LOCATION.-- Lat 41°24'22", long 88°10'04" (NAD of 1983), in NW1/4NE1/4NW1/4 sec. 26, T.34N., R.9E, Hydrologic Unit 07120004, Piezometer PZ4, about 3 miles southeast of Channahon. Owner: U.S. Forest Service, Midewin National Tallgrass Prairie.

AQUIFER.-- Glacial drift of Quaternary age.

WELL CHARACTERISTICS.-- diameter 1.0 inch, depth 4.5 feet, cased to 2.0 feet, slotted screen, observation.

PERIOD OF RECORD.--

GROUND-WATER LEVELS: October 2003 through September 2004.

INSTRUMENTATION.-- Electronic data logger--60-minute recording.

DATUM.-- Land-surface datum is 535.85 ft above NAVD of 1988. Measuring point: Top of PVC casing, 3.0 ft above land-surface datum.

REMARKS.-- Piezometer open to fine-grained deposits.

EXTREMES FOR PERIOD OF RECORD.--

GROUND-WATER LEVELS: Highest recorded water level, 0.67 ft above land surface datum, Nov. 18, 2003; lowest recorded, 2.78 ft below land surface datum, Aug. 3, 2004.