The department may initiate appropriate enforcement actions if an owner is out of compliance with these rules or any applicable drinking water regulations. These actions may include any one or combination of the following:

(1) Issuance of informal letters instructing or requiring appropriate corrective measures; or

(2) Issuance of a compliance agreement or schedule; or

(3) Issuance of departmental orders requiring any person to apply for an operating permit as required by these rules and RCW 70.119A.110 or to comply with applicable drinking water regulations imposed as part of an operating permit; or

(4) Issuance of civil penalties for up to five thousand dollars per day per violation for failure to comply with departmental orders issued in accordance with subsection (3) of this section; or

(5) Legal action by the attorney general or local prosecutor.