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- Water-Year Summary reports summarize a year of hydrologic data in a printer-friendly format.
- For water years 2014 onward, choose a water year and parameter and an on-demand Water-Year Summary report will be generated.
- For water years 2006 through 2013, choose a water year and an Annual Water Data Report will be provided.
- For water years 2005 and earlier, Annual Water Data Reports may be available in digital format.
- Not all sites have reports available for every water year.
USGS Water-Year Summary 2024
133628144513271 EX-8 Northwest Field, Guam
Other aquifers
LOCATION - Lat 13°36'34.02", long -144°14'0.16" referenced to North American Datum of 1983, Guam County, GM, Hydrologic Unit 22010000, 1.3 mi north of Potts Junction and 3.0 mi south of Ritidian Point.
GROUNDWATER RECORDS
WELL CHARACTERISTICS - Depth 658 ft. Upper casing diameter 8 in; top of first opening undefined, bottom of last opening undefined. Sounded depth, October 21, 2010: 643 feet.
DATUM - Land-surface datum is 461.71 ft above undefined vertical datum. Measuring point: top of pvc casing, marked, 462.54 ft above Guam Vertical Datum of 2004, Nov. 29, 2010 to present. Water level elevations are referenced to the Guam Vertical Datum of 2004 (GUVD04) beginning January 12, 2012.
PERIOD OF RECORD - Manual measurements: September 14, 1981 to January 14, 2011. Continuous water-level record: November 29, 2010 to January 14, 2011, and January 12, 2012 to current year.
EXTREMES FOR PERIOD OF RECORD - Highest water level, 4.49 feet above mean sea level, May 28, 1986; lowest water level, 1.86 feet above mean sea level, February 23, 1983.
WATER-QUALITY RECORDS
WELL CHARACTERISTICS - Depth 658 ft. Upper casing diameter 8 in; top of first opening undefined, bottom of last opening undefined. Sounded depth, October 21, 2010: 643 feet.
DATUM - Land-surface datum is 461.71 ft above undefined vertical datum. Measuring point: top of pvc casing, marked, 462.54 ft above Guam Vertical Datum of 2004, Nov. 29, 2010 to present. Water level elevations are referenced to the Guam Vertical Datum of 2004 (GUVD04) beginning January 12, 2012.
PERIOD OF RECORD - Specific-conductance profiles using a conductivity-temperature-pressure sensor (CTD): 2000-2002, 2004-2005, 2010 to present. Unpublished records available upon request.
Discrete-depth sampling, analysis for specific conductance and chloride concentration: 1982-1985. Unpublished records available upon request.
Fluid-resistivity profiles: 1981 to 1983. Unpublished records available upon request.
INSTRUMENTATION - Water-quality monitor with recorder set to approximately 1-second recording interval. Monitor is trolled over the total depth of the well.
REMARKS - Two specific-conductance and temperature profiles are measured during each water year; one at the end of the wet season (January) and one at the end of the dry season (June or July).
The CTD is checked against specific-conductance standards. The specific-conductance measurements in the profiles have not been adjusted based on the check measurements, however, the data are available to make adjustments.
Depth is measured using a combination of a marked and calibrated cable and pressure readings from the CTD.
