Document ID: EPA-HQ-OAR-2002-0049-0077
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2022-05-16T04:00Z

From: 
D'Angelo, Wayne J. <WDAngelo@KelleyDrye.com>
Sent:
Jones, DonnaLee <Jones.Donnalee@epa.gov>
To: 
Tuesday, April 27, 2021 5:26 PM
Cc:
Stuart, Eric <stuart@steelnet.org>; Green, Joseph J. <JGreen@KelleyDrye.com>
Subject: 
RE: expanded list of false alarms - One more thing

No problem at all.  It's your job to ask questions and it's my job to answer them as best I can.
Best,
Wayne
 
 
WAYNE D'ANGELO

Kelley Drye & Warren LLP
Tel: (202) 342-8525
Cell: (202) 329-3977

 
From: Jones, DonnaLee <Jones.Donnalee@epa.gov> 
Sent: Tuesday, April 27, 2021 4:46 PM
To: D'Angelo, Wayne J. <WDAngelo@KelleyDrye.com>
Cc: Stuart, Eric <stuart@steelnet.org>; Green, Joseph J. <JGreen@KelleyDrye.com>
Subject: RE: expanded list of false alarms - One more thing
 
Thanks again. Hopefully, this will be the end of my questions for a while. You have been very tolerant. I appreciate it. 
 
Regards,
Donna Lee Jones, Ph.D.
Senior Technical Advisor, Metals Sector
U. S. Environmental Protection Agency
Office of Air Quality Planning and Standards
Sector Policies and Programs Division / Metals & Inorganic Chemicals Group (D243-02)
Research Triangle Park, NC  27711  Tele:  (919)  541-5251  Fax  (919)  541-3207
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
"Reasonableness never fails to be appreciated."  - anon.
 
Pronouns - She/Her/Hers
Salutation - Dr./Ms.
 
From: D'Angelo, Wayne J. <WDAngelo@KelleyDrye.com> 
Sent: Tuesday, April 27, 2021 4:27 PM
To: Jones, DonnaLee <Jones.Donnalee@epa.gov>
Cc: Stuart, Eric <stuart@steelnet.org>; Green, Joseph J. <JGreen@KelleyDrye.com>
Subject: RE: expanded list of false alarms - One more thing
 
Dr. Jones,  I cannot speak to the frequency of false and positive alarms but I will ask around to see if I can give you some reasonable estimates.
Best,
Wayne
 
 
WAYNE D'ANGELO

Kelley Drye & Warren LLP
Tel: (202) 342-8525
Cell: (202) 329-3977
 
From: Jones, DonnaLee <Jones.Donnalee@epa.gov> 
Sent: Tuesday, April 27, 2021 4:07 PM
To: D'Angelo, Wayne J. <WDAngelo@KelleyDrye.com>
Cc: Stuart, Eric <stuart@steelnet.org>; Green, Joseph J. <JGreen@KelleyDrye.com>
Subject: RE: expanded list of false alarms - One more thing
 
I forgot to ask how often, on a broad-scale average, do facilities have to chase down a false alarm? If its possible, include also the number, on average, of real alarms related to leaks? You can estimate on whatever time basis that makes sense, i.e., weekly, monthly, yearly. From this we also will see the % of alarms that are false. 
 
Regards,
Donna Lee Jones, Ph.D.
Senior Technical Advisor, Metals Sector
U. S. Environmental Protection Agency
Office of Air Quality Planning and Standards
Sector Policies and Programs Division / Metals & Inorganic Chemicals Group (D243-02)
Research Triangle Park, NC  27711  Tele:  (919)  541-5251  Fax  (919)  541-3207
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
"Reasonableness never fails to be appreciated."  - anon.
 
Pronouns - She/Her/Hers
Salutation - Dr./Ms.
 
From: Jones, DonnaLee 
Sent: Tuesday, April 27, 2021 3:51 PM
To: D'Angelo, Wayne J. <WDAngelo@KelleyDrye.com>
Cc: Stuart, Eric <stuart@steelnet.org>; Green, Joseph J. <JGreen@KelleyDrye.com>
Subject: RE: expanded list of false alarms
 
This additional information also is helpful. I will circle back with you when I develop a draft list, possibly after discussion with my team.
 
