EPA 520/1-88-023
                                March  1989
 GROUND-WATER PROTECTION STANDARDS
FOR INACTIVE URANIUM TAILINGS SITES
            (40  CFR 192)

       BACKGROUND  INFORMATION
                FOR
             FINAL RULE
    Office of  Radiation Programs
  Environmental Protection Agency
       Washington,  D.C. 20460

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                              CONTENTS
Chapter 1:  Introduction 	   1-1
          References	1-2

Chapter 2:  Background	2-1
     2.1  Legislative history	2-1
     2.2  Rulemaking  history 	   2-1
     2.3  Information considered in developing  the  standards  .   2-2
     2.4  References	2-3

Chapter 3:  Site Description and Status	3-1
          References	3-30

Chapter 4:  Compilation and Analysis of Ground  Water Data
            for 14 Sites	*	4-1
     4.1   Introduction	4-1
     4.2   Ambrosia Lake, New Mexico	4-3
     4.3   Canonsburg, Pennsylvania	'	4-18
     4.4   Durango, Colorado 	   4-26
     4.5   Grand Junction, Colorado  	   4-40
     4.6   Gunnison,  Colorado   	   4-50
     4.7   Lakeview,  Oregon  	   4-58
     4.8   Mexican Hat, Utah	4-72
     4.9   Monument Valley, Arizona  	   4-78
     4.10  Riverton, Wyoming 	   4-104
     4.11  Salt Lake  City, Utah	  .   4-118
     4.12  Shiprock,  New Mexico	4-124
     4.13  Tuba City, Arizona	4-129
     4.14  Green River, Utah	4-137
     4.15  Rifle, Colorado (old and new sites)	4-151
     4.16  Current uses of contaminated ground  water 	   4-162
     4.17  Organic contaminants in ground water   	   4-179
     4.18  Ground-water classification 	   4-191
     4.19  References	4-194

Chapter 5:  Ground-Water Restoration 	   5-1
     5.1  Treatment technology  	   5-1
     5.2  Volumes of contaminated ground water  	   5-12
     5.3  Aquifer restoration cost ranges   	   5-17
     5.4  References	5-19

Chapter 6:  Costs of Ground-Water Restoration and Monitoring  .   6-1
     6.1  Amount of contaminated ground water   	   6-1
     6.2  Amount of ground water to be removed	6-1
     6.3  Treatment of contaminated ground water  	   6-3
     6.4  Estimated cost of restoration treatment   	   6-3
     6.5  Estimated cost of monitoring	6-4
          6.5.1  Estimated monitoring costs at  treatment
                 plants	6-4
          6.5.2  Estimated monitoring costs of  ground water   .   6-6
     6.6  Total estimated cost	6-6
                                 111

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     6.7  Review of DOE cost estimates	6-7
          6.7.1  DOE cost  estimates	6-7
          6.7.2  Evaluation of DOE cost  estimates	6-8
     6.8  References	6-12

Chapter 7:  Other Considerations  .	7-1
     7.1  Concentrations limits for  molybdenum,  uranium,
          radium and nitrates	7-1
          7.1.1  Molybdenum   	  .....   7-1
          7.1.2  Uranium	7-3
          7.1.3  Radium  	  .....   7-6
          7.1.4  Nitrates	7-6
     7.2  Institutional control	   7-6
     7.3  Post-remediation ground-water  contamination   ....   7-17
          7.3.1  Groundwater  intrusion	   7-17
          7.3.2  Precipitation	7-18
          7.3.3  Construction water	   7-18
          7.3.4  Construction of  final  cover	   7-18
     7.4  References	   7-23
                           List of Figures
Number
Page
3-1  Location  -  UMTRA  project  sites   	  .....   3-2

4-1  Approximate location  of  domestic wells sampled
         at  Gunnison	   4-176
4-2  Locations of monitor  wells  for  UMTRA investigation
         (Gunnison)  	  .....   4-177
4-3  Uranium plume near  pile  (Gunnison)   	,  .  .   4-178
4-4  DOE monitor well  locations,  Monument Valley site  .....   4-180
4-5,  Sulfate plume,  Monument  Valley  site	  .  .   4-186
4-6  Nitrate plume,  Monument  Valley  site	   4-187
4-7  Uranium plume,  Monument  Valley  site	„  .  .   4-188

.5-1  Location  -  UMTRA  project  sites	   5-2
5-2  Low-permeability  barrier  reduces induced flow
         from river	   5-5
5-3  Chemical  precipitation and  associated process steps  „  .  .   5-7
5-4  Schematic of ion  exchange	   5-9
5-5  Schematic of carbon adsorption	   5-1.1

7-1  Typical UMTRA project pile  layout	  .   7-19
7-2   "Checklist" top cover 	 .......   7-21
                            List of Tables
 Number
Page
 3-1   Demographics of inactive uranium mill tailings sites  .  .   3-3

                                  iv

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                     List of Tables (continued)
Number
3-2

3-3

3-4
3-5

3-6

4-1

4-2

4-3

4-4

4-5

4-6

4-7

4-8

4-9

4-10

4-11

4-12

4-13

4-14

4-15

4-16

4-17

4-18

4-19

4-20

4-21
Summary descriptions of inactive uranium mill
   tailings sites .  	
Meteorological data for inactive uranium mill
   tailings sites 	  	
Radioactivity in inactive uranium mill tailings piles
Average concentration of elements found in  inactive
   uranium mill tailings  	 	
Ground water matrix  	  .
Site water quality compared to EPA standards
   at 40 CFR 192.32(a), Ambrosia Lake, New Mexico  .
Site water quality compared to other EPA standards,
   Ambrosia Lake, New Mexico   	
Site water quality compared to EPA standards
   at 40 CFR 192.32(a), Canonsburg, Pennsylvania
Site water quality compared to other EPA standards,
   Canonsburg, Pennsylvania 	
Site water quality compared to EPA standards
   at 40 CFR 192.32(a), Durango, Colorado  	
Site water quality compared to other EPA standards,
   Durango, Colorado   	
Site water quality compared to EPA standards
   at 40 CFR 192.32(a), Grand Junction, Colorado
Site water quality compared to other EPA standards,
   Grand Junction, Colorado	  .  .
Site water quality compared to EPA standards
   at 40 CFR 192.32(a), Gunnison, Colorado   .  .  .  .
Site water quality compared to other EPA standards,
   Gunnison, Colorado  	  	
Site water quality compared to EPA standards
   at 40 CFR 192.32(a), Lakeview, Oregon   	
Site water quality compared to other EPA standards,
   Lakeview, Oregon  	  	
Site water quality compared to EPA standards
   at 40 CFR 192.32(a), Mexican  Hat, Utah  	
Site water quality compared to other EPA standards,
   Mexican Hat, Utah   	
Site water quality compared to EPA standards
   at 40 CFR 192.32(a), Monument Valley, Arizona
Site water quality compared to other EPA standards,
   Monument Valley, Arizona 	  .  	
Site water quality compared to EPA standards
   at 40 CFR 192.32(a), Riverton, Wyoming  	
Site water quality compared to other EPA standards,
   Riverton, Wyoming	  .  .
Site water quality compared to EPA standards
   at 40 CFR 192.32(a), Salt Lake City, Utah   .  .  .
Site water quality compared to other EPA standards,
   Salt Lake City, Utah 	
Site water quality compared to EPA standards
   at 40 CFR 192.32(a), Shiprock, New Mexico   .  .  .
                                                           Page
3-4

3-15
3-16

3-18
3-19
4-4

4-10

4-20

4-22

4-27

4-32

4-41

4-45

4-51

4-54

4-59

4-64

4-73

4-75

4-79

4-89

4-105

4-110

4-119

4-121

4-125
                                  v

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                     List of Tables  (continued)
Number
Page
4-22 Site water quality compared  to  other  EPA  standards,
        Shiprock, New Mexico	4-127
4-23 Site water quality compared  to  EPA  standards
        at 40 CFR 192.32(3),  Tuba City,  Arizona	4-130
4-24 Site water quality compared  to  other  EPA  standards,
        Tuba City, Arizona  .  ........  .  .  .......   4,~133
4-25 Site water quality compared  to  EPA  standards
        at 40 CFR 192.32(a),  Green River,  Utah	4-139
4-26 Site water quality compared  to  other  EPA  standards,
       •Green River, Utah   .  .  .  . .  ....  .  .  .  .  .  .;  .  .  .'   4-144
4-27 Site water quality compared  to  EPA  standards  .     '
        at 40 CFR 192.32(a),  Rifle,  Colorado  (new  site)   .  .  .„  4-154
4-28 Site water quality compared  to  other  EPA  standards,
        Rifle, Colorado (new  site) .  .  .  .  .  .  .  .  .  .  .  .  .  .   4-156
4-29 Site water quality compared  to  EPA  standards
        at 40 CFR 192.32(a),  Rifle,  Colorado  (old  site)   ...   4-158
4-30 Site water quality compared  to  other  EPA  standards,
        Rifle, Colorado (old  site) .  .  .  ...	  .  .   4-160
4-31 Ground-water quality - Gunnison - downgradient  .....   4-1.63
4-32 Ground-water qualrty - Gunnison - upgradient   .  .  .  ,'." ..   4-171
4-33 Ground-water quality - Gunnison - crossgradient  .  .  .  .  ."  4-174
4-34 Exceedence of water-quality  standards                   -.'..''
        at Monument Valley  .  .  .  .  ."'"%~v -;/ .  .  .  .  .  .V .  .  .  "4-181
4-35 Background water quality in  alluvial  aquifer,
        Monument Valley site  .  .  .  . .  .  . .  .  .  .  .  .  .  . '..  '.   4-182
4-36 Background wate'r quality,  Shinarump and  DeChellyh
        sandstone aquifers 'at Monument Valley   ........   4-184
4-37 Sampling for hazardous constituents' in uranium
        mill tailings liquids'  .  .  . .  •.' . .  ....  '.;',  .  .  .   4-189

5-1  Volumes of contaminated  ground  water  at  selected
        inactive UMT sites  	 	  ......   5-18

6-1  Aquifer restoration cost estimates   	   6-2
6-2  Ground-water restoration cost estimates  at  17  sites
        chosen by DOE for active  restoration  .  .....  .  .  .   6-5
6-3  Summary table - aquifer  restoration costs .  .  .  .  ...  .   6-9
6-4  Comparison of DOE and  EPA cost  estimates  for  restoration
        of ground water at  the inactive  uranium  mill  tailings
        sites	 .  .  .  ;.  .  .  ...  ...  .  , 6-11

7-1  Summary of uranium concentrations  in  ground  water           .
        at inactive uranium mill  tailing sites .  .  ...  .' .  .  ' 7-5
                                  VI

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                            Chapter 1

                           INTRODUCTION
In enacting  the Uranium  Mill  Tailings  Radiaton Control Act of
1978  (Public Law 95-604,  42 USC  7901),  the  Congress  found that:

      o     "Uranium mill  tailings located  at active and inactive
           mill operations may pose  a potential and significant
           radiation health hazard to the  public,  and that..."

      o     "Every reasonable effort  should be made to provide for
           the stabilization,  disposal,  and  control in a safe and
           environmentally sound  manner  of such tailings in order
           to prevent or  minimize radon  diffusion  into the
           environment and to  prevent or minimize  other
           environmental  hazards..."

To these ends, the, Act required  the Environmental Protection
Agency (EPA) to set generally applicable  standards to protect
the public against both  radiological and  nonradiological  hazards
posed by residual radioactive materials at  the 22 uranium mill
tailings sites designated in  the Act and  at additional sites
where these materials are deposited that  may be designated by
the Secretary of the Department  of Energy (DOE),   Residual
radioactive material means (1) tailings waste resulting from the
processing of ores for the extraction of  uranium  and other
valuable constituents, and (2) other wastes,  including
unprocessed ores or low  grade materials,  as determined by the
Secretary.of Energy, at  sites related to  uranium  ore
processing.  We will use the  term tailings  to refer^to all of
these wastes.

Standards  were promulgated on January 5,  1983,  however,  they
were challenged in the Tenth  Circuit Court  of Appeals by  several
industrial and environmental  groups (Case Nos.  83-1014,  83-1041,
83-1206,  and 83-1300).   On September 3, 1985,  the court
dismissed  all challenges except  one:  it  set  aside the
ground-water provisions  of the regulations  at 40  CFR
192.20(a)(2)-(3) and remanded  them to EPA "...to  treat these
toxic chemicals that pose a ground-water  risk as  it  did  in the
active mill site regulations."

In the active mill site  regulations (40 CFR 192 Su^parts  D and
E), the EPA set general  numerical standards  to  which the
owners/operators of the  active sites had  to  conform  to receive a
license from the Nuclear Regulatory Commission  (NRG).   For the
Title I sites, EPA set qualitative standards  for  ground water
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protection that allowed the DOE and NRG to determine what
actions were needed on a site-by-site basis.   It was this
standard that was rejected by the courts and  has resulted  in the
rulemaking for which this is the Background Information  Document
(BID).

Standards were proposed on September  24, 1987 for  ground water
protection at the inactive uranium mill tailings sites  (EPA
87a).  Public hearings were held in Durango,  Colorado on October
29, 1987.  The public comment period  was closed on January 29,
1988 (EPA 88).  A draft Background Information Document  was
issued with the proposed standards (EPA 87b). Comments  received
during the public comment period have been considered and
incorporated where applicable in the  development of the  final
standards.  A separate "Response to Comments" document  (EPA
520/1-88-055) contains EPA's detailed responses to the comments
received and is available upon  request.

The purpose of this final BID is to summarize the  information
and data considered by the Agency  in  developing the ground-water
protection standards.  New information  supplied by the
Department of. Energy has also been included.   Information  in  the
final environmental impact statements for previous rulernakings
for uranium mill tailings  (EPA82,  EPA83) was  also  considered  in
this rulemaking.  Further, the  National Academy of Science
report,  "Scientific Basis  for Risk Assessment and  Management  of
Uranium  Mill Tailings,"  (NAS86) was also considered by  the
Agency.

Chapter  2 of the BID presents a brief description  of the Title
II ground water standard and how it can be used to develop the
Title I  rulemaking.  A description of the  24  designated  uranium
tailings sites and their current status in the DOE remedial
action program is included  in Chapter 3.  Chapter  4 presents  a
detailed analysis of the available data on the ground water in
the  vicinity of 14 of the  24 sites.

Chapter  5 describes different methods that can be  used  ฃor the
restoration of ground water.  DOE  may use  these methods  or may
use  others that they consider more appropriate.   The costs of
using these restoration  methods are  discussed in  Chapter 6.
Lastly,  Chapter 7 contains  other considerations pertinent  to  the
proposed standards.

REFERENCES

EPA82   ENVIRONMENTAL PROTECTION AGENCY,  Final Environmental
        Impact  Statement  for  Remedial  Action  Standards  for
        Inactive Uranium  Processing Sites  (40 CFR  192),  EPA
        520/4-82-013-1 and  2,  U.S.  Environmental Protection
        Agency,  401  M  St,  SW,  Washington,  D.C. 20460 (October
        1982)
                                1-2

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EPA83  ENVIRONMENTAL PROTECTION AGENCY, Final Environmental
       Impact Statement for Standards for the Control of
       Byproduct Materials from Uranium Ore Processing  (40 CFR
       192), EPA 520/1-83-008-1 and 2, U.S. Environmental
       Protection Agency, 401 M St, SW, Washington, B.C. 20460
       (September 1983)

EPA87a ENVIRONMENTAL PROTECTION AGENCY, Standards for Remedial
       Actions at Inactive Uranium Processing Sites; Proposed
       Rule, 52 FR 36000, Sept 24, 1987.

EPA87b ENVIRONMENTAL PROTECTION AGENCY, Ground Water Protection
       Standards for Inactive Uranium Tailings Sites -
       Background Information for Proposed Rule, EPA
       520/1-87-014, July 1987.

EPA88  ENVIRONMENTAL PROTECTION AGENCY, Standards for Remedial
       Actions at Inactive Uranium Processing Sites, 53FR  1641,
       January 21, 1988.                       ———

NAS86  NATIONAL ACADEMY OF SCIENCE, NATIONAL RESEARCH COUNCIL,
       Scientific Basis for Risk Assessment and Management of
       Uranium Mill Tailings, National Academy Press,
       Washington, B.C. 20418  (1986)
                                1-3

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                            Chapter  2

                           BACKGROUND
2.1  LEGISLATIVE HISTORY

The early history of uranium milling was discussed  in Chapter  2
of the Final Environmental Impact Statement for Remedial Action
Standards for Inactive Uranium Processing Sites (40  CFR 192),
EPA 520/4-82-013-1, October 1982.In 1978 Congress  passed
Public Law 95-604, the Uranium Mill Tailings Radiation Control
Act of 1978 (UMTRCA).  UMTRCA was divided into two  parts; Title
I covering 22 inactive and abandoned sites and Title II covering
those sites for which licenses had been issued by the Nuclear
Regulatory Commission or its predecessor or by an Agreement
State.  Under this Act, the Environmental protection Agency  was
charged with developing standards of general application to
govern the remedial activities of the Secretary of  Energy or his
designee under section 275a. of  the Atomic Energy Act of 1954
for those sites identified under Title I.  The Department of
Energy identified  two additional sites to be included under  the
provisions of Title I, bringing  the total number of sites under
Title I to 24.  The standards to be promulgated under Title  I
were  required, to  the maximum extent practicable, to be
consistent with the requirements of the Solid Waste Disposal Act
(SWDA) as amended.  The SWDA includes the provisions of the
Resource Conservation and Recovery Act  (RCRA).

2.2   RULEMAKING HISTORY

On June 11, 1979,  a Federal Register Notice  requesting
information and data  relevant to the development of the
standards and of  a report to Congress on  uranium mining wastes.
Because UMTRCA  required EPA to promulgate  standards before  DOE
could begin cleanup of  tailings  and because  some  buildings  had
been  found to be  contaminated with tailings  resulting  in
radiation levels  which  were highly dangerous  to  anyone  exposed
to them for a long time,  interim standards  for  cleanup  of
residual  radioactivity  that had  contaminated  land  and  buildings
were  published  in the  Federal Register  on  April  22, 1980.   This
allowed DOE to  proceed  with the  cleanup  of  offsite  tailings
contamination without  waiting for  the formal promulgation  of a
 regulation  through the  EPA  rulemaking process.   At  the  same
time, proposed  standards  for  the cleanup  of  the  inactive  mill
tailings  were published  for comment.

The  proposed  cleanup  standards were  followed  by proposed
disposal  standards that  were  published  in the  Federal  Register
on January  9,  1981.   The  disposal  standards  applied to  the
 tailings  at  the 24 designated  sites  and were  designed  to  place

                               2-1

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them  in  a  condition  which  will  be safe for a long time.   Final
standards  for  the  disposal and  cleanup of inactive uranium mill
tailings were  issued on  January 5,  1983.   The American Mining
Congress and others  immediately petitioned the Tenth Circuit
Court of Appeals for a  review of the standards.

On September 3, 1985, the  Tenth Circuit Court of Appeals  upheld
the inactive mill  tailings standards except for  the ground-water
protection portions  located at  40 CFR 192.20(a)(2) and (3) which
were  remanded  to EPA for revision.   EPA had promulgated
qualitative standards for  ground water protection and the Court
found that quantitative  standards similar to those promulgated
for the  sites  that were  regulated under UMTRCA Title II were
necessary.  The Court did  not set a time  limit on establishing
the new  standards.   On June 2,  1986,  the  U.S.  Supreme Court
declined to review all appeals  of decisions on this case.  As
noted in Chapter 1,  the  Agency   proposed  ground  water standards
on September 24, 1987.

2.3   INFORMATION CONSIDERED IN  DEVELOPING THE STANDARDS

In 1986, Congress passed the  Superfund Amendments and
Reauthorization Act  which  amended the Comprehensive
Environmental  Response,  Compensation,  and Liability Act of
1980.  In  the  discussion of this bill,  Congress  established the
concept  that the Administrator  be allowed to use alternate
technologies where applicable standards set under other
environmental  laws are based  on specific  technologies.  The RCRA
amendments to  SWDA provided only minimal  direction from Congress
for the  cleanup of old contamination  that' existed before  RCRA
was promulgated.  Therefore,  EPA is using part of the SARA
philosophy in  the the cleanup portions  of the Title I standards
by incorporating some of the  provisions from SARA into the Title
I ground-water standards.   These provisions are  an exemption if
it can be  shown that  the cleanup of contaminated ground water is
technically impracticable  from  an engineering  perspective and an
exemption  if it can  be shown  that cleanup of the contaminated
ground water would cause more environmental harm than it  would
prevent  if the water were  not cleaned  up.

The Office of  Ground Water  Protection  in  EPA has developed draft
guidelines for classifying  ground water based  on its use  or
potential use  as a source  of  drinking  water.   EPA is allowing
the use  of alternate standards  for  Class  III ground water as
defined  by the ground water classification system established in
EPA's 1984 Ground Water  Protection  Strategy.

Procedures for classifying  ground water are presented in
"Guidelines for Ground-Water  Classification under the EPA
Ground-Water Protection  Strategy"  released in  final draft in
December 1986  and due to be finalized  during the fall of  1988.
Under these draft guidelines, Class I  ground waters would
encompass resources  of particularly high  value or that are
highly vulnerable; e.g.   an  irreplaceable  source  of drinking

                               2-2

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water or ecologically vital ground water.  Class II ground
waters would include all non-Class I ground water that  is
currently used or is potentially adequate for drinking  water or
other beneficial use.  Class III would encompass ground waters
that are not a current or potential source of drinking  water due
to widespread, ambient contamination caused by natural  or
human-induced conditions or inadequate capacity to provide
sufficient quantities of water to meet the needs of an  average
household.  Human-induced conditions would specifically exclude
the contribution from the uranium mill tailings being
regulated.  At sites with Class III ground water, the proposed
supplemental standards would require only such management of
contamination due to tailings as would be required to prevent
any additional adverse impacts on human  health and the
environment from that contamination.

2.4  REFERENCES

EPA79  ENVIRONMENTAL PROTECTION AGENCY,  Development of  Standards
       for Uranium Mill Tailings and Report on Uranium  Mining
       Wastes; Call  for Information and  Data, U.S. Environmental
       Protection Agency, Washington, D.C. 20460, Federal
       Register, V.  44, No. 113, p. 33433  (June 11, 1979)

EPASOa ENVIRONMENTAL PROTECTION AGENCY,  Interim Cleanup
       Standards for Inactive Uranium Processing Sites, U.S.
       Environmental Protection Agency,  Washington, D.C.  20460,
       Federal Register, V. 45, No. 79,  pp. 27366-8  (April  22,
       1980)

EPASOb ENVIRONMENTAL PROTECTION AGENCY,  Proposed Cleanup
       Standards for Inactive Uranium Processing Sites;
       Invitation for Comment, U.S. Environmental Protection
       Agency, Washington,  D.C. 20460, Federal Register,  V.  45,
       No.  79, pp.  27370-5  (April  22, 1980)

EPA81  ENVIRONMENTAL PROTECTION AGENCY,  Proposed Disposal
       Standards for Inactive Uranium Processing Sites;
       Invitation for Comment, U.S. Environmental Protection
       Agency, Washington,  D.C. 20460, Federal Register,  V.  46,
       No.  6, pp. 2556-63  (January  9, 1981)

EPA82  ENVIRONMENTAL PROTECTION AGENCY,  Final  Environmental
       Impact Statement for Remedial  Action Standards  for
       Inactive  Uranium Processing  Sites (40  CFR  192),  EPA
       520/4-82-013-1, U.S. Environmental  Protection  Agency,  401
       M St,  SW, Washington,  D.C.  20460  (October  1982)

EPA83  ENVIRONMENTAL PROTECTION AGENCY,  Standards  for  Remedial
       Actions  at Inactive  Uranium  Processing  Sites,  U.S.
       Environmental Protection Agency,  Washington,  D.C.  20460,
       Federal  Register,  V.  48, No.  3, pp.  590-606  (January 5,
        1983)
                                2-3

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                            CHAPTER 3
                   SITE DESCRIPTIONS AND STATUS
There are 24 processing sites (Fig. 3-1) designated under
Title I of the Uranium Mill Tailings Radiation Control Act
(UMTRCA).  All but one of these sites are located in the
generally semi-arid to arid western United States.  Detailed
site descriptions have been presented in Engineering Assess-
ment Reports prepared on each site for the Department of
Energy by Ford, Bacon & Davis Utah Inc.  These have been
supplemented by more specific site investigations, remedial
action plans, environmental analyses and detailed ground
water quality investigations as necessary.

The sites vary in location from isolated sparsely-populated
rural settings to populated urban communities.  Demographic
information for each site is presented in Table 3-1.

The sites typically are in areas of alluvium underlain by
poorly to moderately consolidated sedimentary formations.
Ground water tends to be scarce and of poor quality.
Pertinent summary information regarding the topography,
geology, hydrology, and soil characteristics of each site is
presented in Table 3-2.

The majority of the sites occur in the semi-arid to arid
western United States, in areas characterized by infrequent
but often very intense rainstorms.  In the northern areas,
much of the annual precipitation may occur in the winter
months as snowfall.  Site-specific precipitation and wind
records for many of the sites are lacking because of the
remote locations.  Meteorological information from the
nearest comparable localities are summarized for each site
in Table 3-3.

The tailings contain residual.radioactive materials, in-
cluding traces of unrecovered uranium and most of the
daughter products, as well as various heavy metals and other
elements often at levels exceeding established standards.
The quantity of tailings, contained radioactivity, and
proposed remedial action are summarized for each site in
Table 3-4.  The concentrations of specific elements which
could present public health risks through ground water con-
tamination are given in Table 3-5.

All of the sites investigated show at least local contam-
ination of groundwater by surface waters and precipitation
leaching through the tailings materials.  Areal extent of
contamination ranges from the immediate vicinity of the site
to as far as 1/2 mi down-gradient.  Available groundwater
contamination data are summarized in Table 3-6.
                              3-1

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                  Unllad Btatas Dapartniant of Enargy
  Uranium Mill Tilling*
Rarnadlit Action Program
                                       UMTRA SITE LOCATIONS
oo
ro
                  HIGH HEALTH HAZARD
               O  MiOiUfi HEALTH HA1AR8
               O  LOW HEALTH HAZARD
                                                                        NOTE: EOQEMONT SOUTH DAKOTA VICINITY
                                                                           PROPERTIES ONLY
                                      Figure 3-1. LOCATION - UMTRA PROJECT SITES

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                         Table 3-1.   DEMOGRAPHICS OF  INACTIVE URANIUM HILL TAILINGS SITES
SITE NAME

Honuaent Valley, A2

Tuba City, A2
Durango, CO
Grand Junction, CO

Gunnison, CO
Hay bell, CO
Naturita (SB), CO
New Rifle, CO
| Old Rifle, CO
LO ti'
Slick Rock (NO, CO
Slick Rock (UC), CO
Louean," ID
ABbrosia Lake, NH
Shiprock, NH
Belfield, ND
Bowsan , ND

Lakeview, OS
Canonsburg, PA
Falls City, TX
Green River, UT
Hex i can Hat, UT
Salt Lake City, UT

Converse Co. , HY
Rlverton, UY
COUNTY
NAHE '
Navajo

Coconino
La Plata
Hesa

Gunnison
Hoffat
Hontrose
Garfield
Garf ield

San Higuel
San Miguel
Boise
HcKinley
San Juan
Stark
Bowaan

Lake
Washington
Karnes
Grand
San Juan
Salt Lake

Converse
Freaont
POPULATION
O-lkn
20

18
1221
843

396
0
3
96
1471

5
39
85
0
155
65
3

16
39 1O
3
14
4
203

0
.63
0-3ka
44

45
726O
16634

6523
0
3
693
5251

1O
39
172
2
3O93
1428
15

2263
17024
21
1081
384
18468

9
1069
O-5kB
6O

64
12058
38011

7315
0
3
723
5659

1O
39
218
2
4948
1584
33

4184
22135
45
1498
384
91498

18
11738
NEAREST COMMUNITY LOCAL LAND USE
NAME DISTANCE
Monuaent
Valley
Tuba City
Durango
Grand
Junction
Gunnison
Craig
Naturita
Rifle
Rifle

Slick Rock
Slick Rock
Lounan
Grants
Shiprock
Belfield
Bouaan

Lakeview
Canonsburg
Falls City
Green River
Mexican Hat
Salt Lake
City
Glenrock
Ri verton
	

S.Sai
	
	

	
25ni
2o i
	
	

3ni
3ai
	
25ปi
	
O.Sni
7ai

	
—
lOai
Ini
1.5B1
	

32n i
3ai
rural grazing, IR*

rural grazing, IR*
urban, industrial
urban, industrial

urban
rural grazing
rural grazing
urban, agri-
cultural
urban, agri-
cultural
rural, grazing
rural, grazing
rural, grazing
rural, grazing
urban, aixed, IR*
urban, industrial
rural, agri-
cultural
urban, industrial
urban, industrial
rural, grazing
urban, nixed
rural, grazing, IR*
urban, industrial

rural, grazing
urban, nixe'd, IR*
                                                                                           WATER USES IN AREA


                                                                                           2 alluvial uell and seeps, domestic 8.  livestock

                                                                                           2 sources within 2 ni

                                                                                           none uithin 2 ni

                                                                                           local sources fron deeper aquifers

                                                                                           numerous shallow donestic wells uithin  1 ai of site

                                                                                           douestic water veils 4-6 ai froป site

                                                                                           3 alluvial wells upgradient, river water downstream
                                                                                           used for irrigation, 1 deep well within 2 ai

                                                                                           47 wells within 2 ni,  1 used by South Rifle for donestic
                                                                                           water, Colorado River  major source of domestic water


                                                                                           local needs supplied by deep bedrock aquifers


                                                                                           shallow wells and surface water usage

                                                                                           none known

                                                                                           local use of groundwater from floodplain

                                                                                           scattered domestic and stock use

                                                                                           doaestic and stock use

                                                                                           donestic, irrigation and municipal wells 100' or more

                                                                                           none known

                                                                                           4 livestock wells uithin 2 mi

                                                                                           no groundwater usage near site;  Green River fn tapped

                                                                                           none known

                                                                                           shallow water not used, nuaerous domestic wells

                                                                                           feu local wells, doaestic and stock watering

                                                                                           local wells belou 100  ft;  United use of shallower
                                                                                           uater
Indian  Reservation

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                                             Table 3-2.   SUHHASY DESCRIPTIONS OF INACTIVE URAHIUH HILL TAILINGS SITES
                    Honument Valley,  AZ
                                                                                            Tuba City,  AZ
Location,           The site is on the Navajo Indian  Reservation  in  Cane  Valley,
 Topography         east of Honuaent Valley,  AZ.   The area is  arid desert with  hills,
                    steep ridges,  and nesas.   Red sandstone cliffs are  proninent  on
                    the west edge  of Cane Valley.
                                                                                            The  site is  on  the  Navajo  Indian Reservation,  5.5 ป1 east of Tuba
                                                                                            City in  Coconino  County, AZ,  and 85 Mi north of Flagstaff.  The
                                                                                            area includes occasional dry  washes,  nesas,  and rolling hills.
Geology
                   The site  is  located  in a strike-valley developed on shale nenbers
                   of the Chinle Fornation.  The site is bordered on the west by an
                   outcropping  of the Shinarunp Henber of the Chinle Fornation and
                   on the east  by Comb  Ridge, a hogback of resistant sandstones of
                   Triassic  and Jurassic age.
                                                                                            The tailings rest on a sand layer from less than 1 ft to 20 ft
                                                                                            thick derived from the underlying Navajo Sandstone, a weakly
                                                                                            cemented,  nediun-grained,  crossbedded sandstone.  The Navajo
                                                                                            Sandstone  dips at a low angle (2 deg) away froo the town of Tuba
                                                                                            City towards the  axis of the Tuba City syncline.  This axis runs
                                                                                            in  a northwest-southeast direction about 1 ni east of the tail-
                                                                                            ings site.   The Navajo Sandstone is exposed south of the mil-
                                                                                            site along Hoenkopi  Hash.
Surface Water      There are no continually active streams in the area.  The site
 Hydrology         drains naturally into Cane Valley Wash.  Approximately 1,000
                   acres of land are in the drainage basin that passes through the
                   tailings area to the wash.
                                                                                            There  are  no  surface  waters  of  consequence near the Tuba City
                                                                                            tailings site.   Surface  drainage  runs  to the Hoenkopi  Wash about
                                                                                            1.5  mi south  of  the tailings.   There  is  evidence of minor sheet
                                                                                            erosion in the area.   To the north  of  the highway,  a large de-
                                                                                            pression known as Greasewood Lake depression drains to the west-
                                                                                            southwest.
Ground Water        Unconfined ground water  is very near the surface along the main
 Hydrology          axis of Cane Valley Wash because the area is underlain by imper-
                    meable beds of Honitor Butte and Petrified Forest members of the
                    Chinle formation.  These members consist of siltstones and clay-
                    stones and are about 700 ft. thick in the nillsite area.  The un-
                    confined water moves through the alluvium of Cane Valley Wash and
                    is recovered near the site from shallow wells.  These shallow
                    wells and springs are water table sources and their recharge is
                    from local runoff.
                                                                                           The principal aquifer in the Tuba City-Hoenkopi area  is a mul-
                                                                                           tiple aquifer xsysteป ponsisting of the Navajo Sandstone and some
                                                                                           sandstone beds in the underlying Kayenta Formation.   This aquifer
                                                                                           is recharged by winter and spring precipitation in the Kaibito
                                                                                           Plateau highlands some distance north of Tuba City.   Water in the
                                                                                           multiple aquifer system moves southward from the highlands;  its
                                                                                           principal discharge area is along Hoenkopi Wash.  Thus, the tail-
                                                                                           ings are situated in the discharge rather than the recharge area
                                                                                           of the aquifer system.  Water in this multiple aquifer system is
                                                                                           unconfined.
Waste and Soil
 Characteristics
                   The new tailings pile (85%) is coarse-grained sand and small
                   pebbles containing less than 2X minus 200-mesh material.   The old
                   tailings pile (15X) is slightly finer.   Bulk densities run be-
                   tuesn 97 and 1O3 Ib/cu ft.   Soil bsnsath both pllss is sainly
                   f iise-tsxtisred sand containing little soisture.  The Cninle ?or=a-
                   tion underlies this alluvium.
The tailings are finely ground particles, a high-clay content,
relatively impermeable, and can hold water.  The subsoil consists
mainly of sand and small aggregate eroded from the underlying
Navajo S&ndstone.

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                                                Table 3-2.  SUMMARY DESCRIPTIONS OF INACTIVE URANIUM HILL TAILINGS SITES (conf d)
                       Durango, CO
                                                                                               Grand Junction, CO
     Location,         The site  is located on the southwest side df the city of Durango,
      Topography       in the valley of the Animas River.  The area is surrounded by
                       •esas and mountains typical of the western slopes of the Rocky
                       Mountain  Range.
                                                                       The site  is  located  on  the south side of the city of Grand
                                                                       Junction,  CO,  on  the north bank of the Colorado River and adja-
                                                                       cent to the  industrial  center of the city.  The site is located
                                                                       in the valley  of  the Colorado River, surrounded by generally arid
                                                                       mesas and  nountains.
     Geology
Ui
The site is on a shelf  betueen  the  Aninas  River  on  the northeast
and the sharply rising  Smelter  Mountain  on the southuest.  The
tailings generally lie  directly on  Mancos  Shale  bedrock, but some
of the piles are on alluvium and on slag from the old lead smel-
ter.  The bedrock strata dips 5 to  10  deg  southeastuard.  The
Mancos Shale is hundreds of  feet thick beneath the  tailings and
acts as a barrier to the dounuard and  upward migration of ground
waters.
The site  is located on the  modern  flood plain of the Colorado
River.  A relatively thin  (200-ft)  section of remaining Mancos
Shale underlies the unconsolidated  riverbed deposits and acts as
a barrier to the downward and  upward migration of ground water.
The bedrock strata dip 5 to 10 deg  toward the southwest.
     Surface Hater     Flowing surface waters near the site consist of Lightner Creek
      Hydrology        and  the Animas River.  Neither an intermediate regional flood
                       (100-yr flood) nor a uore severe standard project flood would
                       reach  the tailings nor would such floods erode the slag bank
                       material which provides excellent protection for the toe of the
                       large  pile.  Even so, the potential for flooding at the present
                       location is significant because of the nearness of the site to
                       the  Aninas River.
                                                                       Flowing surface  waters  near  the site consist of the Colorado
                                                                       River, a drainage  ditch,  and several man-made facilities associ-
                                                                       ated with earlier  operations at the site.   The Colorado River at
                                                                       Grand Junction has a  long history of flooding.  During an inter-
                                                                       mediate regional flood  (100-yr flood) or a more severe standard
                                                                       project flood, the tailings  pile would be an island surrounded by
                                                                       flood waters  with  unconfined ground water rising as much as 10 ft
                                                                       into the pile.
     Ground Water       The  unconfined aquifers in the Durango area consist of waters
      Hydrology         within  the recent valley alluvium and glacial deposits.  However,
                        it  is possible that ground waters flowing through the unconsoli-
                        dated material could be contaminated by any such seepage.   The
                        Mancos  Shale acts as a virtually impermeable layer confining the
                        waters  of the Dakota Sandstone.  There is no possibility for con-
                        tamination of this potential aquifer.
                                                                       The unconfined aquifers  in  the  Grand Junction area consist of
                                                                       waters within alluvial deposits,  terrace deposits, weathered
                                                                       rocks and soils,  and  in  the Mancos Shale.   The water table asso-
                                                                       ciated with the Colorado River  fluctuates several feet during the
                                                                       year and may saturate some  of the lowermost tailings.  Any conta-
                                                                       mination due to water table fluctuations would be carried by un-
                                                                       confined ground waters into the Colorado River.   The Mancos Shale
                                                                       acts as a virtually impermeable layer that confines the waters of
                                                                       the Dakota Sandstone and other  stratigraphically lower aquifers.
     Haste and Soil
      Character!sties
Materials consist of uranium and vanadium  tailings,  lead smelter
slag, rubble,  and contaminated  earth.   The tailings  consist of
grey, finely ground sands with  a low  clay  content, and bulk den-
sities of the  material  range between  95 and 102  Ib/cu ft.
Materials include uranium and vanadium  tailings,  rubble,  and con-
taminated earth.  The tailings consist  of  gray,  finely-ground
sands and purple slimes.  Bulk densities of  the  materials range
between 70.1 and 109.9  Ib/cu ft.

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                                                         Table  3-2.   DZSC3IPTIOHS OF  INACTIVE UBAHIUH  HILL TAILIHGS SITES  (confd)
                        Cunnison,  CO
                                                                                               Haybell,  CO
     Location,
      Topography
The site is located on the southwest aide of Gunnison, in the
valley of Gunnison Eiver and Tonichi Creek.  The area is sur-
rounded by aountains uhich rise to 12,000 ft above sea level.
The site is located approxiaately 25 ai uest of the toun of
Craig, 5 ซi north of the Yampa Elver in a rolling, sagebrush-
covered area.
CO
     Geology
The site is located on flood plain gravels of the Gunnison Biver
and Toaichi Creek.  The unconsolidated river-run aaterial under-
lying the site is at least 100 ft thick and probably 200 ft
thick.  Bedrock geology consists of Hesozoic sedinentary rocks
that overlie Precaabrian igneous and aetanorphic baseaent.
The site is located on a gentle southwestern slope  near  the  head
of a saall drainage systen.  The Brouns Park Foruation underlies
the site and in turn is underlain by the Hancos  Shale Foraation.
The Browns Park Foraation priaarily is coaposed  of  sandstone
units, and soae shale layers within the fornation act as barriers
to the downward and upward aigration of ground waters.
     Surface Hater
      Hydrology
The tailings pile is located 1.5 mi froa the confluence of the
Gunnison Elver and Tonichi Creek.  Flooding of the tailings as a
result of peak discharges of these rivers is unlikely because the
land surface at the tailings is  10 ft above the streaa beds and
the flood plains are extensive.  Under unusual conditions, such
as ice jaas in the Gunnison Eiver at the bridge of U.S. Highway
50, soae of the tailings could becoae saturated by flood waters.
The natural surface drainage froa the site is to the southwest to
the Gunnison Elver or to Toaichi Creek.
The Yaapa Eiver, 5 ai south,  is the closest  perennial  streaa
flowing through the area doundralnage  froa the  site.   Drainage  at
the site includes diversion ditches around the  pile  and  drainage
channels into Johnson Wash, a dry tributary  of  Lay Creek.   Lay
Creek enters the Yaapa Eiver  approxinately 2.5  ai  downstreaa  of
Johnson Wash.  Other surface  water near  the  site consists  of
standing water in the inactive Bob Pit.
     Ground Water
      Hydrology
The unconfined ground water in the unconsolidated riverbed aate-
rial of the valley floor is the aajor aquifer-for city and pri-
vate water supplies.  The general direction of ground water flow
parallels surface water flow to the southwest.  The city's water
supplies are upgradlent froa the pile.  There are. water wells
southwest of the pile and a potential for additional ground water
developaent.  There has been no evidence of contaaination of
ground or surface waters, but there is a potential for such con-
taainatlon.
The unconfined ground waters of  the  area  are  within the Browns
Park Foraation and  in unconsolidated valley deposits.   The water
table at the site is  150  ft below  the tailings-soil interface,
and the flow gradient is  to the  west-southwest.   The confined
ground waters are either  contained in the lower  sections of the
Browns Park Foraation by  shale  layers,  or are very deep aquifers
confined by the thick sequence  of  Hancos  Shale.
     Uaste and Soil
      Characteristics
The aaterlal consists of uranlua tailings, dike material, and
stabilization cover.  The tailings are gray-to-white finely
ground sands with a aediua clay content!  bulk densities of the
saterial range bstaeen 114.6 and 127.5 Ib/cu ft.
Finely-ground sands  with  soae  slioe and slight clay contents.
Bulk  densities run between  84  and 97 Ib/cu ft.  The soil beneath
the tailings consists  of  clayey  and silty fine sands,  of aedlua
density.

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                                                  Table  3-2.   SUMMARY  DESCRIPTIONS OF  INACTIVE URANIUM HILL TAILINGS SITES (confd)
                         Naturita,  CO
                                                                        Rifle, CO  (Old Rifle, Neu Rifle)
     Location,
      Topography
The site is located 2 mi northwest of the town of Haturita,  in
the San Miguel River Valley.  The locale is arid Uith canyons,
mesas, steep cliffs, and valleys.
The original tailings site was just east of Rifle;   later  dis-
posal was on land about 2 mi west of Rifle.  Both sites  are  on
the north bank of the Colorado River.
     Geology
-J
The site is located on the uest bank of the modern flood plain of
the San Miguel River, which flows northwestward through the nar-
row San Miguel River Valley.  Approximately 50 ft of alluvium
overlie the shales, sandstones, and conglomerates of the Brushy
Basin Member of the Morrison Formation.  Bedrock strata dip 2 to
4 deg northeastward.  The Brushy Basin Member is 100 to 200 ft
thick and is underlain by the sandstones and shales of the Salt
Wash Summerville Formation.
The sites are on unconsolidated Colorado River  alluvium,  under-
lain by the Shire Member of the Hasatch Formation.   In  this area
the member is characterized by up to  1600  ft  of thick  impermeable
claystone and siltstone beds.  Geologic structure  includes the
Piceance Basin north and west of Rifle and the  White River uplift
northeast.  The Wasatch Formation dips 3 deg  or less to west or
northwest at the site.
     Surface Water
      Hydrology
Flowing surface waters adjacent to or near the site consist of
the San Miguel River and intermittent streams that drain the
neighboring canyons.  Waters have flowed onto the former pile
area from the diversion ditch along the southwestern border of
the site and from drainage at the northwest of the site.  The
area has been inundated by flood waters since the tailings were
removed.
Surface water at the sites  include  drainage  ditches,  water-
accumulation ponds, and some marsh  areas.  Both  sites are in the
floodplain of the Colorado  River.   The  main  channel  has undergone
six major redirections  in the past  100  years because  of major
floods.  Computed flows are 45,000  cfs  for  100-year  flood and
65,000 cfs for 500-year flood but,  because of the  wide floodplain
in this area, flood velocities  would  be on the order  of 3 feet
per second.
     Ground Water
      Hydrology
The unconfined aquifers in the San Miguel River Valley consist of
waters within the recent valley alluvium.  Except during flooding
season, the water table lies 3 to 10 ft below the former tail-
ings-subsoil interface.  During an intermediate regional flood or
more severe floods, the water table would rise within the allu-
vium.  Potential confined ground water aquifers consist of sand-
stone strata within the Morrison Formation and the sandstone
units within the Entrada Formation.  The Summerville Formation
separates the Morrison Formation from the Entrada Formation and
prevents downward migration of water.
Both bedrock and alluvial  groundwater  subsystems are present.
The bedrock system, the  Molina  Member  of  the Wasatch is under
artesian pressure and probably  provides a small  recharge to the
alluvial system.  At the old  site  alluvial ground water repre-
sents a small, nearly isolated  system  recharged  by flow from the
river, precipitation, and  return  irrigation flows.  A ground
water mound beneath the  pile  keeps the tailings  saturated even
during periods of low water.  At  the new  site the alluvial aqui-
fer is recharged by infiltration  from  the Colorado River, preci-
pitation,  side-channel  flow,  and  seepage  from Rifle sewage faci-
lities.
     Waste and Soil
      Characteristics
The tailings were removed from the site and reprocessed.   The
soil beneath the former tailings pile area is composed of allu-
vial deposits of the San Miguel River.
Materials  include  uranium  and  vanadium tailings,  rubble, conta-
minated  earth  and  stabilization  cover.   The tailings are on un-
consolidated Colorado  River  alluvium 16 to 21 ft  thick at the old
site  and 20 to 25  ft thick at  the new Site.

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                                                  Table 3-2.  SUHHARY DESCRIPTIONS OF IHACT1VE  URAM1UH  HILL TAILINGS SITES  Cconfd)
                         Slick Rock, CO   (Union Carbide, North Continent)
                                                                                                 Louaan,  ID
     Location,

      Topography
Tuo sites, the  Union Carbide Corporation  (UC) site and the North
Continent  (NO  site, about 0.9 mi apart.  The sites are  located
approxinately 25  ni north of Dove Creek,  CO, and 3 mi northwest
of Slick Rock,  CO,  in the Dolores Eiver Valley.
 The site is located approxinately 75 Bi northeast of Boise, ID,
 in a pine-covered uountain valley in the Boise National Forest,
 on a west-facing terrace of the Sawtooth Mountain Range.  Drain-
 age from the site is into Clear Creek .
     Geology
i,
The sites are  located on the flood plain of the Dolores River.
Bedrock consists of sedimentary strata:  Navajo Sandstone at the
UC site and the Salt Wash Heaber of the Morrison Fornation at the
NC site.  The  bedrock strata dip gently to the northeast.
 The site is located on a glacial  terrace,  incised by Clear Creek.
 A lower river-laid terrace,  on which a settling pond area was
 constructed,  is adjacent to  the higher nillsite terrace.  The
 glacial terrace material is  composed of deep sandy and loamy
 soils,  gravels,  sands,  boulders,  and cobbles.   The lower alluvial
 terrace is  river-run material.   Igneous granite bedrock
 (granodiorite),  underlies the  site.
     Surface Hater
      Hydrology
The flowing surface waters near the sites consist of the Dolores
River and three of  its tributaries.  An  intermediate regional
flood (100-yr  flood) or  larger flood would inundate the base of
the piles and  could erode part of the UC dike earth cover and
possibly the tailings themselves.  The flow of flood waters
across  the base of the NC site would not be as swift.  Overland
flow across the piles is limited almost entirely to the precipi-
tation  that falls on the piles.
 Flowing surface  waters  near  the  site  include Clear Creek,  the
 South  Fork  Payette  River,  and  intermittent flow in ditches on the
 site.   Clear  Creek,  a swiftly  flowing stream,  intersects the
 South  Fork  Payette  River approximately 0.5 mi  south of  the site.
 The  lower terrace which borders  the creek  could be eroded  by
 flood  waters  of  Clear Creek, with resulting undercutting and ero-
 sion of the piles.   Erosion  at the site, aggravated by  the steep
 banks  of the  piles,  has resulted in gullies up to  10 ft deep.
     Ground Hater
      Hydrology
Contamination of confined water systems theoretically is possible
because the bedrock strata are permeable and waters of the
Dolores River recharge the aquifers.  The quantity of recharge
from the Dolores River would dilute any leaching from the tail-
ings piles.
Local aquifers are shallow and unconfined.  Clear Creek  and  the
South Fork Payette River are gaining streams fed by  flows  from
unconfined ground waters.  The terrace materials tend to filter
sediments from the waters and act as buffers to regulate overland
and subsurface flow.  The interface between the unconsolidated
surficial materials and bedrock acts as the surface  for  lateral
ground water flow.  Seeps and springs are common in  the  area,
particularly at the exposure of this interface.
     Haste and Soil
      Characteristics
The UC tailings are coarse-grained sand, while the NC tailings
are finer-grained with a clay content.  Bulk densities run be-
tween 88 and 97 Ib/cu ft.
The materials are angular, dense, coarse-grained sands;  some
gray and white, black (magnetite) and red (garnet).  The under-
lying soil is mountain loam, nearly black in color, with gravelly
aggregates resulting froa glacial deposits in some locations.

