Geologic, Water-Chemistry, and 

Hydrologic Data from Multiple-Well 

Monitoring Sites and Selected 

Water-Supply Wells in the 

Santa Clara Valley, California, 1999–2003

By M.W. Newhouse, R.T. Hanson, C.M. Wentworth, Rhett R. Everett, 

C.F. Williams, J.C. Tinsley, T.E. Noce, and B.A. Carkin

In cooperation with the

Santa Clara Valley Water District

Scientific Investigations Report 2004-5250

U.S. Department of the Interior

U.S. Geological Survey
U.S. Geological Survey, Reston, Virginia: 2004

For sale by U.S. Geological Survey, Information Services

Box 25286, Denver Federal Center

Denver, CO 80225-0286

U.S. Department of the Interior

Gale A. Norton, Secretary

U.S. Geological Survey

Charles G. Groat, Director

For more information about the USGS and its products:

Telephone: 1-888-ASK-USGS

World Wide Web: http://www.usgs.gov/

Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply 

endorsement by the U.S. Government.

Although this report is in the public domain, permission must be secured from the individual copyright owners to 

reproduce any copyrighted materials contained within this report.

Suggested citation:

Newhouse, M.W., Hanson, R.T., Wentworth, C.M., Everett, R.R., Williams, C.F., Tinsley, J.C., Noce, T.E., and Carkin, 

B.A., 2004, Geologic, water-chemistry, and hydrologic data from multiple-well monitoring sites and selected watersupply wells in the Santa Clara Valley, California, 1999–2003: U.S. Geological Survey Scientific Investigations Report 

2004–5250, 134 p.
iii

Contents

Abstract. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Purpose and Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Approach. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Description of Study Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Acknowledgments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Design of Monitoring Sites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Geologic Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Lithologic Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Geophysical Logs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Coyote Creek Outdoor Classroom (CCOC) Site . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Willow (WLLO) Site . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

McGlincey (MGCY) Site . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Santana Park (STPK) Site . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Guadalupe (GUAD) Site . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Eleanor Park (ELNR) Site . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Saratoga (STGA) Site . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Evergreen (EVGR) Site . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Core Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

 Physical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Observational Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Core Subsample Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Water-Chemistry Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Selected Chemical Attributes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Major, Minor, and Trace Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Major ions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Selected Minor Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Selected Trace Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Dissolved Nitrogen and Carbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Isotopes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Hydrologic Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Ground-Water Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Hydraulic Properties of Aquifers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Accessing Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Summary and Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

References Cited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
iv

Figures

Figure 1. Map showing multiple-well monitoring sites and selected watersupply wells, Santa Clara County, California . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Figure 2. Map showing geologic outcrops and major structural features, 

Santa Clara County, California . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Figure 3. Graphs showing geophysical logs, well-construction diagram, and

generalized lithologic description for Coyote Creek Outdoor 

Classroom (7S/1E-9L4–8) multiple-well site, Santa Clara County, California . . . . . . 6

Figure 4. Graphs showing geophysical logs, well-construction diagram, and 

generalized lithologic description for Willow (7S/1E-19B2–7) multiplewell site, Santa Clara County, California. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Figure 5. Graphs showing geophysical logs, well-construction diagram, and

generalized lithologic description for McGlincey (7S/1W-35L12–16) 

multiple-well site, Santa Clara County, California. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Figure 6. Graphs showing geophysical logs, well-construction diagram, and 

generalized lithologic description for Santana Park (7S/1W-14P1–5) 

multiple-well site, Santa Clara County, California. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Figure 7. Graphs showing geophysical logs, well-construction diagram, and 

generalized lithologic description for Guadalupe (6S/1W-26Q1–4) 

multiple-well site, Santa Clara County, California. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Figure 8. Graphs showing geophysical logs, well-construction diagram, and 

generalized lithologic description for Eleanor Park (5S/3W-36P2–5) 

multiple-well site, Santa Clara County, California. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Figure 9. Graphs showing geophysical logs, well-construction diagram, and

generalized lithologic description for Saratoga (7S/1W-29C3–6) 

multiple-well site, Santa Clara County, California. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Figure 10. Graphs showing geophysical logs, well-construction diagram, and 

generalized lithologic description for Evergreen (7S/2E-19C5–9) 

multiple-well site, Santa Clara County, California. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Figure 11. Histogram show primary-wave velocity measurements for all cores 

and average per core collected from multiple-well monitoring sites, 

Santa Clara County, California . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Figure 12. Histogram showing density measurements for all cores and average 

per core collected from multiple-well monitoring sites, Santa Clara 

County, California . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Figure 13. Histogram showing magnetic susceptibility measurements for all cores and 

average per core collected from multiple-well monitoring sites, 

Santa Clara County, California . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Figure 14. Graphs showing trilinear diagrams of major-ion chemistry for multiplewell monitoring sites and selected water-supply wells, 

Santa Clara County, California . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Figure 15. Graphs showing stable isotopes for multiple-well monitoring sites and 

selected water-supply wells, Santa Clara County, California. . . . . . . . . . . . . . . . . . . 35

Figure 16. Graph showing ground-water levels for selected multiple-well monitoring

sites, Santa Clara County, California . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
v

Tables

Table 1. Summary of multiple-well monitoring sites, Santa Clara County, California....... . 48

Table 2. Summary of well completions for multiple-well monitoring sites, 

Santa Clara County, California............................................................ 49

Table 3. Lithologic shaker logs for Coyote Creek Outdoor Classroom

(7S/1E-9L4-8) multiple-well monitoring site, Santa Clara County, California...... . . 50

Table 4. Lithologic shaker logs for Willow (7S/1E-19B2-7) multiple-well 

monitoring site, Santa Clara County, California..................................... . . . 53

Table 5. Lithologic shaker logs for McGlincey (7S/1W-35L12-16) multiple-well

monitoring site, Santa Clara County, California..................................... . . . 58

Table 6. Lithologic shaker logs for Santana Park (7S/1W-14P1-5) multiple-well 

monitoring site, Santa Clara County, California..................................... . . . 63

Table 7. Lithologic core-summary log for Guadalupe (6S/1W-26Q1-4) multiple-well

monitoring site, Santa Clara County, California..................................... . . . 67

Table 8. Lithologic shaker logs for Eleanor Park (5S/3W-36P2-5) multiple-well 

monitoring site, Santa Clara County, California..................................... . . . 72

Table 9. Lithologic shaker logs for Saratoga (7S/1W-29C3-6) multiple-well 

monitoring site, Santa Clara County, California..................................... . . . 75

Table 10. Lithologic shaker logs for Evergreen (7S/2E-19C5-9) multiple-well 

monitoring site, Santa Clara County, California................................. . . . . . . 79

Table 11. Summary of multi-sensor logging data for cores collected from 

multiple-well monitoring sites, Santa Clara County, California.................. . . . . 82

Table 12. Summary of consolidation analysis for selected core samples collected

from multiple-well monitoring sites, Santa Clara County, California......... . . . . . . 93

Table 13. Summary of hydraulic property estimates from selected core samples 

collected from multiple-well monitoring sites, Santa Clara County, California...... 95

Table 14. Summary of selected U.S. Geological Survey water-chemistry data

from multiple-well monitoring sites, Santa Clara County, California................ . 96

Table 15. Summary of pore water-chemistry data from selected core samples 

collected from multiple-well monitoring sites, Santa Clara County, California . . . .104

Table 16. Summary of selected U.S. Geological Survey water-chemistry data from

selected water-supply wells, Santa Clara County, California.........................108

Table 17. Summary of slug-test estimates of hydraulic properties for selected 

multiple-well monitoring sites, Santa Clara County, California..................... . .132
vi

Conversion Factors, Vertical Datum, WaterChemistry (and other) Units, and Abbreviations

CONVERSION FACTORS 

Temperature in degrees Celsius (oC) may be converted to degrees Fahrenheit (oF) as follows:

oF=1.8 oC+32.

VERTICAL DATUM

Sea level, in this report, refers to the National Geodetic Vertical Datum of 1929 (NGVD of 1929)—

a geodetic datum derived from a general adjustment of the first-order level nets of both the 

United States and Canada, formerly called Sea Level Datum of 1929. 

WATER-CHEMISTRY (AND OTHER) UNITS

Specific conductance is given in microsiemens per centimeter at 25 degrees Celsius (μS/cm at 

25°C). Concentrations of chemical constituents in water are given in milligrams per liter (mg/L) or 

micrograms per liter (μg/L).

Stable-isotope data for oxygen and hydrogen are reported in delta (δ) notations as per mil (parts 

per thousand). Carbon-14 is reported as percent modern carbon (pmc). Tritium activity is 

reported in picocuries per liter (pCi/L).

Core-sample density is reported in grams per cubic centimeter (g/cm3).

ABBREVIATIONS

bls below land surface

CCOC Coyote Creek Outdoor Classroom

cm centimeter

CPT cone penetrometer test

ELNR Eleanor Park

EM electromagnetic conductivity

EVGR Evergreen

ft bls foot below land surface

Multiply By To obtain

acre 0.4047 square hectometer

foot (ft) 0.3048 meter

foot per day (ft/d) 0.3048 meter per day

foot per second (ft/s) 0.3048 meter per second

square foot per day (ft2/d) 0.09290 square meter per day

inch (in.) 25.4 millimeter

mile (mi) 1.609 kilometer

square mile (mi2) 2.590 square kilometer

pound (lb) 0.4536 kilogram
vii

GUAD Guadalupe

kg/cm2 kilogram per square centimeter

km/sec kilometer per second

MGCY McGlincey

mm millimeter

MSL multi-sensor logger

NWIS (USGS) National Water Information System

PDB Peedee Belemnite

PVC polyvinyl chloride

p-wave primary-wave (velocity)

STGA Saratoga

STPK Santana Park

VSMOW Vienna Standard Mean Ocean Water

WLLO Willow 

WRRDU Western Region Research Drilling Unit (USGS)

ybp years before present

Organizations

Cal-EPA California Environmental Protection Agency

SCVWD Santa Clara Valley Water District

USGS U.S. Geological Survey
viii

Well-Numbering System

Wells are identified and numbered according to their location in the rectangular 

system for the subdivision of public lands. Identification consists of the township 

number, north or south; the range number, east or west; and the section number. Each 

section is divided into sixteen 40-acre tracts lettered consecutively (except I and O), 

beginning with “A” in the northeast corner of the section and progressing in a sinusoidal 

manner to “R” in the southeast corner. Within the 40-acre tract, wells are sequentially 

numbered in the order they are inventoried. The final letter refers to the base line and 

meridian. In California, there are three base lines and meridians; Humboldt (H), Mount 

Diablo (M), and San Bernardino (S). All wells in the study area are referenced to the 

Mount Diablo base line and meridian (M). Well numbers consist of 15 characters and 

follow the format 007S001E26D002M. In this report, well numbers are abbreviated and 

written 7S/1E-26D2. Wells in the same township and range are referred to only by their 

section designation, 26D2. The following diagram shows how the number for well 

7S/1E-26D2 is derived.

IMPORT figure saved as PDF into text/anchored f rame below.

D C B A

E F G H

M L K J

N P Q R

6 5 4 3 2

7 8 9 10 11 12

18 17 15 14 13

19 20 21 22 23 24

30 29 28 25

31 32 33 34 35 36

27

R2E R3E

T6S

T5S

T4S

R1E

RANGE

R2W R1W

T7S

T8S

R1E

Well-numbering diagram (Note: maps in this report use abbreviated well numbers such as "26D2") Mount Diablo Meridian

SECTION 26

T7S

7S/1E-26D2

1

16

26
Geologic, Water-Chemistry, and Hydrologic Data 

from Multiple-Well Monitoring Sites and Selected 

Water-Supply Wells in the Santa Clara Valley, 

California, 1999–2003

By M.W. Newhouse, R.T. Hanson, C.M. Wentworth, Rhett R. Everett, C.F. Williams, J.C. Tinsley, 

T.E. Noce, and B.A. Carkin

Abstract

To better identify the three-dimensional geohydrologic 

framework of the Santa Clara Valley, lithologic, geologic, 

geophysical, geomechanical, hydraulic, and water-chemistry 

data were collected from eight ground-water multiple-well 

monitoring sites constructed in Santa Clara County, California, 

as part of a series of cooperative studies between the U.S. 

Geological Survey and the Santa Clara Valley Water District. 

The data are being used to update and improve the threedimensional geohydrologic framework of the basin and to 

address issues related to water supply, water chemistry, 

sequence stratigraphy, geology, and geological hazards. This 

report represents a compilation of data collected from 1999 to 

2003, including location and design of the monitoring sites, 

cone penetrometer borings, geologic logs, lithologic logs, 

geophysical logs, core analysis, water-chemistry analysis, 

ground-water-level measurements, and hydraulic and 

geomechanical properties from wells and core samples.

Exploratory cone penetrometer borings taken in the upper 

17 to 130 feet at six of the monitoring sites identified the base 

of Holocene as no deeper than 75 feet in the central confined 

area and no deeper than 35 feet in the southern unconfined 

areas of the valley. Generalized lithologic characterization 

from the monitoring sites indicates about four to six different 

aquifer units separated by relatively fine-grained units occur 

within the alluvial deposits shallower than 860 feet deep. 

Analysis of geophysical logs indicates that coarse-grained units 

varied in thickness between 10 and 25 feet in the southeastern 

unconfined area of the valley and between 50 and 200 feet in 

the south-central and southwestern areas of the valley. 

Deviations from temperature-gradient logs indicate that the 

majority of horizontal ground-water flow occurs above a depth 

of 775 feet in the south central and above 510 feet in the southeastern areas of the valley. Bulk physical properties from more 

than 1,150 feet of core samples indicate an average primarywave velocity of about 5,515 feet per second, a bimodal 

distribution of density between 2.19 and 2.32 grams per cubic 

centimeter with an average of 2.16 grams per cubic centimeter, 

and a magnetic susceptibility that generally ranged between 

9 and 40 with an average of 22. 

Water-chemistry data indicate that the ground water in the 

alluvial aquifers generally is low in total dissolved solids and 

chloride and of good quality. Isotopic data indicate that water 

from artificial recharge is present throughout the shallower 

parts of the aquifer system but may not be present toward the 

center of the valley. The percentage of water from artificial 

recharge present in ground water ranges from 0 to 61 percent 

for water-supply wells. The age of most shallow ground water 

is less than 2,000 years before present, and the age of deeper 

ground water is as much as 39,900 years before present, as 

determined from carbon age dates. 

Initial water-level data from the multiple-well monitoring 

sites indicate seasonal water-level fluctuations as great as 

60 feet and water-level differences between aquifers as great as 

10 feet. The water-level hydrographs indicate different waterlevel changes and relations between aquifers in different parts 

of the basin. However, most of these hydrographs indicate the 

potential for downward water-level gradients, with lower 

hydraulic heads in the deeper monitoring wells.

Hydraulic properties of selected new monitoring wells 

indicate that horizontal hydraulic conductivities range from 

0.1 to 583 feet per day. Hydraulic testing of selected core 

samples yielded vertical hydraulic conductivity values ranging 

from 8 × 10−4 to 0.3 feet per day, and effective porosity values 

ranging from 0.21 to 0.4. Geomechanical properties estimated 

from one-dimensional consolidation tests of selected core 

samples resulted in geometric mean inelastic and elastic 

specific storage values of 1.5 × 10−4 and 1.2 × 10−5 per foot, 

respectively.
2 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

Introduction

Ground-water levels in the Santa Clara Valley have been 

recovering since the mid-1960s as a result of better resource 

management, conservation, imported water, and artificial 

recharge (Santa Clara Valley Water District, 2004; Poland and 

Ireland, 1988). The Santa Clara Valley Water District 

(SCVWD) needs to meet future ground-water demands during 

drought conditions while at the same time limiting land 

subsidence. The complexities of subsidence and ground-water 

flow in the Santa Clara Valley still are not completely 

understood. The existing monitoring and modeling tools need 

to be upgraded and updated to provide water managers with 

necessary data and tools to address the water-management 

issues. Improvement of the subsidence-monitoring network 

was addressed by the SCVWD and the U.S. Geological Survey 

(USGS) in 1998 (Galloway and others, 2000). Several studies, 

including the SCVWD modeling efforts (CH2M Hill, 1992), 

completed since the original USGS subsidence studies (Poland 

and Ireland, 1988) have attempted to address the issues of 

regional ground-water development and the related effects of 

subsidence. However, none of these studies include recent data 

or much geochemical data, geomechanical data, or threedimensional water-level data, which are needed to address the 

complex water-resources management issues facing the 

SCVWD. 

Purpose and Scope

The purpose of this report is to present a compilation and 

summary of all data collected at eight new multiple-well 

monitoring sites along with related tests and measurements in 

the Santa Clara Valley completed between 2000 and 2003 and 

water-chemistry data collected between 1999 and 2003. To 

better identify the three-dimensional geohydrologic 

framework of the Santa Clara Valley and improve the groundwater management strategy, gaps in the ground-water 

monitoring network were identified previously (Jaimes, 1998). 

Included in the current report are lithologic and geologic data, 

geophysical data, water-chemistry data, and hydrologic data. 

In addition to summarizing data collection, this report presents 

initial interpretations and estimates from these data. The 

geologic interpretations include thicknesses, Holocene and 

bedrock depths, specific storage, and core attributes. The 

water-chemistry interpretations include age dates and 

estimates of percentages of artificial recharge. The hydrologic 

interpretations include water-level differences and estimates of 

hydraulic conductivity.

Approach

The multiple-well monitoring site locations were selected 

jointly by the SCVWD and the USGS on the basis of scientific 

merit, access, and safety. Eight multiple-well monitoring well 

sites include a total of 38 individual ground-water monitoring 

wells and 6 cone penetrometer exploratory borings. Seven of 

the monitoring site boreholes were designed to have a total 

depth of 1,000 ft below land surface (bls), and one site was 

designed to have a total depth about 1,300 ft bls in order to 

penetrate the top of the underlying basement rocks. The sites 

were completed with either continuous drilling, continuous 

drilling with selected coring, or continuous coring. Two sites 

were drilled with continuous drilling, five sites were drilled 

with selected coring, and one site was drilled with continuous 

coring to 1,000 ft bls and then selected coring to the underlying 

basement rocks at selected depths. 

The Earthquake Hazards Program Research Cone 

Penetrometer Drilling Unit of the USGS performed 

exploratory cone penetrometer tests (CPT) at seven sites. 

Subsequent to the CPT, the USGS Western Region Research 

Drilling Unit (WRRDU) drilled and cored a borehole to target 

depth or bedrock at each site. After the borehole was drilled, 

the WRRDU collected borehole geophysical data and installed 

the multiple wells separated vertically by seals in the borehole. 

At some sites the shallowest well was installed in a separate 

shallow borehole. Subsequent well development and water 

sampling were performed by either USGS or SCVWD 

personnel. Slug tests were performed at three of the eight sites. 

Most water-chemistry analysis was done by the USGS, with 

additional water-chemistry analysis performed by SCVWD. 

The types of data collected at each site were dependent, in part, 

on the scope of drilling, construction, and testing designated 

for each site. 

Cores collected from boreholes varied in length from a 

target length of 2.5 ft to 5 ft. All cores were analyzed for 

geology, lithology, and various physical properties at the 

USGS Marine Geology Core Laboratories in Menlo Park, 

California. Geologic and lithologic descriptions and highresolution digital photography were completed on all cores, 

and selected whole-core samples were collected for selected 

physical properties. Physical properties measured from wholecore samples included acoustic velocity, bulk density, and 

magnetic susceptibility. Whole-core subsamples were 

measured for thermal conductivity, hydraulic conductivity, 

magnetic orientation, compressibility, and pore-water 

chemistry.
Design of Monitoring Sites 3

Description of Study Area

The Santa Clara Valley is a broad plain extending about 

25 mi southeast from San Francisco Bay (fig. 1). The valley 

drains an area of about 240 mi2 of coastal central California by 

a network of about 700 mi of tributaries and rivers that flow 

toward the southern end of San Francisco Bay. Beneath the 

valley is an alluvial basin bounded on the southwest and 

northeast by faults and adjacent mountain ranges. The basin has 

undergone extensive ground-water development in the upper 

aquifers, which are composed of Quaternary and Pleistocene 

fluvial and marine deposits (fig. 2). Extensive ground-water 

development also has occurred below these deposits in the 

Pleistocene and Pliocene fluvial deposits that are herein 

referred to as the “lower aquifers.” The alluvial deposits that 

form the regional aquifer systems are unconformably underlain 

by the Miocene Monterey Formation (not shown in fig. 2), and 

the Mesozoic Great Valley Sequence, Franciscan complex, 

including serpentinite (fig. 2). These rocks form the relatively 

impermeable base of the regional aquifer systems in the Santa 

Clara Valley.

The alluvial aquifer systems are composed of a complex 

sequence of discontinuous layers of fluvial sand and gravel and 

fluvial fine-grained silt and clay. The multiple-well monitoring 

sites completed by the USGS indicate that the fine-grained 

layers generally are 5- to 30-ft thick and generally are thinner 

than previously depicted (California Department of Water 

Resources, 1967, fig. 3). These wells also indicate that the 

aquifer systems contain extensive coarse-grained waterbearing zones. This is exemplified by the lithologic and 

geophysical logs completed at the Coyote Creek Outdoor 

Classroom (CCOC) site (fig. 3) where coarse-grained layers 

extend to depths greater than 800 ft bls (Hanson and others, 

2002).

The target depth of 1,000 ft at each monitoring-well site 

was designed to penetrate all of the water-bearing alluvium 

penetrated by water-supply wells. Previous geologic 

investigations have identified the materials between 670 to 

1,000 ft bls in the Santa Clara Valley as undifferentiated fluvial 

sediments that were grouped with shallower sediments as part 

of the lower aquifer system (for example, CH2M Hill, 1992). 

The completion of the monitoring-well sites and analyses of 

related data summarized in this report will provide a basis for 

the reevaluation of the stratigraphy and grouping of the upper 

and lower regional aquifer systems within the Santa Clara 

Valley.

Acknowledgments

This study could not have been accomplished without the 

assistance of personnel from the Santa Clara Valley Water 

District. In particular Bezhad Ahmadi, Mark Merritt, Vanessa 

Reymers, Roger Pierno, Randy Behrens, and Chanie Wossen 

Abuye of the SCVWD Ground-Water Management group are 

especially acknowledged for their assistance with compilation 

of data needed to site, drill, and complete the new network of 

multiple-well monitoring sites. Guidance with sediment 

description and associated research was provided by Dave 

Anderson and Malia Burrows, San Jose State University. In 

addition, we acknowledge the valuable guidance of U.S. 

Geological Survey geologists and geophysicists of the Earth 

Surface Processes Group, Earthquake Hazards Group, Coastal 

Marine Geology Group, and Urban Hazards Group and thank 

them for their efforts supporting the selection of sites, 

collection of data, and subsequent analysis. In particular we 

thank Robert Jachens, Robert Williams, and Richard Stanley 

for their contribution to seismic imaging and other geophysical 

analyses, core descriptions, and basin stratigraphy and 

structure. We also thank Peter Martin for his assistance and 

technical guidance in drilling and geophysical log analysis. In 

addition, two of the sites were completed in cooperation with 

the SCVWD and the California Department of Water 

Resources under the AB303 grant program (California 

Department of Water Resources, 2003).

Design of Monitoring Sites

Between 1999 and 2003, 38 monitoring wells were 

installed at 8 sites in the Santa Clara Valley Water District area, 

Santa Clara County, California (fig. 1 and table 1, at end of 

report). Each site consists of more than one well and is referred 

to as a “multiple-well monitoring site.” The borehole is a 

telescoping-diameter design, ranging from 6 to 17.5 in. in 

diameter, with the smallest drilled diameter at total depth and 

largest drilled diameter at the land surface. In some instances 

10- to 12-in. surface conductor casing was used in accordance 

with Santa Clara Valley Water District Wells and Water 

Production Unit requirements (Lorance and Iwamura, 1989). 

The construction of these wells enables the collection of depthspecific water-level, water-chemistry, and aquifer hydraulicproperty data. The final well completions of the eight multiplewell monitoring sites for this study are summarized in table 2, 

at end of report.
4 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

680

880

84

280

35

237

130

280

87

85

35

101

17 101

Wells

Water-supply wells

 with wellbore flow

 and depth-dependent

 samples

USGS multiple-well

 monitoring sites

 and depth-specific

 samples (see Table 1

 for well information) Extensometer

Water-supply wells

Water-supply wells

 with greater than

 15 percent estimated

 artificial recharge

 (refer to table 16)

River or stream

Reservoir

Artificial-

 recharge

 percolation

 pond

Alluvial basin

 boundary

EXPLANATION

Extent of confined

 aquifer zone

Selected generalized

 ground-water flow-

 path directions

Santa Clara Valley

 Water District

 Boundary within the

 Santa Clara Valley

Pacific Ocean

Area of

 map

California

12th Street

no. 10

(16C8)

12th Street

no. 10

(16C8)

22G9

35G10

20L3

19H2 19M10

19M1

32D1 33C1 34G2

3H1

3P1

1E3 2G29

9D3,5,9

7R4

17F1

26D2

7A12

32G3

13K4

13E3,4

22E12

22E3 23R5

23R3 24J3

34F1 26R3

34F1

33F6

32G1 31K1

SANTA CLARA

COUNTY

ALAMEDA COUNTY

SANTA CRUZ

COUNTY

SAN MATEO

COUNTY

WLLO

STPK

SUNNYVALE

(16C11)

GUAD

MGCY

STGA

CCOC

EVGR

0 2 4 6 8 10 MILES

0 2 4 6 8 10 KILOMETERS

1B2

29B2

26D2

24B5 13F6

22P2

1L1

6P1

32H1

10D10

14B1

18P1

29A1 26R4

26R4

11A4

12P1

18E11

2B1

18K1

T9S T8S T7S T6S T5S T4S

Stevens 

Flow Path

Los Gatos 

Flow Path

Coyote 

Flow Path

11D2

Pe mr anente Creek

Thompson Creek

Guadalupe

Creek

Coyote Creek

Los Gatos Creek

Penitencia Creek

Alamitos

Creek

Saratoga Creek

Stevens Creek

R3W R2W R1W R1E R2E

122 15’ 121 45’

37

30’

37

15’

San

Francisco

Bay

8Q2

16K5

Mountain View

no. 20

(27G2)

California Water

Service no. 17

(34K2)

Williams no. 3

(22E2)

SAN JOSE

(24C3,4,7)

SAN JOSE

(24C3,4,7)

ELNR

Figure 1. Multiple-well monitoring sites and selected water-supply wells, Santa Clara County, California.
Design of Monitoring Sites 5

Qh

Qp

Qp

Qp

sp

sp

Qhbm

QT

QT

Ts

Ts

Ts

Ts

KJf

KJf

KJs KJf

SAN ANDREAS FAULT

MONTE

VISTA

FAULT

CALAVERAS

SILVER CREEK FAULT

FAULT

BERROCAL FAULT

0 2 4 6 8 10 MILES

0 2 4 6 8 10 KILOMETERS

EXPLANATION

Mesozoic—Consolidated rock

Franciscan assemblage

Great Valley sequence

Serpentinite and associated

Coast Range ophiolite complex

KJf

KJs

Tertiary—Consolidated/unconsolidated sedimentary deposits

Pliocene-Quaternary-age sedimentary deposits (Santa Clara

 Formation and equivalents)

Tertiary-age sedimentary deposits (includes some volcanics

 and the Monterey Formation)

QT

Ts

sp

Quaternary—Unconsolidated sedimentary deposits

Faults—Dashed where inferred

Late-Pleistocene-age deposits

Holocene-age deposits

Holocene-age Bay muds

Qp

Qh

Qhbm

Alluvial basin boundary

San

Francisco

Bay

USGS multiple-well monitoring sites

 and depth-specific samples

 (see Table 1 for well information)

WLLO

STPK

GUAD

MGCY

STGA

CCOC

EVGR

Thompson Cre ek

ELNR

Oak Hill

Figure 2. Geologic outcrops and major structural features, Santa Clara County, California.
6 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

10

0

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

850

900

950

1,000

1,050

CALIPER,

IN INCHES

5 7.5 0 100 200

BULK NATURAL-GAMMA

RAY, IN API-GR

25 75 100 0 50 25

0 25 50 75 100

TEMPERATURE GRADIENT,

IN DEGREES CELSIUS

PER KILOMETER

0 150 300

ELECTROMAGNETIC

CONDUCTIVITY, 

IN MILLIMHOS PER METER

ACOUSTIC-LOG VELOCITY,

IN MICROSECONDS

PER FOOT. BOREHOLE

COMPENSATED DELTA TIME

0 150 300

0 25 50

CALCULATED ACOUSTIC-LOG

POROSITY, IN PERCENT

LONG AND SHORTNORMAL RESISTIVITY,

IN OHM-METERS

16 inch

64 inch

Lateral

EXPLANATION Estimated

porosity from

whole core

subsamples

DEPTH BELOW LAND SURFACE, IN FEET 

SPONTANEOUS POTENTIAL,

IN MILLIVOLTS

50 75 100

Total drill depth 1,006 

Calculated Porosity

Zones with lateral ground-water flow2

1

3

4

5

6

CCOC

Estimated Porosity from

whole core subsamples

Figure 3. Geophysical logs, well-construction diagram, and generalized lithologic description for Coyote Creek Outdoor Classroom (7S/1E-9L4–8) multiple-well 

site, Santa Clara County, California.
Design of Monitoring Sites 7

0 2,000 4,000 6,000 8,000 10,000

0

50

200

300

400

500

100

600

700

800

900

250

350

450

550

150

650

750

850

950

1,000

1,050

1 234 5

DEPTH, IN FEET

8 0 0 25

125

100

50

75

25

0

DEPTH BELOW LAND SURFACE, IN FEET 

R1-R2 Shear-wave velocity (Vs)

R1-R2 Primary-wave velocity (Vp)

Basal

aquifer

Base of Holocene-aged deposits

Gravelly sandy clayey silt

Gravelly silty sand

Gravelly sandy silty clay

Gravelly silty clay

Gravelly silty clay

Gravelly silty clay

Sandy silty clayey gravel

Sandy silty clayey gravel

Sandy gravel

Silty clay

Sandy gravel

Sandy gravel

Sandy gravel

Sandy gravel

Sandy gravel

Sandy gravel

Sandy gravel

Silty sandy gravel

Sandy gravel

Sandy silty clay

Gravelly sand

Silty sand

Sandy silt

Gravelly silty clay

Sandy clayey silt

Sandy gravel

Sandy gravel

Sandy gravel

Sandy gravel

Sandy silty clay

Sandy silty clay

Sandy silty clayey gravel

Gravelly silty sand

Gravelly silty sand

Gravelly silty sand

Gravelly silty sand

Gravelly silty sand

Gravelly sandy clayey silt

Gravelly sandy clayey silt

CORE

LOG

WELL

CONSTRUCTION

LITHOLOGY

Core log Well construction

Gravel

Sandy gravel

Silty sandy gravel

Clay and gravel

Gravelly sand

Gravelly silty sand

Sand

Silty sand

Clayey silty sand

Sandy silt

Clayey silt

Clay

Sandy silty clay

Silty clay

Gravelly clay

Weathered Rock

SUSPENSION-LOG VELOCITY,

IN FEET PER SECOND

EXPLANATION

Bentonite seal

Sand pack

Surface casing

Screened interval

CONE PENETRATION

TEST (CPT)

RATIO Fs/Qt

, IN PERCENT

QC = TIP RESISTANCE

 = MEGANEWTONS

 PER SQUARE

 METER 

FS = Sleeve friction

 = KiloNewtons

 per square

 meter

*

*

Total drill depth

1,006 

CCOC

Figure 3.—Continued.
8 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

12

0

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

850

900

950

1,000

1,050

CALIPER, 

IN INCHES

5 8.5 0 100 200

100 0 100

0 25 50 75 100

TEMPERATURE GRADIENT,

IN DEGREES CELSIUS

PER KILOMETER

0 150 300

0 150 300

0 25 50

LONG AND SHORTNORMAL RESISTIVITY,

IN OHM-METERS

Estimated porosity

from whole

core subsamples

BULK NATURAL-GAMMA

RAY, IN API-GR

ELECTROMAGNETIC

CONDUCTIVITY, 

IN MILLIMHOS PER METER

ACOUSTIC-LOG VELOCITY IN 

MICROSECONDS PER FOOT.

BOREHOLE COMPENSATED

DELTA TIME

ACOUSTIC LOG ESTIMATED

POROSITY, IN PERCENT

16 inch

64 inch

Lateral

EXPLANATION

SPONTANEOUS POTENTIAL,

IN MILLIVOLTS

0 25 50

Total drill depth 850 

Zones with lateral ground-water flow

1

2

3

4

5

6

8

7

DEPTH BELOW LAND SURFACE, IN FEET 

WLLO

Figure 4. Geophysical logs, well-construction diagram, and generalized lithologic description for Willow (7S/1E-19B2–7) multiple-well site, Santa Clara County, 

California.
Design of Monitoring Sites 9

1234 5 6

DEPTH, IN FEET

8 0 0 40

50

60

70

80

40

20

30

10

0 Sandy silt

Sandy clayey silt

Gravelly sand

Sandy gravel

Gravel

Gravelly silty sand

Sandy gravel

Clayey silty sandy gravel

Sightly sandy gravel

Gravelly silty sand

Sandy silty clay

Silty sandy gravel

Gravelly silty sand

Sandy gravel

Silty sandy gravel

Sandy gravel

Sandy silty clay

Sandy silty gravel

Silty clay

Silty sandy gravel

Sandy silt

Silty sandy gravel

Sandy silty clay

Clayey silty sand

Silty sandy gravel

Bedrock: Serpentinite with

iron stained microfractures

Total drill depth 850 

Basal

aquifer

Base of Holocene-aged deposits

50

0

200

300

400

500

100

600

700

800

900

250

350

450

550

150

650

750

850

950

1,000

1,050

CORE

LOG

WELL

CONSTRUCTION

LITHOLOGY CONE PENETRATION

TEST (CPT)

RATIO Fs/Qt

, IN PERCENT

Core log Well construction

Gravel

Sandy gravel

Silty sandy gravel

Clay and gravel

Gravelly sand

Gravelly silty sand

Sand

Silty sand

Clayey silty sand

Sandy silt

Clayey silt

Clay

Sandy silty clay

Silty clay

Gravelly clay

Weathered Rock

EXPLANATION

Bentonite seal

Sand pack

Surface casing

Screened interval

*

DEPTH BELOW LAND SURFACE, IN FEET 

QC = TIP RESISTANCE

 = MEGANEWTONS

 PER SQUARE

 METER 

FS = Sleeve friction

 = KiloNewtons

 per square

 meter

*

WLLO

Figure 4.—Continued.
10 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

10 15

0

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

850

900

950

1,000

1,050

5 0 100 200

300 50 500

0 25 50 75 100 0 150 300

0 150 300

0 25 50

0 50 100

Total drill depth

873 

CALIPER, 

IN INCHES

BULK NATURAL-GAMMA

RAY, IN API-GR

TEMPERATURE GRADIENT,

IN DEGREES CELSIUS

PER KILOMETER

ELECTROMAGNETIC

CONDUCTIVITY, 

IN MILLIMHOS PER METER

ACOUSTIC-LOG VELOCITY IN 

MICROSECONDS PER FOOT.

BOREHOLE COMPENSATED

DELTA TIME

ACOUSTIC LOG ESTIMATED

POROSITY, IN PERCENT

LONG AND SHORTNORMAL RESISTIVITY,

IN OHM-METERS

SPONTANEOUS POTENTIAL,

IN MILLIVOLTS

Zones with lateral ground-water flow

1

2

3

4

Basal aquifer Base of Holocene-aged deposits

DEPTH BELOW LAND SURFACE, IN FEET 

MGCY

16 inch

64 inch

Lateral

EXPLANATION

Figure 5. Geophysical logs, well-construction diagram, and generalized lithologic description for McGlincey (7S/1W-35L12–16) multiple-well site, Santa Clara 

County, California.
Design of Monitoring Sites 11

123 5 4

DEPTH, IN FEET

5 0 0 25

6

2

4

10

12

14

16

18

8

0

0 2,000 4,000 6,000 8,000 10,000

0

50

200

300

400

500

100

600

700

800

900

250

350

450

550

150

650

750

850

950

1,000

1,050

DEPTH BELOW LAND SURFACE, IN FEET 

CORE

LOG

WELL

CONSTRUCTION

LITHOLOGY

Core log Well construction

Gravel

Sandy gravel

Silty sandy gravel

Clay and gravel

Gravelly sand

Gravelly silty sand

Sand

Silty sand

Clayey silty sand

Sandy silt

Clayey silt

Clay

Sandy silty clay

Silty clay

Gravelly clay

Weathered Rock

SUSPENSION-LOG VELOCITY,

IN FEET PER SECOND

EXPLANATION

Bentonite seal

Sand pack

Screened interval

CONE PENETRATION

TEST (CPT)

RATIO Fs/Qt, IN PERCENT

QC = TIP RESISTANCE

 = MEGANEWTONS

 PER SQUARE

 METER 

FS = Sleeve friction

 = KiloNewtons

 per square

 meter

*

Sandy gravel

Sandy silty gravel

Sandy gravel

Silty sandy gravel

Silty sand

Silty sandy gravel

Sandy gravel

Gravelly sand

Silty sandy gravel

Gravelly silty sand

Sandy gravel

Silty sandy gravel

Sandy gravel

Gravelly silty sand

Sandy clayey silt

Sitly sandy gravel

Gravelly silty sand

Silty sandy gravel

Silty sandy gravel

Sandy silty clay

Sandy silt

Silty sandy gravel

Sandy gravel

Silty sandy gravel

Silty sand

Gravelly sandy silt

Sandy silty clay

Silty sand

Bedrock: Monterey

Formation, approximately

late-Miocene age

Total drill depth

873 

MGCY

R1-R2 Shear-wave velocity (Vs)

R1-R2 Primary-wave velocity (Vp)

Figure 5.—Continued.
12 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

12

0

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

850

900

950

1,000

1,050

4 8 0 100 200

200 100 0 100

0 25 50 75 100 0 150 300

16 inch

64 inch

Lateral

EXPLANATION

Zones with lateral ground-water flow

1

2

3

4

6

5

DEPTH BELOW LAND SURFACE, IN FEET 

0 25 50

Total drill depth 1,000 

CALIPER, 

IN INCHES

BULK NATURAL-GAMMA RAY, 

IN API-GR

TEMPERATURE GRADIENT,

IN DEGREES CELSIUS

PER KILOMETER

ELECTROMAGNETIC

CONDUCTIVITY, 

IN MILLIMHOS PER METER

LONG AND SHORTNORMAL RESISTIVITY,

IN OHM-METERS

SPONTANEOUS POTENTIAL,

IN MILLIVOLTS

STPK

Figure 6. Geophysical logs, well-construction diagram, and generalized lithologic description for Santana Park (7S/1W-14P1–5) multiple-well site, Santa Clara 

County, California.
Design of Monitoring Sites 13

1234 5

DEPTH, IN FEET

6 0 0 50

45

35

25

15

5

0

55

65

0 2,000 4,000 6,000 8,000 10,000

0

50

200

300

400

500

100

600

700

800

900

250

350

450

550

150

650

750

850

950

1,000

1,000

1,050

DEPTH BELOW LAND SURFACE, IN FEET 

CORE

LOG

WELL

CONSTRUCTION

LITHOLOGY

Core log Well construction

Gravel

Sandy gravel

Silty sandy gravel

Clay and gravel

Gravelly sand

Gravelly silty sand

Sand

Silty sand

Clayey silty sand

Sandy silt

Clayey silt

Clay

Sandy silty clay

Silty clay

Gravelly clay

Weathered Rock

EXPLANATION

Bentonite seal

Sand pack

Surface casing

Screened interval

CONE PENETRATION

TEST (CPT) Base of Holocene-aged deposits

RATIO Fs/Qt, IN PERCENT

QC = TIP RESISTANCE

 = MEGANEWTONS

 PER SQUARE

 METER 

FS = Sleeve friction

 = KiloNewtons

 per square

 meter

*

*

Sandy gravel

Sandy gravel

Sandy gravel

Gravelly sand

Gravelly sand

Gravelly sand

Sandy gravel

Sandy gravel

Sandy silt

Sandy silt

Sandy clay

Sandy clay

Sandy clay

Sandy silt

Sandy silt

Sandy silt

Gravel

Clayey gravel

Clayey silt

Silty clay

Silty sand

Silty sand

Silty sandy gravel

Silty sandy gravel

Gravelly silty sand

Gravelly silty sand

Gravelly sandy silt

Gravelly silty sand

Gravelly silty sand

Gravelly clayey sand

Total drill

depth

SUSPENSION-LOG VELOCITY,

IN FEET PER SECOND

R1-R2 Shear-wave velocity (Vs)

R1-R2 Primary-wave velocity (Vp)

STPK

Figure 6.—Continued.
14 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

10 15

0

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

850

900

950

1,000

1,050

1,100

1,150

1,200

1,250

1,300

1,350

1,400

5 0 100 200

250 150 50 50 150 250

2.75 3.25 3

0 25 50 75 100

FLUID RESISTIVITY, IN

OHM-METERS

0 150 300

0 150 300

0 25 50

16 inch

64 inch

Lateral

EXPLANATION

ACOUSTIC-LOG VELOCITY IN 

MICROSECONDS PER FOOT.

BOREHOLE COMPENSATED

DELTA TIME

ACOUSTIC LOG ESTIMATED

POROSITY, IN PERCENT

100 200 300

Total drill depth 1,370

CALIPER, 

IN INCHES

BULK NATURAL-GAMMA

RAY, IN API-GR

TEMPERATURE GRADIENT,

IN DEGREES CELSIUS

PER KILOMETER

ELECTROMAGNETIC

CONDUCTIVITY, 

IN MILLIMHOS PER METER

LONG AND SHORTNORMAL RESISTIVITY,

IN OHM-METERS

SPONTANEOUS POTENTIAL,

IN MILLIVOLTS

Zones with lateral ground-water flow

1

2

5

6

3

4

DEPTH BELOW LAND SURFACE, IN FEET 

GUAD

Figure 7. Geophysical logs, well-construction diagram, and generalized lithologic description for Guadalupe (6S/1W-26Q1–4) multiple-well site, Santa Clara 

County, California
Design of Monitoring Sites 15

1234

DEPTH, IN FEET

9 0 0 70

0

10

20

30

40

50

60

70

DEPTH BELOW LAND SURFACE, IN FEET 

0

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

850

900

950

1,000

1,050

1,100

1,150

1,200

1,250

1,300

1,350

1,400

Sandy clay

Sandy gravel

Clay

Gravelly sand

Gravelly sand

Sandy clay

Silty sand

Clay

Silty sand

Fine sandy silt

Sandy silty gravel

Silty clay

Sand

Clay

Gravelly sand

Clay

Sand

Sand

Silty clay

Sand

Clay

Sand

Sandy clay

Clay

Sandy clay

Sandy clay

Silty clayey sand

Sandy clay

Bedrock: Mesozoic-aged

Great Valley sequence or

Franciscan assemblage

Sandy clay

Total drill depth 1,370

0 2,000 4,000 6,000 8,000 10,000

CORE

LOG

WELL

CONSTRUCTION

LITHOLOGY

Well construction

SUSPENSION-LOG VELOCITY,

IN FEET PER SECOND

EXPLANATION

Bentonite seal

Sand pack

Surface casing

Screened interval

No core recovery

Data available

See table 7

Estimated base of

Holocene-aged deposits

Basal aquifer

GUAD

CONE PENETRATION

TEST (CPT)

RATIO Fs/Qt

, IN PERCENT

QC = TIP RESISTANCE

 = MEGANEWTONS

 PER SQUARE

 METER 

FS = Sleeve friction

 = KiloNewtons

 per square

 meter

*

*

R1-R2 Shear-wave velocity (Vs)

R1-R2 Primary-wave velocity (Vp)

Figure 7.—Continued.
16 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

0 150 300

Total drill depth

932 

10 13

0

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

850

900

950

1,000

1,050

7 0 80 160 0 25 50 75 100 0 150 300

16 inch

64 inch

Lateral

EXPLANATION

0 25 50

ELNR

25 75 125

CALIPER, 

IN INCHES

BULK NATURAL−GAMMA RAY, 

IN API-GR

ELECTROMAGNETIC

CONDUCTIVITY, 

IN MILLIMHOS PER METER

ACOUSTIC−LOG VELOCITY IN 

MICROSECONDS PER FOOT.

BOREHOLE COMPENSATED

DELTA TIME

ACOUSTIC LOG ESTIMATED

POROSITY, IN PERCENT

LONG AND SHORTNORMAL RESISTIVITY,

IN OHM−METERS

SPONTANEOUS POTENTIAL,

IN MILLIVOLTS

DEPTH BELOW LAND SURFACE, IN FEET 

Figure 8. Geophysical logs, well-construction diagram, and generalized lithologic description for Eleanor Park (5S/3W-36P2–5) multiple-well site, Santa Clara 

County, California.
Design of Monitoring Sites 17

1234 0

50

200

300

400

500

100

600

700

800

900

250

350

450

550

150

650

750

850

950

1,000

1,050

Total drill

depth

932 

Surface fill

Gravelly sandy clay

Gravel

Clay

Gravelly clay

Gravelly clay

Sandy clay

Sandy clay

Sandy clay

Clayey sand

Clayey sand

Clayey sand

Clayey sand

Clayey sand

Clayey sand

Clayey sand

Sand

Sand

Bedrock: Franciscan 

 assemblage

Sand

Sand

Gravelly sand

Gravelly sand

Clayey sand

Sandy clay

Sandy clay

Sandy clay

Sandy clay

Sandy clay

Silty clayey sand

WELL

CONSTRUCTION

LITHOLOGY

DEPTH BELOW LAND SURFACE, IN FEET 

ELNR

Well construction

EXPLANATION

Bentonite seal

Sand pack

Surface casing

Screened interval

Figure 8.—Continued.
18 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

Total drill depth 1,000 

9 11

0

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

850

900

950

1,000

1,050

CALIPER, 

IN INCHES

7 0 100 200

BULK NATURAL-GAMMA

RAY, IN API-GR

0 50 100

0 25 50 75 100

TEMPERATURE GRADIENT,

IN DEGREES CELSIUS

PER KILOMETER

0 150 300

ELECTROMAGNETIC

CONDUCTIVITY, IN MILLIMHOS

PER METER

ACOUSTIC-LOG VELOCITY IN

MICROSECONDS PER FOOT.

BOREHOLE COMPENSATED

DELTA TIME

0 150 300

0 25 50

ACOUSTIC LOG ESTIMATED

POROSITY, IN PERCENT

LONG AND SHORTNORMAL RESISTIVITY,

IN OHM-METERS

16 inch

64 inch

Lateral

EXPLANATION

Base of Holocene-aged deposits

Basal aquifer

DEPTH BELOW LAND SURFACE, IN FEET 

STGA

SPONTANEOUS POTENTIAL,

IN MILLIVOLTS

125 175 225

Zones with lateral ground-water flow

1

2

3

4

5

Figure 9. Geophysical logs, well-construction diagram, and generalized lithologic description for Saratoga (7S/1W-29C3–6) multiple-well site, Santa Clara 

County, California.
Design of Monitoring Sites 19

1234

0

50

200

300

400

500

100

600

700

800

900

250

350

450

550

150

650

750

850

950

1,000

1,050

DEPTH BELOW LAND SURFACE, IN FEET 

Sandy gravel

Sandy clay

Sandy clay

Sandy clay

Sand

Sand

Sandy clay

Sandy clay

Sandy gravel

Sandy clay

Gravelly clay

Gravelly clay

Clay

Clay

Gravelly sandy clay

Gravelly sandy clay

Gravelly sand

Gravelly sand

Gravelly sand

Clayey silty sand

Gravelly sand

Clayey sand

Clayey sand

Clayey sand

Clayey gravel

Clayey gravel

Clayey gravel

Clayey sand

Clayey sand

Clayey sand

Total drill depth

WELL

CONSTRUCTION

SUSPENSION-LOG VELOCITY, LITHOLOGY

IN FEET PER SECOND

1,000

0 2,000 4,000 6,000 8,000 10,000

R1-R2 Shear-wave velocity (Vs)

R1-R2 Primary-wave velocity (Vp)

STGA

Well construction

EXPLANATION

Bentonite seal

Sand pack

Surface casing

Screened interval

Figure 9.—Continued.
20 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

Total drill depth 1,030

8.5 12

0

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

850

900

950

1,000

1,050

CALIPER, 

IN INCHES

5 0 100 200

BULK NATURAL-GAMMA

RAY, IN API-GR

0 50 100

0 25 50 75 100

TEMPERATURE GRADIENT,

IN DEGREES CELSIUS

PER KILOMETER

0 150 300

ELECTROMAGNETIC

CONDUCTIVITY, 

IN MILLIMHOS PER METER

ACOUSTIC-LOG VELOCITY IN 

MICROSECONDS PER FOOT.

BOREHOLE COMPENSATED

DELTA TIME

0 150 300

0 25 50

ACOUSTIC LOG ESTIMATED

POROSITY, IN PERCENT

LONG AND SHORTNORMAL RESISTIVITY,

IN OHM-METERS

16 inch

64 inch

Lateral

EXPLANATION

DEPTH BELOW LAND SURFACE, IN FEET 

EVGR

SPONTANEOUS POTENTIAL,

IN MILLIVOLTS

75 125 175

Zones with lateral ground-water flow1

2

3

Figure 10. Geophysical logs, well-construction diagram, and generalized lithologic description for Evergreen (7S/2E-19C5–9) multiple-well site, Santa Clara 

County, California.
Design of Monitoring Sites 21

1234 5

DEPTH, IN FEET

10 0 0 20

0

10

20

30

40

50

60

70

80

90

0

50

200

300

400

500

100

600

700

800

900

250

350

450

550

150

650

750

850

950

1,000

1,050

DEPTH BELOW LAND SURFACE, IN FEET 

Total drill depth 1,030

CORE

LOG

WELL

CONSTRUCTION

LITHOLOGY

Core log Well construction

Gravel

Sandy gravel

Silty sandy gravel

Clay and gravel

Gravelly sand

Gravelly silty sand

Sand

Silty sand

Clayey silty sand

Silt

Sandy silt

Clayey silt

Clay

Sandy Clay

Sandy silty clay

Silty clay

Gravelly clay

Weathered Rock

EXPLANATION

Bentonite seal

Sand pack

Surface casing

Screened interval

CONE PENETRATION

TEST (CPT)

RATIO Fs/Qt

, IN PERCENT

QC = TIP RESISTANCE

 = MEGANEWTONS

 PER SQUARE

 METER 

FS = Sleeve friction

 = KiloNewtons

 per square

 meter

*

*

Blank

Silty gravelly sand

Sandy gravelly clay

Gravelly sandy silt

Gravelly silt

Silty sand

No recovery

Silty clay

Gravelly sand

Gravelly silty clayey sand

Gravelly silty clayey sand

Gravelly silty clayey sand

Gravelly sand

Sandy gravel

Silty clayey sandy gravel

Gravelly sandy silty clay

Gravelly silty clayey sand

Gravelly silty clayey sand

Base of Holocene-aged deposits

Basal aquifer

EVGR

Figure 10.—Continued.
22 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

The boreholes at the multiple-well monitoring sites were 

drilled using direct mud rotary for continuous drilling, selected 

coring, and continuous coring. For coring, 94-mm wire-line 

core barrels and core pipe were used. After total depth was 

achieved, geophysical logging was completed in each 

borehole. These logs were used to aid in the interpretation of 

cuttings and cores, and to select completion intervals for the 

monitoring wells. These wells were constructed using 2- or 

3-in.-diameter schedule-80 polyvinyl chloride (PVC) casing. 

Each well consisted of a 20-ft PVC slotted-screen interval (slot 

size is 1.5 in. × 0.020 in.) and a number 3 sand filter pack 

providing communication with the depth-specific aquifers 

selected for monitoring. The wells within the borehole are 

environmentally sealed from each other using a 30-percentsolids bentonite nonhardening grout mixture. A wellconstruction diagram is included for each site

(figs. 4, 5, 6, 7, 8, 9, and 10).

Well development, using extensive airlifting and surging 

techniques with compressed air in each well, was done to break 

down the mudcake that had developed between the borehole 

and the surrounding formation during drilling and to remove 

any drilling mud from the aquifer opposite the well screens. 

Specific conductance, pH, temperature, apparent color, and 

turbidity, along with the discharge rate and total volume, were 

recorded during well development. Well development 

continued until no discernible drilling mud was present and 

field measurements had stabilized.

Geologic Data 

Geologic data collected at each site will help to 

characterize and correlate stratigraphic units and boundaries 

associated with the regional stratigraphic units and aquifer 

systems. This information includes lithologic descriptions of 

the drill cuttings and a suite of geophysical logs. Cores were 

analyzed for geologic structures, composition, and physical 

properties.

Core samples collected from the bottom of well bores 

from three sites (WLLO, MGCY, and GUAD) and cuttings 

from a fourth site (ELNR) indicated the presence of bedrock 

underlying the water-bearing alluvium—WLLO at 

802.4 ft bls, MGCY at 787.3 ft bls, ELNR at 922 ft bls, and 

GUAD at 1,335.5 ft bls. The bottom core from WLLO was 

composed entirely of serpentinite, a hydrothermally altered 

ultramafic rock associated with outcrops to the south on Oak 

Hill (fig. 2). The bottom core from MGCY was identified, 

through use of diatom taxa contained in the sample (Lisa 

White, San Francisco State University, unpub. data, 2004), as 

Monterey Formation of approximately late-Miocene age (not 

shown in fig. 2). A dark shale was penetrated at ELNR, which 

is probably associated with the Franciscan Assemblage of 

Mesozoic age. The bottom core at GUAD was identified as 

Great Valley sequence or Franciscan Assemblage. Although 

drilling was expected to penetrate bedrock at EVGR on the 

basis of data from nearby water-supply wells, the deeper 

sediments included clasts of the Great Valley sequence.

