a regulated AST. A tank intended for use as a UST shall not be installed as an AST.

(b) Secondary Containment. All ASTs regulated under this Section shall be constructed with secondary containment equal to at least 110% of storage capacity of the largest single AST within the secondary containment wall. The owner and/or operator of any AST shall control runoff captured inside the secondary containment system and ensure that runoff is free of floating oils prior to discharge from the secondary containment structure. Secondary containment shall be constructed of materials that are:

  • (i) Fireproof; and
  • (ii) Compatible with the regulated substance stored.

(c) Vehicle Impact Protection. ASTs shall be protected against vehicle impact by barriers. Barriers are required on any side of the AST subject to impact by a vehicle traveling on any surface accessible to the public. Vehicle impact protection is not required for tanks meeting UL-Standard 2085, as referenced in Section 2, if the manufacturer certifies that the tank provides vehicle impact protection. Barriers shall meet one of the following specifications:

  • (i) Guard posts constructed of concrete-filled steel no less than 4 inches in diameter, spaced not more than 4 feet apart, and set not less than 3 feet above ground in a concrete-filled footing. Footing shall be 15 inches minimum diameter and set into the ground a minimum of 3 feet deep. Posts shall not be located less than 5 feet from the tanks.
  • (ii) Concrete secondary containment walls that are at least 5 feet from the tanks; extend at least 3 feet above ground level on the outside of the containment wall; and contain a minimum of two, 5/8-inch reinforcing rods placed in the concrete as a continuous band within 1 foot of the top of the containment wall. Concrete secondary containment structures that do not meet this requirement may be approved by the department on a case-by-case basis.
  • (iii) Concrete barriers constructed to Department of Transportation specifications for use as barriers along highways. These barriers are commonly called "jersey barriers."

(d) Corrosion Protection. AST systems shall be protected against corrosion using one of the following methods:

  • (i) Sacrificial/Galvanic Anode CP System. Sacrificial/galvanic anode CP systems shall be tested by a CP tester at least once every 3 years for proper operation. These systems shall be designed by a corrosion expert. Owners and/or operators of ASTs protected by sacrificial/galvanic anode systems shall also comply with Section 11;
  • (ii) Impressed Current CP System. Impressed current CP systems shall be checked at least once every 60 days by the owner and/or operator and tested by a CP tester at least once every 3 years for proper operation. These systems shall be designed by a corrosion expert. Owners and/or operators of ASTs protected by impressed current systems shall also comply with Section 11; or
  • (iii) Isolation. Isolating the AST system from the ground by placing the tank on a bed of dry and freely draining gravel, at least 3 inches thick, on a concrete floor within a concrete secondary containment system. Horizontal cylindrical tanks on saddles and tanks that meet the requirements of UL Standard 2085, as referenced in Section 2, meet this corrosion protection method.

(e) Additional Requirements for Cathodic Protection.

  • (i) Both sacrificial/galvanic anode and impressed current CP systems on ASTs shall be designed and installed with test stations to enable the owners and/or operators to monitor the operation of the CP system.
  • (ii) All CP systems installed on ASTs shall be designed by a corrosion expert. All CP systems shall be designed, installed, inspected and maintained to meet or exceed one or more of the following industry standards or practices:
    • (A) NACE Standard SP0193, as referenced in Section 2;
    • (B) NACE Standard SP0285, as referenced in Section 2; and/or
    • (C) API Standard 651, as referenced in Section 2.

(f) Overfill Protection. ASTs shall have overfill protection as follows:

  • (i) Systems shall sound an audible or visible alarm at the filling rack when the AST is 90% full;
  • (ii) Systems shall close valves and prevent overfilling the tank before the AST is 95% full; and
  • (iii) The system for tanks larger than 100,000 gallons shall sound a second audible and visible alarm at the filling rack when the AST is 95% full.

(g) Spill Prevention. AST systems shall have fill lines protected with a double-check valve to prevent backflow from the tank and a self-closing fire valve, activated by a frangible, fusible link. Additionally, spill prevention equipment shall meet one of the following:

  • (i) The fill lines shall be completely enclosed within the secondary containment system; or
  • (ii) Each fill line shall have its own system to control spillage.

