TY - RPRT TI - Hydrogeology and water quality of sand and gravel aquifers in McHenry County, Illinois, 2009–14, and comparison to conditions in 1979 AU - Amy M. Gahala PY - 2017 DO - 10.3133/sir20175112 UR - https://pubs.usgs.gov/publication/sir20175112 ID - sir20175112 ER -