As used in this chapter, unless a different meaning is plainly required by the context:

(1) "Department" - Refers to the department of retirement systems established pursuant to chapter 41.50 RCW as now existing or hereafter amended;

(2) "Receivable" - Refers to an amount owed to DRS, where there is a legal obligation to pay DRS and DRS has a legal obligation to collect the amount owed. That includes, but is not limited to, amounts owed to trust funds administered by the department of retirement systems;

(3) "Close of business day" - Refers to 5:00 p.m. of a business day;

(4) "Overdue receivable" - Refers to a receivable with an unpaid balance at the close of business three business days after the due date;

(5) "Employer receivable" - Refers to a receivable which is owed by any one of the employers within the retirement systems and programs administered by the department as defined in RCW 41.50.030;

(6) "Member receivable" - Refers to a receivable which is owed by any one of the current or previous members of the retirement systems and programs administered by the department as defined in RCW 41.50.030, or is owed by a member's beneficiary, legal owner payee, or other agent in conjunction with the member's account;

(7) "Administrative receivable" - Refers to any receivable owed the department which is not considered an employer receivable or a member receivable.