(1) The "acceptance date of the public works project" referred to in RCW 39.12.065 is the date that the contract awarding agency formally accepts the completed public works project pursuant to state law.

(2) RCW 39.12.050 and 39.12.065 refer to "inadvertent filing or reporting error." The department defines an error as "inadvertent" if it is made by a contractor, as defined by WAC 296-127-010(5), or employer that shows that the error was made notwithstanding the use of due care by the contractor or employer. The burden of proving that an error is inadvertent rests with the contractor or employer charged with the error.

(3) The definition of "locality" in RCW 39.12.010(2) contains the phrase "wherein the physical work is being performed." The department interprets this phrase to mean the actual work site. For example, if nonstandard items specifically produced for public works projects are prefabricated in a county other than the county wherein the public works project is to be completed, the wage for the offsite prefabrication shall be the applicable prevailing wage for the county in which the actual prefabrication takes place. Workers who deliver such nonstandard items, as well as materials pursuant to the terms of WAC 296-127-018, shall be paid the applicable prevailing wage for the county in which the public works project is located.

(4) In the implementation and enforcement of RCW 39.12.050 the terms "contractor" and "subcontractor" include an entity, however organized, with substantially identical corporate and/or operational structure to an entity that has been found to violate RCW 39.12.050. The factors used to determine substantial identity shall include an assessment of whether there is: Substantial continuity of the same business operation; use of the same machinery and/or equipment; similarity of jobs and types of working conditions; continuity of supervisors; and similarity of product or services.