U.S. GEOLOGICAL SURVEY
Data Series 258
Version 1.1, June 2011
Ground-Water Quality Data in the Monterey Bay and Salinas Valley Basins,
California, 2005—Results from the California GAMA Program
Prepared in cooperation with the California State Water Resources
Control Board
By Justin T. Kulongoski and Kenneth Belitz
Table of Contents
Abbreviations
and Acronyms
Abstract
Introduction
Hydrogeologic
Setting of the Monterey Bay and Salinas Valley GAMA Study Unit
Methods
Results
Summary
References
Figures
Figure
1. The 10 hydrogeologic provinces identified for the California GAMA study
with the Monterey Bay and Salinas Valley GAMA study unit outlined.
Figure
2. The Monterey Bay and Salinas Valley GAMA study unit, locations of study
areas, major cities, rivers, creeks, ground-water basins, and subbasins.
Figure
3. The Santa Cruz study area, the locations of the randomized sampling grid
cells, and the randomized public-supply wells sampled in the Monterey Bay
and Salinas Valley GAMA study, California.
Figure
4. The Monterey Bay study area, the locations of the randomized sampling
grid cells, the flow-path and monitoring wells sampled, and the randomized
public-supply wells sampled in the Monterey Bay and Salinas Valley GAMA study,
California.
Figure
5. The Salinas Valley study area, the locations of the randomized sampling
grid cells, and the randomized public-supply wells sampled in the Monterey
Bay and Salinas Valley GAMA study, California.
Figure
6. The Paso Robles study area, the locations of the randomized sampling grid
cells, and the randomized public-supply wells sampled in the Monterey Bay
and Salinas Valley GAMA study, California.
Figure
7. The Monterey Bay and Salinas Valley GAMA study unit, locations of study
areas, target wells, and 10-square-mile randomized sampling grid cells.
Tables
Table 1. Identification, sampling, and construction information for wells sampled for the Monterey Bay and Salinas Valley Ground-Water Ambient Monitoring and Assessment (GAMA) study, California, July to October 2005.
Table 2A. Volatile organic compounds and gasoline additives, primary use or source,
U.S. Geological Survey (USGS) parameter code, Chemical Abstract Service
(CAS) number, laboratory reporting level (LRL) for the USGS National Water
Quality Laboratory analytical schedule 2020, type of comparison threshold for
ground-water detections, and the corresponding threshold value.
Table 2B. Gasoline additives, gasoline oxygenates, and gasoline degradates, primary use
or source, U.S. Geological Survey (USGS) parameter code, Chemical Abstract Service (CAS) number, laboratory reporting level (LRL) for the USGS National
Water Quality Laboratory analytical schedule 4024, type of comparison threshold
for ground-water detections, and the corresponding threshold value.
Table 2C. Pesticides and pesticide degradates, primary use or source, U.S. Geological
Survey (USGS) parameter code, Chemical Abstract Service (CAS) number,
laboratory reporting level (LRL) for the USGS National Water Quality Laboratory analytical schedule 2003, type of comparison threshold for ground-water
detections, and the corresponding threshold value.
Table 2D. Pesticides and pesticide degradates, primary use or source, U.S. Geological
Survey (USGS) parameter code, Chemical Abstract Service (CAS) number,
laboratory reporting level (LRL) for the USGS National Water Quality Laboratory analytical schedule 2060, type of comparison threshold for ground-water
detections, and the corresponding threshold value.
Table 2E. Constituents of special interest, primary use or source, Chemical Abstract Service (CAS) number, Montgomery Watson-Harza Laboratory minimum reporting level (MRL), type of comparison threshold for ground-water detections, and the corresponding threshold value.
Table 2F. Nutrients and dissolved organic carbon, U.S. Geological Survey (USGS)
parameter code, Chemical Abstract Service (CAS) number, laboratory reporting
level (LRL) for the USGS National Water Quality Laboratory (NWQL) analytical schedule 2755 and laboratory code 2613, type of comparison threshold for
ground-water detections, and the corresponding threshold value.
Table 2G. Major and minor ions and trace elements, U.S. Geological Survey (USGS)
parameter code, Chemical Abstract Service (CAS) number, laboratory reporting
level (LRL) for the USGS National Water Quality Laboratory analytical schedule
1948, type of comparison threshold for ground-water detections, and the
corresponding threshold value.
Table 2H. Arsenic, chromium, and iron speciation, U.S. Geological Survey (USGS)
parameter code, Chemical Abstract Service (CAS) number, method detection
level (MD), for the USGS Trace Metal Laboratory, Boulder, Colorado, type of comparison threshold for ground-water detections, and the corresponding
threshold value.
Table 2I. Isotopic and radioactive constituents, U.S. Geological Survey (USGS)
parameter code, Chemical Abstract Service (CAS) number, reporting level type, reporting level or uncertainty, type of comparison threshold for ground-water detections, and the corresponding threshold value.
Table 2J. Tritium and noble gases, Chemical Abstract Service (CAS) number, method uncertainty (MU) and reporting units for the Lawrence Livermore National Laboratory, type of comparison threshold for ground-water detections, and
the corresponding threshold value.
Table 2K. Microbial constituents, U.S. Geological Survey (USGS) parameter code,
primary use or source, and method detection limit (MDL) for the USGS Ohio Microbiology Laboratory.
