Prepared in cooperation with the 

U.S. Air Force 

Radiochemical Sampling and Analysis of 

Shallow Ground Water and Sediment at the 

BOMARC Missile Facility, East-Central 

New Jersey, 1999–2000 

Scientific Investigations Report 2005-5062 


U.S. Department of the Interior 

U.S. Geological Survey 
Radiochemical Sampling and Analysis of 

Shallow Ground Water and Sediment at the 

BOMARC Missile Facility, East-Central 

New Jersey, 1999–2000

By Zoltan Szabo, Otto S. Zapecza, Jeannette H. Oden, and Donald E. Rice

U.S. Department of the Interior

U.S. Geological Survey

Prepared in cooperation with the U.S. Air Force

Scientific-Investigations Report 2005-5062
U.S. Department of the Interior

Gale A. Norton, Secretary

U.S. Geological Survey

Charles G. Groat, Director

U.S. Geological Survey, Reston, Virginia: 2005

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

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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.
 iii

Contents

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

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

Review of Previous Radiochemical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Purpose and Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Site Hydrogeology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Detection of Colloids, Radionuclides, and Trace Elements in Ground Water . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Size Classification of Aquatic Particles. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Mobility of Colloids, Radionuclides, and Trace Elements in Ground Water . . . . . . . . . . . . . . . . . . . . . . . . 7

Tangential-Flow Ultrafiltration as a Technique for Removal and Characterization of 

Colloids in Ground Water. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Methods of Radiochemical Sampling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Design of Field-Sampling Experiment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Sampling Network. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Preparation for the Field-Sampling Experiment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Well Development and Settled-Sediment Sampling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Geophysical Logging and Placement of the Sampling Pump. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Well Sampling Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Low-Flow Purge and Monitoring of Turbidity, Other Physical Characteristics, and 

Water Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Sample Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Sample Collection with Filtration and Tangential-Flow Ultrafiltration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Safety Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Techniques of Quality Assurance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Laboratory Analysis for Radionuclides. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Detection Methods. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Reporting of Analytical Results for Radionuclides . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Analysis of Shallow Ground Water and Settled Sediment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Quality-Assurance Evaluation of Laboratory Results for Equipment Blanks . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Turbidity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Concentrations of Plutonium, Americium, Uranium, and Thorium in Water . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Concentrations of Plutonium, Americium, and Uranium in Settled Sediment . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Summary and Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

References Cited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Glossary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Appendix 1. Natural Gamma Ray Logs, Screened Interval, and Pump Setting for Wells at the

BOMARC Missile Facility, Ocean County, N.J. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
iv 

Figures

1–2. Maps showing—

1. Location of BOMARC Missile Facility, Ocean County, New Jersey . . . . . . . . . . . . . . . . . . . . . . . . . . . .2

2. The potentiometric surface, Kirkwood-Cohansey aquifer system, BOMARC Missile Facility, 

Ocean County, New Jersey, March 30, 2000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

3. Schematic diagram showing size classification of aquatic particles and effective pore sizes of 

selected filters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

4–5. Schematic designs showing—

4. The device used to sample settled sediment in a well . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

5. Sample-splitting equipment for simultaneously collected filtered, tangential-flow 

ultrafiltered, and unfiltered samples. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

6. Flow diagram showing components of simultaneous tortuous-path and tangential-flow filtered 

sample collection consequent to collection of unfiltered samples and stabilization of turbidity. . . . . 18

7. Flow chart showing sequential collection of equipment-blank samples for quality assurance. . . . . . 18

8–10. Graphs showing—

8. Turbidity and purging rate for the observation wells at or near the BOMARC Missile 

Facility, Ocean County, New Jersey, 1999–2000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

9. Concentrations of (a) plutonium-238 (Pu-238), (b) plutonium-239+240 (Pu-239+240), 

(c) americium-241 (Am-241), (d) uranium-234 (U-234), (e) uranium-235 (U-235), 

(f) uranium-238 (U-238), (g) thorium-228 (Th-228), (h) thorium-230 (Th-230), and 

(i) thorium-232 (Th-232) in water samples from observation wells at or near the 

BOMARC Missile Facility, Ocean County, New Jersey, 1999–2000, grouped by 

sample collection technique. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

10. Concentrations of (a) plutonium-238 (Pu-238), (b) plutonium-239+240 (Pu-239+240), 

(c) americium-241 (Am-241), (d) uranium-234 (U-234), (e) uranium-235 (U-235), and 

(f) uranium-238 (U-238) in samples of sediment settled to the bottom of observation 

wells at or near the BOMARC Missile Facility, Ocean County, New Jersey, 1999 . . . . . . . . . . . . 36

Tables

1. Well-construction data and water levels on March 30, 2000, for selected wells screened 

in the Kirkwood-Cohansey aquifer system at or near the BOMARC Missile Facility, 

Ocean County, New Jersey. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

2. Conditions of well redevelopment for sampled observation wells at or near the BOMARC 

Missile Facility, Ocean County, New Jersey. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

3. Results of field monitoring of purge rate, drawdown, and turbidity that satisfied guidelines

for low-flow sampling for selected wells at or near the BOMARC Missile Facility, Ocean 

County, New Jersey. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

4. Filtration equipment and sampling bottles used for field experiment sampling at or near 

the BOMARC Missile Facility, Ocean County, New Jersey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

5. Laboratory cleaning process for filtration, pumping, and sampling equipment used for the 

low-level ground-water trace-element sampling protocol of Ivahnenko and others (1996) 

or established during the field experiment at or near tha BOMARC Missile Facility, 

Ocean County, New Jersey. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

6. Concentrations of radionuclides in equipment blanks used for the field experiment 

sampling protocol at or near the BOMARC Missile Facility, Ocean County, New Jersey . . . . . . . . . . . 23
 v

7A. Concentrations of radionuclides in filtered and unfiltered samples of water from observation 

wells and properties measured in the field at or near the BOMARC Missile Facility, 

Ocean County, New Jersey, 1999–2000. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

7B. Concentrations of radionuclides in filtered and unfiltered concurrent laboratory duplicate and 

sequential replicate samples of water from observation wells and equipment blank, at or near

 the BOMARC Missile Facility, Ocean County, New Jersey, 1999–2000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

8. Concentrations of radionuclides in sediment samples from the bottom of selected 

observation wells at or near the BOMARC Missile Facility, Ocean County, New Jersey, 1999. . . . . . 24

Conversion Factors, Vertical Datum, and 

Abbreviated Water-Quality Units

Multiply By To obtain

Length

inch (in.) 25.4 millimeter (mm)

foot (ft) 0.3048 meter (m)

mile (mi) 1.609 kilometer (km)

Area

square mile (mi2) 2.590 square kilometer (km2)

Volume

ounce, fluid (fl. oz) 29.57 milliliter

ounce, fluid (fl. oz) 0.02957 liter (L)

gallon (gal) 3.785 liter (L)

Flow rate

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

Mass

ounce, avoirdupois (oz) 28.35 gram

ounce, avoirdupois (oz) 28,349 milligram

ounce, avoirdupois (oz) 28,349,000 microgram

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

°C = (°F – 32) / 1.8

Vertical coordinate information is referenced to the National Geodetic Vertical Datum of 1929 

(NGVD of 29).

Horizontal coordinate information is referenced either to the North American Datum of 1983 

(NAD 83) or North American Datum of 1927 (NAD 27).
vi 

Water-quality abbreviations:

nm nanometer

μm micrometer

ng/L nanograms per liter

μg/L micrograms per liter

mg/L milligrams per liter

μg/kg micrograms per kilogram

μg/g micrograms per gram

pCi picocurie

pCi/L picocurie per liter

pCi/g picocurie per gram

HCl hydrochloric acid

pCi/μg picocurie per microgram

mg/m3 milligrams per cubic meter

DIW deionized water

< less than

> greater

≤ less than or equal to

≥ greater than or equal to

SSMDC sample specific minimum detectable concentration

PE precision estimate

M Molar, or moles

μM micromolar

Am americum

Cs cesium

Pu plutonium

Th thorium

U uranium

Ra radium

KeV kiloelectron volts

MeV million electron volts

LRL laboratory reporting limit

HNO3 nitric acid
Radiochemical Sampling and Analysis of Shallow Ground 

Water and Sediment at the BOMARC Missile Facility, 

East-Central New Jersey, 1999–2000

By Zoltan Szabo, Otto S. Zapecza, Jeannette H. Oden, and Donald E. Rice

Abstract

A field sampling experiment was designed using low-flow 

purging with a portable pump and sample-collection equipment 

for the collection of water and sediment samples from observation wells screened in the Kirkwood-Cohansey aquifer system 

to determine radionuclide or trace-element concentrations for 

various size fractions. Selected chemical and physical characteristics were determined for water samples from observation 

wells that had not been purged for years. The sampling was 

designed to define any particulate, colloidal, and solution-phase 

associations of radionuclides or trace elements in ground water 

by means of filtration and ultrafiltration techniques. Turbidity 

was monitored and allowed to stabilize before samples were 

collected by means of the low-flow purging technique rather 

than by the traditional method of purging a fixed volume of 

water at high-flow rates from the observation well. A minimum 

of four water samples was collected from each observation well. 

The samples of water from each well were collected in the following sequence. (1) A raw unfiltered sample was collected 

within the first minutes of pumping. (2) A raw unfiltered sample 

was collected after at least three casing volumes of water were 

removed and turbidity stabilized. (3) A sample was collected 

after the water was filtered with a 0.45-micron filter. (4) A sample was collected after the water passed through a 0.45-micron 

filter and a 0.003-micron tangential-flow ultrafilter in sequence. 

In some cases, a fifth sample was collected after the water 

passed through a 0.45-micron filter and a 0.05-micron filter in 

sequence to test for colloids of 0.003 microns to 0.05 microns 

in size. The samples were analyzed for the concentration of 

manmade radionuclides plutonium-238 and -239 plus -240, and 

americium-241. The samples also were analyzed for concentrations of uranium-234, -235, and -238 to determine whether uranium-234 isotope enrichment (resulting from industrial processing) is present. A subset of samples was analyzed for 

concentrations of thorium-232, -230, and -228 to determine if 

thorium-228 isotope enrichment, also likely to result from 

industrial processing, is present.

Concentrations of plutonium isotopes and americium-241 

in the water samples were less than 0.1 picocurie per liter, the 

laboratory reporting level for these manmade radionuclides, 

with the exception of one americium-241 concentration from a 

filtered sample. A sequential split sample from the same well 

did not contain a detectable concentration of americium-241, 

however. Other filtered and unfiltered samples of water from 

the same well did not contain quantities of americium-241 

nearly as high as 0.1 pCi/L. Therefore, the presence of americium-241 in a quantifiable concentration in water samples from 

this well could not be confirmed. Neither plutonium nor americium was detected in samples of settled sediment collected from 

the bottom of the wells. Concentrations of uranium isotopes 

(maximum of 0.05 and 0.08 picocuries per liter of uranium-238 

and uranium-234, respectively) were measurable in unfiltered 

samples of turbid water from one well and in the settled bottom 

sediment from 6 wells (maximum concentrations of 0.25 and 

0.20 picocuries per gram of uranium-238 and uranium-234, 

respectively). The uranium-234/uranium-238 isotopic ratio was 

near 1:1, which indicates natural uranium. The analytical 

results, therefore, indicate that no manmade radionuclide contamination is present in any of the well-bottom sediments, or 

unfiltered or filtered water samples from any of the sampled 

wells. No evidence of manmade radionuclide contamination 

was observed in the aquifer as settled or suspended particulates, 

colloids, or in the dissolved phase.

Introduction

A fire at the BOMARC (Boeing Michigan Aeronautical 

Research Center) Missile Facility, hereafter called the Facility, 

in June 1960 caused the release of a small amount of plutonium 

(Pu) to the environment. The Facility is located in Plumstead 

Township in Ocean County in east-central New Jersey in the 

Pine Barrens Preserve and is underlain by the sediments that 

compose the Kirkwood-Cohansey aquifer system (fig. 1). The 

aquifer system is the sole source of drinking water in the area. 

The fire at the Facility occurred in missile-launch Shelter 204 

(fig. 2). A missile and its nuclear warhead were partially consumed in the fire. An estimated 300 grams of Pu was flushed 

from the site during fire-fighting activities. Most of the Pu 

was recovered during cleanup and restoration activities. 

Local contamination of shallow soil by radioactivity has been
Field

Building

Dirt road

Fence

EXPLANATION

Unnamed Tributary

Success Branch

Elisha Branch

BOMARC Missile Facility

Colliers Mills Wildlife Management Area

Lakehurst Naval Air Station

Fort Dix Military Reservation

Route 539

Military boundary

Ephemeral stream

Intermittent stream

74°26'00"

40°

02'

00"

74°26'30" 74°25'30"

0 200 METERS

1,000 FEET

40°

02'

30"

0

OCEAN

COUNTY BURLINGTON

COUNTY

Route 539

Route 70

Route 571

BOMARC Missile Facility

Pine Barrens Preserve

EXPLANATION

74°30' 74°15'

39°

45'

0 10 KILOMETERS

0 10 MILES

40°

Site location

Pine Barrens

Preserve

74

41

39

75

0 10 20 MILES

0 10 20 KILOMETERS

40

Updip extent of

Kirkwood Formation

NEW

JERSEY

2 Radiochemical Sampling and Analysis of Shallow Ground Water and Sediment at the BOMARC Missile Facility, N.J.

Figure 1. Location of BOMARC Missile Facility, Ocean County, New Jersey.
74°26'30" 74°26'00"

40°

02'

00"

40°

02'

15"

Route 539

200 400 600 800

0 200 METERS

0 1,000 FEET

122

123

124

125

126

126.5

127.5

127

127.7

127.09

127.15 127.35

127.42

127.7

127.72

127.45

126.45 126.51

126.77 126.97

127.77

126.74

127.42 127.49

127.99

127.64

127.75

127.64

127.55 126.98

126.81

126.85

126.2

125.81

125.91

125.32

122.87

122.3

121.33

121.45

122.1

123.65

127.48

127.66

126.93

125.13

126.24 122.18

127.75

291398

291399

291401

291397

291396

291392

291400

291393

291390

291388 291387

291384

291382

291379

291371

291434

291370

291446

291440

291444

291441

291435 291437

291436

291438

291439

29-1378

29-1376

291394

291377 291389 291375 291374

291447

291203

291372

291445 291386

291383

291209

291442

291395

291443

127.91

Building

Shelter 204

POTENTIOMETRIC CONTOUR--Shows altitude at which water level

would have stood in tightly cased wells. Contour interval (in feet) is 

variable. Datum is NGVD of 1929

Dirt road

Fence

OBSERVATION WELL--Upper number is well number and lower number 

is altitude of water level, in feet. Datum is NGVD of 1929

Elisha Branch

Succes Branch

Unnamed Branch

126

EXPLANATION

127.75

291443

Introduction 3

Figure 2. The potentiometric surface, Kirkwood-Cohansey aquifer system, BOMARC Missile Facility, Ocean 

County, New Jersey, March 30, 2000.
4 Radiochemical Sampling and Analysis of Shallow Ground Water and Sediment at the BOMARC Missile Facility, N.J.

documented in the vicinity of missile Shelter 204, however 

(Earth Technology Corporation, 1991). Plutonium and americum (Am) are strongly adsorbed to, and are retained on, soil 

particles (Krey, 1976; Hulse and others, 1999). Environmental 

concerns regarding the potential for radionuclide contamination 

of ground water from the accident have prompted additional 

investigations, including this investigation, of the environmental fate of any unrecovered Pu. An additional concern was the 

possibility that radionuclides might have migrated as colloids 

suspended in the ground water. Colloidal transport of Pu has 

been documented at other sites where Pu has been released to 

the environment (Penrose and others, 1990; Harnish and others, 

1995). The Kirkwood-Cohansey aquifer system, composed of 

fine to coarse quartz sand, has poor sorption capacity and contains acidic water (Szabo and others, 1997). These two factors 

strongly contribute to the documented mobility of naturally 

occurring radionuclides (primarily radium (Ra)) in the water 

from this aquifer system (Kozinski and others, 1995; Szabo and 

others, 1997). Colloids with positive surface charge can be 

mobile in acidic environments (Seaman and others, 1995). 

High concentrations (higher than 60 mg/L) of colloids also have 

been found in water samples from this aquifer system collected 

at some sampling sites (Ryan and Gschwend, 1990). Hence, 

concern regarding Pu mobility as colloids in the aquifer system 

is warranted.

The U.S. Geological Survey (USGS), in cooperation with 

the U.S. Air Force (USAF), conducted a study to evaluate the 

use of a stringent sampling protocol to determine the presence 

of radionuclides in the Kirkwood-Cohansey aquifer system near 

the Facility as a result of the fire of 1960. The field-sampling 

experiment was developed by the USGS and the USAF to evaluate the effectiveness of the low-flow sampling technique for 

collecting representative samples from infrequently used observation wells for determination of trace-element and radionuclide concentrations. The field-sampling experiment facilitates 

the characterization of changes in particulate concentration during well purging with turbidity as a surrogate, the recovery of 

sediment settled to the bottom of observation wells for chemical 

analysis, and the characterization of the total (including the particulate), dissolved, and colloidal phases of constituents in 

water samples upon stabilization of turbidity through the use of 

various filtration and ultrafiltration techniques. The radionuclide data obtained and the sampling methods used in this investigation can be used to address environmental and regulatory 

concerns regarding potential radionuclide contamination in the 

subsurface. The stringent sampling protocol was carefully followed and results documented to avoid potentially biased analytical results from samples. In addition, determination of the 

particulate, colloidal, and dissolved phase concentrations of the 

radionuclides in ground water by means of filtration and tangential-flow ultrafiltration in conjunction with the low-flow 

sampling method provides increasingly accurate information of 

the nature of the mobile phase relative to previous sampling 

techniques.

Review of Previous Radiochemical Data

During sampling programs conducted at the Facility during 1985–94 by contractors, filtered and unfiltered water samples were collected from observation wells completed in the 

Kirkwood-Cohansey aquifer system and analyzed for concentrations of gross alpha- and beta-particle activity and isotopes of 

Pu. Limited concentration data were evaluated for isotopes of 

uranium (U), thorium (Th), americium (Am), and cesium (Cs). 

In some cases, the data indicated alpha- and beta-particle activity greater than background activity. Various measurements of 

concentrations of Pu and U isotopes were reported but were not 

reproducible in laboratory split samples or in repeated fieldsampling efforts. A comparison of the analytical results of filtered and unfiltered samples indicated that the higher concentrations of all the isotopes were associated with unfiltered 

samples. This difference indicates the possible occurrence of 

colloidal transport of the radionuclides in the ground water at 

the Facility.

During the previous sampling programs, sampling techniques were not well documented and did not include consistent 

protocols; the techniques allowed for variations in the amount 

of particulate matter in the samples, which led to poor reproducibility of, and possibly high bias in, the analytical results. The 

unfiltered samples were collected by means of a technique 

called bailing. Bailing for a water sample stirs the bottom sediment into the water column in the well. This stirring can introduce into the sample substantial amounts of particulate matter 

that had settled to the bottom of the well but were not actually 

mobile in the aquifer system. Such particulate material is not a 

mobile colloid and is likely to have a particle size greater than 

the standard 0.45-μm (micron) filter typically used for groundwater sampling (fig. 3). Bailing also can cause large variations 

in concentrations of particles and trace elements between samples from the same well because of variation in the amount of 

agitation during sample collection. Large amounts of particulate material in water samples from wells at the Facility are 

noted in a qualitative sense in the contractor reports on the sampling studies but are not documented in a quantitative sense.

Purpose and Scope

This report presents a discussion of the presence of radionuclides in the Kirkwood-Cohansey aquifer system at the Facility as a result of human activities and a description of a stringent 

sampling protocol and equipment designed to obtain water samples that are representative of water in the aquifer system from 

10 observation wells. The sampling protocol was designed to 

minimize turbidity in the water samples so that an accurate 

assessment could be made of the presence of particulate, colloidal, and dissolved-phase concentrations of radionuclides. The 

water samples, along with bottom-sediment samples from eight 

observation wells, were analyzed for isotopes of plutonium, 

americum, uranium, and thorium to determine whether these 

radionuclides are present in the Kirkwood-Cohansey aquifer
Introduction 5

system at the Facility in concentrations greater than background. Gross alpha-particle and beta-particle activity were 

measured for comparison with those from previous studies conducted during 1985–94 for the purpose of characterizing background conditions. Concentrations of radionuclides present in 

water samples and in bottom-sediment samples collected during 

the current study are shown in tables and figures.

Site Hydrogeology

The water-table aquifer that underlies the Facility is 100 ft 

thick and is composed predominantly of unconsolidated sand of 

the Kirkwood and Cohansey Formations. Together, these 

formations compose the Kirkwood-Cohansey aquifer system. 

This aquifer system, a major regional aquifer system in the 

Coastal Plain of New Jersey, thickens considerably southeast of 

the Facility. The regional extent and thickness of this aquifer 

system was mapped and described in detail by Zapecza (1989). 

The Cohansey Sand, middle Miocene in age, is a marginal 

marine deposit composed of a light-colored medium- to coarsegrained quartz sand with some gravel and silt (Zapecza, 1989). 

The Kirkwood Formation, lower to middle Miocene in age, is 

composed of clays interbedded with sand and gravel in coastal 

areas that grade to a fine- to medium-grained quartz and silty 

sand inland.

The predominant source of recharge to the KirkwoodCohansey aquifer system is precipitation that falls directly onto 

the aquifer system outcrop. Ground water flows from topographic highs to streams along both shallow and deep flow systems (Rhodehamel, 1973). Ground-water flow to deeper confined aquifers (below the Kirkwood-Cohansey aquifer system) 

in the area is restricted by a regionally extensive confining unit 

which is hundreds of feet thick.

Suspended particles

Bacteria

Phytoplankton

Dissolved Particulate

2.9-nm (10,000 Dalton) filter: Sample contains dissolved constituents only

50-nm (0.05 micron) fliter: Sample contains colloids and dissolved constituents

Standard 450-nm (0.45 micron) filter: Sample contains small and medium colloids and dissolved constituents

Unfiltered sample: Sample contains all suspended particles, all colloids, and all dissolved constituents

Nanometers (nm): 10 1 10 10 10 10 10 10 -1 2 3 4 5 6

10,000-

Dalton

filter

50-nm

filter

450-nm

filter

2.9 nm 50 nm 450 nm

Viruses

Molecules

Colloidal

Humic acid

Fulvic acid

Filter size:

Colloids

107

Figure 3. Size classification of aquatic particles and effective pore sizes of selected filters.
6 Radiochemical Sampling and Analysis of Shallow Ground Water and Sediment at the BOMARC Missile Facility, N.J.

The ground-water flow system of the Kirkwood-Cohansey 

aquifer system generally can be divided into shallow local-flow 

systems and deeper regional-flow systems (Rhodehamel, 

1973). Actual ground-water flow patterns probably are more 

complex than the conceptualized patterns and are affected by 

local heterogeneities in the aquifer material and by seasonal 

changes in precipitation, evapotranspiration, and water use. An 

example of the effects of aquifer-material heterogeneities on the 

orientation of flow paths in the aquifer system is given by Rice 

and Szabo (1997). About half the water that enters the aquifer 

system as recharge in a typical first-order stream basin adjoining a surface-water divide is discharged to the nearby stream 

within about 20 years (Rice and Szabo, 1997). The Facility 

(fig. 1) is situated within such a first-order stream basin adjacent 

to a major surface-water divide. The aquifer system is highly 

conductive; results of a regional-scale numerical flow model 

calibrated for an area to the north of the Facility indicated that 

horizontal conductivity is 80 to 100 feet per day (Nicholson and 

Watt, 1997).

Currently (2000), contamination of the water supply is not 

an issue at or near the Facility site because the nearest watersupply wells within the aquifer system are located miles from 

the Facility. On the basis of the measured water-table altitude at 

the Facility, actual ground-water flow is predominantly from 

the area of the highest altitude on the Facility towards the areas 

of lower altitude (areas of discharge) in the adjoining wetlands 

and the Success Branch to the east (fig. 2).

Because of the presence of the Pine Barrens Preserve in 

much of the southeastern part of the State (fig. 1), land use 

within the area underlain by the outcrop of the KirkwoodCohansey aquifer system in this region is largely undeveloped, 

especially near the Facility. Urbanization has encroached 

appreciably on both agricultural and previously undeveloped 

areas within the past decade; this urbanization has occurred 

mostly in the southwestern and northeastern parts of the aquifer 

system outcrop area, not in the vicinity of the Facility.

Detection of Colloids, Radionuclides, and 

Trace Elements in Ground Water

The concentrations of radionuclides and other trace elements can be substantially greater when particulate matter is 

present in unfiltered samples than when it is absent because 

many of these constituents have a strong tendency to sorb onto 

particulates. The analysis of samples with large amounts of particulate material can be difficult as a result of “matrix effects” 

that often result in poor precision and interferences. These factors can, in turn, cause measured concentrations of constituents 

in samples with abundant particulate matter to exceed concentrations in samples without abundant particulate matter. The 

variability of the quantity of particulates from sample to sample 

is likely the major factor that made it difficult, if not impossible, 

for the contract laboratory to reproduce analytical results, indicating the need to use consistent, strict, and appropriate samplecollection protocols. 

The radioactive material Pu is a component of nuclear 

weaponry but also can be present in the environment from global atmospheric fallout to which the nuclear power industry, as 

well as nuclear weapons testing, has contributed. The isotope 

Pu-239 readily undergoes nuclear fission when a neutron collides with the nucleus, and the nucleus releases small product 

nuclides as well as two or three additional neutrons, which can 

then continue to fuel fission reactions. The isotope is, therefore, 

a necessary component of nuclear weapons fueled by Pu. Weapons-grade Pu contains lesser amounts of Pu-240 relative to Pu239 than is typical for the ratio of these two isotopes in global 

fallout (Liator, 1999). Pu-240 and Pu-239 are more abundant 

than Pu-238 at nuclear-weapons facilities. Weapons-grade Pu 

contains almost no Am-241 (Hulse and others, 1999) because of 

rigorous purification and concentration of the Pu-239 isotope. 

The Am-241 to Pu-239 isotope activity ratio increases after the 

purification process. The Am-241 originates from in-growth 

from the minor amounts of the Pu-241 isotope (about 1 percent 

of Pu in weapons) that decay with a 14.4-year half-life. 

All isotopes of U are naturally occurring and are ubiquitous in soils, rock, and most waters. Isotopes of U are found at 

low concentrations (much less than 1 pCi/g) in the sediments 

that form the Kirkwood-Cohansey aquifer system (Szabo and 

others, 1997); correspondingly, concentrations of U are also 

low in the water from the aquifer (less than 1 μg/L). The naturally occurring isotope of U, U-235, is also a component of 

nuclear weapons because it readily undergoes fission. Because 

U-238 is far more abundant than U-235, the U-235 has to be 

concentrated in the laboratory, resulting in U-235-rich material 

known as “enriched uranium.” The process used to enrich 

U-235 also concentrates the U-234 isotope. Distinguishing naturally occurring U from industrially altered contaminants from 

weapons can be difficult unless anomalous U-234:U-238 isotopic ratios far greater than the natural background ratio of about 

1.0 are encountered. The natural weathering process may 

slightly enrich U-234 relative to U-238 in water but rarely by 

more than a factor of 2 (Osmond and Cowart, 1976). 

Radium is a progeny of a radioactive decay of U and is soluble in acidic water. Radionuclides of Ra are present in water 

from the Kirkwood-Cohansey aquifer system in widespread 

areas, often at concentrations high enough to cause concern for 

health risk (Szabo and others, 1997). The Ra likely is mobilized 

by weathering. The presence of elevated amounts of Ra in the 

water also results in high gross alpha-particle radioactivity 

(Kozinski and others, 1995). Because the water could contain 

substantial amounts of alpha radioactivity even under natural 

conditions, the presence of elevated alpha radioactivity alone is 

not an indicator of manmade contamination.

Considerable improvements in field-sampling procedures 

and laboratory analytical techniques and technology in the 

1990s have led to the increased capability to detect and quantify 

concentrations of colloids, radionuclides, and trace elements in 

water samples, including ground-water samples with complex 

matrix. These improvements were incorporated, where possible, into the field-sampling experiment and are briefly summarized here.
Introduction 7

Size Classification of Aquatic Particles

Water in the environment can contain large quantities of 

foreign particles of various sizes, shapes, and densities. Some 

are small in size, low in density (close to that of water), and of 

such shape that they do not obey Stokes’ Law of settling 

(formulated in 1845); they remain in suspension even in still 

water (see Gibbs and others, 1971, for further discussion).

Colloids have generally been defined as those particles 

about 0.002 μm (micron) (2 nm (nanometers)) to 1 μm 

(1,000 nm) in size that do not settle from suspension in still 

water. Therefore, colloids can often pass through many pore 

sizes of filters (Kennedy and others, 1974) but ultimately are 

retained on a 10,000-Dalton ultrafilter, which has a nominal 

pore size of 0.0029 μm (fig. 3). A Dalton is defined as being 

equal to a predefined nominal molecular weight (NMWL). The 

nominal pore size of a filter is defined operationally by the size 

of the particles which are retained with 98-percent efficiency 

during the filtration process. The pore sizes of 10,000 and 

100,000 Daltons correspond to nominal pore sizes of about 

0.0029 and 0.0062 μm, respectively.

