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MENTOR AND MICROBIAL ECOLOGY PIONEER – PROFESSOR THOMAS D. BROCK – 1926 TO 2021

Today’s ASM News Digest reported that on 04 April, Thomas D. (Tom) Brock passed away at the age of 94 (Microbiologist Thomas Brock Dies at 94 | The Scientist Magazine® (the-scientist.com). This week there was also a column about him in the New York Times (Thomas Brock, Whose Discovery Paved the Way for PCR Tests, Dies at 94 – The New York Times (nytimes.com)).  Here I’ll share my personal story.

Although Tom spent most of his career as a professor at the University of Wisconsin-Madison, I had the great fortune of having been one of his students during his tenure (1960 to 1971) at Indiana University (IU).  By the first semester of my senior year at IU, I had completed all of my required course work but still needed 12 credits to graduate.  At that time, one of Tom’s graduate students was developing radiotracer methods for investigating the ecology of microbes that grew on rock and plant surfaces (the term biofilm had yet to be coined).  In late 1969, I approached Tom and asked if he would support having me work in his lab and earn my remaining credits performing a research project.  Tom agreed, took me under wing and assigned me lab space where I would be working alongside his team of graduate students. 

To report that working as one of Tom’s disciples during my last semester at IU was a foundational experience would be an understatement.  I had decided that I wanted to become a marine microbiologist and had developed a keen interest in the ecology of extremophiles (microbes that thrived in extreme environments such as deep ocean thermal vents, under and within polar ice, and at high – > 200 atmospheres – pressures).  After learning about the vast network of underground rivers that flowed through Southern Indiana and being advised by a geology professor that the underground river temperatures remained a constant 10 °C (50 °F) throughout the year, I hypothesized that these rivers might be habitats for obligate psychrophiles (microbes that grew optimally at temperatures £20 °C – £68 °F).   Tom encouraged me to take up spelunking and to use a nearby underground rivers as my field sites.  I set up arrays of microscope slide coverslips midstream in several cave rivers, then recovered coverslips every few hours for the next several days.  I then ran a battery of tests on the recovered coverslips.  The first thing I learned was that the coverslip populations reached a dynamic steady state within 24h.  The next thing I learned was that, based on both radiotracer and culture testing, the populations preferred life at 25 °C to 30 °C.   My work resulted in a publication (Absence of Obligately Psychrophilic Bacteria in Constantly Cold Springs Associated with Caves in Southern Indiana on JSTOR) – making 2020 the 50th anniversary of my first published research work. 

Beyond the mechanics of various laboratory methods, Tom taught me that in the world of microbial ecology, hypothesis were tools for helping one to think about a topic and to design a test plan.  Hypotheses should not become theories to be proved.  In the half-century since I learned in Tom’s lab, I’ve encountered too many instances in which researchers became fixated on their hypotheses and took measures to ensure that their data supported those hypotheses.  I can also attribute my general distrust of culture test data to Professor Brock.  Having pioneered a number of non-culture methods, he advised against over-reliance on the stories told by the relatively few microbes that we knew how to culture (see FUEL & FUEL SYSTEM MICROBIOLOGY PART 3 – TESTING – Biodeterioration Control Associations, Inc. (biodeterioration-control.com)).   In addition to my primary research, I had an opportunity to dabble in acid mine drainage stream microbiology.  Populations of acid-loving (acidophiles) thrived in pH 2 (essentially, concentrated sulfuric acid) streams – talk about extreme environments!

While I was under his wing, Tom published the first edition of Biology of Microorganisms (the 15th edition was published in 2018).  When the book was published, Tom offered his ducklings $1 per error we found.  Each of us made out quite well in several respects.  Biology of Microorganisms was the first microbiology textbook that presented the topic from a microbial ecology, rather than clinical microbiology, perspective.  We each received a few dollars by detecting errors.  Our close, critical reading of the text and inspection of each figure was educationally rewarding.  As an undergraduate, the experience taught me that regardless of how many times a paper is reviewed, errors are likely to slip by, undetected.  Later in my career, I formulated this lesson into a meme: even after you have 100 people review a manuscript, the 101st reviewer will catch errors everyone else has missed. 

Culminating the tremendous mentorship Tom provided, I’m convinced that his recommendation paved the way for my successful application to graduate school.  In 1988, Professor Brock received the American Society of Microbiology’s Carski Award for Undergraduate Education.  Writing one of the letters in support of his nomination to receive the gave me an opportunity to repay his kindness in a small way.  Despite having had many great teachers over the years, I still refer to myself as a Brock acolyte.  The lessons I learned from Tom inform me to this day.  He was one of microbial ecology’s great pioneers. 

DORMANT MICROBES IN METALWORKING AND OTHER INDUSTRIAL FLUIDS


John Cleese and Michael Palin of Monty Python’s Flying Circus in the “Dead Parrot Sketch”, first aired in December 1969.
What is a dead microbe and why might we care?

I today’s post, I’m returning to a topic I first discussed in 2019 (https://biodeterioration-control.com/2019/07/). In the Monty Python’s Flying Circus “Dead Parrot Sketch”, John Cleese plays the role of an unhappy customer who believes that he has just purchased a dead parrot. Michael Palin – playing the shopkeeper – insists that the parrot is not dead. Rather, it is “simply napping.”

When we monitor microbial contamination in industrial systems, we are typically interested in both how much microbial contamination is present and what damage risk the population poses to the system and the fluids it contains.

Last week, I received an email from a metalworking fluid (MWF) manager who wrote: ““We have another situation with dormant bacteria. In this case we find we have to keep hitting it with biocide more and more often. When the bacteria do start to grow again as the biocide level drops, we see huge pH, alkalinity drops within a week and there is often a bad smell associated. I worry that this is partially due to a large population of dormant bacteria (104 CFU mL-1 to 105 CFU mL-1 on paddles) that is able to wake up and grow more quickly. Is there a way to get at these bacteria and kill them to reduce their population?”

With the MWF manager’s approval, today’s article draws heavily on my response to his email.

Dormant cells

Bacterial endospores

Endospores are special structures formed by a few types of bacteria. Endospores are metabolically inactive (i.e., dormant). There have been reports of microbiologists inducing endospores that have been dormant for more than a million years to germinate into vegetative (i.e., metabolically active) cells. Until recently (i.e., the past ~ 15 years), microbiologists believed that only endospore-forming microbes like Bacillus sp. (Gram +, spore-forming aerobic rods) and Clostridium sp. (Gram +, spore-forming anaerobic rods), could survive for long periods in a dormant – metabolically inactive state (Figure 1).

Fig 1.
Fig 1. Bacterial endospores – a) Bacillus subtilis; b) Clostridium tetani. In these photomicrographs, the B. subtilis endospores appear as green spheroids and the C. tetani endospores appear as blue spheroids (sources: a) asmscience.org; b) https://www.researchgate.net).

