Hydrogeologic and Water-Quality Reconnaissance

of the Artesian Aquifer Under the Shoalwater Bay

Indian Reservation and Tokeland Peninsula,

Pacific County, Washington, 1998-99

Prepared in cooperation with the

Shoalwater Bay Indian Tribe

U.S. GEOLOGICAL SURVEY

Water-Resources Investigations Report 01-4023
U.S. GEOLOGICAL SURVEY

Water-Resources Investigations Report 01-4023

Hydrogeologic and Water-Quality

Reconnaissance of the Artesian Aquifer 

Under the Shoalwater Bay Indian Reservation 

and Tokeland Peninsula,

Pacific County, Washington, 1998–99

Prepared in cooperation with the

SHOALWATER BAY INDIAN TRIBE

01-XXXX

By R.C. Lane and J.C. Ebbert

Tacoma, Washington

2002
U.S. DEPARTMENT OF THE INTERIOR

GALE A. NORTON, Secretary

U.S. GEOLOGICAL SURVEY

Charles G. Groat, Director

For additional information write to:

District Chief

U.S. Geological Survey

1201 Pacific Avenue – Suite 600

Tacoma, Washington 98402

http://wa.water.usgs.gov

Copies of this report can be purchased

from:

U.S. Geological Survey

Information Services

Building 810

Box 25286, Federal Center

Denver, CO 80225-0286

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.

District Chief

U.S. Geological Survey

1201 Pacific Avenue – Suite 600

Tacoma, Washington 98402

http://wa.water.usgs.gov
Contents iii

CONTENTS

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

Introduction .......................................................................................................................................................... 1

Purpose and Scope ...................................................................................................................................... 1

Description of the Study Area..................................................................................................................... 2

 Previous Studies......................................................................................................................................... 2

 Well-Numbering System............................................................................................................................ 2

Acknowledgments....................................................................................................................................... 2

Hydrogeology....................................................................................................................................................... 2

Regional Hydrogeology .............................................................................................................................. 3

Local Hydrogeology.................................................................................................................................... 3

Ground-Water Levels.................................................................................................................................. 3

Flow Directions........................................................................................................................................... 4

Water Use.................................................................................................................................................... 4

Water Quality ....................................................................................................................................................... 4

General Findings ......................................................................................................................................... 4

Specific Concerns........................................................................................................................................ 5

Summary .............................................................................................................................................................. 6

Selected References.............................................................................................................................................. 7

Appendix A. Water-Quality Methods .................................................................................................................. 44

Field Methods.............................................................................................................................................. 44

Quality Assurance ....................................................................................................................................... 45

Quality Control............................................................................................................................................ 45
FIGURES

iv Contents

Figure 1. Map showing location of the Shoalwater Bay Indian Reservation and Tokeland Peninsula 

study area, of wells used in this study, and of the trace of hydrogeologic section A-A’................... 10

Figure 2. Diagram showing well-numbering system used by the U.S. Geological Survey in the State 

of Washington.................................................................................................................................... 11

Figure 3. Diagram showing construction, completion and generalized lithologic data for newly 

constructed tribal wells 14N/11W-02C01, 14N/11W-02C02, and 14N/11W-03F01........................ 12

Figure 4. Generalized hydrogeologic section A-A’ in the Shoalwater Bay Indian Reservation and 

Tokeland Peninsula study area .......................................................................................................... 15

Figure 5. Graphs showing water levels and tidal fluctuations in selected wells in the Shoalwater Bay 

Indian Reservation and Tokeland Peninsula study area .................................................................... 16

Figure 6. Map showing ground-water altitudes and tidal efficiencies in the artesian aquifer under the 

Shoalwater Bay Indian Reservation and Tokeland Peninsula study area.......................................... 18

Figure 7. Map showing location of wells sampled for water quality in the artesian aquifer underlying 

the Shoalwater Bay Indian Reservation and Tokeland Peninsula study area .................................... 19
Contents v

TABLES

Table 1. Information for selected wells in the Shoalwater Bay Indian Reservation and 

Tokeland Peninsula study area ............................................................................................................. 21

Table 2. Construction and completion information for selected wells in the Shoalwater Bay 

Indian Reservation and Tokeland Peninsula study area ....................................................................... 22

Table 3. Lithologic data, as reported by water-well drillers, for selected wells in the 

Shoalwater Bay Indian Reservation and Tokeland Peninsula study area ............................................ 23

Table 4. Depth to tops of hydrogeologic units in selected wells in the Shoalwater Bay 

Indian Reservation and Tokeland Peninsula study area ....................................................................... 29

Table 5. Water levels and water-level altitudes for selected wells in the Shoalwater Bay Indian 

Reservation and Tokeland Peninsula study area, September 1998 through August 1999 .................. 30

Table 6. Values of field measurements in ground-water samples from the Shoalwater Bay Indian 

Reservation and Tokeland Peninsula study area ................................................................................. 34

Table 7. Concentrations of major inorganic ions in ground-water samples from the 

Shoalwater Bay Indian Reservation and Tokeland Peninsula study area............................................. 35

Table 8. Concentrations of selected metals in ground-water samples from the 

Shoalwater Bay Indian Reservation and Tokeland Peninsula study area............................................. 36

Table 9. Concentrations of selected nutrients and methylene blue-active substances in 

ground-water samples from the Shoalwater Bay Indian Reservation and 

Tokeland Peninsula study area ............................................................................................................. 38

Table 10. Concentrations of selected pesticides in ground-water samples from the 

Shoalwater Bay Indian Reservation and Tokeland Peninsula study area............................................. 39
vi Conversion Factors and Vertical Datum

CONVERSION FACTORS AND VERTICAL DATUM

CONVERSION FACTORS

VERTICAL DATUM

Sea level: In this report, “sea level” 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.

Multiply By To obtain

inch (in) 25.4 millimeters

foot (ft) 0.3048 meters

square foot (ft2) 0.0929 square meters

acre 0.4047 hectares

4,047 square meters

mile (mi) 1.609 kilometers

gallon (gal) 3.785 liters

Termperature in degrees Fahrenheit (oF) can be converted to degree Celsius (oC) as follows: oC = 5/9 (oF-32).

Temperature in degrees Celsius (oC) can be converted to degrees Fahrenheit (oF) as follows: oF = 1.8 (oC+32).
Introduction 1

Hydrogeologic and Water-Quality Reconnaissance 

of the Artesian Aquifer Under the Shoalwater Bay 

Indian Reservation and Tokeland Peninsula, 

Pacific County, Washington, 1998–99

By R.C. Lane and J.C. Ebbert

ABSTRACT

The U.S. Geological Survey (USGS) 

collected and compiled hydrogeologic and waterquality data from September 1998 through 

September 1999 to describe the hydrogeologic 

setting and to assess the quality of the water in the 

artesian aquifer under the Shoalwater Bay Indian 

Reservation and the adjacent Tokeland Peninsula 

area of Pacific County, Washington. 

Hydrogeologic data include descriptions of 38 

wells, lithologic data for 27 wells, and water-level 

data for 17 wells and 1 tidal station. Water-quality 

data include field measurements for temperature, 

specific conductance, pH, alkalinity, bicarbonate, 

carbonate, dissolved oxygen, and laboratory 

analyses for major inorganic ions, metals, 

nutrients, methylene blue-active substances, and 

pesticides. None of the 93 field measurements or 

chemicals analyzed for exceeded the U.S. 

Environmental Protection Agency (USEPA) 

primary standards for drinking water and only 2 

constituents (iron and manganese) exceeded the 

USEPA secondary standards. Sixty-six of the 

constituents (including all 53 pesticides) were at or 

below the reporting or detection levels established 

by the USGS National Water Quality Laboratory.

INTRODUCTION

The Shoalwater Bay Indian Tribe of 

southwestern Washington is concerned about the 

quality of ground water in the artesian aquifer under 

their Reservation and the adjacent Tokeland Peninsula 

(fig. 1). This aquifer is the primary source of water in 

the study area and supplies water to the Tribe’s main 

production well, 14N/11W-03J01. The Tribe’s 

concerns include seawater intrusion due to 

overpumping, contamination by nitrate and bacteria 

from septic systems, and contamination by pesticides 

that were used on agricultural and forested areas 

adjacent to the reservation. In order to address these 

issues and to improve knowledge of the aquifer system, 

the U.S. Geological Survey (USGS), in cooperation 

with the Shoalwater Bay Indian Tribe under a grant 

from the Bureau of Indian Affairs, collected 

hydrogeologic and water-quality data on the 

Reservation and the Tokeland Peninsula area from 

September 1998 through September 1999. 

Purpose and Scope

This report presents the results of the 

reconnaissance study to describe the hydrogeologic 

setting to the extent allowed by the data and to describe 

the quality of water in the artesian aquifer. The report 

includes the hydrogeologic and water-quality data 

collected and compiled for the study from September 

1998 through September 1999, as well as an appendix 

containing methods used for collecting and analyzing 

the water-quality data. (All figures and tables are 

located at the end of the report.)
2 Hydrogeologic and Water-Quality Reconnaissance, Shoalwater Bay Indian Reservation and Tokeland Peninsula, Washington

Description of the Study Area

The study area includes the Shoalwater Bay 

Indian Reservation and the adjacent Tokeland 

Peninsula region of southwestern Washington (fig. 1). 

Located in Pacific County on the north side of Willapa 

Bay, the peninsula covers 1.75 square miles 

(1,120 acres) of coastal lowlands. The reservation, 

situated north and west of the peninsula, covers 

0.75 square mile (480 acres) and extends 1 mile east to 

west and 0.75 mile north to south. One-third of the 

reservation is tidelands, one-third is lowlands ranging 

in altitude from sea level to 40 feet above sea level, and 

one-third is forested uplands ranging from 40 feet to 

more than 300 feet above sea level. The tidelands are 

primarily used for recreational and commercial fishing 

and shellfishing, the lowlands for residential and 

commercial activities; the uplands are largely 

undeveloped and sparsely populated. The permanent 

population of the study area was reported to be 963 

people; tourism and seasonal use account for an 

additional 600 people during the period from Memorial 

Day to Labor Day (Steve Spencer, Shoalwater Bay 

Tribe Environmental Office, written commun., 2000).

The temperate maritime climate of the study area 

is characterized by warm, dry summers and mild, wet 

winters. Average monthly temperatures range from 

40 degrees Fahrenheit in January (the coldest month) to 

60 degrees Fahrenheit in July and August (the warmest 

months). Precipitation averages 70 inches per year, 

most of which occurs as steady low- to mediumintensity rainfall. Three-quarters of the annual 

precipitation falls between October and March 

(National Oceanic and Atmospheric Administration, 

1999).

 Previous Studies

Other USGS reports pertaining to the water 

resources in the study area include a reconnaissance 

study of the water resources of the Shoalwater 

Reservation by Lum (1984), studies of seawater 

intrusion along the Washington coast by Walters (1971) 

and Dion and Sumioka (1984), and a water-quality 

assessment study of southwest Washington by Ebbert 

and Payne (1985). Additional water-quality data for the 

Tribe’s main production well can be found in an 

assessment report by the U.S. Environmental 

Protection Agency (1997).

 Well-Numbering System

The well-numbering system used by the USGS 

in the State of Washington is based on the Public Land 

Survey rectangular grid system (fig. 2). The Willamette 

base line and meridian form the basis of a grid that 

indicates township, range, section, and 40-acre tract 

within the section which are used to assign a unique 

number to each well identified by the Washington 

District. For example, in well number 14N/10W18D02, the part preceding the slash (14N) indicates the 

township north of the Willamette base line; the part 

between the slash and the hyphen (10W) indicates the 

range west of the Willamette meridian; the number 

following the hyphen (18) indicates the section; and the 

letter (D) gives the 40-acre tract (quarter-quarter) 

within the section. The number following the quarterquarter (02) is the serial number of the well, indicating 

the order that wells were inventoried by USGS 

personnel. A suffix, such as D1, indicates a well has 

been deepened or otherwise modified after its initial 

construction.

Acknowledgments

Individual members and employees of the 

Shoalwater Bay Indian Tribe and other residents of the 

study area provided help and assistance during the field 

investigation. The late James R. Lyles of the U.S. 

Geological Survey provided valuable assistance in 

preparing this report.

HYDROGEOLOGY

The primary source of hydrogeologic data for the 

study area was the USGS National Water Information 

System (NWIS) data base and supporting water-well 

report files in the USGS's Washington District Office. 

All licensed well drillers in the State of Washington are 

required to file a water-well report with the Washington 

State Department of Ecology (Ecology) whenever the 

driller constructs, repairs, modifies, or decommissions 

a well. Ecology then forwards a copy of the report to 

the USGS Washington District Office.
Hydrogeology 3

The NWIS data base and support files included 

information on 35 flowing wells that are completed in 

the artesian aquifer under the study area. A field 

inventory of these wells determined the accurate 

location and the suitability of each site for water-level 

measurements and water-quality sampling. Location 

and other information for all 35 wells is given in 

table 1, construction and completion details in table 2, 

and lithologic data in table 3.

In addition, the Tribe had three new wells 

(14N/11W-02C01, 14N/11W-02C02, and 14N/11W03F01) installed near the northern edge of the 

reservation (fig. 1). The Tribe planned to install two 

wells in order to obtain water-quality samples from the 

artesian aquifer upgradient from the Tribe's main 

supply well (14N/11W-03J01). However, a break in the 

casing prevented 02C01 from being completed at the 

desired depth, and a third well (02C02) had to be 

installed. Construction, completion, and lithologic data 

for all three wells are shown on figure 3 and tables 1, 2, 

and 3.

Regional Hydrogeology

The generalized lithology of coastal Pacific 

County consists of bedrock overlain by sedimentary 

deposits (Lum, 1984). The bedrock consists primarily 

of weathered and eroded basalt and other volcanic 

rocks. Some water may exist in the bedrock, but the 

quantity and quality of the water is unknown and was 

not investigated for this report because there are no 

known wells in or near the study area that fully 

penetrate the overlying sedimentary deposits.

The sedimentary deposits consist of terrace 

deposits, alluvium, and beach sands. The geologic 

maps and lithologic data available for the study area are 

not detailed enough to provide thickness data for these 

deposits. However, the lithologic data for wells 

14N/11W-13A04 and 14N/11W-13A05 indicate that 

the deposits are at least 350 feet thick (table 3), and 

Lum (1984) says that the thickness is greater than 

400 feet. The terrace deposits contain numerous 

unconsolidated and partially compacted layers 

containing various mixtures of clay, silt, sand, and 

gravel. Ground water occurs in most of the 

unconsolidated terrace deposits under confined and 

unconfined conditions. The alluvium, composed of 

reworked terrace deposits, and the beach sands may 

also contain ground water, but these potential sources 

were not investigated for this report.

