See the latest EHS federal and state regulatory updates due to COVID-19

For existing sources, the compliance deadline for the National Emission Standards for Hazardous Air Pollutants (NESHAP) for industrial, commercial, and institutional boilers and process heaters at major sources (40 CFR 63, Subpart DDDDD; the “Boiler MACT”) of January 31, 2016 is still months away, while new sources impacted by the rule must comply upon startup. For existing sources, most of the focus thus far has been on determining how to meet the emission limitations via capital improvements and scheduling necessary upgrade work and testing for compliance purposes. These facilities should consider important lessons learned from new sources that have met the testing, monitoring, reporting and recordkeeping requirements already. Specifically, it is important to anticipate the level of effort, detail, and challenges associated with the initial performance testing and subsequent notice of compliance status (NOCS) submittals.

The Boiler MACT requires sources to complete both initial and continuous (ongoing) compliance demonstrations. Most solid and liquid fuel boilers as well as some gas fired boilers are subject to specific emission limits under the rule which require performance stack testing, fuel analysis and/or a continuous monitoring system (CMS) for compliance.

Initial Performance Testing – How Bad Could it Be?

Most sources will choose to demonstrate compliance with Boiler MACT using performance testing for at least one pollutant. For a single fuel boiler, initial performance testing (IPT) under Boiler MACT is complex; for multifuel boilers, it may seem next to impossible to determine the necessary performance testing requirements while also allowing for optimization of factors such as operating capacity, fuel types, and power or raw material usages for control devices.

The Boiler MACT requires boilers that demonstrate compliance via performance testing to do the following:

  • Conduct IPT according to specified requirements
  • Conduct fuel analyses (with some exceptions)
  • Establish operating limits
  • Conduct CMS performance evaluations

One benefit of a single fuel boiler is that fuel analyses are not required if conducting an IPT; however, they could be used for a source that decides to comply via fuel analysis rather than through performance testing. Excluding fuel analyses, an owner/operator must only complete performance testing related to the following pollutants and compliance options:

  • Filterable particulate matter (PM) or Total Selected Metals (TSM)1
  • Hydrogen Chloride (HCl)
  • Mercury (Hg)
  • Carbon Monoxide (CO)

Depending on your compliance strategy, initial performance testing may simply involve traditional reference test methods, establishment of operating limits, and evaluation of any CMS. As an example, Table 1 summarizes the number of tests required and run times for a single fuel fluidized bed biomass boiler choosing stack testing for all pollutant demonstrations. Note the complexity (and expense) involved even for a single fuel boiler to demonstrate initial compliance. For each pollutant relying on performance testing for compliance, a source must establish an operating load limit based on the operating load during the performance test in addition to parametric monitoring ranges applicable to the control devices operated. For boilers complying with the CO emission limit using performance testing, an oxygen analyzer or continuous oxygen trim system must be operated at or above the oxygen level established during your performance test.

EQ Summer 2014 Boiler MACT Table 1

Now, consider the challenges multiplied with a multi-fuel boiler. Boiler MACT requires that performance tests be conducted while combusting the type of fuel or mixture of fuels that has the highest content of chlorine and mercury (and TSM for sources opting to comply with TSM alternative). So, one must first establish what that scenario may be – and the complexity involved grows exponentially the more fuels the boiler is capable of combusting. This evaluation can be further complicated by ensuring the unit is operating at maximum capacity during the performance tests.

EQ Summer 2014 Boiler MACT Box 1For multi-fuel boilers, even if performance testing indicates compliance, fuel analyses and development of a site-specific fuel analysis plan are typically still required. In addition to establishing operating limits and parametric monitoring conditions during the performance test, after the IPT multi-fuel boilers face the challenge of ensuring that the fuel input of chlorine, mercury, and TSM does not exceed the maximum input value calculated from the IPT. Thus, the design of the performance test directly impacts the flexibility in fuels that may be fired in the boiler. To maximize this flexibility, one must carefully design the performance tests and consider conducting multiple performance tests for each pollutant. It is possible to have a situation for a multi-fuel boiler where the fuel with the highest mercury, chlorine, or TSM content cannot or would not normally be fired in a manner that allows the boiler to operate at its highest operating load condition. In this case, one must carefully balance achieving both highest operating load and highest maximum pollutant input during the performance test.

Fuel Analyses – An Option Worth Considering?

