USGS Water-Year Summary 2023
405125073420702 N 6282. 2
Northern Atlantic Coastal Plain aquifer system
North Shore Aquifer
LOCATION - Lat 40°51'24.8", long 73°42'05.3" referenced to North American Datum of 1983, Nassau County, NY, Hydrologic Unit 02030201, Located at Helen Keller National Center for Deaf-Blind Youths and Adults, 300 ft north of Middle Neck Road, westernmost well, Sands Point.
GROUNDWATER RECORDS
WELL CHARACTERISTICS - Depth 396 ft. Upper casing diameter 6 in; top of first opening 378 ft, bottom of last opening 388 ft. Datum of gage is NGVD of 1929.
PERIOD OF RECORD - December 1960 to January 2000, January 2002 to current year. Unpublished records for August 1957 to September 1975 are available in the files of the U.S. Geological Survey.
GAGE - Water-level recorder installed January 2003; 15-minute recording interval. Periodic manual measurements made by USGS personnel.
EXTREMES FOR PERIOD OF RECORD - Highest water level measured, 11.49 ft above NGVD of 1929, May 31, June 1, 1983; lowest recorded, 50.36 ft below NGVD of 1929, Aug. 27, 2016.