5 Colo. Code Regs. § 1001-30-B-I

Current through Register Vol. 47, No. 24, December 25, 2024

Section 5 CCR 1001-30-B-I - Control of Emissions from Engines

I.A Requirements for new and existing engines.

I.A.1. The owner or operator of any natural gas-fired stationary or portable reciprocating internal combustion engine with a manufacturer's design rate greater than 500 horsepower commencing operations in the 8-hour Ozone Control Area on or after June 1, 2004 shall employ air pollution control technology to control emissions, as provided in Section I.B.

I.A.2. Any existing natural gas-fired stationary or portable reciprocating internal combustion engine with a manufacturer's design rate greater than 500 horsepower, which existing engine was operating in the 8-hour Ozone Control Area prior to June 1, 2004, shall employ air pollution control technology on and after May 1, 2005, as provided in Section I.B.

I.A.3. Stationary natural gas fired reciprocating internal combustion engines state-wide with a manufacturer's design rate greater than or equal to 1000 horsepower are subject to Section I.D.5.

I.B. Air pollution control technology requirements

I.B.1. For rich burn reciprocating internal combustion engines, a non-selective catalyst reduction and an air fuel controller shall be required. A rich burn reciprocating internal combustion engine is one with a normal exhaust oxygen concentration of less than 2% by volume.

I.B.2. For lean burn reciprocating internal combustion engines, an oxidation catalyst shall be required. A lean burn reciprocating internal combustion engine is one with a normal exhaust oxygen concentration of 2% by volume, or greater.

I.B.3. The emission control equipment required by this Section I.B shall be appropriately sized for the engine and shall be operated and maintained according to manufacturer specifications.

I.C. The air pollution control technology requirements in Sections I.A. and I.B. do not apply to:

I.C.1. Non-road engines, as defined in Regulation Number 3, Part A, Section I.B.36.

I.C.2. Reciprocating internal combustion engines that the Division has determined will be permanently removed from service or replaced by electric units on or before May 1, 2007. The owner or operator of such an engine shall provide notice to the Division of such intent by May 1, 2005 and shall not operate the engine identified for removal or replacement in the 8-hour Ozone Control Area after May 1, 2007.

I.C.3. Any emergency power generator exempt from APEN requirements pursuant to Regulation Number 3, Part A.

I.C.4. Any lean burn reciprocating internal combustion engine operating in the 8-hour Ozone Control Area prior to June 1, 2004, for which the owner or operator demonstrates to the Division that retrofit technology cannot be installed at a cost of less than $5,000 per ton of VOC emission reduction. Installation costs and the best information available for determining control efficiency shall be considered in determining such costs. In order to qualify for such exemption, the owner or operator must submit an application making such a demonstration, together with all supporting documents, to the Division by May 1, 2005. Any reciprocating internal combustion engine qualifying for this exemption shall not be moved to any other location within the 8-hour Ozone Control Area.

I.D. Control of emissions from new, modified, existing, and relocated natural gas fired reciprocating internal combustion engines.

I.D.1. (State Only) Exemptions

I.D.1.a. The requirements of this Section I.D. do not apply to any engine having actual uncontrolled emissions below permitting thresholds listed in Regulation Number 3, Part B.

I.D.1.b. Internal combustion engines that are subject to an emissions control requirement in a federally maximum achievable control technology (MACT) standard under 40 CFR Part 63 (July 1, 2022), a Best Available Control Technology (BACT) limit, or a New Source Performance Standard (NSPS) under 40 CFR Part 60 (July 1, 2022) are not subject to Section I.D.3.

I.D.2. (State Only) General Provisions

I.D.2.a. At all times, including periods of start-up and shutdown, engines and their associated equipment must be maintained and operated in a manner consistent with good air pollution control practices for minimizing emissions. Determination of whether or not acceptable operation and maintenance procedures are being used will be based on information available to the Division, which may include, but is not limited to, monitoring results, opacity observations, review of operation and maintenance procedures, and inspection of the source.

I.D.2.b. All engines and their associated equipment must be operated and maintained pursuant to the manufacturing specifications or equivalent to the extent practicable, and consistent with technological limitations and good engineering and maintenance practices. The owner or operator must keep manufacturer specifications or equivalent on file.

I.D.2.c. Any of the effective dates for installation of controls on internal combustion engines as required in Section I.D.3. may be extended at the Division's discretion for good cause shown.

I.D.3. (State Only) New, Modified and Relocated Natural Gas Fired Reciprocating Internal Combustion Engines

I.D.3.a. Except as provided in Section I.D.3.b., the owner or operator of any natural gas fired reciprocating internal combustion engine that is either constructed or relocated to the state of Colorado from another state, on or after the date listed in Table 1 shall operate and maintain each engine according to the manufacturer's written instructions or procedures to the extent practicable and consistent with technological limitations and good engineering and maintenance practices over the entire life of the engine so that it achieves the emission standards required in Section I.D.3.b. Table 1.

I.D.3.b. Actual emissions from natural gas fired reciprocating internal combustion engines shall not exceed the emission performance standards in Table 1 as expressed in units of grams per horsepower-hour (G/hp-hr)

TABLE 1
Maximum Engine Hp	Construction or Relocation Date	Emission Standards is G/hp-hr
NOx	CO	VOC
< 100 Hp	Any	NA	NA	NA
>= 100 Hp and < 500 Hp	On or after January 1, 2008 On or after January 1, 2011	2.0 1.0	4.0 2.0	1.0 0.7
>= 500 Hp	On or after July 1, 2007 On or after July 1, 2010	2.0 1.0	4.0 2.0	1.0 0.7

*These engines may also be subject to emission standards under Section I.D.5.

I.D.4. Existing Natural Gas Fired Reciprocating Internal Combustion Engines

I.D.4.a. (Regional Haze SIP) Rich Burn Reciprocating Internal Combustion Engines

I.D.4.a.(i) Except as provided in Sections I.D.4.a.(i)(B) and (C) and I.E.4.a.(ii), all rich burn reciprocating internal combustion engines with a manufacturer's name plate design rate greater than 500 horsepower, constructed or modified before February 1, 2009 shall install and operate both a non-selective catalytic reduction system and an air fuel controller by July 1, 2010. A rich burn reciprocating internal combustion engine is one with a normal exhaust oxygen concentration of less than 2% by volume.

I.D.4.a.(i)(A) All control equipment required by this Section I.D.4.a. shall be operated and maintained pursuant to manufacturer specifications or equivalent to the extent practicable, and consistent with technological limitations and good engineering and maintenance practices. The owner or operator shall keep manufacturer specifications or equivalent on file.

I.D.4.a.(i)(B) Internal combustion engines that are subject to an emissions control requirement in a federal maximum achievable control technology ("MACT") standard under 40 CFR Part 63 (July 1, 2022), a Best Available Control Technology ("BACT") limit, or a New Source Performance Standard under 40 CFR Part 60 (July 1, 2022) are not subject to this Section I.D.4.a.

I.D.4.a.(i)(C) The requirements of this Section I.D.4.a. do not apply to any engine having actual uncontrolled emissions below permitting thresholds listed in Regulation Number 3, Part B.

