2015 National Ambient Air Quality Standards for Ozone

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In accordance with a federal court order, the United States Environmental Protection Agency (USEPA) signed a final rule on October 1, 2015, revising the National Ambient Air Quality Standards (NAAQS) for ground level ozone, lowering the primary and secondary standards to 70 ppb, a decrease of 5 ppb from the 2008 ozone NAAQS. The USEPA believes that this standard should be attainable for most areas based on the implementation of other large regulations recently promulgated, e.g., Tier 3 vehicle standards, the Mercury and Air Toxics Standards (MATS) and the Clean Power Plan. The rule was published in the Federal Register on October 26, 2015, and becomes effective on December 28, 2015.

Based on clinical studies and analyses of the effect of ozone exposure, the USEPA concluded a primary ozone NAAQS of 70 ppb is sufficient to protect public health with an adequate margin of safety. Likewise, the USEPA concluded that a secondary ozone NAAQS of 70 ppb is sufficient to protect public welfare, e.g., protection of the forests in Class I areas. The averaging time and form of the standards will remain the same. Compliance is demonstrated when the fourth-highest daily maximum 8-hour ozone concentration per year, averaged over three years, is less than or equal to 70 ppb. The USEPA deemed the 70 ppb standards to be “requisite to protect public health and welfare,” meaning that the level is neither more nor less stringent than necessary.

The implementation timeline for the 2015 ozone NAAQS is as follows:

  • October 2016 – States recommend non-attainment designations to USEPA, based on monitoring data from the previous three-year period (2013-2015).
  • October 2017 – USEPA makes final non-attainment designations based on monitoring data from 2014-2016.
  • 2020-2021 – State Implementation Plans (SIPs) due (date dependent on severity of non-attainment designation).
  • 2020-2037 – States must comply with the standard (date dependent on severity of non-attainment designation).

As presented above, states are required to submit recommended non-attainment designations to USEPA by October 2016, based on monitoring data from the previous three-year period. USEPA plans to issue guidance documents in early 2016 to facilitate the designation process.

Several states in the western U.S. have expressed concern regarding the impact of background ozone concentration on ambient air quality and counties’ abilities to demonstrate compliance with the more stringent ozone standards. The USEPA believes that background ozone will not prevent areas from attaining the 70 ppb ozone standards; however, to address this concern, USEPA plans to update the Exceptional Events Rule, which allows states to exclude “uncontrollable pollution,” such as increased ozone levels due to wildfires. Additionally, the USEPA plans to issue a white paper on background ozone and hold a stakeholder workshop. The USEPA will also work with states to address interstate transport of ozone and ozone precursors, especially in areas affected by high background concentrations of ozone due to long-range transport of ozone from other countries and wildfires.

The final regulation also provides a transition mechanism for PSD permitting projects currently underway via a grandfathering provision. Projects subject to this provision must demonstrate compliance with the 75 ppb ozone NAAQS standards from 2008 but will not be required to demonstrate compliance with the 2015 standards. This will allow these projects to proceed without the significant delay associated with preparation of a new compliance demonstration. In order to qualify for the provision, the facility must have achieved one of the following milestones:

  • The permitting agency formally determined the application to be complete as of October 1, 2015; or
  • The public notice for a draft permit or preliminary determination will have been published prior to December 28, 2015, the date the revised ozone standards become effective.

For 33 states and regions, the USEPA has also increased the length of the ozone monitoring season to address findings that ozone levels can be elevated earlier in the spring and later in the fall than the current monitoring time frame. This extension ranges from the addition of one month for 22 states and the District of Columbia to an additional seven months for Utah. The revised standard also requires that ozone monitors located at multi-pollutant NCore monitoring sites operate year-round. These changes will become effective January 1, 2017.

Additional changes to the NAAQS include updating the Air Quality Index (AQI), streamlining and modernizing the Photochemical Assessment Monitoring Stations (PAMS) network, and updating the Federal Reference Method for ozone to include an additional method for measuring ozone in outdoor air.

Many state agencies will host stakeholder meetings over the next year as they begin to identify potential ozone non-attainment areas. Check your state’s website to follow their activities.

If you have any questions about the 2015 ozone NAAQS and their implications to your facility, please contact either Amy Ritts (; 888-598-6808). More information on the ozone standards is available at

Proposed Revisions to National Ambient Air Quality Standards for Ozone

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On November 25, 2014 the USEPA (EPA) proposed to lower the primary and secondary national ambient air quality standards (NAAQS) for ground-level ozone (the main component of smog).  The proposed revision was published in the Federal Register on December 17, 2014, and comments were accepted through March 17, 2015.  The final rule will be issued by October 1, 2015.

