Any such fund may be established in the county treasurer's office or the city treasurer's office of a first-class city according to the type of local health department organization existing.
In a district composed of more than one county, the county treasurer of the county having the largest population shall be the custodian of the fund, and the county auditor of said county shall keep the record of receipts and disbursements; and shall draw and the county treasurer shall honor and pay all such warrants.
Into any such fund so established may be paid:
Any school district may contract in writing for health services with the health department of the county, first-class city or health district, and place such funds in the public health pooling fund in accordance with the contract.
RCW 70.12.040