Particles other than colloids become suspended at various 

rates of water flow. In general, these suspended particulates are 

larger than colloids and are greater than about 0.45 μm in diameter (fig. 3), though exceptions occur.

The terms colloid and particulate are size classifications 

and do not define the chemical composition or chemical reactivity of the particle. The size range of colloids, which do not 

settle from still water, overlaps that of particulates, which do. 

For this sampling program, particulates were defined as all particles retained by the 0.45-μm filter and colloids as particles 

retained by the 10,000-Dalton ultrafilter. These definitions are 

consistent with the terminology used by Harnish and others 

(1995). The chemical capability of colloids to transport trace 

elements and radionuclides has been recognized for many years 

(Gibbs, 1973; Gibs and others, 2000; Hoffman and others, 

1981; Penrose and others, 1990).

Trace elements are present in ground water as solutes and 

in association with particles, particularly colloids. The historical operational definition of “dissolved” as the capability to 

pass through a 0.45-μm-pore filter is commonly used for convenience and to maintain historical continuity despite clear evidence that these filters allow passage of some particles and colloids (Kennedy and others, 1974). As a result, data obtained 

from the analysis of water that has passed through a 0.45-μmpore filter does not necessarily represent concentrations of dissolved trace elements only.

Mobility of Colloids, Radionuclides, and Trace Elements 

in Ground Water

Few sites or wells are present for which both the truly dissolved component and the mobile particulate or colloidal fraction of trace-element or radionuclide contaminants are well 

characterized. The presence of abundant colloids in shallow 

ground water in some geochemical environments was demonstrated by Ryan and Gschwend (1990) with samples collected 

from the Kirkwood-Cohansey aquifer system. Harvey and others (1993) also were able to recover what they considered 

mobile colloids from pumped wells. Ryan and Gschwend 

(1990) indicated that 10 to 20 casing volumes of water had to be 

purged before stable turbidity was achieved and colloid concentrations were considered reliable. Results of their field investigation indicated that low colloid concentrations (low turbidity) 

could be the norm in oxidizing environments. Concentrations of 

particles measured in their field experiment in the oxidizing 

environment of the Kirkwood-Cohansey aquifer system were 

less than 1 mg/L, which is consistent with most of the colloidconcentration data tabulated for other sites by Kearl and others 

(1992). Colloid concentrations as high as 60 mg/L have been 

documented, however, by Ryan and Gschwend (1990) in water 

from sandy Coastal Plain aquifers under anoxic conditions; the 

colloids ranged in size from 0.03 μm to about 2 μm. Microspheres with a maximum diameter of 1 to 2 μm have been 

recovered from sand aquifers by Harvey and others (1993) and 

Bales and others (1997), who interpreted this result to indicate 

that transport of colloids of this size occurs in the environment. 

Bales and others (1997), however, applied appreciable stress to 

the aquifer in terms of rapid pumping (30 L/min (liters per 

minute)), which could lead to a flow velocity much greater than 

the typical flow velocity in the environment.

Ryan and Gschwend (1992) hypothesize that the concentration and mobility of colloids depends on the geochemistry of 

the aquifer, especially the oxidation-reduction potential. Colloids with net positive surface charge are as likely to be mobile 

in water with acidic conditions and high concentrations of dissolved solids as are dissolved cationic trace elements (Seaman 

and others, 1995) and radionuclides with positive charge. High 

concentrations of dissolved solids, especially in association 

with acidic water, also tend to increase the mobility of dissolved 

trace elements because the available sorption capacity of aquifer solids decreases in acidic water; therefore, sorption sites are 

more likely to be completely saturated by the large amount of 

cations present in mineralized water. For example, the mobility 

of radium (Ra), a naturally occurring radionuclide present as a 

divalently charged cation under almost all geochemical conditions (Langmuir and Riese, 1985), was assessed by Kozinski 

and others (1995) and Szabo and others (1997) in filtered samples from the Kirkwood-Cohansey aquifer system; the mobility 

likely is a result of acidic conditions and the presence of moderately high dissolved solids concentrations (250 mg/L). Concentrations of combined radium (Ra-228 plus Ra-226) were 

greater than the 5 pCi/L (picocuries per liter), the Maximum 

Contaminant Level (MCL), in 37 percent of 88 samples collected by Kozinski and others (1995). Colloids from sandy 

Coastal Plain aquifers have been found to have a large organic 

carbon component (Ryan and Gschwend, 1990). The organic 

carbon component could affect the transport characteristics of 

organic contaminants and colloids as well as those of radionuclides and trace elements (Ryan and Gschwend, 1992). Because 

pH and oxidation-reduction potential also affect the speciation 
8 Radiochemical Sampling and Analysis of Shallow Ground Water and Sediment at the BOMARC Missile Facility, N.J.

of truly dissolved U, Am, and Pu (Lemine and Tremaine, 1980), 

and thereby affect the mobility of these constituents, the pH and 

the dissolved oxygen content are important characteristics to 

determine in the field whether truly dissolved-phase or colloidal 

transport is being investigated. Penrose and others (1990) and 

Harnish and others (1995) discuss colloidal transport of Pu and 

Am and report that Pu is more likely than Am to be transported 

in the colloidal and particulate phase. 

Tangential-Flow Ultrafiltration as a Technique for 

Removal and Characterization of Colloids in 

Ground Water

Further characterization of both the colloidal and dissolved 

phases of trace elements and radionuclides and their transport in 

ground water is needed for sites where such contamination has 

been found. This characterization is especially important in the 

Coastal Plain where the typical shallow aquifer is unconfined 

and acidic and, therefore, is ideal for cationic and colloidal 

mobility (Seaman and others, 1995). Few methods exist for separating colloids of various sizes from water, however. The 

equipment used is cumbersome, often produces artifacts, and 

generally is not portable (Buffle and Leppard, 1995).

Tangential-flow ultrafiltration overcomes all the difficulties given above for separating colloidal fractions from water 

and produces a sample that contains only dissolved constituents 

or that includes colloids of a predetermined size range. In tangential-flow ultrafiltration, most of the water passes across, 

rather than through, the filter, and the thickness of the diffusion 

layer of the filter membrane, where colloids can coagulate, is 

minimized by the high flow rate parallel to the membrane. Particles, whether suspended in the water or formed by colloid 

coagulation, generally do not build up on the filter. Particles are 

moved by the flow across the filter surface rather than forced 

onto the surface of the filter material. The general absence of 

particles on the filter is an advantage because the effective pore 

size changes only to a minimum degree as filtering proceeds. 

Therefore, the process increases sample comparability, 

increases confidence in the quantification of colloid concentrations and of colloidal and non-colloidal concentrations of trace 

elements, and results in reliable data. Particle build up on the 

commonly used plate and capsule filters can reduce the effective pore size of the filters (Horowitz and others, 1996). 

The water collected after passing across the tangentialflow ultrafilter is the desired sample if characterization of the 

colloidal component of a specified size range (greater than the 

nominal pore size of the filter) is the objective of sample collection. The water collected after passing through the tangentialflow ultrafilter is the desired sample if composition of water 

without colloids of the specified size range is the objective. The 

use of tangential-flow ultrafiltration in the field has become 

increasingly commonplace because the technique allows for the 

removal of particles with diameters greater than or equal to 

0.0029 μm (or about 10,000 Daltons). Terms used to define 

aspects of the tangential-flow ultrafiltration process are defined 

in the Glossary at the back of the report, and are used throughout this report.

Quantification of the concentrations of solutes (in this 

study, defined as passing through a tangential-flow ultrafilter 

with nominal pore size of 10,000 Daltons) is desirable for four 

reasons. First, solutes generally are considered biologically 

available to humans and other biota, whereas particulate-bound 

trace elements may or may not be biologically available. Therefore, quantification of solute concentrations provides a minimum measure of biological availability. Because biologically 

available concentrations of trace elements, especially radionuclides, are identified as human-health risks upon ingestion, the 

quantification of solute concentrations is an important goal for 

any monitoring program concerned with health effects. Second, 

samples containing only solutes may be more representative of 

trace elements that actually move in ground water than unfiltered samples, especially if the sample was collected without 

strict adherence to rigorous purging and sampling protocols 

(Gibs and others, 2000). Particulates in ground-water samples 

are commonly an artifact of high-flow velocities induced near 

the well bore during well purging (Kearl and others, 1992; 

Backhus and others, 1993; Gibs and others, 2000) and may be 

composed, in part, of particulate material that was introduced 

into the aquifer matrix during the drilling of the well. A third 

reason for determining solute concentrations is to further the 

understanding of processes that affect trace-element and radionuclide concentrations dissolved in ground water. A final, 

fourth, benefit of using ultrafiltration or tangential-flow ultrafiltration is the removal of biota that can change the chemical species in samples, such as nitrogen, iron, and arsenic species.

Trace-element-bearing colloids or particulates can be artificially mobilized during the well-purging process in many 

ways, including agitation of the standing water column in the 

well during submersion of the pump and increased shear in the 

aquifer from overpumping (Kearl and others, 1992; Backhus 

and others, 1993). The artificially mobilized particulates could 

be incorporated into water samples during collection. For measurement of dissolved constituents, an objective of the sampling 

process is to decrease the concentration of artificially mobilized 

colloids and the associated turbidity, not to increase it. Oneacre 

and Figueras (1996) demonstrated that for a suite of 15 trace 

elements recoverable from whole water, the detection rate was 

17 percent greater in ground-water samples with turbidities of 

25 to 49 nephelometric turbidity units (NTU) than in samples 

with turbidities less than or equal to 24 NTU. Turbidity 

(assumed to be primarily from artificially mobilized particulates) directly correlated with trace-element concentrations in 

sequentially collected raw-water samples (Gibs and others, 

2000). Artificially mobilized particulates can be removed 

through standard filtration techniques, but filtration alone 

results in the presence of sampling artifacts from the removal of 

particulates or colloids that actually were mobile in the ground 

water (Horowitz and others, 1996). If colloids themselves are to 

be separated and characterized, ideally, the presence of artificially mobilized particulates in the water must be minimized.
Methods of Radiochemical Sampling 9

The low-flow sampling technique is a natural fit with 

tangential-flow ultrafiltration because it is designed to 

minimize the presence of artificially mobilized particulates 

and colloids. The low-flow sampling technique (Puls and 

Barcelona, 1995) generally has been recommended to minimize 

the presence of artificially mobilized particulates in unfiltered 

water samples. The low-flow rates also minimize colloid 

coagulation during the tangential-flow ultrafiltration process 

(Buffle and Leppard, 1995).

Field-sampling techniques that rigorously ensure the 

integrity of the collected filtered and unfiltered ground-water 

samples are required. State-of-the-art analytical techniques are 

not useful if the sample-collection and -handling procedures 

introduce random trace-element contamination or artifacts. 

Techniques for the collection and handling of samples for precise and unbiased analysis of trace elements at low concentrations in ground water have been refined and improved (Ivahnenko and others, 1996; 2001). Improvements to the groundwater sampling technique for low-concentration trace elements 

includes rigorous cleaning of sampling equipment, increased 

care during sample handling, and strict quality assurance, in 

addition to the low-flow-sampling technique to minimize artifacts produced by the mobilization of particulates during the 

well-purging and sampling process.

Methods of Radiochemical Sampling

The field-sampling experiment used in this investigation 

was designed to determine the presence of any particulate, colloidal, and dissolved-phase concentrations of radionuclides in 

water samples from the water-table aquifer that might be attributable to the fire of 1960. Water samples were collected from 10 

observation wells. Isotopes of Pu, Am, U, and Th that could be 

associated with the warhead were selected as the constituents to 

be analyzed. Gross alpha-particle and beta-particle activity 

were measured to provide an overall screen for radionuclides in 

ground water and for comparison with results from previous 

studies and with background data provided by Szabo and others 

(1997). Analysis for Th isotopes was completed for the first 

five, but not the last five, wells sampled. Results of analysis for 

radionuclides in soil samples at the Facility indicated that Th 

concentrations and isotope ratios in surface soils were typical 

for the region and did not represent radionuclide contamination 

(Steven Raddemacher, U.S. Air Force, oral commun., 1999). 

In order to address environmental and regulatory concerns, 

specific attention was placed on size fractionation during sampling to determine if any radioactive contaminants were sorbed 

to potentially mobile particles (colloids) in ground water, and to 

particles that may settle from the ground water. Settled particulates at the bottom of the well also were collected and analyzed.

Design of Field-Sampling Experiment

The development of the field-sampling experiment took 

into account the large amount of particulate matter observed in 

all the previous radiochemical sampling at the Facility. The 

sampling methods were required to result in samples that 

contain a true representation of both particle and radionuclide 

concentrations within the water of the aquifer system. It was not 

known whether elevated concentrations of radionuclides 

(elevated above background levels) reported for some of the 

previously collected unfiltered samples resulted from the 

presence of immobile particles introduced from land surface 

during well drilling that settled to the bottom of the well, from 

particles from the aquifer materials that were artificially 

mobilized by well purging or turbulence from the use of bailers, 

from particles mobile in the water as colloids, or simply from 

analytical problems that were compounded by matrix effects in 

turbid samples.

The low-flow sampling technique (Puls and Barcelona, 

1995) was selected to minimize the presence of artificially 

mobilized particulates or colloidal material in unfiltered water 

samples. Changes in particulate concentration during well purging were characterized by monitoring turbidity. Sediment that 

settled to the bottom of the observation wells was collected for 

chemical analysis. Water samples that represent the total (unfiltered), truly dissolved, and colloidal phases of radionuclides 

were collected upon stabilization of turbidity through the use of 

various sequential filtration and tangential-flow ultrafiltration 

techniques. Colloids are retained on filters with nominal pore 

sizes that are smaller than the diameter of the colloidal particles, 

such as the 10,000 Dalton filter. The colloids are assumed to be 

of a smaller size than the particulates and are assumed to pass 

through the 0.45 μm but not the 10,000 Dalton filter. It is 

assumed that only dissolved constituents pass through the 

10,000 Dalton filter.

Sampling Network

Ten previously installed observation wells were selected 

for sampling (fig. 2; table 1). Information on the construction, 

altitude, and location of wells included in this report is stored 

under a 6-digit unique well number in the Ground-Water Site 

Inventory database maintained by the USGS. This well number 

consists of a 2-digit county code followed by a 4-digit sequence 

number. The county code used in this report is 29 (Ocean 

County). For example, well number 29-1379 is the 1,379th well 

inventoried in Ocean County. Well-construction data in the 

tables in this report are sorted by well number, but water-quality 

information presented in tables is sorted by well depth, not by 

well number. 

Wells 29-1203, 29-1371, 29-1372, 29-1374, 29-1375,

29-1377, and 29-1379 were installed during 1986–87 for the 

primary purpose of determining the degree of radionuclide contamination in water at the Facility. The previously obtained 

radionuclide data for these wells were reviewed and found 

to be highly variable and without documentation of purging
10 Radiochemical Sampling and Analysis of Shallow Ground Water and Sediment at the BOMARC Missile Facility, N.J.

Table 1. Well-construction data and water levels on March 30, 2000, for selected wells screened in the Kirkwood-Cohansey aquifer 

system at or near the BOMARC Missile Facility, Ocean County, New Jersey.—Continued

[--, data not available; NAD27, North American Datum of 1927; NAD83, North American Datum of 1983; *, water samples collected from this well; USGS, U.S. 

Geological Survey. Altitudes are reported relative to the National Geodetic Vertical Datum of 1929 (NGVD29).]

Well 

name

USGS 

well 

number

New 

Jersey 

permit 

number

Latitude 

(decimal 

units)

Longitude 

(decimal

units)

Datum

Altitude of 

land 

surface 

(feet above 

NGVD29)

Depth of open 

interval

(feet below land 

surface)

Well

diameter 

(inches)

Water 

level

(feet above 

NGVD29) Top Bottom

PU6 291203* 28-17921-8 400204 742651 NAD27 166.24 35 50 2 127.7

BM3 291209 28-17925-1 400145 742628 NAD27 141.10 10 25 2 127.55

MW101 291370* 28-27380 400152.54 742633.85 NAD27 127.11 32 42 2 127.75

PU5 291371* 28-18291-0 400201.35 742642.5 NAD27 166.4 37 52 2 127.72

PU2 291372* 28-17919-6 400201.45 742636.49 NAD27 171.71 43 58 2 127.42

PU1 291374* 28-17918-8 400205.42 742631.66 NAD27 180.14 53 68 2 127.15

PU3 291375* 28-17920-0 400206.62 742636.24 NAD27 174.71 47 62 2 127.35

MW2 291376* -- 400206.34 742621.73 NAD27 148.9 79.6 89.6 4 --

PU7 291377* 28-18292-8 400206.34 742622.40 NAD27 150.06 22 37 2 126.45

MW4 291378* -- 400207 742615 NAD27 137.54 103.6 113.6 4 --

MW49 291379* 28-17922-6 400210.56 742632.83 NAD27 164.7 38 53 2 127.085

MW-104 291382 28-27393-1 400149 742618 NAD27 133.42 10 20 2 126.98

BM-4 291383 28-17933-1 400154 742619 NAD27 138.21 9 24 2 126.81

MW-08 291384 -- 400158 742610 NAD27 129.04 9.7 24.7 4 126.85

MW-105 291386 28-27394-0 400158 742621 NAD27 147.01 18 28 2 126.765

MW-11 291387 -- 400203 742605 NAD27 126.21 34 49 4 125.13

MW-07 291388 -- 400203 742609 NAD27 132.13 27 42 4 126.195

MW-107 291389 28-27396-6 400206 742622 NAD27 148.78 52 62 2 126.505

MW-108 291390 28-27411 400207 742615 NAD27 138.58 30 40 2 125.81

MW-10 291392 -- 400210 742601 NAD27 126.35 35.4 50.4 4 123.65

MW-06 291393 -- 400210 742616 NAD27 136.13 43 58 4 125.914

MW-X48 291394 28-17923-4 400210 742621 NAD27 143.65 17 32 2 126.24

MW-14 291395 -- 400211 742557 NAD27 122.55 40 50 4 122.18

MW-15 291396 -- 400211 742557 NAD27 122.34 6 16 122.1

MW-01 291397 -- 400214 742601 NAD27 126 40.4 55.4 4 122.87

MW-12 291398 -- 400215 742555 NAD27 122.41 40 50 4 121.325

MW-13 291399 -- 400215 742555 NAD27 122.41 5 15 4 121.445

MW-05 291400 -- 400215 742613 NAD27 131.25 41.5 56.5 4 125.315

MW-09 291401 -- 400220 742602 NAD27 124.84 44.7 59.7 4 122.295

BM-1 291434 28-17924-2 400149.39 742629.91 NAD83 142.81 12 27 2 127.48
Methods of Radiochemical Sampling 11

conditions or evidence of physical stabilization of properties at 

the time of sample collection. A water-level synoptic study for 

the purpose of determining the potentiometric surface was completed in March 2000 (fig. 2). A reconnaissance water-level synoptic study to determine which wells would be sampled was 

completed as part of the project-planning phase in the autumn 

(October 1998) preceding the sample collection when no precipitation had fallen for at least 7 days (results not shown). 

Water levels that provided the basic data for the potentiometric 

surface were measured with an accuracy of +0.01 ft by use of a 

weighted steel tape from a designated measuring point, usually 

a groove in the top of the well casing with a surveyed altitude 

within an accuracy of +0.1 ft. Measurements were repeated 

until two consecutive readings were within an accuracy of 

+0.01 ft. Additional wells not previously sampled but selected 

for this study are 29-1370, 29-1376 and 29-1378; the wells were 

selected on the basis of the synoptic water-level data collected 

in October 1998 and March 2000 (fig. 2). The remainder of the 

wells at the Facility were used for water-level measurements 

(fig. 2; table 1). Samples from the 10 wells selected were collected from August 19, 1999, to February 23, 2000.

Wells 29-1374, 29-1376, 29-1377, and well 29-1378 are 

situated parallel to the natural ground-water flow path that 

trends east in this part of the unconfined aquifer and are immediately downgradient from the accident site. Well 29-1378 is 

500 feet downgradient from the eastern boundary of the Facility. It was selected for sampling because the open interval at a 

depth of 110 feet (table 1) is positioned near the base of the 

Kirkwood-Cohansey aquifer system. Well 29-1378 is completed in the deepest part of the aquifer and provides a control 

point to determine whether any radioactive contaminant has 

moved off site at depth. Well 29-1377, a shallow well open 

from 22 to 37 feet below land surface, and well 29-1376, a deep 

well open from about 80 to 90 feet, are nested; they were 

selected to provide information on radionuclide concentrations 

with depth in the aquifer system. Well 29-1379, which is offset 

(to the north) from the flow path that trends away from Shelter 

204, and well 29-1370, which is about 0.25 miles south of Shelter 204, were selected to provide potential background information. Well 29-1370 is downgradient from the stormwater culvert 

located on the west side of the major local roadway, Route 539 

(fig. 2). This well was sampled to determine whether any 

ground-water contamination is present in this part of the Facility from runoff into the adjacent drainage ditch during the fire 

fighting. Wells 29-1203, 29-1371, and 29-1372 are adjacent to 

the drainage ditch to the west near Shelter 204. Well 29-1373, 

though near Shelter 204 (about 200 feet, but not shown in 

fig. 2), was not sampled because it was determined during well 

redevelopment that this well did not yield sufficient quantities 

of water to fill the volume requirements for sample collection.

MW-X45 291435 28-17930-7 400150.79 742628.59 NAD83 148.73 20 35 2 127.635

MW-X46 291436 28-17931-5 400151.39 742628.12 NAD83 148.11 20 35 2 127.635

MW-X44 291437 28-17929-3 400151.65 742629.17 NAD83 150.17 20 35 2 127.66

MW-17 291438 28-13807 400152.63 742628.92 NAD83 153.38 14 29 4 127.99

MW-102 291439 28-27391 400152.93 742628.41 NAD83 153.86 50 60 2 127.49

MW-X16 291440 28-13817 400153.32 742628.35 NAD83 154.05 21 36 4 127.905

MW-X43 291441 28-17928-5 400153.67 742627.04 NAD83 152.96 25 40 2 127.42

MW-X42 291442 28-17927-7 400154.32 742626.97 NAD83 153.86 22 37 2 126.735

MW-X41 291443 28-17926-9 400155.40 742629.69 NAD83 157.98 27 42 2 127.75

MW-103 291444 28-27392 400156.12 742627.37 NAD83 157.71 25 35 2 127.77

BM-2 291445 28-18289-8 400158.59 742622.45 NAD83 151.81 21.5 36.5 2 126.97

MW-X47 291446 28-17932-3 400158.79 742625.31 NAD83 167.17 37 52 2 127.45

MW-106 291447 28-27395 400201.66 742623.37 NAD83 170.28 40 52 2 126.925

Table 1. Well-construction data and water levels on March 30, 2000, for selected wells screened in the Kirkwood-Cohansey aquifer 

system at or near the BOMARC Missile Facility, Ocean County, New Jersey.—Continued

[--, data not available; NAD27, North American Datum of 1927; NAD83, North American Datum of 1983; *, water samples collected from this well; USGS, U.S. 

Geological Survey. Altitudes are reported relative to the National Geodetic Vertical Datum of 1929 (NGVD29).]

Well 

name

USGS 

well 

number

New 

Jersey 

permit 

number

Latitude 

(decimal 

units)

Longitude 

(decimal

units)

Datum

Altitude of 

land 

surface 

(feet above 

NGVD29)

Depth of open 

interval

(feet below land 

surface)

Well

diameter 

(inches)

Water 

level

(feet above 

NGVD29) Top Bottom
12 Radiochemical Sampling and Analysis of Shallow Ground Water and Sediment at the BOMARC Missile Facility, N.J.

Preparation for the Field-Sampling Experiment

Low-flow sampling is intended to produce representative 

samples with minimal artifacts from artificially mobilized particles. It is nevertheless assumed that the sampled wells are 

properly developed. The previous collection of particle-laden 

samples and the absence of written records describing well 

development indicated that adequate well development may not 

have occurred. Therefore, the observation wells were redeveloped, settled sediment was removed, and the sampling pump 

was placed in the screened area after geophysical logging.

Well Development and Settled-Sediment Sampling

Before sampling began in October 1999, the wells were 

developed sufficiently to lower the water turbidity to levels of 

less than 5 NTU in each well. Guidelines for successful well 

development consisted of removal of sediment settled in the 

bottom of the well and the development of steady pumping rates 

greater than those to be used for sampling, that is, much greater 

than 0.5 L/min (liters per minute) with turbidity less than 5 

NTU. Conditions of well redevelopment are listed in table 2.

The observation wells had not been purged or sampled in 

more than 10 years in some cases. Large amounts of sediment 

most likely settled to the bottom over time. In addition, supporting documentation describing initial well development was not 

available. Inadequate well development routinely leads to difficulty in sampling because of the presence of a large amount of 

settled sediment (Koterba and others, 1995). Sediment in the 

bottom of each well ranged in thickness from 0.05 to 5.75 ft 

(table 2). This thick deposit of sediment was considered to be a 

major factor contributing to the high particulate matter in turbid 

water collected during previous sampling programs. This particulate matter caused water turbidities in the bailed, unfiltered 

sample to be higher than actual levels in water from the aquifer 

system, and the particulate-rich matrix likely was not acceptable for precise analysis.

Before pumping for well development began, sediment 

from the bottom of each well was removed by collecting it into 

a stiff 1-inch polyvinyl chloride (PVC) tube with suction 

applied from a large-volume portable centrifugal pump. A 

weighted steel tape was used to sound the depth of the well. The 

difference between the measured depth and the depth from 

well-construction records (table 2) was estimated as the thickness of the settled sediment, which ranged from about 0.05 to 

5.75 ft. The PVC tube was lowered into the well and manually 

forced down into the sediment layer about 3 inches at a time 

with the centrifugal pump producing suction. With the pump 

turned on and producing suction, the PVC tube was manually 

pulled back to the surface. A ball-type check valve (Brady foot 

valve FV/SFV 100) attached to the base of the PVC tube prevented back flow and the loss of sediment (fig. 4). Generally, 

3 to12 inches of sediment could be removed at one time using 

this technique (table 2). At land surface, the check valve was 

released. If a sufficient quantity of sediment was retrieved, it 

was poured into wide-mouth 0.5-L glass-sampling jars for analytical purposes.

Sediment samples from the bottom of all wells except 29-

1378 were submitted, mostly in duplicate, for analysis of Pu isotopes 238, 239+240; Am-241; and U isotopes 234, 235, and 

238. Bottom sediment was first centrifuged in high-density 

polyethylene centrifuge bottles at 10,000 revolutions per 

minute for 20 minutes to separate the sediment from the water. 

Analytical results of radionuclide concentrations in the settled 

sediment could provide the worst-case scenario with respect to 

the degree of contaminant sorption on particulates or particleborne radiochemical contamination deposited into the well during well construction. (The bottom sediment sample from well 

29-1372 was accidentally discarded at the laboratory before 

analysis was complete.)

Over-pumping rates (American Society for Testing and 

Materials, 1994) were maintained at about 30 to 40 L/min for a 

period of about 60 minutes or more, if needed, to develop the 

wells sufficiently to lower the water turbidity to levels of about 

5 NTU or less in each well. The pumping rate was rapidly varied to initiate surging action in wells that did not clear. Turbidity 

was monitored every 5 minutes by use of a Hach Ratio/X-2100 

Portable Turbidimeter using procedures recommended by 

Wilde and Radtke (1999) and Gibs and others (2000). The 

pumping of water was accomplished with a portable centrifugal 

or portable submersible pump. A Grundfos Rediflo-2 pump that 

was not used for sampling was set nearly in the center of the 

well screen for the well-development process. The level of the 

submersible pump during redevelopment is provided, when 

applicable, in table 2; the pump was not lowered to the bottom 

of the well for redevelopment purposes.

Geophysical Logging and Placement of the Sampling Pump

Prior to placement of the sampling equipment, a gamma 

ray log was run in each well to determine the most permeable 

section of the screened interval. The logging tool included a 

3-inch sodium iodide (NaI) crystal and was lowered and raised 

in the well bores at 2 ft per minute. The most permeable interval 

was determined by evaluating gamma ray response for each 

screened interval; the least radioactive zone was assumed to be 

the coarsest grained and, thus, most permeable. The dedicated 

portable Grundfos Rediflo-2 submersible sampling pump was 

set in the screened interval of each well adjacent to the most permeable interval for a minimum of 24 hours before pumping in 

accordance with criteria established for low-flow purging 

(Kearl and others, 1992; Puls and Barcelona, 1995). The level 

of pump during purging is given in table 3. Once the pump was 

set, it was not raised or lowered before or during well purging 

or sampling. Natural gamma ray logs, the screened interval, and 

the pump setting for collection of water samples are shown in 

appendix 1.
Table 2. Conditions of well redevelopment for sampled observation wells at or near the BOMARC Missile Facility, Ocean County, New Jersey.[BLS, below land surface; NTU, nephelometric turbidity unit; NA, not available; --, no data; data sorted in order of well depth]

U.S. 

