USGS Water-Year Summary 2023
392813092124701 Madison
Cambrian-Ordovician aquifer system
LOCATION - Lat 39°28'13.1", long 92°12'47.6" referenced to North American Datum of 1983, in NE 1/4 SW 1/4 NE 1/4 sec.14, T.54 N., R.12 W., Monroe County, MO, Hydrologic Unit 07110006,
REVISIONS HISTORY - Revisions: Land-surface datum was updated to 796.40 ft NAVD88 on May 22, 2023, as determined by a GNSS Level II Survey. Land-surface datum was previously published as 795 ft NGVD29 from topographic map (furnished). Discrete water-level measurements prior to May 22, 2023, are referenced to the original datum.
GROUNDWATER RECORDS
WELL CHARACTERISTICS - Depth 677 ft. Upper casing diameter undefined; top of first opening 175 ft, bottom of last opening 677 ft.
DATUM - Land-surface datum is 796.4 ft above North American Vertical Datum of 1988. Measuring point: unknown, 3.4 ft above land-surface datum, Jun. 19, 1979 to present.
PERIOD OF RECORD - December 11 2019 to present