vvEPA
United States
Environmental Protection
Agency
Office of Radiation and
Indoor Air
Washington, DC 20460
EPA
June 1998
EPA-402-R-98-002
Long Term Hydrological
Monitoring Program:
Amchitka, Alaska
1997
-------
C'
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Long Term Hydrological Monitoring Program
Amchitka, Alaska
1997
S.H. Faller and D.E. Farmer
Prepared for the U.S. Department of Energy
under Interagency Agreement
DE-AI08-96NVl1969
RADIATION AND INDOOR ENVIRONMENTS NATIONAL LABORATORY
OFFICE OF RADIATION AND INDOOR AIR
U.S. ENVIRONMENTAL PROTECTION AGENCY
P.O. BOX 98517
LAS VEGAS, NV 89193-8517
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NOTICE
The illformation in this document has been funded wholly or in part by the United States
Environmental Protection Agency (EP A) through Interagency Agreement (lAG) DE-AI08-96NV
11969 from the United States Department of Energy (DOE). This document has been subjected
to the Agency's peer and administrative review, and it has been approved for publication as an
EP A document. Mention of trade names or commercial products does not constitute
endorsement or recommendation for use.
11
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ABSTRACT
Surface water samples were collected on the island of Amchitka, Alaska during the month of June
1997 as part of the Environmental Protection Agency's Long Term Hydrological Monitoring
Program. The samples were scanned for the presence of gamma-ray emitting radio nuclides and
analyzed to determine tritium concentrations. Both conventional and enrichment methods were
used. No man made gamma-ray emitters were detected and results of the tritium analyses are
consistent with historical values. Trends in decreasing concentration appear to be due to
radioactive decay and to dilution.
111
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This page left blank intentionally
IV
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CONTENTS
Pa~e
Notice. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Abstract. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. III
Contents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v
Acronyms and Abbreviations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Vll
Acknowledgments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. viii
Site Background. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I
Surface Contamination. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Monitoring History. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Sample Collection and Preparation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Sample Analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Sample Results. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Discussions and Conclusions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Glossary of Terms. . . . . . . . . . . . . . . . . . . . . . . . . . . .. ......................... .. 11
Appendix A (Summary of Analytical Procedures) .................................. 12
Appendix B (Graphical Listings of Historic LTHMP Tritium Concentrations) .......... 13
v
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FIGURES
Pa~e
1. Locations of Arhchitka Island, Alaska. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Amchitka Island and Camp Area. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Long Shot/Milrow Surface ground Zero Area. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
4. Cannikin Surface Ground Zero Area. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
TABLES
Pa~e
1. Sampling Locations Established at the Long Shot Site. . . . . . . . . . . . . . . . . . . . . . . . 7
2. Sampling Locations Established at the Milrow Site. . . . . . . . . . . . . . . . . . . . . . . . . . 8
3. Sampling Locations Established at the Cannikin Site. . . . . . . . . . . . . . . . . . . . . . . . . 9
4. Sampling Locations Established to Provide Background Data. . . . . . . . . . . . . . . . . . . 9
VI
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DOE
RSL
EMSL
EPA
lAG
L THMP
MDA
pCi/L
R&IE
GZ
SGZ
SOP
USGS
ACRONYMS AND ABBREVIATIONS
Department of Energy
Radiation Sciences Laboratory
Environmental Monitoring Systems Laboratory
Environmental Protection Agency
Interagency Agreement
Long-Term Hydrological Monitoring Program
minimum detectable activity
picocuries per liter = 10-12 curies per liter = 1/1 ,000,000,000,000 curies per liter
Radiation and Indoor Environments National Laboratory
ground zero
surface ground zero
standard operating procedure
U.S. Geological Survey
Vll
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ACKNOWLEDGMENTS
The authors would like to acknowledge Don James, James Harris, and the staff of the
hydrological monitoring group, EPA, for their dedication to quality and tireless work in the
execution of the sampling and laboratory analysis effort. The authors would also like to thank
Terry Mouck for her desktop publishing support.
vm
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Site Background
Amchitka island is the southernmost member of the Rat Island group of the Aleutian Chain, Alaska
(see Figures 1 and 2). It is approximately 42 miles long, varies from two to four miles in width,
and lies between longitudes 178° 21' and 179° 29' east and latitudes 51 ° 21' and 5 P 39' north. It is
bounded by the Bering Sea to the north and the Pacific Ocean to the south.