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                                              Table 3-2.   SUMMARY DESCRIPTIONS OF INACTIVE URANIUM HILL TAILINGS SITES (cont'd)
                     Aabrosia Lake, NH
                                                                                           Shiprock,  NH
 Location,
  Topography
 The  site  is  located  in a valley 25 mi north of Grants and 85 ปi
 northwest of Albuquerque, NM.  Mesas and steep cliffs surround
 the  valley and reach elevations about 2OO ft above the site.
 The site is located on the Navajo  Indian  Reservation,  on the
 south side of the San Juan River at  the town  of  Shiprock,  NH.
 The area is arid and desert-like,  with  low  rolling  hills and oc-
 casional steep ridges and mesas.
Geology
 The  site  is on a pediment sloping southuestuard from the base of
 San  Hateo Mesa.  The underlying Hancos Shale bedrock dips gently
 toward the northeast, opposite the direction of surface drainage,
 and  acts as a barrier to the downward and upward migration of
 ground water in bedrock.  Unconsolidated materials separating the
 tailings pile from bedrock are composed of clays and silts,  con-
 tain some water, and do not exceed 15 ft in thickness.
                                                                                           The  site  is  situated on an ancient river terrace adjacent to the
                                                                                           southwest bank  of  the San Juan River.  Up to 10 ft of terrace de-
                                                                                           posits  fom  a  layer between the Mancos Shale and the tailings.
                                                                                           The  aaterials are  poorly sorted and range in size from 12-in
                                                                                           boulders  to  sand-  and silt-sized particles that are cemented to-
                                                                                           gether  in places.   The Mancos Shale directly below this alluvium
                                                                                           is at least  several  hundred feet thick.
Surface Water        There are  no  perennial  surface streams near the site.  Dry washes
 Hydrology           drain near the site  and some  runoff can  flow toward the site.
                     Surface waters near  the site  include ponded waters on the tail-
                     ings pile  itself  and near the mill.  Tailings have been eroded
                     from the pile by  storn  runoff.
                                                                      The elevated topography at the oillsite eliminates the possibi-
                                                                      lity of flooding or erosion of the tailings by the waters of the
                                                                      San Juan River.   South and west of the tailings, the terrain is
                                                                      relatively flat  near the site.  Drainage from the higher ground
                                                                      farther to the south is carried to Dead Mans Wash, which empties
                                                                      into the San Juan River about O.5 mi southeast of the site.
Ground Water         The tailings  lie on unconsolidated materials which contain sone
 Hydrology           unconfined ground waters.  Seepage through the pile is possible.
                     The confined  ground waters of the area are protected by Hancos
                     Shale  froป the downward flow of contaminants from the tailings
                     pile.   The Dakota Sandstone underlies the Mancos Shale and is a
                     potential aquifer.  The Westwater Canyon Sandstone Member of the
                     Morrison Formation is tapped as the major aquifer in the area,
                     which  is unusual since it serves as the chief uraniuซ-bearing
                     horizon of the vicinity.
                                                                      The  confined  ground water aquifers underlying the site are pro-
                                                                      tected  against  contamination by both an upward pressure gradient
                                                                      and  thick  impermeable  strata.   There is a potential for further
                                                                      contamination of  the terrace gravel immediately underlying the
                                                                      tailings piles  if sufficient water is allowed to collect and
                                                                      percolate  through the  piles.
Haste and Soil
 Characteristics
The tailings are white  to  pink  finely-ground  sand  with some clayi
bulk densities range from  100 to  108  Ib/cu  ft.   Material beneath
the site is a thin  alluvial  layer  of  clay and silt  derived from
the surrounding highlands.
Materials include a combination  of  uranium  and  vanadium tailings,
dike material, rubble, and stabilization cover  of  pit-run  gravel
Bulk densities range between 82  and 107  Ib/cu ft.   The  soil  on
the site is a combination of decomposed shale and  a conglomerate
of river-deposited sand and cobbles.

-------
                                                  Table 3-2.  SUHHAKY DESCRIPTIONS OF INACTIVE UKAHIUH HILL TAILINGS SITES  (confd)
     Location,
     Topography
     Geology
I—1
o
     Surface  Hater
      Hydrology
Lakevieu, OS


The site 13 located In Goose Lake Valley 96 mi east of Klamath
Falls, OR.  Hountains surrounding the site on the east and west
reach elevations of 8,000 ft.


The Lakevlew site is located in an unconsolldated valley fill
consisting of clays, sands and gravels that overlie sedimentary
rocks of lacustrine and fluvial origin.  The site is at the
eastern boundary of the Goose Lake Graben, uhich Is block-faulted
by northerly and northeasterly normal faults.
The surface  eaters near the site consist of drainage ditches,
ponded  water after rains, and an unnamed stream from Haamersley
Canyon  that  is routed between the tailings pile and the adjacent
evaporation  ponds.  There is no evidence that the stream flow has
eroded  the tailings pile or the embankaents surrounding the eva-
poration  ponds.
Canonsburg, PA


The site is located within the corporate Halts of the borough of
Canonsburg, PA.  The site slopes to the east toward Chartiers
Creek.


The unconsolidated materials at the site are of fluvial origin.
Underlying these deposits are sediaentary strata of the Penn-
sylvanian Systea, consisting of sandstone with a little conglo-
merate, shale, liaestone, clay, and numerous beds of coal.  The
site  lies on top of the Conemaugh Formation, which is predomi-
nantly shale with abundant sandstone beds and some limestone,
clay, and coal.


Abundant surface waters in the area include several streams, nu-
merous  intermittent drainages, and several reservoirs and  ponds.
Surface waters in the vicinity of the site include Chartiers
Creek and several ditches which carry runoff.  At a gauging sta-
tion  in Carnegie, about 12 mi northeast of Canonsburg, the annual
average flow of Chartiers Creek was recorded at 287 cfs.   The
estimated annual average flow of Chartiers Creek in Canonsburg  is
between 90 and  130 cfs.
     Ground Hater
      Hydrology
Ground  water occurs under confined and unconfined conditions.
There  is a strong upward flow gradient from leaky artesian aqui-
fers  in the thin,  unconsolldated  lacustrine sediments.  Conta-
mination of the  ground  water is unlikely.  A known geotheraal
area  is located  adjacent to Harner Mountain, and the surface
water  temperature at  Hunters Hot  Springs,  1 mi northwest of the
site,  is 212 F.
 Confined  ground-water  systems  in  the  Conemaugh  Foraation  under
 the  site  occur  largely in  the  sandstone  beds  with limited quanti-
 ties in the  bedding-plane  passages  and  in  joint planes of the
 shales and limestones.  Yields are  variable and unpredictable but
 generally range from  small to  moderate.  A median yield for wells
 in this aquifer is 5  gal/Bin.   Yields large enough for industrial
 or municipal purposes  are  difficult to  obtain.   Unconfined ground
 water at  the site is  found in  fill  materials  and in alluvial
 deposits.
     Haste and Soil
      Characteristics
 The  uranium tailings  are  of a  fine brown sand.  The natural soil
 on which the tailings rest  is  a  rich dark brown-to-black  loam.
                                                                                                  Tailings have been stabilized in place.

-------
                                                  Table 3-2.  SUHHARY DESCRIPTIONS OF INACTIVE URANIUM HILL TAILINGS SITES  (confd)
                         Belfield, ND
                                                                                                 Bounan, ND
    Location,
     Topography
The site is located about  19 mi uest of Dickinson,  ND,  on nearly
level land immediately south of the North Branch of the Heart
River.  The Heart River, an interaittent strean, flows  generally
uest to east in a channel  10 to 15 ft belou the general elevation
of the site.
The site is at the Griffin siding  about  7  ni  uest  of  Bowman.   It
is on nearly level land  near  the head of Spring  Creek,  a part  of
the Grand River drainage basin.  An  interaittent drainage to the
uest joins Spring Creek  less  than  0.5 mi southwest of the site.
(jo
I
    Geology
    Surface Water
     Hydrology
The site is located on alluvial deposits of the Heart River uhich
are largely silt and clay uith a few beds of sand and gravel.
Underlying bedrock is poorly consolidated.  A lignite bed occurs
at 50 ft depth.  In many localities scoria beds are present, from
burned lignite beds.


The site is located on the south side of the north branch of the
Heart River.  In the vicinity of the site, the river is an inter-
mittent streaa draining only a small area.  During summer months
there may be areas of stagnant water in the streaabed.   Surface
flows arise only from rainfall directly on the site.  Precipita-
tion on the site drains either to the Heart River or to ponds on
the site.
The site is underlain by the Bullion Creek Formation,  sometimes
called the Tongue River in this  area.  The formation consists  of
light layers of silt, clay, and  sand with interbedded  sandstone,
lignite, baked clay, and limestone.
The site is located  1 mi north of Spring Creek  in the headwaters
of the North Fork of the Grand River, a tributary of the  Missouri
River.  A small intermittent drainage runs along the uest side  oi
the site and joins Spring Creek 0.5 ui southuest of the site.
Precipitation tends to pond in local low spots  and generally eva-
porates uith some infiltration into the clayey-silty soils on the
site.  Numerous small reservoirs in the vicinity of the site are
generally used for stockwater, irrigation, and  recreation.
     Ground Water
     Hydrology
There are four najor usable aquifer systems underlying the site.
The uppermost, the Sentinal Butte Formation, outcrops much of the
area and supplies rural livestock and domestic wells. , The next
lower system, the Ludlou and Tongue River, Is probably comprised
of several aquifers.  The upper aquifers may be unconfined, are
interconnected uith and recharge the louer part of the system.
The Upper Hell Creek and Lower Cannonball-Ludlow Formation form
the third aquifer system and is not extensively tapped in this
area.  The lowermost system, the Fox Hills and Basal Hell Creek
Formation, is not heavily used in this area but is tapped by tuo
Belfield city uells.  The minimal water in the alluvial deposits
on the Heart River in this area may contribute to local wells.
The water table  is about 40 ft below the surface.
There are four major usable aquifer systems beneath the  site.
These include from highest down, the Upper Ludlow and Tongue
River Aquifer, Middle Ludlow Aquifer System, Upper Hill  Creek  anc
Louer Ludlou Aquifer System, and the Fox Hills and Basal  Hill
Creek System. 'The upper three are locally interconnected, with
recharge from precipitation and seepage from surface waters and
are used locally for domestic and stock purposes.  The louer
aquifer. Fox Hills and Basal Hill Creek System,  is recharged by
percolation from overlying beds, is most reliable and serves
municipal needs.
     Haste  and Soil
      Characteristics
No mill material  is present!  all ash from the kiln was shipped
to Rifle, CO.  However, radiation measurements showed that most
of the surrounding soil at the site is contaminated to depths of
6 to 12 in,  locally to 4 ft.  The soils present on the site are
Savage silty clay loams;  soil and subsoil are 2 to 3 ft thick.
Hill materials (ash from the kiln) was collected and shipped to
Grants, NH, for further processing.  The soil at the site  is con-
taminated to depths of about 3 ft.  Soils are silts and clays up
to 7 ft in depth, with sands below that.  Bedrock  is not consoli-
dated and is less than 2O ft below the surface, at which depth a
coal bed is located.

-------
              TABLE 3-5.  AVERAGE CONCENTRATION  OF ELEMENTS FOUND IN  INACTIVE URANIUM MILL TAILINGS  (a)
                                                          (in  ppm)
GO

I—>
CO
ELEHENT

As Ba
Cd
Arsenic Barium Cadmium
Tailings Pile
Arizona
Monument Valley
Tuba City
Colorado
Uurango
Grand Junction
Gunnison
fiaybell
Naeurita ,
New Kitle
Old Rifle
Slick Rock NC
Slick Rock UC
New Mexico
Ambrosia Lake
Shiprock
Utah
Green River
Mexican Hat
Vitro Uranium^0'
Vitro Vanadium^0'
Wyoming
Spook
Riverton
"Typical" Soil^J
^a^ Adapted from G. Markos
^Table 3-1 (1 pCi/g = 1


1.5
82 86

0.80 82
14 121
254 66
1.5 18
59 - 172
4.2 100
3.7 155
34 453
6.6 134

2.6 96
0.004

1.9 73
63 12
210 2130
244 3860

87 46
161 64
6 500
and K.J. Bush,
x 10~ฐppm, for


-
4

0.20
1.6
0.26
0.09
0.07-
1.1
8.7
0.027
0.074

3.6
-

0.40
0.70
-
-

0.37
0.32
0.06
Cr .
Chromium


-
6

8.8
29
5.2
9.3 ;
- 3-5 y
55
20
4.9
3.4

8
-

17
1.0
1010
2030

26
23
100
Cu
Copper


-
1160

95
14
30
3.1
54
8
18
35
17

58
-

102
488
310
1080

14
21
20
"Physico-Chemical Processes
Ra-226) .


Fe
Iron


-
7230

62
1170
20800
2100
16400
807
8250
6540
4080

90
—

1210
3650
31100
213000

15299
21800
38000
in Uranium

Pb
Lead


—
812

62
50
137
13
48-
187
38
1250
29

—
—

121
40
3060
350

2.5
3.2
10
Hg
Mercury


—
0.001

0.87
0.026
—
0.09
• - — -
0.001
0.25
109
0.074

0.002
—

0.001
—
—
—

—
~
0.03
Mill Tailings and


Se Ag
Selenium Silver


0.064 —
10 6

1.2 1.2
3.1 0.72
1 3.8
13 0.15
0.47 1.1
1.9 1.4
2.7 0.46
0.76 1.7
2.2 0.57

68 0.15
0.18

231 0.070
6 1.0
0.022
0.066

262 2.2
391 2.4
0.2 0.1
Their Relationship

U
Uranium


60
370

480
180
90
120
500 -
240
380
80
50

210
120

60
140
180
50

130
70
1.0
V
Vanadium


1850
620

3900
1760
80
120
2890
3990
520
620
1480

1590
330

1390
1350
100
830

350
240
100
to Contamination"



Zn Ra-226W
Zinc Radium
(x 10"6)

50
249 920

304 700
45 780
120 420
17 274
75
31 870
359 1000
21 780
21 690

47 640
700

21 810
57 780
340
350 900

31 340
38 560
50 1.5
(MacSla)

               different parts of the Vitro Site, Salt Lake City, Utah.

-------
                                                  TABLE 3-8.  GROUND  HATES HATSIX
           SJTg_GRQyNJ::HATER_CHARACTERISTICS
           AREAL AND VERTICAL EXTENT
           OF GROUND-HATER CONTAMINATION
u>
i
           NATURE AND DEGREE OF
           CONTAMINATION  RELATIVE TO
           DRINKING HATER STANDARDS
           NATURAL GROUND-HATER  QUALITY
           EXISTING  USE  OF  GROUND  HATER
FATE OF THE PLUME(S)
AHBEQSIA_LAKEA_MH
Primarily in alluvium & Tres
Heraanos-Ci  Hay eventually dis-
charge into Hestuater Canyon.
Approximate volumes:
  Alluviun - 450 Billion gal.
  Tres H.C - 225 Billion gal.

Host samples exceed standards
for Co,Hn,Ho,Radiua,5O4, and TDS
A snail # of saales exceed stds
for As,B,Cd,Cl,Cr,F,G Alpha,Fe,
N03,pH,Se,Ag, and U.

The alluvium and Tres Heraanos-C
sandstone were probably unsat^
urated prior to aining and
Billing.

None in alluvium & Tres Heraanos
sandstone:Hestuater Canyon sand-
stone is major water supply.

Eventual discharge to Bine
shafts and vents into Hestwater
Canyon Sandstone.
                                                                        Sentinel Butte Formation, extent
                                                                        not yet determined.
                                                                        Not yet deterained.
                                                                        High concentration of SO4, TDS
Stock uells, soae domestic
uells aostly for purposes other
than drinking.

Possible discharge to the Heart
River.
           FEASIBILITY  OF  INSTITUTIONAL
           CONTROLS
           ALTERNATE DISPOSAL SITE
           DEPTH TO HATER TABLE  AT
           ALTERNATE DISPOSAL SITE

           HATER QUALITY AT  ALTERNATE SITE
                                     Because only unused and unusable
                                     grounduater has been and Hill be
                                     significantly impacted there is
                                     no need for inst.  controls.

                                     None.
                                     N/A
                                     N/A
                                   State of North Dakota requires
                                   well permits for domestic uells.
                                   Bull creek or stabilization
                                   with tailings at Bowman, ND.

                                   Bull Creek - 50 feet
                                   Bouaan - 10 to 15 feet

                                   Bouman - high SO4, TDS
                                   Bull Creek - unkoun, probably
                                   similar to Belfield and Bouaan
          EXPECTED  IMPACT ON HATER
          QUALITY AT ALTERNATE SITE

          NAME OF NEAREST CITY, DISTANCE
          FROM TAILINGS PILE.
                                     N/A
                                     Grants,  NM  - 8 Biles.
                                   Minimal.
                                   Belfield, ND - 1/2 mile.

-------
                                             TABLE 3-6.  GROUND MATER MATRIX Ccont'd)
           SITJ_GROyNJrWATER_CHARACTIRISTICS
           AEEAL AND VERTICAL EXTENT
           OF GROUND-HATER CONTAMINATION
           NATURE AND DEGREE OF
           CONTAMINATION RELATIVE TO
           DRINKING WATER STANDARDS

           NATURAL GROUND-WATER QUALITY
           EXISTING USE OF GROUND WATER
           FATE OF THE PLUME(S)
!SHHAH*_ND
Tongue River Formation, extent
not yet determined.
Not yet quantified.
High concen-tration of S04,TDS
Stock wells and a feu domestic
wells, not normally used for
drinking.

To be determined.
Onsite in alluvium. Hay extend*
into upper shale/limestone bed-
rock. Some indication of alight
contamination.
Volume approx. 1OO million gal.

Cosntituents above standards  in
onsite, alluvial waters are:
C1,S04, and TDS.

Background alluvial uater sample
NO3 exceeds standard.

Limited use, primarily for
gardening. Note: More data will be
forthcoming from S&M oonitoring.

Probably discharging to Chartier
Creek although there maybe aone
underflow in shallow bedrock.
00
to
o
           FEASIBILITY OF INSTITUTIONAL
           CONTROLS
State of North Dakota requires
uell permits for domestic uells.
High feasibility given limited
use & discharge of contamination
to Char-tiers Creek at site bound
           ALTERNATE DISPOSAL SITE
           DEPTH TO WATER TABLE AT
           ALTERNATE DISPOSAL SITE

           WATER QUALITY AT ALTERNATE SITE
           EXPECTED IMPACT ON WATER
           QUALITY AT ALTERNATE SITE

           NAME OF NEAREST CITY,  DISTANCE
           FROM TAILINGS SITE.
Bull Creek, approximately
50 Biles north of Bowman.

5O feet.
Unknown, likely to be similar to
the background water quality at
Bowman and Bel field.

Minimal.
Bowman, ND - 7 miles.
                                                                                   N/A
                                                                                   N/A
N/A
                                                                                   N/A
Canonsburg, PA - in town.

-------
                                            TABLE 3-6.  GROUND WATER MATRIX (cont'd)
          SITE GROUND-WATER_CHARACTERISTICS
          AREAL~AND~VERTICAL~IXTENT
          OF GROUND-HATER CONTAMINATION
          NATURE AND DEGREE OF
          CONTAMINATION RELATIVE TO
          DRINKING WATER STANDARDS
          NATURAL GROUND-WATER QUALITY
          EXISTING USE OF GROUND WATER
          FATE OF THE PLUME(S)
DURANGgฑ_CO
DUR01 (piles)  - alluviums approx-
50 acres x 2O-30 feet deep.
DURO2 (ponds)  - alluviums approx-
55 acres x 3O-40 feet deep.
Henefee Fm. one well 50-70'  deep
DUR01 - alluviums CL-4x,  Fe-2x,
As- lOOx,Se-lOOx,S04-15x,U(6.2mg/
DUR02 - alluviums Cl-5x,As-5x,
Se-40x, S04-115X, U(2.4mg/L)
DUR02 - Menefee Fm: Cl-6x,  Se-2x

slightly elevated Cl,  Fe, TDS, U
but drinking water quality

No current users within two
miles downgradient.

Discharge to Animas River within
100 to 500 feet of the piles and
ponds.
K>
     _._
Unconfined system  (Dewesville/
Conquista) 7OO ac  x 60-70  feet.
   approx. 4 billion  gallons.
Semi-confined (Dilworth)s
contamination in 2-4  wells,  120
to 150 feet deep.

Unconfined system: Cl-23x,Fe-40x
Mn-200x,S04-20X,TDS-26X,Ra-226
(lOOpc i/L),U(67mg/L)
Semi-confined systems  Cl-4x,
S04-8x,TDS-15x,U(3.2mg/L).

SO4,Cl,Fe,Mn,TDS exceed drinking
water stds, U=  1OO-300 ppb.

Four livestock wells  within  two
miles. No domestic consumption.

Discharge to San Antonio  R.  NE
of site in 150 to  200 years.
Discharge to Borrego  Cr.  SW  of
site in 30O to 4OO years.
          FEASIBILITY OF INSTITUTIONAL
          CONTROLS

          ALTERNATE DISPOSAL SITE

          DEPTH TO WATER TABLE AT
          ALTERNATE DISPOSAL SITE

          WATER QUALITY AT ALTERNATE SITE
          EXPECTED IMPACT ON WATER
          QUALITY AT ALTERNATE SITE
          NAME OF NEAREST CITY, DISTANCE
          FROM TAILINGS SITE
Have been recommended to the
state.

Bada Canyon

20 to 4O feet
S04, TDS,  Fe,  Mn exceed
drinking water standards.

Minimal; shallow system
discharges to Animas River
within two miles of the site.

Durango, Colorado -
1.5 ailes NE of Bada Canyon site
State of Texas requires  well
permits for domestic  wells.

Not evaluated.

N/A


N/A


N/A
Falls City, Texas
of tailings site.
                                                                                                     -  9  miles  NE

-------
                                             TABLE 3-6.  GROUND HATER MATRIX (cont'd)
to
           งITJJ5RgyND-HATER_CHARACTERISTICS
           AREAL~AND~VEBi?ICAL~IXTlNT
           OP GROUND-HATER CONTAHINATION
           NATURE AND DEGREE OF
           CONTAHINATION RELATIVE TO
           DRINKING  HATER STANDARDS
           NATURAL  GROUND-HATER  QUALITY
           EXISTING USE OF GROUND HATER
          FATE OF THE PLUHE(S)
 G?AND_jyNCTIONt_CO
          FEASIBILITY OF INSTITUTIONAL
          CONTROLS
          ALTERNATE DISPOSAL SITE

          DEPTH TO HATER TABLE AT
          ALTERNATE DISPOSAL SITE

          HATER QUALITY AT ALTERNATE SITE

          EXPECTED IHPACT ON HATER
          QUALITY AT ALTERNATE SITE

          NAME OF NEAREST CITY,  DISTANCE
          FROM TAILINGS SITE
 Proa the site to the vest,  up to
 1/2 Hi downgradient of site in
 alluviua.  SOBฎ entats, aay  enter
 Dakota Ss 8 subcrop 1/2 mi  west.

 Relative to atds and background,
 the 5 critical contaminants are:
 Cl,F,Fe,S04,  and Cd,
 Host  background saaples exceed
 standards  for  Cl,Fe,Hn,304,8. TDS

 No  knoun use of alluvial or
 Dakota  sandstone  uater.

 Discharge  to the  Colorado River
 or  enter the Dakota  SS  and dis-
 perse through  space  and time.
Highly feasible:  DThe site  is
w/in a municipality. 2)Contaain-
ated uater has not been used &
has liaited value.

Cheney Reservoir

Approxiaately 30 feet.


Brackish. Seasonally perched.

No impact on any potential water
resource.

Grand Junction, CO - in town.
 Brown's Hash Aluvium - <= 9 ac
    x 7 feet
 Cedar Mountain Fa. - <= 9 ac
    x 25 feet.

 Alluvium - N03-lix, NH4(4Dag/L),
   UC1.19ag/L),Hn-10x.
 Cedar Htn.  FB.  - N03-llx,
    NH4(30ag/L),  UCl,86mg/L),
    Hn-25x

 Not suitable for drinking uater.
 High cone,  of  TDS, SO4,  Cl,  Se, F.

 None.
                                                                                   Alluvium  -  discharge into Brown's
                                                                                    Hash  approx  4OO feet froa pile.
                                                                                   Cedar  Htn.  FB.  - no discharge
                                                                                   point  identified.  Pluae will
                                                                                   disperse  in this aquifer.
State of Utah requires  well
peraits for domestic  use.
Recommended stabilization  on  site

N/A


N/A

N/A
Green River, UT
rt-f o 4 + A
                                                   -  1 mile NH

-------
                                            TABLE  3-6. GROUND HATES MATRIX  (confd)
          SITE_GROUND-HATER CHARACTERISTIOS
          ARlAL AND~vlRTICAL~EXTlNT
          OF GROUND-HATER CONTAMINATION
          NATURE AND DEGREE OF
          CONTAMINATION RELATIVE TO
          DRINKING HATER STANDARDS
          NATURAL GROUND-HATER QUALITY
          EXISTING USE OF GROUND HATER
          FATE OF THE PLUME(S)
GUNNISON, CO
NJ
approximately 1 sq. Bile;
depth (thickness) approx. 10O ft
Voluee approx. 2 billion gal.
Ud.l ag/L>, N03-3x, S04-7x,
Se-lOx,  Fe-5Ox (based on max.
values.)
Potable,  TDS-300 mg/L.
Domestic.
Disperse to below drinking
water standards.  Discharge to
Gunnison R. & Tonichi Creek.
Approx 1/4 to 1/2 Bile doungrad-
ient to 5O-75 ft depth in uucon-
solidated deposits.
Volume approx. 3 billion gal.

As,B,Cl,F,Mn,S04,& TDS standards
are exceeded in nany onsite and
doungradient shallow sample.  Cd
Fe, & pH are exceeded in a feu
instances.  The exceedances are
rarely greater than 1O tines std

Non-geothermal background is
potable,except Mn std exceeded
in some cases. Geotherual bckgrd
exceeds std for As,F,& TDS.

Considerable use for domestic,
agricultural,Municipal,industry.
Most use is at depth >1OO ft.

Disperse & dilute as the
contaminants move doungradient
in the unconsolidated deposits.
          FEASIBILITY OF INSTITUTIONAL
          CONTROLS
          ALTERNATE DISPOSAL SITE

          DEPTH TO HATER TABLE AT
          ALTERNATE DISPOSAL SITE

          HATER QUALITY AT ALTERNATE  SITE

          EXPECTED IMPACT ON HATER
          QUALITY AT ALTERNATE SITE
          NAME OF NEAREST CITY,  DISTANCE
          FROM TAILINGS PILE
The state of Colorado requires
well permits for domestic use.
East Gold Basin.

10O - 20O feet.


Potable,  TDS-600 ng/L.

Under evaluation.



Gunnison, CO - 1OOO ft.
The contaminant levels are  lou
enough that only shallow ground
water close to the site may need
to be controlled.  Therefore
institution controls are feasible

Collins Ranch.

Greater than 3O feet.


Potable without treatment.

Minimal impact; i.e.,stds should
not be exceeded at closest well
for at least 1000-yrs.

Lakeview, OR - in town.

-------
                                             TABLE 3-6.  GROUND  WATER  HATHIX  Ccont'd)
           งITg_GigyND-WATER_CHABACTERISTICS
           ARBAL AND VERTICAL EXTENT
           OF GROUND-WATER CONTAMINATION
iQHHANx_ID
To be determined.
HAYBELLA_CO
To be determined  in  FY87.
           NATURE AND DEGREE OF
           CONTAMINATION RELATIVE TO
           DRINKING WATER STANDARDS
           NATURAL GROUND-WATER  QUALITY
           EXISTING USE OF GROUND  WATER
To be determined.
           FATE-OF-THE PLUHE(S)
Drinking water quality
TDS < 250 mg/L.

Surface and ground water used
for drinking uater supplies.
To be deterained.
U, N03, S04, Cl, and  possibly
trace elements  (As, Se,  Mo)  are
constituents of tailings seepage
Site hydrogeological  conditions
are not complete & solutes that
exceed Standards not  yet known.

Possible drinking uater  quality.
TDS as high as  12OO Mg/L.

Ground uater within the  alluvium
used for drinking uater  supply
in Haybell. Brouns Park  Fra.  is  a
regional source of drinking
water supply.

To be determined.
00

to
           FEASIBILITY  OF  INSTITUTIONAL
           CONTROLS   .

           ALTERNATE  DISPOSAL SITE
           DEPTH  TO  WATER  TABLE AT
           ALTERNATE DISPOSAL SITE

           WATER  QUALITY AT ALTERNATE SITE
          EXPECTED  IMPACT ON WATER
          QUALITY AT ALTERNATE SITE

          NAME OF NEAREST CITY, DISTANCE
          FROM TAILINGS PILE
To be determined.
Possibly along Highway 21, east
of the tailings, not yet
positively identified.

Unknown..
Unknown, probably similar to
Unknown.
Louman, Idaho - 1/4 mile.
State of Colorado requires  well
permits for domestic  wells.

Johnson Pit — located approx.
0.25 mile south of  tailings site.
Unknown.
Unknown, possibly similar to
Maybe 11,.

Unknown.
Maybell, CO - 7.3 miles SW.

-------
                                           TABLE 3-6. GROUND NATES MATRIX  (cont'd)
         SITE GROUND-HATER_CHAJACTERISTICS
         AREAL~AND~VERTICAL~ixfEMT
         OF GROUND-HATER CONTAMINATION

         NATURE AND DEGREE OF
         CONTAMINATION RELATIVE TO
         DRINKING HATER STANDARDS

         NATURAL GROUND-HATER QUALITY
         EXISTING USE OF GROUND HATER
         FATE OF THE PLUME(S)
                                     300 acres X 40 feet.
                                     Mn-26x,NO3-2x vS05-9x,TDS-8x
                                     UC0.43 mg/L)
                                     High cone,  of SO4 and TDS;
                                     unsuitable for drinking water.

                                     None.
                                     Seepage into Gypsum wash and
                                     movenent to San Juan R. No
                                     contamination in the river.
                                   MONyHENT_VALLEYi_AZ
                                   570 acres x 80 feet.
                                   NO3-24x,S04-6x,U(O.03 ปg/L>
                                   Mn-12x,TDS-7x
                                   Drinking water quality
                                   TDS < 500 ซg/L.

                                   A few handpunp wells  for  local
                                   residents.

                                   Natural dispersion, 20 to 20O yr
                                   to reach background.  Possibly
                                   some discharge to Cane Valley
                                   Hash during storms.
oo
to
Ol
FEASIBILITY OF INSTITUTIONAL
CONTROLS

ALTERNATE DISPOSAL SITE
         DEPTH TO HATER TABLE AT
         ALTERNATE DISPOSAL SITE

         HATER QUALITY AT ALTERNATE SITE
         EXPECTED  IMPACT ON HATER
         QUALITY AT ALTERNATE SITE
         NAME OF NEAREST CITY, DISTANCE
         FROM TAILINGS PILE
Navajo Tribe requires well
permits for domestic wells.

Not evaluated.
                                     N/A
                                     N/A
                                     N/A
                                     Mexican Hat, Utah - one mile.
                                     Halchita,  Utah - O.25 Biles.
Navajo Tribe approves/records
all wells.

Yazzie Mesa approx. 1/2 mile
southwest of the tailings.

160 feet.
                                   Drinking water quality    ..-••-.-
                                   TDS < 500 mg/L.

                                   Minimal; water table separated
                                   from tailings by relatively
                                   impermeable Moenkopi Formation.

                                    Mexican Hat, Utah.

-------
                                            TABLE 3-6. GROUND HATER MATRIX (cont'd)
(JO

NJ
          STTE GRgiJND-HATER_CHARACTBRISTIC5
          AR!AL~AND VERTICAL'EXTENT
          OF GROUND-WATER CONTAHINATION
          NATURE AND DEGREE OF
          CONTAHINATION RELATIVE TO
          DRINKING HATER STANDARDS
                                      HATURITAj^CO
          NATURAL GROUND-HATER QUALITY
          EXISTING USE OF GROUND HATER
          FATE OF THE PLUME(S)
                                      Alluvium -  73  ac  x 20 feet.
                                        95 million gallons.
                                      Fe-3x,Hn-65x,S04-4x,
                                      TDS-4x,UC2.Sปg/L)
                                     Marginally suitable  for  drinking
                                     water. S04 and TDS slightly
                                     above standards.

                                     None.
                                     Discharge into adjacent San
                                     Hlguel River.
RIFLEt_CO
RFO - alluviua, 9 ac x 30 feet
RFN - alluvium, 4OO ac x 30 feet
RFN - Haaatch F*., 150 ac x 50 ft.

RFO - alluvium S04-10x; TDS-10x{
U  (2.08 mg/L)
RFN - alluvium N03-19x; S04-100x
TDS-BOx; U(1.3mg/L); Ho(12.0*g/L
NH4(6100 mg/L)
RFN - Hasatch 304-104x5 NO3-2x;
TDS-7Bxt NH4(290O mg/L); U(0.76
Ho(5 mg/L)

High cone, of S04, Hn, Fe,
NH4, Cl, TDS. Unsuitable for
drinking water.

Wasatch aquifer not used.
Alluvial sq. used for livestock
and irrigation.  City uses
Colorado River water.

Natural seepage to river adjacent
to both sites. Return to backgrn
in a minimum of 2yrs for RFO and
45yrs for alluvium at RFN.
          FEASIBILITY OF INSTITUTIONAL
          CONTROLS

          ALTERNATE DISPOSAL SITE
DEPTH TO HATER TABLE AT
ALTERNATE DISPOSAL SITE

HATER QUALITY AT ALTERNATE SITE

EXPECTED IMPACT ON HATER
QUALITY AT ALTERNATE SITE

NAME OF NEAREST CITY, DISTANCE
FROM TAILINGS PILE
                                     State of Colorado requires well
                                     permits for domestic wells.

                                     Not evaluated.
N/A


N/A

N/A


Naturita, Colorado - 2 miles.
State of Colorado requires well
permits for domestic wells.

Estes Gulch, ground water not
used in a 2 mi. radius of site.

> 280 feet through Wasatch.
                                                                                  Unknown.

                                                                                  None. 800 yr travel time to
                                                                                  first possible ground water.

                                                                                  Rifle, Colorado - Tailings

-------
                                          TABLE 3-6. GROUND WATER MATRIX  (confd)
         SITE_GROUND-WATER_CHARACTER1STICS
         ARiAL  AND~VERT?CAL EXTENT
         OF  GROUND-MATER CONTAMINATION
         NATURE  AND DEGREE OF
         CONTAMINATION RELATIVE TO
         DRINKING  WATER STANDARDS
         NATURAL GROUND-WATER QUALITY

         EXISTING USE OF GROUND WATER

         FATE OF THE PLUME(S)
                                     From site to the Little  Wind
                                     riverCapprox.1/2 mile) through
                                     the alluvium & unconfined  SS
                                     (approx. 20 ft thick).
                                     Volume approx. 1 billion gal.

                                     Key contaminants w/  exceedence
                                     of stds are Fe,Hn,S04,Cl,and  a
                                     feu samples of exceedences for
                                     radium and selenium.  U as  high
                                     as 2 mg/L, & Mo max  is 4 mg/L.

                                     Brackish in alluvium.

                                     Minor stock watering.

                                     Discharge to Little  Wind River.
                                   From site possibly  to  the  Jordan
                                   River and Hill Creek  in the
                                   unconfined aquifer  to  depth of
                                   approx. 3O to 4O  feet.
                                   Volume approx. 1.5  billion gal.

                                   Key contaminants  are:   As, Cl,
                                   Fe, W04, TDS, and Gross Alpha.
                                   None in unconfined system.

                                   Discharge tot  he  Jordan River
                                   and Mill Creek.
CO
I
FEASIBILITY OF INSTITUTIONAL
CONTROLS
         ALTERNATE  DISPOSAL SITE
         DEPTH TO WATER TABLE AT
         ALTERNATE DISPOSAL SITE

         WATER QUALITY AT  ALTERNATE SITE

         EXPECTED IMPACT ON WATER
         QUALITY  AT ALTERNATE SITE

         NAME OF  NEAREST CITY, DISTANCE
         FROM TAILINGS PILE
High feasibility because limited
use or potential use of alluvial
ground water.
                                     American  Nuclear  Corporation in,
                                     Gas  Hills.

                                     Unknown.
                                     Unknown.

                                     Unknown.


                                     Riverton,  WY  -  3 miles.
High feasibility  due  to  lack  of
existing & potential  use and
availability of public water
supply.

dive, Utah.
                                   Approximately  3O to 40 feet.


                                   Brackish.

                                   None on potential water resource.


                                   South Salt Lake  - in town.

-------
                                            TABLE 3-6.  GROUND HATER MATRIX (confd)
              _             CHARACTERISTICS
          AREAL AND vlRTICAL EXTENT
          OF GROUND-WATER CONTAHINATION
          NATURE AND DEGREE OF
          CONTAHINATION RELATIVE TO
          DRINKING WATER STANDARDS
          NATURAL GROUND-WATER QUALITY.
          EXISTING  USE OF  GROUND WATER
          FATE  OF THE PLUHE(S)
 SHIPROCKi_ NH
oo

N3
C3
 Beneath  site & below aite in
 floodplain  alluvium.  Depth is 10
 to  30 ft, to top of competent
 Hancoa Shale.  Floodplain vol.
 Onsite approx.  850 Billion gal.

 Significant exceedences of stds
 for Cl,Cr,Hn,N03,Se,S04,and TDS,
 UC3.5 Bg/L).
On escarpnent,  poor  to  non-
existent; on  floodplain,  slight
exceedence of SO4  &  TDS stds.

Some doaestic use  and potential
Municipal use of floodplain
ground water  and San Juan River
water.

Appears to be relatively  stag-
nant but eventually  should dis-
charge to the San  Juan  River.
 NC  Site  - 23 acres x 2O feet.
  30 Billion gallons.
 UC  Site  - 17 acres x 20 feet.
  23 Billion gallons.
NC site*  Fe-9x,Hn-9x,S04-5x,
  TDS-5x,U(2.5ng/L)
UC site:  N03-34x,Cl-l.lx,Fe-8x,
  Hn-5Ix,S04-7x,TDS-Bx,
  UC0.09  Bg/L).

Alluviua  - high cone, of Hn,  S04
TDS. Not  drinking water quality.
Navajo Ss. - drinking water qual.

No use of alluvial ground water.
Navajo aquifer supplies all
needs.
Discharge into adjacent Dolores
River.
         FEASIBILITY OF  INSTITUTIONAL
         CONTROLS
         ALTERNATE DISPOSAL SITE

         DEPTH TO WATER TABLE AT
         ALTERNATE DISPOSAL SITE

         WATER QUALITY AT ALTERNATE SITE
         EXPECTED IHPACT ON WATER
         QUALITY AT ALTERNATE SITE

         NAHE OF NEAREST CITY/DISTANCE
         FROH TAILINGS PILE
Could be fenced, plus the
Navajo Tribe has a well permit
requirement.

N/A

N/A
N/A
N/A
Shiprock, NH - in town.
State of Colorado requires well
permits for domestic wells.
Disappointment Valley.

approx. 40 feet below land
surface in Mancos Shale.

High TDS reported. Unsuitable
for drinking water.

Not evaluated.
Naturita, CO - approx 46 Biles.

-------
                                          TABLE  3-6. GROUND  HATER MATRIX (cont'd)
         SI TE_GROU NDrHATER_CHARACTER ISTICS     SPOOK JL_HY
         AREAL~AND VERTICAL~EXTENT  "           To  be  determined  in  1987.
         OF  GROUND-WATER  CONTAMINATION
         NATURE AND DEGREE  OF
         CONTAMINATION RELATIVE  TO
         DRINKING HATER STANDARDS

         NATURAL GROUND-HATER  QUALITY
         EXISTING USE OF GROUND HATER
         FATE OF THE PLUHE(S)
                                              To  be  determined in 1987.
Drinking uater quality.
Domestic, agricultural, and
livestock use.
                                              To be determined in 1987.
                                   TUBA_CITYi_AZ
                                   110 acres x  110  feet  of the
                                   Navajo Sandstone.
                                   Approx.  1.2  billion gallons.

                                   NO3-34x$ S04-9x;  U-O.45 mg/L;
                                   Fe-2x; Mn-13x; TDS-12x.
Drinking uater quality.
TDS < 5OO mg/L.

Municipal uell field  for Tuba
City is 5 mi. from site. One
domestic uell is  1.5  mi. cross-
gradient.

Discharge to Hoenkopi  Hash
10,000 feet from  leading edgee
of plume.  First  arrival of
plume at Hash in  100  years.
GO
I
to
vD
         FEASIBILITY OF INSTITUTIONAL
         CONTROLS

         ALTERNATE DISPOSAL SITE

         DEPTH TO HATER TABLE AT
         ALTERNATE DISPOSAL SITE

         WATER QUALITY AT ALTERNATE SITE

         EXPECTED IMPACT ON HATER
         QUALITY AT ALTERNATE SITE

         NAME OF NEAREST CITY,  DISTANCE
         FROM TAILINGS PILE
State of Wyoming.


None.

N/A


N/A

N/A
Navajo Tribe approves/records
all uells.    i

None.               •

N/A


N/A

N/A
Douglas, HY - approx. 45  miles.     Tuba City,  AZ - approx. 5 miles.

-------
                                  REFERENCES
1. Fordป Bacon & Davis Utah, Inc.  April  1981.
   Inactive Uranium Mill  Tailings - Vitro Site,
                                                  Engineering Assessment of
     	            	. Salt Lake City  Utah.
     DOE/UMT-0102, prepared for the U.S. Department of Energy by Ford, Bacon &
     Davis Utah, Inc., Salt Lake City, Utah.

  2. Ford, Bacon & Davis Utah, Inc.  June 1981.  Engineering Assessment of
     Inactive Uranium Mill Tailings - Durango Site, Durango, Colorado^
     DOE/UMT-0103, prepared for the U.S. Department of Energy by Ford, Bacon &
     Davis Utah, Inc., Salt Lake City, Utah.

  3. Ford, Bacon & Davis Utah, Inc.  July 1981.  Engineering Assessment of
     Inactive Uranium Mill  Tailings - Grand Junction Site, Grand Junction
     Colorado.DOE/UMT-0105,  prepared for the U.S.  Department of Energy by
     Ford, Bacon & Davis  Utah, Inc., Salt Lake City, Utah.

  4. Ford, Bacon &  Davis  Utah, Inc.  July 1981.   Engineering Assessment of
     Inactive Uranium Mill  Tailings -  Naturita Site, Naturita, CoToFadoT—
     DOE/UMT-0112,  prepared for the U.S.  Department  of Energy  by FordT~Bacon &
     Davis Utah, Inc.,  Salt Lake  City,  Utah.

  5. Ford, Bacon &  Davis  Utah, Inc.  July 1981.   Engineering Assessment of
     Inactive Uranium Mill  Tailings -  Shiprock Site, Shiprock,  New Mexico.
     DOE/UMT-0104,  prepared for the U.S.  Department  of Energy  by ford,  Bacon &
     Davis Utah, Inc.,  Salt Lake  City,  Utah.

  6. Ford, Bacon &  Davis  Utah, Inc. August  1981.  Engineering  Assessment  of
     Inactive Uranium Mill  Tailings -New and  Old RTfTe Sites,  Rifle	
     Colorado.DOE/UMT-0108,  prepared  for the U.S.  Department  of Energy  by
     Ford,  Bacon  &  Davis  Utah,  Inc., Salt Lake City, Utah.

  7.  Ford,  Bacon &  Davis  Utah,  Inc.  August 1981.  Engineering  Assessment  of
     Inactive  Uranium Mill  Tailings - Riverton Site, Riverton, Wyoming.	
     DOE/UMT-0106,  prepared for the U.S.  Department of Energy by FordT  Bacon &
     Davis  Utah,  Inc., Salt Lake City, Utah.

 8.  Ford, Bacon &  Davis  Utah,  Inc.  September 1981.  Engineering Assessment of
     Inactive  Uranium Mill  Tailings - Gunnison Site, Gunnison, ColoraaoT	
     DOE/UMT-0107,  prepared for the U.S.  Department of Energy by FordT~Bacon &
    Davis  Utah, Inc., Salt Lake City, Utah.

 9. Ford, Bacon & Davis Utah, Inc.  September 1981.   Engineering Assessment of
    Inactive Uranium Mill Tailings - Lowman Site, Lowman, Idaho.DOE/UMT-	
    0118, prepared for the U.S. Department of Energy by Ford, Bacon & Davis
    Utah, Inc., Salt Lake City, Utah.

10. Ford, Bacon & Davis Utah,  Inc.  September 1981.   Engineering Assessment of
    Inactive Uranium Mill Tailings - Maybell  Site.  Maybe11 , Colorado!	
    DOE/UMT-0116, prepared for the U.S. Department  of Energy by Ford", Bacon &
    Davis Utah,. Inc., Salt Lake City,  Utah.
                                3-30

-------
11. Ford, Bacon & Davis Utah, Inc.  September 1981.  Engineering Assessment of
    Inactive Uranium Mill  Tailings - Mexican Hat Site, Mexican Hat, Utah.
 17,
    DOE/ UMT-0109, prepared for the U.S. Department oT
    Davis Utah, Inc., Salt Lake City, Utah.
                                                   Energy  by  Ford,  Bacon  &
12  Ford, Bacon & Davis Utah, Inc.  September 1981.  Engineering Assessment of
    Inactive Uranium Mill  Tailings - Slick Rock Sites, Slick Rock, Colorado.
    DOE/UMT-0115, prepared for the U.S. Department of Energy By Ford, Bacon &
    Davis Utah, Inc., Salt Lake City, Utah.

13  Ford  Bacon & Davis Utah, Inc.  September 1981.  Engineering Assessment of
    Inactive Uranium Mill  Tailings - Tuba City Site, Tuba City, Arizona.
    1I1QL.V.IVC \J* dill Win iii i '   ivป ' ' ' *' j *"    •	-" ~  **      •*_         •"
    DOE/UMT-0120, prepared for the U.S. Department of Energy by For
    Davis Utah, Inc., Salt Lake City, Utah.
                                                               d,  Bacon &
14  Ford  Bacon & Davis Utah, Inc.  October 1981.  Engineering Assessment of
    Inactive Uraniucn Mill Tailings - Falls City Site, Falls City, Texas.
    DOE/UMT-0111, prepared for the U.S. Department of
    Davis Utah,  Inc., Salt Lake City, Utah.
                                                  Energy by Ford, Bacon &
15  Ford  Bacon & Davis  Utah,  Inc.  October  1981.   Engineering  Assessment of
    Inactive Uranium Mill Tailings - Lakeview  Site, Lakeview, Oregon.
    DOE/UMT-0110, prepared  for the U.S.  Department  of  Energy by Ford,  Bacon
    Davis Utah, Inc., Salt  Lake  City,  Utah.

