Data sets for: Variations on a method for evaluating decadal-scale changes in the groundwater quality of two GAMA coastal study units 2004-2014, California GAMA Priority Basin Project
Kent, R.H., 2018, U.S. Geological Survey data release
Related Study Unit(s): Monterey Bay and Salinas Valley Basins Groundwater Resources Used for Public Supply, North Coast Ranges Groundwater Resources Used for Public Supply, North San Francisco Bay Basins Groundwater Resources Used for Public Supply
The U.S. Geological Survey collected samples from 50 public supply wells during two distinct sampling episodes (2004-2005 and 2014) on the North-Central California coast. During each sampling episode, the samples were analyzed for 160 water-quality constituents, including water-quality indicators, nutrients, major and minor ions, trace elements, volatile organic compounds, and pesticide compounds. The paired-sample results were submitted to an evaluation method to determine whether or not step trends had occurred in the concentrations of each constituent. Quality-control samples were collected at a subset of the wells. The datasets presented here consist of a list and description of the 160 constituents, an Excel workbook which details the step trend evaluation method, and a summary of the quality-control data results.