1. Groundwater quality data from the national water-quality assessment project, May 2012 through December 2013;Arnold,2016
2. Groundwater-quality data from the national water-quality assessment project, January through December 2014;Arnold,2017
3. Groundwater-quality and select quality-control data from the national water-quality assessment project, January through December 2015, and previously unpublished data from 2013 to 2014;Arnold,2018
4. Metrics for assessing the quality of groundwater used for public supply, CA, USA: equivalent-population and area;Belitz;Environ. Sci. Technol.,2015
5. Estimation of aquifer scale proportion using equal area grids: assessment of regional scale groundwater quality;Belitz;Water Res. Res.,2010