U.S. Department of the Interior

U.S. Geological Survey

Open-File Report 03-344

Prepared in cooperation with

Department of the Navy

Engineering Field Activity, Northwest

Naval Facilities Engineering Command

Selected Natural Attenuation Monitoring Data,

Operable Unit 1, Naval Undersea Warfare Center,

Division Keyport, Washington, June 2001

science for a changing world

SR

308

SR

303

BROWNSVILLE HIGHWAY

LIB E R T Y B A Y

Dogfish Bay

Shallow

lagoon

Tide

flats

KEYPORT

VIRGINIA

POINT

Landfill

(Operable Unit 1)

Port

Orchard

Naval Undersea

Warfare Center,

Keyport
Selected Natural Attenuation Monitoring Data, 

Operable Unit 1, Naval Undersea Warfare 

Center, Division Keyport, Washington, June 2001

By R.S. Dinicola

Tacoma, Washington

2003

Open-File Report 03-344

U.S. GEOLOGICAL SURVEY

Prepared in cooperation with

DEPARTMENT OF THE NAVY

ENGINEERING FIELD ACTIVITY, NORTHWEST

NAVAL FACILITIES ENGINEERING COMMAND
U.S. DEPARTMENT OF THE INTERIOR

GALE A. NORTON, Secretary

U.S. GEOLOGICAL SURVEY

Charles G. Groat, Director

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.

For additional information write to:

Director, Washington Water Science Center

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

Suggested citation:

Dinicola, R.S., 2003, Selected natural attenuation monitoring data, Operable Unit 1, Naval Undersea 

Warfare Center, Division Keyport, Washington, June 2001: U.S. Geological Survey Open-File Report 

03-344, 17 p.
Contents iii

CONTENTS

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

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

Purpose and Scope ...................................................................................................................................... 3

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

Methods and Data Analysis.................................................................................................................................. 6

Natural Attenuation Monitoring Data .................................................................................................................. 7

Geochemical Data and Predominant Redox Conditions............................................................................. 7

Comparison of Unfiltered (Total) and Filtered (Dissolved) Organic Carbon Concentrations .......... 14

Chlorinated Volatile Organic Compound Data........................................................................................... 15

Summary .............................................................................................................................................................. 16

References Cited .................................................................................................................................................. 16
iv Figures

FIGURES

Figure 1. Map showing location of Operable Unit 1 study area, Naval Undersea 

Warfare Center, Division Keyport, Washington................................................................................ 2

Figure 2. Map showing location of June 2001 data-collection sites and other features 

at Operable Unit 1, Naval Undersea Warfare Center, Division Keyport, Washington ..................... 4

Figure 3. Graph showing unfiltered and filtered organic carbon concentrations for 

June 2001 at Operable Unit 1, Naval Undersea Warfare Center, 

Division Keyport, Washington .......................................................................................................... 14
Tables v

TABLES

Table 1. Construction data and water-level measurements for monitoring wells and 

piezometers sampled during June 2001 at Operable Unit 1, Naval Undersea 

Warfare Center, Division Keyport, Washington................................................................................ 5

Table 2. Predominant redox conditions and ground-water geochemical data collected 

from 1996 to 2001 at Operable Unit 1, Naval Undersea 

Warfare Center, Division Keyport, Washington................................................................................ 8

Table 3. Concentrations of selected chlorinated volatile organic compounds in ground 

water from piezometers sampled from 1999 to 2001 by the U.S. Geological 

Survey at Operable Unit 1, Naval Undersea Warfare Center, 

Division Keyport, Washington .......................................................................................................... 15
vi Conversion Factors and Datums

CONVERSION FACTORS AND DATUMS

CONVERSION FACTORS

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

oF = (1.8 oC)+32.

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

oC = (oF-32)/1.8.

Concentrations of chemical constituents in water are given in milligrams per liter, micrograms per 

liter, or nanomoles per liter (nanomolar). One milligram per liter is equivalent to one thousand micrograms per liter. One microgram per liter is equivalent to “parts per billion.”

DATUMS

Vertical coordinate information is referenced to the National Geodetic Vertical Datum of 1988 

(NGVD of 1988).

Horizontal coordinate information is referenced to the NAD27.

Multiply By To obtain

acre 4,047 square meter

acre 0.4047 hectare

foot (ft) 0.3048 meter
Introduction 1

Selected Natural Attenuation Monitoring Data, 

Operable Unit 1, Naval Undersea Warfare Center, 

Division Keyport, Washington, June 2001

By R.S. Dinicola

ABSTRACT

Previous investigations have shown that 

natural attenuation and biodegradation of 

chlorinated volatile organic compounds (CVOCs) 

are substantial in shallow ground water beneath 

the 9-acre former landfill at Operable Unit 1 (OU 

1), Naval Undersea Warfare Center (NUWC), 

Division Keyport, Washington. The U.S. 

Geological Survey (USGS) has continued to 

monitor ground-water geochemistry to assure that 

conditions remain favorable for contaminant 

biodegradation. This report presents the groundwater geochemical and selected CVOC data 

collected at OU 1 by the USGS during June 11-14, 

2001 in support of the long-term monitoring for 

natural attenuation.

Overall, the June 2001 data indicate that 

redox conditions in the upper aquifer remain 

favorable for reductive dechlorination of CVOCs 

because strongly reducing conditions persisted 

beneath much of the former landfill. Redox 

conditions in the intermediate aquifer down 

gradient of the landfill appear to have become 

more favorable for reductive dechlorination 

because June 2001 dissolved hydrogen 

concentrations indicated strongly reducing 

conditions there for the first time. Although 

changes in redox conditions were observed at 

certain wells during 2001, a longer monitoring 

period is needed to ascertain if phytoremediation 

activities are affecting the ground-water chemistry.

A minor change to future monitoring is 

proposed. Filtered organic carbon (previously 

referred to as dissolved, and defined as that which 

passes through a 0.45-micrometer membrane 

filter) should be analyzed in the future rather than 

unfiltered (previously referred to as total) organic 

carbon because the filtered analysis may be a 

better measure of bioavailable organic carbon. 

Unfiltered and filtered organic carbon data were 

collected during June 2001 for comparison. 

Filtered organic carbon data collected in the future 

could be reasonably compared with historical 

unfiltered organic carbon data by multiplying the 

historical data by a factor of about 0.9. 

INTRODUCTION

Chlorinated volatile organic compounds 

(CVOCs) have migrated to ground water beneath the 

former landfill at Operable Unit 1 (OU 1) of the Naval 

Undersea Warfare Center (NUWC), Division Keyport. 

The NUWC is located mostly on a small peninsula in 

Kitsap County, Washington, in an extension of Puget 

Sound called Liberty Bay (fig. 1). The 9-acre former 

landfill at OU 1 is on the narrow strip of connecting 

land and is adjacent to some tidal flats that are an 

extension of Dogfish and Liberty Bays. The OU 1 

landfill is unlined at the bottom and was constructed in 

a former marshland. The landfill was the primary 

disposal area for domestic and industrial wastes 

generated by NUWC Keyport from the 1930s through 

1973. Paints, thinners, solvents, acids, dried sludge 

from a wastewater-treatment plant, and other industrial 

wastes were disposed of at various locations in the 

landfill. The most concentrated disposal area for waste 

paints and solvents was at the southern end of the 

landfill.
2 Selected Natural Attenuation Monitoring Data, Operable Unit 1, Naval Undersea Warfare Center, Division Keyport, Washington, June 2001

SR

308

BROWNSVILLE

HIGHWAY

SR

303

1000 2000 3000 FEET

0 900 METERS

0

300 600

Base map modified from URS Consultants, Inc., 1997,

Projection: Washington State Plane, North Zone

Location of figure 2 

WASHINGTON

Seattle

Bremerton

Figure

location

L I B E R T Y

B A Y

Dogfish Bay

Shallow

lagoon

Tide

flats

Marsh

KEYPORT

VIRGINIA POINT

Landfill

(Operable Unit 1)

P o r t

O r c h a r d

Naval Undersea

Warfare Center,

Keyport

Figure 1. Location of Operable Unit 1 study area, Naval Undersea Warfare Center, Division Keyport, Washington.
Introduction 3

Chlorinated VOCs are present in the upper and 

intermediate aquifers and in surface water at OU 1. 