Lithologic Descriptions

Detailed lithologic logs were compiled from descriptions 

of drill cuttings collected at each borehole site and from 

observations recorded during drilling (tables 3–10, at end of 

report). Cuttings were collected at 10- to 20-ft intervals during 

drilling using a number 80 or finer mesh sieve. The lithology 

of drill cuttings was described under a binocular microscope 

for grain size, texture, sorting, rounding, color, and any other 

noticeable features, such as wood or shell fragments. Texture 

was determined on all cuttings using a method developed by 

Folk (1954), and particle-size descriptions follow the National 

Research Council (1947) classification. This classification 

allows for the correlation of general grain-size terms (such as 

“sand”) with size limits determined in millimeters or inches. 

Color, determined on moist samples, follows the alphanumerical color designations in Munsell Soil Color Charts 

(Munsell Color, 1994). 

Geophysical Logs

A cone penetrometer test (CPT) was performed at six 

sites to identify the base of Holocene sediments as a coring 

target. In this test a conical tip and trailing friction sleeve are 

pushed slowly down into the ground and tip resistance and 

sleeve friction are continuously measured. These parameters 

and their ratio can be used to estimate soil properties. The 

contrasting soil properties between the Holocene and the 

underlying Pleistocene sediments make the CPT ideal for 

shallow geologic mapping.

Wire-line geophysical logging, done either in the open 

borehole or in the completed well casing, provided additional 

information about the distribution of aquifers, fine-grained 

interbeds and confining units between aquifers, the relation of 

water quality and depth, and the nature of ground-water flow 

(figs. 3, 4, 5, 6, 7, 8, 9, and 10). These logs will also aid in 

stratigraphic analysis and seismic hazards in the Santa Clara 

Valley.

Some geophysical logs were collected in the open 

borehole after the site was drilled, and others were collected 

after well completion. The logs completed after drilling were 

caliper, bulk-natural gamma, spontaneous potential, 16-in. and 

64-in. normal resistivity, lateral resistivity, electromagnetic 

conductivity (EM), acoustic velocity, suspension, and 

temperature logs. High-resolution temperature logs at six sites 

were used to estimate temperature gradient logs. 

Caliper devices are used to measure the diameter of the 

borehole. The caliper log can be used to show the existence of 

consolidated layers, washed-out sand, or the presence of 

swelling clay. Caliper logs also are useful in the construction 

of multiple-well sites by providing accurate borehole-volume 
Geologic Data 23

calculations for placement of sand filter packs and 

environmental sealing materials. 

The bulk-natural gamma and spontaneous potential logs 

are used to help locate low-permeability silt and clay layers. 

Bulk-natural gamma logs measure the intensities of gamma-ray 

emissions resulting from the natural decay of potassium-40 and 

of the daughter products of uranium and thorium 

(Schlumberger, 1972). Clay, feldspar-rich sand and gravel, and 

granite are relatively more radioactive materials and generally 

emit higher intensity gamma rays. These radiogenic silt and 

clay layers represent potential confining units between 

aquifers. Spontaneous potential logs are helpful indicators of 

stratigraphic boundaries and changes in lithology. In cases 

where the CPT could not directly map the base of the Holocene, 

the spontaneous potential log helped in providing a 

geophysical interpretation of the base.

Resistivity tools measure the apparent resistivity of a 

volume of sample material under the direct application of an 

electrical current (Keys and MacCary, 1985). These logs can be 

used to determine the formation and fluid resistivity of 

subsurface units and to estimate formation porosity. In the 

alluvial setting of the Santa Clara Valley, low resistivity 

generally indicates fine-grained deposits such as silt, clay, and 

shale, whereas high resistivity indicates coarser material such 

as sand or gravel. The 16-in. normal resistivity records the 

apparent resistivity of material adjacent to the borehole that 

was probably invaded with drilling fluid, and the 64-in. normal 

resistivity records the apparent resistivity beyond the invaded 

zone that is saturated with formation water. The combinations 

of both logs are useful indicators of potential poor water 

quality.

Electromagnetic-conductivity logs yield detailed 

information on the vertical electrical conductivity of a 

formation and of pore water (McNeill, 1986). Because the 

electromagnetic-induction tool responds to changes in 

dissolved-solids concentration (total dissolved solids) of 

ground water, it is possible to repeatedly track and map 

electrical anomalies associated with changes in dissolvedsolids concentration of ground water over time (Williams and 

others, 1993).

Two types of acoustic-velocity logs—acoustic (sonic) 

logs and suspension logs—were measured in the uncased 

borehole. Sonic logs measure the time it takes for a pulsed 

compressional sound wave to travel from a downhole source to 

downhole receivers. The sonic tool used has two receivers, and 

porosity is estimated from the difference in arrival time of the 

near and far receivers. In unconsolidated material, sonic logs 

are principally used to measure porosity of the aquifer 

materials. Variations in porosity, and therefore transit time, can 

help to identify contacts between lithologic units that were 

penetrated by the borehole. Formation porosity is calculated 

from empirical data using the Raymer-Hunt Formula (Century 

Geophysical Corporation, 2004). Suspension logs also were 

collected at selected drill holes using the OYO P-S logging 

system, which measures both shear waves (S-waves) and faster 

compressional waves (P-waves) in open boreholes 

(GEOVISION, 2003). Suspension velocity logs provide direct 

measurements of seismic velocity that are useful in basinwide 

stratigraphic correlation, the generation of synthetic 

seismograms, and seismic ground motion studies.

High-resolution borehole temperature logs were collected 

several weeks after well completion and local thermal 

gradients were stabilized. These data were used to estimate 

temperature-gradient profiles that can be useful in identifying 

zones of ground-water flow by deviations from the natural 

thermal gradient, as well as in the study of regional heat flow.

Coyote Creek Outdoor Classroom (CCOC) Site 

The CCOC site is located in the south-central part of the 

basin in the confined aquifer zone and adjacent to Coyote 

Creek (fig 1). The CPT log at the CCOC site reached a total 

depth of 125 ft (fig. 3). The base of the Holocene sediments is 

marked at a depth of 75 ft by an increase in resistance to 

penetration. Analysis of borehole geophysical logs indicates 

more gravel and coarse-grained units than anticipated on the 

basis of nearby drillers logs of other ground-water monitoring 

wells and geophysical logs from a nearby extensometer site 

(Poland and Ireland, 1988) (fig. 1). Approximately 5 to 6 

coarse-grained units ranging in thickness from 30 to 80 ft were 

identified above 850 ft bls. Four ground-water monitoring 

wells were screened and open to selected intervals between 360 

and 850 ft bls and a fifth was installed just below the HolocenePleistocene boundary (75 ft bls) in a second borehole (fig. 3 and 

table 2, at the end of the report). The temperature-gradient log 

indicates a near-linear conductive geothermal gradient from the 

bottom up to a depth of 670 ft, above which the gradient is 

disturbed (fig. 3 and table 2, at end of report). As many as six 

zones are delineated by disturbances in the temperaturegradient log from CCOC (fig. 3). These disturbances likely are 

due to lateral flow of water in the gravel layers, which are the 

main sources for nearby water-supply wells (fig. 1).
24 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

Willow (WLLO) Site

The WLLO site is located in the south-central part of the 

basin in the edge of the confined aquifer zone and adjacent to 

Los Gatos Creek (fig 1). The CPT log at the WLLO site 

reached a total depth of 78 ft (fig. 4). The base of the Holocene 

was estimated at 47 ft bls. Analysis of borehole geophysical 

logs indicates multiple layers of coarse-grained material 

separated by fine-grained material. Roughly seven to eight 

coarse-grained units ranging in thickness from 30 to 80 ft were 

identified above 800 ft bls. Five monitoring wells were 

screened and open to selected intervals between 200 and 800 ft 

and a sixth was installed below the Holocene boundary in a 

second borehole (fig 4 and table 2, at end of report). The 

temperature-gradient log measured from WLLO indicates 

near-linear conductive geothermal gradient from the bottom up 

to a depth of 775 ft, above which the gradient is disturbed by 

as many as eight zones of lateral ground-water flow in the 

coarse-grained layers (fig. 4). 

McGlincey (MGCY) Site

The MGCY site is located in the southwestern part of the 

basin outside the confined aquifer zone, adjacent to SCVWD 

artificial recharge ponds and Los Gatos Creek (fig 1). The base 

of the Holocene probably was not reached by the short 17-ft 

CPT log, but limited core information indicates that it is no 

deeper than 34 ft. The boundary also has been estimated from 

the interpretation of relative changes in the CPT, normal 

resistivity, and spontaneous-potential geophysical logs to be at 

a depth of about 33 ft. Analysis of the borehole-geophysical 

logs indicate that most of the coarse-grained material in the 

well is above 500 ft, with only scattered, relatively thin deeper 

layers of coarse-grained material below. About three to four 

coarse-grained units ranging in thickness from 40 to 220 ft 

were identified above 650 ft bls. Five ground-water monitoring 

wells were screened and open to selected intervals between 

155 and 655 ft bls (fig. 5 and table 2, at end of report). The 

temperature-gradient log calculated from MGCY indicates a 

near-linear conductive geothermal gradient from the bottom up 

to a depth of 690 ft, above which the gradient is disturbed by 

at many as four zones of lateral ground-water flow in the 

coarse-grained layers (fig. 5). 

Santana Park (STPK) Site

The STPK site is located in the south-central part of the 

basin within the confined aquifer zone (fig 1). The CPT log at 

the STPK site reached a total depth of 62 ft (fig. 6), and 

penetrates the base of the Holocene at a depth of 31.4 ft. 

Composite analyses of borehole geophysical logs indicate a 

relatively large amount of coarse-grained material; the results 

are similar to those from the CCOC multiple-well site (fig. 3). 

About five to six coarse-grained units ranging in thickness 

from 30 to 150 ft were identified above 725 ft bls. Five groundwater monitoring wells were screened and open to selected 

intervals between 107 and 720 ft bls (fig. 6 and table 2, at end 

of report). The temperature-gradient log calculated from 

STPK-1 indicates a near-linear conductive geothermal 

gradient from the bottom up to a depth of 710 ft, above which 

the gradient is disturbed by as many as six zones of lateral 

ground-water flow in the coarse-grained units (fig. 6).

Guadalupe (GUAD) Site

The GUAD site is located in the central part of the basin 

in the confined aquifer zone and adjacent to Guadalupe Creek 

(fig 1). The CPT log at the GUAD reached a total depth of 

61 ft without a marked indication of the base of the Holocene, 

but the base is estimated to be between 52 and 69 ft bls on the 

basis of core information and is shown at about 57 ft (fig. 7). 

Analysis of borehole geophysical logs indicates relatively 

more fine-grained units in comparison with the CCOC and 

STPK sites. Coarse-grained units are generally thinner, 

ranging from 25 to 50 ft in thickness, and were identified 

mostly above 860 ft bls. Four ground-water monitoring wells 

were screened and open to selected intervals between 310 and 

860 ft bls (fig. 7 and table 2, at end of report). The temperaturegradient log measured from GUAD indicates a near-linear 

conductive geothermal gradient from the bottom up to a depth 

of 660 ft, with some minor disturbances between 1,000 and 

1,125 ft. Above 660 ft, there are as many as six zones in which 

the gradient is disturbed by lateral ground-water flow in the 

coarse-grained units, with four zones above 250 ft (fig. 7).

Eleanor Park (ELNR) Site

The ELNR site is located in the northwestern part of the 

basin in the confined aquifer zone near San Francisco Bay 

(fig 1). A CPT log was not collected at the ELNR site. The base 

of the Holocene has been estimated from interpretation of 

relative changes in the normal-resistivity and gamma 

geophysical logs to be at a depth of about 50 ft. Analysis of 

geophysical logs indicates four to five poorly defined coarsegrained units ranging in thickness from 10 to 80 ft located 

above 880 ft bls (fig. 8). The gamma log at ELNR indicates 

that most of the fine-grained material is located above 500 ft 

bls. Four ground-water monitoring wells were screened and 

open to selected intervals between 145 and 880 ft bls (fig. 8 and 

table 2, at end of report). A temperature-gradient log was not 

collected at the ELNR site owing to flowing artesian 

conditions which prevented local thermal equilibrium from 

being established.
Geologic Data 25

Saratoga (STGA) Site

The STGA site is located in the southwestern part of the 

basin outside the confined aquifer zone and adjacent to 

Saratoga Creek (fig 1). A CPT log was not collected at the 

STGA site. The base of the Holocene has been estimated from 

the interpretation of relative changes in the normal-resistivity 

and spontaneous- potential geophysical logs to be around 

32.5 ft bls. Composite analysis of borehole geophysical logs 

indicates five or six coarse-grained units ranging in thickness 

from 20 to 100 ft located above 750 ft bls (fig. 9). Four groundwater monitoring wells were screened and open to selected 

intervals between 205 and 723 ft bls (fig. 9 and table 2 at end 

of report). The temperature-gradient log indicates a near-linear 

conductive geothermal gradient from the bottom up to a depth 

of about 600 ft, above which the gradient is disturbed by as 

many as five zones of lateral ground-water flow through the 

coarse-grained units (fig. 9). 

Evergreen (EVGR) Site

The EVGR site is located in the southeastern part of the 

basin outside the confined aquifer zone and adjacent to 

Thompson Creek (fig 1). The CPT log at EVGR reached a total 

depth of 89 ft (fig. 10). Although the base of the Holocene is 

not clearly defined in the CPT log, it was estimated from the 

CPT and normal- resistivity and spontaneous-potential 

geophysical logs to be about 35 ft bls (fig. 10). Analysis of 

borehole geophysical logs indicates relatively more finegrained units in comparison with the CCOC and STPK sites. 

Several coarse-grained units ranging in thickness from 10 to 

25 ft were identified between 100 and 775 ft bls. Five groundwater monitoring wells were screened and open to selected 

intervals between 120 and 774 ft bls (fig 10 and table 2 at end 

of report). The temperature-gradient logs could not be 

completed below 725 ft bls because of relatively dense drilling 

fluid inside the casing. From 725 ft bls to a depth of 510 ft bls, 

the temperature-gradient log indicates a near-linear conductive 

geothermal gradient, above which it is disturbed by at many as 

three zones of lateral ground-water flow through the coarsegrained units (fig. 10).

Core Measurements

Core samples were collected at selected depths at CCOC, 

WLLO, MGCY, STPK, and EVGR, and continuously from 

land surface to 1,000 ft bls at GUAD. No core samples were 

collected at ELNR or STGA. All together, 425 cores, totaling 

over 1,150 ft in collective length, were collected in the Santa 

Clara Valley as part of the cooperative studies between 1999 

and 2003. 

The cores were collected with a wire-line coring system 

that pushes a core barrel ahead of the drill bit to cut relatively 

undisturbed 2.5-in.-diameter cylinders of sediment. A plastic 

liner is placed inside a steel core barrel to receive the cylinder 

of sediment during drilling. The wire-line system allows the 

core to be recovered without removing the drilling pipe. Each 

coring “push” retrieves a cylinder of sediment as long as 5 ft in 

length. The cores were sealed and stored until the core 

measurements and sampling were completed. Coring was 

performed selectively during the drilling with an attempt to 

retrieve sediments in coarse- and fine-grained layers for 

hydrologic, geochemical, and geomechanical sampling. To 

sample potential geologic unconformities, cores were taken in 

an attempt to capture sediments that may be spanning potential 

transitions of sedimentary layers and other geochronological 

indicators within the sediments, and to obtain sediments that 

would be representative of the water-bearing zones. 

Core samples were systematically analyzed for bulk 

physical properties with a multi-sensor data logger (MSL). 

After MSL logging was completed, whole-core subsamples 

were taken for analysis of hydraulic and geomechanical 

properties. After subsampling, whole cores were then split in 

half and photographed with a high-resolution digital camera 

(not shown in this report), and the composition and structure of 

the sediment were described. Core sub-samples were 

selectively taken for further analysis of physical properties, 

magnetic orientation, and pore-water chemistry.

Physical Data

Multi-sensor logging of the intact cores included primarywave (p-wave) velocities derived from an acoustic transducer 

source, bulk density derived from an active gamma-radiation 

source, magnetic susceptibility derived from an induced 

magnetic field, and calculated acoustic impedance derived 

from the multiplication of the primary-wave velocity and the 

density. The logging frequency was 0.4 in. (1 cm) along the 

length of each core. 

Measured p-wave velocity from core samples ranged from 

4,700 to 6,100 ft/s with an average of 5,515 ft/s (fig. 11). 

Approximately 1 percent of recorded velocity data for all cores 

were at a low velocity mode of 4,700 to 4,800 ft/s (fig. 11) that 

may be related to voids or open space in the core filled with 

drilling fluid. Cores with such anomalously low velocities were 

found from CCOC, WLLO, MGCY, and GUAD. Average core 

values given in table 11 have been annotated with an “(L)” if 

the core contained a low-velocity data value between 4,700 and 

4,800 ft/s.
26 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

Average core velocity

Maximum core velocity

Minimum core velocity

Average: 5,515

PRIMARY-WAVE CORE VELOCITY,

IN FEET PER SECOND

Maximum: 6,100

Minimum: 4,700

Histogram For All Core Data, Santa Clara CA

Histogram For Average Per-Core Data, Santa Clara, CA

NUMBER OF MEASUREMENTS TAKEN NUMBER OF CORE SAMPLES 140

120

100

80

20

15

10

5

0

60

40

20

0

914.4 1,066.8 1,219.2 1,371.6 1,524 1,676.4 1,828.8 1,981.2

VELOCITY, IN METERS PER SECOND

3000 3500 4000 4500 5000 5500 6000 6500

VELOCITY, IN FEET PER SECOND

Possible voids filled

with drilling fluid

A

B

Figure 11. Primary-wave velocity measurements for all cores and average per core collected from multiple-well monitoring sites, Santa Clara County, California.
Geologic Data 27

Measured density from the core samples ranged from 

0.68 to 2.89 g/cm3 and is bimodal in its distribution for average 

values per core (modal picks at about 2.19 and 2.32 g/cm3), 

with an overall average of 2.16 g/cm3 for all core data (fig. 12). 

Less then 1 percent of all measured densities were below 1.20 

g/cm3 and are annotated with an “(L)” in table 11. About 22 

percent of all measured densities were above 2.25 g/cm3

(fig. 12A) and are annotated with an “(H)” in table 11. A total 

of 111 (24 percent) of the 425 cores had an average per core 

value of 2.27 g/cm3 or greater (fig. 12B) and most were 

collected from the MGCY and EVGR sites outside the 

confined aquifer zone of the basin (table 11, fig. 1).

The magnetic susceptibility is a unitless measure that is 

controlled by the character and abundance of magnetic mineral 

grains in the sediment when placed in an inducing magnetic 

field. Magnetic susceptibilities for sedimentary rocks have a 

maximum value of about 25,000 and have an average range 

between 0 and 360 (Reynolds, 1997). While the measured 

magnetic susceptibility from all core samples ranged from 0 to 

793 with an average of 22, the average per core magnetic 

susceptibilities ranged from 0 to 246 with most cores ranging 

between 9 and 40 (table 11, fig. 13). 

Observational Data

Cores were split in half along their long axes. One of the 

halves was prepared and photographed with a high resolution 

digital camera, sealed in plastic, and stored in refrigerated 

archive. The other half was described for lithologic, 

stratigraphic, and structural features, and signs of mechanical 

disturbance from the core-collection process. These 

descriptions included color, hydrocarbon inclusions, lithology, 

sorting, roundness, accessories (wood, shells, and so forth), 

bioturbation, Unified Soil Classification System textures, and 

compressive strength estimated with a pocket penetrometer. 

Core Subsample Data 

Consolidation tests were performed on core subsamples 

taken from selected fine-grained cores (table 12). The 

properties estimated from these consolidation tests include the 

coefficients of inelastic and elastic consolidation, maximum 

past stress, and initial void ratio. From these properties, values 

of inelastic and elastic specific storage can be estimated for the 

simulation of land subsidence. One-dimensional consolidation 

tests were completed on 75 whole-core subsamples from the 

CCOC, WLLO, MGCY, STPK, GUAD, and EVGR sites. 

Consolidation tests were interpreted on the basis of the 

methods presented by Schmertmann (1953). The geometric 

means of inelastic and elastic specific storages were estimated 

to be 1.5 × 10−4 ft−1 and 1.2 × 10−5 ft−1, respectively. These 

estimates are within the range of values from the extensometer 

sites (fig 1). Reported inelastic specific storage values for the 

Santa Clara Valley range from 1.5 × 10−4 ft−1 to 

1.3 × 10−3 ft−1 (Poland and Ireland, 1988). Elastic specific 

storage values estimated from extensometer data range from 

1.5 × 10−6 ft−1 to 1.5x10−5 ft−1.

Hydraulic tests were performed on whole-core 

subsamples from selected fine- to medium-grained cores from 

wells at the CCOC and WLLO sites (table 13). Core samples 

were analyzed by the USGS laboratory using the American 

Society for Testing and Materials procedure, ASTM-D-5048, 

and USGS laboratory procedure, YMP-USGS-HP-229. 

Properties estimated from these tests include vertical hydraulic 

conductivity, particle density, bulk density, porosity, water 

content, percent saturation, effective porosity, and effective 

saturation. The vertical hydraulic conductivity estimates from 

selected core samples ranged from 8 × 10−4 to 3.2 × 10−1 ft/d 

(table 13). The estimated total porosities from selected core 

samples ranged from 0.23 to 0.43 and the effective porosity 

ranged from 0.22 to 0.40 (table 13). These porosity values are 

relatively smaller than porosities calculated from sonic logs for 

comparable depths, which ranged from 0.35 to 0.45 (figs. 3

and 4). The relative changes in porosity between those 

estimated from the hydraulic tests and those calculated from 

the sonic logs agreed within 2 percent. The difference between 

the porosity calculated from the sonic log and the porosity 

estimated from the whole-core subsamples may be a result of 

the assumed travel time associated with the matrix 

compressibility in the sonic log, and may be accounted for by 

a linear transformation of the sonic-log estimates of porosity. 
28 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

100

200

300

400

500

0

1

0

5

10

15

20

25

1. 2 1. 4 1. 6 1. 8 2 2. 2 2. 4 2. 6 2. 8 3

Histogram For All Core Data, Santa Clara, CA

DENSITY, IN GRAMS PER CUBIC CENTIMETER (g/cm3)

Histogram for Average Per-Core

Data, Santa Clara, CA

Average 2.16

CORE DENSITY, IN GRAMS

PER CUBIC CENTIMETER

Maximum 2.89

Minimum 0.68

NUMBER OF MEASUREMENTS TAKEN NUMBER OF CORE SAMPLES

2.32 grams per

cubic centimeter

2.19 grams per

cubic centimeter

22% of measurements were greater

than 2.25 grams per cubic centimeter

and were mostly located at MGCY

and EVGR multiple-well sites.

A

B

Figure 12. Density measurements for all cores and average per core collected from multiple-well monitoring sites, Santa Clara County, California.
Geologic Data 29

0

500

1,000

1,500

2,000

2,500

3,000

Histogram For All Core Data, Santa Clara CA

Histogram For Average Per-Core Data, Santa Clara, CA

0 10 20 30 40 50 60 70 80 90 100

0 10 20 30 40 50 60 70 80 90 100

10

20

30

40

50

MAGNETIC SUSCEPTIBILITY, κ (unitless)

0

Average core κ: 22

Maximum core κ: 793

Minimum core κ: 0

NUMBER OF MEASUREMENTS TAKEN NUMBER OF CORE SAMPLES

A

B

Figure 13. Magnetic susceptibility measurements for all cores and average per core collected from multiple-well monitoring sites, Santa Clara County, 

California.
30 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

Water-Chemistry Data

The water-chemistry data obtained from sampling and 

analysis of the multiple-well monitoring sites and selected 

water-supply wells are summarized in tables 14 and 16, 

respectively. Additional water-chemistry data were obtained 

from the selective analyses of the pore fluids extracted from 

selected cores from multiple-well monitoring sites (table 15). 

Additional water-chemistry data from selected water-supply 

wells for depth-dependent samples also are included in 

table 16. Samples for analysis of boron and strontium isotopes 

(tables 14 and 16) were collected along with the other waterchemistry samples for the multiple-well monitoring sites and 

water-supply wells and were analyzed by Tom Bullen and 

John Fitzpatrick (Research Geochemists, U.S. Geological 

Survey, unpub. data, 2001). Water-chemistry data from other 

water-supply wells were obtained from joint sampling and 

analysis (table 16) performed by the USGS, and Lawrence 

Livermore National Laboratories (Barbara Dawson, 

Hydrologist, U.S. Geological Survey, unpub. data, 2004). 

Water-chemistry samples were collected from the ELNR site 

using the USGS sampling protocol and were analyzed by a 

SCVWD-certified laboratory (Cal-EPA lab certification no. 

CA00193). In this study, depth-specific samples refer to 

samples collected from monitoring wells with small screened 

intervals. Depth-dependent samples refer to samples collected 

from water-supply wells at selected depths under full pumping 

conditions (Izbicki and others, 1999), while composite 

samples refer to samples collected from water-supply wells at 

the point of surface discharge.

The water-chemistry samples from the multiple-well 

monitoring sites (table 14) and water-supply wells (table 16, at 

the end of the report) were collected under the USGS protocol 

established for water-chemistry sampling (Wilde and others, 

1998). Depth-specific water-chemistry samples (table 16) 

were obtained from the upper and lower aquifer system 

monitoring wells with positive-displacement pumps after well 

development. Water-chemistry samples from water-supply 

wells were collected from composite surface discharge from 

the well or from depth-dependent sampling down the wellbore 

at selected depths under full pumping conditions (Izbicki and 

others, 1999). Selected cores of the finer-grained deposits were 

also sampled for pore fluids by mechanically squeezing 

subsamples of these cores. 

The water-chemistry data are summarized by groups of 

constituents that can be used for geochemical and hydrologic 

interpretations. These groups include selected chemical 

attributes such as dissolved-solids concentration, specific 

conductance, pH, temperature, and dissolved oxygen content; 

major and minor anions; other selected trace elements; 

dissolved nitrogen and carbon; stable isotopes of deuterium, 

oxygen, boron, and strontium; tritium isotope content; and the 

carbon isotopes.

Selected Chemical Attributes

Chemical attributes such as dissolved-solids 

concentration (total dissolved solids), specific conductance, 

pH, temperature, and dissolved oxygen were selectively 

measured on samples from multiple-well monitoring sites 

(table 14), water-supply wells (table 16), and pore waters 

(table 15). Total dissolved solids ranged from 249 to 2,700 

mg/L (table 14) in samples from monitoring wells and from 

281 to 970 mg/L (table 16) in samples from water-supply 

wells. The laboratory specific conductance ranged from 393 to 

4,540 μS/cm (table 14) in samples from monitoring wells and 

from 456 to 1,020 μS/cm (table 14) in samples from watersupply wells. The highest dissolved-solids and specific 

conductance values were from the ground-water sample from 

the second-deepest monitoring well at the ELNR site (table 

14). The lowest dissolved-solids and specific-conductance 

values were in water from the second-deepest well at the 

GUAD monitoring-well site (table 14).

The pH values generally are basic values, ranging from 

7.2 to 8.1 for the monitoring-well samples and from 6.9 to 8.0 

for the water-supply-well samples. The pore-water samples 

from cores showed the widest range in pH values, 6.6 to 9.5. 

The temperature of the water samples ranged from 19 to 

26 degrees Celsius (οC) for the monitoring wells and from 

17 to 26οC for the water-supply wells. The dissolved-oxygen 

concentration measured in ground-water samples ranged from 

0.1 to 7.3 mg/L for the monitoring wells and ranged from 0.4 

to 3.5 mg/L for the water-supply wells.

Major, Minor, and Trace Elements

The analysis of major, minor, and trace elements is used 

to assess the chemical characteristics of the ground-water 

samples and to help determine the source and movement of the 

ground water.

Major ions

Major anions were analyzed in samples from monitoring 

wells, supply wells, and pore waters derived from cores. 

Chloride concentrations from monitoring-well samples ranged 

from 9.24 to 1,360 mg/L (table 14). The most saline samples 

from water-supply wells ranged from than 14.2 to 63 mg/L of 

chloride (table 16). Sulfate concentrations ranged from 0.5 to 

101 mg/L for monitoring-well samples (table 14) and from 

22.2 to 77.3 mg/L for water-supply-well samples (table 16). 

The most saline pore-water samples generally occurred in 

deeper cores at CCOC and MGCY, and overall ranged from 

16 to 1,200 mg/L (table 15). Sulfate concentrations in porewater samples ranged from 10 to 410 mg/L (table 15).
Water-Chemistry Data 31

Major cations were analyzed in samples from monitoring 

and supply wells. Concentrations of calcium, magnesium, and 

sodium were generally below 80, 30, and 60 mg/L, 

respectively, for both monitoring-well and water-supply-well 

samples. The one exception was ELNR-2, which had a sodium 

concentration of 649 mg/L. 

The combination of major ions allows for the additional 

assessment of ground-water groupings, source, age, and 

movement relative to streamflow that is a form of natural 

recharge in the Santa Clara Valley. Major-ion diagrams (Piper, 

1944) were used to identify groups of wells having ground 

water of similar major-ion chemistry and to interpret mixing 

and other chemical reactions that occur along flow paths 

through aquifers. These diagrams show the concentration of 

major cations and anions, in milliequivalents per liter, relative 

to the total ionic content of the water. In addition the water 

samples from the multiple-well monitoring sites, depthdependent water-supply well samples, and composite watersupply well samples are compared with three potential surfacewater end members. The blue shaded region (fig. 14) 

represents the major-ion composition of streamflow from 

Permanente and Saratoga Creeks on the west side of the valley 

(Myhre and Bencala, 1998). The purple shaded region 

represents the composition of streamflow on Saratoga Creek 

that includes imported-water artificial recharge added to the 

streamflow (Myhre and Bencala, 1998). The yellow shaded 

region represents the imported water used, in part, for artificial 

recharge, and represents samples that preceed and span the 

1976–77 drought (Seena Hoose, geologist, Santa Clara Valley 

Water District, unpub. data, 2004). These samples of imported 

water were collected during some of the same years as the 

isotope samples that are used by Muir and Coplen (1981) for 

comparison (fig. 15). The samples from shallower monitoring 

wells group with streamflow from the western side of the 

valley as shown by the blue shaded area in figure 14A. In 

contrast, most of the deeper monitoring wells appear to have 

different major-ion chemistry and may represent different 

waters from the deeper aquifers that may not receive recent 

streamflow or artificial recharge (fig. 14A). In particular, some 

of the samples from the ELNR site are relatively more saline 

and may represent very different waters relative to the other 

deep monitoring wells. Similarly, most supply wells appear to 

group with the monitoring wells and with the west-side 

streamflow samples (fig. 14B). However, some of the deeper 

supply wells in the central part of the basin, such as Gish No. 

2, SC5-2, SC-26, and Berryessa No. 1, appear to group with the 

deeper monitoring wells and are not coincident with the 

samples from west-side streamflow or imported water 

(fig. 14B). Similarly, the depth-dependent data show that the 

deeper samples in the same supply wells only show a slight 

trend toward a mixture with the deeper monitoring-well 

compositions (fig. 14C). The majority of these samples are 

similar in composition to the west-side streamflow samples, 

which may suggest that downward wellbore flow is occurring 

in these water-supply wells. These results collectively indicate 

that water entering the deeper perforations of multiple-aquifer 

supply wells and water from the deeper monitoring wells 

represent deeper aquifers with different water chemistry, but 

downward wellbore flow may be affecting the chemistry of 

deeper samples in water-supply wells.

Selected Minor Elements

Selected minor elements that directly impact the water 

quality include iron and manganese, fluoride, boron, and 

bromide. Iron and manganese concentrations from monitoringwell samples ranged from less than 10 to 1,300 μg/L and from 

not detected to 517 μg/L, respectively (table 14). For watersupply wells, iron and manganese concentrations ranged from 

less than 1.0 to 544 μg/L and from less than 0.1 to 42 μg/L, 

respectively (table 16). Low fluoride concentrations, ranging 

from below detection limits to 0.3 mg/L, were typical of all 

samples from monitoring and supply wells. Boron 

concentrations were less than 200 mg/L in all samples, with the 

exception of the high values of 3,380 mg/L (MGCY-4), 3,860 

mg/L (MGCY-1), 1,690 mg/L (ELNR-1), and 1,360 mg/L 

(ELNR-2) for four monitoring-well samples (table 14). 
32 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

EXPLANATION

CCOC

GUAD

MGCY

STPK

WLLO

ELNR

Annual Average imported

 water for selected years

 100

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 100 0

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 0 100

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 0

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 0

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PERCENT IN MILLIEQUIVALENTS PER LITER

Calcium (Ca)

CATIONS ANIONS

Magnesium (Mg)

Sodium (Na) + Potassium (K)

Chloride (Cl), Fluoride (F)

Carbonate (C03) + Bicarbonate (HC03)

Sulfate (S04)

Sulfate (S04) + Chloride (Cl)

Calcium (Ca) + Magnesium (Mg)

Depth-specific multiple-well

 monitoring site samples

 (see table 2 for well-depth

 and site information)

1974

1975

1977

1977

ELNR-2

CCOC-1

ELNR-1

ELNR-3

ELNR-4

CCOC-5

CCOC-3

WLLO-3

WLLO-5

WLLO-6

WLLO-4

STPK-4

STPK-5 STPK-1

STPK-3

CCOC-4 CCOC-2

GUAD-1

MGCY-1

MGCY-4

MGCY-5

MGCY-2

MGCY-3

STPK-2

GUAD-2

GUAD-4

GUAD-3

WLLO-2

WLLO-1

A

Streamflow samples from Santa Cruz Mountain-front

 runoff 1996−97 (Myhre and Bencala, 1998)

Streamflow samples downstream of imported-water

 discharge to Saratoga Creek 1996−97 

 (Myhre and Bencala, 1998)

Monthly imported water 1974,

 1975, 1977, Santa Clara

 Valley Water District

Figure 14. Trilinear diagrams of major-ion chemistry for multiple-well monitoring sites and selected water-supply wells, Santa Clara County, California.
Water-Chemistry Data 33

EXPLANATION

Streamflow samples downstream of imported-water

 discharge to Saratoga Creek 1996−97 

 (Myhre and Bencala, 1998)

Monthly imported water 1974,

 1975, 1977, Santa Clara

 Valley Water District

Coyote flow path

Composite water-supply

 well samples grouped

 by flow path (see figure 1)

Los Gatos flow path

Stevens flow path

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 0

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 100 0

 0

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B

PERCENT IN MILLIGRAMS PER LITER

Calcium (Ca)

CATIONS ANIONS

Magnesium (Mg)

Sodium (Na) + Potassium (K)

Chloride (Cl), Fluoride (F)

Carbonate (C03) + Bicarbonate (HC03)

Sulfate (S04)

Sulfate (S04) + Chloride (Cl)

Calcium (Ca) + Magnesium (Mg)

17th Street No. 12

17th Street No. 7

SC21

SC-26

Berryessa No. 1

Meridian No. 2

Gish No. 2

SC5-2

Streamflow samples from Santa Cruz Mountain-front

 runoff 1996−97 (Myhre and Bencala, 1998)

Figure 14.—Continued.
34 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

12th Street no. 10

EXPLANATION

Mountain View no. 20

Williams no. 3

California Water

 Service no. 17

Streamflow samples downstream of imported−water

 discharge to Saratoga Creek 1996-97 

 (Myhre and Bencala, 1998)

Monthly imported water 1974,

 1975, 1977, Santa Clara

 Valley Water District

 100

 80

 60

 40

 20

 0

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 0

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 0

 0

PERCENT IN MILLIEQUIVALENTS PER LITER

Calcium (Ca)

CATIONS ANIONS

Magnesium (Mg)

Sodium (Na) + Potassium (K)

Chloride (Cl), Fluoride (F)

Carbonate (C03) + Bicarbonate (HC03)

Sulfate (S04)

Sulfate (S04) + Chloride (Cl)

Calcium (Ca) + Magnesium (Mg)

Depth-dependant samples grouped by

 water-supply well (see figure 1)

C

669 feet 560 feet

510 feet 280 feet

Streamflow samples from Santa Cruz Mountain-front

 runoff 1996−97 (Myhre and Bencala, 1998)

Figure 14.—Continued.
Water-Chemistry Data 35

Meteoric Water Line

Santa Clara Valley

West-Side Creeks

Northern California Imported Water

 (Piedmont average) (Muir and Coplen, 1981)

δ OXYGEN-18, IN PER MIL

δ DEUTERIUM, IN PER MIL

12 10 8 6 4

20

30

40

50

60

70

80

EXPLANATION

MGCY-1

MGCY-3

MGCY-4

MGCY-5

Coyote Creek

Upper Penitencia Creek

Alamitos Creek

Stevens Creek

Los Gatos Creek

Saratoga Creek

CCOC-4

CCOC-3

CCOC-2

CCOC-1

CCOC-5

ELNR-1

ELNR-2

ELNR-3

ELNR-4

GUAD-1

GUAD-2

GUAD-3

Native Surface Water

Native Ground Water

STPK-1

STPK-2

STPK-3

STPK-4

STPK-5

Streamflow samples

 (Muir and Coplen, 1981)

Monitoring-well samples

Depth-dependent 

 water-supply wells

 (see table 16 for

 well information)

PRECIPITATION -

 Santa Maria

Three Mile No. 5 (420)

WLLO1-1

WLLO1-3

WLLO1-5

A

Composite-wells

 samples 1996−1997

 (Muir and

 Coplen, 1981)

Figure 15. Stable isotopes for multiple-well monitoring sites and selected water-supply wells, Santa Clara County, California.
36 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

B

−12 −10 −8 −6 −4

−20

−30

−40

−50

−60

−70

−80

Native Ground Water

Native Surface Water

Northern California Imported Water (Piedmont average)

Meteoric Water Line

δ OXYGEN-18, IN PER MIL

δ DEUTERIUM, IN PER MIL

Three Mile No. 5 (420)

Figure 15.—Continued.
Water-Chemistry Data 37

EXPLANATION FOR FIGURE 15B

Coyote Creek

Upper Penitencia 

 Creek

Alamitos Creek

Stevens Creek

Los Gatos Creek

Saratoga Creek

Meridian No. 2 (24J3)

SC-2-2 (11D2)

SC-5-2 (2B1)

Ridgely No. 2 (26R3)

Bascom No. 4 (13E3)

Main P (7R4)

12th street No. 10 (16C8)

17th street No. 7 (9D5)

17th street No. 12 (9D9)

17th street No. 12 (9D9)

Senter (26D2)

Gish No. 2 (31K1)

3 mile No. 3 (23R3)

3 mile No. 5 (23R5)

3 mile No. 5 (23R5) at 420

Streamflow samples

 (Muir and Coplen, 1981)

Composite samples water-supply wells

PRECIPITATION−Santa Maria

Composite-wells samples 

 1996−1997

 (Muir and Coplen, 1981)

 PA Hale St No. 3 (35G10)

Cropley No. 3 (16K5)

Berryessa No.1 (32G1)

Marbury No. 1 (33F6)

Agnews No. 6 (13F6)

SJC No. 1 (24B5)

SC-26 (26D2)

SC-21 (32H1)

CWS No. 121-02 (19H2)

CWS No. 123-01 (19M1)

CWS No. 123-02 (19M10)

CWS No. 119-03 (20L3)

MV-21(22G9)

MV-19 (22P2)

MV-20 (27G2)

CWS No. 116 (29B2)

CWS No. 104-02 (32D1)

MV-9 (33C1)

CWS No. 39-01 (34G2)

CWS No.17 (34K2)

PA Rinconda (1B1)

17th St. No.3 (9D3)

Malone No. 1 (29A1)

Koch No. 1 (32G3)

SC-3-02 (2G29)

CWS No. 20-10 (6P1)

SC-28 (10D10)

Bascom No.5 (13E4)

Buena Vista No. 6 (13K4)

O’Connor Hospital (14B1)

CWS No. 29-01 (18K1)

Williams No. 3 (22E2)

Ridgley No. 3 (26R4)

Virginia No. 1 (34F1)

CWS No. 27-01 (1E3)

CWS No. 31-01 (1L1)

CWS No. 18-02 (3H1)

CWS No. 15-01 (3P1)

GOWC No. 8 (11A4)

GOWC No. 2 (12P1)

SJC No. 11 (7A12)

GOWC No. 21 (8Q2)

GOWC No. 12 (18E11)

Depth-dependent 

 water-supply wells

Figure 15.—Continued.
38 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

Selected Trace Elements

Ground-water samples at monitoring-well sites contained 

iodide concentrations ranging from 0.001 to 0.246 mg/L for 

well WLLO-1, and concentrations at water-supply wells 

ranged from less than 0.001 mg/L to as large as 0.09 mg/L for 

Berryessa 1 (table 16). Barium concentrations at monitoringwell sites ranged from 43.2 μg/L for well WLLO-2 to 320 μg/L 

for well ELNR-1, and concentrations at water-supply wells 

ranged from 55 μg/L to 270 μg/L for the Senter well (table 16). 

Strontium concentrations at multiple-well monitoring sites 

ranged from 95 μg/L (MGCY-1) to as large as 868 μg/L for 

well CCOC-5, and concentrations at water-supply wells ranged 

from 252 μg/L to as large as 585 μg/L for the Senter well (table 

16). Most bromide concentrations also were relatively low (less 

than 0.3 mg/L) in most monitoring-well samples, with the 

exception of samples from MGCY-1, MGCY-4, STPK-3, 

WLLO-1, ELNR-1, ELNR-2, and ELNR-3 which ranged from 

0.44 to 6.74 mg/L. Bromide appears to covary with chloride for 

selected pore-water samples, ranging from less than detection 

limits to 5.6 mg/L for core MGCY-75 (table 15). Similarly, 

bromide concentrations at water-supply wells ranged from 0.11 

mg/L to as large as 0.22 mg/L for the Meridian No. 2 well 

(table 16). Arsenic concentrations at the multiple-well 

monitoring sites ranged from not detected mg/L to as large as 

10.8 mg/L at MGCY-1, and concentrations ranged from less 

than 0.2 mg/L to nearly 2 mg/L at water-supply wells Williams 

No. 3 and 12th St. No. 10 (table 16). A few samples were 

collected for selected metals such as chromium at the WLLO 

site, where total dissolved chromium was 4.6 mg/L at WLL0-5 

and total chromium was 6.7 mg/L at WLLO-4. Oze and others 

(2003) provide additional discussion and analyses of the 

relation between concentrations of the trace metals and core 

mineralogy for the WLLO site.

Dissolved Nitrogen and Carbon

The concentration of dissolved nitrate at the multiple-well 

monitoring sites ranged from less than 0.05 mg/L for WLLO-1 

and MGCY-1 to 9.3 mg/L for WLLO-5 of nitrite (NO2) plus 

nitrate (NO3) as total nitrogen (N) (table 14). The dissolved 

nitrate concentrations from the water-supply wells ranged from 

0.23 mg/L as total N for Berryessa 1 to 7.3 mg/L for CWS 

No. 17 at a depth of 280 ft bls (table 16). Nitrate concentrations 

varied in pore-water samples from less than 0.03 mg/L to as 

much as 25 mg/L in the shallower core samples at STPK 

(table 15).

The concentration of total dissolved organic carbon at the 

multiple-well monitoring sites ranged from less than 0.2 mg/L 

for GUAD-2, GUAD-3, and GUAD-4, to 0.9 mg/L for 

MGCY-5. Total inorganic carbon in pore-water samples 

ranged from 15 to 108 mg/L (table 15).

Isotopes

Isotope samples collected from selected monitoring and 

water-supply wells included oxygen (oxygen-18), hydrogen 

(deuterium H2), boron (10/11B), strontium (strontium-87/86), 

tritium (H3), and carbon (carbon-13/12 ratio, carbon-14, as 

percent modern carbon). Stable isotopes of oxygen 

(oxygen-18) and hydrogen (deuterium H2) are used to help 

determine the source of water and in particular have been used 

in the Santa Clara Valley to determine the percentage of 

artificial recharge that has mixed with natural recharge or 

native ground water (Muir and Coplen, 1981). Isotopes of 

boron can help to identify the source of dissolved ions that 

contribute to poor-quality water (Bassett, 1990; Vengosh and 

others, 1994). Isotopes of strontium are used to help infer the 

geologic source of the sediments that the water flows through 

(Izbicki and others, 1994). 

Oxygen-18 and deuterium are naturally occurring stable 

isotopes of oxygen and hydrogen. Oxygen-18 (18O) and 

deuterium (D) abundances are expressed as ratios in delta 

notation as per mil (parts per thousand) differences relative to 

the standard known as Vienna Standard Mean Ocean Water 

(VSMOW) (Gonfiantini, 1978). Because the source of most of 

the world's precipitation is the evaporation of seawater, the 

delta-18O and delta-D composition of precipitation throughout 

the world is linearly correlated. This relation is known as the 

meteoric water line (Craig, 1961). The delta-18O and delta-D 

composition of ground water relative to the meteoric water line 

and relative to the isotopic composition of water from other 

sources is an indicator of the source and movement of ground 

water. The delta-18O and delta-D composition of water from 

monitoring wells ranged from −8.3 to −6.1 per mil and

−64 to −41.1 per mil, respectively (table 14, fig. 15A). The 

delta-18O and delta-D composition of water from water-supply 

wells ranged from −8.2 to −5.6 per mil and −57.7 to

−40.1 per mil, respectively (table 16, fig. 15B). 

Imported water from northern California that is artificially 

recharged into the aquifer systems by the SCVWD is relatively 

enriched in lighter isotopes of hydrogen (−74 per mil) and 

oxygen (−10.2 per mil) (Muir and Coplen, 1981). The 

differences in isotopic composition allows for a direct 

comparison with native ground water (−41 per mil δ-D and

−6.1 per mil δ18O) and potential natural recharge from local 

surface water (−40 per mil δ-D and −6.0 per mil δ18O), such 

as Coyote Creek streamflow, which is isotopically heavier than 

imported water (Muir and Coplen, 1981). As local and 

imported water is recharged and mixes with native ground 

water, a directly proportional change in isotopic composition 

occurs and the percentage of artificial recharge can be 

estimated using simple fractions of isotopic data (Muir and 

Coplen, 1981). 
Water-Chemistry Data 39

The percentage of artificial recharge can be estimated for 

monitoring-well and water-supply-well samples assuming a 

binary mixture, following the method from Muir and Coplen 

(1981), and using the isotopic deuterium values for local and 

imported-water recharge (Hanson and others, 2002). 

The result of these mixing estimates for samples from 

monitoring wells ranges from almost no artificial recharge,

0 percent (MGCY-3) and 2 percent (CCOC-4), to as much as

70 percent (MGCY-5) of imported-recharge water directly 

beneath the recharge ponds adjacent to Los Gatos Creek 

(fig. 1). The recharge ponds adjacent to Los Gatos Creek are 

supplied with local and imported water for artificial recharge. 

The distribution of well-sample isotopic values between the 

imported water and local streamflow that represents local 

ground-water recharge indicates that the monitoring wells 

located along the western margin tend to contain more 

artificial recharge, whereas wells located in the center of the 

valley contain less artificial recharge and generally are closer 

to the isotopic composition (O-18 and D) of local streamflow 

(fig. 15A). 

Samples from water-supply wells show similar 

distributions of isotopes indicative of mixtures of artificial 

recharge of imported water and natural recharge from local 

streamflow isotopic composition (fig.15B). On the basis of the 

stable isotope binary mixtures (Hanson and others, 2002) of 

local recharge and imported-water recharge (Muir and Coplen, 

1981), the estimated percentage of artificially recharged, 

imported water detected in water-supply wells ranges to as 

much as 40 percent artificial recharge (table 16). As in 

monitoring wells, the isotopic composition indicates larger 

percentages of artificial recharge to water- supply wells near 

artificial-recharge sites on the western side of the valley. Wells 

having indications of imported-water recharge greater than 15 

percent are Bascom Nos. 4 and 5, BuenaVista No. 6, Cropley 

No. 3, Berryessa No. 1, Marbury No. 1, Agnews No. 6, PA 

Rinconada, Malone No. 1, Meridian No. 2, O'Connor Hospital, 

CWS No. 29-01, Williams No. 12, Three Mile Nos. 3 and 5, 

GOWC No. 8,Williams No. 3 and 12, and Rigley Nos. 2 and 3 

(fig. 15, table 16). Mixtures from monitoring wells such as 

CCOC and STPK (table 14, fig. 15) also are similar to mixtures 

in depth-dependent samples from nearby water-supply wells 

such as 12th St. No. 10 and Williams No. 3 (figs. 15A and B), 

respectively.

Boron-10 and boron-11 are naturally occurring stable 

isotopes of boron. Natural and anthropogenic processes 

fractionate the boron-11 content relative to boron-10. The 

abundance of boron-11 (11B) is expressed in delta notation 

(del) as per mil (parts per thousand) differences relative to the 

standard reference boron isotopic ratio of boron-11 to boron10 of 4.161 for National Bureau of Standards boric acid sample 

No. 951 (Tom Bullen, Research Geochemist, U.S. Geological 

Survey, unpub data, 2001). Delta-boron-11 content in groundwater samples from the multiple-well monitoring sites ranged 

from 5.5 to 25.47 per mil, and the content in samples from the 

water-supply wells ranged from 6.7 to 32.22 per mil. 

Strontium-87/86 isotopes are naturally occurring stable 

isotopes of strontium and are expressed as a ratio (Faure and 

Powell, 1972). Strontium in ground water undergoes cation 

exchange between calcium and strontium in the surrounding 

sediments. This exchange process is relatively rapid for most 

ground-water flow rates and results in a strontium isotopic 

composition of ground water that reflects the isotopic 

composition of the aquifer sediments. This makes strontium 

isotopes a useful indicator of the source of the sediments that 

compose the aquifer. Strontium isotopes also can be affected 

by base-ion exchange during seawater intrusion, but this effect 

may be too localized to be discernable from sampling of 

ground water on a regional scale. The strontium-87/86 ratio of 

ground water from the multiple-well monitoring sites ranges 

from 0.70566 to 0.70780. The strontium isotope ratios for 

samples from water-supply wells ranged from 0.70718 to 

0.70773. 
40 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

 Unstable isotopes of water and carbon are used to 

identify the age of ground-water samples. Tritium (H3) is a 

naturally occurring radioactive isotope of hydrogen having a 

half-life of 12.4 years. The activity of tritium is measured in 

picocuries per liter (pCi/L); and one pCi/L is equivalent to 

about 2.2 disintegrations of tritium per minute or about one 

tritium atom in 3.1 × 1017 atoms of hydrogen. Prior to 1952, 

the tritium concentration of precipitation in coastal California 

was about 6.5 pCi/L (Izbicki, 1996). Beginning in 1952, about 

800 kilograms (1,760 lb) of tritium was released as a result of 

the atmospheric testing of nuclear weapons (Michel, 1976), 

and the tritium activity of precipitation at Santa Maria, 

California, increased to more than 2,200 pCi/L (International 

Atomic Energy Agency, 1981). This release stopped in 1962 

with the signing of treaties banning the atmospheric testing of 

nuclear weapons. Since that time, tritium activity in 

precipitation has decreased to pre-1952 levels. Because tritium 

can be part of the water molecule and tritium activities are not 

significantly affected by reactions other than radioactive 

decay, it is an excellent tracer of the movement of water and 

relative age of water on time scales ranging from 0 to 50 years 

before present (Izbicki and others, 1993). Tritium 

concentrations in samples ranged from less than 0.2 to 15.9 

pCi/L for multiple-well monitoring sites and from 0.3 to 18.3 

pCi/L for water-supply wells. The monitoring wells that lack 

tritium or have trace amounts below the measurement 

uncertainty (0.58 to 1 pCi/L) include most of the deepest wells 

at CCOC-1, MGCY-1, WLLO-1, GUAD-1, and ELNR-1, 

along with intermediate and shallow wells at MGCY-4, 

GUAD-2,4, and ELNR-2, -3, and -4 (table 14). The lack of 

tritium in the shallowest monitoring well at the GUAD site 

suggests that little to no recent recharge has reached this part 

of the basin below the regional fine-grained confining layer. 

Water-supply wells with less than 6 pCi/L of tritium include 

SC-5-2, Gish No. 2, SC-21, SC-26, MV-21, Berryessa No. 1, 

and CWS-20-10 (table 16). The water-supply wells with the 

least tritium are those away from the artificial-recharge 

facilities and toward the center of the valley. The highest 

values of tritium in monitoring wells generally occur in the 

shallowest wells of CCOC-5, WLLO-5, STPK-5, and MGCY5 (table 14). In addition, tritium was also found in the deep and 

intermediate wells of CCOC-2 through -4, WLLO-2 and -3, 

MGCY-2, STPK -2 through -4, and GUAD-3 (table 14). These 

elevated tritium concentrations, combined with older carbon14 age dates (see next paragraph), may reflect downward 

wellbore flow in nearby water-supply wells. Similarly, the 

presence of tritium near the bottom of 12th St. No. 10 suggests 

that recent water is being pumped from the deeper screened 

intervals of this water-supply well (table 16). The tritium 

distribution at depth in this water-supply well is different from 

that at the nearby monitoring-well site (CCOC), suggesting 

that downward wellbore flow may contribute recent water to 

the deeper aquifers in clusters of wells such as the 12th St well 

field.

Carbon-14 (14C) is a naturally occurring radioactive 

isotope of carbon that has a half-life of about 5,730 years. 

Carbon-14 data are expressed as percent modern carbon (pmc) 

by comparing carbon-14 activities with the specific activity of 

National Bureau of Standards oxalic acid: 12.88 

disintegrations per minute per gram of carbon in the year 1950 

equals 100 percent modern carbon. In addition to the naturally 

occurring carbon-14, carbon-14 also was produced during the 

atmospheric testing of nuclear weapons. As a result, carbon-14 

activities can exceed 100 percent modern carbon. Carbon-14 is 

a tracer of the movement and relative age of water on time 

scales ranging from several hundred to more than 30,000 years 

before present. Because carbon-14 is not part of the water 

molecule, carbon-14 activities are affected by chemical 

reactions between dissolved constituents and aquifer material. 

