Environmental Code

Canadian Council of Ministers of the Environment - Environmental Code of Practice for Aboveground and Underground Storage Tank Systems Containing Petroleum and Allied Petroleum Products

3.9.1 (1) Subject to Sentences (2) and (3), a secondary containment system for an aboveground storage tank shall:

(1) for a storage tank system that consists of a single storage tank, have a volumetric capacity of not less than 110% of the capacity of the tank; or

(2) for a storage tank system that consists of more than one storage tank, have a volumetric capacity of not less than the sum of:

(a) the capacity of the largest storage tank located in the contained space; and

(b) 10% of the greater of:

(i) the capacity specified in Clause (a); or

(ii) the aggregate capacity of all other storage tanks located in the contained space.

3.9.1 (2) A secondary containment system for a shopfabricated storage tank shall be designed, built, and approved in conformance with:

(a) ULC-S653-1994, “ Contained Aboveground Steel Tank Assemblies”;

(b) ULC-S655-1998, “Aboveground Protected Tank Assemblies”;

(d) a recognized standard for double-wall tanks

3.9.1 (3) A secondary containment system for a fielderected aboveground storage tank shall be:

(a) a single-wall and single-bottom storage tank placed entirely within a dyked area, with an impermeable barrier in the floor of the containment area and in the dyke walls;

(b) a single-wall, double-bottom storage tank placed entirely within a dyked area, with an impermeable barrier in the floor of the containment area and in the dyke walls, sealed to the perimeter of the storage tank or pad when the liner is not installed under the tank;

(d) a double-wall storage tank placed entirely within a dyked area, with an impermeable barrier in the floor of the containment area and in the dyke walls, for a storage tank with a capacity of more than 50 000 L.

3.9.2 (1) Except as provided in Sentence (2), a secondary containment impermeable barrier shall be:

(a) designed, built, and approved in conformance with:

(i) ORD-C58.9-1997, “Secondary Containment Liners for Underground and Aboveground Tanks”; or

(ii) ORD-C142.20-1995, “Aboveground Secondary Containment Tanks”; and

(b) installed so that:

(i) the liner is sealed to the perimeter of the storage tank or pad when the liner is not installed under the tank;

(ii) the liner extends to the top of the dyke wall;

(iii) the liner is covered with a noncombustible material of such nature and thickness that it will not fail when the secondary containment is exposed to fire; and

(iv) liners that are intended to be exposed in service are listed for aboveground (exposed) use.

3.9.2 (2) A secondary containment impermeable barrier that does not conform to Sentence

(1) shall:

(a) use material compatible with the product being stored and acceptable to the authority having jurisdiction (See Appendix B, note 3.9.2(2)(a)); and

(b) be designed, constructed, and maintained to ensure a maximum hydraulic conductivity of 1 x 10-6 cm/s.

3.9.3 (1) Liner penetrations shall be located at the high point or in a raised part of the dyke floor. (See Appendix B, note B.3.9.3(1))

3.9.3 (2) All liner penetrations shall be sealed.

3.9.4 Monitoring of the interstitial space of the secondary containment system shall be provided in conformance with Part 6 of this Code.

The entire Environmental Code of Practice can be accessed here.