 So, well, we're really happy to have Greg here today. Greg Omula needs, I mean, Siacy will do a proper presentation, but I'm very excited that we can have a discussion on everything that is happening at scales that normally escape the capacity of architects to work in. And actually that's something that in Greg's work, he was just mentioning that he found a great joy and potential in collaborating with NGOs and with other organizations. And we hope this is the beginning of a long conversation where this collaboration could also happen with architects. Because actually architecture, a big part of what is important for architecture happens at scales that our tools are not accurate enough to work there. We cannot sense that. Neither we have the knowledge. It's a great opportunity and kind of a call for collaboration. And this is a series of, the Techno Critical Assembly series of meetings in which we actually build up conversations with representatives from other fields that are working on inquires that are very relevant to architecture, but that somehow we are not prepared to deal with. And also acknowledging that this is a field where not only, let's say, knowledge has been innovated or challenged, but also where politics and criticality is also built up. So Greg, I don't think there's anyone better than you to have this discussion today and we're really excited about that. So the format that CSC will be presenting you properly, then you present your work and then we will engage on a discussion. I encourage everyone to take notes so we can make the best of this huge opportunity to have Greg here with us. Great, thank you so much. Thanks for you. Okay, so hi everyone. Welcome again to tonight's this week's Techno Critical Assemblies with Dr. Gregory Mullen. So Greg is a professor in the School of Earth and Environmental Sciences at Queens College CUNY. His doctorate was completed at Princeton University and the postdoc training at Columbia's Lamont-Doherty Earth Observatory. And I believe your research group there still specializes in environmental microbiology and pollution assessments and urban environments sort of focus on aquatic sort of environments, right? For us, we are super excited to talk to you as a group of architects because we understand architectural practice today and of course for the future is firmly rooted and situated in the very specific realities of climate change and the real critical needs to build a literacy with other disciplines and their knowledge in addressing the environment that we all share in inhabiting but that we all share in constructing, right? And even more so, Dr. Mullen's research and specific knowledge of New York City sort of scales both down to the microscopic but up to the entire Hudson River estuary which is one of the most complex and entangled and dense built and natural sort of entanglements on the planet, right? And it's particularly as we often use this term in our program, a trans-scaler and we understand this term trans-scaler as a way of addressing design as a practice in which actions at the scale of buildings or infrastructure that we're more familiar with is also reflecting and affects simultaneous realities are happening at much smaller or much larger scales. So in a way, we are both practicing at skills that sometimes we cannot see, you know, we can't see with a naked eye something that's microscopic but nor can we see something with a naked eye that's, you know, in the scale of a city or at the scale of a watershed, right? So in building this world that's quantifiably linked by, you know, the microscopic to scale of a pipe or a building or a neighborhood or a city, you know, we recognize in both our disciplines that it's really enacted on by humans, by other species, by policy, by politics, you know, commerce, agriculture, et cetera, et cetera. I mean, it's enacted upon by everything. And for this, we are super excited to have this conversation with you and understand really from, you know, from your expertise how we can start to build this conversation exchange between us. So with that, I welcome Dr. Amulan and I turn it over to you for your talk. All right, thank you so much. I'm excited to be here tonight to have the opportunity to speak with you all. I think this is really appropriate in a variety of ways. I will probably be often out of my depth in thinking about the translation of some of the things that I sometimes spend a lot of time thinking about to the built world from your perspectives. So that's exciting to me, right? That's great. That's where exciting things happen. I've spent a lot of my career interacting with very diverse groups from NGOs and agencies, community scientists, trying to stretch the boundaries of what I had 15 years ago viewed as the role of academic science and academic scholarly activity. And it's at those boundaries that I've actually found the most joy, the most excitement, the most challenge. But also, I think where the rubber really has met the road in a variety of ways with my science where I could start to see the impact of the work potentially changing little things that were being made beyond and which you have to have, right? As the backup for a lot of it. But it's been on the edges of that that I've kind of found the most excitement. So I hope that you all, it sounds like this is a great opportunity to explore those boundaries. I hope that you continue to do that throughout your career because that's where it gets really exciting. When you start to get a little nervous and you start to have to rely on other people's skill sets and knowledge, that's each environmental microbiology and often are talking about global biogeochemical cycles, thinking about carbon cycling or nitrogen cycling at the scale of an ocean. And yet, we're trying to understand the mechanisms that are driving this both at the ecosystem level, as well as at the cellular level. And the challenge of thinking, for example, of, I was talking earlier today about a paper from 1961, I believe, thinking about how is the water column of a lake or the ocean able to support so much diversity with the concepts of competitive exclusion? This seems like a very stable, simple, homogeneous environment. How do we maintain the kind of microbial diversity in this? And how do we balance that with this view of competitive exclusion and natural selection? And it turns out there's a whole variety of answers to that. But one of them is, of course, that our view of that water column as being homogeneous is not the microbial view. At the level of the microbe, at the micron scale, that seemingly homogeneous environment is actually full of particles of different size. It's full of gradients. It has boundaries at which there are different energetic reactions occurring that can very easily be overlooked. But you can't really understand system level process unless you have some appreciation for the cellular level interactions. So this is something that I think, I'm not sure I'm good at, but it's a challenge, right? And it's a fun challenge to be able to view the world through a variety of different lenses. Like you said, larger, it's difficult to view the city as a whole or the Pacific Ocean as a whole, but also at the micron scale where a lot of the chemistry and the cellular interactions are occurring. And not just within a cell, but even the kind of concept of the community metabolism of microbes and not really viewing it from a pure culture microbiology standpoint, but from this assemblage of environmental microbes that together have emergent function. So I think it's really appropriate that we probably wrestle with many of the same kind of issues of scale. So with that said, I'm excited to talk with you. I hope that you find some of what I have to say. I wasn't exactly sure which aspects to be highlighting tonight. And it may be that actually our most interesting conversations have very little to do with our slides. We'll find out. So won't that be fun? So here we go. I'm gonna share screen now and bring up some slides that I'll just confirm that the slides are visible. Yes, they are. Yes, okay, great. So I wanted to talk to you today about microbial dynamics in urban aquatic environments. I've been introduced. I should introduce a few of the people who are responsible for some of the various aspects that'll be talked about today. And this actually is, of