As a result, carbon-14 data must be corrected using chemical, 

mineralogical, and carbon-13 data to evaluate chemical 

reactions that occur within an aquifer and to estimate the actual 

age of a water sample. Davis and Bentley (1982) estimated that 

errors in uncorrected carbon-14 ages may be as much as 100 

percent. 

The carbon-14 ages in this study were adjusted on the 

basis of the percentage of carbon-14 for ground-water 

considered to represent relatively recent recharge. The carbon14 content of the upper screen sample from well 12th St No. 10 

at a depth of 300 ft bls was used as an assumed initial ground 

water; carbon-14 content was 93.5 pmc and tritium was 

present. This sample represents a relatively recently recharged 

ground water. The percent of modern carbon-14 is increased 

by the resulting ratio of carbon-14 values to the 93.5 percent 

for the initial water of recent aquifer recharge. The values for 

uncorrected pmc at the multiple-well monitoring sites ranged 

from 0.78 for ELNR-3 to more than 100 pmc for several of the 

shallowest monitoring wells and MGCY-2 (table 14). This 

results in uncorrected and initial-water corrected ages for 

depth-specific ground-water samples from monitoring wells 

that range from 0 to 39,900 years before present (ybp) 

(table 14). On the basis of carbon-14 ages of more than 

10,000 ybp, the deeper monitoring wells such as at CCOC-1, 

WLLO-1, and ELNR-1 through -3 indicate anomalous 

mixtures that may represent ground water recharged from 

ancient times when the climate was colder (Izbicki, 1996) and 

do not represent recent (less than 50 ypb) recharge.

The oldest ground-water ages generally occur in the 

deepest monitoring wells at each site and in the complete set of 

wells at the ELNR site. Except for the ELNR, MGCY, and 

GUAD sites, the shallower monitoring wells typically contain 

ground water that is less than 2,000 ybp (table 14). The 

uncorrected percent modern carbon for water-supply wells 

ranged from 35.7 for Gish No. 2 to more than 100 for Three 

Mile No. 5 (table 16). These results yield uncorrected ages for 

composite water-supply well samples that range from 0 to 

8,500 ybp. Ages for an initial-water corrected groundwater 

pmc range from 0 to 8,000 ybp for water-supply wells, with the 

oldest ground water (greater than 5,000 ybp) occurring in wells 

toward the center of the basin (SC-5-2 and Gish No. 2) 

(table 16).
Hydrologic Data 41

Carbon-13 is a stable isotope of carbon. Carbon-13 data 

are expressed as ratios in delta notation as per mil differences 

relative to the ratio of carbon-13 to the more common isotope 

carbon-12 in standard Peedee Belemnite (PDB) (Gonfiantini, 

1978). The delta-carbon-13 values for the multiple-well 

monitoring sites ranged from −5.68 per mil (MGCY-1) to 

−32.36 per mil (ELNR-2) (table 14). The delta-carbon-13 

values for the water-supply wells ranged from −13.26 per mil 

for well Bascom No. 4 to −15.63 per mil near the bottom 

(730 ft bls) of 12th St. No. 10. The age dates from the bottom 

of 12th St. No. 10 also indicate that recent water is pumped 

from the deeper screened intervals. 

Hydrologic Data

Hydrologic data from the monitoring-well sites include 

water-level measurements and estimates of hydraulic 

conductivity. Measurements from the multiple-well 

monitoring sites provide information on water levels and 

aquifer properties of the deep aquifer system. The water levels, 

the water-level differences between aquifers, and the relation to 

the offshore equivalent freshwater heads in San Francisco Bay 

are all aspects of pressure within the aquifer system that help 

assess the potential for land subsidence, seawater intrusion, and 

intraborehole flow in the upper and lower aquifer systems. 

Estimates of hydraulic conductivity from slug tests of 

monitoring wells and their relation to aquifer tests of the deepaquifer system water-supply wells provide some comparison of 

hydraulic transmission properties of the deep-aquifer system. 

Ground-Water Levels 

Periodic ground-water-level measurements at the 

multiple-well monitoring sites (fig. 16) were initiated in the 

Santa Clara Valley by SCVWD (Mark Merritt, Santa Clara 

Valley Water District, unpub. data, 2003). Water levels for 

wells CCOC-1 through -4 ranged from 57 ft above sea level to 

25 ft below sea level (fig. 16A). Seasonal fluctuations of greater 

than 60 ft are superimposed on a multi-year decline for these 

several dry years (2000–03). Water-level differences of about 

5 to 10 ft persist between CCOC-1 through -3 and CCOC-4 and 

are superimposed on the seasonal water-level fluctuations. The 

water levels from the shallowest monitoring well, CCOC-5, 

indicate smaller seasonal water-level fluctuations that lag 

slightly in time behind the fluctuations of the deeper 

monitoring wells. Water levels at the WLLO site (fig. 16B) 

adjacent to Los Gatos Creek, follow a similar pattern. The 

water levels at the MGCY site (fig. 16C), which is located at 

the artificial-recharge ponds upstream from WLLO and 

adjacent to Los Gatos Creek, show a much different pattern of 

water levels, seasonal fluctuations, and water-level differences. 

Although the water levels in the shallowest well at MGCY may 

reflect artificial-recharge events, there appears to be little or no 

relation between the water-level changes in the shallowest well 

and those in the deeper wells (fig. 16C). The water levels at 

STPK (fig. 16D) show seasonal water-level fluctuations 

similar to those at other sites, except for the shallowest well. 

The water levels for STPK-5 (fig. 16D) indicate an even larger 

lag behind the water-level change than measured at the CCOC 

and WLLO sites (figs. 16A,B,D).

Hydraulic Properties of Aquifers

Hydraulic conductivity estimates (table 17) for the 

multiple-aquifer systems at three of the multiple-well 

monitoring sites (CCOC, WLLO, and MGCY) were obtained 

using pressure-pulse “slug” tests and ranged between 0.1 and 

583 ft/d. This test is very useful in small-diameter wells that 

have a small screened interval. Unlike longer term tests, the 

results are based on very small changes in water level measured 

over very short periods and, therefore, represent the hydraulic 

response from only a small volume of aquifer material adjacent 

to the well screen.

Estimates of hydraulic conductivity from time and waterlevel data were performed using two methods. The CooperBredehoeft-Papadopulus (Cooper and others, 1967) method 

was used for overdamped responses and the Van Der Kamp 

(1976) method was used for underdamped responses. Both 

methods calculate values for the transmissivity based on an 

estimated storativity. Values for the specific storage of 

1 × 10−5 ft−1 and 1 × 10−6 ft−1 were selected to bracket the 

estimated specific storage of the aquifers. These values were 

selected on the basis of the work of Hanson and Nishikawa 

(1996). The equivalent storage coefficients then were used to 

calculate two values for the transmissivity (table 17).

Several assumptions are made by both methods. The 

Cooper-Bredehoeft-Papadopulus method assumes that the 

aquifer is confined, homogeneous, isotropic, and of uniform 

thickness, and that the flow is horizontal and radially 

symmetric. The Van Der Kamp (1976) method assumes that 

the aquifer is homogeneous, the flow is horizontal and radially 

symmetric, the variation of the water level about the steady 

state is much smaller in magnitude than the height of the water 

column, and frictional forces within the casing are negligible. 

For both methods it is assumed that the aquifer thickness is 

equal to the length of the screened interval of the monitoring 

well and that the response is representative of the entire 

screened interval.

The Cooper-Bredehoeft-Papadopulus method was 

employed using Aqtesolv 2.5 (Duffield, 1999) computer 

software. Aqtesolv uses a nonlinear least-squares parameter 

estimation procedure to calculate a match curve without giving 

a match point. All points in the measured response curve were 

weighted equally. The accuracy of the fit between the match 

curve and the measured response curve is best characterized by 

the residual standard error (Std. Error). 
42 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California WATER-LEVEL ALTITUDE, IN FEET ABOVE SEA LEVEL

Coyote Creek Outdoor Classroom (CCOC)

McGlincey (MGCY)

Willow (WLLO)

A

B

C

100

75

50

25

0

25

50

100

75

50

25

0

25

50

200

175

150

125

100

75

50

COCC-5 (62−72)

COCC-4 (405−425)

COCC-3 (520−540)

COCC-2 (620−640)

COCC-1 (820−840)

EXPLANATION

WLLO-5 (220−240)

WLLO-6 (75−85)

WLLO-4 (345−365)

WLLO-3 (435−455)

WLLO-2 (570−590)

WLLO-1 (770−790)

MGCY-5 (160−180)

MGCY-4 (280−300)

MGCY-3 (390−410)

MGCY-2 (510−530)

MGCY-1 (630−650)

D Santana Park (STPK)

125

100

75

50

25

0

25

1/1/00 12/31/00 12/31/01 12/31/02 12/31/03

STPK-5 (130−150)

STPK-4 (340−360)

STPK-3 (420−440)

STPK-2 (540−560)

STPK-1 (680−700)

EXPLANATION

EXPLANATION

EXPLANATION

Water level Depth of

screened

interval

Water level

Depth of

screened

interval

Water level

Depth of

screened

interval

Water level

Depth of

screened

interval

Figure 16. Ground-water levels for selected multiple-well monitoring sites, Santa Clara County, California.
Accessing Data 43

The Van Der Kamp method uses an approximation 

described as an exponentially damped cyclic fluctuation 

wherein the two match points are the damping constant and the 

frequency of oscillation (Halford and Kuniansky, 2002). Two 

graphs are used to estimate the match points of absolute 

displacement versus time and another of displacement versus 

time. On each graph a line is hand fitted to estimate the match 

points. The geometric mean of the results for the CCOC, 

WLLO, and MGCY sites are presented in table 17. 

Accessing Data

Users of the data presented in this report are encouraged 

to access information through the USGS National Water 

Information System web page (NWIS Web) located at 

http://waterdata.usgs.gov/nwis/.

NWIS Web serves as an interface to a database network of 

site information and real-time, ground-water, surface-water, 

and water-quality data collected from locations throughout the 

50 states and elsewhere. Data are updated from the database 

network on a regularly scheduled basis.

Data are retrieved by category and geographic area, and 

the retrieval can be selectively refined by specific location or 

parameter field. NWIS Web can output water-level and waterquality graphs, site maps, data tables (in HTML and ASCII 

format) and develop site-selection lists.

Updates to data presented in this report after publication 

will be made to the U.S. Geological Survey's NWIS. 

Additional geophysical logs, sample-collection notes, and 

other information not contained in NWIS are kept on file at the 

USGS office in San Diego, California. Formal requests for 

specific data should be directed to the U.S. Geological Survey, 

California District Office, Hydrologic Data Center located in 

Sacramento, California.

Summary and Conclusions

Between 1999 and 2003, 38 ground-water monitoring 

wells were constructed at 8 multiple-well monitoring sites in 

Santa Clara County, California, in a cooperative study between 

the U.S. Geological Survey and the Santa Clara Valley Water 

District. Lithologic, geologic, geophysical, geomechanical, 

hydrologic, and geochemical data were collected from a 

combination of drill cuttings and (or) cores from the boreholes 

at each site. In addition, geophysical, water-chemistry, and 

hydrologic data were collected from the monitoring-wells and 

selected water-supply wells. These data will be used to update 

and improve the three-dimensional geohydrologic framework 

of the basin and to address several issues of water-supply, 

water-chemistry, sequence stratigraphy, geology, and 

geological hazards.

Geophysical logs yielded additional information about the 

distribution, and properties of ground water, and the nature of 

ground-water flow in aquifers. Logs indicate that all eight 

multiple-well sites consisted of about four to six different 

aquifer units separated by relatively fine-grained units. 

Analysis of geophysical logs indicated that most coarsegrained aquifers were shallower than 860 ft deep in the central 

and south-central part of the basin and shallower than 650 ft 

deep in the southwestern part of the basin. Coarse-grained units 

encountered at new monitoring sites varied in thickness from 

10 to 25 ft (EVGR) in the southeastern areas of the valley and 

between 50 and 200 ft (CCOC, WLLO, MGCY, STPK, and 

STGA) in the south-central and southwestern areas of the 

valley. Coarse-grained units in the central valley ranged in 

thickness from 25 to 50 ft (GUAD). Deviations from 

temperature-gradient logs indicated that the majority of 

horizontal ground-water flow was above 775 ft (WLLO) in the 

south-central valley and above 510 ft (EVGR) in the 

southeastern valley. In the southwestern part of the valley the 

deepest aquifers were above 725 ft (MGCY) and closely 

matched disturbed temperature-gradient logs. 

Analysis of more than 1,150 ft of core included bulk 

physical properties of primary-wave acoustic velocity, density, 

and magnetic susceptibility. Primary-wave velocity values 

were normally distributed with a mean of 5,515 ft/s and ranged 

from 4,700 to 6,100 ft/s. Average core density was bimodal in 

its distribution for average value per core between 2.19 and 

2.32 g/cm2 with an average of 2.16 g/cm2 for all core data. 

About 24 percent of all core sampled had an average bulk 

density greater than 2.27; these cores were mostly from the 

EVGR and MGCY sites in the southern unconfined areas of the 

valley. Average per core magnetic susceptibilities ranged from 

0 to 246, and most cores ranged between 9 and 40 with an 

average of 22. 

Water-chemistry data indicate that the ground water in the 

alluvial aquifers is generally of good quality that is low in total 

dissolved solids and chloride. Isotopic data indicate that 

artificial recharge is occurring throughout the shallower parts 

of the aquifer system and that recent recharge (less than 50 

years old) occurs throughout most of the basin but may not be 

present toward the center of the basin at GUAD below the 

extensive fine-grained confining units. The percentage of 

artificial recharge ranges from 0 to 61 percent for water-supply 

wells. Ground-water ages indicate a wide range in ages: the age 

of most shallow ground water at the multiple-well monitoring 

sites is less than 2,000 ybp and the age of deeper ground water 

is as much as 39,900 ybp. 
44 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

Preliminary water-level data from the multiple-well 

monitoring sites indicate seasonal water-level fluctuations as 

great as 60 ft and water-level differences between aquifers as 

great as 10 ft. The water-level hydrographs indicate different 

water-level changes and relations between aquifers in different 

parts of the basin. However, most of these hydrographs 

indicate the potential for downward water-level gradients, with 

lower water levels in the deeper monitoring wells.

Estimates of hydraulic and geomechanical properties 

were made from tests of whole-core samples and tests at 

selected monitoring wells. Slug tests from monitoring wells 

indicate horizontal hydraulic conductivities that range from

0.1 to 583 ft/d. Laboratory tests of selected whole cores 

indicate vertical hydraulic conductivities for the finer grained 

sands, silts, and clays that range from 8 × 10−4 to 0.3 ft/d and 

effective porosities that range from 0.21 to 0.4. Consolidation 

tests of finer grained whole-core samples resulted in geometric 

mean inelastic and elastic specific storage values of 

1.5 × 10−4 ft−1 and 1.2 × 10−5 ft−1, respectively.

References Cited

Bassett, R.L., 1990, A critical evaluation of the available 

measurements for the stable isotopes of boron: Journal of 

Applied Geochemistry, v. 5, p. 541–554.

California Department of Water Resources, 1967, Evaluation 

of Ground Water Resources, South Bay, appendix A: 

Geology: Bulletin 118-1, 153 p.

California Department of Water Resources, 2003, 

http://www.cadwr.gov/, February, 2003

CH2M Hill, 1992, Santa Clara Valley groundwater model 

project, GIS data base and utility program documentation, 

prepared for City of San Jose and Santa Clara Valley Water 

District [variously paged].

Century Geophysical Corporation, 2004, http://centurygeo.com/9320-index.html/, accessed July 23, 2004

Craig, H., 1961, Isotopic variation in meteoric waters: Science, 

v. 133, p. 1702–1703.

Cooper, H.H., Bredehoeft, J.D., and Papadopulus, S.S., 1967, 

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46 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California
Tables 47

Tables
48 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

Table 1. Summary of multiple-well monitoring sites, Santa Clara County, California

[ft bls, feet below land surface]

Common name State 

well No.

Site 

identification No. 

Drilling start

date

Drilling end 

date

Total drilled 

depth

(ft bls)

Coyote Creek Outdoor Classroom (CCOC) 007S001E09L004–8 372012121521001–5 09/15/00 10/21/00 1,006

Willow (WLLO) 007S001E19B002–7 371858121541201–6 03/23/01 04/18/01 850

McGlincey (MGCY) 007S001W35L012–16 371636121563401–5 08/04/01 08/31/01 873

Santana Park (STPK) 007S001W14P001–5 371904121563601–5 02/21/02 03/21/02 1,000

Guadalupe (GUAD) 006S001W26Q001–4 372241121561201–4 08/22/02 09/29/02 1,372

Eleanor Park (ELNR) 005S003W36P002–5 372701122083401–4 02/04/03 02/26/03 932

Saratoga (STGA) 007S001W29C003–6 371802121595001–4 03/03/03 03/17/03 1,000

Evergreen (EVGR) 007S002E19C005–9 371858121475001–5 03/31/03 04/19/03 1,030
Table 17 49

Table 2. Summary of well completions for multiple-well monitoring sites, Santa Clara County, California

[depth in feet below land surface; see table 1 for definitions of local well names]

Local well name State well No. Depth to bottom 

of well

Depth to top of 

perforations

Depth to bottom of 

perforations

Depth to top of 

sand pack

Depth to bottom of 

sand pack

CCOC-1 007S001E09L004M 1,000 820 840 790 850

CCOC-2 007S001E09L005M 640 620 640 599 655

CCOC-3 007S001E09L006M 540 520 540 478 556

CCOC-4 007S001E09L007M 425 405 425 360 425

CCOC-5 007S001E09L008M 72 62 72 60 80

WLLO-1 007S001E19B003M 850 770 790 740 800

WLLO-2 007S001E19B007M 590 570 590 550 610

WLLO-3 007S001E19B004M 455 435 455 415 475

WLLO-4 007S001E19B005M 365 345 365 315 375

WLLO-5 007S001E19B006M 240 220 240 200 260

WLLO-6 007S001E19B002M 85 75 85 60 100

MGCY-1 007S001W35L012M 850 630 650 588 655

MGCY-2 007S001W35L013M 530 510 530 458 535

MGCY-3 007S001W35L014M 410 390 410 352 415

MGCY-4 007S001W35L015M 300 280 300 263 320

MGCY-5 007S001W35L016M 180 160 180 155 208

STPK-1 007S001W14P001M 980 680 700 653 720

STPK-2 007S001W14P002M 560 540 560 522 603

STPK-3 007S001W14P003M 440 420 440 395 468

STPK-4 007S001W14P004M 360 340 360 315 375

STPK-5 007S001W14P005M 150 130 150 107 178

GUAD-1 006S001W26Q001M 1,360 810 830 792 860

GUAD-2 006S001W26Q002M 600 580 600 522 606

GUAD-3 006S001W26Q003M 460 440 460 386 460

GUAD-4 006S001W26Q004M 330 310 330 310 370

ELNR-1 005S003W36P002M 930 830 850 793 880

ELNR-2 005S003W36P003M 740 720 740 700 763

ELNR-3 005S003W36P004M 560 540 560 508 570

ELNR-4 005S003W36P005M 200 180 200 145 210

STGA-1 007S001W29C003M 1,000 630 650 615 723

STGA-2 007S001W29C004M 550 530 550 500 585

STGA-3 007S001W29C005M 380 360 380 343 412

STGA-4 007S001W29C006M 270 250 270 205 305

EVGR-1 007S002E19C005M 1,030 740 760 700 774

EVGR-2 007S002E19C006M 630 610 630 560 683

EVGR-3 007S002E19C007M 390 370 390 333 400

EVGR-4 007S002E19C008M 290 270 290 248 310

EVGR-5 007S002E19C009M 150 130 150 120 175
50 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

Table 3. Lithologic shaker logs for Coyote Creek Outdoor Classroom (CCOC) (7S/1E-9L4–8) multiple-well monitoring site, Santa Clara County, California—

Continued

Depth (ft)

Description

 From To

0 141 Sandy gravel, granular to small pebble-sized gravel with very fine to fine sand; moderately sorted; subrounded 

to rounded; olive gray (5Y 5/2)

141 151 Silty sandy gravel, granule to large pebble-sized gravel with very fine sand and some minor silt; very poorly 

sorted; subangular to subrounded; olive (5Y 5/3)

151 161 Sandy gravel, granule to large pebble-sized gravel with very coarse sand; very poorly sorted; angular to 

rounded; very dark grayish brown (2.5Y 3/2)

161 171 Silty sandy gravel, granule to large pebble-sized gravel with very fine to fine sand and some minor silt; very 

poorly sorted; subangular to subrounded; olive brown (2.5Y 4/3)

171 181 Silty gravelly sand, fine to very fine sand with some granule to small pebble-sized gravel and silt; moderately 

sorted; subangular to subrounded; dark olive gray (5Y 3/2)

181 191 Sandy silt, silt with minor very fine sand; well sorted; subangular to subrounded; olive gray (5Y 5/2)

191 211 Clayey silty sandy gravel, granule to small pebble-sized gravel with coarse to very coarse sand, silt and clay; 

moderately sorted; angular to subangular; olive gray (5Y 4/2)

211 221 Slightly gravelly silty clay, clay with silt and minor granule to small pebble-sized gravel; moderately to well 

sorted; subangular to subrounded; dark gray (5Y 4/1)

221 231 Silty clay; clay with some silt; well sorted; subangular to subrounded; dark gray (5Y 4/1)

231 291 Silty sandy gravel, granule to large pebble-sized gravel with very fine to very coarse sand and some silt; very 

poorly sorted; subangular to subrounded; dark olive gray (5Y 3/2)

291 311 Sandy gravel, granule to large pebble-sized gravel with very coarse sand and silt; very poorly sorted; 

subangular to subrounded; pale olive (5Y 6/3)

311 331 Clayey silty gravel, granule to medium pebble-sized gravel with silt and clay; poorly sorted; angular to 

subrounded; olive gray (5Y 5/2)

331 341 Slightly gravelly silty clay, clay with silt, granular; moderately sorted; subrounded; dark gray (5Y 4/1) to pale 

olive (5Y 5/2)

341 361 Gravelly silty sand, coarse to very coarse sand with granule to large pebble-sized gravel and some minor silt; 

poorly sorted; angular to subrounded; olive gray (5Y 5/2)

361 371 Gravelly silty sand, coarse to very coarse sand with granule to large pebble-sized gravel and some minor silt; 

poorly sorted; angular to subrounded; olive gray (5Y 4/2)

371 381 Sandy gravel, granule to large pebble-sized gravel with coarse to very coarse sand; moderately sorted; 

subangular to rounded; dark greenish gray (10Y 4/1)

381 391 Silty sandy gravel, granule to large pebble-sized gravel with coarse to very coarse sand and minor silt; 

moderately sorted; subangular to rounded; olive gray (5Y 4/2)

391 401 Silty gravelly sand, coarse to very coarse sand with granule to large pebble-sized gravel and some silt; 

moderately sorted; subangular to rounded; olive gray (5Y 4/2)

401 410 Clayey silty sandy gravel, granule to large pebble-sized gravel with coarse to very coarse sand and minor silt 

and clay; very poorly sorted; subangular to well rounded; light yellowish brown (2.5Y 6/4)

410 420 Sandy gravel, granule to large pebble-sized gravel and minor coarse to very coarse sand; well sorted; 

subangular to subrounded; mainly dark gray (5Y 4/1)

420 430 Silty gravelly sand, very coarse sand with granule to medium pebble-sized gravel and minor silt; moderately 

sorted; subangular to subrounded; olive (5Y 5/3)

430 440 Slightly sandy clayey silt, silt with some clay and minor very fine to very coarse sand; well sorted; subangular 

to subrounded; olive gray (5Y 5/2)

440 450 Slightly gravelly clayey silt, silt with clay and granule to large pebble-sized gravel; moderately sorted; 

subangular to rounded; olive gray (5Y 5/2)

Table 3. Lithologic shaker logs for Coyote Creek Outdoor Classroom (CCOC) (7S/1E-9L4-8) multiple-well monitoring site, Santa Clara County, California

[Altitude of land surface, approximately 93 ft.; depth is in feet below land surface; soil and rock color notation from Munsell Color (1994); drilled by U.S. 

Geological Survey Western Region Research Drilling Unit, using mud-rotary, August–September 2000; total depth drilled 1,006 ft.; screened intervals: 62–72; 

405–425; 520–540; 620–640; 820–840 ft; ft, foot]
Table 3 51

450 511 Silty sandy gravel, granule to medium pebble-sized gravel with coarse to very coarse sand and some minor silt; 

moderately sorted; subangular to subrounded; dark gray (5Y 4/1)

511 521 Clayey silty sandy gravel, granule to large pebble-sized gravel with very fine to very coarse sand, silt and clay; 

poorly sorted; angular to subangular; dark gray (5Y 4/1)

521 531 Slightly silty sandy gravel, granule to medium pebble-sized gravel; moderately sorted; subangular to rounded; 

olive gray (5Y 5/2)

531 541 Silty sandy gravel; granule to large pebble-sized gravel with coarse to very coarse sand and silt; poorly sorted; 

angular to subrounded; greenish gray (10Y 5/1)

541 551 Clayey silty sandy gravel, granule to large pebble-sized gravel with some very fine to fine sand, silt and minor 

clay; poorly sorted; angular to subrounded; dark greenish gray (5GY 3/1)

551 601 Silty sandy gravel, granule to medium pebble-sized gravel with very fine to fine sand and some silt; moderately 

sorted; angular to subangular; light olive brown (2.5Y 5/3)

601 611 Gravelly silty clay, clay with silt and minor granule to small pebble-sized gravel; moderately sorted; subangular 

to well rounded; olive brown (2.5Y 4/3)

611 621 Gravelly sandy clayey silt, silt with clay, very fine to fine sand and some granule to small pebble-sized gravel; 

moderately sorted; subangular to rounded; olive brown (2.5Y 4/3)

621 631 Silty sandy gravel, granule to large pebble-sized gravel with some coarse to very coarse sand and silt; well 

sorted; subangular to subrounded; light olive brown (2.5Y 5/3)

631 651 Silty sandy gravel, granule to medium pebble-sized gravel with coarse to very coarse sand and silt; well sorted; 

subangular to subrounded; light olive brown (2.5Y 5/3)

651 661 Gravelly silty sand, coarse to very coarse sand with silt and granule to large pebble-sized gravel; moderately 

sorted; subangular to rounded; grayish brown (2.5Y 5/2)

661 671 Silty sandy gravel, granule to medium-sized gravel with some medium to very coarse sand and minor silt; 

poorly sorted; subangular to rounded; grayish brown (2.5Y 5/2)

671 691 Clayey silty sandy gravel, granule to large pebble-sized gravel with very fine to very coarse sand, silt and clay; 

very poorly sorted; angular to subrounded; dark greenish gray (10Y 4/1)

691 701 Gravelly silty sand, very fine to very coarse sand with silt and some granule to medium pebble-sized gravel; 

poorly sorted; angular to rounded; olive brown (2.5Y 4/3)

701 711 Sandy gravel, granule to medium pebble-sized gravel with very coarse sand; moderately sorted; angular to well 

rounded; grayish brown (2.5Y 5/2)

711 751 Sandy silty clay, clay with silt and some very fine to very coarse sand; moderately sorted; angular to 

subrounded; light olive brown (2.5Y 5/3)

751 761 Silty sandy gravel, granule to small pebble-sized gravel with coarse to very coarse sand and silt; well sorted; 

angular to subrounded; grayish brown (2.5Y 5/2)

761 771 Slightly gravelly sandy silty clay, clay with silt, coarse to very coarse sand and minor granule to medium 

pebble-sized gravel; moderately sorted; angular to subrounded; dark gray (5Y 4/1)

771 791 Clayey silty sandy gravel, granule to medium pebble-sized gravel with very coarse sand, silt and clay; 

moderately sorted; subrounded to rounded; dark gray (5Y 4/1)

791 801 Silty sandy gravel, granule to medium pebble sized gravel with coarse to very coarse sand and silt; well sorted; 

subangular to rounded; light olive brown (2.5Y 5/4)

801 811 Silty sandy gravel, granule to medium pebble-sized gravel with fine to very coarse sand and minor silt; poorly 

sorted; angular to subrounded; light yellowish brown (2.5Y 6/4)

811 841 Silty sandy gravel, granule to large pebble-sized gravel with coarse to very coarse sand and minor silt; 

moderately sorted; angular to subrounded; light yellowish brown (2.5Y 6/3)

841 851 Slightly silty sandy gravel, granule to medium pebble-sized gravel with coarse to very coarse sand and minor 

silt; poorly sorted; angular to well rounded; light olive brown (2.5Y5/3)

851 861 Slightly gravelly sandy silty clay, clay with silt, medium to very coarse sand and minor granule to small pebblesized gravel; poorly sorted; subangular to subrounded; gray (5Y 5/1)

861 871 Sandy silty clay, clay with silt and fine to very coarse sand; moderately sorted; subangular to subrounded; dark 

gray (5Y 4/1)

Table 3. Lithologic shaker logs for Coyote Creek Outdoor Classroom (CCOC) (7S/1E-9L4–8) multiple-well monitoring site, Santa Clara County, California—

Continued

Depth (ft)

Description

 From To
52 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

871 881 Slightly gravelly sandy silty clay, clay with silt, medium to very coarse sand and minor granule to large pebble 

sized gravel; poorly sorted; subrounded to well rounded; dark gray (5Y 4/1) to very dark gray (5Y 3/1)

881 911 Silty sandy gravel, granule to medium pebble-sized gravel with medium to very coarse sand and some silt; 

moderately sorted; subangular to subrounded; olive gray (5Y 5/2)

911 921 Slightly gravelly sandy clayey silt, silt with some clay, coarse to very coarse sand and granule to medium 

pebble-sized gravel; poorly sorted; angular to subrounded; olive gray (5Y 5/2)

921 931 Slightly gravelly sandy clayey silt, silt with clay, coarse to very coarse sand and granule to medium pebblesized gravel; poorly sorted; angular to rounded; dark greenish gray (10Y 3/1)

931 941 Sandy silty clay, clay with silt and minor coarse to very coarse sand; well sorted; subrounded to rounded; dark 

greenish gray (10Y 4/1)

941 951 Gravelly sand, coarse to very coarse, and granule to medium pebble-sized gravel; well sorted; angular to 

subangular; olive gray (5Y 5/2)

951 961 Sandy silty clay, clay with some silt and coarse to very coarse sand; moderately sorted; angular to subrounded; 

dark gray (5Y 4/1)

961 981 Slightly gravelly sandy silty clay, clay with silt, fine to very coarse sand and granule to medium pebble-sized 

gravel; poorly sorted; angular to subrounded; dark gray (5Y 4/1)

981 991 Slightly gravelly sandy silty clay, clay with silt, fine to very coarse sand and granule to small pebble-sized 

gravel; poorly sorted; angular to rounded; dark greenish gray (10Y 4/1)

991 1,006 CORE: Peat above gravel

Table 3. Lithologic shaker logs for Coyote Creek Outdoor Classroom (CCOC) (7S/1E-9L4–8) multiple-well monitoring site, Santa Clara County, California—

Continued

Depth (ft)

Description

 From To
Table 4 53

Table 4. Lithologic shaker and core logs for Willow (WLLO) (7S/1E-19B2–7) multiple-well monitoring site, Santa Clara County California—Continued

Depth (ft)

Description

 From To

0 5 Silty sand, very fine to very coarse sand with silty; well sorted; angular to subrounded; dark olive gray 

(5Y 3/2)

5 15 Sandy silt, silt with very fine to coarse sand; well sorted; subangular to subrounded; olive brown (2.5Y 4/3)

20 25 Silty sand, very fine to very coarse sand with silt; well sorted; subangular to subrounded; olive brown 

(2.5Y 4/3)

25 30 Silty sand, very fine to very coarse sand with silt; well sorted; angular to subrounded; brown (10YR 4/3)

30 35 Sandy clayey silt, silt with clay and very fine to fine sand; very well sorted; angular to subrounded; olive 

brown (2.5Y 4/3)

35 40 Slightly gravelly sandy silt, silt with very fine to coarse sand and minor granule to pebble-sized gravel; 

moderately sorted; angular to subrounded; olive brown (2.5Y 4/3)

45 CORE: Gravelly sand, very fine to very coarse sand and granule to pebble-sized gravel; moderately sorted; 

angular to subrounded; olive (5Y 5/3)

50 CORE: Gravelly sand, very fine to very coarse sand and granule to pebble-sized gravel; poorly sorted; 

angular to subrounded; brown (10YR 4/3)

55 CORE: Silty sand, very fine to medium sand and silt; very well sorted; subangular to subrounded; light olive 

brown (2.5Y 5/4)

60 CORE: Gravelly sand, very fine to medium sand and pebble-sized gravel; poorly sorted; angular to 

subrounded; olive (2.5Y 5/4)

65 CORE: Sandy gravel, pebble-sized gravel with medium to very coarse sand; poorly sorted; angular to 

rounded; light olive brown (2.5 5/3)

65 70 Gravelly sand, medium to very coarse sand with granule to pebble-sized gravel; well sorted; angular to 

rounded; dark grayish brown (2.5Y 4/2)

70 75 Sandy gravel granule to pebble-sized gravel with medium to very coarse sand; poorly sorted; angular to 

rounded; dark grayish brown (2.5Y 4/3)

75 80 Gravelly sand, coarse to very coarse sand with granule to pebble-sized gravel; moderately sorted; angular to 

well-rounded; very dark gray (2.5Y 3/1)

80 85 Gravelly sand, medium to very coarse sand with granule to pebble-sized gravel; well sorted; angular to 

rounded; dark grayish brown (2.5Y 4/2)

85 CORE: Sandy gravel, granule to pebble-sized gravel with fine to very coarse sand; very poorly sorted; 

subangular to rounded; olive brown (2.5Y 4/3)

88 CORE: Sandy gravel, granule to pebble-sized gravel with fine to very coarse sand; very poorly sorted; 

subangular to rounded; olive brown (2.5Y 4/3)

88 CORE: Sandy gravel, granule to pebble-sized gravel with fine to very coarse sand; very poorly sorted; 

subangular to rounded; olive brown (2.5Y 4/3)

90 CORE: Sandy gravel, granule to pebble-sized gravel with fine to very coarse sand; very poorly sorted; 

angular to rounded; olive brown (2.5Y 4/3)

95 CORE: Gravel, pebble-sized gravel; very well sorted; angular to rounded; dark greenish gray 

100 CORE: Gravel, pebble-sized gravel; very well sorted; angular to rounded; dark greenish gray 

100 110 Slightly gravelly sandy silt, silt with very fine to medium sand and minor pebble-sized gravel; poorly sorted; 

subrounded to rounded; olive brown (2.5Y 4/3)

115 CORE: Sand, very fine to very coarse sand; well sorted; subangular to subrounded; dark greenish black

(2.5Y 4/3)

115 120 Slightly gravelly silty sand, very fine to very coarse sand with silt and minor granule to pebble-sized gravel; 

poorly sorted; angular to rounded; dark grayish brown (2.5Y 4/2)

120 130 Slightly gravelly silty sand; very fine to very coarse sand with silt and minor granule to pebble-sized gravel; 

poorly sorted; angular to rounded; olive brown (2.5Y 4/3)

Table 4. Lithologic shaker and core logs for Willow (WLLO) (7S/1E-19B2–7) multiple-well monitoring site, Santa Clara County California

[Altitude of land surface, approximately 95 ft. Depth is in feet below land surface; soil and rock color notation from Munsell Color (1994); drilled by U.S. 

Geological Survey Western Region Research Drilling Unit, using mud-rotary, April 2001; total depth drilled 850 ft.; screened intervals 75–85; 220–240; 

345–365; 435–455; 570–590; 770–790 ft; ft, foot]
54 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

130 140 Sandy gravel, granule to pebble-sized gravel with very fine to very coarse sand; poorly sorted; subangular to 

subrounded; yellowish brown (10YR 5/4)

140 150 Sandy gravel, granule to pebble-sized gravel with medium to very coarse sand; poorly sorted; angular to 

well-rounded; very dark grayish brown (2.5Y 3/2)

150 160 Sandy gravel, granule to pebble-sized gravel with medium to very coarse sand; poorly sorted; angular to 

well-rounded; very dark grayish brown (2.5Y 3/2)

160 170 Clayey silty sandy gravel, granule to pebble-sized gravel with very fine to very coarse sand, silt, and some 

clay; very poorly sorted; angular to well-rounded; light olive brown (2.5Y 5/3)

170 180 Clayey silty sandy gravel; granule to pebble-sized gravel with very fine to very coarse sand, silt, and clay; 

very poorly sorted; angular to rounded; light olive brown (2.5Y 5/4) dark olive gray (5Y 3/2)

180 200 Sandy gravel, granule to pebble-sized gravel with very fine to very coarse sand; moderately sorted; angular to 

subrounded; dark grayish brown (2.5Y 4/2)

200 210 Slightly sandy gravel, granule to pebble-sized gravel with minor coarse to9 very coarse sand; well sorted; 

angular to rounded; dark yellowish brown (10YR 4/4)

210 220 Silty sandy gravel, granule to pebble-sized gravel with very fine to very coarse sand and silt; poorly sorted; 

angular to rounded; olive brown (2.5Y 4/3)

220 230 Gravelly silty sand, very fine to very coarse sand with silt and granule-sized gravel; poorly sorted; angular to 

rounded; light olive brown (2.5Y 5/4)

230 240 Sandy gravel, granule to pebble-sized gravel with medium to very coarse sand; moderately sorted; angular to 

rounded; dark grayish brown (2.5Y 4/2)

240 250 Gravel, pebble-sized gravel; very well sorted; subangular to rounded; dark grayish brown (2.5Y 4/2)

250 260 Gravelly silty sand, very fine to very coarse sand with silt and granule to pebble-sized gravel; poorly sorted; 

angular to well-rounded; light olive brown (2.5Y 5/4)

260 280 Gravelly silty sand, very fine to very coarse sand with silt and granule to pebble-sized gravel; poorly sorted; 

subangular to rounded; light olive brown (2.5Y 5/4)

280 290 Gravelly silty sand, very fine to very coarse sand with silt and granule to pebble-sized gravel; poorly sorted; 

angular to rounded; light olive brown (2.5Y 5/4)

300 CORE: Silty sand, very fine to medium-sized sand with some silt; very well sorted; angular to subrounded; 

olive brown (2.5Y 4/3)

305 CORE: Sandy silty clay, clay with silt and very fine to fine sand; well sorted; subangular to subrounded; olive 

gray (5Y 4/2)

310 CORE: Silty sand, very fine to medium sand and silt; well sorted; subangular to subrounded; olive gray 

(5Y 4/2)

315 CORE: Sandy silty clay, clay with silt and very fine to coarse sand; moderately sorted; subangular to 

rounded; olive gray (2.5Y 4/3)

315 320 Gravelly silty sand, very fine to very coarse sand with silt and granule-sized gravel; poorly sorted; subangular 

to subrounded; olive gray (5Y 4/2)

320 330 Gravelly sand, very fine to very coarse sand with granule to pebble sized gravel; poorly sorted; angular to 

rounded; olive (5Y 5/3)

330 340 Sandy gravel, granule to pebble-sized gravel with fine to very coarse sand; poorly sorted; subangular to well 

rounded; olive (5Y 4/3)

340 350 Silty sandy gravel, granule to pebble-sized gravel with very fine to very coarse sand and silt; very poorly 

sorted; angular to well-rounded; light olive brown (2.5Y 5/3)

350 360 Sandy gravel, granule to pebble-sized gravel with fine very coarse sand; poorly sorted; angular to rounded; 

dark olive gray (5Y 3/2)

360 370 Silty sandy gravel, granule to pebble-sized gravel with very fine to very coarse sand and silt; very poorly 

sorted; angular to rounded; light olive brown (2.5Y 5/3)

370 380 Gravel, pebble-sized gravel; well sorted; subangular to subrounded; light yellowish brown (2.5Y 5/3)

Table 4. Lithologic shaker and core logs for Willow (WLLO) (7S/1E-19B2–7) multiple-well monitoring site, Santa Clara County California—Continued

Depth (ft)

Description

 From To
Table 4 55

380 390 Silty sandy gravel, granule to pebble-sized gravel with very fine to very coarse sand and silt; very poorly 

sorted; subangular to rounded; olive brown (2.5Y 4/3) to dark olive brown (2.5Y 3/3)

390 400 Gravelly silty sand, very fine to very coarse sand with silt and granule to pebble-sized gravel; very poorly 

sorted; subangular to rounded; olive brown (2.5Y 4/3)

400 410 Gravelly silty sand, very fine to very coarse sand with silt and granule to pebble-sized gravel; poorly sorted; 

angular to subrounded; olive brown (2.5Y 4/3)

414 CORE: Sandy gravel, granule to pebble-sized gravel with very fine to very coarse sand; poorly sorted; 

angular to subrounded; olive brown (2.5Y 4/3)

414 420 Silty sandy gravel, granule to pebble-sized gravel with very fine to very coarse sand and some silt; poorly 

sorted; angular to rounded; light olive brown (2.5Y 5/3)

420 430 Sandy gravel, granule to pebble-sized gravel with very fine to very coarse sand; moderately sorted; angular to 

rounded; light olive brown (2.5Y 5/3)

430 440 Sandy gravel, granule to pebble-sized gravel with fine to very coarse sand; moderately sorted; angular to 

rounded; olive brown (2.5Y 4/3); accessory: red chert

440 450 Silty sandy gravel, granule to pebble-sized gravel with very fine to very coarse sand and some silt; poorly 

sorted; angular to rounded; olive brown (2.5Y 4/3)

450 460 Sandy gravel, granule to pebble-sized gravel with very fine to very coarse sand; moderately sorted; angular to 

rounded; very dark grayish brown (2.5Y 3/2)

460 470 Sandy gravel, granule to pebble-sized gravel with very fine to very coarse sand; moderately sorted; angular to 

rounded; very dark grayish brown (2.5Y 3/2)

470 480 Sandy gravel, granule to pebble-sized gravel with very fine to very coarse sand; moderately sorted; angular to 

rounded; light olive brown (2.5Y 5/4)

480 490 Sandy gravel, granule to pebble-sized gravel with very fine to very coarse sand; moderately sorted; angular to 

rounded; light olive brown (2.5Y 5/4)

493 CORE: Sandy silty clay, clay with some silt and some very fine to very coarse sand; poorly sorted; 

subangular to subrounded; dark grayish brown (10YR 4/2)

493 500 Gravel, pebble-sized gravel; well sorted; subrounded; dark greenish gray (10YR 3/1)

500 510 Sandy gravel, granule to pebble-sized gravel with fine to very coarse sand; moderately sorted; angular to 

subrounded; olive brown (2.5Y 4/8)

510 520 Silty sandy gravel, granule to pebble-sized gravel with very fine to very coarse sand and silt; very poorly 

sorted; angular to rounded; brown (10YR 4/3)

520 522.5 Silty sandy gravel, granule to pebble-sized gravel with fine to very coarse sand and silt; very poorly sorted; 

angular to rounded; brown (10YR 4/3)

522.5 530 Silty sandy gravel, granule to pebble-sized gravel with very fine to very coarse sand and silt; very poorly 

sorted; angular to rounded; dark grayish brown (2.5Y 4/2)

530 540 Slightly sandy gravel, granule to pebble-sized gravel with minor very coarse sand; poorly sorted; angular to 

subrounded; greenish gray (5GY 5/1); accessory: red chert

540 550 Slightly sandy gravel, granule to pebble-sized gravel with minor very coarse sand; poorly sorted; angular to 

subrounded; greenish gray (5GY 5/1); ); accessory: red chert

550 560 Sandy gravel, granule to pebble-sized gravel with medium to very coarse sand; poorly sorted; angular to 

rounded; light olive brown (2.5Y 5/4)

560 570 Sandy gravel, granule to pebble-sized gravel with medium to very coarse sand; poorly sorted; angular to 

rounded; light olive brown (2.5Y 5/4)

570 580 Gravel, pebble-sized gravel; well sorted; angular to subangular; dark greenish gray (10GY 4/1); accessory: 

chert

580 590 Gravel, pebble-sized gravel; well sorted; angular to rounded; greenish gray (5GY 5/1)

592.5 CORE: Silty sandy gravel, granule to pebble-sized gravel with very fine to very coarse sand and silt; very 

poorly sorted; angular to subrounded; dark grayish brown (2.5Y 4/2)

595.5 CORE: Silty sandy gravel, granule to pebble-sized gravel with very fine to very coarse sand and silt; very 

poorly sorted; angular to rounded; olive brown (2.5Y 4/3)

Table 4. Lithologic shaker and core logs for Willow (WLLO) (7S/1E-19B2–7) multiple-well monitoring site, Santa Clara County California—Continued

Depth (ft)

Description

 From To
56 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

598 CORE: Silty sandy gravel, granule to pebble-sized gravel with very fine to very coarse sand and silt; very 

poorly sorted; angular to subrounded; olive brown (2.5Y 4/2)

600 CORE: Silty sandy gravel, granule to pebble-sized gravel with very fine to very coarse sand and silt; very 

poorly sorted; angular to subrounded; olive brown (2.5Y 4/3)

600 610 Silty sandy gravel, granule to pebble-sized gravel with very fine to very coarse sand and silt; very poorly 

sorted; angular to subrounded; olive brown (2.5Y 4/3)

610 620 Silty sandy gravel, granule to pebble-sized gravel with very fine to very coarse sand and silt; very poorly 

sorted; angular to subrounded; light olive brown (2.5Y 5/3)

623 CORE: Silty sandy gravel, granule to pebble-sized gravel with very fine to very coarse sand and silt; very 

poorly sorted; angular to subrounded; olive brown (2.5Y 5/4)

623 630 Silty sandy gravel, granule to pebble-sized gravel with very fine to very coarse sand and silt; very poorly 

sorted; angular to subrounded; light olive brown (2.5Y 5/3)

630 640 Gravel, pebble-sized gravel; well sorted; angular to subrounded; dark olive gray (5Y 3/2)

640 650 Silty sandy gravel, granule to pebble-sized gravel with very fine to very coarse sand and silt; very poorly 

sorted; angular to rounded; light olive brown (2.5Y 5/3); accessory: red chert

650 660 Silty sandy gravel, granule to pebble-sized gravel with very fine to very coarse sand and silt; very poorly 

sorted; angular to subrounded; light olive brown (2.5Y 5/3); accessory: red chert

660 670 Silty sandy gravel, granule to pebble-sized gravel with very fine to very coarse sand and silt; very poorly 

sorted; angular to rounded; olive brown (2.5Y 4/3); accessory: red chert

673 CORE: Silty clay, clay with silt; very well sorted; angular to subrounded; light olive brown (2.5Y 5/3)

678 CORE: Silty sandy gravel, granule to pebble-sized gravel with very fine to very coarse sand and silt; very 

poorly sorted; angular to subangular; light olive brown (2.5Y 5/3)

678 680 Silty sandy gravel, granule to pebble-sized gravel with very fine to very coarse sand and minor silt; very 

poorly sorted; angular to subrounded; light olive brown (2.5Y 5/3)

680 690 Silty sandy gravel, granule to pebble-sized gravel with very fine to very coarse sand and minor silt; very 

poorly sorted; angular to rounded; olive brown (2.5Y 4/3)

690 700 Silty sandy gravel, granule to pebble-sized gravel and very fine to very coarse sand and silt; very poorly 

sorted; angular to rounded; dark grayish brown (2.5Y 4/2)

708 CORE: Sandy silt, silt with very fine sand; very well sorted; angular to subrounded; light olive brown 

(2.5Y 5/3)

708 720 Silty sandy gravel, granule to pebble-sized gravel and very fine to very coarse sand and silt; very poorly 

sorted; angular to rounded; light olive brown (2.5Y 4/3)

720 730 Silty sandy gravel; granule to pebble sized gravel and very fine to very coarse sand and silt; very poorly 

sorted; angular to rounded; light olive brown (2.5Y 5/3)

 738 CORE: Sandy silty clay; clay with silt and very fine sand; very well sorted; angular to subrounded; brown 

(10YR 4/3) 

 741 CORE: Sandy silty clay; clay with silt and very fine sand; very well sorted; angular to subrounded; olive 

brown (2,5Y 4/3)

 746 CORE: Silty sand; very fine to medium sand with silt; well sorted; angular to subrounded; olive brown 

(2.5Y 4/3)

 750 CORE: Sandy silty clay; clay with silt and very fine to medium silt; well sorted; angular to subrounded; 

brown (10YR 4/3)

 755 CORE: Gravelly silty sand; very fine to very coarse sand with silt and granule to pebble sized gravel; poorly 

sorted; angular to subrounded; brown (10YR 4/3)

 760 CORE: Clayey silty sand; very fine to fine sand with silt and clay; very well sorted; angular to rounded; 

brown (10YR 4/3)

760 770 Silty sand; very fine to very coarse sand with silt; moderately sorted; angular to rounded; dark grayish brown 

(10YR 4/2)

Table 4. Lithologic shaker and core logs for Willow (WLLO) (7S/1E-19B2–7) multiple-well monitoring site, Santa Clara County California—Continued

Depth (ft)

Description

 From To
Table 4 57

770 780 Gravelly silty sand; very fine to very coarse sand with silt and granule sized gravel; very poorly sorted; 

angular to subrounded; olive brown (2.5Y 4/3); accessory: Serpentenite

785 CORE: Clayey silty sand; very fine to fine sand with silt and some clay; very well sorted; angular to 

subrounded; brown (10YR 4/3)

785 790 Silty sandy gravel; granule to pebble sized gravel with very fine to very coarse sand and silt; very poorly 

sorted; angular to subrounded; dark grayish brown (2.5Y 4/2)

 790 800 Slightly silty sandy gravel; granule to pebble sized gravel with minor very fine to very coarse sand and minor 

silt; poorly sorted; angular to subrounded; olive gray (5Y 4/2)

800 810 Silty sandy gravel; granule to pebble sized gravel with very fine to very coarse sand and silt; poorly sorted; 

angular to subrounded; olive brown (2.5Y 4/3)

810 820 Sandy silty clay; clay with silt and very fine to very coarse sand; poorly sorted; angular to subrounded; olive 

gray (5Y 4/2)

820 830 Sandy silt; silty with very fine to very coarse sand; poorly sorted; angular to subrounded; olive gray 

(5Y 4/2); accessory: red chert

831 CORE: Gravel; granule to pebble sized gravel; well sorted; angular to subangular; greenish-gray

(10GY 6/1); Serpentenite with iron stained microfractures

840.5 CORE: Sandy gravel; granule to pebble sized gravel with fine to very coarse sand; well sorted; angular to 

subangular; light greenish gray (5GY 7/1); Serpentenite with iron stained microfractures

841 CORE: Sandy gravel; granule to pebble sized gravel with fine to very coarse sand; well sorted; angular to 

subangular; light greenish gray (5GY 7/1); Serpentenite with iron stained microfractures

841.5 CORE: Sandy gravel; granule to pebble sized gravel with fine to very coarse sand; well sorted; angular to 

subangular; light greenish gray (5GY 7/1); Serpentenite with iron stained microfractures

Table 4. Lithologic shaker and core logs for Willow (WLLO) (7S/1E-19B2–7) multiple-well monitoring site, Santa Clara County California—Continued

Depth (ft)

Description

 From To
58 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

Table 5. Lithologic shaker and core logs for McGlincey (MGCY) (7S/1W-35L12–16) multiple-well monitoring site, Santa Clara County, California—Continued

 Depth (ft)

Description

From To 

0 9 Sandy gravel; granule- to medium pebble-sized gravel with medium to very coarse sand; moderately sorted; 

subangular to rounded; very dark grayish brown (2.5Y 3/2)

9 14 Sandy gravel; granule- to medium pebble-sized gravel with medium to very coarse sand; poorly sorted; angular to 

rounded; very dark grayish brown (2.5Y 3/2) 

14 19 Sandy gravel; granule- to small pebble-sized gravel with medium to very coarse sand; moderately sorted; angular 

to rounded; dark olive brown (2.5Y 3/3)

19 21 Slightly gravelly sand; medium to very coarse sand with minor granule-sized gravel; well sorted; very angular to 

subangular; olive gray (5Y 4/2) 

21 24 Sandy gravel; granule- to medium pebble-sized gravel with medium to very coarse sand; poorly sorted; subangular 

to rounded; olive gray (5Y 4/2)

24 29 Gravelly sand; medium to very coarse sand with granule-sized gravel; well sorted; subangular to rounded; olive 

brown (2.5Y 4/3)

34 CORE: Silty sandy gravel; granule- to large pebble-sized gravel with some very fine to very coarse sand and silt; 

very poorly sorted; subangular to rounded; olive (5Y 4/4)

39 CORE: Silty sandy gravel; granule- to very large pebble-sized gravel with some very fine to very coarse sand and 

silt; very poorly sorted; angular to rounded; olive (5Y 4/4) 

44 CORE: Sandy gravel; granule- to small pebble-sized gravel with coarse to very coarse sand; well sorted; angular 

to rounded; very dark gray (5Y 3/1)

46.5 CORE: Sandy gravel; granule- to medium pebble-sized gravel with medium to very coarse sand; poorly sorted; 

angular to rounded; very dark gray (10YR 3/1)

49 CORE: Sandy gravel; granule- to medium pebble-sized gravel with medium to very coarse sand; poorly sorted; 

angular to subrounded; very dark gray (10YR 3/1)

54 CORE: Silty gravel; granule- to large pebble-sized gravel with some silt; well sorted; angular to rounded; dark 

yellowish brown (10YR 4/4)

59 CORE: Silty sandy gravel; granule- to very large pebble-sized gravel with some very fine to very coarse sand and 

silt; very poorly sorted; angular to subrounded; dark yellowish brown (10YR 4/4)

64 CORE: Silty sandy gravel; granule- to very large pebble-sized gravel with some very fine to very coarse sand and 

silt; very poorly sorted; angular to subrounded; dark yellowish brown (10YR 4/4)

69 CORE: Silty sandy gravel; granule- to large pebble-sized gravel with some very fine to very coarse sand and silt; 

very poorly sorted; subangular to subrounded; dark yellowish brown (10YR 4/4)

69 89 Sandy gravel; granule- to medium pebble-sized gravel with very fine to very coarse sand; poorly sorted; angular to 

rounded; olive brown (2.5Y 4/3)

89 109 Sandy gravel; granule- to medium pebble-sized gravel with very fine to very coarse sand; poorly sorted; angular to 

rounded; olive brown (2.5Y 4/3)

109 129 Sandy gravel; granule- to medium pebble-sized gravel with very fine to very coarse sand; poorly sorted; angular to 

rounded; olive brown (2.5Y 4/3)

131.5 CORE: Silty sandy gravel; granule- to large pebble-sized gravel with some very fine to very coarse sand and silt; 

very poorly sorted; angular to rounded; dark yellowish brown (10YR 4/4)

134 CORE: Silty sandy gravel; granule- to large pebble-sized gravel with some very fine to very coarse sand and silt; 

very poorly sorted; angular to rounded; dark yellowish brown (10YR 4/4)

136.5 CORE: Silty sandy gravel; granule- to large pebble-sized gravel with some very fine to very coarse sand and silt; 

very poorly sorted; angular to subrounded; very dark grayish brown (10YR 3/2

139 CORE: Silty sandy gravel; granule-to medium pebble-sized gravel with some very fine to very coarse sand and 

silt; very poorly sorted; angular to rounded; olive brown (2.5Y 4/4)

141.5 CORE: Silty sandy gravel; granule- to large pebble-sized gravel with some very fine to very coarse sand and silt; 

very poorly sorted; subangular to rounded; olive brown (2.5Y 4/4)

Table 5. Lithologic shaker and core logs for McGlincey (MGCY) (7S/1W-35L12–16) multiple-well monitoring site, Santa Clara County, California

[Altitude of land surface, approximately 213 ft; depth is in feet below land surface; soil and rock color notation from Munsell Color (1994); drilled by U.S. 

