Groundwater-quality and select quality-control data from the National Water-Quality Assessment Project, January 2017 through December 2019

Abstract

Sustaining the quality of the Nation's water resources and the health of our diverse ecosystems depends on the availability of sound water-resources data and information to develop effective, science-based policies. Effective management of water resources also brings more certainty and efficiency to important economic sectors. Taken together, these actions lead to immediate and long-term economic, social, and environmental benefits that make a difference to the lives of the almost 400 million people projected to live in the United States by 2050.In 1991, Congress established the National Water-Quality Assessment (NAWQA) Project to address where, when, why, and how the Nation's water quality has changed, or is likely to change in the future, in response to human activities and natural factors. Since then, NAWQA has been a leading source of scientific data and knowledge used by national, regional, State, and local agencies to develop science-based policies and management strategies to improve and protect water resources used for drinking water, recreation, irrigation, energy development, and ecosystem needs (htt ps://water .usgs.gov/ nawqa/ applications/ ). Plans for the third decade of NAWQA (2013-23) address priority water-quality issues and science needs identified by NAWQA stakeholders, such as the Advisory Committee on Water Information and the National Research Council, and are designed to meet increasing challenges related to population growth, increasing needs for clean water, and changing land-use and weather patterns.NAWQA is assessing the quality of groundwater used for public and domestic drinking-water supply. NAWQA obtains samples from public-supply wells, domestic wells, and shallow monitoring wells and analyzes those samples for a large number of chemical constituents. These data are used to assess the suitability of the resource for human consumption, as well as to evaluate changes in groundwater quality over a variety of time scales. Groundwater quality also is assessed at multiple scales: locally, regionally, and nationally. Groundwater-quality data collected by the NAWQA Project during each year are published in annual data series reports. This report, the fifth in the series, combines groundwater-quality data collected at 983 sites to provide a summary of groundwater quality in selected aquifers across the Nation during the sampling period. All NAWQA reports are available online at htt ps://water .usgs.gov/ nawqa/ bib/ .We hope this publication will provide you with insights and information to meet your waterresource needs and will foster increased citizen awareness and involvement in the protection and restoration of our Nation's waters. The information in this report is intended primarily for those interested or involved in resource management and protection, conservation, regulation, and policymaking at the regional and national levels.

Karst Groundwater Vulnerability Determined by Modeled Age and Residence Time Tracers

“…Sampling, analysis, and quality‐control are described in Kingsbury et al. (2021) and Musgrove et al. (2023).…”

“…Groundwater samples were collected from 81 sites during 2017-2018 and analyzed for a range of organic and inorganic constituents, including environmental age tracers. Sampling, analysis, and quality-control are described in Kingsbury et al (2021) and Musgrove et al (2023). Data are provided in a companion data release (Musgrove et al, 2023).…”

Quality of Groundwater Used for Public Supply in the Continental United States: A Comprehensive Assessment

“…Prevalence at the national scale requires accounting for the relative area of each PA (area-weighted detection frequency). Additional information about the PA networks is provided in USGS Data Series Reports − and in the Supporting Information.…”

“…Samples were also collected for quality assurance and quality control (QAQC). Additional information about methods, well characteristics, water quality data, and analysis of QAQC data, including data presented in this paper, have been published in USGS Data Series Reports. − Age-tracer data, computations based on the data, and models of groundwater age distribution have also been published …”