I.D.4.a.(ii) Any rich burn reciprocating internal combustion engine constructed or modified before February 1, 2009, for which the owner or operator demonstrates to the Division that retrofit technology cannot be installed at a cost of less than $ 5,000 per ton of combined volatile organic compound and nitrogen oxides emission reductions (this value shall be adjusted for future applications according to the current day consumer price index) is exempt complying with Section I.D.4.a. Installation costs and the best information available for determining control efficiency shall be considered in determining such costs. In order to qualify for such exemption, the owner or operator must submit an application making such a demonstration, together with all supporting documents, to the Division by August 1, 2009.

I.D.4.b. (State Only) Lean Burn Reciprocating Internal Combustion Engines

I.D.4.b.(i) Except as provided in Section I.D.4.b.(ii), all lean burn reciprocating internal combustion engines with a manufacturer's nameplate design rate greater than 500 horsepower shall install and operate an oxidation catalyst by July 1, 2010. A lean burn reciprocating internal combustion engine is one with a normal exhaust oxygen concentration of 2% by volume, or greater.

I.D.4.b.(ii) Any lean burn reciprocating internal combustion engine constructed or modified before February 1, 2009, for which the owner or operator demonstrates to the Division that retrofit technology cannot be installed at a cost of less than $ 5,000 per ton of volatile organic compound emission reduction (this value shall be adjusted for future applications according to the current day consumer price index) is exempt complying with Section I.D.4.b.(i). Installation costs and the best information available for determining control efficiency shall be considered in determining such costs. In order to qualify for such exemption, the owner or operator must submit an application making such a demonstration, together with all supporting documents, to the Division by August 1, 2009.

I.D.4.c. (Ozone SIP) Engines with a Manufacturer's Design Rate Greater than or Equal to 1000 horsepower in the 8-hour Ozone Control Area or Northern Weld County.

I.D.4.c.(i) The owner or operator of an engine identified in Table A must comply with the current NOx allowance specified for that engine by the compliance date indicated.

I.D.4.c.(ii) Owners or operators of engines identified in Table A must keep the following records for a period of five (5) years and make records available to the Division upon request.

I.D.4.c.(ii)(A) APENs submitted for a Table A engine on or after May 1, 2021.

I.D.4.c.(ii)(B) Records documenting engine retrofit or replacement.

I.D.4.c.(ii)(C) Results of the most recent performance test if updated permitted emission factors are used to comply with the NOx emission requirements.

Table A
Facility AIRS ID	AIRs Point(s)	Prior NOx allowance (tpy)_	Current NOx allowance (tpy)	Emission Reduction method	Compliance Date
001-0025	004	234.2	32.2	Retrofit	05/2023
001-0025	006	128.0	15.9	Retrofit	05/2023
001-0025	007	128.0	15.9	Retrofit	05/2022
01-0025	032	234.2	32.2	Retrofit	05/2022
001-0036	005	150.50	8.6	Permitted Hours Reduced	05/2023
001-0036	005	150.50	8.6	Permitted Hours Reduced	05/2023
005-0055	001	148.92	20.6	Retrofit	05/2022
005-0055	001	148.92	20.6	Retrofit	05/2022
005-0055	001	148.92	20.6	Retrofit	05/2022
005-0055	011	133.78	18.6	Retrofit	05/2022
123-0015	051	11.9	9.5	Retrofit	05/2022
123-0015	052	24.0	9.5	Retrofit	05/2022
123-0015	053	23.8	9.5	Retrofit	05/2022
123-0015	055	23.8	9.5	Retrofit	05/2022
123-0015	056	11.9	9.5	Retrofit	05/2022
123-0015	057	24.0	9.28	Retrofit	05/2022
123-0015	060	19.3	7.7	Retrofit	05/2022
123-0015	081	23.8	9.5	Retrofit	05/2022
123-0048	015	16.9	6.3	Retrofit	05/2022
123-0049	101	21.2	8.5	Retrofit	05/2023
123-0049	102	7.8	6.2	Retrofit	05/2023
123-0049	103	26.1	10.4	Retrofit	05/2023
123-0049	107	16.3	6.2	Retrofit	05/2023
123-0049	108	13.0	10.4	Retrofit	05/2023
123-0049	110	18.6	7.1	Retrofit	05/2023
123-0049	113	16.3	6.2	Retrofit	05/2023
123-0049	114	7.8	6.2	Retrofit	05/2023
123-0049	140	14.3	11.4	Retrofit	05/2023
123-0098	001	18.19	10.51	Permitted EF Change	05/2021
123-0098	039	15.78	12.62	Permitted EF Change	05/2021
123-0099	106	21.24	8.5	Retrofit	05/2022
123-0099	107	24.0	8.5	Retrofit	05/2022
123-0099	108	8.65	6.9	Retrofit	05/2022
123-0099	109	21.24	8.5	Retrofit	05/2022
123-0099	110	24.0	8.5	Retrofit	05/2022
123-0184	018	25.1	8.7	Retrofit	05/2022
123-0184	019	8.7	6.9	Retrofit	05/2022
123-0468	011	18.9	15.5	Retrofit	05/2022
123-0468	012	19.5	15.5	Replace	05/2022
123-0595	002	30.82	13.0	Retrofit	05/2023
123-0595	003	30.82	13.0	Retrofit	05/2023
123-0595	004	30.82	13.0	Retrofit	05/2023
123-0595	006	25.69	10.8	Retrofit	05/2023
123-0595	007	25.69	10.8	Retrofit	05/2023
123-0595	008	27.12	11.4	Retrofit	05/2023
123-1351	005	12.8	10.4	Retrofit	05/2022
123-9E80	008	0.00	0.00	Replace	05/2022

I.D.4.c.(iii) The owner or operator of an engine identified in Table B must shutdown that engine by the compliance date indicated.

I.D.4.c.(iv) Owners or operators of engines identified in Table B must keep the following records for a period of five (5) years and make records available to the Division upon request.

I.D.4.c.(iv)(A) APENs cancellations submitted for a Table B engine on or after May 1, 2021.

Table B
Facility AIRS ID	AIRs Point(s)	Previously Permitted NOx allowance (tpy)	Shutdown Compliance Date
123-0057	004	90.2	05/2022
123-0473	015	6.42	05/2021
123-1351	001	15.8	05/2022
123-9CD2	004	5.81	05/2021
123-9CD2	005	6.39	05/2021

I.D.5. (State Only) Additional Requirements for Natural Gas Fired Reciprocating Internal Combustion Engines

I.D.5.a. Applicability

I.D.5.a.(i) This Section I.D.5. applies to stationary natural gas fired reciprocating internal combustion engines state-wide with a manufacturer's design rate greater than or equal to 1000 horsepower.

I.D.5.a.(i)(A) For purposes of this Section I.D.5., modified means any physical change to the engine or change in method of operation that results in an increase in the emission rate of any air pollutant, and does not include any physical or operational changes excluded by 40 C.F.R. 60.14(e).