Ground water beneath OU 1 occurs within a series of 

aquifers that are composed of permeable sand, gravel, 

or fill materials separated by finer grained silt or clay 

layers. Contamination at OU 1 is known to occur only 

in about the top 60 feet of the unconsolidated deposits 

in the hydrogeologic units referred to as the 

unsaturated zone, the upper aquifer, the middle 

aquitard, and the intermediate aquifer. Ground water in 

the unconfined upper aquifer generally flows from east 

to west towards Dogfish Bay. Ground water in the 

predominantly confined intermediate aquifer generally 

flows from south and west to beneath the landfill, and 

then to the northwest towards Dogfish Bay. Two 

perennial freshwater creeks drain the marsh adjacent to 

the landfill.

The predominant contaminants in ground water 

are trichloroethene (TCE) and its degradation byproducts cis-1,2-dichloroethene (cis-DCE) and vinyl 

chloride (VC). The compound 1,1,1-trichloroethane 

(TCA) and its degradation by-products 1,1-

dichloroethane (1,1-DCA), 1,1-dichloroethene (1,1-

DCE), and chloroethane (CA) are of concern at a few 

locations at OU 1. A need for remedial action was 

identified because those hazardous compounds present 

a potential risk to humans (URS Consultants, Inc., 

1998). Phytoremediation combined with on-going 

natural attenuation processes were chosen by the Navy 

as the preferred remedy (URS Consultants, Inc., 1998). 

The Navy planted two hybrid poplar plantations on the 

landfill (fig. 2) in the spring of 1999 to remove and 

control the migration of CVOCs in shallow ground 

water (URS Greiner, Inc., 1999).

Purpose and Scope

The Navy began a cooperative effort with the 

USGS in 1995 to investigate various natural attenuation 

mechanisms at OU 1. Field and laboratory studies 

conducted from 1996 through 2000 have shown that 

natural attenuation and biodegradation of CVOCs in 

shallow ground water at OU 1 are substantial (URS 

Consultants, Inc., 1997; Bradley and others, 1998; 

Dinicola and others, 2002). The USGS has continued 

to monitor the geochemistry of ground water to assure 

that conditions remain favorable for contaminant 

biodegradation, a critical mechanism of natural 

attenuation. 

This report presents the ground-water 

geochemical and selected CVOC data collected by the 

USGS at OU 1 during June 11-14, 2001 in support of 

the long-term monitoring for natural attenuation. 

USGS data collected from 1996 through 2000 were 

presented in Dinicola and others (2002). The June 2001 

data collection focused on constituents used to evaluate 

ground-water redox conditions. The USGS collected 

ground-water samples from 13 wells and 6 piezometers 

(table 1 and fig. 2). Concentrations of various 

geochemicals were determined in all samples, however, 

concentrations of VOCs were determined by the USGS 

in samples from the six piezometers only. The Navy 

collected additional samples to determine VOC 

concentrations at OU 1 monitoring wells, and those 

data were presented in The TEC LTM Team (2002). 

The June 2001 data were not interpreted in detail for 

this report because natural attenuation will again be 

thoroughly evaluated at OU 1 in support of the 5-year 

review scheduled for 2004.

Acknowledgments

The author thanks Sandra Keinholz and Matthew 

Butler of the Naval Facilities Engineering Command, 

Engineering Field Activity, Northwest (EFANW) for 

their guidance and funding for the continued 

monitoring. James Reeves of EFANW and Gene Ellis 

of Naval Undersea Warfare Center, Keyport provided 

logistic support for field activities. Stephen Cox, CG 

Laird, and Rose Eppers of the U.S. Geological Survey, 

Tacoma, Washington assisted with data collection and 

analysis.
4 Selected Natural Attenuation Monitoring Data, Operable Unit 1, Naval Undersea Warfare Center, Division Keyport, Washington, June 2001

Keys Road

BROWNSVILLE HIGHWAY

Bradley Road

Shapely Road

SR

308

SR

303

Tide flats

Marsh

Landfill

DOGFISH BAY

Shallow

lagoon

NUWC

Keyport

50 200 250 METERS 100 150

200

0

0 400 800 FEET 600

N-1

N-2

N-3

N-5 N-4

N-7 N-6

N-8

C-1

C-2

C-3

S-1

S-2

S-3

S-4

S-5

S-6

DB-14

TF19

MA09

MA11

MA10

MA12

MA13

MW1-22

MW1-30

PZ1-5

MW1-23

MW1-24

1MW-4

MW1-36

MW1-37

MW1-39

MW1-38

MW1-32

MW1-21

MW1-29

MW1-40

MW1-25

MW1-28

MW1-9

PZ1-2

PZ1-4

MW1-7

MW1-31

MW1-27 MW1-11

MW1-33

PZ1-3

1MW-5

MW22-7

MW1-19

MW1-18

MW22-6

MW1-3

MW1-17

1MW-1 MW1-15

MW1-2

PZ1-1

Private

Well 1

Private

Well 2

MW1-10

MW1-14

MW1-41

P1-1

P1-2 P1-3

MW1-6 MW1-35

MW22-5

MW3-5

MW22-1

MW1-20

MW22-2

MW1-34

MW1-8

P1-4 P1-5

P1-6

P1-7

P1-8

P1-9

P1-10

MW1-5

MW1-16

MW1-4

MW1-1

Diffusion sampler, not sampled

Surface-water sampling site,

 not sampled

EXPLANATION

NUWC, KEYPORT

FORMER LANDFILL

PHYTOREMEDIATION PLANTATION

SURFACE WATER

DATA-COLLECTION SITES–

 MW – monitoring wells

 P – piezometers

Monitoring well or piezometer

 in upper aquifer, sampled

Monitoring well in intermediate

 aquifer, sampled

Monitoring well or piezometer

 in upper aquifer, not sampled

Monitoring well in intermediate

 aquifer, not sampled

Base map modified from URS Consultants, Inc., 1997,

Projection: Washington State Plane, North Zone

Figure 2. Location of June 2001 data-collection sites and other features at Operable Unit 1, Naval Undersea Warfare Center, 

Division Keyport, Washington.
Introduction 5

Table 1. Construction data and water-level measurements for monitoring wells and piezometers sampled during June 2001 at Operable Unit 1, Naval 

Undersea Warfare Center, Division Keyport, Washington

[Well No.: MW, monitoring well; P, piezometer. USGS site No.: Unique number for each site based on latitude and longitude of the site. First six digits are 

latitude, next seven digits are longitude, and final two digits are a sequence number to uniquely identify each site. Altitudes of water levels and measuring 

points are given in feet above or below (-) NAVD88. Water level is in feet below measuring point (bmp). Depth of well and screened interval are in feet 

below land surface. Measuring point: Water levels in wells are usually reported as depths below land surface, although the measuring point can be any 

convenient fixed place near the top of the well. For these wells and piezometers, the measuring points are marked points on the tops of well casings—they vary 

from being near the ground surface to a few feet above ground surface. The altitude of the measuring point is commonly recorded so that static water levels can 

also be reported as altitudes. Volatile organic compounds (VOCs) sampled: USGS, U.S. Geological Survey. Abbreviations: ROD, Record of Decision; dup, 

field duplicate sample. Symbols: –, not sampled]

Well No. USGS site No. Date/time 

sampled

Waterlevel 

altitude

(ft)

Waterlevel

(ft bmp)

Altitude 

of measuring 

point (ft)

Depth of 

well (ft)

Casing 

diameter 

(in)

Screened 

interval 

(ft)