16  Ford, Bacon & Davis  Utah,  Inc.  October  1981.   Engineering  Assessment of
    Inactive Uranium Mill Tailings - Monument  Valley Site.  Monument  Valley,
                	—---  "-=  =	^  -f Energy by
r u i u $ u a *-• w 11 IA L/WVIปJ w w ซซ> 9 .•. i. v •  >*•	—  — --  -  	-*•-       —-
Inactive Uranium Mill  Tailings - Monument Valley Site. Mon
Arizona.DOE/UMT-0117, prepared for the U.S. Department o
Ford, Bacon & Davis Utah, Inc., Salt Lake City, Utah.

Ford  Bacon & Davis Utah, Inc.  October 1981.  Engineering Assessment of
Inactive Uranium Mill  Tailings - Philips/United Nuclear Site, Ambrosia
    EakeT New  Mexico.   DOE/UMT-0113.  prepared  for  the  U.S.  Department  01
    Energy by  Ford,  Bacon  &  Davis  Utah,  Inc.,  Salt Lake  City,  Utah.

 18  Ford   Bacon &  Davis Utah,  Inc. October 1981.   Engineering Assessment of
    Inactive Uranium Mill  Tailings -  Spook  Site, Converse County,  Wyoming.
    DOE/UMT-0119,  prepared for the U.S.  Department of  Energy by Ford,  Bacon &
    Davis  Utah,  Inc.,  Salt Lake City, Utah.
 19.  Ford,  Bacon & Davis Utah, Inc.
     Inactive Uranium Mill  Tailings
                                the
                                November 1981.  Engineering  Assessment of
                               - Bel field  Site, Bel field
DOE/UMT-0122, prepared
Davis  Utah, Inc., Salt
for the U.S. Department
Lake City, Utah.
	South
 of  Energy  by  Ford,
                                         Dakota.
                                           Bacon &
 20. Ford, Bacon & Davis Utah, Inc.
     Inactive Uranium Mill  Tailings^
                                 November  1981
                               - Bowman  Site,
                      .  Engineering
                       Bowman, South
                                                                 Assessment of
     DOE/UMT-0121, prepared
     Davis Utah, Inc., Salt
                        for the  U.S.  Department  of
                        Lake  City,  Utah.
    	Dakota.
    Energy by Ford,  Bacon
                                    3-31

-------
21. Douglas,  Richard L.,  and Joseph M. Hans, Jr.  August  1975.   Gamma
    ladiation_Survexs_at_^nactive_Uranium_Miii_Sites.   ORP/LV-75-5,
    prepared  for  the U.S.  Environmental Protection  Agency,  Office of
    Radiation Programs - Las Vegas Facility, Las Vegas, Nevada.

22. Young,  J.K.,  L.W.  Long and J.W. Reis.  April 1982.  Environmental
    Factors_Affecting_Long-Term_Stabil.izatio
    Covers_f or_Uranium_Mill._Taiiings.  NUREG/CR-2564,  prepared  for the
    U.S. Nuclear  Regulatory Commission by Pacific Northwest Laboratory,
    Richland,  Washington.

23. Pacific Northwest  Laboratory.   January 1984.  Estimated_Pop_ul.ation
    MlSE-Uranium_Tailings.   PNL-4959/UC-70, prepared for  the U.S.
    Environmental  Protection Agency by Pacific Northwest  Laboratory,
    Richland,  Washington.

24. U.S. EPA.  October 1982.   Finai_Environmental._Imp_act_Statement_f or
    SฃSง.di.ai._Action_Standards_f or_inactive_Uranium_Prgcess_ing_Sites
    11Q.CFR1.92)..   EPA-520/4/82/013-1 ,  Office of Radiation  Programs,  EPA,
    Washington, D.C.

25. U.S. DOE.  January 7,  1987.   Uranium_Mil.i_Taiiinฃs_Remedial._Action
    Pr o j.ect_Ground_Water_Matr i x.
                                  3-32

-------
                            CHAPTER 4

   COMPILATION  AND  ANALYSIS OF  GROUNDWATER DATA FOR 14 SITES

4.1  INTRODUCTION

Groundwater quality data for 14 Uranium Mill Tailings  Remedial
Action .(UMTRA) Project sites are analyzed  in this  chapter.   The
14 UMTRA sites are:

                    Ambrosia Lake,  New Mexico
                    Canonsburg, Pennsylvania
                    Durango, Colorado
                    Grand  Junction,  Colorado
                    Green  River, Utah
                    Gunnison, Colorado
                    Lakeview, Oregon
                    Mexican Hat, Utah
                    Monument Valley, Arizona
                    Rifle,  Colorado
                    Riverton, Wyoming
                    Salt Lake City,  Utah
                    Shiprock, New  Mexico
                    Tuba City,  Arizona

This  task  analyzes  the groundwater quality data collected from
wells  on the  sites  and from wells  surrounding  the sites.  These
data  have  been  compared to the  standards  given or referenced in
Table  A  of 40 CFR 192.32(a),  which are  as follows:
      Constituent
      Arsenic
      Barium
      Cadmium
      Chromium
      Gross Alpha Particle
      Activity (including radium-226
               but excluding radon
        uranium)

      Lead
      Mercury
      Combined radium-226
        and radium-228
      Selenium
      Silver
Maximum Concentration
     0.5  mg/1
     1.0  mg/1
     •0.01 mg/1
     0.05 mg/1
     15.0 pCi/1
     0.05 mg/1
     0.002 mg/1
     5.0 pCi/1

     0.01 mg/1
     0.05 mg/1
 These comparisons are in Table 1 for each  of  the  14  sites.
                                4-1

-------
 In addition to the constituents listed above, six pesticides
 were also referenced in 40 CFR 192.32 (a).   No water quality
 comparisons were performed for endrin, lindane,
 methoxychlor,  toxaphene,  2,4-D, or 2,4,5,  TP.  Water samples
 from the    sites were rarely analyzed for these pesticides.
 These pesticides were undetected in the occasional samples
 that were analyzed.

 Three additional water quality comparisons  beyond those  in
 Table A of 40  CFR 192.32(a),  but related to leachate from
 uranium mill tailings, are:
      Constituent
      Molybdenum
      Uranium
      Nitrate (nitrogen)
Maximum Concentration
     0.10 mg/1
     30 pCi/1 (0.044 mg/1)
     10 mg/1
These^comparison  are  in  Table  2  for  each  of  the     sites.
Also in Table  2 are comparisons  to EPA primary and  secondary
drinking water standards not contained in Table  1.
A summary of the  water quality data  has been prepared for
each site.  The tabular  data are presented after each site
summary.  The  site summaries discuss the  key contaminantis
and their significance of occurrence within  the  context of
the site hydrogeologic setting and local  groundwater use.

The fate of the contaminant plume was modeled at 9  of the
sites.  The results indicate natural reduction of the mobile
contaminants (nitrates,  chlorides, sulfates, and total
dissolved solids) to  standards or background levels in 100
years or less  at  6 of the 9 sites modeled.   The  longest
period indicated was  for the Mexican Hat  site where over 500
years will be  required for natural flushing  of the mobile
contaminants.  Purging of the  attenuated  contaminants
(uranium, molybdenum, and other metals) typically takes 2 to
3 times as long and only at one  site are  levels  predicted to
reach standards or background  levels within  100  years.  At 6
of the sites it appears  that purging' of these may be accom-
plished within 300 years.
                              4-2

-------
4.2  AMBROSIA LAKE, NEW MEXICO - SUMMARY  OF WATER QUALITY

The saturated formations at the Ambrosia Lake site include
the alluvium, Tres Hermanos Sandstones, Dakota Sandstone and
Westwater Canyon Sandstone.  Prior to mining and milling
activities, it appears that the alluvium and Tres Hermanos-C
Sandstone were unsaturated.  Their current saturation is
believed to be a result of mine water discharges and perco-
lation from tailings slurry water.

The alluvium and Tres Hermanos Sandstone are not currently
used as a water supply source.  The Westwater Canyon Sand-
stone is presently a major water supply formation.  Contami-
nated water in the Tres Hermanos-C Sandstone may eventually
flow into the Westwater Canyon Sandstone via the Ann Lee
Mine shaft or other mine shafts or vents.

Groundwater quality data were analyzed for the alluvium,
Tres Hermanos Cl and C2 Sandstone and from beneath saturated
uranium mill tailings present on the site.  The alluvium
data include background, upgradient, cross-gradient, on-site
and down gradient samples.  The Tres Hermanos-Cl Sandstone
data are from only down gradient samples.  The Tres
Hermanos-C2 Sandstone data are from cross-gradient and down
gradient samples.

Levels for arsenic, cadmium, chromium, gross alpha, radium,
selenium, and silver exceeded the standards in some samples.
Chromium concentrations were higher in on-site and down
gradient samples in the tailings, alluvium and Tres Hermanos
Sandstones than in background or cross-gradient samples.
Twenty four out of 68 analyses for selenium exceeded the
limits for the standard; concentrations are highest in the
background and upgradient alluvium.  Radium concentrations
from samples in the on-site tailings and alluvium were
substantially higher than in background, upgradient,
cross-gradient or down gradient samples.  The one upgradient
sample analyzed for gross alpha exceeded the standard by
more than a factor of 15.

The contaminated water in the alluvium and Tres Hermanos
Formation is draining into mine shafts and vents, mixing
with groundwater in the Westwater Canyon Sandstone.  Model-
ing indicates that contaminants are dispersed in the
Westwater Canyon Sandstone within 400 feet of the mixing
zone and that drainage and dilution of the contaminated
water will be completed in about 100 years.
                              4-3

-------
TABLE 4-1
Site Name:  Ambrosia Lake (New Mexico)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards from 40 CFR 192.32(a)
Data Interval:  06/25/80 to 01/09/87
                                                                                                         Page 1 of 6


Constituent
Arsenic













Standard Hydraulic Flow
(mg/1) I/ Relationship
0.05 Background
Upgradient
Cross-gradient
Cross-gradient

On-Site
On-Site

Down gradient
Down gradient

Down gradient


Formation of
Completion
Alluvium
Alluvium
Alluvium
Tres Hermanos-
C 2 Sandstone
Alluvium
Uranium Mill
Tailings
Alluvium
Tres Hermanos-
C 1 Sandstone
Tres Hermanos-
C 2 Sandstone

Number of
Analyses
8
4
2
2

18
12

3
12

7

Number of
Analyses Percent
Exceeding Exceeding
Standard Standard
1 12
___ 	
	 	
— 	

1 5
___ — _

	 	
___ 	 	

	

Maximum
Value
Obtained
(mg/1) I/
0.18
	
	
	

0.33
	

	
— -— -

	

Barium
                     1 . 0
Background
Upgradient
Cross-gradient
Cross-gradient

On-Site
On-Site

Down gradient
Down gradient

Down gradient
Alluvium            1
Alluvium            2
Alluvium            1
Tres Hermanos-      1
C 2 Sandstone
Alluvium            7
Uranium Mill       10
Tailings
Alluvium            2
Tres Hermanos-      8
C 1 Sandstone
Tres Hermanos-      3
C 2 Sandstone
                                                              4-4

-------
TABLE 4-1
Site Name:  Ambrosia Lake (New Mexico)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards from 40 CFR 192.32(a)
Data Interval:  06/25/80 to 01/09/87
Page 2 of 6
Standard Hydraulic Flow
Constituent (mg/1) I/ Relationship
Cadmium 0.01 Background
Upgradient
Cross-gradient
Cross-gradient

On-Site
On-Site

Down gradient
Down gradient

Down gradient

Chromium 0.05 Background
Upgradient
Cross-gradient
Cross-gradient

On-Site
On-Site

Down gradient
Down gradient

Down gradient

•Formation of Number of
Completion Analyses
Alluvium
Alluvium
Alluvium
Tres Hermanos-
C 2 Sandstone
Alluvium
Uranium Mill
Tailings
Alluvium
Tres Hermanos-
C 1 Sandstone
Tres Hermanos-
C 2 Sandstone
Alluvium
Alluvium
Alluvium
Tres Hermanos-
C 2 Sandstone
Alluvium
Uranium Mill
Tailings
Alluvium
Tres Hermanos-
C 1 Sandstone
Tres Hermanos-
C 2 Sandstone
7
4
1
2

16
12

3
12

7

7
4
1
2

16
12

3
12

7

Number of
Analyses
Exceeding
Standard
E

i
—

—
—

—

___
—
—
—

2
1

1
1

2

Percent
Exceeding
Standard
E

6
— _

	
—

	

___
	
	
	

12
8

33
8

28

Maximum
Value
Obtained
(mg/1) I/
	

0.10
___

— -
— — —

	

	
	 	
—
— — —

0.20
0.10

0.17
0.21

0.11

                                                               4-5

-------
TABLE 4-1
Site Name:  Aabrosia Lake (Hew Mexico)
Data Evaluation:  Site Water Quality Coapared to U.S. EPA Standards from 40 CFR 192.32(a)
Data Interval:  06/25/80 to 01/09/87
Page 3 of 6
Standard Hydraulic Flow
Constituent (mg/1) I/ Relationship
Gross Alpha 15.0 pCi/1 Background
(excluding radon Upgradient
and uranium) Cross-gradient
Cross-gradient

On-Site
On-Site

Down gradient
Down gradient

Down gradient

Lead 0 . 05 Background
Upgradient
Cross-gradient
Cross-gradient

On-Site
On-Site

Down gradient
Down gradient

Down gradient

Formation of Ni
Completion A]
Alluvium
Alluvium
Alluvium
Tres Hermanos-
C 2 Sandstone
Alluvium
Uranium Mill
Tailings
Alluvium
Tres Hermanos-
C 1 Sandstone
Tres Hermanos-
C 2 Sandstone
Alluvium
Alluvium
Alluvium
Tres Hermanos-
•C 2 Sandstone
Alluvium
Uranium Mill
Tailings
Alluvium
Tres Hermanos-
C 1 Sandstone
Tres Hermanos-
C 2 Sandstone
amber of
nalyses
1
2 2/
1
1

1 3/
1

1
1 3/

1

1
2
1
1

7
10

2
8

3

Number of Maximum
Analyses Percent Value
Exceeding Exceeding Obtained
Standard Standard (mg/1) I/
- _.... _HW ....
1 100 251.72
	 	 	
	 	 	

3/3/3/


	 	 	
3/ 3/ 3/

	 	 	

— — — — ซซ ___
	 	 	
	 	 	
	 	 	

— ___ ___
	 — _ _ —

	 	 	
	 	 	

	 	 	

                                                               4-6

-------
TABLE 4-1
Site Name:  Ambrosia Lake (New Mexico)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards from 40 CFR 192.32(a)
Data Interval:  06/25/80 to 01/09/87
Page 4 of 6
Constituent
Mercury




Ra-226 +
Ra-228
(Radium)


Standard Hydraulic Flow
(mg/1) I/ Relationship
0.002 Background
Upgradient
Cross-gradient
Cross-gradient
On-Site
On-Site
Down gradient
Down gradient
Down gradient
5.0 pCi/1 Background
Upgradient
Cross-gradient
Cross-gradient
On-Site
On-Site
Down gradient
Down gradient
Down gradient
Number of Maximum
Analyses Percent Value
Formation of Number of Exceeding Exceeding Obtained
Completion Analyses Standard Standard (mg/1) I/
Alluvium
Alluvium
Alluvium
Tres Hermanos-
C 2 Sandstone
Alluvium
Uranium Mill
Tailings
Alluvium
Tres Hermanos-
C 1 Sandstone
Tres Hermanos-
C 2 Sandstone
Alluvium
Alluvium
Alluvium
Tres Hermanos-
C 2 Sandstone
Alluvium
Uranium Mill
Tailings
Alluvium
Tres Hermanos-
C 1 Sandstone
Tres Hermanos-
C 2 Sandstone
1 — — — — — — — —
2
6 	 	 	
9 	 	 	
— — — •ป" "-
8 	 	 	
3 	 	 	
1 	 	 	
4 4/ 	 	 	
1 	 	 	
2 4/
8 7 5/ 87 410
10 10 5/ 100 240
1 	 	 	
10 2 5/ 20 22.0
4 1 5/ 25 5.6
                                                               4-7

-------
TABLE 4-1
Site Name:  Ambrosia Lake (New Mexico)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards from 40 CFR 192.32(a)
Data Interval:  06/25/80 to 01/09/87
Page 5 of 6
Standard Hydraulic Flow
Constituent (mg/1) I/ Relationship
Selenium 0.01 Background
Upgradient
Cross-gradient
Cross-gradient

On-Site
On-Site

Down gradient
Down gradient

Down gradient

Silver 0.05 Background
Upgradient
Cross-gradient
Cross-gradient

On-Site
On-Site

Down gradient
Down gradient

Down gradient

Formation of Number of
Completion Analyses
Alluvium
Alluvium
Alluvium
Tres Hermanos-
C 2 Sandstone
Alluvium
Uranium Mill
Tailings
Alluvium
Tres Hermanos-
C 1 Sandstone
Tres Herraanos-
C 2 Sandstone
Alluvium
Alluvium
Alluvium
Tres Hermanos-
C 2 Sandstone
Alluvium
Uranium Mill
Tailings
Alluvium
Tres Hermanos-
C 1 Sandstone
Tres Hermanos-
C 2 Sandstone
8
4
2
2

18
12

3
12

7

1
2
1
1

7
10

2
8

3

Number of
Analyses
Exceeding
Standard
2
2
2
	

6
7

1
4

	

ซ__
	
	
	

1
— r—

	
	

	

Percent
Exceeding
Standard
25
50
100
	

33
58

33
33

	

___
	
	
	

14
	

	
	

	

Maximum
Value
Obtained
(mg/1) I/
0.95
0.53
0.033
	

0.147
0.019

0.127
0.225

	

___
	
	
	

0.15
___

	
	

	

                                                               4-8

-------
TABLE 4-1
Site Name:  Ambrosia Lake (New Mexico)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards from 40 CFR 192.32(a)
Data Interval:  06/25/80 to 01/09/87
                                                                                     Page 6 of 6
Constituent
Standard
(mg/1) I/
Hydraulic Flow
Relationship
Formation of
Completion
Number of
Analyses
Number of
Analyses
Exceeding
Standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/1) I/
I/    Values are reported in mg/1 unless otherwise indicated.
2/    Uranium data available for 1 of 2 samples.
3/    Uranium not analyzed.
4/    Analyses for Ra-226 only.
5/    Ra-226 values.  Ra-228 values were all less than the standard.
	   Standard not exceeded.
                                                                4-9

-------
TABLE 4-2                                                                                           Page 1 of 8
Site Name:   Ambrosia Lake (New Mexico)
Data Evaluation:  Site Water Quality Conpared to U.S.  EPA Standards Not Included  in 40 CFR 192.32{a)
                    plus Uranium and Molybdenum
Data Interval:  06/25/80 to 01/09/87
Standard Hydraulic Flow
Constituent (mg/1) I/ Relationship
Chloride 250 Background
Upgradient
Cross-gradient
Cross-gradient

On-Site
On-Site

Down gradient
Down gradient

Down gradient

Copper 1.0 Background
Upgradient
Cross-gradient
Cross-gradient

On-Site
On-Site

Down gradient
Down gradient

Down gradient

Formation of Number of
Completion Analyses
Alluvium
Alluvium
Alluvium
Tres Hermanos-
C2 Sandstone
Alluvium
Uranium Hill
Tailings
Alluvium
Tres Hermanos-
Cl Sandstone
Tres Hermanos-
C2 Sandstone
Alluvium
Alluvium
Alluvium
Tres Hermanos-
C2. Sandstone
Alluvium
Uranium Mill
Tailings
Alluvium
Tres Hermanos-
Cl Sandstone
Tres Hermanos-
C2 Sandstone
9
4
7-
2

19
11

4
13

8

1
2
1
1

7
10

2
8

3

Number of Maximum
Analyses Percent Value
Exceeding Exceeding obtained
Standard Standard (mg/1) I/
___ — — -
	 	 — -
— 	 - —
	 	 	

4 21 489
— _ — —

2 50 300
2 15 270

	 	 	

___ _ — —
	 	 	
	 	 	
	 ". 	 	

	 	 	
___ . ___ -~

	 	 	
— _ — _ 	

	 . 	 	

                                                              4-10

-------
TABLE 4-2
Site Name:  Ambrosia Lake (New Mexico)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards Not Included
                    plus Uranium and Molybdenum
Data Interval:  06/25/80 to 01/09/87
                  Page 2 of 8
in 40 CFR 192.32(a)
Standard Hydraulic Flow
Constituent (mg/1) I/ Relationship
Fluoride 1.4 Background
Upgradient
Cross-gradient
Cross-gradient

On-Site
On-Site

Down gradient
Down gradient

Down gradient

Hydrogen Sulfide 0.05 Background
Upgradient
Cross-gradient
Cross-gradient

On-Site
On-Site

Down gradient
Down gradient

Down gradient

Formation of Number of
Completion Analyses
Alluvium
Alluvium
Alluvium
Tres Hermanos-
C2 Sandstone
Alluvium
Uranium Mill
Tailings
Alluvium
Tres Hermanos-
Cl Sandstone
Tres Hermanos-
C2 Sandstone
Alluvium
Alluvium
Alluvium
Tres Hermanos-
C2 Sandstone
Alluvium
Uranium Mill
Tailings
Alluvium
Tres Hermanos-
Cl Sandstone
Tres Hermanos-
C2 Sandstone
7
4
1
2

12
11

3
12

7

1
1
1
1

1
1

1
1

1

Number of Maximum
Analyses Percent Value
Exceeding Exceeding Obtained
Standard Standard (mg/1) I/
... ... ...
3 75 2.2
... ... ...
	 _ — 	

2 16 15.0
10 90 21.0

1 33 2.2
6 50 2.1

... ... ...

... ... ...
... ... ...
... — _ ...
... ___ ...

... ... ...
... ... ...

... ... ...
_— _ — —

... ... ...

                                                             4-11

-------
TABLE 4-2
Site Name:  Ambrosia Lake  (Mew Mexico)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards Not Included
                    plus Uranium and Molybdenum
Data Interval:  06/25/80 to 01/09/87
                                                                                Pago 3 of 8
                                                              in 40 CFR 192.32(a)
"Constituent

Iron
Standard    Hydraulic Flow
(mg/1) I/   Relationship
Formation of
Completion
Number of
Analyses
                                                                               Number of
                                                                               Analyses
                                                                               Exceeding
                                                                               Standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/1) I/
Manganese
 0.30       Background
            Upgradient
            Cross-gradient
            Cross-gradient

            On-Site
            On-Site

            Down gradient
            Down gradient

            Down gradient
 0.05       Background
            Upgradient
            Cross-gradient
            Cross-gradient

            On-Site
            On-Site

            Down gradient
            Down gradient

            Down gradient
Alluvium             7
Alluvium             4
Alluvium             1
Tres Hermanos-       2
C2 Sandstone
Alluvium            15
Uranium Mill        11
Tailings
Alluvium             3
Tres Hermanos-      12
Cl Sandstone
Tres Hermanos-       7
C2 Sandstone

Alluvium             7
Alluvium             2
Alluvium             1
Tres Hermanos-       2
C2 Sandstone
Alluvium            15
Uranium Mill        11
Tailings
Alluvium             3
Tres Hermanos-      11
Cl Sandstone
Tres Hermanos-       7
C2 Sandstone
                    6
                    1
                                                                             14
                                                                                                 26
                                                                                                 27

                                                                                                 66
                                                                                                 42
     85
     50
                                                                                                 93
                                                                                                 66
                                                                                                 54

                                                                                                 85
                                             0.61





                                             5.49
                                             1.46

                                             4.13


                                            28.8
     0.17
     0.07
                                                                                                              0.68
                                             4.23
                                             0.13

                                             1.82
                                                              4-12

-------
TABLE 4-2
Site Name:  Ambrosia Lake  (New Mexico)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards Not Included
                    plus Uranium and Molybdenum
Data Interval:  06/25/80 to 01/09/87
                                                                                 Page  4  of 8
                                                              in 40 CFR  192.32(a)
Constituent

Molybdenum
Standard
(mg/1) l/
 Hydraulic Flow
 Relationship
 Formation  of
 Completion
Number of
Analyses
Number of
Analyses
Exceeding
Standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/1) I/
 0.10
Nitrate 2/
44
 Background
 Upgradient
 Cross-gradient
 Cross-gradient

 On-Site
 On-Site

 Down gradient
 Down gradient

 Down gradient
Background
Upgradient
Cross-gradient
Cross-gradient

On-Site
On-Site

Down' gradient
Down gradient

Down gradient
 Alluvium             8
 Alluvium             4
 Alluvium             2
 Tres Hermanos-        2
 C2  Sandstone
 Alluvium            18
 Uranium  Mill         12
 Tailings
 Alluvium             3
 Tres Hermanos-       12
 Cl  Sandstone
 Tres Hermanos-        7
 C2  Sandstone

 Alluvium             8
 Alluvium             4
 Alluvium             6
 Tres Hermanos-        2
 C2  Sandstone
 Alluvium             16
 Uranium Mill         ll
 Tailings
Alluvium              4
Tres Hermanos-       13
Cl Sandstone
Tres Hermanos-        8
C2 Sandstone
                                                                                     7
                                                                                     3
                                                                                     2
                                                                                     2

                                                                                    18
                                                                                    12

                                                                                     3
                                                                                    12
                                                                                     2
                                                                                     1
                                                                                     1
                                                                                     5

                                                                                     2
                                                                                     7
                                                                             88
                                                                             75
                                                                            100
                                                                            100

                                                                            100
                                                                            100

                                                                            100
                                                                            100

                                                                             86
                                                                             25
                                                                             25
                                                                              6
                                                                             45

                                                                             50
                                                                             53
                                             0.22
                                             1.87
                                             0.50
                                             0.17

                                           225
                                           250

                                             3.17
                                            10.3

                                             0.35
                                            49.0
                                            55.0
                                           150
                                          4900

                                           140
                                           400
                                                            4-13

-------
TABLE 4-2
Site Name:  Ambrosia Lake (New Mexico)
Data Evaluation:  Site Water Quality Compared to U.S.
                    plus Uranium and Molybdenum
Data Interval:  06/25/80 to 01/09/87
                                                                                                    Page 5 of 8
                                  EPA Standards Not Included  in 40 CFR 192.32(a)
Constituent

PH 3/
Standard    Hydraulic Flow
(mg/1)  I/   Relationship
                  Formation of   Number of
                  Completion     Analyses
                                                                               Number of
                                                                               Analyses
                                                                               Exceeding
                                                                               Standard
                                          Percent
                                          Exceeding
                                          Standard
                     Maximum
                     Value
                     Obtained
                     (mg/1)  I/
6.5 to 8.5  Background
            Upgradient
            Cross-gradient
            Cross-gradient

            On-Site
            On-Site

            Down gradient
            Down gradient

            Down gradient
Sulfate
 250
Background
Upgradient
Cross-gradient
Cross-gradient

On-Site
On-Site

Down gradient
Down gradient

Down gradient
Alluvium             9
Alluvium             4
Alluvium             7
Tres Hermanos-       2
C2 Sandstone
Alluvium            18
Uranium Mill        11
Tailings
Alluvium             4
Tres Hermanos-      13
Cl Sandstone
Tres Hermanos-       8
C2 Sandstone

Alluvium             9
Alluvium             4
Alluvium             7
Tres Hermanos-       2
C2 Sandstone
Alluvium            19
Uranium Mill        12
Tailings
Alluvium             4
Tres Hermanos-      13
Cl Sandstone
Tres Hermanos-       8
C2 Sandstone
                                                                                     3
                                                                                    10

                                                                                     1
                                                                                     3
 9
 4
 7
 2

19
12

 4
11
                                                                100

                                                                 16
                                                                 90

                                                                 25
                                                                 23

                                                                 12
100
100
100
100

100
100

100
 84

100
                         12.2

                          9.97
                         10.13

                         11.18
                         12.46

                         11.92
  4940
  2750
  2440
   633

10,300
11,000

  4440
  4010

  3970
                                                              4-14

-------
TABLE 4-2
Site Name:  Ambrosia  Lake  (New Mexico)
Data Evaluation:   Site Water Quality Compared to U.S. EPA Standards Not  Included
                    plus Uranium and Molybdenum
Data Interval:  06/25/80 to  01/09/87
                                                                                  Page 6 of 8
                                                                in 40  CFR 192.32(a)
Constituent

Sulfide
 Standard
 (mg/1) I/
Hydraulic Flow
Relationship
Formation of
Completion
Number of
Analyses
Number of
Analyses
Exceeding
Standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/1) I/
                     0.05
Total Solids
500
             Background
             Upgradient
             Cross-gradient
             Cross-gradient

             On-Site
             On-Site

             Down gradient
             Down gradient

             Down gradient
                                Background
                                Upgradient
                                Cross-gradient
                                Cross-gradient

                                On-Site
                                On-Site

                                Down gradient
                                Down gradient

                                Down gradient
                  Alluvium             l
                  Alluvium             l
                  Alluvium             l
                  Tres Hermanos-       1
                  C2 Sandstone
                  Alluvium             6
                  Uranium Mill         9
                  Tailings
                  Alluvium             2
                  Tres Hermanos-       7
                  Cl Sandstone
                  Tres Hermanos-       3
                  C2 Sandstone

                  Alluvium             8
                  Alluvium             4
                  Alluvium             2
                  Tres Hermanos-       2
                  C2 Sandstone
                  Alluvium            17
                  Uranium  Mill        10
                  Tailings
                  Alluvium             3
                  Tres Hermanos-       12
                  Cl Sandstone
                  Tres Hermanos-        7
                  C2  Sandstone
                                                                                      1
                                                                                      1

                                                                                      6
                                                                                      9

                                                                                      2
                                                                                      7
                                                                  8
                                                                  4
                                                                  2
                                                                  2

                                                                 17
                                                                 10

                                                                  3
                                                                 12
                                              100
                                              100

                                              100
                                              100

                                              100
                                              100

                                              100
                                              100
                                              100
                                              100
                                              100

                                              100
                                              100

                                              100
                                              100

                                              100
                                              0.10
                                              0.10

                                              0.10
                                              0.10

                                              0.10
                                              0.10

                                              0.10
                                          8080
                                          4400
                                          4060
                                          1880

                                        20,900
                                        25,800

                                          7250
                                          7190

                                          6490
                                                             4-15

-------
TABLE 4-2                                                                                           Pa9e 7 of 8
Site Kama:  Ambrosia Lake (New Mexico)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards Not Included  in 40 CFR 192.32(a)
                    plus Uranium and Molybdenum
Data Interval:  06/25/80 to 01/09/87
Constituent

Uranium 4/
Standard    Hydraulic Flow
(mg/1) I/   Relationship
                  Formation of
                  Completion
               Number of
               Analyses
                                                                               Number of
                                                                               Analyses
                                                                               Exceeding
                                                                               Standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/1) I/
0.044
Zinc
 5.0
Background
Upgradient
Cross-gradient
Cross-gradient

On-Site
On-Site

Down gradient
Down gradient

Down gradient
Background
Upgradient
Cross-gradient
Cross-gradient

On-Site
On-Site

Down gradient
Down gradient

Down gradient
Alluvium             8
Alluvium             3
Alluvium             2
Tres Hermanos-       2
C2 Sandstone
Alluvium            17
Uranium Mill        10
Tailings
Alluvium             3
Tres Hermanos-      11
Cl Sandstone
Tres Hermanos-       7
C2 Sandstone

Alluvium             1
Alluvium             1
Alluvium             1
Tres Hermanos-       1
C2 Sandstone
Alluvium             6
Uranium Mill         9
Tailings
Alluvium             2
Tres Hermanos-       7
Cl Sandstone
Tres Hermanos-       3
C2 Sandstone
                                                                                    17
                                                                                    10

                                                                                     2
                                                                                     8
     37
    100
    100
                                                                            100
                                                                            100

                                                                             66
                                                                             72

                                                                             29
     1.26
     3.31
     5.34
                 14.70
                 10.70

                  2.80
                 11.80

                  1.25
                                                              4-16

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TABLE 4-2                                                                                           page 8 of 8
Site Name:  Ambrosia Lake (New Mexico)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards Not Included  in 40 CFR 192.32(a)
                    plus Uranium and Molybdenum
Data Interval:  06/25/80 to 01/09/87
Constituent
Standard
(mg/1)  I/
Hydraulic Flow
Relationship
Formation of
Completion
Number of
Analyses
Number of
Analyses
Exceeding
Standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/1) I/
I/    Values are reported in mg/1 unless otherwise indicated.
2/    Concentrations of nitrate as nitrogen at a level of  10 mg/1  is equivalent to concentration of nitrate as nitrate at a
      level of 44 mg/1.  All analyses are reported in terms of  nitrate as nitrate.
3/    pH reported in standard units.
4/    30 pci/l of uranium is equivalent of 0.044 mg/1, assuming the  bulk of uranium is U-238.   All analyses are reported as
      total uranium in mg/1.
      Standard not exceeded.
                                                             4-17

-------
4.3  CANONSBURG, PENNSYLVANIA - SUMMARY OF WATER QUALITY

The collection of hydrogeological and groundwater quality
data for the Canonsburg site began in 1979.  However, due to
the potential for high levels of radioactive contamination,
the location of wells was restricted.  Also, aquifer pump
tests were prohibited due to the potential for withdrawing
radioactively contaminated groundwater.  In 1982, additional
drilling was conducted to further characterize the ground-
water regime.  The 1982 effort concluded that significant
data gaps still existed regarding the hydrogeological
information.

From December 1982 through March 1983, a third field effort
was undertaken to characterize the site hydrogeology.
During this effort, monitoring wells were constructed
on-site in the overburden and in the bedrock.  Off-site
monitoring wells were constructed south of the site.
Aquifer data from the unconsolidated material and the
bedrock were collected.  Surface water data from Chartiers
Creek were collected to determine the hydrological relation-
ship between the groundwater and Chartiers Creek.

The amount of groundwater quality data for the period 1979
to March 1983 is minimal.  The value of these data may be
limited with regards to site groundwater quality character-
ization.  This is primarily due to the early drilling
restrictions which applied to most of the site.  The data
that are available for this period of time show that several
constituents in the groundwater beneath the site, and in the
vicinity of the site, exceeded existing standards.  Some
on-site groundwater samples exceeded existing standards for
arsenic, chloride, iron, pH, selenium and sulfate.  Nitrate,
pH and selenium exceeded the existing standards in some
off-site groundwater samples.

Remedial action at the process site is complete.  The data
evaluated and presented in the following tables represent
post-closure groundwater quality data.  These data are from
two quarterly post-remedial sampling efforts conducted
between 08/05/86 and 11/06/86.  Presently, seven wells (four
on-site and three off-site) comprise the primary monitoring
network.

Two saturated zones are presently monitored.  These are the
unconsolidated  soils and shallow shale and limestone.

Recharge is from the east and discharge occurs to Chartiers
Creek to the north, west, and south.  Some groundwater may
flow beneath Chartiers Creek in the shallow shale/limestone.
Approximately 12 wells have been identified within a one-
mile radius on  the site.  Most of these wells have been
abandoned  , with the remaining wells receiving limited use,
primarily for watering gardens.

                              4-18

-------
Monitoring data from the site include upgradient, cross-
gradient and down gradient samples.  Background data are not
available.  Table 1 shows that none of the constituents
exceeded standards.  However, this must be evaluated in
terms of the data time interval  (six months) and that the
data are from post-closure monitoring.

Most of the groundwater from the contaminated alluvium
discharges to Chartier Creek within a few hundred feet of
the site; some may underflow the creek in shallow bedrock.
Modeling indicates that discharges of the mobile contami-
nants (NO3, Clf SO4, TDS) will be within standards within 60
years and discharges of the attenuated contaminants (U, Mo,
metals)  in excess of standards will continue for two to
three times as long.
                              4-19

-------
TABLE 4-3
Site Name:  Canonsburg (Pennsylvania)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards fron 40  CFR 192.32(a)
Data Interval:  08/05/86 to 11/06/86
Page 1 of 2
Constituent
Arsenic
Barium
Cadmium
Chromium
Gross Alpha
(excluding radon
and uranium)
Standard
(mg/1) I/
0.05
1.0
0.01
0.05
15.0 pCi/1
Hydraulic Flow
Relationship
Upgradient
Cross-gradient
On-Site
Upgradient
Cross-gradient
On-Site
Upgradient
Cross-gradient
On-Site
Upgradient
Cross-gradient
On-Site
Upgradient
Cross-gradient
On-Site
Formation of
Completion
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Number of
Analyses
5
2
8
5
2
8
5
2
8
5
2
8
1
1
1
Number of
Analyses
Exceeding
Standard
• •^
~ — ซ••
ซ••""
• HM
___
Percent
Exceeding
Standard
ซซ•ป
_ป
Mซซ
__.
__ซ
Maximum
Value
Obtained
(mg/1) I/
__~
	
:::
—
—
                                                             4-20

-------
TABLE 4-3
Site Name:  Canonsburg (Pennsylvania)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards from 40 CFR 192.32(a)
Data Interval:  08/05/86 to 11/06/86
Page 2 of 2
Constituent
Lead
Mercury
Ra-226 + Ra-228
(Radium)
Selenium
Silver
Standard Hydraulic Flow
(mg/1) I/ Relationship
0.05 Upgradient
Cross-gradient
On-Site
0.002 Upgradient
Cross-gradient
On-Site
5.0 pCi/1 Upgradient
Cross-gradient
On-Site
0 . 01 Upgradient
Cross-gradient
On-Site
0.05 Upgradient
Cross-gradient
On-Site
Formation of
Completion
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Number of
Analyses
5
2
8
5
2
8
4
2
8
5
2
8
5
2
8
Number of
Analyses
Exceeding
Standard
	
___
	
	
	
Maximum
Percent Value
Exceeding Obtained
Standard (mg/1) I/
— — — — — —
	 	
••ป__ • III •!
— — — — — —
	 	
I/    Values are reported in mg/1 unless otherwise indicated.
      Standard not exceeded.
                                                               4-21

-------
TABLE 4-4                                                                                          Page 1 of 4
Sitฉ Kama:  Canonaburg (Pennsylvania)
Data Evaluation:  Site Water Quality Compared to U.S.  EPA Standards Not Included  in 40 CFR 192.32(a)
                    plus Uranium and Molybdenum
Data Interval:  08/05/86 to 11/06/86
Constituent
Chloride
Copper
Fluoride
Hydrogen Sulfide
Standard
(mg/1) I/
250
1.0
1.4
0.05
Hydraulic Flow
Relationship
Upgradient
Cross-gradient
On-Site
Upgradient
Cross-gradient
On-Site
Upgradient
Cross-gradient
On-Site
Upgradient
Cross-gradient
On-Site
Formation of
Completion
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Number of
Analyses
5
2
8
5
2
8
5
2
8
1
1
1
Number of
Analyses
Exceeding
Standard
••_—
••ซซ
— — —
—
Percent
Exceeding
Standard
•••ปซ•
	
—
— -
Maximum
Value
Obtained
(mg/1) I/
••••
ซ•_
ซH
— " —
                                                                 4-22 i

-------
TABLE 4-4
Site Name:  Canonsburg (Pennsylvania)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards Not Included
                    plus Uranium and Molybdenum
Data Interval:  08/05/86 to 11/06/86
                  Page 2 of 4
in 40 CFR 192.32(a)
Constituent
Iron
Manganese
Molybdenum
Nitrate 2/
Standard
(mg/1) I/
0.30
0.05
0.10
44
Hydraulic Flow
Relationship
Upgradient
Cross-gradient
On-Site
Upgradient
Cross-gradient
On-Site
Upgradient
Cross-gradient
On-Site
Upgradient
Cross-gradient
On-Site
Formation of
Completion
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Number of
Analyses
5
2
8
5
2
8
5
2
8
5
2
8
Number of
Analyses
Exceeding
Standard
4
2
2
5
2
8
5
2
8
	
Percent
Exceeding
Standard
80
100
25
100
100
100
100
100
100
—
Maximum
Value
Obtained
(mg/1) I/
14.5
1.42
14.7
3.32
11.5
9.41
0.27
0.18
0.20
___
                                                             4-23

-------
I
           TABLE 4-4
           Site Name:  Canonsburg  (Pennsylvania)
           Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards Not Included  in 40 CFR 192. 32 (a)
                               plus Uranium and Molybdenum
           Data Interval:  08/05/86 to 11/06/86
                                                                                                                    3 Of 4
            Constituent

            PH 3/
 Standard    Hydraulic Flow
 (mg/1)  I/   Relationship
                  Formation of   Number of
                  Completion     Analyses
                                                                                          Number of
                                                                                          Analyses
                                                                                          Exceeding
                                                                                          Standard
                                          Percent
                                          Exceeding
                                          Standard
                                  Maximum
                                  Value
                                  Obtained
                                   (mg/1) I/
            Sulfate
            Sulfide
            Total Solids
 6.5 to 8.5
  250
  0.05
500
Upgradient
Cross-gradient
On-Site

Upgradient
Cross-gradient
On-Site

Upgradient
Cross-gradient
On-Site

Upgradient
Cross-gradient
On-Site
Alluvium
Alluvium
Alluvium

Alluvium
Alluvium
Alluvium

Alluvium
Alluvium
Alluvium

Alluvium
Alluvium
Alluvium
 5
 2
 8

 5
 2
 8

 4
 2
 8

•5
 2
 8
3

6
 60

 75




100

100
100
100

 40

100
5.60

6.34
                                                                                                                       626
                         0.10
                         0.10
                         0.10
                       802

                      1310
                                                                         4-24

-------
TABLE 4-4
Site Name:  Canonsburg (Pennsylvania)
Data Evaluation:  Site Water Quality compared to U.S. EPA Standards Not Included
                    plus Uranium and Molybdenum
Data interval:  08/05/86 to 11/06/86
                  Page 4 of 4
in 40 CFR 192.32(a)
Constituent
Uranium 4/
Zinc
Standard
(mg/1) I/
0.044
5.0
Hydraulic Flow
Relationship
Upgradient
Cross-gradient
On-Site
Upgradient
Cross-gradient
On-Site
Formation of
Completion
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Number of
Analyses
5
2
8
5
2
8
Number of
Analyses
Exceeding
Standard
2
2
	
Percent
Exceeding
Standard
100
25
•
Maximum
Value
Obtained
(mg/1) I/
0.0221
0.0492
___
I/    Values are reported in mg/1 unless otherwise indicated.
2/    Concentrations of nitrate as nitrogen at a level of 10 mg/1 is equivalent to concentration of nitrate as nitrate at a
      level of 44 mg/1.  All analyses are reported in terms of nitrate as nitrate.
3/    pH reported in standard units.
4/    30 pCi/1 of uranium is equivalent of 0.044 mg/1, assuming the bulk of uranium is U-238.  All analyses are reported as
      total uranium in mg/1.
—   Standard not exceeded.
                                                             4-25

-------
4.4  DURANGO, COLORADO - SUMMARY OF WATER QUALITY

The analysis of groundwater quality at the Durango site
involved upgradient and down gradient data.  No background
or preprocessing era data were available.  There are no
current groundwater users within two miles down gradient of
the site.

Levels of arsenic, chromium and selenium exceeded the
standards in some samples.  Selenium exceeded the standard
in one upgradient sample by a factor of 35 and in nearly 80
percent of the down gradient samples by factors as high as
190.  Arsenic and chromium exceeded the standards only in
the down gradient samples, arsenic by a factor of 16 and
chromium by a factor of two.