Local Hydrogeology

The sedimentary deposits in the study area can 

be divided into a sand-dominated water-table aquifer 

underlain by a clay-and-silt-dominated semiconfining 

unit that is underlain by the gravel-and-sand-dominated 

artesian aquifer that is the focus of this study. These 

three major hydrogeologic units were defined by using 

the logs from seven wells running northwest to 

southeast in the study area (fig. 4) and grouping layers 

together based on their dominate lithology as reported 

by various well drillers (table 3). Depths to the top of 

each unit for selected wells are given in table 4. The 

variability in depth to the top of each unit is due to the 

complexity of the deposits and to the manner that 

individual drillers identify and report lithologic layers. 

The available data are not sufficient to allow detailed 

mapping of individual lithologic layers within the 

hydrogeologic units.

Although this three-unit separation is a 

reasonable interpretation of the existing data, it is not 

the only possible one. And while this interpretation is 

consistent with previous work in the study area, it does 

have some significant differences from Lum’s (1984) 

work. For example, the lithologic data for wells 

14N/11W-13A04 and 14N/11W-13A05 indicate the 

possibility of a second, deeper semiconfining unit and a 

second, deeper artesian aquifer. Also, the lithologic 

data for the Tribe’s three new wells establish that while 

the artesian aquifer does extend northward beneath 

both the uplands and the lowlands, the water-table 

aquifer extends inland only in the lowlands (fig. 4).

Ground-Water Levels

Water-level data from 17 wells were collected at 

various times from September 1998 through August 

1999 and are presented in table 5. Water levels were 

measured in 14 wells on November 18, 1998, to 

investigate the relation between ocean tides and 

ground-water levels in the study area and to establish 

directions of ground-water flow within the artesian 

aquifer (table 5). Six of the 14 wells were measured 

hourly during one complete 12-hour tidal cycle (low 

tide to low tide); the other eight wells were measured 

once during the same tidal cycle. While the observed 

tidal flux at the Toke Point Tidal Station was 9.3 feet, 

water levels in the six observation wells changed by 0.7 

to 2.9 feet and lagged the tidal flux by as much as 

2 hours (fig. 5). Tidal efficiencies (defined as the 
4 Hydrogeologic and Water-Quality Reconnaissance, Shoalwater Bay Indian Reservation and Tokeland Peninsula, Washington

change in the observed water level divided by the 

change in the tide, expressed as a percent) ranged from 

8 percent in the northern part of the study area to 

31 percent near the southern end of the Tokeland 

Peninsula. As shown on figure 6, adjacent wells have 

similar tidal efficiencies and would thus show a similar 

change in water levels for a given tidal flux.

To compensate for this observed tidal effect, 

water levels at all 14 wells were adjusted to the hightide point of the tidal cycle. For the six wells measured 

hourly, this adjustment was done by interpolating the 

water-level data shown in table 5 and on figure 5. For 

the eight wells measured once, the adjustment was 

done using the estimated change in water levels at a 

nearby hourly well. For example, the water level in 

well 13A06 was 14.9 feet at 14:12 (table 5). At about 

that time (14:05) the water level in well 13A05 was 

estimated to be 15.7 feet, or 0.9 foot below the water 

level of 16.6 feet observed at the high-tide point. 

Applying the 0.9 foot water-level change to the 

observed water level of 14.9 feet at well 13A06 gives 

an adjusted high-tide water level of 15.8 feet. As shown 

on figure 6, the adjusted high-tide water levels for all 

14 wells ranged from 15.1 to 17.7 feet. This small 

variation in the adjusted water levels and the distance 

between the wells made it impossible to produce a 

reasonable contour map of water levels within the 

study area.

Flow Directions

The general direction of horizontal ground-water 

flow within the artesian aquifer is from the north to the 

south (fig. 6). This flow direction places the recharge 

area for the aquifer north of and at a higher elevation 

than the study area. It also means that chemicals and 

other substances could possibly enter the artesian 

aquifer in the recharge area and be transported into the 

study area. All observed water levels in the artesian 

aquifer (except at well 14N/11W-03F01) were above 

land surface, indicating that there is an upward 

component of flow from the artesian aquifer through 

the semi-confining unit and into the water-table aquifer. 

This upward component of flow minimizes the risk of 

contaminants moving from the land surface downward 

to the artesian aquifer.

Water Use

Within the study area ground water from the 

artesian aquifer is used primarily for domestic 

purposes, and is estimated to have been less than 

33 million gallons during calendar year 1999. This 

estimate is based on a reported permanent population 

of 963 people, a seasonal increase of 600 people (Steve 

Spencer, Shoalwater Bay Tribe Environmental Office, 

written commun., 2000), and the average United States 

domestic per capita use of 80 gallons per day per 

person (Solley and others, 1998). Lum (1984) indicates 

that the actual per capita use rate in the study area is 

probably significantly less than the national average 

per capita rate used in this estimate.

WATER QUALITY

Ground-water samples were collected from 10 

wells at various times from December 1998 through 

September 1999 (fig. 7). All samples were collected in 

accordance with the protocols described by Koterba 

and others (1995) in order to assure representative 

samples of ground water. Field measurements were 

made for temperature, specific conductance, pH, 

alkalinity, bicarbonate, carbonate, and dissolved 

oxygen (table 6). Samples from each of the 10 wells 

were processed and shipped to the USGS National 

Water Quality Laboratory (NWQL) in Denver, Colo., 

for the analysis of major inorganic ions (table 7). In 

addition, samples from 5 of the 10 wells were analyzed 

for metals (table 8), nutrients and methylene blueactive substances (table 9), and pesticides (table 10). 

Details on field and laboratory methods, quality control 

and assurance procedures, and drinking water 

standards are given in appendix A at the end of the 

report.

General Findings

Results of the water-quality analyses indicate 

that the sampled ground water generally meets the 

established standards for safe drinking water. None of 

the 93 properties measured or chemicals analyzed for 

exceeded U.S. Environmental Protection Agency 

(USEPA) Maximum Contaminant Levels (MCL’s) for 

drinking water (appendix A); however, concentrations 

of iron and manganese were slightly greater than 

secondary drinking water standards in some samples. 
Water Quality 5

Secondary drinking water standards are established for 

taste and aesthetic purposes, and exceedance of these 

standards does not indicate a threat to human health. 

Sixty-six of the constituents (including all 53 

pesticides) were at or below the reporting or detection 

level established by NWQL (Childress and others, 

1999).

Specific Concerns

Chloride concentrations ranged from 8.8 to 

20 milligrams per liter (mg/L) and were not indicative 

of seawater intrusion (table 7). Dion and Sumioka 

(1984) reported that uncontaminated ground water in 

most coastal areas of Washington generally contains 

less than 10 mg/L of chloride; however, they suggested 

an arbitrary threshold of 100 mg/L as an indicator of 

seawater intrusion. The median concentration of 

11 mg/L chloride in sampled wells was far below this 

arbitrary threshold and is less than the median of 

19 mg/L in samples collected by Dion and Sumioka in 

Pacific County in 1978.

Arsenic concentrations in sampled wells ranged 

from less than 1 to 9 micrograms per liter (μg/L) 

(table 8), and were below the current MCL of 50 μg/L. 

Recently, the National Research Council (1999) 

recommended lowering the current MCL for arsenic to 

more adequately protect public health. In response, the 

USEPA (U.S. Environmental Protection Agency, 2000) 

has proposed to lower the MCL to 5 μg/L. The 

proposed arsenic standard is intended to protect 

consumers against the effects of long-term, chronic 

exposure to arsenic in drinking water. The new 

standard would apply to all community water systems 

that serve 15 locations or 25 residents year-round (that 

is, most cities and towns, apartments, and mobile home 

parks with their own water supplies). Only one 

sampled well (14N/11W-02C02) exceeded this 

proposed limit. 

Methylene blue-active substances (MBAS), an 

indicator of septage, were found at a concentration 

slightly greater than the detection limit in only one of 

the 10 sites sampled for this assessment (table 9). The 

concentration of nitrate (nitrite plus nitrate unless 

otherwise defined) was 0.22 mg/L or less in sampled 

ground water (table 9). Nitrate in ground water is a 

good indicator of urban and agricultural land-use 

activities. Background concentrations of nitrate in the 

Puget Sound Basin are about 1 mg/L, and average 

concentrations in ground water underlying an urban 

and an agricultural area in the Puget Sound Basin are 

about 4 and 13 mg/L, respectively (Inkpen and others, 

2000). One reason nitrate concentrations were low is 

that the concentration of dissolved oxygen was 1 mg/L 

or less in all but four of the sampled wells (table 6). 

Without oxygen, nitrate is not stable in ground water 

(Tesoriero and others, 2000); however, nitrate 

concentrations were low even in ground water 

containing more than 1 mg/L dissolved oxygen. These 

low concentrations of MBAS and nitrate indicate that 

water in the artesian aquifer is minimally affected by 

activities at the land surface.

The absence in the ground-water samples of any 

of the 53 pesticides analyzed for (see table 10) was 

another indicator that ground water in the artesian 

aquifer is minimally affected by land-use activities. 

Pesticides are often found in shallow ground water in 

areas where pesticides are used. For example, in the 

Puget Sound Basin, pesticides were found in shallow 

ground water underlying areas of all land-use 

categories except unused land (Inkpen and others, 

2000).
6 Hydrogeologic and Water-Quality Reconnaissance, Shoalwater Bay Indian Reservation and Tokeland Peninsula, Washington

SUMMARY

The objective of this study was to describe the 

hydrogeologic setting and the quality of water in the 

artesian aquifer under the Shoalwater Bay Indian 

Reservation and the adjacent Tokeland Peninsula. 

Specific water-quality concerns include seawater 

intrusion, septage, and pesticides. Selected 

hydrogeologic and water-quality data were collected 

and compiled to conduct this assessment.

The hydrogeology of the study area consists of 

numerous unconsolidated and partially compacted 

layers containing various mixtures of clay, silt, sand, 

and gravel. This complex assemblage may be viewed 

as consisting of a sand-dominated water-table aquifer, a 

clay-and-silt-dominated semiconfining unit, and the 

gravel-and-sand-dominated artesian aquifer that is the 

focus of this study. Available water-level data indicate 

that the primary direction of horizontal ground-water 

flow within the artesian aquifer is from north to south. 

The data also indicate an upward vertical gradient 

between the artesian aquifer and the water-table 

aquifer. The north-south horizontal flow means that 

contaminates could enter the artesian aquifer in the 

recharge area north of the reservation and be 

transported into the study area. However, the upward 

vertical gradient and the semiconfining unit would tend 

to prevent contaminates in the water-table aquifer 

within the study area from entering the underlying 

artesian aquifer.

Samples of ground water from the artesian 

aquifer generally met the standards for safe drinking 

water. None of the 93 properties measured and 

chemicals analyzed for exceed the primary USEPA 

standard for drinking water and only 2 constituents 

(iron and manganese) exceed the USEPA secondary 

standards. Sixty-six of the constituents (including all 

53 pesticides) were at or below the reporting or 

detection levels established by the USGS National 

Water Quality Laboratory.

Chloride concentrations ranged from 8.8 to 

20 mg/L and are not indicative of seawater intrusion, 

and the median concentration of 11 mg/L is below the 

median concentration of 19 mg/L found in samples 

collected throughout Pacific County during 1978. The 

low concentrations of methylene blue-active substances 

(0.04 mg/L or less) and nitrate (0.22 mg/L or less) and 

the absence of detectable pesticides suggest water in 

the artesian aquifer is currently minimally affected by 

land-use activities within and north of the study area.

The absence in the ground-water samples of 

significant concentrations of any of the chemicals 

analyzed for does not rule out the possibility that these 

or other chemicals may be found in the artesian aquifer 

upgradient from the study area. Given the north-south 

horizontal direction of ground-water flow within the 

artesian aquifer, any chemicals entering the artesian 

aquifer upgradient from the study area could eventually 

migrate into the study area.
Selected References 7

SELECTED REFERENCES

Burkhardt, M.R., Cinotto, P.J., Frahm, G.W., Woodworth, 

M.T., and Pritt, J.W., 1995, Methods of analysis by the 

U.S. Geological Survey National Water Quality 

Laboratory—Determination of methylene blue-active 

substances by spectrophotometry: U.S. Geological 

Survey Open-File Report 95-189, 20 p. 

Childress, C.J., Oblinger, Foreman, W.T., Connor, B.F., and 

Maloney, T.J., 1999, New reporting procedures based 

on long-term method detection levels and some 

considerations for interpretations of water-quality data 

provided by the U.S. Geological Survey National Water 

Quality Laboratory: U.S. Geological Survey Open-File 

Report 99-193, 19 p.

Dion, N.P., and Sumioka, S.S., 1984, Seawater intrusion into 

coastal aquifers in Washington, 1978: Washington State 

Department of Ecology Water-Supply Bulletin 56, 

13 p., 14 pl.

Ebbert, J.C., and Payne, K.L., 1985, The quality of water in 

the principal aquifers of southwest Washington: U.S. 

Geological Survey Water-Resources Investigations 

Report 84-4093, 59 p., 5 pl.

Faires, L.M., 1993, Methods of analysis by the U.S. 

Geological Survey National Water Quality 

Laboratory—Determination of metals in water by 

inductively coupled plasma-mass spectrometry: U.S. 

Geological Survey Open-File Report 92-634, 28 p. 

Fishman, M.J., 1993, Methods of analysis by the U.S. 

Geological Survey National Water Quality 

Laboratory—Determination of inorganic and organic 

constituents in water and fluvial sediments: U.S. 

Geological Survey Open-File Report 93-125, 217 p. 

Fishman, M.J., and Friedman, L.C., 1989, Methods for 

determination of inorganic substances in water and 

fluvial sediments: U.S. Geological Survey Techniques 

of Water-Resources Investigations, book 5, chap. A1, 

545 p.

Foxworthy, B.L., and Walters, K.L., 1971, Description of a 

test-observation well near Westport, Grays Harbor 

County, Washington: U.S. Geological Survey Open-File 

Report, 30 p.

Inkpen, E.L., Tesoriero, A.J., Ebbert, J.C., Silva, S.R., and 

Sandstrom, M.W., 2000, Ground-water quality in 

regional, agricultural, and urban settings in the Puget 

Sound Basin, Washington and British Columbia, 1996-

1998: U.S. Geological Survey Water-Resources 

Investigations Report 00-4100, 66 p.

Jones, S.R., and Garbarino, J.R., 1999, Methods of analysis 

by the U.S. Geological Survey National Water Quality 

Laboratory—Determination of arsenic and selenium in 

water and sediment by graphite furnace-atomic 

absorption spectrometry: U.S. Geological Survey 

Open-File Report 98-639, 39 p. 

Koterba, M.T., Wilde, F.D., and Lapham, W.W., 1995, 

Ground-water data-collection protocols and procedures 

for the National Water-Quality Assessment Program—

collection and documentation of water-quality samples 

and related data: U.S. Geological Survey Open-File 

Report 95-399, 113 p.

Lindley, C.E., Steward, J.T., and Sandstrom, M.W., 1996, 

Determination of low concentrations of acetochlor in 

water by automated solid-phase subtraction and gas 

chromatography with mass-selective detection: Journal 

of AOAC International, v. 79, no. 4, p. 962-966.