course, only a partial list. But Eli Duker, who was a graduate student at Columbia University and did a postdoc in my laboratory. I've been interacting with him for coming up on two decades associated with particularly the bio aerosol components of what I'll talk about. He's now a tenured professor up at Bard. Angel Montero, who's a recent master's student at Queens College. Andy Joule, who's at Lamont Doherty, who's been a collaborator for over a decade. Suzanne Young, who now is working with the World Health Organization and Riverkeeper, with whom a lot of this work has been done in collaboration with and in parallel with. So I just wanna make sure that I acknowledge some of those people up front. Okay, so what I wanna do is start with some overarching questions. And we're overarching goals, rather. The goal of my work more broadly is kind of to understand patterns of microbial sewage pollution in the urban environment. New York City tending to be my test to answer that question, but hopefully with things that come out of it that are both locally applicable, but also more broadly applicable to other urban centers. We wanna improve, not just understand the patterns, but we want to actually be able to improve the management, make better decisions when it comes to water quality management, as well as I've become convinced the importance of some of this. And therefore, I try to convince others. I try to motivate, frankly, improvement in urban infrastructure to create benefits both for environmental health and public health. So it's this boundary of the built environment of New York City and its waterway. New York City, of course, has over 500 miles of coastline. We are a city of islands. And with that, there's a long history of pollution issues, but there's a long history of connection to the water. And as the city has developed its infrastructure is still rather old in many cases that I'll talk about. And that has created pressure on the environment and it has changed the way in which we view the quality of this environment. And sometimes we can think about the aquatic environment in New York is something that doesn't have a lot of value or something that is beyond repair. And I'm just convinced that neither of those things are true, right? It is something tremendously valuable to our coastal city. And it's something that has been improving and really can continue to improve, but it takes an active decision to make that happen. So it's in that light that I'll go about talking about some of the microbial interactions today. Okay, so New York City has 14 highly functioning wastewater treatment plants. These are, the picture here is this on the edge of Newtown Creek at the boundary of Brooklyn and Queens with the Manhattan skyline in the background. This is just one of the highly functioning plants. If we can get our waste to these plants, they do a rather good job of cleaning the water before it is discharged back into the environment. This particular plant is also used for energy creation in the process of cleaning that water, right? And actually has also taken on organic from food waste in addition to, but that doesn't mean just because these plants are highly functioning, it doesn't mean that our waterways are free of sewage pollution. And it also doesn't mean that more plants are gonna solve the problem. The issue upon infrastructure that's often more than a hundred years old and the population of the city has expanded tremendously since many of the pipes in this delivery system were put into place. In order to understand the delivery system, we have to understand that we have both a combined and separated sewer system. So the two images on the top here are cartoons, if you will, of a combined sewer system. And I'm sure many of you are aware of this, but just in case it needs some refreshing. So during dry weather, the simplified version that we have here is that sanitary sewage from our buildings, from industry, goes into a delivery system that makes its way to a wastewater treatment plant. And during dry weather, this system generally is able to process all of that waste at the wastewater treatment plants quite well. And this has resulted in major improvements in water quality over the last hundred years as the number of plants and the technology at these plants has expanded to treat them. However, the drains that are on the side of the street are often connected to this same sewage infrastructure in this combined system. And the combination of additional buildings and additional drains and impervious surface creates a load that the pipes in this delivery system are often unable to handle. So it's beyond the capacity of those pipes, but it was designed with a series of overflow points. And this, of course, is a good idea from the perspective of avoiding surface flooding or the inability to add more flow to these pipes. You wouldn't want to say, okay, well, this building can't be running the sink or the showers or the whatever. So unfortunately, this means that a combination of rainwater and sanitary sewage overflows without any treatment at all during wet weather into local waterways, a portion of the waste that does not make it to a wastewater treatment plant. In other parts of the city, the sanitary system is separated so that all of the sanitary waste goes to a wastewater treatment plant and the storm drains on the side of the street are directly discharging in wet weather when they are receiving flow into a waterway without treatment. Those are that kind of the generalized version of this combined and separated sewers. We have addressed some of the concerns associated with this combined sewer system with long-term control plans and New York State and New York City, actually a number of years ago signed entered into a consent order because the city on a variety of discharge pipes I'm about to show you and those pipes, those permitted discharges where sanitary waste is going into waterways were causing the waterways around New York City not to meet state standards. And as a result, there could be fines that were put into place according to the Clean Water Act which the federal government gives the state the responsibility of overseeing those water quality guidelines. So to avoid finding the city who was the permit holder there was a consent order that was entered into that said they would study the issue and they would put into place management steps to begin to improve water quality such that stop impairment of our surface waters. This has led to a multi-billion dollar investment in upgrading the sewer systems in New York City. However, it's not enough, right? A multi-billion dollar investment does make substantial progress but it is not enough to avoid these combined sewer overflows. Many remain and many will remain once this long-term control plan is fully executed. We've also had some changes in management in recent years that even these separated stormwater pipes are now permitted discharges under what's referred to as the MS4 permit. This was new in 2015 for New York City and these are now permitted discharges and the city has to come up with management plans to deal with the pollution that is delivered via this stormwater system as well and those are thousands of additional pipes now are under management by the city. So this is a image in green. We have the roughly 60% of the city that is in a combined sewer system and in orange the roughly 40% that is in a separated Manhattan here and showing some of the areas that are going to various wastewater treatment plants these sewer sheds if you will. And each of these dots represents a combined sewer overflow point. So these are the points where this combined stormwater and sanitary sewage would flow into the local waterway without any treatment due to the capacity issue in the delivery system. This results in about 20 billion gallons approaching a 100 billion liters of CSO discharge per year and that's what we're trying to avoid by upgrading the primary thing from a bacterial water quality perspective that we would traditionally be concerned about here is that this sewage contamination is increasing pathogen load and that those who come into contact with it in this case this is kids jumping off a dock just north of the city up in the Tappan Z area. The concern is that they could become ill from coming into contact with water that has sewage