 

Persister Cells

In the late 1980s, microbiologists started to report on the existence of persister cells – non-sporeformers that seemed to be able to withstand biocide treatment. In some respects, persister cells are like trees that are dormant during the winter but become active as spring arrives. When conditions are unfavorable, these cells become metabolically inactive and can remain in this state for thousands of years. Unlike endospore-forming bacteria, persister cells do not form any special structures.

Understanding of persister cells grew as biofilm research advanced. It turned out that persister cells were often resistant to biocide treatment because they were metabolically inactive – much like endospores but without the unique endospore cell wall chemistry. Thus, the study of persister cells evolved into the study of dormant cells. Thus, the terms persister and dormant are used to describe cells that can become metabolically during tough times and then become active after prolonged periods (1,000s of years) of inactivity. The biology of dormancy and reactivation is still a hot research topic.

Viable but not culturable (VBNC) cells

The rapid development of non-culture microbiological test methods, starting with protein concentration testing in the 1940s, ATP testing in the 1950s, and rudimentary genomic testing in the 1970s (my lab used to test seawater samples for total DNA concentration among other microbiological parameters), led to an awareness that not all microbes were readily detected by culture methods. In 1982, a ground-breaking study focused on a disconnect between the incidence of cholera disease among Chesapeake Bay area restaurant patrons and the inability of the local Department of Public Health to recover the bacterium Vibrio cholera form suspect oyster meat. A post-doctoral fellow at the University of Maryland decided to compare microscope direct counts with culture data. He came of with the idea of treating specimens with a reagent that prevented cell division but permitted cell growth. Metabolically active V. cholera cells would show up as >10x their normal size. Dormant and moribund cells would be visible as normal sized cells. Low and behold, shellfish samples that yielded no culturable V. cholera actually had 106 to 109 metabolically active – i.e., quite viable cells mL-1! That work precipitated an avalanche of research on VBNC microbes.

The term VBNC includes two distinct categories of microbes.

Injured cells – The first category includes cells like the aforementioned V. cholerae that sometimes can be cultured but not reliably. These normally culturable cells are unable to reproduce on or in the growth medium that was designed to detect them if they are injured. Since the early 1980s, process steps have been added to culture test to help injured cells recover before they are cultured for enumeration.

Most types of bacteria – The second category includes microbe we do not yet know how to culture. They do not product colonies on any of the available growth media, under commonly used growth conditions (i.e., temperature, oxygen availability, etc.). Current estimates suggest that for every organism that has been successfully cultured, 1 million to 1 billion that exist in nature have not been cultured.

Metalworking Fluid Microbial Contamination Condition Monitoring

Choosing one or more test methods

If you test a population of people for height and weight you will find that – generally speaking – people’s weight increases with their height (Figure 2a). However, the relationship falls within a cloud around the trendline. Contrast this with the relationship between refractive index (°Brix) and metalworking fluid concentration ([MWF]) shown in Figure 2b. The trend lines in both graphs have the same slope, but the data point spread around the trend line is much greater for the height versus weight plot than it is for the °Brix versus [MWF] plot.

 

Fig 2. Correlations between pairs of parameters – a) human height versus weight (a significant, but weak correlation); b) refractive index (°Brix) versus [MWF] (significant and strong correlation).

 

I’ve discussed this concept in previous What’s New posts (see https://biodeterioration-control.com/microbial-damage-fuel-systems-hard-detect-part-3-testing/, https://biodeterioration-control.com/2019/07/, and https://biodeterioration-control.com/2020/03/)

The relationships among different microbiological test methods reflects the fact, that like Figure 2a, above, each method measures a different property (see https://biodeterioration-control.com/2017/07/).

Each test method tells a story

Between the dormant cell and VBNC cell factors, there are quite a few reasons that culture and non-culture testmethods can tell different stories. In some cases, culture data suggest a greater biodeterioration risk than actually exists (i.e., substantial bioburdens are not damaging the MWF). In others, culture data suggest that there is negligible biodeterioration risk but other data – such as ATP – indicate that the biodeterioration risk is great. This happens when a substantial portion of the metabolically active population is either non-culturable or clumped into masses (flocs) of cells and each such mass (100s to 1000s of cells) forms a single colony. So how do we interpret apparently conflicting data from two different methods. I’ll use culture (CFU mL-1) and cellular ATP concentration ([cATP] in pg mL-1) to illustrate the concepts.

When culture testing indicates high bioburden, but ATP data does not – if the population is dormant in the MWF but becomes metabolically active after being transferred to a growth medium, the population represents a potential risk. It is not causing damage at present, but could become metabolically active at some future point, as I will discuss below. As illustrated in Figure 3, the biodeterioration risk is moderate.

When culture testing indicates low bioburden, but ATP data indicates high bioburden – if a substantial percentage of the population is VNBC but metabolically active, it represents a current risk. Even though culture recoveries are minimal, the population is using MWF components as food and is producing acids and other metabolites that can degrade MWF performance. Per Figure 3, the biodeterioration risk is high.

It should be obvious that when both culture and ATP-bioburdens are low, the biodeterioration risk is low. Conversely, when both culture and ATP-bioburdens are high, the biodeterioration risk is high.

 

Fig 3. Biodeterioration risks based on culture and ATP-bioburden data.

 

Assessing microbicide performance in MWF systems

Based on the preceding background discussion, if microbicide treatments are not having the desired effect, it is important to assess whether the population in the treated MWF is dormant populations or not. because of the MWF dynamics, the available biocide concentration rapidly decreases to less than the critical (i.e., minimum effective) concentration with sufficient speed that bioburdens seem to yo-yo quickly (see the August 2018 What’s New article for an explanation of critical microbicide concentration).

For example, in a system with 10 % turnover per day, fluid loss through turnover rate will drop 2000 ppm biocide to 1,180 ppm in five-days. Add to that biological demand (microbicide consumption as it kills microbes) and chemical demand (microbicide reactions with other organic compounds in the MWF, dissolved metals, and salts, causing the microbicide molecule to either breakdown or become biologically unavailable) and it is easy to see how the concentration of biologically active microbicide can fall to below its critical concentration (1,000 ppm for triazine) within 4 to 5 days.

Dealing with rapidly restored bioburdens

Case 1 – Culturability is affected but [cATP] is not – If the population drops shortly after biocide addition, then the biocide is effective when it is present in the >critical concentration range. If you have a field test for microbicide concentration ([microbicide]), you can do a quick trial to track [cATP], CFU mL-1, and [microbicide] before treatment and at 8h to 12h intervals post-treatment. If the treatment is effective, within 24h the [cATP] should drop by ³2 orders of magnitude. Determine the [microbicide] at which [cATP] begins to climb and the number of days post-treatment it takes for that to happen.