Lum, W.E. II, 1984, A reconnaissance of the water resources 

of the Shoalwater Bay Indian reservation and adjacent 

areas, Pacific County, Washington, 1978-79: U.S. 

Geological Survey Water-Resources Investigations 

Report 83-4165, 34 p.

McFarland, C.R., 1979, Oil and gas exploration in 

Washington 1900-1978: Washington Division of Mines 

and Geology Information Circular 67, 119 p.

National Oceanic and Atmospheric Administration, at 

www.noaa.gov, Tides Online, accessed 11/09/1988.

———1999, Climatological data annual summary, 

Washington, 1998, volume 1 of 2, number 13.

National Research Council, 1999, Arsenic in drinking water: 

Washington, D.C., National Academy Press, 273 p.

Newcomb, R.C., 1947, Ground water of the South-Bar area, 

Grays Harbor, Washington: U.S. Geological Survey 

Open-File Report, 12 p., 2 plates.

Nowell, L.H., and Resek, E.A., 1994, Summary of national 

standards and guidelines for pesticides in water, bed 

sediment, and aquatic organisms and their application 

to water-quality assessments: U.S. Geological Survey 

Open-File Report 94-44, 115 p.

Patton, C.J., and Truitt, E.P., 1992, Methods of analysis by 

the National Water Quality Laboratory—determination 

of total phosphorus by a Kjeldahl digestion method and 

an automated colorimetric finish that includes dialysis: 

U.S. Geological Survey Open-File Report 92-146, 39 p.

Pritt, J.W., and Raese, J.W., 1995, Quality assurance/quality 

control manual, National Water Quality Laboratory: 

U.S. Geological Survey Open-File Report 95-443, 

35 p.
8 Hydrogeologic and Water-Quality Reconnaissance, Shoalwater Bay Indian Reservation and Tokeland Peninsula, Washington

Sandstrom, M.W., Wydoski, D.S., Schroeder, M.P., 

Zamboni, J.L., and Foreman, W.T., 1992, Methods of 

analysis by the National Water Quality Laboratory —

determination of organonitrogen herbicides in water by 

solid-phase extraction and capillary-column gas 

chromatography/mass spectrometry with selection-ion 

monitoring: U.S. Geological Survey Open-File 

Report 91-519, 26 p.

Shelton, L.R., 1994, Field guide for collecting and 

processing stream-water samples for the National 

Water-Quality Assessment Program: U.S. Geological 

Survey Open-File Report 94-455, 42 p.

Solley, W.B., Pierce, R.R., and Perlman, H.A., 1998, 

Estimated use of water in the United States in 1995: 

U.S. Geological Survey Circular 1200, 71 p.

Tesoriero, A.J., Liebscher, H., and Cox, S.E., 2000, The 

mechanism and rate of nitrate reduction in an 

agricultural watershed—Electron and mass balance 

along groundwater flow paths: Water Resources 

Research, v. 36, no. 6 p. 1,545-1,560.

U.S. Environmental Protection Agency, 1995, Lead and 

copper rule fact sheet: U.S. Environmental Protection 

Agency, Office of Water, EPA 570/9-91-400, January 

1995, 2 p.

———1996, Drinking water regulations and health 

advisories: Washington, D.C., U.S. Environmental 

Protection Agency, Office of Water, EPA 822-B-96-

002, October, 1996, 11 p.

U.S. Environmental Protection Agency, 1997, The 

Shoalwater Bay Reservation—a limited environmental 

assessment—1945–1995: U.S. Environmental 

Protection Agency EPA 910/R96-013, 190 p.

———2000, Proposed revision to arsenic drinking water 

standard: accessed on 7/31/00 at URL 

http://www.epa.gov/safewater/ars/proposalfs.html

Wagner, Duane E., 1956, Preliminary investigation of 

ground water in the Grayland Watershed, Grays Harbor 

and Pacific Counties, Washington: U.S. Geological 

Survey Open-File Report, 32 p., 1 plate.

Walters, K.L., 1971, Reconnaissance of sea-water intrusion 

along coastal Washington, 1966-1968: Washington 

Department of Ecology Water-Supply Bulletin 32, 

208 p.

Wershaw, R.L., Fishman, M.J., Grabbe, R.R., and Lowe, 

L.E., eds., 1987, Methods for the determination of 

organic substances in water and fluvial sediments: U.S. 

Geological Survey Techniques of Water-Resources 

Investigations, book 5, chap. A3, 80 p. 

Zaugg, S.D., Sandstrom, M.W., Smith, S.G., and Fehlberg, 

K.M., 1995, Methods of analysis by the U.S. 

Geological Survey National Water Quality 

Laboratory—Determination of pesticides in water by 

C-18 solid-phase extraction and capillary-column gas 

chromatography/mass spectrometry with selected-ion 

monitoring: U.S. Geological Survey Open-File Report 

95-181, 60 p.
Figures 9

Figures 1 – 10
F

igures10

SR

105

R.11 W

13

15 14 16

9

10

11

12

1

2

3 4

A

124°02'30" 1

46°44'46°42'30"

11H01D1

11G02

11R01

12M02 11R02

11R03

12M01

12P04

12L01

12R01

13A07

13A06

1

13A02

13A03

02L01

03F01

03J01

03J02

02C02 02C01

02P01

11C01

11C03

11F01

11C04

11B01

Willapa Bay

Kindred Slough

Teal Duck Slough

Kindred

 Island

Empire Spit

Tokelan Exposed sand at d Peninsula low tide

North Cove

E

6 

12L01

A A

0.2

00

Figure 1. Location of the Shoalwater Bay Indian Reservation and Tokeland Peninsula study area, of wells used in this study, and of thA-A’.
11 Hydrogeologic and Water-Quality Reconnaissance, Shoalwater Bay Indian Reservation and Tokeland Peninsula, Washington

Willamette Meridian

Willamette Base Line

SECTION 18

14N/10W-18D02

D C B A

EFGH

M L K J

NPQR

R. 10 W.

T.

14

 N.

6 5 4 3 2 1

7 12

18 13

19 24

30 25

31 32 33 34 35 36

W A S H I N G T O N

Figure 2. Well-numbering system used by the U.S. Geological Survey in the State of Washington.
Figures 12

|

92 - 102 feet

Screen

0 - 18 feet 

Bentonite

Chips

18 - 230 feet 

Native

LOCAL WELL NUMBER: 14N/11W-02C01

0

50

100

150

200

Land Surface Datum

Casing 6-inch steel

+1 - 92 feet

0 19.6

-41

Depth

(feet)

Altitude

(feet)

Land Surface

61

Sand with clay, brown

Sand with clay, blue

Sand, gray, shells,

 water bearing

Sand with fine clay, brown,

 water bearing

Sand & gravel, gray,

 water bearing

Sand, fine with clay

68 -48

91 -71

120 -100

184 -164

194 -174

220 -200

230 -210

Clay, blue

Clay, gray

end of hole

Original hole went to 

230 feet but casing broke 

during pullback. Driller

did not discover break 

until he had set the first 

screen. He then completed

the well shown above.

Unknown length of

6-inch steel casing and

10 feet of screen.

AS-BUILT WELL DATA LITHOLOGY

DEPTH, IN FEET

Figure 3. Construction, completion and generalized lithologic data for newly constructed tribal wells 14N/11W-02C01, 

14N/11W-02C02, and 14N/11W-03F01. 

This figure is a combination of data and information reported by the well driller and field observations made by U.S. 

Geological Survey personnel during the drilling and construction phases.
13 Hydrogeologic and Water-Quality Reconnaissance, Shoalwater Bay Indian Reservation and Tokeland Peninsula, Washington

Screen 6 inches x 0.030 inch

Stainless steel 

210 - 220 feet

0 - 18 feet 

Bentonite

Chips

18 - 220 feet 

Native

Land Surface Datum

Casing 6-inch steel

+1 - 210 feet

0

50

100

150

200

LOCAL WELL NUMBER: 14N/11W-02C02

-42

0 19.6

Depth

(feet)

Altitude

(feet)

Land Surface

62

Sand, brown shells, 

 water bearing

Sand & clay, blue

Sand, gray,

 water bearing

Sand with clay, brown

Sand & gravel, gray, shells,

 water bearing

78 -58

89 -69

120 -100

184 -164

194 -174

220 -200

Clay, blue

Clay, gray

end of hole

AS-BUILT WELL DATA

DEPTH, IN FEET

LITHOLOGY

Figure 3.—Continued.
Figures 14

0 - 18 feet 

Bentonite

Chips

18 - 425 feet 

Native

LOCAL WELL NUMBER: 14N/11W-03F01

0 0

50

100

150

200

250

300

350

400

Water level =

 250 feet

268

210

3

-41

-98

-131

-157

Depth

(feet)

Altitude

(feet)

Land Surface

58

265

309

366

399

425

Clay w/sand & silt, layered, 

 yellow, brown, green, & blue, 

 DRY

Sand w/clay, layered brown,

 green, & yellow, DRY

Sand with clay, yellow,

 water bearing

Sand with clay, gray,

 water bearing

Sand with clay, brown,

 water bearing

Sand & gravel, with clay

 brown, water bearing

end of hole

Screen 6 inches x 0.030 inch

Stainless steel 

408 - 423 feet

Land Surface

Casing 6-inch steel

+2 - 408 feet

AS-BUILT WELL DATA LITHOLOGY

DEPTH, IN FEET

Figure 3.—Continued.
15 Hydrogeologic and Water-Quality Reconnaissance, Shoalwater Bay Indian Reservation and Tokeland Peninsula, Washington NORTH 

Sea level 250 300 200 150 10050 -50 -100 -150 -200 -250 -300 -350

ALTITUDE, IN FEET

A 

03F01

(268.1)

03J01

(14.2)

11C04

(13.5)

11H01D01

(11)

12M02

(13)

12R01

(12)

VERTICAL EXAGGE

WATER-TABLE UNIT

SEMICONFINING UNIT

0.25 0.50 MILE

0.25 0.50 KILOMETER

00

ARTESIAN UNIT

Clay, silt, sand, or gravel

Sand, silt, clay, or bay mud

Gravel, sand, silt, or clay

03J01 Well identifier

Land surface altitude in feet above sea level

(12)

Simplified Lithologies

(in approximate order of abundance)

EXPLANATION

Figure 4. Generalized hydrogeologic section A-A’ in the Shoalwater Bay Indian Reservation and Tokeland Peninsula study areTrace of the section is shown on figure 1. See table 3 for detailed lithologies of wells.
Figures 16

Figure 5. Water levels and tidal fluctuations in selected wells in the Shoalwater Bay Indian Reservation and 

Tokeland Peninsula study area. 

Because water-level measurements were stopped at the low point of the tidal cycle (about 19:30) and there is about 

a 2-hour lag time, water levels in the wells did not reach their lowest point; therefore, the total fluctuations in these 

wells were somewhat greater than shown. Tidal efficiency equals the observed water-level change in the well 

divided by the change in the tide, expressed as a percent.

18

-6

-4

-2

0

2

4

6

8

10

12

14

16

18

-6

-4

-2

0

2

4

6

8

10

12

14

16

06:00 08:00 10:00 12:00 14:00 16:00 18:00 20:00

18

-6

-4

-2

0

2

4

6

8

10

12

14

16

 ALTITUDE, IN FEET

(pumping)

TIME, IN HOURS

06:01 16.0 -2.2

07:14 16.0 -1.7

07:59 16.0 -0.8

08:55 16.1 0.7

09:55 16.1 2.3

10:49 16.3 3.6

11:52 16.6 4.3

12:44 16.7 4.0

13:31 16.5 3.2

14:48 16.3 1.1

15:43 16.2

16:39 16.2 -2.6

 -1.5

17:27 16.1 -3.9

18:27 16.1 -5.0

19:44 16.0 -4.8

05:54 16.7 -2.2

07:09 16.5 -1.7

07:52 16.4 -1.0

08:49 16.5

09:48 16.8 2.1

 0.5

10:38 17.1 3.3

11:39 17.3 4.2

12:35 17.3 4.1 

13:24 17.2 3.3

14:32 16.9 1.6

15:29 16.7 -0.3

16:30 16.6 -2.3

17:17 16.5 -3.7

18:21

19:52

 16.4

 16.3

 -4.9

 -4.6

Time

Water-Level

Altitude

Water-Level

Altitude

Water-Level

Altitude

Tide

Altitude

Time

Tide

Altitude

Time

Tide

Altitude

05:50 14.5 -2.2

06:40 15.0 -2.0

07:29 13.7 -1.4

08:29 14.9 -0.1

09:10 15.3 1.1

10:05 16.0 2.5

11:00 16.6 3.7

12:02 17.0 4.3

12:53 16.9 3.9

14:04 16.5 2.4

15:05 15.7 0.5

16:04 15.9 -1.5

16:52 15.4 -3.0

17:45 15.0 -4.4

19:17 14.6 -5.0

18 November 1998

Well 14N/10W-18D02D1

Water-level altitude

Tidal altitude

Tidal efficiency 27 percent

Water-level altitude

Tidal altitude

Well 14N/11W-03J02

Tidal efficiency 8 percent

Well 14N/11W-11F01

Water-level altitude

Tidal altitude

Tidal efficiency 10 percent
17 Hydrogeologic and Water-Quality Reconnaissance, Shoalwater Bay Indian Reservation and Tokeland Peninsula, Washington

Figure 5. —Continued.

(No data)

06:19 16.6 -2.2

06:53 16.5 -1.9

07:42 16.5 -1.2

08:38 16.6 0.2

09:34 16.8 1.8

11:10 17.3 3.9

12:15 17.6 4.3

13:06 17.6 4.0

14:19 17.4 2.0

15:17 17.1

16:16 16.9 -1.9

 0.1

17:02 16.7 -3.3

18:09 16.5 -4.8

19:28 16.3 -5.0

06:00 14.8 -2.2

06:45 14.6 -2.0

07:35 14.1 -1.3

08:32 14.4

09:27 15.0 1.5

 0.0

10:10 15.4 2.7

11:08 16.2 3.9

12:07 16.6 4.3

12:57 16.4 3.8

14:05 15.7 2.4

15:10 15.2

16:10 14.6 -1.7

 0.4

16:55 14.4 -3.1

18:03 13.9 -4.7

19:21 13.7 -5.0

Time

Tide

Altitude

Time

Tide

Altitude

Time

Tide

Altitude

06:12 15.9 -2.2

07:04 13.6 -1.8

07:47 15.8 -1.1

08:43 16.0

09:41 16.3 1.9

 0.3

10:31 16.3 3.2

11:32 16.3 4.1

12:27 16.2 4.2

13:17 16.2 3.5

14:24 16.3 1.8

15:24 16.3

16:24 16.1 -2.1

 -0.1

17:08 15.9 -3.5

18:15 15.6 -4.9

19:36 15.3 -4.9

Water-Level

Altitude

Water-Level

Altitude

Water-Level

Altitude

(recently 

pumping)

18

-6

-4

-2

0

2

4

6

8

10

12

14

16

18

-6

-4

-2

0

2

4

6

8

10

12

14

16

06:00 08:00 10:00 12:00 14:00 16:00 18:00 20:00

18

-6

-4

-2

0

2

4

6

8

10

12

14

16

TIME, IN HOURS

18 November 1998

 ALTITUDE, IN FEET

Well 14N/11W-11R01

Water-level altitude

Tidal altitude

Tidal efficiency 11 percent

Well 14N/11W-12L01

Water-level altitude

Tidal altitude

Tidal efficiency 14 percent

Well 14N/11W-13A05

Water-level altitude

Tidal altitude

Tidal efficiency 31 percent
Figures 18

Figure 6. Ground-water altitudes and tidal efficiencies in the artesian aquifer under the Shoalwater Bay Indian Reservation and Tokeland Water levels in wells measured hourly during the tidal cycle were adjusted by interpolation of graphs and data shown on figure 5. Water le

during the tidal cycle were adjusted on the basis of estimated water-level changes in adjacent hourly wells. Water levels in wells 14N/11W

were measured by the well driller on July 4, 1999, and August 3, 1999, respectively, and are not adjusted for tidal effects. Tidal efficiency level change in the well divided by the change in the tide, expressed as a percent. 