Regards,
Donna Lee Jones, Ph.D.
Senior Technical Advisor, Metals Sector
U. S. Environmental Protection Agency
Office of Air Quality Planning and Standards
Sector Policies and Programs Division / Metals & Inorganic Chemicals Group (D243-02)
Research Triangle Park, NC  27711  Tele:  (919)  541-5251  Fax  (919)  541-3207
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
"Reasonableness never fails to be appreciated."  - anon.
 
Pronouns - She/Her/Hers
Salutation - Dr./Ms.
 
From: D'Angelo, Wayne J. <WDAngelo@KelleyDrye.com> 
Sent: Tuesday, April 27, 2021 3:38 PM
To: Jones, DonnaLee <Jones.Donnalee@epa.gov>
Cc: Stuart, Eric <stuart@steelnet.org>; Green, Joseph J. <JGreen@KelleyDrye.com>
Subject: RE: expanded list of false alarms
 
I really can't estimate the percentage of false/nuisance alarms this would cover, but these are likely only a subset of the false/nuisance alarms facilities encounter.  We limited our list to those types of instances where the operator could directly correlate an BLDS alarm to a condition other than a broken, leaking, or dislodged bag.  A significant number of BLDS alarms are only triggered momentarily and for reasons that may not be ascertainable.  For instance, a larger chunk of caked up or accumulated dust can break off at any point in the normal course of operating the baghouse and trigger a BLDS alarm.  It may be impossible to definitively determine that a dislodged dust accumulation caused the brief alarm, but the operator could still use a visual emissions observation and BLDS readout data to determine that there is no broken, leaking, or dislodged bag.   Indeed, for the overall class of short-lived nuisance alarms that cannot be correlated to any of the potential causes/conditions I described in my prior email, I suspect the primary means by which facilities would determine that a momentary alarm was not caused by a broken, leaking, or dislodged bag is to conduct a visual observation/inspection and confirm through readout data that particulate loading levels are normal.
 
To your question about whether facilities can live with an explicit list, I am not sure I understand how the list will be used.  Am I correct that the "list" is referring to various ways a facility can use "operator's knowledge or other acceptable means" to determine that a BLDS alarm was not caused by a broken, leaking, or deislodged bag?   If so, I would say the list should broadl include: (1) alarm-triggering actions/event/conditions that can be correlated to the BLDS alarm and which do not involve broken, leaking, or dislodged bags (this broadly emompasses everything in my previous email); (2) VE observations; (3) BLDS readout data that shows the alarm was short-lived and particulate loads normalized; (4) physcial observations and maintenance inspections.
Please let me know if I've not answered your question or if this doesn't make sense.  I'm also happy to discuss.
Best,
Wayne
WAYNE D'ANGELO

Kelley Drye & Warren LLP
Tel: (202) 342-8525
Cell: (202) 329-3977
 
From: Jones, DonnaLee <Jones.Donnalee@epa.gov> 
Sent: Tuesday, April 27, 2021 2:06 PM
To: D'Angelo, Wayne J. <WDAngelo@KelleyDrye.com>
Cc: Stuart, Eric <stuart@steelnet.org>; Green, Joseph J. <JGreen@KelleyDrye.com>
Subject: RE: expanded list of false alarms
 
Thank you. Fantastic descriptions. So if we add these instances to the rule, will this cover 99.9% of the reasons for false alarms, along with items already listed in that section of the rule? In other words, could the facilities live with this explicit list (added to what's already in the rule)?
 
Regards,
Donna Lee Jones, Ph.D.
Senior Technical Advisor, Metals Sector
U. S. Environmental Protection Agency
Office of Air Quality Planning and Standards
Sector Policies and Programs Division / Metals & Inorganic Chemicals Group (D243-02)
Research Triangle Park, NC  27711  Tele:  (919)  541-5251  Fax  (919)  541-3207
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
"Reasonableness never fails to be appreciated."  - anon.
 
Pronouns - She/Her/Hers
Salutation - Dr./Ms.
 
