(1)    In the first instance the county or counties operating an infirmary shall defray the actual per capita cost of treatment, care and maintenance. To the extent that a patient is a public charge, such county or counties shall be reimbursed for such expenditures, as determined from annual infirmary reports filed with the department under s. 46.18 (8), (9) and (10), by the county of residence.

   (2)   To the extent that a patient is not a public charge, such cost shall be charged and paid in advance for each calendar month, and payment may be enforced by the board of trustees.

   (4)   The records and accounts of each county infirmary may be audited by the department. In addition to other findings, such audits shall ascertain compliance with the mandatory uniform cost record-keeping system requirements of s. 46.18 (8), (9) and (10), and verify the actual per person cost of maintenance, care and treatment of patients.