The following records shall be maintained at the permanent mixing/loading site or at the nearest local office from which the site is administered:

(1) A record of construction materials and methods of construction to show compliance with WAC 16-229-400. These records shall be maintained as permanent records.

(2) A record of the method(s) used to use or dispose of product or contaminated materials recovered from discharges outside the operational area containment facility. This record applies only to discharges required to be reported to the Washington state department of ecology by the Washington state dangerous waste regulations, chapter 173-303 WAC. These records shall be maintained for a period of at least three years.

(3) Inspection and maintenance records required by WAC 16-229-430. These records shall be maintained for a period of at least three years.

(4) Manufacturer's compatibility statements required by WAC 16-229-400 if synthetic materials are used in the construction of the facility. These records shall be maintained as permanent records.

(5) A copy of the spill response plan required in WAC 16-229-450. This record shall be maintained as a permanent document.

(6) Records required by WAC 16-229-420 for use or disposal of rinsate and contaminated precipitation. These records shall be maintained for a period of at least three years.

(7) Records required by WAC 16-229-240, Backflow prevention.