Figure 4 illustrates Case 1. Initial treatment causes both CFU mL-1 and [cATP] to drop as expected. This indicates that the microbicide is effective at recommended end-use concentration. However, over time, both [microbicide] and CFU mL-1 show a seesaw pattern. As the [microbicide] decreases, CFU mL-1 increases. The [cATP] remains unaffected. This indicates that even at 750 mg L-1 (ppm), the microbicide is working as a biostat – keeping most of the population dormant.

 

Fig 4. Microbicide effect on bioburden – Case 1.

 

Case 2 – [cATP] is affected but culturability is not – In this case, the CFU mL-1 is not affected by microbicide dosing. However, there is an inverse relationship between [cATP] and [microbicide]. The [cATP] initially drops in response to 2,000 mg L-1 microbicide dosing but recovers as the [microbicide] falls. Regardless of the [microbicide] the CFU mL-1 remain within the test method’s (paddles) normal variability range (±1 order of magnitude). Figure 5 illustrates Case 2.

 

Fig 5. Microbicide effect on bioburden – Case 2.

 

Case 3 – [cATP] and culturability are affected – In this scenario, illustrated in Figure 6, microbicide treatment causes both parameters to fall. As the [microbicide] decreases, both culturable and ATP-bioburdens recover. Note that after a microbicide addition, the impact on CFU mL-1 is faster than the effect on [cATP]. This is because cell injuries are likely to inhibit culturability almost immediately after treatment. However, it takes longer for cells to actually die. A full effective microbicide treatment will produce data similar to that shown inf figure 6. Keep in mind that Figures 4, 5 and 6 all pertain to a high-turnover system in which dilution is the primary factor affecting the microbicide’s half-life. That said, in systems with low turnover rates (< 5 % per day), the patterns will be similar but the x-axis will stretch out.

Fig 5. Microbicide effect on bioburden – Case 3.

Sorting out the three cases

AxP testing – AxP testing uses ASTM Test Method E2694 for Measurement of Adenosine Triphosphate in Water-Miscible Metalworking Fluids to obtain extracts that include ATP, adenosine diphosphate (ADP), and adenosine monophosphate (AMP). The “x” in AxP is used to indicate that the method tests for all three molecules. Recently, Drs. Peter Küenzi, Jordan Schmidt, and I collaborated to asses the relationship between MWF additives and Adenylate Energy Charge – AEC (see https://biomedgrid.com/fulltext/volume7/adenylate-energy-charge-new-tool-for-determining.001178.php). The AxP data are used to compute AEC. Dormant or moribund populations have AEC <0.5. Healthy populations have AEC ³0.7.

Per the preceding discussion of VBNC and dormant cells, high AEC with low CFU mL-1 signals the presence of an active but non-culturable population. Conversely, high CFU mL-1 and low AEC signals that the microbes recovered by culture testing are not causing damage in the MWF. They are either dormant or dying off, but able to recover in the growth medium. I do not recommend AxP for routine testing. It is useful to make seemingly confusing or questionable data make sense.

Test for biofilm growth and biocide effect against biofilms

Commonly, we ignore biofilms (the November 2017 What’s New article discusses biofilms in fuel systems) growing on MWF system surfaces. Research has shown that both the dose needed to disinfect biofilms is typically 10x that used to kill planktonic – free-floating -cells (See December 2019’s What’s New). Additionally, the soak interval – period of contact – must be at least 24h. Biofilms periodically launch cells into the overlying fluid so that they can be transported to new surface colonization sites.

If you do not periodically eliminate biofilm populations, cells from MWF system biofilms readily reinfect the recirculating fluid as soon as the biocide concentration approaches the critical concentration. This is not an issue of dormant cells or VBNC cells. It is simply a reinfection process.

Use the DSA test method to evaluate biofilm accumulation in the system. If your DSA results are ³103 pg cm-2, you will need to do a full system clean out and recharge before you’ll be able to restore reliable bioburden control.

Summary

Although culture and ATP data generally tell the story, sometimes they do not.

If the population initially responds to microbicide treatment but recovers quickly, the two most likely causes are:

  • 1. Reinoculation from biofilm communities, and
  • 2. Recovery of the planktonic population when the microbicide’s half-life is shorted faster than assumed.

ATP by both ASTM Test Method E2694 & DSA testing can tell you if Cause 1 is at play. If biofilm growth is causing the data pattern you have reported, you will need to do a drain, clean, and recharge to break the cycle.

ATP, culture, & [microbicide] can tell you if cause 2 is at play. If short half-life is the issue, you’ll have to rethink your dosing plan.

AxP can tell you if there is a dormant population affecting your test results.

For more information, contact me at fredp@biodeterioration-control.com

COVID-19 WEBINAR AND WEBCAST

On 29 July 2020, Drs. Neil Canter, John Howell, and I, and Mr. Bill Woods presented an STLE webinar panel discussion about reducing COVID-19 risk in the metalworking workplace environment. You can access the webinar at: https://www.stle.org/files/TLTArchives/2020/10_October/Webinars.aspx?WebsiteKey=a70334df-8659-42fd-a3bd-be406b5b83e5.

Last week Ms. Vicky Villena-Denton, Editor-in-Chief at F & L Asia, Ltd., interviewed me as episode six of the F + L Webcast series. During the interview, Vicky and I discussed COVID-19 epidemiology and risk mitigation – particularly as it pertains to the petroleum sector. I invite you to listing to the webcast at https://anchor.fm/fuelsandlubes/episodes/Episode-6—Fred-Passman-discusses-how-to-minimise-risks-from-Covid-19-exposure-in-the-industrial-workplace-ekfsd8 and look forward to receiving your comments and questions about the conversation.

As always, you can reach me at fredp@biodeterioration-control.com.

How to Remain Safe and Productive in Working with Metalworking Fluids During the COVID-19 Pandemic.

How to Remain Safe and Productive in Working with Metalworking Fluids During the COVID-19 Pandemic.
Live webinar taking place July 29th, 2020 12pm CT

Three colleagues and I will be discussing COVID-19 risk mitigation in the workplace environment.  If you are interested, I recommend signing-up early.  Per the STLE blurb I’ve copied in its entirety below, participation is limited to the first 100 who sign up.

 Participants:

Dr. John Howell

Dr. Fred Passman

Bill Woods, Technical Marketing and Training Manager, Pilot Chemical

Dr. Neil Canter

 

Abstract:

The onset of the COVID-19 pandemic has presented major challenges to the metalworking fluid industry. Concern has been expressed about how to be productive in working with metalworking fluids in production facilities and laboratories yet remain safe from exposure to COVID-19.

STLE presents a webinar that will address this concern and present useful information on proper procedures and safeguards for working with metalworking fluids during these challenging times. The webinar will start with a one hour presentation covering three subject areas.

