The proposed bill, HB2030, mandates that cities or towns in Arizona with populations exceeding 240,000 and designated as having an assured water supply must conduct a full rate audit and cost-of-service study of their water and sewer services. This audit must be performed by an independent auditor if the municipality has engaged in specific activities, such as contracting with the Central Arizona Project or receiving federal funds for conservation measures. The auditor's report will be a public record, and the city or town is required to provide all necessary records to the auditor.

Additionally, the bill outlines detailed aspects that the auditor must investigate, including the cost and revenue from hookup fees, the use of excess capacity, and the reasonableness of capital expenditures. The city or town must submit the auditor's report to state officials by January 1, 2025, and the requirement for the audit will be repealed after December 31, 2026. This legislation aims to enhance transparency and accountability in municipal water service management.