contamination. That issue of swim ability is something that I've been actively involved in for about 15 years. So when I came to New York City, I was surprised at the lack of information and especially publicly available information to answer very simple questions about how the water is, what was the quality of the water? And I became involved with Riverkeeper in collecting data initially that was brought back to a laboratory space at Columbia University and then became through a mobile lab on the boat. We did monitoring at 75 locations which has been going on now for more than 12 years between Albany and New York City and thousands of samples have been collected to characterize and make that information available to the public and to managers about the quality of the water from a bacterial water quality perspective as well as oxygen levels and a variety of other things. So this was the first involvement that I had in gathering information and engaging with partners to improve decision making with additional information. Okay, so this was a seasonal sampling program that goes April through November, conducted primarily from the Hudson Riverkeeper. The primary bit of information that I'm gonna talk to you about is Enterococcus which is an EPA approved fecal indicator bacterium. So this is commonly used at marine swimming beaches to determine can you go in the water? Do we shut down Jones Beach, right? That's the concept here. There are guidelines that the EPA has put into place that New York State accepts and therefore we can measure the level of sewage pollution and compare it to a regulatory framework. That's really the power of this approach. It's rather simplistic but it is linked to a regulatory framework and that has a lot of power, okay? So the other part of that information was just making that information available to the public, engaging them in the scale and the patchiness of contamination issues. And we'd often find that communities on two sides of the river in very close proximity to one another had very different water quality and with that information became a lot of power to start to figure out why and to start to think about local solutions to something that may have been viewed by some as this is a regional issue. But that local patch size to contamination actually was empowering to change. So the indicator enterococcus. So the concept is enterococcus is in all of our guts. So it's not the dominant microbe in our gastrointestinal tract but it is ubiquitous. So we all have it, okay? There are EPA approved methodologies and there's regulatory guidance for how much is too much from a primary contact point of view. So swimming, waiting, et cetera. So the concept is we expel waste in fecal material which has a large microbial load. Enterococcus is just one of the microbes that is present in that waste. There's also lots of other fecal microbes some of which are pathogenic. Enterococcus is not the primary microbe that is causing illness. It is simply what we use as a tracer of that waste. So the concept is the sewage microbes. There's all of these other microbes that we don't routinely measure. And we measure enterococcus with approved methodologies and utilize that information to essentially track the other fecal microbes as well. So when this goes into a natural waterway is like this map of the New York bite here and the Hudson River and East River and Long Island sound polluted waterway, a pristine waterway has still lots of bacteria in it, right? A million bacteria per milliliter or something like that, right? However, a polluted waterway is going to have all of those background microbes that are present in the pristine system plus these sewage microbes. And then a small percentage of them are gonna be the fecal indicator bacteria that the EPA guidelines are based upon or targeting. So that's enterococcus, okay? By a decade's worth of data collection, one of the trends that we see is over long periods of time, over decades, there's information in New York City especially to show that water quality's been getting a lot better, right? Management action is making a difference. The water quality is better than it has been in decades. Despite that, there are a large portion of samples that are unacceptable according to EPA guidelines from a fecal pollution perspective. If we look across all of the weather conditions, we see that about 23% what's here in red are the samples that would be considered unsafe for primary contact, okay? About approaching a quarter of all of the samples, you wouldn't want to be coming into contact with swimming in, et cetera. This gets worse if we look at the percentage of samples broken down wet versus dry. The levels in wet are almost three times that of the dry weather samples. So wet weather discharges appear to be very clearly raising the level of fecal contamination. If we compare the urban centers to some of the areas, I mean other parts of the river, this is clearly an issue in New York City but it is not restricted to New York City at all. Okay, so these are patterns that suggest both, there's a lot of room for improvement still. A lot of the samples are unacceptable when we go out and collect between Albany and New York City and that there is a pretty strong connection to the wet weather pattern of discharge, okay? So moving closer to my laboratory, Flushing Bay is an embayment near LaGuardia Airport, right? That I'm sure you're all familiar with. We have the US tennis center and city fields right on the shoreline of Flushing Bay. And you see it here circled. These are representing the red dots are the largest CSOs, the largest combined sewer discharge points in the city. And two of them are located right here in Flushing Bay. So this is a place that we wanted to study a little bit more because it was close to the laboratory. We could do some high frequency sampling. And the image you see here is a public launch. You can go here, people are commonly launching jet skis or kayaks. There's a very active dragon boating racing community that's here. People are on the water a lot. So what we did was we looked at the level of enterococcus, which is that fecal indicator bacteria under wet and dry conditions at the public boat launch, not right next to one of these overflow points at the public boat launch. And we saw that the levels of the fecal indicator, which you see on the orders of magnitude higher, about a hundred times higher in wet weather than in dry weather. We also went and looked at cultivating antibiotic resistant bacteria, both tetracycline resistant bacteria and ampicillin resistant bacteria. And what we found was they had a very similar pattern of increase in wet weather. And the reason for this was pretty clear. And we've sampled directly in this CSO discharge to show these concentrations are highest there. So this here is one of these big CSOs, entering flushing, entering flushing bay. This is about 15 feet. And it is a river of sewage during wet weather events. It can be bottled up by the tide. So it has influenced the level of that pipe and the tidal height can act to stop or some of that flow under certain conditions. But it is actively impacting the waterways around it with unacceptable levels of fecal indicator, but also other microbes of concern, such as these antibiotic resistant microbes that are clearly things we want to minimize in the environment. So another approach beyond measuring the occultivation, our scientists, this is a study led by Orin Shanks at the EPA who went around to all different parts of the country and really around the world. And they sampled untreated wastewater and they used high throughput DNA sequencing to characterize the shared microbial community that was found in this untreated fecal waste everywhere. So this is the core microbiome. And what they did was they found samples that or they found species rather and actually often broader taxonomic groups even at the family level that were overrepresented in sewage. And this became microbes that were indicators of this kind of contamination. And this has been utilized in a variety of systems since to track pollution in natural environments from these kinds of discharges. So we come up with a group of sewage fecal taxa that are dominant in these wastewater systems across a variety of geographic locations. So what we did was we went and sampled stormwater coming off the streets