Section 175.425  UST Wiring Procedures

a)         Unless otherwise specified in this Section, all wiring at UST locations shall be in accordance with the Edition of NFPA 70 in force at the time of installation of the electrical equipment.

b)         Wiring within 20 feet of tanks and product piping, dispenser pumps or product lines shall be installed in rigid metallic conduit, threaded steel conduit, or any petroleum or product resistant rigid nonmetallic conduit listed and manufacturer-approved for that use. Rigid nonmetallic conduit must have written verification of its approval for petroleum or other product use. The approval must be via manufacturer's certification or third-party listing and must be kept on site and must be submitted with any applicable permit application. Electrical conduit shall maintain at least 6 inches of separation from product piping to avoid damage from abrasion or stray electrical current and shall be routed in compliance with subsection (e) when it becomes necessary to locate electrical wiring in the same trench as product piping.

c)         A minimum of 24 inches of cover is required over all UST wiring conduit. When rigid nonmetallic conduit is used, threaded rigid metal conduit or threaded steel intermediate metal conduit shall be used for the last 2 feet of the underground run to emergence or to the point of connection to the aboveground raceway. 

d)         Intrinsically safe wiring shall be in conduit when installed within Class I locations, as specified in NFPA 70. Caution shall be taken when grounding not to impair cathodic protection of metallic tanks or piping.

e)         When locating electrical wiring in the same trench as the product lines, the conduit shall be positioned on either side of the product piping but not above or below the product piping. The electrical conduit shall cross over the top of any product piping whenever a crossover is necessary, unless all connections and fittings in the conduit run are liquid-tight.  A minimum 6 inch separation shall be maintained at all times, even during a crossover. All crossovers shall be kept to a minimum.

f)         All electrical power shall be shut off at the immediate location where installations, repairs or upgrades are in progress.

g)         All electrical seal-offs are to be properly filled whether being used or for future use.

h)         On or after October 13, 2018, all electrical conduit run to under-dispenser containment sumps shall enter the sump by going over the top of the side wall of the containment sump. No penetration of the under-dispenser sump by electrical conduit shall be allowed. 

(Source:  Amended at 47 Ill. Reg. 6837, effective May 2, 2023)