STLE Fellow, Dr. Fred Passman will give a presentation on virology that provides background information on viruses with a focus on the virus that causes COVID-19, SARS CoV-2. Passman will also discuss whether COVID-19 can survive in metalworking fluids.

STLE Fellow, Dr. John Howell will cover industrial hygiene issues including how to minimize the risk of exposure to COVID-19 in dealing with metalworking fluids. Subjects that will be covered include common exposure pathways to COVID-19, how to minimize risk in the working environment, a discussion on system startups and cleanouts and how should incoming samples be handled prior to analysis.

Bill Woods of Pilot Chemical will discuss the role of disinfectants in deactivating COVID-19. Included will be basic information on what are disinfectants, how to use them and how to read disinfectant labels.

STLE Fellow, Dr. Neil Canter will act as the moderator for the webinar.

Once the presentations have finished, the webinar will conclude with a 30 minute Q&A session to answer as many attendee questions as possible. Attendees are encouraged to submit questions to scarrera@stle.org using the subject line “MWF Covid-19 webinar questions.”

About the Speakers:

John Howell

Dr. John Howell has over 50 years of experience in metal finishing and metalworking R&D, R&D management and chemical health, safety and environmental management.

Currently, Dr. Howell is president of GHS Resources, Inc. and he prepares GHS compliant SDSs and consults with clients and trade associations to improve their environmental and health & safety performance.

 

Fred Passman

Dr. Fred Passman is an ASTM Fellow, STLE Fellow and Certified Metalworking Fluids Specialist with more than 45 years’ experience in environmental-industrial microbiology. He is the principal of Biodeterioration Control Associates .

Since 1973, Dr. Passman has conducted research and consulted to government and private industry on topics as diverse as composting municipal sewage sludge, U.S. EPA criteria for various groups of toxic substances in fresh-water systems, microbially enhanced oil recovery, and microbial contamination control in industrial process-fluids.

Bill Woods

Bill Woods provides marketing support for the Pilot Chemical Company antimicrobial products sold through the Mason Chemical business unit. Woods’ responsibilities include identifying new opportunities for Pilot Chemical Company antimicrobials, monitoring new trends in disinfection and training their sales managers.

Woods has over 30 years of experience in various commercial and technical capacities including: sales, marketing, technical service and product development at Arch Chemicals, CasChem, Galaxy Surfactants and Lonza. He has a M.B.A in Marketing, M.A. in Science and a B.A. in Chemistry/Biology.

Neil Canter

Dr. Neil Canter is a STLE Fellow and a Certified Metalworking Fluids Specialist with more than 35 years of experience in working with metalworking fluids. He is the principal of Chemical Solutions.

Dr. Canter has a strong background in the chemistry of metalworking fluids and in regulations impacting their use. He is a member of American Chemical Society, the Society of Automotive Engineering, STLE and a contributing editor to the STLE Magazine, TLT.

Sign-up here:

https://www.stle.org/ItemDetail?iProductCode=LMS20_4&Category=FREE&WebsiteKey=a70334df-8659-42fd-a3bd-be406b5b83e5

Live viewing is restricted to 100 viewers.

Links to the webinar will be sent out the day before the webinar.

A recording will be available for those who cannot attend live.

REMEMBERING A MENTOR AND A MENSCH – PROFESSOR EUGENE D. WEINBERG 1922 TO 2019

This morning, while reading the Fall 2019 issue of Indiana University Alumni Magazine, I was saddened to read Gene Weinberg’s name in the list of recently deceased IU faculty and staff.
Professor Emeritus Eugene D. Weinberg died on 08 March – less than a week after having celebrated his 97th birthday. Gene was the first academician to have had a profound effect on my life’s path. I know that his memory will be a blessing to all of us who had the privileged and pleasure of knowing him.

I first met Professor Weinberg in 1966 – a few weeks into my first semester at IU. My initial plan was to have been a math major, but within a month, I began to rethink that plan. Having been tinkering with microbiology since my parents made the mistake of presenting me with a microscope for my eighth birthday, I decided to explore the possibility of changing majors to microbiology. In late October 1966, I visited with Professor Weinberg in his Jordan Hall office to explore my options. He advised me that the courses that I was taking were perfectly aligned with those that would be part of a microbiology major. He contacted my original, math department advisor and agreed to become my faculty advisor. From that date through my graduation in June 1970, Gene was always available to offer guidance and to facilitate my efforts to perform extracurricular studies under various Microbiology Department professors. Although I never saw it, I have no doubt that Gene’s letter of recommendation helped me to get accepted into graduate school and receive a full fellowship for my studies at University of New Hampshire.

Gene’s research interest was in medical microbiology. Knowing that my passion was microbial ecology, while I was taking his course in Medial Microbiology, he encouraged me to make my class project ecologically focused. When I went home for Thanksgiving, 1968, I took a suitcase full of sterile, 100 mL glass bottles with me. One the Friday after Thanksgiving, I drove to the Delaware River’s source. From there, and at various bridges located at 50 mi intervals – ending at the Delaware Memorial Bridge, I used a fishing pool, jury-rigged sampling setup to collect samples from each bank and the middle of the river. I then carried the full bottles back to Bloomington (good thing this was before there were suitcase weight limitations or TSA) where I proceed to run culture tests and biochemical taxonomic profiles on each type of microbe that I had detected. I rationalized this survey effort by noting that there was a possibility that the taxonomic profiles along the river’s length might have been indicative of public health risks.

I didn’t realize it at the time, but that project marked the start of my career as a microbial ecologist. I did realize from the outset that Gene was a supportive, encouraging mentor. When others might have said: “you can’t do that!” Gene would always tell me that I had a great idea, asked me if I had thought about various details – which of course I hadn’t, and suggest research papers that might help me to refine my thoughts. Gene was one of perhaps four mentors whose influence shaped my career as a microbiologist. I feel most fortunate for having known him and have benefited from his wisdom, his kindness, and his mentorship.

You can find Gene’s full obituary article at https://www.hoosiertimes.com/herald_times_online/obituaries/eugene-weinberg-phd/article_f86ed715-7dde-5789-9916-40d1e0fb0bfe.html.

Beginner’s Mind – What does this have to do with fluid management?

In the June issue of Lubes’n’Greases, Jack Goodhue wrote a an article about the Zen concept – shoshin – beginner’s mind.  Normally a fan of Jack’s Your Business column, I was surprised by how far off the mark he was in his understanding of shoshin.  I wrote a letter to the editor to express my concerns, and a condensed version of my letter was published in this month’s issue. I believe that when used appropriately, shoshin is of tremendous value to business leaders.  My full letter to the editor (Caitlin Jacobs) provides a more detailed argument than the version of the letter as it appeared in Lubes’n’Greases. I’ve copied and pasted it here.  In the version below, I’ve added a few links to articles that explain shoshin in more detail than I have in my letter. I look forward to reading your comments.

