Authority: IC 13-14-8-1; IC 13-14-9; IC 13-17-3-4

Affected: IC 13-17-3

Sec. 1. (a) Unless exempted under section 7 of this rule, the requirements of this rule apply to any facility that emits NOx in Calumet, Hobart, North, Ross, or St. John townships in Lake County, or Center, Jackson, Liberty, Pine, Portage, Union, Washington, or Westchester townships in Porter County that meets the following conditions:

(1) Is an existing, new, or modified:

(A) very large, large, mid-size, or small boiler;

(B) stationary combustion turbine;

(C) stationary internal combustion engine;

(D) reheat, annealing, or galvanizing furnace; or

(E) unit with specific requirements in section 8 of this rule.

(2) Is located at a stationary source that emits or has the potential to emit a total of more than one hundred (100) tons per year of NOx emissions from all emissions units at that source as of the effective date of this rule or the date of the initial startup, whichever is later.

(b) Any new or modified emission unit in Calumet, Hobart, North, Ross, or St. John townships in Lake County, or Center, Jackson, Liberty, Pine, Portage, Union, Washington, and Westchester townships in Porter County is subject to the requirements of this rule unless the emissions limitations and requirements of an applicable new source performance standard under 40 CFR Part 60* is more stringent than the emissions limitations and requirements of this rule.

(c) Any existing emission unit in Calumet, Hobart, North, Ross, or St. John townships in Lake County, or Center, Jackson, Liberty, Pine, Portage, Union, Washington, and Westchester townships in Porter County that no longer meets an applicable exemption under section 7 of this rule immediately becomes subject to the requirements of this rule.

*These documents are incorporated by reference. Copies may be obtained from the Government Publishing Office, www.gpo.gov, or are available for review at the Indiana Department of Environmental Management, Office of Legal Counsel, Indiana Government Center North, 100 North Senate Avenue, Thirteenth Floor, Indianapolis, IN 46204.

(Air Pollution Control Division; 326 IAC 10-7-1; filed Oct 27, 2025, 10:54 a.m.: 20251126-IR-326250204FRA)