Three high-yield underground nuclear tests were conducted by the Atomic Energy Commission
on Amchitka between 1965 and 1971. They were:
.
Project Long Shot, an 80 kiloton yield test on October 29, 1965 to improve the
capability to detect, locate, and identify nuclear explosions.
.
Project Milrow, a 1 megaton yield test on October 2, 1969 to determine the
island's suitability to be the site of the larger test to follow (Cannikin).
.
Project Cannikin, a 5 megaton yield test on November 6, 1971, to test the Spartan
Anti- Ballistic Missile warhead.
General area maps of these sites are shown in Figures 3 and 4.
Surface Contamination
Several weeks following the Long Shot test in 1965, tritium was detected near the surface ground
zero (SGZ) area in the water of sump ponds used for drilling mud and in associated
drainage ditches. In 1971, several shallow wells were drilled in the area to determine the
distribution of the tritium. Samples indicate that the region of maximum contamination lies
between 200 and 300 feet, and in the immediate area of the SGZ. No radioactive strontium
or cesium was detected in the samples. Periodic sampling, as part of the Amchitka Long
Term Hydrological Monitoring Program (L THMP), indicates that the tritium concentrations
are decreasing faster than would be expected from radioactive decay alone, indicating that
dilution is also taking place.
Drillback operations were conducted only at the Cannikin site on Amchitka. After core
samples were taken, water used for decontamination of equipment was injected into the
collapse chimney. Contaminated drilling tools were abandoned in the reentry hole, which
was sealed at the termination of the program. Other items, such as valves and pipes that
contained tritium, were cut into pieces and buried beneath cement in the Cannikin reentry
well cellar.
1
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::):!:!'>:: MAIN Ma~n.ten~nce ~ Iii:'.::
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Figure 2. Amchitka Island and Camp Area
3
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~
N
o
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Scale in Feet
600
I
o
200 400
Scale in Meters
. Surface Ground Zero
. Water Sampling
Locations
o Not Sampled This Year
I
. Surface Ground
Zero
. Water Sampling
Locations
- Streams
Scale in Feet
o 300
~
o 100
Scale in Meters
W-13
LINEAR ~
FRACTU~E.~
Cleven er ~ ..:.::K::.
c.e~,,: ;8
MILROW
LONG SHOT
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Pond 3
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Figure 3. Long ShotfMilrow Surface Ground Zero Area
4
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,
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(f;~/
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Monitoring History
Hydrological monitoring on Amchitka was initiated by the U.S. Geological Survey (USGS)
in 1963 to collect environmental background information prior to the Long Shot test. The
program was continued after the test for safety prediction verification, and similar hydrologic
monitoring was conducted before and after the Milrow and Cannikin tests until 1974, when
the program was terminated. The Amchitka L THMP was instated in 1977 with sample
collection and analysis performed by the EP A Environmental Monitoring Systems
Laboratory (EMSL) in Las Vegas, Nevada. This work continues under the EPA Radiation
and Indoor Environments National Laboratory (R&IE).
Sample Collection and Preparation
Sample collection on Amchitka in 1997 took place between June 3 and 17. Field collection
procedures and sampling locations are described in standard operating procedure (SOP)
CER-203 and the Amchitka, Alaska Long Term Hydrologic Monitoring Plan. Samples for
gamma-ray analysis were collected in 3500 ml plastic cubitainers and acidified for
preservation. Water samples collected for tritium analysis were collected in 500 ml glass
bottles and were not preserved. The chain of custody procedures used in the transfer of the
samples to the laboratory are described in SOP's NRA 3.50, NRO 1.04, and CER-203.