I.D.5.a.(i)(B) For purposes of this Section I.D.5., placed in service means the bringing of an engine on-site for use. The placed in service date is the date the engine begins to operate. The following is not considered placed in service:

(1) moving an engine subject to an Alternative Company-Wide Compliance Plan to another site with the same owner or operator;

(2) for engines in service on or before January 30, 2024, replacement under an authorized alternative operating scenario.

I.D.5.a.(i)(C) For purposes of this Section I.D.5., relocated means the bringing of an engine into the 8-Hour Ozone Control Area from outside the 8-Hour Ozone Control Area or the bringing of an engine into the State of Colorado from outside the State of Colorado. The relocation date is the date the subject engine begins to operate.

I.D.5.a.(ii) Exemptions.

I.D.5.a.(ii)(A) Engines that burn less than 100 MMBtu per year of natural gas on a rolling-12-month basis are not subject to Sections I.D.5.b., I.D.5.d., I.D.5.e., I.D.5.f.(i)-(iii) and (v)-(vi), or I.D.5.g.

I.D.5.a.(ii)(B) Non-road engines, as defined in Regulation Number 3, Part A, Section I.B.36 are not subject to this Section I.D.5.

I.D.5.a.(ii)(C) Any emergency power generator exempt from APEN or construction permit requirements pursuant to Regulation Number 3, Parts A or B are not subject to this Section I.D.5.

I.D.5.a.(ii)(D) Emergency power generators that operate less than 250 hours per year on a rolling-12-month basis are not subject to Sections I.D.5.b., I.D.5.d., I.D.5.e., I.D.5.f.(i)-(iii) and (v)-(vi), or I.D.5.g.

I.D.5.b. Emission Standards for Engines Subject to Section I.D.5.a.

I.D.5.b.(i) The owner or operator of any stationary natural gas fired reciprocating internal combustion engine that is placed in service, modified, or relocated after November 14, 2020, must comply with the emission standards in Table 2 upon placement in service, modification, or relocation, as applicable.

I.D.5.b.(ii) The owner or operator of any stationary natural gas fired reciprocating internal combustion engine not subject to Section I.D.5.b.(i) must comply with the emission standards in Table 2 in accordance with the timing set forth Section I.D.5.b.(v).

TABLE 2
Engine Type	Emission Standards (g/hp-hr)
	NOx	CO	VOC
4-Stroke Lean Burn engines in service on or before November 14, 2020, (unless subject to a more stringent emission standard under Section I.D.3.b, above)	1.2	2.0	0.7
Rich Burn engines in service on or before November 14, 2020	0.8	2.0	0.7
4-Stroke Lean Burn engines placed in service, modified, or relocated after November 14, 2020	0.7	2.0	0.7
Rich Burn engines placed in service, modified, or relocated after November 14, 2020	0.5	2.0	0.7
4-Stroke Lean Burn engines placed in service, modified, or relocated after January 30, 2024	0.5	2.0	0.7
2-Stroke Lean Burn engines	3.0	2.0	0.7

I.D.5.b.(iii) By May 1, 2021, owners and operators of an engine placed in service on or before November 14, 2020, that is subject to an emission standard in Table 2 must submit a notification to the Division containing the following information:

I.D.5.b.(iii)(A) The list of engines subject to an emission standard in Table 2, including AIRS number, location (inside or outside the 8-Hour Ozone Control Area and facility name), historical annual hours of operation averaged over calendar years 2017, 2018, and 2019, manufacturer model, serial number, horsepower, and engine configuration. The notification must also identify or calculate the g/hp-hr limit in an existing permit and the g/hp-hr at which the engine is operating on or before November 14, 2020, if different than the permitted rate. Engine configuration (e.g. rich burn or lean burn) for purposes of the emission standards in Table 2 is determined by the characterization on the engine's permit or APEN as of May 1, 2021. If the engine configuration is not identified in a permit or APEN, the owner or operator must submit an APEN with the current configuration information as determined by the owner or operator by May 1, 2021 to the Division.

I.D.5.b.(iii)(B) An identification of the applicable standard and a declaration as to whether each subject engine meets the applicable standard as of May 1, 2021. If an engine will meet the applicable standard through a permit modification only, as described in Section I.D.5.b.(iv)(A), the declaration should note the date of permit modification submittal.

I.D.5.b.(iii)(C) For all engines that do not meet the applicable emission standard as of May 1, 2021 or that cannot comply through a permit modification described in Section I.D.5.b.(iv)(A), a declaration of what action the owner or operator will take to meet the standard (e.g., control equipment installation, retrofit, replacement, electrification, shut-down). This declaration can be amended at any time prior to the applicable compliance date for that engine.

I.D.5.b.(iii)(D) The compliance deadline for each engine under Sections I.D.5.b.(i) or I.D.5.b.(v). An owner or operator may change a proposed compliance deadline for an engine subject to Section I.D.5.b.(v)(B) prior to that engine's compliance deadline, only after submittal of an updated notification to the Division that includes the updated compliance date and a demonstration that the requirements of Table 3 are met.

I.D.5.b.(iii)(E) Owners or operators that submit an Alternative Company-Wide Compliance Plan under Section I.D.5.c. are not subject to this Section I.D.5.b.(iii) for the emission standards in Table 2 for the engines covered by the Alternative Company-Wide Compliance Plan.

I.D.5.b.(iv) Permit Modification.

I.D.5.b.(iv)(A) An engine in service on or before November 14, 2020 that requires only a modification of an existing permit to meet the emission standards in this Section I.D.5.b. must submit a complete permit application containing the necessary limitations no later than May 1, 2021.

I.D.5.b.(iv)(B) For any engine not subject to Section I.D.5.b.(iv)(A), owners and operators must modify existing permits to reflect the emission standards or other operating conditions necessary to achieve compliance with Table 2. Complete permit applications must be submitted to the Division at least 365 days prior to the date established in Section I.D.5.b.(iii)(D) for that engine.

I.D.5.b.(v) Compliance Deadlines for engines subject to Section I.D.5.b.(ii).

I.D.5.b.(v)(A) Engines that comply with the emission standards on or before November 14, 2020, or are subject to Section I.D.5.b.(iv)(A) must meet the emission standards in Table 2 by May 1, 2022.

I.D.5.b.(v)(B) Engines not subject to Section I.D.5.b.(v)(A) must meet the emission standards in Table 2 in accordance with the timing set forth in Table 3.

TABLE 3
Location of Subject Engines by Owner or Operator	Compliance Deadlines
	May 1, 2022	May 1, 2023	May 1, 2024	May 1, 2025	May 1, 2026
	Percent (%) of engines that must comply with Table 2 limits
Inside, or inside and outside, the 8-Hour Ozone Control Area	At least 34% of engines inside the 8-Hour Ozone Control Area	At least 67% of engines inside the 8-Hour Ozone Control Area; and at least 25% of engines outside the 8-Hour Ozone Control Area	100% of engines in the 8-Hour Ozone Control Area; and at least 50% of engines outside the 8-Hour Ozone Control Area	At least 75% of engines outside the 8-Hour Ozone Control Area	100% of all engines
Outside the 8-Hour Ozone Control Area only	At least 20%	At least 40%	At least 60%	At least 80%	100%

I.D.5.b.(vi) If an owner or operator replaces an engine subject to an emission standard under this Section I.D.5.b. with a different stationary natural gas fired reciprocating internal combustion engine, the replacement engine must:

I.D.5.b.(vi)(A) if being placed under an alternative operating scenario pursuant to an existing Division issued permit, meet the same emission standard as the engine being replaced; or

I.D.5.b.(vi)(B) if the owner or operator of an engine chooses to comply via an Alternative Company-Wide Compliance Plan under Section I.D.5.c., meet an emission standard at least as stringent as the engine being replaced as provided for in the applicable Alternative Company-Wide Compliance Plan.