===

Dear Caitlin:

I generally enjoy reading Mr. Goodhue’s Your Business articles in each month’s LNG, but found myself scratching my head while reading his critique of shoshin in his June 2019 offering. His comments made me think of novice mariners failing to recognize that, as important lighthouses are as aides to navigation, their very presence represents a hazard to navigation – follow the line of sight track toward the beacon for too long and you’ll run aground.

No doubt, Mr. Goodhue accurately reported Mr. Fogel’s comment about shoshin. It’s a shame that he didn’t then do a bit of research on the beginner’s mind concept before writing his essay. Prof. Daniel Kahneman, a psychologist who is also Nobel laureate in economics has waxed long and poetic about our tendency to be blinded by preconceptions. In many professions, true experts are able to respond to cues and react appropriately seemingly without thought. Air Force Col. John Boyd canonized this ability as the OODA – observe, orient, decide, act – loop in areal combat. The pilot with the shortest OODA loop wins the dogfight. In Prof. Kahneman’s terms this is “fast thinking.” Malcom Gladwell’s “Blink: The Power of Thinking Without Thinking” is a paean to fast thinking. However, as Prof. Kahneman explains in “Thinking, Fast and Slow,” although the ability to react quickly with limited data is no doubt beneficial in some circumstances, it is not universally so. Snap decisions – used inappropriately – can lead to disastrous results. This often the case when complex issues are being considered.

Developing long-term strategic business plans is one example and root cause analysis is another in which a beginner’s mind is more likely to lead to success. As explained by D. T. Suzuki – the Japanese Buddhist scholar largely responsible for expanding western readers’ awareness of Buddhist and Zen thought – the concept underlying shoshin is to strive to become aware of your biases and preconceptions and to – at least temporarily – set them aside when examining an issue. The idea is to adopt an open mind and to avoid drawing conclusions based on preconceptions rather than available, objective information – first observe without judgment (this is the philosophy underlying brainstorming efforts). With a beginner’s mind, one can accept data, ideas, and information without critique – without filtering through the lens of personal bias. Embracing beginner’s mind during the early stages of problem-solving efforts or during the listening phase of conversations makes an individual more receptive to insights they would otherwise miss.

I’ll offer a case study to illustrate my point. In my work with the petroleum retail sector I often hear about filter plugging from clients who would be better advised to report the issue as slow flow. Retail fuel dispensers are set to deliver product at a maximum flow rate of 10 gpm (40 L/min). Although there are typically at least six different phenomena that can individually cause, or collectively contribute to, reduced flowrate, too many retail site operators assume that slow flow is a symptom only of filter-plugging. A shoshin approach would have stakeholders focus on the objective reality – reduced flowrate. And to ask beginner’s mind questions, such as: “What are all of the things in a retail fuel system that can contribute to flowrate reduction?” Note here, no one is asked to discard their previous knowledge or experience. They are only asked to set them aside in order to see the actual situation more clearly. By understanding that premature filter plugging is only one of several phenomena that cause flowrate reduction, stakeholders are better able to develop a cost effective plan to minimize both the risk and impact of fuel dispenser slow-flow (The opportunity cost of flowrates <8 gpm at an urban fuel retail site is >$250,000 per dispenser per year at a site with 12 dispensers, that per dispenser cost translates to $3 million lost fuel sales opportunity. Beginner’s mind thinking could mean $millions in increased revenue).

I fully agree with Mr. Goodhue. “Achieving shoshin would be difficult for most business people or anyone else more than three years old.” So is metadata analysis. The difficulty of achieving shoshin should not discourage either technical or managerial folks from cultivating the skill. The return on effort and investment in cultivating a beginner’s mind can be enormous when the mindset is used appropriately.

Sincerely,

Frederick J. Passman, Ph.D.

Predicting Water-Miscible Metalworking Fluid Foaming Tendency

In May 2018, ASTM Subcommittee E34.50 on Health and Safety Standards for Metal Working Fluids commissioned a new Task Force (TF) to develop a new Standard Guide for Evaluating Water Miscible Metalworking Fluid Foaming Tendency. Justin Mykietyn, of Munzing, is chairing the TF and the work is being completed under ASTM Work Item 64558. The details are explained in an article that appeared in the August 2019 issue of Lubes’n’Greases magazine, pages 30 to 32. To learn more about the challenges to predicting metalworking fluid foaming tendency in end-use applications, read the article available electronically at ASTM Drafts Guide to Fight Foam.

FUEL & FUEL SYSTEM MICROBIOLOGY PART 28 – IS THE SULFUR IN HIGH SULFUR DIESEL TOXIC?

Diesel fuel biodeterioration is not affected by the fuel’s sulfur content.

There is a broadly embraced misperception about the relationship between diesel fuel’s sulfur content and its toxicity to microorganisms. This misperception is driven by two logical flaws.

Logical argument #1:

There has been an increase in the number of microbially contaminated fuel systems since the use of ultra-low-sulfur diesel (ULSD) became mandatory.

Therefore, microbial contamination in low sulfur diesel (LSD) and high sulfur diesel must have occurred less frequently than in currently does in ULSD.

Logical argument #2:

If argument #1 is valid, then the removed sulfur must have had a biostatic (ability to prevent microbes from growing) or biocidal effect.

“Get your facts first, and then you can distort them as much as you please.”

This quote was reportedly part of a session that Samuel Clemens (Mark Twain) has with young reporters sometime in the 1890s. More recently, in one of his many books on Zen, the philosopher Alan Watts, observed that humankind is unique in our uncanny ability to make precise and accurate observations only to use them to draw erroneous conclusions. Finally, in an earlier post I quoted Daniel Kahneman’s adage: “What you see is all there is.” (WYSIATI).

Logical argument #1 fallacies:

This argument assumes that the increased incidence of reports in a particular market sector (fuel retail) is equivalent to the increased incidence of microbial contamination in diesel fuels and fuel systems. But how do we know whether stakeholders are simply more aware of something that has been going on since diesel fuels were first used? The history of marine fuel oil biodeterioration that date back to the transitions from coal to oil and from burner oils to marine diesel fuel oil (more on this, in response to argument #2). Distillate aviation fuel biodeterioration has been recognized since the Korean War.

