020-17 Wyo. Code R. §§ 17-35 - 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 after the effective date of these regulations. After the effective date of these regulations, no tank intended for use as an UST shall 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 insure 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;

(ii) Compatible with the regulated substance stored.

(c) Vehicle impact protection. All ASTs regulated under this section shall be protected against vehicle impact by barriers. Barriers are required on any side subject to impact by a vehicle traveling on any surface accessible to the public. Barriers shall meet one of the following specifications:

(i) Guard posts constructed of steel no less than four (4) inches in diameter and concrete filled, spaced not more than four (4) feet apart, and set not less than three (3) feet above ground in a concrete filled footing 15 inches minimum diameter and a minimum of three feet deep. Posts shall not be located less than five (5) feet from the tanks.

(ii) Concrete secondary containment walls if the wall is at least five (5) feet from the tanks, and extends at least three (3) feet above ground level on the outside of the structure, and contains a minimum of two 5/8 inch reinforcing rods placed in the concrete as a continuous band within one foot of the top of the structure. Secondary containment structures constructed of concrete block, lightweight steel, or earth do not meet this requirement. Concrete secondary containment structures which do not meet this requirement may be approved by the department on a case by case basis.

(iii) Concrete barriers constructed to DOT specifications for use as a barrier along highways. These barriers are commonly called "jersey barriers".

(iv) UL-2085 tanks do not require separate vehicle impact protection, provided that the manufacturer certifies that the tank provides vehicle impact protection.

(d) Corrosion protection. All AST systems regulated under this section shall be protected against corrosion using one of the following methods:

(i) A sacrificial anode CP system. Such systems shall be checked annually for proper operation by a CP tester, and shall be designed by a corrosion expert. Owners and/or operators of all ASTs protected by sacrificial anode systems shall also comply with Section 11 of this Chapter;

(ii) An impressed current CP system. Such systems shall be checked monthly by the owner and/or operator and annually for proper operation by a CP tester, and shall be designed by a corrosion expert. Owners and/or operators of all ASTs protected by impressed current systems shall also comply with Section 11 of this Chapter; or

(iii) Isolation of the AST System from the ground by placing the tank on a bed of dry and freely draining gravel at least three (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 2085 are also isolated from ground contact.

(e) Additional requirements for cathodic protection.

(i) Both sacrificial 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 installed, inspected and maintained to meet or exceed one or more of the following industry standards and practices:

(A) NACE Standard RP0193-2001, "External Cathodic Protection of On-Grade Carbon Steel Storage Tank Bottoms";

(B) NACE Standard RP0285-2002, "Control of External Corrosion on Metallic Buried, Partially Buried, or Submerged Liquid Storage Systems".; or

(C) API Recommended Practice 651, "Cathodic Protection of Aboveground Storage Tanks."

(f) Overfill protection. All ASTs regulated under this section 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) For tanks larger than 100,000 gallons, the following shall also be provided: a system shall sound a second audible and visible alarm at the filling rack when the AST is 95% full.

(g) Spill prevention. All AST Systems regulated under this section shall have spill prevention equipment as follows:

(i) all fill lines shall be protected with a double check valve to prevent backflow from the tank and a self closing fire valve, activated by a frangible, fusible link;

(ii) the fill lines shall be completely enclosed within the secondary containment system; or

(iii) each fill line shall have its own system to control spillage.

(h) Connected Lines. All underground pipe lines connected to ASTs regulated under this section shall be non-corrodible, double walled lines equipped with working leak detection equipment. All above ground lines shall be steel. All connections between above ground lines and underground lines shall be made inside accessible leak proof sumps.

(i) Applicable Standards for new ASTs. All new AST systems installed after the date of these regulations must meet the requirements of one or more of the following industry standards or practices:

(i) Field Constructed Steel Tanks.

(A) API Standard 12D, "Specification for Field Welded Tanks for Storage of Production Liquids";

(B) API Standard 620, "Design and Construction of Large, Welded Low-Pressure Storage Tanks";

(C) API Standard 650, "Welded Steel Tank for Oil Storage";

(D) NFPA Standard 30, "Flammable and Combustible Liquids Code";

(E) NFPA Standard 30A, "Motor Vehicle Fueling Stations and Repair Garages Code";

(F) API Standard 653, "Tank Inspection, Repair, Alteration, and Reconstruction";

(G) PEI Recommended Practice 200-2003, "Recommended Practices of Installation of Aboveground Storage Systems for Motor Vehicle Fueling"; and/or

(H) Other standards approved by the department.

(ii) Shop Constructed Tanks.

(A) UL 2085, "Protected Aboveground Tanks for Flammable and Combustible Liquids;

(B) UL 142, "Standard for Aboveground Flammable and Combustible Liquid Storage Tanks"; or

(C) API Standard 650 Appendix J, "Shop-Assembled Storage Tanks";

(D) NFPA Standard 30, "Flammable and Combustible Liquids Code";

(E) ASME, "Boiler & Pressure Vessel Code, Section VIII, Division 1, Design and Fabrication of Pressure Vessels

(F) API Standard 653, "Tank Inspection, Repair, Alteration, and Reconstruction";

(G) PEI Recommended Practice 200-2003, "Recommended Practices of Installation of Aboveground Storage Systems for Motor Vehicle Fueling";

(j) ASTs installed after the effective date of these regulations.