Sample Analysis
Gamma-ray analysis was performed by placing water samples in a calibrated geometric
configuration (3.5 L marinelli beaker) and on a high-purity germanium detector for a known
data collection periods. Spectrometric data were saved and analyzed with a computer based
multichannel analyzer. The technique is useful for the identification and quantification of a
large number of man-made radionuc1ides. Collection times of approximately 100 min
allowed a minimum detectable concentration ofCs-137 of no more than 5 pCi/L to be
obtained. Operation ofthe gamma-ray detector systems is specified in SOP NRA 2. 17.
Conventional tritium analysis was performed primarily to screen the water samples for gross
contamination. The process is used to detect concentrations above 400 pCi/L directly by
distillation and liquid scintillation analysis. The only sample found to exceed this
concentration, Longshot Well GZ No.1, was not analyzed by tritium enrichment to avoid
any possible contamination of the equipment.
Tritium analysis by enrichment was performed by slow electrolysis which preferentially
concentrates tritiated water. The sensitivity of the method allows the tritium concentrations
to be determined to levels below those expected for worldwide surface waters. Procedures
for both methods are described in SOP's NRA 1. 14 and NRA 1. 07.
6
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Sample Results
No manmade gamma-ray emitting radionuclides were detected in the samples within the
scan periods used in the gamma-ray spectrometric analysis. Tritium values for the samples
are given in Tables-I, 2, 3, and 4. For each sample collected in the 1997 project, a graph of
all sample data for that location since the inception ofthe LTHMP is given in the Appendix.
Moderate weather on the island precluded the collection of rain water during this sampling
project.
Discussion and Conclusion
Tritium concentrations on Amchitka Island, Alaska follow a decreasing trend established
from prior LTHMP sampling. At locations around the Longshot SGZ where contamination
is known to exist, concentrations continue to decrease faster than would be expected from
tritium decay alone indicating that dilution is also an important factor.
Table 1. Sampling Locations Established at the Long Shot Site (Figure 3).
pCiIL
Wells 2-sigma MDA
Tritium
WL-l 12 3 5
WL-2 41 4 5
GZ-l 938 152 223
GZ-2 48 4 5
EPA-l 12 4 6
Surface Locations
Reed Pond 15 4 6
Mud Pit No.1 83 4 5
Mud Pit NO.2 113 5 5
Mud Pit No.3 157 5 5
Stream East of Long Shot 110 5 5
Long Shot Pond No.1 13 3 5
Long Shot Pond No.2 13 3 5
Long Shot Pond No.3 19 3 5
7
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Table 2. Sampling Locations Established at the Milrow Site (Figure 3).
pCiIL
Tundra Holes 2-sigma
Tritium MDA
W-2 8 136 223*
W-3 0 4 6
W-4 18 4 6
W-5 Not Sampled - well dry
W-6 Not Sampled - well dry
W-7 12 3 5
W-8 0.5 3.5 5.8
W-9 Not Sampled - well head under water
W-10 0.3 3.5 5.8
W-ll 5.1 3.5 5.6
W-12 Not Sampled - well head under water
W-13 20 4 6
W-14 13 3 5
W-l5 2.3 3.5 5.6
W-16 13 4 6
W-17 Not Sampled - well head under water
W-l8 21 4 6
W-l9 Not Sampled - well head under water
Surface Locations
Heart Lake 0.0 4.8 7.9
Duck Cove Creek 5.4 3.5 5.6
Clevenger Creek 23 4 6
* Insufficient sample for enrichment, conventional screening only.