I.D.5.c. Alternative Company-Wide Compliance Plan.

I.D.5.c.(i) Owners and operators with five or more engines that are subject to Section I.D.5.b.(v)(B) may comply with the NOx requirements of Section I.D.5.b. through an Alternative Company-Wide Compliance Plan. Any owner or operator electing to develop an Alternative Company-Wide Compliance Plan must submit a Compliance Plan that meets the requirements of Section I.D.5.c.(ii) on or before May 1, 2021.

I.D.5.c.(i)(A) Only engines subject to an emission standard in Table 2 and that were placed in service on or before the November 14, 2020, can be included in an Alternative Company-Wide Compliance Plan submitted pursuant to this Section I.D.5.c.

I.D.5.c.(i)(B) Engines in an Alternative Company-Wide Compliance Plan must still meet the VOC and CO standards in Table 2 by the deadline established for that engine pursuant to Table 4.

I.D.5.c.(i)(C) Owners and operators owned by the same parent company may collectively submit a Compliance Plan in accordance with this Section I.D.5.c. However, the Compliance Plan must be signed and certified by a responsible official from each owner or operator with engines subject to the Compliance Plan acknowledging that each owner and operator is jointly and severally liable for compliance with the Compliance Plan and the provisions of this Section I.D.5.c. No engine may be included in multiple Alternative Company-Wide Compliance Plans.

I.D.5.c.(ii) The Compliance Plan must be submitted on the Division-approved form and include all of the following elements:

I.D.5.c.(ii)(A) A list of all of the engines that will rely on this Section I.D.5.c. to comply with the standards established in Section I.D.5.b. Each engine must be identified by AIRS number, location (inside or outside the 8-Hour Ozone Control Area and facility name), horsepower, manufacturer, model and serial number, historical annual operating hours (averaged over 2017, 2018, and 2019), and engine configuration.

I.D.5.c.(ii)(B) For each engine included in the Alternative Company-Wide Compliance Plan:

I.D.5.c.(ii)(B)(1) Identification of the most stringent NOx emission standard (in g/hp-hr or converted to g/hp-hr, if not expressed as such in the applicable permit) and operating conditions applicable to the engine under any rule or permit condition in effect on or before November 14, 2020.

I.D.5.c.(ii)(B)(2) Identification of the g/hp-hr at which the engine is operating on or before November 14, 2020, if different than the rate identified in Section I.D.5.c.(ii)(B)(1).

I.D.5.c.(ii)(B)(3) The emission standards (in g/hp-hr) and any operating conditions with which each engine will comply under the Alternate Company-Wide Compliance Plan, including any intended shut-downs, including any modifications or changes made to comply with the VOC or CO standards in Table 2.

I.D.5.c.(ii)(B)(4) The date by which each engine will meet the emission standards or other operating conditions identified in Section I.D.5.c.(ii)(B)(3), consistent with Table 4.

I.D.5.c.(ii)(B)(5) The maximum allowable NOx emissions (in tons/year) based on limits applicable on or before November 14, 2020, as identified in Section I.D.5.c.(ii)(B)(1).

I.D.5.c.(ii)(B)(6) The historic NOx emissions (in tons/year) averaged over calendar years 2017, 2018 and 2019, based on actual operating hours and permitted emission standards.

I.D.5.c.(ii)(B)(7) The NOx emissions that would be allowed on an annual basis (in tons/year) assuming the engine was complying with the emission standards established in Table 2.

I.D.5.c.(ii)(B)(8) Each engine's allowable NOx emissions (in tons/year) when operated in accordance with limitations identified in Section I.D.5.c.(ii)(B)(3), including any increase in NOx emissions that result from modifications or changes made to comply with the VOC or CO standards in Table 2.

I.D.5.c.(ii)(C) The total allowable NOx emissions (in tons/year) calculated for all engines in the Alternative Company-Wide Compliance Plan, as specified in Section I.D.5.c.(ii)(B)(5).

I.D.5.c.(ii)(D) The total NOx emissions (in tons/year) calculated for all engines in the Alternative Company-Wide Compliance Plan, as specified in Section I.D.5.c.(ii)(B)(6).

I.D.5.c.(ii)(E) The total NOx emissions calculated for all engines included in the Alternate Company-Wide Compliance Plan assuming all engines were complying with the emission standards established in Table 2, as specified in Section I.D.5.c.(ii)(B)(7).

I.D.5.c.(ii)(F) The total allowable NOx emissions (in tons/year) calculated for all engines included in the Alternate Company-Wide Compliance Plan, as specified in Section I.D.5.c.(ii)(B)(8).

I.D.5.c.(ii)(G) A calculation of:

I.D.5.c.(ii)(G)(1) The difference between Section I.D.5.c.(ii)(C) and Section I.D.5.c.(ii)(F). This difference is called the "Plan Emission Reductions".

I.D.5.c.(ii)(G)(2) The difference between total historic NOx emissions as calculated in Section I.D.5.c.(ii)(D) and the total allowable NOx emissions (in tons/year) for all engines included in the Alternate Company-Wide Compliance Plan assuming all engines were complying with Table 2, as specified in Section I.D.5.c.(ii)(E).

I.D.5.c.(ii)(G)(3) The difference between total historic NOx emissions as calculated in Section I.D.5.c.(ii)(D) and the total allowable NOx emissions (in tons/year) for all engines included in the Alternate Company-Wide Compliance Plan, as specified in Section I.D.5.c.(ii)(F).

I.D.5.c.(ii)(H) A demonstration that:

I.D.5.c.(ii)(H)(1) The total NOx emissions allowed under the Alternative Company-Wide Compliance Plan (Section I.D.5.c.(ii)(F)) are less than or equal to the total NOx emissions that would be allowed under Table 2 (Section I.D.5.c.(ii)(E)).

I.D.5.c.(ii)(H)(2) The reductions from emissions achieved by the Alternative Company-Wide Compliance Plan are greater than or equal to the reductions from actual emissions achieved by Table 2 (i.e. that the figure calculated in Section I.D.5.c.(ii)(G)(3) is greater than or equal to the figure calculated in Section I.D.5.c.(ii)(G)(2)).

I.D.5.c.(ii)(I) A certification by the owner or operator that based on information and belief formed after reasonable inquiry, the statements and information in the Compliance Plan are true, accurate, and complete.

I.D.5.c.(iii) Any owner or operator utilizing this Alternative Company-Wide Compliance Plan must meet the emission standards for NOx, CO and VOC as identified in I.D.5.c.(ii)(B)(3) by the compliance deadlines listed in Table 4.