Geological 

Survey 

well 

number

Well

diameter 

(inches)

Screened 

interval

(feet BLS)

Date of 

redevelopment

(month/

day/year)

Altitude of 

measuring point 

(feet)

Depth to 

water

(feet 

BLS)

Casing 

volume 

(liters)

Over 

pumping 

duration 

(minutes)

Number 

of casing 

volumes 

purged

Initial over 

pumping 

rate

(liters per 

minute)

Final over 

pumping 

rate

(liters per 

minute)

Level of 

pump 

during 

redevelopment 

(feet BLS)

Initial 

turbidity 

(NTU)

Lowest 

turbidity 

(NTU)

In

me

d

(fee

291377 2 22–37 10/25/99 152.16 23.75 7.36 65 327.6 37.1 37.1 NA 27.3 0.63 3291370 2 32–42 11/5/99 129.91 31.59 6.24 79 412.1 32.6 32.6 NA 43.1 .76 4291203 2 35–50 10/25/99 168.24 38.93 4.66 60 385.0 29.9 29.9 39.29 79.0 1.01 4291379 2 37–52 10/22/99 166.97 38.02 8.06 27 126.8 37.9 37.9 NA 5.13 .49 5291371 2 37–52 10/26/99 168.99 39.03 7.53 100 407.2 30.7 30.7 39.56 169 4.17 4291372 2 42–57 10/18/99 174.17 NA 7.29 NA NA NA NA NA NA NA 5

10/19/99 174.17 44.51 7.29 135 522.9 1.42 22.7 NA 100 46.0 510/21/99 174.17 NA 7.29 68 224.9 29.9 8.7 47.54 39.3 7.2 

291375 2 47–62 10/21/99 176.92 47.74 7.90 50 192.1 30.3 30.7 50.20 1.88 1.34 5291374 2 52–67 10/21/99 182.75 53.29 6.42 57 236.0 33.3 7.57 54.28 4.29 2.10 6291376 4 80–90 10/28/99 151 21.66 166.9 238 44.38 33.3 17.0 28.62 306 7.63 8291378 4 103.6–

113.6

NA 141.6 14.40 244.1 NA NA NA NA NA NA NA 1
Stiff polyvinyl chloride tube

Water level

One-way foot valve

Well casing

Suction

Centrifugal pump

Tarp

Wide-mouth

glass samplecollection bottle

Sediment from

well stored for

appropriate

further action

or disposal

Tarp

Mound of sediment

settled in well screen

Well screen

Direction of water flow

Not to scale

14 Radiochemical Sampling and Analysis of Shallow Ground Water and Sediment at the BOMARC Missile Facility, N.J.

Figure 4. The device used to sample settled sediment in a well.
Methods of Radiochemical Sampling 15

Well Sampling Procedures

Stabilization and minimization of turbidity, as well as the 

absence of decline in the water level during low-flow purging, 

were considered the most important components in determining 

when to initiate sample collection (table 3). The low-flow purge 

rate used during sampling was that recommended in the lowflow purging technique of Puls and Barcelona (1995). The 

pumping rates for the observation wells ranged from 0.29 to 

0.68 L/min (table 3). These rates were necessary for adequate 

flow through the sequential filters from which samples were 

ultimately collected. The submersible pump could not consistently maintain enough pressure to force flow through the filters 

at purge rates lower than the rates given above because of cavitation resulting from gas bubbles.

Low-Flow Purge and Monitoring of Turbidity, Other 

Physical Characteristics, and Water Levels

Table 3. Results of field monitoring of purge rate, drawdown, and turbidity that satisfied guidelines for low-flow sampling for selected

wells at or near the BOMARC Missile Facility, Ocean County, New Jersey.

[BLS, below land surface; NTU, Nephelometric Turbidity Units; italic print where guideline was not satisfied; purge rate is the most frequently occurring value; 

data sorted in order of well depth; <, less than; negative drawdown indicates water-level rise]

U.S. 

Geological 

Survey 

well 

number

Sampling 

date 

(month/ 

day/year)

 Purge 

rate1

 

(liters 

per 

minute)

Level of 

pump 

during 

purging 

(feet 

BLS)

Initial 

depth to 

water 

(feet 

BLS)

Depth to 

water at 

stable

turbidity2

(feet BLS)

Drawdown 

(feet)

Purging 

duration 

(minutes)

Number 

of casing 

volumes 

purged

Initial

turbidity 

(NTU)

Maximum 

turbidity 

(NTU)

Final 

stable 

turbidity3 

(NTU)

2/7/00 7.16 23.77 0.17 68 10.2 28.2 0.12

2/11/00 .56 31.60 .01 63 12.5 12.5 0.38

2/23/00 .29 38.76 .31 115 0.81 15.6 1.23

1/6/00 .44 37.87 .01 65 185 185 1.14

12/8/99 .36 39.05 0 245 83.4 83.4 2.76

2/1/00 .49 44.33 -.05 63 1.25 1.39 .59

12/3/99 1.15 47.67 .03 184 5.11 5.11 .32

12/15/99 .45 53.35 -.02 63 4.46 4.50 .28

2/15/00 .47 21.73 .06 81 3.94 5.74 1.33

8/25/99 .68 14.40 0 322 30.8 40.4 18.0

1

 Guideline: Purge rate less than 0.5 liter per minute if possible (Puls and Barcelona, 1995).

2

 Guideline: Minimal drawdown (<0.5 feet) while pumping from the most productive interval (Puls and Barcelona, 1995).

3

 Guideline: Final stable turbidity that is less than 5 NTU if possible (Gibs and others, 2000).

The pumping rate, water level, and water turbidity were 

monitored as continuously as possible, beginning when the submersible pump was turned on. To maintain a consistent flow 

rate, a small peristaltic pump was placed in line with the discharge line from the submersible pump before the filtration 

assemblage (fig. 5). The peristaltic pump was calibrated in the 

laboratory and was set to the same pumping rate as the submersible pump to maintain consistent positive pressure through the 

filter assemblage. The entire pumping scheme was established 

and maintained throughout well purging and sampling to avoid 

artifacts (artificially mobilized particles) resulting from 

changes in the pumping scheme.

Turbidity was monitored during well purging by use of a 

Hach 2100P Portable Turbidimeter; values were recorded every 

2 minutes, if possible. Turbidity was used as a surrogate for particulate material that might be present in the sampled water. 

Unfiltered samples were collected throughout the purge period 

to determine changes in trace-element and radionuclide concentrations with changes in particle concentrations. Collection of 

filtered samples concurrently with unfiltered samples was 

delayed until turbidity stabilized. The stability-criteria concept 

used for this study was based on the published instrument analytical precision data as defined by Gibs and others (2000). The 

2100P Portable Turbidimeter has a precision of +0.4 NTU at 

less than 20 NTU (Hach Inc., 1991). Turbidity was considered 

stable, and a water-quality sample was collected, when four 

consecutive readings 5 minutes apart did not vary by more than 

twice the instrumental precision of +0.4 NTU; that is, 0.8 NTU. 

On the basis of previous research, stable turbidity of less than 

5 NTU was considered to be a representative value for the 

aquifer system, especially in the oxic environment encountered 

(Ryan and Gschwend, 1990; Gibs and others, 2000; and 

Ivahnenko and others, 2001).

291377 26.0 23.94 66.2

291370 34.1 31.61 5.7

291203 40.0 39.07 7.0

291379 44.0 37.88 3.5

291371 44.0 39.05 11.7

291372 45.8 44.28 4.2

291375 50.0 47.70 26.6

291374 60.0 53.33 4.4

291376 82.0 21.79 .2

291378 105.0 14.40 .9
Retentate flow Clamp

Permeate flow

Sample from

10,000-Dalton

filter

(F0.0029)

Sample from

0.45-μm filter

Feed

from

well

0.45-μm

capsule filter

(F0.45a)

Clamp

Raw

sample (R1, R2, RTi, R3)

Peristaltic

pump for

flow rate

stabilization

Well

Sample from

0.45-μm

capsule filter

(F0.45)

0.05-μm

capsule filter

Flow splitter

Flow splitter

Clamp

Sample from

0.05-μm

capsule filter

(F0.05)

Clamp

Tangential-flow

cartridge filter

Permeate

port

Retentate

Feed port

Tangential-flow

plate filter can be

substituted for

cartridge in line

EXPLANATION

(F0.45) Sample sequence number in figure 6

(μm, micron)

16 Radiochemical Sampling and Analysis of Shallow Ground Water and Sediment at the BOMARC Missile Facility, N.J.

Figure 5. Sample-splitting equipment for simultaneously collected filtered, tangential-flow ultrafiltered, and unfiltered 

samples.

The water level was measured two to four times with an 

accuracy of +0.01 ft by use of a weighted steel tape during the 

first 10 minutes after initiation of purging. The purging rate was 

reduced if drawdown was appreciable. An electric tape was 

lowered into the well with the sensor set about 0.5 ft below the 

water table. Cessation of the electric signal did not occur, indicating that drawdown had stabilized. The water level was measured about every 20 minutes thereafter with the weighted steel 

tape. Drawdown at the time of collection of the filtered samples 

was determined by measurement with the steel tape (table 3).

In addition to turbidity and water level, the field-determined properties pH, specific conductance, and water temperature were monitored as described by Wilde and Radtke (1999) 

but without use of a flow-through chamber. Measurements were 

made in a glass beaker that was continuously flushed with purge 

water. The concentration of dissolved oxygen was not monitored but was determined by Winkler Titration (iodometric with 

azide modification; Wilde and Radtke, 1999) at the time of stabilization of turbidity.
Methods of Radiochemical Sampling 17

Sample Type

A minimum of four types of water samples was collected 

from each observation well (fig. 6). The samples were collected 

in the following sequence. (1) A raw unfiltered sample was 

collected within the first minutes of pumping when turbidity 

was at or near the maximum. (2) A raw unfiltered sample was 

collected after turbidity stabilized. (3) A sample was filtered 

through a 0.45-μm filter. (4) A sample was passed through a 

0.45-μm filter and a 0.0029-μm (10,000 Dalton) filter in 

sequence (figs. 5 and 6). (The same sequence as for sample 

collection and equipment cleaning was maintained for the 

collection of equipment-blank samples, as detailed in figures 5, 

6, and 7.) In some cases, a fifth sample was collected after the 

water passed through a 0.45-μm filter and a 0.05-μm filter, in 

sequence, to evaluate the presence of colloids ranging from 

0.0029 μm to 0.05 μm in size. A minimum of two unfiltered 

samples per well also was collected for determination of 

suspended sediment concentration in addition to monitoring for 

turbidity. The first suspended sediment sample was collected 

concurrently with the initial unfiltered radionuclide sample. 

The second sample was collected immediately before the 

commencement of filtration. In cases where turbidity was high 

at the initiation of purging (>10 NTU) but decreased rapidly or 

turbidity was extremely variable (changing by about 5 NTU 

per measurement), additional samples of unfiltered water were 

collected for determination of suspended sediment and 

radionuclide concentrations. Last, an unfiltered sample of water 

was collected from most wells after a minimum of one to two 

casing volumes of water were removed. From the radionuclide 

concentrations in these unfiltered samples, differences in 

contaminant concentrations in samples with different turbidities, and affinity with particles, could be determined. The final 

field-monitoring data for each well sampled, especially the 

initial, peak, and final stable turbidity when samples were 

collected, are listed in table 3.

Each sample bottle was labelled with the collection date 

and time and a predetermined sequence code which denoted the 

sequence status of the sample (filtered or not, and filter pore 

size, if applicable). The initial raw unfiltered sample (designated R1) was collected 1 to 3 minutes after initiation of well 

purging. This sample represents the concentration of constituents mobile in the raw water and constituents likely to sorb onto 

settled particulates at the bottom of the well casing and to be 

artificially mobilized by the initiation of well purging activity. 

The additional raw unfiltered samples that were collected while 

turbidity varied (designated R2 and RTi) provided an estimate 

in the variation of contaminant concentration with variation in 

particulate concentration. Unfiltered samples designated RTi, 

in general, were collected when the turbidity varied during 

purging by more than +33 percent in a 3-minute interval or 

increased by about 3–5 full NTU. The unfiltered sample at the 

time of turbidity stabilization (designated R3) is used to establish concentrations of contaminants mobile in the raw water, 

including those sorbed onto particulate material generated by, 

and mobile within, the aquifer matrix. Sequential filtering of 

water through a 0.45-μm filter and either a 0.05-μm filter or a 

0.0029-μm filter provided a sample that contains concentrations 

of contaminants dissolved and sorbed to all colloids (designated 

F0.45), dissolved and sorbed to colloids less than 0.05 μm in 

size (designated F0.05), and in the truly dissolved phase (molecules and molecular complexes less than 0.0029 μm in size, designated F0.0029). The sample designations also are noted in 

figure 5 which details the actual sample-splitting design.

Sample Collection with Filtration and Tangential-Flow 

Ultrafiltration

A diagram of the sampling apparatus used for unfiltered 

and filtered sample collection is shown in figure 5, and the 

filtration equipment used is listed in table 4. Tortuous-path, 

0.45-μm Gelman polyethersulfone capsule filters were used to 

filter particulates from raw water and provide the sample stream 

for the tangential-flow ultrafiltration system. A Millipore 

Prep/Scale-TFF tangential-flow ultrafiltration spiral-wound 

cartridge system was used to capture the colloidal phase and 

provide colloid-free water for collection of the truly dissolved 

phase. 

The ultrafiltration cartridge system has three ports—the 

feed port, retentate port, and permeate port. The feed port is the 

input port. The feed port was connected to cleaned tubing in 

sequence after the 0.45-μm capsule filters. The feed process 

consists of the water passing through the 0.45-μm capsule 

filters. The ultrafiltration filter cartridge was mounted on a 

plastic bracket within the portable glove-bag chamber with the 

feed port pointed downward. The discharge or filtrate from the 

retentate port is the part of the sample that has flowed over the 

surface of the filter substrate, not through it. This part of the 

sample is the F0.45 (0.45-μm) sample collected from all well 

sites (fig. 5). The filtrate that flows from the permeate port is the 

F0.0029 (10,000 Dalton (0.003-μm)) sample, or the truly 

dissolved phase, collected from all wells. For additional details 

and limitations regarding the use of tangential-flow ultrafilter as 

described here, see Szabo and others (2002). For additional 

information regarding the limitations of using these filters from 

an overall sampling perspective, see Babiarz and others (2000) 

and Hoffman and others (2000).

All ground-water samples were collected using rigorous 

“clean sampling” techniques and equipment cleaning (table 5) 

following procedures documented by Ivahnenko and others 

(1996; 2001) and Horowitz and others (1994). A strict sampling 

protocol was maintained in order to insure that sample handling 

and processing did not compromise sample integrity. All samples were collected as raw water drawn directly from the observation well by one of the dedicated small portable stainlesssteel submersible pumps (fig. 5). The person collecting the sample wore powder-free latex gloves and did not handle any of the 

field monitoring or pumping equipment (Horowitz and others, 

1994). PVC sample bottles were acid rinsed in the laboratory 

(table 4); before sample collection, additional rinsing was performed with deionized water (1L) and native purge water
Collected in first minutes after initiation of purge

Turbidity > 10 NTU

Continue purging to reduce turbidity

R1

Purge 1 to 3 casing volumes

Collected when turbidity < 10 NTU

Continue purging to reduce turbidity

R2

Collected when field characteristics

have stabilized

Turbidity stable < 5 NTU

R3

Collected during purging if turbidity rebounds to > 10 NTU,

or turbidity varies by mor than 5%

Turbidity > 10 NTU or highly variable

RTi

Collected with Gelman 0.45-micron capsule filter

concurretly with F0.05 and F0.0029

F0.45

Turbidity stable < 5 NTU

Fibercore 0.05-micron capsule filter

Collected concurrently with F0.45 and F0.0029

in line, post 0.45-micron filter

F0.05

Millipore Prep - TFF Tangential-flow 0.0029-micron filter

Collected concurrently with F0.45 and F0.05

in line, post 0.45-micron filter

F0.0029 (or 10,000 Dalton)

Turbidity > 10 NTU Purge to reduce turbidity Turbidity Stable < 5

+–

18 Radiochemical Sampling and Analysis of Shallow Ground Water and Sediment at the BOMARC Missile Facility, N.J.

Figure 6. Components of simultaneous tortuous-path and tangential-flow filtered sample collection consequent to collection of 

unfiltered samples and stabilization of turbidity.

Figure 7. Sequential collection of equipment-blank samples for quality assurance.

Lot-analyzed USGS IBW

Source blank

Acid-cleaned high-density polyethylene tubing.

IBW pumped with peristalic pump

through pump tubing

Tubing blank

Cleaned sampling pump with tubing.

IBW pumped through tubing by sampling pump

Stainless-steel submersible 

sampling pump blank Cleaned sampling pump, tubing, filter.

IBW pumped through filter attached to tubing.

Pump rate: 1 liter per minute

Filter blank (Gelman 0.45-micron capsule)

Cleaned sampling pump, tubing, filter.

IBW pumped through filter attached to tubing.

Pump rate: 1 liter per minute

Filter blank (Fibercore 0.05-micron capsule)

Millipore Prep - TFF Tangential-flow 0.003-micron filter.

Inline, post 0.045-micron filter.

Rate: 0.75 liters per minute

Tangential-flow filter retentate blank

Millipore Prep - TFF Tangential-flow 0.003-micron filter.

In line, post 0.45-micron filter.

Rate: 0.25 liters per minute

Tangential-flow filter permeate blank

Filter blanks

Equipment blanks, unfiltered

Collection sequence

or
Methods of Radiochemical Sampling 19

(0.25L). Reduction of sample exposure to wind-blown aerosol 

particles was accomplished with a portable enclosed samplecollection chamber. Some samples were not collected within the 

confines of the designated dedicated clean sampling van as recommended by Ivahnenko and others (1996), however, because 

of concern over the accumulation of organic vapors within the 

clean sampling van from the water sample. Dust and aerosol 

control was maintained in the vicinity of the sample by enclosure within portable glove-bag chambers on a small portable 

table and the use of a disposable heavy tarp on the ground in the 

sample-collection area. Ultra-pure nitric acid was used to preserve samples to be analyzed for trace elements and radionuclides (table 4). The acid was added to the bottles in a separate 

preservation glove-bag chamber (Horowitz and others, 1994) 

after sample collection. This process, which required the 

reopening of the sample bottle for brief moments of time, was 

always accomplished inside the dedicated clean sampling van 

(Ivahnenko and others, 1996).

Safety Considerations

Table 4. Filtration equipment and sampling bottles used for field experiment sampling at or near tha BOMARC Missile Facility, Ocean 

County, New Jersey.

Filters

Pore size 

(micron) Equipment1 Design

Surface 

area

(square 

feet)

Quality assurance

(per 10 samples) Material

Gelman

12175

Tortuos-path capsule 0.79 2 blanks Polyethersulfone

Fibercor

Fiber-Flo 50

Pleated fiber cartridge 0.6 1 blank Polysulfone

Millipore

Prep/Scale-TFF

Tangential- flow spiral 

wound cartridge

0.9 2 blanks Polyethersulfone

Millipore

Minitan-S

Tangential- flow filter 

plate

0.056 1 blank Polysulfone

Sampling bottles

Type Quality assurance Sample type

High-density polyethelyne, acid washed, 1 liter None (internal quality assurance) Filtered trace elements, 

radionuclides

Glass, wide-mouth None Suspended sediment

Glass, cuvettes, 25 milliliters Day blanks (10 total) Turbidity

Tubing, preservatives

Type Quality assurance Sample type

High-density polyethelyne tubing 2 blanks associated with pump; tubing 

acid-washed for trace elements, deionized water rinsed for radionuclides

All pumped samples

Nitric acid, Ultrex, in high-density polyethelyne container Used in all blanks; each lot, internal 

quality assurance analyses

Trace elements, radionuclides

Reagent grade lot analyzed hydrochloric acid Lot analysis; used only to acid wash 

tubing fittings and tubing

Trace elements

4 The use of brand names is for identification purposes only and does not constitute endorsement by the U.S. Government.

Because of the possible presence of mixed inorganic and 

organic wastes at the observation-well sites, the team safety 

officer initially checked the headspace in the well to be sampled 

for organic vapors, then both the initial discharge water and the 

ongoing purge water, with a portable photo-ionization detector 

(H-nu Systems Model PI-101; 10.2 eV lamp). During sampling, 

an individual checked the air quality near the portable glove bag 

as well as the breathing zone of the sampler. When organic 

vapors were detected near the portable glove bag or in the 

breathing zone of the sampler, sampling proceeded only after 

engineering solutions to remove organic vapors were put in 

place: the van door was opened, the ceiling fan was turned on, 

and a window fan was set up to exhaust the air in the van. If 

these steps did not resolve the problem of detectable vapor 

buildup inside the sampling area (partially enclosed van) or 

were too obtrusive for the sampler, the portable sampling glove

0.45

0.05

0.0029

0.0029
20 Radiochemical Sampling and Analysis of Shallow Ground Water and Sediment at the BOMARC Missile Facility, N.J.

bags were moved outside onto a tarp-covered area to complete 

sampling. Although this process is a slight departure from the 

technique of Ivahnenko and others (1996), the use of heavy tarp 

on the ground and the portable glove-bag chambers minimized 

or eliminated the risk to the sampling team and at the same time 

did result in preservation of sample integrity.

A portable scintillometer with an alpha-particle sensitive 

probe (Ludlum 2221) was used to check the outer protective 

field garments (disposable Tyvex and rubber boots) of the sampling team for contamination with alpha-particle emitting radioisotopes such as Pu and Am. Because alpha particles are 

strongly attenuated even by air (Knoll, 1989), the detector was 

placed as close as possible to the surface of the garment being 

monitored. The outer protective field garments of the sampling 

team were scanned for contamination on an occasional basis 

during field operations to insure that personnel were not contaminated with “hot particles,” a matter of concern for safety 

and for preservation of sample integrity by avoiding accidental 

contamination with “hot particles” during sample handling. A 

final probe scan was done before departure from each site to 

insure radioactive “hot particles” were not transported away 

from the site. Although a portable gamma ray detection device 

may be more readily available and will detect the presence of 

Am (Ibrahim and others, 1995), the response from such a device 

may be difficult to interpret in typical field areas because of the 

background gamma emissions from potassium in naturally 

occurring clay particles. Individual whole-body radiation dose 

was monitored by radiation badges worn at chest height.

Techniques of Quality Assurance

For quality control and to determine any variability in 

constituent concentrations caused by varying amounts of 

particulate matter during sampling, many replicate samples 

were collected from each well. In most cases, a complete 

sequential replicate sampling of the entire initial and final 

unfiltered sampling was performed (8 of 10 sites); the filtered 

sequence of samples was replicated less frequently (3 of 10 

Table 5. Laboratory cleaning process for filtration, pumping, and sampling equipment used for the low-level ground-water traceelement sampling protocol of Ivahnenko and others (1996) or established during the field experiment at or near tha BOMARC Missile 

Facility, Ocean County, New Jersey.

[DIW, deionized water; HCl, hydrochloric acid; %, percent; NA, not applicable]

Equipment Cleaning steps Solution Volume

(liters)

Rate

(liters/ 

minute)

Time

(minutes) Flow control

Ultra-filter Preservative solution; drained Ammonia-based preservative1 NA NA NA NA

Initial rinse Sterile DIW NA Retentate clamp open

Permeate Sterile DIW NA Retentate clamp 

Retentate Sterile DIW NA Retentate clamp open

Capsule filter Initial rinse Sterile DIW NA NA

Pump Disassemble pump; rinse out 

lubrication reservoir

Sterile DIW As needed NA NA NA

Scrub impellers 0.1% Liquinox solution As needed NA NA NA

Wash Recycled 0.1% liquinox solution Pump rate

Flush Recycled sterile DIW 10, repeat 

2 times

Pump rate

Flush Sterile DIW NA Pump rate

Tubing Flush Recycled sterile DIW 15, repeat NA

Flush Sterile DIW As needed NA

Fittings Sonicator bath 0.1% liquinox solution NA NA

Sonicator bath Sterile DIW NA 5, repeat NA

Acid rinse, freshly made 5% reagent grade HCL As needed NA NA

Flush Sterile DIW As needed NA

5

 alkyl- benzyl- dimethyl ammonia chloride.

2 1.0

4 .5

1 1.0

.25 .5

4 4.0 25

4 4.0

4 1.0

8 1.0

1.0 10

5 5

5

60

1.0 5
Methods of Radiochemical Sampling 21

sites) because of the time-consuming nature of tangential-flow 

ultrafiltration. Laboratory duplicate analysis of randomly 

selected samples also was provided by the analytical laboratory. 

At least one sample was randomly selected for duplicate 

analysis from 7 of the 10 sites. To determine the amounts of 

trace-element contamination introduced during the sampling 

process, equipment and process blank samples were collected 

(Ivahnenko and others, 2001) and analyzed for trace elements 

(indicative of contamination during sample handling and 

processing), as well as the radionuclides of interest. Inorganic 

blank water (IBW), certified by the USGS, was passed through 

field equipment in the laboratory; filtered and unfiltered 

samples of the IBW were collected using the same procedures 

used for ground-water samples (fig. 7).

For the ground-water trace-element sampling techniques 

used, cleaning of the pump between each sample collection was 

required (table 5). This cleaning is necessary to avoid possible 

cross-contamination among samples. The stainless-steel submersible pump was cleaned with a soap solution, rinsed with tap 

water, then rinsed with DIW before use. Acid rinse is not used 

in the pump cleaning process because it would etch the stainless-steel surfaces on the submersible pump (Wilde and others, 

1998; Ivahnenko and others, 2001). Etched surfaces increase 

the rate of leaching of trace elements from stainless steel (chromium, iron, manganese, molybdenum, and nickel), which could 

contaminate samples (Wilde and others, 1998). The pump was 

stored in disposable plastic bags after air drying. The cleaning 

procedures for the single-use disposable high-density polyethylene tubing and PVC tube fittings were similar to the pump 

cleaning procedures, but a dilute hydrochloric acid (HCl) rinse 

was used; the procedures are described in detail by Horowitz 

and others (1994) and Ivahnenko and others (1996). The sample 

tubing was discarded immediately after use. The cleaning techniques have produced acceptable results as determined on the 

basis of analyses of trace-element-free blanks collected from 

the tubing and the pump (Ivahnenko and others, 1996; 2001).

Laboratory Analysis for Radionuclides

Concentrations and activities of radionuclides were determined by use of standard methods approved by the U.S. Environmental Protection Agency and USGS (Krieger and Whittaker, 1980; Thatcher and others, 1977). Gross radioactivity of 

ground-water samples was measured as gross alpha-particle 

activity and gross beta-particle activity. The specific isotopes of 

radionuclides analyzed for in water from all wells are Pu-238 

and 239+240; Am-241; and U-238, -234, and -235. Concentrations of these same isotopes were analyzed for in the settledsediment samples recovered from the bottoms of the observation wells. Isotopes of Th-228, -230, and -232 were analyzed for 

in water samples from 5 of the 10 wells.

All radiochemical samples were analyzed by Severn Trent 

Laboratories in Richland, Washington. Personnel at the USGS 

National Water Quality Laboratory (NWQL) reviewed all 

internal laboratory quality-assurance data from standards, 

blanks, and laboratory splits, and had the authority to order the 

reanalysis of any batch of samples if quality-assurance guidelines were not met. Samples were reanalyzed when initial 

results were considered questionable because of lack of precision for duplicates, high background radiation, or other analytical problems related to instrument operating conditions.

Detection Methods

Concentrations of isotopes of Pu within the water samples 

were determined by alpha spectrometry, the most commonly 

used technique to determine concentrations of Pu isotopes. The 

Pu is first separated and purified. Pu-242 is added before sample 

preparation to provide determination of chemical yield (Sill and 

others, 1979). The evaporated residue from the water samples is 

dissolved in nitric acid (HNO3) and heated. The Pu oxidation 

state is adjusted to the +4 valence with sodium nitrite. The Pu 

is then separated from major and many trace elements by 

adsorption onto an anion-exchange column (BioRad AG 1-X8 

50–100 mesh resin). After the interfering elements, such as U, 

Th, and Am, are separated with HNO3 and HCl washes, Pu is 

desorbed from the resin by washing with ammonium iodide 

solution in HCl. The Pu is concentrated further and residual 

iodine from the elution is eliminated by adding HNO3 and 

evaporating the solution to dryness. The Pu is electroplated onto 

stainless-steel disks. The isotopic concentrations are then 

measured by alpha spectrometry. The Pu-238 (alpha particle 

energy, 5.50 MeV (million electron volts)) concentration can be 

distinguished from that of Pu-239 and Pu-240 and is reported as 

the concentration of this single isotope. Pu-239 cannot be 

differentiated from Pu-240 by alpha spectrometry, however, 

because the energy of the emitted alpha particles is nearly 

identical (5.15 and 5.16 MeV, respectively). The concentrations 

of Pu-239 and Pu-240 are reported as the concentration of 

Pu-239 plus Pu-240 (Pu-239+240). The thermal ionization 

mass spectrometry technique (TIMS) must be used in order to 

distinguish the concentration of Pu-239 from that of Pu-240 

(Liator, 1999), but it was not used for this study. A final 

complication in the analysis of the alpha-particle emitting 

Pu radionuclides is that naturally occurring Th-228 emits alpha 

particles with energies of 5.42 MeV; hence, even if the greatest 

care is taken to distinguish the Th-228 from Pu-238, 

interference, overlap, or misidentification of the isotopes is 

possible when using the alpha-spectrometry technique. In 

addition, Pu-241 undergoes beta decay and, thus, cannot be 

detected with alpha spectrometry. Pu-241 decays to Am-241 

but has a relatively short half-life (14.4 years), which makes it 

hard to detect in the environment 15–20 years after dispersal 

(low concentrations as a result of rapid decay). 