of New York. So this would be coming out of a separated system. And it turns out actually there's very high levels of the fecal indicator bacteria coming off the street surface. But when we sequenced those street water samples, the level of the taxa associated with human fecal waste as based upon the prior studies that I was just mentioning, it tended to be 1% or less, a fraction of 1% of the microbial community when we came up with all of the taxa that were represented, the composition in street water is very low from a fecal perspective. If instead we look at that combined discharge of stormwater with sanitary sewage waste, it jumps to the majority of microbes are often within these taxa that are associated with raw sewage. So very clearly there is a human fecal signal within these combined sewer overflows, which is of course what we would expect. If we look at Flushing Bay, what we see is just like that fecal indicator that the EPA uses, the microbial community shifts dramatically. It goes from just a fraction of a percent to upwards of 10% in some cases of the microbes in Flushing Bay, this is essentially becoming an extension of the sewage system under these wet weather conditions. But remarkably during dry weather, just a few days after rain, that bay returns to a condition that actually would be acceptable according to EPA guidelines for safe swimming in most dry weather days. So there's this major change that's happening to the quality of that water based upon how frequently there's been this pulse of sewage. So it's a very dynamic environment, flushed out by the tide and these many of the microbes that are being added to the system are not persisting there. This is not their natural environment. They're often reproducing within the gut. They're discharged into a salty water system. They don't last very long, but it causes this change in the quality of that water from a bacterial water quality perspective based upon rainfall, right? Based upon triggering of wet weather discharge. Okay, so that's a story that you've probably heard a variety of times in different places you're generally aware of. Also about the connections of this. We tend to think about New York City coastal water. I talk to people all the time and their response is, yeah, I know it's polluted. I would never go in there. Almost like it's not a problem. They've kind of ridden it off and it's at arm's length, right? Yeah, okay, but I don't go in the water anyway is a lot of people's response to this. We mostly view sewage contamination as a concern moving from land to contaminated water that we may or may not be using for certain types of activities. I've become convinced that sewage pollution is not only a land to water connection. We need to understand the full range of connections. To give you an example of this, I actually was out on a boat with a deputy director of the New York City Department of Environmental Protection soon after she came from the west coast of the area. And we are touring up and down Newtown Creek, which is one of the most heavily polluted locations in New York City. It's a federal superfund site and it has, again, some of the biggest CSOs in the city. And on this particular day in late fall, there weren't many people who were out on the water and that comment was made, okay, we understand that this needs to improve, but there aren't many people out here. Is this the top priority? And what I was able to say was, in the days after Hurricane Sandy, I spent the days crawling around basements in this neighborhood. And what's viewed as a polluted waterway that runs on the edge of some of our neighborhoods didn't stay on the edge of our neighborhoods. This was a waterway that instead, flowed up over the banks, was in the streets, right? There were marks on the buildings as to where the floodwaters had risen. People were actively pumping out their basements. They were using shovels to remove the sediment that had been delivered during these flood events from one of the most heavily contaminated waterways in the nation. So that water doesn't always stay there, right? It doesn't always stay at arm's length. There are connections that occur. And flooding during these storm events is one example of a land to water connection that brings that waste back and makes it perhaps more of a public health concern, okay? Another is that we know there are aerosols that can be formed off the water surface that can be blown back inland, but we haven't really studied this very much. And more importantly, there's absolutely no regulatory framework to say how much is too much of bacteria in air or the types of bacteria in air. We just haven't gotten there yet. But I'm convinced that this is an important interaction and that we need to be concerned in New York and in many other parts of the world about polluting our waterways because it is also creating an air quality concern, okay? To give you a little bit of insight to this, we often think about water as a microbial habitat and polluted water as a microbial habitat, but air is also a microbial habitat. It's a very diverse, rich microbial habitat. So this is from a 2019 paper that Eli Duker was the lead author who's the professor up at Bard now. And we took paired water samples around the coastline, paired water and air samples around the coastline of New York City. And we collected DNA out of it and we sequenced the community that was there. And what this graph is showing you is the number of species by sampling effort, okay? Sequence sample size. So this is how many DNA sequences from the water sample or air sample did we get? And then how many of them represent a unique species is something about the diversity of that sample, okay? So a factory that is showing a lot of curvature is going to have reduced diversity compared to one that is extending more vertically, okay? What that means is per unit sampling effort. Well, let's get 10 more sequences. Are we gonna get any more, any new species or not? What was surprising here was that in paired water samples of water and air, what we found was there were more microbes, types of microbes, the diversity of microbes in air than there were in water at these paired locations. This is from New York City's coastline, as I said. So air is a very diverse microbial habitat, okay? This is interesting because we also compared the same type of paired samples just with much less sampling on the coast of Maine. What we saw was the opposite path the ocean in Maine actually had very low microbial diversity. There's still microbes in it. There's plenty of microbes in it. But the number of types of microbes was far reduced compared to what was in the water itself. In the urban environment of New York City, the air was tremendously diverse microbial habitat. So I just wanna put that in your mind that air is something that we can kind of think, ah, there's nothing living in this, but of course there. I'm particularly interested along with Eli Duker in this connection of water and air quality. So here we have Johnny sitting on the dock fishing, right? And there is a connection, although we don't see it, being formed from the water surface that are emitting droplets of water up into the air, especially when there's turbulence. The water is interacting with the shoreline. Wind is creating white caps. A boat drives by and there's a wake. There's a whole variety of interactions that cause these micro droplets to be jettisoned into the air in small water particles. And they carry with them microbes from that water surface that are still viable in most cases. We can grow them on Petri dishes, okay? And with onshore winds, this is connecting microbes that are in water transported through air and being deposited, either respired, inhaled, or just deposited on surfaces in the built environment, okay? So this is interesting. We kind of have always known that this was occurring, but we can't particularly interested in this in the concept, in the context of urban sewage pollution, right? And all of the things that we think about in water as being of concern, but what is that connection back to air quality in a densely populated area in a coastal city like New York City? The idea here is that the public health impact of sewage contamination may not end at the shoreline. And what we discharge into that water may not remain there. Portions of it are coming back onto