A Comptroller and Auditor General audit covering 17 sand-mining quarries in the Cauvery delta — concentrated in Tiruchirappalli, Thanjavur and Mayiladuthurai — flagged "material irregularities" in 9 quarries during the field-audit phase that wound up in November 2024. The final report was due by 31 March 2025.

As of May 2026 the audit remains parked at "with department for compliance reply" — 14 months past its original deadline. There is no quarterly update on the Public Works Department's status page since the original flag.

TN-Info maintains a tracker of all CAG audits where the compliance-reply phase has exceeded six months. Of 47 such audits across TN, 12 are now over a year old; the Cauvery sand audit is the longest-pending in the natural-resources category.