Abstract

\\nIn the U.S., up to 14% of people rely on private wells for their drinking water. The thing is, the U.S. government doesn’t regulate contaminants in these private wells. This study wanted to check the water quality of unregulated private wells within one mile (1.6 kilometers) of an effluent-dominated river in the arid Southwest. We also wanted to see how contaminant levels changed between wet and dry seasons, and if human sources were contributing by specifically measuring man-made organic contaminants like PFOA, PFOS, and sucralose. We collected samples during two dry seasons and two wet seasons over two years. Then, we checked for microbial contaminants (Escherichia coli), inorganic ones (arsenic, cadmium, chromium, copper, lead, mercury, nitrate), and synthetic organic ones (PFOA, PFOS, and sucralose). We found arsenic, nitrate, and Escherichia coli concentrations were higher than what’s considered safe: 0.01 mg/L, 10 mg/L, and 1 colony forming unit (CFU)/100 mL, respectively. The PFOA and PFOS levels we measured were also higher than the Public Health Advisory level. Arsenic, PFOA, PFOS, and sucralose were significantly higher during the dry seasons, but E. coli was higher during the wet seasons. Some contaminants were linked, like arsenic and mercury (r = 0.87) or PFOA and PFOS (r = 0.45). But since different types of contaminants didn’t always line up, it means they probably come from different places. We need a bunch of different approaches to help reduce exposure to drinking water that’s above health guidelines.\\n\\n