Primary NAAQS establish pollutant concentrations intended to protect public health with an “adequate margin of safety,” as required by the Clean Air Act.  Secondary NAAQS are set to protect the public welfare (such as trees, plants and ecosystems) from “any known or anticipated adverse effects.”  In accordance with the Clean Air Act, the EPA is required to review the NAAQS every 5 years to determine whether the standards remain “requisite to protect public health” (i.e., neither more or less stringent than necessary).  The primary and secondary ozone NAAQS were last set in 2008, when the 75 ppb, 8-hour standard became effective.

The EPA proposed that the current primary ozone NAAQS of 75 ppb is no longer sufficient to protect public health with an adequate margin of safety and should be lowered into the range of 65 to 70 ppb.  The averaging time and form of the standard will remain the same, with compliance demonstrated when the fourth-highest daily maximum 8-hour ozone concentration per year, averaged over 3 years, is less than or equal to the level of the standard.  The EPA accepted comments on setting the standard as low as 60 ppb, as well as retaining the current standard of 75 ppb.  Likewise, the EPA proposed that the current secondary ozone NAAQS is no longer sufficient to protect public welfare and should be revised to between 13 and 17 ppm-hrs, as defined in terms of seasonal index W126, which is equivalent to between 65 to 70 ppb.  The EPA accepted comments on defining the level of protection as low as 7 to 13 ppm-hrs, as well as retaining the existing standard.

Based on the three-year average of monitoring data collected in 2011 through 2013, 358 counties (shown on the map below) would violate the NAAQS if lowered to 70 ppb and 200 additional counties (558 counties, total) would violate the NAAQS if lowered to 65 ppb.  (Please note:  This includes calendar year 2012 data which reflects increased ozone formation due to above-average temperatures and below-average humidity in central and eastern parts of the country.  The final attainment designations will be based on monitoring data from the three-year period of 2014 through 2016, and it is possible that some of the counties that are projected to be in violation of the new standard will actually be in attainment.)


If a county is designated as nonattainment, new major sources or existing major sources planning to make a major modification in that area will become subject to nonattainment new source review (NNSR) considerations for ozone.  There are many challenges associated with NNSR permitting including evaluation and implementation of lowest available emission rate (LAER).  With LAER, the highest level of control is required without regard to cost.  In addition, facilities are required to achieve a net reduction of the nonattainment pollutant emissions by obtaining emission offsets.  Offsets can be expensive due to high demand and limited quantity.  Facilities which have preconstruction permit applications well under the review process will be grandfathered at the time the final standard is issued.

The EPA has also proposed extending the monitoring season in 33 states to address findings that ozone levels can be elevated earlier in the spring and later in the fall than the current monitoring season time frame.  This extension ranges from the addition of one month for some states to requiring year-round monitoring for others.  The proposed effective date for the extended monitoring season is January 1, 2017.

The current timeline for EPA issuing a final regulation either leaving the NAAQS at the current standard or lowering the value, as well as all associated activities, is as follows:

  • October 2015 – EPA finalizes standard
  • October 2016 – States recommend non-attainment designations to EPA
  • October 2017 – EPA makes final non-attainment designations
  • 2020-2021 – State Implementation Plans (SIPs) due (date dependent on severity of non-attainment designation
  • 2020-2037 – States must comply with the standard (date dependent on severity of non-attainment designation)

On March 17, 2015, the U.S. Senate and the House of Representatives introduced bills to block the proposed changes to the ozone NAAQS based largely on economic concerns.  The bills, presented by senators Joe Manchin (D-WV) and John Thune (R-SD) and Representatives Pete Olson (R-TX) and Robert E. Latta (R-OH)  would prevent the EPA from lowering the standard until at least 85% of U.S. counties that are currently not in attainment with the 2008 standard attain the 75 ppb ground-level ozone concentration level.  It is unclear what effect these bills may have, considering the Supreme Court’s 2001 affirmation in Whitman v. American Trucking Associations, Inc. that the Clean Air Act “unambiguously bars cost considerations from the NAAQS setting process.”  However the bills help to focus attention on the importance of economic costs when the EPA and states work to implement new air quality standards.  CEC will follow how the proposed bills will impact EPA’s deadline to finalize the rule as well as any impacts on the final standards set in the final rule.