I.D.5.c.(iv) Owners and operators must modify existing permits to reflect the emission standards or other operating conditions identified in the Compliance Plan (Section I.D.5.c.(ii)(B)(3)) for that engine. Permit applications must be submitted to the Division at least 365 days prior to the date established in Section I.D.5.c.(ii)(B)(4) for that engine.

I.D.5.c.(v) Compliance Plan Updates. By May 1st of each year (beginning in 2022) and continuing through and including the final year of a Compliance Plan, an owner or operator must submit an update to the Compliance Plan with the following information:

I.D.5.c.(v)(A) For each engine, any change in location and any action taken under the Compliance Plan (e.g., permit modification applied for, engine retrofit completed, engine taken offline) and the date;

I.D.5.c.(v)(B) A calculation of the percentage of Plan Emission Reductions achieved as of the date of submittal of the update (in each compliance period and cumulatively);

I.D.5.c.(v)(C) Any changes made to the Compliance Plan (e.g. change in compliance date for an engine). No change to the compliance date for an engine can be made after the date established in the Compliance Plan for that engine.;

I.D.5.c.(v)(D) If ownership or operation of an engine in the Compliance Plan for which emission reductions were included in the calculation of Plan Emission Reductions was sold or transferred in the previous year, an identification of how the owner or operator will achieve the portion of Plan Emission Reductions attributed to that engine under the Compliance Plan (the difference between Section I.D.5.c.(ii)(B)(5) and (8)).

I.D.5.c.(v)(E) A certification by the owner or operator that based on information and belief formed after reasonable inquiry, the statements and information in the update are true, accurate, and complete.

I.D.5.c.(vi) Nothing in this Section I.D.5.c exempts an engine that is part of an Alternative Company-Wide Compliance Plan from compliance with the performance testing, monitoring, recordkeeping or reporting requirements of this Section I.D.5.

TABLE 4
Location of Subject Engines covered by the Alternative Company-Wide Compliance Plan	Compliance Deadlines
	May 1, 2022	May 1, 2023	May 1, 2024	May 1, 2025	May 1, 2026
	Percent (%) of Plan Emission Reductions Achieved
Inside, or inside and outside, the 8-Hour Ozone Control Area	At least 50% of Plan Emission Reductions from engines inside the 8-Hour Ozone Control Area	At least 75% of Plan Emission Reductions from engines inside the 8-Hour Ozone Control Area; and at least 25% of Plan Emission Reductions from engines outside the 8-Hour Ozone Control Area	100% of Plan Emission Reductions from engines inside the 8-Hour Ozone Control Area; and at least 50% of Plan Emission Reductions from engines outside the 8-Hour Ozone Control Area	At least 75% of Plan Emission Reductions from engines outside the 8-Hour Ozone Control Area	100%of Plan Emission Reductions
Outside the 8-Hour Ozone Control Area only	At least 20%	At least 40%	At least 60%	At least 80%	100%

I.D.5.d. Performance Testing

I.D.5.d.(i) Engines subject to this Section I.D.5. must conduct a performance test consistent with the requirements of this Section I.D.5.d.

I.D.5.d.(i)(A) The owner or operator of an engine subject to Section I.D.5.b.(ii) must conduct a performance test for NOx, CO, and O2 by May 1, 2021.

I.D.5.d.(i)(B) The owner or operator of an engine placed in service, modified, relocated or replaced after May 1, 2021 must conduct a performance test within 12 months of the date the engine is placed in service, modified, relocated or replaced.

I.D.5.d.(i)(C) The following engines are exempt from the requirements of this Section I.D.5.d.

I.D.5.d.(i)(C)(1) Engines subject to the performance testing requirements of 40 C.F.R. Part 60, Subpart JJJJ (July 1, 2019).

I.D.5.d.(i)(C)(2) Engines subject to at least semi-annual portable analyzer testing or ongoing performance testing in a permit issued on or before November 14, 2020.

I.D.5.d.(i)(D) A performance test conducted in accordance with 40 C.F.R. § 60.4244 (July 1, 2019) between January 1, 2020 and May 1, 2021 will satisfy the initial performance testing requirements in Section I.D.5.d.(i)(A).

I.D.5.d.(ii) Performance tests must be conducted in accordance with the applicable reference test methods of 40 C.F.R. Part 60, Appendix A (July 1, 2019), and a test protocol submitted to the Division for review at least thirty (30) days prior to testing and in accordance with AQCC Common Provisions Regulation Section II.C.

I.D.5.d.(iii) Tuning of an engine prior to the performance test required by this Section I.D.5.d is not a violation of this rule. However, readjustment of an engine set point following the performance test that would negatively impact the performance of the engine (i.e. result in increased emissions above applicable permit limits) is a violation of this rule.

I.D.5.e. Monitoring. Except as provided in Section I.D.5.a.(ii), owners or operators of an engine subject to Section I.D.5.a must:

I.D.5.e.(i) Beginning on May 1, 2022, conduct semi-annual portable analyzer monitoring for NOx, CO, and O2. At least one calendar month must separate the semi-annual tests.

I.D.5.e.(i)(A) If the engine is operated for less than 200 hrs in any semi-annual period, then the portable analyzer monitoring need not occur during that semi-annual period (i.e. the engine does not need to be started for the sole purpose of portable monitoring).

I.D.5.e.(i)(B) All portable analyzer testing required by this section must be conducted using the Division's Portable Analyzer Monitoring Protocol (version: March 2006).

I.D.5.e.(i)(C) Tuning of an engine prior to semi-annual monitoring events required by this Section I.D.5.e.(i) is not a violation of this rule. However, readjustment of an engine set point following the monitoring event that would negatively impact the performance (i.e. result in increased emissions above applicable permit limits) of the engine is a violation of this rule.

I.D.5.e.(i)(D) A performance test conducted pursuant to Section I.D.5.d., 40 C.F.R. Part 60, JJJJ, or a permit requirement may take the place of the next required semi-annual portable analyzer test required by this section.

I.D.5.e.(i)(E) An engine subject to at least semi-annual portable analyzer testing requirements in an existing permit issued by the Division can comply with this Section I.D.5.e.(i) by complying with the testing requirements in the permit.

I.D.5.e.(ii) Beginning May 1, 2021, if a catalyst is used to reduce emissions:

I.D.5.e.(ii)(A) Monitor the inlet temperature to the catalyst daily and conduct maintenance if the temperature is not within applicable limits.

I.D.5.e.(ii)(B) Measure the pressure drop across the catalyst monthly and conduct maintenance if the pressure drop is greater than 2 inches outside the baseline value established after each semi-annual portable analyzer monitoring.

I.D.5.e.(ii)(C) Engines that are subject to catalyst temperatures and catalyst pressure drop monitoring requirements in an existing permit issued by the Division or 40 C.F.R. Part 63, Subpart ZZZZ (July 1, 2019) satisfy the monitoring requirements of this Section I.D.5.e.(ii).

I.D.5.e.(iii) Beginning May 1, 2021 or the date the engine is placed in service, modified, relocated or replaced (if later), install (if not already) and operate an hour meter or Division approved alternate method to continuously track the hours of operation of the subject engine.

