Ind. Admin. Code tit. 326, r. 10-7-6 – RACT studies for major stationary sources

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

Sec. 6. (a) Any affected facility that is:

(1) not subject to the emissions limitations specified in section 4 paragraphs (b) through (e) of this rule and is not exempt under section 7 of this rule; or

(2) subject to the emissions limitations specified in section 4 paragraphs (b) through (e), but for which the owner or operator claims achievement of an applicable emissions limitation is technically infeasible or economically unreasonable;

shall conduct an engineering study.

(b) The study required by subsection (a) shall determine the economic and technical feasibility of reducing NOx emissions and define RACT for the facility. The engineering study shall be conducted by an engineering consulting firm or other person or persons experienced in the field of air pollution control, and provide the following information:

(1) The complete affected source name, source identification number, and address.

(2) The name, title, address, and telephone number of the owner's or operator's representative within the company who is the contact person for this source regarding the engineering study and affected facilities.

(3) The name, title, address, and telephone number of the official who is responsible for approval of the engineering study.

(4) The standard industrial classification code and source classification code numbers applicable to the source's operation.

(5) The following general information for each affected facility:

(A) IDEM Permit application number.

(B) Company identification and facility identification number.

(D) Month and year installed.

(E) Normal operating schedule, including:

(i) hours per day;

(ii) days per week; and

(iii) weeks per year.

(F) Annual production rates for each of the three full calendar years preceding the effective date of this rule.

(G) Average and maximum daily production rates for each of the three full calendar years preceding the effective date of this rule.

(H) The type of control equipment employed and the date installed.

(6) A plot plan which shows the general layout of the source and the affected facility.

(7) The following emissions data for each affected facility:

(A) Average pounds per day of operation NOx emissions based upon the highest average daily production rate for each of the three (3) full calendar years preceding the effective date of this rule or any other year that may be representative of the highest average daily emissions.

(B) Maximum pounds per day of operation NOx emissions based upon the highest maximum daily production rate for each of the three (3) full calendar years preceding the effective date of this rule or any year that may be more representative of the highest maximum daily emissions.

(C) Annual tons of NOx emissions based upon the highest annual production rate for each of the three (3) full calendar years preceding the effective date of this rule or any year period that may be more representative of the annual production rate.

(D) Documentation of:

(i) the efficiency of the existing control equipment; and

(ii) any emissions testing which has been performed.

(E) A detailed discussion of the technical feasibility of employing each of the following types of control measures for each affected facility, or combination of facilities, unless the control measures are not applicable to a particular facility:

(i) Low-NOx burners.

(ii) Close coupled or separated over-fire ports.

(iii) Flue gas recirculation.

(iv) Low-NOx burners with external flue gas recirculation.

(v) Burners out of service.

(vi) Steam or water injection.

(vii) Dry low-NOx burners.

(viii) Ignition timing retard.

(ix) Separate circuit after-cooling.

(x) Fuel emulsification.

(xi) Selective noncatalytic reduction.

(xii) Nonselective catalytic reduction.

(xiii) Selective catalytic reduction using urea ammonia and methane as reducing agents.

(xiv) Incineration (for facilities other than boilers).

(xv) Scrubbing (for facilities other than boilers).

(xvi) Process modification.

(xvii) Fuel switching.

(xviii) Adjustment of air fuel ratio (for internal combustion engines).

(xix) Low excess air.

(xx) Mid-kiln firing.

(xxi) Mid-kiln air injection.

(xxii) Gaseous fuels reburn.

(xxiii) Any other such RACT alternatives not listed in this rule that may be applicable to an affected facility, or as are proposed by the owner or operator.

(F) For each type of control measure that is determined to be technically feasible, an estimate of the:

(i) control efficiency that can be achieved;

(ii) capital cost;

(iii) annualized cost, including capital and operating costs; and

(iv) the cost-effectiveness as measured by the annual dollars per ton of NOx removed annually.

(G) A comparison and discussion of the advantages and disadvantages of the control options that are determined to be technically feasible.

(H) A recommended definition of RACT for the facility, including one or more of the following:

(i) Enforceable production limitations.

(ii) Emissions limitations.

(iii) Control efficiencies.

(iv) Operating requirements.

(v) An expeditious schedule for implementing the recommended definition of RACT, including milestones for awarding contracts, initiating construction, completing construction, and performing emissions testing, if necessary, to demonstrate compliance with the approved definition of RACT.

(vi) Clean and detailed documentation of all calculations of the NOx emissions, including all assumptions made.

(I) Capital and operating costs and the cost-effectiveness estimates calculated in a manner consistent with the most recent edition of the "U.S. EPA air pollution control cost manual."*

(c) Any facility that is subject to an emissions limitation contained in section 4 of this rule shall no longer be subject to the emissions limitations if the department approves a definition of RACT and a schedule of compliance for the facility pursuant to this section.

(d) Any facility that is subject to an emissions limitation contained in section 4 of this rule shall remain subject to those limitations and compliance deadlines contained in section 9 if:

(1) the department disapproves a definition of RACT and a schedule of compliance for the facility pursuant to this section;

(2) the RACT study determines the applicable NOx emissions limitations contained in section 4 of this rule are technically feasible and cost-effective to achieve; or

(3) The department disapproves of a variance application pursuant to section 6 of this rule.

(e) If within the five years prior to the effective date of this rule, the owner or operator of an affected facility subject to this rule has employed, or has committed to employ, the best available control technology for NOx emissions, as determined by the department pursuant to 326 IAC 2-2, the owner or operator may provide the following information to the department in satisfaction of section 5 of this rule:

(1) The complete affected source name, source identification number, and address.

(3) The standard industrial classification code and source classification code numbers which are applicable to the source's operation.

(4) The following general information for each affected facility:

(A) Part 70 operating permit application number.

(B) Company identification and facility identification number.

(D) Month and year installed.

(E) Normal operating schedule, including:

(i) hours per day;

(ii) days per week; and

(iii) weeks per year.

(F) Annual production rates for each of the three full calendar years preceding the effective date of this rule.

(G) Average and maximum daily production rates for each of the three full calendar years preceding the effective date of this rule.

(H) The type of control equipment employed and the date installed.

(5) The following emissions data for each affected facility:

(D) Documentation of:

(i) the efficiency of the existing control equipment; and

(ii) any emissions testing which has been performed.

(6) Copies of the documents and technical information that support the existing best available technology determination.

(7) The name, title, address and telephone number of the official who is responsible for the information submitted in accordance with section 5 of this rule.

(f) If the department determines that the information provided by an affected facility under subsection (e) of this section does not or may not satisfy the requirements of this rule, the department shall notify the owner or operator. After being notified by the department, the owner or operator must then conduct a full RACT engineering study in accordance with section 6 of this rule.

(g) Any definition of RACT and schedule of compliance for an affected facility that are approved by the department shall be submitted to the U.S. EPA as a revision of the Indiana state implementation plan.

(h) If any unit with a specific emission limit or equipment standards in section 8 of this rule based on actual annual emissions cannot meet that limit, the owner or operator must conduct a new RACT engineering study based on the potential to emit (PTE) and propose revised RACT requirements based on the new study within six (6) months of the determination of noncompliance.

*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 10-7-6; filed Oct 27, 2025, 10:54 a.m.: 20251126-IR-326250204FRA)