The driving force behind my research is the control of waterborne disease transmission from both watershed protection and drinking water treatment perspectives. Slow sand filtration is a water treatment option attractive for rural communities and developing countries because it is reliable, affordable, and requires minimal maintenance. However, each filter run requires a ripening period during which filter effluent must be either wasted or recycled back for refiltration until the filter produces water that meets drinking water standards. I am interested in making slow sand filtration more efficient, economical, and practical by using non-traditional media and media modifiers to enhance filter ripening and delay the onset of filter clogging.
Control of waterborne disease through a better understanding of pathogen ecology is a related research interest. Cryptosporidium parvum is a human and animal parasite responsible for an acute gastrointestinal disease that is self-limiting for otherwise healthy people but prolonged and life-threatening for the immunocompromised population. Cryptosporidium spp. oocysts are a challenge to remove from drinking water supplies because they are resistant to chlorine disinfection and too small to effectively filter. I have completed lengthy environmental studies tracking Cryptosporidium spp. oocysts in the Wachusett Reservoir watershed in central Massachusetts (the drinking water source for Boston and surrounding municipalities) to identify sources and species of Cryptosporidium oocysts as well as any seasonal trends associated with Cryptosporidium spp. presence. I have shown that multiple species and genotypes of Cryptosporidium are present in the watershed, and because not all species cause disease in humans, this finding supports the need for species-specific detection methods to assess the potential health risks of Cryptosporidium spp. presence in the environment. In addition, my work has shown that geese are an important source of Cryptosporidium spp. oocysts, particularly in agricultural areas. I have identified novel 18S rRNA genotypes of Cryptosporidium spp. in geese, revealing more extensive parasite diversity in the environment than was initially reported. The goal of my work is to provide a greater understanding of the environmental behavior of Cryptosporidium spp. oocysts so that watershed management can minimize public exposure to this waterborne pathogen.