If you have any questions about the proposed changes to the ground-level ozone NAAQS and their implications to your facility, please contact either Amy Ritts (; 888-598-6808). More information on the proposed standards is available at

Mandatory Greenhouse Gas Reporting – General Provisions

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If you are following the new 40 CFR 98 Mandatory Greenhouse Gas Reporting Rule (GHG Rule) you will know that facilities were to have started collecting reporting data on January 1, 2010.  You may be studying the requirements specific to your facility or industry group, but be sure to also take a careful look at Subpart A – General Provisions.  Subpart A contains provisions that are applicable to all facilities subject to the GHG Rule requirements.  A thorough understanding of Subpart A is a necessary prerequisite to complying with this new regulation.  Key elements include:

  •  Who must report;
  • When you can stop reporting;
  • How and when reports must be submitted;
  • What the annual report must contain;
  • Special provisions that have been made for 2010 reporting;
  • Recordkeeping requirements;
  • Calibration requirements; and
  • Definitions as well as tables of greenhouse gases (GHGs) and their global warming potentials.

The who, how, and when of reporting were addressed in our December 23, 2009 posting, but it is important to note that reporting is required on a facility-specific basis.  A facility, as defined in Subpart A, can be limited to a single stationary piece of equipment that emits a GHG.

The criteria for determining when reporting can cease is a function of whether or not the facility continues to emit GHGs and at what levels.  Continuous annual reporting is required unless:

  • The facility has five consecutive years of emissions below 25,000 metric tons (mt);
  • Three consecutive years of emissions below 15,000 mt; or
  • All GHG-emitting processes and operations subject to the rule cease to operate (although this provision does not apply to MSW landfills).

At least 60 days prior to submitting the first annual report, an electronic certificate of representation must be submitted to EPA.  EPA expects each facility to have only one designated representative who will be responsible for certifying, signing, and submitting GHG reports.  The contents of the annual report will include:

  • Facility name or supplier name and address;
  • The period of time covered by the report;
  • The date of the report;
  • For facilities – annual emissions of GHG as follows:
    • aggregate annual emissions (excluding biogenic CO2) for all GHG from all applicable source categories and expressed as carbon dioxide equivalents (CO2e);
    • aggregate annual emissions of biogenic CO2e;
    • individual GHG totals for each applicable source category; and
    • other data as specified in the respective subparts.
  • For suppliers – annual quantities of GHG that would be emitted from combustion or use of the supplied products during the year, as follows:
    • aggregate annual emissions for all GHG from all applicable supply categories expressed as CO2e;
    • individual GHG totals for each applicable supply category; and
    • other data as specified in the respective subparts.

One special provision for the 2010 report is the allowance for best available monitoring methods.  EPA expects GHG emissions to be estimated according to the specified methods.  However, due to the limited notice provided prior to the effective date, if it was not reasonably feasible to acquire, install, and operate required monitoring equipment by January 1, 2010, then best available monitoring methods may be used until March 31, 2010.  Best available methods may include:

  • Monitoring methods currently used by the facility that do not meet the specification of the relevant subpart;
  • Supplier data;
  • Engineering calculations; and
  • Other company records.

Extensions for continued use of best available monitoring methods beyond April 1, 2010 may be requested, but such requests need to be submitted by January 28, 2010.

Another special provision for the 2010 report applies to facilities where the only sources of CO2e are general stationary fuel combustion.  For such facilities, a simplified report will be accepted.  It would include the aggregate facility-wide GHG emissions and associated process information as well as general facility information and certification.

Records must be maintained for three years in either electronic or hard-copy format.  Specific records that must be retained include:

  • A list of all units, operations, processes, and activities for which GHG emissions were calculated;
  • The data used to calculate GHG emissions including:
    • emission calculations,
    • analytical results for the development of site-specific emission factors,
    • results of all required analyses (e.g., high heat value and carbon content), and
    • any facility operating data or process information used in GHG calculations,
  • Annual GHG reports;
  • Missing data documentation;
  • A written GHG Monitoring Plan;
  • The results of all required certification and quality assurance (QA) tests of continuous monitoring systems, flow meters, and other instrumentation; and
  • Maintenance records for all continuous monitoring systems, flow meters, and other instrumentation.

The written GHG Monitoring Plan needs to identify who is responsible for collecting the data, what processes and methods are used to collect the data, and what procedures and methods are used for quality assurance, maintenance, and repair of all continuous monitoring systems, flow meters, and other relevant instrumentation.