The contaminated groundwater discharges, to the Animas River
within 100 to 500 feet of the piles and ponds.  Modeling
indicates that the mobile contaminants will be flushed from
the alluvial aquifer in approximately 5 years and from the
Menefee Formation in 40 years.  Flushing of the attenuated
contaminants from the alluvial aquifer will take 15 years
and from the Menefee Formation about 40 years.
                              4-26

-------
TABLE 4-5
Site Name:  Durango (Colorado)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards from 40 CFR 192.32(a)
Data Interval:  09/01/82 to 11/13/85
                                                                                                         Page 1 of 5
Constituent

Arsenic
                    standard    Hydraulic Flow
                    (mg/1) I/   Relationship
                                                  Formation of
                                                  Completion
                                 Number of
                                 Analyses
                                                                               Number of
                                                                               Analyses
                                                                               Exceeding
                                                                               Standard
                                          Percent
                                          Exceeding
                                          Standard
Maximum
Value
Obtained
(mg/1) I/
                     0.05
Barium
                     1 . 0
Upgradient


Down gradient


Down gradient


Down gradient

Upgradient


Down gradient


Down gradient


Down gradient
Gravel or sandy     5
gravel, poorly
graded
Gravel or sandy    21
gravel, poorly
graded
Silty Sand or       6
Silty gravelly
sand
Shale              22

Gravel or sandy     1
gravel, poorly
graded
Gravel or sandy     5
gravel, poorly
graded
Silty Sand or       1
Silty gravelly
sand
Shale               5
                                                                                               28
                                                                                               16
                                                                                                             0.83


                                                                                                             0.10
                                                             4-27

-------
TABLE 4-5
Site Name:  Durango  (Colorado)
Data Evaluation:  site Water Quality Coapared to U.S. EPA Standards fron 40 CFR 192.32(a)
Data Interval:  09/01/82 to 11/13/85
                                                                                    Page 2 of 5
Constituent

Cadmium
                    Standard    Hydraulic Flow
                    (ng/1) I/   Relationship
                             Formation of
                             Completion
               Number of
               Analyses
          Number of
          Analyses
          Exceeding
          Standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/1) I/
Chromium
0.01       Upgradient


           Down gradient


           Down gradient


           Down gradient

0.05       Upgradient


           Down gradient


           Down gradient


           Down gradient
Gravel or sandy
gravel, poorly
graded
Gravel or sandy
gravel, poorly
graded
Silty Sand or
Silty gravelly
sand
Shale

Gravel or sandy
gravel, poorly
graded
Gravel or sandy
gravel, poorly
graded
Silty Sand or
Silty gravelly
sand
Shale
 4


21


 6


20
                                                                                               16
                 0.10
                                                             4-28

-------
TABLE 4-5
Site Name:  Durango (Colorado)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards from 40 CFR 192.32(a)
Data Interval:  09/01/82 to 11/13/85
                                                                                                          Page  3  of  5
Constituent
                    Standard    Hydraulic Flow
                    (mg/1) I/   Relationship
                             Formation of
                             Completion
               Number of
               Analyses
                                                                               Number of
                                                                               Analyses
                                                                               Exceeding
                                                                               standard
Percent
Exceeding
standard
Maximum
Value
Obtained
(mg/1) I/
Gross Alpha         15.0 pCi/1  Upgradient
 (excluding radon
  and uranium)
                                Down gradient
                                Down gradient
Lead
           Down gradient

0.05       Upgradient


           Down gradient


           Down gradient


           Down gradient
Gravel or sandy
gravel, poorly
graded
Gravel or sandy
gravel, poorly
graded
Silty Sand or
Silty gravelly
sand
Shale

Gravel or sandy
gravel, poorly
graded
Gravel or sandy
gravel, poorly
graded
Silty Sand or
Silty gravelly
sand
Shale
                                                                      4


                                                                     21
                                                                     20
                                                             4-29

-------
TABLE 4-5
site Name:  Durango  (Colorado)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards from 40 CFR 192.32(a)
Data Interval:  09/01/82 to  11/13/85
                                                                                    Page 4 of 5
Constituent

Mercury
                    Standard    Hydraulic Flow
                    (mg/1) I/   Relationship
                             Formation of
                             Completion
               Number of
               Analyses
Number of
Analyses
Exceeding
Standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
 (mg/1) I/
Ra-226 + Ra-228
 (Radium)
0.002      Upgradient


           Down gradient


           Down gradient


           Down gradient

5.0 pCi/1  Upgradient


           Down gradient


           Down gradient


           Down gradient
 Gravel  or sandy      1
 gravel, poorly
 graded
 Gravel  or sandy      1
 gravel, poorly
 graded
 silty Sand or        1
 Silty gravelly
 sand
.Shale                l

 Gravel  or sandy      2 2/
 gravel, poorly
 graded
 Gravel  or sandy    12 2/
 gravel, poorly
 graded
 Silty Sand or        2 2/
 Silty gravelly
 sand
 Shale              10 2/
                                                             4-30

-------
TABLE 4-5
Site Name:  Durango (Colorado)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards from 40 CFR 192.32(a)
Data Interval:  09/01/82 to 11/13/85
                                                                                                         Page 5 of 5
Constituent

Selenium
Standard    Hydraulic Flow
(mg/1) I/   Relationship
Formation of
Completion
Number of
Analyses
                                                                               Number of
                                                                               Analyses
                                                                               Exceeding
                                                                               Standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/1) I/
Silver
 0.01       Upgradient


            Down gradient


            Down gradient


            Down gradient

 0.05       Upgradient


            Down gradient


            Down gradient


            Down gradient
Gravel or sandy
gravel, poorly
graded
Gravel or sandy
gravel, poorly
graded
Silty Sand or
Silty gravelly
sand
Shale

Gravel or sandy
gravel, poorly
graded
Gravel or sandy
gravel, poorly
graded
Silty Sand or
Silty gravelly
sand
Shale
                                                                     21
                                                                     22
                  17
                                                                                   18
                                                                           20
                                                                                               80
                                                                                               66
                                                                                               81
                 0.36


                 1.20


                 1.90


                 1.60
I/     Values are reported in mg/1 unless otherwise indicated.
2/     Analyses for Ra-226 only.
—    Standard not exceeded.
                                                             4-31

-------
TABLE 4-6
Site Narset  Durango  (Colorado)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards Not Included  in 40 CFR 192.32(a)
                    plus Uranium and Molybdenum
Data Interval:  09/01/82 to 11/13/85
                                                                                           Page 1 of 8
Constituent

Chloride
standard
(mg/1) I/
Hydraulic Flow
Relationship
Formation of
Completion
Number of-
Analyses
Number of
Analyses',
Exceeding
Standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/1) I/
                    250
Copper
   1.0
Upgradient


Down gradient


Down gradient


Down gradient

Upgradient


Down gradient


Down gradient


Down gradient
Gravel or sandy   5
gravel, poorly
graded
Gravel or sandy  21
gravel, poorly
graded
Silty sand or     6
silty gravelly
sand
Shale            22

Gravel or sandy   4
gravel, poorly
graded
Gravel or sandy  21
gravel, poorly
graded
Silty sand or     6
silty gravelly
sand
Shale            20
                                                                                  12
                                                                                               42
                                                                                               66
                                                                            54
                                         1100


                                          390


                                         1100
                                                             4-32

-------
TABLE 4-6
Site Name:  Durango (Colorado)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards Not Included  in 40 CFR 192.32(a)
                    plus Uranium and Molybdenum
Data Interval:  09/01/82 to 11/13/85
                                                                                           Page 2 of 8
Constituent

Fluoride
Standard
(mg/1) I/
Hydraulic Flow
Relationship
Formation of
Completion
Number of
Analyses
Number of
Analyses
Exceeding
Standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/1) I/
Hydrogen Sulfide
   1.4       Upgradient


             Down gradient


             Down gradient


             Down gradient

   0.05      Upgradient


             Down gradient


             Down gradient


             Down gradient
                  Gravel or sandy
                  gravel, poorly
                  graded
                  Gravel or sandy
                  gravel, poorly
                  graded
                  Silty sand or
                  silty gravelly
                  sand
                  Shale

                  Gravel or sandy
                  gravel, poorly
                  graded
                  Gravel or sandy
                  gravel, poorly
                  graded
                  Silty sand or
                  silty gravelly
                  sand
                  Shale
                                                             4-33

-------
TABLE 4-6

Data SatiSriit?WaSf Quality Compared to U.S. EPA Standards Not Included  in 40 CFR 192.32(a)
                    plus Uranium and Molybdenum
Data Interval:  09/01/82 to 11/13/85
                                                                                                              Page 7  of 8
Constituent

Uranium 4/
Standard
(mg/1) I/

   0.044
 Zinc
   5.0
Hydraulic Flow
Relationship

Upgradient
Down gradient


Down gradient


Down gradient

Upgradient


Down gradient


Down gradient


Down gradient
                                                  Formation of
                                                  Completiqn
               Number of
               Analyses
Number of
Analyses
Exceeding
Standard
Gravel or sandy   5
gravel, poorly
graded
Gravel or sandy  21
gravel, poorly
graded
Silty sand or     6
silty gravelly
sand
Shale            22

Gravel of sandy   4
gravel, poorly
graded
Gravel or sandy  21
gravel, poorly
graded
Silty sand or     6
silty gravelly
sand
Shale            20
Percent
Exceeding
Standard

   20
18
6
22
86
100
100
                                                                                                         Maximum
                                                                                                         Value
                                                                                                         Obtained
                              0.15



                              6.20



                              2.40



                              4.07
                                                             4-38

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TABLE 4-6
Site Name:  Durango (Colorado)
Data Evaluation:  Site Water Quality Compared to U.S.  EPA Standards Not Included
                    plus Uranium and Molybdenum
Data Interval:  09/01/82 to 11/13/85
                                                                                           Page 8 of 8
                                                               in 40 CFR 192.32(a)
Constituent
Standard
(mg/1) I/
Hydraulic Flow
Relationship
Formation of
Completion
Number of
Analyses
Number of
Analyses
Exceeding
standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/1) I/
I/    Values are reported in mg/1 unless otherwise indicated.
2/    Concentrations of nitrate as nitrogen at a level of  10 mg/1  is  equivalent to concentration of nitrate as nitrate at a
      level of 44 mg/1.  All analyses are reported in terms of  nitrate as  nitrate.
3/    pH reported in standard units.
4/    30 pCi/1 of uranium is equivalent of 0.044 mg/1, assuming the bulk of uranium is U-238.   All analyses are reported as
      total uranium in mg/1.
	   Standard not exceeded.
                                                            4-39

-------
4.5  GRAND JUNCTION, COLORADO - SUMMARY OF WATER QUALITY

The Grand Junction process site lies in an industrial area
along the northern bank of the Colorado River.  Sedimentary
units in and around the site are, in ascending order, the
Dakota Sandstone, the Mancos Shale, and alluvium.  Two
drillings programs were conducted; the first phase was to
determine the source of contamination to the alluvium; the
second considered background and down gradient hydraulics
and water quality in the alluvium and underlying beds of the
Mancos Shale and Dakota Sandstone.

Groundwater sampling indicated that limits of concentrations
for arsenic, cadmium, radium, chromium, selenium, and gross
alpha were exceeded.  Arsenic and cadmium concentrations
were higher in on-site (alluvium and tailings) samples than
in other localities sampled in the alluvium.  One of 23
upgradient analyses for chromium and twelve out of 33
on-site analysis for selenium exceeded the limit for the
standard.  Four of 9 down gradient samples exceeded the
standard for gross alpha.  Eight of 18 on-site analyses for
radium as well as three of 30 down gradient radium samples,
exceeded the limit for the standard.

Groundwater flow discharges in the Colorado River with some
possibly contributing to recharge of the Dakota Sandstone at
a subcrop 1/2 mile west of the site.  Based on modeling
results, discharge and dispersal of the mobile contaminants
is expected within 50 to 60 years; uranium and ammonia may
persist in the alluvial aquifers for 150 to 300 years.
                              4-40

-------
TABLE 4-7
Site Name:  Grand Junction (Colorado)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards from 40 CFR 192.32(a)
Data Interval:  09/23/77 to 09/11/85
Page 1 of 4
Standard Hydraulic Flow
Constituent (mg/1) I/ Relationship
Arsenic 0 . 05 Background
Upgradient
Cross-gradient
On-Site
On-Site

Down gradient
Barium 1 . 0 Background
Upgradient
Cross-gradient
On-Site
On-Site

Down gradient
Cadmium 0.01 Background
Upgradient
Cross-gradient
On-Site
On-Site

Down gradient
Formation of 1
Completion 1
Alluvium
Alluvium
Alluvium
Alluvium
Uranium Mill
Tailings
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Uranium Mill
Tailings
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Uranium Mill
Tailings
Alluvium
dumber of
Analyses
6
23
9
32
1

39
6
23
9
30
1

39
6
22
9
24
1

31
Number of
Analyses
Exceeding
Standard
	
- ___
5
1

1
___
___
— _
___
__..ป

	
w__
___
___
6
1

___
Percent
Exceeding
Standard
	
___
15
100

2
HIWW
___
___
___
ปปป

	
_
___
___
25
100

	
Maximum
Value
Obtained
(mg/1) I/
	
__ _
0.18
1.68

0.11
___
___
—
___
___

	
___
___
— — —
0.42
0.035

	
                                                            4-41

-------
TABU; 4-7
Site Name:  Grand Junction (Colorado)
Data Evaluation:  Site Water Quality Compared to U.S.
Data Interval:  09/23/77 to 09/11/85
                                                   Page 2  of 4
EPA Standards from 40 CFR 192.32(a)
Constituent
Chromium






Gross Alpha
(excluding radon
and uranium)




Lead






Standard Hydraulic Flow
(mg/1) I/ Relationship
0.05 Background
Upgradient
Cross-gradient
On-Site
On-Site

Down gradient
15.0 pCi/1 Background
Upgradient
Cross-gradient
On-Site
On-Site

Down gradient
0 . 05 Background
Upgradient
Cross-gradient
On-Site
On-Site

Down gradient
Formation of 1
Completion 1
Alluvium
Alluvium
Alluvium
Alluvium
Uranium Mill
Tailings
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Uranium Mill
Tailings
Alluvium
Alluvium
Alluvium
All-uvium
Alluvium
Uranium Mill
Tailings
Alluvium
Number of
Analyses Percent
lumber of Exceeding Exceeding
Analyses Standard Standard
6 	 	
23 14
9 	 	
31 	 	
1 	 	

39 	 	
2 2/ 2/ 2/
4 2/ 2/ 2/
3 2/ 2/ 2/
4 3/ 3 100
1 	 	

9 4/ 4 100
4
13 	 	
6 	 	
16 	 	
1 	 	

22 	 	
Maximum
Value
Obtained
(mg/1) I/
	
0.07
— —
— — — .
—

™""* —
2/
2/
2/
129.20
— — ""

187.40
	
_•••
ซซ—
— — —
—

— — —
                                                             4-42

-------
TABLE 4-7
Site Name:  Grand Junction (Colorado)
Data Evaluation:  Site Water Quality Compared to U.S.  EPA Standards from 40 CFR 192.32(a)
Data Interval:  09/23/77 to 09/11/85
Page 3 of 4
Standard Hydraulic Flow
Constituent (mg/1) I/ Relationship
Mercury 0.002 Background
Upgradient
Cross-gradient
On-Site
On-Site
Down gradient
Ra-226 + Ra-228 5.0 pCi/1 Background
(Radium) Upgradient
Cross-gradient
On-Site
On-Site

Down gradient
Selenium 0.01 Background
Upgradient
Cross-gradient
On-Site
On-Site

Down gradient
Formation of I
Completion i
Alluvium '
Alluvium
Alluvium
Alluvium
Uranium Mill
Tailings
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Uranium Mill
Tailings
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Uranium Mill
Tailings
Alluvium
Number of
Analyses
6
22
9
24
1
31
5
18
7
18 5/
1

30 5/
6
23
9
32
1

39
Number of
Analyses
Exceeding
Standard
	
	
8 6/
-~

3 6/
1
	
" 	
11
1

1
Percent
Exceeding
Standard
	
_ —
44
___

10
16
___
	
34
100

2
Maximum
Value
Obtained
(mg/1) I/
	
___
29.0
___

18.0
0.014
___
___
0.24
1.69

0.012
                                                            4-43

-------
TABLE 4-7
Site Name;  Grand Junction (Colorado)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards from 40 CFR 192.32(a)
Data Interval:  09/23/77 to 09/11/85
                                                                                     Page 4 of *
Constituent

Silver
Standard    Hydraulic Flow
(mg/1) I/   Relationship
Formation of
Completion
Number of
Analyses
                                                                               Number of
                                                                               Analyses
                                                                               Exceeding
                                                                               Standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/1) I/
 0.05       Background
            Upgradient
            Cross-gradient
            On-Site
            On-Site

            Down gradient
Alluvium            4
Alluvium           13
Alluvium            6
Alluvium           16
Uranium Mill        1
Tailings
Alluvium           22
 I/    Values are  reported  in mg/1 unless otherwise indicated.
 2/    Uranium not analyzed.
 3/    Uranium not analyzed for one sample.
 4/    Uranium analyzed  in  4 of 9 samples.
 5/    Ra-226 only.
 6/    Values for  Ra-226 only.  Ra-228 values were all less than the standard.
 	   Standard not exceeded.
                                                              4-44

-------
TABLE 4-8
Site Name:  Grand Junction (Colorado)
Data Evaluation:  site Water Quality Compared to U.S. EPA Standards Not Included
                    plus Uranium and Molybdenum
Data Interval:  09/23/77 to 09/11/85
                            Page 1 of 5
in 40 CFR 192.32(a)
Constituent
Chloride






Copper






Fluoride






Standard Hydraulic Flow
(mg/1) I/ Relationship
250 Background
Upgradient
Cross-gradient
On-Site
On-Site

Down gradient
1 . 0 Background
Upgradient
Cross-gradient
On-Site
On-Site

Down gradient
1 . 4 Background
Upgradient
Cross-gradient
On-Site
On-Site

Down gradient
Formation of
Completion
Alluvium
Alluvium
Alluvium
Alluvium
Uranium Mill
Tailings
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Uranium Mill
Tailings
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Uranium Mill
Tailings
Alluvium
Number of
Analyses
52
23
9
32
1

40
6
23
9
32
1

39
6
22
9
24
1

31
Number of
Analyses
Exceeding
Standard
39
15
9
32
1

40
••••_
___
___
___
___

	
	
2

20
1

- .. 8
Percent
Exceeding
Standard
75
65
100
100
100

.100
	 _.
___
— ซป
ซ__
— — —

	

9

83
100

25
Maximum
Value
Obtained
(mg/1) I/
473
783
1250
1030
2990

1270
	
___
ป*>ซ.
___
ป_

	

1.60

4.90
16.0

3.70
                                                            4-45

-------
TABLE 4-8
Site Kama:  Grand Junction (Colorado)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards Not Included
                    plus Uranium and Molybdenum
Data Interval:  09/23/77 to 09/11/85
                                                                                                              Page 2  of 5
in 40 CFR 192.32(a)
Constituent
Hydrogen Sulfide



Iron



Manganese



Standard Hydraulic Flow
(mg/1) I/ Relationship
0 . 05 Background
Upgradient
Cross-gradient
On-Site
On-Site

Down gradient
0.30 Background
Upgradient
Cross-gradient
On-Site
On-Site

Down gradient
0.05 Background
Upgradient
Cross-gradient
On-Site
On-Site

Down gradient
Formation of
Completion
Alluvium
Alluvium
Alluvium
Alluvium
Uranium Mill
Tailings
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Uranium Mill
Tailings
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Uranium Mill
Tailings
Alluvium
Number of
Analyses
4
13
6
12
1

18
6
23
9
32
1

39
6
23
9
32
1

39
Number of
Analyses
Exceeding
Standard
4
13
6
12
— -ป~

18
4
10
8
22
__ —

26
6
23
9
32
1

39
Percent
Exceeding
Standard
100
100
100
100


100
66
43
88
68
™"~™

66
100
100
100
10
100

100
Maximum
Value
Obtained
(mg/1) I/
1.20
0.20
0.36
0.20

0*> f\
.20
1.20
3.04
5.70
12.00


16.00
8.74
2.91
4.60
10.00
0.33
1 O A
334
                                                              4-46

-------
TABLE 4-8
Site Name:  Grand Junction (Colorado)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards Not Included
                    plus Uranium and Molybdenum
Data Interval:  09/23/77 to 09/11/85
                            Page 3 of 5
in 40 CFR 192.32(a)
Constituent
Molybdenum






Nitrate 2/






PH 3/






Standard Hydraulic Flow
(mg/1) I/ Relationship
0 . 10 Background
Upgradient
Cross-gradient
On-Site
On-Site

Down gradient
44 Background
Upgradient
Cross-gradient
On-Site
On-Site

Down gradient
6.5 to 8.5. Background
Upgradient
Cross-gradient
On-Site
On-Site

Down gradient
Formation of
Completion
Alluvium
Alluvium
Alluvium
Alluvium
Uranium Mill
Tailings
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Uranium Mill
Tailings
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Uranium Mill
Tailings
Alluvium
Number of
Analyses
6
23
9
32
1

39
8
23
9
28
1

35
52
23
9
32
1

39
Number of
Analyses
Exceeding
Standard
|_1 n la
6
5
24
1

17
	
— — ป
___
1
1

	
	
ซ_ป•
___
___
___

___
Percent
Exceeding
standard
	
26
56
75
100

44
	
___
ป_ซ
3
100

	
	
••ซ_
ซซ•ป
ซ.__
_•ป-•

___
Maximum
Value
Obtained
(mg/1) I/
	
0.15
0.14
0.53
8.65

0.47

•••••
___
50.0
1100

	

•ป•ปป
— _••
ซ>HปM
IT- annul

*.*...
                                                            4-47

-------
TABLE 4-8
Site Name:  Grand Junction (Colorado)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards Not Included
                    plus Uranium and Molybdenum
Data Interval:  09/23/77 to 09/11/85
                                                Page 4 of 5
                                  ,0/ป\
                    in 40 CFR 192. 32 (a)
Constituent
Sulfate





Sulfide





Total Solids





Standard Hydraulic Flow
(mg/1) I/ Relationship
250 Background
Upgradient
Cross-gradient
On-Site
On-Site

Down gradient
0.05 Background
Upgradient
Cross-gradient
On-Site
On-Site

Down gradient
500 Background
Upgradient
Cross-gradient
On-Site
On-Site

Down gradient
Formation of
Completion
Alluvium
Alluvium
Alluvium
Alluvium
Uranium Mill
Tailings
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Uranium Mill
Tailings
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Uranium Mill
Tailings
Alluvium
Number of
Analyses
52
23
9
32
1

39
2
9
3
8
1


52
23
9
32
1

39
Number of
Analyses
Exceeding
Standard
52
20
9
32
1

39
2
9
3
8
—


52
22
9
32
- —

39
Percent
Exceeding
Standard
100
86
100
100
100

100
100
100
100
100
— —


100
95
100
100
— —

100
Maximum
Value
Obtained
(mg/1) I/
4170
3410
4000
4900
6110

4500
0.10
0.10
0.10
0.10
"~ — •"


7220
6930
8530
8100
• ป

12,134
4-48

-------
 TABLE 4-8
 Site Name:   Grand Junction (Colorado)
 Data Evaluation:   Site Water Quality Compared to U.S.  EPA Standards Not Included
                     plus Uranium and Molybdenum
 Data Interval:   09/23/77 to 09/11/85
                                                                                                          Page 5 of 5
                                                                              in 40 CFR 192.32(a)
 Constituent

 Uranium  4/
               Standard
               (mg/1)  I/
Hydraulic Flow
Relationship
Formation of   Number of
Completion     Analyses
Number of
Analyses
Exceeding
Standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/1) I/
Zinc
                  0.044      Background
                            Upgradient
                            Cross-gradient
                            On-Site
                            On-Site

                            Down gradient
                  5.0        Background
                            Upgradient
                            Cross-gradient
                            On-Site
                            On-Site

                            Down gradient
                  Alluvium          i
                  Alluvium          i
                  Alluvium          i
                  Alluvium          3
                  Uranium Mill      i
                  Tailings
                  Alluvium          4
                  Alluvium          6
                  Alluvium         23
                  Alluvium          9
                  Alluvium         32
                  Uranium Mill      i
                  Tailings
                  Alluvium         39
                                                                                               100


                                                                                               100
                                                           0.185


                                                           0.445
i/
2/
I/
	  Standard not exceeded.
Values are reported in mg/1 unless otherwise indicated.
SD^TS^i0"8/?* nฃfate aS nitrฐ9en at a leYel of 10 mg/1 is equivalent to concentration of nitrate  as  nitrate at a
level of 44 mg/1.  All analyses are reported in terms of nitrate as nitrate.
pH reported in Standard units.
                       equivalent ฐf ฐ<044 mg/1' ass™^<3 the bulk of uranium is U-238.  All analyses  are reported as
                                                             4-49

-------
4.6  GUNNISON, COLORADO - SUMMARY OF WATER QUALITY

The site is immediately south of the City of Gunnison,
Colorado; and is between the Gunnison River and Tomichi
Seek   The site overlies the principal.aquifer of the  rea.
SSrl than75 wells, most of them domestic wells less than 30
feet deep, are within one mile of the site.  The city 01
Gunnison operates a municipal well field approximately one
mile north (upgradient) of the site.

The quality of background water is generally potable with
some exceptions.  High concentrations of iron are found in
tte allSvial aquifer?  Hydrogen sulfide is found in a
reducing zone along the Gunnison River.

The groundwater analyses for the Gunnison si^ included
background, upgradient, cross-gradient, on-site jnd down
or-adisnt data.  All data are from wells in the alluvium.
Ia?iiS  was the only constituent which exceeded the stan-
dSSTinthe background samples.  One of 21 background
samples exceeded the barium standard.  No constituents
exceeded the standards in the upgradient or cross-gradient
wells.

Arsenic and gross  alpha exceeded the standards in the
on-site samples.   The  arsenic standard was exceeded in  3 out
of 7  sampSI, with a maximum value exceeding the standard by
* -Factor of more than  four.  One gross alpha sample was
rallied and"it eSeeded the standard by a factor of more
than  ten.

The down gradient  samples contained the greatest number of
contaminants.   In  these  samples  the ^andardj. were egeectod
fn-r arsenic   cadmium,  gross alpha, mercury and selenium.
Twฃ oufo-f^rsamplesexceeded  the arsenic  standard  by a
factor  of  less  than  two.  The maximum values for both
cadmium and  gross  alpha  exceeded standards by more than a
factor  of  three.   The  one mercury sample  analyzed exceeded
the standard by a  factor of  14,300.  Nine  out of  123  samples
analvzSdfor selenium  exceeded  the standard.  The maximum
5SSS for  selenium was more  than a factor  of  10  greater than
the standard.

The contaminants disperse in the alluvial  aquifer which
discharges at the  confluence  of  the Gunnison River  and
Tomichi Creek,  2 miles from the site.  . Modeling  indicates
that  discharges of the mobile contaminants will  reach
background standards in  approximately 75  years.   The  dis-
charge  period of  the attenuated contaminants was not
modeled.
                               4-50

-------
TABLE 4-9
Site Name:  Gunnison (Colorado)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards from 40 CFR 192.32(a)
Data Interval:  10/12/83 to 06/20/85
Page 1 of 3
Constituent
Arsenic




Barium




Cadmium




Chromium




Standard Hydraulic Flow
(mg/1) I/ Relationship
0.05 Background
Upgradient
Cross-gradient
On-Site
Down gradient
1 . 0 Background
Upgradient
Cross-gradient
On-Site
Down gradient
0.01 Background
Upgradient
Cross-grad ient
On-Site
Down gradient
0 . 05 Background
Upgradient
Cross-gradient
On-Site
Down gradient
Formation of
Completion
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Number of
Analyses
21
5
2
7
123
21
5
2
7
123
21
5
2 '
7
123
21
5
2
7
122
Number of
Analyses
Exceeding
Standard
___
	
	
3
2
1
	
	
_ —
	
___
	
	
	
7
H-.W
	
	
~~
	
Percent
Exceeding
Standard
___
___
	
42
2
5
	
	
___
	
___
	
___
— _
6
__ซ
	
___
_ —

Maximum
Value
Obtained
(mg/1) I/
___
	
	
0.23
0.07
1.2
	
___
___
	
M__
	
___
___
0.034
- ซ._•_
___
___
	
	
                                                            4-51

-------
TABLE 4-9
Site Name:  Gunnison (Colorado)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards from 40  CFR 192.32(a)
Data Interval:  10/12/83 to 06/20/85
Page 2 of 3
Constituent
Gross Alpha
(excluding radon
and uranium)


Lead



,
Mercury




Ra-226 + Ra-228
(Radium)



Standard Hydraulic Flow
(mg/1) I/ Relationship
15.0 pCi/1 Background
Upgradient
Cross-gradient
On-Site
Down gradient
0.05 Background
Upgradient
Cross-gradient
On-Site
Down gradient
0.002 Background
Upgradient
Cross-gradient
On-Site
Down gradient
5.0 pCi/1 Background
Upgradient
Cross-gradient
On-Site
Down gradient
Formation of
Completion
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Number of
Analyses
5
1
1
1
11
21 '
5
2
7
121
1
1
1
1
1
6 y
2
1
4 2/
23
Number of
Analyses
Exceeding
Standard
_ —
— —
— — —
1
4
	
— —
	
_ —
— — —
	
	
	
___
1
	
• — _
	
	
	
Percent
Exceeding
Standard
	
—
— — —
100
36
	
— — —
—
	
- •" ••• ~ -
	
— — —
— ~
	
100
	
— — —
—
—
— — —
Maximum
Value
Obtained
(ng/i) I/
	
••— —
— — —
151.12
49.98
	
— — —
— — —
-——
— —
	
— — —
— — —
— — —
28.6
	
— — —
— — —
— — —
— — —
                                                             4-52

-------
TABLE 4-9
Site Name:  Gunnison (Colorado)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards from 40 CFR 192.32(a)
Data Interval:  10/12/83 to 06/20/85
Page 3 of 3



Constituent
Selenium




Silver






Standard
(mg/1) I/
0.01




0.05




I/ Values are reported in
2/ Analyses
	 Standard


Hydraulic Flow
Relationship
Background
Upgradient
Cross-gradient
On-Site
Down gradient
Background
Upgradient
Cross-gradient
On-Site
Down gradient


Formation of
Completion
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium


Number of
Analyses
21
5
2
7
123
1
1
1
1
1
Number of Maximum
Analyses Percent Value
Exceeding Exceeding Obtained
Standard Standard (mg/1) I/
ปซ.ซ •ป— — ซ••.•ซ.
___ _ — - —
___ , 	 — _
___ ___ ___
9 7 0.103
___ ___ •_-•••
___ __— ___
___ — - 	
___ ___ ___
— — — — — — ___
mg/1 unless otherwise indicated.
for Ra-226 only.
not exceeded.




                                                            4-53

-------
TABLE 4-10
Site Haae:  Gunnison (Colorado)
Data Evaluation:  Site Water Quality Coapared to U.S. EPA Standards Not Included
                    plus Uranium and Molybdenum
Data Interval:  10/12/83 to 06/20/85
                            Page 1 of 4
in 40 CER 192.32(3)
Standard
Constituent (mg/1) I/
Chloride 250

Copper 1.0.

Fluoride 1.4

Hydrogen Sulfide 0.05

Iron 0.30

Hydraulic Flow
Relationship
Background
Upgradient. .
Cross-gradient
On-Site
Down gradient
Background
Upgradient
Cross-gradient
On-Site
Down gradient
Background
Upgradient
Cross-gradient
On-Site
Down gradient
Background
Upgradient
Cross-gradient
On-Site
Down gradient
Background
Upgradient
Cross-gradient
On-Site
Down gradient
Formation of
Completion
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Number of
Analyses
21
5
2
7
123
15
3
1
5
81
15
2
1
4
64
1
1
1
1
1
21
5
2
7
122
Number of
Analyses
Exceeding
Standard
^ซ^
___
	
- - __-
	
4
	
— —
10
2
7
69
Percent
Exceeding
Standard
	
—
	
— — - -
	
6
	
™
47
100
100
56
Maximum
Value
Obtained
(mg/1) I/
	
***•••ป
	
- . ~~~ - -
	
2.60
	
— — —
5.63
1.90
37.80
101
                                                             4-54

-------
TABLE 4-10
Site Name:  Gunnison (Colorado)
Data Evaluation:  Site Vfater Quality Compared to U.S. EPA Standards Not Included
                    plus Uranium and Molybdenum
Data Interval:  10/12/83 to 06/20/85
                            Page 2 of 4
in 40 CFR 192.32(a)
Constituent
Manganese




Molybdenum




Nitrate 2/




pH 3/




Sulfate




Standard Hydraulic Flow
(mg/1) I/ Relationship
0.05 Background
Upgradient
Cross-gradient
On-Site 	
Down gradient
0 . 10 Background
Upgradient
Cross-gradient
On-Site
Down gradient
44 Background
Upgradient
Cross-gradient
On-Site
Down gradient
6.5 to 8.5 Background
Upgradient
Cross-gradient
On-Site
Down gradient
250 Background
Upgradient
Cross-gradient
On-Site
Down gradient
Formation of
Completion
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Number of
Analyses
15
5
2
6
101
21
5
2
7
123
21
5
2
7
123
21
5
2
7
117
21
5
2
7
122
Number of
Analyses
Exceeding
Standard
11
2
2
6
85
___
	 .
	
2
	
___
	
	
	 ,
6
___
	
1
7
66
_._
- —
- —
7
62
Percent
Exceeding
Standard
73
40
100
100
84
___
— _
_ —
29
	
__..
—
	
	
4
___
— -
50
100
56
...
___
___
100
50
Maximum
Value
Obtained
(mg/1) I/
4.69
0.29
2.09
34.30
77.00
___
	
_ —
0.18
— -
___
- — _
_ —
___
110
___
___
6.08
5.66
5.08/12.32
...
___
___
1480
1820
                                                             4-55

-------
TABLE 4-10
Site Name:  Gunnison (Colorado)
Data Evaluation:  Site Hater Quality Compared to U.S. EPA Standards Not Included
                    plus Uranium and Molybdenum
Data interval:  10/12/83 to 06/20/85
                            Page 3 of 4
in 40 CFR 192.32(a)
Constituent
Sulfide




Total Solids




Uranium 4/




Zinc




Standard Hydraulic Flow
(mg/1) I/ Relationship
0.05 Background
Upgradient
Cross-gradient
On-Site
Down gradient
500 Background
Upgradient
Cross-gradient
On-Site
Down gradient
0.044 Background
Upgradient
Cross-gradient
On-Site
Down gradient
5 . 0 Background
Upgradient
Cross-gradient
On-Site
Down gradient
Formation of
Completion
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Number of
Analyses
6
2
1
2
43
21
5
2
7
122
15
2
1
5
78
15
3
1
5
82
Number of
Analyses
Exceeding
Standard
6
2
1
2
43
1
	
	
7
78
___
	
	
2
29
___
	
	
___
	
Percent
Exceeding
Standard
100
100
100
100
100
4
___
	
100 .
63
	
	
- —
40
37
	
	
	
	
	
Maximum
Value
Obtained
(mg/1) I/
0.10
0.10
0.10
0.10
1.00
713
— — —
—
2510
3160
	
	
— —
0.1160
1.20
	
— -
—
___
	
                                                            4-56

-------
TABLE 4-10
Site Name:  Gunnison (Colorado)
Data Evaluation:  Site Water Quality Compared to U.S.  EPA Standards Not Included
                    plus Uranium and Molybdenum
Data Interval:  10/12/83 to 06/20/85
                                                                                           Page 4 of 4
                                                               in 40 CFR 192.32(a)
Constituent
Standard
(mg/1) I/
Hydraulic Flow
Relationship
Formation of
Completion
Number of
Analyses
Number of
Analyses
Exceeding
standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/1) I/
I/   Values are reported in mg/1 unless otherwise indicated.
2/   Concentrations of nitrate as nitrogen at a level  of 10 mg/1 is equivalent to concentration of nitrate as nitrate at a
     level of 44 mg/1.  All analyses are reported in terms  of nitrate as nitrate.
3/   pH reported in standard units.
4/   30 pCi/1 of uranium is equivalent of 0.044 mg/1,  assuming the bulk of uranium is U-238.   All analyses are reported as
     total uranium in mg/1.
	  Standard not exceeded.
                                                             4-57

-------
TABIฃ 4-11
Site Name:  Lakaviaw (Oregon)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards from 40 CFR 192.32(a)
Data Interval:  08/17/82 to 10/02/86
Page 2 of 5
Standard Hydraulic Flow
Constituent (mg/1) U Relationship
Cadmium o.Ol Background •


Cross-gradient


On-Site


Down gradient


Chromium 0.05 Background


Cross-gradient


On-Site


Down gradient


Number of
Analyses Percent
Formation of Number of Exceeding Exceeding
Completion Analyses Standard Standard
Sand or gravelly 25 	 	
sand, poorly
graded
Sand or gravelly 7
sand, poorly
graded
Sand or gravelly 18 15
sand, poorly
graded
Sand or gravelly 55 3 5
sand, poorly
graded
Sand or gravelly 12 	 	
sand, poorly
graded
Sand or gravelly 6 	 	
sand, poorly
graded
Sand or gravelly 15 	 	
sand, poorly
graded
Sand or gravelly 46 3 6
sand, poorly
graded
Maximum
Value
Obtained
(mg/1) I/
—


	


0.04


0.31


___


	


	


0.08


                                                             4-60

-------
TABLE 4-11
Site Name:  Lakeview (Oregon)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards from 40 CFR 192.32(a)
Data Interval:  08/17/82 to 10/02/86
Page 3 of 5
Constituent
Gross Alpha
(excluding radon
and uranium)









Lead











Standard Hydraulic Flow
(mg/1) I/ Relationship
15.0 pCi/1 Background


Cross-gradient


On-Site


Down gradient


0.05 Background


Cross-gradient


On-Site


Down gradient


Formation of Number of
Completion Analyses
Sand or gravelly 1
sand, poorly
graded
Sand or gravelly 1
sand, poorly
graded
Sand or gravelly 1
sand, poorly
graded
Sand or gravelly 1
sand, poorly
graded
Sand or gravelly 9
sand, poorly
graded
Sand or gravelly 4
sand, poorly
graded
Sand or gravelly 14
sand, poorly
graded
Sand or gravelly 35
sand, poorly
graded
Number of Maximum
Analyses Percent Value
Exceeding Exceeding Obtained
Standard Standard (mg/1) I/
	 	 	


___ ___ ___


— — — — — — — —


1 100 23.32


	 	 	


	 — — -


	 __- — -


— — — — — — — — —


                                                             4-61

-------
TABLE 4-11
Site Name:  Lakeview (Oregon)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards from 40 CFR 192.32(a)
Data Interval:  08/17/82 to. 10/02/86
Page 4 of 5
Constituent
Mercury











Ra-226 +
Ra-228 (Radium)










Standard Hydraulic Flow
(mg/1) I/ Relationship
0.002 Background


Cross-gradient


On-Site


Down gradient


5.0 pCi/1 Background

Cross-gradient


On-Site


Down gradient


Formation of Number of
Completion Analyses
Sand or gravelly 6
sand, poorly
graded
Sand or gravelly 2
sand, poorly
graded
Sand or gravelly 8
sand, poorly
graded
Sand or gravelly 20
sand, poorly
graded
Sand or gravelly 8
sand, poorly
graded
Sand or gravelly 4
sand, poorly
graded
Sand or gravelly 7
sand, poorly
graded
Sand or gravelly 30
sand, poorly
graded
Number of Maximum
Analyses Percent Value
Exceeding Exceeding Obtained
Standard Standard (mg/1) I/
— — — ___ ___


	 	 	


	 	 ___


_. — .. 	 . 	 . . . .


	 	 	

	 	 	


	 	 	


1 3 76.0


                                                             4-62

-------
TABLE 4-11
Site Name:  Lakeview (Oregon)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards from 40 CFR 192.32(a)
Data Interval:  08/17/82 to 10/02/86
                                                                                                          Page 5 of 5
Standard Hydraulic Flow
Constituent (mg/1) I/ Relationship
Selenium 0.01 Background


Cross-gradient


On-Site


Down gradient


Silver 0.05 Background


Cross-gradient


On-Site


Down gradient


Number of Maximum
Analyses Percent Value
Formation of Number of Exceeding Exceeding Obtained
Completion Analyses Standard Standard (mg/1) I/
Sand or gravelly 10 — 	
sand, poorly
graded
Sand or gravelly 4 	 	 ~~~
sand, poorly
graded
Sand or gravelly 16 3 18 0.243
sand, poorly
graded
Sand or gravelly 38 	 	 	
sand, poorly
graded
Sand or gravelly 5 	 	
sand, poorly
graded
Sand or gravelly 2 	 - — 	
sand, poorly
graded
Sand or gravelly 7 	 	 ™
sand, poorly
graded
Sand or gravelly 19 	 	 	
sand, poorly
graded
I/    Values are reported in mg/1 unless otherwise indicated.
	   Standard not exceeded.
                                                             4-63

-------
TABLE 4-12
Site Name:  Lakeview (Oregon)
Data Evaluation:  Site Water Quality Compared to U.S.  EPA Standards Not Included  in 40 CFR 192.32(a)
                    plus Uranium and Molybdenum
Data Interval:  08/17/82 to 10/02/86
Page 1 of 8
Standard Hydraulic Flow
Constituent (ng/1) I/ Relationship
Chloride 250 Background


Cross-gradient


On-Site


Down gradient


Copper i.o Background


Cross-gradient


On-Site


Down gradient


Formation of Number of
Completion Analyses
Sand or gravelly
sand, poorly
graded
Sand or gravelly
sand, poorly
graded
Sand or gravelly
sand, poorly
graded
Sand or gravelly
sand, poorly
graded
Sand or gravelly
sand, poorly
graded
Sand or gravelly
sand, poorly
graded
Sand or gravelly
sand, poorly
graded
Sand or gravelly
sand, poorly
graded
25


7


18


57


10


4


15


36


Number of Maximum
Analyses Percent Value
Exceeding Exceeding Obtained
Standard Standard (mg/1) I/
ซซ ซ_ซ ซ.ซซ


___ ___ ___


6 33 3400


23 40 2400


— — — ป_ ปปซ


— 	 ___


— - _ — ___


— -_- ___


                                                             4-64

-------
TABLE 4-12
Site Kama:  Lakeview (Oregon)
Data Evaluation:  Site Water Quality Compared to U.S.  EPA Standards Not Included  in 40 CFR 192.32(a)
                    plus Uranium and Molybdenum
Data Interval:  08/17/82 to 10/02/86
                                                                                                              Page 2 of 8
Constituent

Fluoride
Standard    Hydraulic Flow
(mg/1) I/   Relationship
                  Formation of
                  Completion
               Number of
               Analyses
                                                                               Number of
                                                                               Analyses
                                                                               Exceeding
                                                                               Standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/1) I/
 1.4
Hydrogen Sulfide
 0.05
Background


Cross-gradient


On-Site


Down gradient



Background


Cross-gradient


On-Site


Down gradient
Sand or gravelly    25
sand, poorly
graded
Sand or gravelly     7
sand, poorly
graded
Sand or gravelly    18
sand, poorly
graded
Sand or gravelly    57
sand, poorly
graded

Sand or gravelly     1
sand, poorly
graded
Sand or gravelly     1
sand, poorly
graded
Sand or gravelly     1
sand, poorly
graded
Sand or gravelly     1
sand, poorly
graded
                                                                10
                                                                             40
                                                                                           4.7
                                                                                    45
                                                                                                 44
                                                                                                 78
                                                                                                               6.27
                                                                                                               8.8
                                                             4-65

-------
TABLE 4-12
Site Name:  Lakeview  (Oregon)
Data Evaluation:  Site Water Quality Conpared to U.S. EPA Standards Not Included  in 40 CFR 192.32(a)
                    plus Uranium and Molybdenum
Data Interval:  08/17/82 to 10/02/86
                                                                                          Page 3 of 8
Constituent

Iron
Standard    Hydraulic Flow
(mg/1) I/   Relationship
 Formation of
 Completion
Number of
Analyses
Number of
Analyses
Exceeding
Standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/1) I/
Manganese
 0.30       Background


            Cross-gradient


            On-Site


            Down gradient



 0.05       Background


            Cross-gradient


            On-Site


            Down gradient
 Sand  or gravelly    25
 sand, poorly
 graded
 Sand  or gravelly     7
 sand, poorly
 graded
 Sand  or gravelly    19
 sand, poorly
 graded
 Sand  or gravelly    57
 sand, poorly
 graded

 Sand  or gravelly    24
 sand, poorly
 graded
 Sand or gravelly     7
 sand, poorly
 graded
 Sand or gravelly    17
 sand, poorly
graded
Sand or gravelly    54
sand, poorly
graded
                                                                                    12
                                                                                    12
                                                                                    49
                                31



                                21




                                37



                               100



                                70


                                90
                                                                                                              27.0
                                                                                                               9.14
                                                                                                               0.26
                                                                                                               8.30
                                                                                                              25.0
                                                                                                              24.7
                                                             4-66

-------
TABLE 4-12
Site Name:  Lakeview (Oregon)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards Not Included  in 40 CFR 192.32(a)
                    plus Uranium and Molybdenum
Data Interval:  08/17/82 to 10/02/86
Page 4 of 8
Standard Hydraulic Flow
Constituent (mg/1) I/ Relationship
Molybdenum 0.10 Background


Cross-gradient


On-Site


Down gradient


Nitrate 2/ 44 Background


Cross-gradient


On-Site


Down gradient


Formation of Number of
Completion Analyses
Sand or gravelly 6
sand, poorly
graded
Sand or gravelly 2
sand, poorly
graded
Sand or gravelly 9
sand, poorly
graded
Sand or gravelly 27
sand, poorly
graded
Sand or gravelly 25
sand, poorly
graded
Sand or gravelly 7
sand, poorly
graded
Sand or gravelly 18
sand, poorly
graded
Sand or gravelly 57
sand, poorly
graded
Number of Maximum
Analyses Percent Value
Exceeding Exceeding Obtained
Standard Standard (mg/1) I/
1 16 0.11


	 	 	


1 11 0.32


3 11 0.44


— — — ___ ___


	 	 	


	 	 — _


	 	 	


                                                            4-67

-------
TABLE 4-12
Site Name;  LaXeview (Oregon)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards Not Included  in 40 CFR 192.32(a)
                    plus Uranium and Molybdenum
Data Interval:  08/17/82 to 10/02/86
Page 5 of 8
Standard Hydraulic Flow
Constituent (mg/1) I/ Relationship
pH 3/ 6.5 to 8.5 Background


Cross-gradient


On-Site


Down gradient


Sulfate 250 Background


Cross-gradient


On-Site


Down gradient


Formation of Number of
Completion Analyses
Sand or gravelly
sand, poorly
graded
Sand or gravelly
sand, poorly
graded
Sand or gravelly
sand, poorly
graded
Sand or gravelly
sand, poorly
graded
Sand or gravelly
sand, poorly
graded
Sand or gravelly
sand, poorly
graded
Sand or gravelly
sand, poorly
graded
Sand or gravelly
sand, poorly
graded
25


7


18


60


25


7


18


57


Number of
Analyses
Exceeding
Standard
4


	


3


9


	


4


8


35


Percent
Exceeding
Standard
16


— — —


16


15


	


57


44


61


Maximum
Value
Obtained
(mg/1) I/
6.02/8.90


——


5.70


5.58/9.30


	


650


7300


4700


                                                             4-68

-------
TABLE 4-12
Site Name:  Lakeview (Oregon)
Data Evaluation:  Site Water Quality Compared to U.S.  EPA Standards Not Included  in 40 CFR 192.32(a)
                    plus Uranium and Molybdenum
Data Interval:  08/17/82 to 10/02/86
Page 6 of 8
Standard Hydraulic Flow
Constituent (mg/1) I/ Relationship
Sulfide o.05 Background


Cross-gradient


On-Site


Down gradient


Total Solids 500 Background


Cross-gradient


On-Site


Down gradient


Formation of Number of
Completion Analyses
Sand or gravelly
sand, poorly
graded
Sand or gravelly
sand, poorly
graded
Sand or gravelly
sand, poorly
graded
Sand or gravelly
sand, poorly
graded
Sand or gravelly
sand, poorly
graded
Sand or gravelly
sand, poorly
graded
Sand or gravelly
sand, poorly
graded
Sand or gravelly
sand, poorly
graded
1


1


1


1


25


7


18


57


Number of
Analyses
Exceeding
Standard
ซ_ -.


___


	


	


11


4


10


51


Maximum
Percent Value
Exceeding Obtained
Standard (mg/i) I/
— ™— ซ••••


— — _


___ ___


___ _ —


43 992


57 1232


55 13,836


89 12,006


                                                             4-69

-------
TABLE 4-12
Site Name:  Lakeview (Oregon)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards Not Included  in 40 CFR 192.32(a)
                    plus Uranium and Molybdenum
Data Interval:  08/17/82 to 10/02/86
                                                                                                              Page 7 of 8
Standard Hydraulic Flow
Constituent (mg/1) I/ Relationship
Uranium 4/ 0.044 Background
.

Cross-gradient


On-Site


Down gradient


Zinc 5.0 Background


Cross-gradient


On-Site


Down gradient


Number of Maximum
Analyses Percent Value
Formation of Number of Exceeding Exceeding Obtained
Completion Analyses Standard Standard (mg/1) I/
Sand or gravelly
sand, poorly
graded
Sand or gravelly
sand, poorly
graded
Sand or gravelly
sand, poorly
graded
Sand or gravelly
sand, poorly
graded
Sand or gravelly
sand, poorly
graded
Sand or gravelly
sand, poorly
graded
Sand or gravelly
sand, poorly
graded
Sand or gravelly
sand, poorly
graded
7 	 	 	


4 	 	


9 1 11 0.10


30 — - 	 ~"


11 	 	


6 	 	 	


14 	 	


46 	 	 	


                                                              4-70

-------
TABLE 4-12
Site Name:  Lakeview (Oregon)
Data Evaluation:  Site Water Quality Compared to U.S.  EPA Standards Not Included
                    plus Uranium and Molybdenum
Data Interval:  08/17/82 to 10/02/86
                                                                                          Page 8 of 8
                                                              in 40 CFR 192.32(a)
Constituent
Standard
(mg/1) I/
Hydraulic Flow
Relationship
Formation of
Completion
Number of
Analyses
Number of
Analyses
Exceeding
Standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/1) I/
I/    Values are reported in mg/1 unless otherwise indicated.
2/    Concentrations of nitrate as nitrogen at a level of  10 mg/1  is  equivalent to concentration of nitrate as nitrate at a
      level of 44 mg/1.  All analyses are reported in terms of  nitrate as nitrate.
3/    pH reported in standard units.
4/    30 pCi/1 of uranium is equivalent of 0.044 mg/1, assuming the bulk of uranium is U-238.   All analyses are reported as
      total uranium in mg/1.
      Standard not exceeded.
                                                            4-71

-------
4.8  MEXICAN HAT, UTAH - SUMMARY OF WATER QUALITY

The Mexican Hat tailings site is in southeast Utah, approxi-
mately one mile south of Mexican Hat, Utah and the San Juan
River.  Sampling of monitor wells indicate that the tailings
have contaminated approximately 80 million gallons of
groundwater.  Seepage of contaminants into Gypsum Wash (the
major surface drainage area of the site) and subsequent
contamination of the San Juan River are of major concern.
Background water quality is unsuitable for most uses;
currently there are no groundwater withdrawals within the
site.

Of the standards contained in or referenced in 40 CFR
192.32(a), the limits for chromium, gross alpha, mercury,
radium and selenium were exceeded for some samples.  Chromi-
um concentrations were higher in background samples in the
Rico Formation than in down gradient samples.  Two out of 15
background analyses for radium and one out of 15 background
analyses for selenium exceeded the limit for the standard.
Two out of 14 background samples exceeded the standard for
gross alpha.  One out of 2 down gradient analyses for
mercury exceeded the limit for the standard.

