Sec. 599.8. New aboveground tanks

(a) Tanks subject to scouring.

All new aboveground tanks subject to scouring by the inflow of hazardous materials or subject to wear from manual gauging must be equipped with wear plates, diffusers or alternate means to prevent localized wear or corrosion. If wear plates are used, they must cover an area of at least 144 square inches and be installed in a manner which avoids crevice corrosion.

(b) Tank designs.

(1) Aboveground tanks must be of sufficient structural strength to withstand normal handling and use. They must be compatible with the hazardous substance being stored and with adjacent soil. They must be protected from, or resistant to, all forms of internal and external wear, vibration, shock and corrosion. They must have a stable foundation under all operating conditions and be protected from fire, heat, vacuum and pressure which might cause tank failure. Tanks must be protected from physical damage by moving machinery such as forklifts and trucks. If fiberglass-reinforced-plastic material is used, the material must be of sufficient density and strength to form a hard, impermeable shell which will not crack, wick, wear, soften or separate under normal service conditions. All tanks must be designed with a minimum of 30 years of useful life unless a shorter life expectancy is defined in the spill prevention report.

(2) All new aboveground tanks must be designed, constructed and installed or certified by a qualified engineer or technician in accordance with one of the following:

(i) API 650;

(ii) API 620;

(iii) CAN4-S601-M84;

(iv) CAN4-S630-M84;

(v) ASTM D4097-88;

(vi) ASTM D3299-88, (see section 598.1[j] of this Title); or

(vii) a comparable consensus code, standard or practice developed by a nationally recognized association or independent testing laboratory which meet the standards of this section.

(c) Tanks subject to melting.

All aboveground tanks constructed of plastic, cross-linked polyolefin, high density polyethylene, fiberglass-reinforced-plastic or any other material subject to melting when exposed to fire must be suitably protected against fire and located so that any spill or release resulting from the failure of these materials could not expose persons, buildings, structures or the environment.

(d) Corrosion protection for bottoms of on-ground tanks.

(1) The bottom of a new on-ground tank must be protected from external corrosion by one of the following:

(i) corrosion resistant materials; or

(ii) a cathodic protection system.

(2) Cathodic protection must consist of one or a combination of the following:

(i) sacrificial anodes and coating;

(ii) impressed current; or

(iii) another method specified in a consensus code, standard or practice developed by a nationally recognized association or independent testing laboratory such as API 651 (see section 598.1[j] of this Title).

(3) The cathodic protection system must be designed and constructed by a qualified engineer or corrosion specialist and must provide a minimum of 30 years of protection against external corrosion. The engineer or specialist must supervise the installation of all field fabricated systems and pre-fabricated systems where necessary to assure that the system has been installed as designed.

(4) Tanks which are protected with sacrificial anodes must be electrically insulated from the piping if the piping is constructed of a conductive material, unless the cathodic protection system has been designed to protect the entire tank system. Electrical insulation must be provided by dielectric fittings, bushings, washers, sleeves or gaskets which are chemically stable when exposed to the stored substances and soil.

(5) The cathodic protection system must be installed with a monitor that allows for annually review of the adequacy of protection.

(6) The tank must be isolated from or protected against stray electric currents which include underground cables, electric machinery, railroad systems and electrical grounding rods.

(7) Tank and piping connections of two dissimilar metals which create a corrosion inducing galvanic cell are prohibited.

(8) External coatings must be fiberglass-reinforced-plastic, epoxy, or other suitable dielectric material with a minimum thickness of 10 mils after curing. The coating must have a coefficient of thermal expansion compatible with that of steel and be firmly bonded to the steel. It must be of sufficient strength and density to form a hard, impermeable shell that will not crack, wick, wear, soften, flake or separate and must be noncorrodible under adverse underground electrolytic conditions. The application of the coating must be in strict accordance with the instructions of the supplier of the coating material.

(9) Coatings must be inspected for air pockets, cracks, blisters, and pinholes, and must be electrically tested for coating short circuits or coating faults. Any defects must be repaired in accordance with the manufacturer's instructions prior to installation.

(e) Manways.

All new aboveground tanks with a design capacity of 5,000 gallons or more must be provided with an access lid or manhole.

(f) Painting of exterior tank surfaces.

Unless constructed of a corrosion-resistant material, the exterior surfaces of new aboveground tanks must be protected from corrosion. The surface should be prepared to a SSPC SP #6 blast (see section 598.1[j] of this Title), or equivalent method, and protected by an inhibitive primer coat, intermediate inhibitive and two or more final coats of paint, or have an equivalent or better surface coating or protective system designed to prevent corrosion and deterioration.

(g) Impermeable barriers under on-ground tanks.

Any new on-ground tank must be constructed with a double bottom or underlain by an impervious barrier such as a concrete pad or a cutoff barrier. The permeability rate of the barrier relative to the substance stored must be equal to or less than 1 × 10^-6 cm/sec. The barrier must not deteriorate in an underground environment or in the presence of the hazardous substance being stored.

(h) Explosion protection.

Tanks must be protected from explosion in accordance with generally accepted engineering practices. Protection must be provided by fail-safe cooling systems, fire-proofing, depressurizing valves, foundation sloping to prevent burning liquids from accumulating under the tank, or other equally effective means determined by a qualified engineer and acceptable to the department.