Groundwater and groundwater contamination.
Here's a good chapter about the basics of groundwater. Chapter 2. The first 6 pages, including Figure 2-4 are important. You can get the entire document here, but you don't need it for this course. Corps Hydrology. Your textbook has a good description of wells and monitoring systems, which I won't repeat.
Still the most common method of groundwater treatment is "pump and treat." Pull the water to the surface, remove the contaminants, then reinject the water into the soil or let it percolate back in. The most common method of treating the water is air stripping, a physical process we discussed earlier.
UAF offers several graduate courses in groundwater hydrology and contaminant hydrology, but besides getting you to know a few of the general terms in the reference above and what is in your book, we can't go too much deeper into that complicated subject.