The contaminated groundwater appears to occur in perched
zones beneath and adjacent to the site.  Because of the low
rate of movement of the perched water, over 500 years will
be required to flush the mobile contaminants from the
groundwater.
                              4-72

-------
TABLE 4-13
Site Name:  Mexican Hat (Utah)
Data Evaluation:  Site Water Quality Compared to U.S.
Data Interval:  04/10/85 to 11/01/85
                                                   Page 1 of 2
EPA Standards from 40 CFR 192.32(a)
Constituent
Arsenic
Barium
Cadmium

Chromium



Gross Alpha
(excluding radon
and uranium)

Standard Hydraulic Flow
(mg/1) I/ Relationship
0.05 Background
On-Site
Down gradient
Down gradient
1 . 0 Background
On-Site
Down gradient
Down gradient
0.01 Background
On-Site
Down gradient
Down gradient
0.05 Background
On-Site
Down gradient
Down gradient
15.0 pCi/1 Background
On-Site
Down gradient
Down gradient
Formation of
Completion
Rico
Siltstone
Rico
Siltstone
Rico
Siltstone
Rico
Siltstone
Rico
Siltstone
Rico
Siltstone
Rico
Siltstone
Rico
Siltstone
Rico
Siltstone
Rico
Siltstone
Number of
Analyses
15
1
2
1
15
1
2
1
15
1
2
1
15
1
2
1
14
1
1
1
Number of
Analyses
Exceeding
Standard
	
— — —
5
___
1
1
2
	
	
	
Percent
Exceeding
Standard
	
__ซ
33
___
50
100
14
	 .
	
—
Maximum
Value
Obtained
(mg/1) I/
	
_ซป
0.70
— — —
0.21
0.06
25.184
_ — —
— — —
— — —
                                                             4-73

-------
                                                                                                              Pag* 2 of 3
TABLE 4-14
Site Name:  Mexican Hat  (Utah)
Data Evaluation:  Site Water Quality Compared to U.S
                    plus Uranium and Molybdenum
Data Interval:  04/10/85 to 11/01/85
EPA Standards Not Included  in 40 CFR 192.32(a)

Standard
Constituent (ag/1) I/
Manganese 0.05

Molybdenum 0 • 1ฐ

Nitrate 2/ 44


pH 3/ 6.5 to 8.5



Sulfate 250



Hydraulic Flow
Relationship
Background
On-Site
Down gradient
Down gradient
Background
On-Site
Down gradient
Down gradient
Background
On-Site
Down gradient
Down gradient
Background
On-Site
Down gradient
Down gradient

Background
On-Site
Down gradient
Down gradient

Formation of
Completion
Rico
Siltstone
Rico
Siltstone
Rico
Siltstone
Rico
Siltstone
Rico
Siltstone
Rico
Siltstone
Rico
Siltstone
Rico
Siltstone

Rico
Siltstone
Rico
Siltstone

Number of
Analyses
T K
15
1
1
15
1
2
1
15
1
2
1
15
1

1

15
1
2
1

Number of
Analyses
Exceeding
Standard
3
1
3_
1
6
1



1
i
JU

1 R
JLO
i
•)
ฃ•
i
j.

Percent
Exceeding
Standard
20
100
50
100
40
100
100


6
50


100
100
100
100


Value
Obtained
(mg/1) i/ 	
0.06
0.38
0.06
0.15
0.20
0.10
80.0
_ _—

10.24
12.28
*._ซ•

4090
3170
722
947

                                                               4-76

-------
 TABLE 4-14
 Site Name:  Mexican Hat (Utah)
 Data Evaluation:  Site Water Quality Compared to U.S.  EPA  Standards Not Included
                     plus Uranium and Molybdenum
 Data Interval:   04/10/85 to 11/01/85
                                                                                   Page 3 of 3
                                                       in 40 CFR 192.32(a)
Constituent
Sulfide



Total Solids



Uranium 4/


Zinc



I/ Values are
2/ Concentratj
Standard Hydraulic Flow
(mg/1) I/ Relationship
0.05 Background
On-Site
Down gradient
Down gradient
500 Background
On-Site
Down gradient
Down gradient
0.044 Background
On-Site
Down gradient
Down gradient
5 . 0 Background
On-Site
Down gradient
Down gradient
reported _ in mg/1 unless otherwise
Formation of
Completion
Rico
Siltstone
Rico
Siltstone
Rico
Siltstone
Rico
Siltstone
Rico
Siltstone
Rico
Siltstone
Rico
Siltstone
Rico
Rico
indicated.
JVel of in mer/1
Number of
Analyses
15
1
2
1
15
1
2
1
15
1
2
1
15
1
2
1
1 fi Gem i *ra 1 orปH
Number of
Analyses
Exceeding
Standard
15
1
2

15
1
2
1
2
1

	

" _:.:_
„ „ n.
	
h 4*^ /^^\*sx^j^v*^*™-ป
Percent
Exceeding
Standard
100
100
100

100
100
100
100
13
100

—



—

Maximum
Value
Obtained
(mg/1) I/
0.10
0. 10
0. 10

6550
1960
4250
1870
0.0512
OfiO9
. O \J ft
0.0334



	

V
	  Standard not exceeded.
egUlValent ฐf 0'044  -*/1'  assumin* the bulk of uranium is U-238.   All analyses are reported as
                                                            4-77

-------
4.9  MONUMENT VALLEY, ARIZONA - SUMMARY OF WATER QUALITY

Major hydrostratigraphic units at the Monument Valley site
are alluvium and dune sand, the Shinarump Member of the
Sinle Formation, the Moenkopi Formation, and the DeChelly
Sandstone Member of the Cutler Formation.  The alluvium,
Shinarump and the DeChelly Sandstone are aquifers.  The
MoeSSS! is an aguitard which separates the Shinarump from
the underlying DeChelly Sandstone.

The background water quality .in all three of the aquifers is
good.  Only the alluvial aquifer has been appreciably
Iffected by the tailings.  The alluvial groundwater is
unconfined and ranges from . approximately two feet to 45 feet
below the surface in the vicinity of the tailings.
Groundwater use near the site consists of two
alluvial wells which are used by local residents.
production wells are located on and down gradient of the
site   The production  wells supplied water for the former
milling operations but are not presently used.  Two seeps
east of the tailings site are discharges of alluvial ground-
water and are used for watering livestock.  Sampling of
these wells and seeps has not revealed the presence of any
contamination from the tailings.

Chromium exceeded the standard in  some samples from all
three down gradient aquifers.  The down gradient alluvium
had ?he highest value for chromium, as well as, the highest
percentage of samples exceeding the standard.

The gross alpha standard was exceeded  in background samples
of the Ihinaiump Formation  and the down gradient alluvium
and DeChelly Formation  samples.  The highest  values obtained
were  from the down gradient alluvium,  in which the maximum
value exceeded the Standard by more than a  factor of  three.

One of nine radium background  samples  from  the Shinarump
Formation exceeded the  standard.   This sample exceeded the
standard by a factor  of less than  two.
                                                          the
 mobile contaminant plume will dissipate within the
 in approximately 120 years.
                               4-78

-------
TABLE 4-15
Site Name:
            Monument  Valley  (Arizona)
                                                                                                          Page 1 of 10
                                                                          4ฐ
Constituent

Arsenic
                    Standard    Hydraulic Flow
                    (mg/1)  i/   Relationship

                     0.05       Background
                                Background
                                Background
                                Cross-gradient
                                Cross-gradient
                                Cross-gradient


                                On-site
                                Down gradient
                                Down gradient
                                Down gradient
 Formation of
 Completion
Number of
Analyses
Number of
Analyses
Exceeding
Standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/1) I/
 Alluvium             7
 Shinarump  member    10
 of the  Chinle
 Formation
 DeChelly member      9
 of the  Cutler
 Formation
 Alluvium             4
 Shinarump  member     2
 of the  Chinle
 Formation
 DeChelly member      6
 of the  Cutler
 Formation
 DeChelly member      8
 of the  Cutler
 Formation
Alluvium            44
Shinarump member    15
of the Chinle
Formation
DeChelly member      8
of the Cutler
Formation
                                                             4-79

-------
TABLE 4-15
Site Name:  Monument Valley (Arizona)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards from 40 CFR 192.32(a)
Data Interval:  06/08/82 to 04/30/86
                                                                                                         Page 2 of 10
Constituent

Barium
Standard    Hydraulic Flow
(mg/1) I/   Relationship
                                                  Formation of
                                                  Completion
                                 Number of
                                 Analyses
                             Number of
                             Analyses
                             Exceeding
                             Standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
 (mg/1) I/
 1.0
Background
Background
                                Background
                                 Cross-gradient
                                 Cross-gradient
                                 Cross-gradient
                                 On-Site
                                 Down gradient
                                 Down gradient
                                 Down gradient
Alluvium             6
Shinarump member     9
of the Chinle
Formation
DeChelly member      7
of the Cutler
Formation
Alluvium             4
Shinarump member     2
of the Chinle
Formation
DeChelly member      6
of the Cutler
Formation
DeChelly member      8
of the Cutler
Formation
Alluvium            34
Shinarump member    12
of the Chinle
Formation
DeChelly member      4
of the Cutler
Formation
                                                              4-80

-------
TABLE 4-15
Site Name:
            Monument Valley  (Arizona)
                                                                                                          Page 3 of 10
                                     compared to u-s- EPA standards from 4ฐ CFR  i92-32(a)
Constituent

Cadmium
                    Standard    Hydraulic Flow
                    (mg/1) I/   Relationship
Formation of   Number of
Completion     Analyses
Number of
Analyses
Exceeding
Standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/1) I/
                     0.01       Background
                                Background
                                Background
                                Cross-gradient
                                Cross-gradient
                                Cross-gradient
                                On-Site
                                Down gradient
                                Down gradient
                                Down gradient
                                                  Alluvium             e
                                                  Shinarump member    10
                                                  of the Chinle
                                                  Formation
                                                  DeChelly member      8
                                                  of the Cutler
                                                  Formation
                                                  Alluvium             4
                                                  Shinarump member     2
                                                  of the Chinle
                                                  Formation
                                                  DeChelly member      6
                                                  of the Cutler
                                                  Formation
                                                  DeChelly member      8
                                                  of the Cutler
                                                  Formation
                                                  Alluvium           44
                                                  Shinarump member    15
                                                  of the  Chinle
                                                  Formation
                                                  DeChelly  member       8
                                                  of the  Cutler
                                                  Formation
                                                            4-81

-------
TABLE 4-15
Site Name:  Monument Valley (Arizona)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards from 40 CFR 192.32(a)
Data Interval:  06/08/82 to 04/30/86
                                                                                                         Page 4 of 10
Constituent

Chromium
Standard    Hydraulic Flow
(mg/1)  I/   Relationship

 0.05       Background
            Background
                                Background
                                Cross-gradient
                                Cross-gradient
                                 Cross-gradient
                                 On-Site
                                 Down gradient
                                 Down gradient
                                 Down gradient
                                                  Formation of
                                                  Completion
               Number of
               Analyses
Number of
Analyses
Exceeding
Standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/1) l/
Alluvium             6
Shinarump member    10
of the Chinle
Formation
DeChelly member      8
of the Cutler
Formation
Alluvium             4
Shinarump member     2
_of the Chinle
Formation
DeChelly member      6
of the Cutler
Formation
DeChelly member      8
of the Cutler
Formation
Alluvium            44
Shinarump member    15
of the Chinle
Formation
DeChelly member      8
of the Cutler
Formation
                                                               12
                                                                1
                27
                 6
                                                                                               25
                  0.09
                  0.07
                                                                                                              0.07
                                                              4-82

-------
TABLE 4-15
Site Name:  Monument Valley (Arizona)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards from 40 CFR 192.32(a)
Data Interval:  06/08/82 to 04/30/86
                                                                                     Page 5 of 10
Constituent
Standard
(mg/1) I/
Hydraulic Flow
Relationship
Formation of
Completion
Number of
Analyses
Number of
Analyses
Exceeding
Standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/1) I/
Gross Alpha
(excluding radon
and uranium)
15.0 pci/l
Background
Background
Alluvium
Shinarump member
of the Chinle
6
10
1
10
17.104
                                Background
                                Cross-gradient
                                Cross-gradient
                                Cross-gradient
                                On-Site
                                Down gradient
                                Down gradient
                                Down gradient
                              Formation
                              DeChelly member      8
                              of the Cutler
                              Formation
                              Alluvium             4
                              Shinarump member     2
                              of the Chinle
                              Formation
                              DeChelly member      6
                              of the Cutler
                              Formation
                              DeChelly member      8
                              of the Cutler
                              Formation
                              Alluvium            44
                              Shinarump member    15
                              of the Chinle
                              Formation
                              DeChelly member      8
                              of the Cutler
                              Formation
                                                               15
                                                               12
                                                          45.968
                                                          16.372
                                                             4-83

-------
TABLE 4-15
Site Name:  Monument Valley (Arizona)
Data Evaluation:  Site Water Quality Compared to U.S.
Data Interval:  06/08/82 to 04/30/86
                                                       Page 6 of 10
    EPA Standards from 40 CFR 192.32(a)
Constituent
Lead
Standard
(mg/1) I/
0.05
Hydraulic Flow
Relationship
Background
Background
Formation of
Completion
Number of
Analyses
Number of
Analyses
Exceeding
Standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/1) I/
Alluvium 6 	 	 	
Shinarump member 10 	 	
                                Background
                                Cross-gradient
                                Cross-gradient
                                Cross-gradient


                                On-Site
                                Down gradient
                                Down gradient
                                Down gradient
of the Chinle
Formation
DeChelly member      8
of the Cutler
Formation
Alluvium             4
Shinarump member     2
of the Chinle
Formation
DeChelly member      6
of the Cutler
Formation
DeChelly member      8
of the Cutler
Formation
Alluvium            44
Shinarump member    15
of the Chinle
Formation
DeChelly member      8
of the Cutler
Formation
                                                             4-84

-------
TABLE 4-15
Site Name:  Monument Valley  (Arizona)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards from 40 CFR 192.32(a)
Data Interval:  06/08/82 to 04/30/86
                                                                                      Page 7  of 10
Constituent

Mercury
Standard    Hydraulic Flow
(mg/1) I/   Relationship
 Formation of
 Completion
Number of
Analyses
Number of
Analyses
Exceeding
Standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/l> I/
 0.002      Background
            Background
                                Background
                                Cross-gradient
                                Cross-gradient
                                Cross-gradient
                                On-Site
                                Down gradient
                                Down gradient
                                Down gradient
Alluvium              6
Shinarump member      9
of the Chinle
Formation
DeChelly member       7
of the Cutler
Formation
Alluvium              4
Shinarump member      2
of the Chinle
Formation
DeChelly member       6
of the Cutler
Formation
DeChelly member       8
of the Cutler
Formation
Alluvium            34
Shinarump member    12
of the Chinle
Formation
DeChelly member      4
of the Cutler
Formation
                                                             4-85

-------
TABLE 4-15
Site Name:  Monuaent Valley (Arizona)
Data Evaluation:  Site Water Quality Compared to U.S.
Data Interval:  06/08/82 to 04/30/86
                                                                                     Page 8 of 10
                                  EPA Standards from 40 CFR 192.32(a)
Constituent
Standard    Hydraulic Flow
(mg/1) I/   Relationship
Formation of
Completion
Number of
Analyses
                                                                               Number of
                                                                               Analyses
                                                                               Exceeding
                                                                               Standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/1) I/
Ra-226 + Ra-228
 (Radium)
 5.0 pCi/1  Background
            Background
                                Background
                                Cross-gradient
                                Cross-gradient
                                Cross-gradient
                                On-Site
                                Down gradient
                                Down gradient
                                Down gradient
Alluvium             6
Shinarump member     9
of the Chinle
Formation
DeChelly member      7
of the Cutler
Formation
Alluvium             4
Shinarump member     2
of the Chinle
Formation
DeChelly member      6
of the Cutler
Formation
DeChelly member      8
of the Cutler
Formation
Alluvium            34
Shinarump member    12
of the Chinle
Formation
DeChelly member      3
of the Cutler
Formation
                              11
                                            8.8
                                                             4-86

-------
TABLE 4-15
Site Name:  Monument Valley  (Arizona)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards  from 40  CFR 192.32(a)
Data Interval:  06/08/82 to 04/30/86
                                                        Page 9 of 10
Constituent
Selenium
Standard
(mg/1) I/
0.01
Hydraulic Flow
Relationship
Background
Background
Formation of
Completion
Number of
Analyses
Number of
Analyses
Exceeding
Standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/1) I/
Alluvium 7 	 	 	
Shinafump member 10 	 	 	
                                Background
                                Cross-gradient
                                Cross-gradient
                                Cross-gradient


                                On-Site
                                Down gradient
                                Down gradient
                                Down gradient
of the Chinle
Formation
DeChelly member      9
of the Cutler
Formation
Alluvium             4
Shinarump member     2
of the Chinle
Formation
DeChelly member      6
of the Cutler
Formation
DeChelly member      8
of the Cutler
Formation
Alluvium            44
Shinarump member    15
of the Chinle
Formation
DeChelly member      8
of the Cutler
Formation
                                                             4-87

-------
TABLE 4-15
Site Naae:  Monument Valley  (Arizona)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards from 40 CFR 192.32(a)
Data Interval:  06/08/82 to 04/30/86
                                                                                     Page 10 of 10
Constituent

Silver
standard    Hydraulic Flow
(mg/1) I/   Relationship
Formation of
Completion
Number of
Analyses
                                                                               Number of
                                                                               Analyses
                                                                               Exceeding
                                                                               Standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/1) I/
 0.05       Background
            Background
                                Background
                                Cross-gradient
                                Cross-gradient
                                Cross-gradient
                                On-Site
                                Down gradient
                                Down gradient
                                Down gradient
Alluvium             6
Shinarump member     9
of the Chinle
Formation
DeChelly member      7
of the Cutler
Formation
Alluvium             4
Shinarump member     2
of the Chinle
Formation
DeChelly member      6
of the Cutler
Formation
DeChelly member      8
of the Cutler
Formation
Alluvium            34
Shinarump member    12
of the Chinle
Formation
DeChelly member      4
of the Cutler
Formation
I/    Values are reported in mg/1 unless otherwise  indicated.
	   Standard not exceeded.
                                                              4-88

-------
TABLE 4-16
Site Name:  Monument Valley (Arizona)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards Not Included in 40 CFR  192.32(a)
                    plus Uranium and Molybdenum
Data Interval:  06/08/82 to 04/30/86
                                                          Page 1 of 15
Constituent
Chloride
Standard
(mg/1) I/
250
Hydraulic Flow
Relationship
Background
Background
Formation of
Completion
Number of
Analyses
Number of
Analyses
Exceeding
Standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/1) I/
Alluvium 7 	 	
Shinarump member 10 — — • ---
                                Background
                                Cross-gradient
                                Cross-gradient
                                Cross-gradient
                                On-Site
                                Down gradient
                                Down gradient
                                Down gradient
of the Chinle
Formation
DeChelly member      9
of the Cutler
Formation
Alluvium             4
Shinarump member     2
of the Chinle
Formation
DeChelly member      6
of the Cutler
Formation
DeChelly member      8
of the Cutler
Formation
Alluvium            44
Shinarump member    15
of the Chinle
Formation
DeChelly member      8
of the Cutler
Formation
                                                             4-89

-------
TABLE 4-16
Site Name:  Monument Valley (Arizona)
Data Evaluation:  Site Water Quality Compared to U.S.
                    plus Uraniuma and Molybdenum
Data Interval:  06/08/82 to 04/30/86
                                                      Page 4  of 15
EPA Standards Not Included in 40 CFR 192.32(a)
Standard Hydraulic Flow
Constituent (mg/1) I/ Relationship
Hydrogen Sulfide 0.05 Background
Background


Background


Cross-gradient
Cross-gradient


Cross-gradient


On-Site

i
Down gradient
Down gradient


Down gradient


Formation of Number of
Completion Analyses
Alluvium
Shiriarump member
of the Chinle
Formation
DeChelly member
of the Cutler
Formation
Alluvium
Shinarump member
of the Chinle
Formation
DeChelly member
of the Cutler
Formation
DeChelly member
of the Cutler
Formation
Alluvium
Shinarump member
of the Chinle
Formation
DeChelly member
of the Cutler
Formation
1
1


1


1
1


1


1


1
1


1


Number of Maximum
Analyses Percent Value
Exceeding Exceeding Obtained
Standard Standard (ปg/l) !/

— — — — —


	 - — 	


___ — - —
— — — — —


— - 	 —


___ ___ —


	 	 	
___ ___ ___


-: — 	 	


                                                            4-92

-------
TABLE 4-16
Site Name:  Monument Valley (Arizona)
Data Evaluation:  Site Water Quality Compared to U.S.  EPA Standards Not Included in 40 CFR 192.32(a)
                    plus Uranium and Molybdenum
Data Interval:  06/08/82 to 04/30/86
                                                                                        Page 5 of 15
Constituent

Iron
Standard    Hydraulic Flow
(mg/1) I/   Relationship
Formation of
Completion
Number of
Analyses
Number of
Analyses
Exceeding
Standard
                                                                                            Percent
                                                                                            Exceeding
                                                                                            Standard
Maximum
Value
Obtained
(mg/1) I/
 0.30       Background
            Background
                                Background
                                Cross-gradient
                                Cross-gradient
                                Cross-gradient
                                On-Site
                                Down gradient
                                Down gradient
                                Down gradient
Alluvium             7
Shinarump member    10
of the Chinle
Formation
DeChelly member      9
of the Cutler
Formation
Alluvium             4
Shinarump member     2
of the Chinle
Formation
DeChelly member      6
of the Cutler
Formation
DeChelly member      8
of the Cutler
Formation
Alluvium            44
Shinarump member    15
of the Chinle
Formation
DeChelly member      8
of the Cutler
Formation
                                                                                               10
                                             0.33
                                                                                         0.31
                                                             4-93

-------
TABLE 4-16
Site Name;  Monument Valley (Arizona)
Data Evaluation:  Site Water Quality compared to U.S. EPA Standards Not Included in 40 CFR 192.32(a)
                    plus Uranium and Molybdenum
Data Interval:  06/08/82 to 04/30/86
                                                                                        Page 6 of 15
Constituent

Manganese
Standard    Hydraulic Flow
(mg/1) I/   Relationship
Formation of
Completion
Number of
Analyses
Number of
Analyses
Exceeding
Standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/1) I/
 0.05       Background
            Background
                                Background
                                Cross-gradient
                                Cross-gradient
                                Cross-gradient


                                On-Site
                                Down gradient
                                Down gradient
                                Down gradient
Alluvium             6
Shinarump member    10
of the Chinle
Formation
DeChelly member      8
of the Cutler
Formation
Alluvium             4
Shinarump member     2
of the Chinle
Formation
DeChelly member      6
of the Cutler
Formation
DeChelly member      8
of the Cutler
Formation
Alluvium            44
Shinarump member    15
of the Chinle
Formation
DeChelly member      8
of the Cutler
Formation
                                                                                               70
                                            0.10
                                                                           50
                                                                           50
                                            0.09
                                            0.21
                                                               20
                                                                7
                              44
                              46
                                                                                               37
                              0.58
                              0.17
                                                                                         0.11
                                                            4-94

-------
TABLE 4-16
Site Name:  Monument Valley (Arizona)
Data Evaluation:  Site Water Quality Compared to U.S.
                    plus Uranium and Molybdenum
Data Interval:  06/08/82 to 04/30/86
                                                                                                            Page  7  of 15
                                  EPA Standards Not Included in 40 CFR 192.32(a)
Constituent

Molybdenum
Standard    Hydraulic Flow
(mg/1) I/   Relationship
Formation of   Number of
Completion     Analyses
                                                                               Number of
                                                                               Analyses
                                                                               Exceeding
                                                                               Standard
        Percent
        Exceeding
        Standard
          Maximum
          Value
          Obtained
          (mg/1) I/
 0.10       Background
            Background
                                Background
                                Cross-gradient
                                Cross-gradient
                                Cross-gradient


                                On-Site
                                Down gradient
                                Down gradient
                                Down gradient
Alluvium"             7
Shinarump member    10
of the Chinle
Formation
DeChelly member      9
of the Cutler
Formation
Alluvium             4
Shinarump member     2
of the Chinle
Formation
DeChelly member      6
of the Cutler
Formation
DeChelly member      7
of the Cutler
Formation
Alluvium            44
Shinarump member    15
of the Chinle
Formation
DeChelly member      8
of the Cutler
Formation
1
4
                                                                2
                                                                1
                                                               37
                                                               14
14
40
                                                                                                44
           50
           50
                                                                                                83
           84
           93
                                                                           100
0.11
0.22
                                                                                                              0.19
              0.19
              0.16
                                                                                                              0.21
              0.35
              0.25
                                                                                                              0.24
                                                             4-95

-------
TABLE 4-16
Site Name:  Monument Valley  (Arizona)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards Not Included in 40 CFR 192.32(a)
                    plus Uranium and Molybdenum
Data Interval:  06/08/82 to 04/30/86
                                                                                        Page 8 of 15
Constituent

Nitrate 2/
Standard    Hydraulic Flow
(mg/1) I/   Relationship
                  Formation of
                  Completion
               Number of
               Analyses
Number of
Analyses
Exceeding
Standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/1) I/
44
Background
Background
                                Background
                                Cross-gradient
                                Cross-gradient
                                Cross-gradient


                                On-Site
                                Down gradient
                                Down gradient
                                Down gradient
Alluvium             6
Shinarump member    10
of the Chinle
Formation
Dechelly member      8
of the Cutler
Formation
Alluvium             4
Shinarump member     2
of the Chinle
Formation
DeChelly member      6
of the Cutler
Formation
DeChelly member      8
of the Cutler
Formation
Alluvium            44
Shinarump member    15
of the Chinle
Formation
DeChelly member      8
of the Cutler
Formation
                                                               15
                                                               34
                                                                                      1200
                                                            4-96

-------
TABLE 4-16
Site Name:  Monument Valley (Arizona)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards Not Included in 40 CFR 192.32(a)
                    plus Uranium and Molybdenum
Data Interval:  06/08/82 to 04/30/86
                                                                                                            Page 9 of  15
Constituent

pH 3/
 Standard    Hydraulic Flow
 (mg/1) I/   Relationship
 Formation of
 Completion
Number of
Analyses
                                                                               Number of
                                                                               Analyses
                                                                               Exceeding
                                                                               Standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/1) I/
6.5 to 8.5   Background
             Background
                                Background
                                Cross-gradient
                                Cross-gradient
                                Cross-gradient
                                On-Site
                                Down gradient
                                Down gradient
                                Down gradient
 Alluvium             7
 Shinarump member    10
 of the Chinle
 Formation
 DeChelly member      9
 of the Cutler
 Formation
 Alluvium             4
 Shinarump member     2
.of the Chinle
 Formation
 DeChelly member      6
 of the Cutler
 Formation
 DeChelly member      8
 of the Cutler
 Formation
 Alluvium            44
 Shinarump member    15
 of the Chinle
"Formation
 DeChelly member      8
 of the Cutler
 Formation
                                                                                                22
                                                                                                              9.36
                                                                             2
                                                                             6
                                                                                                50
                                             9.68
                                             8.65
                                                                                                              9.89
                                                             4-97

-------
TABLE 4-16
Sitซ Names  Monument Valley (Arizona)
Data Evaluation:  Site Water Quality Coapared t
                    plus Uranium and Molybdenum
Data Interval:  06/08/82 to 04/30/86
                                                                                                            Page 10 of 15
                                                 U.S.  EPA Standards Not Included in 40 CFR 192.32(a)
Constituent

Sulfate
                    Standard    Hydraulic Flow
                    (mg/1)  I/   Relationship
Formation of   Number of
Completion     Analyses
Number of
Analyses
Exceeding
Standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/1) I/
                   250
                                Background
                                Background
                                Background
                                Cross-gradient
                                Cross-gradient
                                Cross-gradient
                                On-Site
                                Down gradient
                                Down gradient
                                Down gradient
Alluvium             7
Shinarump member    10
of the Chinle
Formation
DeChelly member      9
of the Cutler
Formation
Alluvium             4
Shinarump member     2
of the Chinle
Formation
DeChelly member      6
of the Cutler
Formation
DeChelly member      8
of the Cutler
Formation
Alluvium            44
Shinarump member    15
of the Chinle
Formation
DeChelly member      8
of the Cutler
Formation
                                                                                   28.
                63
              3130
                                                            4-98

-------
TABLE 4-16
Site Name:  Monument Valley (Arizona)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards Not Included in 40 CFR 192.32(a)
                    plus Uranium and Molybdenum
Data Interval:  06/08/82 to 04/30/86
                                                                                         Page  11  of  15
Constituent

Sulfide
Standard    Hydraulic Flow
(mg/1)  I/   Relationship
Formation of
Completion
Number of
Analyses
Number of
Analyses
Exceeding
Standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/1) I/
 0.05       Background
            Background
                                Background
                                Cross-gradient
                                Cross-gradient
                                Cross-gradient


                                On-Site
                                Down gradient
                                Down gradient
                                Down gradient
Alluvium             6
Shinarump member     9
of the Chinle
Formation
DeChelly member      7
of the Cutler
Formation
Alluvium             4
Shinarump member     2
of the Chinle
Formation
DeChelly member      6
of the Cutler
Formation
DeChelly member      8
of the Cutler
Formation
Alluvium            34
Shinarump member    12
of the Chinle
Formation
DeChelly member      5
of the Cutler
Formation
                                                                                    3
                                                                                    7
                                                                2
                                                                1
                                                                1



                                                                6
                                                               28
                                                                7
                              50
                              77
                                                                           57
                              50
                              50
                              16


                              75
                              82
                              58
                                                                          100
                              0.10
                              0.10
                                             0.10
                              0.10
                              0.10
                              0.10
                              0.10
                              0.10
                              0.10
                                            0.10
                                                             4-99

-------
I
           TABLE 4-16
           Site Name:  Monument Valley (Arizona)                                            t       m „„„ „, .
           Data Evaluation:  Site Water Quality Compared to U.S.  EPA Standards Not Included in 40 CFR 192.32(a)
                               plus Uranium and Molybdenum
           Data Interval:  06/08/82 to 04/30/86
                                                                                                                       Page 12  of 15
           Constituent

           Total Solids
 Standard    Hydraulic Flow
 (mg/1) I/   Relationship
                  Formation of   Number of
                  Completion     Analyses
                                                                                          Number of
                                                                                          Analyses
                                                                                          Exceeding
                                                                                          Standard
                                          Percent
                                          Exceeding
                                          Standard
Maximum
Value
Obtained
(mg/1) I/
500
Background
Background
                                           Background
                                           Cross-gradient
                                           Cross-gradient
                                           Cross-gradient
                                           On-Site
                                           Down gradient
                                           Down gradient
                                           Down gradient
Alluvium             7
Shinarump member    10
of the Chinle
Formation
DeChelly member      9
of the Cutler
Formation
Alluvium             4
Shinarump member     2
of the Chinle
Formation
DeChelly member      6
of the Cutler
Formation
DeChelly member      8
of the Cutler
Formation
Alluvium            44
Shinarump member    15
of the Chinle
Formation
DeChelly member      8
of the Cutler
Formation
                                                                            28
                                                                                        626
                                                                28
                                                                 6
                                                               63
                                                               40
                                                                                                          25
 5590
  730
                                                                                                                      563
                                                                       4-100

-------
TABLE 4-16
Site Name:  Monument Valley (Arizona)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards Not Included in 40 CFR 192.32(a)
                    plus Uranium and Molybdenum
Data Interval:  06/08/82 to 04/30/86
                                                                                         Page  13  of 15
Constituent

Uranium 4/
Standard    Hydraulic Flow
(mg/1) I/   Relationship
Formation of
Completion
Number of
Analyses
Number of
Analyses
Exceeding
Standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/1) I/
 0.044      Background
            Background
                                Background
                                Cross-gradient
                                Cross-gradient
                                Cross-gradient


                                On-Site
                                Down gradient
                                Down gradient
                                Down gradient
Alluvium             7
Shinarump member    10
of the Chinle
Formation
DeChelly member      9
of the Cutler
Formation
Alluvium             4
Shinarump member     2
of the Chinle
Formation
DeChelly member      6
of the Cutler
Formation
DeChelly member      8
of the Cutler
Formation
Alluvium   „         44
Shinarump member    15
Of the Chinle
Formation
DeChelly member      8
of the Cutler
Formation
                                                                                               13
                                                                                         0.0514
                                                             4-101

-------
TABLE 4-16
Site Name:  Monument valley (Arizona)
Data Evaluation:  Site Water Quality Compared to U.S.
                    plus Uranium and Molybdenum
Data Interval:  06/08/82 to 04/30/86
                                                                                        Page 14  of 15
                                  EPA Standards Not Included in 40 CFR 192.32(a)
Constituent

Zinc
Standard    Hydraulic Flow
(mg/1) I/   Relationship
                  Formation of
                  Completion
               Number of
               Analyses
                                                                               Number of
                                                                               Analyses
                                                                               Exceeding
                                                                               standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/1) I/
 5.0
Background
Background
                                Background
                                Cross-gradient
                                Cross-gradient
                                Cross-gradient


                                On-Site
                                Down gradient
                                Down gradient
                                Down gradient
Alluvium             6
Shinarump member    10
of the Chinle
Formation
DeChelly member      8
of the Cutler
Formation
Alluvium             4
Shinarump member     2
of the Chinle
Formation
DeChelly member      6
of the Cutler
Formation
DeChelly member      8
of the Cutler
Formation
Alluvium            44
Shinarump member    15
of the Chinle
Formation
DeChelly member      8
of the Cutler
Formation
                                                               4-102

-------
TABLE 4-16
Site Name:  Monument Valley .(Arizona)
Data Evaluation:  Site Water Quality Compared to U.S.
                    plus Uranium and Holybedum
Data Interval:  06/08/82 to 04/30/86
                                                       Page  15  of  15
EPA Standards Not Included in 40 CFR 192.32(a)
Constituent
Standard
(mg/1) I/
Hydraulic Flow
Relationship
Formation of
Completion
Number of
Analyses
Number of
Analyses
Exceeding
Standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/1) I/
I/   Values are reported in mg/1 unless otherwise indicated.
2/   Concentrations of nitrate as nitrogen at a level of  10 mg/1 is equivalent to concentration of nitrate as nitrate at a
     level of 44 mg/1.  All analyses are reported in terms of nitrate as nitrate.
3/   pH reported in standard units.
4/   30 pCi/1 of uranium is equivalent of 0.044 mg/1,  assuming the bulk of uranium is U-238.  All analyses are reported as
     total uranium in mg/1.
—  Standard not exceeded.
                                                               4-103

-------
4.10  RIVERTON, WYOMING - SUMMARY OF WATER QUALITY

The Riverton process site lies on the floodplain of the Wind
and Little Wind Rivers. The site rests on, in descending
order, recent alluvium and beds of the Wind River Formation.
There are two aquifers in the site vicinity; the water table
(unconfined)aquifer consisting of alluvium and the uppermost
sandstone of the Wind River Formation (2) the confined
aquifer consisting of deeper sandstone beds.  Contamination
is restricted largely to the unconfined aquifer.  Histor-
ically the unconfined aquifer within the plume area has had
limited use; currently, the aquifer is not being used in
this area.  The confined aquifer does not appear to be
contaminated.

Groundwater sampling indicated that limits of concentration
of gross alpha were exceeded.  The one on-site gravel
analyzed for gross alpha exceeded the standard by more than
a factor of 17.  Concentrations of arsenic, chromium,
barium, silver, cadmium, mercury, radium, lead and selenium
were below the limits for the standard.

Groundwater discharges to the Little Wind River, approxi-_
mately 3000 feet from the site.  Modeling indicates that it
will take 45 to 65 years for the mobile contaminants to
completely flush from the unconfined aquifer.  Based on the
present location of the molybdenum plume relative to the
sulfate plume, it may take 200 to 300 years to flush molyb-
denum from the system.
                               4-104

-------
TABLE 4-17
Site Name:  Riverton  (Wyoming)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards from 40 CFR 192.32(a)
Data Interval:  12/02/83 to 06/05/85
                                                                                     Page 1 of 5
Constituent

Arsenic
Standard    Hydraulic Flow
(mg/1)  I/   Relationship
Formation of
Completion
Number of
Analyses
Number of
Analyses
Exceeding
Standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/1) I/
                     0.05
Barium
                     1.0
            Background
                                On-Site
                                On-Site
                                Down gradient
            Down gradient

            Background


            On-Site


            On-Site
            Down gradient


            Down gradient
Gravel or sandy     8
gravel, poorly
graded
Gravel or sandy     3
gravel, poorly
graded
Sandstone          21
Gravel or sandy     1
gravel, poorly
graded
Sandstone           3

Gravel or sandy     8
gravel, poorly
graded
Gravel or sandy     3
gravel, poorly
graded
Sandstone          21
Gravel or sandy     1
gravel,  poorly
graded
Sandstone           3
                                                           4-105

-------
TABLE 4-17
site Name:  Riverton (Wyoming)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards from 40 CFR 192.32(a)
Data Interval:  12/02/83 to 06/05/85
                                                                                     Page 2 of 5
Constituent

Cadmium
standard    Hydraulic Flow
(mg/1) I/   Relationship
Formation of   Number of
Completion     Analyses
                                                                               Number of
                                                                               Analyses
                                                                               Exceeding
                                                                               Standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/1)
 Chromium
 0.01       Background
                                On-Site
                                On-Site
                                Down gradient
            Down gradient

 0.05       Background


            On-Site


            On-Site
            Down gradient


            Down gradient
Gravel or sandy     8
gravel, poorly
graded
Gravel or sandy     3
gravel, poorly
graded
Sandstone          21
Gravel or sandy     1
gravel, poorly
graded
Sandstone           3

Gravel or sandy     8
gravel, poorly
graded
Gravel or sandy     3
gravel, poorly
graded
Sandstone          21
Gravel or sandy     1
gravel, poorly
graded
Sandstone           3
                                                              4-106

-------
TABLE 4-17
Site Name:  Riverton  (Wyoming)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards from 40 CFR 192.32(a)
Data Interval:  12/02/83 to 06/05/85
                                                                                     Page 3 of 5
Constituent
Standard
(mg/1) l/
Hydraulic Flow
Relationship
Formation of
Completion
Number of
Analyses•
Number of
Analyses
Exceeding
Standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/1) I/
Gross Alpha
 (excluding radon
  and uranium)
Lead
15.0 pci/l  Background


            On-Site


            On-Site
            Down gradient


            Down gradient

 0.05       Background


            On-Site


            On-Site
            Down gradient


            Down gradient
                  Gravel or sandy     9
                  gravel, poorly
                  graded
                  Gravel or sandy     l
                  gravel, poorly
                  graded
                  Sandstone          10
                  Gravel or sandy     l
                  gravel, poorly
                  graded
                  Sandstone           3

                  Gravel or sandy     8
                  gravel, poorly
                  graded
                  Gravel or sandy     3
                  gravel, poorly
                  graded
                  Sandstone          21
                  Gravel or sandy     1
                  gravel, poorly
                  graded
                  Sandstone           3
                                                                                              100


                                                                                               10
                                                         260.8
                                                          65.2
                                                              4-107

-------
TABU: 4-17
site Name:  Riverton  (Wyoming)                                               _     ,,,_\
Data Evaluation:  Site Water Quality Compared to U.S. EPA standards from 40 CFR 192.32(a)
Data interval:  12/02/83 to 06/05/85
                                                                                                         Page 4 of 5
Constituent

Mercury
Standard    Hydraulic Flow
(mg/1) I/   Relationship
Formation of   Number of
Completion     Analyses
                                                                               Number of
                                                                               Analyses
                                                                               Exceeding
                                                                               Standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/1)
 Ra-226 + Ra-228
  (Radium)
 0.002      Background
                                 On-Site
                                 On-Site
                                 Down  gradient
            Down gradient

 5.0 pCi/1  Background


            On-Site


            On-Site
            Down gradient


            Down gradient
Gravel or sandy     8
gravel, poorly
graded
Gravel or sandy     3
gravel, poorly
graded
Sandstone          16
Gravel or sandy     1
gravel, poorly
graded
Sandstone           3

Gravel or sandy     8
gravel, poorly
graded
Gravel or sandy     2 2/
gravel, poorly
graded
Sandstone           7
Gravel or sandy     1
gravel, poorly
graded
Sandstone           3
                                                                4-108

-------
 TABLE 4-17
 Site Name:  Riverton (Wyoming)
 Data Evaluation:   Site Water Quality Compared to U.S. EPA Standards from 40 CFR 192.32(a)
 Data Interval:   12/02/83 to 06/05/85
                                                                                      Page 5 of 5
 Constituent

 Selenium
Standard    Hydraulic Flow
(mg/1) I/   Relationship
 Formation of   Number of
 Completion     Analyses
Number of
Analyses
Exceeding
Standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/1) I/
Silver
 0.01       Background


            On-Site


            On-Site
            Down gradient


            Down gradient

 0.05       Background


            On-Site


            On-Site
            Down gradient


            Down gradient
 Gravel or sandy      8
 gravel, poorly
 graded
 Gravel or sandy      3
 gravel, poorly
 graded
 Sandstone          21
 Gravel or sandy      1
 gravel, poorly
 graded
 Sandstone            3

 Gravel or sandy      8
 gravel, poorly
 graded
 Gravel or sandy      3
gravel, poorly
graded
Sandstone          16
Gravel or sandy     1
gravel, poorly
graded
Sandstone           3
I/    Values are reported in mg/1 unless otherwise indicated.
2/    Analyses for Ra-226 only.
	   Standard not exceeded.
                                                                4-109

-------
TABLE 4-18

Data Evaluation*  Site Water5Quality Coapared to U.S. EPA Standards Not Included  in 40 CFR 192.32(a)
                    plus Uranium and Molybdenum
Data Interval:  12/02/83 to 06/05/85
                                                                                                              Page 1 of 8
Constituent

Chloride
Standard
(ng/D
Hydraulic Flow
Relationship
Formation of   Number of
Completion     Analyses
                                                                               Number of
                                                                               Analyses
                                                                               Exceeding
                                                                               Standard
Percent
Exceeding
Standard
Maximum
.Value
Obtained
 (mg/1) I/
 250
 Copper
                       1.0
Background


On-Site


On-Site
Down gradient


Down gradient

Background


On-Site
                                 On-Site
                                 Down gradient
                                 Down gradient
Gravel or sandy   9
gravel, poorly
graded
Gravel or sandy   3
gravel, poorly
graded
Sandstone        21
Gravel or sandy   1
gravel, poorly
graded
Sandstone         2

Gravel or sandy   8
gravel, poorly
graded
Gravel or sandy   3
gravel, poorly
graded
Sandstone        21
Gravel or sandy   1
gravel, poorly
graded
Sandstone         3
                                                                  4-110

-------
TABLE 4-18
Site Name:  Riverton (Wyoming)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards Not Included
                    plus Uranium and Molybdenum
Data Interval:  12/02/83 to 06/05/85
                            Page 2 of 8
in 40 CFR 192.32(a)
Standard Hydraulic Flow
Constituent (mg/1) I/ Relationship
Fluoride 1.4 Background


On-Site


On-Site
Down gradient


Down gradient
Hydrogen Sulfide 0.05 Background


On-Site


On-Site
Down gradient


Down gradient
Formation of Number of
Completion Analyses
Gravel or sandy
gravel , poorly
graded
Gravel or sandy
gravel, poorly
graded
Sandstone
Gravel or sandy
gravel , poorly
graded
Sandstone
Gravel or sandy
gravel, poorly
graded
Gravel or sandy
gravel, poorly
graded
Sandstone
Gravel or sandy
gravel, poorly
graded
Sandstone
9


3


16
1


2
1


1


1
1


1
Number of Maximum
Analyses Percent Value
Exceeding Exceeding Obtained
Standard Standard (mg/1) I/
™^*™ ~™™ • • • •


— — — _ — -, .....


ป— ป— <_>*•• ••ซ
— — — —__ ซ._ซ


	 	 	
	


— — — ___ ...


ซ — — .ป•*• ซ_ _
•w ...... _ซ•ป ซ__


— — — ™ ..__
                                                            4-111

-------
TABLE 4-18
Site Name:  Riverton (Wyoming)                                                 j  J       „,,„„„„,,
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards Not Included  in 40 CFR 192.32(a)
                    plus Uranium and Molybdenum
Data Interval:  12/02/83 to 06/05/85
                                                                                                              Page 3 of 8
Constituent

Iron
Standard
(mg/1) I/
Hydraulic Flow
Relationship
Formation of   Number of
Completion     Analyses
                                                                               Number of
                                                                               Analyses
                                                                               Exceeding
                                                                               Standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/1) I/
.Manganese
   0.30      Background
                                On-Site
                                On-Site
                                Down gradient
             Down gradient

   0.05      Background


             On-Site


             On-Site
             Down gradient


             Down gradient
                  Gravel or sandy   8
                  gravel, poorly
                  graded
                  Gravel or sandy   3
                  gravel, poorly
                  graded
                  Sandstone        21
                  Gravel or sandy   1
                  gravel, poorly
                  graded
                  Sandstone         3

                  Gravel or sandy   8
                  gravel, poorly
                  graded
                  Gravel or sandy •  3
                  gravel, poorly
                  graded
                  Sandstone        21
                  Gravel or sandy   1
                  gravel, poorly
                  graded
                  Sandstone         3
                                                                                  21
                                                                                   1
                                                                                               19
                                                                                                             0.75
                                                                                              100
                                                                                              100
                                            100
                                            100
                                                           2.26


                                                           0.23
                 5.20
                 1.05
                                                              4-112

-------
 TABLE  4-18
 Site Name:  Riverton  (Wyoming)
 Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards Not Included   in  40 CFR  192.32(a)
                    plus Uranium and Molybdenum
 Data Interval:  12/02/83 to 06/05/85
                                                                                           Page 4 of 8
Constituent

Molybdenum
Standard
(mg/1) I/
Hydraulic Flow
Relationship
Formation of
Completion
Number of
Analyses
Number of
Analyses
Exceeding
Standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/1) I/
Nitrate 2/
   0.10      Background


             On-Site


             On-Site
             Down gradient


             Down gradient

 44           Background


             On-Site
                                On-Site
                                Down gradient
                                Down gradient
                  Gravel or sandy   8
                  gravel, poorly
                  graded
                  Gravel or sandy   3
                  gravel, poorly
                  graded
                  Sandstone        21
                  Gravel or sandy   1
                  gravel, poorly
                  graded
                  Sandstone         3

                  Gravel or sandy   9
                  gravel,  poorly
                  graded
                  Gravel or sandy   3
                  gravel,  poorly
                  graded
                  Sandstone        21
                  Gravel or sandy   1
                  gravel,  poorly
                  graded
                  Sandstone          3
                                                                                               19
                                                           1.69
                                                            4-113

-------
TABLE 4-18
Site Kane:  Rivarton (Wyoming)                                                    .            ,
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards Not Included  in 40 CFR 192.
                    plus Uranium and Holybdenum
Data Interval:  12/02/83 to 06/05/85
                                                                                                              Page 5 of 8
Constituent

PH 3/
  Standard
  (mg/1)  l/

6.5 to 8.5
 Sulfate
                     250
Hydraulic Flow
Relationship

Background
               On-Site


               On-Site
               Down gradient


               Down gradient

               Background


               On-Site
                                 On-Site
                                 Down gradient
                                 Down gradient
Formation of
Completion
                                                                 Number of
                                                                 Analyses
Number of
Analyses
Exceeding
Standard
Gravel or sandy  12
gravel, poorly
graded
Gravel or sandy   1
gravel, poorly
graded
Sandstone        15
Gravel or sandy   3
gravel, poorly
graded
Sandstone         3

Gravel or sandy   9
gravel, poorly
graded
Gravel or sandy   3
gravel, poorly
graded
Sandstone        21
Gravel or sandy   1
gravel, poorly
graded
Sandstone         2
                                                                 19
                                                                  1
Percent
Exceeding
Standard

    8
Maximum
Value
Obtained
(mg/1) y

    9.35
                                                              100

                                                               22


                                                              100
                                                               90
                                                              100
                                                                                                50
                             12.26

                            376


                            577
                            747
                            461
                                                                                                            286
                                                               4-114

-------
TABLE 4-18
Site Name:  Riverton (Wyoming)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards Not Included  in 40 CFR 192.32(a)
                    plus Uranium and Molybdenum
Data Interval:  12/02/83 to 06/05/85
                                                             Page 6  of 8
Standard Hydraulic Flow
Constituent (mg/1) I/ Relationship
Sulfide 0.05 Background


On-Site


On-Site
Down gradient


Down gradient
Total Solids 500 Background


On-Site


On-Site
Down gradient
Formation of Number of
Completion Analyses
Gravel or sandy
gravel , poorly
graded
Gravel or sandy
gravel , poorly
graded
Sandstone
Gravel or sandy
gravel , poorly
graded
Sandstone
Gravel or sandy
gravel , poorly
graded
Gravel or sandy
gravel , poorly
graded
Sandstone
Gravel or sandy
9


1


7
1


3
9


3


21
1
Number of
Analyses
Exceeding
Standard
9


	


7
1


3
2


3


19
1
Percent
Exceeding
Standard
100


—


100
100


100
22


100


90
100
Maximum
Value
Obtained
(mg/1) I/
0.10


— — —


0.10
0.10


0.10
950


1410


1450
1100
                                Down gradient
gravel,  poorly
graded
Sandstone
100
1172
                                                             4-115

-------
TABLE 4-18
Site Naaa:  Rivarton (Wyoming)
Data Evaluation:  Site Water Quality Compared to
                    plus Uraniua and Molybdenum
Data Interval:  12/02/83 to 06/05/85
                                                                                           Page 7  of 8
                              U.S.  EPA standards Not included  in 40  CFR 192.32(a)
Constituent

Uranium 4/
Standard
(mg/1) I/
Hydraulic Flow
Relationship
Formation of
Completion
•Number of
 Analyses
                                                                               Number of
                                                                               Analyses
                                                                               Exceeding
                                                                               Standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/1) I/
   0.044
Zinc
  5.0
Background
                                On-Site
                                On-Site
                                Down gradient
Down gradient

Background


On-Site


On-Site
Down gradient


Down gradient
Gravel or sandy   9
gravel, poorly
graded'
Gravel or sandy   2
gravel, poorly
graded
Sandstone        13
Gravel or sandy   1
gravel, poorly
graded
Sandstone         3

Gravel or sandy   8
gravel, poorly
graded
Gravel or sandy   3
gravel, poorly
graded
Sandstone        21
Gravel or sandy   1
gravel, poorly
graded
Sandstone         3
                                                                           100
                                                                                               15
                                                                             0.415


                                                                             0.305
                                                              4-116

-------
TABLE 4-18
Site Name:  Riverton (Wyoming)
Data Evaluation:  site Water Quality Compared to U.S.  EPA Standards Not Included
                    plus Uranium and Molybdenum
Data Interval:  12/02/83 to 06/05/85
                                                                                           Page 8 of 8
                                                               in 40 CFR 192.32(a)
Constituent
Standard
(mg/1) I/
Hydraulic Flow
Relationship
Formation of
Completion
Number of
Analyses
Number of
Analyses
Exceeding'
Standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/1) I/
I/   Values are reported in mg/1 unless otherwise indicated.
2/   Concentrations of nitrate as nitrogen at a level of 10 mg/1 is equivalent to concentration of nitrate as nitrate at a
     level of 44 mg/1.  All analyses are reported in terms of nitrate as nitrate.
3/   pH reported in standard units.
4/   30 pCi/1 of uranium is equivalent of 0.044 mg/1, assuming the bulk of uranium is U-238.   All analyses are reported as
     total uranium in mg/1.
	  Standard not exceeded.
                                                              4-117

-------
4.11  SALT LAKE CITY, UTAH - SUMMARY OF WATER QUALITY

The groundwater regime at the Vitro site is generally
characterized by two aquifer systems,  a near-surface
unconfined system and a deeper confined system.  Near the
site, both aquifers flow generally to  the west-northwest.
The unconfined aquifer discharges into local surface water
courses.