I.D.5.e.(iv) Conduct the following inspections and adjustments at least annually, unless otherwise specified, beginning in 2022

I.D.5.e.(iv)(A) Change oil and filters as necessary; and,

I.D.5.e.(iv)(B) Inspect air cleaners, fuel filters, hoses, and belts and clean or replace as necessary; and,

I.D.5.e.(iv)(C) Inspect spark plugs and replace as necessary; or,

I.D.5.e.(iv)(D) Conduct a combustion process adjustment according to the manufacturer recommended procedures and schedule. Alternatively, the owner or operator may rely on a combustion process adjustment conducted in accordance with requirements and schedules of a New Source Performance Standard in 40 CFR Part 60 (July 1, 2022) or National Emission Standard for Hazardous Air Pollutants in 40 CFR Part 63 (July 1, 2022) conducted during the same annual period to satisfy the annual combustion process adjustment requirement of this Section I.D.5.e.(iv)(D) for that 12-month period.

I.D.5.f. Recordkeeping. The following records must be kept for a period of five years and made available to the Division upon request.

I.D.5.f.(i) Records of performance tests conducted pursuant to Section I.D.5.d, including I.D.5.d.(i)(D)., including the date, engine settings on the date of the test, and documentation of the methods and results of the testing.

I.D.5.f.(ii) Records of semi-annual portable analyzer monitoring, including the date, engine settings on the date of the monitoring, and documentation of the results of the monitoring. These records must include any demonstration that no semi-annual portable analyzer monitoring was required as provided under Section I.D.5.e.(i)(D) or I.D.5.e.(i)(E), if applicable.

I.D.5.f.(iii) Records of catalyst monitoring required by Section I.D.5.e.(ii) and any actions taken to address monitored values outside the temperature or pressure drop parameters, including the date and a description of actions taken.

I.D.5.f.(iv) If claiming an exemption under Section I.D.5.a.(ii), records demonstrating that fuel combustion was less than 100 MMBtu per year or hours of operation are less than 250 hours per year.

I.D.5.f.(v) Hours of operation as recorded by the hour meteror alternative device approved by the Division continuously tracking hours as required by Section I.D.5.e.(iii), at least on a calendar month basis.

I.D.5.f.(vi) Records of tuning, adjustments, or other combustion process adjustments required under Section I.D.5.e.(iv), including:

I.D.5.f.(vi)(A) The date of the adjustment.

I.D.5.f.(vi)(B) A description of any corrective action taken.

I.D.5.f.(vi)(C) If the owner or operator conducts the combustion process adjustment according to the manufacturer recommended procedures and schedule and the manufacturer specifies a combustion process adjustment on an operation time schedule, the hours of operation since the last combustion process adjustment and the procedures followed. The owner or operator must retain documentation of any relied upon manufacturer recommended procedures, specifications, and maintenance schedule for five years after the owner or operator ceases to rely upon it.

I.D.5.f.(vi)(D) If the owner or operator conducts the combustion process adjustment according to a New Source Performance Standard or National Emission Standard for Hazardous Air Pollutants, what standard applied and what procedures were followed.

I.D.5.g. Reporting. Beginning on the date specified and by May 1 of each year thereafter, the owner or operator of each engine subject to this Section I.D.5. must submit the following information covering the preceding calendar year:

I.D.5.g.(i) Beginning May 1, 2021, a statement of the status of performance testing required under Section I.D.5.d, and the date and results of that testing;

I.D.5.g.(ii) Beginning May 1, 2022, an identification of any engines placed in service, modified, relocated, or replaced, including AIRS number, serial number, location, engine configuration, and a certification as to whether the emission standards in Table 2 are met;

I.D.5.g.(iii) Beginning May 1, 2023, the date on which the monitoring required by Sections I.D.5.e.(iv) was performed;

I.D.5.g.(iv) Beginning May 1, 2023, the date that all required semi-annual portable analyzer testing was performed under Section I.D.5.e.(i), and the results of that testing.

I.D.6. (State Only) Additional Requirements for Internal Combustion Engines

I.D.6.a. Applicability

I.D.6.a.(i) Sections I.D.6.a. through I.D.6.f.(i) apply to stationary rich burn natural gas fired reciprocating internal combustion engines state-wide with a manufacturer's design rate greater than or equal to 100 horsepower but less than 1000 horsepower and lean burn natural gas fired reciprocating internal combustion engines state-wide with a manufacturer's design rate greater than or equal to 250 horsepower but less than 1000 horsepower.

I.D.6.a.(ii) Sections I.D.6. through I.D.6.f.(i) apply to stationary diesel or dual-fuel fired internal combustion engines state-wide with a manufacturer's design rate greater than or equal to 500 horsepower.

I.D.6.a.(iii) For purposes of this Section I.D.6., modified means any physical change to the engine or change in method of operation that results in an increase in the emission rate of any air pollutant, and does not include any physical or operational changes excluded by 40 C.F.R. 60.14(e).

I.D.6.a.(iv) For purposes of this Section I.D.6., placed in service means the bringing of an engine on-site for use. The placed in service date is the date the engine begins to operate. For engines in service on or before January 30, 2024, replacement under an authorized alternative operating scenario, or a one-time only replacement of an engine that cannot achieve an applicable emission standard due to technical or economic infeasibility, is not considered placed in service.

I.D.6.a.(v) For purposes of this Section I.D.6., relocated means

(1) the bringing of an engine into the 8-hour ozone control area or Northern Weld County from outside the 8-hour ozone control area or Northern Weld County, or

(2) the bringing of an engine into the State of Colorado from outside the State of Colorado. The relocation date is the date the subject engine begins to operate.

I.D.6.a.(vi) Exemptions.

I.D.6.a.(vi)(A) Engines that burn less than 100 MMBtu per year of natural gas or diesel fuel on a rolling-12-month basis are not subject to Sections I.D.6.a. through I.D.6.d, or I.D.6.f.

I.D.6.a.(vi)(B) Non-road engines, as defined in Regulation Number 3, Part A, Section I.B.36 are not subject to this Section I.D.6.

I.D.6.a.(vi)(C) Any emergency power generator exempt from APEN or construction permit requirements pursuant to Regulation Number 3, Parts A or B are not subject to this Section I.D.6.

I.D.6.a.(vi)(D) Emergency power generators or engines that are used to meet electrical demand or provide voltage support to the electrical grid that operate less than 250 hours per year on a rolling-12-month basis are not subject to Sections I.D.6.a. through I.D.6.d, or I.D.6.f.

I.D.6.b. Emission Standards for Engines Subject to Section I.D.6.a.

I.D.6.b.(i) The owner or operator of any stationary natural gas-fired reciprocating internal combustion engine that is placed in service, modified, or relocated after January 30, 2024, must comply with the emission standards in Table 5 upon placement in service, modification, or relocation.

I.D.6.b.(ii) The owner or operator of any stationary natural gas-fired reciprocating internal combustion engine not subject to Section I.D.6.b.(i) must comply with the emission standards in Table 5 in accordance with the timing set forth Section I.D.6.b.(vii).

