U.S. Department of the Interior

U.S. Geological Survey

Prepared in cooperation with 

Department of Navy, 

Naval Facilities Engineering Command, 

Engineering Field Activity, Northwest

Scientific Investigations Report 2006–5030

SR

308

SR

303

BROWNSVILLE H GI HWAY

L I B E R T Y B A Y 

Dogfish Bay

Shallow

lagoon

Tide

flats

KEYPORT

VIRGINIA

POINT

P o r t

O r c h a r d

Evidence for Chloroethene Biodegradation in 

Ground Water at the Former Building 957 Drum Storage Area, 

Area 2, Operable Unit 2, Naval Undersea Warfare Center, 

Division Keyport, Washington

Naval Undersea

Warfare Center,

Division Keyport

FORMER BUILDING 957

DRUM STORAGE AREA
Evidence for Chloroethene Biodegradation in 

Ground Water at Former Building 957 Drum 

Storage Area, Area 2, Operable Unit 2, Naval 

Undersea Warfare Center, Division Keyport, 

Washington

By R.S. Dinicola

Prepared in cooperation with

Department of Navy

Naval Facilities Engineering Command

Engineering Field Activity, Northwest

Scientific Investigations Report 2006-5030

U.S. Department of the Interior

U.S. Geological Survey
U.S. Department of the Interior

Gale A. Norton, Secretary

U.S. Geological Survey

P. Patrick Leahy, Acting Director

U.S. Geological Survey, Reston, Virginia: 2006

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

Box 25286, Denver Federal Center

Denver, CO 80225

For more information about the USGS and its products:

Telephone: 1-888-ASK-USGS

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

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

endorsement by the U.S. Government.

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

reproduce any copyrighted materials contained within this report.

Suggested citation:

Dinicola, R.S., 2006, Evidence for chloroethene biodegradation in ground water at former Building 957 drum storage 

area, Area 2, Operable Unit 2, Naval Undersea Warfare Center, Division Keyport, Washington: U.S. Geological Survey 

Scientific Investigations Report 2006-5030, 12 p. 
iii

Contents

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

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

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

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

Hydrogeologic Setting ........................................................................ 4

Surface-Water and Ground-Water Flow ................................................... 4

Acknowledgments ................................................................................. 4

Sample Collection and Analysis ........................................................................ 4

Evidence for Chloroethene Biodegradation in Ground Water ....................................... 6

Geochemical Data and Predominant Redox Conditions ....................................... 6

Possible Biodegradation Mechanisms for Chloroethenes .................................... 8

Chloroethene Data ................................................................................. 8

Evaluation of Evidence for Chloroethene Biodegradation .................................... 10

Summary and Conclusions .............................................................................. 11

References Cited.......................................................................................... 12

Figures

Figure 1. Map showing location of former Building 957 drum storage area, Area 2,

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

Figure 2. Map showing location of monitoring wells and June 2003 water level

altitudes at former Building 957 drum storage area, Area 2, Naval Undersea

Warfare Center, Division Keyport, Washington .......................................... 3

Figure 3. Map showing concentrations of trichloroethene (TCE), cis-dichloroethene

(cis-DCE), and vinyl chloride (VC) in ground water at former Building 957

drum storage area, Area 2, Naval Undersea Warfare Center, Division

Keyport, Washington, June and August 2003 .......................................... 10

Tables

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

wells at former Building 957 drum storage area, Area 2, Naval Undersea

Warfare Center, Division Keyport, Washington, June 23, 2003 ........................ 5

Table 2. Predominant reduction-oxidation (redox) conditions and ground-water

geochemical data collected at former Building 957 drum storage area, 

Area 2, Naval Undersea Warfare Center, Division Keyport, Washington, 

June 23, 2003 ................................................................................. 7

Table 3. Potential relative efficiency of chloroethene biodegradation through

microbial reductive dechlorination or microbial oxidation as a function of 

in situ redox conditions ..................................................................... 8

Table 4. Chloroethene concentrations in ground water at former Building 957 drum

storage area, Area 2, Naval Undersea Warfare Center, Division Keyport,

Washington, 1991 to 2004 .................................................................. 9
iv

Conversion Factors, Datums, and Acronyms and 

Abbreviations 

CONVERSION FACTORS

Multiply By To obtain

acre 4,047 square meter

acre 0.4047 hectare

foot (ft) 0.3048 meter

feet per foot (ft/ft) 0.3048 meter per meter

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

gallon (gal) 3.785 liter

inch (in.) 2.54 centimeter

Temperature in degrees Fahrenheit (°F) may be converted to degrees Celsius (°C) as follows: 

°C=(°F-32)/1.8.

Specific conductance is given in microsiemens per centimeter at 25 degrees Celsius 

(μS/cm at 25 °C).

Concentrations of chemical constituents in water are given either in milligrams per liter (mg/L), 

micrograms per liter (μg/L), 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 North American Vertical Datum of 1988 

(NAVD 1988). 

Horizontal coordinate information is referenced to the North American Datum of 1927 (NAD 27). 

Altitude, as used in this report, refers to distance above the vertical datum.

ACRONYMS AND ABBREVIATIONS

Acronym and abbreviation Meaning

NWQL National Water Quality Laboratory

USGS U.S. Geological Survey

1,2-DCE total 1,2-dichloroethene

cis-DCE cis-1,2-dichloroethene

trans-DCE trans-1,2-dichloroethene

DO dissolved oxygen

H2 dissolved hydrogen

nM nanomolar

PCE Tetrachloroethene

TCE Trichloroethene

VC vinyl chloride 

VOC volatile organic compound

μm micrometer
Abstract

Shallow ground water is contaminated with the 

chloroethenes—trichloroethene (TCE), cis-1,2-dichloroethene 

(cis-DCE), and vinyl chloride (VC)—beneath the former 

Building 957 drum storage area at the Naval Undersea 

Warfare Center, Division Keyport, Washington. Chloroethene 

concentrations, monitored by the U.S. Navy since 1991, 

generally have decreased. To better understand the decrease 

in concentrations, the U.S. Geological Survey collected, 

analyzed, and evaluated water level, geochemical, and 

chloroethene data from eight monitoring wells at the site 

during June and August 2003 for evidence of chloroethene 

biodegradation.

The geochemical and chloroethene data clearly indicated 

that much of the TCE and VC, and some cis-DCE was 

biodegraded in ground water as it flowed beneath and slightly 

beyond the former Building 957 drum storage area. No 

apparent TCE biodegradation through any mechanism was 

indicated at the upgradient margin of the former drum storage 

area where aerobic ground water was indicated. Substantial 

reductive dechlorination of TCE and cis-DCE was indicated 

in the downgradient anaerobic ground water. Reductive 

dechlorination was definitively indicated by the presence 

of daughter products cis-DCE and VC in the downgradient 

wells. Ground-water redox conditions were favorable for 

biodegradation through microbial oxidation of VC (and 

cis-DCE to a lesser extent) in downgradient wells, and 

measured increases in the cis-DCE to VC ratio over time at 

those wells provided strong evidence for microbial oxidation 

of VC. All chloroethene concentrations detected in ground 

water at the former Building 957 drum storage area were 

less than 20 μg/L. In three wells where the 2003 TCE or VC 

concentrations exceeded remediation goals, concentrations 

consistently decreased over time.

