ENVS Summer Research – Kevin and Joe

Kevin in the CNS lab

This summer, we researched a mineral known as pyrrhotite, an iron-sulfide prone to oxidation and subsequent deterioration. It has been implicated in the cracking of foundations in homes across northeastern Connecticut. Such damage can require renovations running into the thousands and even hundreds of thousands of dollars. Therefore, pyrrhotite testing of concrete has been a major subject of focus in the Environmental Science Program, with the main objectives being to develop a comprehensive method for measuring pyrrhotite contamination and estimating probable-effect-concentrations.

Current Trinity sampling methods utilize a combination of X-Ray Diffraction (XRD), Carbon Nitrogen and Sulfur analysis (CNS), and magnetic susceptibility to determine mineralogy and sulfur concentration. In short, sulfur concentration is an indicator of pyrrhotite concentration, but pyrrhotite is not the only sulfur-bearing mineral present in concrete samples. Thus, the objective this summer was to determine the extent to which other sulfur-bearing minerals contribute to overall sulfur concentration. The process involved calibration/adjustment of the CNS analysis method in conjunction with XRD analysis. Our  overall goal is to provide a more comprehensive quantification of pyrrhotite in concrete. We also worked on understanding the relationship between pyrrhotite and its oxidative products. Such knowledge is key to achieving better risk assessment as well as establishing a time scale for concrete deterioration.

Joe breaking apart a concrete core sample.

An X-ray Diffraction (XRD) scan comparing a pure pyrrhotite sample to concrete.



ENVS Research on Concrete Foundations Makes Local News

It all started about a year ago when Jon and Christoph began analyzing crumbling concrete foundations from northeastern Connecticut. The presence of pyrrhotite, a magnetic (you might see where this is going) iron sulfide, in aggregate used for concrete foundation lead to the premature decay of homes as the pyrrhotite decays into a variety of secondary minerals.

In collaboration with the Connecticut Coalition against Crumbling Basements (CCACB) Jon and I started analyzing concrete samples and found that we could detect and quantify pyrrhotite through a combination of magnetic and chemical analyses. In February we submitted a manuscript to Cement and Concrete Research describing our method, talked to homeowners, realtors and engineers, and for the past few months we have been analyzing people’s homes.Trinity’s Alumni Magazine was the first to spread the word. A very famous wall made it on the title page (still bummed that they chose the wall over a heroic portrait of Jon and myself :-), and we got a few pages in he bowels of the issue. The Manchester Journal Inquirer came next, giving us a nice shout-out (yep, you have to read all the way to the end – we’re not that famous), and the Hartford Courant followed suit a few days later. They actually wrote a story about us and, if you are really observant you might see the same wall again in the multi-media part.

In the mean time we got some video practice with Trinity’s video guy who spent a morning interviewing us and our students and shooting video about the process. As far as I know that video is not out yet, but it was great practice for our two seconds of fame when Jon and I were interviewed by the local NBC station.
NBC’s investigative reporter Len Besthoff spent a few hours with us and we ended up with 10 seconds of fame a few hours later. Instant fame ensued: even our neighbors are suddenly recognizing us in the street!

In October Jon and I attended a concrete symposium in Trois-Rivières and just in time, on the up North, we received an e-mail that our paper on thermomagnetic pyrrhotite testing was finally accepted for publication in Cement and Concrete Research. By now it’s actually published and you can download a copy from here (until December 1st ). The meeting in Quebec was amazing. Since my French is pathetic we all got headphones and enjoyed the amazing skills of two simultaneous translators. Jon and I felt like at the United Nations.

At the United Nations :-)

By now we’re working on a new manuscript to be presented at the annual meeting of the American Geophysical Union (AGU) in Washington DC, and are eagerly awaiting our new rock crusher to help with all the concrete cores that are flooding the lab.

I’d say it has been an interesting summer.


Homecoming McCookout was a Blast

Despite my haphazard organizational skills, the first annual (its good to have ambitions !) homecoming McCookout went really well. The weather cooperated, and by noon-ish Joe had the grill going and loaded up with goodies. I would love to claim that the dinosaur cake was the star of the event, but the great pie bake-off between Amber and Jon took center stage.

The epic battle of the pies!

