WRIR 99-4036-Ground-Water and Water-Chemistry Data for the Willamette Basin, Oregon
Entry ID:
WRIR_99_4036
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Summary
Abstract:
This report presents ground-water data collected and compiled as part of a study of the ground-water resources of the Willamette River Basin, Oregon. The report includes tabulated information and a location map for 1,234 field-located water wells and 6 springs, hydrographs showing water-level fluctuations during various time periods for 265 of the wells, borehole geophysical data for 16 wells, and ... water-chemistry analyses from 125 wells and 6 springs. These data, as well as data for 4,752 additional field-located wells and 1 spring, are included on a CD-ROM. In addition, the locations of the field-located wells and springs are provided in geographic information system formats on the CD-ROM. The purpose of the study were to provide a quantitative understanding of the regional ground-water flow system of the Willamette Basin sufficient to effectively evaluate the hydrologic effects of land- and water-use policies and climate changes, to develop the understanding and tools necessary to quantitatively evaluate the effect of ground-water pumping on streamflow, to characterize the unique hydrology of basalt aquifers within the Willamette Basin, particularly as related to water availability, to develop a better understanding of the relations between well yield and factors such as geology, well construction, and siting in areas underlain by low-yield aquifers, and to develop a better understanding of the origins and distribution of selected types of naturally occurring poor-quality ground water. The information gained from the study will provide a knowledge base to support resource-management decisions by State and local governments. The system used for locating wells and springs is based on the rectangular system for subdivision of public land. The State is divided into 36 square-mile townships numbered according to their location relative to the east-west Willamette baseline and a north-south Willamette meridian. The position of a township is given by its north-south "Township" position relative to the baseline and its east-west "Range" position relative to the meridian. Each township is divided into 36 sections approximately 1 square mile (640 acres) in area and numbered from 1 to 36. Data for 5,993 field-located wells and springs were compiled to establish a database for Willamette Basin ground-water investigation. Approximately 500 of the wells were field located during the current investigation. The remaining wells were located during previous USGS and OWRD investigations. Of the 5,993 wells and springs, 1,234 study wells and 6 study springs were chosen for data collection and analysis to delineate the extent and thickness of hydrogeologic units in the basin and to provide data on water levels, water chemistry, and water use. Location, construction, water level, and other data for these study wells and springs. Hydrological units as defined by Gannett and Caldwell (1998) were determined for most of these wells. Locations of the study wells and springs are recorded in several GIS formats on the CD-ROM. Location and selected data were also compiled in text and GIS files on the CD-ROM for the nonstudy wells. Locations of wells visited during this study were determined by plotting the well sites on USGS 7.5 minute series topographic maps (1:24,000 scale) or by using Global Positioning System (GPS) devices. The GPS locations were generally accurate to within 25 feet, depending upon the number of satellites the GPS device could access at the time of measurement. Land-surface altitude at each well site was estimated from elevation contours on USGS 7.5 minute series topographic maps at the plotted location and is considered accurate to approximately one-half of the contour interval (for example, altitudes are accurate to + or - 5 feet for a map with 10-foot contour intervals). Each well was assigned a unique 15-digit USGS site ID (identification number used by the USGS in the National Water Information System database). Where possible, wells were correlated to the corresponding OWRD well-log IDThe OWRD well-log ID is a combination of a four-letter county code and a well-log number with up to 6 digits (e.g. MARI 2218) which uniquely identifies each water well report in Ground Water Resource Information Distribution (GRID), a statewide computer database maintained by OWRD. The county code is assigned based on the county designated by the driller on the water well report at the time the report was filed with the OWRD; however, in some cases, this code may not correspond to the county in which the well is physically located. Water levels were measured periodically in selected wells, referred to as observation wells, to monitor fluctuations in ground-water levels in response to recharge, surface-water conditions, and ground-water pumping. Water levels in approximately 470 wells were measured during a 2-week period in November 1996 to produce a "snapshot", or synoptic measurement, of water-level conditions throughout the Willamette Basin. Water levels in selected wells for this study were generally measured manually with either a steel tape or "electric tape". Steel tapes are standard surveyor tapes that are marked at .01 foot increments. Electric tapes, which use electrical continuity to sense water level, were calibrated by comparision with steel tapes. Measurements with both steel and electric tapes were recorded to the nearest .01 foot. Steel tape measurements are generally accurate to .0.01 foot, while electric tape measurements are accurate to about 0.04 foot for water levels within 200 feet of land surface. The measuring point most commonly used was the top of the well casing. Continuous water-level measurements were monitored at 33 wells using battery-operated electronic data recorders. The water level in the well was measured by either a float-driven digital shaft encoder or a submersible pressure transducer. The shaft encoder sensor uses a 1 foot-circumference wheel and beaded steel cable, and has a measurement acuracy of 0.01 foot Pressure transducers were used in situations where a float system was impractical due to extreme depth to