Water in the unconfined aquifer,  is of  brackish quality with
high total dissolved solids, generally 2000 ppm or greater,
and sulfates on the order of 800 ppm or greater.  Due to its
poor quality and low yields, this water has only very
limited use.  Water in the confined aquifer generally has
dissolved solids concentrations  of about 300 ppm and a
sulfate content of about 20 ppm.  This aquifer is an impor-
tant source of water for domestic, agricultural and indus-
trial uses in the Salt Lake Valley.

In the unconfined aquifer, arsenic, iron and manganese
values exceeded standards in some up-, cross- and down-
gradient samples, with no clear  trend  evident.  Gross alpha
and radium (Ra-226 and 228) values also exceeded standards
in some up-, cross- and downgradient  samples, with signif-
icantly higher values in downgradient  samples.  Some samples
from up-, cross- and downgradient exceeded standards for
total dissolved solids, chloride and  sulfate, with a larger
percentage of samples exceeding  standards and somewhat
higher values in downgradient  samples.

In the confined aquifer, some  downgradient samples exceeded
standards for total dissolved  solids  and sulfate.  Iron
values exceeded standards in up-, cross- and downgradient
samples, but the percentage of samples exceeding standards
was higher and the extent of the difference between the
measured values and the standards was  greater in the down-
gradient samples.

The unconfined groundwater aquifer discharges to the Jordan
River and Mill Creek.  Contaminant plumes have not been
modeled.
                                4-118

-------
TABLE 4-19
Stl SuatiS:LIi?eCWa?erUQuality Compared to U.S. EPA Standards from 40 CFR  192.32(a)
Data Interval: 1982 and 1983
Page 1 of 2

standard
Constituent (mg/1) I/ Aquifer
Arsenic 0.05 Unconfined

Confined


Barium 1 . 0 Unconfined


Confined


Cadmium 0.01 Unconfined


Confined


Chromium 0.05 Unconfined


Confined


Gross Alpha 15.0 pCi/1 Unconfined
(excluding radon
and uranium)
Confined


Lead 0.05 Unconfined


Confined



Hydraulic Flow 1
Relationship i
Upgradient
Crossgradient
Downgradient
Upgradient
Crossgradient
Downgradient
Upgradient
Crossgradient
Downgradient
Upgradient
Crossgradient
Downgradient
Upgradient
Crossgradient
Downgradient
Upgradient
Crossgradient
Downgradient
Upgradient
Crossgradient
Downgradient
Upgradient
Crossgradient
Downgradient
Upgradient
Crossgradient
Downgradient
Upgradient
Crossgradient
Downgradient
Upgradient
Crossgradient
Downgradient
Upgradient
Crossgradient
Downgradient

lumber of
Analyses
14
8
29
3
3
14
14
8
29
3
3
13
14
8
29
3
3
13
14
8
29
3 - -
3
13
10
8
29
3
2
13
14
8
29
3
3
13
Number of
Analyses
Exceeding
Standard
11
4
—
—
__~
	
— -
—
---
---
___
	
---
—
-— -
---
__ซ
___
1
___
—
---
___
6
3
24
2
1
4
2
---
---
---
	
---
Percent
Exceeding
Standard
79
14
__ -.
— — —
^^**
	
- — —
" ~~
— -ป —
— — —
ซ_•
- 	
" ~T""
---
- , ^ __.
— — —
__••
	
12
---
~~r
, , ---
~m*m*
60
37
83
67
50
31
14
T — ""
__'—
"•""•
---
-~~
Maximum
Value
Obtained
(mg/1) I/
0.245
0.5
ซ^ซ
_ซ••

—
•™~~
™ ~~
ซw
— — —

—
•• — —
•*"•""
"••" —
~~~
"*"*""
—
0.08
— •••
__•
•• — — —

600
85.2
1181
30
30
100
0.3
...
•*„•"
""•"•
— — -
~~~
                                                          4-119

-------
TABLE 4-19

DaS Sua?iJn:L|iteCS4rUSuility Compared to U.S. EPA Standards from 40 CFR 192.32U)
Data Interval:  1982 and 1983
Page 2 of 2

Standard
Constituent (mg/1) i/
Mercury 0.002



Ra-226 + Ra-228 5.0 pCi/1
(Radium)



Selenium 0.01





Silver 0.05






Aquifer
Unconfined
Confined


Unconfined
Confined


Unconfined


Confined


Unconfined


Confined



Hydraulic Flow I
Relationship I
Upgradient
Crossgradient
Downgradient
Upgradient
Crossgradient
Downgradient
Upgradient
Crossgradient
Downgradient
Upgradient
Crossgradient
Downgradient
Upgradient
Crossgradien
Downgradient
Upgradient
Crossgradient
Downgradient
Upgradient
Crossgradient
Downgradient
Upgradient
Crossgradient
Downgradient

lumber of
Uialyses
14
8
29
3
3
13
10
8
27
3
2
12
14
8
29
3
3
13
14
8
29
3
3
13
Humber of
Analyses
Exceeding
Standard
1
— — ซ
___
V — —
1
3
5
___
1
1
	
___
---
— —
---
*•"*""
— T
---
---
	
__-
"" 	
Percent
Exceeding
Standard
3
wซw
~~*"

10
37
18
— ~—
50
8
	 .
— "•"•
— __
"~~
"*™~
'
-•—
"•""
~™*~
— .— -ป
— ••••

Maximum
Value
Obtained
(mg/1) I/
0.003

___

14
12.5
114
51
.1
91
.1
	

~*"~
ซ^ซ
""""™

	
^^^
^^^
"™^^
•"•••

y  Values are reported in mg/1  unless otherwise indicated.
— Standard not exceeded.
                                                           4-120

-------
TABLE 4-20
Site Name:  Salt Lake City, Utah                                                 .
Data Evaluation:  Site Water Quality Compared to  U.S.  EPA Standards Not  Included in
                    plus Uranium and Molybdenum
Data Interval:  1982 and 1983
                          Page  1  of  3
40 CFR 192.32(a)
Standard
Constituent (mg/1) I/
Chloride 250




Copper 1 . 0





Fluoride 1 . 4





Hydrogen Sulfide 0.05





Iron 0.3





Manganese 0.05




Aquifer
Unconfined

Confined


Unconfined


Confined


Unconfined


Confined


Unconfined


Confined


Unconfined


Confined


Unconfined

Confined


Hydraulic Plow 1
Relationship i
Upgradient
Crossgradient
Downgradient
Upgradient
Crossgradient
Downgradient
Upgradient
Crossgradient
Downgradient
Upgradient ,
Crossgradient
Downgradient
Upgradient
Crossgradient,
Downgradient
Upgradient
Crossgradient
Downgr adient
Upgradient
Crossgradient
Downgradient
Upgradient
Crossgradient
Downgradient
Upgradient
Crossgradient
Downgradient
Upgradient
Crossgradient
Downgradient
Upgradient
Crossgradient
Downgradient
Upgradient
Crossgradient
Downgradient
dumber of
Analyses
9
5
21
3
2
14
14
8
29
3
3
13
1
4
5
1
1
4
1
4
6
1
1
4
15.
8
35
3
. 3.
17
8
6
18
1
2
10
Number of
Analyses
: Exceeding
Standard
5
5
17
	
---
5
	
— —
—
—-—
— :_
— — —
	
	
5
	
	
___
	
---
2
---
1
1
8
6
25
; i
2
11
7
6
17
	
'2
10
Percent
Exceeding
Standard
56
100
81
— _
___
36
	
— —
— — —
— — —
__- -
_ซซ
	
— — —
100 .
-- —
	 	
___
	
— — —
33
— — —
100
25
53
75
71 '
33
67
65
87
100
94
---
100
100
Maximum
Value
Obtained
(mg/1) I/
4900
2883
5400
___
__ซ
410
	
™ — ™
___
__ซ
--ป-
fm — ซ
	
"••"""
6.1
"•""•
— """
.__ .
	
_ซ
0.08
" — —
0.09
0.07
70
44
58
0.61
0.92
4.6
1.6
1.85
4.02
—"••
1.5
0.60
                                                          4-121

-------
TABLE 4-20
Site Name:  Salt Lake City,  Utah                                                             ...
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards Not Included in 40 CFR 192.32U)
                    plus Uranium and Molybdenum
Data Interval:  1982 and 1983
Page 2 of 3
Standard
Constituent (mg/1) I/
Molybdenum 0.10
Nitrate 2/ 44
pH 3/ 6.5 to 8.5

Sulfate 250





Total Solids 500





Uranium 4_/ 0.044





Aquifer
Unconfined
Confined
Unconfined
Confined
Unconfined
Confined

Unconfined


Confined


Unconfined


Confined


Unconfined


Confined


Hydraulic Flow 1
Relationship J
Upgradient
Crossgradient
Downgradient
Upgradient
Crossgradient
Downgradient
Upgradient
Crossgradient
Downgradient
Upgradient
Crossgradient
Downgradient
Upgradient
Crossgradient
Downgradient
Upgradient
Crossgradient
Downgradient
Upgradient
Crossgradient
Downgradient
Upgradient
Crossgradient
Downgradient
Upgradient
Crossgradient
Downgradient
Upgradient
Crossgradient
Downgradient
Upgradient
Crossgradient
Downgradient
Upgradient
Crossgradient
Downgradient
{umber of
taalyses
14
8
29
3
3
13
5
6
12
3
2
6
12
6
25
3
2
14
9
5
21
3
2
14
12
5
25
3
2
15
11
8
33
3
2
16
Number of
Analyses
Exceeding
Standard
1
1
___
4
5
18
	

5
10
5
22
---
---
11
	
1
24
---

---
Percent
Exceeding
Standard
3
17
— — —
44
100
86
---
---
36
83
100
88
___
_ซ._
73
	
12
73
___
---
___
Maximum
Value
Obtained
(mg/1) I/
0.2
™.~™
4300
2000
7800
___
~ — ""
590
16100
6002
21000
— — —
— — —
1800
	
31.1
2.24
__ —
— — —
wซ
                                                         4-122

-------
 TABLE  4-20
 Site Name:  Salt Lake City, Utah
 Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards Not Included in 40 CFR 192.32(a)
                    plus Uranium and Molybdenum
 Data Interval:  '1982 and 1983
Page 3 of 3
Constituent
Zinc
Standard Hydraulic Flow
(mg/1) I/ Aquifer Relationship
5 . 0 Unconf ined Upgradient
Crossgradient
Downgradient
Confined Upgradient
Crossgradient
Downgradient
Number of
Analyses
14
8
29
3
3
13
Number of
Analyses
Exceeding
Standard
1
Percent
Exceeding
Standard
3
Maximum
Value
Obtained
(mg/1) I/
110
^/  Values are reported in mg/1 unless otherwise indicated.
2/  Concentrations of nitrate as nitrogen at a level of 10 mg/1  is  equivalent to concentration of nitrate as nitrate
    at a level of 44 mg/1.  All analyses are reported in terms of nitrate as nitrate.
3_/  pH reported in standard units.
4/  30 pci/l of uranium is equivalent of 0.044 mg/1, assuming the bulk of uranium is U-238.  All analyses are
    reported as total uranium in mg/1.
— Standard not exceeded.
                                                          4-123

-------
 4.12  SHIPROCK, NM  -  SUMMARY OF WATER QUALITY

 The Shiprock  site is  in northwestern New Mexico and rests on
 the escarpment above  the  floodplain of the San Juan River.
 The remedial  action is complete.  The underlying groundwater
 (divided into two units)  is definitely contaminated.
 Groundwater in the  floodplain unit has been used and is
 potentially useable in the future; contamination in the
 floodplain appears  tq be  relict, i.e., from past discharges.
 A key issue is the  extent and characteristics of the flood-
 plain contamination.  The second groundwater unit is perched
 within the soils and  fractured Mancos Shale on the escarp-
 ment above the floodplain.

 Chromium, selenium  and silver exceeded the standard for some
 samples.  Eight out of 29 analysis for chromium down gradi-
 ent samples exceed  the standard.  One of 29 down gradient
 samples exceeded the  standard for silver.  Thirteen of 77
 down gradient selenium samples exceeded standards.  Arsenic,
barium, cadmium, gross alpha, lead, mercury, and radium
 concentrations are within limits of the standards.

 Contaminated water occurs in the floodplain.  Groundwater in
the alluvium discharges to the San Juan River.   The contami-
nant plume has not been modeled; existing data show little
 if any flushing of contaminants in the alluvium.
                             4-124

-------
TABLE 4-21
Site Name:  Shiprock (New Mexico)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards from 40 CFR 192.32(a)
Data Interval:  10/16/84 to 09/20/86
Page 1 of 2
Constituent
Arsenic
Barium
Cadmium
Chromium
Gross Alpha
(excluding radon
and uranium)
Lead
Mercury
Standard
(mg/1) I/
0.05
1.0
0.01
0.05
15.0 pCi/1
0.05
0.002
Hydraulic Flow
Relationship
Upgradient
Down gradient
Upgradient
Down gradient
Upgradient
Down gradient
Upgradient
Down gradient
Upgradient
Down gradient
Upgradient
Down gradient
Upgradient
Down gradient
Formation of
Completion
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Number of
Analyses
2
29
2
29
2
77
2
29
1
1
2
29
2
29
Number of
Analyses
Exceeding
Standard
	
	
	
8
	
— — —
— — —
Percent
Exceeding
Standard
—
—- •
___
27
	

___
Maximum
Value
Obtained
(mg/1) I/
— —
	
	
0.11
	
• w*ป
—
                                                             4-125

-------
TABLE 4-21
Site Name:  shiprock (New Mexico)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards from 40 CFR 192.32(a)
Data Interval:  10/16/84 to 09/20/86
Page 2 of 2
Constituent
Ra-226 + Ra-22ฃ
(Radium)
Selenium
Silver
Standard Hydraulic Flow
(mg/1) I/ Relationship
t 5.0 pci/l Upgradient
Down gradient
0 . 01 Upgradient
Down gradient
0 . 05 Upgradient
Down gradient
Formation of Number of
Completion Analyses
Alluvium 2 2/
Alluvium 23
Alluvium 2
Alluvium 77
Alluvium 2
Alluvium 29
Number of Maximum
Analyses Percent Value
Exceeding Exceeding Obtained
Standard standard (mg/1) !/
-— ___ ___
13 16 0.91
1 3 0.10
I/    Values are reported in mg/1 unless otherwise indicated.
2/    Analyses for Ra-226 only.
	   Standard not exceeded.
                                                             4-126

-------
TABLE 4-22
Site Name:  Shiprock (New Mexico)                                                  .
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards Not Included  in 40 CFR 192.32(a)
                    plus Uranium and Molydbenum
Data Interval:  10/16/84 to 09/20/86
                                                                                                    Page 1 of 2
Constituent
Chloride
Copper
Fluoride
Hydrogen Sulfide
Iron
Manganese
Molybdenum
Nitrate 2/
Standard
(mg/1) I/
250
1.0
1.4
0.05
0.30
0.05
0.10
44
Hydraulic Flow
Relationship •
Upgradient
Down gradient
Upgradient
Down gradient
Upgradient
Down gradient
Upgradient
Down gradient
Upgradient
Down gradient
Upgradient
Down gradient
Upgradient
Down gradient
Upgradient
Down gradient
Formation of
Completion
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Number of
Analyses
2
77
2
77
2
77
1
1
2
77
2
77
2
77
2
77
Number of
Analyses
Exceeding
Standard
27
— — —
48

1
18
2
76
1
53
57
Percent
Exceeding
Standard
35
— — —
62
— — —
50
23
100
98
50
69
77
Maximum
Value
Obtained
(mg/1) I/
2200
	
14.0
	
1.14
2.05
0.74
9.60
0.16
0.44
3600
                                                              4-127

-------
TABLE 4-22
Site Naปe;  Shiprock (New Mexico)
Data Evaluation:  Site Water Quality compared to U.S. EPA Standards Not Included  in 40 CFR I92.32(a)
                    plus Uranium and Molybdenum
Data Interval:  10/16/84 to 09/20/86
Page 2 of 2
Constituent
pH 3/
Sulfate
Sulfide
Total Solids
Uranium 4/
Zinc
Standard Hydraulic Flow
(mg/1) I/ Relationship
6.5 to 8.5
250
0.05
500
0.044
5.0
Upgradient
Down -gradient
Upgradient
Down gradient
Upgradient
Down gradient
Upgradient
Down gradient
Upgradient
Down gradient
Upgradient
Down gradient
Formation of
Completion
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Number of Maximum
Analyses Percent Value
Number of Exceeding Exceeding Obtained
Analyses Standard Standard (mg/1) I/
2
77
2
77
1
23
2
77
1
71
2
77
I/ Values are reported in mg/1 unless otherwise indicated.
2/ Concentrations of nitrate as nitrogen at a level of 10 mg/1 is equivalent to
level of 44 mg/1. All analyses are reported in terms of nitrate as nitrate.
3/ pH reported in standard units.
4/ 30 pCi/1 of uranium is equivalent of 0.044 mg/1, assuming the bulk of uranium
total uranium in mg/1.
	 Standard not exceeded.
.__
77
1
23
1
77
55
—
___
100 19,
100
200
50
100 32,
77
	
concentration of nitrate
is U-238. All analyses
___
200
0.10
0.10
534
600
7.21
	
as nitrate at a
are reported as
                                                              4-128

-------
4.13  TUBA CITY, ARIZONA - SUMMARY OF WATER QUALITY

The Tuba City site is located in northeastern Arizona about
five miles east of Tuba City.  The site rests on the Nava^o
Sandstone which contains the primary water source in the
area.  Background monitor wells reveal good water quality
(TDS < 500 mg/1) with minor exceptions.  The tailings pile
has contaminated approximately one billion gallons of
groundwater.                               :

Cadmium concentrations were higher in on-site and down
gradient samples than in background or upgradient samples.
Seven of 48 down gradient analyses for chromium and four of
13 upgradient analyses for radium exceeded the limit for the
standard.  Maximum selenium concentrations exceeded the
standard by a factor of 6.  One of 4 on-site samples^for
gross alpha, as well as one of 14 down gradient samples,
exceed the standard for gross alpha.

Groundwater flow and at least partial discharge of contami-
nated water is into the Moenkopi Wash, about 2 miles from
the edge of the tailing pile.  Modeling shows discharge of
the trailing edge of the mobile contaminant plume to Moen-
kopi Wash in 300 years.  Discharge of the uranium plume was
not modeled but is estimated to be several hundred years
after the mobile plume.
                               4-129

-------
TABLE 4-23
Site Name:  Tuba City (Arizona)
Data Evaluation:  Site Water Quality Compared to U.S.
Data Interval:  06/09/82 to 04/11/86
                                                                                     Page 1 of 3
                                  EPA standards from 40 CFR 192.32(a)
Constituent

Arsenic
Standard
(mg/1) I/
Hydraulic Flow
Relationship
Formation of
Completion
Number of
Analyses
Number of
Analyses
Exceeding
standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
 (mg/1) I/
Barium
Cadmium
Chromium
 0.05       Background .
            Upgradient
            On-Site
            Down gradient

 1.0        Background
            Upgradient
            On-Site
            Down gradient

 0.01       Background
            Upgradient
            On-Site
            Down gradient

 0.05       Background
            Upgradient
            On-Site
            Down gradient
                  Navajo Sandstone    6
                  Navajo Sandstone   13
                  Navajo Sandstone    6
                  Navajo Sandstone   20

                  Navajo Sandstone    6
                  Navajo Sandstone   13
                  Navajo Sandstone    6
                  Navajo Sandstone   20

                  Navajo Sandstone   10
                  Navajo Sandstone   18
                  Navajo Sandstone    6
                  Navajo Sandstone   48

                  Navajo Sandstone   10
                  Navajo Sandstone   18
                  Navajo Sandstone    6
                  Navajo Sandstone   48
                                                                                    4
                                                                                   10
                                             66
                                             20
                                                                                               14
                                            0.031
                                            0.039
                                                           0.08
                                                            4-130

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TABLE 4-23
Site Name:  Tuba City (Arizona)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards from 40 CFR 192.32(a)
Data Interval:  06/09/82 to 04/11/86
Page 2 of 3
Constituent
Gross Alpha
(excluding radon
and uranium)

Lead



Mercury



Ra-226 + Ra-228
(Radium)


Selenium



Standard Hydraulic Flow
(mg/1) I/ Relationship
15.0 pCi/1 Background
Upgradient
On-Site 	
Down gradient
0 . 05 Background
Upgradient
On-Site
Down gradient
0 . 002 Background
Upgradient
On-Site
Down gradient
5.0 pCi/1 Background
Upgradient
On-Site
Down gradient
0.01 Background
Upgradient
On-Site
Down gradient
Formation of Number of
Completion Analyses
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
4
9
4 '
14
6
13
6
20
6
13
6
20
6
13
6
20
10
18
6
48
Number of
Analyses
Exceeding
Standard
___
	
1
1
___
—
__._
1
___
	
___
1
___
4
	
— — —
1
- —
6
10
Percent
Exceeding
Standard
—
	
25
7
___
,. - - —
— -
5
___
	
— -
5

30
	
— — —
10
—
100
20
Maximum
Value
Obtained
(mg/1) I/
—
—
33.2
27.2
___
— - •
	
0.06
___
- —
—
0.0029
___
7.0
— -
— — —
0.018
	
0.039
0.066
                                                              4-131

-------
TABLE 4-23
Site Mama:  Tuba city (Arizona)
Data Evaluation:  Site Water Quality Compared to U.S.
Data Interval:  06/09/82 to 04/11/86
                                                                                                        Page  3  of  3
                                                      EPA Standards from 40 CFR 192. 32 (a)
Constituent
Silver
Standard
(mg/1) I/
0.05
Hydraulic Flow
Relationship
Background
Upgradient
On-Site
Down gradient
Formation of Number of
Completion Analyses
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
8
13
6
33
Number of
Analyses
Exceeding
Standard
1
Percent
Exceeding
Standard
12
Maximum
Value
Obtained
(mg/1) I/
0.10
I/     Values are reported in mg/1 unless otherwise indicated.
	    Standard not exceeded.
                                                               4-132

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TABLE 4-24
Site Name:  Tuba City (Arizona)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards Not Included in 40 CFR 192.32(a)
                    plus Uranium and Molybdenum
Data Interval:  06/09/82 to 04/11/86
Page 1 of 4
Standard Hydraulic Flow
Constituent (mg/1) I/ Relationship
Chloride 250
Copper 1 . 0
Fluoride . 1.4 .
Hydrogen Sulfide 0.05
Background
Upgradient
On-Site
Down gradient
Background
Upgradient
On-Site
Down gradient
Background
Upgradient
On-Site
Down gradient
Background
Upgradient
On-Site
Down gradient
Number of Maximum
Analyses Percent Value
Formation of Number of Exceeding Exceeding Obtained
Completion Analyses Standard Standard (mg/1) I/
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone -
Navajo Sandstone
10 	 	 	
17 	 	 	
48 	 	 	
8 	 	 	
13 	 	 	
6 	 	 	
33 	 	 	
6 	 	 	
12 2 16 4.60
20 	 	 —
1 — — — ซ•ปซ• __ซ
1 — — ; —
                                                             4-133

-------
TABIฃ 4-24
site Hams:  Tuba city (Arizona)
Data Evaluation:  Site Hater Quality Compared to U.S. EPA Standards Not Included in 40 CFR 192.32(a)
                    plus Uranium and Molybdenum
Data Interval:  06/09/82 to 04/11/86
Pag* 2 of 4
Constituent
Iron



Manganese



Molybdenum



Nitrate 2/



Standard Hydraulic Flow
(mg/1) I/ Relationship
0.30 Background
Upgradient
On-Site
Down gradient
0.05 Background
Upgradient
On-Site
Down gradient
0 . 10 Background
Upgradient
On-Site
Down gradient
44 Background
Upgradient
On-Site
Down gradient
Formation of Number of
Completion Analyses
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
8
13
6
33
8
9
6
33
8
18
6
48
10
17
6
48
Number of
Analyses
Exceeding
Standard
__—
3
3
1
___
1
6
11
3
5
1
28
___
	
6
24
Percent
Exceeding
Standard
___
23
50
3
___
11
100
33
38
27
17
58
___
	
100
50
Maximum
Value
Obtained
(mg/1) I/
___
2.25
1.14
1.96
___
0.10
2.40
0.35
0.21
0.20
0.21
0.24
___
	
1800
1500
                                                            4-134

-------
TABLE 4-24
Site Name:  Tuba City (Arizona)
Data Evaluation:  Site Hater Quality Compared to U.S. EPA Standards Not Included in 40 CFR 192.32(a)
                    plus Uranium and Molybdenum
Data Interval:  06/09/82 to 04/11/86
Page 3 of 4
Constituent
PH 3/



Sulfate



Sulfide



Total Solids



Standard Hydraulic Flow
(mg/1) I/ Relationship
6.5 to 8.5 Background
Upgradient
On-Site
Down gradient
250 Background
Upgradient
On-Site
Down gradient
0.05 Background
Upgradient
On-Site
Down gradient
500 Background
Upgradient
On-Site
Down gradient
Formation of Number of
Completion Analyses
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
Navajo Sandstone
10
18
6
48
10
17
6
48
4
8
4
17
10
13
6
48
Number of
Analyses
Exceeding
Standard
7
1
4
25
— — —
	
6
20
4
8
4
17
___
1
6
29
Percent
Exceeding
Standard
70
5
66
52
___
- —
100
41
100
100
100
100
___
7
100
60
Maximum
Value
Obtained
(mg/1) I/
10.10
8.79
6.19
6.33/12.75
___
	
2600
4010
0.10
0.10
0.10
0.10
___
600
7000
8550
                                                             4-135

-------
TABLE 4-24
Site Name:  Tuba City (Arizona)
Data Evaluation:  Site Hater Quality Compared to U.S. EPA Standards Not Included in 40 CFR 192.32(a)
                    plus Uranium and Molybdenum
Data Interval:  06/09/82 to 04/11/86
                                                                                              Page 4 of 4
Constituent
Uranium 4/
Standard
(mg/1) I/
0.044
Hydraulic Flow
Relationship
Background
Upgradient
On-Site
Down gradient
Formation of Number of
Completion Analyses
Navajo Sandstone 8
Navajo Sandstone 17
Navajo Sandstone 4
Navajo Sandstone 45
Number of
Analyses
Exceeding
Standard
4
19
Percent
Exceeding
Standard
100
42
Maximum
Value
Obtained
(mg/1) I/
2.40
0.21
Zinc
5.0
Background
Upgradient
On-Site
Down gradient
Navajo Sandstone    8
Navajo Sandstone    9
Navajo Sandstone    6
Navajo Sandstone   33
I/   Values are reported in mg/1 unless otherwise indicated.
2/   Concentrations of nitrate as nitrogen at a level of 10 mg/1 is equivalent to concentration of nitrate as nitrate at a
     level of 44 mg/1.  All analyses are reported in terms of nitrate as nitrate.
3/   pH reported in standard units.
4/   30 pCi/1 of uranium is equivalent of 0.044 mg/1, assuming the bulk of uranium is U-238.   All analyses are reported as
     total uranium in mg/1.
-—  Standard not exceeded.
                                                              4-136

-------
GREEN RIVER—SUMMARY OF WATER QUALITY

This site is located in the floodplain  of  Brown's  Wash,  an
intermittent tributary of the Green River  which  flows  southward
and discharges into the Colorado River  about  60  miles  south  of
Green River, Utah.  The site is on the  nose of shallow north
plunging anticline that is repeated by  the arcuate
eastnortheast-westnorthwest trending Little Grand  Wash fault
three miles south of the site.  Sedimentary units  of Cretaceus
and Jurassic age outcrop in the area; units at the site  include
the Quaternary Brown's Wash alluvium underlying  the tailings
pile and alluvial terrace deposits beneath the proposed  disposal
site. These are underlain by the Tununk  Shale Member of  the
Mancos Shale, the Dakota Sandstone and  the Cedar Mountain
Formation, all of Cretaceous age.  Four  distinct water-bearing
units were defined within the upper 200  feet  of  Quaternary and
Cretaceous sediments at the site.  These are, from the surface
down:

     -the zero to 35 feet thick Brown's  Wash  alluvium  is
comprised of silt, sand, gravel and some small cobbles and
extends 300 to 400 feet on either side  of  Brown's  Wash.  A
paleochannel of Brown's Wash has eroded  away  the Dakota
Sandstone beneath the tailings site, and the  alluvium  directly
overlies shale of the Cedar Mountain Formation;  this unit does
not extend south of the tailings pile or under the proposed
disposal site. Groundwater of this unit  is locally perched;

     -the upper-middle unit is comprised of up to  30 feet of
alternating layers of shale, limestone  and mudstone of the Cedar
Mountain Formation; this unit is continuous beneath both the
existing and proposed tailings sites;

     -the lower-middle unit is a relatively thick  but  laterally
limited sandstone and conglomerate channel deposit within the
Cedar Mountain Formation; this unit intertongues with  the
middle-upper unit and also is continuous beneath both  tailings
sites;

     -the bottom unit is the 15 to 25'feet thick Buckhorn
Conglomerate Member of the Cedar Mountain  Formation; this basal
sandstone and sandstone conglomerate unit  is  confined  by
overlying shale and mudstone and is continuous beneath both
tailings sites.

Contamination from the tailings pile is  confined to the  upper
two units by strong upward hydraulic gradients between the
upper-middle unit and the underlying units; the  maximum  depth of
contamination at the site is about 65 feet (DOE-88).   In both
the top and upper middle units gross alpha activity, molybdenum,
nitrate, selenium and uranium exceed background  levels and
proposed EPA and State of Utah groundwater standards beneath
and downgradient of the tailings.
                              4-137

-------
TABLE 4-26  (continued)
qihe Name:  Green Rivet (Utah)
Ilia Elation:  Site Water Quality Compared to 0.
                    plus Uranium and Molybdenum
Data Interval:  7/14/82 - 1/12/88
                                S.  EPA Standards Not Included in 40 CFR 192.32(a)
Constituent
Manganese
Standard
(rag/1) I/
 0.05
 Molybdenum
                      0.10
Hydraulic Flow
Relationship
Background
            Upgradient
            Cross-gradient
            On-site

            Down gradient

            Background

            Upgradient
            Cross-gradient
             On-site

             Down gradient
Formation of Number of
Completion Analyses
.___——————-—————•
Alluvium
Shale
Conglomerate
Sandstone
Shale
Sandstone
Alluvium
Conglomerate
Alluvium
Shale
Conglomerate
Alluvium
Shale
Conglomerate
Sandstone
Alluvium
Shale
Conglomerate
Sandstone
Shale
Sandstone
Alluvium
Conglomerate
Alluvium
. Shale
Conglomerate
Alluvium
Shale
Conglomerate
Sandstone
____.—-.———
13
4
9
10
2
6
5
5
21
6
4
2 - - - -
16
2
6
13
4
9
10
2
6
5
5
21
6
4
2
16
2
6
Number of
Analyses
Exceeding
Standard
_ — —
1


—
— — —
— — —

11
0
ฃ.
— — —


ซ~.~





*L







—
• — — ~

Maximum
Percent Value
Exceeding Obtained
Standard (mg/1) I/

50
78




40
52
33


31


Oft
•J O
44
10
50

40
40
38
JO
100

50




0.06
0.21
0.49
	
___
	
..__
0.87
0.98
2.3
— — —
	
0.21
_. — —
— . — —
0.20

0.22
0.14
0.11
____
0.13
0.15
0.27
0.20
_._ 	
0.104
_ — —
'
	

                                                          4-146

-------
TABLE 4-26  (continued)
Site Name:  Green River (Utah)
Data Evaluation:   Site Water  Quality  Compared  to U. S. EPA Standards Not  Included  in  40  CPR 192.32(a)
    plus Uranium  and Molybdenum
Data Interval:   7/14/82 - 1/12/88
Standard Hydraulic Flow
Constituent (mg/1) I/ Relationship
Nitrate 2/ 44 Background



Upgradient

Cross-gradient

On-site


Down gradient



pH 3/ 6.5-8.5 Background



Upgradient

Cross-gradient

On-site


Down gradient



Formation of l
Completion I
Alluvium
Shale
Conglomerate
Sandstone
Shale
Sandstone
Alluvium
Conglomerate
Alluvium
Shale
Conglomerate
Alluvium
Shale
Conglomerate
Sandstone
Alluvium
Shale
Conglomerate
Sandstone
Shale
Sandstone
Alluvium
Conglomerate
Alluvium
Shale
Conglomerate
Alluvium
Shale
Conglomerate
Sandstone
lumber of
Analyses
13
4
9
10
2
6
5
5
21
6
4
2
16
2
6
13
4
9
10
2
6
5
5
21
6
4
2
16
2
6
Number of
Analyses
Exceeding
Standard
3
2
6
	
2
	
	
	
943440
6
	
	
2
	
	
	
	
	
6
	
1
	
	
	
	
	
	
2
	
1
Percent
Exceeding
Standard
23
50
67
___
100
	
	
	

100
	
	
13
	
	 	
	
	
	
60
	
17
	
	
	
	
	
	
13
	
17
Maximum
Value
Obtained
(mg/1) I/ .
140
93
173
	
975
	
	
	

2480
• 	
	
71
	
	
	
	
	
11.61

8.65

	
__— —
___
	 	
— — _
9.08
	
8.84
                                                     4-147

-------
TABLE 4-26  (continued)
Site Name:  Green River (Utah)
Data Evaluation:  Site Water Quality Compared to U.  S.  EPA  Standards Not Included in 40 CFR 192.32{a)
    plus Uranium and Molybdenum
Data Interval:  7/14/82 - 1/12/88
Standard Hydraulic Flow
Constituent (mg/1) I/ Relationship
Sulfate 250 Background



Upgradient

Cross-gradient

On-site


Down gradient



Total Solids 500 Background



Upgradient

Cross-gradient

On-site


Down gradient



Formation of b
Completion ?
Alluvium
Shale
Conglomerate
Sandstone
Shale
Sandstone
Alluvium
Conglomerate
Alluvium
Shale
Conglomerate
Alluvium
Shale
Conglomerate
Sandstone
Alluvium
Shale
Conglomerate
Sandstone
Shale
Sandstone
Alluvium
Conglomerate
Alluvium
Shale
Conglomerate
Alluvium
Shale
Conglomerate
Sandstone
lumber of
analyses
13
4
9
10
2
6
5
5
21
6
4
2
16
2
6
13
4
9
10
2
6
5
5
21
6
4
2
16
2
6
Number of
Analyses
Exceeding
Standard
13
4
9
10
2
4
5
5
21
7
4
2
16
2
6
13
4
9
10
2
6
5
5
21
7
4
2
16
2
vS
Percent
Exceeding
Standard
100
100
100
100
100
67
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
Maximum
Value
Obtained
(mg/1) I/
6210
3940
4600
1193
4160
674
6280
700
6890
3610
2570
5000
3270
572
2120
9560
7300
7980
2480
9540
2170
10400
2120
10800
7160
4790
8030
6200
2930
3820
                                                            4-148

-------
TABLE 4-26  (continued)
Site Name:  Green River (Utah)
Data Evaluation:  Site Water Quality Compared  to  U.  S. EPA Standards Not  Included  in  40  CFR  192.32(a)
    plus Uranium and Molybdenum
Data Interval:  7/14/82 - 1/12/88


Standard Hydraulic Flow
Constituent (mg/1) I/ Relationship


Uranium 4/ 0.044 Background



Upgradient

Cross-gradient

Ofi-site


Down gradient
: 
-------
TABLE 4-26  (continued)
Site Name:  Green River (Otah)
Data Evaluation:  Site Water Quality Compared to U. S. EPA Standards Not Included in 40 CFR 192.32(a)
    plus Uranium and Molybdenum
Data Interval:  7/14/82 - 1/12/88
Constituent
Standard
(mg/1) V
Hydraulic Flow
Relationship
Formation of  Number of
Completion    Analyses
Number of
Analyses
Exceeding
Standard
Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/1) I/
On-site


Down gradient



Alluvium
' Shale
Conglomerate
Alluvium
Shale
Conglomerate
Sandstone
2i
6
4
2 — :- 	
16
2 — -
6 — '.- 	

	
	
	
	
	
	
I/    Values are reported in mg/1 unless otherwise indicated. •2/    Concentrations of nitrate as nitrogen at a  level
of 10 mg.l is equivalent to concentration of nitrate as nitrate at a level of, 44 mg/1.  All analyses are  reported  in
terms of nitrate as nitrate.  3/    pH reported in standard units.  4/    30 pCi/1 of uranium is equivalent, of 0.044
mg/1, assuming the bulk of uranium is U-238.  All analyses are reported as total uranium in mg/1.	  Standard not
exceeded.
                                                           4-150

-------
RIFLE (OLD AND NEW SITES)  -  SUMMARY OF WATER  QUALITY

Both sites are located on the floodplain alluvium  of  the
Colorado  River valley.  Of the four aquifers in the  Rifle
area, only two are affected by the  tailings  piles  - the
unconfined alluvium and the underlying Wasatch  Formation.
(DOE 87)

The alluvial aquifer is about 20 feet thick  at  the old site  and
25 to 30 feet thick at the new site, with  depths to water
ranging from 2 to 12 feet below land surface.   Recharge  of the
aquifer is primarily from the Colorado River and its
tributaries; discharge at the site  is primarily to the Colorado
River, though there is some groundwater flow between  the
alluvial aquifer and the underlying Wasatch  aquifer.  Water
levels are influenced by the Colorado River  and fluctuate  more
than 7 feet annually, being highest in the summer  and lowest in
the winter.  Groundwater flow is generally westward,  roughly
parallel to the Colorado River channel.  Discharge from  a
drainage ditch at the north edge of the pile at the old  site
percolates through the alluvium, causing a groundwater mound
beneath the pile in that area.

Ground water within the Wasatch Formation  is confined by shales
and claystones of low permeability, interbedded with  more
permeable sand-stones.  Hydraulic heads are  10  to  20  feet  above
the Wasatch-alluvium contact.  The primary recharge area for
the Wasatch is probably the Grand Hogback, an area of nearly
vertical strata.  Flow seems to be generally westward but  is
poorly defined because of anomalous water  levels resulting from
the discontinuous character of the Wasatch strata. Drainage  is
to the alluvial aquifer along the Colorado River and, probably,
to its tributaries.

In the alluvial aquifer, analsyes show that  sodium and calcium
are the dominant cations and sulfate and bicarbonate  are the
dominant anions.  The water is neutral pH  and has  a mean TDS
concentration of 1900 mg/1.  Fluoride exceeds the  EPA primary
drinking water standards in one well at the  new site.Gross
alpha levels exceeded EPA primary standards  in  a number  of
samples but are believed to result from the  high levels  of
naturally occurring uranium in the water.  Manganese, iron and
chlorine levels in several wells and sulfate and TDS  levels  in
nearly all of the wells exceeded EPA secondary  standards.   Even
though much of the alluvial water in the area is in Use
Category 1 under the Colorado classification system,  it may  not
be suitable for domestic purposes because  of the high levels of
natural contaminants.

The Wasatch aquifer is much higher  in sodium and chloride  and
lower in calcium and sulfate than the alluvial  aquifer.  The
water, is slightly alkaline and has a mean  TDS concentration  of
about 3600 mg/1.  Back-ground levels for some constituents
                             4-151

-------
exceed EPA primary drinking water standards: barium  (2 of  7
samples), radium-226 and radium-228 combined (1 of 5 samples),
fluoride (1 of 7 samples).  Also, background levels  exceed EPA
secondary drinking water standards for several constituents:
chloride (17 of 19 samples), pH was over  8.5 in 7 samples,
sulfate  (4 of 19 samples), and TDS was over 500 mg/1 in  all
wells.  Of the 19 wells monitored, 13 are  in Use Category  1,  5
in Use Category 2 and 1 is Use Category 3  under Colorado's
classification system.  However, the high  concentrations of
naturally occurring contaminants may preclude domestic use of
the Wasatch Formation water.