Geological Survey Western Region Research Drilling Unit, using mud-rotary, April 2001; total depth drilled 873 ft; screened intervals 160–180; 280–300; 

90–410; 510–530; 630–650 ft; ft, foot]
Table 5 59

149 CORE: Silty sandy gravel; granule- to large pebble-sized gravel with some very fine to very coarse sand and silt; 

very poorly sorted; angular to subrounded; dark yellowish brown (10YR 3/6)

151.5 CORE: Silty sand; very fine to fine sand with silt; well sorted; subangular to subrounded; light olive brown (2.5Y 

5/4)

154 CORE: Silty sand; very fine to medium sand with silt; well sorted; angular to rounded; olive brown 

(2.5Y 4/4)

159 CORE: Silty sandy gravel; granule- to large pebble-sized gravel with some very fine to very coarse sand and silt; 

very poorly sorted; angular to subrounded; brown (10YR 4/3)

164 CORE: Silty sandy gravel; granule- to large pebble-sized gravel with very fine to very coarse sand and silt; very 

poorly sorted; subangular to subrounded; light olive brown (2.5Y 5/4)

169 CORE: Silty sandy gravel; granule- to large pebble-sized gravel with very fine to very coarse sand and silt; very 

poorly sorted; subangular to subrounded; light olive brown (2.5Y 5/4); 

169 179 Gravelly sand; very fine to very coarse sand with granule- to small pebble-sized gravel; moderately sorted; angular 

to subrounded; light olive brown (2.5Y 5/4)

179 189 Sandy gravel; granule- to medium pebble-sized gravel with very fine to very coarse sand; moderately sorted; 

angular to subrounded; light olive brown (2.5Y 5/4)

189 209 Sandy gravel; granule- to medium pebble-sized gravel with very fine to very coarse sand; moderately sorted; 

angular to subrounded; light olive brown (2.5Y 5/4)

209 219 Sandy gravel; granule- to large pebble-sized gravel with very fine to very coarse sand; poorly sorted; angular to 

subrounded; light olive brown (2.5Y 5/4)

219 229 Gravelly sand; fine to very coarse sand with granule- to medium pebble-sized gravel; moderately sorted; angular to 

subrounded; light olive brown (2.5Y 5/4)

234 CORE: Silty sandy gravel; granule- to large pebble-sized gravel with very fine to very coarse sand and silt; very 

poorly sorted; angular to subrounded; dark yellowish brown (10YR 4/4)

239 CORE: Silty sandy gravel; granule- to very large pebble-sized gravel with very fine to very coarse sand and silt; 

very poorly sorted; angular to subangular; dark yellowish brown (10YR 4/4); graywacke

241 CORE: Gravel; very large pebble-sized gravel; only one piece; subangular; olive brown (2.5Y 4/3); graywacke

249 CORE: Silty sandy gravel; granule- to large pebble-sized gravel with very fine to very coarse sand and silt; very 

poorly sorted; angular to subangular; light olive brown (2.5Y 5/6); sandstone

251.5 CORE: Slightly gravelly silty sand; mostly very fine to medium sand with silt and minor coarse to very coarse 

sand and small to medium pebble-sized gravel; moderately sorted; subangular to rounded; dark yellowish brown 

(10YR 4/6)

251.5 259 Gravelly silty sand; very fine to very coarse sand with silt and some granule-sized gravel; moderately sorted; 

subangular to rounded; light olive brown (2.5Y 5/6)

259 270 Gravelly silty sand; very fine to very coarse sand with silt and some granule- to small pebble-sized gravel; 

moderately sorted; subangular to rounded; light olive brown (2.5Y 5/6)

270 280 Sandy gravel; granule- to medium pebble-sized gravel with very fine to very coarse sand; poorly sorted; very 

angular to subrounded; olive brown (2.5Y 4/3)

280 290 Sandy gravel; granule- to medium pebble-sized gravel with very fine to very coarse sand; poorly sorted; very 

angular to subrounded; olive brown (2.5Y 4/3)

290 300 Sandy gravel; granule- to medium pebble-sized gravel with very fine to very coarse sand; poorly sorted; very 

angular to rounded; olive brown (2.5Y 4/3)

300 310 Sandy gravel; granule- to medium pebble-sized gravel with very fine to very coarse sand; poorly sorted; very 

angular to subrounded; olive brown (2.5Y 4/3)

314 CORE: Silty sandy gravel; granule- to medium pebble-sized gravel with very fine to very coarse sand and silt; 

very poorly sorted; angular to subrounded; olive brown (2.5Y 4/3)

317.5 CORE: Silty sandy gravel; granule- to large pebble-sized gravel with very fine to very coarse sand and silt; very 

poorly sorted; angular to subrounded; olive brown (2.5Y 4/4); gravel is quartz wacke

320 CORE: Silty sandy gravel; granule- to large pebble-sized gravel with very fine to very coarse sand and silt; very 

poorly sorted; subangular to subrounded; olive brown (2.5Y 4/4); gravel is graywacke

Table 5. Lithologic shaker and core logs for McGlincey (MGCY) (7S/1W-35L12–16) multiple-well monitoring site, Santa Clara County, California—Continued

 Depth (ft)

Description

From To 
60 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

322.5 CORE: Sandy silt; silt with very fine to very coarse sand; well sorted; light olive brown (2.5Y 5/6); white and lime 

green lithic clast of unknown origin

325 CORE: Sandy silt; silt with very fine to medium sand; well sorted; brown (7.5YR 5/4)

329 CORE: Silty sandy gravel; granule- to large pebble-sized gravel with very fine to very coarse sand and silt; very 

poorly sorted; angular to subrounded; olive brown (2.5Y 4/4); gravel is wacke

331 CORE: Sandy clayey silt; silt with clay and very fine to medium sand; well sorted; light olive brown 

(2.5Y 5/6)

334 CORE: Sandy clayey silt; silt with clay and very fine to medium sand; well sorted; light olive brown 

(2.5Y 5/6)

339 CORE: Sandy clayey silt; silt with clay and very fine to medium sand; well sorted; light olive brown 

(2.5Y 5/6)

341.5 CORE: Silty sand; very fine to medium sand and silt; well sorted; subangular to rounded; light olive brown (2.5Y 

5/6)

341.5 349 Sandy gravel; granule- to small pebble-sized gravel with very fine to very coarse sand; very poorly sorted; angular 

to subrounded; olive brown (2.5Y 4/3)

349 359 Sandy gravel; granule- to small pebble-sized gravel with very fine to very coarse sand; very poorly sorted; angular 

to subrounded; olive brown (2.5Y 4/3)

359 369 Sandy gravel; granule- to medium pebble-sized gravel with very fine to very coarse sand; very poorly sorted; 

angular to subrounded; olive brown (2.5Y 4/3)

369 379 Sandy gravel; granule- to small pebble-sized gravel with very fine to coarse sand; very poorly sorted; angular to 

subrounded; olive brown (2.5Y 4/3)

379 389 Sandy gravel; granule- to medium pebble-sized gravel with very fine to very coarse sand; very poorly sorted; 

angular to rounded; olive brown (2.5Y 4/3)

389 399 Sandy gravel; granule- to large pebble-sized gravel with very fine to very coarse sand; very poorly sorted; angular 

to subrounded; dark yellowish brown (10YR 4/4)

399 410 Sandy gravel; granule- to large pebble-sized gravel with medium to very coarse sand; poorly sorted; subangular to 

subrounded; dark yellowish brown (10YR 4/4)

412 CORE: Silty sandy gravel; granule- to large pebble-sized gravel with very fine to very coarse sand and silt; very 

poorly sorted; subangular to subrounded; olive brown (2.5Y 4/4)

414 CORE: Silty sandy gravel; granule- to medium pebble-sized gravel with very fine to very coarse sand and silt; 

very poorly sorted; angular to rounded; light olive brown (2.5Y 5/4)

419 CORE: Silty sandy gravel; granule- to medium pebble-sized gravel with very fine to very coarse sand and silt; 

very poorly sorted; angular to subrounded; light olive brown (2.5Y 5/4); accessory: red chert

421.5 CORE: Slightly gravelly silty sand; very fine to coarse sand with silt and some minor granule- to small pebblesized gravel; poorly sorted; angular to subrounded; light olive brown (2.5Y 5/4)

424 CORE: Sandy clayey silt; silt with clay and very fine to coarse sand; well sorted; dark yellowish brown (10YR 

4/4)

429 CORE: Sandy clayey silt; silt with clay and very fine to medium sand; well sorted; dark yellowish brown (10YR 

4/4)

434 CORE: Silty sandy gravel; granule- to large pebble-sized gravel with very fine to very coarse sand and silt; very 

poorly sorted; angular to rounded; light olive brown (2.5Y 5/4)

436.5 CORE: Silty sandy gravel; granule- to large pebble-sized gravel with very fine to very coarse sand and silt; very 

poorly sorted; angular to subrounded; dark yellowish brown (10YR 4/4)

439 CORE: Silty sandy gravel; granule- to large pebble-sized gravel with very fine to very coarse sand and silt; very 

poorly sorted; angular to subrounded; dark yellowish brown (10YR 4/4); gravel is graywacke

439 449 Sandy gravel; granule- to medium pebble-sized gravel with very fine to very coarse sand; poorly sorted; angular to 

subrounded; olive brown (2.5Y 4/4)

449 459 Sandy gravel; granule- to medium pebble-sized gravel with very fine to very coarse sand; poorly sorted; angular to 

subrounded; olive brown (2.5Y 4/4)

Table 5. Lithologic shaker and core logs for McGlincey (MGCY) (7S/1W-35L12–16) multiple-well monitoring site, Santa Clara County, California—Continued

 Depth (ft)

Description

From To 
Table 5 61

459 469 Gravelly silt; silt with granule- to small pebble-sized gravel; very poorly sorted; olive brown 

(2.5Y 4/4)

469 479 Silty sandy gravel; granule- to medium pebble-sized gravel with very fine to very coarse sand and silt; very poorly 

sorted; angular to subrounded; brown (10YR 4/3)

479 489 Sandy gravel; granule- to medium pebble-sized gravel with very fine to very coarse sand; very poorly sorted; 

angular to subrounded; olive brown (2.5Y 4/4)

491.5 CORE: Slightly gravelly silty sand; very fine to very coarse sand with silt and minor 

granule-sized gravel; moderately sorted; angular to rounded; dark yellowish brown (10YR 4/4)

494 CORE: Slightly gravelly silty sand; very fine to very coarse sand with silt and minor 

granule-sized gravel; moderately sorted; angular to rounded; dark yellowish brown (10YR 4/4)

499 CORE: Slightly gravelly silty sand; very fine to very coarse sand with silt and minor granule-sized gravel; 

moderately sorted; angular to rounded; dark yellowish brown (10YR 4/4)

504 CORE: Slightly gravelly silty sand; very fine to very coarse sand with silt and minor granule- to small pebblesized gravel; moderately sorted; angular to subrounded; dark yellowish brown (10YR 4/4)

509 CORE: Sandy silt; silt with very fine to medium sand; well sorted; dark yellowish brown (10YR 4/4)

514 CORE: Silty sandy gravel; granule- to small and very large pebble-sized gravel with some very fine to very coarse 

sand and silt; very poorly sorted; subangular to rounded; yellowish brown (10YR 5/4); gravel is graywacke

519 CORE: Silty sandy gravel; granule- to large pebble-sized gravel with very fine to very coarse sand and silt; very 

poorly sorted; subangular to subrounded; brown (10YR 4/3)

529 CORE: Slightly sandy gravel; granule- to medium pebble-sized gravel with minor fine to very coarse sand; very 

well sorted; angular to rounded; dark olive brown (2.5Y 3/3)

529 539 Sandy gravel; granule- to medium pebble-sized gravel with very fine to very coarse sand; poorly sorted; angular to 

rounded; dark olive brown (2.5Y 3/3)

539 549 Silty sandy gravel; granule- to medium pebble-sized gravel with very fine to very coarse sand and silt; very poorly 

sorted; angular to rounded; brown (10YR 4/3)

549 559 Sandy gravel; granule- to medium pebble-sized gravel with very fine to very coarse sand; poorly sorted; angular to 

subrounded; brown (10YR 4/3)

559 569 Silty sandy gravel; granule- to medium pebble-sized gravel with very fine to very coarse sand and silt; very poorly 

sorted; angular to rounded; brown (10YR 4/3)

569 579 Slightly gravelly sandy clayey silt; silt with clay and some very fine to medium sand and granule- to small pebblesized gravel; poorly sorted; brown (10YR 4/3)

581.5 CORE: Silty sand; very fine to very coarse sand with silt; moderately sorted; subangular to subrounded; dark 

greenish gray (10Y 4/1)

584 CORE: Sandy silt; silt with very fine to medium sand; well sorted; dark greenish gray (10Y 4/1) 

589 CORE: Sandy silty clay; clay with silt and some very fine to medium sand; well sorted; olive gray (5Y 4/2)

594 CORE: Sandy silty clay; clay with silt and some very fine to medium sand; moderately sorted; olive gray (5Y 4/2)

599 CORE: Sandy clayey silt; silt with some clay and very fine to fine sand; well sorted; dark greenish gray (5GY 4/1) 

604 CORE: Slightly clayey sandy silt; silt with very fine to medium sand and minor clay; well sorted; dark greenish 

gray (5GY 4/1) 

609 CORE: Sandy silt; silt with very fine to fine sand; very well sorted; dark greenish gray (10Y 4/1) 

614 CORE: Silty sand; very fine to coarse sand with silt; well sorted; subangular to subrounded; dark greenish gray 

(10Y 3/1) 

619 CORE: Silty sandy gravel; granule- to large pebble-sized gravel with very fine to very coarse sand and silt; very 

poorly sorted; subangular to rounded; dark greenish gray (10Y 4/1); accessory: packstone

624 CORE: Silty sandy gravel; granule- to large pebble-sized gravel with very fine to very coarse sand and silt; very 

poorly sorted; subangular to rounded; dark greenish gray (10Y 4/1); accessory: red chert

629 CORE: Silty sand; very fine to fine sand with silt; very well sorted; subangular to subrounded; dark greenish gray 

(10Y 4/1) 

634 CORE: Silty sand; very fine to fine sand with silt; very well sorted; subangular to subrounded; dark greenish gray 

(10Y 4/1) 

Table 5. Lithologic shaker and core logs for McGlincey (MGCY) (7S/1W-35L12–16) multiple-well monitoring site, Santa Clara County, California—Continued

 Depth (ft)

Description

From To 
62 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

639 CORE: Slightly sandy gravel; granule- to medium pebble-sized gravel with minor very fine to very coarse sand; 

well sorted; angular to subrounded; dark greenish gray (10Y3/1); accessory: red chert

639 649 Sandy gravel; granule- to medium pebble-sized gravel with very fine to very coarse sand; poorly sorted; angular to 

subrounded; dark greenish gray (10Y3/1)

649 659 Slightly sandy gravel; granule- to medium pebble-sized gravel with minor very fine to very coarse sand; well 

sorted; angular to rounded; dark greenish gray (10Y 3/1); accessory: red chert

659 669 Sandy gravel; granule- to small pebble-sized gravel with very fine to very coarse sand; poorly sorted; angular to 

rounded; dark greenish gray (10Y 3/1); accessory: red chert

669 679 Slightly gravelly sand; mainly very fine to medium sand with some coarse to very coarse sand and minor granulesized gravel; well sorted; angular to rounded; olive (5Y 4/3)

679 689 Silty sandy gravel; granule- to small pebble-sized gravel with very fine to very coarse sand and silt; very poorly 

sorted; subangular to rounded; dark grayish brown (2.5Y 4/2) 

689 699 Silty sandy gravel; granule- to small pebble-sized gravel with very fine to very coarse sand and silt; very poorly 

sorted; subangular to rounded; dark grayish brown (2.5Y 4/2) 

704 CORE: Sandy silt; silt with very fine to fine sand; very well sorted; olive gray (5Y 4/2)

709 CORE: Sandy silt; silt with very fine to fine sand; very well sorted; dark greenish gray (10Y 4/1) 

714 CORE: Sandy silt; silt with very fine to fine sand; very well sorted; dark greenish gray (10Y 4/1) 

719 CORE: Sandy clayey silt; silt with clay and very fine sand; very well sorted; dark greenish gray (10Y 4/1) 

724 CORE: Sandy clayey silt; silt with clay and very fine sand; very well sorted; dark greenish gray (10Y 4/1) 

729 CORE: Gravel; small to large pebble-sized gravel; very well sorted; angular to subrounded; dark greenish gray 

(5GY 4/1); metamorphosed serpentenite

729 739 Slightly gravelly sandy silt; silt with very fine to very coarse sand and granule- to small pebble-sized gravel; very 

poorly sorted; dark greenish gray (10Y 4/1) 

739 749 Slightly sandy silty gravel; granule- to medium pebble-sized gravel with silt and minor very fine to fine sand; 

moderately sorted; subangular to rounded; dark grayish brown (2.5Y 4/2) 

749 759 Sandy silty clay; clay with silt and very fine to very coarse sand; very poorly sorted; olive gray (5Y 4/2)

759 769 Sandy gravel; granule- to medium pebble-sized gravel with fine to very coarse sand; poorly sorted; angular to 

subrounded; dark grayish brown (2.5Y 4/2) 

774 CORE: Gravelly sand; very fine to coarse sand with some granule- to medium pebble-sized gravel; well sorted; 

angular to subrounded; greenish gray (10Y 5/1); accessory: red chert

779 CORE: Sandy gravel; granule- to medium pebble-sized gravel with very fine to very coarse sand; very poorly 

sorted; angular to rounded; dark greenish gray (10Y 4/1); accessory: red chert

779 784 Sandy gravel; granule- to medium pebble-sized gravel with very fine to very coarse sand; very poorly sorted; 

angular to rounded; dark greenish gray (10Y 4/1) 

789 CORE: Silty sand; very fine to medium sand with silt; well sorted; subangular to subrounded; olive (5Y 5/4)

794 CORE: Clayey silty sand; very fine to fine sand with silt and some clay; well sorted; subangular to subrounded; 

olive (5Y 5/3)

794 809 Slightly gravelly sandy silty clay; clay with silt and very fine to very coarse sand and minor granule-sized gravel; 

very poorly sorted; olive gray (5Y 4/2)

809 819 Silty clay; clay with silt; very well sorted; dark olive gray (5Y 3/2)

819 829 Silty clay; clay with silt; very well sorted; dark olive gray (5Y 3/2)

831.5 CORE: Sandy silt; silt with very fine to fine sand; very well sorted; black (5Y 2.5/1) 

831.5 839 Sandy silt; silt with very fine to fine sand; very well sorted; very dark gray (5Y 3/1)

839 849 Sandy silt; silt with very fine to fine sand; very well sorted; very dark gray (5Y 3/1)

852.5 CORE: Sandy silt; silt with very fine to fine sand; very well sorted; very dark gray (5Y 3/1); accessory: fibrous 

serpentinite

869 CORE: Sandy silt; silt with very fine to fine sand; very well sorted; very dark gray (5Y 3/1); accessory: fibrous 

serpentinite

Table 5. Lithologic shaker and core logs for McGlincey (MGCY) (7S/1W-35L12–16) multiple-well monitoring site, Santa Clara County, California—Continued

 Depth (ft)

Description

From To 
Table 6 63

Table 6. Lithologic shaker logs for Santana Park (STPK) (7S/1W-14P1–5) multiple-well monitoring site, Santa Clara County, California—Continued

Depth (ft)

Description

From To

0 10 Silty clay; clay and silt; well sorted; dark olive brown (2.5Y 3/3)

10 20 Gravelly silty clay; clay and silt with granules and pebbles; moderately sorted; pebbles are <8 mm in diameter; dark olive 

brown (2.5Y 3/3)

20 30 Gravelly silty clay; clay and silt with granules and pebbles; moderately sorted; pebbles are <8 mm in diameter; olive 

brown (2.5Y 4/3)

30 40 Gravelly sand; coarse to very coarse sand with granules and pebbles; moderately sorted; subangular; pebbles are <8 mm 

in diameter; very dark grayish brown (2.5Y 3/2)

40 50 Sandy gravel; granules and pebbles with coarse and very coarse sand; moderately sorted; subangular; pebbles are <8 mm 

in diameter; very dark grayish brown (2.5Y 3/2) 

50 60 Sandy gravel; granules and pebbles with coarse and very coarse sand; moderately sorted; subangular to subrounded; 

pebbles are <8 mm in diameter; very dark grayish brown (2.5Y 3/2) 

60 70 Sandy gravel; granules and pebbles with very coarse sand; moderately sorted; subangular; pebbles are <12 mm in 

diameter; very dark grayish brown (2.5Y 3/2)

70 80 Clayey gravel; pebbles with some clay; well sorted; subrounded; pebbles are <25 mm in diameter; olive gray 

(5Y 5/2)

80 90 Clayey gravel; pebbles with some clay; well sorted; subrounded; pebbles are <15 mm in diameter; olive gray 

(5Y 5/2)

90 100 Gravelly sand; coarse to very coarse sand with granules and pebbles; moderately sorted; subangular; pebbles are 

<12 mm in diameter; very dark grayish brown (2.5Y 3/2)

100 110 Gravelly sand; coarse to very coarse sand with granules and pebbles; moderately sorted; subangular; pebbles are

<12 mm in diameter; very dark grayish brown (2.5Y 3/2)

110 120 Gravel; granules and pebbles; well sorted; subrounded; pebbles are <20 mm in diameter; olive brown (2.5Y 4/3) 

120 130 Sandy gravel; granules and pebbles with coarse to very coarse sand; moderately sorted; subangular to subrounded; 

pebbles are <15 mm in diameter; very dark grayish brown (2.5Y 3/2)

130 140 Sandy gravel; granules and pebbles with coarse to very coarse sand; moderately sorted; subangular to subrounded; 

pebbles are <15 mm in diameter; very dark grayish brown (2.5Y 3/2)

140 150 Gravelly sand; coarse to very coarse sand with granules and pebbles; moderately sorted; subrounded; pebbles are 

<15 mm in diameter; very dark grayish brown (2.5Y 3/2)

150 160 Sandy gravel; granules and pebbles with some coarse to very coarse sand; moderately sorted; subrounded; pebbles are 

<20 mm in diameter; very dark grayish brown (2.5Y 3/2)

160 170 Sandy gravel; granules and pebbles with some coarse to very coarse sand; moderately sorted; subrounded; pebbles are 

<25 mm in diameter; very dark grayish brown (2.5Y 3/2)

170 180 Sandy gravel; granules and pebbles with some coarse to very coarse sand; moderately sorted; subrounded; pebbles are 

<25 mm in diameter; very dark grayish brown (2.5Y 3/2)

180 190 Gravel; pebbles and granules; well sorted; subrounded to rounded; pebbles are <20 mm in diameter; light olive brown 

(2.5Y 5/4)

190 209 Gravel; pebbles and granules; well sorted; subrounded; pebbles are <20 mm in diameter; light olive brown (2.5Y 5/4)

209 214 Silty gravel; granules and pebbles with silt; moderately sorted; subrounded; pebbles are <10 mm in diameter; pale yellow 

(2.5Y 7/4) 

214 224 No sample collected

224 229 Silty clayey gravel; granules and pebbles with silt and clay; moderately sorted; subrounded; pebbles are <8 mm in 

diameter; pale yellow (2.5Y 7/4) 

229 234 Sandy silt; silt to very fine sand; well sorted; pale yellow (2.5Y 7/4) 

234 239 Sandy silt; silt to very fine sand; well sorted; pale yellow (2.5Y 7/4) 

239 244 Sandy silt; silt to very fine sand; well sorted; pale yellow (2.5Y 7/4) 

244 249 Sandy silt; silt to very fine sand; well sorted; pale yellow (2.5Y 7/4) 

249 254 Silty sand; silt to medium sand; moderately sorted; subrounded; pale yellow (2.5Y 7/4) 

Table 6. Lithologic shaker logs for Santana Park (STPK) (7S/1W-14P1–5) multiple-well monitoring site, Santa Clara County, California

[Altitude of land surface, approximately 143 ft; depth is in feet below land surface; soil and rock color notation from Munsell Color (1994); drilled by U.S. 

Geological Survey Western Region Research Drilling Unit, using mud-rotary, April 2001; total depth drilled 1,000 ft; screened intervals 130–150; 340–360; 

420–440; 540–560; 680–700 ft; ft, foot; <, less than; mm, millimeter]
64 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

254 259 Gravelly silty sand; fine to very coarse sand with silt and granules to pebbles; poorly sorted; subangular; pebbles are 

<10 mm in diameter; light olive brown (2.5Y 5/4)

259 269 Gravelly sand; coarse to very coarse sand with granules and pebbles; moderately sorted; subangular; pebbles are 

<20 mm in diameter; olive brown (2.5Y 4/3) 

269 279 Gravelly silty sand; coarse to very coarse sand with silt and granules; moderately sorted; subrounded; light yellowish 

brown (2.5Y 6/4) 

279 289 Silty sandy gravel; pebbles and granules with silt and very coarse sand; moderately sorted; subrounded; pebbles are 

<20 mm in diameter; light yellowish brown (2.5Y 6/4) 

289 299 Sandy gravel; granules and pebbles with coarse to very coarse sand; moderately sorted; subangular to subrounded; 

pebbles are <15 mm in diameter; light olive brown (2.5Y 5/3)

299 309 Sandy gravel; granules and pebbles with coarse to very coarse sand; moderately sorted; subangular to subrounded; 

pebbles are <10 mm in diameter; light olive brown (2.5Y 5/3)

309 319 Sandy gravel; granules and pebbles with coarse to very coarse sand; moderately sorted; subangular to subrounded; 

pebbles are <20 mm in diameter; light olive brown (2.5Y 5/3)

319 324 No sample collected

324 329 Gravelly silty sand; very fine to very coarse sand with silt and granules to pebbles; very poorly sorted; subangular; 

pebbles are <30 mm in diameter; light olive brown (2.5Y 5/4)

329 334 Silty sandy gravel; granules and pebbles with silt to medium sand; poorly sorted; subrounded; pebbles are <15 mm in 

diameter; light olive brown (2.5Y 5/4)

334 349 Gravelly sand; coarse sand to pebbles; moderately sorted; subangular to subrounded; pebbles are <10 mm in diameter; 

light olive brown (2.5Y 5/3)

349 359 Sandy gravel; granules and pebbles with coarse to very coarse sand; moderately sorted; subangular; pebbles are <20 mm 

in diameter; light olive brown (2.5Y 5/3)

359 369 Sandy gravel; granules and pebbles with coarse to very coarse sand; moderately sorted; subangular; pebbles are <20 mm 

in diameter; light olive brown (2.5Y 5/3)

369 379 Sandy gravel; granules and pebbles with coarse to very coarse sand; moderately sorted; angular to subangular; pebbles 

are <20 mm in diameter; light olive brown (2.5Y 5/3)

379 384 Gravel; granules and pebbles; well sorted; subangular to subrounded; pebbles are <25 mm in diameter; light olive brown 

(2.5Y 5/3)

384 389 Sandy gravel; granules and pebbles with coarse to very coarse sand; moderately sorted; subangular; pebbles are <30 mm 

in diameter; light olive brown (2.5Y 5/3)

389 399 Gravelly silty sand; very fine to very coarse sand with silt and granules and pebbles; very poorly sorted; angular to 

subangular; pebbles are <8 mm in diameter; light yellowish brown (2.5Y 6/4)

399 409 Sandy gravel; granules and pebbles with some coarse to very coarse sand; moderately sorted; angular; pebbles are 

<20 mm in diameter; light olive brown (2.5Y 5/3)

409 419 Gravelly sand; coarse sand to pebbles; moderately sorted; angular to subangular; pebbles are <10 mm in diameter; light 

olive brown (2.5Y 5/3)

419 429 Gravel; pebbles and granules; well sorted; angular to subangular; pebbles are <15 mm in diameter; light olive brown 

(2.5Y 5/3)

429 439 Gravelly sand; coarse to very coarse sand with granules and pebbles; moderately sorted; angular to subangular; pebbles 

are <10 mm in diameter; yellowish brown (10YR 5/4)

439 449 Gravel; pebbles and granules; well sorted; subangular to subrounded; pebbles are <20 mm in diameter; light olive brown 

(2.5Y 5/3)

449 454 No sample collected

454 464 Silty sand; very fine to fine sand with silt; moderately sorted; subangular; yellowish brown (10YR 5/4)

464 469 Gravelly sand; fine to very coarse sand with granules; moderately sorted; angular to subangular; light olive brown 

(2.5Y 5/4)

469 479 Sandy gravel; granules and pebbles with very coarse sand; moderately sorted; subangular; pebbles are <20 mm in 

diameter; light olive brown (2.5Y 5/3)

Table 6. Lithologic shaker logs for Santana Park (STPK) (7S/1W-14P1–5) multiple-well monitoring site, Santa Clara County, California—Continued

Depth (ft)

Description

From To
Table 6 65

479 489 Silty gravel; granules and pebbles with some silt; moderately sorted; subangular; pebbles are <20 mm in diameter; light 

olive brown (2.5Y 5/3)

489 499 Silty sandy gravel; granules and pebbles with coarse to very coarse sand and silt; moderately sorted; subangular; pebbles 

are <15 mm in diameter; light yellowish brown (2.5Y 6/4)

499 509 Silty sandy gravel; granules and pebbles with coarse to very coarse sand and silt; moderately sorted; angular; pebbles are 

<10 mm in diameter; light yellowish brown (2.5Y 6/4) 

509 519 Sandy silt; silt with fine to very coarse sand; moderately sorted; light yellowish brown (2.5Y 6/4)

519 529 Gravelly silty sand; very fine to very coarse sand with granules to pebbles and silt; very poorly sorted; angular; pebbles 

are <8 mm in diameter; light yellowish brown (2.5Y 6/4)

529 539 Gravelly sand; medium to very coarse sand with granules and pebbles; moderately sorted; angular to subangular; pebbles 

are <8 mm in diameter; light olive brown (2.5Y 5/3)

539 549 Sandy gravel; pebbles and granules with very coarse sand; moderately sorted; subangular; pebbles are <20 mm in 

diameter; light olive brown (2.5Y 5/3)

549 559 Sandy gravel; pebbles and granules with very coarse sand; moderately sorted; subangular; pebbles are <15 mm in 

diameter; light olive brown (2.5Y 5/3)

559 569 Silty sandy gravel; granules and pebbles with very coarse sand and silt; moderately sorted; subrounded; pebbles are 

<8 mm in diameter; light yellowish brown (2.5Y 6/4)

569 579 Sandy silt; silt with some very coarse sand; well sorted; light yellowish brown (2.5Y 6/4)

579 584 Sandy silt; silt with some very coarse sand; well sorted; light yellowish brown (2.5Y 6/4)

584 589 Sandy gravel; pebbles and granules with medium to very coarse sand; moderately sorted; subangular; pebbles are 

<15 mm in diameter; light olive brown (2.5Y 5/3)

589 594 Silty sandy gravel; granules and pebbles with silt and very fine to very coarse sand; very poorly sorted; subangular; 

pebbles are <15 mm in diameter; light olive brown (2.5Y 5/3)

594 604 Gravelly silty sand; coarse sand to pebbles with silt; moderately sorted; subangular; pebbles are <8 mm in diameter; light 

yellowish brown (2.5Y 6/4)

604 609 Gravelly silty sand; coarse sand to pebbles with silt; moderately sorted; angular to subangular; pebbles are <8 mm in 

diameter; light yellowish brown (2.5Y 6/4)

609 619 Gravelly silty sand; medium sand to pebbles with silt; poorly sorted; subangular; pebbles are <15 mm in diameter; 

yellowish brown (10YR 5/4)

619 624 Gravelly silty sand; medium sand to pebbles with silt; poorly sorted; subangular; pebbles are <15 mm in diameter; light 

yellowish brown (2.5Y 6/4)

624 629 No sample collected

629 639 Gravelly sand; coarse sand to pebbles; moderately sorted; angular to subangular; pebbles are <8 mm in diameter; light 

olive brown (2.5Y 5/3)

639 649 Gravelly sand; coarse sand to pebbles; moderately sorted; angular to subangular; pebbles are <10 mm in diameter; light 

olive brown (2.5Y 5/3)

649 659 Gravelly silty sand; coarse sand to pebbles with silt; moderately sorted; subangular; pebbles are <8 mm in diameter; light 

olive brown (2.5Y 5/3)

659 669 Sandy silt; silt and very fine sand; well sorted; light yellowish brown (2.5Y 6/4)

669 679 Silty sandy gravel; granules and pebbles with very coarse sand and silt; moderately sorted; subangular; pebbles are 

<25 mm in diameter; light olive brown (2.5Y 5/3)

679 684 Silty sandy gravel; granules and pebbles with medium to very coarse sand and silt; poorly sorted; subangular; pebbles are 

<20 mm in diameter; light olive brown (2.5Y 5/3)

684 689 Sandy gravel; granules and pebbles with coarse to very coarse sand; moderately sorted; angular to subangular; pebbles 

are <10 mm in diameter; light olive brown (2.5Y 5/3)

689 699 Gravelly sand; fine sand to pebbles; poorly sorted; angular to subangular; pebbles are <8 mm in diameter; light olive 

brown (2.5Y 5/3)

699 709 Gravelly silty sand; coarse sand to pebbles with silt; moderately sorted; subangular; pebbles are <8 mm in diameter; light 

olive brown (2.5Y 5/3)

709 714 No sample collected

714 719 Slightly gravelly sandy silt; silt with coarse sand to granules; moderately sorted; light yellowish brown (2.5Y 6/4)

Table 6. Lithologic shaker logs for Santana Park (STPK) (7S/1W-14P1–5) multiple-well monitoring site, Santa Clara County, California—Continued

Depth (ft)

Description

From To
66 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

719 726.5 Sandy silt; silt and very fine sand; well sorted; light yellowish brown (2.5Y 6/4)

726.5 729 No sample collected

729 739 Gravelly sand; coarse sand to granules; moderately sorted; subangular; light olive brown (2.5Y 5/3)

739 749 Gravelly silty sand; medium sand to pebbles with silt; poorly sorted; angular to subangular; pebbles are <8 mm in 

diameter; light olive brown (2.5Y 5/3)

749 759 Gravelly silty sand; medium sand to granules with silt; moderately sorted; subangular; light olive brown (2.5Y 5/3)

759 764 No sample collected

764 769 Silty sandy gravel; granules and pebbles with medium to very coarse sand and silt; poorly sorted; pebbles are <25 mm in 

diameter; light olive brown (2.5Y 5/3)

769 774 Sandy silt; silt with very fine to medium sand; moderately sorted; light yellowish brown (2.5Y 6/4)

774 779 Sandy silt; silt with very fine sand; well sorted; light yellowish brown (2.5Y 6/4)

779 789 Sandy clay; clay with coarse to very coarse sand; moderately sorted; brown (10YR 4/3) 

789 799 Clayey sand; coarse to very coarse sand with some clay; moderately sorted; subrounded; olive brown (2.5Y 4/3)

799 804 Sandy silt; silt and very fine sand; well sorted; yellowish brown (10YR 5/4) 

804 809 Gravelly silty sand; medium sand to pebbles with silt; poorly sorted; angular; pebbles are <10 mm in diameter; light olive 

brown (2.5Y 5/3)

809 819 Silty sand; coarse to very coarse sand with silt; moderately sorted; angular; light olive brown (2.5Y 5/4)

819 831.5 No sample collected

831.5 837.5 Sandy gravel; granules and pebbles with coarse to very coarse sand; moderately sorted; subrounded; pebbles are <25 mm 

in diameter; light olive brown (2.5Y 5/3)

837.5 849 Gravelly clayey sand; coarse sand to granules with clay; moderately sorted; subangular; olive brown (2.5Y 4/3)

849 859 Sandy clay; clay with medium to very coarse sand; moderately sorted; light olive brown (2.5Y 5/4)

859 869 Sandy clay; clay with medium to very coarse sand; moderately sorted; olive brown (2.5Y 4/4)

869 874 Sandy silt; silt and very fine sand; well sorted; light yellowish brown (2.5Y 6/4)

874 878 Clayey silt; silt and clay; well sorted; light olive brown (2.5Y 5/3)

878 889 Silty sand; coarse to very coarse sand with silt; moderately sorted; subrounded; light olive brown (2.5Y 5/3)

889 899 Sandy clay; clay with coarse to very coarse sand; moderately sorted; olive brown (2.5Y 4/3)

899 909 Clayey sand; coarse to very coarse sand with clay; moderately sorted; subrounded; olive brown (2.5Y 4/3)

909 919 Gravelly silty sand; fine sand to granules with silt; moderately sorted; subangular; light olive brown 

(2.5Y 5/3)

919 924 Clayey silt; silt and clay; well sorted; yellowish brown (10YR 5/4) 

924 929 Sandy silt; silt and very fine sand; well sorted; light olive brown (2.5Y 5/3)

929 939 Silty sand; coarse to very coarse sand with silt; moderately sorted; angular to subangular; light olive brown (2.5Y 5/3)

939 949 Silty sand; coarse to very coarse sand with silt; moderately sorted; angular to subangular; light olive brown (2.5Y 5/3)

949 959 Gravelly silty sand; medium sand to granules with silt; moderately sorted; subangular; light olive brown (2.5Y 5/3)

959 969 Gravelly sand; coarse sand to pebbles; moderately sorted; subangular; pebbles are <10 mm in diameter; light olive brown 

(2.5Y 5/3)

969 979 Gravelly sand; coarse sand to granules; moderately sorted; angular to subangular; light olive brown (2.5Y 5/3)

979 989 Gravelly sand; coarse sand to granules; moderately sorted; angular to subangular; light olive brown (2.5Y 5/3)

989 996.5 Silty sandy gravel; granules and pebbles with medium to very coarse sand and silt; poorly sorted; subangular; pebbles are 

<20 mm in diameter; light olive brown (2.5Y 5/3)

996.5 1,000 Silt; silt; very well sorted; light yellowish brown (2.5Y 6/4)

Table 6. Lithologic shaker logs for Santana Park (STPK) (7S/1W-14P1–5) multiple-well monitoring site, Santa Clara County, California—Continued

Depth (ft)

Description

From To
Table 7 67

]

Table 7. Lithologic core logs for Guadalupe (GUAD) (6S/1W-26Q1–4) multiple-well monitoring site, Santa Clara County, California—Continued

Core ID 

(site-core

#-section)

Top of

core 

interval

(ft bls)

Bottom

of core 

interval

(ft bls)

Total 

core-interval 

length 

(ft)

Total length

of recovery 

(cm)

Total length 

of core 

recovered

(in percent)*

Description

GUAD-1C-1 9.0 14.0 5.0 143.0 94 Clay

GUAD-2C-1 14.0 19.0 5.0 112.5 74 V. coarse, gravelly

GUAD-3C-1 19.0 24.0 5.0 73.0 48 Gravel

GUAD-4C-1 24.0 29.0 5.0 128.0 84 Medium sand

GUAD-5C-1 29.0 34.0 5.0 136.0 89 Clayey silt

GUAD-6C-1 34.0 39.0 5.0 110.0 72 Clay

GUAD-7C-1 39.0 44.0 5.0 90.5 59 Clay

GUAD-8C-1 44.0 49.0 5.0 92.0 60 Silty sand

GUAD-9C-1 49.0 54.0 5.0 23.5 15 Sandy clay

GUAD-10C-1 54.0 59.0 5.0 .0 0 No recovery

GUAD-11C-1 59.0 64.0 5.0 .0 0 No recovery

GUAD-12C-1 64.0 69.0 5.0 8.0 5 Sandy gravel

GUAD-13C-1 69.0 74.0 5.0 66.0 43 Sandy clay with some gravel

GUAD-14C-1 74.0 79.0 5.0 83.5 55 Clayey sandy gravel

GUAD-15C-1 79.0 84.0 5.0 24.0 16 Loose sand (soupy)

GUAD-16C-1 84.0 89.0 5.0 87.5 57 Clay

GUAD-17C-2 89.0 89.5 .5 16.0 100 Section 2: clay

GUAD-17C-1 89.5 94.0 4.5 125.0 92 Clay

GUAD-18C-1 89.0 94.0 5.0 125.0 82 Clay

GUAD-19C-1 99.0 104.0 5.0 .0 0 No recovery

GUAD-20C-1 104.0 109.0 5.0 104.5 69 Clay

GUAD-21C-1 109.0 114.0 5.0 160.0 105 Clay

GUAD-22C-1 114.0 119.0 5.0 157.0 103 Clay

GUAD-23C-1 119.0 124.0 5.0 62.5 41 Clay

GUAD-24C-1 124.0 129.0 5.0 49.0 32 Sand

GUAD-25C-1 129.0 134.0 5.0 113.5 74 Gravelly silty sand

GUAD-26C-1 134.0 139.0 5.0 103.5 68 Sandy clay

GUAD-27C-1 139.0 144.0 5.0 91.5 60 Clay

GUAD-28C-1 144.0 149.0 5.0 116.0 76 Clay

GUAD-29C-1 149.0 154.0 5.0 .0 0 No recovery

GUAD-30C-1 154.0 159.0 5.0 164.0 108 Clay

GUAD-31C-1 159.0 164.0 5.0 135.0 89 Mottled blue clay

GUAD-32C-1 164.0 169.0 5.0 135.0 89 Medium grain moderately sorted sand 

GUAD-33C-1 169.0 173.1 4.1 125.0 100 Silty clay

GUAD-33C-2 173.1 174.0 .9 25.0 91 V. fine silty sand

GUAD-34C-1 174.0 179.0 5.0 481.0 316 Well sorted v. fine sand

GUAD-35C-1 179.0 184.0 5.0 158.0 104 Clay

GUAD-36C-1 184.0 189.0 5.0 134.0 88 Silty sand

GUAD-37C-1 189.0 194.0 5.0 40.0 26 Blue clay

GUAD-38C-1 194.0 199.0 5.0 .0 0 No recovery

GUAD-39C-1 199.0 204.0 5.0 103.0 68 Coarse silty sand

GUAD-40C-1 204.0 209.0 5.0 95.0 62 Clay

GUAD-41C-1 209.0 214.0 5.0 38.0 25 Fine silty sand

Table 7. Lithologic core logs for Guadalupe (GUAD) (6S/1W-26Q1–4) multiple-well monitoring site, Santa Clara County, California

[Altitude of land surface, approximately 33 ft; depth is in feet below land surface; drilled by U.S. Geological Survey Western Region Research Drilling Unit, 

using mud-rotary, August–September 2002; total depth drilled 1,370 ft; screened intervals—310–330; 440–460; 580–600; 810–830 ft; ft, foot; bls, below land 

surface; cm, centimeter; v, very; *, total length of core recovered may be greater than 100 percent]
68 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

GUAD-42C-1 214.0 219.0 5.0 97.0 64 V. fine silty sand

GUAD-43C-1 219.0 224.0 5.0 66.0 43 Clayey sand with wood

GUAD-44C-1 224.0 229.0 5.0 119.0 78 Gravel

GUAD-45C-1 229.0 234.0 5.0 .0 0 No recovery

GUAD-46C-1 234.0 236.2 2.5 66.0 100 Silty sand to silt

GUAD-46C-2 236.2 239.0 2.5 120.0 139 Gravelly coarse sand

GUAD-47C-1 239.0 244.0 5.0 42.0 28 Gravelly sand

GUAD-48C-1 244.0 249.0 5.0 26.0 17 No entry

GUAD-49C-1 249.0 254.0 5.0 99.5 65 Clayey silt

GUAD-50C-1 254.0 259.0 5.0 143.5 94 Fine sand-silt

GUAD-51C-1 259.0 264.0 5.0 97.0 64 Fine to coarse

GUAD-52C-1 264.0 269.0 5.0 .0 0 Shaker: coarse sand-small pebbles

GUAD-53C-1 269.0 274.0 5.0 117.5 77 Clay

GUAD-54C-1 274.0 279.0 5.0 160.0 105 Clay

GUAD-55C-1 279.0 284.0 5.0 81.5 53 Clay

GUAD-56C-1 284.0 289.0 5.0 155.5 102 Clay

GUAD-57C-1 289.0 294.0 5.0 88.5 58 V. fine silty sand

GUAD-58C-1 294.0 299.0 5.0 .0 0 No recovery

GUAD-59C-1 299.0 304.0 5.0 123.5 81 Silt

GUAD-60C-1 304.0 309.0 5.0 111.5 73 Silty clay

GUAD-61C-1 309.0 314.0 5.0 89.5 59 Silt (14 cm liner added to shoe)

GUAD-62C-1 314.0 319.0 5.0 108.5 71 Gravelly clay

GUAD-63C-1 319.0 324.0 5.0 .0 0 Gravel on shaker

GUAD-64C-1 324.0 329.0 5.0 163.0 107 Clay (liner reconstructed)

GUAD-65C-1 329.0 334.0 5.0 107.0 70 Clay

GUAD-66C-1 334.0 339.0 5.0 149.5 98 Silt-vf sand

GUAD-67C-1 339.0 344.0 5.0 83.5 55 Gravelly clay

GUAD-68C-1 344.0 349.0 5.0 72.0 2 Clayey silty gravel

GUAD-69C-1 349.0 354.0 5.0 .0 0 No recovery

GUAD-70C-1 354.0 359.0 5.0 161.0 106 Clay

GUAD-71C-1 359.0 364.0 5.0 96.0 63 Silt to gravel

GUAD-72C-1 364.0 369.0 5.0 45.0 30 Silt to gravel

GUAD-73C-1 369.0 374.0 5.0 63.0 41 Sandy silty clay

GUAD-74C-1 374.0 376.9 2.9 88.0 100 No liner in barrel

GUAD-74C-2 376.9 379.0 2.1 80.0 124 Clay

GUAD-75C-1 379.0 384.0 5.0 107.0 70 Silt to fine

GUAD-76C-1 384.0 389.0 5.0 64.5 42 Silt to fine sand

GUAD-77C-1 389.0 394.0 5.0 161.0 106 Silty clay

GUAD-78C-1 394.0 399.0 5.0 8.0 5 No entry

GUAD-79C-1 399.0 404.0 5.0 152.0 100 Silty very fine–fine sand

GUAD-80C-1 404.0 409.0 5.0 75.5 50 Clayey gravel

GUAD-81C-1 409.0 414.0 5.0 75.5 50 No entry

GUAD-82C-1 414.0 419.0 5.0 120.5 79 Blue clay

GUAD-83C-1 419.0 424.0 5.0 75.5 50 Med gr. sand, light brown

Table 7. Lithologic core logs for Guadalupe (GUAD) (6S/1W-26Q1–4) multiple-well monitoring site, Santa Clara County, California—Continued

Core ID 

(site-core

#-section)

Top of

core 

interval

(ft bls)

Bottom

of core 

interval

(ft bls)

Total 

core-interval 

length 

(ft)

Total length

of recovery 

(cm)

Total length 

of core 

recovered

(in percent)*

Description
Table 7 69

GUAD-84C-1 424.0 429.0 5.0 .0 0 No recovery

GUAD-85C-1 429.0 434.0 5.0 140.0 92 Bluish gray clayey silt (not clay)

GUAD-86C-1 434.0 439.0 5.0 .0 0 No recovery

GUAD-87C-1 439.0 444.0 5.0 25.5 17 No recovery

GUAD-88C-1 444.0 449.0 5.0 136.0 89 Orange-brown clay

GUAD-89C-1 449.0 454.0 5.0 69.0 45 Med-coarse sand with gravel

GUAD-90C-1 454.0 459.0 5.0 62.5 41 Coarse sand and gravel

GUAD-91C-1 459.0 464.0 5.0 .0 0 No recovery shaker: coarse sand

GUAD-92C-1 464.0 469.0 5.0 75.0 49 Gray-brown clay

GUAD-93C-1 469.0 474.0 5.0 156.5 103 Blue clay w/ fine sand

GUAD-94C-1 474.0 479.0 5.0 94.0 62 No entry

GUAD-95C-1 479.0 484.0 5.0 151.0 99 Silty clay

GUAD-96C-1 484.0 489.0 5.0 159.0 104 V. fine sandy silt

GUAD-97C-1 489.0 494.0 5.0 154.0 101 Med sand

GUAD-98C-1 494.0 499.0 5.0 156.5 103 Blue clay

GUAD-99C-1 499.0 504.0 5.0 146.0 96 Blue clay

GUAD-100C-1 504.0 509.0 5.0 45.0 30 Fine to med sand

GUAD-101C-1 509.0 509.8 .8 25.0 100

GUAD-101C-2 509.8 514.0 4.2 20.0 16 Green clay

GUAD-102C-1 514.0 519.0 5.0 129.0 85 Mottled blue green clay

GUAD-103C-1 519.0 524.0 5.0 153.0 100 Mottled blue clay

GUAD-104C-1 524.0 529.0 5.0 123.0 81 Grayish brown clay

GUAD-105C-1 529.0 534.0 5.0 89.0 58 Blue clay

GUAD-106C-1 534.0 539.0 5.0 101.0 66 V. fine sand

GUAD-107C-1 539.0 544.0 5.0 89.0 58 Yellow gray clay

GUAD-108C-1 544.0 549.0 5.0 61.0 40 Brown gravelly clay

GUAD-109C-1 549.0 554.0 5.0 95.0 62 Brown gravelly sand

GUAD-110C-1 554.0 559.0 5.0 85.0 56 Brown gravelly clay

GUAD-111C-1 559.0 564.0 5.0 92.0 60 No entry

GUAD-112C-1 564.0 569.0 5.0 68.5 75 Green-gray clay

GUAD-113C-1 569.0 574.0 5.0 39.0 26 Light green hard clay – serpentinite

GUAD-114C-1 574.0 579.0 5.0 131.0 86 Green-gray clay

GUAD-115C-1 579.0 584.0 5.0 41.5 27 Dark green-brown sandy clay and tuff 

clasts

GUAD-116C-1 584.0 589.0 5.0 125.0 82 Fine–medium sand with clay, sparsegravel

GUAD-117C-1 589.0 594.0 5.0 83.0 54 Sandy gravel

GUAD-118C-1 594.0 599.0 5.0 .0 0 No recovery

GUAD-119C-1 599.0 604.0 5.0 92.5 61 Dark gray sandy clay

GUAD-120C-1 604.0 609.0 5.0 .0 0 No recovery

GUAD-121C-1 609.0 614.0 5.0 158.5 104 Dark green gray clay

GUAD-122C-1 614.0 619.0 5.0 148.5 97 Green clay

GUAD-123C-1 619.0 624.0 5.0 134.0 88 Silt

GUAD-124C-1 624.0 629.0 5.0 159.0 104 Green clay with white clasts

GUAD-125C-1 629.0 634.0 5.0 134.0 88 V. fine silty sand

GUAD-126C-1 634.0 639.0 5.0 152.0 100 Clay

GUAD-127C-1 639.0 644.0 5.0 142.5 94 Greenish clay

Table 7. Lithologic core logs for Guadalupe (GUAD) (6S/1W-26Q1–4) multiple-well monitoring site, Santa Clara County, California—Continued

Core ID 

(site-core

#-section)

Top of

core 

interval

(ft bls)

Bottom

of core 

interval

(ft bls)

Total 

core-interval 

length 

(ft)

Total length

of recovery 

(cm)