Amber’s was all whole-wheaty and supposedly healthy (but we all know there is no healthy pie crust worth the try …), while Jon went crazy with his mysterious “cinnamon pen” decorating the top with fancy swirly designs. About two dozen testers declared the pies worthy, but with room for improvement (we hope for more of them in the near future !!). Alumni were a bit slow in showing up. Only Adam remembered that “the early student gets the cake” and was there half an hour early. Good man!

The early crowd at McCookout. Once the party got going I was having too much fun to take pictures, but you can believe me – it was huge! Bigger than the last presidential inauguration. :-)

In the end we had maybe two, three dozen students and alumni attending. Our guest star was Joan Morrison, who came all the way from New Mexico. I’d say Lauren came in second,all the way from Portland, Maine. Stephani and Adam tied for closest commute: both made it all the way through town.

Unbeknownst to us we even had a satellite event! Hi Kelsey and Kate! Thanks for saying Hi. From the background it looks you two went all veggie. Oh, succulents – i get it.

Kelsey and Kate celebrating with us in San Diego! OK, Joan, you just got booted to number two.

We had so much fun that we decided to do it again next year. Always god academics we promptly founded a Homecoming McCookout Organizing Committee (HMcCOC) to make next year’s event even bigger and better: Vania and Lucian happily agreed to help out, so stay tuned.

We’re all looking forward to seeing you next year.

P.S. The dinosaur cake was eaten first – take that you apple pies!

ENVS Summer Research – Shane, Bobbie, and Joe

This summer, Shane McLaughlin (’19), Anna Maria “Bobbie” Imwalle (’20), and Joe Ruggiero (‘19) worked with me (Dr. Amber Pitt) to investigate the impacts of human activity on wildlife populations and freshwater ecosystems in urban Connecticut and rural Pennsylvania.

Getting the dirt on urban ponds and streams

Bobbie collecting urban pond sediment


Ponds and streams can serve as critical habitats for wildlife in urban settings. However, they also can become ecological traps for wildlife if they are contaminated with toxins that decrease reproduction and survival. Wildlife can accumulate toxins through direct contact with the substances in the environment, as well as by consuming contaminated food sources such as plants and animal prey species. Shane and Bobbie took to the ponds, while Joe took to the streams, in parks in the Greater Hartford Area to explore contaminant levels in sediments and plants found within these ecosystems. Shane and Bobbie also assessed amphibian, reptile, and bird diversity in these ecosystems. They found that some ponds and stream segments were more impaired than others with contaminants such as mercury. Results were somewhat surprising though in that some of the most impacted ponds were located in the more beautiful, highly vegetated settings. It’s likely that those results were due to the application of lawn and gardening chemicals that contain mercury. These results suggest that use of such chemicals may pose a threat to wildlife in these habitats, as well as to people who recreate in and consume fish from these ecosystems.

Helping the hellbender

Shane, Bobbie, and I headed to Pennsylvania to continue research on hellbenders. Hellbenders are giant salamanders that live in streams and rivers in the eastern United States, from southern New York to northern Georgia, and west to Missouri. Their populations are declining throughout much of their range, and the Pitt lab has been researching the drivers of this decline so that we can better understand how to reverse these trends and conserve this species. Donning masks and snorkels, we took to the streams to survey the hellbender population.

Bobbie and Shane getting ready to snorkel.

While many hellbender populations show no signs of recruitment, our efforts uncovered a larval hellbender, indicating a healthy, reproducing population.

A larval hellbender we found.

Going to bat for bats

As an extra treat while in Pennsylvania, Shane, Bobbie, and I joined one of my former graduate students, Jamie Shinskie, for a night of bat surveys. Bat populations have declined precipitously due to white-nose syndrome, and an important step in conserving bats is to monitor their populations to understand how the populations are changing over time.

Shane setting up a mist net to catch bats.

One of the bats captured in the mist net.

Shane and Bobbie recording morphometric data for the bat researchers.

Oh Canada

With data and presentations in hand, Shane, Joe, and I headed to Canada to share the results of our research! Shane and Joe presented the urban pond and stream research and I presented hellbender research at the North American Congress for Conservation Biology in Toronto, ON. This professional scientific conference was attended by more than 800 people who specialize in conservation science, policy, and communication.