Isotopic concentrations of U and Th and concentrations of 

Am-241 were determined by alpha spectrometry after individual pre-concentration, separation, and purification procedures. 

In general, the most important step is the actual separation procedure using anion-exchange resins (BioRad AG 1-X4 and 

1-X8) to capture, then elute, the target radionuclide. The U and 
22 Radiochemical Sampling and Analysis of Shallow Ground Water and Sediment at the BOMARC Missile Facility, N.J.

Am-241 were eluted with 8 M (molar) HNO3, whereas Th was 

eluted with 8 M HCl from the anion exchange column. The U is 

further purified by extraction from a second anion-exchange 

column with methyl isobutyl ketone. Oxalate co-precipitation 

was used to pre-concentrate Am-241. Am-241 then required 

further purification and separation by placement on an additional anion-exchange column (BioRad AG 1-X4 100–200 

mesh) and elution with an alcohol solution. (Am-241 also can 

be determined by gamma spectroscopy (Hulse and others, 

1999), but alpha-spectroscopy is preferable for low concentrations because the background radiation noise is less than that for 

gamma spectroscopy. Therefore, the gamma spectroscopic 

technique is used mostly for quick surveys in the field where 

high concentrations are suspected (Ibrahim and others, 1995).

Gross alpha-particle activity and gross beta-particle activity were determined by counting in a low-background gas proportional alpha-beta-particle counter for 100 minutes. The samples were first evaporated to dryness; the residues then were 

deposited on a stainless-steel planchet and dried in a desiccator. 

Residues were weighed before counting to ensure that the mass 

did not impair counting efficiency. For particle-laden or mineralized water samples, excessive sample mass could considerably attenuate radiation emission, resulting in poor precision 

(non-reproducibility) and possible high or low bias. Calibrations for the counter were made with Th-230 standards for gross 

alpha-particle activity and with cesium-137 (Cs-137) standards 

for gross beta-particle activity (Krieger and Whittaker, 1980).

Reporting of Analytical Results for Radionuclides

The raw, unrounded values for all radionuclide concentrations in picocuries per liter (pCi/L) are reported by the laboratory. The laboratory also reports the precision estimate (P.E.), 

which is another term for measurement uncertainty and measurement error, computed at two standard deviations about the 

count value (labeled 2-Sigma P.E.). The 2-Sigma P.E. is provided by the laboratory for each analysis because the rate of 

radioactive decay varies at any instant in time even though the 

long-term decay rate is stable. All measurements of radioactivity are associated with a degree of uncertainty in the measurement, which is also known as the counting uncertainty. Other 

laboratory sources of measurement uncertainty and error are 

added to the counting uncertainty. The degree of uncertainty of 

the radioactivity measurement is the confidence interval 

expressed as two standard deviations; that is, 95 of 100 measurements of radioactivity of the sample would fall in the range 

denoted by the reported radioactivity, plus or minus the 2-sigma 

P.E. (precision estimate, composite of laboratory error, and 

counting uncertainty).

Finally, the sample-specific minimum detectable concentration (SSMDC) determined by the laboratory for each sample 

is reported. Instruments that count radioactivity record both the 

radioactivity of the water sample and the background radioactivity during the time the sample is being measured. Quantifying small amounts of radiation in a given sample is difficult 

because the analytical instruments record the background radiation during their operation. The radiation emitted from the 

radionuclide being quantified must be clearly distinguishable 

above the instrumental background radiation. The minimum 

quantity of a specific radionuclide detected by the counting 

instrument for any given analysis with the unique instrument 

operating conditions and background radiation is defined as the 

minimum detectable concentration (MDC) (Strom and MacLellan, 2001). In general, MDC is further defined by the requirement that the counted radioactivity must differ from the 

background count by 6 times the standard deviation of the background count or twice the critical level where the likelihood of 

a false positive is 5 percent or less (Currie, 1968). This value is 

computed individually for each radionuclide analysis on the 

basis of the instrument operating conditions at the time of analysis; the SSMDC is reported for each analysis for each isotopic 

constituent. The laboratory reporting level (LRL) is defined as 

the minimum quantity of a specific radionuclide that can be 

quantified routinely and reliably with general instrument operating conditions. The LRL is a target value for detection capability already known prior to analysis and readily achievable 

with routine operating conditions. The LRL is typically at least 

a factor of 2 to 3 times the SSMDC for laboratory blanks 

(results for which vary with background radioactivity). The 

LRL target was 0.1 pCi/L for all the radionuclides in this study, 

and the reported values of the SSMDCs indicate measurement 

performance was satisfactory. The LRL can be changed when 

changes occur in instrumentation, radiation background, typical 

counting times, routine sample volumes, the long-term average 

of individual analysis SSMDCs, and other factors. These analytical terms are described in detail in the Glossary at the back 

of the report.

Analysis of Shallow Ground Water and 

Settled Sediment

The raw, unrounded radiochemical analytical data for 

constituent concentrations in water as reported by the 

laboratory and values for the characteristics turbidity, water 

level, water temperature, specific conductance, and pH, which 

were continuously monitored in the field during sampling, are 

presented in this section. Results of analyses for radionuclides 

in equipment-blank samples are provided in table 6. Results of 

radiochemical analysis are provided for about 90 samples from 

10 observation wells in table 7A (back of report). The 

laboratory-reported 2-Sigma P.E. and the laboratory reported 

SSMDC for each individual sample are listed in tables 6 to 8. 

The depth of the open interval for each well is provided in 

table 1, and the depth of the pump setting within the well is 

provided in table 3. The “sample-type” column in table 7A 

and 7B (back of report) lists whether the sample is the raw, 

unfiltered, or a type of filtered sample. A detailed explanation 

of the sample types and how they were collected is provided in 

the section “Sample Type.” Data for each well are presented in
Table 6. Concentrations of radionuclides in equipment blanks used for the field experiment sampling protocol at or near the BOMARC Missile Facilit

New Jersey.[10K ultrafilter, 10,000 Dalton tangential-flow ultrafilter cartridge; μg/L, microgram per liter; pCi/L, picocuries per liter; P.E., precision estimate; SSMDC, sample-specific mini<, less than; --, no data; number in parenthesis is parameter code used to identify the constituent, property, or characteristic in the U.S. Geological Survey water-quality database ples are identified by sample number. Equipment blanks collected 8/26/99 at well 29-1378 and at well 29-1203 on 2/17/00 and 3/17/00 and 3/15/00]

Blank type Sample number Date (month/ day/year) Time Uranium, total (μg/L) (22703) Plutonium- 238 (pCi/L) (22001) Plutonium- 238, 2SIGMA P.E. (pCi/L) (49939) Plutonium- 238, SS MDC (pCi/L) Plutonium -239+240, (pCi/L) (49940) Plutonium -239+240, 2SIGMA P.E. (pCi/L) (49941) Plutonium -239+240, SS MDC (pCi/L) Americ

241 (pCi/

(2986

-- -0.000572 0.00115 0.00808 -0.000572 0.00115 0.00808 0.0037-- -- -- -- -- -- -- .0020

<.2 -- -- -- -- -- -- .0023<.2 0 .00351 .00388 -.000572 .00115 .00809 .0003<.2 -.000854 .00365 .0122 .000284 .00577 .01490 .0032

-- .000404 .00492 .0158 -- -- -- .0037

<.2 -.000586 .00118 .00828 .00293 .00416 .00397 -- <.2 -- -- -- -- -- -- -- <.2 -- -- -- -- -- -- -- 

Blank type

Date

(month/

day/year)

Time

Uranium238

(pCi/L)

(22603)

Uranium-238,

2SIGMA P.E.

(pCi/L)

(75991)

Uranium238,

SSMDC

(pCi/L)

Uranium234

(pCi/L)

(22610)

Uranium234,

2SIGMA P.E.

(pCi/L)

(75992)

Uranium234

SSMDC

(pCi/L)

Uranium

(pCi/

(2262

-0.00253 0.00256 0.0217 0.0108 0.00147 0.0272 -0.0012

Blank type

Date

(month/

day/year)

Time

Thorium232

(pCi/L)

(75976)

Thorium-232,

2SIGMA P.E.

(pCi/L)

(75999)

Thorium232,

SSMDC

(pCi/L)

Thorium230

(pCi/L)

(26503)

Thorium230,

2SIGMA P.E.

(pCi/L)

(75997)

Thorium230

SSMDC

(pCi/L)

(61738)

Thorium

(pCi/

(6173

0.00467 0.012 0.028 -0.00351 0.00414 0.0369 -0.017 

Pump, unfiltered 99900169 8/26/99 1450Deionized water source unfiltered 00000351 2/17/00 1550Retentate flow (10K ultrafilter) 00000074 2/17/00 1551Permeate flow (10K ultrafilter) 00000075 2/17/00 15520.45 Filter 00000098 2/17/00 15530.45 Filter, concurrent split 00000352 2/17/00 15530.05 Filter 00000076 2/17/00 1555Reused retentate flow (10K ultrafilter)

00000077 3/15/00 1353

Reused permeate flow (10K ultrafilter)

00000078 3/15/00 1354

Pump, unfiltered 99900169 8/26/99 1450Pump, unfiltered 99900169 8/26/99 1450
Table 8. Concentrations of radionuclides in sediment samples from the bottom of selected observation wells at or near the BOMARC Missile Facility, 

1999. [Data sorted by well depth. pCi/g, picocuries per gram; P.E., precision estimate; SSMDC, sample-specific minimum detectable concentration; number in parentheses is parameter 

uent, property, or characteristic in the U.S. Geological Survey water-quality database (NWIS) in which individual samples are identified by sample number] U.S. Geological Survey well number Date (month/day/ year) Begin time Plutonium- 238 (pCi/g) (49974) Plutonium- 238, 2SIGMA P.E. (pCi/g) (49975) Plutonium- 238, SSMDC (pCi/g) Plutonium- 239+240 (pCi/g) (49976) Plutonium- 239+240, 2SIGMA P.E. (pCi/g) (49977) Plutonium- 239+240, SSMDC (pCi/g) Americum-241 (pCi/g) (49980) Americium-241, 2SIGMA P.E. (pCi/g) (49981) A

291377 10/25/1999 1025 -0.000471 0.000945 0.0237 0 0.0143 0.0159 -0.000367 0.000737 291370 11/5/1999 1200 .00385 .00842 .0169 -.000668 .000951 .0191 0 .00704 291203 10/25/1999 1200 0 .0286 .0316 .0214 .0332 .0531 .00382 .00768 291203 10/25/1999 1201 0 .0153 .0169 0 .0153 .0169 .00377 .00758 291379 10/22/1999 1200 .00575 .0115 .0156 .0163 .0201 .0262 .00421 .00845 291379 10/22/1999 1201 -.000329 .00066 .0165 0 .01 .0111 .00795 .0123 291379 10/22/1999 1201 .00422 .00924 .0185 .00458 .00918 .0124 -.000316 .000635 291379 10/22/1999 1201 0 .00946 .0105 -.000617 .000878 .0176 291371 10/26/1999 1410 -.000585 .00117 .0294 .0073 .0147 .0198 -.000277 .000556 291371 10/26/1999 1411 .00512 .0136 .0336 .00619 .0136 .0271 0 .00952 291371 10/26/1999 1411 0 .025 .0276 0 .025 .0276 .00698 .0108 291372 10/18/1999 1335 Samples spilled at laboratory -- -- -- -- -- 291375 10/21/1999 1000 0 .0212 .0234 -.00138 .00197 .0394 0 .0111 291374 10/21/1999 1200 0 .0134 .0148 0 .0133 .0148 0 .0101 291376 10/27/1999 1200 0 .0148 .0163 .00 .0147 .0163 0 .0108 291376 10/27/1999 1201 -.000448 .000899 .0225 .00 .0136 .0151 .00865 .0129 
Table 8. Concentrations of radionuclides in sediment samples from the bottom of selected observation wells at or near the BOMARC Missile Facility, 

1999.—Continued

U.S. Geological 

Survey well 

number

Uranium-238, 

2SIGMA P.E. 

(pCi/g)

(04113)

Uranium-238,

SSMDC 

(pCi/g)

Uranium-234 

(pCi/g)

(75942)

Uranium-234, 

2SIGMA P.E. 

(pCi/g)

(04111)

Uranium-234,

SSMDC 

(pCi/g)

Uranium-235 

(pCi/g)

(75975)

Uranium

2SIGMA 

(pCi/

(7594

291377291370291203291203291379291379291379291379291371291371291371291372 Samples spilled at laboratory291375291374291376291376

0.0488 0.025 0.106 0.0514 0.0345 0.00341 0.0102 

.0798 .0112 .173 .0625 .0188 .00412 .0082.0286 .028 .0216 .024 .0371 -.0042 .0027.00736 .0147 .00366 .00734 .00991 .00 .0089.0454 .00982 .0828 .038 .0166 .00667 .0104 .0584 .0283 .118 .0568 .0283 .0166 .0199 .0346 .0153 .0455 .0276 .0103 .00 .0093 .0204 .00839 .0217 .0168 .00839 .00 .0075.015 .00893 .0362 .0228 .00893 .00659 .0093.0269 .0149 .037 .0244 .01 .00739 .0105 

-- -- -- -- 

.0263 .0263 .0149 .0202 .0325 .00919 .0165 .0369 .0113 .0292 .0227 .0113 -.000334 .0006.0683 .016 .2 .0646 .00951 .0102 .0123 .0679 .00964 .16 .0562 .00964 .00712 .0102 
26 Radiochemical Sampling and Analysis of Shallow Ground Water and Sediment at the BOMARC Missile Facility, N.J.

order by date and time of day the sample was collected. Replicate, triplicate, and laboratory duplicate samples also are listed 

among the specific raw unfiltered and filtered samples in order 

by the time the sample was collected in table 7B. Results of 

analyses for radionuclides in bottom sediment are given in 

table 8.

Quality-Assurance Evaluation of Laboratory Results for 

Equipment Blanks

The absence of detectable radionuclides of concern in the 

equipment-blank sample before or after filtration (table 6) indicates that the samples are not contaminated with low concentrations of radionuclides by the pumping equipment, filter material, or field or laboratory sample handling. This result verifies 

the adequacy of the care taken on site to avoid exposure of samples, sampling equipment, and personnel to radioactive “hot 

particles” possibly present in soil and of the extensive cleaning 

of pumping equipment using the protocols of Ivahnenko and 

others (2001) and Wilde and others (1998) to avoid sample 

cross-contamination. Contamination in the laboratory or excessive background radiation is not indicated by results of analyses 

of blank waters.

Manganese, cobalt, and zinc were detected in at least one 

equipment blank sample; other trace elements were not detected 

in any equipment blank samples. (See Szabo and others, 2002, 

table 6.) Manganese was detected in IBW that passed through 

the portable stainless-steel pump but not in IBW that passed 

through the pump and one of the filters. Detection of manganese 

in blank samples collected unfiltered from the stainless-steel 

pump is consistent with the results of Ivahnenko and others 

(2001) and indicates minor contamination from corrosion of the 

stainless steel. The filters, in general, do not add to the low-level 

trace-element contamination introduced by the portable stainless-steel pump. Internal quality assurance, analysis of standards, and examination of control charts at the laboratory 

resulted in identification of occasional and random high bias for 

cobalt in late 2000 (Connor and others, 2001); the information 

was not available to Szabo and others (2002) before publication 

of their report.

Turbidity

In general, turbidity decreased by an order of magnitude or 

more during the first 10 to 15 minutes of well purging (fig. 8). 

Turbidity was high initially, increased in some cases during the 

first 2 to 3 minutes of pumping until a peak value was reached, 

then decreased quickly at first, then more gradually. For most 

wells, turbidity continued to decrease gradually for 60 to 

120 minutes until a steady-state value of less than 1 NTU was 

reached (fig. 8). As the steady state was approached, the 

minute-to-minute variability in turbidity decreased to less than 

+10 percent, and variability, even over a 5- to 10-minute interval, was generally within +40 percent. Typically, a minimum of 

60 minutes of well purging was required before a steady state 

was achieved with no more than +0.8 NTU variability in turbidity of less than 5 NTU for four consecutive readings, 5 minutes 

apart. These results are consistent with those of Ivahnenko and 

others (2001), who also report a minimum of 60 minutes of well 

purging before steady-state values of turbidity were achieved. 

For a number of wells (4 of 10; wells 29-1371, 29-1375, 29-

1377, and 29-1379), turbidity varied by about an order of magnitude over random spans of 10 to 15 minutes during purging 

(fig. 8) and did not stabilize until 120 minutes or more of purging. Turbidity for two of the wells (wells 29-1203 and 29-1375) 

did not stabilize even after 240 minutes of purging. It is possible 

that the slight variation in pumping rate was a reason that the 

turbidity did not stabilize. These wells were sampled after about 

240 minutes or more, using a relaxed standard that required turbidity to vary by less than +25 percent within a 10-minute 

period. Turbidity remained greater than 15 NTU even after 

420 minutes of purging for well 29-1378.

Initial particle concentrations and variations in particle 

concentrations were highest among sample sets with the highest 

turbidity (table 7). Because Pu is known to be transported as 

colloidal particles (Penrose and others, 1990; Harnish and 

others, 1995), variation in particle concentrations is a concern; 

therefore, a summary of additional investigations regarding 

particle concentrations in ground water at this and other sites is 

provided. 

Concentrations of particles in the water at the Facility 

determined by settling correlate strongly with turbidity (Szabo 

and others, 2002, fig. 10), but the high LRL (1 mg/L) makes the 

technique applicable only to turbid water (turbidity > 5 NTU). 

Provisional particle concentrations in water samples determined with the light scattering technique (Szabo and others, 

2002, fig. 9) also correlate strongly with turbidity, but the sensitivity of this technique to particle size and shape makes the 

technique easily applicable only to non-turbid water (turbidity 

< 3 NTU). The apparent trend lines shown by Szabo and others 

(2002, figs. 9 and 10) of particle concentration as a function of 

turbidity indicate that a low concentration (less than the LRL of 

both the settling and light scattering techniques) of particles can 

be present in the samples even with low, stable turbidity. The 

longest purge time in this field experiment was nearly 6 hours; 

the possibility that particle concentrations may be reduced with 

purging for more than 6 hours was not investigated. Results of 

this investigation reaffirm that in the oxic environments 

encountered, low particle (low colloid) concentrations (thus, 

low turbidity) with a few exceptions could be the norm in the 

aquifer system itself; the nature of long-term variability could 

not be readily determined with available instrumentation. 

Particle concentrations and turbidities determined in this 

study of the Kirkwood-Cohansey aquifer system are similar 

(< 1 mg/L and < 1 NTU, respectively) to those noted by Ryan 

and Gschwend (1990) in similarly oxidizing environments in 

this same aquifer system after considerable purging. The 

turbidity and particle concentrations are consistent with most of 

the colloid-concentration data reported for other sites by 

Backhus and others (1993). The results for turbidity over time
0.1

1

10

100

1,000

0 60 120 180 240 300 360 420

TURBIDITY, IN NEPHELOMETRIC TURBIDITY UNITSWell 291379 turbidity measurement Well 291371 turbidity measurement Well 291370 turbidity measurement Collection of unfiltered water sample Turbidity measurement and collection of unfilitered water sample Initiation of filtered-sample collection

0.80.70.60.50.40.30.20.10.00 60 120 180 240 300 360 420

PURGE TIME, IN MINUTES

FLOW RATE, IN LITER PER MINUTE Well 29-1379 flow measurement Well 29-1371 flow measurement Well 29-1370 flow measurement

29-1371 29-1379 29-1370

Stable turbidity reached

Analysis of Shallow Ground Water and Settled Sediment 27Figure 8. Turbidity and purging rate for the observation wells at or near the BOMARC Missile Facility, Ocean County, New Jersey, 1999–2000.
8.0

6.04.02.00.0

18.016.014.012.010.0

0 60 120 180 240 300 360 420 480

TURBIDITY, IN NEPHELOMETRIC TURBIDITY UNITS

3.02.52.01.51.00.50.0

0 60 120 180 240 300 360 420 480

PURGE TIME, IN MINUTES

FLOW, IN LITERS PER MINUTE

Well 29-1375 turbidity measurementWell 29-1203 turbidity measurementCollection of unfiltered water sampleTurbidity measurement and collection of unfiltered water sampleInitiation of filtered-sample collection

Well 29-1375 flow measurementWell 29-1203 flow measurement

28 Radiochemical Sampling and Analysis of Shallow Ground Water and Sediment at the BOMARC Missile Facility, N.J. Figure 8. Turbidity and purging rate for the observation wells at or near the BOMARC Missile Facility, Ocean County, New Jersey, 1999–2000.—Continued
6

5

4

32

1

0

0 60 120 180 240 300 360 420

TURBIDITY, IN NEPHELOMETRIC TURBIDITY UNITS

1.81.61.41.21.00.80.60.40.20.0

0 60 120 180 240 300 360 420

PURGE TIME, IN MINUTES

FLOW RATE,

IN LITERS PER MINUTE

29-1376 29-1374 29-1372

Well 29-1376 turbidity measurementWell 29-1374 turbidity measurementWell 29-1372 turbidity measurementCollection of unfiltered water sampleTurbidity measurement and collection of unfiltered water sampleInitiation of filtered-sample collection

Well 29-1376 flow measuremnetWell 29-1374 flow measurementWell 29-1372 flow measurement

Stable turbidity reached

Analysis of Shallow Ground Water and Settled Sediment 29 Figure 8. Turbidity and purging rate for the observation wells at or near the BOMARC Missile Facility, Ocean County, New Jersey, 1999–2000. —Continued
30 Radiochemical Sampling and Analysis of Shallow Ground Water and Sediment at the BOMARC Missile Facility, N.J.

presented here are similar to those of Ryan and Gschwend 

(1990), who report that 10 to 20 casing volumes of water may 

need to be purged during 6 hours or more before stable turbidity 

is reached. The resuspension of settled particles with the initiation of sampling, characterized for this investigation by detailed 

monitoring of turbidity throughout well-purging activities (fig. 

8), is consistent with the result of Backhus and others (1993), 

Kearl and others (1992), and Gibs and others (2000) and may 

give the false impression that the water in the aquifer system is 

turbid.

Even with low-flow sample-collection techniques, considerable purging is required to reduce turbidity. Unfiltered samples collected by means of the traditional approach of initiating 

sampling after purging a fixed volume or time interval could 

contain particulates mobilized by the surging action of pumping, and a positive bias in trace-element concentration could 

result. This result is especially likely when the samples are collected from infrequently purged observation wells, such as 

those utilized in this study. The field experiments conducted by 

Gibs and others (2000) and Szabo and others (2002) demonstrate the potentially large effect of turbidity on concentrations; 

particle-rich turbid samples collected soon after purging was 

initiated contained greater trace-element concentrations than 

samples with low turbidity collected after substantial purging.

Strict documentation of turbidity in the sampling program 

presented here provides an indication that stable turbidity was 

reached within the limits of available field-detection instruments. Precautions were taken to reduce particulate artifacts in 

samples analyzed for trace elements and radionuclides. Concentrations of Pu, Am, U, and Th in water can be expected to be 

reasonably representative of that in the aquifer system within 

the limits of the analytical capability.

Concentrations of Plutonium, Americium, Uranium, 

and Thorium in Water

The concentrations reported for Pu isotopes and Am-241 

are, in all but one case, less than the 0.1-pCi/L LRL for these 

radionuclides and are, in all but a few isolated cases, less than 

the SSMDC of the counting instrument (table 7). Concentrations greater than the SSMDC are the true detection of 

radiation at greater than the 95-percent degree of confidence. 

There is less than a 5-percent chance of a false negative, the 

situation where radiation is present but is “falsely” not recorded 

on the instrumentation; see Currie (1968) and Strom and 

MacLellan (2001). Many measured concentrations were less 

than 0.01 pCi/L and were substantially less than the LRL and 

0

5

10

15

20

25

30

35

40

45

0 60 120 180 240 300 360 420 480 540

TURBIDITY, IN NEPHELOMETRIC TURBIDITY UNITS

PURGE TIME, IN MINUTES

Well 29-1378 turbidity measurement

Collection of unfiltered water sample

Turbidity measurement and collection of

unfiltered water sample

Initiation of filtered sample

Figure 8. Turbidity and purging rate for the observation wells at or near the BOMARC Missile Facility, Ocean County, New Jersey, 

1999–2000.—Continued
Analysis of Shallow Ground Water and Settled Sediment 31

the SSMDC. Many of the concentration results from the study 

are negative numbers; the negative numbers indicate the results 

of analysis were actually less than the amount typical of 

routinely measured background radiation. In other words, 

negative radionuclide concentration results indicate that the 

radioactivity of the sample could not be distinguished from, 

and, in fact, was lower than typical background radioactivity in 

the laboratory.

The raw analytical concentration results for each radionuclide ideally are interpreted in the context of the plus or minus 

error associated with the 2-Sigma P.E. In the few cases where 

the reported analytical concentration is slightly greater than the 

SSMDC, the reported analytical concentration result minus the 

2-Sigma P.E. is less than or equal to the SSMDC. This result 

indicates that, although a minute amount of radiation above 

background levels was detected, at a 95-percent confidence 

level the analytical result cannot be differentiated quantitatively 

from the SSMDC.

Concentrations of each of the radionuclides are shown for 

all wells for each sample type (unfiltered, filtered, tangentialflow ultra filtered) in figure 9. Where sequential duplicates were 

collected, the concentrations of these samples are included. For 

each sample type, the median of the individual concentrations 

of each radionuclide for all wells was computed and is indicated 

in figure 9. For each sample type, the median of the individual 

SSMDCs for each radionuclide was computed and is indicated 

in figure 9; the maximum SSMDC for each radionuclide for 

each sample type also is provided. Individual sample concentrations also were compared to the median and maximum SSMDC 

(fig. 9), thereby placing constituent concentrations in context 

not only with the individual SSMDC, but with the typical 

SSMDC (median) and the most conservative SSMDC with 

regard to analytical capability (maximum SSMDC). Most constituent concentrations were less than the individual as well as 

the median SSMDC; that is, the radiation could not be considered greater than background at that instant in time. The LRL of 

0.1 pCi/L is not shown in figure 9 because all but one constituent concentration was substantially less than this value. A concentration reported at or greater than the LRL was of concern 

because, at this level, the result was considered to be readily 

verifiable (reproducible) and quantifiable using routine procedures. Concentrations of radionuclides that exceeded the individual SSMDCs but were substantially less than the LRL were 

considered with caution because the amount of radioactivity 

present was so small that it could not be considered to be quantifiable above background radiation on a routine basis. Furthermore, at the concentration level of the SSMDC, a small but nevertheless real likelihood remains of the occurrence of “false 

positive” results when instruments indicate the presence of 

radioactivity though none is truly there. In the few cases where 

the reported concentration was slightly greater than the 

SSMDC, the result was carefully evaluated to determine the significance in the context of the 2-sigma P.E., the SSMDC, the 

LRL, and the information gained from quality-assurance samples, including replicates and equipment blanks; each of these 

samples is discussed below. The results were termed “qualified” if concentration results were not verified by analysis of 

sequential replicate or laboratory duplicate samples or were not 

consistent with results of concurrent samples. Concentrations of 

the radionuclides that exceed the individual sample SSMDCs 

are denoted with a different symbol in figure 9 than those that 

were less than the SSMDCs.

Concentrations of radionuclides in the colloid-bearing 

fraction in the retentate flow that does not pass the tangentialflow ultrafilter could require correction based on the concentration factor (CF) used during tangential-flow ultrafiltration (See 

concentration factor (CF) in Glossary; Hoffman and others, 

1981; 2000). The CF was determined in the field (Szabo and 

others, 2002), but the use of the CF was not necessary for computing the radionuclide concentrations determined for the samples because results are less than the SSMDC.

The median concentration of isotopes of Pu-238 and 

Pu-239+240 are about zero in all water-sample types (figs. 9a, 

9b) and are much less than either the median or maximum 

SSMDC. Many negative concentrations were reported. In the 

few cases where the reported analytical result is slightly greater 

than the individual SSMDC, the reported analytical result 

minus the 2-Sigma P.E. is less than the SSMDC, indicating that 

quantification above the SSMDC is uncertain. 

