<b>EXPLORATION OF PRIVATE WELL WATER MICROBIOMES AND DEVELOPMENT OF ALTERNATIVE METHODS FOR DRINKING WATER MONITORING</b>

<p dir="ltr">While drinking water is often safe in developed countries, thousands of people still die from water related illness every year. We are just beginning to understand how factors like source water, plumbing material, and water age are affecting not only waterborne pathogens, but the entire drinking water microbiome. This thesis uses molecular-based techniques to characterize the microbiome of drinking water in homes that are supplied by private wells, which are not treated or monitored by the government, and investigates a novel method for monitoring drinking water using low volumes.</p><p dir="ltr">To characterize and investigate the microbiome of drinking water in homes with private wells, 35 suburban/rural Midwest homes were sampled by untrained members of each household. Each home provided a sample from an outdoor hose/spigot, a first flush from the kitchen sink, and a flowing hot water sample. Some resampling occurred across seasons. Alongside physicochemical analyses, DNA in the water was extracted to use for qPCR and 16S rRNA gene sequencing. <i>Mycobacterium </i>was highly prevalent in the water, being detected in over 87% of samples. <i>Legionella pneumophila</i> was also detected (30% of the outdoor hose/spigot samples, over 20% of the first flush kitchen faucet samples). High metals concentrations were also found, with nine homes having arsenic concentrations above the EPA MCL of 10 ppb. Iron averaged 778 ppb for the outdoor hose/spigots and 309 ppb for the kitchen cold samples. More bacteria were found in well water compared to municipal systems, possibly due to a lack of treatment. Proteobacteria dominated most samples, but was less abundant than in municipally treated drinking waters. Bacteroidota and Desulfobacterota were also common. Outdoor hose/spigot had similar microbiomes across homes, suggesting similar environmental conditions across homes. The home itself was found to be a major driver of the microbiome, influencing composition more than location within the home, season, or county.</p><p dir="ltr">Drinking water microbiome monitoring often requires large volumes of water to capture sufficient biomass, often making monitoring difficult. Magnetic beads are a novel biomass concentration method, potentially allowing for lower required volumes and automated workflows. This study compares coated magnetic particles to traditional filters for capturing both the entire drinking water microbiome and <i>Legionella pneumophila</i>, specifically,<i> </i>in drinking water. Filters and beads both capture similar microbiomes, although the beads show higher relative abundances of <i>Pseudomonas</i>, possibly due to contamination. Both methods recover <i>Legionella pneumophila </i>in drinking water, both in waters with and without background microbiomes.</p><p dir="ltr">This work furthers public health for rural communities by both identifying potential health concerns in drinking water, and evaluating methods that make routine monitoring of waters more accessible.</p>