Additionally, the argument ignores various confounding factors (in statistics, a confounding factor is an unobserved variable that affects observed variables: in our case sulfur concentration and biodeterioration are observed variables. Before concluding that removing sulfur made diesel fuel more vulnerable to biodeterioration consider these four confounding factors (there are others, but these five illustrate the concept):

  • Hydrotreatment to remove sulfur also removes aromatic compounds – especially high molecular weight, toxic, polynuclear aromatic compounds.
  • During the past three decades, the fuel distribution infrastructure has evolved from vertically integrated control (the refiner controlled all stages from refinery to retail site) to fungible (common pipelines transport products from refinery tank farms to terminals from which independent and branded retailers draw product from tanks that can that can be mixtures of product from numerous refineries – >100 refineries produce product that is stored in in New Jersey terminal tanks). Fungible product comingling means that cradle to grave product stewardship is more complex than it was historically.
  • Product transport from terminals to fleet operators and retailers is typically done my third-party transport companies. Switch-loading (a given tank compartment can carry gasoline on one trip and diesel on the next) is occurring more frequently. The probability of cross-contamination between two fuel-grades is a hotly debated issue at present.
  • Although the trend is beginning to reverse itself, between 1990 and 2010, total diesel storage capacity shrunk annually as product demand grew. Consequently, residence time in terminal storage tanks has decreased. Although best practice is to give water and particulates time to settle before drawing product from a tank to the fueling rack, product demand can inspire terminal operators to begin drawing product early. Consequently, any water, particulates, or both that have not settled to below the suction zone will be transported with the fuel.
  • Dispensing system technology has become more sophisticated. Systems that might not have be affected historically, are now failing – primarily due to corrosion damage. As a microbiologist, I’d like to think that all fuel system corrosion is microbiologically influenced corrosion (MIC). However, if ethanol enters diesel fuel systems (either because of switch loading or vapor recovery unit vapor comingling) it can be chemically oxidized to acetic acid. Therefore, unless other low molecular weight (4 to 6-carbon) organic acids are also present, high concentrations of acetic acid in fuel-associated water is likely to be a symptom of chemical – not microbial – activity.

Logical argument #2 fallacies:

This argument is built on argument #1’s house of cards. It falls apart if the statement: “There has been an increase in the number of microbially contaminated fuel systems since the use of ultra-low-sulfur diesel (ULSD) became mandatory.” is false. As noted above, increased incidence and increased reports are two very different concepts.

To illustrate this point, consider the respiratory disease, legionellosis. The disease was given its name because the first recognized outbreak was among American Legion members attending a convention at the Bellevue-Strafford Hotel, in Philadelphia. It is beyond improbable that the bacterium that causes legionellosis – Legionella pneumophila – came into existence in 1976. However, in late July and early August 1976, after 221 American Legion convention attendees developed pneumonia-like symptoms, and 34 of the patients died, the medical establishment (physicians and epidemiologists) took note. It took a couple of years to figure out how to culture L. pneumophila, and there was wild speculation regarding the likely relationship between environmental conditions and the microorganism’s ability to grow. Forty years down the road, we know that L. pneumophila is ubiquitous – it can be found in many different environments where biofilms develop (relax – none yet recovered from fuel systems; but don’t relax too much – shower-head aerator screens tend teem with L. pneumophila). The good news is that only immunosuppressed individuals tend to develop the legionellosis.

What does this have to do with the relationship between sulfur concentration in fuel and biodeterioration risk? In both cases, the microbes causing the symptoms have been around for a long time. In the health sector, for centuries (if not millennia) L. pneumophila has caused an unknown percentage of all pneumonia cases, but it was never identified because there had never been (i.e., since the advent of modern medical microbiology, immunology, and epidemiology) such a large number of folks getting sick at the same time and place. Similarly, fuel biodeterioration was well known from the earliest days of gasoline and diesel production. However, there was no database documenting each biodeterioration event.

Prior to 2012 the upper limit for sulfur in marine diesel was 4.5 %. Before 1986, on-highway diesel typically had 0.1 % to 0.5 % (by volume) sulfur. If the sulfur in these historical fuels had been biostatic, fuel biodeterioration would have not occurred until ULSD came onto the market. Filter plugging on ships and aircraft had a more serious impact than filter plugging on dispensers, locomotives, and other land-based diesel fuel systems. However, efforts to control microbial contamination in the marine and aviation sectors were not general knowledge among fuel retailers and fleet operators. Ironically – because they ignored the biocidal effect of tetraethyl lead – folks were convinced that gasoline was too toxic to support microbial growth and that only diesel fuels and fuel systems were affected.

Despite all of this, isn’t it fair to say that ULSD biodeterioration is more pervasive than that of diesel grades with greater sulfur concentrations? My answer is: Not necessarily. There are no hard statistics on the average number of ULSD biodeterioration incidents per year since 1986 and there are certainly no reliable statistics for the decades before the switch to ULSD (or in off-highway systems using low or high sulfur diesel). The assessment that the incidence rate has increased since ULSD replaced other fuel grades for on-highway use is purely subjective. One more time: increased awareness (as in the case of legionellosis) is not the same as increased incidence. The switch to ULSD and biodiesel blends was highly visible to the industry. From the outset, stakeholders wanted to know what the change might do to their systems. Consequently, they now notice damage more quickly than they had in the past. Okay, this is an optimistic statement. In two recent fuel quality surveys, sites originally identified as control sites (no reported problems) had more microbial contamination and corrosion than he problem sites. In the more recent, US EPA-sponsored study, operators were unaware of any problems at 87 % of the moderately to heavily corroded sites.

The Science:

There is no question that some organosulfur compounds are biocidal. For example, two of the few fuel-treatment biocides are mixtures of organosulfur compounds:

CIT/MIT (also referred to as CMIT): 5-Chloro-2-methyl-3(2H)-isothiazolone + 2-methyl-3(2H)-isothiazolone (isothiazolinones are ring structured molecules with the chemical formula: C₃H₃NOS).

MECT: 2-(Thiocyanomethylthio)benzothiazole + Methylene bis(thiocyanate) (the thio in each molecule’s name indicates that they are organosulfur compounds)

However, sulfur is one of the five primary elements (the other four are: carbon, hydrogen, nitrogen, and oxygen) on which all life depends.

Studies on fuel biodegradability have shown that the aromatic content, rather than the sulfur content is a primary factor affecting diesel biodegradability. Regardless of sulfur concentration, fuels with higher aromatic concentrations or more complex aromatic compounds biodegrade more slowly than more severely hydrotreated fuels from which aromatics have been substantially removed. The same hydrotreating process that removes sulfur also reduces fuel’s aromatic content. Note that although there are no aromatic biocides approved for fuel treatment, there are numerous aromatic biocides approved for other applications.

    Bottom line:

If ULSD fuels are more susceptible than higher sulfur content fuels are to biodeterioration, it is due to the reduced concentration of complex, toxic polynuclear aromatic compounds – not because of sulfur’s inherent toxicity.

FUEL & FUEL SYSTEM MICROBIOLOGY PART 26 – THE NFPA CONUNDRUM

I thank Michelle Hilger for inspiring me to write about today’s topic – the disconnect between the guidance NFPA provides about emergency generator fuel supplies and reality. Michelle chairs the Emergency Generating Systems Association’s (EGSA’s) Fuel: Fact or Fiction Working Group.