The maximum concentration of Pu-238, shown in 

figure 9a as a “qualified” result, was 0.0154 pCi/L and was 

present in an unfiltered sample from well 29-1203 that was 

collected during well purging when the water had moderate 

turbidity (2.29 NTU). The reported analytical result minus 

the 2-Sigma P.E. of 0.01 pCi/L is slightly greater than the 

individual SSMDC but is nearly an order of magnitude less than 

the LRL. The well is outside the fence adjacent to the drainage 

ditch where runoff from fire fighting was diverted. None of the 

other filtered or unfiltered water samples from this well (29-

1203) contained a Pu-238 concentration that exceeded 

individual SSMDCs. Furthermore, the sample did not contain 

detectable Pu-239+240. On the basis of this information, this 

single result was “qualified” because a concentration of the 

same order of magnitude was not reproduced in any other 

sample from the well. At about the level of the SSMDC, the 

likelihood of false positive results is about 5 percent; thus, for 

90 samples at this concentration level, one or more false 

positive results would not be unexpected. Because the collected 

sample was moderately turbid relative to the final measured 

turbidity of 1.12 NTU and was unfiltered, the possibility of a 

“hot particle” could not be completely ruled out, although the 

absence of detected Pu-239+240 in the same sample seems to 

indicate that the most plausible explanation is the presence of 

minor laboratory “noise”. Liator (1999) reports that “...errors 

(that) were originated from the high variability in plutonium 

activity...” in soils (that can be attributed in part to “hot 

particles”) pose substantial difficulty for any sampling program 

assessing dispersion of these manmade radionuclides. In an 

earlier study, Sill (1975) reached the same conclusion regarding 

environmental sampling of dispersed plutonium, stating 

“...the major problems arise in obtaining sufficient samples... 

and homogeneous samples for analysis.” 
SAMPLE TYPE

-0.01

0.00

0.01

0.02

0.03

0.04

CONCENTRATION, IN PICOCURIE PER LITER

R1 R2 RTi R3 F0.45F0.45aF0.0029

(a) Pu-238

SAMPLE TYPE

-0.01

0.00

0.01

0.02

0.03

0.04

R1 R2 RTi R3F0.45F0.45a

F0.0029

(b) Pu-239+240

SAMPLE TYPE

-0.01

0.03

0.11

0.15

CONCENTRATION, IN PICOCURIE PER LITER

R1 R2 RTi R3 F0.45 F0.45a F0.0029

(c) Am-241

0.00

CONCENTRATION, REPORTED AT OR BELOW THE SSMDC

MEDIAN

MEDIAN SSMDC

MAXIMUM SSMDC

CONCENTRATION, QUALIFIED RESULT BASED ON QUALITY ASSURANCE

EXPLANATION

32 Radiochemical Sampling and Analysis of Shallow Ground Water and Sediment at the BOMARC Missile Facility, N.J.

Figure 9. Concentrations of (a) plutonium-238 (Pu-238), (b) plutonium-239+240 (Pu-239+240), 

(c) americium-241 (Am-241), (d) uranium-234 (U-234), (e) uranium-235 (U-235), (f) uranium-238 

(U-238), (g) thorium-228 (Th-228), (h) thorium-230 (Th-230), and (i) thorium-232 (Th-232) in water samples from observation wells at or near the BOMARC Missile Facility, Ocean County, 

New Jersey, 1999–2000, grouped by sample collection technique.
Analysis of Shallow Ground Water and Settled Sediment 33

The median concentrations of the radioisotope Am-241 are 

about zero in all water-sample types but one (fig. 9c) and are 

generally much less than either the median or maximum 

SSMDC. Many negative values for Am-241 concentrations 

were reported for all sample types. The sole exception is the 

median concentration of Am-241 in the initial unfiltered samples from the wells that also tended to be the most turbid; for 

these initial unfiltered samples with substantial particle 

concentration, the median Am-241 concentration was about 

0.01 pCi/L, a result that is about equal to the median SSMDC 

for that sample type. Two turbid, unfiltered water samples from 

well 29-1371 with 5.46 and 8.02 NTU contained Am-241 concentrations of 0.0149 and 0.0341 pCi/L, respectively, that were 

greater than the respective SSMDC; a third unfiltered sample 

contained an Am-241 concentration that exceeded the SSMDC, 

but the result did not exceed the SSMDC when the 2-sigma P.E. 

was considered (subtracted). For two of the turbid samples collected at about the same time, the Am-241 concentration minus 

the 2-Sigma P.E. was slightly less than the SSMDC (fig. 9c), 

indicating that the concentration cannot be reliably distinguished from the SSMDC. The Am-241 concentrations for the 

initial unfiltered samples are considered “qualified.” 

The maximum concentration of Am-241, shown in 

figure 9c as a “qualified” result, was 0.127 pCi/L in a sample 

from well 29-1371 that was filtered through the 0.45-μm capsule filter (F0.45a). The sample result minus the 2-Sigma P.E. 

of 0.0337 pCi/L was slightly less than the LRL of 0.1 pCi/L. 

The concentration of Am-241 in a sequential duplicate sample 

(table 7B) that passed the same filter was less than the individual SSMDC of 0.0145 pCi/L, however. The concentration of 

Am-241 in the retentate sample (F0.45) that passed over the 

0.0029-μm ultrafilter and also passed through the 0.45-μm capsule filter was 0.0129 pCi/L, but the analytical result minus the 

2-Sigma P.E. of 0.0088 pCi/L equaled the SSMDC within the 

rounding error (third significant figure). The corresponding permeate samples were filtered through the 0.0029-μm ultrafilter 

(F0.0029), collected, and analyzed in triplicate; the Am-241 

concentration was less than the SSMDC in one of the replicates 

(tables 7A and 7B). Am-241 concentrations were 0.0298 and 

0.0513 in the other replicates, and the reported analytical results 

minus the 2-Sigma P.E. were greater, albeit barely, than the 

SSMDC (fig. 9c). The corresponding unfiltered samples (R3), 

collected while filtration progressed, did not contain concentrations of Am-241 greater than the SSMDC, however (fig. 9c).

SAMPLE TYPE

-0.02

0.02

0.06

0.10

0.14

R1 R2 RTi R3 F0.45 F0.45a

F0.0029

CONCENTRATION, REPORTED AT OR BELOW THE SSMDC

MEDIAN

MEDIAN SSMDC

MAXIMUM SSMDC

CONCENTRATION, QUALIFIED RESULT BASED ON 

QUALITY ASSURANCE

CONCENTRATION, REPRODUCED RESULT

-0.02

0.00

0.02

0.04

0.06

0.08

0.10

CONCENTRATION, IN PICOCURIE

PER LITER

(d) U-234

R1 R2 RTi R3 F0.45 F0.45a

F0.0029 -0.02

0.00

0.02

0.04

0.06

0.08

0.10

(e) U-235

R1 R2 RTi R3 F0.45 F0.45a

F0.0029

(f) U-238

CONCENTRATION, IN PICOCURIE

PER LITER

EXPLANATION

SAMPLE TYPE

Figure 9. Concentrations of (a) plutonium-238 (Pu-238), (b) plutonium-239+240 (Pu-239+240), (c) americium-241 

(Am-241), (d) uranium-234 (U-234), (e) uranium-235 (U-235), (f) uranium-238 (U-238), (g) thorium-228 (Th-228), (h) thorium-230 (Th-230), and (i) thorium-232 (Th-232) in water samples from observation wells at or near the BOMARC 

Missile Facility, Ocean County, New Jersey, 1999–2000, grouped by sample collection technique.—Continued
34 Radiochemical Sampling and Analysis of Shallow Ground Water and Sediment at the BOMARC Missile Facility, N.J.

Concentrations of Am-241 indicate a lack of correspondence 

among the filtered and unfiltered water samples from well 29-

1371 and among replicates of the filtered samples. On the basis 

of this information, the Am-241 concentration results from the 

filtered samples were qualified because detectable Am-241 concentrations of the same order of magnitude were not routinely 

reproduced in the unfiltered samples collected at about the same 

time from the well. The most likely explanation for the lack of 

reproducibility of Am-241 concentrations in the filtered samples is minor laboratory “noise.” 

The possibility of Am-241-bearing “hot particles” occurring randomly in turbid unfiltered samples cannot be ruled out. 

The possibility that a colloidal “hot particle” containing Am241 passed through the 0.45-μm capsule filter, thus, also cannot 

be completely ruled out as contributing to the presence of Am241 in the filtered sample. A similar explanation, a rarely occurring “hot particle”, is possible for sample (R1) with the most 

turbidity, collected from this well (29-1371) just after purging 

was initiated. The filtered samples were collected at the end of 

purging when the purged water was not turbid (final turbidity 

less than or about 1 NTU; tables 3 and 7). Szabo and others 

(2002) show, however, that a minute amount of particles not 

quantifiable even with the most highly sensitive analytical technique (laser light-scattering) were present in ground water with 

turbidity less than 1 NTU. The occasional but not reproducible 

presence, of Am-241 in the samples from well 29-1371 typically at concentrations less than 0.1 pCi/L indicates that if “hot 

particles” are truly present, they are few in number (possibly as 

few as 1–5 “hot” particles per liter) and not readily quantifiable 

by the sampling technique used.

The concentration of Am-241 in the permeate flow from 

the 0.0029-μm ultrafilter (F0.0029) minus the 2-Sigma P.E. was 

slightly greater than the SSMDC for the sample from well 

29-1379. The duplicate sample of permeate flow from the 

0.0029-μm ultrafilter was spilled in the laboratory before it 

could be analyzed, so confirmation of the Am-241 concentration was not obtained. The corresponding unfiltered samples 

(R3) did not contain detectable Am-241, however (fig. 9c). 

Well 29-1379 is located in an area that probably does not intercept water from flow paths that could have originated near 

Shelter 204 (fig. 2). Therefore, Am-241 concentration for the 

permeate-flow sample from well 29-1379 is considered “qualified” and probably represents laboratory “noise” (fig. 9c).

-0.10

0.06

0.50

0.70

CONCENTRATION, IN PICOCURIE

PER LITER

(g) Th-228

R1 R2 RTi R3 F0.45 F0.45a

F0.0029

SAMPLE TYPE

-0.01

0.04

0.09

0.14

0.19

0.24

0.29

(h) Th-230

CONCENTRATION, REPORTED AT OR BELOW THE SSMDC

MEDIAN

MEDIAN SSMDC

MAXIMUM SSMDC

R1 R2 RTi R3 F0.45 F0.45aF0.0029

SAMPLE TYPE

-0.01

0.04

0.09

0.14

0.19

0.24

0.29

(i) Th-232

R1 R2 RTi R3 F0.45 F0.45a

F0.0029

CONCENTRATION, IN PICOCURIE

PER LITER

EXPLANATION

Figure 9. Concentrations of (a) plutonium-238 (Pu-238), (b) plutonium-239+240 (Pu-239+240), (c) americium-241 

(Am-241), (d) uranium-234 (U-234), (e) uranium-235 (U-235), (f) uranium-238 (U-238), (g) thorium-228 (Th-228), (h) thorium-230 (Th-230), and (i) thorium-232 (Th-232) in water samples from observation wells at or near the BOMARC 

Missile Facility, Ocean County, New Jersey, 1999–2000, grouped by sample collection technique.—Continued
Analysis of Shallow Ground Water and Settled Sediment 35

The medians of concentrations of the isotopes of U-238 

and U-234 are about 0.01 pCi/L in all types of the water 

samples, except one (figs. 9d and f), and typically are less than 

either the median or maximum SSMDC. Occasionally, negative 

concentrations were reported for U isotopes, indicating that 

some samples contained no U. The exception is the group of 

initial unfiltered (R1) samples; the median U-238 and U-234 

concentrations in this sample type were about 0.02 pCi/L, a 

result that is about equal to the median SSMDC for that sample 

type. These initial unfiltered samples also tended to be the most 

turbid. The particles in the sample may contain U isotopes; the 

sediment that composes the aquifer system contains small 

quantities of U (Szabo and others, 1997). The low concentration 

of U isotopes in the ground-water samples at the Facility is 

typical for water from the Kirkwood-Cohansey aquifer system 

as a whole; Kozinski and others (1995) report a median 

concentration of 0.03 μg/L for 80 samples of water from the 

aquifer system. Kozinski and others (1995) also measured 

U-234 to U-238 isotope ratios of about 1:1 in water from the 

Kirkwood-Cohansey aquifer system. Assuming the isotope 

ratio of naturally occurring U in water from the aquifer system 

is 1:1, the median concentration of U (0.03 μg/L) determined 

by Kozinski and others (1995) would be the equivalent of 

0.02 pCi/L of radioactivity resulting from naturally occurring 

U isotopes (0.67 pCi/μg; see Schlein, 1992), which is nearly 

identical to the median U isotope concentration in water from 

the aquifer system at the Facility.

The initial unfiltered sample from well 29-1378 and a 

sequential replicate contained U-238 and U-234 concentrations 

of 0.05 and 0.08 pCi/L, respectively, and turbidity was 38 and 

38.9 NTU, respectively (tables 7A, 7B). The similar results in 

replicate samples indicate that the U concentration is reproducible even in turbid water. This reproducible result indicates that 

naturally occurring U is present in small amounts, especially in 

particulates present in the turbid unfiltered samples. It is also 

likely, however, that the particulates in this turbid initial purge 

water were not actually mobile in the aquifer system but were 

part of the particulate material that settled to the bottom of the 

well and resuspended during the sampling event. (Well 29-1378 

was not redeveloped before sampling and remained turbid 

throughout purging.) It is likely that turbid samples (turbidity 

>100 NTU) from improperly developed and purged wells contain large amounts of resuspended sediment and minor amounts 

of associated uranium. The association between trace elements 

and sediment resuspended during purging has been documented 

by Gibs and others (2000).

Concentrations of the isotopes of Th typically are less than 

either the median or the maximum SSMDC (figs. 9g–i). Occasionally, negative concentration results were reported. The concentration of Th isotopes in ground water typically is low 

because Th is insoluble in virtually all natural conditions (Langmuir and Herman, 1980). The presence of minor amounts of Th 

in sediments of the aquifer system has been documented by 

Szabo and others (1997); thus, as for U, the presence of minor 

amounts of Th in turbid samples may not be unreasonable.

Gross alpha-particle activity and gross beta-particle activity are low. Gross alpha-particle activity typically was less than 

the LRL of 3 pCi/L, and gross beta-particle activity in most 

samples was below the LRL of 4 pCi/L. These crude measurement techniques can be good indicators of the presence of radionuclides whose concentrations are not specifically determined 

but that are greater than the LRL (by 2–3 pCi/L). The “gross” 

analytical techniques cannot detect minor amounts of radiation, 

however. The measurement 2-Sigma P.E. is typically about the 

same magnitude as the LRL for samples with activities of about 

the LRL because of the substantial analytical uncertainty of the 

“gross” techniques. If gross alpha-particle or beta-particle 

activity of considerable magnitude were detected, the additional 

radiochemical analyses conducted to determine the concentrations of specific nuclides also could be used to determine the 

exact nature of the radiation-emitting nuclides. On the other 

hand, in the absence of gross radioactivity of a magnitude 

greater than the LRL, as is the case at the Facility, these “gross” 

measurement techniques will not provide useful screening 

information regarding radioactive contamination.

Water in the Kirkwood-Cohansey aquifer system, especially in the southwestern part of the system (southwestern New 

Jersey), typically contains gross alpha-particle activity of about 

10 to 15 pCi/L, but does not always contain naturally elevated 

gross alpha-particle activity, especially in the Pine Barrens Preserve area. The low activities of gross-alpha and gross-beta particles in water at the Facility are in the range reported previously 

for the Pine Barrens Preserve in northern Atlantic County, 

south-central Burlington County, and central Ocean County 

(Szabo and others, 1997, table 2B). 

The only notable trend in radioactivity at the Facility was 

that gross alpha-particle activity was highest in the water from 

the shallowest two wells; pH was lowest in the shallow waters. 

(Data are sorted by well depth in the tables with the intent of 

evaluating the approximate depth of penetration of any manmade radionuclide contamination. See Rice and Szabo (1997) 

for discussion of depth of penetration of manmade contaminants into the Kirkwood-Cohansey aquifer system). The results 

from this sampling experiment at the Facility are consistent 

with those reported for the Kirkwood-Cohansey aquifer system 

by Szabo and others (1997), who show that the highest concentrations of the naturally occurring radionuclides (radium-226 

and radium-228) in water from the aquifer system are found at 

shallow depths where pH is lowest. The low but detectable 

gross alpha-particle activity at shallow depths in relation to nondetectable radioactivity at substantial depth is consistent with 

the typical conditions of the aquifer system.

On the basis of the results of analyses reported in table 7 

and shown in figure 9 and a review of the qualified data, no evidence was observed of any unqualified and routinely reproducible, detectable, and quantifiable manmade radionuclide contamination in any of the set of raw unfiltered or filtered water 

samples from the 10 observation wells. All quality-assurance 

data, including results of laboratory duplicates and sequential 

field replicates, are in agreement with the results of the analyses 

of initial environmental samples that indicate no discernible 
36 Radiochemical Sampling and Analysis of Shallow Ground Water and Sediment at the BOMARC Missile Facility, N.J.

radionuclide concentrations are present at greater than background levels (tables 6, 7A, and 7B). Results of analyses of 

equipment blanks indicate that random contamination from 

sample handling was not introduced. Thus, there is no evidence 

of manmade radionuclide contamination in the aquifer system 

in the form of particulates, colloids, or truly dissolved 

radionuclides.

Concentrations of Plutonium, Americium, and Uranium 

in Settled Sediment

The concentrations of isotopes of Pu and Am-241 in settled sediments recovered from the bottom of the observation 

wells were less than the SSMDC (fig. 10; table 8). The concentrations are well below the 0.1 pCi/g (picocuries per gram) considered the average background fallout concentration level 

reported by Earth Technology Corporation (1991) and are similar to those low levels noted by Lee and others (1998) for fallout in soil in New Mexico and by Hulse and others (1999) for 

background levels in soil in Colorado.

The concentrations of U isotopes in these well-bottom 

sediments generally were less than the SSMDCs, which were 

substantially less than 0.1 pCi/g. The concentrations of U-238 

and U-234 were greater than the SSMDCs and ranged from 

about 0.05 to 0.25 pCi/g in sediment samples retrieved from the 

bottom of three observation wells, 29-1371, 29-1376, and 

29-1379 (fig. 10; table 8). U-isotope concentrations were within 

the range of naturally occurring U-isotope concentrations in the 

aquifer sediments. Concentrations of Ra-226 in samples of sand 

from the Kirkwood-Cohansey aquifer system from southwestern New Jersey were at about the same activity level, 

typically 0.05 to 0.2 pCi/g (Szabo and others, 1997); this decay 

product of U was present in solids at activities of about the same 

level as U-238. The isotopic ratio of U-234 to U-238 in the 

sediment samples of about 1:1 also is consistent with that of

29-1203

29-1370

29-1371

29-1374

29-1375

29-1376

29-1377

29-1379

-0.01

0.01

0.03

0.05

0.07

CONCENTRATION, IN PICOCURIE

PER GRAM

(a) Pu-238

29-1203

29-1370

29-1371

29-1374

29-1375

29-1376

29-1377

29-1379

WELL NUMBER 

-0.01

0.01

0.03

0.05

0.07

(b) Pu-239+240

29-1203

29-1370

29-1371

29-1374

29-1375

29-1376

29-1377

29-1379

WELL NUMBER

-0.001

0.004

0.009

0.014

0.019

0.024

(c) Am-241

CONCENTRATION, IN PICOCURIE

PER GRAM

EXPLANATION

CONCENTRATION, REPORTED AT OR BELOW THE SSMDC

MEDIAN

MEDIAN SSMDC

MAXIMUM SSMDC

Figure 10. Concentrations of (a) plutonium-238 (Pu-238), (b) plutonium-239+240 (Pu-239+240), (c) americium-241 (Am-241), 

(d) uranium-234 (U-234), (e) uranium-235 (U-235), and (f) uranium-238 (U-238) in samples of sediment settled to the bottom of 

observation wells at or near the BOMARC Missile Facility, Ocean County, New Jersey, 1999.
Analysis of Shallow Ground Water and Settled Sediment 37

natural sediment (Osmond and Cowart, 1976). (Unfortunately, 

the bottom-sediment sample from well 29-1372 was accidentally discarded at the laboratory before U analysis was complete, and a sediment sample was not recovered from the bottom 

of well 29-1378.) 

The low Pu, Am, and U concentrations indicate that there 

is not at present (2000) a reservoir of sediment contaminated 

with manmade radionuclides in the bottom of the observation 

wells. The result is consistent with the absence of quantifiable 

concentrations of manmade radionuclides in samples of even 

the most turbid water collected initially from the observation 

wells. (The U-234 and U-238 present in a few turbid samples 

with an isotopic ratio indicative of natural, not industrial, origin 

are likely derived from aquifer system sediment settled to the 

bottom of the wells.) Of the wells with detectable U in bottom 

sediment, only well 29-1379 contained detectable U (U-234) in 

an initially turbid water sample. (Replicate and duplicate samples selected for analysis at random were not chosen for analysis for the concentration of U for well 29-1379; therefore, the 

sample result, although reasonable, could not be verified with a 

replicated sample.)

Water samples collected with strict adherence to low-flow 

protocols have low turbidity and particulate concentrations, and 

are representative of the shallow ground water at the Facility, as 

opposed to the samples collected without such protocols. 

Before this study, water samples from the aquifer system at the 

Facility were collected without the use of low-flow sample-collection techniques and purging to stabilize and minimize turbidity; therefore, the samples could have contained a much higher 

concentration of particulates, as well as concentrations of U 

associated with those particulates, than samples collected for all 

sampling events during this study with the strict adherence to 

low-flow sampling protocols. Szabo and others (2002) demonstrated with water samples from the Facility that, even when 

low-flow sampling techniques are used, initial samples collected from observation wells before turbidity is stabilized 

could contain considerable concentrations of particulates and 

trace elements associated with these particulates. Despite that 

Pu and Am were not detected in the well-bottom sediments, the 

presence of naturally occurring U and Th could have resulted in 

spectral interference in turbid sediment-laden water samples 

collected in the past by use of the bailing technique.

29-1203

29-1370

29-1371

29-1374

29-1375

29-1376

29-1377

29-1379

0.00

0.05

0.10

0.15

0.20

0.25

0.30

CONCENTRATION, IN PICOCURIE

PER GRAM

(d) U-234

29-1203

29-1370

29-1371

29-1374

29-1375

29-1376

29-1377

29-1379

WELL NUMBER

0.00

0.05

0.10

0.15

0.20

0.25

0.30

(f) U-238

CONCENTRATION, QUALIFIED RESULT BASED

ON QUALITY ASSURANCE

CONCENTRATION, REPRODUCED RESULT

29-1203

29-1370

29-1371

29-1374

29-1375

29-1376

29-1377

29-1379

WELL NUMBER

-0.01

0.00

0.01

0.02

0.03

0.04

(e) U-235

CONCENTRATION, IN PICOCURIE

PER GRAM

EXPLANATION

CONCENTRATION, REPORTED AT OR BELOW 

THE SSMDC

MEDIAN

MEDIAN SSMDC

MAXIMUM SSMDC

Figure 10. Concentrations of (a) plutonium-238 (Pu-238), (b) plutonium-239+240 (Pu-239+240), (c) americium-241 (Am241), (d) uranium-234 (U-234), (e) uranium-235 (U-235), and (f) uranium-238 (U-238) in samples of sediment settled to the 

bottom of observation wells at or near the BOMARC Missile Facility, Ocean County, New Jersey, 1999.—Continued
38 Radiochemical Sampling and Analysis of Shallow Ground Water and Sediment at the BOMARC Missile Facility, N.J.

Summary and Conclusions

The U.S. Geological Survey (USGS), in cooperation with 

the U.S. Air Force (USAF), designed a detailed radiochemical 

sampling field experiment at the BOMARC Missile Facility in 

the Pine Barrens Preserve in Ocean County, New Jersey, to 

address concerns regarding potential radionuclide contamination in the unconfined aquifer (Kirkwood-Cohansey aquifer 

system) and the quality of analytical results based on sampling 

technique. A fire in 1960 at the Facility and the subsequent 

release of plutonium (Pu) from a warhead to the environment 

have raised environmental and regulatory concerns regarding 

the potential for Pu dispersal and ground-water contamination. 

Of special concern was the possible migration of colloid-size 

particles in the aquifer system because these are known to facilitate transport of Pu and the Americum (Am) products of Pu 

decay. A review of radiochemical data previously obtained during numerous samplings at the site during 1985–94 indicated, 

however, that previous sampling techniques (bailing) and variations in particulate matter in the samples, as well as the lack of 

documentation of this variability, did not lead to reproducibility 

of analytical results. In order to address the environmental and 

regulatory concerns, specific attention was placed on developing a stringent sampling protocol to ensure the collection of 

samples that are representative of water in the KirkwoodCohansey aquifer system and various size particles to determine 

if any contaminants were sorbed to potentially mobile particles 

in the ground water, especially colloids of 0.45 micrometer 

(μm) or less. The sampling protocol was designed to determine 

the occurrence of any particulate, colloidal, and dissolvedphase concentrations of radionuclides present in the unconfined 

aquifer system that might be attributable to release during the 

fire. Isotopes of plutonium (Pu-238 and Pu-239+Pu-240), Am 

(Am-241), and uranium (U) (U-238 and U-234) that could be 

associated with the warhead were selected as the constituents to 

be analyzed. The concentrations of the isotopes of thorium (Th) 

also were determined in water samples from some of the wells. 

Gross alpha-particle and beta-particle activity were measured to 

provide overall screening for radionuclides in the ground water 

and for comparison with previous sampling results for the Facility and previously obtained data on background concentrations 

of radionuclides in samples from the aquifer system.

Water samples were collected from 10 observation wells 

and bottom-sediment samples were collected from 9 of the 

wells for radiochemical analysis from August 1999 to February 

2000. All observation wells sampled have screened intervals 

in the unconfined aquifer system underlying the Facility. 

Sampling was performed by collecting sequential samples of 

raw unfiltered and filtered water using low-flow purging 

techniques coupled with size fractionation with the use of 

tangential-flow ultrafiltration. Turbidity was monitored 

continuously to characterize changes in particulate matter 

during purging and sampling. Turbidity was used to determine 

the most appropriate times for sample collection. Initial turbid 

purge water was sampled unfiltered, and additional unfiltered 

samples were collected as purging progressed and turbidity 

decreased. Where possible, the final unfiltered and filtered 

samples were not collected until stable (+0.8 nephlometric 

turbidity units (NTU), four consecutive readings, each 5 

minutes apart) turbidity of less than 5 NTU was achieved. 

Stable turbidity was achieved at all but two of the wells. Filtered 

water was collected through various nominal pore-size filters 

using standard filtration and tangential-flow ultrafiltration 

techniques after turbidity stabilized.

A certified laboratory performed the radiochemical analysis. Standard alpha spectroscopic techniques were used to determine concentrations of alpha-particle emitting radionuclides of 

Pu, Am, U, and Th in water, and after digestion in sediment. 

Raw (unrounded and uncensored) concentration results are 

reported to allow for comprehensive data evaluation. Extensive 

quality assurance, including analysis of blank and replicate 

samples, verified acceptable performance of the laboratory.

No evidence was observed of any detectable manmade 

radionuclide contamination in any of the well-bottom sediment 

samples, or in raw unfiltered or filtered water samples from any 

of the wells. All radionuclide concentrations from water samples, whether raw or filtered, were less than the 0.1 pCi/L (picocuries per liter) typically associated with routine laboratory 

(minimum) reporting levels (LRL) for these manmade radionuclides. The Am-241 concentration in one sample was about 

0.1 pCi/L (the LRL of 0.1 pCi/L was within the bounds of the 

2-Sigma P.E. for the sample result), but this result could not be 

reproduced in subsequent analyses of concurrent samples or 

splits. Most manmade radionuclide concentrations were less 

than 0.01 pCi/L, and negative values were commonly reported. 

These results indicated that the radioactivity of most of the samples could not be distinguished from background radioactivity 

in the laboratory. All quality-assurance data from laboratory 

duplicates and sequential field replicates are in agreement with 

the results of initial sample analyses that indicate no discernible 

concentrations above current background radiation were 

present. The analytical results for isotopes of Am-241 and Pu in 

sediments settled to the bottom of the wells also were below the 

LRL. The range of concentrations of U isotopes in the water and 

sediment matched nearly exactly those determined during previous regional studies of the water from the aquifer system and 

the aquifer sediment (about 0.2 pCi/g in sediment). Maximum 

concentrations of uranium isotopes (U-238 and U-234 were 

0.05 and 0.08 pCi/L in water, respectively, and 0.25 and 

0.20 pCi/g in sediment, respectively. Thus, the concentration of 

U does not indicate the presence of weapons-grade U-234 isotopes or atypically elevated U (above background levels) in 

either water or sediment. Gross alpha-particle activity and gross 

beta-particle activity were low (<5.5 pCi/L in all cases); these 

results are at the low end of the typical range reported previously for samples from the Kirkwood-Cohansey aquifer system 

in the Pine Barrens Preserve in southeastern New Jersey. No 

evidence was observed of manmade radionuclide contamination in the aquifer system as particulates or colloids or in the 

dissolved phase.
Acknowledgments 39

Acknowledgments

The authors gratefully acknowledge King Mak of the 

USAF for assistance in gaining access to observation-well sites. 