Introduction

Shallow ground water is contaminated with chloroethenes 

beneath the former Building 957 drum storage area at 

the Naval Undersea Warfare Center, Division (NUWCD) 

Keyport, Washington (figs. 1 and 2). Solvents, fuel, and oil 

were stored on the formerly unpaved area, and an estimated 

4,000-8,000 gal of these chemicals were discharged to the 

ground (URS Consultants, Inc., 1993). Administratively, the 

site is part of Area 2 of Operable Unit 2 at NUWCD Keyport, 

and is being remediated under authority of the Comprehensive 

Environmental Response, Compensation, and Liability Act.

Primary contaminants of concern in ground 

water at Area 2 are the chloroethene compounds—

trichloroethene (TCE) and vinyl chloride (VC), although 

cis-1,2-dichloroethene (cis-DCE) and BTEX (benzene, 

toluene, ethylbenzene, and xylene) also have been detected 

(URS Consultants, Inc., 1993). Contaminant concentrations 

at the site always have been relatively low, so human health 

risks, ecological risks, and the potential for offsite migration 

were determined to be low (URS Consultants, Inc., 1993). 

Therefore, remedies selected for Area 2 were ground-water 

monitoring to document the expected decrease of chloroethene 

concentrations, and institutional controls to exclude residential 

use and prevent construction of water-supply wells (URS 

Consultants, Inc., 1994).

Chloroethene concentrations in ground water at former 

Building 957 drum storage area have been monitored 

regularly by the U.S. Navy since 1995 to document the 

expected decreases in concentration due to natural attenuation 

processes. Data indicate that concentrations generally have 

decreased (CH2M HILL Constructors, Inc., 2003). To better 

understand the measured decreases in concentrations, the U.S. 

Geological Survey (USGS) collected water samples from 

wells at former Building 957 drum storage area, analyzed the 

samples for geochemical and chloroethene concentrations, 

and evaluated the data for evidence of chloroethene 

biodegradation.

Evidence for Chloroethene Biodegradation in Ground 

Water at Former Building 957 Drum Storage Area, Area 2, 

Operable Unit 2, Naval Undersea Warfare Center, Division 

Keyport, Washington 

By R.S. Dinicola
wa9FAT2_02_fig01

SR

308

BROWNSVILLE SR

303

HIGHWAY

1000 2000 3000 FEET 

0 900 METERS 

0

300 600

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

Projection: Washington State Plane, North Zone 

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 

FORMER BUILDING 957

DRUM STORAGE AREA

P o r t 

O r c h a r d 

NAVAL UNDERSEA

WARFARE CENTER,

DIVISION KEYPORT

Location of 

figures 2 and 3 

Van Meter Road 

Figure 1. Location of former Building 957 drum storage area, Area 2, Naval Undersea Warfare Center, Division Keyport, 

Washington.

   Chloroethene in Ground Water, Area 2, Operable Unit 2, Naval Undersea Warfare Center, Division Keyport, WA
wa9FAT2_02_fig02

FORMER BUILDING 734 

DRUM STORAGE AREA 

VAN METER ROAD

SPILL AREA

FORMER BUILDING 

957 DRUM

STORAGE AREA 

0

0 10 20 30 40

50

50 METERS

100 150 200 250 FEET

Water level altitude contour (feet)

Creek

Fence line

Topographic contour

Monitoring wells sampled

Monitoring wells not sampled

EXPLANATION

MW2-7

2MW-1

25

20

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

Projection: Washington State Plane, North Zone

VAN METER ROAD 

25

15

25

30

20

20

122°37’30” 122°37’25”

47°

41’

30”

47°

41’

35”

12

14

16

18

20

22

24

MW2-10

MW2-7

MW2-6

MW2-8

MW2-5

2MW-6 

2MW-5 

2MW-1 

2MW-4 

2MW-3 

2MW-2 

Figure 2. Location of monitoring wells and June 2003 water level altitudes at former Building 957 drum storage area, Area 2, Naval 

Undersea Warfare Center, Division Keyport, Washington.

Purpose and Scope

This report describes the results of a study to evaluate 

evidence for biodegradation of chloroethenes in ground water 

at former Building 957 drum storage area, Area 2, Naval 

Undersea Warfare Center, Division Keyport, Washington. 

Water level, geochemical, and chloroethene data collected 

by the USGS from eight wells during 2003 are presented and 

evaluated along with data collected by the U.S. Navy from 

1991 to 2004.

Description of Study Area

NUWCD Keyport is mostly on a small peninsula in 

Kitsap County, Wash., in an extension of Puget Sound called 

Liberty Bay (fig. 1). The base occupies the eastern part of the 

peninsula, which is connected to the mainland by a narrow 

strip of land that was mostly tidal wetland before it was filled 

in by the Navy by the 1940s. The mainland to the west and 

southwest of Keyport peninsula rises steeply to rolling uplands 

at an altitude of 200–400 ft.

Introduction 
Keyport has a temperate marine climate characterized 

by warm, dry summers and cool, wet winters (Washington 

State University, 1968). Mean annual temperature is about 

51°F; January is the coolest month and July is the warmest. 

Mean annual precipitation is about 31 in., 77 percent of which 

falls from October through March. Snowfall is infrequent and 

rainfall generally is not intense.

Area 2 is in the southwest corner of NUWCD Keyport 

(fig. 1), and includes three distinct contaminant sites: Van 

Meter Road spill area, former Building 734 drum storage area, 

and former Building 957 drum storage area (fig. 2). The onethird acre former Building 957 drum storage area is the focus 

of this report. The site is about 500 ft southwest of a shallow 

lagoon that is an extension of Liberty Bay, and is about 40 ft 

south of an unnamed creek that drains into the lagoon (fig. 1). 

The altitude of the site is 20 to 25 ft, and the land rises steeply 

to the south and west of the site. The area immediately 

surrounding the site is primarily forested. 

Hydrogeologic Setting

NUWCD Keyport is in the Puget Sound Lowland, a 

topographic and structural depression between the Cascade 

Range to the east and the Olympic Mountains to the west. 

