USGS Water-Year Summary 2019
Sand and gravel aquifers (glaciated regions)
LOCATION - Lat 42°29'25", long 88°25'54" referenced to North American Datum of 1983, in NW 1/4 SW 1/4 SW 1/4 sec.04, T.46 N., R.7 E., McHenry County, IL, Hydrologic Unit 07120006, 93 feet east of Freeman Road and 24 feet north of farm lane on McHenry County Conservation District property, 0.3 miles south of Illinois/Wisconsin State Line Road, 1.2 miles north of Hebron, and 0.1 miles north of DeYoung Creek. Owner: McHenry County.
- Revisions: Groundwater levels for the period Sep. 13, 2017 to Nov. 08, 2019 caused a revision on Nov. 22, 2019, because the Measuring Point (MP) 1 correction length was incorrect in SVMAQ. Previous MP correction length was 2.61 ft above LSD in SVMAQ. New corrected MP length is 2.52 ft above LSD based on last 3 years of levels.
WELL CHARACTERISTICS - Depth 66.3 ft. Upper casing diameter undefined; top of first opening 61.3 ft, bottom of last opening 65.8 ft. Well-casing includes 2-inch schedule 40 PVC pipe, 8 in. diameter borehole with bentonite seal, artesian observation well.
DATUM - Land-surface datum is 867.93 ft above North American Vertical Datum of 1988. Measuring point: Top of PVC casing; High point marked, 2.61 ft above land-surface datum, Sep. 26, 2008 to Sep. 13, 2017; Top of PVC casing; High point mark, 2.52 ft above land-surface datum, Sep. 13, 2017 to present.
PERIOD OF RECORD -
GROUND-WATER LEVELS: April 2009 to current.
CHEMICAL: Water year 2011.
GAGE - Water level recorder and satellite telemeter.
EXTREMES FOR PERIOD OF RECORD - Highest water level, -16.57 ft below land-surface datum, June 25, 2009; lowest, -10.20 ft below land-surface datum, January 28, 2013.