One possible way to avoid the difficulties related to performance testing is to demonstrate compliance with HCl, mercury, and/or TSM emissions limits using fuel analyses. Under this compliance option, an owner/operator demonstrates that the pre-control emission rate of the boiler is less than the Boiler MACT emission limit. If the potential emission rate of the fuel or fuel mixture exceeds the applicable Boiler MACT emission limit, then this is not an option. For some sources, this may provide a less expensive compliance option than stack testing for each pollutant.

Under this option, a site-specific fuel analysis plan is required. On a monthly basis, three composite samples of each fuel type fired are needed. The maximum pollutant input level for the pollutant of concern is then calculated while considering the fraction of the total heat input from each fuel type. One must maintain the 12-month rolling average pollutant input at or below the applicable emission limit. For an individual fuel type, the sampling frequency may be reduced to quarterly if results are less than 75% of the applicable limit for 12 consecutive months.

How About a CEMS?

EQ Summer 2014 Boiler MACT Box 2Another option to avoid the complexities of performance testing and/or fuel analysis is a continuous emissions monitoring system (CEMS). Boiler MACT allows the use of CO, mercury, and HCl CEMS as a compliance alternative, however this can be an expensive solution. It is important to note that the CO limit applicable to the source differs depending on whether demonstrating compliance using performance testing or a CEMS.

Reporting – The Worst is Over….Isn’t It?

Having survived the performance testing, one might hope that the reporting should be relatively simple. Unfortunately, this may not be the case. Most importantly, do not procrastinate as waiting until the day before the deadline to start working on report submittals may cause missed deadlines.

First, performance testing and CEMS performance evaluation reports should be submitted to the state agency and electronically via EPA’s Central Data Exchange (CDX) – Compliance and Emissions Data Reporting Interface (CEDRI). CDX – CEDRI requires a substantial amount of manual data entry, so it is important to request that stack testing vendors include data entry as part of their services. While CDX- CEDRI does allow the user to save PDF versions of the test reports, when viewed in the system the reports may look incomplete or appear to have inaccurate data in some instances. Note that not all state agencies are accepting the submittals via CDX – CEDRI, so hard copy submittals may be necessary.

Next, the notification of compliance status (NOCS) must include the following:

  • General boiler specifications
  • Relevant emission limits
  • Methods used to demonstrate compliance
  • Testing/compliance demonstration results
  • Established operating limits
  • Certification of compliance status with emission limits, operating limits, and work practices

For both boilers that are subject to emission limits and boilers that are only required to conduct a tune-up, compliance reports must be submitted in CDX-CEDRI. Again, significant data entry is required, and a paper compliance report with this information is often required by the state agency as well. Boilers that must conduct a tune-up, but which are not subject to emission limits or operating requirements, must submit a compliance report after each compliance period during which a tune-up was conducted. Boilers that are subject to emission limits must submit semiannual compliance reports in CDX-CEDRI.

Nearing the home stretch, it is important to have the responsible official approved to certify within CDX-CEDRI well in advance of the deadline for report submittal. It is a multi-step and complex process to receive that approval, and one that may require some guidance to your certifying official to streamline the process.

EQ Summer 2014 Boiler MACT Table 2

If You Can’t Avoid It…Plan Accordingly

The complexity of the Boiler MACT and its compliance requirements calls for significant planning and allowing sufficient time in your compliance schedule to accommodate the challenges associated with the initial performance testing and subsequent reporting. Identify early on the following key elements:

  • A plan to demonstrate initial and continuous compliance for each pollutant
  • When the stack test should be conducted
  • What monitoring systems at the facility are CMS that will be used to demonstrate compliance with Boiler MACT
  • Who will complete the electronic reports (possibly ask stack testing company to include as part of their testing scope)
  • How to track ongoing compliance with limits
  • Who will electronically certify and submit compliance report (responsible official must be approved in CDX-CEDRI early)

Planning early will save you sleepless nights in the effort to meet the applicable compliance timeframes. For assistance in developing a compliance calendar and strategies for handling the myriad of details associated with Boiler MACT, or for other related questions, please call your local Trinity office or (800) 229-6655.

EQ Summer 2015 Boiler MACT Training Box


1 TSM is defined in the Boiler MACT to be the sum of arsenic, beryllium, cadmium, chromium, lead, manganese, nickel, and selenium.