land, okay? So in order to demonstrate this with data and in fairness, this is an image of white caps that's not from Flushing Bay. I didn't have a good image of white caps from Flushing Bay. So this is something I've pulled from elsewhere. So, but the idea is when wind moves across water, it creates, when you get to about four meters per second of sustained wind, you start to form white caps and the breaking of these small waves at the water surface creates the white that we see when we look across New York Harbor on a windy day. And what that is are these bursting bubbles that are ejecting particles into the air. And with that, water droplets are viable microbes. So what we did is we took a Anderson sampler which is a pump that size fractionates particles in air and impacts them on petri dishes. So we can actually grow the microbes through the air that we are pumping onto these plates. What we found was that on relatively calm days, wind speeds under four meters per second, there certainly were microbes in the air, but on those windy days with onshore wind, what the wind was carrying, first of all, the particle size became larger because it was instead of fine particles that have been transmitted long distances, it was locally produced water droplets coming off the water surface that became a larger percentage of the particles in air. We know this with particle counters as well as the size fractions of the petri dishes that the particles were impacted upon with the sampler. And the total number of bacteria, these are colony forming units per cubic meter of air that grow on a particular type of media. This is certainly not all of the microbes, they're growing on one particular type of media. Increased substantially under these high wind conditions when there was more activity at that water air interface associated with white caps. So this is an indication that wind can be one mechanism that drives and that increases the connection between what's in water and what's in air, while also actively transporting it back on to shore, okay? Another way that this happens is through management action. New York City has a number of waterways where sewage contamination enters these systems, the Gowanus Canal, Newtown Creek, and the systems because of reduced circulation and all of that extra organic material and microbial biomass that enters the system through that combined sewage overflow. The oxygen levels are drawn down, okay? And because the oxygen levels are low, it is not a suitable habitat for a lot of wildlife and it can smell. And importantly, there are regulations and the regulations say you have to do something about this. Just like the bacterial level is too high, there are sources of impairment for low oxygen. So New York City is actively bubbling like a fish tank, right? Some of our waterways as a way of increasing artificially the level of oxygen to meet standards. This to me is absolutely treating of the symptom instead of the source of the problem. We're not, we are in fairness, we are taking steps to reduce the level of sewage contamination, but not enough to address the oxygen issue. So instead we treat the symptom, we bubble it, right? So that the oxygen level comes up. And this is, you know, there are reasons that maybe this is a good idea, right? In fact, it does become a more hospitable environment for some organisms, but it's still heavily polluted. If we could instead address the source of that contamination, we'd be much better off. But more importantly, perhaps we know that these waterways are very heavily contaminated. And the act of bubbling them as you see in these images is creating frothing at the surface, very much like the shoreline interactions where the boat wake or the white caps that form those aerosols. And sure enough, when we go and sample there, again, not just with DNA-based approaches, we've done that a number of times, but with cultivation-based approaches. So we know that these bacteria are capable of growth and potentially capable of causing infection. These are microbes that when the aerator is on, there's about two times as many viable microbes in the air above this waterway as when the waterways, the aeration system is turned off. And we see from deep DNA similarity, the microbes in air start to look more like the water as well. Okay, so this is a management connection between water and air that is moving contaminated water up into the air mass, but there's no rules for that. And that's the issue. We talk to local management agencies and they say, okay, but there's rules about what's in water. There's no rules about what's in air. It's hard for us to act on that if there's no regulatory framework to say, this is bad, right? This is too much. Okay, there really are no regulations for bacteria and urban air in general. One of the few places where we come closer to it is associated with cooling towers. In addition to there not just being regulations, we have a very limited understanding of what are the major sources of microbes to air in these kind of urban built environments. But there is recent focus upon cooling towers which are on the top of most of these buildings in the city, right? And they're associated with heat exchange and they have streams of water that are being passed down, a honeycomb high surface area system with air blown counter to the flow of water and aerosol particles are known to be produced. This is a concern in association with Legionnaires' disease, right, an intense form of pneumonia that can be lethal. And in 2015, there was a large Legionnaires outbreak that was the largest in New York City history, at least identified in New York City history. And as a result, New York City took very aggressive actions to regulate the water within these cooling towers. Not the aerosols, but the reason they're doing it is because of aerosol production. They're not measuring the microbes in air, but this is a place where actually policy is starting to identify the movement from water to air in the built environment as a result of an engineering intervention. Similar to what we do in aeration of waterways, but we haven't gotten there yet. Okay, so this is an area in the built environment where we are starting to take into account the ways in which we're altering the distribution of microbes and especially microbes put into air that can be a cause of concern for respiratory illnesses. I think there are lots of examples in the built environment where we have similar concerns. We just haven't necessarily gotten to the point of directly managing them yet. Okay, so this is kind of the closest parallel we have. I also wanna put this into, without being scary or alarmist, put this into the context of the recent pandemic that's going on. I last spring was associated with some work that was measuring of SARS-CoV-2, the cause of the agent of COVID. And this was occurring in sewage impacted waters. We now know, which was unclear actually when we started some of that work, we now know that one of the best ways to study the levels of SARS-CoV-2 impact in the public, its prevalence and some of the sources are actually to study wastewater, right? This is instead of having to go and sample individual people, it's aggregating that signal from particular sewer sheds. And without having to track all of the people, we can look at changes in the level of that virus in wastewater. Now, there's been a lot of World Health Organization and CDC guidance about wastewater treatment plants. The good news is SARS-CoV-2 is actually rather easy to kill. There are a lot of common disinfectants that do a good job of removing it from surfaces. Chlorination in wastewater treatment plants has seemed to be pretty effective. So the sewage treatment, the sewage treated waters aren't really of concern, but we know it is present in fecal material. There's some evidence that it may be able to cause infection through those pathways. So what about those connections to all of this untreated sewage that's entering our waterways? Well, I was able to, at the peak of the cases last spring, detect in sewage where it was entering our waterways, SARS-CoV-2, from an RNA perspective. We still do not have an indication as to whether it was or was not capable of causing infection. Was it just RNA or was it viable? Was it a virus that was able to cause infection? We don't know, but it is well known now that there can