Draft Antidegradation Rule – changes from 3-14-08 draft to 6-05-08 draft

1. Draft Antidegradation Rule – changes from 3-14-08 draft to 6-05-08 draft Presented by IDEM at the June 25, 2008 Antidegradation Stakeholder Meeting

2. Overall • Tried to streamline and clarify as well as address some issues raised.

3. Sec 1. Applicability • Clarified reasonable potential to exceed procedure will be used to determine if an antidegradation demonstration is needed.

4. Sec 2. Definitions • Some additions, some deletions and some refinements for clarity and consistency.

5. Sec 3. Antidegradation Standards • Some minor refinements for clarity and consistency.

6. Sec 4, Non-significant lowering • Changed to “exempt” activities. • Some refinements for clarity and consistency. • Includes de minimis discharges – see # 13 • de minimis definition simplified to: • Less than 10% of unused loading for non-OSRW; • No dilution for OSRW; • Placeholder for % cap increase in representative background for non-OSRW; • Placeholder for % cap increase in representative background for OSRW.

7. Sec 5. Exemption Justification • Submitted with permit application with no separate PN.

8. Sec 6. Was De minimis, now Antidegradation Demonstration • note: former Sec 7 “Antidegradation Implementation Procedures” was deleted – info was redundant, no value added. • Includes necessary, social-economic and, if necessary, alternative treatment. • Requirements made to parallel the elements of the Commissioner’s review. • Retained requirement for separate PN, but allows submission in conjunction with permit application.

9. Sec 7. Commissioner’s review of Antidegradation Demonstration • Review elements parallel demonstration requirements.

10. Sec 8. Water Quality Improvement Project Application • Same info required whether implement or fund the project. • PNed with antidegradation demonstration.

11. 327-IAC 5-2, Sec 11.2 – PN requirements • Eliminated requirement for separate PN of non-significant (exemption) application.