Lead and zinc mining in the Tri-State Mining District (covering parts of Oklahoma, Kansas, and Missouri) took place for over 100 years and now abandoned mines, piles of waste tailings, boreholes, and underground workings have resulted in contaminated land and water in the district. One of the US Environmental Protection Agency (EPA)-designated Superfund sites related to the contamination from the mining is in the Jasper County, Missouri, portion of the District One area of Jasper County, along a stretch of County Road 200 (just south of the town of Alba and east of Oronogo), was sampled for this study. The shallow aquifer and surface waters of this portion of southwest Missouri have been shown to be affected by heavy metal contamination. Thirty-one residential groundwater wells used for drinking water were sampled for lead, cadmium, and zinc, with water from six wells sampled before and after water softener treatment. Some levels of lead and cadmium exceeding maximum contaminant levels (MCLs) for drinking water were found in samples. High levels of zinc were also found. Notable increases of zinc were found in samples following softener treatment. In addition, the use of residential water softener units does not appear to reduce levels of these heavy metals in water. Further sampling and research on the effects on ground and surface waters of the mined lands would need to be done for identifying the locations and tracking the source(s) of the high levels of metals.