VOCs sampled by

USGS Navy

Geochemical 

sampling 

specified 

in ROD

1MW-1 474151122373201 06-11-01 

15:00

3.06 7.00 10.06 16.5 2 5.5–15.5 – X X

MW1-2 474153122373101 06-12-01 

17:15

1.84 10.05 11.89 18.5 4 12.5–17.5 – X X

MW1-3 474152122372501 06-12-01 

10:30

9.34 4.21 13.55 11.5 4 5.5–10.5 – – –

MW1-4 474145122372801 06-14-01 

10:30

5.67 6.53 12.20 13.0 4 7–12 – X X

MW1-5 474146122373201 06-13- 01 

15:45

4.33 8.75 13.08 12.0 4 6–11 – X X

MW1-16 474146122372801 06-14-01 

10:40

5.53 7.30 12.83 12.0 2 6–11 – X X

MW1-17 474150122373201 06-12-01 

11:15

3.92 8.02 11.94 13.5 2 7.5–12.5 – X –

MW1-20 474145122372501 06-13-01 

12:00

6.68 3.76 10.44 16.0 2 10–15 – – –

MW1-25 474154122373201 06-12-01 

13:30

2.29 9.62 11.91 49.0 2 38–48 – – X

MW1-28 474153122373301 06-12-01 

14:00

-0.75 10.98 10.23 45.0 2 39–44 – – X

MW1-33 474140122373201 06-11-01 

11:00

11.12 0.38 11.50 41.0 2 30–40 – – –

MW1-39 474157122373701 06-12-01 

15:30

-0.42 10.27 9.85 33.7 2 27.7–32.7 – X X

MW1-41 474152122372901 06-11-01 

12:45

6.41 8.80 15.21 15.0 2 5–15 – X –

P1-4 474152122373101 06-13-01 

14:00 

4.74 7.81 12.55 15.0 1 10–15 X – –

Dup 14:01 X

P1-6 474146122373001 06-14-01 

15:00

5.39 7.37 12.76 15.0 1 10–15 X – –

P1-7 474145122373101 06-14-01 

13:15

5.23 6.89 12.12 15.0 1 10–15 X – –

P1-8 474147122372801 06-14-01 

16:15

6.19 5.87 12.06 15.0 1 10–15 X – –

P1-9 474145122372901 06-14-01 

11:45

5.48 6.43 11.91 15.0 1 10–15 X – –

P1-10 474145122372601 06-13-01 

12:15

6.59 5.27 11.86 15.0 1 10–15 X – –
6 Selected Natural Attenuation Monitoring Data, Operable Unit 1, Naval Undersea Warfare Center, Division Keyport, Washington, June 2001

METHODS AND DATA ANALYSIS

Sample collection, processing, and field analyses 

were in accordance with applicable USGS procedures 

(U.S. Geological Survey, 1997 to 2001). The analytical 

methods used for the June 2001 data-collection 

activities generally were consistent with previous 

USGS data-collection activities at OU 1, with the 

exception that the laboratories used to determine 

methane concentrations changed from year to year.

The geochemical concentrations determined for 

samples from all wells and piezometers included 

dissolved hydrogen (H2), dissolved oxygen, unfiltered 

and filtered organic carbon, filtered nitrate plus nitrite, 

filtered manganese, filtered iron (II), filtered sulfate, 

unfiltered sulfide, dissolved methane, filtered 

bicarbonate, pH, specific conductance, oxidationreduction potential (ORP), and filtered chloride. The 

concentrations of 64 VOCs, including all CVOCs of 

interest at OU 1, also were determined for samples 

from the piezometers. Monitoring wells and 

piezometers sampled at OU 1 are of different depths 

and diameters (table 1), but all were constructed with 

PVC casings and screens with sand filter packs.

All samples were collected with a peristaltic 

pump and single-use polyurethane tubing. A stainlesssteel weight was attached to the bottom of the premeasured length of tubing to accurately collect a 

sample from the mid-screen altitude in each well or 

piezometer. Samples were collected after 

approximately three casing-volumes of water were 

purged from the wells or piezometers and after 

allowing pH, specific conductance, and dissolved 

oxygen to stabilize within 0.1 units, 5 percent, and 0.3 

mg/L, respectively. Those three analytes, as well as 

oxidation reduction potential, were measured in a flowthrough chamber using temperature compensated 

probes and meters. The specific conductance probe was 

checked daily with standard reference solutions; the pH 

probe was calibrated daily with two pH standards; and 

the dissolved oxygen probe was calibrated daily with 

water-saturated air and occasionally verified with zero 

dissolved oxygen solution. Dissolved oxygen analyses 

were confirmed with samples from selected wells or 

piezometers using 0 to-1 milligram per liter (mg/L) 

CHEMets Rhodazine-DTM colorimetric ampoules 

(manufactured by CHEMetrics, Inc., Calverton, 

Virginia). The ampoules were filled directly from the 

sampling tube after well purging was complete.

Bicarbonate (HCO3) concentration was 

measured in the field by titration of a sample passed 

through 0.45-micrometer (μm) membrane filter and the 

concentration was calculated from the titration results. 

The inflection points of the titration curve were used to 

determine equivalence end-points. Concentrations of 

iron (II) were measured in the field in a sample passed 

through 0.45-μm membrane filter using a colorimetric 

1,10 phenanthroline indicator method and a Hach 

Model 2010 spectrophotometer according to Hach 

analytical method number 255 (Hach Company, 1998). 

Concentrations of sulfide were measured in the field on 

an unfiltered sample using a colorimetric methylene 

blue indicator method using the same 

spectrophotometer according to analytical method 

number 690 (Hach Company, 1998).

Dissolved H2 in ground water was sampled using 

the bubble-strip method of Chapelle and others (1997) 

and concentrations were measured in the field using a 

gas chromatograph equipped with a reduction gas 

detector. Initial gas samples from each well or 

piezometer were collected and analyzed after at least 

20 minutes of stripping; subsequent samples were 

collected and analyzed at about 5-minute intervals until 

consecutive hydrogen concentrations stabilized to 

within 10 percent. If dissolved H2 did not stabilize and 

did not consistently increase or decrease over time, the 

range over which the concentrations fluctuated was 

reported. 

Samples for analysis of nitrate, manganese, 

sulfate, and chloride were passed through 0.45-μm 

membrane filter into polyethylene bottles, chilled, and 

sent to the USGS National Water Quality Laboratory 

(NWQL). The manganese sample was acidified in the 

field with nitric acid to a pH of less than 2, and then 

analyzed at NWQL by inductively coupled plasma, as 

described by Fishman (1993). Chloride and sulfate 

were analyzed using ion chromatography, as described 

by Fishman and Friedman (1989). Nitrate plus nitrite 

(reported as nitrite plus nitrate as N) were analyzed 

colorimetrically by cadmium reduction and 

diazotization, as described by Fishman (1993). The 

results for the nitrite plus nitrate analyses are referred 

to as simply nitrate in this report because of the 

expected small contribution of nitrite to the total 

concentration determined.
Natural Attenuation Monitoring Data 7

Unfiltered (total) organic carbon and filtered 

(dissolved) organic carbon samples were collected in 

amber glass bottles, chilled to less than 4 °C, and 

shipped to the USGS laboratory in Ocala, Florida., for 

analysis. The filtered sample was passed through a 

0.45-μm membrane filter between the pump and the 

bottle. Organic carbon concentrations were determined 

using high temperature combustion according to 

Standard Method 5310B, as described by Franson 

(1992).

Dissolved methane samples were collected in 

serum bottles, preserved with mercuric chloride, sealed 

with Teflon® septa, chilled, and analyzed at the USGS 

Washington Water Science Center laboratory in 

Lakewood, Washington, using a gas chromatograph 

with a flame-ionization detector as described by 

Kampbell and others (1989). The same method was 

used for methane analyses of OU 1 samples prior to 

2001, although the 1996-97 samples were analyzed at 

the USGS Microbial Studies Group Laboratory in 

Columbia, South Carolina and the 2000 samples were 

analyzed at Transglobal Environmental Geosciences 

Northwest, Inc. in Lacey, Washington. It is uncertain if 

the same sample processing and holding-time protocols 

were followed at the three different laboratories.