Keyport peninsula and surrounding areas are composed 

primarily of unconsolidated Pleistocene glacial and 

interglacial deposits overlying Tertiary and older bedrock 

(Blunt and others, 1987). A veneer of more recent alluvium, 

including stream, beach, landslide, and marsh deposits, covers 

the youngest glacial deposits in some areas. Unconsolidated 

deposits are more than 1,500 ft thick beneath the Keyport 

peninsula (Jones, 1999). 

Ground water beneath Area 2 is in a series of aquifers 

composed of permeable sand, gravel, or fill materials 

separated by finer grained silt or clay layers. Contamination at 

Area 2 is known to occur only in the approximately 30-ft thick 

unconfined aquifer beneath the site, and only that aquifer is 

described in this report; see Kahle (1998) and Jones (1999) for 

information about deeper sediments.

 The unconfined aquifer consists of five defined waterbearing units, many present over limited areas, overlying a 

regionally extensive and thick confining unit consisting of 

clay and silt (URS Consultants, Inc., 1993). The uppermost 

water-bearing unit consists of about 10 ft of artificial fill. Most 

fill is unsaturated and has variable lithology and permeability. 

A discontinuous unit consisting of as much as a few feet of 

organic-rich silt, clay, and sand lies beneath the fill. These 

marsh and tide flats deposits are mostly fine-grained, but 

generally are not compacted and are somewhat permeable. A 

discontinuous unit consisting of as much as 15 ft of sand and 

sandy gravel lies beneath the marsh and tide flats deposits. 

These advance glacial outwash deposits are highly permeable. 

A continuous unit consisting of as much as 25 ft of silt, fine 

sand, and clay lies beneath the outwash deposits. These 

non-glacial deposits have relatively low permeability, but not 

low enough to be considered a confining layer by previous 

site investigators.The lowest part of the uppermost aquifer is 

a continuous unit consisting of 2-7 ft of clean to silty sand 

with local gravel. These non-glacial deposits have moderate 

permeability.

Surface-Water and Ground-Water Flow

Small perennial creeks north and south of the former 

Building 957 drum storage area flow from the southwest to 

the northeast towards the shallow lagoon. Ground water flows 

from the southwest towards the northeast beneath the site, 

and likely discharges to the northern creek at some distance 

downgradient from storage area (fig. 2). Water levels at 

the site are not tidally influenced. The horizontal hydraulic 

gradient beneath the site is about 0.05 ft/ft (URS Consultants, 

Inc., 1993), and the estimated hydraulic conductivities for the 

uppermost aquifer range from 0.14 to 11 ft/d, with a geometric 

mean of 1.2 ft/d (URS Consultants, Inc., 1993). The slug tests 

used to estimate hydraulic conductivities did not indicate 

any depth specific or consistent spatial trends. Assuming an 

effective porosity of 0.25 for the aquifer, the estimated linear 

ground-water flow velocity ranges from 0.03 to 2.2 ft/d with 

an assumed geometric mean of 0.24 ft/d.

Acknowledgments

The author thanks Douglas Thelin of the Naval Facilities 

Engineering Command, Engineering Field Activity, Northwest 

for his guidance and for securing funding for the continued 

monitoring. Gene Ellis of NUWCD Keyport provided logistic 

support for field activities. Bernie Wong of CH2M HILL 

Constructors, Inc., in Bellevue, Wash. provided additional 

chloroethene data. 

Sample Collection and Analysis

Water-level measurements and sample collection, 

processing, and field analyses were made in accordance with 

applicable USGS procedures (U.S. Geological Survey, 1997 

to 2004) except samples were collected using a peristaltic 

pump. The geochemical measurements and concentrations 

determined for water samples from wells included dissolved 

hydrogen (H2), dissolved oxygen (DO), filtered organic 

carbon, filtered nitrate plus nitrite, filtered manganese, 

filtered iron (II), filtered sulfate, unfiltered sulfide, dissolved 

methane, dissolved carbon dioxide, pH, specific conductance, 

and filtered chloride. Concentrations of 64 volatile organic 

compounds (VOCs), including the chloroethenes of interest, 

were analyzed by the USGS for water samples from five of 

the wells, and chloroethene concentrations were analyzed by 

the Navy for samples from three other wells. Monitoring wells 

sampled were different depths and diameters (table 1), but 

all were constructed with PVC casings and screens with sand 

filter packs.

 Chloroethene in Ground Water, Area 2, Operable Unit 2, Naval Undersea Warfare Center, Division Keyport, WA
After measuring depth to water, all samples were 

collected with a peristaltic pump and single-use polyurethane 

tubing. A stainless-steel weight was attached to the bottom 

of the tubing to accurately collect the sample from the midscreen elevation in each well. Samples were collected after 

approximately three casing-volumes of water were purged 

from the wells and after allowing pH, specific conductance, 

and DO to stabilize (within 0.1 units, 5 percent, and 0.3 mg/L, 

respectively). The three analytes were measured in a 

flow-through chamber using temperature-compensated sensors 

from a YSITM data sonde. The specific conductance sensor 

was checked daily with standard reference solutions; the pH 

sensor was calibrated daily with two pH standards; and the 

dissolved-oxygen sensor was calibrated daily with watersaturated air and occasionally verified with zero dissolvedoxygen solution. Dissolved-oxygen analyses were confirmed 

for most water samples using 0 to 1 mg/L CHEMets 

Rhodazine-DTM colorimetric ampoules (manufactured 

by CHEMetrics, Inc., Calverton, Va.). The ampoules were 

filled directly from the sampling tube after well purging was 

complete.

Iron (II) concentrations were measured in the field in 

a sample filtered through a 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 8146 (Hach Company, 1998). 

Sulfide concentrations were measured in the field using a 

colorimetric methylene-blue indicator method using the 

same spectrophotometer according to analytical method 

number 8131 (Hach Company, 1998). Information about 

the methodologies used to determine iron and sulfide 

concentrations is described at http://www.hach.com. Dissolved 

carbon dioxide (CO2) concentrations were measured in the 

field using Titret®-Sodium hydroxide tirtrant with a pH 

indicator (manufactured by CHEMetrics, Inc., Calverton, Va.).

Dissolved H2 in ground water was sampled using 

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

Concentrations were measured in the field using a gas 

chromatograph equipped with a reduction gas detector. Initial 

gas samples from each well were collected and analyzed 

after at least 20 minutes of stripping; subsequent samples 

were collected and analyzed at about 5-minute intervals until 

consecutive H2 concentrations stabilized to within 10 percent, 

a process that often required 1 hour or more.

Samples collected to determine nitrate, manganese, 

sulfate, and chloride concentrations were filtered through a 

0.45-μm membrane filter into polyethylene bottles, chilled, 

and sent to the USGS National Water Quality Laboratory 

(NWQL) in Lakewood, Colo. The manganese sample was 

acidified in the field with nitric acid to a pH less than 2, 

and then analyzed at NWQL by inductively coupled plasma 

as described by Fishman (1993). Chloride and sulfate 

concentrations were analyzed using ion chromatography as 

described by Fishman and Friedman (1989). Nitrate plus 

Table 1. Construction data and water-level measurements for selected monitoring wells at former Building 957 drum storage area, Area 2, 

Naval Undersea Warfare Center, Division Keyport, Washington, June 23, 2003.