The authors also thank Dr. Steven Raddemacher of the USAF, 

and Vincent T. dePaul and Larry R. Shelton of the USGS for 

advice in designing the sampling program.

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2001, Newton, Mass., p. 42–61.

Thatcher, L.L., Janzer, V.J., and Edwards, K.W., 1977, Methods for determination of radioactive substances in water and 

fluvial sediments: U.S. Geological Survey Techniques of 

Water-Resources Investigations, book 5, chap. A5, 95 p.

Wilde, F.D., and Radtke, D.B., 1999, Field measurements: U.S. 

Geological Survey Techniques of Water-Resources Investigations, book 9, chap. A6, 68 p.

Wilde, F.D., Radtke, D.B., Gibs, Jacob, and Iwatsubo, R.T., 

1998, Cleaning of equipment for water sampling: U.S. Geological Survey Techniques of Water-Resources Investigations, book 9, chap. A3, 65 p.

Zapecza, O.S., 1989, Hydrogeologic framework of the New 

Jersey Coastal Plain: U.S. Geological Survey Professional 

Paper 1404-B, 49 p., 24 pls.

Glossary 43

Glossary

A

Actinide A group of chemical elements with 

an atomic number greater than 88, all of which 

are radioactive and have similar chemical 

properties (multiple valence states range from 

+1 to +7).

Activity The amount of radioactivity in a 

given volume of such material as water or air. 

For water, activity is generally expressed in 

units of picocuries per liter.

Alpha radiation Alpha radiation is composed 

of a particle, consisting of two protons and two 

neutrons, spontaneously emitted from the 

nucleus of a subset of radioactive elements 

(mostly the heaviest elements) during radioactive decay. Alpha radiation is ionizing radiation, meaning that it strips electrons from adjacent atoms as it passes. Alpha radiation cannot 

penetrate skin; thus, an alpha-particle emitting 

radionuclide must be ingested in order to contact internal tissue. Because of the large size, 

alpha particles are likely to collide with cell tissue, causing tissue damage. An accumulation 

of tissue damage in the cell nucleus may lead to 

cell mutation and potential cancer formation.

Alpha radioactivity, gross A laboratory measurement of total alpha radioactivity emitted 

by a sample. This measurement includes alpha 

particle radioactivity emitted by isotopes of 

naturally occurring uranium, thorium, radium, 

and progeny such as polonium, as well as alpha 

particles emitted from isotopes of plutonium or 

americium, which are not naturally occurring. 

Long-term measurement, usually conducted 

from 20 to 30 days after sample collection, 

measures only the amount of alpha radiation 

present from long-lived radionuclides, such as 

naturally occurring uranium-238 or radium226 (half-life, 1,602 years), or the isotopes of 

plutonium and americium. The plutonium and 

americium isotopes considered in this study 

are alpha-particle emitting nuclides.

Alpha radioactivity count An analytical technique that specifies alpha radioactivity emitted 

by a chemically purified sample that contains 

only one radionuclide of interest. The alphaparticle activity is counted in a low-background gas proportional counter.

Alpha spectrometry An analytical technique 

that specifies the amount of alpha radiation 

emitted at specified energy levels, thus, allowing determination of individual radionuclide 

concentrations (from known energy levels of 

alpha particles unique to each radionuclide). 

The gridded-pulse-ionization chamber is the 

most sensitive and most commonly used 

instrument.

Americium Americium is a radioactive 

actinide element derived from the radioactive 

decay of manmade plutonium.

B

Bailing (sampling technique) A water 

sample is removed (abstracted) from a well by 

the process of lowering an empty container 

(usually a hollow tube with a valve at the bottom, termed the bailer) into the well then hoisting it out after the container fills.

Beta radioactivity Beta radiation is composed of a particle, consisting of an electron, 

spontaneously emitted from the nucleus of a 

subset of radioactive elements during radioactive decay. Beta radiation, like alpha radiation, 

is ionizing radiation—it strips electrons from 

adjacent atoms as it passes. Beta radiation can 

penetrate only the surface layer of skin; thus, a 

beta-particle emitting radionuclide must be 

ingested in order to contact internal organs or 

tissues. An accumulation of tissue damage in 

the cell nucleus may lead to cell mutation and 

potential cancer formation.

Beta radioactivity, gross A laboratory measurement of total beta radioactivity emitted by 

a sample. This measurement includes radioactivity emitted by naturally occurring progeny 

of uranium and thorium, such as radium-228 

and lead-210, and numerous other naturally 

occurring beta-particle-emitting radioactive 

isotopes such as potassium, as well as a host of 

manmade radionuclides. 

Beta radioactivity count An analytical technique that specifies total beta radioactivity 

emitted by a chemically purified sample that 

contains only one radionuclide of interest. The 

beta-particle activity is counted in a low-background gas proportional counter.
44 Radiochemical Sampling and Analysis of Shallow Ground Water and Sediment at the BOMARC Missile Facility, N.J.

C

Concentration Factor (CF) The ratio of the 

initial feed flow rate relative to the final retentate flow rate.

Contaminant As defined in the Safe Drinking 

Water Act, any physical, chemical, biological, 

or radiological substance or matter in water.

D

Decay product of radiation The isotope 

remaining after radioactive decay.

F

False negative The analytical instrumention 

records no radioactivity above the background 

level when radioactivity is present.

False positive The analytical instrumentation records radioactivity above the background level when no such radioactivity is 

present.

Fission, nuclear The splitting of an atomic 

nucleus into two smaller nuclear particles coupled with the release of one or more neutrons 

and nuclear energy.

G

Gamma radioactivity Gamma radiation is 

composed of packets of energy, also known as 

photons or photon particles, termed collectively as gamma rays, spontaneously emitted 

from the nucleus of most radioactive elements 

during radioactive decay. Gamma radiation is 

ionizing radiation meaning that it strips electrons from adjacent atoms as it passes. Gamma 

radiation can penetrate through skin into internal tissues as opposed to alpha and beta radiation, which cannot. An accumulation of tissue 

damage in the cell nucleus from gamma radiation may lead to cell mutation and potential 

cancer formation.

H

Half-life The interval of time required for 

exactly half the atoms of a given radionuclide 

to undergo radioactive decay.

“Hot” particles A subset of particles randomly dispersed in a population of particles 

that have rarely occurring (typically manmade) 

radionuclides attached to them.

I

Isotope Various forms of a single element 

differing in the number of neutrons in the 

nucleus. Unstable isotopes of an element decay 

through the emission of a form of radioactivity. 

L

Laboratory reporting level (LRL) The laboratory reporting level is a minimum concentration pre-determined by the laboratory personnel before the sample analysis begins; 

generally, it is based on typical counting 

results under routine analytical instrument 

operating conditions in a given sample matrix 

using known standards and blank samples 

(American Society for Testing Materials, 

1999), which the laboratory personnel define 

as a level of detection they can routinely 

achieve. It is generally defined by the requirement that the counted radioactivity must differ 

from the background count by three to six 

times the standard deviation of the background 

count. The LRL was set at 0.1 pCi/L for the 

radionuclides in this study.

M

Matrix effect Analytical uncertainty or difficulty in quantifying the target analyte as a 

result of the composition or concentration of 

non-target compounds in the sample.

Maximum contaminant level (MCL) The 

maximum permissible level of a contaminant 

in water that is delivered to the free flowing 

outlet of the ultimate user of a public watersupply system. The MCL for radionuclides is 

an expression of the acceptable health risk of 

developing or dying from cancer per unit 

ingestion of water containing a harmful substance entering the body (exposure). The 

MCLs for Radium-226, Radium-228, uranium 

and gross alpha-particle activity in community 

water systems are as follows: (a) Sum of 

Radium-226 and Radium-228, 5 pCi/L, 

(b) Uranium, 30 microgram per liter, and

(c) Gross alpha-particle activity (including 

Ra-226 but excluding radon and uranium), 

15 pCi/L.

Minimum detectable concentration, samplespecific (SSMDC) The minimum quantity of 

a specific radionuclide detectable at potentially 

quantifiable level by the counting instrument 

for any given sample for a given analysis 

defined by instrument operating conditions, 

sample recovery, and variation in background 

radiation at the time of analysis. This value is 

computed individually for each radionuclide 
Glossary 45

analysis on the basis of instrument operating 

conditions at the time because of the variability 

in background radioactivity and instrument 

performance over time. For purposes of this 

report, the SSMDC generally will be referred 

to when a sample result is evaluated unless otherwise specified. The SSMDC differs from the 

LRL, in that it is specific to the individual sample, whereas the LRL is a pre-determined minimum concentration set by laboratory personnel before sample analysis begins that can be 

achieved routinely; it is generally based on typical results under routine operating conditions 

in a given matrix using known standards 

(American Society for Testing Materials, 

1999). In most cases, the SSMDC is less than 

the LRL. In some cases, such as in a complex 

sample matrix, the SSMDC can exceed the 

LRL (because of matrix interference or effect, 

or other analytical complication).

N

Negative result A result from a radiation 

measurement (count) of a sample over a fixed 

interval of time where the measured radioactivity from the sample is less than the longterm average background radiation reported 

routinely by the instrument. In practical terms, 

the result is less than the sample-specific minimum detectable concentration and indicates 

that radioactivity was not detected.

P

Picocurie per liter A measurement unit that 

expresses the amount of radioactivity in water. 

One picocurie per liter (pCi/L) equals 2.2 

radioactive disintegrations per minute per liter 

of water.

Plutonium Plutonium (Pu) is a manmade 

radioactive actinide element. It is not a normal 

part of rocks. Much soil, air, and water has 

been contaminated by release of Pu from 

nuclear weapons testing and other activities. 

Three important isotopes of Pu are Pu-239, 

Pu-240, and Pu-241.

Precision estimate (P.E.) or uncertainty A 

calculated measure of uncertainty of the laboratory analysis. Determination of the precision 

estimate for radionuclides includes the evaluation of many sources of error, some that are 

unique to radionuclides. Because radioactive 

elements decay randomly at any given instant 

of time, any measurement of radioactivity has 

an associated uncertainty (also called “counting error”) independent of, and in addition to, 

laboratory sources of analytical uncertainty. In 

most circumstances, counting error decreases 

with increasing counting time. Uncertainty can 

be reported in a variety of ways; the most 

common are (1) the sum of the laboratory and 

counting uncertainty, known as the “precision 

estimate” or the “combined standard uncertainty (CSU)” (or less frequently as the “total 

propagated uncertainty”) and (2) a counting 

error or counting uncertainty only. There is a 

67-percent or 95-percent probability (based on 

one or two standard deviations, respectively, of 

the radioactivity count) that the true value of 

the radionuclide concentration is within the 

range of the reported measured value plus or 

minus the precision estimate or uncertainty. 

The precision estimate or uncertainty values 

are generally smaller than the measured value 

except when the measured values are low concentrations (near the LRL). The precision estimates associated with the various radionuclide 

concentrations determined by the alpha spectrometry measurement technique and presented in this report are given as the two standard deviation (propagated) precision 

estimates.

R

Radionuclide An isotope of an element that 

emits radiation.

Targential-flow filtration: Filtration technique 

where particles are moved by liquid flow 

across the filter surface rather than forced onto 

the surface of the filter material. The process 

minimizes colloid coagulation.

T

Thorium Thorium is a naturally occurring 

radioactive actinide element.

Tortuous path filtration Filtration where the 

liquid is passed through a meshed media (usually encapsulated) with randomly occurring 

pathways designed to retain particles of greater 

diameter than that for which the filter is rated 

while passing the fluids and particles of 

smaller size than the rating.

U

Uranium Uranium is a naturally occurring 

radioactive actinide element. It is a normal part 

of rocks, soil, air, and water. Natural uranium 
46 Radiochemical Sampling and Analysis of Shallow Ground Water and Sediment at the BOMARC Missile Facility, N.J.

is a mixture of three isotopes, U-234, U-235, 

and U-238. U-238 is by far the most common 

type of uranium on earth and is the least radioactive. U-234 is the most radioactive type of 

uranium. U-235 is used as a fuel in power 

plants and weapons. The amount of U-234 and 

U-235 in natural uranium is increased through 

the industrial process called enrichment. Uranium can react with tissues in the body and 

may damage the kidneys, as well as pose a 

radiation-induced cancer risk.

Ultrafiltration Filtration of particle sizes of 

0.1 micron or smaller at high pressure.

W

Weapons-grade plutonium Weapons-grade 

plutonium (Pu) is plutonium with less than 

7 percent plutonium-240 content and usually 

less than 1 percent Pu-241 and Am-241 content. Weapons-grade Pu can be in a variety of 

chemical or physical forms. The weapon core 

(or pit) is composed primarily of the Pu-239 

isotope enclosed within a casing material.
Tables 7A–7B
Table 7A. Concentrations of radionuclides in filtered and unfiltered samples of water from observation wells and properties measured in the field at o

Facility, Ocean County, New Jersey, 1999–2000.—Continued [Data are sorted by well depth; mg/L, milligram per liter; pCi/L, picocurie per liter; P.E., precision estimate; SSMDC, sample-specific minimum detectable concentration; NTU, 

μS/cm, microsiemens per centimeter at 25 degrees Celsius; BLS, below land surface; <, less than; K, thousand; NA, not applicable; --, no data. Number in parentheses is paramestituent, property, or characteristic in the U.S. Geological Survey water-quality database (NWIS) in which individual samples are identified by sample number.] U.S. Geological Survey well number Sample designation (and filter type)1 Date (month/ day/year) Begin sample collection, time End sample collection, time Quality- assurance data indicator2 (code) (99911) Plutonium -238 (pCi/L) (22012/ 22001) Plutonium -238, 2 SIGMA P.E. (pCi/L) (61949/49939) Plutonium -238, SSMDC (pCi/L) Plutoniu

-239+24

(pCi/L) (49475/ 49940) 

291377 R2 (NA) 2/7/2000 1017 1036 100 0 0.0042 0.00465 0 

291377 R3 (NA) 2/7/2000 1104 1118 30 .00246 .00625 .0141 .0073

291377 0.45F (ULTRAFILTER, RETENTATE) 2/7/2000 1140 1225 30 0 .00316 .0035 .0020

291377 0.0029F (ULTRAFILTER, 10K DALTON PERMEATE) 2/7/2000 1140 1229 30 -.00125 .00533 .0179 .0020

291370 R2 (NA) 2/11/2000 0926 1001 30 -.00166 .00237 .0143 -.0016

291370 R3 (NA) 2/11/2000 1022 1043 30 .00152 .00306 .00413 .0045

291370 0.45F (ULTRAFILTER, RETENTATE) 2/11/2000 1112 1216 -- -.000641 .00129 .00906 0 

291370 0.0029F (ULTRAFILTER, 10K DALTON PERMEATE) 2/11/2000 1112 1211 20 0 .00417 .00461 -.0006

291203 R2 (NA) 2/23/2000 0955 1033 30 -.00266 .00269 .0143 -.0046

291203 RT1 (NA) 2/23/2000 1053 1056 -- 0 .00355 .00392 .0014

291203 RT2 (NA) 2/23/2000 1108 1111 -- 0 .00421 .00466 .0010

291203 RT3 (NA) 2/23/2000 1115 1117 -- .0154 .01 .00416 -.0006

291203 RT4 (NA) 2/23/2000 1120 1122 -- -.00119 .00169 .0102 -.0023

291203 R3 (NA) 2/23/2000 1142 1324 100 -.00186 .00217 .0121 0 291203 0.45F (ULTRAFILTER, RETENTATE) 2/23/2000 1448 1714 -- 0 .00442 .00489 -.0007

291203 0.0029F (ULTRAFILTER, 10K DALTON PERMEATE) 2/23/2000 1449 1714 10 -.00163 .0019 .0106 -.0024

291203 0.45Fa (CAPSULE FILTER) 2/23/2000 1450 1658 100 .000373 .00428 .0128 0 

291203 0.05F (SEQUENTIAL CAPSULE FILTERS) 2/23/2000 1451 1713 10 -- -- -- -- 

291371 R1 (NA) 12/8/1999 1103 1108 30 -- -- -- -- 291371 R1 (NA) 12/8/1999 1112 1117 30 0 .00325 .00359 0 
291371 R2 (NA) 12/8/1999 1305 1310 30 0 0.00325 0.00359 0.0007

291371 R3 (NA) 12/8/1999 1451 1503 30 -.00151 .00214 .0129 .0003

291371 0.45F,

(ULTRAFILTER, RETENTATE)

12/8/1999 1559 1630 30 0 .00326 .00361 -.0005

291371 0.0029F 

(ULTRAFILTER, 10K DALTON PERMEATE)

12/8/1999 1559 1640 30 -.000532 .00107 .00752 0 

291379 R2 (NA) 1/6/2000 0954 1034 100 .00494 .00679 .0107 0 

291379 R3 (NA) 1/6/2000 1042 1106 -- .00124 .00249 .00336 0 

291379 0.45F

(ULTRAFILTER, RETENTATE)

1/6/2000 1155 1301 20 0 .00332 .00367 0 

291379 0.0029F 

(ULTRAFILTER, 10K DALTON PERMEATE)

1/6/2000 1155 1307 20 .00178 .00356 .00481 -.0014

291372 R2 (NA) 2/1/2000 1001 1030 100 0 .00344 .00381 0 

291372 R3 (NA) 2/1/2000 1046 1108 20 -.00178 .00207 .0116 .0002

291372 0.45F

(ULTRAFILTER, RETENTATE)

2/1/2000 1141 1234 -- 0 .00413 .00457 .0050

291372 0.0029F 

(10K DALTON PERMEATE)

2/1/2000 1141 1239 -- -.00139 .00197 .0119 -.0013

291375 R2 (NA) 12/3/1999 1100 1200 -- 0 .0063 .00698 -.0010

291375 R3 (NA) 12/3/1999 1334 1347 -- 0 .0061 .00673 0 291375 0.45F

(ULTRAFILTER, RETENTATE)

12/3/1999 1454 1507 20 -.0029 .0029 .0249 .0036

291375 0.0029F 

(ULTRAFILTER, 10K DALTON PERMEATE)

12/3/1999 1524 1613 20 0 .0067 .00745 0 

291374 R2 (NA) 2/15/1999 1007 1054 30 -.00145 .00207 .0205 .0058 

291374 R3 (NA) 2/15/1999 1055 1122 -- -.000533 .00107 .0128 0 291374 0.45F 

(ULTRAFILTER, RETENTATE)

2/15/1999 1150 1325 -- .00228 .00583 .0137 0 

291374 0.0029F 

(ULTRAFILTER, 10K DALTON PERMEATE)

2/15/1999 1150 1330 -- -.00194 .00226 .0204 .0032

Table 7A. Concentrations of radionuclides in filtered and unfiltered samples of water from observation wells and properties measured in the field at o

Facility, Ocean County, New Jersey, 1999–2000.—Continued

[Data are sorted by well depth; mg/L, milligram per liter; pCi/L, picocurie per liter; P.E., precision estimate; SSMDC, sample-specific minimum detectable concentration; NTU, μS/cm, microsiemens per centimeter at 25 degrees Celsius; BLS, below land surface; <, less than; K, thousand; NA, not applicable; --, no data. Number in parentheses is paramestituent, property, or characteristic in the U.S. Geological Survey water-quality database (NWIS) in which individual samples are identified by sample number.]

U.S. 

Geological 

Survey

well 

number

Sample designation

(and filter type)1

Date 

(month/ 

day/year)

Begin 

sample 

collection, 

time

End 

sample 

collection, 

time

Qualityassurance 

data 

indicator2

(code) 

(99911)

Plutonium

-238 

(pCi/L)

(22012/

22001)

Plutonium

-238,

2 SIGMA P.E. 

(pCi/L)

(61949/49939)

Plutonium

-238,

SSMDC

(pCi/L)

Plutoniu

-239+24

(pCi/L)

(49475/

49940)
291376 R2 (NA) 2/15/2000 1012 1050 100 0.00959 0.0113 0.0187 0.0091

291376 R3 (NA) 2/15/2000 1119 1207 30 -.00157 .00223 .0135 0 

291376 0.45F (ULTRAFILTER, RETENTATE) 2/15/2000 1313 1518 100 0 .00445 .00492 -.0007

291376 0.0029F (ULTRAFILTER, 10K DALTON PERMEATE) 2/15/2000 1314 1525 100 -.000755 .00107 .00648 -.0003

291376 0.05F (SEQUENTIAL CAPSULE FILTERS) 2/15/2000 1338 1500 -- -- -- -- -- 

291378 R1 (NA) 8/25/1999 1128 1137 30 -.00169 .00197 .011 .00 

291378 R3 (NA) 8/25/1999 1640 1700 10 .0014 .0028 .00379 .0014 

291378 0.45F (ULTRAFILTER, RETENTATE) 8/25/1999 1700 1810 -- -.000566 .0011 .008 .0014

291378 0.0029F (ULTRAFILTER, 10K DALTON PERMEATE) 8/25/1999 1750 1810 -- .00147 .00295 .00398 -.0005

Table 7A. Concentrations of radionuclides in filtered and unfiltered samples of water from observation wells and properties measured in the field at o

Facility, Ocean County, New Jersey, 1999–2000.—Continued [Data are sorted by well depth; mg/L, milligram per liter; pCi/L, picocurie per liter; P.E., precision estimate; SSMDC, sample-specific minimum detectable concentration; NTU, 

μS/cm, microsiemens per centimeter at 25 degrees Celsius; BLS, below land surface; <, less than; K, thousand; NA, not applicable; --, no data. Number in parentheses is paramestituent, property, or characteristic in the U.S. Geological Survey water-quality database (NWIS) in which individual samples are identified by sample number.] U.S. Geological Survey well number Sample designation (and filter type)1 Date (month/ day/year) Begin sample collection, time End sample collection, time Quality- assurance data indicator2 (code) (99911) Plutonium -238 (pCi/L) (22012/ 22001) Plutonium -238, 2 SIGMA P.E. (pCi/L) (61949/49939) Plutonium -238, SSMDC (pCi/L) Plutoniu

-239+24

(pCi/L) (49475/ 49940) 
Table 7A. Concentrations of radionuclides in filtered and unfiltered samples of water from observation wells and properties measured in the field, at 

Missile Facility, Ocean County, New Jersey, 1999–2000.—Continued

U.S. 

Geological 

Survey 

well 

number

Sample designation

(and filter type)1

Date 

(month/ 

day/year)

Begin 

sample 

collection, 

time

End 

sample 

collection, 

time

Americium

-241

(pCi/L)

(29867)

Americium

-241,

2 SIGMA 

P.E. 

 (pCi/L)

(49942)

Americium

-241,

SSMDC

(pCi/L)

Uranium

-238

(pCi/L)

(22603)

Uranium

-238,

2 SIGMA 

P.E.

(pCi/L)

(75991)

Urani

-238

SSMD

(pCi/

291377 R2 (NA) 2/7/2000 1017 1036 0.00319 0.00588 0.0113 0.0388 0.0271 0.0345 

291377 R3 (NA) 2/7/2000 1104 1118 -.000804 .00161 .0114 .045 .0345 .0536 

291377 0.45F

(ULTRAFILTER, RETENTATE)

2/7/2000 1140 1225 -.000797 .0016 .0113 .0743 .0413 .0444 

291377 0.0029F 

(ULTRAFILTER, 10K DALTON 

PERMEATE)

2/7/2000 1140 1229 0 .00407 .0122 .0536 .0345 .0329 

291370 R2 (NA) 2/11/2000 0926 1001 .00539 .00743 .0117 .00822 .0134 .0257 

291370 R3 (NA) 2/11/2000 1022 1043 -.00083 .00167 .0117 .0191 .0181 .019

291370 0.45F

(ULTRAFILTER, RETENTATE)

2/11/2000 1112 1216 .00117 .00419 .011 .00727 .0146 .003

291370 0.0029F 

(ULTRAFILTER, 10K DALTON 

PERMEATE)

2/11/2000 1112 1211 .00419 .0125 .022 .025 .0444 

291203 R2 (NA) 2/23/2000 0955 1033 .000393 .00452 .0135 .00193 .00752 .0179 

291203 RT1 (NA) 2/23/2000 1053 1056 -- -- -- -- -- -- 

291203 RT2 (NA) 2/23/2000 1108 1111 -- -- -- -- -- -- 

291203 RT3 (NA) 2/23/2000 1115 1117 -- -- -- -- -- -- 291203 RT4 (NA) 2/23/2000 1120 1122 -- -- -- -- -- -- 291203 R3 (NA) 2/23/2000 1142 1324 .0159 .0114 .0119 .00729 .00808 .0119 

291203 0.45F 

(ULTRAFILTER, RETENTATE)

2/23/2000 1448 1714 .000329 .00379 .0113 .0102 .00998 .0135 

291203 0.0029F 

(ULTRAFILTER, 10K DALTON 

PERMEATE

2/23/2000 1449 1714 .00277 .00511 .00979 .00261 .00713 .016 

291203 0.45Fa

(CAPSULE FILTER)

2/23/2000 1450 1658 .00442 .00608 .00961 -.00103 .00439 .0147 

291203 0.05F 

(SEQUENTIAL CAPSULE FILTERS)

2/23/2000 1451 1713 -- -- -- -- -- -- 

291371 R1 (NA) 12/8/1999 1103 1108 .00164 .00329 .00444 -- -- -- 

291371 R1 (NA) 12/8/1999 1112 1117 .0341 .0169 .00513 .00887 .0119 .022 
291371 R2 (NA) 12/8/1999 1305 1310 0.00462 0.00538 0.00417 0 0.00839 0.0213 

291371 R3 (NA) 12/8/1999 1451 1503 .00724 .00724 .0089 .0106 .0101 .0142 

291371 0.45F (ULTRAFILTER, RETENTATE) 12/8/1999 1559 1630 .0129 .00883 .00389 .00594 .0068 .0093291371 0.0029F (ULTRAFILTER, 10K DALTON PERMEATE) 12/8/1999 1559 1640 .0298 .014 .008 .0031 .00516 .0096291379 R2 (NA) 1/6/2000 0954 1034 .00785 .00713 .00426 .0311 .0166 .0154 

291379 R3 (NA) 1/6/2000 1042 1106 .00956 .00794 .00432 .0108 .0147 .0275 

291379 0.45F (ULTRAFILTER, RETENTATE) 1/6/2000 1155 1301 .0156 .0101 .00422 .0121 .0144 .0259 291379 0.0029F (ULTRAFILTER, 10K DALTON PERMEATE) 1/6/2000 1155 1307 .0355 .0155 .00401 .00404 .00912 .0193 291372 R2 (NA) 2/1/2000 1001 1030 -.00244 .00246 .0131 .00454 .00818 .0163 

291372 R3 (NA) 2/1/2000 1046 1108 -.00129 .00184 .0111 .017 .013 .0175 

291372 0.45F (ULTRAFILTER, RETENTATE) 2/1/2000 1141 1234 .00349 .00496 .00473 .00719 .00798 .011

291372 0.0029F (ULTRAFILTER, 10K DALTON PERMEATE) 2/1/2000 1141 1239 -.00182 .00213 .0119 .00175 .00681 .0162 

291375 R2 (NA) 12/3/1999 1100 1200 -.00068 .0014 .0163 .00522 .0245 .0579 291375 R3 (NA) 12/3/1999 1334 1347 .00329 .0066 .00893 .00000 .00742 .0249 

291375 0.45F (ULTRAFILTER, RETENTATE) 12/3/1999 1454 1507 0 .0083 .00915 .00265 .00993 .0259 

291375 0.0029F (ULTRAFILTER, 10K DALTON PERMEATE) 12/3/1999 1524 1613 .0103 .013 .0176 .00632 .0101 .016

291374 R2 (NA) 12/15/1999 1007 1054 0 .00797 .00881 -.00001 .0406 .115 

291374 R3 (NA) 12/15/1999 1055 1122 -.000701 .00141 .0168 .0037 .011 .0272 

291374 0.45F (ULTRAFILTER, RETENTATE) 12/15/1999 1150 1325 .000678 .00731 .0233 .0276 .0226 .0299 

Table 7A. Concentrations of radionuclides in filtered and unfiltered samples of water from observation wells and properties measured in the field, at 

Missile Facility, Ocean County, New Jersey, 1999–2000.—Continued U.S. Geological Survey well number Sample designation (and filter type)1 Date (month/ day/year) Begin sample collection, time End sample collection, time Americium -241 (pCi/L) (29867) Americium -241, 2 SIGMA P.E. (pCi/L) (49942) Americium -241, SSMDC (pCi/L) Uranium -238 (pCi/L) (22603) Uranium -238, 2 SIGMA P.E. (pCi/L) (75991) Urani

-238

SSMD

(pCi/
291374 0.0029F 

(ULTRAFILTER, 10K DALTON 

PERMEATE)

12/15/1999 1150 1330 0 0.00868 0.00961 0.0151 0.0199 0.0377 

291376 R2 (NA) 2/15/2000 1012 1050 0.0016 .00321 .00433 .00854 .0101 .0167 291376 R3 (NA) 2/15/2000 1119 1207 -.00247 .0025 .0133 .00943 .00977 .015 

291376 0.45F 

(ULTRAFILTER, RETENTATE)

2/15/2000 1313 1518 .00152 .00304 .00411 .00393 .0054 .0085

291376 0.0029F 

(ULTRAFILTER, 10K DALTON 

PERMEATE)

2/15/2000 1314 1525 .00434 .00597 .00943 -.00356 .00323 .0165 

291376 0.05F 

(SEQUENTIAL CAPSULE FILTERS)

2/15/2000 1338 1500 -- -- -- -- -- -- 

291378 R1 (NA) 8/25/1999 1128 1137 0 .00638 .00706 .0508 .0259 .0137 

291378 R3 (NA) 8/25/1999 1640 -- -.00156 .00222 .0134 .0161 .016 .019

291378 0.45F 

(ULTRAFILTER, RETENTATE)

8/25/1999 1700 -- .00111 .004 .0105 -.0155 .01864 .0582 

291378 0.0029F 

(ULTRAFILTER, 10K DALTON 

PERMEATE)

8/25/1999 1750 1810 -.00128 .00182 .011 -- -- -- 

Table 7A. Concentrations of radionuclides in filtered and unfiltered samples of water from observation wells and properties measured in the field, at 

Missile Facility, Ocean County, New Jersey, 1999–2000.—Continued

U.S. 