TABLE 5
Engine Type	Emission Standards
	NOx (g/hp-hr)
Lean Burn engines in service on or before January 30, 2024	0.8
Lean Burn engines placed in service, modified, or relocated after January 30, 2024	0.5
Rich Burn engines	0.5

I.D.6.b.(iii) The owner or operator of any stationary diesel or dual-fuel internal combustion engine that is placed in service, modified, or relocated after January 30, 2024, must achieve or exceed EPA Tier IV standards for NOx upon placement in service, modification, or relocation.

I.D.6.b.(iv) The owner or operator of any stationary diesel or dual-fuel internal combustion engine not subject to Section I.D.6.b.(iii) must achieve or exceed EPA Tier IV standards for NOx in accordance with the timing set forth Section I.D.6.b.(vii).

I.D.6.b.(v) The owner or operator of any engine that meets all of the criteria described in Sections I.D.6.b.(v)(A) through (E) may submit a request to the Division for an alternative emission standard for a specific engine based on technical or economic infeasibility. To qualify for an alternative emission standard, an owner or operator must submit to the Division a reasonable demonstration detailing why it is not technically or economically feasible for the individual engine to achieve the emission standard in Section I.D.6.b.(ii) by January 30, 2025. Within a reasonable amount of time after receipt, the Division will grant an alternative emission standard where the Division determines a satisfactory source-specific demonstration has been made. The Division will set an appropriate alternative emission standard considering control technology that will achieve the maximum degree of emission control that a particular source is capable of meeting and that is reasonably available considering technological and economic feasibility. Any granted alternative emission standard will be included in the applicable permit pursuant to Section I.D.6.b.(vi)

I.D.6.b.(v)(A) Stationary natural gas-fired lean burn reciprocating internal combustion engine;

I.D.6.b.(v)(B) Located outside northern Weld County and the 8-Hour Ozone Control Area;

I.D.6.b.(v)(C) Placed in service on or before January 30, 2024;

I.D.6.b.(v)(D) With greater than or equal to 400 horsepower; and

I.D.6.b.(v)(E) With a NOx emission factor of less than or equal to 3.0 g/hp-hr as reflected by the APEN on file as of January 30, 2024.

I.D.6.b.(vi) Permit Modification.

I.D.6.b.(vi)(A) An engine in service on or before January 30, 2024, that requires only a modification of an existing permit to meet the emission standards in this Section I.D.6.b. must submit a complete permit application containing the necessary limitations by the following deadlines.

I.D.6.b.(vi)(A)(1) For individual construction permit or Title V operating permit significant modification applications, by no later than May 1, 2024.

I.D.6.b.(vi)(A)(2) For general construction permit or Title V operating permit minor modification applications, by no later than January 30, 2025.

I.D.6.b.(vi)(B) For any engine in service on or before January 30, 2024, and not subject to Section I.D.6.b.(vi)(A), owners and operators must modify existing permits to reflect the emission standards or other operating conditions necessary to achieve compliance with Table 5. Complete permit applications must be submitted to the Division by the following deadlines:

I.D.6.b.(vi)(B)(1) For individual construction permit or Title V operating permit modifications applications, at least 365 days prior to the date established in Section I.D.6.(vii) for that engine; and

I.D.6.b.(vi)(B)(2) For general construction permit modification applications, at least 90 days prior to the date established in Section I.D.6.b.(vii) for that engine.

I.D.6.b.(vii) Compliance deadlines for engines subject to Sections I.D.6.b.(ii) or I.D.6.b.(iv).

I.D.6.b.(vii)(A) Engines that comply with the emission standards on or before January 30, 2024, or are subject to Section I.D.6.b.(vi)(A) must meet the emission standards in Table 5 by May 1, 2025. If an owner or operator has submitted a complete application in compliance with Section I.D.6.b.(vi)(A) and has not been issued the relevant permit by May 1, 2025, the Division may extend the compliance deadline for an engine as necessary to align with issuance date of the permit.

I.D.6.b.(vii)(B) Engines not subject to Section I.D.6.b.(vi)(A) must meet the emission standards in Table 5 in accordance with the timing set forth in Table 6. If an owner or operator has submitted a complete application requesting the emission standards or other operating conditions necessary to achieve compliance with Table 5 and has not been issued the relevant permit by the applicable compliance deadline in Table 6, the Division may extend the compliance deadline for an engine as necessary to align with issuance date of the permit.

TABLE 6
Location of Subject Engines by Owner or Operator	Compliance Deadlines
	May 1, 2025	May 1, 2026	May 1, 2027	May 1, 2028	May 1, 2029
	Percent (%) of engines that must comply with Table 5 limits
Natural Gas-Fired Engines Inside, or inside and outside, the 8-Hour Ozone Control Area	At least 34% of engines inside the 8-Hour Ozone Control Area	At least 67% of engines inside the 8-Hour Ozone Control Area; and at least 25% of engines outside the 8-Hour Ozone Control Area	100% of engines in the 8-Hour Ozone Control Area; and at least 50% of engines outside the 8-Hour Ozone Control Area	At least 75% of engines outside the 8-Hour Ozone Control Area	100% of all engines
Natural Gas-Fired Engines Outside the 8-Hour Ozone Control Area only	At least 20%	At least 40%	At least 60%	At least 80%	100%
Diesel and Dual Fuel Engines State-wide	At least 50%	100%

I.D.6.b.(viii) If an owner or operator replaces an engine subject to an emission standard under this Section I.D.6.b. with a different stationary engine under an alternative operating scenario pursuant to an existing Division issued permit, the replacement engine must, meet the same emission standard as the engine being replaced.

I.D.6.c. Performance Testing

I.D.6.c.(i) Engines subject to this Section I.D.6. must conduct a performance test consistent with the following requirements.

I.D.6.c.(i)(A) The owner or operator of an engine subject to Section I.D.6.b.(ii) must conduct a performance test for NOx by May 1, 2025 or within 6 months of any Division established compliance deadline pursuant to Section I.D.6.b.(vii).

I.D.6.c.(i)(B) The owner or operator of an engine placed in service, modified, relocated or replaced after January 30, 2024, must conduct a performance test within 12 months of the date the engine is placed in service, modified, relocated or replaced.

I.D.6.c.(i)(C) The following engines are exempt from the requirements of this Section I.D.6.c.

I.D.6.c.(i)(C)(1) Engines subject to the performance testing requirements of 40 C.F.R. Part 60, Subpart JJJJ (July 1, 2023) or 40 C.F.R. Part 60, Subpart IIII (July 1, 2023).

I.D.6.c.(i)(C)(2) Engines subject to at least semi-annual portable analyzer testing or ongoing performance testing in a permit issued on or before January 30, 2024.

I.D.6.c.(i)(D) A performance test conducted in accordance with 40 C.F.R. § 60.4244 (July 1, 2023) or 40 C.F.R. § 60.4212 or 60.4213 (July 1, 2023) between January 1, 2023 and May 1, 2025, will satisfy the initial performance testing requirements in Section I.D.6.c.(i)(A).