[Well No.: MW, monitoring well. 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: Feet above 

or below (-) NAVD 88. Depth of well and screened interval: Feet below land surface. Measuring point: Water levels in wells usually are reported as depths 

below land surface, although the measuring point can be any convenient fixed place near the top of well. For these wells and piezometers, measuring points are 

marked points on the tops of well casings and vary from being near the land surface to a few feet above land surface. Altitude of the measuring point commonly 

is recorded so static water levels also can be reported as altitudes. Abbreviations: ft, foot; in., inch; –, no data]

Well No. USGS site No. Time

Water level

altitude

(ft)

Water level

(ft below 

measuring 

point)

Altitude of 

measuring

point

(ft)

Depth of well

(ft)

Casing 

diameter

(in.)

Screened 

interval

(ft)

2MW–1 474134122372601 1145 18.71 4.69 23.40 19.0 2 3–18

2MW–2 474136122372501 1335 14.29 5.81 20.10 21.0 2 5–20

2MW–3 474136122372301 1415 12.32 6.78 19.10 20.0 2 4.5–19.5

2MW–4 474132122372601 1710 24.41 7.25 31.66 18.5 2 7.5–17.5

2MW–5 – – – – – – – –

2MW–6 474136122372401 1530 11.17 7.15 18.32 19.0 2 7–14

MW2–5 474136122372601 1115 16.43 4.73 21.16 16.0 4 5–15

MW2–6 – – – – – 37.0 4 26–36

MW2–7 – – – – – 32.0 4 21–31

MW2–8 474134122372301 1245 14.19 4.70 18.89 13.0 4 7–12

MW2–10 474137122372301 1615 11.20 6.70 17.90 12.8 4 6.8–11.8

Sample Collection and Analysis   
nitrite concentrations (reported as nitrite plus nitrate as N) 

were analyzed colorimetrically by cadmium reduction and 

diazotization as described by Fishman (1993). Results for the 

nitrate plus nitrite analyses are referred to simply as nitrate in 

this report because of the expected small nitrite contribution to 

the total concentration.

Samples for dissolved organic carbon analysis were 

filtered through a 0.45-μm filter, collected in amber glass 

bottles, acidified in the field with sulfuric acid to a pH less 

than 2, chilled to less than 4°C, and shipped to the USGS 

laboratory in Ocala, Fla., for analysis. Organic carbon 

concentrations were measured using high temperature 

combustion according to Standard Method 5310B as described 

by Franson (1992).

Samples for dissolved methane analysis were collected 

in 150-mL glass bottles, sealed with rubber stoppers, chilled 

to less than 4°C, and analyzed at the USGS Field Services 

Unit in Tacoma, Wash. Samples were analyzed using a gas 

chromatograph with a flame-ionization detector as described 

by Kampbell and others (1989). Samples for VOC analysis 

were collected in pre-acidified 40-mL glass vials, placed on 

ice, and shipped to the Severn Trent Laboratories in Denver, 

Colo., for analysis using purge and trap capillary-column gas 

chromatography/mass spectrometry (Method 8260B, U.S. 

Environmental Protection Agency, 1996).

Evidence for Chloroethene 

Biodegradation in Ground Water

Geochemical Data and Predominant Redox 

Conditions

June 2003 geochemical data and inferred predominant 

reduction-oxidation (redox) conditions are shown in 

table 2. The predominant redox conditions were inferred by 

considering dissolved oxygen and dissolved H2 concentrations 

combined with other geochemical concentrations. Dissolvedoxygen concentrations greater than 1 mg/L generally indicate 

aerobic conditions and concentrations less than 1 mg/L 

indicate one of the anaerobic conditions. Exceptions are 

possible when water levels in low-yield monitoring wells are 

drawn down by pumping while being sampled, or when long 

well screens intersect aerobic ground water near the water 

table and anaerobic ground water at greater depths. Chapelle 

and others (1995) developed a method to determine the 

specific redox condition of anaerobic ground water based on 

dissolved H2 concentrations, where less than 0.05 nanomolar 

(nM) indicates manganese or nitrate reduction, 0.1-0.8 nM 

indicates iron reduction, 1-5 nM indicates sulfate reduction, 

and greater than 5 nM indicates methanogenesis. Exceptions 

are common in contaminant plumes because of complicating 

effects from different absolute concentrations of dissolved 

redox species, from different iron-oxide minerals that serve as 

electron acceptors, from different ground-water temperatures, 

and from overlapping and not exclusive redox conditions 

(Hoehler and others, 1998; Jakobsen and others, 1998; 

Christensen and others, 2000). Therefore, all geochemical 

data and best professional judgment were used to infer the 

predominant redox conditions listed in table 2. For instance, 

at well MW2-8, the 1.5 mg/L of dissolved oxygen measured 

was not likely indicative of predominantly aerobic conditions 

in the aquifer. The dissolved-oxygen concentration at MW2-8 

decreased steadily to less than 1 mg/L during the first 

30 minutes of low-flow purging, but the concentration then 

increased steadily to 1.5 mg/L as purging continued and the 

well nearly went dry. Ground water entering the well and 

trickling down the screen to the pump intake likely added 

dissolved oxygen to the sample. The manganese concentration 

of 3.0 mg/L at MW2-8 is not consistent with aerobic 

conditions in the aquifer, and manganese concentrations are 

not affected by drawdown during sampling.

At former Building 957 drum storage area, aerobic 

redox conditions were inferred only at well 2MW-1 near the 

southwest corner of the site. Dissolved-oxygen concentration 

at well 2MW-1 was 1.0 mg/L, nitrate concentration was 

0.62 mg/L, and only trace concentrations of iron (II) and 

manganese were detected. These data clearly indicate that the 

15-ft long screen intersects aerobic ground water, but also may 

intersect anaerobic water at depth. The lowest concentrations 

of dissolved organic carbon (3.7 mg/L) and carbon dioxide 

(35 mg/L) were measured in a water sample collected from 

well 2MW-1, which is consistent with relatively low microbial 

activity and limited dissolved-oxygen consumption.

The anaerobic redox conditions and geochemical 

concentrations detected in seven of eight wells sampled 

varied considerably across the relatively small site. Although 

all dissolved H2 concentrations indicated iron reduction 

as the predominant redox condition, other geochemical 

concentrations indicated additional redox conditions 

were present in the shallow aquifer at the site. Manganese 

concentrations at wells 2MW-3, 2MW-4, and MW2-8 nearly 

equaled or exceeded iron (II) concentrations, indicating 

substantial manganese reduction at or near those wells. 

