Tuesday, July 27, 2021

EPA's cordwood test protocol for wood stoves moves forward

 AGH wrote to the EPA in June and again in early July, requesting public information about the stove testing that it is undertaking.  We had seen numerous references about the stove testing but could not find more details about it.  Rather than submitting a Freedom of Information request, which would likely provide a jumble of emails and miscellaneous documents, we urged the EPA to provide an overview.  Details about the EPA’s stove testing program are well known by HPBA insiders, and by staff at NESCAUM and NSERDA, yet we have consistently found that the EPA, nor those organizations, share information very well. This blog may be updated soon with rejoinders from experts who take issue with the EPA's narrative.  

This letter from the EPA partially explains how and why the EPA approved an IDC (ALT-140) test method without a full certification test report using that method.  NYSERDA and NESCAUM still have not produced certification level test data for their IDC method "although we [the EPA] understand that Alaska will be providing us with additional data demonstrating use of the ALT-140 for compliance testing."  

In the past 10 years, the EPA has rarely had any budget for lab testing, so its current budget of one million is significant.  AGH believes that its imperative for the EPA to develop its own data and not just rely either on industry or groups like NESCAUM and NYSERDA.  We reproduce below the email verbatim from Stef Johnson, leader of the EPA's Measurement Technology Group.  The photos were added by us.

July 20, 2021

Dear Mr. Ackerly: 

 

Thank you for the questions you forwarded in your July 9, 2021 email.  I appreciate the thoughtfulness of you questions and the opportunity to engage with you on this important topic.  In particular, I’d like to clarify the steps in EPA’s processes for: 


·         New Test Method Development and

·         Alternate Test Methods (ATM) 

 

New Test Method Development 

 

In the method development process, EPA creates new measurement methods for regulatory purposes.  In the case of EPA developing new test methods for wood heaters, EPA has embarked on a public process that engages stakeholders as we develop a new measurement method for this sector.  EPA’s Measurement Technology Group, the group I lead, began the process by convening a Roundtable consisting of manufacturers, Hearth Patio & Barbeque Association (HPBA) staff, state and local regulators, test lab technical staff, and multijurisdictional organization (MJO) representatives.  The Roundtable participants gathered to discuss the use and vetting of the Integrated Duty Cycle (IDC) method for certification of wood fired stoves and consider making that testing approach an EPA test method.   

 

After the January 2020 meeting where we discussed the IDC approach and the ASTM E3053 test approach, the agency determined that we would pursue development of the IDC as an EPA method.  We have been working in that direction ever since.  The process to conduct method precision testing of an IDC for wood heaters, one for hydronic heaters, one for forced-air furnaces, and one for pellet heaters is resource intensive and complex.   

 

EPA remains committed to transparency and open dialogue as we explore and develop new methods for compliance testing of wood heating appliances.  We have provided the Roundtable group information about our Quality Assurance Project Plan (QAPP), the IDC method for wood heaters -- the current subject of our trials, and the Tapered Element Oscillating Microbalance (TEOM) Standard Operating Procedures.  We have also shared supporting spreadsheets for using these methodologies.  We have posted this and other information in a public docket (EPA-HQ-OAR-2016-0130) and we have begun using this posted IDC, along with TEOM measurements in our contracted laboratory.     

 

The EPA is paying for 26 tests at PFS-
TECO testing in Portland, OR.

We are conducting 52 tests (26 paired tests) at a West Coast lab (PFS-TECO) and will be comparing those data to a duplicate effort that will be funded by NYSERDA and conducted at ClearStak laboratories in Connecticut.  Within each lab, we are doing paired testing to look at intra-laboratory variability -- known as repeatability testing.  We will be comparing the inter-lab variability (method reproducibility) between these bi-coastal sets of 26 test pairs.  This helps us understand the test method performance with respect to overall variability and informs our decisions as to the appropriateness of the test method for use with a given emissions standard.  EPA has committed nearly $1,000,000 to the West Coast portion of wood heater test method work, and to a study of TEOM precision to be done at EPA’s facility in Research Triangle Park, NC.  This type of data has never been collected for any wood burning appliance test method to date.   