Total length 

of core 

recovered

(in percent)*

Description
70 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

GUAD-128C-1 644.0 649.0 5.0 114.0 75 Brown clay

GUAD-129C-1 649.0 654.0 5.0 159.0 104 Brown gravelly clay

GUAD-130C-1 654.0 659.0 5.0 81.5 53 Brown gravelly sand

GUAD-131C-1 659.0 664.0 5.0 127.5 84 Gravelly clay

GUAD-132C-1 664.0 669.0 5.0 95.0 62 Gravelly sand

GUAD-133C-1 669.0 674.0 5.0 39.5 26 Coarse gravelly sand

GUAD-134C-1 674.0 679.0 5.0 129.0 85 Greenish clay

GUAD-135C-1 679.0 684.0 5.0 122.0 80 Silty clay

GUAD-136C-1 684.0 689.0 5.0 113.0 74 Clayey silt

GUAD-137C-1 689.0 694.0 5.0 160.0 105 Gray clayey silt

GUAD-138C-1 694.0 699.0 5.0 137.0 90 Gray silty sand

GUAD-139C-1 699.0 704.0 5.0 150.0 98 Gray clay

GUAD-140C-1 704.0 709.0 5.0 105.0 69 Brown clay

GUAD-141C-1 709.0 714.0 5.0 61.0 40 Coarse sand to granules

GUAD-142C-1 714.0 719.0 5.0 120.5 79 Silty clay

GUAD-143C-1 719.0 722.0 3.0 57.0 62 Clay 

GUAD-144C-1 722.0 724.0 2.0 62.5 103 Silty clay

GUAD-145C-1 724.0 729.0 5.0 71.0 47 No shoe sample

GUAD-146C-1 729.0 734.0 5.0 30.5 20 No shoe sample

GUAD-147C-1 734.0 739.0 5.0 30.0 20 Sandy granules

GUAD-148C-1 739.0 741.5 2.5 50.0 66 Clay

GUAD-149C-1 741.5 744.0 2.5 79.5 52 Clayey silt

GUAD-150C-1 744.0 749.0 5.0 148.5 97 No entry

GUAD-151C-1 749.0 754.0 5.0 149.0 98 Gravelly clay

GUAD-152C-1 754.0 759.0 5.0 159.0 104 Silty clay

GUAD-153C-1 759.0 764.0 5.0 108.0 71 Silty clay

GUAD-154C-1 764.0 769.0 5.0 .0 0 No recovery

GUAD-155C-1 769.0 774.0 5.0 160.5 105 Dark brown clayey silt

GUAD-156C-1 774.0 779.0 5.0 28.5 19 No entry

GUAD-157C-1 779.0 784.0 5.0 136.5 90 No entry

GUAD-158C-1 784.0 789.0 5.0 .0 0 No recovery

GUAD-159C-1 789.0 794.0 5.0 159.5 105 Silt

GUAD-160C-2 794.0 797.6 3.6 110.0 100

GUAD-160C-1 797.6 799.0 1.4 29.5 70 Silt [core hanging below shoe]

GUAD-161C-1 799.0 804.0 5.0 128.5 84 Gravelly clay

GUAD-162C-1 804.0 809.0 5.0 99.0 65 No shoe sample

GUAD-163C-1 809.0 814.0 5.0 92.0 60 Medium sand and granules

GUAD-164C-1 814.0 819.0 5.0 58.5 38 Medium to coarse sand and granules

GUAD-165C-1 819.0 824.0 5.0 74.0 49 Brown clay

GUAD-166C-1 824.0 829.0 5.0 118.0 77 Gray silty clay

GUAD-167C-1 829.0 834.0 5.0 23.0 15 Gray-green pebbly silt

GUAD-168C-1 834.0 839.0 5.0 97.2 64 Gray clay

GUAD-169C-1 839.0 844.0 5.0 109.5 72 Gray silty clay

GUAD-170C-1 844.0 849.0 5.0 137.5 90 Dark gray clay

Table 7. Lithologic core logs for Guadalupe (GUAD) (6S/1W-26Q1–4) multiple-well monitoring site, Santa Clara County, California—Continued

Core ID 

(site-core

#-section)

Top of

core 

interval

(ft bls)

Bottom

of core 

interval

(ft bls)

Total 

core-interval 

length 

(ft)

Total length

of recovery 

(cm)

Total length 

of core 

recovered

(in percent)*

Description
Table 7 71

GUAD-171C-1 849.0 854.0 5.0 115.0 75 Gray clay

GUAD-172C-1 854.0 859.0 5.0 56.5 37 Gray clay

GUAD-173C-1 859.0 864.0 5.0 158.0 104 Hard gray clay

GUAD-174C-1 864.0 869.0 5.0 28.5 19 Dense-hard gray clay

GUAD-175C-1 869.0 874.0 5.0 138.5 91 Dense stiff gray clay

GUAD-176C-1 874.0 879.0 5.0 143.5 94 Brown clay

GUAD-177C-1 879.0 884.0 5.0 102.0 67 No entry

GUAD-178C-1 884.0 889.0 5.0 107.5 71 Brown silty sand

GUAD-179C-1 889.0 894.0 5.0 154.0 101 Brown-gray interbedded sands

GUAD-180C-1 894.0 899.0 5.0 155.5 102 Gray sand

GUAD-181C-1 899.0 904.0 5.0 107.5 71 Gray sand

GUAD-182C-1 904.0 909.0 5.0 121.0 79 Dark gray silty sand

GUAD-183C-1 909.0 914.0 5.0 158.5 104 Dark gray sand with pebbles, wood 

fragments

GUAD-184C-1 914.0 919.0 5.0 153.5 101 Gray med sandy clay

GUAD-185C-1 919.0 924.0 5.0 64.5 42 Gray sand

GUAD-186C-1 924.0 929.0 5.0 137.0 90 Gray sandy clay

GUAD-187C-1 929.0 934.0 5.0 157.5 103 Med gray sand

GUAD-188C-1 934.0 939.0 5.0 94.0 62 Gray-green silty sand | grayish-white 

carbonite with fossils

GUAD-189C-1 939.0 941.5 2.5 8.0 11 Blue-gray marl

GUAD-190C-1 941.5 944.0 2.5 .0 0 No recovery

GUAD-191C-1 944.0 945.0 1.0 5.0 17 Brown clay

GUAD-192C-1 949.0 954.0 5.0 160.0 106 Fine-med brown sand

GUAD-193C-1 954.0 959.0 5.0 128.0 85 Dark gray ductile clay, medium sand 

bottom liner

GUAD-194C-1 959.0 964.0 5.0 130.0 86 Dark grayish green sandy clay

GUAD-195C-1 964.0 969.0 5.0 125.0 83 Dark gray sandy clay

GUAD-196C-1 969.0 974.0 5.0 160.0 106 Dark greenish gray clay

GUAD-197C-1 974.0 979.0 5.0 118.0 78 Sandy silty clay with chert pebbles

GUAD-198C-1 979.0 984.0 5.0 158.0 104 Dark gray clay

GUAD-199C-1 984.0 989.0 5.0 103.0 68 Gray sandy clay

GUAD-200C-1 989.0 994.0 5.0 66.0 44 Brown clay

GUAD-201C-1 994.0 999.0 5.0 85.0 56 Brown clay

GUAD-202C-1 999.0 1,004.0 5.0 15.0 10 Hard greenish clay

Table 7. Lithologic core logs for Guadalupe (GUAD) (6S/1W-26Q1–4) multiple-well monitoring site, Santa Clara County, California—Continued

Core ID 

(site-core

#-section)

Top of

core 

interval

(ft bls)

Bottom

of core 

interval

(ft bls)

Total 

core-interval 

length 

(ft)

Total length

of recovery 

(cm)

Total length 

of core 

recovered

(in percent)*

Description
72 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

Table 8. Lithologic shaker logs for Eleanor Park (ELNR) (5S/3W-36P2–5) multiple-well monitoring site, Santa Clara County, California—Continued

Depth (ft)

Description

From To

0 10 Slightly gravelly sandy silty clay; clay and silt with coarse sand to granules; moderately sorted; black (10YR2/1) 

10 20 No sample collected

20 30 Gravelly sand; coarse sand to granules; moderately sorted; subrounded to rounded; olive brown (2.5Y 4/3) 

30 40 No sample collected

40 50 No sample collected

50 60 No sample collected

60 70 Silty clay; clay and silt; well sorted; dark grayish brown (2.5Y 4/2)

70 80 Slightly gravelly sandy silty clay; clay and silt with coarse sand to pebbles; poorly sorted; pebbles are <15 mm in 

diameter; olive gray (5Y 4/2)

80 90 Silty clay; clay and silt; well sorted; olive gray (5Y 4/2)

90 100 Silty clay; clay and silt; well sorted; olive gray (5Y 4/2)

100 110 Gravelly silty clayey sand; coarse sand to granules with clay and silt; moderately sorted; subangular; olive gray 

(5Y 4/2)

110 120 Slightly gravelly sandy silty clay; clay and silt with coarse sand to granules; moderately sorted; olive gray 

(5Y 4/2)

120 130 Slightly gravelly sandy silty clay; clay and silt with coarse sand to pebbles; poorly sorted; pebbles are <10 mm in 

diameter; olive gray (5Y 4/2)

130 140 Slightly gravelly sandy silty clay; clay and silt with coarse sand to pebbles; poorly sorted; pebbles are <15 mm in 

diameter; olive gray (5Y 4/2)

140 150 Slightly gravelly sandy silty clay; clay and silt with coarse sand to pebbles; poorly sorted; pebbles are <10 mm in 

diameter; olive gray (5Y 4/2)

150 160 Slightly gravelly sandy silty clay; clay and silt with coarse sand to pebbles; poorly sorted; pebbles are <15 mm in 

diameter; shell fragments; dark greenish gray (10Y 4/1) 

160 170 Gravelly sand; coarse sand to pebbles; moderately sorted; subangular; pebbles are <15 mm in diameter; dark olive 

brown (2.5Y 3/3)

170 180 Gravelly silty sand; coarse sand to pebbles with occasional silt; moderately sorted; subrounded; pebbles are 

<10 mm in diameter; dark olive brown (2.5Y 3/3)

180 190 Slightly gravelly silty clay; clay and silt with granules and pebbles; moderately sorted; pebbles are 

<10 mm in diameter; olive gray (5Y 4/2)

190 200 Slightly gravelly silty clay; clay and silt with granules and pebbles; moderately sorted; pebbles are

<10 mm in diameter; olive gray (5Y 4/2)

200 210 Sandy silty clay; clay and silt with coarse to very coarse sand; moderately sorted; olive gray (5Y 5/2) 

210 220 Slightly gravelly sandy clayey silt; silt and clay with coarse sand to pebbles; poorly sorted; pebbles are <10 mm in 

diameter; olive gray (5Y 4/2)

220 230 Slightly gravelly sandy silty clay; clay and silt with coarse sand to granules; moderately sorted; olive (5Y 5/3) 

230 240 Sand; medium sand to very coarse sand; moderately sorted; subrounded; olive (5Y 4/3) 

240 250 Gravelly silty clayey sand; coarse sand to granules with silt and clay; moderately sorted; subrounded; olive (5Y 4/3) 

250 260 Slightly gravelly sandy silty clay; clay and silt with coarse sand to pebbles; poorly sorted; pebbles are <10 mm in 

diameter; dark greenish gray (10Y 3/1)

260 270 Slightly gravelly sandy silty clay; clay and silt with coarse sand to granules; moderately sorted; olive gray (5Y 4/2)

270 280 Slightly gravelly sandy silty clay; clay and silt with coarse sand to granules; moderately sorted; olive gray (5Y 4/2)

280 290 Slightly gravelly sandy silty clay; clay and silt with coarse sand to granules; moderately sorted; olive gray (5Y 4/2)

290 300 Slightly gravelly sandy silty clay; clay and silt with coarse sand to granules; moderately sorted; olive gray 

(5Y 4/2)

Table 8. Lithologic shaker logs for Eleanor Park (ELNR) (5S/3W-36P2–5) multiple-well monitoring site, Santa Clara County, California

[Altitude of land surface, approximately 23 ft; depth is in feet below land surface; soil and rock color notation from Munsell Color (1994); drilled by U.S. 

Geological Survey Western Region Research Drilling Unit, using mud-rotary, April 2001; total depth drilled 932 ft; screened intervals 180–200; 540–560; 

720–740; 830–850 ft; ft, feet; <, less than; mm, millimeter]
Table 8 73

300 310 Gravelly silty clayey sand; coarse sand to granules with clay and silt; moderately sorted; subrounded; olive gray 

(5Y 4/2)

310 320 Gravelly silty clayey sand; coarse sand to granules with clay and silt; moderately sorted; subrounded; olive gray

(5Y 4/2)

320 330 Gravelly silty clayey sand; coarse sand to pebbles with clay and silt; poorly sorted; subrounded; pebbles are 

<25 mm in diameter; olive gray (5Y 4/2)

330 340 Slightly gravelly sandy silty clay; clay and silt with coarse sand to granules; moderately sorted; olive gray (5Y 4/2)

340 350 Slightly gravelly sandy silty clay; clay and silt with coarse sand to granules; moderately sorted; olive gray (5Y 4/2)

350 360 Silty clay; clay and silt; well sorted; olive gray (5Y 4/2)

360 370 Sandy clayey silt; silt and clay with fine to coarse sand; moderately sorted; olive (5Y 4/3)

370 380 Gravelly silty clayey sand; coarse sand to granules with clay and silt; moderately sorted; subrounded; olive (5Y 4/3)

380 390 Gravelly silty clayey sand; coarse sand to granules with clay and silt; moderately sorted; subrounded; olive (5Y 4/3)

390 400 Slightly gravelly sandy silty clay; clay and silt with coarse sand to pebbles; poorly sorted; pebbles are <10 mm in 

diameter; olive (5Y 4/3)

400 410 Slightly gravelly sandy silty clay; clay and silt with coarse sand to granules; moderately sorted; olive (5Y 4/3)

410 420 Silty clay; clay and silt; well sorted; olive (5Y 4/3)

420 430 No sample collected

430 440 No sample collected

440 450 Sandy silty clay; clay and silt with fine to coarse sand; moderately sorted; olive (5Y 4/3)

450 460 Sandy silty clay; clay and silt with fine to coarse sand; moderately sorted; olive (5Y 4/3)

460 470 Sandy silty clay; clay and silt with fine to very coarse sand; poorly 

470 480 Sandy silty clay; clay and silt with fine to very coarse sand; poorly sorted; olive (5Y 4/3)

480 490 Slightly gravelly sandy silty clay; clay and silt with coarse sand to granules; moderately sorted; olive gray 

(5Y 4/2)

490 500 Slightly gravelly sandy silty clay; clay and silt with coarse sand to granules; moderately sorted; olive gray 

(5Y 4/2)

500 510 Slightly gravelly sandy silty clay; clay and silt with coarse sand to granules; moderately sorted; olive gray 

(5Y 4/2)

510 520 Silty clayey sand; fine to coarse sand with silt and clay; moderately sorted; subangular to subrounded; olive gray 

(5Y 4/2)

520 530 Silty clayey sand; fine to very coarse sand with silt and clay; poorly sorted; subangular to subrounded; olive 

(5Y 4/3)

530 540 Sandy silty clay; clay and silt with fine to very coarse sand; poorly sorted; olive (5Y 4/3)

540 550 Gravelly sand; coarse sand to pebbles; moderately sorted; subrounded; pebbles are <10 mm in diameter; dark olive 

gray (5Y 3/2)

550 560 Gravelly sand; coarse sand to pebbles; moderately sorted; subrounded; pebbles are <10 mm in diameter; dark olive 

gray (5Y 3/2)

560 570 Gravelly silty clayey sand; fine sand to granules with silt and clay; poorly sorted; subangular; olive 

(5Y 4/3)

570 580 Slightly gravelly sandy silty clay; clay and silt with medium sand to granules; poorly sorted; olive

(5Y 4/3)

580 590 Gravelly sand; coarse sand to granules; moderately sorted; subangular to subrounded; dark olive gray 

(5Y 3/2)

590 600 Gravelly sand; coarse sand to granules; moderately sorted; subrounded; dark olive gray (5Y 3/2)

600 610 Slightly gravelly sandy silty clay; clay and silt with coarse sand to granules; moderately sorted; light olive brown 

(2.5Y 5/3) 

610 620 Gravelly silty clayey sand; coarse sand to granules with occasional silt and clay; moderately sorted; subrounded; olive 

brown (2.5Y 4/3)

620 630 Gravelly sand; coarse sand to granules; moderately sorted; subangular; olive brown (2.5Y 4/3)

630 640 Gravelly sand; coarse sand to granules; moderately sorted; subangular; olive brown (2.5Y 4/3)

Table 8. Lithologic shaker logs for Eleanor Park (ELNR) (5S/3W-36P2–5) multiple-well monitoring site, Santa Clara County, California—Continued

Depth (ft)

Description

From To
74 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

640 650 Gravelly sand; coarse sand to granules; moderately sorted; subangular; olive brown (2.5Y 4/3)

650 660 Slightly gravelly sandy silty clay; clay and silt with coarse sand to pebbles; poorly sorted; pebbles are <10 mm in 

diameter; light olive brown (2.5Y 5/3)

660 670 Gravelly silty sand; fine sand to granules with silt; poorly sorted; subangular; brown (10YR 4/3)

670 680 Slightly gravelly sandy silty clay; clay and silt with coarse sand to granules; moderately sorted; light olive brown 

(2.5Y 5/6)

680 690 No sample collected

690 700 Silty clayey sand; medium to very coarse sand with occasional silt and clay; moderately sorted; subrounded; olive 

brown (2.5Y 4/3)

700 710 Gravelly sand; coarse sand to granules; moderately sorted; subangular; olive brown (2.5Y 4/4)

710 720 Gravelly sand; coarse sand to granules; moderately sorted; subangular; olive brown (2.5Y 4/4)

720 730 Gravelly sand; medium sand to granules; moderately sorted; subrounded; brown (10YR 4/3) 

730 740 Gravelly sand; medium sand to granules; moderately sorted; subrounded; brown (10YR 4/3)

740 750 Gravelly sand; medium sand to granules; moderately sorted; subrounded; dark brown (10YR 3/3) 

750 760 Gravelly silty sand; medium sand to granules with silt; moderately sorted; subrounded; dark brown (10YR 3/3) 

760 770 Gravelly sand; coarse sand to pebbles; moderately sorted; subangular; pebbles are <8 mm in diameter; brown 

(10YR 4/3)

770 780 Gravelly sand; medium sand to pebbles; poorly sorted; subangular; pebbles are <10 mm in diameter; brown 

(10YR 4/3)

780 790 Sand; fine to coarse sand; moderately sorted; subangular to subrounded; brown (10YR 4/3)

790 800 Gravelly sand; medium sand to pebbles; poorly sorted; subrounded; pebbles are <10 mm in diameter; brown

(10YR 4/3)

800 810 Gravelly sand; medium sand to granules; moderately sorted; subrounded; brown (10YR 4/3)

810 820 Gravelly sand; medium sand to pebbles; poorly sorted; subangular to subrounded; pebbles are <10 mm in diameter; 

brown (10YR 4/3)

820 830 Gravelly sand; medium sand to pebbles; poorly sorted; subrounded; pebbles are <10 mm in diameter; brown

(10YR 4/3)

830 840 Gravelly sand; coarse sand to pebbles; moderately sorted; subangular; pebbles are <10 mm in diameter; brown

(10YR 4/3)

840 850 Gravelly sand; medium sand to pebbles; poorly sorted; subangular to subrounded; pebbles are <10 mm in diameter; 

dark greenish gray (10Y 3/1)

850 860 Gravelly sand; medium sand to pebbles; poorly sorted; subrounded; pebbles are <10 mm in diameter; dark greenish 

gray (10Y 3/1)

860 870 Gravelly sand; medium sand to pebbles; poorly sorted; subrounded; pebbles are <10 mm in diameter; dark greenish 

gray (10Y 3/1)

870 880 Gravelly sand; medium sand to pebbles; poorly sorted; subangular to subrounded; pebbles are <10 mm in diameter; 

dark greenish gray (10Y 3/1)

880 890 Slightly gravelly sandy silty clay; clay and silt with medium sand to pebbles; poorly sorted; pebbles are <10 mm in 

diameter; dark greenish gray (10Y 3/1)

890 900 Gravelly sand; medium sand to pebbles; poorly sorted; subrounded to very angular; pebbles are <10 mm in diameter; 

dark olive gray (5Y 3/2)

900 910 Slightly gravelly sandy silty clay; clay and silt with medium sand to granules; poorly sorted; dark greenish gray

(10Y 3/1)

910 920 Gravelly silty clayey sand; coarse sand to granules with silt and clay; moderately sorted; subrounded to rounded; dark 

greenish gray (10Y 4/1)

920 930 Slightly gravelly sandy clayey silt; silt and clay with coarse sand to granules; moderately sorted; dark greenish gray 

(10Y 3/1)

Table 8. Lithologic shaker logs for Eleanor Park (ELNR) (5S/3W-36P2–5) multiple-well monitoring site, Santa Clara County, California—Continued

Depth (ft)

Description

From To
Table 9 75

Table 9. Lithologic shaker logs for Saratoga (STGA) (7S/1W-29C3–6) multiple-well monitoring site, Santa Clara County, California —Continued

Depth (ft)

Description

From To

0 10 Slightly gravelly sandy silty clay; clay and silt with medium sand to granules; poorly sorted; very dark grayish brown 

(2.5Y 3/2)

10 20 Gravelly silty clayey sand; medium sand to pebbles with clay and silt; poorly sorted; subrounded; pebbles are <20 mm 

in diameter; very dark grayish brown (2.5Y 3/2)

20 30 Slightly gravelly sandy silty clay; clay and silt with occasional medium sand to pebbles; poorly sorted; pebbles are 

<10 mm in diameter; dark yellowish brown (10YR 4/4)

30 40 Clayey silty sandy gravel; granules and pebbles with medium to very coarse sand and clay and silt; poorly sorted; 

subrounded; pebbles are <10 mm in diameter; very dark grayish brown (2.5Y 3/2)

40 50 Gravel; granules and pebbles; well sorted; subrounded to subangular; pebbles are <20 mm in diameter; very dark 

grayish brown (2.5Y 3/2)

50 60 Silty clayey sandy gravel; granules and pebbles with occasional silt and clay with medium to very coarse sand; poorly 

sorted; subangular; pebbles are <25 mm in diameter; very dark grayish brown 

(2.5Y 3/2)

60 70 Silty clayey sandy gravel; granules and pebbles with silt and clay and medium to very coarse sand; poorly sorted; 

subrounded; pebbles are <20 mm in diameter; dark yellowish brown (2.5Y 3/2)

70 80 Silty clayey sandy gravel; granules and pebbles with silt and clay and medium to very coarse sand; poorly sorted; 

subrounded; pebbles are <15 mm in diameter; very dark grayish brown (2.5Y 3/2)

80 90 Silty clayey sandy gravel; granules and pebbles with silt and clay and medium sand to very coarse sand; poorly sorted; 

subrounded; pebbles are <15 mm in diameter; very dark grayish brown (2.5Y 3/2)

90 100 Slightly gravelly sandy silty clay; clay and silt with medium sand to pebbles; poorly sorted; pebbles are <10 mm in 

diameter; dark yellowish brown (10YR 4/4)

100 110 Slightly gravelly sandy silty clay: clay and silt with medium sand to pebbles; poorly sorted; pebbles are <10 mm in 

diameter; dark yellowish brown (10YR 4/4)

110 120 Slightly gravelly sandy silty clay; clay and silt with occasional medium sand to pebbles; poorly sorted; pebbles are 

<8 mm in diameter; dark yellowish brown (10YR 4/4)

120 130 Slightly gravelly sandy silty clay; clay and silt with medium sand to pebbles; poorly sorted; pebbles are <8 mm in 

diameter; dark yellowish brown (10YR 4/4)

130 140 Sandy gravel; granules and pebbles with medium to very coarse sand; moderately sorted; subrounded; pebbles are 

<15 mm in diameter; light olive brown (2.5Y 5/6)

140 150 Silty clayey sandy gravel; granules and pebbles with silt and clay and medium to very coarse sand; poorly sorted; 

subrounded; pebbles are <15 mm in diameter; dark yellowish brown (10YR 4/4)

150 160 Silty clayey sandy gravel; granules and pebbles with silt and clay and medium to very coarse sand; poorly sorted; 

subrounded; pebbles are <10 mm in diameter; light olive brown (2.5Y 5/4)

160 170 Sandy gravel; granules and pebbles with medium to very coarse sand; moderately sorted; subangular to subrounded; 

pebbles are <10 mm in diameter; olive brown (2.5Y 4/3)

170 180 Slightly gravelly sandy silty clay; clay and silt with medium sand to pebbles; poorly sorted; pebbles are <10 mm in 

diameter; light olive brown (2.5Y 5/4)

180 190 Silty clayey sandy gravel; granules and pebbles with silt and clay and medium to very coarse sand; poorly sorted; 

subrounded; pebbles are <10 mm in diameter; olive brown (2.5Y 4/3)

190 200 Gravelly silty clayey sand; medium sand to pebbles with occasional silt and clay; poorly sorted; subrounded; pebbles 

are <10 mm in diameter; olive brown (2.5Y 4/3)

200 210 Gravelly silty clayey sand; medium sand to granules with silt and clay; poorly sorted; subrounded; light olive brown 

(2.5Y 5/4)

210 220 Gravelly silty clayey sand; medium sand to granules with silt and clay; poorly sorted; subrounded; light olive brown 

(2.5Y 5/4)

220 230 Slightly gravelly sandy silty clay; clay and silt with medium sand to pebbles; poorly sorted; pebbles are <10 mm in 

diameter; light olive brown (2.5Y 5/4)

Table 9. Lithologic shaker logs for Saratoga (STGA) (7S/1W-29C3–6) multiple-well monitoring site, Santa Clara County, California

[Altitude of land surface, approximately 225 ft; depth is in feet below land surface; soil and rock color notation from Munsell Color (1994); drilled by U.S. 

Geological Survey Western Region Research Drilling Unit, using mud-rotary; total depth drilled 1,000 ft; screened intervals 250–270; 360–380; 530–550; 

630–650 ft; ft, foot; <, less than; mm, millimeter]
76 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

230 240 Slightly gravelly sandy silty clay; clay and silt with medium sand to pebbles; poorly sorted; pebbles are <10 mm in 

diameter; light olive brown (2.5Y 5/4)

240 250 Slightly gravelly sandy silty clay; clay and silt with medium sand to granules; poorly sorted; light olive brown

(2.5Y 5/4)

250 260 Slightly gravelly sandy silty clay; clay and silt with medium sand to granules; poorly sorted; light olive brown 

(2.5Y 5/4) 

260 270 Slightly gravelly sandy silty clay; clay and silt with medium sand to granules; poorly sorted; light olive brown 

(2.5Y 5/4) 

270 280 Slightly gravelly sandy silty clay; clay and silt with medium sand to granules; poorly sorted; light olive brown 

(2.5Y 5/4) 

280 290 Slightly gravelly sandy silty clay; clay and silt with medium sand to pebbles; poorly sorted; pebbles are <10 mm in 

diameter; light olive brown (2.5Y 5/4) 

290 300 Slightly gravelly sandy silty clay; clay and silt with coarse sand to granules; moderately sorted; dark yellowish brown 

(10YR 4/4) 

300 310 Sandy silty clay; clay and silt with coarse to very coarse sand; moderately sorted; yellowish brown 

(10YR 5/4) 

310 320 Slightly gravelly sandy silty clay; clay and silt with medium sand to granules; poorly sorted; light olive brown

(2.5Y 5/4) 

320 330 Gravelly silty clayey sand; medium sand to granules with occasional clay and silt; poorly sorted; subangular to 

subrounded; olive brown (2.5Y 4/4) 

330 340 Gravelly silty clayey sand; medium sand to granules with occasional clay and silt; poorly sorted; subangular to 

subrounded; olive brown (2.5Y 4/4) 

340 350 Slightly gravelly sandy silty clay; clay and silt with medium sand to pebbles; poorly sorted; pebbles are <15 mm in 

diameter; light olive brown (2.5Y 5/4) 

350 360 Gravelly silty clayey sand; medium sand to granules with silt and clay; poorly sorted; subrounded; light olive brown 

(2.5Y 5/4) 

360 370 Gravelly sand; fine sand to granules; moderately sorted; subangular to subrounded; olive brown (2.5Y 4/4) 

370 380 Gravelly sand; fine sand to pebbles; poorly sorted; subangular to subrounded; pebbles are <10 mm in diameter; olive 

brown (2.5Y 4/4) 

380 390 Gravelly silty sand; medium sand to pebbles with occasional silt; poorly sorted; subangular to subrounded; pebbles are 

<10 mm in diameter; light olive brown (2.5Y 5/4) 

390 400 Gravelly sand; medium sand to granules; moderately sorted; subangular to subrounded; light olive brown 

(2.5Y 5/4) 

400 410 Slightly gravelly sandy silty clay; clay and silt with medium sand to granules; poorly sorted; light olive brown 

(2.5Y 5/4) 

410 420 Gravelly silty clayey sand; medium sand to pebbles with occasional clay and silt; poorly sorted; subangular; pebbles 

are <10 mm in diameter; mm in diameter; light olive brown (2.5Y 5/4) 

420 430 Gravelly silty clayey sand; medium sand to granules with silt and clay; poorly sorted; subangular; light olive brown 

(2.5Y 5/4) 

430 440 Gravelly sand; coarse sand to granules; moderately sorted; subangular to subrounded; light yellowish brown (2.5Y 6/4) 

440 450 Slightly gravelly sandy silty clay; clay and silt with medium sand to granules; poorly sorted; light olive brown 

(2.5Y 5/4) 

460 460 Slightly gravelly sandy silty clay; clay and silt with medium sand to granules; poorly sorted; light olive brown 

(2.5Y 5/4) 

460 470 Gravelly silty clayey sand; medium sand to granules with silt and clay; poorly sorted; subangular; light olive brown 

(2.5Y 5/4) 

470 480 Slightly gravelly sandy silty clay; clay and silt with medium sand to granules; poorly sorted; light olive brown 

(2.5Y 5/4) 

Table 9. Lithologic shaker logs for Saratoga (STGA) (7S/1W-29C3–6) multiple-well monitoring site, Santa Clara County, California —Continued

Depth (ft)

Description

From To
Table 9 77

480 490 Gravelly silty clayey sand; medium sand to granules with silt and clay; poorly sorted; subrounded; olive brown 

(2.5Y 4/4) 

490 500 Gravelly sand; medium sand to pebbles; moderately sorted; subrounded to subangular; pebbles are <10 mm in 

diameter; olive brown (2.5Y 4/4) 

500 510 Slightly gravelly sandy silty clay; clay and silt with medium sand to pebbles; poorly sorted; pebbles are <10 mm in 

diameter; light olive brown (2.5Y 5/4) 

510 520 Gravelly silty clayey sand; medium sand to granules with silt and clay; poorly sorted; subangular to subrounded; light 

olive brown (2.5Y 5/4) 

520 530 Gravelly silty clayey sand; medium sand to granules with silt and clay; poorly sorted; subrounded; light olive brown 

(2.5Y 5/4) 

530 540 Gravelly silty clayey sand; medium sand to granules with silt and clay; poorly sorted; subrounded; light olive brown 

(2.5Y 5/4) 

540 550 Gravelly silty clayey sand; fine sand to granules with occasional silt and clay; poorly sorted; subrounded; light olive 

brown (2.5Y 5/4) 

550 560 Silty clayey sand; fine to very coarse sand with silt and clay; poorly sorted; subrounded; light olive brown (2.5Y 5/4) 

560 570 Slightly gravelly sandy silty clay; clay and silt with medium sand to granules; poorly sorted; light olive brown 

(2.5Y 5/4) 

570 580 Gravelly silty clayey sand; medium sand to granules with silt and clay; poorly sorted; subrounded; olive brown 

(2.5Y 4/4) 

580 590 Slightly gravelly sandy silty clay; clay and silt with medium sand to granules; poorly sorted; light olive brown 

(2.5Y 5/3) 

590 600 Slightly gravelly sandy silty clay; clay and silt with occasional medium sand to granules; poorly sorted; olive brown 

(2.5Y 4/4) 

600 610 Gravelly sand; medium sand to pebbles; moderately sorted; subangular to subrounded; pebbles are <10 mm in 

diameter; olive (5Y 4/3) 

610 620 Slightly gravelly sandy silty clay; clay and silt with coarse sand to pebbles; poorly sorted; pebbles are <10 mm in 

diameter; light olive brown (2.5Y 5/4) 

620 630 Slightly gravelly sandy clayey silt; silt and clay with medium sand to granules; poorly sorted; light olive brown

(2.5Y 5/4) 

630 640 Gravelly sand; coarse sand to pebbles; moderately sorted; subangular; pebbles are <15 mm in diameter; olive (5Y 5/3) 

640 650 Gravelly sand; coarse sand to pebbles; moderately sorted; subangular; pebbles are <15 mm in diameter; olive (5Y 5/3)

650 660 Gravelly sand; coarse sand to pebbles; moderately sorted; subangular to subrounded; pebbles are <15 mm in diameter; 

olive (5Y 5/3) 

660 670 Slightly gravelly sandy silty clay; clay and silt with coarse sand to granules; moderately sorted; light olive brown 

(2.5Y 5/4) 

670 680 Slightly gravelly sandy silty clay; clay and silt with medium sand to pebbles; poorly sorted; pebbles are <10 mm in 

diameter; light olive brown (2.5Y 5/4) 

680 690 Gravelly sand; coarse sand to granules; moderately sorted; subrounded; olive (5Y 5/3) 

690 700 Slightly gravelly sandy silty clay; clay and silt with medium sand to granules; poorly sorted; light olive brown 

(2.5Y 5/4) 

700 710 Slightly gravelly sandy silty clay; clay and silt with coarse sand to granules; moderately sorted; light olive brown 

(2.5Y 5/4) 

710 720 Gravelly silty clayey sand; medium sand to granules with silt and clay; poorly sorted; subangular; olive (5Y 5/3) 

720 730 Gravelly silty clayey sand; coarse sand to granules with silt and clay; moderately sorted; subangular to subrounded; 

olive brown (2.5Y 4/3) 

730 740 Gravelly silty clayey sand; coarse sand to granules with clay and silt; moderately sorted; subangular to subrounded; 

olive brown (2.5Y 4/3) 

740 750 Slightly gravelly sandy silty clay; clay and silt with coarse sand to granules; moderately sorted; light olive brown 

(2.5Y 5/4) 

750 760 Slightly gravelly sandy silty clay; clay and silt with coarse sand to granules; moderately sorted; light olive brown

(2.5Y 5/4)

Table 9. Lithologic shaker logs for Saratoga (STGA) (7S/1W-29C3–6) multiple-well monitoring site, Santa Clara County, California —Continued

Depth (ft)

Description

From To
78 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

760 770 Gravelly sand; coarse sand to granules; moderately sorted; subangular; olive (5Y 5/3) 

770 780 Gravelly sand; coarse sand to pebbles; moderately sorted; subangular; pebbles are <10 mm in diameter; olive (5Y 5/3) 

780 790 Gravelly sand; coarse sand to pebbles; moderately sorted; subangular; pebbles are <8 mm in diameter; olive (5Y 5/3) 

790 800 Sandy gravel; pebbles and granules with coarse to very coarse sand; moderately sorted; subangular to subrounded; 

pebbles are <12 mm in diameter; olive (5Y 4/3) 

800 810 Gravelly sand; coarse sand to granules; moderately sorted; angular to subangular; olive (5Y 4/3) 

810 820 Gravelly sand; coarse sand to pebbles; moderately sorted; angular to subangular; pebbles are <12 mm in diameter; 

olive (5Y 4/3)

820 830 Gravelly clayey sand; coarse sand to granules with clay; moderately sorted; subangular; olive gray (5Y 4/2) 

830 840 Gravelly sand; coarse sand to granules; moderately sorted; subangular; olive (5Y 4/3)

840 850 Gravelly sand; coarse sand to granules; moderately sorted; subangular; dark olive gray (5Y 3/2)

850 860 Slightly gravelly sandy clay; clay with coarse sand to granules; moderately sorted; olive gray (5Y 4/2) 

860 870 Gravelly clayey silty sand; coarse sand to granules with silt and clay; moderately sorted; subangular; olive (5Y 5/3)

870 880 Gravelly sand; coarse sand to granules; moderately sorted; subangular; olive (5Y 4/3)

880 890 Gravelly sand; coarse sand to granules; moderately sorted; subangular; dark olive gray (5Y 3/2) 

890 900 Gravelly sand; coarse sand to granules; moderately sorted; subangular; dark olive gray (5Y 3/2) 

900 910 Gravelly sand; coarse sand to pebbles; moderately sorted; subangular; pebbles are <10 mm in diameter; dark olive gray 

(5Y 3/2)

910 920 Gravelly clayey sand; coarse sand to pebbles with clay; moderately sorted; subrounded; pebbles are 

<10 mm in diameter; olive gray (5Y 4/2) 

920 930 Slightly gravelly sandy silty clay; clay and silt with coarse sand to pebbles; poorly sorted; pebbles are <10 mm in 

diameter; olive gray (5Y 4/2)

930 940 Gravelly sand; coarse sand to granules; moderately sorted; subangular; olive gray (5Y 4/2) 

940 950 Gravelly silty clayey sand (gmS); coarse sand to granules with clay and silt; moderately sorted; subrounded; olive gray 

(5Y 4/2)

950 960 Slightly gravelly sandy silty clay; clay and silt with coarse sand to pebbles; poorly sorted; pebbles are <10 mm in 

diameter; olive gray (5Y 4/2)

960 970 Gravelly sand; coarse sand to granules; moderately sorted; subangular; dark olive gray (5Y 3/2)

970 980 Gravelly clayey silty sand; coarse sand to granules with clay and silt; moderately sorted; subangular; olive gray 

(5Y 4/2)

980 990 Slightly gravelly sandy silty clay; clay and silt with coarse sand to granules; moderately sorted; olive gray (5Y 4/2)

990 1,000 Slightly gravelly sandy silty clay; clay and silt with coarse sand to granules; moderately sorted; olive gray (5Y 4/2)

Table 9. Lithologic shaker logs for Saratoga (STGA) (7S/1W-29C3–6) multiple-well monitoring site, Santa Clara County, California —Continued

Depth (ft)

Description

From To
Table 10 79

Table 10. Lithologic shaker logs for Evergreen (EVGR) (7S/2E-19C5–9) multiple-well monitoring site, Santa Clara, California—Continued

Depth (ft)

Description

From To

60 70 Gravelly silty clayey sand; coarse sand to pebbles with silt and clay; poorly sorted; subrounded; pebbles are 

<10 mm in diameter; dark yellowish brown (10YR 4/4)

70 80 Gravelly silty clayey sand; coarse sand to granules with silt and clay; moderately sorted; subrounded; dark 

yellowish brown (10YR 4/4)

80 90 Gravelly silty clayey sand; coarse sand to pebbles with silt and clay; poorly sorted; subrounded; pebbles are 

<10 mm in diameter; dark yellowish brown (10YR 4/4) 

90 100 Silty clayey sandy gravel; granules and pebbles with coarse to very coarse sand and silt and clay; poorly 

sorted; subrounded; pebbles are <8 mm in diameter; light olive brown (2.5Y 5/6)

100 110 Slightly gravelly sandy silty clay; clay and silt with coarse sand to granules; moderately sorted; light olive 

brown (2.5Y 5/6)

110 120 Slightly gravelly sandy silty clay; clay and silt with coarse sand to granules; moderately sorted; light olive 

brown (2.5Y 5/6)

120 130 Slightly gravelly sandy silty clay; clay and silt with coarse sand to granules; moderately sorted; light olive 

brown (2.5Y 5/6)

130 140 Gravelly silty clayey sand; coarse sand to granules with silt and clay; moderately sorted; subangular to 

subrounded; light olive brown (2.5Y 5/6)

140 150 Gravelly silty clayey sand; coarse sand to pebbles with silt and clay; poorly sorted; subangular to subrounded; 

pebbles are <12 mm in diameter; light olive brown (2.5Y 5/4)

150 160 Gravelly silty clayey sand; coarse sand to pebbles with occasional silt and clay; poorly sorted; subrounded; 

pebbles are <8 mm in diameter; light olive brown (2.5Y 5/4)

160 170 Gravelly silty clayey sand; coarse sand to granules with silt and clay; moderately sorted; subangular; light 

olive brown (2.5Y 5/4)

170 180 Gravelly silty clayey sand; coarse sand to pebbles with silt and clay; poorly sorted; subrounded; pebbles are 

<12 mm in diameter; light olive brown (2.5Y 5/4)

180 210 Gravelly silty clayey sand; coarse sand to granules with silt and clay; moderately sorted; subrounded; light 

olive brown (2.5Y 5/4)

210 220 Gravelly silty clayey sand; coarse sand to granules with silt and clay; moderately sorted; subangular to 

subrounded; light olive brown (2.5Y 5/4)

220 230 Sandy gravel; granules and pebbles with coarse to very coarse sand; moderately sorted; subangular; pebbles 

are <10 mm in diameter; light olive brown (2.5Y 5/4)

230 240 Clayey silty sandy gravel; granules and pebbles with coarse to very coarse sand and clay and silt; poorly 

sorted; subrounded; pebbles are <8 mm in diameter; light olive brown (2.5Y 5/4)

240 270 Gravelly silty clayey sand; coarse sand to granules with silt and clay; moderately sorted; subangular; light 

olive brown (2.5Y 5/4)

270 280 Gravelly silty clayey sand; coarse sand to granules with silt and clay; moderately sorted; subangular to 

subrounded; light olive brown (2.5Y 5/4)

280 290 Gravelly silty clayey sand; coarse sand to granules with occasional silt and clay; moderately sorted; 

subangular; light olive brown (2.5Y 5/4)

290 330 Gravelly sand; coarse sand to granules; moderately sorted; subangular to subrounded; light olive brown 

(2.5Y 5/4)

330 340 Gravelly sand; coarse sand to granules; moderately sorted; subangular to subrounded; light olive brown

(2.5Y 5/4)

340 350 Gravelly sand; coarse sand to granules; moderately sorted; subangular to subrounded; light olive brown 

(2.5Y 5/4)

350 360 Gravelly silty clayey sand; coarse sand to pebbles with occasional silt and clay; poorly sorted; subangular; 

pebbles are <8 mm in diameter; light olive brown (2.5Y 5/4)

Table 10. Lithologic shaker logs for Evergreen (EVGR) (7S/2E-19C5–9) multiple-well monitoring site, Santa Clara, California

[Altitude of land surface, approximately 183 ft; depth is in feet below land surface; soil and rock color notation from Munsell Color (1994); drilled by U.S. 

Geological Survey Western Region Research Drilling Unit, using mud-rotary, April 2001; total depth drilled 1,030 ft; screened intervals 130–150; 270–290; 

370–390; 610–630; 740–760 ft; ft, foot; <, less than; mm, millimeter]
80 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

360 370 Gravelly silty clayey sand; coarse sand to granules with occasional silt and clay; subangular; light olive brown 

(2.5Y 5/4)

370 380 Gravelly silty clayey sand; coarse sand to granules with occasional silt and clay; subangular; light olive brown 

(2.5Y 5/4)

380 390 Gravelly silty clayey sand; coarse sand to granules with occasional silt and clay; moderately sorted; 

subangular to subrounded; light olive brown (2.5Y 5/4)

390 420 Gravelly silty clayey sand; coarse sand to pebbles with occasional silt and clay; poorly sorted; subangular; 

pebbles are <8 mm in diameter; light olive brown (2.5Y 5/4)

420 430 Gravelly silty clayey sand; coarse sand to granules with silt and clay; moderately sorted; subangular to 

subrounded; light olive brown (2.5Y 5/4)

430 440 Gravelly silty clayey sand; coarse sand to granules with silt and clay; moderately sorted; subangular; light 

olive brown (2.5Y 5/4)

440 450 Gravelly sand; coarse sand to granules; moderately sorted; subrounded; olive brown (2.5Y 4/4)

450 480 Gravelly sand; coarse sand to granules; moderately sorted; subangular to subrounded; light olive brown

(2.5Y 5/4)

480 490 Gravelly sand; coarse sand to granules; moderately sorted; subangular to subrounded; light olive brown

(2.5Y 5/4)

490 500 Gravelly sand; coarse sand to granules; moderately sorted; subangular to subrounded; light olive brown

(2.5Y 5/4)

500 510 Gravelly sand; coarse sand to pebbles; moderately sorted; subangular; pebbles are <8 mm in diameter; light 

olive brown (2.5Y 5/3)

510 520 Gravelly sand; coarse sand to pebbles; moderately sorted; subangular; pebbles are <8 mm in diameter; light 

olive brown (2.5Y 5/3)

520 530 Gravelly sand; coarse sand to pebbles; moderately sorted; subangular; pebbles are <8 mm in diameter; light 

olive brown (2.5Y 5/3)

530 540 Gravelly sand; coarse sand to granules; moderately sorted; subangular to subrounded; light olive brown 

(2.5Y 5/4)

540 560 Gravelly silty clayey sand; coarse sand to granules with occasional silt and clay; moderately sorted; 

subangular to subrounded; light olive brown (2.5Y 5/4)

560 570 Gravelly silty clayey sand; coarse sand to granules with occasional silt and clay; subrounded; light olive 

brown (2.5Y 5/4)

570 600 Gravelly silty clayey sand; coarse sand to granules with occasional silt and clay; subrounded; light olive 

brown (2.5Y 5/4)

600 610 Gravelly silty clayey sand; coarse sand to granules with occasional silt and clay; subrounded; light olive 

brown (2.5Y 5/4)

610 620 Gravelly silty clayey sand; coarse sand to granules with occasional silt and clay; moderately sorted; 

subangular; light olive brown (2.5Y 5/4)

620 630 Gravelly silty clayey sand; coarse sand to granules with occasional silt and clay; moderately sorted; 

subrounded; light olive brown (2.5Y 5/4)

630 640 Gravelly silty clayey sand; coarse sand to granules with occasional silt and clay; moderately sorted; 

subrounded; light olive brown (2.5Y 5/4)

640 670 Gravelly silty clayey sand; coarse sand to granules with occasional silt and clay; moderately sorted; 

subangular; light olive brown (2.5Y 5/4)

670 680 Gravelly silty clayey sand; coarse sand to granules with occasional silt and clay; moderately sorted; 

subangular; light olive brown (2.5Y 5/4)

680 690 Gravelly silty clayey sand; coarse sand to granules with occasional silt and clay; moderately sorted; 

subangular; light olive brown (2.5Y 5/4)

690 700 Gravelly sand; coarse sand to pebbles; moderately sorted; subrounded; pebbles are <8 mm in diameter; olive 

brown (2.5Y 4/4)

Table 10. Lithologic shaker logs for Evergreen (EVGR) (7S/2E-19C5–9) multiple-well monitoring site, Santa Clara, California—Continued

Depth (ft)

Description

From To
Table 10 81

700 710 Gravelly silty clayey sand; coarse sand to granules with occasional silt and clay; moderately sorted; 

subangular; olive brown (2.5Y 4/3)

710 720 Gravelly silty clayey sand; coarse sand to pebbles with occasional silt and clay; poorly sorted; subangular; 

pebbles are <8 mm in diameter; olive brown (2.5Y 4/3)

720 730 Gravelly silty clayey sand; coarse sand to granules with occasional silt and clay; moderately sorted; 

subangular; olive brown (2.5Y 4/3)

730 740 Gravelly sand; coarse sand to pebbles; moderately sorted; subangular; pebbles are <8 mm in diameter; olive 

brown (2.5Y 4/3)

740 750 Gravelly silty clayey sand; coarse sand to granules with silt and clay; moderately sorted; subrounded; light 

olive brown (2.5Y 5/4)

750 760 Gravelly silty clayey sand; coarse sand to granules with occasional silt and clay; moderately sorted; 

subrounded; olive brown (2.5Y 4/3)

760 770 Gravelly sand; coarse sand to pebbles; moderately sorted; subrounded; olive brown (2.5Y 4/3)

770 800 Gravelly silty clayey sand; coarse sand to granules with occasional silt and clay; moderately sorted; 

subrounded; light olive brown (2.5Y 5/4)

800 810 Gravelly silty clayey sand; coarse sand to granules with occasional silt and clay; moderately sorted; 

subrounded; light olive brown (2.5Y 5/4)

810 820 Gravelly silty clayey sand; coarse sand to granules with occasional silt and clay; moderately sorted; 

subangular; olive brown (2.5Y 4/4)

820 830 Gravelly silty clayey sand; coarse sand to granules with occasional silt and clay; moderately sorted; 

subrounded; olive brown (2.5Y 4/4)

830 840 Gravelly silty clayey sand; coarse sand to pebbles with occasional silt and clay; poorly sorted; subrounded; 

pebbles are <15 mm in diameter; olive brown (2.5Y 4/4)

840 850 Gravelly silty clayey sand; coarse sand to granules with occasional silt and clay; moderately sorted; 

subrounded; light olive brown (2.5Y 5/4)

850 860 Gravelly silty clayey sand; coarse sand to granules with occasional silt and clay; moderately sorted; 

subrounded; light olive brown (2.5Y 5/4)

860 870 Gravelly silty clayey sand; coarse sand to granules with occasional silt and clay; moderately sorted; 

subrounded; light olive brown (2.5Y 5/4) 

870 880 Gravelly silty clayey sand; coarse sand to granules with occasional silt and clay; moderately sorted; 

subangular; light olive brown (2.5Y 5/4)

880 890 Gravelly silty clayey sand; coarse sand to granules with occasional silt and clay; moderately sorted; 

subangular; light olive brown (2.5Y 5/4) 

890 900 Gravelly silty clayey sand; coarse sand to granules with occasional silt and clay; moderately sorted; 

subrounded; light olive brown (2.5Y 5/4)

900 910 Gravelly silty clayey sand; coarse sand to granules with silt and clay; moderately sorted; subrounded; light 

olive brown (2.5Y 5/4)

910 920 Gravelly silty clayey sand; coarse sand to granules with silt and clay; moderately sorted; subrounded; olive 

brown (2.5Y 4/4)

920 930 Gravelly silty clayey sand; coarse sand to granules with occasional silt and clay; moderately sorted; 

subrounded; light olive brown (2.5Y 5/4)

930 940 Sandy gravel; pebbles and granules with coarse to very coarse sand; moderately sorted; subrounded; pebbles 

are <15 mm in diameter; olive brown (2.5Y 4/4)

940 950 Gravelly silty clayey sand; coarse sand to granules with occasional silt and clay; moderately sorted; 

subangular; light olive brown (2.5Y 5/4)

950 960 Gravelly silty clayey sand; coarse sand to pebbles with silt and clay; poorly sorted; subangular; pebbles are 

<10 mm in diameter; light olive brown (2.5Y 5/4)

Table 10. Lithologic shaker logs for Evergreen (EVGR) (7S/2E-19C5–9) multiple-well monitoring site, Santa Clara, California—Continued

Depth (ft)

Description

From To
82 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

Table 11. Summary of multi-sensor logging data for cores collected from multiple-well monitoring sites, Santa Clara County, California—Continued

Core ID

(Site-core

#-section)

Depth to

top 

of core

(ft bls)

Depth to 

bottom

of core

(ft bls)

Total core 

length

(ft)

Primary 

velocity

(km/sec)

Average core 

velocity

(ft/sec)

Average 

core 

density

(g/cm3)

Average 

core 

magnetic 

susceptibility

(unitless)

CCOC-1C-1 0.0 1.8 1.8 — — 1.82 16

CCOC-2C-1 11.0 14.3 3.3 — — 2.02 6

CCOC-4C-1 20.9 24.2 3.3 1.7016 5,475.7 2.11 (H) 15

CCOC-5C-1 26.0 29.9 3.9 1.5926 5,125.0 2.03 14

CCOC-6C-1 31.0 32.8 1.8 1.5585 5,015.3 1.95 13

CCOC-7C-1 36.0 38.1 2.1 1.5635 5,031.3 2.00 8

CCOC-8C-1 41.0 43.5 2.5 1.6133 5,191.6 2.00 0

CCOC-9C-1 56.0 59.3 3.3 1.6839 5,418.8 2.12 (H) 11

CCOC-11C-1 63.5 64.3 .8 — — 1.74 (L)(H) 5

CCOC-12C-1 66.0 67.4 1.4 1.468 4,724.0 (L) 2.30 (H) 20

CCOC-13C-1 68.1 69.5 1.4 1.5128 4,868.2 2.10 (H) 27

CCOC-15C-1 75.6 78.1 2.5 — — 2.04 (H) 12

CCOC-15C-2 73.1 75.7 2.6 1.623 5,222.8 2.08 16

CCOC-16C-1 78.5 80.6 2.1 — — 1.94 9

CCOC-17C-1 80.8 83.5 2.7 — — 2.05 (H) 16

CCOC-18C-1 85.5 88.2 2.7 1.6937 5,450.3 2.13 (H) 14

CCOC-19C-1 91.0 95.2 4.2 1.6841 5,419.4 2.14 (H) 16

CCOC-20C-1 96.0 100.5 4.5 1.6974 5,462.2 2.09 13

CCOC-21C-1 101.0 105.5 4.5 1.6156 5,199.0 1.99 11

CCOC-22C-1 106.0 108.6 2.7 1.6651 5,358.3 2.08 9

CCOC-23C-1 111.0 115.7 4.7 1.5698 5,051.6 1.95 15

CCOC-24C-1 115.9 120.4 4.5 1.6422 5,284.6 2.02 18

CCOC-25C-1 121.0 123.1 2.1 1.7025 5,478.6 2.19 (H) 19

CCOC-26C-1 125.8 128.5 2.6 1.6935 5,449.7 2.10 (H) 14

CCOC-27C-1 128.5 131.0 2.5 1.7114 5,507.3 2.14 14

CCOC-28C-1 130.4 134.4 4.1 1.6627 5,350.6 2.06 10

CCOC-29C-1 231.0 234.1 3.1 1.7558 5,650.2 2.13 0

CCOC-30C-1 236.0 238.7 2.7 1.7055 5,488.3 2.11 7

CCOC-31C-1 241.0 244.3 3.3 1.6651 5,358.3 2.31 (H) 24

CCOC-32C-1 245.4 247.8 2.4 1.7116 5,507.9 2.27 (H) 23

CCOC-33C-1 251.0 254.1 3.1 1.7466 5,620.6 2.36 (H) 16

CCOC-34C-1 256.0 260.1 4.1 1.7434 5,610.3 2.14 (H) 24

CCOC-35C-1 261.0 264.4 3.4 1.7509 5,634.4 2.18 (H) 21

CCOC-36C-1 265.9 266.5 0.5 — — 2.24 (H) 14

CCOC-37C-1 271.0 271.7 0.7 — — 2.36 (H) 11

CCOC-38C-1 275.4 277.1 1.6 — — 2.27 (H) 44

CCOC-39C-1 471.0 471.9 0.9 1.7294 5,565.2 2.17 14

CCOC-40C-1 476.0 480.9 4.9 1.7658 5,682.3 2.19 (H) 9

CCOC-45C-1 498.5 499.3 0.8 — — 2.39 (H) 20

CCOC-46C-1 550.7 553.1 2.4 1.7765 5,716.8 2.16 10

Table 11. Summary of multi-sensor logging data for cores collected from multiple-well monitoring sites, Santa Clara County, California