(h) Connected Lines. All underground pipelines connected to ASTs shall be non-corrodible, double-wall lines equipped with working leak detection equipment. All aboveground lines shall be steel. All connections between aboveground lines and underground lines shall be made inside accessible leak-proof sumps. All new and replacement underground piping shall be double-wall and interstitially monitored.

(i) Applicable Standards for New ASTs. All new AST systems shall meet the requirements of one or more of the following industry standards or practices:

  • (i) Field Constructed Steel Tanks.
    • (A) API Specification 12D, as referenced in Section 2;
    • (B) API Standard 620, as referenced in Section 2;
    • (C) API Standard 650, as referenced in Section 2;
    • (D) NFPA Standard 30, as referenced in Section 2;
    • (E) NFPA Standard 30A, as referenced in Section 2;
    • (F) API Standard 653, as referenced in Section 2;
    • (G) PEI RP200, as referenced in Section 2; and/or
    • (H) Other standards approved by the department.
  • (ii) Shop Constructed Tanks.
    • (A) UL Standard 2085, as referenced in Section 2;
    • (B) UL Standard 142, as referenced in Section 2;
    • (C) API Standard 650, as referenced in Section 2;
    • (D) NFPA Standard 30, as referenced in Section 2;
    • (E) API Standard 653, as referenced in Section 2; and/or
    • (F) PEI RP200, as referenced in Section 2.

(j) ASTs Installed After the Effective Date of These Regulations.

  • (i) ASTs shall have a foundation designed by a Registered Professional Engineer, licensed in the State of Wyoming. The foundation design shall provide positive drainage of water away from the base. ASTs located in areas subject to flooding shall be anchored to prevent flotation. The foundation shall also meet one of the following:
    • (A) Capable of supporting the tank, when full, without excessive differential settlement as defined in API Standard 653, as referenced in Section 2; or
    • (B) Designed per the manufacturer's recommendation.
  • (ii) ASTs installed or re-installed shall meet all requirements of Part I before being placed in service.
  • (iii) ASTs shall be placed on a release prevention barrier. The integrity of the barrier shall not deteriorate due to exposure to the elements or soil contaminated by regulated substances. Double-wall vaulted tanks with an interstitial monitoring device shall meet all requirements for both secondary containment and the release detection barrier. The following are acceptable release prevention barriers:
    • (A) An impermeable geosynthetic clay liner with a permeability of 10-6 cm/sec or less;
    • (B) An impermeable geosynthetic liner installed in accordance with manufacturer's recommendations, such as a 60-mil unreinforced liner or a 40-mil reinforced liner, or a material of similar or more stringent specifications that is compatible with the regulated substance stored; or
    • (C) A double-bottom tank equipped with a leak detection system that will detect the presence of the regulated substance in the space between the bottoms.
    • (D) For tanks of less than 100,000 gallons capacity, an impermeable reinforced concrete slab.
  • (iv) Owners and/or operators of field constructed ASTs shall keep on file for the life of the tank, and make available to the department upon request, the following:
    • (A) Floor and wall/shell thickness measurements;
    • (B) Material certifications for all materials used in the construction of the AST system, including secondary containment and release prevention barriers; and
    • (C) A report including welding procedures, welding certification reports, and any non-destructive testing performed on the AST.
  • (v) Owners and/or operators of shop fabricated ASTs shall keep on file for the life of the tank, and make available to the department on request, the following:
    • (A) The floor and wall/shell thickness measurement if a UL label does not exist on the tank; and
    • (B) Material certifications for all materials used in the construction of the entire AST system.
  • (vi) All exposed exterior surfaces of field constructed ASTs shall be protected against corrosion. This requirement may be met using field applied coatings, compatible with the stored regulated substance, on visible tank surfaces.
  • (vii) The completed installation of metallic field constructed ASTs shall be inspected and certified by a certified API Standard 653, as referenced in Section 2, inspector.
  • (viii) Owners and/or operators of shop fabricated ASTs shall keep on file for the life of the AST, and provide to the department on request, a report including welding procedures, welding certification reports, and any non-destructive testing performed on the AST.
  • (ix) Owners and/or operators of ASTs shall provide a certificate of installation to the department that meets the requirements of Section 6(e).

