IIA Exam IIA-CIA-Part2 Topic 3 Question 84 Discussion

During a review of the organization's waste management processes, the internal auditor discovered that wastewater is being disposed of inappropriately. The auditor's recommendations, suggested to mitigate the risk of regulatory sanctions and reputational damages, were accepted and timelines for implementation were agreed. However, during the internal audit activity's periodic follow-up exercise, management indicated that the recommendation was too expensive to implement and the current disposal method has been cost-effective. What should the chief audit executive do in this case?