[km/sec, kilometers per second; ft, foot; ft/sec, foot per second; bls, below land surface; g/cm3, grams per cubic centimeter; (H), core contains relatively greater 

velocity or density; (L), core contains relatively lower velocity or density; —, no data]
Table 11 83

CCOC-47C-1 553.4 554.9 1.4 1.762 5,670.1 2.24 (H) 20

CCOC-48C-1 558.1 560.0 1.9 1.7904 5,761.5 2.27 (H) 28

CCOC-49C-1 561.0 565.5 4.5 1.7754 5,713.2 2.17 33

CCOC-50C-1 566.0 570.3 4.3 1.7831 5,738.0 2.18 (H) 22

CCOC-51C-1 571.0 574.8 3.8 1.7599 5,663.4 2.23 (H) 27

CCOC-52C-1 575.9 578.6 2.7 1.7897 5,759.3 2.25 (H) 19

CCOC-53C-1 581.0 581.9 .9 — — 2.50 (H) 55

CCOC-54C-1 585.9 588.4 2.5 1.8182 5,851.0 2.23 (H) 34

CCOC-55C-1 588.5 590.0 1.5 1.8019 5,798.5 2.29 (H) 32

CCOC-56C-1 636.0 637.3 1.3 — — 2.20 (H) 11

CCOC-57C-1 638.5 639.7 1.2 — — 2.20 (H) 23

CCOC-58C-1 640.8 643.0 2.2 — — 2.38 (H) 46

CCOC-59C-1 643.3 644.5 1.1 1.7341 5,580.3 2.21 (H) 29

CCOC-60C-1 670.8 675.9 5.1 1.771 5,699.1 2.21 (L)(H) 43

CCOC-61C-1 676.0 679.4 3.4 1.7457 5,617.7 2.15 (H) 36

CCOC-62C-1 716.0 718.2 2.2 1.6162 5,200.9 2.39 (H) 26

CCOC-63C-1 721.0 722.6 1.6 — — 2.36 (H) 57

CCOC-64C-1 726.0 726.9 .9 1.7791 5,725.1 2.34 (H) 30

CCOC-65C-1 731.0 734.6 3.6 1.7514 5,636.0 2.18 21

CCOC-66C-1 736.0 738.8 2.8 1.7685 5,691.0 2.19 27

CCOC-67C-1 781.0 785.4 4.4 1.7581 5,657.6 2.21 (H) 47

CCOC-68C-1 816.0 818.4 2.4 1.6883 5,432.9 2.15 (H) 47

CCOC-69C-1 821.0 822.3 1.3 1.6825 5,414.3 2.14 34

CCOC-70C-1 826.0 826.5 .5 — — 2.25 (H) 11

CCOC-71C-1 881.0 882.9 1.9 1.7981 5,786.3 2.21 (H) 33

CCOC-72C-1 886.0 890.8 4.8 1.7193 5,532.7 2.05 (H) 27

CCOC-73C-1 891.0 893.7 2.7 1.801 5,795.6 2.21 (H) 39

CCOC-74C-1 896.0 897.3 1.3 1.7667 5,685.2 2.13 5

CCOC-75C-1 961.0 962.8 1.8 1.7595 5,662.1 2.23 (H) 27

CCOC-76C-1 966.0 969.0 3.0 — — 2.35 (L)(H) 39

CCOC-77C-1 996.0 998.3 2.3 1.7455 5,617.0 2.45 (H) 27

CCOC-78C-1 1001.0 1002.4 1.4 1.7996 5,791.1 2.17 10

CCOC-79C-1 1006.0 1009.2 3.2 1.6484 5,304.6 2.28 (H) 18

WLLO1-1C-1 39.6 44.6 4.9 1.6 5,148.8 1.97 (H) 3

WLLO1-2C-1 45.0 47.8 2.8 1.5963 5,136.9 2.14 (L)(H) 6

WLLO1-3C-1 49.7 54.6 5.0 1.6673 5,365.4 2.09 (H) 6

WLLO1-4C-1 55.0 59.1 4.1 1.6954 5,455.8 2.10 (H) 5

WLLO1-5C-1 60.0 62.2 2.2 — — 2.35 (H) 16

WLLO1-10C-1 85.0 86.9 1.9 — — 2.40 (H) 21

WLLO1-11C-1 87.8 88.5 .7 — — 2.35 (H) 9

WLLO1-14C-1 109.7 114.3 4.7 1.6351 5,261.8 2.05 (H) 9

WLLO1-15C-1 294.8 299.1 4.3 1.6495 5,308.1 2.08 8

WLLO1-16C-1 300.0 302.9 2.9 1.6983 5,465.1 2.11 9

WLLO1-17C-1 305.0 310.0 5.0 1.6854 5,423.6 2.11 21

WLLO1-18C-1 310.0 315.0 5.0 1.7147 5,517.9 2.14 (H) 23

Table 11. Summary of multi-sensor logging data for cores collected from multiple-well monitoring sites, Santa Clara County, California—Continued

Core ID

(Site-core

#-section)

Depth to

top 

of core

(ft bls)

Depth to 

bottom

of core

(ft bls)

Total core 

length

(ft)

Primary 

velocity

(km/sec)

Average core 

velocity

(ft/sec)

Average 

core 

density

(g/cm3)

Average 

core 

magnetic 

susceptibility

(unitless)
84 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

WLLO1-19C-1 410.0 412.9 2.9 1.7464 5,619.9 2.19 (H) 25

WLLO1-20C-1 490.0 490.8 .8 — — 2.16 (H) 26

WLLO1-21C-1 494.8 495.4 .6 1.4169 4,559.6 2.10 (H) 11

WLLO1-24C-1 592.5 593.9 1.4 — — 2.27 (H) 28

WLLO1-25C-1 310.0 315.0 5.0 — — 2.44 (H) 29

WLLO1-26C-1 598.0 599.7 1.7 — — 2.44 (H) 28

WLLO1-27C-1 620.0 623.1 3.1 — — 2.39 (H) 38

WLLO1-28C-1 670.0 673.0 3.0 1.6938 5,450.6 2.13 28

WLLO1-29C-1 673.0 675.2 2.2 1.6496 5,308.4 2.15 (H) 28

WLLO1-30C-1 705.0 710.0 5.0 1.6904 5,439.7 2.09 15

WLLO1-31C-1 735.0 736.2 1.2 1.8435 5,932.4 2.15 54

WLLO1-32C-1 738.0 740.5 2.5 1.7209 5,537.9 2.11 40

WLLO1-33C-1 741.0 746.0 5.0 1.6943 5,452.3 2.09 33

WLLO1-34C-1 746.0 749.0 3.0 1.6687 5,369.9 1.79 229

WLLO1-36C-1 755.0 759.4 4.4 1.7108 5,505.4 2.08 64

WLLO1-37C-1 780.0 784.0 4.0 1.7078 5,495.7 1.88 232

WLLO2-1C-1 30.0 32.8 2.8 1.6474 5,301.3 2.02 0

WLLO2-2C-1 34.8 39.2 4.4 1.6325 5,253.4 1.99 9

WLLO2-3C-1 40.0 43.1 3.1 1.6257 5,231.5 1.99 4

WLLO2-4C-1 45.0 45.9 .9 1.6316 5,250.5 2.28 5

WLLO2-5C-1 50.0 54.9 4.9 1.674 5,386.9 2.07 8

WLLO2-6C-1 55.0 59.4 4.4 1.6795 5,404.6 2.10 5

WLLO2-7C 82.2 83.5 1.3 1.3845 4,455.3 (L) 2.23 13

MGCY-1C-1 13.8 14.6 .9 — — 2.27 (H) 17

MGCY-3C-1 28.0 29.5 1.5 1.3314 4,284.4 (L) 2.18 (H) 20

MGCY-4C-1 33.6 36.1 2.5 1.5499 4,987.6 2.33 (H) 45

MGCY-9C-1 54.0 55.1 1.1 — — 2.40 (H) 19

MGCY-10C-1 58.8 60.1 1.2 — — 2.44 (H) 246

MGCY-11C-1 64.0 65.3 1.3 — — 2.37 (H) 24

MGCY-13C-1 129.0 130.7 1.7 — — 2.36 (H) 25

MGCY-15C-1 134.0 135.3 1.3 — — 2.24 (H) 10

MGCY-16C-1 136.5 138.2 1.7 — — 2.33 (H) 25

MGCY-17C-1 139.0 141.4 2.4 — — 2.31 (H) 25

MGCY-14C-1 130.5 134.9 4.4 — — 2.17 (H) 22

MGCY-20C-1 146.4 148.3 1.9 — — 2.33 (H) 17

MGCY-21C-1 148.8 149.7 .8 1.674 5,386.9 2.22 (H) 11

MGCY-22C-1 151.3 153.7 2.4 1.6406 5,279.5 2.00 21

MGCY-23C-1 154.0 156.4 2.4 1.6518 5,315.5 2.05 (H) 24

MGCY-24C-1 159.0 161.5 2.5 — — 2.42 (H) 20

MGCY-25C-1 164.0 166.4 2.4 — — 2.37 (H) 28

MGCY-26C-1 229.9 232.8 2.9 — — 2.30 (H) 38

MGCY-27C-1 234.0 237.0 3.0 — — 2.35 (H) 32

MGCY-29C-1 244.0 245.1 1.1 — — 2.34 (H) 13

Table 11. Summary of multi-sensor logging data for cores collected from multiple-well monitoring sites, Santa Clara County, California—Continued

Core ID

(Site-core

#-section)

Depth to

top 

of core

(ft bls)

Depth to 

bottom

of core

(ft bls)

Total core 

length

(ft)

Primary 

velocity

(km/sec)

Average core 

velocity

(ft/sec)

Average 

core 

density

(g/cm3

)

Average 

core 

magnetic 

susceptibility

(unitless)
Table 11 85

MGCY-30C-1 249.0 253.9 4.9 1.7445 5,613.8 2.17 (H) 13

MGCY-31C-1 309.0 311.2 2.2 — — 2.39 (H) 2

MGCY-32C-1 314.0 316.1 2.1 — — 2.40 (H) 30

MGCY-33C-1 317.5 320.8 3.3 — — 2.40 (H) 22

MGCY-34C-1 320.0 322.6 2.6 1.788 5,753.8 2.26 (H) 23

MGCY-35C-1 322.5 325.1 2.6 — — 2.33 (H) 21

MGCY-36C-1 325.0 326.7 1.7 — — 2.34 (H) 22

MGCY-37C-1 329.0 332.8 3.8 — — 2.33 (H) 31

MGCY-38C-1 331.5 334.0 2.5 1.7631 5,673.7 2.13 18

MGCY-39C-1 334.0 335.1 1.1 1.7388 5,595.5 2.06 16

MGCY-40C-1 339.0 342.7 3.7 1.6289 5,241.8 2.09 17

MGCY-41C-1 410.0 411.1 1.1 — — 2.32 (H) 11

MGCY-42C-1 411.8 414.0 2.2 — — 2.39 (H) 19

MGCY-43C-1 414.0 416.3 2.3 — — 2.37 (H) 13

MGCY-44C-1 419.0 424.1 5.1 1.7348 5,582.6 2.17 (H) 11

MGCY-45C-1 421.5 424.1 2.6 1.7796 5,726.8 2.16 14

MGCY-46C-1 424.0 426.5 2.5 1.7549 5,647.3 2.17 (H) 19

MGCY-47C-1 429.0 432.9 3.9 1.6867 5,427.8 2.21 (H) 29

MGCY-48C-1 434.0 438.9 4.9 — — 2.35 (H) 30

MGCY-49AC-1 436.5 438.3 1.8 — — 2.42 (H) 38

MGCY-49BC-1 489.0 490.8 1.8 1.6496 5,308.4 2.08 (H) 37

MGCY-50C-1 491.2 494.0 2.8 1.7545 5,646.0 2.26 (H) 27

MGCY-51C-1 494.0 498.2 4.2 1.79 5,760.2 2.17 (H) 31

MGCY-52C-1 499.0 503.4 4.4 1.7543 5,645.3 2.13 31

MGCY-54C-1 509.0 512.8 3.8 — — 2.37 37

MGCY-55C-1 514.0 518.0 4.0 — — 2.40 43

MGCY-56C-1 579.0 581.4 2.4 1.7161 5,522.4 2.14 33

MGCY-57C-1 581.5 582.1 0.6 — — 1.95 28

MGCY-57C-2 582.1 584.9 2.8 1.7532 5,641.8 2.14 38

MGCY-58C-1 584.0 588.4 4.4 1.8034 5,803.3 2.22 (H) 39

MGCY-59C-1 589.0 590.5 1.5 1.5149 4,874.9 1.74 26

MGCY-60C-1 594.0 596.5 2.5 1.7055 5,488.3 2.13 43

MGCY-61C-1 599.0 604.0 5.0 1.8038 5,804.6 2.20 (H) 57

MGCY-62C-1 604.0 609.2 5.2 1.7462 5,619.3 2.11 43

MGCY-63C-1 609.0 613.7 4.7 1.7069 5,492.8 2.21 (H) 56

MGCY-64C-1 614.0 619.2 5.2 1.5257 4,909.7 2.20 (H) 41

MGCY-65C-1 619.0 622.7 3.7 1.8185 5,851.9 2.30 (H) 36

MGCY-66C-1 624.0 628.8 4.8 1.7633 5,674.3 2.21 (H) 44

MGCY-68C-1 699.0 703.5 4.5 1.7937 5,772.1 2.19 60

MGCY-69C-1 704.0 708.7 4.7 1.7886 5,755.7 2.19 (H) 59

MGCY-70C-1 709.0 713.8 4.8 1.8035 5,803.7 2.18 49

MGCY-71C-1 714.0 718.4 4.4 1.7576 5,656.0 2.15 41

MGCY-72C-1 719.0 723.3 4.3 1.7926 5,768.6 2.20 (H) 21

MGCY-73C-1 724.0 727.1 3.1 1.8009 5,795.3 2.26 (H) 25

MGCY-74C-1 768.7 771.1 2.4 1.8153 5,841.6 2.38 (H) 36

Table 11. Summary of multi-sensor logging data for cores collected from multiple-well monitoring sites, Santa Clara County, California—Continued

Core ID

(Site-core

#-section)

Depth to

top 

of core

(ft bls)

Depth to 

bottom

of core

(ft bls)

Total core 

length

(ft)

Primary 

velocity

(km/sec)

Average core 

velocity

(ft/sec)

Average 

core 

density

(g/cm3)

Average 

core 

magnetic 

susceptibility

(unitless)
86 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

MGCY-75C-1 774.0 778.0 4.0 1.8007 5,794.7 2.33 (H) 40

MGCY-76C-1 779.0 782.4 3.4 — — 2.36 (H) 57

MGCY-77C-1 781.9 790.2 8.3 — — 2.32 (H) 49

MGCY-78C-1 789.0 793.9 4.9 1.8286 5,884.4 2.16 5

MGCY-79C-1 829.0 830.3 1.3 1.8001 5,792.7 2.15 3

MGCY-80C-1 849.0 857.7 8.7 — — 2.01 2

MGCY-81C-1 866.5 882.6 16.1 — — 2.04 4

MGCY-81C-2 866.5 866.5 .0 — — 1.98 3

STPK-1C-1 30.0 33.6 3.6 — — 2.05 9

STPK-2C-1 34.0 38.8 4.8 — — 2.01 9

STPK-3C-1 39.0 41.3 2.3 — — 1.95 12

STPK-4C-1 43.8 48.6 4.8 — — 1.98 14

STPK-5C-1 49.0 51.0 2.0 — — 2.13 16

STPK-6C-1 54.0 56.6 2.6 — — 2.42 21

STPK-8C-1 134.0 135.0 1.0 — — 2.27 14

STPK-11C-1 184.0 187.5 3.5 1.7373 5,590.6 2.24 17

STPK-13C-1 224.0 226.5 2.5 1.6551 5,326.1 2.09 10

STPK-15C-1 229.0 232.8 3.8 1.7393 5,597.1 2.15 13

STPK-16C-1 234.0 238.3 4.3 1.6563 5,330.0 2.04 9

STPK-17C-1 239.0 243.7 4.7 1.6791 5,403.3 2.09 10

STPK-18C-1 244.0 246.7 2.7 1.6233 5,223.8 1.99 6

STPK-19C-1 249.0 252.6 3.6 1.7019 5,476.7 2.20 16

STPK-20C-1 254.0 257.7 3.7 1.7265 5,555.9 2.15 13

STPK-21C-1 324.0 328.1 4.1 1.7599 5,663.4 2.22 23

STPK-22C-1 329.0 330.3 1.3 — — 2.43 26

STPK-23C 379.0 380.3 1.3 — — 2.35 26

STPK-25C-1 384.0 385.1 1.1 — — 2.39 38

STPK-27C-1 399.0 400.6 1.6 — — 2.46 41

STPK-28C-1 404.0 404.9 .9 — — 2.37 32

STPK-29C-1 454.0 457.9 3.9 1.701 5,473.8 2.15 8

STPK-30C-1 459.0 460.3 1.3 1.8 5,792.4 2.23 8

STPK-31C-1 464.0 466.7 2.7 1.7531 5,641.5 2.35 15

STPK-32C-1 469.0 472.2 3.2 — — 2.33 20

STPK-33C-1 474.0 476.4 2.4 — — 2.38 20

STPK-34C-1 479.0 481.8 2.8 1.7232 5,545.3 2.27 18

STPK-35C-1 484.0 486.3 2.3 — — 2.41 28

STPK-36C-1 569.0 570.6 1.6 1.6822 5,413.3 2.16 17

STPK-36C-2 569.0 571.6 2.6 1.6906 5,440.4 2.09 12

STPK-37C-1 574.0 575.4 1.4 1.6872 5,429.4 2.18 15

STPK-37C-2 574.0 575.3 1.3 1.7925 5,768.3 2.23 16

STPK-38C-1 579.0 582.2 3.2 1.7553 5,648.6 2.23 16

STPK-39C-1 584.0 585.4 1.4 1.7838 5,740.3 2.29 19

STPK-40C-1 589.0 591.7 2.7 1.6057 5,167.1 2.33 21

Table 11. Summary of multi-sensor logging data for cores collected from multiple-well monitoring sites, Santa Clara County, California—Continued

Core ID

(Site-core

#-section)

Depth to

top 

of core

(ft bls)

Depth to 

bottom

of core

(ft bls)

Total core 

length

(ft)

Primary 

velocity

(km/sec)

Average core 

velocity

(ft/sec)

Average 

core 

density

(g/cm3

)

Average 

core 

magnetic 

susceptibility

(unitless)
Table 11 87

STPK-41C-1 609.0 612.5 3.5 1.7663 5,684.0 2.19 17

STPK-42C-1 614.0 615.4 1.4 1.7718 5,701.7 2.30 23

STPK-43C-1 619.0 621.4 2.4 — — 2.38 29

STPK-44C-1 624.0 626.4 2.4 — — 2.35 26

STPK-45C-1 659.0 662.8 3.8 1.7804 5,729.3 2.17 15

STPK-46C-1 664.0 667.7 3.7 1.7523 5,638.9 2.16 15

STPK-47C-1 669.0 670.7 1.7 1.7703 5,696.8 2.26 29

STPK-48C-1 674.0 676.7 2.7 — — 2.36 28

STPK-49C-1 679.0 681.1 2.1 — — 2.26 33

STPK-50C-1 709.0 712.6 3.6 1.691 5,441.6 2.18 17

STPK-51C-1 714.0 717.9 3.9 1.8149 5,840.3 2.33 34

STPK-52C-1 719.0 723.3 4.3 1.744 5,612.2 2.19 37

STPK-53C-1 724.0 724.7 .7 1.8263 5,877.0 2.28 34

STPK-54C-1 759.0 762.9 3.9 — — 2.34 21

STPK-56C-1 769.0 772.6 3.6 1.7873 5,751.5 2.25 13

STPK-57C-1 774.0 779.0 5.0 1.7921 5,767.0 2.21 19

STPK-58C-1 799.0 802.6 3.6 1.7663 5,684.0 2.16 27

STPK-59C-1 804.0 807.4 3.4 1.839 5,917.9 2.22 39

STPK-60C-1 829.0 830.9 1.9 — — 2.29 26

STPK-61C-1 831.5 833.5 2.0 — — 2.44 38

STPK-63C-1 869.0 870.3 1.3 1.7289 5,563.6 2.15 26

STPK-63C-2 869.0 872.0 3.0 1.714 5,515.7 2.16 25

STPK-64C-1 874.0 877.0 3.0 1.7785 5,723.2 2.18 22

STPK-65C-1 919.0 923.3 4.3 1.7844 5,742.2 2.31 41

STPK-66C-1 924.0 925.8 1.8 1.6876 5,430.7 2.16 27

STPK-67C-1 989.0 990.2 1.2 1.7968 5,782.1 2.23 20

STPK-68C-1 994.0 996.0 2.0 1.6547 5,324.8 2.31 31

GUAD-1C-1 9.0 13.7 4.7 1.6213 5,217.3 2.10 4

GUAD-2C-1 14.0 17.7 3.7 1.6619 5,348.0 2.14 (H) 5

GUAD-3C-1 19.0 21.4 2.4 1.6622 5,349.0 2.28 (H) 10

GUAD-4C-1 24.0 28.1 4.1 1.6222 5,220.2 2.05 (H) 15

GUAD-5C-1 29.0 33.2 4.2 1.6527 5,318.4 2.10 19

GUAD-6C-1 34.0 37.6 3.6 1.6445 5,292.0 2.06 26

GUAD-7C-1 39.0 42.0 3.0 1.5959 5,135.6 1.99 16

GUAD-8C-1 44.0 47.0 3.0 1.6312 5,249.2 2.05 17

GUAD-13C-1 69.0 70.8 1.8 1.6374 5,269.2 2.31 (H) 16

GUAD-14C-1 74.0 76.7 2.7 1.594 5,129.5 2.05 (H) 11

GUAD-16C-1 84.0 86.9 2.9 1.6859 5,425.2 2.15 22

GUAD-17C-1 89.5 93.4 3.9 1.6411 5,281.1 2.08 17

GUAD-18C-1 94.0 97.8 3.8 1.6493 5,307.4 2.10 12

GUAD-20C-1 104.0 107.4 3.4 1.7254 5,552.3 2.18 (H) 17

GUAD-21C-1 109.0 113.2 4.2 1.6342 5,258.9 2.01 15

GUAD-22C-1 114.0 119.2 5.2 1.6666 5,363.1 2.04 14

GUAD-23C-1 119.0 121.6 2.6 1.5811 5,088.0 1.91 11

GUAD-24C-1 124.0 125.6 1.6 1.7026 5,479.0 2.06 12

Table 11. Summary of multi-sensor logging data for cores collected from multiple-well monitoring sites, Santa Clara County, California—Continued

Core ID

(Site-core

#-section)

Depth to

top 

of core

(ft bls)

Depth to 

bottom

of core

(ft bls)

Total core 

length

(ft)

Primary 

velocity

(km/sec)

Average core 

velocity

(ft/sec)

Average 

core 

density

(g/cm3)

Average 

core 

magnetic 

susceptibility

(unitless)
88 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

GUAD-25C-1 129.0 132.4 3.4 1.5962 5,136.6 2.25 (L)(H) 0

GUAD-26C-1 134.0 137.1 3.1 1.6642 5,355.4 2.11 (H) 70

GUAD-27C-1 139.0 141.7 2.7 1.662 5,348.3 2.05 64

GUAD-28C-1 144.0 147.5 3.5 1.6987 5,466.4 2.05 57

GUAD-30C-1 154.0 158.0 4.0 1.6068 5,170.7 1.93 57

GUAD-31C-1 159.0 163.4 4.4 1.6866 5,427.5 2.09 8

GUAD-32C-1 164.0 168.3 4.3 1.6853 5,423.3 2.08 19

GUAD-33C-1 169.0 173.1 4.1 1.6419 5,283.6 1.93 (L) 11

GUAD-34C-1 174.0 177.7 3.7 1.6465 5,298.4 2.02 9

GUAD-35C-1 179.0 183.5 4.5 1.5932 5,126.9 1.93 7

GUAD-36C-1 184.0 188.3 4.3 1.6685 5,369.2 2.11 (H) 6

GUAD-37C-1 189.0 190.1 1.1 1.5094 4,857.2 1.66 4

GUAD-39C-1 199.0 202.0 3.0 — — 2.32 (H) 11

GUAD-40C-1 204.0 206.9 2.9 1.701 5,473.8 2.18 (H) 9

GUAD-42C-1 214.0 216.5 2.5 1.7316 5,572.3 2.13 4

GUAD-43C-1 219.0 220.5 1.5 1.7427 5,608.0 2.14 3

GUAD-44C-1 224.0 227.7 3.7 1.6954 5,455.8 2.07 (H) 6

GUAD-46AC-1 234.0 236.1 2.1 1.7438 5,611.5 2.13 8

GUAD-46BC-1 234.0 237.6 3.6 1.5445 4,970.2 2.08 (H) 23

GUAD-47C-1 239.0 240.1 1.1 — — 2.37 (H) 23

GUAD-48C-1 244.0 244.9 .9 — — 2.15 (H) 12

GUAD-49C-1 249.0 251.9 2.9 1.6934 5,449.4 2.08 18

GUAD-50C-1 254.0 258.4 4.4 1.6319 5,251.5 2.03 19

GUAD-51C-1 259.0 261.9 2.9 1.7187 5,530.8 2.16 (H) 23

GUAD-53C-1 269.0 272.5 3.5 1.6759 5,393.0 2.08 24

GUAD-54C-1 274.0 278.8 4.8 1.6208 5,215.7 1.98 13

GUAD-55C-1 279.0 281.4 2.4 1.6637 5,353.8 2.04 12

GUAD-56C-1 284.0 288.9 4.9 1.6471 5,300.4 2.02 12

GUAD-57C-1 289.0 291.5 2.5 1.7639 5,676.2 2.12 11

GUAD-59C-1 299.0 302.8 3.8 1.7241 5,548.2 2.10 7

GUAD-60C-1 304.0 305.9 1.9 1.6725 5,382.1 2.04 8

GUAD-61C-1 309.0 311.2 2.2 1.7465 5,620.2 2.21 (H) 7

GUAD-62C-1 314.0 315.4 1.4 1.7094 5,500.8 2.09 6

GUAD-64C-1 324.0 329.0 5.0 1.6615 5,346.7 2.01 9

GUAD-65C-1 329.0 332.2 3.2 1.7032 5,480.9 2.05 2

GUAD-66C-1 334.0 338.6 4.6 1.7404 5,600.6 2.13 6

GUAD-67C-1 339.0 341.7 2.7 1.752 5,637.9 2.26 (H) 8

GUAD-68C-1 344.0 346.4 2.4 — — 2.38 (H) 23

GUAD-70C-1 354.0 358.5 4.5 1.7058 5,489.3 2.09 8

GUAD-71C-1 359.0 361.9 2.9 1.7458 5,618.0 2.11 0

GUAD-72C-1 364.0 365.2 1.2 — — 2.38 (H) 19

GUAD-73C-1 369.0 370.8 1.8 1.7532 5,641.8 2.12 3

GUAD-74C-2 376.9 379.1 2.2 — — 2.06 9

Table 11. Summary of multi-sensor logging data for cores collected from multiple-well monitoring sites, Santa Clara County, California—Continued

Core ID

(Site-core

#-section)

Depth to

top 

of core

(ft bls)

Depth to 

bottom

of core

(ft bls)

Total core 

length

(ft)

Primary 

velocity

(km/sec)

Average core 

velocity

(ft/sec)

Average 

core 

density

(g/cm3

)

Average 

core 

magnetic 

susceptibility

(unitless)
Table 11 89

GUAD-75C-1 379.0 382.2 3.2 1.7413 5,603.5 2.09 16

GUAD-76C-1 384.0 385.9 1.9 1.7251 5,551.4 2.06 17

GUAD-77C-1 389.0 394.0 5.0 1.6585 5,337.1 2.05 18

GUAD-79C-1 399.0 403.7 4.7 1.6883 5,432.9 2.12 (H) 4

GUAD-80C-1 404.0 406.5 2.5 — — 2.23 (H) 11

GUAD-81C-1 409.0 411.2 2.2 — — 2.32 (H) 25

GUAD-82C-1 414.0 417.8 3.8 1.7238 5,547.2 2.14 21

GUAD-83C-1 419.0 420.7 1.7 1.6596 5,340.6 2.04 9

GUAD-85C-1 429.0 433.2 4.2 1.7154 5,520.2 2.09 15

GUAD-88C-1 444.0 448.1 4.1 1.7156 5,520.8 2.16 (H) 3

GUAD-89C-1 449.0 450.4 1.4 1.7533 5,642.1 2.16 5

GUAD-90C-1 454.0 455.7 1.7 — — 2.32 (H) 12

GUAD-92C-1 464.0 466.1 2.1 — — 2.44 (H) 13

GUAD-93C-1 469.0 473.8 4.8 1.797 5,782.7 2.19 (H) 0

GUAD-94C-1 474.0 476.5 2.5 1.7369 5,589.3 2.14 10

GUAD-95C-1 479.0 483.7 4.7 1.7667 5,685.2 2.15 (H) 8

GUAD-96C-1 484.0 488.9 4.9 1.7105 5,504.4 2.14 11

GUAD-97C-1 489.0 494.0 5.0 1.7123 5,510.2 2.14 10

GUAD-98C-1 494.0 498.9 4.9 1.6885 5,433.6 2.08 13

GUAD-99C-1 499.0 503.5 4.5 1.75 5,631.5 2.15 18

GUAD-101C-1 509.0 509.8 0.8 1.6986 5,466.1 2.07 19

GUAD-102C-1 514.0 517.9 3.9 1.7938 5,772.4 2.15 20

GUAD-103C-1 519.0 523.7 4.7 1.6467 5,299.1 2.02 13

GUAD-104C-1 524.0 527.7 3.7 1.7627 5,672.4 2.13 (H) 19

GUAD-105C-1 529.0 531.6 2.6 1.6551 5,326.1 2.05 18

GUAD-106C-1 534.0 537.1 3.1 1.7329 5,576.5 2.11 (H) 26

GUAD-107C-1 539.0 541.2 2.2 1.6897 5,437.5 2.09 20

GUAD-108C-1 544.0 545.7 1.7 1.7646 5,678.5 2.19 17

GUAD-109C-1 549.0 551.9 2.9 — — 2.26 (H) 21

GUAD-110C-1 554.0 556.5 2.5 1.7863 5,748.3 2.18 19

GUAD-111C-1 559.0 562.0 3.0 1.7215 5,539.8 2.13 (H) 7

GUAD-112C-1 564.0 565.8 1.8 1.7437 5,611.2 2.11 6

GUAD-114C-1 574.0 578.0 4.0 1.8198 5,856.1 2.19 3

GUAD-115C-1 579.0 580.0 1.0 — — 2.10 6

GUAD-116C-1 584.0 587.8 3.8 1.7874 5,751.9 2.16 11

GUAD-117C-1 589.0 591.7 2.7 — — 2.29 (H) 17

GUAD-119C-1 599.0 601.0 2.0 1.708 5,496.3 2.10 12

GUAD-121C-1 609.0 613.9 4.9 1.677 5,396.6 2.04 14

GUAD-122C-1 614.0 618.5 4.5 — — 2.13 20

GUAD-123C-1 619.0 623.1 4.1 1.7468 5,621.2 2.08 19

GUAD-124C-1 624.0 628.9 4.9 1.7126 5,511.1 2.01 (H) 0

GUAD-125C-1 629.0 632.8 3.8 1.7008 5,473.2 2.11 10

GUAD-126C-1 634.0 638.8 4.8 1.7497 5,630.5 2.17 (H) 0

GUAD-127C-1 639.0 643.1 4.1 1.6765 5,395.0 2.12 6

GUAD-128C-1 644.0 647.7 3.5 1.805 5,808.5 2.17 (H) 8

Table 11. Summary of multi-sensor logging data for cores collected from multiple-well monitoring sites, Santa Clara County, California—Continued

Core ID

(Site-core

#-section)

Depth to

top 

of core

(ft bls)

Depth to 

bottom

of core

(ft bls)

Total core 

length

(ft)

Primary 

velocity

(km/sec)

Average core 

velocity

(ft/sec)

Average 

core 

density

(g/cm3)

Average 

core 

magnetic 

susceptibility

(unitless)
90 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

GUAD-129C-1 648.8 653.6 4.8 1.712 5,509.2 2.10 (H) 10

GUAD-130C-1 654.0 656.3 2.3 — — 2.38 (H) 22

GUAD-131C-1 659.0 662.9 3.9 1.7384 5,594.2 2.16 16

GUAD-132C-1 664.0 667.0 3.0 — — 2.32 (H) 12

GUAD-133C-1 669.0 670.3 1.3 — — 2.32 (H) 24

GUAD-134C-1 674.0 677.8 3.8 1.7666 5,684.9 2.17 (H) 20

GUAD-135C-1 679.0 682.6 3.6 1.7476 5,623.8 2.21 (H) 28

GUAD-136C-1 684.0 687.4 3.4 1.706 5,489.9 2.10 22

GUAD-137C-1 689.0 693.9 4.9 1.7763 5,716.1 2.14 (H) 22

GUAD-138C-1 694.0 698.1 4.1 1.6971 5,461.3 2.11 20

GUAD-139C-1 699.0 703.6 4.6 1.7847 5,743.2 2.19 (H) 20

GUAD-140C-1 704.0 707.1 3.1 1.7345 5,581.6 2.12 (H) 10

GUAD-141C-1 709.0 710.9 1.9 1.7035 5,481.9 2.20 (H) 10

GUAD-142C-1 714.0 717.8 3.8 1.7021 5,477.4 2.08 0

GUAD-143C-1 719.0 720.5 1.5 1.7034 5,481.5 2.07 4

GUAD-144C-1 722.0 723.8 1.8 1.663 5,351.5 2.10 (H) 7

GUAD-145C-1 724.0 726.3 2.3 1.8097 5,823.6 2.28 (H) 25

GUAD-148C-1 739.0 740.2 1.2 1.708 5,496.3 2.09 2

GUAD-149C-1 741.5 743.6 2.1 1.7502 5,632.1 2.09 0

GUAD-150C-1 744.0 748.4 4.4 1.7056 5,488.6 2.04 8

GUAD-151C-1 749.0 753.8 4.8 1.5334 4,934.5 1.47 0

GUAD-152C-1 754.0 758.8 4.8 1.6881 5,432.3 2.08 20

GUAD-153C-1 759.0 762.3 3.3 1.7659 5,682.7 2.19 (H) 27

GUAD-155C-1 769.0 774.0 5.0 1.7411 5,602.9 2.14 0

GUAD-157C-1 779.0 783.1 4.1 1.8003 5,793.4 2.20 (H) 0

GUAD-159C-1 789.0 793.9 4.9 1.7669 5,685.9 2.11 28

GUAD-160C-2 794.0 797.6 3.6 1.7384 5,594.2 2.11 9

GUAD-161C-1 799.0 802.9 3.9 1.8333 5,899.6 2.20 0

GUAD-162C-1 804.0 807.2 3.2 1.7328 5,576.2 2.31 (H) 0

GUAD-163C-1 809.0 811.8 2.8 — — 2.41 (H) 15

GUAD-164C-1 814.0 815.6 1.6 — — 2.42 (H) 13

GUAD-165C-1 819.0 821.1 2.1 — — 2.42 (H) 17

GUAD-166C-1 824.0 826.9 2.9 1.7254 5,552.3 2.13 0

GUAD-167C-1 829.0 830.1 1.1 1.7346 5,581.9 2.08 6

GUAD-168C-1 834.0 836.9 2.9 1.7648 5,679.1 2.36 (H) 0

GUAD-169C-1 839.0 842.3 3.3 1.8011 5,795.9 2.19 (H) 38

GUAD-170C-1 844.0 848.2 4.2 1.686 5,425.5 2.09 40

GUAD-171C-1 849.0 852.4 3.4 1.7239 5,547.5 2.05 0

GUAD-172C-1 854.0 855.5 1.5 1.7694 5,693.9 2.13 0

GUAD-173C-1 859.0 863.9 4.9 1.8037 5,804.3 2.14 (H) 0

GUAD-175C-1 869.0 873.2 4.2 1.8001 5,792.7 2.17 (H) 20

GUAD-176C-1 874.0 878.4 4.4 1.7022 5,477.7 2.11 (H) 0

GUAD-177C-1 879.0 882.3 3.3 1.7352 5,583.9 2.17 13

Table 11. Summary of multi-sensor logging data for cores collected from multiple-well monitoring sites, Santa Clara County, California—Continued

Core ID

(Site-core

#-section)

Depth to

top 

of core

(ft bls)

Depth to 

bottom

of core

(ft bls)

Total core 

length

(ft)

Primary 

velocity

(km/sec)

Average core 

velocity

(ft/sec)

Average 

core 

density

(g/cm3

)

Average 

core 

magnetic 

susceptibility

(unitless)
Table 11 91

GUAD-178C-1 884.0 887.2 3.2 1.798 5,786.0 2.18 (H) 15

GUAD-179C-1 889.0 893.8 4.8 1.5601 5,020.4 1.55 0

GUAD-180C-1 894.0 898.9 4.9 1.7998 5,791.8 2.19 (H) 37

GUAD-181C-1 899.0 902.1 3.1 1.6963 5,458.7 2.10 25

GUAD-182C-1 904.0 907.7 3.7 1.7211 5,538.5 2.14 (H) 34

GUAD-183C-1 909.0 913.9 4.9 1.6603 5,342.8 2.08 (H) 25

GUAD-184C-1 914.0 918.8 4.8 1.7366 5,588.4 2.16 (H) 42

GUAD-185C-1 919.0 920.6 1.6 1.6742 5,387.6 2.10 22

GUAD-186C-1 924.0 928.2 4.2 1.7351 5,583.6 2.09 0

GUAD-187C-1 929.0 933.9 4.9 1.5978 5,141.7 2.00 30

GUAD-188C-1 934.0 936.8 2.8 1.7617 5,669.2 2.11 (H) 27

GUAD-192C-1 949.0 954.0 5.0 1.6714 5,378.6 2.01 (H) 31

GUAD-193C-1 954.0 958.0 4.0 1.715 5,518.9 2.15 54

GUAD-194C-1 959.0 963.0 4.0 1.809 5,821.4 2.19 (H) 53

GUAD-195C-1 964.0 968.1 4.1 1.6992 5,468.0 2.09 40

GUAD-196C-1 969.0 973.9 4.9 1.6489 5,306.2 2.06 (H) 39

GUAD-197C-1 974.0 977.5 3.5 1.7135 5,514.0 2.14 60

GUAD-198C-1 979.0 983.9 4.9 1.6408 5,280.1 1.76 0

GUAD-199C-1 984.0 987.3 3.3 1.7176 5,527.2 2.11 20

GUAD-200C-1 989.0 990.8 1.8 1.7284 5,562.0 2.12 15

GUAD-201C-1 994.0 996.5 2.5 1.6567 5,331.3 2.02 (H) 10

EVGR-1C-1 0.5 3.5 3.0 — — 2.21 (H) 28

EVGR-2C-1 4.5 7.2 2.7 — — 2.12 29

EVGR-3C-1 9.5 12.6 3.1 — — 2.23 (H) 36

EVGR-4C-1 14.5 18.8 4.3 — — 2.29 (H) 22

EVGR-5C-1 19.5 23.7 4.2 — — 2.28 (H) 17

EVGR-6C-1 24.5 27.8 3.3 — — 2.33 (H) 14

EVGR-7C-1 29.5 32.9 3.4 — — 2.25 (H) 20

EVGR-8C-1 34.5 36.9 2.4 1.7058 5,489.3 2.25 (H) 16

EVGR-9C-1 39.5 43.9 4.4 1.7255 5,552.7 2.30 (H) 12

EVGR-10C-2 44.5 46.7 2.2 1.654 5,322.6 2.16 (H) 24

EVGR-10C-1 47.7 49.3 1.6 1.7474 5,623.1 2.19 (H) 21

EVGR-11C-1 49.5 54.2 4.7 1.681 5,409.5 2.22 (H) 19

EVGR-13C-1 59.5 64.4 4.9 1.65 5,309.7 2.08 (H) 18

EVGR-14C-1 179.5 184.2 4.7 1.7829 5,737.4 2.21 (H) 23

EVGR-15C-1 184.5 189.0 4.5 1.6745 5,388.5 2.31 (H) 33

EVGR-16C-1 189.5 192.0 2.5 1.809 5,821.4 2.25 (H) 22

EVGR-17C-1 194.5 199.2 4.7 1.7475 5,623.5 2.18 (H) 35

EVGR-18C-1 239.5 244.4 4.9 1.7783 5,722.6 2.19 (H) 19

EVGR-19C-1 244.5 247.2 2.7 1.7689 5,692.3 2.18 22

EVGR-20C-1 249.5 251.4 1.9 1.8065 5,813.3 2.14 12

EVGR-21C-1 254.5 257.6 3.1 1.7655 5,681.4 2.19 8

EVGR-22C-1 294.5 299.0 4.5 1.7305 5,568.7 2.18 (H) 16

EVGR-23C-1 299.5 304.4 4.9 1.7471 5,622.2 2.13 (H) 19

EVGR-24C-1 304.5 309.1 4.6 1.7705 5,697.5 2.19 (H) 15

Table 11. Summary of multi-sensor logging data for cores collected from multiple-well monitoring sites, Santa Clara County, California—Continued

Core ID

(Site-core

#-section)

Depth to

top 

of core

(ft bls)

Depth to 

bottom

of core

(ft bls)

Total core 

length

(ft)

Primary 

velocity

(km/sec)

Average core 

velocity

(ft/sec)

Average 

core 

density

(g/cm3)

Average 

core 

magnetic 

susceptibility

(unitless)
92 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

EVGR-25C-1 309.5 314.1 4.6 1.734 5,580.0 2.23 (H) 19

EVGR-26C-1 394.5 398.0 3.5 — — 2.33 (H) 44

EVGR-27C-1 399.5 404.1 4.6 1.7692 5,693.3 2.26 (H) 21

EVGR-28C-1 404.5 406.7 2.2 — — 2.20 (H) 30

EVGR-29C-1 407.0 409.0 2.0 1.7488 5,627.6 2.17 20

EVGR-30C-1 409.5 414.0 4.5 1.8055 5,810.1 2.24 (H) 18

EVGR-31C-1 449.5 454.0 4.5 1.7359 5,586.1 2.31 (H) 22

EVGR-32C-1 454.5 458.2 3.7 1.8127 5,833.3 2.30 (H) 24

EVGR-34C-1 464.5 469.3 4.8 1.7559 5,650.5 2.20 (H) 26

EVGR-35C-1 539.5 543.2 3.7 1.8321 5,895.7 2.33 (H) 32

EVGR-36C-1 544.5 549.1 4.6 1.8409 5,924.0 2.25 (H) 26

EVGR-37C-1 574.5 578.4 3.9 1.8248 5,872.2 2.25 (H) 33

EVGR-38C-1 579.5 582.1 2.6 1.7639 5,676.2 2.18 30

EVGR-39C-1 582.0 586.8 4.8 1.7543 5,645.3 2.16 (H) 13

EVGR-40C-1 587.0 591.9 4.9 1.8096 5,823.3 2.21 (H) 14

EVGR-41C-2 592.0 596.8 4.8 1.7692 5,693.3 2.25 (H) 33

EVGR-42C-1 644.5 648.0 3.5 1.8352 5,905.7 2.27 (H) 28

EVGR-43C-1 649.5 653.9 4.4 1.882 6,056.3 2.34 (H) 30

EVGR-44C-1 654.5 659.4 4.9 — — 2.38 (H) 22

EVGR-45C-1 769.5 772.2 2.7 1.8231 5,866.7 2.24 (H) 20

EVGR-46C-1 774.5 777.9 3.4 1.8298 5,888.3 2.31 (H) 15

EVGR-47C-1 779.5 780.7 1.2 1.7987 5,788.2 2.37 (H) 24

EVGR-48C-1 784.5 789.5 5.0 — — 2.22 (H) 12

EVGR-49C-1 900.5 904.1 3.6 1.8309 5,891.8 2.20 (H) 15

EVGR-50C-1 905.5 907.9 2.4 1.7819 5,734.2 2.32 (H) 14

EVGR-52C-1 989.5 991.0 1.5 1.8356 5,907.0 2.26 (H) 26

EVGR-53C-1 994.5 996.1 1.6 1.8037 5,804.3 2.18 (H) 15

EVGR-54C-1 999.4 1,004.3 4.9 1.8039 5,805.0 2.18 (H) 19

Table 11. Summary of multi-sensor logging data for cores collected from multiple-well monitoring sites, Santa Clara County, California—Continued

Core ID

(Site-core

#-section)

Depth to

top 

of core

(ft bls)

Depth to 

bottom

of core

(ft bls)

Total core 

length

(ft)

Primary 

velocity

(km/sec)

Average core 

velocity

(ft/sec)

Average 

core 

density

(g/cm3

)

Average 

core 

magnetic 

susceptibility

(unitless)
Table 12 93

Table 12. Summary of consolidation analysis for selected core samples collected from multiple-well monitoring sites, Santa Clara County, California—

Continued

Core No.

Depth to top 

of core 

interval

(ft bls)

Depth to 

bottom of 

core 

interval

(ft bls)

Maximum 

past

stress, 

(kg/cm2)

Coefficient 

of inelastic 

consolidation 

(Cc)

Coefficient 

of elastic 

consolidation

(Cr)

General 

lithology

Initial 

void

ratio 

(eo)

Inelastic 

specific 

storage

(per ft)

Elastic 

specific 

storage 

(per ft)

CCOC-5C-1 26 31 — — 0.02 Clayey silt 0.69 — —

CCOC-17C-1 81 86 — — .01 Clayey silt .54 — —

CCOC-20C-1 96 101 — — .03 Silty clay .77 — —

CCOC-23C-1 111 116 10 0.36 .02 Clay .768 2.70 × 10−4 1.50 × 10−5

CCOC-29C-1 231 236 24.4 .194 .01 Clayey silt .582 6.60 × 10−5 3.40 × 10−6

CCOC-34C-1 256 261 22.2 .35 .03 Clayey silt .736 1.20 × 10−4 1.00 × 10−5

CCOC-35C-1 261 266 28 .4 .01 Sand .736 1.10 × 10−4 2.70 × 10−6

CCOC-40C-1 476 481 26.6 .24 .02 Sand-silt-clay .597 7.50 × 10−5 6.20 × 10−6

CCOC-46C-1 551 553.5 26.6 .32 .03 Sand-silt-clay .652 9.60 × 10−5 9.00 × 10−6

CCOC-49C-1 561 566 29 .33 .02 Clayey silt .889 8.00 × 10−5 4.80 × 10−6

CCOC-55C-1 588.5 592 22 .18 .01 Sand-silt-clay .447 7.50 × 10−5 4.20 × 10−6

CCOC-60C-1 671 676 35.3 .32 .02 Sand-silt-clay .891 6.30 × 10−5 4.00 × 10−6

CCOC-65C-1 731 736 24 .29 .04 Silty clay .663 9.60 × 10−5 1.30 × 10−5

CCOC-71C-1 881 886 24.2 .23 .01 Clayey silt .729 7.30 × 10−5 3.20 × 10−6

CCOC-75C-1 961 966 38.2 .39 .03 Clay 1 6.80 × 10−5 5.20 × 10−6

WLLO2-3C-1 40 45 — — .03 Silty clay .95 — —

WLLO2-5C-1 40 45 — — .01 Sandy-silty clay .69 — —

WLLO2-6C-1 50 55 — — .003 Sand and silt .53 — —

WLLO1-16C-1 300 305 20 .42 .04 Stiff silty clay .851 1.50 × 10−4 1.40 × 10−5

WLLO1-17C-1 305 310 23 .34 .02 Sand-silt-clay .66 1.20 × 10−4 6.90 × 10−6

WLLO1-18C-1 310 315 23 .33 .01 Sand-silt-clay .758 1.10 × 10−4 3.30 × 10−6

WLLO1-28C-1 670 673 32 .4 .04 Stiff silty clay .826 9.90 × 10−5 9.90 × 10−6

WLLO1-31C-1 735 738 36.3 .29 .03 Very stiff silty clay .67 6.00 × 10−5 6.20 × 10−6

WLLO1-33C-1 741 746 — — .05 Silt-clay .75 — —

WLLO1-34C-1 746 750 25 .52 .07 Sand-silt-clay 1.451 1.60 × 10−4 2.10 × 10−5

WLLO1-36C-1 755 760 32 .32 .03 Silty clay .727 8.30 × 10−5 7.80 × 10−6

WLLO1-37C-1 780 785 — — 0 Silt-clay .6 — —

MGCY-23C-1 154 159 — — .01 Fine sand .77 — —

MGCY-30C-1 249 251.5 20 .3 .02 Silty sand .657 9.30 × 10−5 6.20 × 10−6

MGCY-44C-1 419 421.5 32 .42 .07 Silt-clay 1.123 1.10 × 10−4 1.80 × 10−5

MGCY-45C-1 421.5 424 — — .04 Silt-clay .57 — —

MGCY-46C-1 424 429 — — .03 Sand-silt-clay .54 — —

MGCY-51C-1 494 499 — — .02 Sand-silt-clay .53 — —

MGCY-58C-1 584 589 — — .03 Sand-silt-clay .47 — —

MGCY-71C-1 714 719 40 .3 .02 Stiff silt .8 0 0

STPK-1C-1 30 34 — — .01 Silt-sand-clay — — —

STPK-11C-1 184 189 13 .13 .02 Clay .46 1.30 × 10−4 2.00 × 10−5

STPK-15C-1 229 234 — — .02 Silt-clay — — —

STPK-29C-1 454 459 24 .3 .03 Silt-clay-sand .531 1.70 × 10−4 1.70 × 10−5

STPK-46C-1 664 669 33 .26 .01 Sand-silt .531 1.00 × 10−4 4.00 × 10−6

STPK-51C-1 714 719 24 .26 .03 Silt-sand-clay .469 1.40 × 10−4 1.70 × 10−5

STPK-52C-1 719 724 27 0.23 0.01 Sand-silt-clay 0.431 1.10 × 10−4 4.90 × 10−6

STPK-64C-1 874 878 — — .04 Silty clay — — —

Table 12. Summary of consolidation analysis for selected core samples collected from multiple-well monitoring sites, Santa Clara County, California 

[see table 1 for definitions of acronyms in first column; kg/cm2, kilometer per square centimeter; ft, foot; bls, below land surface; —, indicates no data estimated]
94 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

GUAD-7C-1 39 44 3.2 .28 .03 Silty clay .9024 1.20 × 10−3 1.20 × 10−4

GUAD-16C-1 84 89 9.2 .23 .01 Silty clay .581 3.30 × 10−4 1.40 × 10−5

GUAD-22C-1 114 119 10 .3 .05 Clay .7143 4.00 × 10−4 6.60 × 10−5

GUAD-30C-1 154 159 7.4 .44 — Clay .8595 7.90 × 10−4

GUAD-30C-1 154 159 7.6 .38 .08 Clay .8 6.60 × 10−4 1.40 × 10−4

GUAD-35C-1 179 184 13 .57 .1 Clay .9405 5.80 × 10−4 1.00 × 10−4

GUAD-40C-1 204 209 — — .03 Silty sand-silty clay — — —

GUAD-40C-1 204 209 — — .03 Silty clay — — —

GUAD-54C-1 274 279 23.4 .46 .04 Clay .75 2.60 × 10−4 2.30 × 10−5

GUAD-54C-1 274 279 25 .28 .04 Silty clay .8 1.50 × 10−4 2.10 × 10−5

GUAD-70C-1 354 359 23 .41 .06 Silty clay .681 2.40 × 10−4 3.50 × 10−5

GUAD-80C-1 404 409 24 .26 .01 Silty sand .491 1.40 × 10−4 5.50 × 10−6

GUAD-82C-1 414 419 — — .03 Silty clay-silt — — —

GUAD-85C-1 429 434 — — .01 Silty sand — — —

GUAD-88C-1 444 449 — — .03 Silty clay — — —

GUAD-98C-1 494 499 — — .03 Silty clay — — —

GUAD-107C-1 539 544 — — .01 Silty clay-very fine 

sand

— — —

GUAD-114C-1 574 579 30 .29 .03 Silty clay/clay .519 1.30 × 10−4 1.30 × 10−5

GUAD-122C-1 614 619 25.4 .34 .04 Silty clay .619 1.80 × 10−4 2.10 × 10−5

GUAD-139C-1 699 704 — — .02 Silty clay — — —

GUAD-166C-1 824 829 — — .02 Silty-clayey sand — — —

GUAD-186C-1 924 929 44 .38 .04 Silty clay .569 1.10 × 10−4 1.20 × 10−5

GUAD-198C-1 979 984 40 .48 .04 Clay .65 1.60 × 10−4 1.30 × 10−5

EVGR-18C-1 239.5 244.5 30 .24 .02 Silty clay .469 1.10 × 10−4 8.80 × 10−6

EVGR-22C-1 294.5 299.5 — — .02 Clayey silt — — —

EVGR-24C-1 304.5 309.5 — — .01 Pebbly sand-silt — — —

EVGR-29C-1 407 409.5 — — .02 Clayey silt — — —

EVGR-37C-1 574.5 579.5 37 .2 .02 Sandy silty clay .46 7.20 × 10−5 7.20 × 10−6

EVGR-41C-2 597.1 597.4 41 .18 .02 Sandy silt .391 5.80 × 10−5 6.50 × 10−6

EVGR-41C-2 597.1 597.4 — — .02 Sandy silt — — —

EVGR-49C-1 900.5 905.5 — — .03 Silty clay — — —

EVGR-54C-1 999.5 1004.5 — — .03 Clayey silt — — —

Table 12. Summary of consolidation analysis for selected core samples collected from multiple-well monitoring sites, Santa Clara County, California—

Continued

Core No.