be high levels in fecal material and therefore this mode of transmission is something that we are much more aware of now. We're also starting to look more at those aerosol connections. In the last couple of weeks, I've actually reviewed two papers about this topic. It's really just starting to come around that we're thinking about these untreated flows to the environment and whether that is or is not causing some kind of a feedback for public health. It's unclear, but this is an area where contact with contaminated water, the water itself, but potentially also aeration is of concern. From a built environment perspective, in New York State, many wastewater treatment plants only disinfect their waste during the recreational season. They'll start in May and they end in about October. Out of season in winter, many of those plants are not disinfecting. This is true in the Tappan Z just north of the city. In New York City, disinfection happens year-round in fairness. Okay, this is something that for a whole variety of reasons may need to be reconsidered. We haven't taken into account the full range of connections or the reservoirs, particularly in particles and sediment, that these bacteria can actually persist for long periods of time. So you may encounter water in the recreational season with microbes that are persisting from weeks before when it was discharged in the non-recreational season. I'm convinced that that's an important area for continued management. These waterway aeration systems, again, are creating this aerosol connection that we don't yet understand. These are actively occurred this past summer. I talked to local management agencies about it and it proceeded. There is not yet enough knowledge to really determine whether this is a risk factor or not for transmission. But we need to have a better understanding. I'm convinced of bio aerosol formation. We've started to take it into account with things like the air handlers and cooling towers, but there are other sources of aerosol transmission in the built environment that we have not yet addressed. But the bottom line is there is not yet a framework in which to evaluate that connection as there is in water. So this is an example where the infrastructure, the built components of the system are altering the distribution of microbes in ways that we just don't yet understand. What are some of the solutions to this? Well, solutions can be to reduce water pollution, right? So we need to be less concerned about aerosol formation if we're not polluting our waterways. That comes back to an infrastructure investment. Many of the pipes that we've put into the ground in the city, again, are over 100 years old and the connections to them are far beyond their capacity in wet weather. We can upgrade the sewer delivery system. We've already upgraded a lot of the plants. There's room to do a little bit more of that. And urban planning for ways to take into account sewer connections is incredibly important in urban environments. We need to be expanding green infrastructure that can infiltrate like this bioswale that you see here with the curb cuts that can take that water before it enters the combined sewer system and infiltrate it. It also is a way of greening our city. But the primary reason to do this here is to prevent stormwater from entering that combined system. There's also retention tanks that have been, for example, on the edge of Flushing Creek, which runs into Flushing Bay, it's a 50 million gallon tank that has been put in there as a retention tank as a sewage control system. We need to have expanded design innovation, expanded regulation beyond just water and better permitting of these pollution discharge sources as well as things like aeration sources that can act as aerosol formation and transmission distribution systems for microbes in the environment. And finally, I think public education is one of the things that's really necessary. So we have a lot of tools to address this, but we haven't really taken into account the full range of our impact on the environment or its connections with public health. And I think that there's lots of opportunities to do that in urban infrastructure outside of buildings, right? Thinking about the sewage delivery systems. I think there's also a lot of opportunities to do that within buildings. Thinking about air handling systems. And now more and more we're thinking about biofiltration systems that can be removing both harmful, volatile compounds and microbes as they're moving through these systems. Anyway, that's what I'd like to present and I'd be very happy to have any questions or discussion. Thank you so much. Thank you, Greg. This was really so rich. And thank you very much for showing opening the kind of laboratory and actually laboratory that is very integrated in the city and beyond. And maybe I'd like to start with a question about systems, the articulation of systems, which I found fascinating, both in your discourse, but also in the images that you showed and the diagrams. How basically the way that you were describing many of these microbial crises, situations was very much the result of how different systems were negotiating with each other or articulating or collaborating. And I wanted to ask you, because at least one of the last things that you said that I found very important is the relevance of finding frames to work with and to evaluate. And I wonder what's the way that you see within these systems of systems, within this kind of entanglement or interconnection of bodies, water bodies, infrastructures, buildings, the ocean, earth systems. What are the parts that are more prepared for knowledge to be applied and to be interviewed? And what are the ones that you would like to basically have tools to operate them? Yeah, so there's a variety of ways to approach that, I think. Thinking about the interconnectedness of these urban systems, one of the tools that I've recently found are historians are actually useful. And I wouldn't have thought this, understanding the connections of these systems. There's an example in Queens, where in association with the building of the alteration of Queens for the 1939 World's Fair, there was a waterway put underground. Soon after that, the population of Queens was expanding and there were sewer mains put in. It turns out that the city doesn't know what's connected to a variety of those pipes. Why? Because it happened a long time ago and there just aren't good records. One of the things that's motivated a conversation that in this case had to connect New York City parks and New York City Department of Environmental Protection to agencies that may or may not be well integrated into one another from this kind of a management perspective. They have shared projects was images that actually were from an archive that showed the concrete structure and when it was put into the ground and motivated some sampling that now is trying to untangle where some of those connections are and actually how they may be able to eliminate sewage flow into Flushing Creek. So even getting information from historians that can help untangle what was the sequence of development that occurred was useful. I didn't expect as a microbiologist to be needing to talk to historians. But that is very much in an urban environment. There's agencies that are responsible for certain components and yet the city was built in a way that is interconnected. But the management of it is subdivided and many of these issues require coordination. And this is something that society actually has dealt with from a homeland security perspective. Oh, first responders and we need to be able to have communication systems that have well this is true of the environment too. We have created localized systems of management but the urban environment is so interconnected from water and air and green space and Department of Transportation that we need to have shared goals across agencies. And frankly, that only happens with relationship building. It's the soft skill and convincing people on the inside, hey, what do you think? I think there may be an inter and you get a couple people together and the next thing you know a project is possible. So persistence and being willing to pull groups of people together is actually one component of this. I think another is simply an understanding of public health or environmental question comes