Table 3. Classes of chemical and microbial constituents and water-quality indicators
collected for the fast, slow, and monitoring well sampling schedules in the
Monterey Bay and Salinas Valley Ground-Water Ambient Monitoring and Assessment (GAMA) study, California, July to October 2005.
Table 4. Analytical methods used for the determination of organic, inorganic, and
microbial constituents by the U.S. Geological Survey (USGS) National Water
Quality Laboratory (NWQL) and additional contract laboratories.
Table 5. Constituents analyzed in ground-water samples collected for the Monterey-
Salinas Ground-Water Ambient Monitoring and Assessment (GAMA) study, California, July to October 2005, that appear on multiple analytical schedules, primary constituent classification, analytical schedules each constituent
appears on, and preferred analytical schedule.
Table 6. Quality-control summary for volatile organic compounds, gasoline additives, pesticides, pesticide degradates, major and minor ions, trace elements,
nutrients, and dissolved organic carbon detected in source-solution blanks,
field blanks, and the minimum concentrations in ground-water samples collected
for the Monterey Bay and Salinas Valley Ground-Water Ambient Monitoring and Assessment (GAMA) study, California, July to October 2005.
Table 7. Quality-control summary of replicate samples for constituents collected for the Monterey Bay and Salinas Valley Ground-Water Ambient Monitoring and Assessment (GAMA) study, California, July to October 2005.
Table 8A. Quality-control summary of matrix spike recoveries of volatile organic compounds, gasoline additives, NDMA, perchlorate, and 1,2,3-trichloropropane in samples collected for the Monterey Bay and Salinas Valley Ground-Water Ambient Monitoring and Assessment (GAMA) study, California, July to October 2005.
Table 8B. Quality-control summary of matrix spike recoveries of pesticides and pesticide degradates in samples collected for the Monterey Bay and Salinas Valley
Ground-Water Ambient Monitoring and Assessment (GAMA) study, California,
July to October 2005.
Table 9. Quality-control summary of surrogate recoveries in environmental, blank, and replicate samples for volatile organic compounds, gasoline additives, pesticides, pesticide degradates, and constituents of special interest, collected for the Monterey Bay and Salinas Valley Ground-Water Ambient Monitoring and
Assessment (GAMA) study, California, July to October 2005.
Table 10. Water-quality indicators determined in the field for the Monterey Bay and
Salinas Valley Ground-Water Ambient Monitoring and Assessment (GAMA)
study, California, July to October 2005.
Table 11. Results of analyses for volatile organic compounds (VOCs) and gasoline
additives in unfiltered ground-water samples collected for the Monterey Bay
and Salinas Valley Ground-Water Ambient Monitoring and Assessment (GAMA) study, California, July to October 2005.
Table 12. Pesticides and pesticide degradates detected in filtered ground-water samples collected for the Monterey Bay and Salinas Valley Ground-Water Ambient Monitoring and Assessment (GAMA) study, California, July to October 2005.
Table 13. Results of analyses by Montgomery Watson-Harza Laboratory for the constituents of special interest: perchlorate, N-nitrosodimethylamine (NDMA), and 1,2,3-trichloropropane (1,2,3-TCP) in the unfiltered ground-water samples collected
for the Monterey Bay and Salinas Valley Ground-Water Ambient Monitoring and Assessment (GAMA) study, California, July to October 2005.
Table 14. Nutrients and dissolved organic carbon in filtered ground-water samples
collected for the Monterey Bay and Salinas Valley Ground-Water Ambient Monitoring and Assessment (GAMA) study, California, July to October 2005.
Table 15. Major and minor ions and dissolved solids in filtered ground-water samples collected for the Monterey Bay and Salinas Valley Ground-Water Ambient Monitoring and Assessment (GAMA) study, California, July to October 2005.
Table 16. Trace elements in filtered ground-water samples collected for the Monterey
Bay and Salinas Valley Ground-Water Ambient Monitoring and Assessment
(GAMA) study, California, July to October 2005.
Table 17. Inorganic arsenic and iron speciation results for filtered ground-water samples collected for the Monterey Bay and Salinas Valley Ground-Water Ambient Monitoring and Assessment (GAMA) study, California, July to October 2005.
Table 18. Chromium speciation results for filtered ground-water samples collected for the Monterey Bay and Salinas Valley Ground-Water Ambient Monitoring and Assessment (GAMA) study, California, July to October 2005.
Table 19. Summary of radioactive constituents and carbon isotopes for filtered ground-
water samples collected for the Monterey Bay and Salinas Valley Ground-Water Ambient Monitoring and Assessment (GAMA) study, California, July to
October 2005.
Table 20. Hydrogen and oxygen isotopes in unfiltered ground-water samples collected
for the Monterey Bay and Salinas Valley Ground-Water Ambient Monitoring and Assessment (GAMA) study, California, July to October 2005.
Table 21. Tritium and noble gas results, analyzed at Lawrence Livermore National Laboratory,
for unfiltered ground-water samples collected for the Monterey Bay and Salinas
Valley Ground-Water Ambient Monitoring and Assessment (GAMA) study, California,
July to October 2005.
Table 22. Summary of microbial indicators detected in ground-water samples collected for the Monterey Bay and Salinas Valley Ground-Water Ambient Monitoring and Assessment (GAMA) study, California, July to October 2005.
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Send questions or comments about this report to the author, Justin
Kulongoski, (619) 225-6122
For more information about USGS activities in California, visit the USGS
California Water Science Center home page.
U.S.
Department of the Interior | U.S. Geological Survey