VOC samples were collected in 40-mL glass 

vials, acidified to a pH of less than 2 with hydrochloric 

acid, sealed, and placed on ice. The samples were 

shipped to the NWQL for analysis using purge and trap 

capillary-column gas chromatography/mass 

spectrometry (Connor and others, 1998).

NATURAL ATTENUATION MONITORING 

DATA

The data collected in support of long-term 

monitoring for natural attenuation included 

geochemical and selected CVOC data. The 

predominant redox conditions at each sample location 

were determined from the geochemical data. Both 

unfiltered and filtered organic carbon data were 

collected in June 2001 in order to compare the two 

types of analyses.

Geochemical Data and Predominant Redox 

Conditions

The June 2001 data and the previous 

geochemical data collected by USGS at OU 1 (Dinicola 

and others, 2002) are shown in table 2. Duplicate 

samples were collected and analyzed for piezometer 

P1-4. With the exception of methane concentrations, 

the duplicate sample analyses were consistent within 0 

to 30 percent. Methane concentrations determined for 

duplicate samples collected from P1-4 during 2001 

were substantially different (0.9 and 3.2 mg/L). A 

possible cause of that difference was different 

laboratory holding times for the duplicate samples, 

although the laboratory documentation on holding-time 

protocols used is incomplete. 

The predominant redox conditions for June 2001 

samples were determined primarily by dissolved 

oxygen and dissolved H2 concentrations. The process 

and uncertainties in determining the predominant redox 

conditions from geochemical data are described in 

greater detail in Dinicola and others (2002). Generally, 

dissolved-oxygen concentrations greater than 1 mg/L 

indicated aerobic conditions, and dissolved-oxygen 

concentrations less than 1 mg/L indicated anaerobic 

conditions. More specific anaerobic conditions were 

indicated by dissolved H2 concentrations: 0.2 to 0.8 

nanomolar (nM) indicated iron reduction, 1 to 5 nM 

indicated sulfate reduction, and greater than 5 nM 

indicated methanogenesis. Anaerobic ground water 

with a dissolved H2 concentration less than 

1 nM is referred to as mildly reducing, and water with a 

dissolved H2 concentration greater than 1 nM is 

referred to as strongly reducing. Those more general 

terms for describing anaerobic redox conditions are 

useful because reductive dechlorination of CVOC 

contaminants is much more likely to occur under 

strongly reducing conditions (McCarty and Semprini, 

1994; Gossett and Zinder, 1996).
8 Selected Natural Attenuation Monitoring Data, Operable Unit 1, Naval Undersea Warfare Center, Division Keyport, Washington, June 2001

Table 2. Predominant redox conditions and ground-water geochemical data collected from 1996 to 2001 at Operable Unit 1, Naval Undersea 

Warfare Center, Division Keyport, Washington

[All data except those shaded were published previously in Dinicola and others (2002). Predominant redox conditions: A, aerobic; Fe, iron reducing; 

M, methanogenic; Mn, manganese reducing; S, sulfate reducing. Abbreviations: mg/L, milligrams per liter; nM, nanomolar; μS/cm, microsiemens per 

centimeter at 25o Celsius; mV, millivolt. Symbols: <, actual value is less than value shown; >, actual value is greater than value shown; –, not analyzed]

Well No. Date 

sampled

Predominant 

redox 

condition

Dissolved 

H2

(nM)

Dissolved

oxygen

(mg/L)

Unfiltered 

(total) organic 

carbon (mg/L)

Filtered 

(dissolved) 

organic 

carbon (mg/L)

Filtered 

nitrate

+nitrite

(mg/L as N)

Filtered 

manganese 

(mg/L)

Filtered

iron (II) 

(mg/L)

1MW-1 09-17-96 Fe 0.4 2.8 7.0 – <0.02 0.18 0.24

04-16-97 Fe 0.8 0.4 – – 0.11 – 8.0

03-05-98 Fe/S 0.2 0.1 8.3 – – 0.39 12

10-09-98 Fe 0.2 0.5 – – – 0.08 0.39

06-21-00 Mn/Fe 0.1 0.5 12 – <0.05 0.96 13

06-11-01 Fe 0.6 0.7 13 12 <0.05 0.24 2.9

1MW-4 09-17-96 Fe 0.6 1.6 23 – <0.02 0.77 1.5

04-16-97 S 1.8 0.0 – – 0.03 – 1.7

MW1-2 09-17-96 Fe 0.5 2.4 6.0 – <0.02 0.05 0.23

04-16-97 Fe 0.7 0.2 – – <0.02 – 0.13

03-02-98 Fe 0.3 – – – – – 0.16

10-07-98 Fe 0.1 0.1 – – – 0.05 0.14

06-09-99 Fe 0.9 0.2 – – – 0.08 0.09

06-21-00 Fe 0.3 0.1 6.0 – <0.05 0.06 0.10

06-12-01 S 3.5 0.3 5.3 5.0 <0.05 0.08 0.29

MW1-3 06-09-99 Fe 0.8 0.4 – – – 0.07 <0.01

06-20-00 Fe 0.2 0.3 2.0 – 0.99 0.08 <0.01

06-12-01 A – 4.0 2.3 1.1 1.1 0.04 0.02

MW1-4 09-17-96 Fe 0.5 2.8 2.0 – <0.02 0.28 1.8

04-16-97 Fe 0.6 0.4 – – 0.24 – <0.01

03-03-98 S 1.7 0.2 4.0 – – 0.10 0.01

10-08-98 Fe 0.2 0.5 – – – – 0.28

06-07-99 Fe 0.9 0.1 – – – 0.20 1.2

06-22-00 Fe 0.2 0.1 8.6 – – 0.70 .–

06-14-01 S 0.9 – 3.2 0.5 2.9 2.5 0.08 0.54 1.6

MW1-5 09-17-96 S 1.2 0.0 15 – <0.02 1.6 19

04-16-97 Fe 0.5 0.0 – – 0.08 – 3.1

03-04-98 Fe 0.7 0.0 12 – – 1.3 4.5

10-08-98 S 2.4 0.0 – – – 1.5 11

06-08-99 Fe 0.6 0.3 – – – 1.2 31

06-22-00 Fe .– 0.0 17 – – 1.5 39

06-13-01 Fe 0.8 0.3 10 9.6 0.12 1.5 25

MW1-6 09-17-96 S 1.1 0.0 33 – 1.2 1.2 30

04-16-97 Fe/S 0.5 0.0 – – 0.07 – 36

10-08-98 Fe 0.2 0.0 – – – 1.1 32

MW1-14 09-17-96 Fe 0.6 0.0 42 – <0.02 2.0 67

04-16-97 Fe 0.7 0.0 – – 0.05 – 78

03-04-98 Fe/S .– 0.1 36 – – 11 68

10-07-98 S 1.2 0.0 – – – 1.5 48

06-09-99 S 1.0 0.3 – – – 0.30 57

MW1-15 09-16-96 Fe 0.2 0.0 50 – <0.02 5.7 68

04-16-97 Fe/S 0.8 0.0 – – <0.02 – 77

03-05-98 S 1.2 0.0 33 – – 18 51

10-09-98 S 2.9 0.0 – – – 5.8 64
Natural Attenuation Monitoring Data 9

Table 2. Predominant redox conditions and ground-water geochemical data collected from 1996 to 2001 at Operable Unit 1, Naval Undersea 

Warfare Center, Division Keyport, Washington—Continued

[All data except those shaded were published previously in Dinicola and others (2002). Predominant redox conditions: A, aerobic; Fe, iron reducing; 

M, methanogenic; Mn, manganese reducing; S, sulfate reducing. Abbreviations: mg/L, milligrams per liter; nM, nanomolar; μS/cm, microsiemens per 

centimeter at 25o Celsius; mV, millivolt. Symbols: <, actual value is less than value shown; >, actual value is greater than value shown; –, not analyzed]

Well No.