Depth to top 

of core 

interval

(ft bls)

Depth to 

bottom of 

core 

interval

(ft bls)

Maximum 

past

stress, 

(kg/cm2)

Coefficient 

of inelastic 

consolidation 

(Cc)

Coefficient 

of elastic 

consolidation

(Cr)

General 

lithology

Initial 

void

ratio 

(eo)

Inelastic 

specific 

storage

(per ft)

Elastic 

specific 

storage 

(per ft)
Table 13 95

Table 13. Summary of hydraulic property estimates from selected core samples collected from multiple-well monitoring sites, Santa Clara County, California

[See table one for definition of acronyms in column one; ft, foot; ft/day, foot per day; bls, below land surface; g/cm3, gram per cubic centimer; cm3/cm3, cubic 

centimeter per cubic centimer]

Core

No.

Core sample

depth interval

(ft bls)

General

lithology

Vertical

hydraulic

conductivity

(ft/day)

Particle 

density 

(g/cm3)

Bulk 

density

(g/cm3)

Porosity 

(cm3/cm3)

Volumetric

water

content 

(cm3/cm3

)

Initial 

saturation

(percent)

Residual

water

content

(cm3/cm3)

Effective 

porosity

(cm3/cm3)

Effective 

saturation

(cm3/

cm3)

CCOC-5C-1 29.38–29.87 Clay 0.0051 2.667 1.55 0.42 0.406 0.966 0.025 0.40 0.963

CCOC-19C-1 91.0–91.49 Silt-clay .0014 2.636 1.51 .426 .411 .964 .07 .36 .957

CCOC-20C-1 99.71–100.20 Silty clay .0014 2.642 1.59 .397 .374 .944 .043 .35 .937

CCOC-24C-1 119.90–120.42 Silt-clay .075 2.668 1.58 .407 .388 .952 .017 .39 .950

CCOC-27C-1 128.50–128.99 Gravelly clay .0009 2.619 1.74 .336 .326 .971 .041 .30 .967

CCOC-31C-1 243.82–244.31 Gravel-sand-clay .078 2.703 2.08 .232 .21 .903 .024 .21 .892

CCOC-35C-1 263.6–264.1 Silt-clay .074 2.658 1.67 .371 .351 .944 .03 .34 .940

CCOC-39C-1 471.43–471.99 Silt-clay .0011 2.649 1.74 .344 .333 .967 .04 .30 .962

CCOC-48C-1 559.52–560.01 Clay .0031 2.672 1.94 .274 .219 .799 .051 .22 .752

CCOC-54C-1 587.90–588.40 Clay .0008 2.662 1.96 .263 .121 .461 .047 .22 .345

CCOC-76C-1 968.52–969.01 Gravel-sand-clay .032 2.708 1.96 .278 .246 .887 .029 .25 .873

WLLO1-33C-1 745.10–745.59 Sand-silt-clay .32 2.633 1.61 .39 .369 .947 .054 .34 .938
96 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

Table 14. Summary of selected U.S. Geological Survey (USGS) water-chemistry data from multiple-well monitoring sites in the Santa Clara County, 

California—Continued

State 

well No.

Local 

well name

Depth of 

screened 

interval

Date Time

Water 

temperature

(

οC)

(00010)

Air 

temperature

(

οC)

(00020)

Total

dissolved

solids

(mg/L)

(70300)

5S/3W-36P2 ELNR-1 830–850 04/15/2003 1545 26 — 1,500

5S/3W-36P3 ELNR-2 720–740 04/15/2003 1430 26 — 2,700

5S/3W-36P4 ELNR-3 540–560 04/14/2003 1715 24.5 — 770

5S/3W-36P5 ELNR-4 180–200 04/14/2003 1615 21 — 440

6S/1W-26Q1 GUAD-1 810–830 11/19/2002 1400 22.5 — 322

6S/1W-26Q2 GUAD-2 580–600 11/19/2002 1600 23 — 249

6S/1W-26Q3 GUAD-3 440–460 11/20/2002 1140 21.5 — 341

6S/1W-26Q4 GUAD-4 310–330 07/23/2003 1400 21.5 — 253

7S/1E-9L4 CCOC-1 820–840 10/24/2000 1610 23.5 22.5 345

7S/1E-9L4 CCOC-1 820–840 08/30/2001 1630 24 — 334

7S/1E-9L5 CCOC-2 620–640 10/23/2000 1315 23.5 23 406

7S/1E-9L5 CCOC-2 620–640 08/29/2001 1630 22.5 — 356

7S/1E-9L6 CCOC-3 520–540 10/23/2000 1404 20.5 24 492

7S/1E-9L6 CCOC-3 520–540 08/29/2001 1300 21.4 — —

7S/1E-9L7 CCOC-4 405–425 10/23/2000 1630 21.5 24 528

7S/1E-9L7 CCOC-4 405–425 08/29/2001 1010 20.2 — —

7S/1E-9L8 CCOC-5 62–72 10/24/2000 1015 19 18.5 658

7S/1E-9L8 CCOC-5 62–72 08/28/2001 1540 20.4 — —

7S/1E-19B2 WLLO-1 770–790 04/24/2001 1530 24.5 — 520

7S/1E-19B3 WLLO-2 570–590 04/26/2001 1130 23.3 — 324

7S/1E-19B4 WLLO-3 435–455 04/25/2001 1210 23.7 — 402

7S/1E-19B4 WLLO-3 435–455 12/17/2001 1500 — — —

7S/1E-19B5 WLLO-4 345–365 04/25/2001 1500 22.4 — —

7S/1E-19B5 WLLO-4 345–365 08/31/2001 1030 19.7 — 508

7S/1E-19B5 WLLO-4 345–365 12/17/2001 1540 — — —

7S/1E-19B6 WLLO-5 220–240 04/25/2001 1730 21 — 521

7S/1E-19B6 WLLO-5 220–240 12/17/2001 1640 — — —

7S/1E-19B7 WLLO-6 75–85 04/25/2001 1000 20.7 — 493

7S/1W-14P1 STPK-1 680–700 04/04/2002 1900 18.5 12.5 293

7S/1W-14P2 STPK-2 540–560 04/03/2002 1750 19.5 — 299

7S/1W-14P3 STPK-3 420–440 04/02/2002 1230 20 22 358

7S/1W-14P4 STPK-4 340–360 04/01/2002 1720 19.5 18.5 342

7S/1W-14P5 STPK-5 130–150 04/04/2002 1600 17.5 15.5 617

7S/1W-35L13 MGCY-2 510–530 12/12/2001 1330 20.4 — 288

7S/1W-35L14 MGCY-3 390–410 12/16/2001 2030 21.5 10 292

7S/1W-35L15 MGCY-4 280–300 12/11/2001 1500 21.7 15 732

7S/1W-35L16 MGCY-5 160–180 12/11/2001 1200 20.8 — 312

7S/1W-35L12 MGCY-1 630–650 12/13/2001 2000 21.5 11.5 744

Table 14. Summary of selected U.S. Geological Survey (USGS) water-chemistry data from multiple-well monitoring sites in the Santa Clara County, California

[Major chemistry data for ELNR wells came from Santa Clara Valley Water District; number in parentheses below the compound is the data parameter code, 

which is a 5-digit number used in the USGS computerized data system, National Water Information System (NWIS), to uniquely identify a specific constituent or 

property; oC, degrees Celsius; μS/cm, microseimen per centimeter; mg/L, milligram per liter; μg/L, microgram per liter; pmc, percent modern carbon; per mil, 

parts per thousand; pCi/L, picocuries per liter; —, no data; <, less than; E, estimated data; M, presence of constituent verified but not quantified; ND, not 

detected; NT, no trace]
Table 14 97

Table 14. Summary of selected U.S. Geological Survey (USGS) water-chemistry data from multiple-well monitoring sites in the Santa Clara County, California—

Continued

Local well 

name

Field, specific

conductance

(μS/cm@25οC)

(00095)

Lab, specific

conductance

(μS/cm)

(90095)

Dissolved 

oxygen

(mg/L)

(00300)

Field pH

(Standard units)

(00400)

Lab pH

(Standard units)

(00403)

Field, 

alkalinity

(mg/L as CaCO3)

(39036)

Lab,

alkalinity

(mg/L as CaCO3)

(29801)

Field, 

incremental

alkalinity

(mg/L)

(39086)

ELNR-1 2,710 2,570 — 7.8 8.0 — 165 —

ELNR-2 4,480 4,540 — 7.4 8.0 — 111 —

ELNR-3 1,140 1,420 — 7.9 8.0 — 172 —

ELNR-4 782 737 — 7.7 8.3 — 250 —

GUAD-1 549 522 — 8 8.1 — 176 —

GUAD-2 411 393 — 8 8 — 158 —

GUAD-3 560 532 — 7.8 7.9 — 201 —

GUAD-4 388 398 1 7.8 7.9 — 177 —

CCOC-1 626 632 0.2 7.8 7.9 170 182 —

CCOC-1 614 617 0.1 7.8 8 — 177 —

CCOC-2 670 677 0.2 7.9 7.8 190 208 —

CCOC-2 668 664 0.2 7.7 7.9 — 204 —

CCOC-3 822 823 0.2 7.5 7.6 260 284 —

CCOC-3 789 — 0.1 7.4 — — — —

CCOC-4 875 883 0.6 7.7 7.6 320 334 —

CCOC-4 834 — 0.1 7.4 — — — —

CCOC-5 1,070 1,090 0.5 7.3 7.4 400 411 —

CCOC-5 888 — 0.5 7.2 — — — —

WLLO-1 867 881 0.1 7.6 7.8 170 175 168

WLLO-2 557 553 0.2 7.6 8.3 200 204 201

WLLO-3 647 652 2.7 7.4 7.6 200 210 204

WLLO-3 — — — — — — — —

WLLO-4 850 — 4.6 7.2 — — — —

WLLO-4 838 834 5.9 7.3 7.6 — 265 242

WLLO-4 — — — — — — — —

WLLO-5 829 841 6.6 7.3 7.5 260 268 259

WLLO-5 — — — — — — — —

WLLO-6 786 789 2.7 6.8 6.8 230 243 231

STPK-1 473 483 6.9 7.8 7.8 150 158 —

STPK-2 506 513 6 7.6 7.8 120 135 —

STPK-3 555 563 6.3 7.6 7.6 150 158 —

STPK-4 563 569 7.3 7.4 7.6 150 170 —

STPK-5 973 985 — 7.4 7.4 320 354 —

MGCY-2 471 484 1.5 7 8 120 132 —

MGCY-3 471 489 2.4 7.4 7.8 170 189 —

MGCY-4 1,300 1,340 0.2 7.8 8 280 296 —

MGCY-5 566 559 0.6 6.9 7.5 93 102 —

MGCY-1 1,330 1,360 0.9 8.1 8.1 280 306 —
98 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

Table 14. Summary of selected U.S. Geological Survey (USGS) water-chemistry data from multiple-well monitoring sites in the Santa Clara County, 

California—Continued

Local well 

name

Calcium

(mg/L)

(00915)

Magnesium

(mg/L)

(00925)

Sodium

(mg/L)

(00930)

Potassium

(mg/L)

(00935)

Chloride

(mg/L)

(00940)

Sulfate

(mg/L)

(00945)

Fluoride

(mg/L)

(00950)

Field, 

bicarbonate

(mg/L)

(29804)

Incremental 

bicarbonate

(mg/L)

(00453)

ELNR-1 93.7 18.1 447.4 1.98 750 5.5 0.1 — —

ELNR-2 22.0 47.9 649 2.50 1,360 2.2 .1 — —

ELNR-3 45.1 11.9 237 .84 360 10.4 .1 — —

ELNR-4 57.6 11.6 96.4 1.25 66 55.6 .2 — —

GUAD-1 20.7 7.54 95.4 1.11 65.1 11.6 <.17 — —

GUAD-2 29.1 9.42 47.9 1.06 22.7 26.2 <.17 — —

GUAD-3 58.6 16.2 38.5 1.24 25.8 54.8 <.17 — —

GUAD-4 41.3 11.4 29.7 1.02 9.24 28.8 .2 — —

CCOC-1 22.3 9.67 94.7 1.11 77.9 21.7 E.2 — —

CCOC-1 23.2 10 94 1.04 78.8 19.4 .2 — —

CCOC-2 51.9 16.8 60.4 1.48 39.5 60.2 E.1 — —

CCOC-2 55.1 17.7 63.2 1.21 42.1 61.7 E.1 — —

CCOC-3 74 30.7 50.9 1.87 55.3 62.6 E.1 — —

CCOC-3 — — — — — — — — —

CCOC-4 74.1 36.6 55.5 3.08 38.6 78.9 .2 — —

CCOC-4 — — — — — — — — —

CCOC-5 90.6 65.1 46.1 1.88 63 101 .2 — —

CCOC-5 — — — — — — — — —

WLLO-1 39.4 32.7 83.1 1.98 152 29.2 E.1 205 205

WLLO-2 37.2 15.7 58.5 1.53 29.7 33.9 E.1 243 245

WLLO-3 66.8 19.9 35.1 1.85 40.5 44.8 E.1 245 249

WLLO-3 — — — — — — — — —

WLLO-4 — — — — — — — — —

WLLO-4 98.9 27.3 41.6 1.88 60 67.2 E.1 — —

WLLO-4 — — — — — — — — —

WLLO-5 90.5 30.1 35.2 2.19 47.9 67.9 E.1 316 316

WLLO-5 — — — — — — — — —

WLLO-6 70.5 34.2 37.9 1.7 47.5 69.2 E.1 279 282

STPK-1 48.1 15.7 27.8 1.5 29.2 42.2 .1 — —

STPK-2 49.3 18 25.4 1.42 53.5 39.6 .2 — —

STPK-3 55.7 21.8 26.2 1.58 51.9 49.7 .1 — —

STPK-4 57.4 20.8 26.9 1.47 44 51.2 .1 — —

STPK-5 100 40.4 53.7 2.63 58.5 75 .2 — —

MGCY-2 51.7 16.9 18.7 1.18 43.6 50.4 .1 — —

MGCY-3 47.7 17.4 27.9 1.44 18.4 38.9 .1 — —

MGCY-4 16.4 9.41 241 .62 249 1.6 E.1 — —

MGCY-5 32.7 16.2 52.1 3.14 81.3 46 .2 — —

MGCY-1 13.9 8.84 261 .55 256 .5 E.1 — —
Table 14 99

Table 14. Summary of selected U.S. Geological Survey (USGS) water-chemistry data from multiple-well monitoring sites in the Santa Clara County, California—

Continued

Local well 

name

Nitrite as nitrogen

(mg/L as N)

(00613)

Nitrite plus nitrate 

as nitrogen

(mg/L as N)

(00631)

Organic

ammonia

(mg/L as N)

(00623)

Nitrogen,

ammonia

(mg/L as N)

(00608)

Phosphorus

(mg/L as P)

(00666)

Ortho-phosphate

(mg/L as P)

(00671)

Organic carbon

(mg/L as C)

(00681)

ELNR-1 — — — — — — —

ELNR-2 — — — — — — —

ELNR-3 — — — — — — —

ELNR-4 — — — — — — —

GUAD-1 <0.008 <0.06 E0.09 E0.03 0.09 0.07 E0.3

GUAD-2 <.008 <.06 E.06 <.04 .12 .1 E.2

GUAD-3 .01 1.36 E.05 <.04 .12 .09 E.2

GUAD-4 — — — — — — E.2

CCOC-1 .011 .07 <.10 <.04 E.05 .04 .2

CCOC-1 <.006 E.03 <.10 <.04 E.03 E.03 —

CCOC-2 .021 6.29 <.10 E.03 E.06 .05 .4

CCOC-2 E.006 E5.47 <.10 <.04 E.04 E.03 —

CCOC-3 .103 3.75 E.05 E.04 .06 .06 .5

CCOC-3 — — — — — — —

CCOC-4 .103 3.31 .39 .4 .31 .28 .5

CCOC-4 — — — — — — —

CCOC-5 .04 1.95 E.06 E.03 E.06 .05 .6

CCOC-5 — — — — — — —

WLLO-1 <.006 <.05 <.10 <.04 1.3 .5 .2

WLLO-2 .049 3.46 <.10 <.04 .65 .23 .2

WLLO-3 .043 5.62 <.10 <.04 .31 .09 .3

WLLO-3 <.008 5.15 <.10 <.04 .3 .27 —

WLLO-4 .257 8.75 <.10 <.04 3.59 .4 —

WLLO-4 E.028 E8.02 <.10 <.04 1.38 E.51 .6

WLLO-4 E.007 7.41 <.10 <.04 1.47 1.25 —

WLLO-5 .21 9.3 <.10 <.04 .39 .12 .4

WLLO-5 .008 8.69 <.10 <.04 .28 .23 —

WLLO-6 .007 9.22 E.06 <.04 .09 .05 .5

STPK-1 E.006 1.08 <.10 <.04 .64 .24 .3

STPK-2 E.006 .94 <.10 <.04 .8 .28 1.7

STPK-3 .012 1.58 <.10 <.04 2.2 .42 .6

STPK-4 E.006 1.68 <.10 <.04 1.63 .23 .4

STPK-5 .089 6.56 <.10 <.04 2.39 .74 .7

MGCY-2 E.004 <.05 E.09 .07 .52 .48 .4

MGCY-3 <.008 .7 <.10 <.04 .35 .26 .4

MGCY-4 <.008 .44 E.07 E.02 1.7 1.01 <.3

MGCY-5 <.008 .48 <.10 <.04 1.17 .24 .9

MGCY-1 <.008 <.05 .13 .09 .22 .2 .4
100 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

Table 14. Summary of selected U.S. Geological Survey (USGS) water-chemistry data from multiple-well monitoring sites in the Santa Clara County, 

California—Continued

Local well 

name

Barium

(μg/L)

(01005)

Boron

(μg/L)

(01020)

Iron

(μg/L)

(01046)

Manganese

(μg/L)

(01056)

Strontium

(μg/L)

(01080)

Iodide

(mg/L)

(71865)

Bromide

(mg/L)

(71870)

Silica

(mg/L)

(00955)

ELNR-1 320 1,690 150 134 — — 4.14 47

ELNR-2 180 1,360 1,300 517 — — 6.74 47

ELNR-3 130 205 120 155 — — 1.86 36

ELNR-4 ND 215 470 ND — — .26 27

GUAD-1 199 153 <10 37.9 183 0.116 .24 23.3

GUAD-2 151 149 <10 50.5 291 .053 .1 23.9

GUAD-3 211 99 <10 91.1 420 .005 .09 25.9

GUAD-4 109 80 E4 44.2 233 .014 .03 27.9

CCOC-1 182 179 <10 22.7 182 .152 .19 26

CCOC-1 207 187 <10 24.5 192 .148 .3 24.7

CCOC-2 185 137 <10 27.2 366 .004 .15 25.8

CCOC-2 227 146 <10 21.4 403 .004 .16 24.5

CCOC-3 240 128 <10 32.6 515 .012 .17 30.7

CCOC-3 — — — — — — — —

CCOC-4 187 108 <10 26.3 461 .003 .17 28.6

CCOC-4 — — — — — — — —

CCOC-5 51.1 163 <10 29.3 868 .002 .25 26.7

CCOC-5 — — — — — — — —

WLLO-1 119 165 E5 39.5 334 .246 .54 30.3

WLLO-2 43.2 204 <10 .5 230 .006 .11 24.9

WLLO-3 102 100 <10 4.5 360 .001 .15 25.4

WLLO-3 — — — — — — — —

WLLO-4 — — — — — — — —

WLLO-4 133 90 <10 9.1 589 .002 .2 27.2

WLLO-4 — — — — — — — —

WLLO-5 123 91 <10 5 516 .002 .2 28

WLLO-5 — — — — — — — —

WLLO-6 107 106 <10 4 417 .002 .22 22

STPK-1 94.5 56 <10 27.1 264 <.002 .12 25.4

STPK-2 76.9 58 <10 32.5 266 <.002 .19 24.7

STPK-3 72 68 198 54.4 288 <.002 .44 25.7

STPK-4 91.1 74 24 23 302 E.001 .15 25.9

STPK-5 92.8 72 23 23.2 308 E.001 .22 23.3

MGCY-2 47.5 95 28 33.5 298 <.002 .14 21.7

MGCY-3 58.3 82 E6 23.2 248 .002 .07 28

MGCY-4 55.6 3,380 E6 98 124 .189 .83 24.2

MGCY-5 52.4 102 34 98.2 290 .006 .25 15.4

MGCY-1 141 3,860 68 36.7 95.4 .205 .9 25
Table 14 101

Table 14. Summary of selected U.S. Geological Survey (USGS) water-chemistry data from multiple-well monitoring sites in the Santa Clara County, California—

Continued

Local well 

name

Aluminum

(μg/L)

(01106)

Arsenic

(μg/L)

(01000)

Lithium

(μg/L)

(01130)

Chromium

(μg/L)

(01030)

Raw 

chromium

(μg/L)

(01034)

Lead

(μg/L)

(01049)

Mercury

(μg/L)

(71900)

Nickel

(μg/L)

(01065)

Zinc

(μg/L)

(01090)

ELNR-1 80 6 — ND — ND NT ND NT

ELNR-2 62 ND — ND — ND NT ND NT

ELNR-3 229 ND — ND — ND NT ND NT

ELNR-4 ND ND — ND — ND NT ND NT

GUAD-1 E1 2 7 — — — — — —

GUAD-2 E1 2.4 7 — — — — — —

GUAD-3 M 1.4 9 — — — — — —

GUAD-4 E1 1.7 7 — — — — — —

CCOC-1 <20 1.4 6 — — — — — —

CCOC-1 1 1.5 6 — <1.0 E0.07 <0.01 <0.06 2

CCOC-2 <20 1.2 8 — — — — — —

CCOC-2 <1 1.1 9 — <1.0 <.08 <.01 <.30 <1

CCOC-3 <20 1.1 11 — — — — — —

CCOC-3 — — — — — — — — —

CCOC-4 <20 2 10 — — — — — —

CCOC-4 — — — — — — — — —

CCOC-5 <20 1.5 13 — — — — — —

CCOC-5 — — — — — — — — —

WLLO-1 4 1.7 9 <0.8 <1.0 .11 — 1.04 3

WLLO-2 2 1.6 7 — <1.0 <.08 — <.06 2

WLLO-3 4 .6 5 3.6 5.3 E.08 — .23 <1

WLLO-3 — — — — — — — — —

WLLO-4 — — — — — — — — —

WLLO-4 2 1.6 6 — 6.7 E.04 <.01 <.30 <1

WLLO-4 — — — — — — — — —

WLLO-5 3 1.3 6 4.6 3.2 E.07 — E.06 1

WLLO-5 — — — — — — — — —

WLLO-6 <1 .6 7 1 <1.0 .1 — .88 3

STPK-1 <20 .9 6 — — — — — —

STPK-2 <20 1 6 — — — — — —

STPK-3 290 1.2 6 — — — — — —

STPK-4 E10 1.3 5 — — — — — —

STPK-5 E10 3 5 — — — — — —

MGCY-2 M .5 E4 — — — — — —

MGCY-3 <20 .8 5 — — — — — —

MGCY-4 <20 11.5 8 — — — — — —

MGCY-5 E10 .9 7 — — — — — —

MGCY-1 <20 10.8 7 — — — — — —
102 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

Table 14. Summary of selected U.S. Geological Survey (USGS) water-chemistry data from multiple-well monitoring sites in the Santa Clara County, 

California—Continued

Local 

well name

Delta deuterium

(per mil)

(82082)

Delta oxygen

(per mil)

(82085)

Percent artificial 

recharge

from delta 

deuterium

Percent artificial 

recharge

from delta oxygen

Tritium

(pCi/L)

(07000)

Strontium 87/86

(Ratio)

(75978)

Delta boron-11

(per mil)

ELNR-1 −48.2 −6.88 22 19 M 0.70606 21.82

ELNR-2 −46.1 −6.59 15 12 0 .70566 15.45

ELNR-3 −49 −7.06 24 23 0 .70626 24.24

ELNR-4 −44.5 −6.66 11 14 1 .70727 10.61

GUAD-1 −47.9 −7.14 21 25 0 — —

GUAD-2 −41.7 −6.62 2 13 .3 — —

GUAD-3 −42.3 −6.7 4 15 8.7 — —

GUAD-4 — — — — M — —

CCOC-1 −49.6 −7.25 26 28 .4 .70719 25.47

CCOC-1 — — — — — — —

CCOC-2 −44.3 −6.46 10 9 10.7 .70733 21.73

CCOC-2 — — — — — — —

CCOC-3 −42.2 −6.13 4 1 9.8 .70736 18.48

CCOC-3 — — — — — — —

CCOC-4 −41.8 −6.2 2 2 10.5 .70749 20.48

CCOC-4 — — — — — — —

CCOC-5 −42.4 −6.08 4 0 11.9 .70764 11.24

CCOC-5 — — — — — — —

WLLO-1 −48.5 −7.2 23 27 .2 — —

WLLO-2 −42.4 −6.49 4 10 8.2 — —

WLLO-3 −44.4 −6.45 10 9 12.9 — —

WLLO-3 — — — — — — —

WLLO-4 — — — — — — —

WLLO-4 — — — — — — —

WLLO-4 −43.1 −6.28 6 4 — — —

WLLO-5 −43.6 −6.26 8 4 14 — —

WLLO-5 — — — — — — —

WLLO-6 −42.9 −6.3 6 5 12 .70747 22.23

STPK-1 −44.2 −6.92 10 20 — .70763 21.98

STPK-2 −52.6 −7.41 35 32 15.9 .70754 22.23

STPK-3 −55.2 −7.68 43 39 12.2 .70756 16.48

STPK-4 −55 −7.67 42 38 11.5 .70780 14.99

STPK-5 −48.7 −6.99 23 22 11.5 — —

MGCY-2 −52.4 −7.38 35 31 12.3 .70777 5.49

MGCY-3 −41.1 −6.37 0 7 3.6 .70758 17.11

MGCY-4 −43.7 −6.66 8 14 0 .70749 21.48

MGCY-5 −64 −8.29 70 53 12.1 .70761 18.98

MGCY-1 −45.3 −6.66 13 14 .2 .70731 22.23
Table 14 103

Table 14. Summary of selected U.S. Geological Survey (USGS) water-chemistry data from multiple-well monitoring sites in the Santa Clara County, California—

Continued

Local well name

Carbon 13/12

(per mil)

(82081)

Carbon-14

(pmc)

(49933)

Uncorrected age

(years before present)

Initial water corrected

(years before present)

ELNR-1 −27.37 2.3 31,200 30,500

ELNR-2 −32.36 2.26 31,184 30,800

ELNR-3 −17.6 .78 39,900 39,900

ELNR-4 −15.04 28.19 10,500 9,900

GUAD-1 — — — —

GUAD-2 — — — —

GUAD-3 — — — —

GUAD-4 −13.67 54.73 4,600 4,400

CCOC-1 −16.77 12.33 17,300 16,700

CCOC-1 — — — —

CCOC-2 −14.91 73.99 2,500 1,900

CCOC-2 — — — —

CCOC-3 −14.83 77.92 2,100 1,500

CCOC-3 — — — —

CCOC-4 −15.09 81.77 1,700 1,100

CCOC-4 — — — —

CCOC-5 −16.19 79.71 1,900 1,300

CCOC-5 — — — —

WLLO-1 −16.93 4.74 25,300 24,600

WLLO-2 −13.77 61.66 4,000 3,400

WLLO-3 — — — —

WLLO-3 −14.42 79.92 1,900 1,300

WLLO-4 — — — —

WLLO-4 −15.71 89.23 950 400

WLLO-4 — — — —

WLLO-5 — — — —

WLLO-5 — — — —

WLLO-6 −15.87 102.6 0 0

STPK-1 −12.79 71.96 2,700 2,200

STPK-2 −13.11 88.22 1,000 500

STPK-3 −14.34 101.7 0 0

STPK-4 −14.75 101.3 0 0

STPK-5 — — — —

MGCY-2 −12.96 108 0 0

MGCY-3 −15.85 65.91 3,400 2,900

MGCY-4 −10.96 11.79 17,700 17,100

MGCY-5 — — — —

MGCY-1 −5.68 10.79 18,400 17,900
104 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

Table 15. Summary of pore water-chemistry data from selected cores samples collected from multiple-well monitoring-well sites, Santa Clara County, 

California—Continued

Drill site

(core No.)

Depth to 

top of 

coresample 

interval

(ft bls)

Depth to 

bottom of 

coresample 

interval

(ft bls)

Percent salt

(grams 

NaCl per 

100 grams 

water)

pH,

standard 

units

Total 

inorganic 

carbon

(mg/L as C)

Nitrite as 

nitrogen

(mg/L 

as N)

Nitrate as 

nitrogen

(mg/L 

as N)

Chloride, 

dissolved

(mg/L)

(00940)

Bromide,

dissolved

(mg/L)

(71870)

Ortho 

phosphorous 

(mg/L as P)

(00671)

Sulfate,

dissolved

(mg/L)

(00945)

CCOC-4C-1 21 23 10 7.7 — 0.3 3.07 125 0.5 1.1 210

CCOC-5C-1 26 29 9 7.7 — <.02 .43 — — — —

CCOC-6C-1 32 33 10 7.7 108 .1 .39 — — — —

CCOC-7C-1 36 38 8 7.8 81 .08 .75 — — — —

CCOC-8C-1 41 43 6 7.9 87 .08 .59 85 <.5 <.4 120

CCOC-9C-1 56 59 3 8 72 .02 1.33 54 <.5 <.4 69

CCOC-12C-1 67 67 6 7.8 — .12 2.29 66 <.5 <.4 135

CCOC-15C-2 74 76 5 7.7 61 — — — — — —

CCOC-15C-1 76 78 5 7.7 65 <.02 .31 32 <.5 <.4 260

CCOC--16C-1 79 80 5 7.7 --- .03 .49 29 <.5 <.4 190

CCOC-17C-1 81 83 3 7.9 61 .03 .49 37 <.5 <.4 120

CCOC-18C-1 86 88 4 8.5 67 .02 .52 25 <.5 <.4 130

CCOC-19C-1 93 95 3 8.6 46 .02 .21 25 <.5 <.4 49

CCOC-19C-2 91 93 — — — .03 .52 31 <.5 <.4 76

CCOC-20C-1 96 100 2 8.6 — .03 .35 33 <.5 <.4 42

CCOC-21C-1 101 105 2 8.5 64 <.02 .6 27 <.5 <.4 42

CCOC-22C-1 106 108 3 7.8 64 .05 .86 28 <.5 <.4 43

CCOC-23C-1 111 115 4 8.3 71 .06 1.16 35 <.5 <.4 55

CCOC-24C-1 116 119 4 8.5 72 .06 1.02 35 <.5 <.4 65

CCOC-25C-1 121 123 5 8.3 — .18 .65 52 <.5 <.4 100

CCOC-26C-1 126 128 4 8.1 69 — — — — — —

CCOC-27C-1 129 130 4 7.9 — — — — — — —

CCOC-28C-1 131 134 3 7.9 62 .05 .88 39 <.5 <.4 59

CCOC-29C-1 231 233 4 7.8 55 — — — — — —

CCOC-31C-1 241 242 4 7.8 — — — — — — —

CCOC-31C-2 242 244 5 7.9 — .28 2.65 52 <.5 <.4 155

CCOC-32C-1 246 248 4 7.8 — .05 3.04 47 <.4 <.6 94

CCOC-33C-1 251 254 4 7.9 — .07 2.22 46 <.8 <1.2 86

CCOC-34C-1 256 260 3 8.6 39 — — — — — —

CCOC-35C-1 261 264 3 8.1 54 .02 1.37 38 <.4 <.6 59

CCOC-36C-1 266 266 5 7.8 59 — — — — — —

CCOC-39C-1 471 471 2 8.2 51 .06 1.75 39 <.4 <.6 72

CCOC-40C-1 476 480 2 9.1 26 .11 1.31 38 <.4 <.6 70

CCOC-46C-1 551 553 3 8.6 — — — — — — —

CCOC-47C-1 554 554 3 8.2 51 <.04 3.19 43 .4 <.6 88

CCOC-47C-2 555 555 5 8.1 — .73 4.57 55 .6 <.6 160

CCOC-48C-1 559 559 2 8.2 — <.04 1.71 32 <.4 <.6 72

CCOC-49C-1 561 565 2 9.3 18 — — — — — —

CCOC-50C-1 566 570 2 9 24 .08 .77 29 <.4 <.6 56

CCOC-51C-1 571 575 3 7.9 — — — — — — —

CCOC-52C-1 576 579 3 7.8 46 .28 1.59 39 <.4 <.6 64

CCOC-54C-1 586 588 3 7.9 50 — — — — — —

Table 15. Summary of pore water-chemistry data from selected cores samples collected from multiple-well monitoring-well sites, Santa Clara County, 

California

[Number in parentheses below the compound is the data parameter code, which is a 5-digit number used in the U.S. Geological Survey computerized data system, 

National Water Information System (NWIS), to uniquely identify a specific constituent or property; ft, foot; bls, below land surface; mg/L, milligrams per liter; <, 

less than; —, no data]
Table 15 105

CCOC-55C-1 589 590 4 7.9 48 — — — — — —

CCOC-57C-1 639 640 2 8 34 — — — — — —

CCOC-58C-1 642 643 6 8.1 38 — — — — — —

CCOC-59C-1 644 644 3 7.8 32 — — — — — —

CCOC-60C-1 673 675 2 9.4 20 <0.04 0.66 37 <0.4 <0.6 70

CCOC-61C-1 677 679 2 9.2 14 — — — — — —

CCOC-62C-1 717 717 5 8.1 — .53 .78 45 <.4 <.6 165

CCOC-63C-1 721 722 6 8.1 — .97 2.15 73 <.4 <.6 180

CCOC-64C-1 727 727 3 7.9 — — — — — — —

CCOC-66C-1 736 738 5 7.8 — — — — — — —

CCOC-67C-1 781 785 3 9.4 24 .18 1.95 62 <.4 <.6 120

CCOC-68C-1 816 818 3 9.2 — .11 1.38 57 <.4 <.6 100

CCOC-69C-1 821 822 2 8.9 28 .11 .32 54 <.4 <.6 57

CCOC-71C-1 881 882 2 7.9 15 — — — — — —

CCOC-72C-1 886 891 3 7.7 26 — — — — — —

CCOC-74C-1 896 897 3 7.5 23 — — — — — —

CCOC-75C-1 961 962 4 7.9 — .32 1.83 114 <.4 <.6 72

CCOC-77C-1 996 996 5 8.1 — .68 2.52 93 <.4 <.6 94

WILO1-1C-1 40 45 5 7.3 — .09 5.11 71 <.4 <.6 82

WILO1-3C-1 50 55 5 7.2 — .02 2.1 80 <.4 <.6 90

WILO1-4C-1 55 60 5 7.4 — .01 .26 116 <.4 — 61

WILO1-14C-1 110 115 3 8.4 — .02 .57 33 <.4 — 73

WILO1-15C-1 295 300 3 7.6 — .07 .09 29 .3 <.3 61

WILO1-16C-1 300 305 2 7.7 — <.01 <.02 23 <.2 <.3 47

WILO1-17C-1 305 310 3 8.3 — .01 <.02 28 <.2 <.3 69

WILO1-18C-1 310 315 2 8.3 — .02 .02 29 <.2 <.3 54

WILO1-28C-1 670 673 3 7.3 — — — — — — —

WILO1-30C-1 705 708 4 7.3 — <.01 <.02 98 <.2 <.3 79

WILO1-32C-1 738 741 4 7.1 — — — — — — —

WILO1-33C-1 741 746 4 7.3 — <.01 .04 98 <.2 <.3 72

WILO1-34C-1 746 750 3 7.1 — .01 <.02 110 .3 <.3 26

WILO1-35C-1 750 755 5 7 — — — — — — —

WILO1-37C-1 780 784 4 7 — — — — — — —

WILO2-1C-1 30 35 2 6.7 — — — — — — —

WILO2-3C-1 40 45 4 7 — .12 4.55 65 <.2 <.3 91

WILO2-5C-1 50 55 5 7.1 — .02 1.69 62 <.4 <.6 87

WILO2-6C-1 55 60 5 7.1 — .08 1.13 89 <.4 — 79

MGCY-4C-1 35 35 3 6.6 — — — — — — —

MGCY-22C-1 152 154 3 7 — — — — — — —

MGCY-23C-1 155 157 3 6.9 — — — — — — —

MGCY-30C-1 249 251 3 7.2 — .06 .95 63 < .6 < .8 67

MGCY-34C-1 321 321 2 7 — — — — — — —

MGCY-38C-1 332 332 2 7.1 — — — — — — —

MGCY-39C-1 335 335 2 7 — — — — — — —

MGCY-44C-1 420 421 3 7 — — — — — — —

MGCY-45C-1 422 423 4 7.4 — — — — — — —

MGCY-46C-1 426 426 4 7.5 — — — — — — —

Table 15. Summary of pore water-chemistry data from selected cores samples collected from multiple-well monitoring-well sites, Santa Clara County, 

California—Continued

Drill site

(core No.)

Depth to 

top of 

coresample 

interval

(ft bls)

Depth to 

bottom of 

coresample 

interval

(ft bls)

Percent salt

(grams 

NaCl per 

100 grams 

water)

pH,

standard 

units

Total 

inorganic 

carbon

(mg/L as C)

Nitrite as 

nitrogen

(mg/L 

as N)

Nitrate as 

nitrogen

(mg/L 

as N)

Chloride, 

dissolved

(mg/L)

(00940)

Bromide,

dissolved

(mg/L)

(71870)

Ortho 

phosphorous 

(mg/L as P)

(00671)

Sulfate,

dissolved

(mg/L)

(00945)
106 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

MGCY-47C-1 430 430 5 7.2 — — — — — — —

MGCY-50C-1 492 492 8 7.2 — — — — — — —

MGCY-52C-1 500 500 8 7.5 — — — — — — —

MGCY-56C-1 581 581 7 7.9 — 0.04 0.11 270 1.2 <0.8 25

MGCY-57C-1 584 584 8 8.2 — <.04 .15 320 1.5 <.8 23

MGCY-60C-1 594 594 6 7.5 — — — — — — —

MGCY-61C-1 601 601 6 8 — .04 .16 200 1.3 <.8 23

MGCY-62C-1 604 604 6 8.6 — .04 <.08 180 .7 <.8 45

MGCY-63C-1 610 610 7 9 — <.04 <.08 300 1.1 <.8 64

MGCY-65C-1 622 622 7 8.4 — — — — — — —

MGCY-66C-1 627 627 6 9.2 — .05 <.08 190 .9 <.8 26

MGCY-68C-1 701 701 17 8.5 — < .2 <.4 910 3.3 <4 18

MGCY-69C-1 707 708 18 8.1 — — — — — — —

MGCY-70C-1 713 713 19 8.4 — < .2 <.4 960 4.4 <4 18

MGCY-71C-1 716 717 17 8.4 — < .2 <.4 890 2.4 <4 17

MGCY-73C-1 726 726 11 8.7 — — — — — — —

MGCY-75C-1 777 778 23 8.3 — < .2 <.4 1,200 5.6 <4 16

MGCY-78C-1 793 793 21 7.3 — — — — — — —

MGCY-79C-1 830 830 27 7.7 — — — — — — —

MGCY-81C-1 867 867 23 7.3 — — — — — — —

STPK-2C-1 34 39 7 7.1 — <.03 25.15 140 <2 <2 120

STPK-3C-1 39 44 6 7.2 — <.03 7.59 99 <2 <2 260

STPK-11C-1 184 189 2 7.4 — .05 3.28 48 <.5 <.5 90

STPK-13C-1 224 226.5 2 7.4 — .07 2.27 46 <.5 <.5 80

STPK-15C-1 229 234 1 7.4 — .04 1.17 26 <.5 <.5 30

STPK-18C-1 244 249 2 7.4 — .03 2.37 51 <.5 <.5 90

STPK-20C-1 254 259 2 7.3 — .05 2.12 75 <.5 <.5 80

STPK-34C-1 479 484 2 7.4 — .07 2.34 58 <.5 <.5 70

STPK-36C-1 569 574 2 7.4 — .18 .64 45 <.5 <.5 80

GUAD-1C-1 9 14 9 7.7 — <.24 1.94 99 1 <4 360

GUAD-2C-1 14 19 9 7.8 — <.06 1.16 100 1 <2 370

GUAD-4C-1 24 29 6 8 — .02 .78 79 .7 3 160

GUAD-5C-1 29 34 3 8 — .02 .73 62 .2 <1 110

GUAD-6C-1 34 39 2 7.6 — .04 1.32 45 <.6 <1 69

GUAD-8C-1 44 49 4 8 — .03 1.68 130 <.6 <1 140

GUAD-13C-1 69 74 7 7.7 — <.06 2.54 99 <.6 <2 410

GUAD-14C-1 74 79 8 7.5 — .04 .93 110 <.6 2 410

GUAD-16C-1 84 89 7 7.9 — <.06 1.14 90 .2 2 310

GUAD-17C-1 89 94 3 8 — .02 .71 67 <.6 .8 71

GUAD-18C-1 89 94? 1 8.4 — <.06 .64 39 <.6 <1 37

GUAD-20C-1 104 109 2 7.8 — .03 .77 20 <.6 <1 46

GUAD-21C-1 109 114 1 8.4 — .02 .91 22 <.6 <1 42

GUAD-22C-1 114 119 1 8.6 — .03 1.17 29 <.6 <1 37

GUAD-23C-1 119 124 2 7.7 — .06 .43 21 <.6 <1 41

GUAD-27C-1 139 144 3 8.3 — .02 1.22 41 <.6 <1 63

Table 15. Summary of pore water-chemistry data from selected cores samples collected from multiple-well monitoring-well sites, Santa Clara County, 

California—Continued

Drill site

(core No.)

Depth to 

top of 

coresample 

interval

(ft bls)

Depth to 

bottom of 

coresample 

interval

(ft bls)

Percent salt

(grams 

NaCl per 

100 grams 

water)

pH,

standard 

units

Total 

inorganic 

carbon

(mg/L as C)

Nitrite as 

nitrogen

(mg/L 

as N)

Nitrate as 

nitrogen

(mg/L 

as N)

Chloride, 

dissolved

(mg/L)

(00940)

Bromide,

dissolved

(mg/L)

(71870)

Ortho 

phosphorous 

(mg/L as P)

(00671)

Sulfate,

dissolved

(mg/L)

(00945)
Table 15 107

GUAD-28C-1 144 149 1 8.8 — 0.03 1.8 41 <0.6 <1 36

GUAD-30C-1 154 159 1 9.5 — .43 .7 20 <.6 <1 75

GUAD-31C-1 159 164 1 8.5 — .09 1.01 26 <.6 <1 40

GUAD-32C-1 164 169 1 8.4 — .16 1.22 27 <.6 <1 52

GUAD-33C-1 169 174 1 7.5 — .14 .33 23 <.6 <1 49

GUAD-34C-1 174 179 1 7.5 — .04 .17 21 <.6 <1 30

GUAD-35C-1 179 184 1 8.5 — .05 .46 19 <.6 .6 33

GUAD-36C-1 184 189 1 7.4 — .07 .56 22 <.6 <1 24

GUAD-40C-1 204 209 1 7.5 — .15 .8 39 <.6 <1 68

GUAD-42C-1 214 219 — — — .07 .62 47 .2 <1 50

GUAD-46C-1 234 239 — — — .19 .87 45 <.6 <1 82

GUAD-49C-1 249 254 — — — .03 .14 38 <.6 <1 33

GUAD-50C-1 254 259? — — — .03 .08 17 <.6 <1 32

GUAD-50C-2 254 259? — — — .02 <.12 15 <.6 <1 29

GUAD-50C-3 254 259? — — — .02 .04 19 <.6 <1 27

GUAD-53C-1 269 274 — — — .02 .2 19 <.6 <1 10

GUAD-54C-1 274 279 — — — .05 .23 31 <1.2 <2 15

GUAD-55C-1 279 284 — — — .05 .18 23 <.6 <1 17

GUAD-56C-1 284 289 — — — .04 .27 29 .2 <1 30

GUAD-57C-1 289 294 — — — .04 .25 24 <.6 .6 25

GUAD-59C-1 299 304 — — — .02 .1 16 <.6 <1 24

GUAD-60C-1 304 309 — — — .05 .27 23 <.6 <1 31

GUAD-61C-1 309 314 — — — .03 .08 14 <.6 <1 28

GUAD-62C-1 314 319 — — — .03 .07 15 <.6 <1 35

GUAD-64C-1 324 329 — — — <.06 <.12 19 <.6 <1 25

GUAD-65C-1 329 334 — — — .04 .08 15 <.6 <1 16

GUAD-66C-1 334 339 — — — .03 .36 27 <.6 <1 33

GUAD-67C-1 339 344 — — — .03 1.2 26 <.6 <1 47

GUAD-70C-1 354 355 — — — .04 1.75 37 <.6 <1 56

GUAD-70C-2 355 356.6 — — — .08 .74 22 <.6 <1 53

GUAD-71C-1 359 364 — — — .05 1.71 38 <.6 <1 38

GUAD-73C-1 369 374 — — — .03 .81 26 <.6 <1 39

GUAD-74C-1 374 379? — — — .03 1.01 23 <.6 <1 33

GUAD-75C-1 379 384 — — — .03 1.82 33 <.6 <1 37

GUAD-76C-1 384 389 — — — .04 .12 16 <.6 <1 40

Table 15. Summary of pore water-chemistry data from selected cores samples collected from multiple-well monitoring-well sites, Santa Clara County, 

California—Continued

Drill site

(core No.)

Depth to 

top of 

coresample 

interval

(ft bls)

Depth to 

bottom of 

coresample 

interval

(ft bls)

Percent salt

(grams 

NaCl per 

100 grams 

water)

pH,

standard 

units

Total 

inorganic 

carbon

(mg/L as C)

Nitrite as 

nitrogen

(mg/L 

as N)

Nitrate as 

nitrogen

(mg/L 

as N)

Chloride, 

dissolved

(mg/L)

(00940)

Bromide,

dissolved

(mg/L)

(71870)

Ortho 

phosphorous 

(mg/L as P)

(00671)

Sulfate,

dissolved

(mg/L)

(00945)
108 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

Table 16. Summary of selected U.S. Geological Survey (USGS) water-chemistry data from selected water-supply wells, Santa Clara County, California—

Continued

State 

well No.

Local 

well name

Depth of 

screened 

interval

Date Time

Water 

temperature

(

οC)

(00010)

Air

temperature

(

οC)

(00020)

Total 

dissolved solids

(mg/L)

(70300)

5S/3W-35G10 PA Hale St No. 3 — 08/08/2001 1150 — — —

6S/1E-16K5 Cropley No. 3 — 06/25/2001 1710 — — —

6S/1E-31K1 Gish No.2 412–662 09/09/1999 1520 24.5 23 292

6S/1E-32G1 Berryessa No.1 315–745 06/25/2001 1520 — — 430

6S/1E-33F6 Marbury No. 1 — 06/26/2001 0900 — — —

6S/1W-13F6 Agnews No. 6 — 06/28/2001 1500 — — —

6S/1W-24B5 SJC No. 1 — 08/09/2001 1010 — — —

6S/1W-26D2 SC-26 295–665 08/02/2001 0830 — — 316

6S/1W-32H1 SC-21 290–650 08/02/2001 1140 — — 343

6S/2W-19H2 CWS No. 121-02 — 08/01/2001 0840 — — —

6S/2W-19M1 CWS No. 123-01 — 07/31/2001 1050 — — —

6S/2W-19M10 CWS No. 123-02 — 07/31/2001 1040 — — —

6S/2W-20L3 CWS No. 119-03 — 07/31/2001 1400 — — —

6S/2W-22G9 MV-21 — 08/09/2001 1210 — — —

6S/2W-22P2 MV-19 — 08/08/2001 1310 — — —

6S/2W-27G2 MV-20 214–670 08/14/2001 1830 — — 300

6S/2W-27G2 MV-20 214–670R 08/14/2001 1900 — — —

6S/2W-27G2 MV-20 (235) 08/15/2001 0900 — — 310

6S/2W-27G2 MV-20 (280) 08/15/2001 1400 — — —

6S/2W-29B2 CWS No. 116 — 07/31/2001 1500 — — —

6S/2W-32D1 CWS No. 104-02 — 07/31/2001 0910 — — —

6S/2W-33C1 MV-9 — 08/08/2001 1410 — — —

6S/2W-34G2 CWS No. 39-01 — 07/31/2001 0800 — — —

6S/2W-34K2 CWS No.17 310–734 07/17/2001 0830 — — 418

6S/2W-34K2 CWS No.17 310–734R 07/17/2001 1800 — — 400

6S/2W-34K2 CWS No.17 (280) 07/19/2001 1400 — — —

6S/2W-34K2 CWS No.17 — 07/19/2001 1410 — — —

6S/2W-34K2 CWS No.17 310–734R 07/19/2001 1800 — — 412

6S/2W-34K2 CWS No.17 (320) 07/20/2001 1600 — — —

6S/2W-34K2 CWS No.17 (440) 07/21/2001 1200 — — 970

6S/2W-34K2 CWS No.17 (460) 07/21/2001 1500 — — —

6S/2W-34K2 CWS No.17 (510) 07/21/2001 1730 — — —

6S/3W-1B2 PA Rinconda — 08/08/2001 1040 — — —

7S/1E-7R4 Main P 418–784 09/09/1999 1010 19.8 20 384

7S/1E-7R4 Main P 418–784 06/26/2001 1520 — — —

7S/1E-9D3 17th St. No.3 295–467 09/16/1999 1430 20 25.5 502

7S/1E-9D3 17th St. No.3 295–467 06/26/2001 1020 — — —

7S/1E-9D5 17th St. No. 7 526–708 09/09/1999 1350 22 25 396

7S/1E-9D9 17th St. No.12 425–828 09/16/1999 1345 22 24 372

7S/1E-9D9 17th St. No.12 425–828 06/26/2001 1130 — — —

Table 16. Summary of selected U.S. Geological Survey (USGS) water-chemistry data from selected water-supply wells, Santa Clara County, California

[Number in parentheses below the compound is the data parameter code, which is a 5-digit number used in the U.S. Geological Survey computerized data system, 

National Water Information System (NWIS), to uniquely identify a specific constituent or property; οC, degrees Celsius; μS/cm, microseimen per centimeter; 

mg/L, milligram per liter; μg/L, microgram per liter; pmc, percent modern carbon; per mil, parts per thousand; pCi/L, picocuries per liter; — no data; <, less than; 

E, estimated data; M, presence of constituent verified but not quantified; R, repeated sample depth; ( ), depth-dependent sample at a specified depth]
Table 16 109

7S/1E-16C8 12th St. No.10 265–774 09/15/1999 1150 20 27 504

7S/1E-16C8 12th St. No.10 (300) 09/15/1999 1200 26 27 438

7S/1E-16C8 12th St. No.10 (315) 09/15/1999 1600 23.8 22 474

7S/1E-16C8 12th St. No.10 (350) 09/15/1999 1800 17.6 — 495

7S/1E-16C8 12th St. No.10 (560) 09/15/1999 2040 16.7 — 468

7S/1E-16C8 12th St. No.10 (730) 09/15/1999 2220 17.2 — 481

7S/1E-16C8 12th St. No.10 (730)R 05/23/2000 2350 17 17 493

7S/1E-16C8 12th St. No.10 265–774R 05/24/2000 0200 19.7 17 501

7S/1E-16C8 12th St. No.10 — 06/18/2001 1430 — — —

7S/1E-17F2 Grant & Vine 2 — 06/27/2001 0910 — — —

7S/1E-18P1 Home No. 3 — 06/25/2001 1340 — — 391

7S/1E-26D2 Senter 385–454 09/09/1999 1240 19 24 532

7S/1E-26D2 Senter 385–454 08/01/2001 1540 — — —

7S/1E-26D2 Senter 385–454 08/01/2001 1540 — — —

7S/1E-29A1 Malone No. 1 — 06/26/2001 1350 — — —

7S/1E-32G3 Koch No. 1 — 06/27/2001 1320 — — —

7S/1W-2B1 SC-5-2 558–510 09/08/1999 0920 25.1 22 284

7S/1W-2B1 SC-5-2 558–510 08/02/2001 0940 — — —

7S/1W-2G29 SC-3-02 — 08/02/2001 1400 — — 379

7S/1W-6P1 CWS No. 20-10 274–682 08/01/2001 0940 — — 442

7S/1W-10D10 SC-28 298–810 08/02/2001 1040 — — 395

7S/1W-11D2 SC-2-2 342–493 09/08/1999 1030 18.8 22 359

7S/1W-13E3 Bascom No. 4 560–577 09/08/1999 1515 — 25.5 281

7S/1W-13E4 Bascom No. 5 334–792 08/01/2001 1410 — — 307

7S/1W-13K4 Buena Vista No. 6 — 06/27/2001 1450 — — 372

7S/1W-14B1 O’Connor Hospital 213–260 06/27/2001 1110 — — 418

7S/1W-18K1 CWS No. 29-01 — 08/01/2001 1050 — — —

7S/1W-22E2 Williams No. 3 (314) 05/31/2000 1300 — — 409

7S/1W-22E2 Williams No. 3 (344) 05/31/2000 1421 — — 391

7S/1W-22E2 Williams No. 3 (364) 05/31/2000 1508 — — 380

7S/1W-22E2 Williams No. 3 300–770 05/31/2000 1638 — — 367

7S/1W-22E2 Williams No. 3 300–770 05/31/2000 1700 — — 374

7S/1W-22E2 Williams No. 3 (430) 05/31/2000 1800 — — 373

7S/1W-22E2 Williams No. 3 (504) 05/31/2000 1900 — — 380

7S/1W-22E2 Williams No. 3 (564) 05/31/2000 2040 — — 369

7S/1W-22E2 Williams No. 3 (634) 05/31/2000 2230 — — 351

7S/1W-22E2 Williams No. 3 (669) 05/31/2000 2330 — — 339

7S/1W-22E2 Williams No. 3 — 06/19/2001 1400 — — —

7S/1W-22E2 Williams No. 3 — 06/19/2001 1650 — — —

7S/1W-22E2 Williams No. 3 300–770 06/19/2001 1745 — 26.5 390

7S/1W-22E2 Williams No. 3 — 06/19/2001 1900 — — —

7S/1W-22E3 Williams No. 4 — 07/30/2001 1410 — — —

7S/1W-22E12 Williams No. 12 — 07/30/2001 1440 — — —

7S/1W-23R3 Three Mile No. 3 378–818 09/14/1999 1055 17 20 —

7S/1W-23R3 Three Mile No. 3 378–818 06/28/2001 1300 — — —

Table 16. Summary of selected U.S. Geological Survey (USGS) water-chemistry data from selected water-supply wells, Santa Clara County, California—

Continued

State 

well No.

