Groundwater Level Monitoring in McLean, Tazewell, and Logan Counties, Illinois
The work entails monitoring water levels in observation wells installed by the ISWS and ISGS in 1992, 1993, 1994, and 1997 as part of their investigation of the groundwater resources in the confluence of the Mahomet and Mackinaw bedrock valleys. This effort is a continuation of the monitoring conducted from 1999 to date.. The project includes quarterly sampling of observation wells at approximately 33 locations and the Mackinaw River elevation at three locations. In addition, the sites are mowed twice a year, and those wells exhibiting an iron bacteria problem will beare periodically chlorinated. One well, MTH-7, which is near an existing irrigation system, will continue to be monitored continuously with a pressure transducer installed for this task.
Findings to Date: The development of a long-term record of water levels in the Mahomet and Glasford aquifers in McLean, Tazewell, and Logan Counties have given researchers a wealth of information that has been used to assist in continued development and calibration of a groundwater flow model of the Mahomet aquifer. In addition, the observation wells have been available for other research interests, including water quality sampling and research related to understanding the chemistry of the aquifer.
Each year, the ISWS submits a letter report to the Mayor of Normal, along with other interested sponsors and interested groups in the area. The letter contains hydrographs of each well, a summary of the information gathered to date, and some analysis of the data where findings warrant it.