CSO wet weather limited use subcategory established; application after approval of long term control plan; other requirements; EPA approval; monitoring and review; rules
Ind. Code § 13-18-3-2.5
in effectSec. 2.5. (a) A CSO wet weather limited use subcategory is established for waters affected by receiving combined sewer overflows, as specified in an approved long term control plan. The CSO wet weather limited use subcategory applies to a specific water body after implementation of an approved long term control plan for the combined sewer system whose overflow discharges affect those waters is implemented and the conditions of subsection (b) are satisfied. The following requirements apply to the CSO wet weather limited use subcategory:
(1) The water quality based requirements associated with the CSO wet weather limited use subcategory that apply to waters affected by wet weather combined sewer overflows are determined by an approved long term control plan for the combined sewer system. The water quality based requirements remain in effect during the time and to the physical extent that the recreational use designation that applied to the waters immediately before the application to the waters of the CSO wet weather limited use subcategory is not attained, but for not more than four (4) days after the date the overflow discharge ends.
(2) At all times other than those described in subdivision (1), the water quality criteria associated with the appropriate recreational use designation that applied to the waters immediately before the application to the waters of the CSO wet weather limited use subcategory apply unless there is a change in the use designation as a result of a use attainability analysis.
(b) The CSO wet weather limited use subcategory applies if:
(1) the department has approved a long term control plan for the NPDES permit holder for the combined sewer system;
(2) the approved long term control plan:
(A) is incorporated into:
(i) the NPDES permit holder's NPDES permit; or
(ii) an order of the commissioner under IC 13-14-2-6;
(B) satisfies the requirements of section 2.3 of this chapter; and
(C) specifies the water quality based requirements that apply to combined sewer overflows during and immediately following wet weather events, as provided in subsection (a)(1);
(3) the NPDES permit holder has implemented the approved long term control plan; and
(4) subject to subsection (c), 40 CFR 131.10, 40 CFR 131.20, and 40 CFR 131.21 are satisfied.
(c) For purposes of subsection (b)(4), 40 CFR 131.10 may be satisfied by including appropriate data and information in the long term control plan.
(d) The department shall implement the CSO wet weather limited use subcategory and associated water quality based requirements under this section when the subcategory and requirements are approved by the United States Environmental Protection Agency. The department shall seek approval of the United States Environmental Protection Agency in a timely manner.
(e) The NPDES permit holder shall monitor its discharges and the water quality in the affected receiving stream periodically as provided in the long term control plan. The NPDES permit holder shall provide all such information to the department.
(f) In conjunction with a review of its long term control plan under section 2.4 of this chapter, the NPDES permit holder shall review information generated after the use attainability analysis was approved by the department to determine whether the conclusion of the use attainability analysis is still valid. The NPDES permit holder shall provide the results of the review to the department.
(g) The board shall adopt rules under IC 13-14-8 and IC 13-14-9 to implement this section.
As added by P.L.140-2000, SEC.20. Amended by P.L.54-2005, SEC.4; P.L.135-2026, SEC.147.
Source: Open US Law by Vaquill AI (CC BY 4.0)URL: https://iga.in.gov/laws/2026/ic/titles/13Fetched: 10/17/2026