Odor Denial Syndrome: Can we have an "impossible biosolids" without odor?

I believe our biosolids profession suffers from an “Odor Denial Syndrome.”  Despite repeated evidence in my Google Alerts for “biosolids” that odor complaints precipitate most cases of adverse media coverage, you wouldn’t guess that this is a problem for us, based on the scant attention to odors during recent months of technical conferences.  April’s WEF biosolids conference in Fort Lauderdale offered 100 technical papers, yet only one dealt with odors, and those odors were in-plant emissions during drying. The IWA’s Leading Edge Conference on Water and Wastewater Technologies was held in Edinburgh in June 2019, and no technologies offered odor mitigation as an attribute. Our own organization, Mid Atlantic Biosolids Association, put out a call this past winter for presentations for its July 2019 conference, and no presentation proposal dealt with odors. (Still, please come, it will be great! Check out the brochure!)

The Merriam-Webster on-line definition of “syndrome” is “a set of concurrent things (such as emotions or actions) that usually form an identifiable pattern.” One non-medical example posted to the Internet is a “not-in-my-backyard syndrome.” So, I think I have a case here for calling out our “odor denial syndrome.” It is a concurrence of odor nuisance complaints by communities and an absence of effective mitigation measures by agencies and their contractors.

The power of syndromes was hammered home in what was, frankly, an unexpected article in the New York Times about the “Havana Syndrome”. This is a strange “brain” ailment suffered by employees of the U.S. Embassy in Cuba, first reported several years ago.  One suggested cause of the brain ailment was a microwave “acoustic attack” (Microwave weapon caused syndrome in diplomats in Cuba, US medical team believes), and another suggestion was poisonings (Were the Cuban ‘Sonic Attack’ Victims Actually Poisoned?).  But by the time of the recent NYTimes article Was It an Invisible Attack on U.S. Diplomats, or Something Stranger? a third hypothesis had gained primacy: “the diplomats’ symptoms are primarily psychogenic.” In other words, the diplomats’ ailments were what is popularly called “mass hysteria,” but more scientifically termed “mass psychogenic illness,” a premise well covered in the article “Mad Gassers, toxic buses and the Havana Syndrome: What society still gets wrong about the way stress can make us sick.”

I have been following the term “mass psychogenic illness” with Google Alerts for well over a decade, since I first made a case for biosolids odorants as a trigger for a special kind of syndrome. I put together a research paper in 2007 titled Biosolids Odorant Emissions as a Cause of Somatic Disease:  What is Our Profession’s Response? I argued that biosolids odorants are of a chemical nature likely to trigger in susceptible people a “psychogenic illness,” which manifests as symptoms that align with the “sludge syndrome” put forth in Ellen Z Harrison’s paper Investigation of alleged health incidents associated with land application of sewage sludges.  According to Harrison, the symptoms of the sludge syndrome “most common are respiratory and gastrointestinal symptoms, skin disorders and headaches. Other symptoms frequently reported by numerous people include nosebleeds, burning eyes, throat or nose, flu-like symptoms, and fatigue.” 

In my 2007 paper, I argued that “sludge syndrome” symptoms arising from odor nuisances are predictable.  The human nose is exquisitely sensitive to organic sulfide and nitrogen compounds, and adverse reactions may be genetically “hard-wired.” I argued that biosolids managers ought to plan for maximum odor containment and be prepared with an appropriate, proactive response to those people who display such reactions. I had push back from the some biosolids practitioners because I had amplified the suggestion of adverse health effects from odors.  Activists caught wind of the paper and were angered by my assertion that the “sludge syndrome” was all in their heads. I couldn’t win. What is more, the Havana Syndrome is, for me, evidence of how powerful psychological responses are as “health effects,” and of how important it is for our industry to better manage biosolids odorant emissions. If highly trained intelligence officials can be brought down by environmental triggers, so too can the neighbors to our land application sites.

What has been the history of our wastewater industry’s response to the very significant issues of odors? Well, until about the year 2000, we had had essentially no response. In that year we pulled together, both through MABA and joined by the Water Environment Research Foundation, a significant research focus. Now that we are in 2019, can we say we have solved our odor problems?  After all, many dozens of journal articles and conference presentations have been prepared, and WERF has its four-phase report, leading to the “Biosolids Odor Reduction Roadmap.” We learned that adding iron salts ahead of dewatering seemed to be one strategy, that using presses instead of centrifuges for dewatering seems to be an option, and that waiting a couple of days after dewatering for odorants to subside was also a useful idea.  But, for all our effort, no breakthrough on odor mitigation was discovered.  Yet, it seems that WERF declared the research done. My faithful attendance at technical conferences and recent Google Scholar searches did not reveal any recent U.S. based research project.