water, obstructions in the well, or small diameter well casing. The transducers' accuracies are estimated to be about 0.05 feet. The recorded data include the date and time of measurements and the distance from the land surface to the water level. Data were recorded at 2-hour intervals. In addition to the water-level data, barometric pressure data were collected for several locations. Each water-level recorder was visited on a 1-2 month schedule. Data were recorded to a computer file and graphed in the field to verify operation of the sensor. The current reading of the sensor was verified by a manual water-level measurement, either by steel or electric tape. When necessary, corrections were applied to the raw data, based on the manual measurements. Sixteen wells in the Willamette Basin were geophysically logged to determine the stratigraphy of the valley-fill sediments and the stratigraphy and fracturing of the rocks of the Columbia River Basalt Group. Fluid and geologic material properties were measured using three geophysical probes: (1) fluid probe, which measures the temperature and conductivity of the fluit in the borehole and natural gamma radiation from the geologic material, (2) a caliper probe, which measures borehole diameter, and (3) an induction probe, which measures bulk conductivity. The following fluid and geologic material properties that were measured included: borehole diameter, bulk conductivity (of the combined pore water and rock or soil matrix), natural gamma radiation, fluid temperature, and fluid conductivity. Measurements of bulk conductivity and borehole diameter were limited to the uncased sections of the wells. Measurements of fluid conductivity and temperature were limited to sections below the level of standing water in the borehole. Natural gamma radiation was measured for all wells, regardless of water level or the presence or absence of casing. All of the wells penetrated valley-fill deposits, seven wells penetrated the Columbia River Basalt Group, and six wells penetrated rocks of marine or western Cascade volcanic origin. Water samples were collected at selected wells and springs to improve the understanding of the occurrence and distribution of concentrations of arsenic and chloride and specific conductance of ground water of the Willamette Basin. The water samples were collected at 125 wells and 6 cold (non-thermal) springs during the period August 1996 to September 1997. The sites had not previously been sampled for arsenic by the USGS. Water samples from wells were collected prior to passage of the water through water softeners. The samples were not filtered. Most (116) wells were actively used domestic wells. These wells were sampled after a minimum purge time of 1 minute. Longer purge times, characteristic of most USGS ground-water-quality studies were deemed unnecessary for these wells because of the well purging effects resulting from the frequent use of the wells. The remaining 9 wells consisted of 3 public-water-supply, 3 industrial, 2 irrigation, and 1 livestock well. Of these nine additional wells, the wells that were not actively used were purged a minimum of three casing volumes prior to sampling. The springs sampled were flowing springs. Samples from springs were filtered 0.45 micron pore size filters. Arsenic samples for wells and springs were field-acidified with nitric acide to a pH less than 2.0. Arsenic and chloride analyses were performed at the USGS National Water-Quality Laboratory in Arvada, Colorado. Analysis of arsenic was done by hydride atomic absorption. Chloride was measured colorimetrically. Specific conductance was measured in the field for water from 33 wells and 6 springs ("field specific conductance"), and in the USGS Oregon District laboratory for water from 81 wells ("laboratory specific conductance") The information for this metadata was taken from the Online Publications of the Oregon District at http://oregon.usgs.gov/pubs_dir/online_list.html .
Related URL
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Description:
Metadata in National Biological Information Infrastructure format.
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Geographic Coverage
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Spatial coordinates
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N: 46.0
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S: 43.5
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E: -121.9
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W: -123.5
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Data Set Citation
Dataset Originator/Creator:
Leonard L. Orzol, Karl C. Wozniak, Tiffany R. Meissner, and Douglas B. Lee
Dataset Title:
Ground-Water and Water-Chemistry Data for the Willamette Basin, Oregon
Dataset Release Date:
unknown
Dataset Release Place:
Portland, Oregon
Dataset Publisher:
U.S. Geological Survey
Data Presentation Form:
database
Online Resource:
http://oregon.usgs.gov/pubs_dir/Cd/WRIR99-4036/index.html
Temporal Coverage
Start Date:
1996-08-01
Stop Date:
1998-04-01
Quality
For the borehole geophysical data as a result of instrument problems, some logs were not recorded for some wells.
Access Constraints
None
Use Constraints
None
Data Set Progress
COMPLETE
Personnel
Role:
TECHNICAL CONTACT
Phone:
(503) 251-3270
Fax:
(503) 251-3470
Email:
llorzol at usgs.gov
Contact Address:
U.S. Geological Survey
10615 SE Cherry Blossom Dr.
City:
Portland
Province or State:
Oregon
Postal Code:
97216
Country:
USA
Role:
DIF AUTHOR
Phone:
(301) 614-6898
Fax:
301-614-5268
Email:
Tyler.B.Stevens at nasa.gov
Contact Address:
NASA Goddard Space Flight Center
Global Change Master Directory
City:
Greenbelt
Province or State:
MD
Postal Code:
20771
Country:
USA
Publications/References
Orzol, L.L., Wozniak, K.C., Meissner, T.R. and Lee, D.B., 2000 Ground-Water and Water-Chemistry Data for the Willamette Basin, Oregon U.S. Geological Survey Water Resources Investigation Report - 99-4036 Portland , Oregon U.S. Geological Survey, 141 pages http://oregon.usgs.gov/pubs_dir/Pdf/99-4036.pdf
Extended Metadata Properties
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Creation and Review Dates
DIF Creation Date:
2001-06-27
Last DIF Revision Date:
2012-12-12
Future DIF Review Date:
2002-06-27
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