8
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Table 3. Sampling Locations Established at the Cannikin Site (Figure 4).
pCiIL
Wells
Tritium 2-sigma MDA
HTH-3 19 3 5
Surface Locations
Cannikin Lake, north end 15 3 5
Cannikin Lake, south end 13 3 5
Ice Box Lake 16 4 6
Pit south of Cannikin GZ 9.1 3.4 5.3
DK-45 Lake 14 4 6
White Alice Creek 13 4 6
Table 4. Sampling Locations Established to Provide Background Data.
pCiIL
Wells
Tritium 2-sigma MDA
Army Well No.1 15 5 8
Army Well No.2 9 3.2 5
Army Well No.3 Not Collected - well blocked
Army Well No.4 9.4 2.5 3.8
Exploratory Hole D Not Collected - well blocked
Exploratory Hole E Not Collected - well blocked
Surface Locations
Jones Lake 12 3 5
Constantine Spring 32 5 7
Clevenger Lake 19 4 5
TX Site Spring 13 3 5
Precipitation None Collected
9
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REFERENCES
u.s. Atomic Energy Commission. Project (Cannikin. May, 1971 (internal document).
u.s. Department of Energy, Nevada Operations Office, Health Physics Division,
Environmental Branch. Long-Term Hydrologic Monitoring Program Amchitka Island,
Alaska. Las Vegas, NY: U.S. Department of Energy, Nevada Operations Office; NYO-242;
1982.
u.s. Environmental Protection Agency, Office of Radiation and Indoor Air. Amchitka,
Alaska Long Term Hydrologic Monitoring Plan. Las Vegas, NY: U.S. Environmental
Protection Agency, Radiation and Indoor Environments National Laboratory. Submitted to
U.S. Department of Energy April, 1997.
10
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GLOSSARY OF TERMS
Background Radiation
The radiation in man's environment, including cosmic rays and radiation from naturally-occurring
and man-made radioactive elements, both outside and inside the bodies of humans. and animals.
The usually quoted average individual exposure from background radiation is 125 millirem per
year in mid-latitudes at sea level.
Curie (Ci)
The basic unit used to describe the rate of radioactive disintegration. The curie is equal to 37
billion disintegrations per second, which is the equivalent of 1 gram of radium. Named for Marie
and Pierre Curie who discovered radium in 1898. One microcurie (/lCi) is 0.000001 Ci.
Isotope
Atoms of the same element with different numbers of neutrons in the nuclei. Thus 12C, l3C, and
14C are isotopes of the element carbon, the numbers denoting the approximate atomic weights.
Isotopes have very nearly the same chemical properties, but have different physical properties (for
example 12C and l3C are stable, 14C is radioactive).
Enrichment Method
A method of electrolytic concentration that increases the sensitivity of the analysis of tritium in
water. This method is used if the tritium concentration is less than 400 pCiIL.
Minimum Detectable Concentration (MDC)
The smallest amount of radioactivity that can be reliably detected with a probability of Type I and
Type II errors at 5 percent each (DOE 1981).
Offsite
Areas exclusive of the immediate RIO BLANCO Test Site Area.
Type I Error
The statistical error of accepting the presence of radioactivity when none is present. Sometimes
called alpha error.
Type n Error
The statistical error of failing to recognize the presence of radioactivity when it is present.
Sometimes called beta error.
11
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APPENDIX A
Summary of Analytical Procedures
Type of
Analysis
Analytical
Equipment
Counting
Period (Min)
Analytical
Procedures
Sample
Size
Approximate
Detection Limit"
HpGe
Gammab
HpGe detector
calibrated at 0.5 keV/
channel (0.04 to 2 MeV
range) individual detector
Efficiencies ranging from
15 to 35%.
100
Radionuclide concen-
tration quantified from
gamma spectral data by
online computer program.
3.5L
Varies with radionuclides.
3H
Automatic liquid
scintillation counter
300
Sample prepared by
distillation.
5 to 10 mL
300 to 700pCiIL
3H+ Automatic liquid
Enrichment scintillation counter
(L THMP
samples)
The detection limit is defined as the smallest amount of radioactivity that can be reliably detected, Le., probability of
Type 1 and Type n error at 5 percent each (DOE 1981).
Gamma spectrometry using a high purity intrinsic germanium (HpGe) detector.
300
Sample concentrated by
electrolysis followed by
distillation.