Relative to QA, EPA expects facilities to calibrate their flow meters and other measurement devices prior to April 1, 2010.  Fuel billing meters are exempted from the requirement, but unless a device cannot be removed because of continuous operation, calibration in accordance with manufacturer recommendations is required.  If a postponement in calibration is needed due to continuous operations, it must be documented in the GHG Monitoring Plan.

Other important elements of Subpart A include definitions that are applicable to the remaining subparts as well as Table A-1 that lists all 70 GHGs and their respective assigned global warming potentials.

CEC recommends that facilities develop a thorough GHG Monitoring Plan to document both the applicability determination as well as procedures that will be used to collect the required data, meet the QA requirements, and estimate emissions.  In our next posting we will take an in-depth look at Subpart C – General Stationary Fuel Combustion Sources.

If you have any questions regarding the requirements of Subpart A or other portions of the GHG Rule, please contact one of CEC’s GHG experts, Kris Macoskey. Their contact information can be found on the CEC Experts page.

Mandatory Greenhouse Gas Monitoring for MSW Landfills Begins January 1, 2010

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The U.S. EPA promulgated the Mandatory Greenhouse Gas Reporting Rule (GHG Rule) on October 30, 2009.  Sections applicable to Municipal Solid Waste (MSW) Landfills include various provisions of the general requirements (Subparts A, B and C) as well as Subpart HH which sets forth MSW Landfill compliance obligations.  The Rule becomes effective December 29, 2009 with key provisions of the GHG Rule, including obligations regarding data collection, beginning on January 1, 2010.

In general, the portions of the GHG Rule applicable to MSW landfills appears to have been crafted following the protocol for GHG accounting established by various international organizations including the United Nations Framework Convention on Climate Change (UNFCCC).  Several calculation methodologies and “verification” procedures included in the GHG Rule mimic those established by the UNFCCC and the associated Intergovernmental Panel on Climate Change (IPCC).  As a result, the GHG Rule is not well coordinated with existing Clean Air Act (CAA) standards already applicable to MSW landfills. 

Although a convincing argument can be made that all of the data required by the GHG Rule could easily be gathered under existing CAA regulations within a reasonable degree of accuracy and repeatability and with no additional cost for affected landfill facilities, that approach is not acceptable under the GHG Rule.  In general, most MSW landfills currently fall short of minimum GHG Rule requirements for both landfill gas metering and sampling frequency.  CEC has developed an alternative strategic GHG compliance strategy to reduce the cost of complying with the GHG Rule.

In summary, two specific standards – 98.343(b)(1) and 98.343(b)(2) – are set forth in the GHG Rule for measurement of landfill gas volume and methane content.  For the purposes of this discussion, each standard is referred to by its paragraph designation, namely b(1) and b(2):

  •  Standard b(1) represents the most rigorous and costly compliance option, requiring considerable and costly upgrades in existing flow and methane measurement equipment for most MSW landfill facilities.  For compliance with standard b(1) “spec” metering equipment must conform to 40 CFR §98.344 and includes use of gas chromatographs for methane content determination and differential pressure meters for flow determination (various alternates/options are also available although costs are comparable).  Implementation of this standard would require upgrade of both flow and methane content measurement devices for most MSW Landfill facilities at an estimated cost of approximately $50,000 per facility.
  • Standard b(2) in comparison is less rigorous with respect to equipment specifications and costs, but potentially more labor intensive, requiring weekly monitoring of various gas flow and methane content parameters.  However, at least a portion of existing “non-spec” gas monitoring equipment (flow meters) can be utilized at most facilities.  This will result in lesser initial capital costs for equipment but may result in increased long-term costs (e.g., labor) if weekly manual monitoring is utilized.  However, if b(2) level monitoring is coupled with remote data collection, savings of long-term labor costs will be realized.  Based on the most cost efficient strategy evaluated by CEC under this standard, implementation costs are estimated at $25,000 per facility. 

CEC notes that landfills already equipped with flow and methane monitoring equipment meeting the “b(1)” or §98.344 specifications are obligated to use this equipment for data GHG emission calculations.  Section III.HH of the GHG Rule preamble as well as paragraphs b(1) and b(2) which set forth these requirements are listed as follows:

Preamble Section III.HH.  “We do require landfill gas collection systems already equipped with continuous monitoring systems to determine daily average flow and concentrations and to use these data in their gas recovery calculations.  For collection systems that do not have continuous gas monitors, weekly sampling is required.  Weekly monitoring provides an adequate number of samples to evaluate the variability and uncertainty associated with methane generation.”