SR

105

14 13 15 16

9

10

11 12

1 3 2

4

R.11 W. 

0

0.25 

00

E

6 Se

ShIndStu

MeMe

 We U.S top  mi lev nu in 

To

Me

Willapa Bay

Exposed sand at low tide

North Cove

11G02

11R01

12M01

12L01

13A06

1

03J02

02P01

11C03

11F01

11C04

Kindred Slough

Teal Duck Slough

Kindred

 Island

Tokeland Peninsula

Empire Spit

03F01

02C02

16.7

20

20.1

17.3

17.7

17.3

17.3

16.3

15.4

17.6

15.8

17.0

8%

10%

11%

14%

124°02'30" 1

46°

44'

46°42'30"
19 Hydrogeologic and Water-Quality Reconnaissance, Shoalwater Bay Indian Reservation and Tokeland Peninsula, Washington Figure 7. Location of wells sampled for water quality in the artesian aquifer underlying the Shoalwater Bay Indian Reservation and Tok

SR105 

R.11 W. 

13 

15 14 16

9

10

11

12

1

2

3

4

124°02'30" 12

46°44'46°42'30"

11G02

11R01 12P04

03F01

03J01

02C02

11F01

11C04

Willapa Bay

Kindred Slough

Teal Duck Slough

Kindred

 Island

Empire Spit

Tokelan

Ex

d Peninsula

posed sand at low tide

N

orth Cove

EX

6 Sec

meGeo

12L01

ShoInd

ProWeAlsnut

0

0.25 

00

Sammeamaj
Tables 20

Tables 1 – 10
Tables 21

Table 1. Information for selected wells in the Shoalwater Bay Indian Reservation and Tokeland Peninsula study area

[Latitude: Location of site in degrees, minutes, and seconds north of the Equator. Longitude: Location of sites in degrees, minutes, and seconds west of the 

Greenwich Meridian. Location Method: Map, field located on 7.5-minute U.S. Geological Survey Topographic Map; Survey, located using a TOPCONTM 

Total Station Survey Instrument; Estimated, from adjacent surveyed wells. --, data not available]

Well No. Latitude Longitude

Accuracy of 

location 

(feet)

Location 

method Land use Water use

Well 

depth 

(feet)

14N/10W-18C02 46 42 19 123 58 14 100 Map Commercial Public Supply 205

14N/10W-18C03 46 42 20 123 58 07 100 Map Commercial Public Supply 340

14N/10W-18C04 46 42 19.9 123 58 10.4 10 Survey Residential Unused --

14N/10W-18C05 46 42 17 123 58 07 100 Map Residential Domestic 145

14N/10W-18C06 46 42 17 123 58 10 100 Map Residential Domestic 222

14N/10W-18D01 46 42 20.9 123 58 24.2 10 Survey Residential Irrigation 200

14N/10W-18D02D1 46 42 17.5 123 58 27.8 10 Survey Residential Domestic 240

14N/10W-18D03 46 42 18 123 58 25 100 Map Residential Domestic 279

14N/11W-02C01 46 43 57.6 124 00 41.9 10 Survey Wetland Unused 102

14N/11W-02C02 46 43 57.7 124 00 41.9 10 Estimated Wetland Unused 220

14N/11W-02L01 46 43 35.1 124 00 43.9 10 Survey Commercial Commercial 223

14N/11W-02P01 46 43 18.0 124 00 50.4 10 Survey Residential Unused 176

14N/11W-03F01 46 43 50.1 124 01 52.4 10 Survey Forested Unused 423

14N/11W-03J01 46 43 32.1 124 01 24.1 10 Survey Residential Public Supply 224

14N/11W-03J02 46 43 32.9 124 01 23.1 10 Survey Residential Public Supply 160

14N/11W-11B01 46 43 11 124 00 28 100 Map Residential Domestic 198

14N/11W-11C01 46 43 07 124 00 52 100 Map Commercial Public Supply 192

14N/11W-11C03 46 43 05.3 124 00 49.5 10 Survey Residential Domestic 230

14N/11W-11C04 46 43 14.5 124 00 36.1 10 Survey Residential Domestic 281

14N/11W-11F01 46 43 02.7 124 00 44.2 10 Survey Commercial Public Supply 290

14N/11W-11G02 46 42 52.6 124 00 17.9 10 Survey Residential Domestic 193

14N/11W-11H01D1 46 42 58 124 00 16 100 Map Residential Domestic 190

14N/11W-11R01 46 42 34.2 124 00 12.6 10 Survey Residential Domestic 237

14N/11W-11R02 46 42 36 124 00 02 100 Map Residential Domestic 227

14N/11W-11R03 46 42 35 124 00 04 100 Map Residential Domestic 235

14N/11W-12L01 46 42 42.5 123 59 19.4 10 Survey Residential Domestic 285

14N/11W-12M01 46 42 40.4 123 59 38.4 10 Survey Residential Domestic 216

14N/11W-12M02 46 42 42 123 59 52 100 Map Residential Domestic 250

14N/11W-13A01 46 42 25 123 58 42 100 Map Residential Domestic 172

14N/11W-13A02 46 42 20 123 58 39 100 Map Commercial Unused 200

14N/11W-13A03 46 42 20 123 58 40 100 Map Commercial Unused 200

14N/11W-13A04 46 42 18.2 123 58 38.5 10 Survey Commercial Commercial 350

14N/11W-13A05 46 42 19.8 123 58 41.3 10 Survey Commercial Unused 350

14N/11W-13A06 46 42 22.9 123 58 52.1 10 Survey Residential Domestic 240

14N/11W-13A07 46 42 22 123 58 55 100 Map Residential Domestic 189

14N/11W-13A08 46 42 23 123 58 51 100 Map Residential Domestic 238

14N/11W-12P04 46 42 34.7 123 59 28.9 10 Survey Residential Public Supply 230

14N/11W-12R01 46 42 27 123 58 53 100 Map Residential Domestic 220
Tables 22

Table 2. Construction and completion information for selected wells in the Shoalwater Bay Indian Reservation and Tokeland 

Peninsula study area

[Location Method: Map, field located on 7.5 minute USGS Topographic Map; Survey, located using a TOPCONTM Total Station Survey 

Instrument; Leveled, elevation determined by hand level from adjacent surveyed well. --, data not available]

Well No.

Land surface 

altitude (feet)

Accuracy of land 

surface altitude 

(feet)

Location 

method

Hole 

depth 

(feet)

Well 

depth 

(feet)

Casing, inside 

diameter 

(inches) Type

Interval (feet 

below land 

surface)

14N/10W-18C02 12 2 Map 221 205 2 Open end 205

14N/10W-18C03 12 2 Map -- 340 6 Open end 340

14N/10W-18C04 12.1 0.2 Survey -- -- -- -- --

14N/10W-18C05 12 2 Map 145 145 6 Open end 145

14N/10W-18C06 12 2 Map 223 222 6 Screened 217 - 222

14N/10W-18D01 12.7 0.2 Survey -- 200 2 Sand Point 198 - 200

14N/10W-18D02D1 13.2 0.2 Survey 240 240 6 Screened 235 - 240

14N/10W-18D03 13 2 Map 280 279 6 Screened 274 - 279

14N/11W-02C01 19.6 0.2 Survey 230 102 6 Screened 92 - 102

14N/11W-02C02 19.6 0.2 Leveled 220 220 6 Screened 210 - 220

14N/11W-02L01 10.4 0.2 Survey -- 223 2.5 -- --

14N/11W-02P01 15.6 0.2 Survey -- 176 2.5 -- -- 

14N/11W-03F01 268.1 0.2 Survey 425 423 6 Screened 408 - 423

14N/11W-03J01 14.2 0.2 Survey 224 224 10 Perforated 206 - 208

14N/11W-03J02 12.3 0.2 Survey 161 160 6 Screened 148 - 158

14N/11W-11B01 12 2 Map 220 198 6 Screened 193 - 198

14N/11W-11C01 12 2 Map 198 192 2 Perforated 189 - 192

14N/11W-11C03 11.9 0.2 Survey -- 230 -- --

14N/11W-11C04 13.5 0.2 Survey 281 281 6 Screened 276 - 281

14N/11W-11F01 12.3 0.2 Survey -- 290 6 -- --

14N/11W-11G02 15.4 0.2 Survey 193 193 2 Open end 193

14N/11W-11HO1D1 11 2 Map 204 190 6 Open end 190

14N/11W-11R01 11.2 0.2 Survey 237 237 6 Screened 232 - 237

14N/11W-11R02 11 2 Map 227 227 6 Screened 222 - 227

14N/11W-11R03 11 2 Map 235 235 6 Screened 230 - 235

14N/11W-12L01 12.2 0.2 Survey -- 285 6 -- --

14N/11W-12M01 13.8 0.2 Survey 225 216 6 Screened 211 - 216

14N/11W-12M02 13 2 Map 250 250 6 Perforated 234 - 248

14N/11W-12P04 14.5 0.2 Survey 233 230 6 Screened 220 - 230

14N/11W-12R01 12 2 Map 220 220 6 Screened 215 - 220

14N/11W-13A01 12 2 Map -- 172 4 -- --

14N/11W-13A02 12 2 Map -- 200 2 -- --

14N/11W-13A03 12 2 Map -- 200 -- -- --

14N/11W-13A04 12.1 0.2 Survey 350 350 6 Screened 324 - 345

14N/11W-13A05 13.2 0.2 Survey 350 350 8 Screened 335 - 350

14N/11W-13A06 12.0 0.2 Survey 240 240 6 Open end 240

14N/11W-13A07 12 2 Map 200 189 2 Open end 189

14N/11W-13A08 12 2 Map 242 238 6 Screened 233 - 238
Tables 23

Table 3. Lithologic data, as reported by water-well drillers, for selected wells in the Shoalwater Bay Indian Reservation and 

Tokeland Peninsula study area–Continued

Well No. Lithologic material

Top of layer (feet 

below land 

surface)

Thickness of 

layer (feet)

14N/10W-18C02 Sand 0 155

Gravel 155 20

Hardpan, gray 175 30

Sand 205 >16

14N/10W-18C05 Topsoil 0 5

Sand, gray 5 50

Sand with clay 55 2

Sand, gray 57 35

Sand, gray (heaving) 92 6

Clay, brown 98 7

Clay, blue 105 13

Sand with clay 118 22

Pea gravel, gray 140 >5

14N/10W-18C06 Sand and clay, brown 0 8

Bay mud, black, sandy 8 52

Sand, blue-gray 60 87

Clay, brown, and rocks 147 6

Sand, blue-gray, fine 153 >70

14N/10W-18D02D1 Sand, brown 0 14

Sand, brown (heaving) 14 30

Sand, brown 44 54

Silt, brown, sandy 98 12

Clay, gray 110 23

Clay, gray, sandy 133 8

Sand, gray 141 3

Sand and gravel, gray, WB 144 6

Clay 150 50

Sand, fine 200 30

Sand, fine, clam shells, WB 230 >10

14N/10W-18D03 Sand, gray, loose 0 140

Clay, sand, and gravel, brown, iron water 140-150 feet 140 14

Clay, blue 154 42

Clay, blue, sandy 196 74

Sand, with clay layers <1 inch thick 270 >10

14N/11W-02C01 Sand, with clay binder, brown 0 61

Sand, with blue clay 61 7

Clay, blue 68 23

Table 3. Lithologic data, as reported by water-well drillers, for selected wells in the Shoalwater Bay Indian Reservation and 

Tokeland Peninsula study area

[<, less than; >, greater than; gpm, gallons per minute; WB, water bearing; 'and', 35 to 50 percent; 'some', 20 to 35 percent; 'little' 10 to 20 percent; 'trace', less 

than to 10 percent.]
24 Hydrogeologic and Water-Quality Reconnaissance, Shoalwater Bay Indian Reservation and Tokeland Peninsula, Washington

14N/11W-02C01 Sand, fine, with clay binder, brown, WB 91 29

Continued Sand, gray, shells, WB 120 64

Clay, gray 184 10

Sand and gravel, gray, WB 194 26

Sand, fine, with clay 220 >10

14N/11W-02C02 Sand, with clay binder, brown, hard 0 5

Sand, with clay binder, brown, soft, WB 5 7

Sand, with clay binder, brown, hard 12 7

Sand, with clay binder, brown, WB 19 9

Sand, with clay binder, brown, dry 28 10

Sand, with clay binder, brown, WB 38 24

Clay, blue 62 16

Sandstone, blue, hard 78 5

Sand, blue, with clay binder 83 6

Sand, brown, WB 89 31

Sand, gray, shells, WB 120 64

Clay, gray 184 10

Sand and gravel, gray, WB 194 >26

14N/11W-03F01 Top soil 0 2

Clay, yellow 2 9

Sand, brown, with clay binder 11 15

Clay, blue 26 5

Clay, yellow-green 31 7

Clay, blue 38 9

Clay, brown, some grit 47 11

Sand, brown, with clay binder 58 92

Sand, yellow, with clay binder 150 21

Clay, blue 171 1

Sand, green and brown, with clay binder 172 16

Clay, gray 188 1

Sand, brown, with clay binder 189 29

Sand, yellow, with clay binder 218 47

Sand, yellow, with clay binder, WB 265 44

Sand, gray, with clay binder, WB 309 57

Sand, brown, with clay binder, WB 366 33

Sand and gravel, brown, with clay binder, WB 399 >26

14N/11W-03J01 Sand, brown 0 15

Sand, blue 15 9

Sand, dark blue 24 11

Sand, fine, silty, WB, flows 15 gpm 35 1

Clay, blue and sand 36 50

Table 3. Lithologic data, as reported by water-well drillers, for selected wells in the Shoalwater Bay Indian Reservation and 

Tokeland Peninsula study area–Continued

Well No. Lithologic material

Top of layer (feet 

below land 

surface)