Geological 

Survey 

well 

number

Sample designation

(and filter type)1

Date 

(month/ 

day/year)

Begin 

sample 

collection, 

time

End 

sample 

collection, 

time

Americium

-241

(pCi/L)

(29867)

Americium

-241,

2 SIGMA 

P.E. 

 (pCi/L)

(49942)

Americium

-241,

SSMDC

(pCi/L)

Uranium

-238

(pCi/L)

(22603)

Uranium

-238,

2 SIGMA 

P.E.

(pCi/L)

(75991)

Urani

-238

SSMD

(pCi/
Table 7A. Concentrations of radionuclides in filtered and unfiltered samples of water from observation wells and properties measured in the field, at 

Missile Facility, Ocean County, New Jersey, 1999–2000.—Continued U.S. Geological Survey well number Sample designation (and filter type)1 Date (month/ day/year) Begin sample collection, time End sample collection, time Uranium -234, SSMDC (pCi/L) Uranium -235 (pCi/L) (22620) Uranium -235, 2 SIGMA P.E. (pCi/L) (75994) Uranium -235, SSMDC (pCi/L) Thorium -228 (pCi/L) (61738) Thorium -228, SIGMA P.E. (pCi/L) (61739) 

291377 R2 (NA) 2/7/2000 1017 1036 0.0295 0.0172 0.0182 0.028 -- -- 

291377 R3 (NA) 2/7/2000 1104 1118 .0352 -.00000145 .00897 .0301 -- -- 

291377 0.45F (ULTRAFILTER, RETENTATE) 2/7/2000 1140 1225 .0384 .017 .0182 .0214 -- -- 291377 0.0029F (ULTRAFILTER, 10K DALTON PERMEATE) 2/7/2000 1140 1229 .0352 .0067 .014 .0302 -- -- 291370 R2 (NA) 2/11/2000 0926 1001 .0371 -.000748 .0015 .0179 -- -- 

291370 R3 (NA) 2/11/2000 1022 1043 .0293 .00716 .0114 .0191 -- -- 

291370 0.45F (ULTRAFILTER, RETENTATE) 2/11/2000 1112 1216 .0315 .000808 .0087 .0277 -- -- 291370 0.0029F (ULTRAFILTER, 10K DALTON PERMEATE) 2/11/2000 1112 1211 .0363 -.00508 .00423 .033 -- -- 291203 R2 (NA) 2/23/2000 0955 1033 .0179 .00154 .00607 .015 -- -- 291203 RT1 (NA) 2/23/2000 1053 1056 -- -- -- -- -- -- 

291203 RT2 (NA) 2/23/2000 1108 1111 -- -- -- -- -- -- 

291203 RT3 (NA) 2/23/2000 1115 1117 -- -- -- -- -- -- 291203 RT4 (NA) 2/23/2000 1120 1122 -- -- -- -- -- -- 291203 R3 (NA) 2/23/2000 1142 1324 .0098 .00139 .00547 .0135 -- -- 

291203 0.45F (ULTRAFILTER, RETENTATE) 2/23/2000 1448 1714 .0111 -.000392 .00477 .0153 -- -- 

291203 0.0029F (ULTRAFILTER, 10K DALTON PERMEATE) 2/23/2000 1449 1714 .0173 .000373 .00454 .0146 -- -- 

291203 0.45Fa (CAPSULE FILTER) 2/23/2000 1450 1658 .0147 .00171 .00668 .0159 -- -- 291203 0.05F (SEQUENTIAL CAPSULE FILTERS) 2/23/2000 1451 1713 -- -- -- -- -- -- 

291371 R1 (NA) 12/8/1999 1103 1108 -- -- -- -- -- -- 291371 R1 (NA) 12/8/1999 1112 1117 .0117 -.00102 .00437 .0146 -- -- 
291371 R2 (NA) 12/8/1999 1305 1310 0.0176 -0.00213 0.00248 0.0138 -- -- 

291371 R3 (NA) 12/8/1999 1451 1503 .0142 .00656 .00751 .0103 -- -- 

291371 0.45F 

(ULTRAFILTER, RETENTATE)

12/8/1999 1559 1630 .0164 .00363 .00604 .0113 -- -- 

291371 0.0029F 

(ULTRAFILTER, 10K DALTON 

PERMEATE)

12/8/1999 1559 1640 .0131 .00225 .00416 .00796 -- -- 

291379 R2 (NA) 1/6/2000 0954 1034 .0223 .0304 .0166 .0166 0.0302 0.0384 

291379 R3 (NA) 1/6/2000 1042 1106 .0298 -.00442 .0061 .0221 .0201 .0332 

291379 0.45F 

(ULTRAFILTER, RETENTATE)

1/6/2000 1155 1301 .013 .000756 .00614 .0162 .0339 .039 

291379 0.0029F 

(ULTRAFILTER, 10K DALTON 

PERMEATE)

1/6/2000 1155 1307 .0158 .00257 .00702 .0158 .00944 .0282 

291372 R2 (NA) 2/1/2000 1001 1030 .0188 -.000757 .00152 .0107 .0715 .0496 291372 R3 (NA) 2/1/2000 1046 1108 .0195 .000707 .00575 .0152 .0284 .0342 

291372 0.45F 

(ULTRAFILTER, RETENTATE)

2/1/2000 1141 1234 .0189 .00377 .00627 .0118 .055 .047 

291372 0.0029F 

(ULTRAFILTER, 10K DALTON 

PERMEATE)

2/1/2000 1141 1239 .0232 .00454 .00625 .00987 .0698 .0468 

291375 R2 (NA) 12/3/1999 1100 1200 .0314 -.000655 .00728 .0255 .0505 .054 291375 R3 (NA) 12/3/1999 1334 1347 .0278 -.000678 .00136 .0162 .0587 .0608 291375 0.45F 

(ULTRAFILTER, RETENTATE)

12/3/1999 1454 1507 .0285 .000662 .00714 .0228 .0979 .0998 

291375 0.0029F 

(ULTRAFILTER, 10K DALTON 

PERMEATE)

12/3/1999 1524 1613 .0222 -.00422 .00351 .0274 .0609 .087 

291374 R2 (NA) 12/15/1999 1007 1054 .0919 -.00642 .0246 .0919 -.0152 .158 291374 R3 (NA) 12/15/1999 1055 1122 .0234 .00962 .0131 .0209 .114 .274 291374 0.45F 

(ULTRAFILTER, RETENTATE)

12/15/1999 1150 1325 .025 .0145 .0167 .0268 .0654 .216 

Table 7A. Concentrations of radionuclides in filtered and unfiltered samples of water from observation wells and properties measured in the field, at 

Missile Facility, Ocean County, New Jersey, 1999–2000.—Continued

U.S. 

Geological 

Survey well 

number

Sample designation

(and filter type)1

Date

(month/ 

day/year)

Begin 

sample 

collection, 

time

End 

sample 

collection, 

time

Uranium

-234,

SSMDC

(pCi/L)

Uranium

-235 

(pCi/L)

(22620)

Uranium

-235,

2 SIGMA 

P.E.

 (pCi/L) 

(75994)

Uranium

-235,

SSMDC

(pCi/L)

Thorium

-228

(pCi/L)

(61738)

Thorium

-228,

SIGMA 

P.E.

(pCi/L)

(61739)
291374 0.0029F (ULTRAFILTER, 10K DALTON PERMEATE) 12/15/1999 1150 1330 0.0227 -0.00648 0.00444 0.0322 -0.0644 0.0418 

291376 R2 (NA) 2/15/2000 1012 1050 .0167 -.00000097 .00649 .018 -- -- 

291376 R3 (NA) 2/15/2000 1119 1207 .0162 .0014 .00551 .0136 -- -- 291376 0.45F (ULTRAFILTER, RETENTATE) 2/15/2000 1313 1518 .0118 -.00121 .00172 .0104 -- -- 291376 0.0029F (ULTRAFILTER, 10K DALTON PERMEATE) 2/15/2000 1314 1525 .0165 -.000356 .00433 .0139 -- -- 

291376 0.05F (SEQUENTIAL CAPSULE FILTERS) 2/15/2000 1338 1500 -- -- -- -- -- -- 

291378 R1 (NA) 8/25/1999 1128 1137 .0137 .00 .007 .00774 -- -- 

291378 R3 (NA) 8/25/1999 1640 1700 .0288 .0021 .00728 .0198 .0377 .0374 291378 0.45F (ULTRAFILTER, RETENTATE) 8/25/1999 1700 1810 .033 -.00582 .00398 .0289 -.00399 .0047 291378 0.0029F (ULTRAFILTER, 10K DALTON PERMEATE) 8/25/1999 1750 1810 -- -- -- -- -- -- 

Table 7A. Concentrations of radionuclides in filtered and unfiltered samples of water from observation wells and properties measured in the field, at 

Missile Facility, Ocean County, New Jersey, 1999–2000.—Continued U.S. Geological Survey well number Sample designation (and filter type)1 Date (month/ day/year) Begin sample collection, time End sample collection, time Uranium -234, SSMDC (pCi/L) Uranium -235 (pCi/L) (22620) Uranium -235, 2 SIGMA P.E. (pCi/L) (75994) Uranium -235, SSMDC (pCi/L) Thorium -228 (pCi/L) (61738) Thorium -228, SIGMA P.E. (pCi/L) (61739) 
Table 7A. Concentrations of radionuclides in filtered and unfiltered samples of water from observation wells and properties measured in the field, at 

Facility, Ocean County, New Jersey, 1999–2000.—Continued

U.S. 

Geological 

Survey 

well 

number

Sample designation

(and filter type)1

Date

(month/ 

day/year)

Begin 

sample 

collection, 

time

End 

sample 

collection, 

time

Thorium

-230,

SSMDC

(pCi/L)

Thorium

-232

(pCi/L)

(75976)

Thorium

-232,

2 SIGMA 

P.E.

(pCi/L)

(75999)

Thorium

-232,

SSMDC

(pCi/L)

Gross 

alpha, 

residue 

procedure,

as TH-230 

(pCi/L)

(04126)

Gross 

alpha,

2 SIGMA 

P.E.

(pCi/L)

(75987)

Gross beta,

 residue

procedure,

as CS-137 

(pCi/L)

(03515)

2 

291377 R2 (NA) 2/7/2000 1017 1036 -- -- -- -- 5.4 2.91 <4 

291377 R3 (NA) 2/7/2000 1104 1118 -- -- -- -- 3.41 2.53 6.13 291377 0.45F 

(ULTRAFILTER, 

RETENTATE)

2/7/2000 1140 1225 -- -- -- -- 4.69 2.8 <4 

291377 0.0029F 

(ULTRAFILTER, 

10K DALTON PERMEATE)

2/7/2000 1140 1229 -- -- -- -- 4.86 2.8 <4 

291370 R2 (NA) 2/11/2000 0926 1001 -- -- -- -- 5.21 2.78 <4 

291370 R3 (NA) 2/11/2000 1022 1043 -- -- -- -- <3 2.25 <4 

291370 0.45 

(ULTRAFILTER, 

RETENTATE)

2/11/2000 1112 1216 -- -- -- -- 3.04 2.36 6.77 

291370 0.0029F 

(ULTRAFILTER, 

10K DALTON PERMEATE)

2/11/2000 1112 1211 -- -- -- -- 5 2.75 4.52 

291203 R2 (NA) 2/23/2000 0955 1033 -- -- -- -- <3 1.78 <4 291203 RT1 (NA) 2/23/2000 1053 1056 -- -- -- -- -- -- -- 

291203 RT2 (NA) 2/23/2000 1108 1111 -- -- -- -- -- -- -- 

291203 RT3 (NA) 2/23/2000 1115 1117 -- -- -- -- -- -- -- 291203 RT4 (NA) 2/23/2000 1120 1122 -- -- -- -- -- -- -- 291203 R3 (NA) 2/23/2000 1142 1324 -- -- -- -- <3 2.06 <4 291203 0.45F 

(ULTRAFILTER, 

RETENTATE)

2/23/2000 1448 1714 -- -- -- -- <3 1.5 <4 

291203 0.0029F 

(ULTRAFILTER, 

10K DALTON PERMEATE)

2/23/2000 1449 1714 -- -- -- -- <3 2.04 5.97 

291203 0.45Fa 

(CAPSULE FILTER)

2/23/2000 1450 1658 -- -- -- -- <3 2.09 4.87 
291203 0.05F (SEQUENTIAL CAPSULE FILTER) 2/23/2000 1451 1713 -- -- -- -- -- -- -- 

291371 R1 (NA) 12/8/1999 1103 1108 -- -- -- -- -- -- -- 

291371 R1 (NA) 12/8/1999 1112 1117 -- -- -- -- -- -- -- 291371 R2 (NA) 12/8/1999 1305 1310 -- -- -- -- -- -- -- 291371 R3 (NA) 12/8/1999 1451 1503 -- -- -- -- -- -- -- 

291371 0.45F (ULTRAFILTER, RETENTATE) 12/8/1999 1559 1630 -- -- -- -- -- -- -- 

291371 0.0029F (ULTRAFILTER, 10K DALTON PERMEATE) 12/8/1999 1559 1640 -- -- -- -- -- -- -- 291379 R2 (NA) 1/6/2000 0954 1034 0.0318 0 0.0163 0.018 <3 1.83 <4 

291379 R3 (NA) 1/6/2000 1042 1106 .0275 -.00115 .00231 .0275 <3 1.79 <4 

291379 0.45F (ULTRAFILTER, RETENTATE) 1/6/2000 1155 1301 .0357 -.00252 .00362 .0357 <3 1.78 <4 

291379 0.0029F (ULTRAFILTER, 10K DALTON PERMEATE) 1/6/2000 1155 1307 .0274 .00457 .0117 .0274 <3 1.52 <4 

291372 R2 (NA) 2/1/2000 1001 1030 .0252 0 .0129 .0143 <3 1.99 <4 291372 R3 (NA) 2/1/2000 1046 1108 .0131 0 .0119 .0131 <3 2.05 4.09 291372 0.45F (ULTRAFILTER, RETENTATE) 2/1/2000 1141 1234 .0257 .00215 .0114 .0339 <3 1.86 <4 291372 0.0029F (ULTRAFILTER, 10K DALTON PERMEATE) 2/1/2000 1141 1239 .0144 .00424 .0109 .0254 <3 2.12 <4 291375 R2 (NA) 12/3/1999 1100 1200 .0338 -.00119 .0024 .0286 <3 2.29 <4 291375 R3 (NA) 12/3/1999 1334 1347 .0356 -.00126 .0025 .0301 <3 2.13 <4 

Table 7A. Concentrations of radionuclides in filtered and unfiltered samples of water from observation wells and properties measured in the field, at 

Facility, Ocean County, New Jersey, 1999–2000.—Continued U.S. Geolog- ical Survey well number Sample designation (and filter type)1 Date (month/ day/year) Begin sample collection, time End sample collection, time Thorium -230, SSMDC (pCi/L) Thorium -232 (pCi/L) (75976) Thorium -232, 2 SIGMA P.E. (pCi/L) (75999) Thorium -232, SSMDC (pCi/L) Gross alpha, residue procedure, as TH-230 (pCi/L) (04126) Gross alpha, 2 SIGMA P.E. (pCi/L) (75987) Gross beta, residue procedure, as CS-137 (pCi/L) (03515) 

2 
291375 0.45F 

(ULTRAFILTER, 

RETENTATE)

12/3/1999 1454 1507 0.0568 -0.00201 0.0041 0.0481 <3 1.94 <4 

291375 0.0029F 

(ULTRAFILTER, 

10K DALTON PERMEATE)

12/3/1999 1524 1613 .0612 -.00217 .0044 .0518 <3 2.28 <4 

291374 R2 (NA) 12/15/1999 1007 1054 .273 .0678 .137 .184 <3 1.87 <4 

291374 R3 (NA) 12/15/1999 1055 1122 .189 -.00558 .0112 .281 <3 2.06 <4 

291374 0.45F 

(ULTRAFILTER, 

RETENTATE)

12/15/1999 1150 1325 .182 .067 .135 .182 <3 1.78 <4 

291374 0.0029F 

(ULTRAFILTER, 

10K DALTON PERMEATE)

12/15/1999 1150 1330 .265 -.00528 .0106 .265 <3 1.84 <4 

291376 R2 (NA) 2/15/2000 1012 1050 -- -- -- -- <3 2.04 <4 

291376 R3 (NA) 2/15/2000 1119 1207 -- -- -- -- <3 2.31 <4 

291376 0.45F 

(ULTRAFILTER, 

RETENTATE)

2/15/2000 1313 1518 -- -- -- -- <3 1.85 <4 

291376 0.0029F 

(ULTRAFILTER, 

10K DALTON PERMEATE)

2/15/2000 1314 1525 -- -- -- -- <3 2.14 <4 

291376 0.05F 

(SEQUENTIAL CAPSULE 

FILTERS)

2/15/2000 1338 1500 -- -- -- -- -- -- -- 

291378 R1 (NA) 8/25/1999 1128 1137 -- -- -- -- -- -- -- 291378 R3 (NA) 8/25/1999 1640 -- .0273 .0285 .0264 .0154 <3 2.28 <4 

291378 0.45F 

(ULTRAFILTER, 

RETENTATE)

8/25/1999 1700 -- .0173 0 .0157 .0173 <3 2 <4 

291378 0.0029F 

(ULTRAFILTER, 

10K DALTON PERMEATE)

8/25/1999 1750 1810 -- -- -- -- -- -- -- 

Table 7A. Concentrations of radionuclides in filtered and unfiltered samples of water from observation wells and properties measured in the field, at 

Facility, Ocean County, New Jersey, 1999–2000.—Continued

U.S. 

Geological 

Survey 

well 

number

Sample designation

(and filter type)1

Date

(month/ 

day/year)

Begin 

sample 

collection, 

time

End 

sample 

collection, 

time

Thorium

-230,

SSMDC

(pCi/L)

Thorium

-232

(pCi/L)

(75976)

Thorium

-232,

2 SIGMA 

P.E.

(pCi/L)

(75999)

Thorium

-232,

SSMDC

(pCi/L)

Gross 

alpha, 

residue 

procedure,

as TH-230 

(pCi/L)

(04126)

Gross 

alpha,

2 SIGMA 

P.E.

(pCi/L)

(75987)

Gross beta,

 residue

procedure,

as CS-137 

(pCi/L)

(03515)

2 
Table 7A. Concentrations of radionuclides in filtered and unfiltered samples of water from observation wells and properties measured in the field, at or near the BOMARC Missile Facility, Ocean County, New Jersey, 1999–2000.—Continued U.S. Geological Survey well number Sample designation (and filter type)1 Date (month/ day/year) Begin sample collection, time End sample collection, time Water level (depth BLS in feet) (72019) Water temperature (degrees Celsius) (00010) Field specific conductance (uS/cm at 25° C) (00095) Oxygen dissolved (mg/L) (00300) pH, field (standard units) (00400) 291377 R2 (NA) 2/7/2000 1017 1036 23.77 14.2 76 4.5 4.47 291377 R3 (NA) 2/7/2000 1104 1118 23.94 14.3 75 4.5 4.58 291377 0.45F (ULTRAFILTER, RETENTATE) 2/7/2000 1140 1225 -- 14.5 75 4.6 4.61 291377 0.0029F (ULTRAFILTER, 10K DALTON PERMEATE) 2/7/2000 1140 1229 -- 14.5 75 4.6 4.61 291370 R2 (NA) 2/11/2000 0926 1001 31.60 15.5 57 -- 4.77 291370 R3 (NA) 2/11/2000 1022 1043 -- 16 58 9.45 4.7 291370 0.45F (ULTRAFILTER, RETENTATE) 2/11/2000 1112 1216 31.61 16 58 -- 4.7 291370 0.0029F (ULTRAFILTER, 10K DALTON PERMEATE) 2/11/2000 1112 1211 31.61 16 58 -- 4.7 291203 R2 (NA) 2/23/2000 0955 1033 38.76 17.3 62.1 -- 5.4 291203 RT1 (NA) 2/23/2000 1053 1056 -- 20.1 56.3 -- 5.48 291203 RT2 (NA) 2/23/2000 1108 1111 39.07 17.7 54.9 -- 5.5 291203 RT3 (NA) 2/23/2000 1115 1117 -- 17.4 54.4 -- 5.44 291203 RT4 (NA) 2/23/2000 1120 1122 -- 17.3 52.9 -- 5.45 291203 R3 (NA) 2/23/2000 1142 1324 -- 17.3 52 -- 5.41 291203 0.45F (ULTRAFILTER, RETENTATE) 2/23/2000 1448 1714 -- 18.2 53 10.1 5.39 291203 0.0029F (ULTRAFILTER, 10K DALTON PERMEATE) 2/23/2000 1449 1714 -- 18.2 53 -- 5.4 291203 0.45Fa (CAPSULE FILTER) 2/23/2000 1450 1658 -- 18.2 53 -- 5.39 291203 0.05F (SEQUENTIAL CAPSULE FILTERS) 2/23/2000 1451 1713 -- 18.2 53 -- 5.39 291371 R1 (NA) 12/8/1999 1103 1108 -- 16.6 112 -- 4.96 291371 R1 (NA) 12/8/1999 1112 1117 39.05 16.5 114 10.5 5.18
291371 R2 (NA) 12/8/1999 1305 1310 -- 17.6 114 -- 5.34

291371 R3 (NA) 12/8/1999 1451 1503 -- 16.9 116 -- 5.38291371 0.45F 

(ULTRAFILTER, RETENTATE)

12/8/1999 1559 1630 -- 17.1 117 -- 5.37

291372 0.0029F 

(ULTRAFILTER, 10K DALTON 

PERMEATE)

2/1/2000 1141 1239 44.28 10.9 49 -- 4.8

291375 R2 (NA) 12/3/1999 1100 1200 47.67 17 47 -- 5.01

291375 R3 (NA) 12/3/1999 1334 1347 16.5 46 -- 5.1

291375 0.45F 

(ULTRAFILTER, RETENTATE)

12/3/1999 1454 1507 47.7 16.5 46 -- 5.1

291375 0.0029F 

(ULTRAFILTER, 10K DALTON 

PERMEATE)

12/3/1999 1524 1613 -- 16.5 54.3 -- 4.67

291374 R2 (NA) 12/15/1999 1007 1054 53.35 17.5 52 -- 5.64291374 R3 (NA) 12/15/1999 1055 1122 53.33 17.2 52 9.3 5.73

291374 0.45F 

(ULTRAFILTER, RETENTATE)

12/15/1999 1150 1325 -- 17.2 53 -- 5.67

291374 0.0029F 

(ULTRAFILTER, 10K DALTON 

PERMEATE)

12/15/1999 1150 1330 53.36 17.2 53 -- 5.67

291376 R2 (NA) 2/15/2000 1012 1050 21.73 14.4 80 -- 5.22

291376 R3 (NA) 2/15/2000 1119 1207 21.79 15.4 79.1 9.6 5.35

291376 0.45F 

(ULTRAFILTER, RETENTATE)

2/15/2000 1313 1518 21.74 15.1 79.6 -- 5.38

291376 0.0029F 

(ULTRAFILTER, 10K DALTON 

PERMEATE)

2/15/2000 1314 1525 -- 15.1 79.6 -- 5.38

291376 0.05F 

(SEQUENTIAL CAPSULE FILTERS)

2/15/2000 1338 1500 -- 15.1 79.6 -- 5.38

291378 R1 (NA) 8/25/1999 1128 1137 14.4 17 46 -- 6.1291378 R3 (NA) 8/25/1999 1640 -- -- 15.5 44 --- 5.91

Table 7A. Concentrations of radionuclides in filtered and unfiltered samples of water from observation wells and properties measured in the field, 

at or near the BOMARC Missile Facility, Ocean County, New Jersey, 1999–2000.—Continued

U.S. 

Geological 

Survey 

well 

number

Sample designation

(and filter type)1

Date 

(month/

day/year)

Begin 

sample 

collection, 

time

End sample 

collection, 

time

Water level 

(depth BLS 

in feet)

(72019)

Water 

temperature 

(degrees 

Celsius) 

(00010)

Field

specific

conductance

 (uS/cm at 

25° C)

(00095)

Oxygen 

dissolved

(mg/L)

(00300)

pH, field

(standard 

units)

(00400)
291378 0.45F (ULTRAFILTER, RETENTATE) 8/25/1999 1700 -- -- 15.5 44 -- 5.91 291378 0.0029F (ULTRAFILTER, 10K DALTON PERMEATE) 8/25/1999 1750 1810 -- 16 43 -- 5.9 1 Sample designation: R1, unfiltered, initial; R2, unfitered, turbidity generally less than 10 NTU and slowly decreasing; RTi unfiltered, turbidity not stable and variable; R3, unfiltered, turbidity stable and generally less than 5 NTU; 0.45Fa, filtered, 45-micron filter; 0.45F, filtered with 45-micron capsule filter and from retentate port from 0.0029-micron ultrafilter, F0.0029, filtered sequentially through 0.45 micron capsule filter and 0.0029-micron ultrafilter; F0.05, filtered sequentially through 0.45-micron and 0.05-micron capsule filters. 2 Associated quality-assurance data indicator code: 10, field or laboratory equipment blank; 10, concurrent duplicate; 30, sequential replicate; 100, multiple types. Table 7A. Concentrations of radionuclides in filtered and unfiltered samples of water from observation wells and properties measured in the field, at or near the BOMARC Missile Facility, Ocean County, New Jersey, 1999–2000.—Continued U.S. Geological Survey well number Sample designation (and filter type)1 Date (month/ day/year) Begin sample collection, time End sample collection, time Water level (depth BLS in feet) (72019) Water temperature (degrees Celsius) (00010) Field specific conductance (uS/cm at 25° C) (00095) Oxygen dissolved (mg/L) (00300) pH, field (standard units) (00400)
Table 7B. Concentrations of radionuclides in filtered and unfiltered concurrent laboratory duplicate and sequential replicate samples of water from 

equipment blank, at or near the BOMARC Missile Facility, Ocean County, New Jersey, 1999–2000.—Continued

[Data are sorted by well depth; pCi/L, picocurie per liter; P.E., precision estimate; SSMDC, sample-specific minimum detectable concentration; <, less than; K, thousand; NA, noin parentheses is parameter code used to identify the constituent, property, or characteristic in the U.S. Geological Survey water-quality database (NWIS) in which individual samnumber.]

U.S. 

Geological 

Survey

well 

number

Sample designation

(and filter type)1

Date 

(month/ 

day/year)

Begin 

sample 

collection, 

time

End 

sample 

collection, 

time

Same 

medium

(code)2

Replicate, 

type3

(code) 

(99912)

Plutonium

-238 

(pCi/L)

(22012/

22001)

Plutonium

-238,

2 SIGMA 

P.E. 