Relatively high sulfide and methane concentrations and 

relatively low sulfate concentration at well 2MW-2 indicated 

sulfate reduction and methanogenesis at or near that well. The 

lack of sulfide and sulfate with corresponding high methane 

concentration at 2MW-6 indicated methanogenesis likely was 

the predominant redox processes at that well.

 Chloroethene in Ground Water, Area 2, Operable Unit 2, Naval Undersea Warfare Center, Division Keyport, WA
A predominant redox condition was inferred for each 

sample, although the geochemical data from most water 

samples did not indicate that the assigned redox condition 

was exclusive. Most wells sampled at the study site are 

screened across at least two of the five defined water-bearing 

units beneath Area 2, and those units vary substantially in 

their organic carbon contents (URS Consultants, Inc., 1993). 

Organic carbon is a primary control of redox conditions, so 

redox conditions likely changed over short vertical distances in 

the heterogeneous aquifer at the site, and sampling drew water 

to the well from zones with different redox conditions.

Historical dissolved iron and manganese concentrations 

measured in selected wells during 1991-92 (URS Consultants, 

Inc., 1993) were similar to those measured in 2003 with two 

exceptions. Neither iron nor manganese was detected in water 

samples from well 2MW-2 during 1992 (with detection limits 

of 0.62 and 0.06 mg/L, respectively), whereas the 2003 iron 

(II) and manganese concentrations were substantially greater 

(25 and 0.65 mg/L, respectively). At well MW2-5, the 1992 

iron and manganese concentrations in samples were <0.62 

and 0.32 mg/L, respectively, whereas the 2003 concentrations 

were substantially greater (10 and 1.5 mg/L, respectively). 

The substantial increases in dissolved-metals concentrations 

may indicate that redox conditions changed from aerobic to 

anaerobic sometime between 1992 and 2003.

The 2003 dissolved organic carbon concentrations in 

water samples from the two most upgradient wells (2MW-1 

and 2MW-4) ranged from 3.7 to 4.2 mg/L, whereas the 

concentration in samples from the other six wells farther 

downgradient ranged from 12 to 30 mg/L. The downgradient 

concentrations are relatively high, and can be reasonably 

expected to help maintain anaerobic conditions in shallow 

ground water in the foreseeable future. Historical carbon data 

are not available for evaluating changes and persistence of 

anaerobic conditions over time.

Table 2. Predominant reduction-oxidation (redox) conditions and ground-water geochemical data collected at former Building 957 drum storage 

area, Area 2, Naval Undersea Warfare Center, Division Keyport, Washington, June 23, 2003.

[Well No.: MW, monitoring well. Predominant redox condition: A, aerobic; Fe, iron reducing; M, methanogenic; Mn, manganese reducing; S, sulfate 

reducing. Abbreviations: nM, nanomolar; mg/L, milligram per liter; N, nitrogen; μS/cm, microsiemen per centimeter at 25° Celsius. –, not analyzed; 

<, actual value is less than value shown]

Well No.

Predominant

redox

condition 

Dissolved

hydrogen

(nM)

Dissolved

oxygen

(mg/L)

Filtered

(dissolved)

organic carbon

(mg/L)

Filtered

nitrate + nitrite

(mg/L as N)

Filtered

manganese

(mg/L)

Filtered iron

(II)

(mg/L)

2MW–1 A – 1.0 3.7 0.62 0.04 0.02

2MW–2 S, M 0.3 .2 20 <1.2 .65 25

2MW–3 Mn, Fe .2 .1 19 <.06 1.8 .95

2MW–4 Mn, Fe .1 .1 4.2 <.06 2.0 2.5

2MW–6 M – .6 17 <.06 .05 .58

MW2–5 Fe .7 <.1 30 <.06 1.5 10

MW2–8 Mn – 1.5 12 <.06 3.0 <.01

MW2–10 Fe .1 <.1 15 <.06 1.5 27 

Well No.

Predominant

redox

condition 

Filtered

sulfate

(mg/L)

Unfiltered

sulfide

(mg/L)

Dissolved

methane

(mg/L)

Dissolved

carbon dioxide

(mg/L)

pH

(units)

Specific

conductance

(μS/cm)

Filtered

chloride

(mg/L)

2MW–1 A 4.7 0.01 0.12 35 6.3 220 4.21

2MW–2 S, M 1.1 .06 13 250 6.3 735 9.56

2MW–3 Mn, Fe 3.5 <.01 .96 250 6.3 794 17.4

2MW–4 Mn, Fe 4.8 <.01 – 140 6.2 431 5.38

2MW–6 M <.2 <.01 9.8 350 6.2 902 12.9

MW2–5 Fe 5.5 <.01 .37 70 6.2 267 4.07

MW2–8 Mn 2.6 – .05 375 6.3 1,220 6.48

MW2–10 Fe 3.3 .03 2.7 180 6.4 439 4.16

Evidence for Chloroethene Biodegradation in Ground Water   
Possible Biodegradation Mechanisms for 

Chloroethenes

The many possible biodegradation mechanisms for 

chloroethenes can be broadly categorized in two groups—

reductive dechlorination and microbial oxidation. Reductive 

dechlorination is a process where electrons are transferred 

from relatively simple organic compounds (electron donors) 

to chloroethenes (electron acceptors), replacing a chlorine 

atom to create daughter products with one less chlorine 

atom. Microbial oxidation is a process where chloroethenes 

serve as the electron donor (are oxidized) directly to chlorine 

and carbon dioxide through various pathways catalyzed 

by micro-organisms. Details of those mechanisms have 

been determined by multiple researchers over the last few 

decades and are not repeated in this report—refer to Bradley 

(2003) for a current and thorough review on the history and 

ecology of chloroethene biodegradation. Occurrence and 

potential efficiency of specific mechanisms for chloroethene 

biodegradation at a given contamination site are particularly 

sensitive to redox conditions of the ground water contaminant 

plume (table 3). Generally, reductive dechlorination 

mechanisms are most favorable under strongly anaerobic 

redox conditions (such as methanogenesis and sulfate 

reduction), and are most efficient for biodegradation of the 

more highly chlorinated compounds tetrachloroethene (PCE) 

and TCE. Reductive dechlorination mechanisms are common 

in anaerobic ground water and are thought to be the primary 

cause for biodegradation of the parent compounds PCE and 

TCE to form the daughter products DCE and VC. Conversely, 

microbial oxidation mechanisms are most favorable under 

aerobic or mildly anaerobic redox conditions (manganese and 

iron reduction), and are most efficient for biodegradation of 

the less chlorinated compounds cis-DCE and VC. Widespread 

occurrence of microbial oxidation mechanisms is not as well 

documented as that of reductive dechlorination, in large part 

because the oxidation daughter products carbon dioxide 

and chloride are not uniquely diagnostic to chloroethene 

biodegradation. Regardless, the potential for microbial 

oxidation mechanisms under aerobic conditions can be 

substantial where an anaerobic contaminant plume encounters 

aerobic water (such as at a discharge point to surface water), 

and the potential for microbial oxidation of VC and DCE 

under anaerobic conditions can be substantial in contaminant 

plumes where redox conditions are only mildly reducing.