Thickness of 

layer (feet)
Tables 25

14N/11W-03J01 Clay, yellow 86 53

Continued Clay, yellow, some gravel 139 4

Sand, fine, and gravel, yellow, WB 143-143.5 feet 143 16

Gravel and sand 159 0.5

Sand, fine 159.5 4.5

Sand and clay, yellow, some gravel 164 11

Gravel and sand 175 0.5

Sand, fine, and clay 175.5 9.5

Gravel and sand 185 1.5

Clay and sand 186.5 19.5

Pea gravel, clean, WB 206 2

Clay and gravel, sandy 208 >16

14N/11W-03J02 Clay, brown, sandy 0 7

Sand, black, coarse, wet 7 12

Clay, gray 19 18

Sand, black, coarse (heaving) 37 32

Sand, brown, medium (heaving) 69 63

Sand and clay, brown, WB 132 4

Clay and gravel, brown, sandy 136 2

Sand, coarse and pea gravel , WB 138 17

Sand, brown, medium, WB 155 >6

14N/11W-11B01 Sand, gray 0 98

Clay, brown 98 22

Sand, gray 120 40

Gravel, gray, coarse, WB (iron in water) 160 2

Sand, gray 162 50

Sand, and pea gravel, gray 212 6

Sand, gray, fine, mucky 218 >2

14N/11W-11C01 Sand 0 23

Clay 23 3

Sand, occasional mud streaks 26 74

Hardpan 100 18

Sand, occasional mud streaks 118 70

Gravel, WB 188 4

Sand, yellow, WB 192 >6

14N/11W-11C04 Sand, with clay binder, yellow 0 10

Sand, gray, WB (heaving) 10 78

Sand, gray, clam shells (heaving) 88 5

Clay, gray, sandy, trace gravel 93 4

Sand, gray, WB (heaving) 97 10

Sand, WB (heaving) 107 63

Table 3. Lithologic data, as reported by water-well drillers, for selected wells in the Shoalwater Bay Indian Reservation and 

Tokeland Peninsula study area–Continued

Well No. Lithologic material

Top of layer (feet 

below land 

surface)

Thickness of 

layer (feet)
26 Hydrogeologic and Water-Quality Reconnaissance, Shoalwater Bay Indian Reservation and Tokeland Peninsula, Washington

14N/11W-11C04 Sand, gray, WB (heaving) 170 14

Continued Sand and gravel, packed (heaving) 184 2

Sand, WB (heaving) 186 17

Pea gravel and sand, WB (heaving) 203 1

Sand and pea gravel (heaving) 204 70

Gravel and coarse sand, WB 274 >7

14N/11W-11G02 Mud, tidal 0 44

Clay, blue 44 138

Sand and gravel, layers 182 8

Gravel, coarse 190 >3

14N/11W-11H01D1 Sand, blue, with shells 0 101

Sand, blue, with wood 101 5

Sand, fine and muck, blue 106 26

Clay, blue, sandy (fine) 132 8

Sand, blue, fine 140 12

Sand, brown 152 38

Sand, brown, rock pieces 190 10

Sand and gravel (eighth-inch), brown and gray WB 200 >4

14N/11W-11R01 Sand with topsoil 0 8

Sand, gray 8 34

Sand, with clay 42 50

Sand and gravel, gray 92 1

Sand, gray 93 2

Silt, gray 95 119

Sand and gravel, gray 214 >23

14N/11W-11R02 Sand, with topsoil 0 3

Sand, gray 3 59

Sand with clay, gray 62 105

Sand, fine, with light clay 167 53

Sand, coarse 220 2

Sand and gravel 222 2

Sand, coarse, WB 224 >3

14N/11W-11R03 Sand with topsoil 0 7

Sand 7 41

Sand and clay, hard 48 46

Sand and gravel 94 2

Sand and clay 96 72

Sand 168 64

Sand and gravel 232 3

Sand 235 >0

Table 3. Lithologic data, as reported by water-well drillers, for selected wells in the Shoalwater Bay Indian Reservation and 

Tokeland Peninsula study area–Continued

Well No. Lithologic material

Top of layer (feet 

below land 

surface)

Thickness of 

layer (feet)
Tables 27

14N/11W-12M01 Sand, black, fine, mucky 0 80

Sand, tan 80 100

Clay and sand, tan 180 30

Sand, blue-gray 210 >15

14N/11W-12M02 Sand, blue 0 30

Mud, blue 30 29

Sand, blue 59 38

Clay, blue 97 31

Sand, brown 128 106

Gravel, blue, WB 234 1

Sand, brown 235 6

Gravel, blue, WB 241 4

Sand, brown 245 2

Gravel, blue, WB 247 1

Sand, brown 248 >2

14N/11W-12P04 Sand, brown 0 2

Sand, brown, WB (iron water) 2 16

Sand, blue-gray, WB (iron water) 18 12

Sand, gray, mucky, with clay and wood, WB (iron water) 30 60

Sand, with clay, blue-gray, hard 90 90

Sand, blue-gray, with shells 180 >53

14N/11W-12R01 Sand, brown, silty 0 10

Sand, gray, soupy 10 30

Sand, gray, white shells and wood, soupy 40 125

Clay and sand, silty, white shells and wood 165 15

Sand, gray, white shells and wood 180 >40

14N/11W-13A04 Clay, yellow, sandy 0 20

Sand, blue 20 55

Clay, blue, sandy 75 7

Sand, blue, fine, WB (sulfur odor) 82 3

Clay, blue, sandy 85 33

Clay, blue 118 37

Clay, blue, trace pea gravel 155 5

Clay, blue 160 36

Sand, blue, fine, WB (flows) 196 1

Clay, blue 197 5

Sand, blue, fine, clam shells 202 67

Sand and fine gravel, blue, clam shells 269 31

Sand, fine, shells 300 2

Sand, coarse and gravel, shells 302 7

Sand, finer 309 1

Table 3. Lithologic data, as reported by water-well drillers, for selected wells in the Shoalwater Bay Indian Reservation and 

Tokeland Peninsula study area–Continued

Well No. Lithologic material

Top of layer (feet 

below land 

surface)

Thickness of 

layer (feet)
28 Hydrogeologic and Water-Quality Reconnaissance, Shoalwater Bay Indian Reservation and Tokeland Peninsula, Washington

14N/11W-13A04 Sand, coarse, and gravel fine 310 5

Continued Sand, finer 315 4

Sand, coarse 319 9

Sand, coarse, and pea gravel 328 18

Sand, fine, clam shells 346 >4

14N/11W-13A05 Clay, yellow, sandy 0 15

Clay, blue, sandy 15 10

Sand, blue 25 55

Clay and sand, blue 80 10

Sand, blue, fine (odor) 90 15

Clay, light blue 105 40

Clay, dark blue 145 13

Clay and pea gravel, blue, wood 158 22

Clay, blue, sandy, WB 180 9

Clay, blue 189 19

Sand, fine, clam shells, WB 208 7

Sand, fine, and silt 215 33

Sand, fine, wood and clam shells 248 27

Clay and sand, blue 275 33

Clay and sand, fine, blue, clam shells 308 2

Sand and gravel, medium, loose, WB 310 25

Sand, coarse, and pea gravel, WB 335 >15

14N/11W-13A06 Loam, brown, sandy 0 7

Sand, gray 7 13

Silt and sand, gray 20 85

Sand, gray, fine 105 16

Silt and sand, gray 121 61

Silt, brown, sandy 182 13

Silt, brown 195 30

Sand, with fossils 225 8

Sand, gray 233 >7

14N/11W-13A07 Sand 0 30

Mud, tidal 30 159

Sandstone 189 7

Sand, coarse 196 >4

14N/11W-13A08 Topsoil 0 1

Sand, brown, wood 1 29

Sand, blue, wood and shells 30 90

Sand, blue, and shells 120 >122

Table 3. Lithologic data, as reported by water-well drillers, for selected wells in the Shoalwater Bay Indian Reservation and 

Tokeland Peninsula study area–Continued

Well No. Lithologic material

Top of layer (feet 

below land 

surface)

Thickness of 

layer (feet)
Tables 29

Table 4. Depth to tops of hydrogeologic units in selected wells in the Shoalwater Bay 

Indian Reservation and Tokeland Peninsula study area

[All measurements in feet; --, not encountered]

Well No.

Land 

surface 

altitude

Depth to top of hydrogeologic unit

Water-table Hole depth

aquifer

Semiconfining 

unit

Artesian 

aquifer

14N/10W-18C02 12 0 175 205 221

14N/10W-18C05 12 0 98 140 145

14N/10W-18C06 12 0 147 153 223

14N/10W-18D02D1 13.2 0 110 141 240

14N/10W-18D03 13 0 154 270 280

14N/11W-02C01 19.0 0 68 120 230

14N/11W-02C02 19.6 0 62 120 220

14N/11W-03F01 268.1 -- 0 399 425

14N/11W-03J01 14.2 0 36 143 224

14N/11W-03J02 12.3 0 19 138 161

14N/11W-11B01 12 0 98 160 220

14N/11W-11C01 12 0 23 188 198

14N/11W-11C04 13.5 0 93 184 281

14N/11W-11G02 15.4 0 44 182 193

14N/11W-11HO1D1 11 0 132 190 204

14N/11W-11R01 11.2 0 42 214 237

14N/11W-11R02 11 0 62 220 227

14N/11W-11R03 11 0 48 232 235

14N/11W-12M01 13.8 0 180 210 225

14N/11W-12M02 13 0 97 234 250

14N/11W-12P04 14.5 0 30 180 233

14N/11W-12R01 12 0 165 180 220

14N/11W-13A04 12.1 0 85 202 350

14N/11W-13A05 13.2 0 80 208 350

14N/11W-13A06 12.0 0 20 225 240

14N/11W-13A07 12 0 30 189 200
30 Hydrogeologic and Water-Quality Reconnaissance, Shoalwater Bay Indian Reservation and Tokeland Peninsula, Washington

Table 5. Water levels and water-level altitudes for selected wells in the Shoalwater Bay Indian Reservation and Tokeland 

Peninsula study area, September 1998 through August 1999–Continued

Well No. Date

Time 

(hours:

minutes)

Land 

surface 

altitude 

(feet)

Water 

level (feet 

above 

land 

surface)

Water 

altitude 

(feet above 

sea level)

Waterlevel 

status

Method of 

measure

-ment

Source of 

measurement

14N/10W-18C04 11-04-98 15:28 12.1 2.5 14.6 -- X USGS

11-18-98 09:57 1.9 14.0 -- X USGS

14N/10W-18D01 11-04-98 15:08 12.7 2.6 15.3 -- X USGS

11-18-98 10:27 1.8 14.5 -- X USGS

14N/10W-18D02D1 11-18-98 05:50 13.2 1.3 14.5 -- X USGS

06:40 1.8 15.0 -- X USGS

07:29 0.5 13.7 P X USGS

08:29 1.7 14.9 -- X USGS

09:10 2.1 15.3 -- X USGS

10:05 2.8 16.0 -- X USGS

11:00 3.4 16.6 -- X USGS

12:02 3.8 17.0 -- X USGS

12:53 3.7 16.9 -- X USGS

14:04 3.3 16.5 -- X USGS

15:05 2.5 15.7 -- X USGS

16:04 2.7 15.9 -- X USGS

16:52 2.2 15.4 -- X USGS

17:45 1.8 15.0 -- X USGS

19:17 1.4 14.6 -- X USGS

14N/11W-02C02 08-03-99 no data 19.6 0.5 20.1 -- T Driller

14N/11W-02P01 11-11-98 15:58 15.6 1.7 17.3 -- X USGS

11-18-98 12:35 1.7 17.3 -- X USGS

14N/11W-03F01 07-04-99 no data 268 -248 20 -- T Driller

14N/11W-03J02 11-04-98 16:08 12.3 3.9 16.2 -- X USGS

11-18-98 06:01 3.7 16.0 -- X USGS

07:14 3.7 16.0 -- X USGS

07:59 3.7 16.0 -- X USGS

08:55 3.8 16.1 -- X USGS

14N/11W-03J02 09:55 3.8 16.1 -- X USGS

Table 5. Water levels and water-level altitudes for selected wells in the Shoalwater Bay Indian Reservation and Tokeland 

Peninsula study area, September 1998 through August 1999 

[Water Level: Minus sign (–) indicates water level is below land surface. Water-Level Status: P, pumping; R, recently pumping; --, not affected by pumping. 

Method of Measurement: O, observed; S, steel tape; T, electrical tape; X, low head flowing tube. Source of Measurement: USGS, U.S. Geological Survey]
Tables 31

Continued 10:49 4.0 16.3 -- X USGS

11:52 4.3 16.6 -- X USGS

12:44 4.4 16.7 -- X USGS

13:31 4.2 16.5 -- X USGS

14:48 4.0 16.3 -- X USGS

15:43 3.9 16.2 -- X USGS

16:39 3.9 16.2 -- X USGS

17:27 3.8 16.1 -- X USGS

18:27 3.8 16.1 -- X USGS

19:44 3.7 16.0 -- X USGS

14N/11W-11C03 11-04-98 12:00 11.9 4.8 16.7 -- X USGS

11-18-98 13:40 4.9 16.8 -- X USGS

14N/11W-11C04 11-04-98 16:24 13.5 4.3 17.8 -- X USGS

11-18-98 12:03 4.2 17.7 -- X USGS

14N/11W-11F01 11-04-98 11:40 12.3 5.5 17.8 -- X USGS

11-18-98 05:54 4.4 16.7 -- X USGS

07:09 4.2 16.5 -- X USGS

07:52 4.1 16.4 -- X USGS

08:49 4.2 16.5 -- X USGS

09:48 4.5 16.8 -- X USGS

10:38 4.8 17.1 -- X USGS

11:39 5.0 17.3 -- X USGS

12:35 5.0 17.3 -- X USGS

13:24 4.9 17.2 -- X USGS

14:32 4.6 16.9 -- X USGS

15.29 4.4 16.7 -- X USGS

16:30 4.3 16.6 -- X USGS

17:17 4.2 16.5 -- X USGS

18:21 4.1 16.4 -- X USGS

19:52 4.0 16.3 -- X USGS

14N/11W-11G02 11-18-98 13:08 15.4 1.9 17.3 -- X USGS

14N/11W-11R01 11-18-98 06:12 11.2 4.7 15.9 -- X USGS

Table 5. Water levels and water-level altitudes for selected wells in the Shoalwater Bay Indian Reservation and Tokeland 

Peninsula study area, September 1998 through August 1999–Continued

Well No. Date

Time 

(hours:

minutes)

Land 

surface 

altitude 

(feet)

Water 

level (feet 

above 

land 

surface)

Water 

altitude 

(feet above 

sea level)

Waterlevel 

status

Method of 

measure

-ment

Source of 

measurement
32 Hydrogeologic and Water-Quality Reconnaissance, Shoalwater Bay Indian Reservation and Tokeland Peninsula, Washington