into play and looking for opportunities for shared progress. And an example of this is one of my PhD students studied the sewage impact in urban waterways from a greenhouse gas perspective. And so the city spending billions of dollars on its sewage infrastructure. It's interesting to think the city also has climate goals. They want to reduce their greenhouse gas impact. If we can quantify the environmental production of methane from these urban waterways as a result of sewage impact, we get the public health benefit we get. So all of a sudden, the public funds that are being used, we're checking off multiple benefits. I don't think we value things properly. In the management conversations, this is the most common thing that comes down to a barrier to progress. Well, there is a valuation process. This is even thinking about storm surge barriers in the Army Corps of Engineers. Ecosystem benefits cannot be properly valued. And therefore, those decisions are driven by real estate costs. They're driven by train lines. They are not taking into account the value that comes from a functioning environment because we don't do a good job of it from an economics perspective. And therefore, just like the air quality, there's no regulation. I don't have the context. I can't build it into my model. I can't tell someone to not aerate the waterway if there's no clear rule. Economics and valuation become so important. Emily, you have a question, right? Maybe you want to read it. I mean, I think this kind of has to do with the question of valuation that you were just bringing up. Basically trying to tie our expertise of design with your expertise of fecal matter and microbes. How can we start to combine those two? So like, are you aware of any design restrictions for creating bioswales specifically designed to purify the water of fecal matter? For example, a certain concentration of microbes requires X amount of surface area of bioswales. I was particularly interested in that last image you showed of the small curb cut and how behind it there was so much impervious surface area compared to the small little bioswale that was in front of the street. I was wondering how much area you would actually need to, I guess, make an effect. So I think a few things there. First of all, this isn't, I think bioswales are great. I've actually, I did a infomercial, if you will, talking about their value for DDC, Division of Design and Construction. And because I think we just need to, first of all, what a terrible name, bioswale. Don't put that in front of my house, right? But that stuff matters, right? Anyway, bioswales are great, but it's like the tool that we have right now. And we're hammering away. And one of the things we need to do is actually start thinking about the properties that are a little bit larger. And we are, but I think there are opportunities to think about the different water retention in the urban environment, which is a huge challenge because there aren't that many big parcels of land. But again, it comes down. It was in the past difficult to take water off the street and move it into a park. Why? Is that park alienation, right? Well, maybe, maybe not, but it's hard, right? It's a cross agency, you know, perspective on the world. Parks are probably the best opportunity we have. School yards are another one. And we're doing a lot in school yards, but there are those pieces of land that have opportunities for enhanced function that, you know, we need to get beyond just the bioswales on the streets. In terms of the functioning of those bioswales, it's really interesting. There's actually a professor at Brooklyn College who does some design work, she's a biogeochemist, but she does work associated with how do we enhance the positive microbial function from a nutrient pollution removal in those bioswales. And one of the things you may not want to do is actually have the water run through them too fast, right? You actually want to create zones of microbial function like you would in a wastewater treatment plant, right? So you want to be able to have smart design of the hydrology of a bioswale, right? It's an area of design innovation that is still needed. So there's a whole variety of ways. Yeah, small curb cuts and, you know, we want to enhance permeability, right? To be able to take on as much water as possible, but there may be circumstances, you know, almost like a green roof. You know, you think about, you know, what's the best way to have a green roof function and to be providing other benefits, right? To the people who install them. You know, is it just a big bladder that should be a blue roof, right? Or is it something that has, you know, plants and the hydrology of water through these systems and what it means for the vegetation, what it means for the microbial action is pretty important, but generally hydrologists don't worry about those things. They worry about, you know, how do I get water from A to B as fast as possible? So it's the interdisciplinary thinking about enhanced function across disciplines that I think things like bioswales can get better. Yeah, perhaps like we also need some landscape architects here to answer the question. Cause if you then just divert the contaminated water to like parks, how good is the park at like disseminating and purifying the water? Cause then you're just moving the contamination to water where then kids are playing on it and then they get contaminated from there. So it's like, you really have to sort of design at the microbial level like you're talking about. Yep, yep, you wanna be purifying that water. You know, so one of the things that I also do is I'm involved in a startup company associated with some technology transfer that's looking at antimicrobial surfaces from a water treatment perspective. And one of the things that I'm convinced in industrial spaces, we tend to use tremendous amount of waters in auto manufacturing facilities, in e-coding, for example, the way that we paint cars, right? Tremendous amounts of water. And also fouling is a real problem because those plants, you go in them and they're like 110 degrees, right? They're like incubators for growing microbes. And the water that they're using for their processed water needs to be treated. So in some cases they'll invest in RO systems, but it actually is the crude filtration processes that causes them to divert to drain. Use new water divert to drain because it's easier. One of the things that they do is they put in tremendous quantities of biocides in solution. But putting biocides, I'm convinced, putting biocides in solution is a really inefficient way to do that. So I like porous media that can have some of that antimicrobial function as water passes through it. So if you can keep it high flow rates passing through a porous media with high surface areas that is having an antimicrobial function without continually dumping chemicals that we then have to at a wastewater treatment plant try to remove or release into the environment. That's an example of, again, it's a design feature. How do we deal with it? Well, here's the tool we have. We dump in the water and it goes away, right? We dump in the biocide and it goes away. Yeah, it's just an efficiency issue, but they're very much become design issues that have these tremendous benefits for chemical use reduction, but also water reduction. So that's, as a microbiologist, that's one of the ways that I think about design is how do we more efficiently create the function that we want without just dumping chemicals at the problem? And what you're saying there about water flowing into parks is absolutely right. We have to think about ways to efficiently polish that water before we can infiltrate it in places where there's a lot of people. And I think that becomes distributed solutions to that, just like energy production needs to be distributed. Water treatment options need to be distributed, especially in urban environments. Wastewater treatment plants are great. There's just a lot of places you can't put them. And we have hundreds or thousands of pipes. It's hard to get them to the wastewater treatment plants. We need distributed treatment solutions. And a lot of that comes down to innovative design. And then that doesn't even get at, I mean, I kind of was talking about it from the industrial perspective, but the reuse components that that then opens