Shane and Joe explaining the urban pond and stream study.

Our group also took some time for bird watching while in Toronto…sort of. With the Rogers Centre just a few blocks from the conference venue, the group decided to take in a Blue Jays game. The Blue Jays may have lost that night, but our lab team shared a winning experience.

Shane, Amber, and Joe at a Toronto Blue Jays game.

ENVS Summer Research – Nicole

The goal of Nicole’s research is to see if it is possible to reconstruct a history of past fires through charcoal analysis. Charcoal is used as an indicator to reconstruct past fire dynamics and, when coupled with other paleoecological proxies, can be used to enhance paleoecological reconstructions.

Soil profile HNC 15-G

The soil samples come from a series of locations within the Hitchcock Nature Center in Pottawattamie County, Iowa (41.4209°N, -95.8659°W). The samples were collected at 5 cm intervals up to a depth of 2.3 meters at each location. A small amount of each sample was mixed with 0.10 M KOH solution in a centrifuge tube. The tubes were then placed in an ultrasonic bath to break up soil fragments and was then passed through a 180 mm screen. The coarse fraction was rinsed with deionized H2O to remove any fine particles and the remaining sample transferred to a petri dish. Charcoal was identified at 20x magnification under a microscope and separated from the rest of the sediment sample for analysis. Charcoal particles were photographed, and their surface area was determined through image analysis performed in ImageJ.

This is what macroscopic charcoal looks like.

Charcoal concentrations are reported in mm2/g. The soil profile was dated using four radiocarbon ages obtained from charcoal fragments and snail shells. All soil ages were in chronological order and the oldest soil samples were approximately 780 years old. Prior to approximately 1870 average charcoal concentrations are low and relatively consistent in most samples.

An image of Nicole’s soil profile, several magnetic parameters, and Nicole’s charcoal counts (in brown). The spike in charcoal occurred approximately at the end of the 19th century.

At a depth of 30 cm below surface, there was a spike in the amount of charcoal up that is higher than most of the rest of the sample. This spike dates to approximately 140 years ago and its timing correlates with the onset of large-scale settlement of Pottawattamie County by European settlers. Settlers likely burned the original forest and grasslands to create viable land for farming. After this initial spike, the level of charcoal decreases but continues to stay elevated. This could be a result of less frequent burning to keep the unwanted biomass at bay.

prescribed fire at Hitchcock Nature Center

ENVS Summer Research – Giles

Giles working hard to become one with his new best friend iTree

In April the City of Hartford asked for help with their tree planting efforts. No, they did not ask for a bunch of kids who’d go out into the neighborhoods, digging holes, and planting trees. They wanted to know how many trees Hartford would have to plant in order to maintain its current canopy cover of 26% or to expand it to 35%.

This question is a little bit less straightforward than one might think, and the answer turned out to be a bit complicated. Luckily, we found Giles Lemmon (’21), who likes environmental problems and data crunching and had no current summer plans. We easily talked him into working as an intern for the City of Hartford. There he worked with Grace Li from the City’s Sustainability Office and Jack Hale, the chair of Hartford’s Tree Advisory Commission. Hartford’s trees follow a rather irregular age distribution, which means that the loss of large, mature trees is not simply compensated by planting an equal number of small trees. In addition, poor and spotty data made Giles’ job even more challenging.

Working with iTree, an open source software package developed in collaboration with the US Forest Service, Giles found that planting trees at a rate of 1000 / year would lead to a canopy loss of 440 acres (9 times the size of Bushnell Park) over the next 30 years. To maintain present canopy cover, he estimates that one would have to plant approximately 1500 trees per year, and an increase in canopy cover to 35% within the next 30 years would require an annual planting of approximately 7000 trees.

At the end of his internship, Giles, who was funded by a Trinity College Catalyst Grant gave a presentation to the City of Hartford and he hopes to continue his work with the City in the future.

ENVS welcomes El Hachemi Bouali as our new Postdoctoral Fellow

El Hachemi Bouali, our new postdoctoral fellow

It’s a bit late (El joined us about a month ago), but we are very happy to announce that Dr. El Hachemi Bouali is our new McKenna Meredith ’48 Postdoctoral fellow in Environmental Science. He follows Krista Ehlert who took a position as assistant professor with the Department of Natural Resources Management at South Dakota State University. Congratulations, Krista!