From: D'Angelo, Wayne J. <WDAngelo@KelleyDrye.com> 
Sent: Tuesday, April 27, 2021 1:23 PM
To: Jones, DonnaLee <Jones.Donnalee@epa.gov>
Cc: Stuart, Eric <stuart@steelnet.org>; Green, Joseph J. <JGreen@KelleyDrye.com>
Subject: RE: expanded list of false alarms
 

Hello Dr. Jones.  I connected with a few environmental managers in the EAF steel industry in order to compile a more extensive list of reasons a BLDS can alarm intermittently and/or when there is no excess emissions or system malfunctions.   Below are a few examples and my best attempt to categorize them:
 
1.            Weather  -  As noted in our prior response, BLDS alarms will occasionally trigger during a heavy downpour or when there are significant changes in temperature or humidity.  Operators can confirm these alarms were not caused by broken bags or bag leaks by correlating the alarm to any significant weather conditions/changes at the time, through visual opacity observations, and through review of the BLDS readout to confirm a return to normal particulate loading following the triggering weather condition.
 
2.            Bag Cleaning Cycle  -  As noted in our prior response and in EPA's BLDS guidance, a BLDS may briefly alarm when the system comes out of a cleaning cycle.  Most often, this is due to the temporary absence of dust in the bags, which acts as an additional filter medium.  Operators can confirm these alarms were not caused by broken bags or bag leaks through visual opacity observations and through review of the BLDS readout to confirm a return to normal particulate loading as the bags re-accumulate dust.
 
3.            New Bag Start  -  Similar to #2 above, BLDS alarms can be triggered immediately following a replacement of some or all of the bags in the baghouse.  These alarms typically cease shortly after the restart as the new bags accumulate dust that acts as an additional filer medium. Operators can confirm these alarms were not caused by broken bags or bag leaks by correlating the alarm to the new bags, conducting visual opacity observations, and reviewing the BLDS readout to confirm a return to normal particulate loading as the new bags accumulate dust.
 
4.            Systems Checks/Testing  -  Some facilities may run systems checks on their BLDS that cause the system to alarm.  For example, a facility can check the sensitivity of a BLDS by introducing a handful of flour into a port upstream from the probe.  In this example, the BLDS alarm will trigger briefly, but the operator conducting the test will surely know that the alarm was not caused by a broken bag or bag leak.  Facilities also evaluate and optimize their BLDS performance through drift checks, response tests, calibration exercises, and other quality assurance procedures.  Some of these procedures require the alarm to be triggered in order to test performance, but in other instances the BLDS alarm may be inadvertently triggered during testing.  Regardless whether the systems check/testing alarm is triggered purposely or inadvertently, the operator can readily correlate the alarm with the systems check, and can confirm through visual observation or otherwise that the alarm was not additionally caused by a broken, leaking, or dislodged bag.  
 
5.            Electrical Malfunctions  -  As BLDS detection is based on contact electrification, alarms can be triggered due to electrical surges impacting the sensors, processing electronics, or the connections between the sensor and processing electronics.  These surges can either be environmental (lightning) or from variations/malfunctions in the BLDS system, its software, or its power source.   Additionally, the abrasive environment in the baghouse duct can deteriorate the probe, probe housing, and housing insulation, which can cause an increase in malfunctions.  The alarms associated with these malfunctions/deterioration may provide the operator notice of the need for repair/maintenance, but they are not reliable indicators of broken, dislodged, or leaking bags.
 
BLDS can also experience electrical malfunctions and software glitches no different than many other types of electrical equipment.  BLDS alarms may be triggered during temporary power lapses or brief connectivity issues between the sensor and the processing electrics, or between the processing electronics and the system output/alarm.    Like any piece of electrical equipment, BLDS can experience brief mechanical or software glitches/errors, including with respect to the sensor's signal amplification or with the configuration of the processing electronics.  In many cases, momentary electrical malfunctions or glitches will cause the BLDS to alarm only briefly, and operators can confirm that these types of alarms were not caused by broken bags or bag leaks by conducting a visual emissions observation, correlating the alarm to a known surge or observable electrical malfunction, reviewing the system readout to confirm no increase in pollutant loading, or through use of other means.  
 
