How were NAWQA aquifer studies selected?
Aquifer studies were selected by local National Water-Quality Assessment (NAWQA) Study Unit teams in collaboration with local organizations, States, and Tribes, as well as NAWQA National Synthesis Teams. In general, the aquifer (or portion thereof) was selected for study on the basis of its national and local significance as a source of drinking water. The sampled wells include new monitoring wells installed by NAWQA as well as existing monitoring, domestic, and public supply wells. Stratified random sampling techniques were used to select both new sampling sites and existing wells so that the results would more effectively characterize the aquifers. The assessment did not focus on specific sites with known water-quality problems or narrowly defined “issues of the day,” but rather on the condition of the total ambient resource.