(k) Labeling. Tanks do not need to be UL labeled but shall be designed, constructed, and tested to the approved standards. ASTs shall bear an all-weather label with the following information: name and address of the tank manufacturer, year the tank was built or date of re-certification, capacity of the tank in U.S. gallons, and the tank construction or inspection standard used.

(l) Operational Venting. Normal operation vents are required to prevent the development of vacuum or pressure within ASTs. Such vents shall be sized in accordance with IFC 5704.2.7.3, as referenced in Section 2, and shall be at least the size of the fill or withdrawal connection but not less than 1-1/4 inches inside diameter. Flammable liquid vents shall terminate not less than 12 feet above grade and 5 feet from a building opening or property line. Vents shall discharge upward and outward. Operational venting shall comply, as applicable, with: API Standard 2000, as referenced in Section 2; NFPA Standard 30, as referenced in Section 2; UL Standard 142, as referenced in Section 2; and UL Standard 2085, as referenced in Section 2.

(m) Emergency Venting. ASTs shall be equipped with adequate additional emergency venting that will relieve excessive internal pressure caused by fire exposure. Emergency venting shall comply, as applicable, with: API Standard 2000, as referenced in Section 2; NFPA Standard 30, as referenced in Section 2; UL Standard 142, as referenced in Section 2; and UL Standard 2085, as referenced in Section 2.

(n) Warning Signs. Signs, product placarding, and no smoking signs shall be properly posted in accordance with IFC 5704.2.3.1, 5704.2.3.2, and 5703.5, all as referenced in Section 2.

(o) Upgrading Existing Tanks. Existing ASTs that do not meet the requirements of this Chapter shall be upgraded to meet all requirements of this Chapter for new ASTs.

(p) Fire Marshall Plan Review. Owners and/or operators of AST systems installed or modified after the date of these rules shall provide documentary proof to the department that the installation plans were reviewed and approved by the appropriate authorizing authority under the State Fire Marshall.

(q) New Installation, Upgrade, and Modification Inspections. AST system upgrades required by this Part, modifications, and new AST installations shall be inspected by the department. Notification of new installations, upgrades, and modifications shall be made to the department in accordance with Section 9.

(r) Access to Tank Tops. ASTs greater than 6 feet in height shall have a permanently mounted, solidly constructed, non-combustible ladder or stairs. The ladder or stairs shall provide access to the top of the AST for visual inspection of venting, overfill equipment, and other equipment requiring inspection. Other Occupational Safety and Health Administration requirements may apply.

(s) Piping Connections. All AST piping connections that are below normal liquid level shall have internal or external fire/impact valves located as close as possible to the tank shell. All lines shall be equipped with anti-siphon devices.

(t) Emergency Switches. Emergency disconnect switches shall be provided at prominent locations to stop the transfer of fuel to the fuel dispenser in the event of a spill or other emergency. These switches shall be within 100 feet, but not less than 20 feet, of dispensers. All emergency disconnect switches shall be labeled: "EMERGENCY FUEL SHUT OFF" using a durable, weatherproof sign that is prominently posted and visible from the dispensers.

(u) Direct Connection Between USTs and ASTs. An existing UST directly connected to an AST shall have an automatic tank gauging system. This system shall be equipped with an audible and visual alarm that will sound when the UST is 90% full or automatically shut off the flow to the UST when the UST is 95% full. This system shall be separate from any system that controls the filling of the UST. New connections shall not be made between a UST and an AST.

(v) Repairs. Repairs to ASTs shall be performed in accordance with Section 8.

(w) Submerged ASTs. ASTs shall not be operated submerged in water.

(x) Site Security. ASTs shall be protected from vandalism and unauthorized product release by security fencing. Security fences shall be galvanized wire mesh, no less than 6 feet high, and topped with three strands of barbed wire on an angled support bracket. Fencing shall be no less than 5 feet from any of the tanks within the secondary containment structure. At facilities where wire fencing is not allowed by any other authority, the owner and/or operator may substitute other types of fencing at least 6 feet high.

(y) Compatibility. AST systems shall be compatible with the substance stored. Owners and/or operators that intend to store biofuel blends in a new or existing AST system shall demonstrate compatibility of the biofuel blend with the AST system in accordance with Section 12.

(z) Monthly Inspections. Monthly inspections shall be completed in accordance with Section 13.

020-1 Wyo. Code R. § 1-35

Adopted, Eff. 6/29/2018.