1. (1) Prefabricated [secondary containment] shall be composed of a rigid prefabricated basin having both a base and walls constructed of steel or synthetic materials which are resistant to corrosion, puncture or cracking. Materials used in the secondary containment shall be chemically compatible with the products being stored within the secondary containment. A written confirmation of compatibility from the basin manufacturer shall be kept on file at the permanent storage facility or at the nearest local office from which the permanent storage facility is administered.

2. (2) The prefabricated secondary containment shall be designed and installed to withstand all foreseeable loading conditions, including the tank load and a full hydrostatic head of any discharged liquid. Multiple basins connected to provide the capacity required in WAC 16-201-025 shall be connected in a manner which assures an adequate transfer of discharged liquid between basins.

   Reviser's note: RCW 34.05.395 requires the use of underlining and deletion marks to indicate amendments to existing rules, and deems ineffectual changes not filed by the agency in this manner. The bracketed material in the above section does not appear to conform to the statutory requirement.

[Statutory Authority: RCW 15.54.800. WSR 00-23-075, § 16-201-040, filed 11/17/00, effective 12/18/00. Statutory Authority: RCW 15.54.800 and 15.58.040. WSR 93-22-093 (Order 5018), § 16-201-040, filed 11/2/93, effective 3/1/94.]