Dr. Thomas Marshall of the SD Department of Agriculture and Natural Resources' SD Geological Survey discussed the Ground Water Quality Monitoring Network at the May 13, 2026 meeting. This network consists of 148 active monitoring wells in 83 sites that track the quality of water in 25 aquifers. The network determines the present ground water quality, short term changes as well as long term trends. To view the presentation on the Club's YouTube channel, click on the image below.