An agency may assess the costs of an investigation to a person found to be in violation of a statute or rule as a result of an adjudicative proceeding or informal disposition. The total costs assessed and any civil penalty that may be imposed as a result of violation may not exceed the statutorily authorized civil penalty for the violation. For the purposes of this section, costs mean reasonable out-of-pocket agency costs, not including any attorney’s fees, actually incurred in conducting the investigation for which they may be assessed. Any such costs paid must be paid into the general fund and are appropriated as a refund to the agency for the purposes of defraying the costs of undertaking the investigation.