Between 2012 and 2015, water-quality samples were collected by the USGS in cooperation with the Clearwater Underground Water Conservation District (CUWCD), the Bell County Adaptive Management Coalition (BCAMC), and other entities, with a primary goal of characterizing the groundwater resources in Bell County, Texas. Water resources associated with the northern segment of the Edwards aquifer near the Village of Salado were of primary interest, but water resources in the Trinity aquifer were also investigated to a lesser degree (the assessment focused on a springs complex in the Village of Salado). Data associated with other water quality samples collected by the USGS in Bell County during 1978 to 2017, outside of the cooperative agreements with CUWCD and the BCAMC, were also included in this data release. Most samples were analyzed for pesticides, nutrients, major and trace elements, and isotopes (strontium-87, oxygen-18 and deuterium in water, and nitrogen-15 and oxygen-18 in nitrate).