Indiana
Indiana Department of Environmental Management
State-DelegatedVerified 2025-01
Construction Permit
- Permit Name
- NPDES Construction Stormwater General Permit (Rule 5 / Permit INR100000)
- Threshold
- ≥ 1 acre of land disturbance; < 1 acre if part of a larger common plan of development or sale
- NOI Lead Time
- NOI must be submitted and approved before earth-disturbing activities begin; no fixed calendar lead time is prescribed, but IDEM review typically takes several business days
- Application Method
- Online via IDEM's myidem.in.gov portal (electronic NOI submission); paper NOI also accepted but online is preferred
- Fee
- $100 per NOI filing (flat fee); no acreage-based scaling
SWPPP Requirements
- SWPPP Required
- Yes
- PE Cert Required
- No
- Template Available
- Yes
SWPPP must be prepared prior to submitting the NOI and must be on site and available for inspection throughout the project. IDEM provides a Rule 5 SWPPP template and construction plan checklist on its website. A PE stamp is not required for the SWPPP itself, though local drainage plans may require engineering sign-off. The SWPPP must be updated whenever site conditions change significantly.
Inspection Requirements
- Frequency
- At least every 7 days and within 24 hours after a storm event producing ≥ 0.5 inches of rainfall in a 24-hour period; frequency may be reduced to every 14 days when the entire site is temporarily stabilized or runoff is unlikely due to winter conditions
- Inspector Qualification
- Inspections must be conducted by a qualified inspector who is knowledgeable about the permit requirements and BMP implementation; Indiana does not mandate a specific state-issued certification, but IDEM recommends Certified Inspector of Sediment and Erosion Control (CISEC) or equivalent training
Discharge Standards
- Turbidity Limit
- No numeric NTU effluent limit in the general permit; narrative standard applies
Indiana's Rule 5 permit does not establish a numeric turbidity limit. Discharges must not cause or contribute to a violation of the state's water quality standards (narrative turbidity and color standards at 327 IAC 2-1-6). Visual monitoring is required at all discharge points. If a discharge causes visible turbidity in the receiving water, corrective action is required.
Post-Construction
- Required
- Yes
Post-construction stormwater quality management is required under Rule 13 (327 IAC 15-13) for regulated MS4 communities and under Rule 15 (327 IAC 15-15) for certain construction projects discharging to regulated MS4s. Requirements include long-term operation and maintenance of structural BMPs. Specific design standards (volume capture, infiltration) are set by the local MS4 entity.
Official Resources
State-Specific Notes
Indiana's construction stormwater program is commonly called 'Rule 5' after 327 IAC 15-5. IDEM issues a state general permit (INR100000) rather than delegating to counties. Operators of sites ≥ 5 acres must also submit a Notice of Termination (NOT) when construction is complete and final stabilization is achieved. Sites < 1 acre that are part of a common plan of development still need coverage. IDEM publishes a Land Quality Rule 5 Technical Guidance Manual that is widely used in practice.
Disclaimer: This information is provided for general reference only and may not reflect the most current regulatory requirements. Always consult the IDEM website and applicable regulations before beginning any construction activity.