At the Old Rifle site, one or more of the  monitoring wells
showed elevated levels of arsenic, lead-210, radium-226,
radium-228, sulfate, thorium-230, uranium  and vanadium.  Of
these, uranium was the only constituent showing a substantial
increase being 20 times background in one  well.  In  a monitor
well 360 feet downgradient, to the southwest, the only
constituent indicating contamination was  ammonium which  was
only slightly above background levels. Though there  is ittle
evidence of lateral movement of leachate  from the pile,  the
alluvial aquifer does appear to be contaminated down to  its
contact with the Wasatch Formation.  There are no monitor  wells
into the Wasatch at or near the periphery  of the Old Rifle
tailings so no samples of the confined aquifer are available  in
this area.  Contamination of this aquifer  would probable be
minor and localized to the area immediately beneath  the
tailings.
                                              i   \
The contaminant plume extends less than 800 feet >.downgradient
from the pile and probably discharges into thexColorado  River
within this distance.  Minimum flushing time, once the tailings
are removed is estimated to be 1.9 years.          \

At the New Rifle site, both the alluvial  and Wasatch aquifers
are contaminated; in each case, the area  of contamination  is
defined  by the sulfate plume. The entire  saturated thickness
(15 to 20 feet) of the alluvial aquifer is contaminated  over  an
area of  at least 400 acres.  Contaminant  concentrations  are
highest  directly under and west of the tailings pile \and the
vanadium ponds. Some contaminated water may discharges, into the
Colorado River 3000 feet southwest of the tailings pile;
contamination can also be detected in a well  8000 feet west  of
the pile. Uranium levels ranged from  3 to 44 times background,
molybdenum from 25 to 150 times background in  2 discrete
localized plumes, sulfate from about  2 to over  40 times
background, ammonium from 525 to  over  16000 times background,
nitrate  concentrations are inversely  related to the  ammonium
levels,  and chloride levels were  up  to 11 times background
(DOE87).  Three contaminants have been identified  in the
Wasatch  Formation aquifer: uranium  (up to 200  times
background), molybdenum  (up to 16 times background), and
sulfate  (up to 117 times background)  (DOE87).              \
                              4-152

-------
The sulfate plume in the alluvial aquifer  extends  at  least  7000
feet downgradient from the tailings pile  and  the plume  in  the
Wasatch extends for 3000 feet downgradient; both plumes  appear
to be actively augmented by  the  tailings  pile.  Calculations
indicate that, once the tailings are  removed,  the  plumes would
be completely dispersed or discharged to  the  Colorado River
within 2 miles downgradient  of the tailings pile.   The
estimated minimum flushing times are  45 years  for  the alluvial
aquifer and 3840 years for the Wasatch Formation aquifer.
                              4-153

-------
TABLE  4-27
Site Name:  Rifle (New Site)
Data Evaluation:  Site Water Quality Compared to U.S.  EPA Standards from 40 CFR 192.32(a)
Data Interval:  06/25/80 to 01/09/87
Page 1 of 2
Constituent
Arsenic



Barium



Cadmium



Chromium



Gross Alpha



Lead



Ra-226 + Ra-228
(Radium)


Standard
(mg/1) I/
0.05



1.0



0.01



0.05



15pCi



0.05



S.OpCi



Hydraulic Flow
Relationship
Cross-gradient
Down gradient
On-Site
Down gradient
Cross-gradient
Down gradient
On-Site
Down gradient
Cross-gradient
Down gradient
On-Site
Down gradient
Cross-gradient
Down gradient
On-Site
Down gradient
Cross-gradient
Down gradient
On-Site
Down gradient
Cross-gradient
Down gradient
On-Site
Down gradient
Cross-gradient
Down gradient
On-Site
Down gradient
Formation of
Completion
Alluvium
Alluvium
Alluvium
Wasatch
Alluvium
Alluvium
Alluvium
Wasatch
Alluvium
Alluvium
Alluvium
Wasatch
Alluvium
Alluvium
Alluvium
Wasatch
Alluvium
Alluvium
Alluvium
Wasatch
Alluvium
Alluvium
Alluvium
Wasatch
Alluvium
Alluvium
Alluvium
Wasatch
Number of
Analyses
1
24
3
13
1
24
3
13
1
24
3
13
1
24
3
13
1
24
3
13
1
24
3
13
1
24
3
13
Number of
Analyses
Exceeding
Standard
	
	
	
	
	
	
	
	
	
1
2
	
	
2
	
	
1
8
	
2
	
	
— i-
_!__
— —
";-
- —
	
Percent
Exceeding
Standard
	
	
	
	
	
	
	
	
	
4
67
	
	
8
	
	
100
34
	
15
	
	
	
	
	
	
	
	
Maximum
Value
Obtained
(mg/1) I/
	
	
	
	
	
	
	
	
	 - -
0.03
0.03
	
	
0.25
	
	
213
660
	
340
	
	
	
	
	
_- —
	
— —
                                                       4-154

-------
TABLE  4-27
Site Name:  Rifle (New Site)
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards from  40  CFR  192.32(a)
Data Interval:  06/25/80 to 01/09/87
                                   Page 2 of  2

Constituent

Standard
(mg/1) I/

Hydraulic Flow
Relationship

Formation of
Completion

Number of
Analyses
Number of
Analyses
Exceeding
Standard

Percent
Exceeding
Standard
Maximum
Value
Obtained
(mg/1) I/
Selenium             0.01       Cross-gradient    Alluvium
                                Down gradient     Alluvium
                                On-Site           Alluvium
                                Down gradient     Wasatch
Silver               0.05       Cross-gradient    Alluvium
                                Down gradient     Alluvium
                                On-Site           Alluvium
                                Down gradient     Wasatch

I/    Values a,re reported in mg/1 unless otherwise indicated.
	   Standard not exceeded.
 1
24
 3
13
 1
24
 3
13
29
33
23
 0.16
0.041
  0.2
                                                   4-155

-------
TABLE  4-28
Site Name:  Rifle (Hew Site)
Data Evaluation:  Site Water Quality Compared to U.S.  EPA Standards Not Included in 40 CFR 192.32{a)
                    plus Uranium and Molybdenum
Data Interval:  06/25/80 to 01/09/87
Page 1 of 2
Constituent
Chloride



Copper



Fluoride



Iron



Manganese



Molybdenum



Nitrate 2/



Standard Hydraulic Flow
(mg/1) I/ Relationship
250 Cross-gradient
Down gradient
On-Site
Down gradient
1.0 Cross-'gradient
Down gradient
On-Site
Down gradient
1.4 Cross-gradient
Down gradient
On-Site
Down gradient
0.3 Cross-gradient
Down gradient
On-Site
Down gradient
0.05 Cross-gradient
Down gradient
On-Site
Down gradient
0.10 Cross-gradient
Down gradient
On-Site
Down gradient
10 Cross-gradient
Down gradient
On-Site
Down gradient
Formation of
Completion
Alluvium
Alluvium
Alluvium
Wasatch
Alluvium
Alluvium
Alluvium
Wasatch
Alluvium
Alluvium
Alluvium
Wasatch
Alluvium
Alluvium
Alluvium
Wasatch
Alluvium
Alluvium
Alluvium
Wasatch
Alluvium
Alluvium
Alluvium
Wasatch
Alluvium
Alluvium
Alluvium
Wasatch
Number of
Analyses
1
24
3
13
1
24
3
13
1
24
3
13
1
24
3
13
. 1
24
3
13
1
24
3
13
1
24
3
13
Number of
Analyses
Exceeding
Standard
___
22
3
13

_ _ _
	
	
1
3
1
2

9
3
9
1
24
3
11
1
12
3
11

13
1
6
Percent
Exceeding
Standard
	
92
100
100

	
___
~_ _
100
12
33
15

38
100
69
100
100
100
85.
100
50
100
85

54
33
46
Maximum
Value
Obtained
(mg/1) I/
	
1360
1400
4200

___
	
	
2.2
6.1
9
5.6

67
44.1
152
8.03
53.9
19.6
18.8
3.0
9.2
12.7
5.07

920
310
97
                                                 4-156

-------
TABLE  4-28
Site Name:  Rifle (New Site)
Data Evaluation:  Site Water Quality Compared to U.S, EPA Standards Not Included in  40  CFR  192.32U)
                    plus Uranium and Molybdenum
Data Interval:  06/25/80 to 01/09/87
Page 2 of 2
Constituent
PH 3/



Sulfate



Total Solids



Uranium 4/



Zinc


Standard Hydraulic Flow
(mg/1) I/ Relationship
6.5-8.5 Cross-gradient
Down gradient
On-Site
Down gradient
250 Cross-gradient -
Down gradient
On-Site
Down gradient
500 Cross-gradient
Down gradient
On-Site
Down gradient
0.044 Cross^gradient
Down gradient
On-Site
Down gradient
5.0 Cross-gradient
Down gradient
On-Site
Formation of
Completion
Alluvium
Alluvium
Alluvium
Wasatch
Alluvium
Alluvium
Alluvium
Wasatch
Alluvium
Alluvium
Alluvium
Wasatch
Alluvium
Alluvium
Alluvium
Wasatch
Alluvium
Alluvium
Alluvium
Number of
Analyses
1
24
3
13
1
24
3
13
1
20
3
13
1
24
3
13
1
24
3
Number of
Analyses
Exceeding
Standard
	
	
	
4
1
24
3
13
	
20
3
13
1
16
2
7
	
	
1
Percent
Exceeding
Standard
	
— -
	
31
100
100
100
100
	
100
100
100
100
67
67
54
	
	
33
Maximum
Value
Obtained
(mg/1) I/
	
— —
	
10.69
2150
29100
34000
30300
	
42050
69300
44000
0.428
0.9070
1.31
0.67
	
	 •
6.3
I/   Values are reported in mg/1 unless otherwise indicated.
2/   Concentrations of nitrate as nitrogen at a level of 10 mg/1 is equivalent  to  concentration of nitrate as nitrate
     at a level of 44 mg/1.  All analyses are reported in terms of nitrate as nitrate.
3/   pH reported in standard units.
4/   30 pCi/1 of uranium is equivalent of 0.044 mg/1, assuming the bulk of uranium is U-238.    All analyses are
     reported as total uranium in mg/1.
	  Standard not exceeded.
                                                  4-157

-------
TABLE 4-29
Site Name:  Rifle (Old Site)
Data Evaluation:  Site Water  Quality Compared to U.S.
Data Interval:  06/25/80 to 01/09/87
EPA Standards from 40 CFR 192.32(a)
                                               Page 1 of 2
Constituent
Arsenic



Barium


Cadmium


Chromium


Gross Alpha



Lead


V
Ra-226 + Ra-228



Standard
(mg/1) I/
0.05



1.0


0.01


0.05


15pCi



0.05



S.OpCi



Hydraulic Flow
Relationship
Upgradient
Down gradient
On-Site
Upgradient
Upgradient
Down gradient
On-Site
Upgradient
Down gradient
On-Site
Upgradient
Down gradient
On-Site
Upgradient
Down gradient
On-Site •
Upgradient
Upgradient
Down gradient
On-Site
Upgradient
Upgradient
Down gradient
On-Site
Upgradient
Formation of
Completion
Alluvium
Alluvium
Alluvium
Wasatch
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Wasatch
Alluvium
Alluvium
Alluvium
Wasatch
Alluvium
Alluvium
Alluvium
Wasatch
Number of
Analyses
2
3
6
2
2
3
6
2
3
6
2
3
6
2
3
6
2
2
2
6
2
2
3
6
2
Number of
Analyses
Exceeding
Standard
	
	
1
.._ซ
	
	 	
	
___
	
	
	
	
	
_ .__
	
	
	
2
2
6
2

	
2

Percent
Exceeding
Standard

	 	
17

— — _
— — _.

	
— _ —

___
— — _

— — —
— _ —
— — —

100
100
100
100

	
34

Maximum
Value
Obtained
(mg/1) I/

___
0.23

	
	


—_ -.

	
	

	
•
	

81
68
980
22

__—
104.6
Ra-226 only
                                                  4-158

-------
TABLE 4-29
Site Name:  Rifle (Old Site)
Data Evaluation:   Site Water  Quality Compared to U.S. EPA Standards from 40 CFR 192.32U)
Data Interval:  06/25/80 to 01/09/87
                                                                                  Page 2 of 2
Constituent


Selenium
Standard    Hydraulic Flow    Formation of   Number of
(mg/1) I/   Relationship      Completion     Analyses
                                                                               Number  of
                                                                               Analyses
                                                                               Exceeding
                                                                               Standard
       Percent
       Exceeding
       Standard
        Maximum
        Value
        Obtained
        (mg/1) I/
Silver
 0.01       Upgradient        Alluvium
            Down gradient     Alluvium
            On-Site           Alluvium
            Upgradient        Wasatch

 0.05       Upgradient        Alluvium
            Down gradient     Alluvium
            On-Site           Alluvium
1
1
2
50
33
33
 0.18
 0.06
0.016
I/   Values are reported in mg/1 unless otherwise indicated.
—  Standard not exceeded.
                                                  4-159

-------
TABLE 4-30
Site Name:  Rifle (Old Site)
Data Evaluation:  Site Water Quality Compared to U.S.  EPA Standards Not Included in 40 CFR 192.32(a)
                    plus Uranium and Molybdenum
Data Interval:  06/25/80 to 01/09/87
Page 1 of  2
Constituent
Chloride


Copper


Fluoride


Iron


Manganese


Molybdenum


Nitrate 2/



PH 3/



Standard Hydraulic Flow
(mg/1) I/ Relationship
250 Upgradient
Down gradient
On-Site
Upgradient
1.0 Upgradient
Down gradient
On-Site
1.4 Upgradient
Down gradient
On-Site
0.3 Upgradient
Down gradient
"On-Site'
Upgradient
0.05 Upgradient
Down gradient
On-Site
Upgradient
0.10 Upgradient
Down gradient •
On-Site
Upgradient
44 Upgradient
Down gradient
On-Site
Upgradient
6.5-8.5 Upgradient
Down gradient
On-Site
Upgradient
Formation of
Completion
Alluvium
Alluvium
Alluvium
Wasatch
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Alluvium
Wasatch
Alluvium
Alluvium
Alluvium
Wasatch
Alluvium
Alluvium
Alluvium
Wasatch
Alluvium
Alluvium
Alluvium
Wasatch
Alluvium
Alluvium
Alluvium
Sasatch
Number of
Analyses
2
2
6
2
2
3
6
2
3
6
2
3
6
2
2
3
6
2
2
3
6
2
2
3
6
2
2
3
6
2
Number of
Analyses
Exceeding
Standard
	
— — —
— — _
2
	
	
	
	

~_ ซ
__ _
1
2
1
2
5
2
1
1
2
2
1
1
1

	
	 	
	
1
Percent
Exceeding
S.tandard
50

	
100



	


	
17
100
50
67
83
100
50
33
38
100
50
33
17




50
Maximum
Value
Obtained
(mg/1) I/
455


5700







0 44
U • *ฑ *ฑ
312
0 80
\J • O \J
2 49
ti • *ฑ _7
i no
j. • u y
15.4
0 .12
0 18
\J • J. O
fi 1 9
U • -L ฃ.
0.16
19.5
^7 9
J / . ฃ.
1 4 fi
,lft.D



9.44
                                                 4-160

-------
TABLE 4-30
Site Name:  Rifle (Old Site)                                                      .
Data Evaluation:  Site Water Quality Compared to U.S. EPA Standards Not Included  in  40  CFR 192.
                    plus Uranium and Molybdenum
Data Interval:  06/25/80 to 01/09/87
                                                                                                      page 2 of 2
Constituent
  Standard     Hydraulic  Flow    Formation  of    Number of
  (mg/1)  I/    Relationship      Completion     Analyses
                                                                                Number  of
                                                                                Analyses
                                                                                Exceeding
                                                                                Standard
                                                             Percent
                                                             Exceeding
                                                             Standard
                                                        Maximum
                                                        Value
                                                        Obtained
                                                        (mg/1) I/
Sulfate
Total Solids
Uranium  4/
                   250
 500
0.044
Upgradient
Down gradient
On-Site
Upgradient
Upgradient
Down gradient
On-Site
Upgradient
Upgradient
Down' "gradient
                                Upgradient
Alluvium
Alluvium
Alluvium
Wasatch
Alluvium
Alluvium
Alluvium
Wasatch
Alluvium
Alluvium
Alluvium
Wasatch
2
1
6
2
2
2
6
2
1
1
4
100
 33
100
100
100
 67
100
100
 50
 33
 67
 2640
 1300
  814
 4910
 5242
 2814
 1750
15000
0.887
0.082
 2.08
 I/    'Values are reported in mg/1 unless otherwise indicated.
 2/     Concentrations of nitrate as nitrogen at a level of 10 mg/1  is  equivalent to concentration of nitrate as nitrate
       at a level of 44 mg/1.  All analyses are reported in terms of nitrate as nitrate.
 3/     pH reported  in standard units.
 4/     30 pCi/1 of  uranium is equivalent of 0.044 mg/1, assuming the bulk  of uranium is U-238.   All analyses are
       reported as  total uranium in mg/1.
 	    Standard not exceeded.
                                                   4-161

-------
4.16  CURRENT USES OF CONTAMINATED  GROUND  WATER

Contaminated ground water is believed  to be  used  as  drinking
water at only two sites:  Gunnison, Colorado,  and Monument
Valley, Arizona  (Le87).  However, because  of the  remoteness of
some sites it is possible that  sporatic use  of contaminated
ground water can occur, especially  by  individuals or  families.

Concentrations of hazardous constituents and other data  in
ground water samples from downgradient wells at Gunnison  are  in
Table 4-1.  These same data for  upgradient wells  are  given  in
Table 4-2 and for crossgradient  wells  in Table 4-3.   The
locations of these wells are shown  in  Figures  '4-1 and 4-2.
This information is from the draft  environmental  assessment for
the Gunnison site (DOE84).

In Table 4-1, the downgradient  domestic wells  are identified  by
names (Hitt, Trainer, Rider, Tomichi,  Collins, David,  Deschene,
Coleman, Corral, Maries, and Valco).   Of these domestic  wells,
five of 19 samples of ground water  exceeded  a  uranium
concentration of 30 pCi/1 (0.044mg/l)  and  one  of  19  samples
exceeded a selenium concentration of 0.01  mg/1.   For  all
downgradient wells, uranium exceeded 30 pCi/1  in  25  of 59
samples and selenium exceeded 0.01  mg/1 in nine of 73 samples.
In addition, for other hazardous constituents, cadmium
concentrations exceeded 0.01 mg/1 in four  of 58 samples  and
nitrate concentrations exceeded  10  mg/1 in seven  of  59 samples.

In Tables 4-2 and 4-3, only three samples  of ground  water
exceeded the drinking water standards  for  hazardous
constituents.  These three samples  contained nitrate  at
concentrations of 22 to 35 mg/1  and were collected immediately
upgradient of the tailings pile.

The Gunnison ground water data  indicate that uranium  and  sulfate
have moved from the tailings area since peak concentrations are
found downgradient from the tailings (DOE86).  It is  reasonable
to suspect, therefore, that concentrations pf  uranium and
sulfate will increase in the downgradient  domestic wells  as
these contaminants move downgradient.  Figure  4-3 depicts the
uranium plume near the Gunnison  pile.

At the Monument Valley site there are  four residences which may
be using ground water as drinking water as shown  in  Figure  4-4.
Ground water quality at these residences is  reflected by
concentration levels in sampling wells 602,  610,  613,  621,  and
622, where chromium and gross alpha exceed drinking  water
                              4-162


-------
                       .-i M c
                                                                  V  V


                                                                00
                     isisssssssss:
                                       งin*ซQO'.tnog>
-------
                                     Table 4-31 Ground-vater quality - GunnliOfi - dowifrtdltnt (Conttnted)
yell
Z03A
2038
2048
205A
2058
206A


2068


207A

207B

208



209A

209B

210A
2108
211 A
21 IB
212A

212B

Date
10/24/83
10/25/83
10/27/83
10/23/83
10/24/83
10/19/83
01/31/84
01/31/84
10/19/82
02/01/84
02/01/84
10/17/83
01/29/84
10/17/83
01/29/84
10/12/83
10/13/83
10/13/83
10/14/83
10/17/83
01/29/84
10/17/83
01/29/84
10/23/84
10/20/83
10/25/83
10/26/83
10/18/83
01/26/84
10/18/83
01/27/84
Kg
26.4
14.6
23.1
61.2
11.8
86.1
75.5
72.0
42.1
36.5
36
64.4
58.0
30.5
28.2
38.4
37.5
37.0
38.1
91.7
96.8
35.0
33.0
78.2
46.8
112
46.2
78.5
66.3
42.6
30.5
m
N/A
N/A
H/A
N/A
H/A
N/A
66.5
77.0
N/A
9.40
9.40
N/A
24.4
N/A
3.36
N/A
N/A
H/A
N/A
N/A
35.5
N/A
4.93
N/A
H/A
H/A
H/A
N/A
38.0
H/A
5.00
Ko
<0.001
X0.001
* 0.058
0.003
0.009
0.008
<0.001
<0.01
0.007
<0.001
<0.010
<0.001
<0.001
0.008
<0.001
<0.001
<0.001
<0.001
<0.001
0.003
<0.001
0.008
<0.001
0.002
0.006
<0.001
0.006
0.002
<0.001
0.007
<0.001
R03
45
50
3.5
11.0
4.8
2.3
3.1
< 1
< 0.7
2.0
< 1.0
1.0
2.4
1.1
2.6
< 0.7
1.1
1.0
< 0.7
. 1.0
2.3
< 0.7
2.1
110
2.3
45
12
1.4
2.3
<0.7
2.3
Ha
41.6
34.8
65.5
88.7
33.2
109
49.9
45
48.6
21.8
18.0
94.4
47.5
43.9
16.6
53.4
53.2
50.1
54.2
96.5
100
44.2
19.3
183
45.1
128
58.0
92.0
54.3
46.6
25.3
81
<0.001
<0.001
0.002
0.061
0.019
0.015
<0.04
<0.04
0.045
<0.04
0.14
0.002
<0.04
0.068
<0.04
0.13
0.13
0.20
0.18
0.002
<0.04
0.049
<0.04
<0.001
0.051
<0.001
0.018
<0.001
<0.004
0.020
<0.004
P
N/A
N/A
N/A
N/A
N/A
N/A
< 5
N/A
H/A
< 5
H/A
H/A
< 5
H/A
< 5
H/A
H/A
H/A
N/A
H/A
< 5
H/A
< 5
H/A
H/A
H/A
H/A
H/A
< 5
H/A
< 5
Pb
0.009
<0.001
<0.001
<0.001
<0.001
<0.001
<0.00i
0.010
0.001
<0.001
<0.010
0.002
<0.001
<0.001

-------
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-------
                                     Tibia  4-31 Ground-water quality - Gunnison - doxngradlint (Conttntad)
Well
213A
2138
214B
Hitt
Trainer
Rider
Tmichi

Collins
David

Deschene

Colemn


Corral
Narks


Valco

Hi list te

SP-1
SP-3
CSU-213
CSU-214
Date
10/18/83
10/18/83
10/26/83
02/02/84
02/07/84
02/27/84
01/30/84
01/30/84
09/16/83
09/16/83
11/01/82
10/11/82
09/16/83
10/11/82
09/15/83
02/07/84
09/16/83
10/07/83
02/01/84
02/01/84
10/11/82
09/16/83
11/01/82
09/16/83
10/12/82
11/01/82
11/01/82
11/01/82
Kg
61.2
28.2
18.3
20.1
27.5
6.48
20.4
20
3.1
9.50
10.0
<1
15.6
16
22.2
14.4
15.3
21.9
22.2
19
18
19.6
17
16.8
16
16
43
11
Hn
H/A
N/A
N/A
2.05
0.06
0.03
0.08
0.07
N/A
N/A
N/A
H/A
H/A
N/A
N/A
0.43
N/A
N/A
0.24
0.18
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
Mo
O.Q04
<0.001
0.007
<0.001
<0.001
<0.001
<0.001
<0.01
<0.00l
<0.001
<0.05
<0.05
<0.001
<0.05
<0.001
<0.001
<0.001
<0.001
<0.001
<0.01
<0.05
<0.001
<0.05
<0.001
<0.05
<0.05
<0.05
<0.05
•s
<0.7
1.0
2.3
2.7
<0.7
<0.7
2.5
<1
<0.7
<0.7
<5
<5
1.5
<5
1.3
1.8
1.3
1.1
2.4
<1
<5
1.7
<5
1.3
<5
<5
115
<5
Ha
75.7
36.0
38.7
13.9
8.13
3.81
10.1
6.5
94.1
25.1
9.0
122
20.5
10
23.4
4.88
17.2
12.9
12.0
6.6
10
19.5
7
16.9
7
11
22
4
Hi
<0.001
<0.001
0.008
<0.004
<0.04
<0.04
<0.04
<0.04
0.053
0.053
H/A
H/A
0.052
N/A
0.072
<0.04
0.042
0.06
<0.04
<0.04
H/A
0.070
N/A
0.064
N/A
N/A
N/A
N/A
P
N/A
N/A
N/A
< 5
< 5
< 5
< 5
N/A
N/A
N/A
N/A
N/A
" N/A
N/A
N/A
< 5
N/A
< 5
< 5
N/A
N/A
N/A
N/A
N/A
N/A
H/A
H/A
N/A
Pb
0.007
<0.001
<0.001
<0.001
<0.001
<0.001
<0.0012
<0.010
<0.001
<0.001
<0.010
<0.010
<0.001
<0.010
<0.001
<0.001
<0.00l
<0.001
<0.001
<0.010
<0.010

-------
41
i
          •11
         UJ O*"
            u
                                                    ^ *^ ^ "
                                 cw in in  ซ*• •• *• ซ*
oo oaooco oa a eo aoeo co ea oo 09 0003 GO eeeo eo
                                                                         ^
                                                                         S
                                                                         5
                                                                         i
                                                      I

-------
                                     Table  4-31 Ground-water quality • fiunnison - doungradient (Continued)
HeU
SP-1


SP-2


SP-3


GUH-209


GUN-212A

GUN -213


GUN-214

Date
08/31/82
05/30/82
11/00/81
08/31/82
06/30/82
11/00/81
08/31/82
06/30/82
11/00/81
08/31/82
06/30/82
11/00/81
08/31/82
06/30/82
08/31/82
06/30/82
11/00/81
08/31/82
06/30/82
*J
16
17
17
82
60
36
21
22
28
47
40
52
46
48
39
44
50
12
12
Hn
0.4
0.03
N/A
8.63
6.20
N/A
.25
0.05
N/A
.43
0.74
N/A
8.79
9.30
8.16
5.20
N/A
0.03
0.11
Ho
N/A
H/A
H/A .
H/A
H/A
H/A
N/A
N/A
H/A
N/A
H/A
N/A
N/A
N/A
N/A
N/A
H/A
H/A
H/A
*o3
H/A
H/A
H/A
H/A
H/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
Ha
.6
6
6
32
17
9
9
22
10
22
22
39
31
34
4
24
26
4
5
Hi
N/A
H/A
N/A
N/A
N/A
N/A
N/A
H/A
N/A
N/A
H/A
H/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
P
N/A
H/A
N/A
N/A
N/A
N/A
N/A
H/A
N/A
H/A
H/A
H/A
N/A
N/A
N/A
N/A
H/A
R/A
N/A
Pb
H/A
H/A
H/A
H/A
H/A
H/A
N/A
N/A
N/A
H/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
so4 s<
14 <0.
34 ?0.
77 ~H/
780 0.
757 0.
1150 H
140 <0.
125 ?0.
562 ~H
460 <0.
422 "0.
1150 N
560 0.
560 0.
480 0.
571 <0.
1440 ~N
16 <0.
43 ?0.
i Si
1 N/A
I N/A
rA N/A
N/A
N/A
A N/A
H/A
H/A
A N/A
fi/A
H/A
A N/A
N/A
N/A
N/A
N/A
A N/A
N/A
N/A
U
N/A
H/A
N/A
N/A
N/A
H/A
H/A
H/A
H/A
N/A
N/A
H/A
N/A
H/A
H/A
H/A
N/A
N/A
N/A
V
N/A
H/ft
N/A
N/A
N/A
H/A
H/A
H/A
N/A
N/A
N/A
H/A
H/A
H/A
H/A
H/A
H/A
H/A
H/A
Zn
H/A
H/A
H/A
N/A
H/A
H/A
H/A
H/A
H/A
B/A
H/A
H/A
H/A
H/A
N/A
H/A
N/A
N/A
N/A
Pb-210
(PCI/1)
N/A
H/A
N/A
N/A
H/A
N/A
N/A
N/A
H/A
H/A
H/A
N/A
H/A
N/A
N/A
H/A
H/A
H/A
N/A
[I/A - Not Available
                                                                  4-168

-------
Table 4-31   Ground-water quality - Gunnison - downgradient (Continued)

Well
203A
203B
204B
205A
205B
206A


206B


207A
207B
208


209A
209B
210A
210B
21 1A
21 IB
212A

212B


Date
10/24/83
10/25/83
10/27/83
10/23/83
10/24/83
10/19/83
01/31/84
01/31/84
10/19/82
02/01/84
02/01/84
10/17/83
01/29/84
10/17/83
01/29/84
10/12/83
10/13/83
10/13/83
10/14/83
10/17/83
01/29/84
10/17/83
01/29/84
10/23/84
10/20/83
10/25/83
10/26/83
10/18/83
01/26/84
10/18/83
01/27/84
Ra-226
(pCi/1)
0.0 + 0.6
0.0 + 0.2
0.9 + 0.6
0.4 + 0.4
0.1 + 0.2
0.7 + 1.0
0.0 + 0.2

0.1 + 0.3 "
0.1 + 0.2
< 1.0
0.1 + 0.1
0.0 + 0.2
0.1 + 0.2
0.1 + 0.2
0.0 + 0.2
0.0 + 0.2
0.0 + 0.2
0.1 + 0.2
0.2 + 0.2
0.0 + 0.2
0.4 + 0.3
0.0 + 0.2
0.0 + 0.6
0.0 + 0.3
0.0 + 0.2
0.4 + 0.5
0.1 + 0.1
0.0 + 0.2
0.2 + 0.2
0.0 + 0.2
Th-230
(pCi/1)
0.0 + 1.9
0.6 + 0.7
8.6 + 2.6
1.2 + L8
0.0 + 0.8
0.4 +* 1.4
"V 9 T • A 0 Tf
0.0 + 0.4

2.8 + 2.4
0.6 + 0.7

2.7 + 2.2
0.4 + 0.6
0.8 + 1.6
0.6 + 0.7
0.0 + 0.5
0.0 + 0.5
0.0 + 0.5
0.0 + 0.5
0.4 + 1.4
0.7 + 0.9
3.6 + 2.6
0.0 + 0.4
2.0 +2.1
3.2 + 2.5
0.4 + 0.6
0.6 + 2.0
0.4 + 1.4
0.4 + 0.6
1.2+1.8
0.3 + 0.6

TOS
624
347
2280
1340
256
m&n
97nA
979(rt
2S50
C>wvU
1420
1410
2420
2440
1720
1690
1700
1730
1870
2570
2120
2400
2760
b ป W
2610
3160
•*ป yf*f
2250
1940
1900
1720
2270
                        4-169

-------
                           Table 4-31  Ground-water quality - GtwnlsM - dwngradtent (Concluded)
Hell


213A
2138
2148

Hitt
Trainer
•Rider
Ton 1 chi

Collins
David

Deschene

Coleman
 Corral
 Marks
 Valco

 Mill site

 SP-1
 SP-3
 CSU-213
 CSU-214
   Date
10/18/83
10/18/83
10/26/83

02/02/84
02/07/84
02/27/84
01/30/84
01/30/84
09/16/83
09/16/83
11/01/82
10/11/82
09/16/83
10/11/82
09/15/83
02/07/84
09/16/83
 10/07/83
 02/01/84
 02/01/84
 10/11/82
 09/16/83
 11/01/82
 09/16/83
 10/12/82
 11/01/82
 11/01/82
 11/01/82
Ra-226
(pCl/1)
0.2 + 0.2
0.2 7 0.2
0.2 + 0.2

0.0 + 0.2
0.0 7 0.2
0.0 7 0.2
0.0 7 0.2
0.1
0.2
       0.2
       0.3
    < 2
 0.5 + 0.4
    <~2
 0.0 + 0.2
 0.2 + 0.3
 0.1 + 0.2
 0.3 + 0.3
 0.0 + 0.2
     71
     < 2
     + 0.2
     ?2
     + 0.2
     72
     < 2
     < 2
     < Z
 0.0

 0.0
Th-230
(pCt/1)
0.4 + 1.4
0.0 7 1.5
1.2 + 2.3
0.0 + 0.4
0.0 + 0.4
0.0 + 0.4
0.1 + 0.5

0.2 + 6.7
0.8 7 1.0
N7A
N/A
0.8 + 1.0
N/A
0.8 + 0.9
0.070.4
1.2 7 1.0
0.9 7 1.1
0.2 + 0.5

N/A*
1.0 + 0.9
N/A
0.7 + 0.8
N/A
N/A
N/A
SI/A

IDS
994
2670
459
370
556
119
401
N/A
277
372
N/A
H/A
302
N/A
481
304
288
500
450
400
N/A
351
N/A
296
N/A
N/A
N/A
N/A
      measurements as  mg>
  N/A • Not analyzed.
                                                        4-170

-------
                                            Table 4-32 Ground-water quality - Gunntson - upgradlmt

Well
201A
2018
202A
2028
Weaver
Cooper
Brat ton
City
City 19
Woods
Singer

Electrical

conductivity Teay.
Date tMho/oi) (ปC)
10/23/83
10/21/83
10/19/83
10/21/83
02/07/84
02/06/84
07/27/84
11/01/82
09/15/83
02/27/84
11/01/82
09/16/83
11/01/82
09/16/83
330
380
350
375
N/A
N/A
N/A
315
355
N/A
280
310
330
350
12
14.5
11.5
14
8.3
7.5
7.0
12
12.0
6.9
15
14.8
14
12

PH
7.57
7.11
7.0
7.1
7.45
7.2
7.4
7.55
6.5
7.4
7.26
6.68
7.86
6.62


Alkalinity
(as CaC03) Al As Ba Ca cd
216
254
240
245
215
130
300
N/A
240
220
N/A
200
N/A
290
<0.002 <0.001 0.021 58.0 <0.0005
<0.003 <0.001 0.028 69.5 0.005
<0.003 <0.001 0.070 85.0 0.008
<0.003 <0.001 0.120 84.9 0.006
0.003 <0.001 0.005 59.8 <0.0001
0.005 <0.001 0.005 35.3 <0.0001
0.006 <0.001 0.002 70.3 <0.0001
<0.10 <0.010 N/A 76 <0.005
0.147 <0.001 0.270 70.8 <0.001
0.002 <0.001 0.002 64.3 <0.0001
<0.10 <0.010 N/A 55 N/A
0.143 <0.001 0.233 61.0 < 0.001
<0.10 <0.010 0.18 70 N/A
0.150 <0.001 0.27S 76.3 <0.001
™" ' •'•' i • i. ..
Cl Cr
8.0 <0.001
9.4 0.003
12 <0.001
11 <0.001
7.8 <0.001
14 <0.001
12.6 <0.001
2 <0.010
3.0 <0.001
5.5 <0.001
2 N/A
4.8 <0.001
1 N/A
5.0 <0.001

Cu F
0.006 <0.1
<0.001 <0.1
<0.001 <0.1
<0.001 <0.1
<0.001 <0.1
<0.001 <0.1
<0.001 <0.1
0.013 <1
<0.001 N/A
<0.001 <0.1
N/A <1
0.046 N/A
N/A <1
<0.001 N/A

Fe
0.011
0.02
0.27
2.80
0.17
0.38
0.05
0.6
0.263
0.11
2.7
0.254
3.3
0.277

Hg
N/A
N/A
N/A
N/A
N/A
N/A
N/A
<0.002
N/A
N/A
N/A
N/A
N/A
N/A

K
5.25
3.69
1.85
3.38
1.30
2.38
14.0'
4
5.05
1.38
3
7.33
1
7.25
[N/A - Mot Analyzed
                                                                 4-171

-------
                                   Table  4-32 Ground-water quality - SanaUoa - upgradleat (CMtlftwd)

Well
201A
201B
202A
202B
Heaver
Cooper
Brattoi!
City
City 19
Moods
Singer


Date
10/23/83
10/21/83
10/19/83
10/21/83
02/07/84
02/06/84
07/27/84
11/01/82
09/15/83
02/27/84
11/01/82
09/16/83
11/01/82
09/16/83


Hg
12.5
13.9
16.8
15.8
13.8
10.3
26.3
14
14.1
13.0
12
14.3
14
15.0


Hn
N/A
H/A
N/A
N/A
N/A
0.23
0.02
H/A
H/A
0.03
N/A
N/A
N/A
N/A


Ho
0.004
<0.001
0.003
0.003
<0.001
<0.001
<0.001
<0.05
<0.001
<0.001
<0.05
<0.001
<0.05
<0.001


N03
35
25
22
3.1
2.0
1.9
1.7
< 5
1.1
< 0.7
< 5
< 0.7
< 5
1.5


Na
39.4
9.22
6.87
7.49
6.78
14.9
19.3
6
15.8
3.83
6
18.1
5
16.2


HI
0.003
<0.001
<0.001
<0.001
<0.04
<0.04
<0.04
N/A
0.071
<0.04
N/A
0.037
N/A
0.043


P
N/A
N/A
N/A
H/A
< 5
< 5
< 5
N/A
N/A
< 5
H/A
N/A
N/A
N/A


Pfa
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.010
<0.001
<0.001
N/A
<0.001
N/A
0.012


so4
24.7
49.5
31.2
28.1
9.9
16.1
36.2
IS
43.8
16.5
11
11.4
15
19.5
••IMMMH^MMH

Se
<0.002
<0.002
<0.002
<0.002
<0.002
<0.002
<0.002
<0.010
<0.002
<0.002
<0.010
<0.002
<0.010
<0.002


SI
5.6
5.1
0.5
5.7
0.6
1.6
5.7
3.2
N/A
1.2
H/A
B/A
H/A
N/A


U
0.0062
0.0038
0.0018
0.0063
0.0020
0.0032
0.0085
0.003
0.0023
0.0021
0.003
0.0078
0.003
0.0039


V
<0.004
<0.004
<0.004
<0.004
<0.004
<0.004
<0.004
<0.05
<0.004
<0.004
<0.05

-------
                   Table  4-32  Ground-water quality - Gunnlson - upgradlent (Concluded)
Well
^•••••••••••wiw^a^
201A
201B
202A
202B
Weaver
Cooper
Bratton
City
City 19
Woods
Singer
Date
10/23/83
10/21/83
10/19/83
10/21/83
02/07/84
02/06/84
07/27/84
11/01/82
09/15/83
02/27/84
11/01/82
09/16/83
11/01/82
09/16/83
Ra-226
(pCi/1)
0.0 + 0.2
0.4 4- 0.4
0.1 + 0.2
0.0 + 0.3
0.0 + 0.2
0.0 + 0.2
0.0 + 0.2
< 2
0.8 + 0.5
0.0 + 0.2
< 2
0.4 + 0.4
< 2
0.3 + 0.3
Th-230
(PCI/1)
0.0 + 0.8
2.4 + 2.2
0.0 + 1.4
0.8 + 1.6
0.1 + 0.5
0.0 + 0.9
0.0 + 0.4
N/A
0.1 + 0.7
0.0 i 0.5
N/A
0.0 + 0.6
N/A
0.5 + 0.8
TOS
291
381
345
359
262
199
401
N/A
262
246
N/A
196
N/A
282
N/A ป Not analyzed.
                                                    4-173

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                                        Table 4-33 Ground-water quality - taiilso* - crositradiiflt
Electrical
conductivity leap. Eh
Well Date (w*o/ซ) CO MO
Tuttle 11/01/82 180
10/26/83 162
Reid 11/01/82 180
Hatcher 10/06/83 160
Sjoberg 10/06/83 155
02/08/84 N/A
Wallace 10/06/83 290
02/08/84 N/A
13.5 N/A
13 162
11 N/A
10 N/A
10 N/A
7.2 N/A
10 N/A
6.0 N/A
pH
7.68
7.03
7.60
6.8
6.81
7.17
7.05
7.0
Alkalinity
(as CaC03) Al As
68
118
N/A
145
115
100
230
205
Ba
<0.10 <0.010 N/A
0.007 <0.001 0.036
<0.10 <0.010 N/A
<0.01 <0.001 0.024
<0.01 <0.001 0.017
0.001 <0.001 0.008
<0.01 <0.001 0.150
0.002 <0.001 0.009
Ca Cd Cl Cr Cu
F
< 1 N/A 1 N/A N/A <1
24.0 <0.0005 3.8 <0.001 0.006 <0.1
36 N/A 1 H/A N/A <1
33.5<0.001 1.6 <0.001 <0.02 <0.1
32.3 <0.001 1.6 <0.001 <0.002 <0.1
31.8 <0.0001 5.9 <0.00i <0.001 <0.1
62.5 <0.001 8.2 <0.001 <0.02 <0.1
62.7 <0.0001 7.5 <0.001 <0.001 <0.1
Ft
0.1
0.652
0.9
0.41
0.57
0.77
9.66
2.03
Hg K
N/A < 1
N/A 2.75
N/A 1
N/A 3.45
N/A 2.73
N/A 1.14
N/A 5.90
N/A 2.63

Well Date Hg
Tuttle 11/01/82 <1
10/26/83 6.33
Reid 11/01/82 8
Hatcher 10/06/83 7.30
Sjoberg 10/06/83 6.20
02/08/84 6.68
Wallace 10/06/83 13.6
02/08/84 13.4
Hn
N/A
N/A
N/A
N/A
N/A
1.02
N/A
4.16
Ho
<0.05
0.003
<0.05
<0.001
<0.001
<0.001
<0.001
<0.001
N03
. , •...• 1 1 i •
<5
6.1
<5
1.0
1.2
<0.7
1.1
<0.7
Na
55
N/A
55
12.3
11.9
4.60
17.8
6.21
,ซ^^— — — •
HI
N/A
0.003
N/A
0.09
0.12
<0.04
0.15
<0.04
.^^ ซ—ซi.ป^— •
P
N/A
N/A
N/A
< 5
< 5
< 5
< S
< 5
Pb
N/A
<0.001
N/A
<0.001
<0.001
<0.001
<0.00l
<0.001
S04 S0
7 <0.010
21.4 <0.002
7 <0.010
<1 <0.01
<1 <0.01
14.8 <0.002
<1 <0.01
21.4 <0.002
Si
N/A
1.0
N/A
4.8
1.4
3.8
1.8
2.6
U
<0.001
0.0006
<0.001
0.0018
0.0009
0.0011
0.0025
<0.0029
V
<0.05
<0.004
<0.05
<0.004
<0.004
<0.004
<0.004
<0.004
Zn
N/A
0.013
N/A
0.024
0.053
0.010
0.014
0.022
Pt>-210
(pCi/1)
N/A
0.2 * 1.3
H/A
0.0 + 0.9
0.0 + 0.8
0.8 * 0.7
0.0 * 0.9
0.9 + 0.9
[a/A - Not Analyzed]
                                                                 4-174

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                                        Table  4-33
Ground-water quality - Gunnlson - crossgradlent (Concluded)
Well
Tuttle
Reid
Hatcher
Sjoberg
Wallace
Date
11/01/82
10/26/83
11/01/82
10/06/83
10/06/83
02/08/84
10/06/83
02/08/84
Po-210
(pCi/1)
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
Ra-226
(pCi/1)
< 2
0.3 + 0.3
0.3 + 0.3
0.0 + 0.2
0.1 + 0.2
0.5 + 0.3
0.4 + 0.3
Ra-228
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
Th-230
(PCI/1)
N/A
2.5 + 1.4
NjA
0.2 + 0.9
0.4 + 0.6
0.2 + 0.9
0.8+1.1
0.0 + 0.4
IDS
N/A
72.0
N/A
117
112
190
281
246
••• — — 	 	 	 	 	
N/A = Not analyzed.
                                                             4-175

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                                  •wain*  TA,LINQ8 PILE
                                           • CITY *8
                                          DIRECTION OF
                                          GROUND WATER
                                          FLOW
                             DE8CHENE*        ซMILL SITE
                                    •COLEMAN
                              ,OSBORN
                         • TRAINER
  RIDER*
•MARKS
•LIGHT
  TOMICHI
• COLLINS
•HITT
                          PIQURE  4-1
APPROXIMATE LOCATION OF DOMESTIC WELLS SAMPLED AT QUNNISON
                                   4-176

-------
                          DKECTtON OF
                         GROUND WATER
                               FLOW
8EWAQE TREATMENT
PLANT
                                    FIGURE  4-2

                                    LOCATIONS OF MONITOR WELLS
                                                                    (GUNNISON)
                                    MOST WELLS INSTALLED AS PAIRS ป10 FT APART
                                    DEPTH OP 'A' WIL1Sซ4ป ft. -f WELLSป10 FT.
                                        4-177

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                                                             TOf Or BXHTIHO
                                                               TMUHQt Pill
                                                 QCSIQNATfO
                                                 •IT! tOUNDANV
   0    MO
   ai
  SCALE IN FEET


-10X = I80PLETH
                                   FIGURE  4-3
                             URANIUM PLUME  NEAR PILE (GUNNISON)
          U AS MULTIPLE OF HIGHEST BACKGROUND CONCENTRATION (0.008 mfl/l)
                         DATA:  83 SAMPLES FROM 48 WELLS
                                           4-178

-------
 standards at 622 and 610, respectively, as shown  in Table  4-4.
 Also, the sulfate concentration is elevated at well 622.

 Background water quality is shown in Table 4-5 for the  alluvial
 aquifer at Monument Valley and in Table 4-6 for the Shinarump
 and DeChelly Sandstone aquifers.  Figure 4-5 illustrates the
 sulphate plume at Monument Valley; Figure 4-6, the nitrate
 plume; and Figure 4-7, the uranium plume.  The locations of the
 four residences are shown in each figure.

 4.17  ORGANIC CONTAMINANTS IN GROUND WATER

 Few data are available regarding organic contaminants in ground
 water.  The NRC is conducting a program of sampling liquids in
 uranium mill tailings impoundments.   This program is to
 establish a data base for hazardous  constituents  (40 CFR 261
 Appendix VIII)  in the tailings (Sm87).

 The laboratory  analyses performed  on these tailings water
 samples indicate positively if any of 150 constituents are
 present in the  tailings solution.   These constituents include 54
 general chemistry (anions,  cations,  metals)  12 volatile organic
 groups,  81 semivolatile groups,  and  three radionuclides.  None
 of  the organics have  been found in the  tailings solutions that
 were  tested  from nine  tailings impoundments  by the NRC.   The
 elemental forms of  15  hazardous constituents  were  identified
 These  organic groups  and  the  15  hazardous constituents that
 tested postive  are  listed in  Table 4-7.

 In  uranium milling, uranium has  been  recovered from leach
 liquors  by three methods:   solvent extraction,  ion exchange, and
 precipitation.   The solvent extraction  method  was  used to
 produce  43%  of  total  uranium  production in  1976 and a  solvent
 extraction/ion  exchange combination  was  used  to produce  18% the
 same year  (NUREG80).   Two processes,  the Dapex  and the Amex, are
 extensively  used.  The  Dapex  process  uses -a 4%  solution  of
 di(2-ethylhexyl)  phosphoric acid (EHPA)  in  kerosene  with
 tributyl phosphate added  as a  modifier.   The Amex  process uses  a
 6%  solution  of  tertiary amine,  such  as  alinine-336,  in kerosene
 with isodecanol  added as a modifier.

 Early  work in solvent extraction was  reviewed  by Flagg  (F161)
 In the early 1940's, diethyl ether was  used to  purify  uranium'in
 the first  large  scale application  of  solvent extraction  in
 nydrometallurgy.  Flagg groups the organic extractants into
organophosphorous compounds, as used  in  the Dapex  process,  and
                              4-179

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     N
                                                      620
                                        TO HALCHITA AND
                                        MEXICAN HAT
                                                     \
              INDIAN SERVICE
              ROUTE 6440
           612.
    • TO MONUMENT
     NO. 2 MINE
LEGEND
c 661
   RESIDENCE
   DOE MONITOR WELL
   EPHEMERAL DRAINAGE
                                                                         • 6S2
                                                                     FEET
   FIGURE   4-4
       DOE MONITOR WELL LOCATIONS,
       MONUMENT VALLEY SITE
                                     4-180 .