07:04 2.4 13.6 R X USGS

07:47 4.6 15.8 -- X USGS

08:43 4.8 16.0 -- X USGS

09:41 5.1 16.3 -- X USGS

10:31 5.1 16.3 -- X USGS

11:32 5.1 16.3 -- X USGS

12:27 5.0 16.2 -- X USGS

13:17 5.0 16.2 -- X USGS

14:24 5.1 16.3 -- X USGS

15:24 5.1 16.3 -- X USGS

16:24 4.9 16.1 -- X USGS

17:08 4.7 15.9 -- X USGS

18:15 4.4 15.6 -- X USGS

19:36 4.1 15.3 -- X USGS

14N/11W-12L01 11-18-98 06:19 12.2 4.4 16.6 -- X USGS

06:53 4.3 16.5 -- X USGS

07:42 4.3 16.5 -- X USGS

08:38 4.4 16.6 -- X USGS

09:34 4.6 16.8 -- X USGS

10:16 -- -- P O USGS

11:10 5.1 17.3 -- X USGS

12:15 5.4 17.6 -- X USGS

13:06 5.4 17.6 -- X USGS

14:19 5.2 17.4 -- X USGS

14N/11W-12L01 11-18-98 15:17 12.2 4.9 17.1 -- X USGS

16:16 4.7 16.9 -- X USGS

17:02 4.5 16.7 -- X USGS

18:09 4.3 16.5 -- X USGS

19:28 4.1 16.3 -- X USGS

14N/11W-12M01 09-22-98 no data 13.8 1.7 15.5 -- S USGS

11-18-98 11:35 1.5 15.3 -- S USGS

14N/11W-12P04 09-23-98 17:55 14.5 1.7 16.2 -- S USGS

Table 5. Water levels and water-level altitudes for selected wells in the Shoalwater Bay Indian Reservation and Tokeland 

Peninsula study area, September 1998 through August 1999–Continued

Well No. Date

Time 

(hours:

minutes)

Land 

surface 

altitude 

(feet)

Water 

level (feet 

above 

land 

surface)

Water 

altitude 

(feet above 

sea level)

Waterlevel 

status

Method of 

measure

-ment

Source of 

measurement
Tables 33

14N/11W-13A05 11-04-98 12:40 13.2 4.1 17.3 -- X USGS

11-18-98 06:00 1.6 14.8 -- X USGS

06:45 1.4 14.6 -- X USGS

07:35 0.9 14.1 -- X USGS

08:32 1.2 14.4 -- X USGS

09:27 1.8 15.0 -- X USGS

10:10 2.2 15.4 -- X USGS

11:08 3.0 16.2 -- X USGS

12:07 3.4 16.6 -- X USGS

12:57 3.2 16.4 -- X USGS

14:05 2.5 15.7 -- X USGS

15:10 2.0 15.2 -- X USGS

16:10 1.4 14.6 -- X USGS

16:55 1.2 14.4 -- X USGS

18:03 0.7 13.9 -- X USGS

19:21 0.5 13.7 -- X USGS

14N/11W-13A06 11-04-98 15:40 12.0 2.1 14.1 -- X USGS

11-18-98 14:12 2.9 14.9 -- X USGS

Table 5. Water levels and water-level altitudes for selected wells in the Shoalwater Bay Indian Reservation and Tokeland 

Peninsula study area, September 1998 through August 1999–Continued

Well No. Date

Time 

(hours:

minutes)

Land 

surface 

altitude 

(feet)

Water 

level (feet 

above 

land 

surface)

Water 

altitude 

(feet above 

sea level)

Waterlevel 

status

Method of 

measure

-ment

Source of 

measurement
34 Hydrogeologic and Water-Quality Reconnaissance, Shoalwater Bay Indian Reservation and Tokeland Peninsula, Washington

Table 6. Values of field measurements in ground-water samples from the Shoalwater Bay Indian Reservation and Tokeland 

Peninsula study area

[Temperature reported in degrees Celsius; specific electrical conductance reported in microsiemens per centimeter at 25 degrees Celsius; pH reported in 

standard units; all other concentrations reported as milligrams per liter; <, less than]

Well No. Date

Open interval 

(feet below land 

surface)

Temperature 

of water

Specific 

conductance pH

14N/10W-18D01 12-16-98 198 - 200 13.0 257 7.5

14N/11W-02C02 08-30-99 210 - 220 10.5 201 8.1

14N/11W-03F01 09-14-99 408 - 423 10.0 166 7.6

14N/11W-03J01 12-16-98 206 - 208 10.0 156 7.5

14N/11W-11C04 12-17-98 276 - 281 11.0 157 8.0

14N/11W-11F01 12-14-98 1290 11.0 158 8.0

14N/11W-11G02 12-15-98 2193 11.5 189 7.8

14N/11W-11R01 12-15-98 232 - 237 12.5 171 8.0

14N/11W-12P04 12-18-98 220 - 230 11.5 188 8.3

14N/11W-13A05 12-17-98 335 - 350 13.0 147 8.5

Well No. Alkalinity (mg/L 

as CaCO3)

Bicarbonate 

(mg/L as 

HCO3)

Carbonate 

(mg/L as 

CO3)

Dissolved oxygen 

(mg/L)

14N/10W-18D01 120 147 0 0.1

14N/11W-02C02 67 82 0 <0.1

14N/11W-03F01 49 60 0 8.2

14N/11W-03J01 55 67 0 7.4

14N/11W-11C04 58 71 0 1.7

14N/11W-11F01 79 96 0 <0.1

14N/11W-11G02 74 90 0 <0.1

14N/11W-11R01 66 80 0 1.2

14N/11W-12P04 71 83 0 <0.1

14N/11W-13A05 54 63 0 <0.1

1 Depth of well, open interval not known.

2 Well open at bottom of casing only.
Tables 35

Table 7. Concentrations of major inorganic ions in ground-water samples from the Shoalwater Bay Indian Reservation and 

Tokeland Peninsula study area

[All concentrations reported in milligrams per liter; <, less than]

Well No. Date

Open interval (feet 

below land 

surface)

Calcium Chloride Fluoride Hardness

14N/10W-18D01 12-16-98 198 - 200 25 11 0.3 95

14N/11W-02C02 08-30-99 210 - 220 21 15 <0.1 73

14N/11W-03F01 09-14-99 408 - 423 11 20 <0.1 48

14N/11W-03J01 12-16-98 206 - 208 11 17 0.1 49

14N/11W-11C04 12-17-98 276 - 281 14 12 <0.1 56

14N/11W-11F01 12-14-98 1290 14 11 <0.1 59

14N/11W-11G02 12-15-98 2193 19 10 0.1 72

14N/11W-11R01 12-15-98 232 - 237 15 10 0.1 62

14N/11W-12P04 12-18-98 220 - 230 26 11 <0.1 74

14N/11W-13A05 12-17-98 335 - 350 16 8.8 <0.1 54

Well No. Magnesium Potassium Silica Sodium Sulfate

14N/10W-18D01 8.2 3.2 44 18 5.0

14N/11W-02C02 5.0 2.2 36 10 4.9

14N/11W-03F01 4.7 0.9 30 14 3.1

14N/11W-03J01 5.1 1.0 34 12 2.2

14N/11W-11C04 5.5 1.1 30 9.4 4.7

14N/11W-11F01 5.6 1.2 27 9.5 5.0

14N/11W-11G02 6.1 2.6 32 10 8.0

14N/11W-11R01 5.7 1.8 34 10 4.3

14N/11W-12P04 1.9 2.0 34 8.2 9.8

14N/11W-13A05 3.3 1.5 30 6.9 6.9

1 Depth of well, open interval not known.

2 Well open at bottom of casing only.
36 Hydrogeologic and Water-Quality Reconnaissance, Shoalwater Bay Indian Reservation and Tokeland Peninsula, Washington

Table 8. Concentrations of selected metals in ground-water samples from the Shoalwater Bay Indian Reservation and 

Tokeland Peninsula study area

Well No. Date

Open interval 

(feet below land 

surface)

Aluminum Antimony Arsenic Barium

14N-10W-18D01 12-16-98 198 - 200 -- -- -- --

14N/11W-02C02 08-30-99 210 - 220 2 <1 9 <1

14N/11W-03F01 09-14-99 408 - 423 3 <1 <1 <1

14N/11W-03J01 12-16-98 206 - 208 <1 <1 1 <1

14N/11W-11C04 12-17-98 276 - 281 -- -- -- --

14N/11W-11F01 12-14-98 1290 <1 <1 5 <1

14N/11W-11G02 12-15-98 2193 -- -- -- --

14N/11W-11R01 12-15-98 232 - 237 -- -- -- --

14N/11W-12P04 12-18-98 220 - 230 3 <1 2 1

14N/11W-13A05 12-17-98 335 - 350 -- -- -- --

Well No. Beryllium Cadmium Chromium Cobalt Copper

14N/10W-18D01 -- -- -- -- --

14N/11W-02C02 <1 <1 <1 <1 <1

14N/11W-03F01 <1 <1 <1 <1 <1

14N/11W-03J01 <1 <1 5 <1 <1

14N/11W-11C04 -- -- -- -- --

14N/11W-11F01 <1 <1 1 <1 <1

14N/11W-11G02 -- -- -- -- --

14N/11W-11R01 -- -- -- -- --

14N/11W-12P04 <1 <1 <1 <1 <1

14N/11W-13A05 -- -- -- -- --

Well No. Iron Lead Manganese Molybdenum Nickel

14N/10W-18D01 240 -- 3150 -- --

14N/11W-02C02 98 <1 443 1 <1

14N/11W-03F01 31 <1 443 <1 <1

14N/11W-03J01 <10 <1 4<1 <1 <1

14N/11W-11C04 <10 -- 3<3 -- --

14N/11W-11F01 24 <1 420 <1 <1

14N/11W-11G02 320 -- 383 -- --

14N/11W-11R01 280 -- 359 -- --

14N/11W-12P04 56 <1 464 <1 <1

14N/11W-13A05 43 -- 321 -- --

Table 8. Concentrations of selected metals in ground-water samples from the Shoalwater Bay Indian Reservation and 

Tokeland Peninsula study area

[Αll concentrations reported in micrograms per liter; all samples were filtered through a 0.45-micrometer pore filter; <, less than; --, not analyzed]
Tables 37

Table 8. Concentrations of selected metals in ground-water samples from the Shoalwater 

Bay Indian Reservation and Tokeland Peninsula study area—Continued

Well No. Selenium Silver Uranium Zinc

14N/10W-18D01 -- -- -- --

14N/11W-02C02 <1 <1 <1 2

14N/11W-03F01 <1 <1 <1 7

14N/11W-03J01 <1 <1 <1 10

14N/11W-11C04 -- -- -- --

14N/11W-11F01 <1 <1 <1 4

14N/11W-11G02 -- -- -- --

14N/11W-11R01 -- -- -- --

14N/11W-12P04 <1 <1 <1 2

14N/11W-13A05 -- -- -- --

1 Depth of well, open interval not known.

2 Well open at bottom of casing only. 3 Inductively-coupled plasma method, reporting level of 3 micrograms per liter. 4 Inductively-coupled plasma/mass spectrometry method, reporting level 1 microgram per liter.
38 Hydrogeologic and Water-Quality Reconnaissance, Shoalwater Bay Indian Reservation and Tokeland Peninsula, Washington

Table 9. Concentrations of selected nutrients and methylene blue-active substances in ground-water samples from the 

Shoalwater Bay Indian Reservation and Tokeland Peninsula study area

[Concentrations reported in milligrams per liter; all samples were filtered through a 0.45-micrometer pore filter; <, less than; e, estimated value (constituent 

qualitatively identified)]

Well No. Date

Open 

interval (feet 

below land 

surface)

Concentrations reported as N

Orthophosphorus, 

as P

Methylene 

blue-active 

Ammonia Nitrite substances

Ammonia 

plus 

organic 

nitrogen

Nitrite 

plus 

nitrate

14N-10W-18D01 12-16-98 198 - 200 0.19 0.01 0.2 <0.05 0.15 <0.02

14N/11W-02C02 08-30-99 210 - 220 <0.02 <0.01 e<0.05 <0.05 0.25 <0.02

14N/11W-03F01 09-14-99 408 - 423 <0.02 <0.01 <0.1 0.22 0.10 0.04

14N/11W-03J01 12-16-98 206 - 208 0.02 <0.01 0.1 0.10 0.12 .--

14N/11W-11C04 12-17-98 276 - 281 0.02 <0.01 <0.1 0.07 0.13 <0.02

14N/11W-11F01 12-14-98 1290 0.04 0.02 <0.1 0.06 0.17 <0.02

14N/11W-11G02 12-15-98 2193 0.16 0.02 0.1 <0.05 0.49 <0.02

14N/11W-11R01 12-15-98 232 - 237 0.77 0.01 0.7 <0.05 0.43 <0.02

14N/11W-12P04 12-18-98 220 - 230 0.03 <0.01 <0.1 <0.05 0.09 <0.02

14N/11W-13A05 12-17-98 335 - 350 0.03 <0.01 <0.1 <0.05 0.07 <0.02

1 Depth of well, open interval not known.

2 Well open at bottom of casing only.
Tables 39

Table 10 Concentrations of selected pesticides in ground-water samples from the Shoalwater Bay Indian Reservation and 

Tokeland Peninsula study area–Continued

Well No. Date

Open interval 

(feet below land 

surface)

Acetochlor Alachlor Atrazine Azinphosmethyl

14N/10W-18D01 12-16 -98 198 - 200 .-- .-- .-- .--

14N/11W-02C02 08-30-99 210 - 220 <0.002 <0.002 <0.001 <0.001

14N/11W-03F01 09-14-99 408 - 423 <0.002 <0.002 <0.001 <0.001

14N/11W-03J01 12-16-98 206 - 208 <0.002 <0.002 <0.001 <0.001

14N/11W-11C04 12-17-98 276 - 281 .-- .-- .-- .--

14N/11W-11F01 12-14-98 1290 .-- .-- .-- .--

14N/11W-11G02 12-15-98 2193 .-- .-- .-- .--

14N/11W-11R01 12-15-98 232 - 237 .-- .-- .-- .--

14N/11W-12P04 12-18-98 220 - 230 <0.002 <0.002 <0.001 <0.001

14N/11W-13A05 12-17-98 335 - 350 .-- .-- .-- .--

Well No. Benfluralin Butylate Carbaryl Carbofuran Chlorpyrifos

14N/10W-18D01 .-- .-- .-- .-- .--

14N/11W-02C02 <0.002 <0.002 <0.003 <0.003 <0.004

14N/11W-03F01 <0.002 <0.002 <0.003 <0.003 <0.004

14N/11W-03J01 <0.002 <0.002 <0.003 <0.003 <0.004

14N/11W-11C04 .-- .-- .-- .-- .--

14N/11W-11F01 .-- .-- .-- .-- .--

14N/11W-11G02. .-- .-- .-- .-- .--

14N/11W-11R01 .-- .-- .-- .-- .--

14N/11W-12P04 <0.002 <0.002 <0.003 <0.003 <0.004

14N/11W-13A05 .-- .-- .-- .-- .--

Well No. Cyanazine DCPA p,p’-DDE Deethylatrazine Diazinon

14N/10W-18D01 .-- .-- .-- .-- .--

14N/11W-02C02 <0.004 <0.002 <0.006 <0.002 <0.002

14N/11W-03F01 <0.004 <0.002 <0.006 <0.002 <0.002

14N/11W-03J01 <0.004 <0.002 <0.006 <0.002 <0.002

14N/11W-11C04 .-- .-- .-- .-- .--

14N/11W-11F01 .-- .-- .-- .-- .--

14N/11W-11G02 .-- .-- .-- .-- .--

14N/11W-11R01 .-- .-- .-- .-- .--

14N/11W-12P04 <0.004 <0.002 <0.006 <0.002 <0.002

14N/11W-13A05 .-- .-- .-- .-- .--

Table 10. Concentrations of selected pesticides in ground-water samples from the Shoalwater Bay Indian Reservation and 

Tokeland Peninsula study area

[Αll values reported in micrograms per liter except for methylene blue-active substances, which are reported in milligrams per liter; all samples for analysis of 

pesticides except for those in Schedule 79 (see table A3) are filtered through a 0.7-micrometer filter; <, less than; --, not analyzed]
40 Hydrogeologic and Water-Quality Reconnaissance, Shoalwater Bay Indian Reservation and Tokeland Peninsula, Washington

Table 10. Concentrations of selected pesticides in ground-water samples from the Shoalwater Bay Indian Reservation and 

Tokeland Peninsula study area–Continued

Well No. Dicamba Dichlorprop Dieldrin Disulfoton EPTC

14N/10W-18D01 .-- .-- .-- .-- --

14N/11W-02C02 <0.01 <0.01 <0.001 <0.017 <0.002

14N/11W-03F01 <0.01 <0.01 <0.001 <0.017 <0.002

14N/11W-03J01 <0.01 <0.01 <0.001 <0.017 <0.002

14N/11W-11C04 .-- .-- .-- .-- --

14N/11W-11F01 <0.01 <0.01 .-- .-- .--

14N/11W-11G02 .-- .-- .-- .-- .--.

