An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

Oklahoma OAC 252:100-25, VISIBLE EMISSIONS AND PARTICULATES, SIP effective January 4, 2016 (OKd15) and September 3, 2019 (OKd27)

Regulatory Text: 
Oklahoma Administrative Code.  Title 252.  Department of Environmental Quality 

Chapter 100.  Air Pollution Control (OAC 252:100)

As approved by EPA August 1, 2019 (84 FR37579), SIP effective September 3, 2019 (OKd27), docket EPA-R06-OAR-2017-0145.

Unless otherwise indicated, sections are:
As adopted in Oklahoma Register May 1, 2000 (17 Ok Reg 1120) effective June 1, 2000, 
Approved by EPA December 29, 2008 (73 FR 79400), SIP effective February 27, 2009 (OKd06), docket EPA-R06-OAR-2006-0389 [OK005].


252:100-25-1.   Purpose, OKd06
252:100-25-2.   General prohibition, OKd06
252:100-25-2.1. Definitions, OKd06
252:100-25-3.   Opacity limit, OKd15
252:100-25-4.   Alternative for particulates, OKd06
252:100-25-5.   Continuous emission monitoring for opacity, OKd27

252:100-25-1.  Purpose

     The purpose of this Subchapter is to control visible emissions and particulate matter from the operation of any air contaminant source.

252:100-25-2.  General prohibition

     No owner or operator of any air contaminant source shall allow emissions from said source so as to cause or contribute to air pollution.

252:100-25-2.1.  Definitions

     The following words and terms when used in this Subchapter shall have the following meaning unless the context clearly indicates otherwise:

     "One-hour period" means, for units with an operable Continuous Opacity Monitor (COM), any 60-minute period commencing on the hour.

     "Opacity" means the degree to which emissions reduce the transmission of light and obscure the view of an object in the background.

     "Six-minute period" means, for units with an operable COM, any one of the ten equal parts of a one-hour period.
     "Unit" means any piece of equipment that has the potential to emit air contaminants in the form of visible emissions.

252:100-25-3.  Opacity limit
As adopted in the Oklahoma Register May 15, 2009 (26 Ok Reg 1177) effective July 1, 2009 and submitted to EPA July 16, 2010 (OK-39) and approved by EPA November 3, 2015 (80 FR 67647) SIP effective January 4, 2016 (OKd15), document EPA-R06-OAR-2011-0034-0004 [OK017.04].

     (a)  Units subject to an opacity limit promulgated under 
section 111 of the Federal Clean Air Act are exempt from this section.

     (b)  No person shall allow the discharge of any fumes, 
aerosol, mist, gas, smoke, vapor, particulate matter, or any 
combination thereof exhibiting greater than 20% opacity except for:
          (1)  Short term occurrences, which consist of not more
than one six-minute period in any consecutive 60 minutes, 
not to exceed three such periods in any consecutive 24 
hours.  For units with COMs operated and maintained in 
accordance with Performance Specification 1 (40 CFR 
Part 60, Appendix B), short term occurrences which 
consist of not more than one six-minute period in any 
one-hour period, not to exceed three such periods in any 
consecutive 24 hours.  In neither case shall the average of 
any six-minute period exceed 60% opacity.
          (2)  Smoke resulting from fires covered by the exceptions 
outlined in OAC 252:100-13-7.
          (3)  An emission, where the presence of uncombined 
water is the only reason for failure to meet the requirements 
of OAC 252:100-25-3(b).
          (4)  Smoke generated due to a malfunction in a facility, 
when the source of the fuel producing the smoke is not 
under the direct and immediate control of the facility and 
the immediate constriction of the fuel flow at the facility 
would produce a hazard to life and/or property.

     (c)  To determine compliance with this Section, opacity shall 
be read by either:
          (1)  A Certified Visible Emission Evaluator using Test 
Method 9 (40 CFR Part 60, Appendix A).
          (2)  A COM installed, calibrated, operated and maintained 
in accordance with Performance Specification 1 (40 CFR Part 60, Appendix B).

252:100-25-4.  Alternative for particulates

     (a)  The 20% opacity limit required under 252:100-25-3 may be increased for particulates only, provided that the owner or operator demonstrates to the satisfaction of the Air Quality Council at public hearing that:
          (1)  The owner or operator has installed air pollution control equipment to attempt to control both visible and particulate matter emissions to the limit required by applicable Subchapters.
          (2)  The pollution control equipment installed:
               (A)  Has been properly maintained.
               (B)  Is in good working order.
               (C)  Is operated to minimize emissions.
          (3)  The installed control equipment does not control opacity to the limit required in 252:100-25-3.
          (4)  The owner or operator has conducted stack test(s) using appropriate test methods as approved by the Division to determine mass emissions at maximum allowed capacity and has determined such emissions meet all applicable particulate matter requirements (i.e., permit limit, rule limit, process limit).
          (5)  The owner or operator has conducted detailed modeling and other measures (e.g., monitoring) deemed necessary by the Executive Director to demonstrate that the maximum impact of any increase of opacity will not exceed 5 μg/m3 PM-10 24-hour average at any point of impact or 1 μg/m3 PM-10 annual average at any point of impact.

     (b)  Upon completion of the demonstration specified in (a) of this Section, the opacity allowed will be based on the opacity read  by a Certified Visible Emission Evaluator at the time of the maximum operation stack test.

     (c)  Applications for an alternative under 252:100-25-4 will be submitted to the Director of the Division for review and recommendation to the Air Quality Council for final action.

252:100-25-5. Continuous emission monitoring for opacity, SIP effective September 3, 2019 (OKd27).
As adopted in Oklahoma Register June 17, 2013 (30 OkReg 1078) effective July 1, 2013.
Submitted to EPA February 14, 2017 (OK-58), document EPA-R06-OAR-2017-0145-0003 [OK028.03] page 432 and 504.
Approved by EPA August 1, 2019 (84 FR 37579) SIP effective September 3, 2019 (OKd27), docket EPA-R06-OAR-2017-0145 [OK028].

     (a)  Owners or operators of the listed emission sources
shall install, calibrate, operate, and maintain all monitoring
equipment necessary for continuously monitoring opacity. These
requirements apply to:
          (1)  fluid bed catalytic cracking unit catalyst regenerators
at petroleum refineries as specified in paragraph 2.4
of 40 CFR Part 51, Appendix P,
          (2)  fossil fuel-fired steam generators as specified in
paragraph 2.1 of 40 CFR Part 51, Appendix P, and
          (3)  any fuel-burning equipment with a design heat input
value of 250 MMBTU/hr or more that does not burn
gaseous fuel exclusively, and that was not in being on or
before July 1, 1972 or that is modified after July 1, 1972.

     (b)  This section shall not apply to such emission sources
that are subject to a new source performance standard promulgated
in 40 CFR Part 60 pursuant to section 111 of the Clean Air Act.

     (c)  Required emission monitoring systems shall be installed,
calibrated, operated, and maintained in accordance
with 40 CFR Part 60, Appendix B, and 40 CFR Part 51,
Appendix P. Alternative monitoring requirements different
from the provisions of Parts 1 through 5 of Appendix P may
be approved by the DEQ on a case-by-case basis if
continuous monitoring cannot be implemented by a source due
to physical plant limitations or extreme economic reasons.

***End 252:100-25-5 SIP effective 9-3-2019***OKd27***OK028***z8s***