250 mL
5 pCiIL
Geometry*
Matrix
Volume
Isotope
Typical MDA Values for Gamma Spectroscopy
(100 minute count time)
Marinelli Model
Water Density
3.5 liter Units
MDA Isotope
430G
1.0 g/ml
pCi/L
MDA
Be-7
K-40
Cr-51
Mn-54
Co-57
Co-58
Fe-59
Co-60
Zn-65
Nb-95
Zr-95
4.56E+01
4.92E+01
5.88E+01
4.55E+01
9.65E+00
4.71E+00
1.07E+01
5.38E+00
1.24E+01
5.64E+00
9.06E+00
Ru-106
Sn-113
Sb-125
1-131
Ba-133
Cs-134
Cs-137
Ce-144
Eu-152
Ra-226
U-235
Am- 241
4.76E+01
8.32E+00
1.65E+01
8.28E+00
9.16E+00
6.12E+00
6.43E+00
7.59E+01
2.86E+01
1.58E+01
1.01E+02
6.60E+01
Disclaimer
The MDA' s provided are for background matrix samples presumed to contain no known analytes and no decay time.
All MDA's provided here are for one specific *Germanium detector and the geometry of interest. The MDA's in no
way should be used as a source ofreference for determing MDA's for any other type of detector. All gamma
spectroscopy MDA' s will vary with different types of shielding, geometries, counting times and decay time of sample.
12
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APPENDIX B
Historic L THMP Tritium Concentrations
Long Shot Site
A1
A2
A3
A4
AS
A6
A7
A8
A9
A10
A11
A12
A13
Milrow Site
A14
A1S
A16
A17
A18
A19
A20
A21
A22
A23
A24
A25
A26
A27
A28
Cannikin Site
A29
A30
A31
A32
A33
A34
A3S
Background
A36
A37
A38
WL-1
WL-2
GZ -1
GZ-2
EPA-1
Reed Pond
Mud Pit NO.1
Mud Pit NO.2
Mud Pit NO.3
Stream East of Long Shot
Long Shot Pond No.1
Long Shot Pond NO.2
Long Shot Pond NO.3
W-2
W-3
W-4
W-7
W-8
W-10
W-11
W-13
W-14
W-15
W-16
W-18
Heart Lake
Duck Cove Creek
Clevenger Creek
HTH-3
Cannikin Lake, north end
Cannikin Lake, south end
Ice Box Lake
Pit south of Cannikin GZ
DK-4S Lake
White Alice Creek
Army Well No.1
Army Well No.2
Army Well No.4
A39
A40
A41
A42
13
Jones Lake
Constantine Spring
Clevenger Lake
TX Site Spring
-------
Note:
The following graphs depict the variation of tritium concentrations at Amchitka sites since sample
collection was begun as part of the Long Term Hydrological Monitoring Program. The error bars of
each point represent a two-sigma uncertainty level. The lines connecting the points have been added
for ease of visual tracking. They are not intended to imply that seasonal or other fluctuations do not
occur. The dashed line represents the rate of decay for the first measured concentration at each site
(T1I2 = 12.3 years).
14
-------
A1. WeIlWL-1
(Longshot) A2. Well WL-2
(Longshot)
140
120 1200
100 1000
~ 80 ~ 800
U
~ U
5
E E
::J 60 ::J 600
.,
'C '. Tritium Decay .,
'C
t- t-
40 400 Tritium Decay
",
20 200
0 0
75 80 85 75 80 85 90 95 100
90 95 100
Year Year
8000
7000
6000
~ 5000
""
U
Q.
E 4000
::J
=E
t- 3000
2000
1000
A3. Well GZ-1
(Longshot)
A4. Well GZ-2
(Longshot)
2200
2000
1800
1600
1400
3
.- 1200
u
.9;
E 1000
@
.= 800
600
400
200
o
75
80
85
90
Tritium Decay
Tritium Decay
/
o
75
95
100
100
80
85
90
95
Year
Year
15
-------
1500
1200
~ 900
(3
-9:
E
~ 600
.'"
f-
300
o
75
2500
2000
1500
:;
'"
U
a.
