Locally Sponsored Research

Guam Hydrologic Survey

Data Availability Reports

Chapter 2: Surface Water Data
by: David Vann & Curt Wexel

This chapter discusses surface water data collection activities for streamflow, production, and water quality. Current points of contact for the agencies and activities that collect or archive surface water data are summarized in Table 2.1.

Table 2.1A. Points of contact for streamflow data collection.

Table 2.1B. Points of contact for water production and quality

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Stream Flow Data

Data Archives

USGS published daily mean stream flow plus statistical summary information annually for water years 1961 through 1976 in Water Resources Data--Hawaii and Other Pacific Areas. Data from 1977 through 1989 were published in Volume 2 of Water Resources Data--Hawaii and Other Pacific Areas. Copies of the reports are available at GEPA (1982-1984 and 1986-1989 reports), WERI (1979 and 1982-1989 reports), and at the UOG RFK Memorial Library (1989 report). The reports can be purchased from the US Department of Commerce at NTIS, 5285 Port Royal Road, Springfield, VA 22161.

Complete periods of record of published USGS data are also available on the USGS web site at http:\\waterdata.usgs.gov/nwis-w/HI/. Historical data are also available on the commercial CD-ROM database, Hydrodata, prepared by Hydrophere??. WERI maintains a subscription to Hydrodata, but there is typically about a one-year delay between data collection and publication in the CD-ROM database.

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SURFACE WATER PRODUCTION DATA

Data Collection Activity

The US Navy produces drinking water from Fena Reservoir, the Almagosa Springs (Chepek and Dobo Springs) and Bona Spring. Water from all of these sources is processed through the Fena Water Treatment Plant. The US Navy Public Works Center (PWC) records daily water production at each of these sources and the Fena Water Treatment Plant.

Surface sources used by the Guam Waterworks Authority include an impoundment on the Ugum River, and diversions from Asan Spring and Santa Rita Spring. GWA meters net production from the Ugum Water Treatment Plant but does not meter raw water drawn from the Ugum River. Water drawn from Asan Springs is metered at the intake. GWA data telemetry from the Santa Rita Spring meter is currently not operational. Previous GWA production data recorders at Malojloj (Pigua Dam) and Umatac (Sapua Spring and Lae Lae River) have been deactivated. Metering status is summarized for each source in Table 2.2.

Table 2.2. Production metering status for surface sources.

Archives

The Navy Public Works Center (PWC) archives daily production flow in spreadsheet files, summarized monthly. GWA keeps daily production estimates at the Ugum treatment plant. Under current environmental regulations, producers are required to provide GEPA with an annual report of water production. Beginning in FY1999, the Guam Hydrologic Survey Program at WERI will maintain, in the Guam Water Resources Data Library, annual summary production statistics compiled from the GEPA consolidated data base. Data in the Guam Water Resources Data Library can be accessed via the WERI/GHS web site (http://uog2.uog.edu/weri/ghs/).

Observations and Recommendation

Metering for the Ugum River production plant and telemetry at the Santa Rita Springs should be re-established.

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Water Quality

Data Collection Activity

Water quality data collected at surface water production sites are summarized in Table 2.3. Testing for the Fena water treatment plant (WTP), Almagosa and Bona Spring is performed by the Navy PWC Fena Laboratory. Testing for the Ugum WTP, and Asan and Santa Rita Spring is performed by the GWA laboratory.

Data Archive

Records of water quality testing performed by the GWA and Navy laboratories are retained at the labs. Summary reports on potable water are forwarded to GEPA, as required. Intermittent periods of record containing this information between December 1975 and June 1995 can be accessed on the USEPA STORET database.

Observations and Recommendations

Both the GWA and Navy laboratories generate data to meet USEPA standards. Data archived by GEPA, however, have not been systematically inserted into the USEPA STORET database since 1990, and can therefore be accessed only from the original hard-copy records at GEPA. Detailed and comprehensive studies of water quality data will be possible only after all the historical data have been entered and new data are systematically maintained in the STORET database.

Table 2.3. Surface water quality tests and collection frequency.

* Spring water is mixed with Fena Lake water in the pit whenever spring water is turbid.

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