14N/11W-11R01 .-- .-- .-- .-- .--

14N/11W-12P04 <0.01 <0.01 <0.001 <0.017 <0.002

14N/11W-13A05 .-- .-- .-- .-- .--

Well No. Ethalfuralin Ethoprophos Fonofos alpha-HCH gamma-HCH

14N/10W-18D01 .-- .-- ..-- .-- .--

14N/11W-02C02 <0.004 <0.003 <0.003 <0.002 <0.004

14N/11W-03F01 <0.004 <0.003 <0.003 <0.002 <0.004

14N/11W-03J01 <0.004 <0.003 <0.003 <0.002 <0.004

14N/11W-11C04 .-- .-- ..-- ..-- .--

14N/11W-11F01 -- .-- ..-- ..-- .--.

14N/11W-11G02 .-- -- ..-- ..-- .--.

14N/11W-1R01 .-- .-- ..-- ..-- .--

14N/11W-12P04 <0.004 <0.003 <0.003 <0.002 <0.004

14N/11W-13A05 .-- .-- .-- .-- .--

Well No. Linuron Malathion Methylparathion Metolachlor Metribuzin

14N/10W-18D01 .-- .-- .-- .-- .--

14N/11W-02C02 <0.002 <0.005 <0.006 <0.002 <0.004

14N/11W-03F01 <0.002 <0.005 <0.006 <0.002 <0.004

14N/11W-03J01 <0.002 <0.005 <0.006 <0.002 <0.004

14N/11W-11C04 .-- .-- .-- .-- .--

14N/11W-11F01 .-- .-- .-- .-- .--

14N/11W-11G02 .-- .-- .-- .-- .--

14N/11W-11R01 .-- .-- .-- .-- .--

14N/11W-12P04 <0.002 <0.005 <0.006 <0.002 <0.004

14N/11W-13A05 .-- .-- .-- .-- .--
Tables 41

Table 10. Concentrations of selected pesticides in ground-water samples from the Shoalwater Bay Indian Reservation and 

Tokeland Peninsula study area–Continued

Well No. Molinate Napropamide Parathion Pebulate Pendimethalin

14N/10W-18D01 .-- ..-- .-- .-- .--

14N/11W-02C02 <0.004 <0.003 <0.004 <0.004 <0.004

14N/11W-03F01 <0.004 <0.003 <0.004 <0.004 <0.004

14N/11W-03J01 <0.004 <0.003 <0.004 <0.004 <0.004

14N/11W-11C04 .-- .-- .-- .-- .--

14N/11W-11F01 .-- .-- .-- .-- .--

14N/11W-11G02 .-- .-- .-- .-- .--

14N/11W-11R01 .-- .-- .-- .-- .--

14N/11W-12P04 <0.004 <0.003 <0.004 <0.004 <0.004

14N/11W-13A05 .-- .-- .-- .-- .--

Well No. cisPermethrin Phorate Picloram Prometon Propargite

14N/10W-18D01 .-- .-- -- .-- --

14N/11W-02C02 <0.005 <0.002 <0.01 <0.018 <0.013

14N/11W-03F01 <0.005 <0.002 <0.01 <0.018 <0.013

14N/11W-03J01 <0.005 <0.002 <0.01 <0.018 <0.013

14N/11W-11C04 .-- .-- .-- .-- .--

14N/11W-11F01 .-- .-- <0.01 .-- .--

14N/11W-11G02 .-- .-- .-- .-- --

14N/11W-11R01 .-- .-- .-- .-- --

14N/11W-12P04 <0.005 <0.002 <0.01 <0.018 <0.013

14N/11W-13A05 .-- .-- .-- .-- .--

Well No. Propachlor Propanil Propyzamide Simazine Tebuthiuron

14N/10W-18D01 .-- .--. .-- .-- .--

14N/11W-02C02 <0.007 <0.004 <0.003 <0.005 <0.01

14N/11W-03F01 <0.007 <0.004 <0.003 <0.005 <0.01

14N/11W-03J01 <0.007 <0.004 <0.003 <0.005 <0.01

14N/11W-11C04 .-- .--. .-- .-- .--

14N/11W-11F01 ..-- .-- .--. .-- .--

14N/11W-11G02 ..-- .-- .--. .-- .--

14N/11W-11R01 ..-- .-- .--. .-- .--

14N/11W-12P04 <0.007 <0.003 <0.003 <0.005 <0.01

14N/11W-13A05 ..-- .-- .-- .-- .--
42 Hydrogeologic and Water-Quality Reconnaissance, Shoalwater Bay Indian Reservation and Tokeland Peninsula, Washington

Table 10. Concentrations of selected pesticides in ground-water samples from the Shoalwater Bay Indian Reservation and 

Tokeland Peninsula study area–Continued

Well No. Terbacil Terbufos Thiobencarb Triallate Trifluralin

14N/10W-18D01 .-- .-- .-- .-- .--

14N/11W-02C02 <0.007 <0.013 <0.002 <0.001 <0.002

14N/11W-03F01 <0.007 <0.013 <0.002 <0.001 <0.002

14N/11W-03J01 <0.007 <0.013 <0.002 <0.001 <0.002

14N/11W-11C04 .-- .-- .-- .-- .--

14N/11W-11F01 . -- .. -- .. -- . -- .--

14N/11W-11G02 . -- . .-- . -- . -- .--

14N/11W-11R01 . -- . .-- . -- . -- .--

14N/11W-12P04 <0.007 <0.013 <0.002 <0.001 <0.002

14N/11W-13A05 . -- .-- . -- . -- .--

Well No. 2,4,-D 2,4,5-T

2-(2,4,5-Tri-) 

chlorophenoxy

propionic acid

2,6-Diethylanaline

14N/10W-18D01 .-- ..-- .-- .--

14N/11W-02C02 <0.01 <0.01 <0.01 <0.003

14N/11W-03F01 <0.01 <0.01 <0.01 <0.003

14N/11W-03J01 <0.01 <0.01 <0.01 <0.003

14N/11W-11C04 .-- .-- .-- .--

14N/11W-11F01 .-- <0.01 .-- .--

14N/11W-11G02 .-- .-- .-- .--

14N/11W-11R01 .-- .-- .-- .--

14N/11W-12P04 <0.01 <0.01 <0.01 <0.003

14N/11W-13A05 .-- .-- .-- --

1 Depth of well, open interval not known.

2 Well open at bottom of casing only.
Appendix A. Water-Quality Methods 43

APPENDIX A. Water-Quality Methods
Appendix A. Water-Quality Methods 44

APPENDIX A. WATER-QUALITY METHODS

Field Methods

All equipment used to collect and process 

samples was cleaned with a 0.2-percent non-phosphate 

detergent, rinsed with deionized water, rinsed with 

pesticide-grade methanol, wrapped in aluminum foil, 

and stored in a dust-free environment prior to, and 

between, sample collection (Shelton, 1994). Wells 

were purged to remove at least three casing volumes of 

water and were sampled when monitored values of pH, 

specific conductance, temperature, and dissolved 

oxygen (DO) were within the allowable differences, as 

specified by Koterba and others (1995). For domestic 

wells, sampling points were located ahead of any water 

treatment, pressure tanks, or holding tanks. Wetted 

surfaces of sampling lines and plumbing fixtures were 

made of polytetraflouroethylene (Teflon) or stainless 

steel, including the submersible pump and lines used to 

sample several wells. One public-supply well with a 

pump suitable for producing samples of acceptable 

quality was sampled as described by Koterba and 

others (1995). 

Water temperature, DO, specific electrical 

conductance, and pH were measured in the field using 

a flow-through chamber so that measurements were 

made prior to contact between sample water and the 

atmosphere. Alkalinity, bicarbonate, and carbonate 

concentrations were measured using water filtered 

through a polypropylene-encapsulated filter with a pore 

size of 0.45 micrometer (μm). Reporting limits and 

USEPA standards for field properties are listed in 

table A1.

Water samples to be analyzed for major 

inorganic ions, metals, and nutrients were filtered 

through a polypropylene-encapsulated filter with a pore 

size of 0.45 μm. Samples to be analyzed for cations or 

metals were preserved with nitric acid. Nutrient 

samples were stored at less than 4 degrees Celsius (oC) 

for shipment to the National Water Quality Laboratory 

(NWQL). Reporting limits and USEPA drinking water 

standards for major inorganic ions, metals, and 

nutrients are listed in table A1; methods and references 

are listed in table A2. (All tables are located at the end 

of the appendix.)

The NWQL analyzed samples of ground water 

for pesticides using either the gas-chromatograph/ 

electron capture (GC/EC) or the gas-chromatograph/ 

mass spectrometry (GC/MS) method, depending on the 

physical characteristics of the pesticide being analyzed 

for. The GC/EC method uses unfiltered samples, 

whereas the GC/MS method uses samples that have 

been filtered through a 0.7 μm pore-size filter. 

Samples to be used in either method were kept at less 

than 4oC prior to the analysis. Additional details on the 

equipment and procedures used to collect and process 

samples are given in Shelton (1994), Koterba and 

others (1995), and in Sandstrom and others (1992). 

Analytical methods and references for pesticides and 

methylene blue-active substances (MBAS) are listed in 

table A1; reporting limits and drinking water standards 

for pesticides are given in table A3.
Appendix A. Water-Quality Methods 45

Quality Assurance

About 15 percent of all samples submitted to the 

laboratory were quality-control samples, which 

included field blanks or equipment blanks used to 

measure possible contamination and bias and replicate 

samples used to measure variability. All samples were 

spiked with surrogate analytes prior to extraction, to 

monitor the accuracy and precision of the analytical 

procedures. For definitions of these quality-control 

samples, see Shelton (1994). Additionally, qualitycontrol samples such as laboratory blanks, internal 

standards, and reagent spikes were routinely analyzed 

as part of the laboratory quality-assurance plan 

described by Pritt and Raese (1995).

Quality Control

 Equipment blanks, composed of analyte-free 

water passed through the sampling filtration equipment 

prior to sampling ground water and were processed and 

submitted for analysis. The equipment-blank samples 

contained low-level detections of several nutrients, 

major ions, and trace metals (table A4). Concentrations 

of orthophosphate and nitrite-plus-nitrate were 

detected in the equipment blank at 0.001 and 

0.005 mg/L, respectively, which is 10 times lower than 

the limit of detection used for the regular analysis of 

orthophosphate in environmental samples and twice as 

low as the limit of detection for the regular analysis of 

nitrite-plus-nitrate in environmental samples. Calcium 

was detected in the equipment blank at 0.004 mg/L, 

which is nearly five times lower than the limit of 

detection for analysis in regular environmental 

samples. Copper and manganese also were detected in 

the equipment blank, at concentrations of 0.81 and 

0.31 μg/L, which is less than the detection limit of 

1 μg/L for the analysis of regular environmental 

samples; but concentrations of zinc were detected in 

the equipment blank at 2.9 μg/L, which is nearly three 

times the detection limit of 1 μg/L. No alteration of the 

data set was made based on these results, although it 

should be noted that results for zinc in environmental 

samples may be biased high.