Local 

well name

Depth of 

screened 

interval

Date Time

Water 

temperature

(

οC)

(00010)

Air

temperature

(

οC)

(00020)

Total 

dissolved solids

(mg/L)

(70300)
110 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

7S/1W-23R5 Three Mile No. 5 39–832 09/13/1999 1530 17.5 25 322

7S/1W-23R5 Three Mile No. 5 (420) 09/13/1999 1535 — — —

7S/1W-24J3 Meridian No. 2 336–882 09/07/1999 1450 20 28.5 377

7S/1W-26R3 Ridgley No. 2 300–803 09/08/1999 1350 21 18 299

7S/1W-26R4 Ridgley No. 3 — 07/30/2001 1700 — — —

7S/1W-34F1 Virginia No. 1 — 07/30/2001 1530 — — —

7S/2W-1E3 CWS No. 27-01 — 07/31/2001 1600 — — —

7S/2W-1L1 CWS No. 31-01 — 08/01/2001 1200 — — —

7S/2W-3H1 CWS No. 18-02 — 07/31/2001 1210 — — —

7S/2W-3P1 CWS No. 15-01 — 08/16/2001 0900 — — —

8S/1E-11A4 GOWC No. 8 — 08/07/2001 1320 — — —

8S/1E-12P1 GOWC No. 2 — 06/28/2001 0920 — — —

8S/2E-7A12 SJC No. 11 — 08/09/2001 0840 — — —

8S/2E-8Q2 GOWC No. 21 105–230 06/28/2001 1000 — — 374

8S/2E-18E11 GOWC No. 12 — 08/07/2001 1210 — — —

Table 16. Summary of selected U.S. Geological Survey (USGS) water-chemistry data from selected water-supply wells, Santa Clara County, California—

Continued

State 

well No.

Local 

well name

Depth of 

screened 

interval

Date Time

Water 

temperature

(

οC)

(00010)

Air

temperature

(

οC)

(00020)

Total 

dissolved solids

(mg/L)

(70300)
Table 16 111

Table 16. Summary of selected U.S. Geological Survey (USGS) water-chemistry data from selected water-supply wells, Santa Clara County, California—

Continued

Local 

well name

Field, specific 

conductance

(μS/cm@25οC)

(00095)

Lab specific

conductance

(μS/cm)

(90095)

Dissolved 

oxygen

(mg/L)

(00300)

Field pH

(Standard units)

(00400)

Lab pH

(Standard units)

(00403)

Field 

alkalinity

(mg/L as CaCO3)

(39036)

Lab 

alkalinity

(mg/L as CaCO3)

(29801)

PA Hale St No. 3 1,400 — — — — — —

Cropley No. 3 — 1,020 — — — — —

Gish No.2 483 488 — 7.8 7.9 180 189

Berryessa No.1 — 745 — — 7.6 — 229

Marbury No. 1 — 881 — — — — —

Agnews No. 6 — 704 — — — — —

SJC No. 1 773 — — — — — —

SC-26 — 522 — — 7.9 — 189

SC-21 — 568 — — 7.7 — 220

CWS No. 121-02 — 760 — — — — —

CWS No. 123-01 — — — — — — —

CWS No. 123-02 — 601 — — — — —

CWS No. 119-03 — 791 — — — — —

MV-21 602 — — — — — —

MV-19 648 — — — — — —

MV-20 — 619 — — 7.9 — 197

MV-20 — — — — — — —

MV-20 — 623 — — 7.8 — 182

MV-20 — 626 — — 7.7 — 231

CWS No. 116 — 682 — — — — —

CWS No. 104-02 — 701 — — — — —

MV-9 888 — — — — — —

CWS No. 39-01 — 743 — — — — —

CWS No.17 — 666 — — 7.6 — 240

CWS No.17 — 653 — — 7.6 — 234

CWS No.17 — 659 — — 7.7 — 234

CWS No.17 — — — — — — —

CWS No.17 — 654 — — 7.6 — 235

CWS No.17 — 659 — — 7.5 — 235

CWS No.17 — 654 — — 7.8 — 230

CWS No.17 — 630 — — 7.6 — 231

CWS No.17 — 623 — — 7.6 — 232

PA Rinconda 1,540 — — — — — —

Main P 677 680 — 7.7 7.7 210 269

Main P — 696 — — — — —

17th St. No.3 824 810 3.5 7.5 7.8 — 317

17th St. No.3 — 805 — — — — —

17th St. No. 7 666 666 .4 7.7 7.8 220 230

17th St. No.12 672 667 .6 7.7 7.8 240 256

17th St. No.12 — 752 — — — — —

12th St. No.10 820 801 — 7.7 7.8 280 302

12th St. No.10 779 780 — 7.5 7.2 290 306

12th St. No.10 784 765 — 7.6 7.8 — 307

12th St. No.10 809 796 1 7.7 7.9 — 298

12th St. No.10 796 790 1.4 7.6 7.9 — 333
112 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

12th St. No.10 830 815 2.8 7.7 7.8 — 322

12th St. No.10 807 811 — 7.7 7.6 280 298

12th St. No.10 809 816 — 7.6 7.6 280 293

12th St. No.10 — — — — — — —

Grant & Vine 2 — 894 — — — — —

Home No. 3 — 664 — — 7.7 — 214

Senter 906 903 — 7.6 7.6 320 342

Senter — 915 — — — — —

Senter — 915 — — — — —

Malone No. 1 — 594 — — — — —

Koch No. 1 — 885 — — — — —

SC-5-2 461 470 — 7.9 8 170 187

SC-5-2 — 456 — — — — —

SC-3-02 — 606 — — 7.7 — 207

CWS No. 20-10 — 733 — — 7.4 — 264

SC-28 — 630 — — 7.6 — 224

SC-2-2 590 594 — 7.5 7.7 200 210

Bascom No. 4 471 470 — 7.7 7.8 150 158

Bascom No. 5 — 537 — — 7.7 — 144

Buena Vista No. 6 — 640 — — 7.5 — 188

O’Connor Hospital — 725 — — 7.6 — 230

CWS No. 29-01 — 581 — — — — —

Williams No. 3 609 686 — 7.4 7.4 — 218

Williams No. 3 660 673 — 7.3 7.3 — 212

Williams No. 3 647 650 — 7.2 7.4 — 203

Williams No. 3 621 627 — 7.4 7.3 — 188

Williams No. 3 635 640 — 7.2 7.3 — 196

Williams No. 3 638 643 — 7.3 7.3 — 202

Williams No. 3 637 642 — 7.5 7.1 — 202

Williams No. 3 — 619 — — 7.5 — 209

Williams No. 3 591 600 — 7.3 7.3 — 208

Williams No. 3 568 580 — 7.3 7.2 — 209

Williams No. 3 — — — — — — —

Williams No. 3 — — — — — — —

Williams No. 3 642 640 — 6.9 7.3 — 196

Williams No. 3 642 — — 7.2 — — —

Williams No. 4 — 688 — — — — —

Williams No. 12 — 555 — — — — —

Three Mile No. 3 539 — — 7.6 — 140 —

Three Mile No. 3 520 — — — — — —

Three Mile No. 5 542 537 — 7.6 7.9 130 140

Three Mile No. 5 — — — — — — —

Meridian No. 2 634 642 — 7.6 7.8 170 187

Table 16. Summary of selected U.S. Geological Survey (USGS) water-chemistry data from selected water-supply wells, Santa Clara County, California—

Continued

Local 

well name

Field, specific 

conductance

(μS/cm@25οC)

(00095)

Lab specific

conductance

(μS/cm)

(90095)

Dissolved 

oxygen

(mg/L)

(00300)

Field pH

(Standard units)

(00400)

Lab pH

(Standard units)

(00403)

Field 

alkalinity

(mg/L as CaCO3)

(39036)

Lab 

alkalinity

(mg/L as CaCO3)

(29801)
Table 16 113

Ridgley No. 2 524 520 — 7.5 7.6 130 140

Ridgley No. 3 — 487 — — — — —

Virginia No. 1 — 516 — — — — —

CWS No. 27-01 — 732 — — — — —

CWS No. 31-01 — 704 — — — — —

CWS No. 18-02 — 652 — — — — —

CWS No. 15-01 — — — — — — —

GOWC No. 8 842 — — — — — —

GOWC No. 2 — 820 — — — — —

SJC No. 11 622 — — — — — —

GOWC No. 21 — 647 — — 7.3 — 234

GOWC No. 12 781 — — — — — —

Table 16. Summary of selected U.S. Geological Survey (USGS) water-chemistry data from selected water-supply wells, Santa Clara County, California—

Continued

Local 

well name

Field, specific 

conductance

(μS/cm@25οC)

(00095)

Lab specific

conductance

(μS/cm)

(90095)

Dissolved 

oxygen

(mg/L)

(00300)

Field pH

(Standard units)

(00400)

Lab pH

(Standard units)

(00403)

Field 

alkalinity

(mg/L as CaCO3)

(39036)

Lab 

alkalinity

(mg/L as CaCO3)

(29801)
114 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

Table 16. Summary of selected U.S. Geological Survey (USGS) water-chemistry data from selected water-supply wells, Santa Clara County, California—

Continued

Local well name

Chloride

(mg/L)

(00940)

Sulfate

(mg/L)

(00945)

Fluoride

(mg/L)

(00950)

Calcium

(mg/L)

(00915)

Magnesium

(mg/L)

(00925)

Potassium

(mg/L)

(00935)

Sodium

(mg/L)

(00930)

PA Hale St No. 3 — — — — — — —

Cropley No. 3 — — — — — — —

Gish No.2 20.6 34.4 0.1 36.8 11.8 1.24 49.4

Berryessa No.1 62 54.6 E.1 49.5 22.4 1.05 73.2

Marbury No. 1 — — — — — — —

Agnews No. 6 — — — — — — —

SJC No. 1 — — — — — — —

SC-26 21.2 48.9 E.1 44.2 14.1 1.02 45

SC-21 28.2 31.4 E.2 57 17.9 1.18 37

CWS No. 121-02 — — — — — — —

CWS No. 123-01 — — — — — — —

CWS No. 123-02 — — — — — — —

CWS No. 119-03 — — — — — — —

MV-21 — — — — — — —

MV-19 — — — — — — —

MV-20 35.1 29.9 E.1 75.9 20.3 1.25 25.3

MV-20 — — — — — — —

MV-20 34.8 29.7 E.1 76.4 20.4 1.27 25.6

MV-20 35 30.4 .2 74.1 19.8 1.26 27.9

CWS No. 116 — — — — — — —

CWS No. 104-02 — — — — — — —

MV-9 — — — — — — —

CWS No. 39-01 — — — — — — —

CWS No.17 43.4 28.6 E.1 80.5 23.1 1.25 26.3

CWS No.17 40.4 27.1 E.1 75.1 21.8 1.21 28.8

CWS No.17 41.6 27.9 E.1 75.7 22.2 1.22 28.5

CWS No.17 — — — — — — —

CWS No.17 40.9 27.5 E.1 77.4 22.3 1.23 28.9

CWS No.17 41.8 27.5 E.1 76.5 22 1.25 28.1

CWS No.17 40.3 25.3 E.1 73.7 22 1.22 29

CWS No.17 42.6 28.9 E.1 75.7 22.1 1.25 27.7

CWS No.17 37.5 26.6 E.1 67.5 20.5 1.15 33

PA Rinconda — — — — — — —

Main P 42.4 49.8 <.1 72 23.9 1.6 31.3

Main P — — — — — — —

17th St. No.3 36.6 74.9 .2 69.7 51.9 1.29 32.3

17th St. No.3 — — — — — — —

17th St. No. 7 36 52 .1 61 24 1.3 46

17th St. No.12 37.2 44.9 .1 58.7 26 1.24 47.1

17th St. No.12 — — — — — — —

12th St. No.10 43.4 73.7 <.1 81.4 41.4 1.36 33.8

12th St. No.10 36.2 67 .2 57.5 54.1 1.15 31.6

12th St. No.10 36.3 67.6 .2 56.7 53.9 1.21 31.9

12th St. No.10 42.3 74 <.1 80.2 39.8 1.4 34.8
Table 16 115

12th St. No.10 40.7 72.9 <0.1 63.7 38.4 1.52 34.5

12th St. No.10 40.5 69.3 <.1 80 45.6 1.33 35.3

12th St. No.10 41.3 68 <.1 78.1 41.5 1.38 38.2

12th St. No.10 42.3 71 <.1 80.9 38.5 1.47 35.9

12th St. No.10 — — — — — — —

Grant & Vine 2 — — — — — — —

Home No. 3 42.1 42.5 E.1 73 21.7 1.43 29.3

Senter 50.4 77.3 .2 61.6 64 1.22 38.1

Senter — — — — — — —

Senter — — — — — — —

Malone No. 1 — — — — — — —

Koch No. 1 — — — — — — —

SC-5-2 14.2 36.9 .1 35.5 10.6 1.06 47.8

SC-5-2 — — — — — — —

SC-3-02 28.4 63.5 E.1 66 24.2 1.16 21.4

CWS No. 20-10 53.2 26.4 .2 69.7 29.7 1.29 37.8

SC-28 31.9 47.6 E.1 77.3 19.6 1.23 24

SC-2-2 29.2 49.4 .1 63.7 25.7 1.32 21.1

Bascom No. 4 27.3 39 .1 47.7 16.5 1.09 23

Bascom No. 5 53.6 42.1 E.1 55.2 21.2 1.23 17.3

Buena Vista No. 6 49.2 46.6 .2 73.7 21.1 1.53 20.7

O’Connor Hospital 49.2 53.6 E.1 78.1 23.8 1.42 19.3

CWS No. 29-01 — — — — — — —

Williams No. 3 47.6 39.4 .1 79 26.8 1.36 24.6

Williams No. 3 47.8 35.6 .1 72.2 27.3 1.34 24.1

Williams No. 3 48.9 34.6 .1 71.9 28.1 1.33 24.6

Williams No. 3 49 36.7 <.1 67.2 24.8 1.25 22.2

Williams No. 3 48.8 35.9 .1 67.3 25.5 1.28 22.2

Williams No. 3 46.5 35.6 .2 69.9 25.3 1.3 23.9

Williams No. 3 44.7 35.5 .1 71.5 25.5 1.31 24.2

Williams No. 3 41 31.1 .1 71.5 25.7 1.31 24.2

Williams No. 3 36.1 26.6 .1 64.3 23.4 1.29 23.5

Williams No. 3 32.6 22.2 .1 62.9 22.6 1.15 22.8

Williams No. 3 — — — — — — —

Williams No. 3 — — — — — — —

Williams No. 3 47 36.9 E.1 72 24.9 1.25 19.9

Williams No. 3 — — — — — — —

Williams No. 4 — — — — — — —

Williams No. 12 — — — — — — —

Three Mile No. 3 — — — — — — —

Three Mile No. 3 — — — — — — —

Three Mile No. 5 60.6 44.2 .1 62.9 18.7 1.22 17.9

Three Mile No. 5 — — — — — — —

Meridian No. 2 63 36.5 .1 55 17.4 1.25 48.1

Ridgley No. 2 51.2 44.5 .1 56.8 18.3 1.13 18.2

Ridgley No. 3 — — — — — — —

Table 16. Summary of selected U.S. Geological Survey (USGS) water-chemistry data from selected water-supply wells, Santa Clara County, California—

Continued

Local well name

Chloride

(mg/L)

(00940)

Sulfate

(mg/L)

(00945)

Fluoride

(mg/L)

(00950)

Calcium

(mg/L)

(00915)

Magnesium

(mg/L)

(00925)

Potassium

(mg/L)

(00935)

Sodium

(mg/L)

(00930)
116 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

Virginia No. 1 — — — — — — —

CWS No. 27-01 — — — — — — —

CWS No. 31-01 — — — — — — —

CWS No. 18-02 — — — — — — —

CWS No. 15-01 — — — — — — —

GOWC No. 8 — — — — — — —

GOWC No. 2 — — — — — — —

SJC No. 11 — — — — — — —

GOWC No. 21 29.7 48.5 0.3 48.7 34.8 0.88 33.1

GOWC No. 12 — — — — — — —

Table 16. Summary of selected U.S. Geological Survey (USGS) water-chemistry data from selected water-supply wells, Santa Clara County, California—

Continued

Local well name

Chloride

(mg/L)

(00940)

Sulfate

(mg/L)

(00945)

Fluoride

(mg/L)

(00950)

Calcium

(mg/L)

(00915)

Magnesium

(mg/L)

(00925)

Potassium

(mg/L)

(00935)

Sodium

(mg/L)

(00930)
Table 16 117

Table 16. Summary of selected U.S. Geological Survey (USGS) water-chemistry data from selected water-supply wells, Santa Clara County, California—

Continued

Local well name

Nitrite as 

nitrogen

(mg/L as N)

(00613)

Nitrite plus nitrate

as nitrogen

(mg/L as N)

(00631)

Organic 

ammonia

(mg/L as N)

(00623)

Nitrogen,

ammonia

(mg/L as N)

(00608)

Phosphorus

(mg/L as P)

(00666)

Orthophosphate

(m/L as P)

(00671)

Organic 

carbon

(mg/L as C)

(00681)

PA Hale St No. 3 — — — — — — —

Cropley No. 3 — — — — — — —

Gish No.2 <0.010 0.68 <0.10 <0.02 0.06 0.04 —

Berryessa No.1 E.005 .23 <.10 E.03 E.03 .06 —

Marbury No. 1 — — — — — — —

Agnews No. 6 — — — — — — —

SJC No. 1 — — — — — — —

SC-26 .007 .66 <.10 <.04 E.05 .05 —

SC-21 .009 2.25 <.10 <.04 <.06 .07 —

CWS No. 121-02 — — — — — — —

CWS No. 123-01 — — — — — — —

CWS No. 123-02 — — — — — — —

CWS No. 119-03 — — — — — — —

MV-21 — — — — — — —

MV-19 — — — — — — —

MV-20 <.006 5.55 E.06 <.04 E.04 .03 2.2

MV-20 <.006 5.56 <.10 <.04 E.04 .04 —

MV-20 <.006 5.32 .16 E.02 <.06 .03 3.1

MV-20 <.006 5.48 E.08 <.04 E.04 .04 .6

CWS No. 116 — — — — — — —

CWS No. 104-02 — — — — — — —

MV-9 — — — — — — —

CWS No. 39-01 — — — — — — —

CWS No.17 E.005 6.11 <.10 <.04 E.03 .03 —

CWS No.17 E.005 6.82 <.10 <.04 E.04 .03 —

CWS No.17 E.005 7.28 3 <.04 .08 E.01 3.7

CWS No.17 — — — — — — —

CWS No.17 E.005 6.86 <.10 <.04 <.06 .03 .3

CWS No.17 <.006 7.07 E.09 <.04 <.06 .02 .8

CWS No.17 <.006 6.92 <.10 <.04 <.06 .02 1.5

CWS No.17 E.003 6.83 <.10 <.04 <.06 <.02 3.9

CWS No.17 <.006 4.86 <.10 <.04 <.06 .03 1.9

PA Rinconda — — — — — — —

Main P <.010 6.31 <.10 <.02 E.05 .03 —

Main P — — — — — — —

17th St. No.3 <.010 3.98 <.10 <.02 E.05 .04 —

17th St. No.3 — — — — — — —

17th St. No. 7 <.010 .756 .11 <.02 E.05 .015 —

17th St. No.12 <.010 2.51 E.06 <.02 E.04 .03 —

17th St. No.12 — — — — — — —

12th St. No.10 <.010 4.23 E.06 <.02 E.04 .02 —

12th St. No.10 <.010 3.02 E.06 <.02 E.04 .03 —

12th St. No.10 <.010 2.95 E.07 <.02 E.04 .03 —

12th St. No.10 <.010 4.29 E.06 <.02 <.05 .02 —

12th St. No.10 <.010 4.25 E.05 <.02 E.03 .02 —
118 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

12th St. No.10 <0.010 3.42 0.11 <0.02 E0.04 0.03 —

12th St. No.10 <.010 3.12 <.10 <.02 E.03 .03 9.5

12th St. No.10 <.010 3.6 <.10 <.02 <.05 .03 23.1

12th St. No.10 — — — — — — —

Grant & Vine 2 — — — — — — —

Home No. 3 .006 5.06 <.10 E.02 E.03 .03 —

Senter .001 3.3 .08 .005 .036 .036 —

Senter — — — — — — —

Senter — — — — — — —

Malone No. 1 — — — — — — —

Koch No. 1 — — — — — — —

SC-5-2 <.010 .51 <.10 <.02 .05 .04 —

SC-5-2 — — — — — — —

SC-3-02 E.005 1.93 <.10 <.04 E.05 .04 —

CWS No. 20-10 E.004 5.71 <.10 <.04 E.03 .05 —

SC-28 E.003 3.73 <.10 <.04 <.06 .03 —

SC-2-2 <.010 3.55 <.10 <.02 .05 .03 —

Bascom No. 4 <.010 1.15 E.09 <.02 E.04 .03 —

Bascom No. 5 <.006 1.04 <.10 <.04 E.04 .03 —

Buena Vista No. 6 E.005 3.12 <.10 E.02 <.06 .04 —

O’Connor Hospital <.006 2.77 <.10 <.04 E.04 .03 —

CWS No. 29-01 — — — — — — —

Williams No. 3 — — — — — — —

Williams No. 3 — — — — — — —

Williams No. 3 <.010 6.58 <.10 <.02 <.05 .02 1.1

Williams No. 3 <.010 5.57 <.10 <.02 <.05 .01 2.9

Williams No. 3 <.010 6.1 <.10 <.02 <.05 .02 .4

Williams No. 3 <.010 6.25 <.10 <.02 <.05 .02 —

Williams No. 3 <.010 6.31 E.07 <.02 <.05 .02 1.1

Williams No. 3 <.010 6.12 <.10 <.02 <.05 .02 1

Williams No. 3 <.010 5.59 <.10 <.02 <.05 .02 .9

Williams No. 3 <.010 5.31 <.10 <.02 <.05 .02 2.9

Williams No. 3 — — — — — — —

Williams No. 3 — — — — — — —

Williams No. 3 <.006 6.24 <.10 <.04 <.06 E.02 —

Williams No. 3 — — — — — — —

Williams No. 4 — — — — — — —

Williams No. 12 — — — — — — —

Three Mile No. 3 <.010 .84 E.08 <.02 <.05 .01 —

Three Mile No. 3 — — — — — — —

Three Mile No. 5 <.010 .95 E.06 <.02 E.03 .02 —

Three Mile No. 5 — — — — — — —

Meridian No. 2 <.010 2.85 E.08 <.02 E.04 .03 —

Table 16. Summary of selected U.S. Geological Survey (USGS) water-chemistry data from selected water-supply wells, Santa Clara County, California—

Continued

Local well name

Nitrite as 

nitrogen

(mg/L as N)

(00613)

Nitrite plus nitrate

as nitrogen

(mg/L as N)

(00631)

Organic 

ammonia

(mg/L as N)

(00623)

Nitrogen,

ammonia

(mg/L as N)

(00608)

Phosphorus

(mg/L as P)

(00666)

Orthophosphate

(m/L as P)

(00671)

Organic 

carbon

(mg/L as C)

(00681)
Table 16 119

Ridgley No. 2 <0.010 4.65 <0.10 <0.02 E0.05 0.02 —

Ridgley No. 3 — — — — — — —

Virginia No. 1 — — — — — — —

CWS No. 27-01 — — — — — — —

CWS No. 31-01 — — — — — — —

CWS No. 18-02 — — — — — — —

CWS No. 15-01 — — — — — — —

GOWC No. 8 — — — — — — —

GOWC No. 2 — — — — — — —

SJC No. 11 — — — — — — —

GOWC No. 21 E.005 2.28 <.10 E.02 <.06 E.01 —

GOWC No. 12 — — — — — — —

Table 16. Summary of selected U.S. Geological Survey (USGS) water-chemistry data from selected water-supply wells, Santa Clara County, California—

Continued

Local well name

Nitrite as 

nitrogen

(mg/L as N)

(00613)

Nitrite plus nitrate

as nitrogen

(mg/L as N)

(00631)

Organic 

ammonia

(mg/L as N)

(00623)

Nitrogen,

ammonia

(mg/L as N)

(00608)

Phosphorus

(mg/L as P)

(00666)

Orthophosphate

(m/L as P)

(00671)

Organic 

carbon

(mg/L as C)

(00681)
120 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

Table 16. Summary of selected U.S. Geological Survey (USGS) water-chemistry data from selected water-supply wells, Santa Clara County, California—

Continued

Local 

well name

Barium

(μg/L)

(01005)

Boron

(μg/L)

(01020)

Iron

(μg/L)

(01046)

Manganese

(μg/L)

(01056)

Strontium

(μg/L)

(01080)

Iodide

(mg/L)

(71865)

Bromide

(mg/L)

(71870)

Silica

(mg/L)

(00955)

PA Hale St No. 3 — — — — — — — —

Cropley No. 3 — — — — — — — —

Gish No.2 144 149 <10 23.8 258 0.022 0.07 28.4

Berryessa No.1 132 137 <10 .2 341 .089 .2 26.6

Marbury No. 1 — — — — — — — —

Agnews No. 6 — — — — — — — —

SJC No. 1 — — — — — — — —

SC-26 175 137 <10 18.1 326 .02 .09 25.3

SC-21 144 181 <10 2.4 311 .008 .11 29.5

CWS No. 121-02 — — — — — — — —

CWS No. 123-01 — — — — — — — —

CWS No. 123-02 — — — — — — — —

CWS No. 119-03 — — — — — — — —

MV-21 — — — — — — — —

MV-19 — — — — — — — —

MV-20 132 106 E8 E2.8 357 <.001 .12 23.9

MV-20 — — — — — — — —

MV-20 137 112 13 4.1 362 <.001 .12 23.8

MV-20 133 115 E9 .7 362 <.001 .12 24.9

CWS No. 116 — — — — — — — —

CWS No. 104-02 — — — — — — — —

MV-9 — — — — — — — —

CWS No. 39-01 — — — — — — — —

CWS No.17 133 130 <10 <3.0 385 <.001 .14 26.1

CWS No.17 128 135 <10 <3.0 366 <.001 .13 26.3

CWS No.17 124 135 58 21.3 369 .001 .13 25.7

CWS No.17 — — — — — — — —

CWS No.17 130 142 <10 <.1 372 .002 .13 26.4

CWS No.17 129 133 <10 <3.0 370 .001 .13 26.2

CWS No.17 128 128 <10 <3.0 361 .001 .13 26.8

CWS No.17 124 128 <10 42.2 371 .001 .14 24.8

CWS No.17 122 139 <10 .2 335 .001 .13 27.4

PA Rinconda — — — — — — — —

Main P 112 92 <10 <2.2 375 .001 .16 27.7

Main P — — — — — — — —

17th St. No.3 172 120 <10 <2.2 504 .001 .15 29.5

17th St. No.3 — — — — — — — —

17th St. No. 7 227 127 <10 <2.2 420 .003 .13 28

17th St. No.12 200 140 <10 <2.2 388 .012 .12 28.4

17th St. No.12 — — — — — — — —

12th St. No.10 225 122 <10 <2.2 539 .001 .17 29.9

12th St. No.10 176 140 44 8.7 455 .001 .14 30.7

12th St. No.10 177 132 156 10.3 448 .001 .15 30.4

12th St. No.10 225 140 15 E1.3 522 .002 .16 29.7
Table 16 121

12th St. No.10 207 124 <10 <2.2 499 0.002 0.16 29.5

12th St. No.10 224 147 E8 <2.2 524 .001 .16 30.3

12th St. No.10 225 161 E6 <2.2 524 .002 .19 29.4

12th St. No.10 228 144 12 <2.2 527 .002 .19 29.6

12th St. No.10 — — — — — — — —

Grant & Vine 2 — — — — — — — —

Home No. 3 117 106 <10 .2 375 <.001 .15 24.4

Senter 270 164 <10 <2.2 585 .001 .2 32.4

Senter — — — — — — — —

Senter — — — — — — — —

Malone No. 1 — — — — — — — —

Koch No. 1 — — — — — — — —

SC-5-2 161 102 <10 14 252 .011 .04 28

SC-5-2 — — — — — — — —

SC-3-02 148 76 <10 .4 340 <.001 .11 26.9

CWS No. 20-10 94.1 195 <10 .7 297 <.001 .22 31.9

SC-28 112 115 <10 <.1 347 <.001 .14 27.9

SC-2-2 132 69 <10 <2.2 305 .001 .13 29.5

Bascom No. 4 93.9 74 E6 <2.2 254 <.001 .1 27

Bascom No. 5 107 88 <10 .6 283 .001 .2 23.4

Buena Vista No. 6 110 94 15 .9 374 <.001 .19 23.2

O’Connor Hospital 102 97 <10 E.1 407 <.001 .2 21.4

CWS No. 29-01 — — — — — — — —

Williams No. 3 115 185 544 E1.9 408 .001 .18 28.4

Williams No. 3 106 154 39 2.3 386 <.001 .16 29.5

Williams No. 3 102 141 22 E2.0 380 .002 .17 29.3

Williams No. 3 99.9 139 27 <2.2 354 <.001 .17 29

Williams No. 3 98.4 137 E7 <2.2 357 .004 .17 29

Williams No. 3 105 158 15 <2.2 373 <.001 .16 28.8

Williams No. 3 106 154 11 <2.2 373 <.001 .17 29.4

Williams No. 3 107 159 21 E1.9 376 <.001 .14 28.4

Williams No. 3 98.5 140 18 E1.3 345 <.001 .13 29.2

Williams No. 3 95.1 135 15 E1.5 334 <.001 .13 29.3

Williams No. 3 — — — — — — — —

Williams No. 3 — — — — — — — —

Williams No. 3 94.4 133 <10 .6 345 <.001 .16 28.9

Williams No. 3 — — — — — — — —

Williams No. 4 — — — — — — — —

Williams No. 12 — — — — — — — —

Three Mile No. 3 — — — — — — — —

Three Mile No. 3 — — — — — — — —

Three Mile No. 5 72.9 92 10 <2.2 313 .001 .2 24

Three Mile No. 5 — — — — — — — —

Meridian No. 2 88.6 301 <10 <2.2 284 .011 .22 25.4

Ridgley No. 2 54.7 112 94 11.7 302 .001 .17 23.3

Ridgley No. 3 — — — — — — — —

Table 16. Summary of selected U.S. Geological Survey (USGS) water-chemistry data from selected water-supply wells, Santa Clara County, California—

Continued

Local 

well name

Barium

(μg/L)

(01005)

Boron

(μg/L)

(01020)

Iron

(μg/L)

(01046)

Manganese

(μg/L)

(01056)

Strontium

(μg/L)

(01080)

Iodide

(mg/L)

(71865)

Bromide

(mg/L)

(71870)

Silica

(mg/L)

(00955)
122 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

Virginia No. 1 — — — — — — — —

CWS No. 27-01 — — — — — — — —

CWS No. 31-01 — — — — — — — —

CWS No. 18-02 — — — — — — — —

CWS No. 15-01 — — — — — — — —

GOWC No. 8 — — — — — — — —

GOWC No. 2 — — — — — — — —

SJC No. 11 — — — — — — — —

GOWC No. 21 104 132 <10 0.1 532 0.002 0.13 24.4

GOWC No. 12 — — — — — — — —

Table 16. Summary of selected U.S. Geological Survey (USGS) water-chemistry data from selected water-supply wells, Santa Clara County, California—

Continued

Local 

well name

Barium

(μg/L)

(01005)

Boron

(μg/L)

(01020)

Iron

(μg/L)

(01046)

Manganese

(μg/L)

(01056)

Strontium

(μg/L)

(01080)

Iodide

(mg/L)

(71865)

Bromide

(mg/L)

(71870)

Silica

(mg/L)

(00955)
Table 16 123

Table 16. Summary of selected U.S. Geological Survey (USGS) water-chemistry data from selected water-supply wells, Santa Clara County, California—

Continued

Local well name

Aluminum

(μg/L)

(01106)

Arsenic

(μg/L)

(01000)

Lithium

(μg/L)

(01130)

Raw chromium

(μg/L)

(01034)

Lead

(μg/L)

(01049)

Mercury

(μg/L)

(71900)

Nickel

(μg/L)

(01065)

Zinc

(μg/L)

(01090)

PA Hale St No. 3 — — — — — — — —

Cropley No. 3 — — — — — — — —

Gish No.2 <20 <1 4 — — — — —

Berryessa No.1 <1 .8 8 <1.0 0.43 — <0.06 4

Marbury No. 1 — — — — — — — —

Agnews No. 6 — — — — — — — —

SJC No. 1 — — — — — — — —

SC-26 2 1.9 7 <1.0 2.74 — <.06 7

SC-21 <1 .7 8 <1.0 1.05 — <.10 6

CWS No. 121-02 — — — — — — — —

CWS No. 123-01 — — — — — — — —

CWS No. 123-02 — — — — — — — —

CWS No. 119-03 — — — — — — — —

MV-21 — — — — — — — —

MV-19 — — — — — — — —

MV-20 <20 .3 6 — — — — —

MV-20 — — — — — — — —

MV-20 <20 .4 6 — — — — —

MV-20 <1 .3 5 2.3 .65 — <.06 4

CWS No. 116 — — — — — — — —

CWS No. 104-02 — — — — — — — —

MV-9 — — — — — — — —

CWS No. 39-01 — — — — — — — —

CWS No.17 <20 .2 5 — — — — —

CWS No.17 <20 .2 5 — — — — —

CWS No.17 <20 .2 5 — — — — —

CWS No.17 — — — — — — — —

CWS No.17 <1 .2 5 1 .39 <0.01 <.06 2

CWS No.17 <20 .3 5 — — — — —

CWS No.17 <20 .3 4 — — — — —

CWS No.17 <20 E.2 E4 — — — — —

CWS No.17 <1 .3 5 <1.0 <.08 <.01 <.06 9

PA Rinconda — — — — — — — —

Main P <20 <1 4 — — — — —

Main P — — — — — — — —

17th St. No.3 <20 <1 9 — — — — —

17th St. No.3 — — — — — — — —

17th St. No.7 <20 <1 4 — — — — —

17th St. No.12 <20 <1 10 — — — — —

17th St. No.12 — — — — — — — —

12th St. No.10 <20 <1 10 — — — — —

12th St. No.10 <20 <1 9 — — — — —

12th St. No.10 <20 <1 7 — — — — —

12th St. No.10 <20 <1 9 — — — — —

12th St. No.10 <20 <1 4 — — — — —

12th St. No.10 E10 <1 10 — — — — —
124 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

12th St. No.10 <20 <2 8 — — — — —

12th St. No.10 <20 <2 8 — — — — —

12th St. No.10 — — — — — — — —

Grant & Vine 2 — — — — — — — —

Home No. 3 <1 .2 5 2.7 2.02 — <0.06 4

Senter E10 <1 4 — — — — —

Senter — — — — — — — —

Senter — — — — — — — —

Malone No. 1 — — — — — — — —

Koch No. 1 — — — — — — — —

SC-5-2 <20 1 4 — — — — —

SC-5-2 — — — — — — — —

SC-3-02 <1 .5 8 3.6 1.13 — <.10 13

CWS No. 20-10 <1 .2 7 E.6 E.08 — 2.31 9

SC-28 <1 .4 6 2.4 0.61 — <.10 9

SC-2-2 <20 <1 4 — — — — —

Bascom No. 4 <20 <1 4 — — — — —

Bascom No. 5 <1 .3 5 3 1.49 — <.10 5

Buena Vista No. 6 <1 .2 4 2.5 1.82 — <.06 16

O’Connor Hospital <1 .3 4 2.3 6.86 — <.06 4

CWS No. 29-01 — — — — — — — —

Williams No. 3 M <2 E4 — — — — —

Williams No. 3 <20 <2 4 — — — — —

Williams No. 3 M <2 E4 — — — — —

Williams No. 3 <20 <2 E4 — — — — —

Williams No. 3 <20 <2 4 — — — — —

Williams No. 3 <20 <2 5 — — — — —

Williams No. 3 <20 <2 E3 — — — — —

Williams No. 3 <20 <2 4 — — — — —

Williams No. 3 <20 <2 5 — — — — —

Williams No. 3 <20 <2 4 — — — — —

Williams No. 3 — — — — — — — —

Williams No. 3 — — — — — — — —

Williams No. 3 <1 E.2 E4 1 .3 — .7 8

Williams No. 3 — — — — — — — —

Williams No. 4 — — — — — — — —

Williams No. 12 — — — — — — — —

Three Mile No. 3 — — — — — — — —

Three Mile No. 3 — — — — — — — —

Three Mile No. 5 <20 <1 E3 — — — — —

Three Mile No. 5 — — — — — — — —

Meridian No. 2 <20 <1 4 — — — — —

Ridgley No. 2 <20 <1 E2 — — — — —

Ridgley No. 3 — — — — — — — —

Table 16. Summary of selected U.S. Geological Survey (USGS) water-chemistry data from selected water-supply wells, Santa Clara County, California—

Continued

Local well name

Aluminum

(μg/L)

(01106)

Arsenic

(μg/L)

(01000)

Lithium

(μg/L)

(01130)

Raw chromium

(μg/L)

(01034)

Lead

(μg/L)

(01049)

Mercury

(μg/L)

(71900)

Nickel

(μg/L)

(01065)

Zinc

(μg/L)

(01090)
Table 16 125

Virginia No. 1 — — — — — — — —

CWS No. 27-01 — — — — — — — —

CWS No. 31-01 — — — — — — — —

CWS No. 18-02 — — — — — — — —

CWS No. 15-01 — — — — — — — —

GOWC No. 8 — — — — — — — —

GOWC No. 2 — — — — — — — —

SJC No. 11 — — — — — — — —

GOWC No. 21 <1 0.4 12 2.2 1.63 — <0.06 6

GOWC No. 12 — — — — — — — —

Table 16. Summary of selected U.S. Geological Survey (USGS) water-chemistry data from selected water-supply wells, Santa Clara County, California—

Continued

Local well name

Aluminum

(μg/L)

(01106)

Arsenic

(μg/L)

(01000)

Lithium

(μg/L)

(01130)

Raw chromium

(μg/L)

(01034)

Lead

(μg/L)

(01049)

Mercury

(μg/L)

(71900)

Nickel

(μg/L)

(01065)

Zinc

(μg/L)

(01090)
126 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

Table 16. Summary of selected U.S. Geological Survey (USGS) water-chemistry data from selected water-supply wells, Santa Clara County, California—

Continued

Local 

well name

Delta deuterium

(per mil)

(82082)

Delta oxygen

(per mil)

(82085)

Percent artificial 

recharge

from delta 

deuterium

Percent artificial 

recharge

from delta oxygen

Tritium

pCi/L)

(07000)

Strontium 87/86

(Ratio)

(75978)

Delta-boron11

(per mil)

PA Hale St No. 3 −45.2 −6.6 13 12 — — —

Cropley No. 3 −45.8 −6.75 15 16 — — —

Gish No.2 −42.8 −6.6 5 12 1.9 0.70730 15.23

Berryessa No.1 −45.5 −6.75 14 16 4.2 — —

Marbury No. 1 −51.1 −7.36 31 31 — — —

Agnews No. 6 −45.5 −6.76 14 16 — — —

SJC No. 1 −42.2 −6.33 4 6 — — —

SC-26 −44 −6.53 9 10 2.8 — —

SC-21 −42.4 −6.33 4 6 1.7 — —

CWS No. 121-02 −42 −6.1 3 0 — — —

CWS No. 123-01 −41.6 −5.6 2 0 — — —

CWS No. 123-02 −41.2 −5.64 1 0 — — —

CWS No. 119-03 −40.8 −6.1 0 0 — — —

MV-21 −41.3 −6.27 1 4 2.7 — —

MV-19 −40.9 −6.33 0 6 — — —

MV-20 −41.6 −6.32 2 5 — — —

MV-20 — — — — — — —

MV-20 −42.7 −6.31 5 5 — — —

MV-20 −41 −6.25 0 4 — — —

CWS No. 116 −43 −6.23 6 3 — — —

CWS No. 104-02 −41 −5.98 0 0 — — —

MV-9 −44.4 −6.33 10 6 — — —

CWS No. 39-01 −43.1 −6.28 6 4 — — —

CWS No.17 — — — — — — —

CWS No.17 — — — — — .70727 13.90

CWS No.17 −41.3 −6.22 1 3 — .70728 12.65

CWS No.17 — — — — — — —

CWS No.17 −40.2 −6.27 0 4 — — —

CWS No.17 −40.8 −6.2 0 2 — .70730 12.65

CWS No.17 −40.4 −6.2 0 2 — .70725 14.15

CWS No.17 −41.6 −6.22 2 3 — .70728 12.90

CWS No.17 −41.8 −6.22 2 3 — .70718 14.24

PA Rinconda −46.2 −6.88 16 19 — — —

Main P −43.8 −6.53 8 10 15.3 .70752 19.48

Main P −44.6 −6.6 11 12 — — —

17th St. No.3 — — — — 16.3 .70736 6.74

17th St. No.3 −42.4 −6.19 4 2 — — —

17th St. No.7 −43.9 −6.43 9 8 11.00 .70733 16.48

17th St. No.12 −42.5 −6.33 5 6 7.6 .70732 18.48

17th St. No.12 −41.9 −6.28 3 4 — — —

12th St. No.10 −43.3 −6.13 7 1 13.5 .70733 20.73

12th St. No.10 −41 −5.8 0 0 18.3 .70731 22.98

12th St. No.10 −41.5 −5.84 2 0 — .70735 18.11
Table 16 127

12th St. No.10 −43 −6.12 6 0 — .70735 16.98

12th St. No.10 −42.9 −6.12 6 0 14.2 .70736 18.36

12th St. No.10 −42.3 −5.98 4 0 15.2 0.70738 18.61

12th St. No.10 −40.9 −6.1 0 0 13.3 .70738 18.23

12th St. No.10 −42.5 −6.1 5 0 12.7 .70735 16.73

12th St. No.10 −42.4 −6.25 4 4 — — —

Grant & Vine 2 −45.2 −6.59 13 12 — — —

Home No. 3 −42.8 −6.57 5 11 14.6 — —

Senter −42.2 −6.01 4 0 16.6 .70740 17.48

Senter −44 −6.06 9 0 — — —

Senter −44 −6.06 9 0 — — —

Malone No. 1 −48.7 −6.59 23 12 — — —

Koch No. 1 −44.8 −6.27 12 4 — — —

SC-5-2 −40.8 −6.47 0 9 .3 .70730 8.74

SC-5-2 −41.4 −6.48 1 9 — — —

SC-3-02 −43.8 −6.66 8 14 10.3 — —

CWS No. 20-10 −44.1 −6.29 9 5 5.2 — —

SC-28 −44.6 −6.83 11 18 9.7 — —

SC-2-2 −44.6 −6.86 11 19 15.6 .70741 12.24

Bascom No. 4 −46.3 −6.92 16 20 15.7 .70748 17.23

Bascom No. 5 −54.7 −7.53 42 35 14.6 — —

Buena Vista No. 6 −49.8 −7.08 27 24 14.7 — —

O’Connor Hospital −51.7 −7.32 32 30 13.1 — —

CWS No. 29-01 −61.1 −8.2 61 51 — — —

Williams No. 3 −42.2 −6.54 4 11 — — —

Williams No. 3 −43.6 −6.56 8 11 — — —

Williams No. 3 −45.2 −6.56 13 11 — .70742 15.48

Williams No. 3 −45.1 −6.7 12 15 16 — —

Williams No. 3 −45.1 −6.67 12 14 — .70741 12.74

Williams No. 3 −43.9 −6.5 9 10 — — —

Williams No. 3 −44.6 −6.55 11 11 16.7 .70741 13.49

Williams No. 3 −43.7 −6.47 8 9 — .70739 13.99

Williams No. 3 −42.5 −6.43 5 8 9.5 .70739 14.24

Williams No. 3 −43.3 −6.42 7 8 — .70743 12.24

Williams No. 3 −43.5 −6.57 8 11 — — —

Williams No. 3 −44.2 −6.64 10 13 — — —

Williams No. 3 — — — — — — —

Williams No. 3 −45.4 −6.76 13 16 — — —

Williams No. 4 −44.5 −6.57 11 11 — — —

Williams No. 12 −48.4 −7.11 22 25 — — —

Three Mile No. 3 −57.4 −7.83 50 42 — .70765 6.74

Three Mile No. 3 −57.7 −7.74 51 40 — — —

Three Mile No. 5 −57.3 −7.84 49 42 16.2 .70766 8.24

Three Mile No. 5 −57.7 −8.04 51 47 — — —

Meridian No. 2 −46.5 −6.68 17 14 12.5 .70751 32.22

Table 16. Summary of selected U.S. Geological Survey (USGS) water-chemistry data from selected water-supply wells, Santa Clara County, California—

Continued

Local 

well name

Delta deuterium

(per mil)

(82082)

Delta oxygen

(per mil)

(82085)

Percent artificial 

recharge

from delta 

deuterium

Percent artificial 

recharge

from delta oxygen

Tritium

pCi/L)

(07000)

Strontium 87/86

(Ratio)

(75978)

Delta-boron11

(per mil)
128 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

Ridgley No. 2 −55.7 −7.61 45 37 14 0.70773 11.49

Ridgley No. 3 −53 −7.52 36 35 — — —

Virginia No. 1 −40.1 −6.36 0 6 — — —

CWS No. 27-01 −40.6 −6.15 0 1 — — —

CWS No. 31-01 −41.6 −6.13 2 1 — — —

CWS No. 18-02 −43.8 −6.45 8 9 — — —

CWS No. 15-01 −40.8 −5.82 0 0 — — —

GOWC No. 8 −45.9 −6.26 15 4 — — —

GOWC No. 2 −42 −6.08 3 0 — — —

SJC No. 11 −41.5 −6.11 2 0 — — —

GOWC No. 21 −43.3 −6.11 7 0 13.4 — —

GOWC No. 12 −41.4 −6.05 1 0 — — —

Table 16. Summary of selected U.S. Geological Survey (USGS) water-chemistry data from selected water-supply wells, Santa Clara County, California—

Continued

Local 

well name

Delta deuterium

(per mil)

(82082)

Delta oxygen

(per mil)

(82085)

Percent artificial 

recharge

from delta 

deuterium

Percent artificial 

recharge

from delta oxygen

Tritium

pCi/L)

(07000)

Strontium 87/86

(Ratio)

(75978)

Delta-boron11

(per mil)
Table 16 129

Table 16. Summary of selected U.S. Geological Survey (USGS) water-chemistry data from selected water-supply wells, Santa Clara County, California—

Continued

Local well name

Carbon 13/12

(per mil)

(82081)

Percent modern carbon

(49933)

Uncorrected age

(years before present)

Initial corrected water age

(years before present)

PA Hale St No. 3 — — — —

Cropley No. 3 — — — —

Gish No.2 −15.08 35.71 8,500 8,000

Berryessa No.1 — — — —

Marbury No. 1 — — — —

Agnews No. 6 — — — —

SJC No. 1 — — — —

SC-26 — — — —

SC-21 — — — —

CWS No. 121-02 — — — —

CWS No. 123-01 — — — —

CWS No. 123-02 — — — —

CWS No. 119-03 — — — —

MV-21 — — — —

MV-19 — — — —

MV-20 — — — —

MV-20 — — — —

MV-20 — — — —

MV-20 — — — —

CWS No. 116 — — — —

CWS No. 104-02 — — — —

MV-9 — — — —

CWS No. 39-01 — — — —

CWS No.17 — — — —

CWS No.17 — — — —

CWS No.17 — — — —

CWS No.17 — — — —

CWS No.17 −13.49 78.28 2,000 1,500

CWS No.17 — — — —

CWS No.17 −14.25 74.93 2,400 1,800

CWS No.17 −13.71 71.23 2,800 2,200

CWS No.17 −13.79 61.5 4,000 3,500

PA Rinconda — — — —

Main P −14.76 79.73 1,400 1,300

Main P — — — —

17th St. No.3 −15.55 81.37 1,700 1,200

17th St. No.3 — — — —

17th St. No.7 −15.4 93.51 560 0

17th St. No.12 −15.03 65.01 3,600 3,000

17th St. No.12 — — — —

12th St. No.10 −15.62 83.17 1,500 960

12th St. No.10 −15.4 93.51 560 0

12th St. No.10 −14.83 82.02 1,600 1,100

12th St. No.10 −15.62 86.74 1,200 600

12th St. No.10 −15.23 84.66 1,400 830

12th St. No.10 −15.63 86.71 1,200 630
130 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

12th St. No.10 −15.21 82.32 1,600 1,100

12th St. No.10 −15.52 83.02 1,500 980

12th St. No.10 — — — —

Grant & Vine 2 — — — —

Home No. 3 — — — —

Senter −15.58 90.18 850 300

Senter — — — —

Senter — — — —

Malone No. 1 — — — —

Koch No. 1 — — — —

SC-5-2 −14.57 43.08 7,000 6,400

SC-5-2 — — — —

SC-3-02 — — — —

CWS No. 20-10 — — — —

SC-28 — — — —

SC-2-2 −14.26 84.49 1,400 830

Bascom No. 4 −13.26 67.45 3,200 2,700

Bascom No. 5 — — — —

Buena Vista No. 6 — — — —

O’Connor Hospital — — — —

CWS No. 29-01 — — — —

Williams No. 3 — — — —

Williams No. 3 — — — —

Williams No. 3 — — — —

Williams No. 3 −15.26 94.36 480 0

Williams No. 3 — — — —

Williams No. 3 — — — —

Williams No. 3 −14.16 88.76 980 430

Williams No. 3 — — — —

Williams No. 3 −13.91 92.51 640 90

Williams No. 3 −15.03 87.77 1,100 520

Williams No. 3 — — — —

Williams No. 3 — — — —

Williams No. 3 — — — —

Williams No. 3 — — — —

Williams No. 4 — — — —

Williams No. 12 — — — —

Three Mile No. 3 — — — —

Three Mile No. 3 — — — —

Three Mile No. 5 −14.28 104.6 0 0

Three Mile No. 5 — — — —

Meridian No. 2 −14.97 56.51 4,700 4,200

Ridgley No. 2 −14.13 98.09 160 0

Ridgley No. 3 — — — —

Table 16. Summary of selected U.S. Geological Survey (USGS) water-chemistry data from selected water-supply wells, Santa Clara County, California—

Continued

Local well name

Carbon 13/12

(per mil)

(82081)

Percent modern carbon

(49933)

Uncorrected age

(years before present)

Initial corrected water age

(years before present)
Table 16 131

Virginia No. 1 — — — —

CWS No. 27-01 — — — —

CWS No. 31-01 — — — —

CWS No. 18-02 — — — —

CWS No. 15-01 — — — —

GOWC No. 8 — — — —

GOWC No. 2 — — — —

SJC No. 11 — — — —

GOWC No. 21 — — — —

GOWC No. 12 — — — —

Table 16. Summary of selected U.S. Geological Survey (USGS) water-chemistry data from selected water-supply wells, Santa Clara County, California—

Continued

Local well name

Carbon 13/12

(per mil)

(82081)

Percent modern carbon

(49933)

Uncorrected age

(years before present)

Initial corrected water age

(years before present)
132 Geologic, Water-Chemistry, and Hydrologic Data from Multiple-Well Monitoring Sites, Santa Clara Valley, California

Table 17. Summary of slug-test estimates of hydraulic properties for 

selected multiple-well monitoring sites, Santa Clara County, California

[Geometric-mean values shown are based on an assumed range in specificstorage values of 1 × 10-5 and 1 ×10-6 ft-1; values in italic are analyzed with 

the Van Der Kamp method; ft2/d, foot squared per day; ft/d, foot per day; —

indicates unable to analyze]

Local well name Transmissivity

(ft2/d)

Hydraulic 

conductivity

(ft/d)

Number of 

tests

CCOC-1 1,234–1,532 61.7–76.6 20

CCOC-2 650–810 32.5–40.5 24

CCOC-3 1,338–1,644 66.9–82.2 26

CCOC-4 1,292–1,586 64.6–79.3 30

CCOC-5 2,798–3,421 280–342 32

MGCY-1 160–196 8.0–9.8 38

MGCY-2 30–38 1.5–1.9 40

MGCY-3 96–116 4.8–5.8 40

MGCY-4 2–2 .1–.1 1

MGCY-5 — — —

WLLO-1 — — —

WLLO-2 168–204 8.4–10.2 40

WLLO-3 70–86 3.5–4.3 40

WLLO-4 192–236 9.6–11.8 40

WLLO-5 1,064–1,324 53.2–66.2 40

WLLO-6 4,804–5,830 480–583 40
Table 17 133
134 

TECHNICAL SUPPORT: Susanna K. Brooks, Rachel Woods, Sean T. 

Devlin, Heather M. Wright, Kathleen D. Gans, Tony Brown, Isabelle 

M. Pimentel, Joseph J. Montrello, Amal Amali, Julia A. Huff, 

Gregory A. Smith, Steven M. Crawford, Jack Hennagan, Robert 

Roche, Raymond McKean, James Huckaby, Roland Gonzales, Mark 

Feyen, Rico Ferrozzo, and Danny Hennagan

EDITORIAL GRAPHICS, LAYOUT, AND REVIEW: Alice I. McCracken, 

Laurel Lynn Rogers, Jerrald A. Woodcox, Sharon Clark, John 

Hoffman, and Jim Walker