Filtered 

sulfate

(mg/L)

Unfiltered 

sulfide

(mg/L)

Dissolved 

methane 

(mg/L)

Filtered 

bicarbonate 

(mg/L)

pH

(units)

Specific 

conductance 

(μS/cm)

ORP

(mV)

Filtered 

chloride 

(mg/L)

1MW-1 7.5 <0.01 10 640 7.9 – – 43

1.4 0.01 29 1,100 7.2 – – –

.– 0.06 .– – .– – – –

.– 0.01 .– 660 7.7 1,080 – –

0.9 <0.01 0.39 590 7.0 1,070 -92 44

2.2 <0.01 5.6 550 7.1 974 -110 50

1MW-4 0.04 <0.01 16 780 7.3 – – 25

0.36 0.02 47 1,300 7.3 – – –

MW1-2 4.6 <0.01 1.2 510 6.9 – – 50

4.6 <0.01 2.5 1,100 6.7 – – –

.– .– .– – .– – – –

.– <0.01 .– 300 6.7 868 – –

.– <0.01 .– 490 6.8 901 – –

4.3 <0.01 0.04 460 6.8 870 37 36

5.4 <0.01 0.78 470 6.5 853 27 48

MW1-3 .– <0.01 .– 81 6.0 202 – –

13 <0.01 0.02 82 5.9 205 180 8.4

14 <0.01 0.12 90 6.1 203 220 10

MW1-4 7.1 <0.01 1.2 130 6.9 – – 15

8.6 <0.01 0.70 270 7.3 – – –

.– <0.01 .– – .– – – –

.– <0.01 .– 170 6.7 368 – –

.– <0.01 .– 180 6.6 350 – –

5.5 <0.01 0.56 230 6.8 412 -26 19

5.4 <0.01 3.7 180 6.5 360 -8 22

MW1-5 6.4 <0.01 2.4 330 6.7 – – 21

2.8 0.03 18 1,400 6.6 – – –

.– <0.01 .– – .– – – –

.– <0.01 .– 410 6.4 1,740 – –

.– 0.01 .– 510 6.5 855 – –

6.4 <0.01 1.1 460 6.6 790 -80 19

6.0 0.01 2.4 470 6.4 766 -70 12

MW1-6 0.10 <0.01 7.0 840 6.7 – – 27

4.1 0.15 15 1,100 6.5 – – –

.– 0.01 .– 720 6.4 1,170 – –

MW1-14 0.27 <0.01 9.2 1,300 6.4 – – 25

0.13 <0.01 46 1,800 6.4 – – –

.– 0.05 .– – .– – – –

.– 0.01 .– 600 6.3 1,450 – –

.– 0.04 .– 810 6.4 1,220 – –

MW1-15 0.11 <0.01 8.8 1,200 .– – – 18

0.08 0.03 44 1,600 6.3 – – –

.– <0.01 .– – .– – – –

.– <0.01 .– 750 6.3 1,110 – –
10 Selected Natural Attenuation Monitoring Data, Operable Unit 1, Naval Undersea Warfare Center, Division Keyport, Washington, June 2001

MW1-16 09-17-96 S 2.1 0.0 480 – <0.02 3.9 130

04-16-97 Fe/S 0.8 0.0 – – <0.02 – 120

03-04-98 Fe 0.7 0.3 350 – – 18 100

10-08-98 M 9.6 0.0 – – – 5.4 180

06-07-99 M 6.8 0.6 – – – >5 140

06-22-00 S .– 0.1 61 – – 1.9 60

06-14-01 S 1.7 0.2 64 66 0.33 2.4 56

MW1-17 09-17-96 Fe 0.7 0.0 23 – <0.02 1.3 62

04-16-97 Fe 0.6 0.0 – – <0.02 – 37

10-09-98 Fe .– 0.0 – – – 0.80 56

06-22-00 S 1.2 0.0 11 – – – 68

06-12-01 S 2.0 – 2.7 0.4 9.2 8 <0.05 1.2 48

MW1-18 09-17-96 Fe/S 1.0 0.0 28 – <0.02 4.0 12

04-16-97 Fe 0.5 0.0 – – 0.05 – 23

10-07-98 Fe .– 0.2 – – – 0.77 3.3

MW1-20 06-08-99 Fe 0.9 0.3 – – – 0.35 0.03

06-21-00 Fe 0.4 0.0 2.2 – <0.05 0.24 0.11

06-13-01 S 2.1 0.2 3.0 1.4 <0.05 0.28 0.01

MW1-25 09-17-96 Fe 0.4 2.7 7.4 – 0.14 0.16 0.74

04-17-97 Fe 0.8 0.1 – – <0.02 – 0.88

03-05-98 Fe 0.3 0.3 7.9 – – 0.20 0.73

10-05-98 Fe 0.2 0.1 – – – 0.19 0.99

06-22-00 Fe 0.4 0.2 6.5 – – 0.16 0.80

06-12-01 S 2.8 – 4.3 0.2 7.1 6.8 <0.05 0.16 0.99

MW1-28 09-16-96 Fe 0.3 2.1 7.2 – <0.02 0.20 1.0

04-17-97 Fe 1.0 0.0 – – 0.04 – 0.99

03-05-98 Fe 0.4 0.5 7.7 – – 0.20 0.67

10-07-98 Fe 0.6 0.0 – – – 0.19 1.0

06-22-00 Fe 0.3 0.0 13 – – 0.16 0.66

06-12-01 S/M 4.1 – 5.7 0.5 10 6.9 <0.05 0.16 0.90

MW1-29 09-16-96 Mn/Fe 0.0 1.9 – – <0.02 0.86 2.0

04-17-97 Fe 0.7 0.0 – – 0.29 – 2.1

MW1-31 09-16-96 Mn/Fe – .– 5.6 – – 3.6 0.32

MW1-32 09-16-96 Fe 0.4 2.7 0.8 – 0.07 0.23 1.3

04-17-97 Fe – 1.2 – – 0.17 – 0.87

03-02-98 Fe – <1.0 – – – 0.10 1.1

10-05-98 Fe 0.1 0.0 – – – 0.36 1.0

MW1-33 10-07-98 A – 3.3 0.1 – – 0.003 <0.01

06-21-00 A – 3.8 0.7 – 1.3 <0.002 <0.01

06-11-01 A – 3.8 1.5 1.4 1.1 <0.003 <0.01

MW1-35 10-07-98 A – 2.4 1.9 – – 0.15 <0.01

06-08-99 A – 2.1 – – – – –

06-20-00 A – 3.0 2.2 – 0.16 <0.002 <0.01

Table 2. Predominant redox conditions and ground-water geochemical data collected from 1996 to 2001 at Operable Unit 1, Naval Undersea 

Warfare Center, Division Keyport, Washington—Continued

[All data except those shaded were published previously in Dinicola and others (2002). Predominant redox conditions: A, aerobic; Fe, iron reducing; 

M, methanogenic; Mn, manganese reducing; S, sulfate reducing. Abbreviations: mg/L, milligrams per liter; nM, nanomolar; μS/cm, microsiemens per 

centimeter at 25o Celsius; mV, millivolt. Symbols: <, actual value is less than value shown; >, actual value is greater than value shown; –, not analyzed]

Well No. Date 

sampled

Predominant 

redox 

condition

Dissolved 

H2

(nM)

Dissolved

oxygen

(mg/L)

Unfiltered 

(total) organic 

carbon (mg/L)

Filtered 

(dissolved) 

organic 

carbon (mg/L)

Filtered 

nitrate

+nitrite

(mg/L as N)

Filtered 

manganese 

(mg/L)

Filtered

iron (II) 