E 1000
.2
'E
f-
500
-500
75
A5. Well EPA-1
(Longshot)
80
85
Year
A7. Mud Pit No.1
(Longshot)
o
80
85
90
Year
" Tritium Decay
90
...!rttlum Decay
J.
95
95
100
100
A6. Reed Pond
(Longshot)
250
200
::J 150
::,
<.)
-9:
E
.2
~ 100
Tritium Decay
...
50
o
75
80
85
90
. 95
100
Year
AB. Mud Pit NO.2
(Longshot)
3000
2500
2000
:;
'"
u
~ 1500
E
:0
;e
f::
1000
500
0
75 80 85 90
Year
. Tritium Decay
95
100
16
-------
A9, Mud Pit No.3
(Longshot)
4000
3500
3000
2500
;;
~ 2000
E
E 1500
'co
I-
1000
500
o
75
85
80
Year
A 11. Pond 1
(Longshot)
60
55
50
45
40
~ 35
U
Co
E 30
::J
:g 25
I-
20
15
10
5
0
60 82 84
86
88
90
Year
Tritium Decay
90
95
".
. Tritium Decay
""
92
94
96
100
98
600
500
400
:J
G 300
E:
E
:::J
!! 200
I-
100
-100
82
70
60
50
:J
G 40
E:
E
:::J
:g 30
I-
20
10
17
A 10. Stream East of
Longshot
o
. Tritium Decay
84
88
94
98
90
Year
92
96
86
A12. Pond 2
(Longs hot)
",:rritium Decay
",
o
80
82
84
86
88
90
92
94
96
98
Year
-------
A13. Pond 3
(Longshot)
80
70
140
120
100
::J'
~ 80
(.)
..9-
E
~ 60
~
40
20
o
75
60
::J'
G 50
..9-
E
::>
'E 40
f-
Tritium Decay
30
"'"
20
10
80
94
96
98
90
92
84
86
88
82
Year
A 14. Well W-2*
(Milrow)
. insufficient sample for enrichment
Tritium Decay
"""
80
85
95
100
90
Year
A15, Well W-3 A16, Well W-4
(Milrow) (Mil row)
120 120
110
100
100
90
80
80
::J' ~ 70
~ 60
(.) (3
..9- ..9-
E E 60 Tritium Decay
~ ::>
40 Tritium Decay "'" 50
~ 'C:
f-
40
20
30
20
0
10
0
75 80 85 90 95 100 75 80 85 90 95 100
Year Year
18
-------
120
100
80
::J
~
U
a.
E 60
"
0:>
."
f-
40
20
o
75
90
80
70
60
~ 50
i:3
a.
E 40
:5
~ 30
20
10
o
-10
75
A17. Well W-7
(Milrow)
. . Tritium Decay
80
85
95
90
Year
A19. Well W-10
(Milrow)
Tritium Decay
80
85
90
95
Year
100
100
~
i:3
s
E 100
.~
.C:
f-
140
120
100
I
~ 80
<::!
i:3
a.
E 60
"
0:>
."
f- 40
19
A18. Well W-8
(Mil row)
250
200
150
50
o
75
80
85
90
95
100
Year
A20. We1lW-11
(Milrow)
20
o
75
80
85
90
95
100
Year
-------
80
70
60
~
~ 50
E
~
""
~ 40
30
20
10
75 80
100
90
80
70
60
~
(3 50
.9;
E 40
~
'"
.<::
I-
30
20
10
o
-10
75
A21. Well W-13
(Milrow)
Tritium Decay
/
~ 30
..J
'=>
c.>
Co
E 25
:5
~ 20
A22. Well W-14
(Milrow)
45
40
35
"'.....Tritium Decay
15
10
5
85 90 95 100 82 84 86 88 I 90 92 94 96 98
Year Year
A23. Well W-15
(Milrow)
60
50
40
:::J
'=> 30
c.>
.9;
E
~
~ 20
I-
10
..
