Section 616.704  Design and Operating Requirements for Above-Ground Storage Tanks

a)         The owner or operator of a tank must not cause or allow:

1)         Materials to be placed in a tank if such materials could cause the tank to rupture, leak, corrode, or otherwise fail.

2)         Uncovered tanks to be placed or operated so as to maintain less than 60 centimeters (2 feet) of freeboard unless:

A)        The tank is equipped with a containment structure (e.g., dike or trench), a drainage control system, or a diversion structure (e.g., standby tank); and

B)        The containment structure, drainage control system, or diversion structure has a capacity that equals or exceeds the volume of the top 60 centimeters (2 feet) of the tank.

3)         Material to be continuously fed into a tank, unless the tank is equipped with a means to stop this inflow (e.g., a feed cutoff system or a bypass system to a standby tank).

4)         Incompatible materials to be placed in the same tank.

5)         Material to be placed in a tank that previously held an incompatible material unless the incompatible material has been washed from the tank.

6)         Ignitable or reactive material to be placed in a tank unless:

A)        The material is stored or treated in such a way that it is protected from any material or conditions that may cause it to ignite or react; or

B)        The tank is used solely for emergencies.

b)         The owner or operator must provide and maintain primary containment for the tank such that:

1)         The tank has a minimum shell thickness that ensures that the tank will not fail (e.g., collapse, rupture).

2)         The tank is compatible with the material to be placed in the tank or the tank is lined with a substance that is compatible with the material to be placed in the tank.

c)         The owner or operator must provide and maintain secondary containment for the tank that:

1)         Is capable of containing the volume of the largest tank or 10% of the total volume for all tanks, whichever is greater;

2)         Is constructed of material capable of containing a spill until cleanup occurs (e.g., concrete or clay).  The base of the secondary containment area must be capable of minimizing vertical migration of a spill until cleanup occurs (e.g., concrete or clay);

3)         Has cover (e.g., crushed rock or vegetative growth) on earthen embankments sufficient to prevent erosion; and

4)         Isolates the tank from storm water drains and from combined storm water drains and sanitary sewer drains.

d)         If incompatible materials are handled at the site, secondary containment sufficient to isolate the units containing the incompatible materials must be provided.

e)         The owner or operator of a tank must also:

1)         Test above-ground tanks and associated piping every five years for structural integrity.

2)         Remove uncontaminated storm water runoff from the secondary containment area immediately after a precipitation event.

3)         Handle contaminated storm water runoff in compliance with 35 Ill. Adm. Code 302.Subpart A.

4)         Provide a method for obtaining a sample from each tank.

5)         Install, maintain, and operate a material level indicator on each tank.

6)         When not in use, lock all gauges and valves that are used to inspect levels in the tank.  All such devices must be located within the containment structure.

(Source:  Amended at 47 Ill. Reg. 7631, effective May 16, 2023)