I.D.6.c.(ii) Performance tests must be conducted in accordance with the applicable reference test methods of 40 C.F.R. Part 60, Appendix A (July 1, 2023), and a test protocol submitted to the Division for review at least thirty (30) days prior to testing and in accordance with AQCC Common Provisions Regulation Section II.C.

I.D.6.c.(iii) Tuning of an engine prior to the performance test required by this Section I.D.6.c. is not a violation of this rule. However, readjustment of an engine set point following the performance test that would negatively impact the performance of the engine (i.e., result in increased emissions above applicable permit limits) is a violation of this rule.

I.D.6.c.(iv) Diesel engines covered by Section I.D.6.b.(iii) or (iv) that are certified by the manufacturer as Tier IV engines do not require the initial performance test under Section I.D.6.c.(i)(B), but must conduct annual performance testing beginning five years after the engine is placed in service.

I.D.6.d. Monitoring. Except as provided in Section I.D.6.a.(vi), owners or operators of an engine subject to Section I.D.6.a. must:

I.D.6.d.(i) Beginning on May 1, 2025 or within 6 months of any Division established compliance deadline pursuant to Section I.D.6.b.(vii)., conduct annual portable analyzer monitoring for NOx. At least six calendar months must separate the annual tests.

I.D.6.d.(i)(A) If the engine is operated for less than 200 hours in any 12-month period, then the portable analyzer monitoring need not occur during that annual period (i.e., the engine does not need to be started for the sole purpose of portable monitoring).

I.D.6.d.(i)(B) All portable analyzer testing required by this section must be conducted using the Division's Portable Analyzer Monitoring Protocol (version: March 2006).

I.D.6.d.(i)(C) Tuning of an engine prior to annual monitoring events required by this Section I.D.6.d.(i) is not a violation of this rule. However, readjustment of an engine set point following the monitoring event that would negatively impact the performance (i.e., result in increased emissions above applicable permit limits) of the engine is a violation of this rule.

I.D.6.d.(i)(D) A performance test conducted pursuant to Section I.D.6.c., 40 C.F.R. Part 60, JJJJ, IIII, or a permit requirement may take the place of the next required annual portable analyzer test required by this section.

I.D.6.d.(i)(E) An engine subject to at least annual portable analyzer testing requirements in an existing permit issued by the Division can comply with this Section I.D.6.d.(i) by complying with the testing requirements in the permit.

I.D.6.d.(ii) For natural gas-fired engines, beginning May 1, 2024, if a catalyst is used to reduce emissions:

I.D.6.d.(ii)(A) Monitor the inlet temperature to the catalyst weekly and conduct maintenance if the temperature is not within applicable limits.

I.D.6.d.(ii)(B) Measure the pressure drop across the catalyst monthly and conduct maintenance if the pressure drop is greater than 2.0 inches of water outside the baseline value established after each annual portable analyzer monitoring.

I.D.6.d.(ii)(C) Engines that are subject to catalyst temperatures and catalyst pressure drop monitoring requirements in an existing permit issued by the Division or 40 C.F.R. Part 63, Subpart ZZZZ (July 1, 2023) satisfy the monitoring requirements of this Section I.D.6.d.(ii).

I.D.6.d.(iii) Conduct the following inspections and adjustments at least annually, unless otherwise specified, beginning in 2025.

I.D.6.d.(iii)(A) Change oil and filters as necessary; and,

I.D.6.d.(iii)(B) Inspect air cleaners, fuel filters, hoses, and belts and clean or replace as necessary; and,

I.D.6.d.(iii)(C) Inspect spark plugs and replace as necessary; or,

I.D.6.d.(iii)(D) Conduct a combustion process adjustment according to the manufacturer recommended procedures and schedule. Alternatively, the owner or operator may rely on a combustion process adjustment conducted in accordance with requirements and schedules of a New Source Performance Standard in 40 CFR Part 60 (July 1, 2023) or National Emission Standard for Hazardous Air Pollutants in 40 CFR Part 63 (July 1, 2023) conducted during the same annual period to satisfy the annual combustion process adjustment requirement of this Section I.D.6.d.(iv)(D) for that 12-month period.

I.D.6.e. Recordkeeping. The following records must be kept for a period of five years and made available to the Division upon request.

I.D.6.e.(i) Records of performance tests conducted pursuant to Section I.D.6.c., including I.D.6.c.(i)(D), including the date, engine settings on the date of the test, and documentation of the methods and results of the testing.

I.D.6.e.(ii) Records of annual portable analyzer monitoring, including the date, engine settings on the date of the monitoring, and documentation of the results of the monitoring. These records must include any demonstration that no annual portable analyzer monitoring was required as provided under Sections I.D.6.d.(i)(D) or I.D.6.d.(i)(E), if applicable.

I.D.6.e.(iii) For natural gas-fire engines, records of catalyst monitoring required by Section I.D.6.d.(ii) and any actions taken to address monitored values outside the temperature or pressure drop parameters, including the date and a description of actions taken.

I.D.6.e.(iv) If claiming an exemption under Section I.D.6.a.(vi), records demonstrating that fuel combustion was less than 100 MMBtu per year or hours of operation are less than 250 hours per year.

I.D.6.e.(v) Hours of operation at least on a calendar month basis.

I.D.6.e.(vi) Records of tuning, adjustments, or other combustion process adjustments required under Section I.D.6.d.(iii), including:

I.D.6.e.(vi)(A) The date of the adjustment.

I.D.6.e.(vi)(B) A description of any corrective action taken.

I.D.6.e.(vi)(C) If the owner or operator conducts the combustion process adjustment according to the manufacturer recommended procedures and schedule and the manufacturer specifies a combustion process adjustment on an operation time schedule, the hours of operation since the last combustion process adjustment and the procedures followed. The owner or operator must retain documentation of any relied upon manufacturer recommended procedures, specifications, and maintenance schedule for five years after the owner or operator ceases to rely upon it.

I.D.6.e.(vi)(D) If the owner or operator conducts the combustion process adjustment according to a New Source Performance Standard or National Emission Standard for Hazardous Air Pollutants, what standard applied and what procedures were followed.

I.D.6.f. Reporting.

I.D.6.f.(i) Beginning on the date specified and by May 1 of each year thereafter, the owner or operator of each engine subject to this Section I.D.6. must submit the following information covering the preceding calendar year.

I.D.6.f.(i)(A) Beginning May 1, 2024, a statement of the status of performance testing required under Section I.D.6.c., and the date and results of that testing (i.e., pass or fail).

II.D.6.f.(i)(B) Beginning May 1, 2025, an identification of any engines placed in service, modified, relocated, or replaced, including AIRS number, serial number, location, engine configuration, and a certification as to whether the emission standards in Table 5 are met.

I.D.6.f.(i)(C) Beginning May 1, 2026, the date on which the monitoring required by Sections I.D.6.d.(iii) was performed.

I.D.6.f.(i)(D) Beginning May 1, 2026, the date that all required annual portable analyzer testing was performed under Section I.D.6.d.(i), and the results of that testing (i.e., pass or fail).

5 CCR 1001-30-B-I

46 CR 10, May 25, 2023, effective 6/14/2023

47 CR 02, January 25, 2024, effective 2/14/2024