Individual Stormwater Permit Requirements

In Indiana, construction projects are required to comply with the Construction Stormwater General Permit (CSGP) that became effective on December 18, 2021..

IDEM does reserve the right to require an Individual NPDES (National Pollutant Discharge Elimination System) Permit rather than issuing coverage under the CSGP. If the agency determines the stormwater run-off from a project could impair the water quality of the receiving stream or is identified as an Outstanding State Resource Water, permittees may be notified by IDEM if they need to apply for an individual stormwater discharge permit.

An individual stormwater permit is not required, unless IDEM determines that the general permit is not sufficient to protect water quality or other factors warrant more specific stormwater control requirements on a project site. According to 327 IAC 15-2-9(c),IDEM will notify a project site owner in writing if an individual stormwater permit is needed. This written notification will include:

1. a brief statement of the reasons for the decision;
2. an application form;
3. a statement setting a time for the project site owner to file the application; and
4. a statement that on the effective date of the individual storm water permit, the general permit rule, as it applies to the project site owner, shall no longer apply.

If a project site owner is requested to obtain an individual stormwater permit, several differences, in contrast to the CSGP requirements, are involved. An individual stormwater permit will be a written document specific to the project and developed over several weeks or months. Before this permit is issued and becomes effective, it must have a 30-day public comment period, typically advertised through a notice placed in a local newspaper where the project site will be developed. In the public notice, the public can request, and be granted, a public hearing on the project site. Until the individual stormwater permit becomes effective and a Construction/Stormwater Pollution Prevention Plan is reviewed and determined to meet the intent of the permit, the project site owner cannot begin land-disturbing activities.

Currently, IDEM will be using the same application form as the one required in the CSGP. However, individual storm water permits also require the submittal of a completed Identification of Potentially Affected Persons - State Form 49456 with the application (available on the IDEM Agency Forms page).