NFPA (National Fire Prevention Association) Standards Related to Fuel Storage

The NFPA provides fuel condition monitoring guidance in two documents:

  • NFPA 110, Standard for Emergency and Standby Power Systems; and
  • NFPA 25, Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems.

During her brief, presented to ASTM D02.14’s Fuel Microbiology Working Group in June 2018, Michelle reported that NFPA 110 prescribes the following:

  • Chapter 8.3.7 -A fuel quality test shall be performed at least annually using appropriate ASTM standards or manufacturer’s recommendation (Revision for 2019 Edition)

She also reported similar language in NFPA 25:

  • Chapter 8.3.4.1 –Diesel fuel shall be tested for degradation no less than annually.
  • Chapter 8.3.4.1.1 –Fuel degradation testing shall comply with ASTM D975, Standard Specification for Diesel Fuel Oils

Ensuring that fuel in emergency system storage tanks is fit for purpose is laudable, but insufficient.

What’s the Problem?

Some years ago, a maintenance engineer at a major resort hotel estimated that if there was a power outage and the hotel’s generators did not start and operate reliably, it would cost the hotel’s owners more than $2 million for each minute the facility was without power. Now ponder what the cost impact might be – in dollars and possibly lives – if a hospital’s emergency power system did not operate when needed (you can find some statistics if you research the impacts of recent hurricane disasters in Florida, Louisiana, Texas, and other southern states.

There is no debate that it is imperative to check the condition of stored fuel periodically. However, just determining that the bulk fuel meets ASTM D975 Table 1 specifications provides no information about the fuel system’s condition.

For several years – beginning with efforts to have proposed revisions incorporated into NFPA 110’s 2016 edition – the ESGA has been trying to educate NFPA stakeholders and broaden the scope of prescribed fuel system inspections.

For those of you who are new to this blog series, I invite you to start with my November 2016 post and read the entire series. This will help you to understand the rationale for ESGA’s efforts. In today’s post, I’ll just highlight two of the most important issues.

Fuel Quality Testing is a Snapshot

ASTM product fuel specifications were developed and are frequently revised to ensure that entities supplying and entities purchasing product have a common understanding of the criteria by which that product is defined as being fit for purpose. ASTM (and other consensus standard bodies – for example the International Standards Organization (ISO)) standards list parameters, test methods and pass/fail criteria that stakeholders can use to ensure that the product is fit-for-use at the time of sampling. Specification test results do not predict the product’s future condition. Under optimal storage conditions, emergency diesel generator fuel can be stored for prolonged periods (years). However, optimal storage isn’t always possible.

Fuel Versus Fuel System

Although my personal focus is microbial contamination and biodeterioration, in ASTM D6469 Guide for Microbial Contamination in Fuels and Fuel Systems I openly acknowledge that one major challenge to biodeterioration diagnosis is the number of symptoms that biodeterioration shares with non-biological (abiotic) fuel and fuel deterioration processes. Fuel can accumulate water and particulate matter. It can also become corrosive. Most engines can operate – at least for some time – using degraded fuel, but there’s a cost. CRC Report 667 Diesel Fuel Storage and Handling Guide (Coordinating Research Council, Alpharetta, GA, 2014) summarizes the most common fuel deterioration symptoms, their causes, and best practices for preventing problems. Two Energy Institute (EI) guidance documents are scheduled for publication in 2019:

  • Guidelines for the investigation of the microbial content of liquid fuels and for the implementation of avoidance and remedial strategies; and
  • Guidelines on detecting, controlling, and mitigating microbial growth in oils and fuels used at power generation facilities.

In the U.S., the Diesel Fuel Oil Group (DFOG) – a consortium of nuclear power industry professionals responsible for diesel fuel oil storage at power generation facilities – in collaboration with the Institute of Nuclear Power Operations (INPO) – has recently published:

Practice Guide: Management of diesel fuel quality for emergency diesel generators at nuclear power stations.

The publications coming from CRC, DFOG & INPO, and EI reflect the stakeholder community’s growing recognition of fuel system condition monitoring in addition to fuel quality testing.

What Needs to Happen

For many owner and operators, NFPA standards don’t just dictate minimum condition monitoring actions, they dictate all actions. If it isn’t prescribed in NFPA 110, then emergency generator system owners typically choose to avoid the incremental expense of fuel system condition monitoring. Historically, emergency standby diesel power generation system failures have cost tens of millions of dollars and countless lives.

EGSA has proposed new language for inclusion in NFPA 110 Chapter 8:

8.3.7 –Diesel fuel maintenance and testing shall begin the day of installation and first fill in order to establish a benchmark guideline for future comparison. Diesel fuel shall be tested for degradation no less than twice annually, with a minimum of six months between testing. All testing shall be performed using ASTM approved test methods and meet engine manufacturer requirements. Fuel testing shall be performed on all diesel fuel sources of EPSS.

8.3.7.1 –Tests shall include at minimum, Microbial Contamination per guidelines referenced under ASTM D6469, Free Water and Sediment (ASTM D2709), and Biodiesel Concentration (ASTM D7371). Similar, modified, and proven methods recognized under ASTM shall be accepted. For acceptable values consult with the engine manufacturer and most current ASTM test documents -ASTM D975-18, and the Appendix X3.1.3 of ASTM D975-18, Standard Specification for Diesel Fuel Oils.

8.3.7.2 –For diesel fuel stored consecutively for 12 months or longer, a diesel fuel stability test shall be performed annually. PetroOxy (ASTM D7545) is the accepted ASTM test method for S15 diesel fuels containing up to a biodiesel blend of 5% and less. Additional methods may be acceptable, refer to most current ASTM test documents -ASTM D975-18, and the Appendix X3.1.3 of ASTM D975-18, Standard Specification for Diesel Fuel Oils.

8.3.7.3 –Any additional testing requirements shall be determined by equipment manufacturer, government regulations, recent test results, and geographical region. Refer to the most current NFPA 110 Annex A, ASTM D975 Appendix, and the CRC Report No. 667, Diesel Fuel Storage and Handling Guide for detailed testing and descriptions.

8.3.7.4 –If diesel fuel is found to be outside of acceptable range in the testing listed in 8.3.7.1, the fuel shall be remediated to bring back to the required fuel quality for long-term storage specified under ASTM. Remediation may be in the form of fuel additives, polishing, tank cleaning, or diesel fuel replacement, and will be dependent of the test results received.

It’s time for NFPA to adopt these proposed changes and thereby substantially reduce the risk of emergency generators failing to operate when needed. Similar changes should also be made to NFPA 25.

As always, please share your thoughts with me by writing to fredp@biodeterioration-control.com. For more information about EGSA’s activities, contact Michelle Hilger at mihilger@gentechus.com.