(pCi/L)

(61949/

49939)

Plutonium

-238,

SSMDC

(pCi/L)

Pluto

-239

(pC

(49

499

291377 R2 (NA) 2/7/2000 1017 1036 S 10 -- -- -- -291377 R2 (NA) 2/7/2000 1019 1028 S 20 0.00146 0.00293 0.00395 0.00291377 R2 (NA) 2/7/2000 1019 1028 S 20 -.00041 .00498 .016 -.00291377 R3 (NA) 2/7/2000 1104 1118 S 20 -.00079 .00158 .0112 -.00291377 0.45F 

(ULTRAFILTER, RETENTATE)

2/7/2000 1140 1225 S 20 -.00042 .00514 .0165 0 

291377 0.0029F 

(ULTRAFILTER, 10K DALTON PERMEATE)

2/7/2000 1140 1229 S 20 -.00193 .00225 .0126 .00

291370 R2 (NA) 2/11/2000 0931 0946 S 20 -.000786 ..00158 .0111 -.00291370 R2 (NA) 2/11/2000 0931 0946 S 20 -.00201 .00235 .0131 -.00291370 R3 (NA) 2/11/2000 1022 1043 S 20 .00215 .00432 .00584 0 291370 0.0029F 

(ULTRAFILTER, 10K DALTON PERMEATE)

2/11/2000 1112 1211 6 10 -.00166 .00236 .0142 0 

291203 R2 (NA) 2/23/2000 0959 1017 S 20 0 .00347 .00384 -.00291203 R3 (NA) 2/23/2000 1143 1323 S 10 .0046 .0126 .0282 .00291203 0.45Fa 

(CAPSULE FILTER BLANK)

2/17/2000 1553 1625 Q 10 .000404 .00492 .0158 -

291371 R1 (NA) 12/8/1999 1124 1128 S 20 .000372 .00754 .0195 -.00291371 R1 (NA) 12/8/1999 1137 1140 S 20 .000811 .00292 .00764 -.00291371 R2 (NA) 12/8/1999 1323 1341 S 20 .00168 .00337 .00455 -.00291371 R3 (NA) 12/8/1999 1507 1521 S 20 -.0021 .00245 .0137 .00291371 0.45F 

(ULTRAFILTER, RETENTATE)

12/8/1999 1640 1712 S 20 .00775 .00644 .0035 -.00

291371 0.0029F 

(ULTRAFILTER, 10K DALTON PERMEATE)

12/8/1999 1640 1720 S 20 -.000561 .00113 .00792 0 

291371 0.45F 

(ULTRAFILTER, RETENTATE)

12/8/1999 1720 -- S 20 -- -- -- -
291371 0.0029F (ULTRAFILTER, 10K DALTON PERMEATE) 12/8/1999 1721 -- S 20 -- -- -- -291379 R2 (NA) 1/6/2000 1011 1019 S 20 0 0.0069 0.00763 -0.00291379 R2 (NA) 1/6/2000 1011 1019 S 10 -0.00056 .00112 .0134 0 291379 0.45F (ULTRAFILTER, RETENTATE) 1/6/2000 1155 1301 S 10 -- -- -- -291379 0.0029F (ULTRAFILTER, 10K DALTON PERMEATE), LAB DUPLICATE 1/6/2000 1155 1307 S 10 0 .00326 .0036 0 291372 R2 (NA) 2/1/2000 1015 1022 S 20 0 .00386 .00428 0 291372 R2 (NA) 2/1/2000 1015 1022 S 10 -- -- -- -291372 R3 (NA) 2/1/2000 1046 1108 S 10 -- -- -- -291375 0.45F (ULTRAFILTER, RETENTATE) 12/3/1999 1454 1507 S 10 -- -- -- 0 291375 0.0029F (ULTRAFILTER, 10K DALTON PERMEATE) 12/3/1999 1524 1613 S 10 -- -- -- -291374 R2 (NA) 2/15/1999 1008 1055 S 20 0 .00686 .00759 .00291376 R2 (NA) 2/15/2000 1016 1036 S 20 0 .00574 .00635 -.00291376 R2 (NA) 2/15/2000 1016 1036 S 10 -- -- -- -291376 R3 (NA) 2/15/2000 1120 1208 S 20 -.000398 .00483 .0155 0 291376 0.45F (ULTRAFILTER, RETENTATE) 2/15/2000 1315 1518 S 20 -.00288 .00292 .0155 -.00291376 0.45F (ULTRAFILTER RETENTATE) 2/15/2000 1315 1518 S 10 -- -- -- -291376 0.45F (ULTRAFILTER, RETENTATE) 2/15/2000 1537 1626 S 20 -.000729 .00146 .0103 .00291376 0.0029F (ULTRAFILTER, 10K DALTON PERMEATE) 2/15/2000 1538 1642 S 20 0 .00389 .00431 0 291376 0.0029F (ULTRAFILTER, 10K DALTON PERMEATE) 2/15/2000 1538 1642 S 10 0 .00435 .00481 -.00291378 R1 (NA) 8/25/1999 1143 1151 S 20 0 .00338 .00374 -.00

Table 7B. Concentrations of radionuclides in filtered and unfiltered concurrent laboratory duplicate and sequential replicate samples of water from 

equipment blank, at or near the BOMARC Missile Facility, Ocean County, New Jersey, 1999–2000.—Continued

[Data are sorted by well depth; pCi/L, picocurie per liter; P.E., precision estimate; SSMDC, sample-specific minimum detectable concentration; <, less than; K, thousand; NA, noin parentheses is parameter code used to identify the constituent, property, or characteristic in the U.S. Geological Survey water-quality database (NWIS) in which individual samnumber.]

U.S. 

Geological 

Survey

well 

number

Sample designation

(and filter type)1

Date 

(month/ 

day/year)

Begin 

sample 

collection, 

time

End 

sample 

collection, 

time

Same 

medium

(code)2

Replicate, 

type3

(code) 

(99912)

Plutonium

-238 

(pCi/L)

(22012/

22001)

Plutonium

-238,

2 SIGMA 

P.E. 

(pCi/L)

(61949/

49939)

Plutonium

-238,

SSMDC

(pCi/L)

Pluto

-239

(pC

(49

499
Table 7B. Concentrations of radionuclides in filtered and unfiltered concurrent laboratory duplicate and sequential replicate samples of water from 

equipment blank, at or near the BOMARC Missle Facility, Ocean County, New Jersey, 1999–2000.—Continued

[Data are sorted by well depth; pCi/L, picocurie per liter; P.E., precision estimate; SSMDC, sample-specific minimum detectable concentration; <, less than; K, thousand; NA, noin parentheses is parameter code used to identify the constituent, property, or characteristic in the U.S. Geological Survey water-quality database (NWIS) in which individual samnumber.]

U.S. 

Geological 

Survey 

well 

number

Sample designation

(and filter type)1

Date 

(month/ 

day/year)

Begin 

sample 

collection, 

time

End 

sample 

collection, 

time

Americium

-241

(pCi/L)

(29867)

Americium

-241,

2 SIGMA 

P.E. 

 (pCi/L)

(49942)

Americium

-241,

SSMDC

(pCi/L)

Uranium

-238

(pCi/L)

(22603)

Uranium

-238,

2 SIGMA 

P.E.

(pCi/L)

(75991)

Uraniu

-238

SSMD

(pCi/L

291377 R2 (NA) 2/7/2000 1017 1036 -- -- -- 0.0478 0.029 0.0307 

291377 R2 (NA) 2/7/2000 1019 1028 -- -- -- -- -- -- 291377 R2 (NA) 2/7/2000 1019 1028 -- -- -- -- -- -- 291377 R3 (NA) 2/7/2000 1104 1118 -- -- -- -- -- -- 291377 0.45F 

(ULTRAFILTER, RETENTATE)

2/7/2000 1140 1225 -- -- -- -- -- -- 

291377 0.0029F 

(ULTRAFILTER, 10K DALTON 

PERMEATE) 

2/7/2000 1140 1229 0.000354 -- -- -- -- -- 

291370 R2 (NA) 2/11/2000 0931 0946 -- -- -- -- -- -- 

291370 R2 (NA) 2/11/2000 0931 0946 -- -- -- -- -- -- 291370 R3 (NA) 2/11/2000 1022 1043 -- -- -- -- -- -- 291370 0.0029F 

(ULTRAFILTER, 10K DALTON 

PERMEATE)

2/11/2000 1112 1211 .000365 -- -- -- -- -- 

291203 R2 (NA) 2/23/2000 0959 1017 -.00234 .00237 .0126 -- -- -- 

291203 R3 (NA) 2/23/2000 1143 1323 .0059 .00829 .0149 .0076 .00898 .0148 

291203 0.45Fa 

(CAPSULE FILTER; BLANK)

2/17/2000 1553 1625 .00372 .0053 .00505 -- -- -- 

291371 R1 (NA) 12/8/1999 1124 1128 .0121 .00958 .0124 .0139 .0145 .0252 291371 R1 (NA) 12/8/1999 1137 1140 .0149 .00967 .00403 .0174 .0156 .0254 291371 R2 (NA) 12/8/1999 1323 1341 .00309 .00439 .00418 .0167 .0134 .019 

291371 R3 (NA) 12/8/1999 1507 1521 .0031 .00442 .00421 .00711 .00814 .0112 

291371 0.45F 

(ULTRAFILTER, RETENTATE)

12/8/1999 1640 1712 .127 .0337 .00836 0 .00817 .0207 

291371 0.0029F 

(ULTRAFILTER, 10K DALTON 

PERMEATE)

12/8/1999 1640 1720 .0513 .0195 .00863 .00455 .0082 .0163 
291371 0.45F (ULTRAFILTER, RETENTATE) 12/8/1999 1720 -- 0.00148 0.00584 0.0145 -- -- -- 

291371 0.0029F (ULTRAFILTER, 10K DALTON PERMEATE) 12/8/1999 1721 -- .00202 .00406 .00549 -- -- -- 291379 R2 (NA) 1/6/2000 1011 1019 0 .00742 .00821 -- -- -- 

291379 R2 (NA) 1/6/2000 1011 1019 0 .00748 .00828 -- -- -- 

291379 0.45F (ULTRAFILTER, RETENTATE) 1/6/2000 1155 1301 -.000681 .00137 .00962 0.00289 0.0105 0.0238 

291379 0.0029F (ULTRAFILTER, 10K DALTON PERMEATE) 1/6/2000 1155 1307 -- -- -- -- -- -- 

291372 R2 (NA) 2/1/2000 1015 1022 0 .00372 .00411 -- -- -- 

291372 R2 (NA) 2/1/2000 1015 1022 .00248 .00678 .0153 -- -- -- 

291372 R3 (NA) 2/1/2000 1046 1108 .00323 .00648 .00876 .0125 .0175 .0332 

29375 045F (ULTRAFILTER, RETENTATE) 12/3/1999 1454 1507 .00344 .0069 .00933 -- -- -- 

291375 0.0029F (ULTRAFILTER, 10K DALTON PERMEATE) 12/3/1999 1524 1613 -- -- -- -.00361 .00328 .0266 

291374 R2 (NA) 12/15/1999 1008 1055 .00326 .00654 .00884 -- -- -- 

291376 R2 (NA) 2/15/2000 1016 1036 .00132 .00519 .0129 -- -- -- 291376 R2 (NA) 2/15/2000 1016 1036 .00192 .00384 .00519 -- -- -- 291376 R3 (NA) 2/15/2000 1120 1208 -.000672 .00135 .00949 .015 .0102 .0088

291376 0.45F (ULTRAFILTER, RETENTATE) 2/15/2000 1315 1518 .00615 .00703 .00965 .0134 .0109 .0128 

291376 0.45F (ULTRAFILTER, RETENTATE) 2/15/2000 1315 1518 -- -- -- 0 .00605 .0168 

Table 7B. Concentrations of radionuclides in filtered and unfiltered concurrent laboratory duplicate and sequential replicate samples of water from 

equipment blank, at or near the BOMARC Missle Facility, Ocean County, New Jersey, 1999–2000.—Continued [Data are sorted by well depth; pCi/L, picocurie per liter; P.E., precision estimate; SSMDC, sample-specific minimum detectable concentration; <, less than; K, thousand; NA, no

in parentheses is parameter code used to identify the constituent, property, or characteristic in the U.S. Geological Survey water-quality database (NWIS) in which individual samnumber.] U.S. Geological Survey well number Sample designation (and filter type)1 Date (month/ day/year) Begin sample collection, time End sample collection, time Americium -241 (pCi/L) (29867) Americium -241, 2 SIGMA P.E. (pCi/L) (49942) Americium -241, SSMDC (pCi/L) Uranium -238 (pCi/L) (22603) Uranium -238, 2 SIGMA P.E. (pCi/L) (75991) Uraniu

-238

SSMD

(pCi/L
291376 0.45F 

(ULTRAFILTER, RETENTATE)

2/15/2000 1537 1626 0.00104 0.00375 0.00984 0.00346 0.00476 0.0075

291376 0.0029F 

(ULTRAFILTER, 10K DALTON 

PERMEATE)

2/15/2000 1538 1642 -.00183 .00214 .0119 .000345 .00397 .0119 

291376 .0029F 

(ULTRAFILTER, 10K DALTON 

PERMEATE)

2/15/2000 1538 1642 -- -- -- -- -- -- 

291378 R1 (NA) 8/25/1999 1143 1151 0 .00824 .00912 .0526 .0247 .0067

Table 7B. Concentrations of radionuclides in filtered and unfiltered concurrent laboratory duplicate and sequential replicate samples of water from 

equipment blank, at or near the BOMARC Missle Facility, Ocean County, New Jersey, 1999–2000.—Continued

[Data are sorted by well depth; pCi/L, picocurie per liter; P.E., precision estimate; SSMDC, sample-specific minimum detectable concentration; <, less than; K, thousand; NA, noin parentheses is parameter code used to identify the constituent, property, or characteristic in the U.S. Geological Survey water-quality database (NWIS) in which individual samnumber.]

U.S. 

Geological 

Survey 

well 

number

Sample designation

(and filter type)1

Date 

(month/ 

day/year)

Begin 

sample 

collection, 

time

End 

sample 

collection, 

time

Americium

-241

(pCi/L)

(29867)

Americium

-241,

2 SIGMA 

P.E. 

 (pCi/L)

(49942)

Americium

-241,

SSMDC

(pCi/L)

Uranium

-238

(pCi/L)

(22603)

Uranium

-238,

2 SIGMA 

P.E.

(pCi/L)

(75991)

Uraniu

-238

SSMD

(pCi/L
Table 7B. Concentrations of radionuclides in filtered and unfiltered concurrent laboratory duplicate and sequential replicate samples of water from 

equipment blank, at or near the BOMARC Missle Facility, Ocean County, New Jersey, 1999–2000.—Continued [Data are sorted by well depth; pCi/L, picocurie per liter; P.E., precision estimate; SSMDC, sample-specific minimum detectable concentration; <, less than; K, thousand; NA, no

in parentheses is parameter code used to identify the constituent, property, or characteristic in the U.S. Geological Survey water-quality database (NWIS) in which individual samnumber.] U.S. Geolog- ical Survey well number Sample designation (and filter type)1 Date (month/ day/year) Begin sample collection, time End sample collection, time Uranium -234, SSMDC (pCi/L) Uranium -235 (pCi/L) (22620) Uranium -235, 2 SIGMA P.E. (pCi/L) (75994) Uranium -235, SSMDC (pCi/L) Thorium -228 (pCi/L) (61738) Thorium -228, SIGMA P.E. (pCi/L) (61739) 

291377 R2 (NA) 2/7/2000 1017 1036 0.0293 -0.000714 0.00143 0.0171 -- -- 291377 R2 (NA) 2/7/2000 1019 1028 -- -- -- -- -- -- 291377 R2 (NA) 2/7/2000 1019 1028 -- -- 291377 R3 (NA) 2/7/2000 1104 1118 -- -- 291377 0.45F (ULTRAFILTER, RETENTATE) 2/7/2000 1140 1225 -- -- -- -- -- -- 291377 0.0029F (ULTRAFILTER, 10K DALTON PERMEATE) 2/7/2000 1140 1229 -- -- -- -- -- -- 291370 R2 (NA) 2/11/2000 0931 0946 -- -- -- -- -- -- 291370 R2 (NA) 2/11/2000 0931 0946 -- -- -- -- -- -- 291370 R3 (NA) 2/11/2000 1022 1043 -- -- -- -- -- -- 291370 0.0029F (ULTRAFILTER, 10K DALTON PERMEATE) 2/11/2000 1112 1211 -- -- -- -- -- -- 291203 R2 (NA) 2/23/2000 0959 1017 -- -- -- -- -- -- 291203 R3 (NA) 2/23/2000 1143 1323 .0148 .00518 .00836 .016 -- -- 291203 0.45Fa (CAPSULE FILTER, BLANK) 2/17/2000 1551 1625 -- -- -- -- -- -- 291371 R1 (NA) 12/8/1999 1124 1128 .0133 .00374 .00844 .0178 -- -- 291371 R1 (NA) 12/8/1999 1137 1140 .0268 .00408 .00919 .0194 -- -- 291371 R2 (NA) 12/8/1999 1323 1341 .0156 .00326 .00677 .0141 -- -- 291371 R3 (NA) 12/8/1999 1507 1521 .0196 -.00158 .00225 .0136 -- -- 291371 0.45F (ULTRAFILTER, RETENTATE) 12/8/1999 1640 1712 .0171 -.000346 .0042 .0135 -- -- 291371 0.0029F (ULTRAFILTER, 10K DALTON 

PERMEATE)

12/8/1999 1640 1720 .0148 .00227 .00579 .013 -- -- 
291371 0.45F 

(ULTRAFILTER, RETENTATE)

12/8/1999 1720 -- -- -- -- -- -- -- 

291371 0.0029F 

(ULTRAFILTER, 10K DALTON 

PERMEATE)

12/8/1999 1721 -- -- -- -- -- -- -- 

291379 R2 (NA) 1/6/2000 1011 1019 -- -- -- -- -- -- 291379 R2 (NA) 1/6/2000 1011 1019 -- -- -- -- -- -- 291379 0.45F 

(ULTRAFILTER, RETENTATE)

1/6/2000 1155 1301 0.0257 0.000825 0.00671 0.0177 -- -- 

291379 0.0029F 

(ULTRAFILTER, 10K DALTON 

PERMEATE)

1/6/2000 1155 1307 -- -- -- -- -- -- 

291372 R2 (NA) 2/1/2000 1015 1022 -- -- -- -- -- -- 291372 R2 (NA) 2/1/2000 1015 1022 -- -- -- -- -- -- 291372 R3 (NA) 2/1/2000 1046 1108 .027 -.00167 .00739 .0219 -- -- 291375 0.45F 

(ULTRAFILTER, RETENTATE)

12/3/1999 1454 1507 -- -- -- -- -- -- 

291375 0.0029F 

(ULTRAFILTER, 10K DALTON 

PERMEATE)

12/3/1999 1524 1613 .0228 .00577 .0104 .0204 -- -- 

291374 R2 (NA) 12/15/1999 1008 1055 -- -- -- -- -- -- 291376 R2 (NA) 2/15/2000 1016 1036 --- -- -- -- -- -- 291376 R2 (NA) 2/15/2000 1016 1036 -- -- -- -- -- -- 291376 R3 (NA) 2/15/2000 1120 1208 .0122 .00188 .00477 .0107 -- -- 291376 0.45F 

(ULTRAFILTER, RETENTATE)

2/15/2000 1315 1518 .0172 -.00111 .00476 .016 -- -- 

291376 0.45F 

(ULTRAFILTER, RETENTATE)

2/15/2000 1315 1518 .0168 .00181 .00706 .0168 -- -- 

Table 7B. Concentrations of radionuclides in filtered and unfiltered concurrent laboratory duplicate and sequential replicate samples of water from 

equipment blank, at or near the BOMARC Missle Facility, Ocean County, New Jersey, 1999–2000.—Continued

[Data are sorted by well depth; pCi/L, picocurie per liter; P.E., precision estimate; SSMDC, sample-specific minimum detectable concentration; <, less than; K, thousand; NA, noin parentheses is parameter code used to identify the constituent, property, or characteristic in the U.S. Geological Survey water-quality database (NWIS) in which individual samnumber.]

U.S. 

Geological 

Survey 

well 

number

Sample designation

(and filter type)1

Date

(month/ 

day/year)

Begin 

sample 

collection, 

time

End 

sample 

collection, 

time

Uranium

-234,

SSMDC

(pCi/L)

Uranium

-235 

(pCi/L)

(22620)

Uranium

-235,

2 SIGMA 

P.E.

 (pCi/L) 

(75994)

Uranium

-235,

SSMDC

(pCi/L)

Thorium

-228

(pCi/L)

(61738)

Thorium

-228,

SIGMA 

P.E.

(pCi/L)

(61739)
291376 0.45F (ULTRAFILTER, RETENTATE) 2/15/2000 1537 1626 0.0104 -0.00106 0.00151 0.00913 -- -- 291376 0.0029F (ULTRAFILTER, 10K DALTON PERMEATE) 2/15/2000 1538 1642 .0119 .00587 .00825 .0148 -- -- 291376 0.0029F (ULTRAFILTER, 10K DALTON PERMEATE) 2/15/2000 1538 1642 -- -- -- -- -- -- 291378 R1 (NA) 8/25/1999 1143 1151 .0141 -.001 .00143 .0141 -- -- 

Table 7B. Concentrations of radionuclides in filtered and unfiltered concurrent laboratory duplicate and sequential replicate samples of water from 

equipment blank, at or near the BOMARC Missle Facility, Ocean County, New Jersey, 1999–2000.—Continued [Data are sorted by well depth; pCi/L, picocurie per liter; P.E., precision estimate; SSMDC, sample-specific minimum detectable concentration; <, less than; K, thousand; NA, no

in parentheses is parameter code used to identify the constituent, property, or characteristic in the U.S. Geological Survey water-quality database (NWIS) in which individual samnumber.] U.S. Geolog- ical Survey well number Sample designation (and filter type)1 Date (month/ day/year) Begin sample collection, time End sample collection, time Uranium -234, SSMDC (pCi/L) Uranium -235 (pCi/L) (22620) Uranium -235, 2 SIGMA P.E. (pCi/L) (75994) Uranium -235, SSMDC (pCi/L) Thorium -228 (pCi/L) (61738) Thorium -228, SIGMA P.E. (pCi/L) (61739) 
Table 7B. Concentrations of radionuclides in filtered and unfiltered concurrent laboratory duplicate and sequential replicate samples of water from 

equipment blank, at or near the BOMARC Missle Facility, Ocean County, New Jersey, 1999–2000.—Continued

[Data are sorted by well depth; pCi/L, picocurie per liter; P.E., precision estimate; SSMDC, sample-specific minimum detectable concentration; <, less than; K, thousand; NA, noin parentheses is parameter code used to identify the constituent, property, or characteristic in the U.S. Geological Survey water-quality database (NWIS) in which individual samnumber.]

U.S. 

Geological 

Survey 

well 

number

Sample designation

(and filter type)1

Date

(month/ 

day/year)

Begin 

sample 

collection, 

time

End 

sample 

collection, 

time

Thorium

-230,

SSMDC

(pCi/L)

Thorium

-232

(pCi/L)

(75976)

Thorium

-232,

2 SIGMA 

P.E.

(pCi/L)

(75999)

Thorium

-232,

SSMDC

(pCi/L)

Gross 

alpha, 

residue 

procedure,

as TH-230 

(pCi/L)

(04126)

Gross 

alpha,

2 SIGMA 

P.E.

(pCi/L)

(75987)

Gross beta,

 residue

procedure,

as CS-137 

(pCi/L)

(03515)

2 

291203 R3 (NA) 2/23/2000 1143 1323 -- -- -- -- <3 1.68 <4 291371 R1 (NA) 12/8/1999 1124 1128 -- -- -- -- -- -- -- 291371 R1 (NA) 12/8/1999 1137 1140 -- -- -- -- -- -- -- 291371 R2 (NA) 12/8/1999 1323 1341 -- -- -- -- -- -- -- 291371 R3 (NA) 12/8/1999 1507 1521 -- -- -- -- -- -- -- 291371 0.45F 

(ULTRAFILTER,

RETENTATE)

12/8/1999 1640 1712 -- -- -- -- -- -- -- 

291371 0.0029F 

(ULTRAFILTER, 

10K DALTON PERMEATE)

12/8/1999 1640 1720 -- -- -- -- -- -- -- 

291371 0.45F 

(ULTRAFILTER, 

RETENTATE)

12/8/1999 1720 -- -- -- -- -- -- -- -- 

291371 0.0029F 

(ULTRAFILTER, 10K 

DALTON PERMEATE)

12/8/1999 1721 -- -- -- -- -- -- -- -- 

291379 R2 (NA) 1/6/2000 1011 1019 -- -- -- -- -- -- -- 291379 R2 (NA) 1/6/2000 1011 1019 -- -- -- -- -- -- -- 291379 0.45F 

(ULTRAFILTER, 

RETENTATE)

1/6/2000 1155 1301 -- -- -- -- -- -- -- 

291379 0.0029F 

(ULTRAFILTER, 

10K DALTON PERMEATE)

1/6/2000 1155 1307 -- -- -- -- -- -- -- 

291372 R2 (NA) 2/1/2000 1015 1022 -- -- -- -- -- -- -- 291372 R2 (NA) 2/1/2000 1015 1022 -- -- -- -- -- -- -- 291372 R3 (NA) 2/1/2000 1046 1108 -- -- -- -- -- -- -- 
291375 0.45F (ULTRAFILTER, RETENTATE) 12/3/1999 1454 1507 -- -- -- -- -- -- -- 291375 0.0029F (ULTRAFILTER, 10K DALTON PERMEATE) 12/3/1999 1524 1613 -- -- -- -- -- -- -- 291374 R2 (NA) 12/15/1999 1008 1055 -- -- -- -- -- -- -- 291376 R2 (NA) 2/15/2000 1016 1036 -- -- -- -- -- -- -- 291376 R2 2/15/2000 1016 1036 -- -- -- -- -- -- -- 291376 R3 (NA) 2/15/2000 1120 1208 -- -- -- -- <3 2.37 <4 291376 0.45F (ULTRAFILTER, RETENTATE) 2/15/2000 1315 1518 -- -- -- -- <3 1.95 <4 291376 0.45F (ULTRAFILTER, RETENTATE) 2/15/2000 1315 1518 -- -- -- -- -- -- -- 291376 0.45F (ULTRAFILTER, RETENTATE) 2/15/2000 1537 1626 -- -- -- -- -- -- -- 291376 0.0029F (ULTRAFILTER, 10K DALTON PERMEATE) 2/15/2000 1538 1642 -- -- -- -- -- -- -- 291376 0.0029F (ULTRAFILTER, 10K DALTON PERMEATE) 2/15/2000 1538 1642 -- -- -- -- -- -- -- 291378 R1 (NA) 8/25/1999 1143 1151 -- -- -- -- -- -- -- 

1 Sample designation type: R1, unfiltered, initial; R2, unfitered, turbidity generally less than 10 NTU and slowly decreasing; RTi, unfiltered, turbidity not stable and variable

and generally less than 5 NTU; 0.45Fa, filtered, 45-micron filter; 0.45F, filtered with 45-micron capsule filter and from retentate port from 0.0029-micron ultrafilter, F0.0029, f

0.45-micron capsule filter and 0.0029-micron ultrafilter; F0.05, filtered sequentially through 0.45-micron and 0.05-micron capsule filters. 2 Sample medium: S, replicate; Q, equipment blank. 3 Replicate: 10, concurrent; 20, sequential. Table 7B. Concentrations of radionuclides in filtered and unfiltered concurrent laboratory duplicate and sequential replicate samples of water from 

equipment blank, at or near the BOMARC Missle Facility, Ocean County, New Jersey, 1999–2000.—Continued [Data are sorted by well depth; pCi/L, picocurie per liter; P.E., precision estimate; SSMDC, sample-specific minimum detectable concentration; <, less than; K, thousand; NA, no

in parentheses is parameter code used to identify the constituent, property, or characteristic in the U.S. Geological Survey water-quality database (NWIS) in which individual samnumber.] U.S. Geolog- ical Survey well number Sample designation (and filter type)1 Date (month/ day/year) Begin sample collection, time End sample collection, time Thorium -230, SSMDC (pCi/L) Thorium -232 (pCi/L) (75976) Thorium -232, 2 SIGMA P.E. (pCi/L) (75999) Thorium -232, SSMDC (pCi/L) Gross alpha, residue procedure, as TH-230 (pCi/L) (04126) Gross alpha, 2 SIGMA P.E. (pCi/L) (75987) Gross beta, residue procedure, as CS-137 (pCi/L) (03515) 

2 
Appendix 1. Natural Gamma Ray Logs, 

Screened Interval, and Pump Setting for Wells at 

the BOMARC Missile Facility, Ocean County, N.J.
74 Radiochemical Sampling and Analysis of Shallow Ground Water and Sediment at the BOMARC Missile Facility, N.J.

Well 29-1374 Well 29-1372

Well 29-1375 Well 29-1371

Screened interval

, ,

, ,

Appendix 1a.
Appendix 1 75

Well 29-1203 Well 29-1377

Well 29-1379 Well 29-1370

Screened interval

Appendix 1b.
76 Radiochemical Sampling and Analysis of Shallow Ground Water and Sediment at the BOMARC Missile Facility, N.J.

Well 29-1376 Well 29-1378

Screened interval

Appendix 1c.
For additional information, write to:

Director

U.S. Geological Survey

New Jersey Water Science Center

Mountain View Office Park

810 Bear Tavern Rd., Suite 206

West Trenton, NJ 08628

or visit our Web site at:

http://nj.usgs.gov/