6.            Repair/Maintenance  -   Some baghouse repair and maintenance activities may be conducted while the baghouse is in operation.  In some cases, proper inspection and repair requires the baghouse to be operating in order to observe and repair malfunctions/maintenance issues.  Often these activities are coordinated with a baghouse operator observing the BLDS readout in real time into order to identify the cause of an earlier alarm or to proactively identify maintenance or performance issues.  In other circumstances, baghouse repair and maintenance activities must be conducted when the baghouse is operating simply because the repair/maintenance is urgently needed and it is infeasible to quickly shut down the baghouse.   Regardless of the specific reason for conducting repair/maintenance activities while the baghouse is operating, it is often the case that these activities will cause BLDS alarms.  As workers open and manipulate compartments and conveyances they can introduce particulates into the system or dislodge caked or accumulated dust.  Some maintenance and repair activities can also directly interfere with the BLDS causing it to trigger.   As these maintenance and repair activities are conducted in conjunction with the baghouse operator, the operator can readily correlate a BLDS alarm to a repair activity occurring at that time.  Moreover, because maintenance personal are directly observing baghouse compartments during alarms such as these, they are in a position to fully confirm that the alarms were not caused by broken, leaking, or dislodged bags.
 
BLDS alarms can also be caused by maintenance and repair activities conducted when the baghouse is not operating.  These activities can introduce foreign material or dislodge accumulations of material from ducts, conveyances, access panels, joints, and other components of the system upstream from the probe.  When the baghouse restarts after such repair and maintenance activities, the newly introduced or dislodged material can cause the BLDS alarm to briefly signal.   Because the operator will know (from direct knowledge or review of the baghouse maintenance log) that these dust-generating activities were conducted in the baghouse while it was idled, the operator can correlate a short-lived alarm upon restart with those maintenance/repair activities.  This correlation can be confirmed through visual opacity observations and review of the BLDS readout to confirm a rapid return to normal particulate loading.
 
Please let me know if you have any questions or want to discuss.  I am still waiting to hear back from a few contacts regarding your questions.  If I receaive any additional informaiton, examples, or better insights in how to best categorize these types of alarms, I will supplement this response.
Thanks for the opportunity to provide this and please do not hesitate to reach out if we can help in any other way.
Best,
Wayne
WAYNE D'ANGELO

Kelley Drye & Warren LLP
Tel: (202) 342-8525
Cell: (202) 329-3977
 
From: Jones, DonnaLee <Jones.Donnalee@epa.gov> 
Sent: Thursday, April 8, 2021 6:56 PM
To: D'Angelo, Wayne J. <WDAngelo@KelleyDrye.com>
Cc: Stuart, Eric <stuart@steelnet.org>; Green, Joseph J. <JGreen@KelleyDrye.com>
Subject: expanded list of false alarms
 
Hi. Back again. I will need an expanded list of reasons for BLDS false alarms and/or intermittent alarms. I noticed that one reason on your list was already on the response list in the rule: §60.273a (f)(5) Cleaning the bag leak detection system probe or otherwise repairing the bag leak detection system.
 
If you can think of category names for groups of two or more items on your list of things that cause false alarms, that would be helpful, e.g., a heading of "weather" and item list of things that cause false alarms to include heavy rain and changes in temperature or humidity.
 
The issue here is not 3 hours vs 24 hours, but documentation of the cause of the alarm (and also the response under 273a(f)(5)), when it is a false alarm and, therefore, no response in terms of stopping a leak is possible.
 
 
Regards,
Donna Lee Jones, Ph.D.
Senior Technical Advisor, Metals Sector
U. S. Environmental Protection Agency
Office of Air Quality Planning and Standards
Sector Policies and Programs Division / Metals & Inorganic Chemicals Group (D243-02)
Research Triangle Park, NC  27711  Tele:  (919)  541-5251  Fax  (919)  541-3207
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
"Reasonableness never fails to be appreciated."  - anon.
 
Pronouns - She/Her/Hers
Salutation - Dr./Ms.