Precision data were obtained for sets of replicate 

samples (table A5). Concentration differences ranged 

from 0.0 to 49.6 percent as measured by relative 

percent difference. No modifications were made to the 

data set based on these results. Approximately 

75 percent of laboratory-reagent spike samples (table 

A6) were within the range of 80 to 160 percent, which 

is generally acceptable for data interpretation; several 

compounds routinely demonstrated variable 

performance because of problems in the GC/MS 

procedure. Because of the poor or variable recoveries 

of these compounds, they are reported with an “e” code 

(estimated value) to qualify the result. 
Appendix Tables 46

Table A1. Method reporting limit and drinking water standards for field properties, nutrients, major ions, and 

metals

[MRL, method reporting limit; MCL, maximum contaminant level (U.S. Environmental Protection Agency, 1996); N, nitrogen; P, 

phosphorous; +, plus; +, plus or minus; na, not applicable; mg/L, milligrams per liter; >, greater than or equal to; <, less than; μS/cm, 

microsiemens per centimeter at 25 degrees Celsius; μg/L, micrograms per liter; ICP, inductively-coupled plasma; MS, mass 

spectrometry]

Analyte or schedule

Chemical 

Abstracts Service 

registry number

MRL (mg/L, unless 

otherwise noted)

MCL (mg/L, 

unless otherwise 

noted)

Field properties

Alkalinity 471-34-1 1+1 mg/L

Dissolved oxygen na 1+ 0.3 mg/L

pH, units na 1+ 0.1 unit of pH 26.5-8.5

Specific conductance na 1+ 5 percent when sample is 

> >100 μS/cm

+3 percent when sample is 

 < 100 μS/cm

Temperature, degrees Celsius na 1+ 0.2 degree Celsius

Nutrients

Ammonia, as N 7664-41-7 0.02 None

Ammonia + organic nitrogen, as N 17778-88-0 0.1 None

Nitrite, as N 14797-65-0 0.01 1

Nitrite + nitrate, as N na 0.05 10

Orthophosphorus, as P 14265-44-2 0.01 None

Major ions and metals

Aluminum, μg/L 7429-90-5 1 250-200

Antimony, μg/L 7440-36-0 1 6

Arsenic, μg/L 7440-38-2 1 50

Barium, μg/L 7440-39-3 1 2,000

Beryllium, μg/L 7440-41-7 1 4

Cadmium, μg/L 7440-43-9 1 5

Calcium 7440-70-2 0.02 None

Chloride 16887-00-6 0.1 2250

Chromium, μg/L 7440-47-3 1 100

Colbalt, μg/L 7440-48-4 1 None

Copper, μg/L 7440-50-8 1 31,300

Fluoride 16984-48-8 0.1 4

Iron, μg/L 7439-89-6 10.0 2300

Lead, μg/L 7439-92-1 1 315

Magnesium 7439-95-4 0.004 None

Manganese, μg/L 7439-96-5 3.0 (ICP) 250

1.0 (ICP/MS)

Molybdenum, μg/L 7439-98-7 1 None

Nickel, μg/L 7440-02-0 1 100

Potassium 7440-09-7 0.100 None

Selenium, μg/L 7782-49-2 1 50

Silica 7631-86-9 0.05 None

Silver, μg/L 7440-22-4 1 2100

Sodium 7440-23-5 0.06 None

Sulfate 14808-79-8 0.100 2250

Uranium, μg/L 7440-61-1 1 420

Zinc, μg/L 7440-66-6 1 25,000

1 Precision of instruments or measurement.

2 Secondary maximum contaminant level (U.S. Environmental Protection Agency, 1996). 3 Action level, which requires treatment if exceeded (U.S. Environmental Protection Agency, 1995). 4 Proposed.
47 Hydrogeologic and Water-Quality Reconnaissance, Shoalwater Bay Indian Reservation and Tokeland Peninsula, Washington

Table A2. Inorganic and organic analytes and schedules, analytical methods, and references

[ICP/MS, inductively-coupled plasma/mass spectrometry; ISE, ion-selective electrode; SPE, solid-phase extraction; GC/MS, gas-chromatography with 

detection by mass spectrometry; GC, gas-chromatography; GFAA, graphite furance, atomic absorption; IC, ion-chromatography; ASF, automated segmented 

flow; AA, atomic absorption]

Analyte or schedule Analytical method Reference

Inorganic Compounds

Nutrients

Ammonia Colorimetry, salicylate-hypochlorite Fishman, 1993

Ammonia + organic nitrogen Colorimetry, microkjeldahl digestion Patton and Truitt, 1992

Nitrite Colorimetry, diazotization Fishman, 1993

Nitrite + nitrate Colorimetry, cadmium reduction-diazotization Fishman, 1993

Orthophosphorus Colorimetry, phosphomolybdate Fishman, 1993

Major ions and Metals

Aluminum ICP/MS Faires, 1993

Antimony ICP/MS Faires, 1993

Arsenic GFAA Jones and Garbarino, 1999

Barium ICP/MS Faires, 1993

Beryllium ICP/MS Faires, 1993

Cadmium ICP/MS Faires, 1993

Calcium ICP Fishman, 1993

Chloride IC Fishman and Friedman, 1989

Chromium ICP/MS Faires, 1993

Cobalt ICP/MS Faires, 1993

Copper ICP/MS Faires, 1993

Fluoride Colorimetry, ASF ISE Fishman and Friedman, 1989

Iron ICP Fishman, 1993

Lead ICP/MS Faires, 1993

Magnesium ICP Fishman, 1993

Manganese ICP/MS Faires, 1993

ICP Fishman, 1993

Molybdenum ICP/MS Fishman, 1993

Nickel ICP/MS Fishman, 1993

Potassium AA, flame Fishman and Friedman, 1989

Selenium GFAA Jones and Garbarino, 1999

Silica Colorimetry, ASF, molybdate blue Fishman and Friedman, 1989

Silver ICP/MS Faires, 1993

Sodium ICP Fishman, 1993

Sulfate IC Fishman and Friedman, 1989

Uranium (natural) ICP/MS Faires, 1993

Zinc ICP/MS Faires, 1993

Organic Compounds

Pesticides

Schedule 2010 SPE technology and GC/MS Zaugg and others, 1995

Schedule 79 Whole-water extraction and GC with electron Wershaw and others, 1987 

 capture detection

Other organic determinations

Methylene blue-active substances Colorometric spectrophotometry Burkhardt and others, 1995
Appendix Tables 48

Table A3. Pesticide analytes, method detection limits, drinking water standards, and health advisories–Continued

Pesticide target 

analyte

Trade or common 

name(s)

Type of 

pesticide

Chemical Abstracts 

Service registry number

Method detection 

limit (μg/L)

MCL, HA-L, or 

RSD (μg/L)

Gas chromatography/mass spectrometry analytical method (Schedule 2010)

Acetochlor Acenit, Sacenid H 34256-82-1 0.002 --

Alachlor Lasso H 15972-60-8 0.002 2

Atrazine AAtrex H 1912-24-9 0.001 3

Azinphos-methyl1 Guthion I 86-50-0 0.001 --

Benfluralin Balan, Benefin H 1861-40-1 0.002 --

Butylate Sutan +, Genate Plus H 2008-41-5 0.002 350

Carbaryl1 Sevin, Savit I 63-25-2 0.003 700

Carbofuran1 Furadan I 1563-66-2 0.003 40

Chlorpyrifos Lorsban I 2921-88-2 0.004 20

Cyanazine Bladex H 21725-46-2 0.004 1

DCPA Dacthal H 1861-32-1 0.002 4,000

p,p’-DDE none T 72-55-9 0.006 0.1

Deethylatrazine1 none T 6190-65-4 0.002 --

Diazinon several I 333-41-5 0.002 0.6

Dieldrin Panoram D-31 I 60-57-1 0.001 0.002

2,6-Diethylanaline none T 579-66-8 0.003 --

Disulfoton Di-Syston I 298-04-4 0.017 0.3

EPTC Eptam, Eradicane H 759-94-4 0.002 --

Ethalfluralin Sonalan, Curbit EC H 55283-68-6 0.004 --

Ethoprophos Mocap I 13194-48-4 0.003 --

Fonofos Dyfonate I 944-22-9 0.003 10

alpha-HCH none T 319-84-6 0.002 0.006

gamma-HCH Lindane I 58-89-9 0.004 0.2

Linuron Lorox, Linex H 330-55-2 0.002 --

Malathion several I 121-75-5 0.005 200

Methyl parathion Penncap-M I 298-00-0 0.006 2

Metolachlor Dual, Pennant H 51218-45-2 0.002 100

Metribuzin Lexone, Sencor H 21087-64-9 0.004 100

Molinate Ordram H 2212-67-1 0.004 --

Napropamide Devrinol H 15299-99-7 0.003 --

Parathion several I 56-38-2 0.004 --

Pebulate Tillam H 1114-71-2 0.004 --

Table A3. Pesticide analytes, method detection limits, drinking water standards, and health advisories

[μg/L, micrograms per liter; --, no criteria established. Type of Pesticide: H, herbicide; I, insecticide; T, transformation product; MCL, drinking-water 

maximum contaminant level (U.S. Environmental Protection Agency, 1996); HA-L (bold), health advisory, 70-kilogram adult, lifetime (U.S. Environmental 

Protection Agency, 1996); U.S. Environmental Protection Agency risk-specific dose health advisory associated with a cancer risk of 10-6 (1 in a million), from 

Nowell and Resek (1994); RSD (italic), risk-specific dose health advisory for drinking water associated with a 10-6 (1 in a million) cancer risk (U.S. 

Environmental Protection Agency, 1996); U.S. Environmental Protection Agency lifetime-health advisory for a 70-kilogram adult, from Nowell and Resek 

(1994)]
49 Hydrogeologic and Water-Quality Reconnaissance, Shoalwater Bay Indian Reservation and Tokeland Peninsula, Washington

Gas chromatography/mass spectrometry analytical method (Schedule 2010) — Continued

Pendimethalin Prowl, Stomp H 40487-42-1 0.004 --

cis-Permethrin Ambush, Pounce I 57608-04-5 0.005 --

Phorate Thimet, Rampart I 298-02-2 0.002 --

Prometon Pramitol H 1610-18-0 0.018 100

Propachlor Ramrod H 1918-16-7 0.007 90

Propanil Stampede H 709-98-8 0.004 --

Propargite Comite, Omite I 2312-35-8 0.013 --

Propyzamide Kerb H 23950-58-5 0.003 50

Simazine Aquazine, Princep H 122-34-9 0.005 4

Tebuthiuron Spike H 34014-18-1 0.01 500

Terbacil1 Sinbar H 5902-51-2 0.007 90

Terbufos Counter I 13071-79-9 0.013 0.9

Thiobencarb Bolero H 28249-77-6 0.002 --

Triallate Far-Go H 2303-17-5 0.001 --

Trifluralin Treflan, Trilin H 1582-09-8 0.002 5

Whole-water extraction and gas chromatography with electron capture detection analytical method (Schedule 79)

2,4-D several H 94-75-7 0.01 70

2,4,5-T several H 93-76-5 0.01 70

2-(2,4,5-Trichloro- Silvex H 93-72-1 0.01 50

 phenoxy) propionic

 acid

Dicamba Banvel H 1918-00-9 0.01 200

Dichlorprop 2,4-DP, Seritox 50 H 120-36-5 0.01 --

Picloram Tordon H 1918-02-1 0.01 500

1Concentrations for these pesticides are qualitatively identified and reported with an e code (estimated value) because of problems with gas 

chromatography or extraction (Zaugg and others, 1995).

Table A3. Pesticide analytes, method detection limits, drinking water standards, and health advisories–Continued

Pesticide target 

analyte

Trade or common 

name(s)

Type of 

pesticide

Chemical Abstracts 

Service registry number

Method detection 

limit (μg/L)

MCL, HA-L, or 

RSD (μg/L)
Appendix Tables 50

Table A4. Concentrations of nutrients, metals, and major 

ions in field and equipment blanks

[mg/L, milligrams per liter; μg/L, micrograms per liter; N, nitrogen; 

P, phosphorous]

Analyte Concentration

Results of equipment blanks

Calcium 0.004 mg/L

Nitrite + nitrate, as N 0.005 mg/L

Orthophosphate, as P 0.001 mg/L

Copper 0.81μg/L

Manganese 0.31 μg/L

Zinc 2.9 μg/L

Results of field blanks

Ammonia, as N 0.02 mg/L

Nitrite + nitrate, as N 0.015 mg/L

Orthophosphorus, as P 0.013 mg/L

Aluminum 1.8 μg/L

Copper 1.5 μg/L

Zinc 1.6 μg/L
51 Hydrogeologic and Water-Quality Reconnaissance, Shoalwater Bay Indian Reservation and Tokeland Peninsula, Washington

Table A5. Concentrations and precision data for major ions, nutrients, metals, and methylene blue-active substances in 

replicate samples

[Concentrations are in milligrams per liter except metals, which are in micrograms per liter; <, less than; --, could not be calculated. Concentrations are 

unrounded for purpose of statistical calculation]

Analyte Concentration 

in replicate

Relative 

percent 

difference

Analyte Concentration in 

replicate

Relative 

percent 

difference

Major ions Metals–Continued

Calcium 13.5 0.4 Arsenic 2.09 49.6

13.45 1.26 

Chloride 12.19 7.8 Barium 1.404 1.6

11.28 1.427

Fluoride <0.1 0.0 Beryllium <1 0.0

<0.1 <1

Magnesium 5.512 0.3 Cadmium <1 0.0

5.494 <1

Manganese1 <3 0.0 Chromium <1 0.0

<3 <1

Potassium 1.12 6.5 Copper <1 0.0

1.05 <1

Silica 30.081 0.7 Cobalt <1 0.0

29.871 <1

Sodium 9.381 0.01 Iron <10 0.0

9.380 <10

Sulfate 4.672 4.5 Lead <1 0.0

4.467 <1

Nutrients Manganese2 64.029 0.6

Ammonia 0.023 9.1 64.437

0.021 Molybdenum <1 0.0

Ammonia plus <0.1 0.0 <1

 organic nitrogen <0.1 Nickel <1 0.0

Nitrite <0.01 0.0 <1

<0.01 Selenium <1 0.0

Nitrite plus nitrate 0.067 11.3 <1

0.075 Silver <1 0.0

Orthophosphorus 0.128 0.0 <1

0.128 Uranium (natural) <1 0.0

Metals <1

Aluminum 3.383 3.4 Zinc 1.772 --

3.271 <1

Antimony <1 0.0 Methylene blue-active substances

<1 Sample 1 <0.02 0.0

Sample 2 <0.02

1 ICP, inductively-coupled plasma.

2 ICP/MS, inductively-coupled plasma/mass spectometry.
Appendix Tables 52

Table A6. Median percent recoveries of laboratory reagent spikes

[Percent recoveries are median of analytical-set batch spikes analyzed with environmental sample for this study; e, estimated value]

Pesticide target analyte Median percentage of 

recovery Pesticide target analyte Median percentage of recovery

Gas chromatoghraphy/mass spectrometry analytical 

method (Schedule 2010)

Gas chromatography/mass spectrometry analytical 

method (Schedule 2010)–Continued

Acetochlor 99 Napropamide 88

Alachlor 102 Parathion 113

Atrazine 96 Pebulate 88

Azinphos-methyl1 e82 Pendimethalin 82

Benfluralin 65 cis-Permethrin2 31

Butylate 83 Phorate 76

Carbaryl1 e183 Prometon 102

Carbofuran1 194 Propachlor 105

Chlorpyrifos 89 Propanil 103

Cyanazine 122 Propargite 63

DCPA 96 Propyzamide 101

p,p’-DDE 49 Simazine 99

Deethylatrazine1 e50 Tebuthiuron 122

Diazinon 94 Terbacil1 e178

Dieldrin 79 Terbufos 75

2,6-Diethylaniline 100 Thiobencarb 110

Disulfoton 72 Triallate 92

EPTC 88 Trifluralin 67

Ethalfluralin 76

Ethoprophos 81

Fonofos 93 Whole-water extraction and gas chromatography with 

electron capture detection analytical method (Schedule 79)

alpha-HCH 93 2,4-D 82

gamma-HCH 99 2,4,5-T 84

Linuron 128 2-(2,4,5-Trichlorophenoxy 81

Malathion 87 propionic acid)

Methyl parathion 99 Dicamba 92

Metolachlor 105 Dichlorprop 76

Metribuzin 88 Picloram 41

Molinate 95

1Concentrations for these pesticides are qualtatively identified and reported with an e code because of problems with extraction or age 

chromatography (Zaugg and others, 1995). 2 Spike solution contains both cis- and trans- permethrin, but only the cis isomer is reported. Cis-permethrin is present at 0.3 nanograms per 

liter, and is commonly recovered at about 40 percent in laboratory spike samples.
Hydrogeologic and Water-Quality Reconnaissance of the Artesian Aquifer

Under the Shoalwater Bay Indian Reservation and Tokeland Peninsula,

Pacific County, Washington, 1998-99

Lane and Ebbert

USGS WRIR 01-4023

Printedonrecycledpaper