(mg/L)
Natural Attenuation Monitoring Data 11

MW1-16 0.17 <0.01 4.3 1,400 6.5 – – 150

2.2 0.06 29 1,800 6.5 – – –

.– 0.01 .– – .– – – –

.– <0.01 .– 1,600 6.3 3,370 – –

.– 0.01 .– 1,200 6.7 1,820 – –

1.2 0.02 1.2 510 6.7 902 -130 43

1.1 0.08 10 610 6.4 953 – 40

MW1-17 4.3 <0.01 8.9 760 6.5 – – 61

68 0.02 23 1,200 6.6 – – –

.– 0.02 .– 510 6.4 1,740 – –

.– 0.02 2.8 450 6.5 1,260 -41 160

12 0.01 9.4 500 6.5 1,200 -280 120

MW1-18 4.6 <0.01 11 880 7.0 – – 86

8.2 <0.01 52 1,500 6.8 – – –

.– <0.01 .– 920 6.6 1,780 – –

MW1-20 .– <0.01 .– 260 6.7 546 – –

16 <0.01 0.01 240 6.8 530 79 14

20 <0.01 0.27 260 6.4 544 250 33

MW1-25 16 <0.01 3.6 360 7.1 – – 140

15 <0.01 7.9 1,000 7.0 – – –

.– <0.01 .– – .– – – –

.– <0.01 .– 450 6.9 1,240 – –

13 <0.01 0.79 380 6.9 1,230 -49 170

13 <0.01 4.7 440 6.7 1180 -36 160

MW1-28 48 <0.01 1.7 350 .– – – 380

51 <0.01 5.3 1,100 7.4 – – –

.– <0.01 .– – .– – – –

.– 0.02 .– 320 6.6 2,630 – –

44 <0.01 0.45 480 7.3 2,460 -87 510

45 <0.01 4.1 480 7.4 2,200 -220 490

MW1-29 1.8 0.02 8.1 300 .– – – 500

1.1 <0.01 18 710 7.3 – – –

MW1-31 .– .– .– – .– – – –

MW1-32 16 0.01 <0.01 110 .– – – 7.4

17 0.01 <0.01 300 7.1 – – –

.– <0.01 .– – .– – – –

.– <0.01 .– 130 7.2 270 – –

MW1-33 .– <0.01 .– 78 6.6 177 – –

7.5 <0.01 0.05 74 6.7 164 150 4.0

8.2 <0.01 0.07 71 6.2 154 300 3.6

MW1-35 .– <0.01 .– 110 6.4 301 – –

.– .– .– 76 6.4 187 – –

3.9 <0.01 0.01 77 6.6 151 360 2.3

Table 2. Predominant redox conditions and ground-water geochemical data collected from 1996 to 2001 at Operable Unit 1, Naval Undersea 

Warfare Center, Division Keyport, Washington—Continued

[All data except those shaded were published previously in Dinicola and others (2002). Predominant redox conditions: A, aerobic; Fe, iron reducing; 

M, methanogenic; Mn, manganese reducing; S, sulfate reducing. Abbreviations: mg/L, milligrams per liter; nM, nanomolar; μS/cm, microsiemens per 

centimeter at 25o Celsius; mV, millivolt. Symbols: <, actual value is less than value shown; >, actual value is greater than value shown; –, not analyzed]

Well No.

Filtered 

sulfate

(mg/L)

Unfiltered 

sulfide

(mg/L)

Dissolved 

methane 

(mg/L)

Filtered 

bicarbonate 

(mg/L)

pH

(units)

Specific 

conductance 

(μS/cm)

ORP

(mV)

Filtered 

chloride 

(mg/L)
12 Selected Natural Attenuation Monitoring Data, Operable Unit 1, Naval Undersea Warfare Center, Division Keyport, Washington, June 2001

MW1-36 10-09-98 Fe – 0.0 – – – 0.30 3.6

06-20-00 Fe 0.5 0.1 2.4 – <0.05 0.28 3.2

MW1-37 09-16-96 Fe 0.8 1.5 6.9 – <0.02 0.12 0.48

04-17-97 S 3.3 0.0 – – <0.02 – 0.80

03-03-98 Fe 0.4 0.4 5.7 – – 0.10 0.86

10-09-98 Fe 0.4 0.0 – – – <0.01 0.43

06-07-99 Fe 0.4 0.4 – – – 0.10 0.32

06-20-00 Fe 0.1 0.1 5.8 – <0.05 0.13 0.25

MW1-38 10-09-98 Fe – 0.1 – – – 0.20 0.08

06-20-00 Fe 0.1 0.2 5.6 – <0.05 0.08 0.10

MW1-39 09-16-96 Fe/S 0.6 2.0 4.4 – <0.02 0.02 <0.01

04-17-97 S 4.5 0.0 – – <0.02 – 0.05

03-03-98 Fe/S 0.3 0.3 3.7 – – 0.10 0.03

10-09-98 Fe/S 0.5 0.0 – – – <0.01 0.04

06-07-99 Fe/S 1.0 0.3 – – – 0.10 0.02

06-20-00 Fe/S 0.5 0.1 2.4 – <0.05 0.01 0.07

06-12-01 S 1.4 0.3 3.4 3.3 <0.05 0.01 <0.01

MW1-41 06-09-99 S 1.0 0.3 – – – 2.2 60

06-21-00 S 1.2 0.1 22 – <0.05 3.5 55

06-11-01 S 2.0 0.3 14 14 <0.05 3.7 66

P1-1 06-09-99 Fe 0.7 0.4 – – – 4.0 59

P1-3 06-09-99 Fe 0.4 0.2 – – – 1.0 19

P1-4 06-09-99 Fe 0.7 0.3 – – – 0.34 2.6

06-13-01 Fe 0.1 0.5 9.8 8.7 <0.05 0.38 3.4

(duplicate) 06-13-01 Fe – – 8.4 6.2 <0.05 0.38 3.6

P1-5 06-08-99 S 3.0 0.3 – – – 3.1 72

P1-6 06-08-99 S 1.8 0.1 – – – 0.12 0.02

06-14-01 S 1.8 0.2 34 34 0.23 0.45 0.95

P1-7 06-08-99 S 1.2 0.1 – – – 0.61 2.1

06-22-00 Mn/Fe – 0.1 19 – – 2.6 3.2

06-14-01 Mn/Fe 0.2 0.2 11 11 <0.05 2.3 2.0

P1-8 06-07-99 S 1.8 0.0 – – – 0.20 0.08

06-14-01 Fe 0.7 0.1 4.8 4.7 0.06 0.16 0.22

P1-9 06-08-99 M 19 0.3 – – – 0.90 0.03

06-22-00 S/M – 0.1 10 – – 0.69 0.20

06-14-01 M 6.7 0.1 2.3 1.7 <0.05 0.19 0.05

P1-10 06-07-99 Fe 0.7 0.3 – – – 0.10 0.11

06-22-00 Fe – 0.0 7.2 – – 0.07 0.25

06-13-01 S 2.0 0.2 3.0 4.2 <0.05 0.07 0.20

Table 2. Predominant redox conditions and ground-water geochemical data collected from 1996 to 2001 at Operable Unit 1, Naval Undersea 

Warfare Center, Division Keyport, Washington—Continued

[All data except those shaded were published previously in Dinicola and others (2002). Predominant redox conditions: A, aerobic; Fe, iron reducing; 

M, methanogenic; Mn, manganese reducing; S, sulfate reducing. Abbreviations: mg/L, milligrams per liter; nM, nanomolar; μS/cm, microsiemens per 

centimeter at 25o Celsius; mV, millivolt. Symbols: <, actual value is less than value shown; >, actual value is greater than value shown; –, not analyzed]

Well No. Date 

sampled

Predominant 

redox 

condition

Dissolved 

H2

(nM)

Dissolved

oxygen

(mg/L)

Unfiltered 

(total) organic 

carbon (mg/L)

Filtered 

(dissolved) 

organic 

carbon (mg/L)

Filtered 

nitrate

+nitrite

(mg/L as N)

Filtered 

manganese 

(mg/L)

Filtered

iron (II) 