FUEL & FUEL SYSTEM MICROBIOLOGY PART 24 – PETROLEUM EQUIPMENT INSTITUTE’S 2018 CONVENTION

The Petroleum Equipment Institute (PEI) held its 2018 convention at the Las Vegas Convention Center from 07 to 10 October 2018. As usual, the PEI convention was held in conjunction with the much larger National Association of Convenience Store (NACS) convention. Today, I’ll focus on a few items that are particularly relevant to fuel and fuel system microbiology. I’m not going to attempt to provide anything approaching an overview of the entire convention. Instead I’ll report and discuss a few statements I heard from speakers during PEI’s Tuesday 09 October education sessions.

Regulatory issues

EPA Regulatory Update – Carolyn Hoskinson, Director of EPA’s Office of Underground Storage Tanks (OUST) and several members of her staff spoke to the current state of affairs regarding UST regulations. Tony Raia reported that with the 13 October 2018 compliance deadline looming, 32 states had updated their UST regulations to harmonize them with the 2015 updated US EPA regulations. Tony identified five state categories:
1. State Program Approval (SPA) States that have completed their updates and which are now in full compliance
2. Non-SPA States that have completed their updates to comply with the 2015 regulations
3. SPA States that have delayed revising their state regulations
4. SPA States that have updates in progress
5. Non-SPA States that have not yet updated their regulations per the US EPA 2015 regulations.
Bottom line is that we are entering a period during which there will be some confusion over compliance.

U.S. EPA UST Enforcement – Mark Barolo – the US EPA OUST official responsible for enforcement – noted that in nearly all cases, individual States were responsible for enforcement. Recognizing the confusion, Mark opined that inspectors were going to address violations on a case-by-case basis. Generally speaking, retailers who had been incompliance, had the required documentation, and demonstrated that they were making good-faith efforts to ensure that they remained in compliance, would experience less enforcement grief than those who have not. Mark’s colleague, Cho Yi Risher noted that the regulations do not prescribe the time permitted for site owners to repair or replace non-compliant equipment. Moreover, the inspections required by the 2015 regulations identify non-compliant equipment. There is no incentive for owners to institute predictive maintenance programs (see my 16 January 2017 post) that would detect failure trends before equipment became non-compliant.

Failure to detect uncontrolled microbial contamination and biodeterioration before they cause valves to seize or tanks and lines to leak is a false economy. A few pennies saved during regulation-mandated inspections can lead to remediation expenses in excess of $0.5 million.
Although for some of us, it’s hard to believe that the UST installed in 1987 – in compliance with the original UST regulations – are now beyond their 30-year warranty life. Discussion during the session’s question and answer period indicated that all stakeholders shared a common interest in ensuring that sites with tanks that were more than 30-years old would be able to continue to operate. I anticipate seeing articles to this issue in PEI Journal in the coming months.

Fuel Quality and Corrosion
Scott Boorse – PEI’s Technical Program Manager; recently retired from a major fuel retailer – made several observations that validated much of what I’ve been discussing in Fuel Microbiology What’s New posts. He suggested that in his experience, 100 % of all retail site fuel systems had some corrosion. He attributed much of this corrosion to the bacterial genus Acetobacter converting ethanol to acetic acid. I am convinced that most of the headspace and spill containment well acid production comes form chemical oxidation of ethanol to acetic acid. Microbes are involved in an estimated 50 % of all system corrosion issues, but – as I’ve written previously – microbes produce a variety of organic acids. These acids can react with chloride, sulfate, and nitrate in fuel-associated water to form organic bases (or salts) and strong, highly corrosive, inorganic acids – hydrochloric, sulfuric, and nitric acids, respectively. Still, Scott was on spot suggesting that UST system corrosion was much more wide-spread than most stakeholders realize.

Rebbeca Moore – GM and chair of the automotive industry’s Top Tier Detergent Gasoline and Diesel Fuel consortia – discussed the importance of fuel quality on engine performance. Top Tier is an auto industry sponsored compliance program intended to go beyond ASTM product specifications typically cited in state regulations. I’ll steer clear of the perennial debates between engine manufactures and petroleum producers that enliven our semi-annual ASTM D02 (Petroleum Products) subcommittee A (Gasoline and Oxygenated Fuels) and E (Burner, Diesel, Non-Aviation Gas Turbine, and Marine Fuels), but Rebbeca made an important point. ASTM specifications are often misused. They are meant to indicate whether a product (i.e., fuel) is fit for use at a single point and place in time (i.e., when and where the sample was collected). The petroleum industry’s infrastructure is vast and complex. Moreover, product ages (if it didn’t it wouldn’t combust so well in engines). Specification tests provide little information about how the product will age during storage.
Rebbeca illustrated the dilemma by listing the typical components of 7,500 gal of in-specification ULSD delivered to UST:
• 1 cup of dirt
• 1 to 2 gallons of water
• Up to 325 gallons of FAME (B5 ULSD is now included in ASTM Specification D975 Diesel Fuel Oils)
• 1 gallon of glycerin
• 5 to 40 gallons of additives
At sites that receive frequent deliveries, these trace amounts of dirt and water add up! Not surprisingly, along with measures that are outside the retail site or fleet owner’s control, Rebecca recommended more aggressive water removal and better dispenser filtration (there is an ongoing debate among stakeholders with some recommending that all dispensers have 5.0 µm, water absorbing filters and others arguing for 100 µm particulate filters). I share Rebecca’s view that all dispensers should have 5.0 µm, water absorbing filters. Marketers who are focused only on low rates and not product quality have argued for eliminating the filtration requirement completely.

Ryan Haerer – of US EPA’s OUST (https://www.epa.gov/ust) – wrapped up the session, sharing a few notable points. First, Ryan reminded attendees that UST regulations apply only to system components that are in contact with the soil. The US EPA does not regulate the condition of internal components that are not in direct contact with the soil (for example, submerged turbine pumps – STP – and their associated hardware). He also explained that under the UST regulations, there is a requirement that system components be compatible with the substance stored. This is likely to become interesting as new products (for example, E15 gasoline or substitution of ethanol with isobutyl alcohol) are introduced into the commercial fuel infrastructure – here I’m using interesting – in the same way it is used in of the phrase: “May you live in interesting times.” (Austen Chamberlain – British Foreign Secretary, 1924 to 1929 wrote that he had been told that this was an ancient Chinese curse, but his claim has never been verified).

Bringing it home

At this point we are enjoying an interesting paradox. Regulators, insurers, and an increasing number of retailers recognize that waiting until fuel systems fail is a problem. However, the system largely provides incentives for site owners to wait until failures have occurred. After failure, insurance covers component replacement costs. In many states, superfund monies cover remediation costs. When site owners invest in predictive maintenance, they only see the costs. Although there are benefits – not the least of which is customer satisfaction and a positive corporate image – they are intangible. How do we break the paradox?

Please share your thoughts on this issue with me at fredp@biodeterioration-control.com. I’ll compile comments and post them anonymously as a future What’s New column.

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