(i) ASTs installed after the effective date of these regulations shall have a suitable foundation capable of supporting the tank full of the regulated substance without excessive differential settlement as defined in API Standard 653 or the manufacturer's recommendation. The foundation shall be 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.

(ii) All ASTs installed or re-installed after the date of these regulations shall meet all the requirements of Part I before being placed in service.

(iii) All ASTs installed after the effective date of these regulations shall be placed on a release prevention barrier. The integrity of the barrier shall not deteriorate due to exposure to the elements or soil in the presence of regulated substances. 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;

(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; or

(D) For tanks of less than 100,000 gallons capacity, an impermeable reinforced concrete slab.

(E) For double walled, vaulted tanks with an interstitial monitoring device, the tank structure meets, by itself, all requirements for both the secondary containment and the release detection barrier.

(iv) The owner and/or operator of every field constructed AST installed after the effective date of these regulations shall keep on file for the life of the tank, and make available to the department upon request, the following baseline data:

(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) The owner and/or operator of all shop fabricated ASTs installed after the effective date of these regulations shall keep on file and make available to the department on request:

(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 all field constructed ASTs installed after the effective date of these regulations shall be protected against corrosion. For surfaces that are visible with the tank in operation, this requirement may be met using field applied coatings that are compatible with the stored regulated substance.

(vii) The completed installation of all metallic Field Constructed ASTs installed after the effective date of these regulations shall be inspected and certified by a certified API 653 inspector.

(viii) The owner and/or operator of any shop fabricated AST 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 nondestructive testing performed on the AST.

(ix) The owner and/or operator of every AST installed after the effective date of these regulations shall provide a certificate of installation to the department that meets the requirements of Section 6(e) of this chapter.

(k) Existing ASTs. Tanks do not need to be UL labeled but must be designed, constructed, and tested to the approved standards. Non-UL labeled tanks 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 US gallons, and the tank construction or inspection standard used. Existing ASTs must meet the substantial requirements of Section 35 no later than October 1, 200 8.

(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 3404.2.7.3 and shall be at least the size of the fill or withdrawal connection but not less than 1 and 1/4 (one and one-quarter) inches inside diameter. Flammable liquid vents must terminate not less than twelve (12) feet above grade and five (5) feet from a building opening or property line. They must discharge upwards and outward. Operational venting shall comply with API-2000, NFPA 30, UL-142 and UL-2085 as applicable.

(m) Emergency venting. Each AST shall be equipped with adequate additional emergency venting that will relieve excessive internal pressure caused by fire exposure. Emergency venting shall comply with API-2000, NFPA 30, UL-142 and UL-2085 as applicable.

(n) Warning signs. Signs, placarding of product and no smoking signs shall be properly posted in accordance with IFC 3404.2.3.2, 3404.2.3.2 and 3403.5.

(o) Upgrading existing tanks. All existing ASTs that do not meet the requirements of this chapter must be upgraded no later than October 1, 2008, to meet all of the requirements of this chapter for new ASTs.

(p) Fire Marshall plan review. All AST systems installed or modified after the date of these rules shall provide documentary proof to the department that the plans have been reviewed and passed by the appropriate authorizing authority under the State Fire Marshall. This "plan review" insures compliance with the applicable fire code as adopted into Wyoming State Statutes.

(q) Installation and modification inspections. AST system upgrades required by this part shall be inspected by the Water Quality Division.

(r) Access to tank tops. Access shall be provided to the top of all ASTs for inspection of venting, overfill equipment and other required equipment. Access shall be by way of permanently mounted, solidly constructed, non-combustible ladders, stairs, catwalks and platforms which comply with Occupational Safety and Health Administration standards.

(s) Tank openings. No AST regulated under this section, which is eleven (11) feet high or less, shall be connected to piping through any opening in a location other than the top. This means that all fill lines and product delivery lines must exit the tank through the top. All lines shall be equipped with anti-syphon devices. ASTs which are higher than eleven (11) feet high, and have penetrations near the bottom of the tank shall be equipped with internal fire valves on all openings which are not in the top of the tank.

(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 one-hundred (100) feet but not less than twenty (20) feet of dispensers. All emergency disconnect switches shall be labeled: "EMERGENCY FUEL SHUT OFF" using a durable, weatherproof, sign with letters a minimum of 6" (six inches) high.

(u) Direct connection between USTs and ASTs. Any existing UST directly connected to an AST must have an automatic tank gauging system equipped with an audible and visual alarm system which will sound when the underground tank is 95% full or automatically shut off the flow to the UST when the UST is 95% full. This system shall be separate from any control system which controls the filling of the UST. After the effective date of these regulations no new connection shall be made between any UST and any AST.

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

(w) Submerged ASTs. After the effective date of these regulations, no AST shall be operated submerged in water.

(x) Site Security. All ASTs shall be protected from vandalism and unauthorized product release by security fencing. Security fences shall be galvanized wire mesh no less than six (6) feet high topped with three (3) strands of barbed wire on an angled support bracket. Fencing shall be no less than five (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/operator may substitute other types of fencing at least six (6) feet high.

Notes

020-17 Wyo. Code R. §§ 17-35