That is why I was so amazed at the odor research work coming out of Australia over the past several years. Specifically, this is research that has Ruth M. Fisher’s name on it, a research associate at the University of New South Wale’s Water Research Centre.  I have now in my library her eight journal articles on the topic of biosolids odorants published between 2017 and 2019 (mind you, Dr. Fisher is only one year out from completing her PhD). Let me list these publications:

·         Variations of odorous VOCs detected by different assessors via gas chromatography coupled with mass spectrometry and olfactory detection port (ODP) system 

·         Odorous volatile organic compound (VOC) emissions from ageing anaerobically stabilised biosolids

·         Distribution and sensorial relevance of volatile organic compounds emitted throughout wastewater biosolids processing

·         Influence of Biosolids Processing on the Production of Odorous Emissions at Wastewater Treatment Plants

·         Sewer catchment effects on wastewater and biosolids odour management

·         Framework for the use of odour wheels to manage odours throughout wastewater biosolids processing

·         Emissions of volatile sulfur compounds (VSCs) throughout wastewater biosolids processing

But it is Fisher’s 2019 review article on biosolids odors that, if I had my way, would be mandatory reading for all practitioners -- Review of the effects of wastewater biosolids stabilization processes on odor emissions.  She reviews over 200 papers, and, importantly, she makes sharp observations and points us to important work ahead.

Fisher makes clear that we do not yet have adequate odor analysis methods, protocols and tools. Let me provide quotations from her review:

·         “However, due to the large range of odorants which have been reported for all stabilization methods, the use any single analyte to represent odor is likely insufficient and will lead to the underestimation of odor impacts… the focus on only TVOSCs is potentially limiting.”

·         “From a methodological perspective, both sensorial and analytical methods are needed for odor characterization.”

·         “…the dominant burnt odor quality detected in emissions from dried biosolids has not currently been linked to a responsible compound, however, it is likely an important odorant.”

·         “...a Dried Sludge Odor Wheel, which reported odorants… shows a need for emission analysis using a combination of chemical and olfactory measurement methods.”

·         “…qualitative approaches to odor control… are limited due to our lack of understanding of emission composition. The identification of odorants and the sensorial implications can provide a clear link between process performance and nuisance impacts.”

Fisher believes we need to study far closer than we have to date the link between processes and odors.  Again, here are some pertinent quotations:

·         “…the upstream plant configuration or operational performance were rarely reported, which makes links between emissions and WWTP performance difficult to establish.”

·         “To date little success has been reported in predicting the odor quality of biosolids produced using other (than anaerobic digestion) stabilization processes based on process operation.”

·         “Despite the large amount of research into emissions from anaerobically stabilized biosolids, no single operational parameter was found to predict biosolids odor. However, general trends between odor emissions and dewatering, storage, digestion and chemical dosing have been identified.... none were able to reliably predict the resulting biosolids odor quality…”

Even when we have some clear relationships between process and odors, Fisher suggests that actions that would reduce odor risks are not chosen. Here are some quotations:

·         “The choice of stabilization methods for biosolids processing should be influenced as much by the operational requirements of the process as the desired properties of the biosolids product.”

·         “It is vital that the odor implications also be considered when evaluating process performance.”

·         “…the emerging relationships between process instability and downstream biosolids odor emissions, reinforce the importance of stable operation and good process monitoring and control.”

·         “Stabilization processes which rely on the disinfection of biosolids, such as alkaline or thermal treatment, are heavily influenced by previous sludge handling as the organic content has not been significantly altered during stabilization.”

·         “When wetted and applied to soil, the dried un-stabilized biosolids were judged as the most offensive, presumably due to the production of VFAs and sulfur compounds due to microbial activity on the remaining organic matter.”

·         “the storage or land application of the stabilized biosolids with high organic matter content typically lead to more unpleasant of odors, compared to those which had originally been digested and had lower organic matter contents.”

The Odor Denial Syndrome is far worse than I have acknowledged to myself in the past. It leaves us vulnerable to justifiable public criticism, and it undermines our claim to environmental stewardship.  Odorant emissions are the biggest source of risk to the wastewater profession arising from community, political and regulatory upset. Yet, our industry persistently fails to hold as a central focus in its design of facilities and operations the objective of minimizing odorant qualities of biosolids. New treatment technologies are almost never evaluated for the odor quality of the biosolids they produce. Standard operating procedures at our plants do not generally encompass “best practices” for minimizing odorant formation in the biosolids product.  Public bidding documents for land application services seldom accommodate contractor activities that are responsive to minimizing odor releases, as might be accomplished through responsive storage and application practices.

I propose we fashion for ourselves an alternative narrative about biosolids odors and to genuinely commit to its outcome: we must develop technologies and practices that prevent public odor nuisances.  To do so, we need to be committed to change.  I recently read that “2019 is the year of faux meat,” as start-up companies are successfully introducing the plant-based Impossible Burger and Beyond Burger for those who wish to change their meat-eating habits. With apologies to their marketing gurus, I propose that we have an alternative so incredibly transformational that we can brand our new narrative the Impossible Biosolids.