El is a geophysicist and earned his masters degree from Western Michigan University where he used persistent scatterer interferometry to study the subsidence of the Nile Delta. He is just about to earn his PhD from Michigan Technological University where he used remote sensing techniques to study landslides.

At Trinity El will use our ground penetrating radar (GPR) equipment to study the extent of groundwater contamination plumes. Don’t be shy: if you are interested in his research pay him a visit in his office (McCook 123), chat for a while and maybe you got yourself a research project.

This Fall El will teach a course on Natural Hazards. It has no prerequisites, meets the natural science general education requirement, the ENVS foundational requirement for a gateway course, and (at this time) has still two open seats. What’s not to love?

ENVS is Searching for a new Postdoctoral Fellow

Krista’s new office, somewhere far, far west of Trinity.

With Krista taking a real job as an assistant professor at the University of South Dakota we are looking for a new postdoctoral fellow. The ad is out, the applications are coming in and we’ll be sifting through them beginning next week.

Over the past seven years our postdocs have taught courses in environmental chemistry, weedology (sorry, Cameron, I had to make that joke), oceanography, ecology and climate change. Our postdocs also taught our regular methods and introductory classes.

weedology headquarters

It all started in 2011, when Sarah Gray became our first McKenna Meredith, Class of ‘48 Postdoctoral Fellow in Environmental Science, taking first place in our ongoing “longest title in ENVS” competition. Sarah came to us from the University of Montana and, while at Trinity, she studied the role of small streams in the carbon cycle. She also taught environmental chemistry and a bunch of other courses for us. After having taught at Armstrong Atlantic University for several years, Sarah just took a professor position at Stockton University in New Jersey.

Sarah enjoying the beautiful summer of Connecticut

In 2013 Cameron Douglass, our next postdoc, came to us from Colorado State, where he earned a PhD in Bioagricultural Sciences & Pest Management, which sounds much less exciting than a PhD in weed science. Nevertheless, Cameron, a conservation biologist, was the first occupant of the Weed Lab, the dedicated research space for our postdocs. Needless to say, the first Weed Lab sign walked out of McCook a few weeks later and probably found a new home in one of the fraternity houses. Cameron stayed with us for three years. He was a mainstay of our methods course, taught Biological Invasions, a course on invasive species (aka weeds), and our introductory course. Cameron studied invasive species management at a property owned and managed by the Avalonia Land Trust. Cameron moved on to join the EPA in 2016.

Cameron pretending to enjoy dinner at Álftavatn, Iceland

Finally, Krista Ehlert, who holds a PhD in Ecology and Environmental Science from Montana State, joined us in 2016. Krista taught introductory courses in environmental and climate science as well as ecology. Her research focused on the link between mice, Japanese barberry and ticks, which was featured in an earlier blog post.

Krista and one of her fans after her seminar presentation

While it might seem like a PhD from a Western Land Grant University (Montana, Colorado State, Montana State) is a prerequisite for the job; that is not the case. All we’re looking for is someone who does cool stuff, likes to teach and provides diversity to our program. At this point we have a wide variety of applications covering biology, chemistry, geography, geology and even geophysics. It will be interesting to see who will come out ahead in the end. We are looking forward to a bunch of exciting Skype interviews and we’ll keep you updated.

Two ENVS Talks at the Science Symposium

At this week’s science symposium we enjoyed two talks from our ENVS majors. Joe Ruggiero presented work on his research on pyrrhotite in Connecticut metamorphic rocks and how it affects the stability of concrete. Pyrrhotite acts as a source of sulfate which can lead to internal sulfate attack (ISA) in concrete foundations. ISA due to pyrrhotite-containing aggregate is the cause of premature concrete failure which affects thousands of homes in northeastern Connecticut.Sarah Messenger, an ENVS / BIOL double major, presented her work on permeable reactive barriers and their role in controlling nitrate inputs into estuaries. Sarah’s thesis started out as a semester-long research project with MBL at Woods Hole. She continued her study on the efficacy of these barriers and is currently working with Dr. Lisa Foster identifying the bacterial communities involved in nitrate reduction.

Both, Joe and Sarah, did an outstanding job. Congratulations!