(mg/L)
Natural Attenuation Monitoring Data 13

MW1-36 .– <0.01 .– 280 7.3 8,610 – –

180 0.02 0.01 270 7.3 7,940 -130 2,300

MW1-37 23 0.03 0.30 280 .– – – 660

27 0.02 0.90 730 7.7 – – –

.– <0.01 .– – .– – – –

.– <0.01 .– 340 7.9 2,440 – –

.– 0.03 .– 340 7.7 2,920 – –

29 0.02 0.07 350 7.6 3,240 -160 840

MW1-38 .– 0.02 .– 310 7.8 1,460 – –

2.3 0.03 0.10 300 7.8 1,240 -130 230

MW1-39 0.71 0.04 1.6 140 .– – – 85

13 0.06 6.1 360 7.9 – – –

.– 0.05 .– – .– – – –

.– 0.07 .– 170 8.1 502 – –

.– <0.01 .– 180 8.0 512 – –

0.2 0.08 0.41 180 8.0 481 -130 61

0.1 0.05 2.7 170 7.8 472 -130 61

MW1-41 .– 0.01 .– 860 6.6 1,260 – –

<0.3 <0.01 1.9 1,000 6.5 1,500 -75 8.3

30 0.02 25 980 6.3 1,330 -89 9.9

P1-1 .– <0.01 .– 930 6.4 1,350 – –

P1-3 .– 0.04 .– 730 6.8 1,470 – –

P1-4 .– 0.02 .– 450 6.9 867 – –

3.8 <0.01 0.9 390 6.6 761 -78 53

(duplicate) 3.8 <0.01 3.2 390 – – – 53

P1-5 .– 0.01 .– 850 6.2 1,320 – –

P1-6 .– 0.04 .– 300 6.8 574 – –

4.9 0.12 6.3 350 6.4 657 -38 47

P1-7 .– <0.01 .– 310 6.7 627 – –

24 <0.01 1.5 400 6.8 851 -35 55

18 <0.01 4.0 320 6.5 666 -32 41

P1-8 .– 0.01 .– 210 7.6 381 – –

0.13 0.02 6.9 200 7.0 363 -73 18

P1-9 .– <0.01 .– 270 6.6 680 – –

6.6 <0.01 1.7 250 6.8 548 -17 59

7.6 <0.01 1.4 200 7.8 289 -120 14

P1-10 .– <0.01 .– 300 6.7 560 – –

<0.31 <0.01 1.3 290 7.1 500 -19 15

0.06 <0.01 4.9 290 7.2 476 -24 15

Table 2. Predominant redox conditions and ground-water geochemical data collected from 1996 to 2001 at Operable Unit 1, Naval Undersea 

Warfare Center, Division Keyport, Washington—Continued

[All data except those shaded were published previously in Dinicola and others (2002). Predominant redox conditions: A, aerobic; Fe, iron reducing; 

M, methanogenic; Mn, manganese reducing; S, sulfate reducing. Abbreviations: mg/L, milligrams per liter; nM, nanomolar; μS/cm, microsiemens per 

centimeter at 25o Celsius; mV, millivolt. Symbols: <, actual value is less than value shown; >, actual value is greater than value shown; –, not analyzed]

Well No.

Filtered 

sulfate

(mg/L)

Unfiltered 

sulfide

(mg/L)

Dissolved 

methane 

(mg/L)

Filtered 

bicarbonate 

(mg/L)

pH

(units)

Specific 

conductance 

(μS/cm)

ORP

(mV)

Filtered 

chloride 

(mg/L)
14 Selected Natural Attenuation Monitoring Data, Operable Unit 1, Naval Undersea Warfare Center, Division Keyport, Washington, June 2001

Overall, geochemical data from water samples 

collected in June 2001 indicate that redox conditions in 

the upper aquifer water remain favorable for reductive 

dechlorination of chlorinated VOCs because strongly 

reducing conditions persisted beneath much of the 

former landfill. Redox conditions in ground water from 

the intermediate aquifer just down gradient of the 

landfill (wells MW1-25 and MW1-28) appear to have 

become more favorable for reductive dechlorination; 

dissolved H2 concentrations indicated strongly 

reducing conditions there for the first time. The range 

over which dissolved H2 concentrations fluctuated was 

reported if dissolved H2 did not stabilize and did not 

consistently increase or decrease over time. Although 

changes in redox conditions were observed at certain 

wells during 2001, a longer monitoring period is 

needed to ascertain if phytoremediation activities are 

affecting the ground-water chemistry.

Comparison of Unfiltered (Total) and Filtered (Dissolved) 

Organic Carbon Concentrations

Prior to 2001, only unfiltered organic carbon data 

were collected by the USGS at OU 1. However, filtered 

organic carbon may be a better measure of bioavailable 

organic carbon. Unfiltered and filtered organic carbon 

analyses were done for all samples collected in June 

2001 in order to compare the two types of data.

As expected, the unfiltered organic carbon 

concentrations were slightly greater than filtered 

organic carbon concentrations for 18 of 20 samples 

(table 2 and fig. 3). On average, unfiltered organic 

carbon concentrations were 0.5 mg/L (11 percent) 

greater than filtered organic carbon concentrations, and 

the median difference between the two measures was 

0.4 mg/L (6 percent). Thus, filtered organic carbon data 

collected in the future could be reasonably compared 

with historical unfiltered organic carbon data by 

multiplying the historical data by a factor of about 0.9.

0

10

20

30

40

50

60

70

0 10 20 30 40 50 60 70

UNFILTERED (TOTAL) ORGANIC CARBON, IN MILLIGRAMS PER LITER

FILTERED (DISSOLVED) ORGANIC CARBON, IN MILLIGRAMS PER LITER

1 to 1 ratio line

Figure 3. Unfiltered and filtered organic carbon concentrations 

for June 2001 at Operable Unit 1, Naval Undersea Warfare Center, 

Division Keyport, Washington.
Natural Attenuation Monitoring Data 15

Chlorinated Volatile Organic Compound Data

June 2001 and previous CVOC data (Dinicola 

and others, 2002) collected from piezometers by the 

USGS at OU 1 are shown in table 3. Duplicate CVOC 

samples were collected and analyzed for piezometer 

P1-4 and the CVOC concentrations agreed within 7 

percent (table 3). Complete analytical results, including 

chlorinated and non-chlorinated VOCs, for June 2001 

and previous years are available from the USGS 

NWISweb site http://waterdata.usgs.gov/wa/nwis/

qwdata. There were a few substantial differences 

between the June 2001 and previously measured 

CVOC concentrations, but neither the cause of those 

differences nor the relation between redox conditions 

and CVOC concentrations throughout OU 1 are 

evaluated in this report.

Table 3. Concentrations of selected chlorinated volatile organic compounds in ground water from piezometers sampled from 1999 to 2001 by the U.S. 

Geological Survey at Operable Unit 1, Naval Undersea Warfare Center, Division Keyport, Washington

[All data except those shaded were published previously in Dinicola and others (2002). Chlorinated volatile organic compounds (CVOCs): PCE, 

tetrachloroethene; TCE, trichloroethene; cis-DCE, cis-1,2-dichloroethene; trans-DCE, trans-1,2-dichloroethene; VC, vinyl chloride; TCA, 1,1,1-

trichloroethane; 1,1-DCA, 1,1-dichloroethane; CA, chloroethane; 1,1-DCE, 1,1-dichloroethene; BTEX, benzene, toluene, ethylbenzene, and xylene; CVOCs, 

chlorinated volatile organic compounds. Abbreviations: μg/L, micrograms per liter. Symbols: <, actual value is less than value shown; –, not analyzed; 

nd, not detected]

Piezometer

No.

