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
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 Unpublished records for August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.
GAGE.--Water-level recorder installed January 2003;
15-minute recording interval. Periodic manual measurements made
by USGS personnel.
REMARKS.--Water level affected by tidal fluctuation and
nearby pumping. Cellular water-level telemeter at
EXTREMES FOR PERIOD OF RECORD.--Highest water level
measured, 11.49 ft above NGVD 29, May 31 and June 1, 1983;
lowest recorded, 50.36 ft below NGVD 29, August 27, 2016.