up, right? And thinking about then incorporating into a landscape design, especially, which is, you know, I just spend more time thinking about landscape than I do the interior of buildings. But, you know, the reuse of resources like water, and, you know, and one of the great things, and I apologize, you know, when I was talking wastewater treatment plants, right? Water resource recovery, you know, plants, this is the, there's no such thing as wastewater anymore, right? But we need to think about that from an urban landscape perspective. How do we, how do we remove pollutants adequately to just avoid smearing it around, right? And we do a huge amount of that. In the Guwanis Canal, decades old, there's a tunnel. The head of canal goes under Brooklyn out to what's called Buttermilk Channel, which is between there and Governor's Island. And what was the solution to the Guwanis Canal turning green and smelling? Well, let's pump it into the harbor, right? Increase flow. And, you know, the guy at River Keeper, who's the boat captain, who's, you know, one of the best scientists I know, although never formally trained at all. You know, he was like, you know, this is like me instead of doing dishes, just taking all my dirty dishes and putting some in the living room and some in my bedroom and some in my closet, I'm just smearing it around the house. That's all I'm doing. And, you know, in essence, we do a lot of that in the city, right? Just pump it elsewhere, you know, put it in the harbor. So we shouldn't be doing that from a green infrastructure perspective. So you're right, we do have to be concerned about. You start putting things into parks. In parks, we should be doing our best to remove some of that risk along the way as we're transporting the water. So thank you so much, Gregory, really have like very informative lecture. And I really appreciate also the solution you proposed that in. So my question would be, because you talk about the Hudson River, is there a way of rethinking the creeks in terms of biology and microbiology and kind of like dissecting the problem and dealing with it in a fracture rather than like an enormous level? And is there another way to do that also in a naturally? So we're using more natural resources with the low cost material to achieve these principles. Yeah, well, so I don't know if I'm gonna fully address this, but I think there's really interesting things happening. You know, and I love actually that one of the places that's really being driven is LaGuardia Community College. They have students who are out there working on small level designs that try to turn bulkheads, right? Which they've got a lot of right out their back door. How do you turn that into a more natural soft habitat, right? And what are the treatment components to that that can? So they've looked at ribbed muscles, for example, and the ability for muscles to be removing particles. And ribbed muscles are like the toughest organisms out there. They live in all kinds of places where you'd be like, well, that's not gonna work. Well, guess what? They live in Newtown Creek and they do just fine. And I put oxygen sensors in there and like, the bacterial levels are crazy. That's a hostile environment. And yet, the ribbed muscles are there and they can remove a lot of particles. And this actually gets to, those particles are such hot spots for microbial activity that things that can play that crude filtration role are really effective. And at the same time, potentially, they have other benefits from a functioning ecosystem. So they're doing things associated with trying to reestablish wetlands in places that were historically hard surface edges of urban waterways. I think things like these thinking about bivalves and the Billion Oyster Project is an example in the city of something that's at a larger scale. Frankly, ribbed muscles are a lot tougher. So, they may be the ones you put into your most aggressive contaminated locations. So, but again, I think there's value in that. This is a real aside. So I humor me, if you will. But I, so about 10 years into studying the Hudson River and I was part of a group that went, myself and Andy Jewel went up to Lake Tier of the Clouds in the Adirondack. So we strapped on incubators and drones and all kinds of things to sample water up into the, at the base of Mount Marcy, which is the highest peak in New York, and not the base, just below the peak rather, of Mount Marcy is Lake Tier of the Clouds, which is the source water of the Hudson River. And at the start of that hike, there's this babbling brook that runs through evergreens. That is called the Hudson River. And I sat there and having studied the Hudson River for 10 years, I was really thinking, wow, we screwed it up elsewhere. And I kind of was thinking, if I could just show some of the people in New York City, this and make this their view of the Hudson River, wouldn't that really change some minds? And I, as a trained ecologist, I was sitting there thinking, this is pristine and what's down in the city is impacted. And we screwed that up down there. This is what the Hudson River should kind of be like. And then I walked another 50 feet and I bumped into a plaque and a big stone tower. And in the 1850s or something like that, this was a smelting location. And in fact, this whole landscape had been deforested and it was pretty much an industrial operation with mining. And yet, as a trained ecologist, 150 plus years later, I walked through and said, oh, it must have always been like this. And in fairness, area that was deforested from an area that was an industrial center, a mining center, and 100 plus years later, you could fool ecologists to say, look at this pristine environment. Well, the same is true of the Guanis Canal. It's a decision, right? How do we wanna treat it? And what should it look like 30 years from now? And who could we fool about what it used to look like? That should be what we're looking for. And anyway, I think that perspective on what's possible matters and therefore incorporating natural features into design, even in places that don't look very natural now can start to lead people to see the natural in places that they often will overlook it. And if you see just a little bit of it, it may give you a glimpse at what it could become. So I think that the remediation approach also can be an inspirational approach. To clean up the water, yeah, but maybe even more so. Maybe it may have more power as a supplemental remedial approach that also kind of reestablishes nature in a place that it isn't. Well, on that note, we really wanna thank you for, one, the presentation is just incredible and the richness of it and really how everything is interconnected and intersecting is really, I think, something that we're deeply interested in. And also your knowledge that you're sharing with us. Of New York City and the entire ecosystem is incredible. And to end with this perspective that, no, not everything is fixed in its current states. And for sure in New York City, that Newtown Creek, I don't know if some of the students have been there, but it's definitely one of... Some of these places are definitely some of the scariest place that you would never wanna fall into. But yeah, there's so many examples, even in the world of where, one of some of the most polluted waterways have been totally rehabbed over the course of 10, 15 years to do somewhere else. I'm thinking of certain neighborhoods in Shanghai, which is like, even historically, for hundreds of years, a city that was built on transport and therefore it was extremely polluted, extremely, extremely polluted. And then over a massive effort, now some of the sort of places where you can swim in and it's sort of a very real sort of example, right? But I wanna thank, I guess, everyone for your questions and your attention and of course to Greg and hopefully we'll continue the conversation in another form. So thank you everyone. All right, thanks so much, I enjoyed being with you. Oh, and sorry, it was small announcement for everyone and I'll share this larger via email, but we are moving this session to Tuesday, 7 p.m. after consulting with you guys. It seems like a better time for more students, but I will send you that schedule in email. So good night, everyone and thank you. Thank you very much, Greg, this was amazing. Okay, thank you, take care. Thank you, bye-bye.