Chloroethene Data

Chloroethene concentrations from 1991 through 2004 

are shown in table 4. August 2003 data were collected and 

analyzed by the USGS; all other data were collected and 

analyzed by the Navy and retrieved in 2004 by the USGS from 

the Navy’s Technical Data Management System. In addition 

to the eight wells sampled for geochemicals by the USGS 

during 2003, data are shown for two wells screened near the 

bottom of the upper aquifer at the site (MW2-6 and MW2-7) 

to illustrate that contaminants have not been detected at depth, 

and one shallower well (2MW-5) to illustrate the decrease in 

upgradient TCE concentrations measured between 1995 and 

1998.

During 2003, only TCE was detected near the upgradient 

margin of former Building 957 drum storage area (well 

2MW-1), and only cis-DCE and VC were detected near the 

downgradient margin of the site (wells 2MW-3 and 2MW-6) 

(fig. 3). Total BTEX was detected only at well 2MW-3 at a 

concentration of 0.21 μg/L (data not shown).

Table 3. Potential relative efficiency of chloroethene biodegradation through microbial reductive dechlorination or microbial oxidation as a function of in 

situ redox conditions.

[Data from Bradley (2003). Contaminant: PCE, tetrachloroehthene; TCE, trichloroethene; cis-DCE, cis-1,2-dichloroethene; VC, vinyl chloride. 

Biodegradation mechanism: MO, microbial oxidation; RD, reductive decholrination. Predominant redox condition: –, indicates no evidence for this 

mechanism under this redox condition]

Contaminant Biodegradation 

mechanism

Predominant redox condition

Aerobic Manganese

reduction Iron reduction Sulfate reduction Methanogenesis

PCE RD – Good Good Excellent Excellent

MO Fair 1 – – – –

TCE RD – Fair Good Good Excellent

MO Good1 – – – –

cis-DCE RD Poor Poor Poor Fair Good

MO Excellent Good Poor Poor Poor

VC RD Poor Poor Poor Fair Fair

MO Excellent Excellent Excellent Good Good2

1Aerobic cometabolism only—considered to be a transient mechanism.

2Associated with humic-acids reduction rather than methanogenic activity.

 Chloroethene in Ground Water, Area 2, Operable Unit 2, Naval Undersea Warfare Center, Division Keyport, WA
Table 4. Chloroethene concentrations in ground water at former Building 957 drum storage area, Area 2, Naval Undersea Warfare Center, 

Division Keyport, Washington, 1991 to 2004.

[All concentrations are in micrograms per liter. All data except those from August 2003 were collected by the U.S. Navy. Positive detections are bold. 

Well No.: MW, monitoring well. Concentrations: PCE, tetrachloroethene; TCE, trichloroethene; cis-DCE, cis-1,2-dichloroethene; trans-DCE, 

trans-1,2-dichloroethene; 1,2-DCE, total 1,2-dichloroethene; VC, vinyl chloride. Abbreviations: na; not applicable. Symbols: <, actual value is less than value 

shown; –, not analyzed]

Well No. Date sampled PCE TCE cis-DCE trans-DCE 1,2-DCE VC cis-DCE:VC

2MW-1 01-16-92 <10 24 – – <10 <10 na

06-22-92 <10 36 – – <10 <10 na

11-21-95 <1 41 <1 <1 – <1 na

09-30-96 <1 29 <1 <1 – <1 na

10-16-97 <1 29 <1 <1 – <1 na

10-08-98 <.2 28 <.2 <.2 – <.2 na

11-22-98 <.5 17 <.5 <.5 – <.5 na

11-17-00 <.5 22 <.5 <.5 – <.5 na

11-19-01 – 16 <.1 – – <.2 na

06-17-02 <.2 11 <.1 <.2 – <.2 na

06-03-03 – 12 <.5 – – <.5 na

06-15-04 – 10 <.5 – – <.5 na

2MW–2 07-10-91 <.01 <.01 – – <5 1 na

01-16-92 <10 <10 – – <10 <10 na

08-19-03 <1 <1 .14 <1 – <1 na

2MW–3 01-16-92 <10 <10 – – 22 4 5.5

11-20-95 <1 1 19 <1 – 4 4.8

08-19-03 <1 1 18 <1 – 1.8 10

2MW–4 11-20-95 <1 <1 <1 <1 – <1 na

08-20-03 <1 <1 <1 <1 – <1 na

2MW–5 11-21-95 <1 11 7 <1 – <1 na

09-29-96 <1 2 <1 <1 – <1 na

10-16-97 <1 2 <1 <1 – <1 na

10-08-98 <.2 2.1 .26 <.2 – <.2 na

11-22-98 <.5 .4 <.5 <.5 – <.5 na

2MW–6 11-20-95 <1 <1 10 <1 – 4 2.5

09-30-96 <1 <1 15 <1 – 5 3.0

10-16-97 <1 <1 11 <1 – 4 2.8

10-08-98 <.2 <.2 9.5 <.2 – 2.7 3.5

11-22-98 <.5 <.5 12 <.5 – 2.7 4.4

11-17-00 <.5 <.5 15 <.5 – 2.9 5.2

11-19-01 – <.2 7.0 – – 1.2 5.8

06-17-02 <.2 <.2 13 <.2 – 2.1 6.2

06-03-03 – <.5 9.9 – – 1.5 6.6

06-15-04 – <.5 6.9 – – .86 8.0

MW2–5 06-21-91 <.01 <.01 – – <5 <.01 na

01-16-92 <10 <10 – – <10 <10 na

08-19-03 <1 <1 <1 <1 <1 <1 na

MW2–6 06-26-91 <.01 <.01 – – <5 <.01 na

06-22-92 <10 <10 – – <10 <10 na

11-01-00 <.5 <.5 <.5 <.5 – <.5 na

MW2–7 06-24-91 <.01 <.01 – – <5 <.01 na

06-22-92 <10 <10 – – <10 <10 na

MW2–8 06-24-91 <.01 <.01 – – <5 <.01 na

01-16-92 <10 <10 – – <10 <10 na

01-04-02 – <.2 .72 – – <.2 na

01-19-02 <.2 <.2 .97 <.2 – <.2 na

06-03-03 – <.5 1.4 – – <.5 na

06-15-04 – <.5 1.9 – – <.2 na

MW2–10 07-10-91 <.01 <.01 – – 5 <.01 na

01-27-92 <10 <10 – – <10 <10 na

08-20-03 <1 <1 .4 <1 – <1 na

Evidence for Chloroethene Biodegradation in Ground Water   
Evaluation of Evidence for Chloroethene 

