Frequently Asked Questions
Major Source Vs. Area Source
Step-by-Step Compliance Guide
Victory Energy Perspectives
Step-by- Step Compliance Guide
Ensuring that your boiler meets the U.S. EPA’s final versions of what are commonly referred to as the Major Source Boiler MACT (published on January 31, 2013) and the Area Source Boiler MACT (February 1, 2013) is critically important. Final compliance for the Major Source Boiler MACT is January 31, 2016 – which ends the three-year grace period from the date final rules were published. The grace period for existing sources was far shorter with compliance being required by March 21, 2014.
Step One: Determine Boiler MACT Applicability – Area Source or Major Source
The determining factors are predicated on the facility’s (not the individual boiler’s) aggregate potential emission rate or hazardous air pollutants (HAPs). While many operators have extensive working knowledge with carbon monoxide (CO), sulfur dioxide (SO2) and nitrogen oxide (NOx), not as many have working knowledge of HAPs. HAPs are a specific set of 187 pollutants that include compounds such as benzene, formaldehyde and certain metals such as chromium. With very few exceptions, a facility’s potential emissions are estimated assuming each emission source operates 24 hours a day, 365 days a year. Those facilities that emit or have the potential to emit at least 10 tons per year of a single HAP, or at least 25 tons per year of a combination of HAPs, are categorized as “major source” within the Major Source Boiler MACT regulations. Otherwise, a facility is deemed to be “area source” and subject to the Area Source Boiler MACT requirements.
Step Two: Defining the Subcategory Allocation
• Fuel Combusted (The type of fuel being burned on an annual basis is the primary factor
used in establishing the applicable subcategory for a boiler.)
• New or existing classification
• Size of the unit (large or small)
• Unit design type (stoker, fluidized bed, etc.)
Step Three: Meeting Initial Requirement Documents
By this time, Initial Notification of Applicability should have been submitted. The due dates were May 31, 2013 for Major Source and January 20, 2014 for Area Source. An initial Notification of Compliance status report must be submitted within 60 days following the completion of all initial compliance demonstrations (tune-ups, energy assessments, and performance tests, where applicable).
Key Notification of Compliance Dates:
• Major Source Boiler MACT – latest date is September 27, 2016
• Area Source Boiler MACT – by July 19, 2014
Step Four: Conduct Initial Tune-Ups and Energy Assessments
• Initial Tune-Ups
Initial tune-ups need to be conducted by the applicable compliance dates for both Major Source (1/31/16) and Area Source (3/21/2014). For new sources (Major Source) the initial tune-up must be completed within the first 13, 25 or 61 months after start-up with (Area Source) being completed within the first 25 or 61 months.
• Energy Assessments
All existing Major Source Boiler MACT units are required to conduct the one-time energy assessment. (New sources are not required to perform the one-time energy assessment.)
Under Area Source Boiler MACT, only existing large units are required to conduct the energy assessment. (Existing small sources and new sources are not required to perform the one-time energy assessment.)
It is strongly recommended and encouraged that a qualified energy assessor performs the energy assessment.
• What are the key elements to look for in a comprehensive energy assessment for both Major Source and Area Source Boiler MACT?
A comprehensive energy assessment is comprised of the following steps that are applicable to both Major and Area Source units.
1. A visual inspection of the boiler or process heater system (e.g., cracks, corrosion, leaks).
2. An evaluation of operating characteristics of the boiler or process heater system,
specifications of energy using systems, operating and maintenance procedures, and
unusual operating constraints.
3. Inventory of major systems consuming energy from affected boiler(s) and
4. A review of available architectural and engineering plans, facility operation and
maintenance procedures and logs, and fuel usage.
5. A review of the facility’s energy management practices with recommendations
6. A list of cost-effective energy conservation measures.
7. A list of the energy savings potential of the energy conservation
8. A comprehensive report detailing the ways to improve efficiency, the cost of specific
improvements, benefits, and the time frame for recouping those investments.
Step Five: Conduct Thorough Performance Tests
For units that are subject to emission limits, compliance must be adhered through conducting performance stack tests. Existing units must have performance tests conducted and in place within 180 days of the compliance date.
Step Six: Compliance Determination
Determine if you are within the data compliance requirements for either Major Source or Area Source based on the work and assessments performed in the above-mentioned steps.
Step Seven: Emissions Limits Cannot Be Met ─ What Options Are Available (Overall Applicability to both Area Source and Major Source)?
There are a number of alternatives and compliance options to consider if your boiler can’t meet Boiler MACT emission limits based on current design and operational limitations. All should be thoroughly evaluated and fully vetted before investing in air pollution control upgrades or new installations.
♦ Replace your older boiler with a more efficient one. Newer boilers are designed to meet
any and all stringent emission limits being set by Boiler MACT.
♦ Modify your boiler to change the subcategory that has more achievable or nonexistent
emission limits (converting a boiler that fires one or more solid or liquid fuels to a natural
♦ Change the way a multi-fuel boiler is operated so that it meets a more favorable
subcategory designation. (A boiler that burns primarily coal and some biomass could
change its fuel mix such that it burns enough biomass on an annual heat input basis to
meet the definition of a biomass boiler.)