0
80
85
90
95
100
Year
20
A24. Well W-16
(Milrow)
Tritium Decay
/
"""
"'"
""
-10
82
96
92
94
84
90
Year
98
86
88
-------
- 100
~
U
.9; 80
E
~
~ 60
40
20
0
75 80
120
100
~ 80
U
.9;
E 60
'"
;g
f-
40
20 -
0
75 80
160
140
120
A2S. Well W-18
(Milrow)
,;rum Decay
85
90
95
Year
A27. Duck Cove Creek
(Background)
Tritium Decay
85
90
95
Year
100
100
40
30
20
10
0
-10
75 80
110
100
90
80
70
~ 60
U
a.
E 50
'E
~
120
100
:J'
""
U
a.
E 60
,;1
'E
f-
21
A26. Heart Lake
(Milrow)
85
95
100
. 90
Year
A28. Clevenger Creek
(MilrDw)
80
40
20
o
75
85
90
95
100
80
Year
-------
A29. Well HTH-3 A30. Cannikin Lake
(Cannikin) (North End)
100 80
90
70
80
60
70
~ :::J
U 60 6 50
~ ~
E E
.:1 50 ~ 40
=E
I- I-
40
30
30 " ""
20 /
20 Tritium Decay
10 10
75 80 85 90 95 100 75 80 85 90 95 100
Vear Year
A31. Cannikin Lake
(South End)
120
120
100
100
80
20
80
~
U
a.
E 60
:€
~
Tritium DeclY
/
~
U
a.
E 60
::J
.,
.t:
I-
40
40
20
o
75
80
85
90
95
100
o
75
Vear
22
A32. Ice Box Lake
(Cannikin)
Tritium Decay
/
80
85
95
100
90
Vear
-------
A33. Pit South of
Cannikin Ground Zero A34. DK-45 Lake
(Cannikin)
120
70
100
60
80
50
~ 60 :::;-
<3
,e, G 40
E ,e, Tritium Decay
.;1 40 E
'EO ::>
I- ~ 30
I-
20
20
Tritium Decay
0
10
-20
0
75 80 85 90 95 100
82 84 86 88 90 92 94 96 98
Year Year
A35. White Alice Creek
(Cannikin)
110
100
90
80
70
:::;-
-
u 60
,e,
E 50
::>
~ Tritium Decay
.'"
I- /
40
30
20
10
0
75 80 85 90 95 100
Year
A36. Army Well 1
(Background)
120
100
:::;- 80
~
u
,e,
E 60
.;1
'EO
I-
40
20
0
75 80 85 90
Year
23
'. Tritium Decay
95
100
-------
A37. Army Well No.2
(Background)
60
50
40
~
i:3
a.
E 30
:>
~
f-
Tritium Decay
/
20
10
o
78
94
96
88
90
92
82
84
86
80
Year
A39. Jones Lake
(Background)
100
90
80
70
:; 60
""
U
.e, 50
E
::>
=E 40
I-
30
20
10
0
75 80
Tritium Decay
/
85
90
95
Year
98
100
90
80
70
60
:;
:::,
() 50
5
E
;g 40
f-
30
20
10
A38. Army Well No.4
(Background)
Tritium Decay
"'"
o
80
94
96
98
82
84
86
88
90
92
Year
A40. Constantine Spring
(Background)
120
100
:; 80
:::,
u
.e,
E 60
::>
00
~
40
20
0
75 80 85 90 95 100
Year
24
-------
,,:
(3
a.
E 40
~
~
A41 . Clevenger Lake
(Background)
70
60
50
30
Tritium Decay
/
20
10
66
94
96
66
90
92
Year
96
30
25
:J 20
""
U
.9;
E
:S
j:: 15
10
25
A42. Transmission (TX) Site Springs
(Background)
. Tritium Decay
5
90
92
93
95
96
97
96
91
94
Year
------- |