Biodegradation

The U.S. Environmental Protection Agency 

protocol (Wiedemeier and others, 1998) for evaluation 

of natural attenuation of chlorinated solvents in ground 

water recommends multiple lines of evidence. Because 

biodegradation is considered a critical component of 

natural attenuation, many of those lines of evidence are 

appropriate, including: (1) demonstration of existence of redox 

conditions conducive to known mechanisms of chloroethene 

Figure 3. Concentrations of trichloroethene (TCE), cis-dichloroethene (cis-DCE), and vinyl chloride (VC) in ground water at former 

Building 957 drum storage area, Area 2, Naval Undersea Warfare Center, Division Keyport, Washington, June and August 2003.

biodegradation; (2) demonstration of production of daughter 

products indicative of chloroethene biodegradation; and 

(3) demonstration of a distinct trend toward decreasing 

chloroethene concentrations. Geochemical and chloroethene 

data collected for this investigation were evaluated according 

to those three lines of evidence.

The potential for specific chloroethene biodegradation 

mechanisms at the former Building 957 drum storage area 

was determined by comparing ground-water redox conditions 

to the data shown in table 4, and the likelihood that the 

mechanisms are actually occurring were inferred from 

wa9FAT2_02_fig03

FORMER BUILDING 734 

DRUM STORAGE AREA 

VAN METER ROAD

SPILL AREA

VAN METER ROAD 

25

15

25

30

20

20

TCE greater than or equal to 5 micrograms per liter

cis-DCE greater than or equal to 

 5 micrograms per liter

VC greater than or equal to 1 microgram per liter

Contamination extent—Dashed where

 poorly constrained

Creek

Fence line

Topographic contour

Monitoring wells sampled

Monitoring wells not sampled

EXPLANATION

MW2-7

2MW-1

25

0

0 10 20 30 40

50

50 METERS

100 150 200 250 FEET Base map modified from URS Consultants, Inc., 1997,

Projection: Washington State Plane, North Zone

122°37’30” 122°37’25”

47°

41’

30”

47°

41’

35”

FORMER BUILDING 

957 DRUM

STORAGE AREA 

MW2-10

MW2-7

MW2-6

MW2-8

MW2-5

2MW-6

2MW-5 

2MW-1 

2MW-4 

2MW-3 2MW-2

10 Chloroethene in Ground Water, Area 2, Operable Unit 2, Naval Undersea Warfare Center, Division Keyport, WA
measured contaminant concentrations. The evaluation 

focused on the presumed contaminant flow path at the site 

extending from well 2MW-1 downgradient to wells 2MW-3 

and 2MW-6. That flow path is consistent with the June 2003 

water levels measured at the site (fig. 2). The three wells 

of interest are the only wells where recent contaminant 

concentrations exceeded the remediation goals established for 

the site. Those remediation goals are 5 μg/L for TCE, 

70 μg/L for cis-DCE, and 1 μg/L for VC (URS Consultants, 

Inc., 1994).

At the upgradient (southwest) corner of the former 

Building 957 drum storage area (well 2MW-1), aerobic redox 

conditions were inferred. Reductive dechlorination of TCE 

does not occur under aerobic conditions, which is consistent 

with the detection of TCE at 2MW-1 and the corresponding 

lack of cis-DCE and VC daughter products. TCE 

concentrations at well 2MW-1 generally decreased between 

1992 and 2004 (table 4, but the lack of daughter products at 

the well indicates that the trend likely is due to non-destructive 

attenuation mechanisms such as dilution or dispersion.

At the two most contaminated downgradient wells 

at the site (2MW-3 and 2MW-6), the inferred redox 

conditions were manganese/iron reducing and methanogenic, 

respectively. The potential for reductive dechlorination of 

TCE is good to excellent under such conditions, which is 

consistent with measured TCE concentrations of only 1 μg/L 

at the manganese/iron reducing well, and <0.5 μg/L at the 

methanogenic well. Concentrations of daughter products 

cis-DCE and VC were substantially greater than the TCE 

concentrations at the downgradient wells. TCE concentrations 

at wells 2MW-3 and 2MW-6 always have been low (table 4) 

and substantially less than the 5 μg/L remediation goal for the 

site. 

The potential for reductive dechlorination of cis-DCE 

is poor under manganese/iron reducing conditions and good 

under methanogenic conditions, consistent with the higher 

cis-DCE concentration of 18 μg/L at the manganese/iron 

reducing well (2MW-3) compared to the lower 9.9 μg/L 

concentration at the methanogenic well (2MW-6). The 

cis-DCE concentrations at wells 2MW-3 and 2MW-6 

always have been less than 20 μg/L with no strong increases 

or decreases during the period of record (table 4). Those 

concentrations are substantially less than 70 μg/L remediation 

goal for the site. However, cis-DCE concentrations less than 

the remediation goal are still a concern because of reductive 

dechlorination into VC, which has a remediation goal of only 

1 μg/L at the site.

The potential for microbial oxidation of VC is excellent 

to good under manganese/iron reducing and methanogenic 

redox conditions, but the potential for reductive dechlorination 

of VC is only fair. In contrast to cis-DCE concentrations, VC 

concentrations at wells 2MW-3 and 2MW-6 have decreased 

over 9 to 14 years, and an increase was measured in the 

ratio of cis-DCE to VC concentrations (table 4). Those 

data indicate that VC is less persistent than cis-DCE in the 

downgradient wells, which is strong evidence for relatively 

efficient microbial oxidation of VC. The potential for 

microbial oxidation of cis-DCE is good under manganese 

reducing conditions (indicated at well 2MW-3 by the 

relatively high manganese concentration of 1.8 mg/L), but 

overall it appears that the biodegradation rate for cis-DCE 

from both reductive dechlorination and microbial oxidation 

is less than the biodegradation rate for VC. The daughter 

products from microbial oxidation of VC are carbon dioxide 

and chloride, and the concentrations of those analytes in 

well 2MW-3 and 2MW-6 were substantially higher than 

those detected upgradient at well 2MW-1 (table 2). Carbon 

dioxide and chloride concentrations were significantly higher 

than concentrations resulting from biodegradation of a few 

micrograms per liter of chloroethenes; therefore, the carbon 

dioxide and chloride data alone are not direct evidence for 

microbial oxidation. The increase in the cis-DCE to VC ratio 

over time, however, is strong evidence for microbial oxidation 

of VC because non-destructive attenuation mechanisms such 

as dispersion or dilution likely would not affect the cis-DCE to 

VC ratio.