• Specific Major Source Boiler MACT Compliance Options:
The primary format of the emission limits in the rule is on a heat input basis. One of the main compliance alternatives available under the rule is using emission limits expressed in different units of measure or using surrogate pollutants in lieu of a primary Boiler MACT pollutant. For example, if you are not able to comply with the heat input-based limits, the rule provides emission limits expressed on an output (steam output or megawatt-hour) basis as on option. If you select this option, you can take credit for implementing energy conservation measures during your energy assessment. The rule also allows the use of emission limits
for total selected metals (TSM) in lieu of complying with the limit for filterable particulate
A continuous emissions monitoring system (CEMS) can be used as an alternative to the stack testing-based limit for CO. Under this option, a facility can install a CO CEMS and, in most cases, take advantage of a longer averaging time (albeit a potentially lower limit) to account for variability in its CO emissions profile. Similarly, a facility can install an SO2 CEMS to demonstrate compliance with the hydrogen chloride (HCl) limit.
• Emissions Averaging
Under Major Source Boiler MACT, if you have more than one existing boiler in any subcategory at your facility, you may demonstrate compliance by emissions averaging if your averaged emissions are not more than 90% of the applicable emission limit. This option is available for PM (or TSM), HCl, and mercury (Hg). You may not include new boilers in an emissions average. The ground rules regarding the emissions averaging provisions are tied to the subcategories of the boilers and the exhaust and control device configuration. Facilities using this option must develop an implementation plan for emission averaging. The plan does not need to be submitted unless it is requested. However, you must keep a copy of the plan as a record.
Step Eight: Staying Within Compliance – Meeting Ongoing Boiler MACT Requirements
There are several ongoing requirements that are key vital elements of Boiler MACT (both Major Source and Area Source) and must be adhered to in order to remain within compliance. The following provides what is required with compliance methodologies that are in place or were put in place.
• Air Pollution Control Devices
For boilers equipped with air pollution control devices, a facility establishes operating limits for air pollution control devices during a performance test. Following the performance test, a facility must demonstrate continuous compliance with the emissions and operating limits by continuously monitoring operating parameters according to the methods specified in the rule. The operating parameters vary by the type of control device used.
♦ Wet scrubber pressure drop, liquid flow rate, and pH
♦ Activated carbon injection rate of a dry scrubber
♦ Total secondary electric power input for an ESP
♦ A bag leak detection system for fabric filters
The concepts presented above for the air pollution control device monitoring systems are analogous to facilities that will use CEMS to directly measure emissions from their affected boilers. Data will be obtained and the necessary rolling average will be collected to demonstrate that the emissions are less than the applicable emission limits. Major Source Boiler MACT facilities are likely to be more accustomed to CEMS than Area Sources since these facilities may already have CEMS in place due to other regulations.
• Monitoring of Operating Parameters and Associated Records
In addition to emissions or parametric monitoring, facilities will be required to continuously monitor the operating load (heat input or steam output), and to calculate a 30-day rolling average. The operating load must be maintained at or below 110% of the operating load established during the performance test.
Facilities must keep records of the type and amount of all fuels burned in each boiler to demonstrate that all fuel types and mixtures of fuels burned would result in either lower emissions of HCl, Hg, and TSM than the applicable emission limit for each pollutant if you demonstrate compliance through fuel analysis, or lower fuel input of chlorine, Hg, and TSM than the maximum values calculated during the last performance test if you demonstrate compliance through fuel analysis. When using the fuel analysis compliance option, facilities must collect and analyze monthly fuel samples, calculate 12-month rolling averages, and maintain the 12-month rolling averages at or below the applicable emission limit. Monthly fuel use records (type and amount) must be maintained. This data would be used to demonstrate that the fuel input levels are less than the values during the most recent performance test.
• Repeat Tune-Ups ─ Facilities must perform ongoing tune-ups as part of the compliance requirements.
Under Major Source Boiler MACT, boilers are subject to tune-up requirements either annually, biennially, or every five years.
♦ Each annual tune-up must be performed no more than 13 months after the
♦ Each biennial tune-up must be performed no more than 25 months after the
♦ Each 5-year tune-up must be performed no more than 61 months after the
Facilities do not need to submit reports regarding the tune-ups; however, records must
Under Area Source Boiler MACT, boilers are subject to tune-up requirements either biennially or every 5 years.
♦ Each biennial turn-up must be performed no more than 25 months after the
♦ Each 5-year tune-up must be performed no more than 61 months after the
Under Major Source Boiler MACT, facilities subject to emission limits must submit semiannual Compliance Certification Reports. For units subject only to a requirement to conduct an annual, biennial, or 5-year tune-up and are not subject to emission limits or operating limits, a facility may submit only an annual, biennial, or 5-year compliance report instead of a semi-annual compliance report.
Under Area Source Boiler MACT, by March 1st of each year facilities must prepare, and submit upon request, annual compliance reports from the previous calendar year. The report must be submitted by March 15th if the source experienced deviations from applicable requirements. Sources subject only to a requirement to conduct a biennial or 5-year tune-up, and not subject to emission limits or operating limits, may prepare only a biennial or 5-year compliance report.
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