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.