USGS Water-Year Summary 2024
404553073351201 N 1616. 3
Northern Atlantic Coastal Plain aquifer system
Glacial Aquifer, Upper
LOCATION - Lat 40°45'53.3", long 73°35'12.0" referenced to North American Datum of 1927, Nassau County, NY, Hydrologic Unit 02030202, at northeast corner of Post Avenue and Advent Street, Old Westbury.
GROUNDWATER RECORDS
WELL CHARACTERISTICS - Depth 74.2 ft. Upper casing diameter 2 in; top of first opening 64.2 ft, bottom of last opening 69.2 ft.
DATUM - Land-surface datum is 121 ft above National Geodetic Vertical Datum of 1929. Measuring point: Well was releveled on 06-25-2015, MP is Top of 2inch PVC casing, 120.29 ft above land-surface datum, Dec. 2, 2004 to present.
PERIOD OF RECORD - December 2004 to current year.
GAGE - Water-level recorder installed December 2004; 15-minute recording interval. Periodic manual measurements made by USGS personnel.
EXTREMES FOR PERIOD OF RECORD - Highest water level recorded, 78.61 ft above NGVD of 1929, May 19, 26, 2010; lowest recorded, 66.64 ft above NGVD of 1929, Oct. 12, 2005.