Sec. 599.6. Installation of underground tank systems

(a) Backfill.

Backfill material must be a non-corrosive, porous, homogeneous substance placed completely around the tank and compacted to ensure that the tank and piping are fully and uniformly supported.

(b) Burial depth.

Underground tanks must be installed at a depth consistent with NFPA 30, section 2-4.2.

(c) Avoiding floatation.

When subject to the buoyancy effect of water, underground tanks must be anchored to prevent floatation.

(d) Connections.

(1) All connections to new underground tanks must be located within a containment chamber constructed of a compatible material and capable of containing hazardous substance leaks from the connections. Such chambers must be fitted with a manhole or other means of access so that connections can be inspected.

(2) Valves and other ancillary equipment must be protected against physical damage by freezing or vehicular traffic.

(e) Inspection of tank systems.

(1) Prior to covering, enclosing, or placing a tank system in use, the tank system must be inspected by a qualified inspector for the following:

(i) weld breaks;

(ii) punctures;

(iii) scrapes of protective coatings;

(iv) cracks;

(v) corrosion;

(vi) other structural damage; and

(vii) improper installation.

(2) Before being placed in service, the tank system must be tested for tightness in accordance with generally accepted practices.

(3) If a tank system is found to be leaking or the tank system or installation is deficient such that a leak is possible, the owner or operator must repair the system prior to the system being placed in use.

(4) Upon completion of the test and inspection, the inspector must sign and date a statement certifying that the system meets the standards of this Part.

(5) The inspector's statement and records of the test and repairs must be kept for five years following the date of installation and made part of the spill prevention report.

(f) Qualifications of tank system installers.

Installation of an underground tank system must be performed by a qualified installer or technician who is trained in the engineering methods for installing underground tank systems.

(g) Installation instructions.

In addition to the above requirements, all tanks must be installed in strict accordance with the manufacturer's instructions or a consensus code, standard or practice of a nationally recognized association or independent testing laboratory such as API 1615 (see section 598.1[j] of this Title). This includes repair of any damage to tank coatings prior to backfilling.