 

All data we develop from our trials will be publicly available and placed into the same docket as the QAPP and IDC /TEOM methodologies.  We will convene the Roundtable after the wood heater precision testing is complete and we have data to discuss.  Certainly, there will be lessons learned along the way and improvements made.  As you may know, NYSERDA is also conducting wood heater precision testing, and we expect that they will make their data public.  East Coast testing will likely begin in mid-September.  We anticipate that a full data set will be available for discussion by in early 2022.  Again, this is for the development of a wood heater IDC compliance test method.  Finally, we will propose, take public comment, and finalize a new compliance test method.  All of this will be a public process, and all of the data will be available for review.   

NYSERDA is paying for 26 tests of
the same stoves at ClearStak in
Connecticut.  ClearStak offers
transparency in testing by video taping 
the tests but it is not known if these 
tests will be videotaped or if the tapes
will be released to the public.

 

Alternative Test Methods 

 

The Alternate Test Method (ATM) approval process is different than compliance test method development.   In the ATM process, the requestor is responsible for providing sufficient information to the agency to demonstrate that the proposed Alternate Test Method is appropriate for compliance testing purposes.   Requesting an ATM is an option available to any affected party. The proposed ATM must be deemed by the Measurement Technology Group to be appropriate with the final air pollution standard.  The entity requesting the ATM must demonstrate compliance with a Federal subpart regulated by 40 CFR Part 60, such as subparts AAA or QQQQ regulating wood burning residential heating appliances. 

 

EPA’s Measurement Technology Group receives requests for alternate means of compliance testing from affected source categories, from electric utilities to wood heater manufacturers and everything in between.  We are responsible for reviewing each request and make a technical determination about the appropriateness.  We either work in a direct back/forth manner with the requestor or we agree to the request with some stipulations. (You will note we listed several in our 2021 ALT-140 approval letter).  

 

In sum, the ATM approval process is a technical exchange with a requestor followed by a technical evaluation by my staff.  The goal is to approve compliance testing that meets a specific need and is appropriate for the compliance purpose as outlined in the rule.  While such evaluations may involve exchange of data between the requestor and EPA, each request is evaluated and assessed on a case-by-case basis.  

 

In situations where there is not any test method available, for example, EPA will evaluate the request differently than in situations where we have already approved an ATM.  With regard to ALT-140, we have had the opportunity to learn about the IDC development process through multi-party meetings from 2017 to 2020.  The information shared during this time about the IDC illustrated that this method provides a more rigorous test assessment of heater performance and therefore, provides a more conservative compliance demonstration approach.  Such conservative approaches (more difficult to pass the test) are nearly ideal for Alternate Test Method processes because one of our goals with the ATM process is to not relax the standard in any manner.   

 

That said, when EPA received Alaska’s request to approve an alternative test method for demonstrating compliance with the New Source Performance Standard Subpart AAA, Standards for New Residential Wood Heaters in December 2020, we were not aware of data that demonstrated that a wood heater could meet the emissions limit of the rule using the IDC.  Therefore, we asked Alaska to provide us with that information.  While what they provided to EPA is not an entire test report, it is credible enough for us to allow the use of the test method for compliance demonstration, where a compliance test must fully document all of the test method QA/QC details to satisfy EPA’s Office of Enforcement and Compliance Assurance (OECA)’s requirements.   

 

Finally, using an ATM itself is optional and my staff ensures that all alternative methods are equivalent or more stringent than the test method in the EPA regulation.  No one need ask to use one unless they decide that it is in their interest to do so.   In the case of the Alaska request, EPA’s approval of ALT-140 provides a cord wood compliance pathway for manufacturers wishing to sell in the Fairbanks-North Star area.  They are also free to conduct crib fuel tests and sell crib fuel tested units in that area.   

 

Finally, EPA has received 5 spreadsheets from NYSERDA/NESCAUM in support the Alaska ALT-140 request and they are available upon request.  To date, EPA has not received any other NYSERDA/NESCAUM test data used for their IDC method development purposes, although we understand that Alaska will be providing us with additional data demonstrating use of the ALT-140 for compliance testing.  

 

I hope this has been helpful for your understanding.   

 

Very sincerely, 

 

Steffan Johnson

Leader - Measurement Technology Group

US Environmental Protection Agency (EPA)



Related stories

Nine states urge the EPA to revoke the ASTM cordwood method (May 2021)

EPA announces overhaul of wood stove certification process (April 2021)

AGH response to NESCAUM report on wood stoves (March 2021)

EPA and states vigorously defend audits of wood stoves (Sept. 2020)

EPA finds lapses in cordwood certification testing (July 2019)



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