Date 

sampled

PCE

(μg/L)

TCE

(μg/L)

cis-DCE

(μg/L)

transDCE

(μg/L)

VC

(μg/L)

1,1,1-

TCA

(μg/L)

1,1-DCA

(μg/L)

CA

(μg/L)

1,1-DCE

(μg/L)

Total

BTEX

(μg/L)

Total

CVOCs

(μg/L)

P1-1 06-09-99 <2 11 6.1 <1 <4 <2 0.24 <4 <2 19 17

P1-3 06-09-99 <16 35 450 20 120 <16 <16 3.6 <16 nd 630

P1-4 06-09-99 <130 160 4,800 56 540 <130 <130 <270 <130 nd 5,600

06-13-01 <20 <20 4,900 46 650 <20 <20 <20 <20 nd 5,600

(duplicate) 06-13-01 <20 <20 5,000 44 670 <20 <20 <20 <20 nd 5,700

P1-5 06-08-99 <13 440 400 3.5 11 <13 <13 15 <13 47 870

P1-6 06-08-99 <400 74 16,000 170 5,400 <400 1,500 300 <400 nd 23,000

06-14-01 <20 370 16,000 220 9,900 <20 4,800 610 11 88 32,000

P1-7 06-08-99 <670 26,000 35,000 210 3,100 <670 <670 <1,300 <670 nd 64,000

06-22-00 3.6 27,000 44,000 220 3,800 0.24 17 8.4 72 16 75,000

06-14-01 <20 26,000 37,000 190 4,000 <20 <20 <20 44 nd 68,000

P1-8 06-07-99 <710 190 25,000 210 3,400 <710 <710 <1,400 <710 nd 29,000

06-14-01 <20 810 8,600 62 4,200 <20 <20 <20 <20 nd 14,000

P1-9 06-08-99 <2,000 48,000 88,000 470 7,200 <2,000 <2,000 <4,000 <2,000 nd 140,000

06-22-00 5.0 88,000 64,000 320 5,800 <10 2.6 <20 47 22 160,000

06-14-01 <40 29,000 7,300 32 450 <40 <40 <40 <40 nd 37,000

P1-10 06-07-99 <1,000 14,000 34,000 270 2,500 <1,000 <1,000 <2,000 <1,000 nd 51,000

06-22-00 1.0 8,700 13,000 100 2,300 <0.1 1.2 0.13 16 12 24,000

06-13-01 <20 6,600 12,000 68 1,900 <20 <20 <20 11 nd 21,000
16 Selected Natural Attenuation Monitoring Data, Operable Unit 1, Naval Undersea Warfare Center, Division Keyport, Washington, June 2001

SUMMARY

Previous investigations have shown that natural 

attenuation and biodegradation of chlorinated volatile 

organic compounds (CVOCs) are substantial in shallow 

ground water beneath the 9-acre former landfill at 

Operable Unit 1 (OU 1), Naval Undersea Warfare 

Center (NUWC), Division Keyport, Washington. The 

U.S. Geological Survey (USGS) has continued to 

monitor ground-water geochemistry to assure that 

conditions remain favorable for contaminant 

biodegradation. This report presents the ground-water 

geochemical and selected CVOC data collected at OU 

1 by the USGS during June 11-14, 2001 in support of 

the long-term monitoring for natural attenuation.

Overall, the June 2001 data indicate that redox 

conditions in the upper aquifer remain favorable for 

reductive dechlorination of CVOCs because strongly 

reducing conditions persisted beneath much of the 

former landfill. Redox conditions in the intermediate 

aquifer down gradient of the landfill appear to have 

become more favorable for reductive dechlorination 

because June 2001 dissolved hydrogen concentrations 

indicated strongly reducing conditions there for the 

first time. Although changes in redox conditions were 

observed at certain wells during 2001, a longer 

monitoring period is needed to ascertain if 

phytoremediation activities are affecting the groundwater chemistry.

A minor change to future monitoring is 

proposed. Filtered organic carbon (previously referred 

to as dissolved, and defined as that which passes 

through a 0.45-micrometer membrane filter) should be 

analyzed in the future rather than unfiltered (previously 

referred to as total) organic carbon because the filtered 

analysis may be a better measure of bioavailable 

organic carbon. Unfiltered and filtered organic carbon 

data were collected during June 2001 for comparison. 

Filtered organic carbon data collected in the future 

could be reasonably compared with historical 

unfiltered organic carbon data by multiplying the 

historical data by a factor of about 0.9. 

REFERENCES CITED

Bradley, P.M, Landmeyer, J.E., and Dinicola, R.S., 1998, 

Anaerobic oxidation of [1,2-14C] dichloroethene under 

Mn(IV)-reducing conditions: Applied and 

Environmental Microbiology, v. 64, no. 4, p. 1560-

1562.

Chapelle, F.H., Vroblesky, D.A., Woodward, J.C., and 

Lovely, D.R., 1997, Practical considerations for 

measuring hydrogen concentrations in groundwater: 

Environmental Science and Technology, v. 31, no. 10, 

p. 2873-2877.

Connor, B.F., Rose, D.L., Noriega, M.C., Murtagh, L.K., and 

Abney, S.R., 1998, Methods of analysis by the U.S. 

Geological Survey National Water Quality 

Laboratory—Determination of 86 volatile organic 

compounds in water by gas chromatography/mass 

spectrometry, including detections less than reporting 

limits: U.S. Geological Survey Open-File Report 97-

829, 78 p. 

Dinicola, R.S., S.E. Cox, J.E. Landmeyer, and P.M. Bradley, 

2002, Natural attenuation of chlorinated volatile 

organic compounds in ground water at Operable Unit 1, 

Naval Undersea Weapons Center, Division Keyport, 

Washington: U.S. Geological Survey Water-Resources 

Investigations Report 02-4119.

Fishman, M.J., ed., 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.

Franson, M.H., ed. 1992, Standard Methods for the 

Examination of Water and Wastewater. l8th Edition: 

American Public Health Association, American Water 

Works Association, and Water Environment Federation, 

Washington D.C. 

Gossett, J.M., and Zinder, S.H., 1996, Microbiological 

aspects relevant to natural attenuation of chlorinated 

ethenes: in Proceedings of the symposium on natural 

attenuation of chlorinated organics in ground water, 

EPA/540/R-96/509, Dallas, TX, September 1996.
References Cited 17

Hach Company, 1998, DR/2010 Spectrophotometer 

Procedures Manual: Hach Company, Loveland, CO.

Kampbell, D.H., Wilson, J.T., and Vandegrift, S.A., 1989, 

Dissolved oxygen and methane in water by a GC 

headspace equilibrium technique: International Journal 

of Environmental. Analytical Chemistry, v. 36, 

p. 249-257.

McCarty, P.L., and Semprini, L., 1994, Ground-water 

treatment for chlorinated solvents: in Handbook of 

Bioremediation: Boca Raton, Lewis Publishers, 

p. 87-116.

The TEC LTM Team, 2002, 2001 annual report Operable 

Unit 1, Area 1, former base landfill, Naval Undersea 

Warfare Center Division, Keyport, Washington: 

Prepared by CH2MHill Constructors, Inc., Seattle, 

Washington, for Engineering Field Activity, Northwest, 

Naval Facilities Engineering Command, Poulsbo, WA, 

28 p.

URS Consultants, Inc., 1997, Final summary data 

assessment report for Operable Unit 1 Naval Undersea 

Warfare Center Division Keyport, Washington: 

Prepared by URS Consultants, Seattle, Washington, for 

Engineering Field Activity, Northwest, Naval Facilities 

Engineering Command, Poulsbo, WA, 3 volumes.

URS Consultants, Inc., 1998, Final record of decision for 

Operable Unit 1 Naval Undersea Warfare Center 

Division Keyport, Washington: Prepared by URS 

Consultants, Seattle, Washington, for Engineering Field 

Activity, Northwest, Naval Facilities Engineering 

Command, Poulsbo, WA, 111 p.

URS Greiner, Inc., 1999, Phytoremediation closure report 

for Operable Unit 1 Naval Undersea Warfare Center 

Division Keyport, Washington: Prepared by URS 

Greiner, Inc., Seattle, Washington for Engineering Field 

Activity, Northwest, Naval Facilities Engineering 

Command, Poulsbo, WA.

U.S. Geological Survey, 1997 to 2001, National field manual 

for the collection of water-quality data: U.S. Geological 

Survey Techniques of Water-Resources Investigations, 

book 9, chaps. A1-A9, 2 v., variously paged. [Also 

available online at http://pubs.water.usgs.gov/twri9A. 

Chapters originally were published from 1997-1999; 

updates and revisions are ongoing and are summarized 

at: http://water.usgs.gov/owq/FieldManual/

mastererrata.html]
Dinicola USGS-OFR 03-344

Printed on recycled paper

Selected Natural Attenuation Monitoring Data, Operable Unit 1,

Naval Undersea Warfare Center, Division Keyport, Washington, June 2001