§98.343 (b)(1).  “…If you continuously monitor the flow rate, CH4 concentration, temperature, pressure, and moisture content of the landfill gas that is collected and routed to a destruction device (before any treatment equipment) using a monitoring meter specifically for CH4 gas, as specified in § 98.344, you must use this monitoring system and calculate the quantity of CH4 recovered for destruction using Equation HH–4 of this section.  A fully integrated system that directly reports CH4 content requires no other calculation than summing the results of all monitoring periods for a given year.”.”

§98.343 (b)(2).  “If you do not continuously monitor according to paragraph (b)(1) of this section, you must determine the flow rate, CH4 concentration, temperature, pressure, and moisture content of the landfill gas that is collected and routed to a destruction device (before any treatment equipment) at least weekly according to the requirements in paragraphs (b)(2)(i) through (b)(2)(iii) of this section…”

CEC would be pleased to provide a compliance summary for your facility.  Items to be evaluated include:

  • Does your landfill generate more than 25,000 metric tons of CO2e?
  • Are you prepared to collect the required data from your landfill?
  • Have you cataloged all of your stationary sources of combustion?

Please call Ralph Hirshberg at CEC Greenhouse Gas Help Line 1-888-364-2324 or Email your questions to

Greenhouse Gas Mandatory Reporting Rule

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2010 Greenhouse Gas Reporting Required

EPA’s December 7, 2009 announcement that CO2 is a “threat” to public health and the environment has brought additional focus to the ongoing legislative debate regarding climate change and the  final Mandatory Greenhouse Gas Reporting rule (40 CFR 98).  This rule was signed on September 22, 2009, published on October 30, 2009, and is effective December 29, 2009.

The rule covers approximately 85 percent of the nation’s greenhouse gas (GHG) emissions and will apply to roughly 10,000 facilities.  EPA will develop an electronic reporting system for calendar year 2010.  Reports for 2010 are due on March 31, 2011.

This rule requires facilities to calculate CO2 emissions or install monitoring systems where valid emission estimating methods are not currently available.  This rule applies to:

  • Operations that are one of 17 source categories (adipic acid production, aluminum production, ammonia manufacturing, cement production, electricity generation, HCFC-22 production, HFC-23 destruction processes, lime manufacturing, manure management systems, municipal solid waste landfills, nitric acid production, petrochemical production, petroleum refineries, phosphoric acid production, silicon carbide production, soda ash production, titanium dioxide production) unless excluded by specific caveats;
  • Operations in one of seven source categories (ferroalloy production, glass production, hydrogen production, iron and steel production, lead production, pulp and paper manufacturing, zinc production) if the facility emits more than 25,000 metric tons (mt) of carbon dioxide equivalents (CO2e);
  • Facilities with annual CO2e emissions from stationary fuel combustion sources (i.e., boilers, stationary internal combustion engines, process heaters, combustion turbines, and other stationary fuel combustion equipment with certain exclusions) that exceed 25,000 mt; and
  • Suppliers of coal-based liquid fuels, natural gas and natural gas liquids, petroleum products, and industrial GHGs (fluorinated gases, nitrous oxide, and carbon dioxide).

To determine whether your facility is subject to the rule, you may wish to use EPA’s applicability tool.

Reporting of indirect electricity use is not required because the electricity generators will report those emissions.  Portable equipment, emergency generators, emergency equipment, flares, and hazardous waste combustors (except those co-fired with fossil fuel) are exempt.

On January 1, 2010, monitoring or use of best available monitoring methods to calculate CO2e emissions must begin.  EPA expects that most facilities will begin to comply with monitoring requirements by April 1, 2010, although extensions for continued use of best available monitoring beyond that date will be considered.  Requests for extensions need to be submitted no later than January 28, 2010.

EPA’s stated purpose for this reporting is to collect accurate and timely data on GHG emissions data that can be used to inform future policy decisions.  Expectations are that the information will be used to help establish emission baselines which will in turn impact future emission allowances, emission offsets, and carbon trading.  The emissions data reported to EPA will be available to the public allowing for the identification of significant GHG emission sources.

If you are unclear about how this rule affects your facility, please contact one of CEC’s GHG experts:

Kris Macoskey (Pittsburgh), 800-365-2324,

You may also email CEC’s GHG team for additional information at