Summary and Conclusions

Geochemical and chloroethene data indicated that much 

of the trichloroethene (TCE) and vinyl chloride (VC), and 

some of the cis-1,2-dichloroethene (cis-DCE) biodegraded 

in ground water as it flowed beneath and slightly beyond 

the former Building 957 drum storage area at the Naval 

Undersea Warfare Center, Division Keyport, Washington. No 

apparent TCE biodegradation through any mechanism was 

indicated at the upgradient margin of the former drum storage 

area where aerobic ground water was indicated. Substantial 

reductive dechlorination of TCE and cis-DCE was indicated 

in the downgradient anaerobic ground water. Reductive 

dechlorination was definitively indicated by the presence 

of the daughter products cis-DCE and VC in downgradient 

wells. Ground-water redox conditions were favorable for 

biodegradation through microbial oxidation of VC (and 

cis-DCE to a lesser extent) in downgradient wells, and 

measured increases in the ratio of cis-DCE to VC over time 

at those wells was strong evidence for microbial oxidation of 

VC. All chloroethene concentrations detected in ground water 

at the former Building 957 drum storage area were less than 

20 micrograms per liter. In the three wells where the 2003 

TCE or VC concentrations exceeded remediation goals, the 

concentrations have consistently decreased over time.

Summary and Conclusions 11
References Cited

Blunt, D.J., Easterbrook, D.J., and Rutter, N.W., 1987, 

Chronology of Pleistocene sediments in the Puget Lowland, 

Washington: Washington Division of Geology and Earth 

Resources, Bulletin 77, p. 321-353.

Bradley, P.M., 2003, History and ecology of chloroethene 

biodegradation: A review: Bioremediation Journal, v. 7, 

no. 2, p. 81-109.

CH2M HILL Constructors, Inc., 2003, Spring 2003 long-term 

monitoring data report, Van Meter Road spill/drum storage 

area, Area 2, Operable Unit 2, Naval Undersea Warfare 

Center Division Keyport, Washington: Prepared under 

Contract Task Order 0062 for Engineering Field Activity 

Northwest, Naval Facilities Engineering Command, 

Poulsbo, Wash.

Chapelle, F.H., McMahon, P.B., Dubrovsky, N.M., Fujii, R.F., 

Oaksford, E.T., and Vroblesky, D.A., 1995, Hydrogen (H2) 

concentrations as an indicator of terminal electron accepting 

processes (TEAP’s) in diverse ground-water systems: Water 

Resources Research, v. 32, p. 359-371.

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.

Christensen, T.H., Bjerg, P.L., Banwart, S.A., Jakobsen, R., 

Heron, G., and Albrechtsen, H.J., 2000, Characterization 

of redox conditions in groundwater contaminant plumes: 

Journal of Contaminant Hydrology, v. 45, p. 165-241.

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 WaterResources Investigations, book 5, chap. A1, 545 p.

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

examination of water and wastewater (18th ed.): 

American Public Health Association, American Water 

Works Association, and Water Environment Federation, 

Washington, D.C.

Hach Company, 1998, DR/2010 Spectrophotometer 

procedures manual: Hach Company, Loveland, Colo.

Hoehler, T.M., Alperin, M.J., Albert, D.B., and Martens, C.S., 

1998, Thermodynamic controls on H2 concentrations in 

anoxic sediments: Geochemica et Cosmochimica Acta, 

v. 62, p. 1745-1746. 

Jakobsen, R., Albrechtsen, H.J., Rasmussen, M., Bay, H., 

Bjerg, P.L., and Christensen, T.H., 1998, H2 concentrations 

in a landfill leachate plume (Grinsted, Denmark): In 

situ energetics of terminal electron acceptor processes: 

Environmental Science and Technology, v. 32, no. 14, 

p. 2142-2148.

Jones, M.A., 1999, Geologic framework for the Puget Sound 

aquifer system, Washington and British Columbia: U.S. 

Geological Survey Professional Paper 1424-C, 31 p. 

Kahle, S.C., 1998, Hydrogeology of Naval Submarine Base 

Bangor and vicinity, Kitsap County, Washington: U.S. 

Geological Survey Water-Resources Investigations 

Report 97-4060, 107 p.

Kampbell, D.H., Wilson, J.T., and Vandergrift, S.A., 

1989, Dissolved oxygen and methane in water by a GC 

headspace equilibrium technique: International Journal of 

Environmental Analytical Chemistry, v. 36, p. 249-457.

U.S. Environmental Protection Agency, 1996: accessed 

December 2, 2005 at: http://www.epa.gov/epaoswer/

hazwaste/test/pdfs/8260b.pdf.

U.S. Geological Survey, 1997 to 2004, 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 vols., variously paged. [Also 

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

Chapters originally were published from 1997-99; updates 

and revisions are ongoing and are summarized at: http://

water.usgs.gov/owq/FieldManual/mastererrata.html.

URS Consultants, Inc., 1993, Final remediation investigation 

report for Naval Undersea Warfare Center Division Keyport, 

Washington: Prepared under Contract No. N62474-89-

D-9295 for Engineering Field Activity Northwest, Naval 

Facilities Engineering Command, Poulsbo, Wash., 6 vols.

URS Consultants, Inc., 1994, Final record of decision for 

Operable Unit 2, Naval Undersea Warfare Center Division 

Keyport, Washington: Prepared under Contract Task Order 

0010 for Engineering Field Activity Northwest, Naval 

Facilities Engineering Command, Poulsbo, Wash.

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 vols.

Washington State University, 1968, Washington climate for 

King, Kitsap, Mason, Pierce Counties: Washington State 

University Cooperative Extension Service, College of 

Agriculture, Pullman, Wash., E.M.2734, 66 p.

Wiedemeier, T.H., Swanson, M.A., Wilson, J.T., Wilson, B.H., 

Kampbell, D.K., Hass, P.E., Miller, R.N., Hansen, J.E., and 

Chapelle, F.H., 1998, Technical protocol for evaluating 

natural attenuation of chlorinated solvents in ground water: 

EPA/600/R-98/128, 78 p.

12 Chloroethene in Ground Water, Area 2, Operable Unit 2, Naval Undersea Warfare Center, Division Keyport, WA
Manuscript approved for publication, January 25, 2006

Prepared by the Enterprise Publishing Network 

Publishing Service Center, Tacoma, Washington

Bill Gibbs 

Debra Grillo

Sharon Wahlstrom

For more information concerning the research in this report, contact the 

Washington Water Science Center Director, 

U.S. Geological Survey, 1201 Pacific Avenue – Suite 600 

Tacoma, Washington 98402

http://wa.water.usgs.gov
Evidence for Chloroethene Biodegradation in Ground Water at the Former Building 957 Drum Storage Area, Area 2, 

Operable Unit 2, Naval Undersea Warfare Center, Division Keyport, Washington

SIR 2006–5030 Dinicola