-------
               Table 4-34    Exceedence of water-quality  standards
                             at Monument Valley

Arsenic
Barium
Cadmium
Chloride
Chromium
Copper
Gross alphabปc

Iron
"lead
Manganese



Mercury
Nitrate (as N)
pHd

Ra-226 + 228ฐ
Selenium
Silver
Sulfate

EPA primary EPA secondary
standard3 standard3
0.05
1.0
0.01
250.0
0.05
1.0
15

0.3
0.05
0.05



0.002
10.0
6.5-8.5

5.0
0.01
0.05
250.0

Exceeded at
none
none
none
none
614, 622
none
606, 610, 614,
657, 662, 620.
614, 610
none
603. 605. 606, 610,
620. 621, 622. 650,
651, 654, 659, 660,
655, 662, 657. 664
none
606, 655. 656
620. 622. 650, 660,
663, 668, 661
none
none
none
605, 606, 622, 653.
655, 656, 662, 669
Total dissolved
  solids

Uranium6

Z1nc
0.015
                   500.0
                     5.0
605. 606. 614,  617,
   620, 622,  657
606. 614. 620,  655.
     657, 662
       none
aM11Hgrams per liter (mg/1) unless otherwise noted.
"P1cocur1es per liter.
cReported  values  of  gross  alpha  may  be  erroneous  at  TDS  levels   above
 500 mg/1.
^Standard units.
eHealth advisory level (Cothern et al., 1983).
                                      4-181

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       Table 4-35   Background water quality 1n alluvial  aquifer,  Monument
                    Valley site                        ;
Constituent
  Observed
concentration   No. of
   range3      analyses
                                             Mean3
   Two       Background
 standard    concentration
deviations3     range3
Alkalinity3
Aluminum
Ammonium
Antimony
Arsenic
Barium
Boron
Bromide
Cadmium
Calcium
Chloride
Chromium
Cobalt
Copper
Cyanide
Fluoride
Gross alphab
Gross betab
Iron
Lead
Magnesium
Manganese
Mercury
Molybdenum
Nickel
Nitrate
Nitrite
Nitrate & Nitrite
(as N)
Total organic
carbon
Lead-210b
pH
Phosphate
Polon1um-2lOb
Potassium
Rad1um-226b
Rad1um-228b
Selenium
Silica
Silver
Sodium
196-293
0.2-0.8
<0.1-0.52
<0. 003-0. 004
<0.01
<0.1-0.3
0.2-0.8

-------
     Table  4-35  Background water quality  1n  alluvial aquifer. Monument
                  Valley site (Concluded)
Constituent
Strontium
Sulfate
SulHde
Thor1um-230b
Tin
Total dissolved
solids
Uranium
Vanadium
Z1nc
Observed
concentration No. of
range3 analyses Mean3
<0.10
55.8-158.0
<0.10
0.0-6.3(+0.7)
<0.005

294.0-626.0
<0. 003-0. 0054
<0. 01-0. 70
<0. 005-1. 6
6
6
6
6
6

6
6
6
6
<0.10
113.0
<0.10
1.2
<0.005

454.5
0.0034
0.30
0.5
Two Background
standard concentration
deviations3 range3
0.0
90.5
0.05
5.03,
0.0

253.2
0.0024
0.66
1.4
<0.10
22.5-203.5
<0.10
<1.0-6.2
^0.005

201.3-707.7
<0. 003-0. 0059
<0. 01 -0.97
<0. 005-1 .8
3In mg/1 unless otherwise noted.
bFor  radlonuclldes,  observed  range  plus analytical
 background range, 1n plcocurles per liter.
error  1s  shown  as  the
                                     4-183

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Table 4-36    Background water quality,  Shlnarump and OeChelly Sandstone
              aquifers  at Monument Valley
Constituent
Alkalinity (as CaC03)
Aluminum
Ammonium
Antimony
Arsenic
Barium
Boron
Bromide
Cadmium
Calcium
Chloride
Chromium
Cobalt
Conductance"
Copper
Cyanide
Fluoride
Gross alpha0
Gross betac
Iron
1 earl
Magnesium
Manganese
Mercury
Molybdenum
Nickel
Nitrate
Nitrite
Nitrate & NUrlte (as N)
Organic carbon
Lead-21QC
pHd
Phosphate (as P)
Polon1um-210c
Potassium
Rad1um-226c
Rad1um-228c
Selenium
Silica
Silver
Sodium
Strontium
Sulfate
Concentration
1n Shlnarumpa
202-220
0.20-0.80
<0. 10-0. 26
<0. 003-0. 005
<0.01
<0. 10-0. 20
0.10-0.50
<0.01
<0.001
3.0-29.2
7.0-15.0
<0. 01-0. 02
<0.05
400-700
<0.02
<0.01
0.20-0.80
0.50-22.0
3.2-12.0
<0. 03-0. 33
<0.01
15.1-20.3
<0. 01 -0.10
<0.0002
<0. 01-0. 22
<0. 04-0. 11
0.5-13.29
<0. 10-1. 65
0.3-3.3
42.0-51.0
0.1-3.7
7.1-8.4
<0. 10-0. 60
0.00-0.60
1.41-3.99
0.10-8.6
0.00-0.50
0.005
9.0-13.0
<0.01
73.7-94.9
<0.10
72.0-128.0
Concentration
1n DeChelly3
97-198
0.30-0.80
<0 . 1 0
<0. 003-0. 004
<0.01
<0. 10-0. 20
0.10-0.90
<0.01
<0.001
6.34-31.7
5.0-10.0
<0. 01-0. 04
<0. 05-0. 06
210-550
<0.02
<0.01
0.20-0.60
1.0-6.10
4.4-8.0
<0. 03-0. 10
<0.01
17.0-28.0
<0. 01 -0.05
O.0002
<0. 01-0. 10
<0. 04-0. 11
1.0-22.0
<0. 10-1. 615
1.3-2.5
22. 0-53. 0
0.0-1.2
7.4-9.4
<0. 10-0. 30
0.00-0.40
1.55-5.25
0.00-0.30
0.00-0.60
<0.005
5.0-11.0
<0.01
6.4-50.2
<0.10
13.2-62.1
                                   4-184

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    Table 4-36    Background water quality,  Shlnarump and  DeChelly  Sandstone
                  aquifers (Concluded)
 Constituent
Concentration
1n Shlnarump3
Concentration
1n DeChellya
Sulflde
Temperature  ฐC
Thor1um-230C
Tin
Total dissolved  solids
Total organic halogens
Uranium
Vanadium
Z1nc
<0.10
 13.0-20.0
 0.00-0.20
<0.005
 348.0-418.0
<0.003-0.007
 0.002-0.008
<0.01-0.60
<0.005-0.09
<0.10
 15.0-19.0
 0.00-0.40
<0.005
 158.0-321.0
<0.003
 0.001-0.008
<0.01-0.80
<0.010-1.26
aAs mg/1 unless otherwise noted.
"umhos/cm2.
cP1cocur1es per liter.
dStandard units.
                                     4-185

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     N

    I
                                          TO HA'.CHITA AND
                                          MEXICAN HAT
               INDIAN SERVICE
               ROUTE 6440
     •TO MONUMENT
      NO. 2 MINE
LEGEND

•  RESIDENCE
•  DOE ALLUVIAL MONITOR WELL
  -VSULFATE ISOPLETH ซmg/l)
fcฐ  daihtd whtrt estimated
                                                                             • 57
                     EVAPORATION
                     POND
                                                      APPROXIMATE SCAi-Ei IN FEET
    FIGURE  4-5      SULFATE PLUME, MONUMENT VALLEY  SITE
                                         4-186

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       n
       I
                 INDIAN SERVICE
                 ROjTE 6440
     •TO MONUMENT
      NO. 2 MINE
LEGEND

•   RESIDENCE
•   DOE ALLUVIAL MONITOR WELL
^f NITRATE ISOPLETH (mg/l as N)
    (dashed whปrป tstimattd)
*   EPA DRINKING WATER LIMIT
                                5 00   0   500     1500

                              APPROXIMATE SCAuE IN FEET
   FIGURE  4-6
NITRATE PLUME,  MONUMENT  VALLEY SITE
                                     4-187

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      N

     I
                                     •

                                     •

TO HALCHiTA AND
MEXICAN HAT
               INDIAN SERVICE
               ROUTE 6440
     "TO MONUMENT

      NO. 2 MINE
LEGEND
   RESIDENCE

   DOE ALLUVIAL MONITOR WELL

        URANIUM ISOPLETH (tng/l)
         ' whซrซ •ttimซtซd)
                                                                               .005
    FIGURE   4-7     URANIUM PLUME,  MONUMET VALLEY SITE
                                        4-188

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      Table 4-37  Sampling for Hazardous Constituents
                in Uranium Mill Tailings  Liquids^3)

Volatile Organic Compounds Not Found '.in- Tailings  Liquids
Bromoform
Carbon tetrachloride
Chlorobenzene
Chlorodibromomethane
Chloroform
Dichlorobromomethane
1,2 - dichloroethane
1,1,2,2  - tetrachloroethane
Tetrachloroethylene
1,1,1 -  trichloroethane
1,1,2 -  trichloroethane
Trichloroethylene,
Semivolatile Organic Compounds Not Found  in Tailings Liquids
2-Chlorophenol
2,4-Dichlorophenol
2,4-Dimethylphenol
4,6 - Dinitro-0-Cresol
2,4-Dinotrophenol
2-Nitrophenol
4-Nitrophenol
P-Chloro-M-Cresol
Pentachlorophenol
Phenol
2,4,6-Trichlorophenol
Acenaphthene
Acenaphtylene
Anthracene
Acenaphtylene
Anthracene
Benzidi.ne
Benzo(a)anthracene
Benzo(a)pyrene
3,4-Benzofluoranthene
Benzo(ghi)Perylene
Benzo(k)fluoranthene
Bis(2-Chloroethoxy) Methane
Bis(2-Chloroisopropyl Ether
Bi.s( 2-Chloroisopropyl) Ether
Bis(2-Ethylhexyl) Phthalate
4-Bromophenyl Phenyl
Butyl Benzyl Phthalate
2-Chloronaphthalene
4-Chlorophenyl Phenyl Ether
Chrysene
Dibenzo(a,h)Anthracene
1,2-Dichlorobenzene
1,3-Dichlorobenzene
Fluoranthene
Fluorene
Hexachlorobenzene
Hexachlorobutadiene
Hexachlorocyclo-pentadiene
Hexachloroethane
Indeno (1,2,3-cd)pyrene
Isophorene
Naphthalene
Nitrobenzene
N-Nitrosodimethylamine
N-Nitrosodi-N-Propylamine
N-Nitrosodiphenylamine
Phenantrhene
Pyrene
1,2,4-Trichlorobenzene
Aldrin
Alpha-BHC
Beta-BHC
Gamma-BHC
Delta-BHC
Chlbrdane
4,4-DDT
4,4-DDE
4,4-DDD
Dieldrin
Alpha-Endosulfan
Beta-Endosulfan
Endosulfan Sulfate
Endrin
Endrin Aldehyde
Heptachlor
Heptachlor Epoxide
PCB-1242
                          4-189

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Table 4-37 (continued)

     I/4-Dichlorobenzene
     3,3'-Dichlorobenzidine
     Diethyl Phthalate
     Dimethyl Phthalate
     Di-N-Butyl Phthalate
     2,4-Dinitrotoluene
     2,6-Dinitrotoluene
     Di-N-Octyl Phthalate
     1,2-Diphenylydrazine
       (as Azobenzene)
                PCB-1254
                PCB-1221
                PCB-1232
                PCB 1248
                PCB-1260
                PCB-1016
                Toxaphene
     Hazardous Constituents Found  in Tailings Liquids
     Arsenic
     Barium
     Beryllium
     Cadmium
     Chromium
Cyanide
Fluorine
Lead
Mercury
Molybdenum
Nickel^
Radium 226 and
Selenium
Thorium
Uranium
228
(a) from TSM87)
                               4-190

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organonitrogen compounds, amines,  as  used  in  the  Amex  process.
Flagg also reports that  there was  "very  extensive research"  in
the development of several organic extractants  for  recovering
uranium from sulfuric acid leach liquors.   Thus,  it appears
reasonable to assume that several  organic  compounds were  used at
uranium mills, probably  in the  1940's and 1950's.

Total organic carbon and total organic halogen  concentrations
were reported by DOE in  ground water  near  several of the
inactive sites, including .some EPA priority pollutants (for
example, see DOE-86a).   While it appears  this contamination  is
not from the tailings (the residual radioactive material),
additional monitoring of ground water near the  tailings sites
may be needed to establish that the contamination is not  a
result of the tailings.

4.18  GROUND WATER CLASSIFICATION

Introduction

In August 1984, the U.S. Environmental Protection Agency  (EPA)
issued a Ground-Water Protection Strategy,  setting  out the
Agency's plans for enhancing ground-water  protection efforts by
EPA and the States.  A central feature of  the Strategy is a
policy framework for EPA1s programs which  accords differing
levels of protection to  ground water based on the resource's
use, value to society, and vulnerability  to contamination.   A
three-tiered ground-water classification system was established
in the Strategy as a key operational tool  to  help implement  this
policy.

The Classification system recognizes that  "special" ground water
exists due to its high vulnerability to contamination  and high
value for drinking water purposes  or its  importance to a  unique
ecological habitat (Class I).  The  vast majority  of the nation's
ground water falls within Class II which encompasses all
non-Class I current or potential sources of drinking water.
Class III ground water is not a potential  source  of drinking
water due to levels of contamination either from  naturally
occurring conditions or  the effects of broadscale human
activity, that cannot be feasibly  cleaned  up.

These Final Guidelines for classifying ground water augment  the
Ground-Water Protection  Strategy by:

     o   Further defining the key  terms and concepts of the
         classification  system,  and
                               4-191

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     o   Describing procedures and information needs to assist  in
         classifying ground water.

The procedures in the Final Guidelines are generally intended for
"site-specific" ground-water classification based on a  review of
the segment of ground water in relatively close proximity to a
particular source.  While the specific procedures are not designed
specifically for broader aquifer classification, many of the
concepts and procedures developed for site-by-site classification
will also be useful in such classification efforts.

The manner and extent to which the Guidelines will be incorporated
in EPA regulatory, permitting, and planning decisions are addressed
in a supplemental Implementation Policy  Statement being issued
concurrently with the Guidelines.

The key criteria for each class, and procedural approaches  for
determining whether the criteria are met are outlined as follows:

Classification Review Area

The first step in making a classification decision is defining  the
area around the source that should be evaluated.  Once  this
Classification Review Area (CRA) has been determined, information
regarding public and private wells, demographics, hydrogeology,  and
surface water and wetlands is collected  and a classification
decision is made based on the criteria for each class as described
below.

The Guidelines specify an initial Classification Review Area  as the
area within a two-mile radius of the boundary of the facility or
activity under review.  Under certain hydrogeologic conditions,  an
expanded or reduced Classification Review Area is allowed.

It should be emphasized that the Classification Review  Area defines
a "study area" necessary to evaluate the appropriate ground-water
class, in connection with a specific site analysis, and not to
imply that action needs to be taken relative to other facilities
within the area.

Class I - Special Ground Water

Class I ground waters are defined as resources of particularly  high
value.  They are highly vulnerable and either an irreplaceable
source of drinking water for a substantial population or
ecologically vital.

     o   Highly vulnerable ground water  is characterized by a
         relatively high potential for contaminants to  enter  and/or
         be transported within the ground-water flow system.   The
         Guidelines provide both quantitative and qualitative
         decision aids for determining vulnerability based  on
         hydrogeologic factors.
                                4-192

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      o   An irreplaceable source of drinking water for a
          substantial population is ground water whose replacement
          by water  of comparable quality and quantity from
          alternative sources in the area would be economically
          infeasible or precluded by institutional barriers.  The
          determination of irreplaceability is based on a three-step
          process  that includes identifying the presence of a
          substantial population, applying screening tests designed
          to produce a preliminary determination,  and reviewing
          relevant  qualitative criteria in order to produce a final
          determination.

      o   Ecologically vital ground water supplies a sensitive
          ecological system located in a ground-water discharge area
          that  supports a unique habitat.   Unique  habitats include
          habitats  for endangered species listed or proposed for
          listing  under the Endangered Species Act as well as
          certain  Federally managed and protected  lands.

Class  II  -  Current  and Potential Sources of Drinking Water and
Ground Water Having Other Beneficial  Uses~~

Class  II  ground waters include all non-Class I ground water that is
currently used or  is potentially available for drinking  water or
other  beneficial  use.

     Subclass  IIA  is a current source of  drinking water.   Ground
     water  is  classified  as IIA if within the Classification Review
     Area there is  aither (1)  one  or  more operating drinking water
     wells  or  springs,  or (2)  a water supply reservoir watershed or
     portion that  is designated for water quality protection by
     either a  State  or  locality.

     Subclass  IIB  is a potential  source of drinking water.   This
     ground water  (1)  can be  obtained in  sufficient quantity to
     meet the  minimum needs of an  average family;  (2)  has total
     dissolved solids  (TDS)  of less than  10,000 milligrams  per
     liter  (mg/1);  and  (3)  is  of  a quality that can be used without
     treatment or that can  be  treated using  methods reasonably
     employed  by public water  systems.

Class  III - Ground Water  Not  a Potential  Source of  Drinking Water
and/or Limited Beneficial Use  "                    ~~	'

Class  III drinking waters  have  either (1)  a  TDS concentration equal
to or greater than 10,000 mg/1; or  (2)  contamination  by naturally
occurring conditions  or by  the  effects  of  broadscale  human  activity
that cannot be cleaned up. using treatment  methods  reasonably
employed in public water  systems.   A  two-step  test,  based  on
technical and economic feasibility, is  presented  in  the
Guidelines.   Class III also  encompasses those  rare  conditions where
yields are insufficient to  meet the minimum  needs of  an average
household.  Subdivisions  within Class  III  include:
                               4-193

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     Subclass IIIA ground water has an intermediate degree of
     Tnterconnection with adjacent ground water units and/or are
     interconnected with surface waters.

     Subclass IIIB ground water has a low degree of interconnection
     with adjacent ground water units.

4.19  REFERENCES

DOE84   U.S. Department of Energy, "Draft Environmental Assessment
        of Remedial Action at the Gunnison Uranium Mill Tailings
        Site," Dec 1984.

DOE86   U.S. Department of Energy, "Remedial Action Plan and Site
        Conceptual Design for Stabilization of the Inactive Uranium
        Mill Tailings Site at Monument Valley, Arizona," Feb 1986.

DOE86a  U.S. Department of Energy, "Draft Environmental Impact ,
        Statement—Remedial Actions at  the Former Climax Uranium
        Company Uranium Mill Site, Grand Junction, Mesa County,
        Colorado," DOE/EIS-0126-D, March 1986.

EPA84   Environmental Protection Agency, "Ground Water Protection
        Strategy," Washington, Aug. 1984.

EPA86a  Environmental Protection Agency, "Guidelines for Ground
        Water Classification under the  EPA Ground Water Protection
        Strategy," Final draft, Washington, Dec. 1986.

EPA86b  Environmental Protection Agency, "Guidance on Remedial
        Actions for Contaminated Ground Water  at Superfund
        Sites," EPA Contract No.  68-01-7090,  Oct.  1986.

F161    Flagg, J.F.,  "Chemical Processing of  Reactor Fuels,"
        Academic Press,  1961.

Le87    Leske, D., Department  of Energy, Albuquerque Operations
        Office, private  communication,  June 1987.

NUREG80 U.S.  Nuclear  Regulatory Commission, Final  Generic
        Environmental Impact Statement  on Uranium  Milling,
        NUREG-0706, Sept  1980.

Sm87    Smith, R.D.,  U.S.  Nuclear  Regulatory  Commission,  "Sampling
        of  Uranium Mill  Tailings  Impoundments for  Hazardous
        Constituents,"  Memorandum  to  Robert E. Browning,  Director,
        Division of Waste  Management,  NMSS, Feb  9,  1987.
                                4-194

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                            CHAPTER  5

                     GROUNDWATER RESTORATION
 5.1  'TREATMENT TECHNOLOGY

 Introduction

 The  purpose  of this chapter is to identify groundwater
 restoration  techniques  that might be applicable to the removal
 and  treatment  of  contamination at inactive uranium mill tailings
 sites  and  to evaluate the cost ranges of applying these
 techniques.  The  locations of the sites are shown in Figure
 5.1.   The  groundwater treatment technologies discussed in this
 summary  are  presently available and applicable to hazardous
 wastes.

 Processes  and  Techniques

 Remedial actions  that protect groundwater resources and
 associated surface  water  resources include aquifer restoration,
 elimination  or limitation of the source of contamination,  and
 containment  of the  contaminated groundwater.   EPA has mandated
 long term, zero or  minimal maintenance remedial actions for the
 UMTRA  Project  sites (40 CFR 192).   Therefore,  aquifer
 restoration  and limitation of the source of contamination  should
 be the primary considerations.   Containment of groundwater
 should be  considered only in support of aquifer restoration.

 An appropriate water resource protection program at an UMTRA
 Project  site might  include some or all of the  following:

     - Physical.removal of contaminated groundwater

     - Temporary  containment  of contaminated groundwater,
       intruding  uncontaminated groundwater  or intruding surface
       water

     - Treatment  of contaminated  water to meet appropriate water
       quality  standards  or  goals

     - Isolation  of the contaminant  source  from the hydrologic
       regime

 Isolation or at least partial  isolation of 'the source of
contamination  is  implemented  by  the  use of  a multi-layered cover
above the source  of contamination  and  possibly a  layer  of
selected and reworked natural materials  underlying  the  source .of
contamination.   This approach  is  used  to  limit future
contamination to  non-pollutant  levels  and  is not  related
directly to aquifer restoration.   Therefore, this  chapter  will
not discuss repository designs  but will  focus  on  the  processes,
technologies and  costs of  contaminated  ground  water  restoration.
                               5-1

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Ui
to
                               GREEN
                               RIVER   *HIFLE(2)
                                   •   GRAND JCT
                       PRIORITIES

                         A- HIGH
                         • - MEDIUM
                         • - LOW
NOTE:
EDGEMONT, SOUTH DAKOTA
VIC8NITY PROPERTIES ONLY
                          FIGURE 5-1 LOCATION - UMTRA PROJECT SITES

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 Physical Removal

 Two methods can be used to remove contaminated  groundwater:
 trenches and wells.  The methodologies and  technical
 considerations are discussed in this section.

 Subsurface Drains/Trenches

 Subsurface drains consist of underground gravel-filled  trenches
 lined with tile or perforated pipe which intercept leachate or
 infiltrating water and transport it away from the wastes to a
 suitable point for treatment and/or disposal.   Subsurface drains
 may be used in low permeability strata, such as clay or silty
 clay with permeability insufficient to maintain adequate flow to
 wells.  The subsurface drain can provide a  sufficient surface to
 create greater discharge rates than a well  or series of wells
 could provide.  Subsurface drains can also  be used in more
 permeable sand and gravel.   For sand and gravel, an open trench
 can be used or the permeability of the material in the trench
 must be significantly greater than the surrounding soil to make
 the trench effective.

 Subsurface trenches are generally constructed by excavating a
 trench,  laying perforated  pipe  or  tile along the bottom, and
 backfilling with  a coarse  gravel to prevent soil fines from
 penetrating and clogging the  soil  pores.   This  procedure is
 confined to situations  in  which the contaminated groundwater is
 at  a depth consistent with  the  capabilities of  the trenching
 equipment,  generally  no more  than  100  feet  below the  land
 surface.   Advantages  of this  type  of  system include low
 operating costs,  since  flow is  by  gravity,  considerable
 flexibility in design and  spacing,  and  fairly good reliability
 when monitoring is provided.

 Wells

 Wells  can be employed to extract or  actively divert groundwater
 at  or  near  a disposal site  and  are  effective in  any porous  or
 fractured media which provide sufficient yields  to wells.   This
 technology  may  be  employed  to. collect  the groundwater  for
 treatment,  contain a  contaminant plume, or  to lower a  water
 table.   The number, spacing, depths, diameters,  and completion
 intervals  of wells in a well field  can  be optimized to  remove
 contaminated groundwater cost-effectively.   The  goals  of a
 restoration program should  be developed and  wells  positioned to
 remove the  specified  contaminated groundwater while extracting
 only a limited  volume of uncontaminated water.   Pumping  to  lower
 a water table may  be'appropriate under  several conditions,  such
 as  1)  lowering  the water table  in an unconfined  aquifer  so  that
 contaminated groundwater dose not discharge  to a
 hydraulically-connected  receiving stream, 2)  lowering the water
 table so that  it is not in direct contact with the waste, or 3)
 lowering the water table to prevent contamination  of an
underlying aquifer.
                               5-3

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Temporary Containment

Physical containment is accomplished through  installation  of  a
relatively impermeable barrier between contaminated  and  clean
portions of the aquifer.  Physical containment  technologies
include slurry walls, grout curtains, and  sheet  piling.
Containment should be considered  as  support  for  physical removal
of contaminated groundwater,  rather  than as  a remedial  action in
itself.  Containment methods  are  not proven  long term solutions,
therefore their application is limited to  support of physical
removal.  For  instance, at  sites  adjacent  to rivers, such as  the
sites  in Grand Junction and Durango, containment may be
considered in  controlling  surface water  inflow into  the area  of
groundwater removal.  Figure  5.2  shows the effect of a  cutoff
wall adjacent  to  a  river.   Also,  containment may be^appropriate
where  the advancing  contaminant plume  is  approaching a  presently
used water resource.

Sheet  Pile Cut-Off  Walls

The  construction  of a  sheet pile  cut-off  wall involves driving
inter-locking  piles into  the  ground  with  a pneumatic or steam
pile driver.   When  first  placed  in the ground, the  sheet pile  ,.
cut-off  allows easy water  flow through the edge interlocks.
However,  with  time,  fine  soil particles  fill the seams and an
effective  barrier is formed.   The performance life  of a sheet
pile cut-off  wall can  vary between seven and 40 years, depending
upon the chemical characteristics of the surrounding soil. p  ._
Sheet  piling  is feasible in situations where the water  table is
 near the surface, a confining layer exists at a depth of  less
 than 100 feet, and surficial materials are fine-grained to allow
 ease in driving the sheet metal.   Sheet piling  is not feasible
 for use in very rocky soils or for long-term containment.

 Slurry Walls

 Installation of a slurry wall involves excavating a trench
 through or under a slurry of bentonite clay  and  water,  then
 backfilling the trench with  the  original  soil  (with or  without
 bentonite mixed in).  The trench  is usually  excavated  down to  a
 relatively impervious substratum  to limit groundwater  underflow.
 During the excavation process, the  trench walls are supported  by
 the slurry, preventing the walls  from slumping  or caving  in, and
 eliminating the  need for additional shoring  materials.   The
 process is designed to force the  bentonite  slurry  through its
 own weight into  the more permeable  surrounding  soils,  forming a
 filter Sake of low  permeability  which lines the walls  and bottom
 of the trench.   The application  of  slurry walls as  relatively
 impermeable barriers  is  limited  to  areas  where materials are
 trenchable and have sufficient permeability to form a  filter
 cake.  Trench  depth is  limited by the capabilities  of  the
 trenching equipment.   This  technology  is  practical  only when
 groundwater contamination  exists near  the surface,  generally

                                5-4

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                   LOW-PERMEABIUTY BARRIER REDUCES INDUCED
                            FLOW FROM RIVER
I
Ui
          DISCHARGING WELL
                                    GROUND SURFACE
                                             RIVER
PUMPING
WATER
LEVEL
            ALLUVIAL AQUIFER
         Y//////////////////X///////////.
            *— CONFINING LAYER
                                   LOW-PERMEABILfTY
                                   SLURRY WALL, GROUT CURTAIN.
                                   OR SHEET PILING CUTOFF WALL
                                RGURE 5.2

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less than 100 feet in depth.  Further, tests must be performed
as part of the remedial action process to determine whether the
slurry could be affected by chemical reactions with the
contaminants, thus rendering it unsuitable for application.
Slurry walls may be more appropriate for protecting surface
water from contamination of discharging groundwater rather than
containing the groundwater itself.

Grout Curtains

Grouting is the pressure injection of special fluids into  a rock
or soil body.  The fluids set or gel in the voids in the rock
and when carried out in the proper pattern and sequence, the
process forms a wall or curtain that is an effective groundwater
barrier.  Due to the high cost of installing grout curtains,
they are usually used only to seal voids in porous or  fractured
rock where other methods to control groundwater  are not
technically feasible.

Treatment Processes

After contaminated groundwater has been collected, the next step
in aquifer restoration involves treatment of the water and the
eventual reinjection into the groundwater or discharge to
surface water.  A variety of methods has been successfully
employed in  treating groundwater contaminated with typical
contaminants  (e.g. uranium, metals, sulfate and  dissolved
solids).  Examples are chemical precipitation, evaporation, ion
exchange, neutralization, and sorption.

Chemical Precipitation

The chemical  precipitation  process  removes  dissolved metals from
aqueous wastes 'by chemically converting the metals into
insoluble forms.  The process is  illustrated  in  Figure 5.3.
Metals may be precipitated  from solution as hydroxides,
sulfides, carbonates or other salts.  Hydroxide  precipitation
with  lime is  most common; however,  sodium  sulfide  is  sometimes
used  to achieve  lower effluent metal  concentration. .  This
involves pH  adjustment followed by  the  addition  of sodium
sulfide and  a flocculant.   Solids  separation  is  achieved by
standard flocculation—coagulation  techniques.   The  resulting
residuals are metal  sludge  and  the  treated  effluent  with an
elevated pH  and,  in  the case  of  sulfide precipitation, excess
sulfide.

This  technology  is  used to  treat  aqueous  wastes  containing
metals, including  zinc, arsenic,  copper,  manganese,  mercury,
cadmium,  trivalent  chromium,  lead  and nickel.   A disadvantage' of
the  method  is that  the pH which  would precipitate  one  metal  may
allow other  metals  to  remain  soluble.   Therefore,  it may be
difficult to attain  an  optimal  pH for a given mix  of metals.
Also,  chelating  or  complexing  agents  may  prevent metals from

                               5-6

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                        CHEMICAL PRECIPITATION AND ASSOCIATED PROCESS STEPS
     CHEMICAL
     PRECtPITANTS
Ln
I
         LIQUID
                            PRECJPfTATOR
                            TANK
CHEMICAL
FLQCCULANTS/
SETTUNG AIDS
                                                                 RjOCCULATION
                                                                 WELL
                              FLOCCULATING
                              PADDLES
                                                       FLQCCULATOR-
                                                       CLARIF1ER
                                                                                           EFFLUENT
                                                                                       BAFFLE
                                                                                    SLUDGE
                                              RGURE 5.3

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precipitating.  Sulfide precipitation has been successfully used
in numerous applications and often achieves lower concentrations
levels than lime precipitation.  However, the process does
require close monitoring to function properly.

Most uranium milling operations employed acid leach processes  to
extract uranium.  Therefore/ chemical precipitation initiated  by
increasing the pH can be very effective in  reducing the
concentrations of radium, thorium, uranium, selenium,1 arsenic,
cadmium, chromium, other trace metals and sulfate.  Although
some chemical precipitation resulted from neutralization  in the
subsoils at most sites due to the abundance of calcite  in the
soils, enhanced precipitation may be applied with a treatment
plant to further lower the concentrations of metals that  complex
with mobile anions.  Sulfide precipitation  may be most  effective
in this enhanced treatment.

Evaporation

Evaporation is defined as the physical  separation of  a  liquid
from a dissolved or suspended solid by  the  application  of energy
to volatilize the liquid.  Evaporation  may  be used  to
concentrate a hazardous or toxic material,  thus  reducing  the
volume of waste requiring subsequent treatment of disposal.
Evaporation can be carried out in a large pond with sunlight
providing the energy.

Most uranium milling sites are in semi-arid climates  where
potential evaporation greatly exceeds precipitation.  Therefore,
a pond to evaporate discharged groundwater  from  dissolved
contamination is a potentially viable treatment  technique.
Following evaporation, the residual solids  could be  incorporated
into the tailing repository for  "permanent" disposal.

Ion Exchange

Ion exchange  removes toxic metal  ions from  solution  by
exchanging one  ion, electrostatically attached to a  solid resin
material, for a dissolved toxic  ion.  The process  is  illustrated
in Figure 5.4.  The resulting  residuals include  spent  resins  and
spent regenerants such as acid,  caustic or  brine.   This
technology is used to treat metal wastes  including  cations
(Ni2+, Cd2+,  Hg2+) and anions  (chromates,  selenates,
arsebates).   The effectiveness of the process may  be  limited  by
competition for exchange  sites between  contaminated  metals.
Other disadvantages are  difficulties  in obtaining  and
maintaining an  optimal pH for  efficient removal  and  the
inefficiency  of the process  in treating groundwater  with high
concentrations  of suspended  solids.   The  oxidizing  agent
concentration should be  greater  than  50 milli-equivalent per
liter  (meq/1) for practical  operation.   Highly  concentrated
waste streams (>2500 mg/1 contaminants) or  high  solid
concentrations  (>50 mg/1)  should be  avoided.
                               5-8

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                                 FIGURE 5.4
                        SCHEMATIC OF ION  EXCHANGE
    TO STORAGE TANK OR
    OTHER TREATMENT SYSTEM
 TO STORAGE TANK OR
 OTHER TREATMENT SYSTEM
INFLUENT
WASTEWATER
                                       BACKFLUSH
                                       WATER
                                     ACID
                                     REGENERANT
                      CATION EXCHANGE
                      SYSTEM

                         BACKaUSH
                         WATER
                         TREATED
                         WASTEWATER
                       CAUSTIC
                       REGENERANT
         ANK>N EXCHANGE
         SYSTEM
TO STORAGE TANK OR
OTHER TREATMENT SYSTEM
TO STORAGE TANK OR
OTHER TREATMENT SYSTEM
                                        5-9

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Neutralization

Neutralization renders acidic or caustic wastes non-corrosive  by
adjustment of the pH.  The residuals include  insoluble  salts,
metal hydroxide sludge, and neutral effluent  containing
dissolved salts.  The final desired pH  is usually between  6.0
and 9.0.

Neutralization is used to treat corrosive wastes, both  acids and
bases.  A disadvantage of the process is the  need to  dispose of
highly concentrated  sludges and solids.

Significant neutralization occurs at Western  uranium  milling
sites directly beneath and downgradient of  the  tailings source
material due to calcite in the shallow  soils.   The
neutralization causes precipitation of  gypsum and the
coprecipitation, occlusion and adsorption of  radionuclides and
trace metals.

Sorption

Contaminants are bound up in  pozzolan-type  matrices  by  physical
sorption or chemisorption yielding a stabilized material which
is easier to handle.  The process  is illustrated  in  Figure 5.5.
Liquid  immobilization depends on added  ingredients.   This
process  results in  high concentrations  of  contaminants  at the
surface  of the material and contaminants may  leach.   The treated
material is permeable.

Sorption can be used for  organics  and  inorganics.   The
advantages to  this  technology are  that  raw  materials are readily
available, the mixing  technology  is  known,  the  waste form is
relatively easy to  handle,  additives are  inexpensive, minimum
pretreatment is required, and bearing  strength  is adequate for
landfill.  Disadvantages  are  that  large volumes of  additives are
needed,  the  results are  sensitive  to  the  placement  and packing
of the  matrices,  free  water may  be  released under pressure and
changes in temperature may  affect  the  results.

Landfarming

Landfarming  is a  technique  where  contaminated soil  is
incorporated  into  the  top 6 to  8  inches of soil along with
concentrated microbial populations.   It is used to  biodegrade,
volatilize or  leach organics.  It  is  not  applicable to the
inorganic  contamination  at  uranium milling sites (WESTON, 1983).
                                                               ,B^>
Reverse Osmosis

Reverse osmosis is a membrane process to remove dissolved ions
from saline  water using  hydrostatic pressure to drive  the
feedwater  through a semipermeable membrane.  The major portion
•of the ions  remain on the feed  side of the membrane, and is

                               5-10

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                         FIGURE 5.5
              SCHEMATIC OF CARBON ADSORPTION
UQUIO
                           CARBON
                           ADSORPTION
                           COLUMN
                           H
                                                TO SERVICE
                                       JT
                                           f
CARBON
ADSORPTION
COLUMN
12
                    SPENT CARBON
                    (ONE UNIT CHANGED
                    PER TIME)
                                                 TO
                                                 REGENERATION
                              5-11

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discharged as waste.  The osmotic pressure needed for successful
treatment can be estimated as 1 psi/100 mg/1 of TDS.

Modern reverse-osmosis membranes are constructed in a modular
form, most common are spiral wound and hollow fine fiber.  The
modules are mounted in containment pressure vessels.  Reverse
osmosis is most successful in treating water with less than
10,000 mg/1 TDS to produce water with less than 500 mg/1,  i.e.,
potable quality (Montgomery, 1985).  The cost for reverse
osmosis ranges from $500 per million gallons treated for water
containing approximately 10,000 mg/1 TDS to $1500 per million
gallons treated for water containing approximately 30,000  mg/1
TDS  (Thompson, 1987).

In Situ Treatment

There are three general categories of in situ treatment
processes for the remediation of contaminated ground water:
biological, chemical, and physical.  Of these,-only the  chemical
treatment technologies are generally capable of neutralizing or
immoblizing the ground water contaminants  normally  found at  the
UMTRA sites.  In situ chemical  treatment involves the  injection
of chemicals  into the contaminated aquifer under carefully
controlled conditions to immobilize or neutralize the
contaminants.  Typical chemical treatments include  neutralizing
the  pH to induce precipitation  of contaminant cations  and/or
anions, change of chemical forms  to encourage chelation, and
formation of  compounds which are  less mobile or  less degrading
to water quality.

Implementation would  require extensive characterizations of  the
local geology, hydrology and geochemistry, followed by
site-specific pilot testing.   The  site geology,  hydrology, and
geochemistry  must allow  adequate  contact  between  the  treatment
agents and the contaminated  ground  water,  control  migration  of
the  treatment agents  and the contaminants,  and  allow  recovery  of
spent  solutions  and/or contaminants  if  necessary.   If  pilot
tests  indicated  the method  to  be  feasible, project  costs would
include  installation  of  wells  and  pumps  for  injection,
withdrawal and monitoriing,  facilities  for handling the
chemicals  for treatment,  control sampling,  etc.   Costs for a
well field and ground water  pumping  would  be 500 to 1500 dollars
per  million  gallons.   Costs  for treatment  of the water and
reinjection  are  estimated  at 500 dollars  per million gallons.
Total  costs  should  be much less than  typical chemical treatment
since  it  is  estimated that only 20%  to 50% of  the contaminated
ground water would  be pumped,  treated,  and reinjected.

5.2  VOLUMES  OF  CONTAMINATED  GROUND WATER

Introduction

Prom a technical standpoint, three factors govern the
feasibility, effectiveness and costs of aquifer restoration.

                                5-12

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 These  are  1)  the  volume  of  contaminated groundwater, 2)  the ease
 with which it can be  removed,  and 3)  its treatability.   When a
 vast volume  of  groundwater  is  contaminated or when an aquifer is
 hydraulically connected  to  a surface  water body,  it may neither
 be  technically  nor  economically feasible to pump,  treat, and
 recharge the  contaminated wastes.  Similarly, in  a situation for
 which  the  aquifer is  thin,  discontinuous,  heterogeneous, or of a
 low permeability,  aquifer restoration also may not be feasible.
 Finally, while  it may be technically  and economically feasible
 to  collect contaminated  groundwater,  it is possible that the
 type and/or  levels  of contamination may not be treatable.   These
 factors must  all  be considered in selecting the scope of aquifer
 restoration  and the applicable technologies.

 Site Descriptions

 In  this section,  each of the sites  is described,  with emphasis
 on  the estimated  volume  of  contaminated groundwater, the
 appropriate method  to extract  the contaminated groundwater, and
 the value  of  the  contaminated  groundwater  relative to its
 present or potential  use.   Volumes  of contaminated groundwater
 are summarized  in Table  5.1.

 Ambrosia Lake

 The estimated volume  of  contaminated  g.roundwater  at the  Ambrosia
 Lake site  is  650  million gallons.   The  tailings lie on
 unconsolidated  materials.   The shallow  groundwater occurs  10 to
 40  feet beneath the ground  surface.   The deeper tailings are
 saturated.  The groundwater  contained in the  tailings,  alluvium,
 fractured Mancos  Shale,  and  Tres  Hermanos  Sandstone probably
 resulted for  surface  discharges of  mine dewatering.   Given that
 the depth  of contamination  is  relatively shallow  and yields to
 wells are minimal,  contaminated groundwater could  be extracted
 more efficiently  with  trenches than with wells.   Following
 remedial action,  given that  mining  and  dewatering  has ceased in
 the area,   the contaminated groundwater  will probably dissipate
 through discharge into the mine shaft in the  Wastewater  Canyon
 Member of the Morrison Formation  and  the presently saturated
 shallow zones will  desaturate.

 Canonsburg

 The volume of contaminated groundwater  at  the  Canonsburg site  is
 approximately 100 million gallons.  The  remedial action  at the
 Canonsburg site was completed  in  1986.   Groundwater  at the
 expanded Canonsburg site is  unconfined  in'  the  unconsolidated
material (fill, soil,  and alluvium) and  is  semi-confined in the
 underlying bedrock.  Given that the contamination  is  relatively
 shallow, trenches would  appear  to be  the preferred  method  for
groundwater removal.  Depth  to groundwater  is  zero  to eight
feet.   Recharge to  the unconsolidated material  is  from direct
infiltration of precipitation  and from  groundwater  flow  onto the

                               5-13

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expanded Canonsburg site from the south.  Chartiers Creek  is the
discharge area on the western, northern, and eastern sides of
the site for the unconfined groundwater.  Groundwater in the
shallow bedrock may pass beneath the site.  Groundwater in the
area has very limited use for gardening and other outdoor  uses.

Durango

Subsurface investigations at  the Durango site  were  limited by
the steep, unstable slopes of tailings and smelter  slag at the
site.  A rough estimate of the volume of contaminated
groundwater at the site is 500 million gallons.  The depth to
groundwater ranges from approximately ten to 50  feet below land
surface.  The contamination is primarily in the  alluvium and  is
naturally contained by a thick bed  of Mancos Shale  underlying
the alluvium.  Trenching would be preferred over pumping to
extract contaminated groundwater due to  the relatively  shallow
depth of contamination.  The  site is within 500  feet of the
Animas River.  A cut-off wall may be necessary during  aquifer
restoration to prevent the inflow of surface water  from the
Animas River.

Grand Junction

The volume  to contaminated groundwater  at  the  Grand Junction
site is approximately  700 million gallons.  Shallow unconfined
groundwater occurs in  the alluvium  on  the  Colorado  River  and  is
separated from confined groundwater by  approximately 200  feet of
relatively  impermeable Mancos Shale.   Shallow  groundwater  is  not
used in the area.  Most of all  of the  contaminated  groundwater
could probably be  removed with  trenches.   A cutoff  wall  may  be
required  during groundwater  removal to  limit  the inflow of water
from the  Colorado  River.  Return irrigation flow passes under
and possibly  through  the  tailings pile.   The  water  table  over
much of  the site  rises above  the base  of the  'tailings.   During
most of  the year,  shallow groundwater  flows toward  the Colorado
River.  Water quality analyses indicate no river contamination
due  to  tailings  seepage.

Gunnison

Approximately two  billion gallons of groundwater are
contaminated  at  the  Gunnison site.   Shallow groundwater is the
major  water supply in the Gunnison area.  The Gunnison site
 rests  on  a  massive alluvial  deposit that is more than 100 feet
 thick.   It  rests at  the confluence of two large regional
 groundwater aquifers comprised of the Gunnison River and Tomichi
 Creek  water sheds.  The depth of the groundwater varies by six
 to eight feet annually and is near or above the base oJ: the
 tailings during the summer months.   Contamination may be_up to
 approximately 100 feet deep.   Because the contamination is
 relatively  deep,  covers a broad area and the  sediments are

                               5-14

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 relatively permeable, pumping is the preferred method for
 groundwater extraction for aquifer restoration.

 Lakeview

 The estimated volume of contaminated groundwater at the Lakeview
 site is three billion gallons.  Groundwater at depths greater
 than 100 feet is the major water supply in the Lakeview area.
 The depth of contamination is approximately 50 to 75 feet below
 land surface.  Groundwater occurs under both confined and
 unconfined conditions with a water table that varies seasonally
 from zero to 15 feet below the ground.   Because the
 contamination is relatively deep and the sediments are
 relatively permeable, pumping is the preferred method for ground
 water  extraction for aquifer restoration.

 Mexican Hat

 The estimated volume of contaminated groundwater at the Mexican
 Hat site is 90 million gallons.   The tailings rest on very
 dense,  tight siltstone.  The Mexican Hat site is about five
 miles  away from the  nearest exposure of permeable strata.
 Except  for areas of  local ponding,  the  fine-grained nature of
 the tailings and the high evaporation rates of the region allow
 only limited:amounts of precipitation to infiltrate into the
 tailing.   Capillary  forces in the tailings may be sufficient to
 preclude percolation of tailings water  to  the underlying
 bedrock.   The depth  to the water table  is  not known but is
 assumed  to be greater than 50 feet.   Because  the contamination
 is  relatively deep,  pumping would be  the preferred method  to
 remove  groundwater for aquifer  restoration.   The ambient water
 quality  is poor  (only industrial use  is possible without
 extensive  treatment).

 Monument  Valley

 Approximately three  billion gallons  of  contaminated  groundwater
 lie  beneath  and  downgradient  of  the Monument  Valley  site.
 Shallow  groundwater  is  used by several  local  dwellers.   The
 tailing  piles  are all  sand  (no slime),  all  precipitation is
 absorbed  and  there is  little  evidence of any  surface  runoff  from
 the_piles.   The  rock  unit  that forms  the shallowest  confined
 aquifer  near  the mill  site  is  the Shinarump Conglomerate Member
 of  the Chinle  Formation.   This rock unit is exposed  immediately
 west of  the  tailings  piles,  and  most  of  the abandoned mill
 building foundations  and  settling pond  sites  are  located on
outcrops.  The Shinarump  Member  consists of poorly  sorted  sand,
grit, and pebble-size conglomerate.   Unconfined  groundwater  is
 very near  the  surface along  the  main  axis of  Cane Valley Wash.
 The unconfined water moves  through the  alluvium  of Cane  Valley
Wash and .is  recovered near  the site from shallow  wells.  These
 shallow wells and springs are recharged  from  local runoff.
Contamination extends to  depths  of up to 100  feet.  The  depth

                              5-15

-------
and large area of contaminated groundwater and relatively
permeable soil and rock indicate that pumping is the preferred
method of groundwater extraction for aquifer restoration.

Riverton

The volume of contaminated groundwater  at  the Riverton  site  is
approximately one billion gallons.  Groundwater levels  are
generally less than six feet below  the  tailings foundation
interface and periodically groundwater  rises toward  and into the
lower portions of the tailings pile.  A confined aquifer system
is present in the underlying bedrock.   The unconfined  system and
the first confined system are separated by about 25  feet of
shale, siltstone, and mudstone bedrock.   The unconfined
groundwater quality is briny and  is not a source of  potable
water.  The unconfined aquifer has  been contaminated.
Contaminated groundwater could be  removed using trenches.   The
confined groundwater is a major  source  of potable  water in  the
Riverton area.   It has not been  contaminated as indicated by
most of the site groundwater quality  data.

Salt Lake City

The volume of contaminated groundwater  at the  Salt Lake City
site is estimated to be  1.6  billion gallons.   The  Salt Lake City
site is underlain by an  unconfined aquifer which  overlies a
confined aquifer.  Both  aquifers consist of  interbedded clays,
silts, and sands.  The  shallow  groundwater has  been
contaminated.   Trenching  could  be used  to extract  the
contaminated  groundwater.   Hydrologic- data indicate the
unconfined aquifer is  about  60  feet thick near  the site.  The
unconfined aquifer is  recharged  by upward leakage  from the
confined aquifer and  infiltration of  precipitation and
snowmelt.  The  unconfined aquifer is  generally encountered
initially  at  a  depth  of  about  75 feet.   The major  source of
recharge to  this aquifer is  infiltration of precipitation and
runoff from  the foothills of the Wasatch Mountains. .The flow
direction  in  both aquifers  is  to the  west and northwest.  The
confined aquifer has  not been  contaminated significantly.   The
unconfined  aquifer  is  characterized by very high total dissolved
solids,  iron,  sulfate,  and  sodium, and is not usable as a
potable  water supply  anywhere  in the area.  The confined aquifer
is potable  and  will  continue to be used as a water supply.

Shiprock

The volume of contaminated groundwater beneath the site  is
estimated  to be 850  million gallons and the contamination of the
floodplain deposits along the San  Juan River is estimated to be
 400 million gallons.   Groundwater  characterized by TDS  in excess
of 20,000  ppm exists in the alluvial deposits and weathered
Mancos Shale between 13 and 50 feet below the surface  underlying
 the tailings repository.  The relatively flat, shallow

                               5-16

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groundwater gradient is towards the escarpment above  the  flood
plain of the San Juan River where only slight seepage has been
found.  The shallow groundwater is contaminated beneath the
tailings; however, it is separated by hundreds of feet of
relatively impermeable Mancos Shale from the regional aquifer.
The contaminated groundwater in the floodplain deposits below
the escarpment along the San Juan River could be extracted with
trenches.  Floodplain groundwater is used for all purposes by
local dwellers across the San Juan River from the site.   Removal
of the contamination beneath the site may require pumping.

Tuba City

Approximately 1.2 billion gallons of groundwater in the Navajo
Sandstone has been contaminated at the Tuba City site.  The
principal aquifer and water supply in the Tuba City-Moenkopi
area is a multiple-aquifer system consisting of Navajo Sandstone
and some sandstone beds in the underlying Kayenta Formation.
This aquifer is recharged by winter and spring precipitation in
the Kaibito Plateau highlands some distance north of  Tuba City.
The depth to the water table is approximately 50 feet.
Contamination has extended to depths of up to 150  feet/
therefore wells would be needed to extract the contaminated
groundwater.

5.3  AQUIFER RESTORATION COST RANGES

Unit costs ranges for groundwater removal methods, cut-off walls
and treatment methods are presented in Table 5.2.  The likely
unit costs are also presented.
                              5-17

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Table 5.1
SITE
Volumes of Contaminated Ground Water at Selected
Inactive UMT Sites
            AMOUNT OF CON-
            TAMINATED WATER
                 (MGAL)
            ,  MIN   :    MAX
            AMOUNT OF CON-
            TAMINATED WATER
                (MGAL)
                LIKELY
Ambrosia Lake
Canonsburg
Durango
Grand Junction
Gunnison
Laheview
Mexican Hat
Monument Valley
River ton
Salt Lake City
Shiprock
Tuba City
500
75
300
500
1500
2500
60
2500
800
1200
1000
1000
BOO
125
700
900
2500
3500
120
3500
1200
2000
1500
1500
650
100
500
700
2000
3000
90
3000
1000
1600
1250
1250
TABLE 5.2.  UNIT COSTS FOR GROUND WATER RESTORATION  METHODS
TREATMENT METHODS
                        TOTAL COST   (DOLLARS)
1)
2)
3)
4)
5)
6)
7)
8)
9)
10)
11)
12)
Slurry Wall
Grout Curtains
Sheet Pilings
Subsurface Drains
Evaporation Ponds
Groundwater Pumping
Chemical Precipitation
Ion Exchange
Neutralization
Sorption
Reverse Osmosis
In Situ Treatmemt
54.
162.
00
00
- 110.00/Cubic
- 330.00/Cubic
Yard
Yard
15.00/Sq Ft of Wall-
500.
1.
500.
500.
500.
500.
1000.
500.
1000.
00
50
00
00
00
00
00
00
00
- 1000.00/MGAL
- 5.00/Sq Foot
- 1500.00/MGAL
- 1200.00/MGAL
- 1000.00/MGAL
- 1200.00/MGAL
- 1400.00/MGAL
- 1500.00/MGAL
- 2000.00/MGAL
Treated
of Pond
Treated
Treated
Treated
Treated
Treated
Treated
Treated
                    Likely Unit Costs  (DOLLARS)
ITEM
              MIN.
MAX.
LIKELY
Containment (/FT2)
Pumping (/MGAL)
Trenching (/MGAL)
Treatment (/MGAL)
10
500
500
500
20
1500
1000
1400
15
1000
750
950
                               5-18

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5.4  REFERENCES                 '              •:

Clean-up of Chemical Contaminated Site, Chemical Engineering,
February 21, 1983, V90, n4, p.73(9)

Environmental Assessment of Remedial Action at the Riverton
Uranium Mill Tailings Site, U.S. Department of Energy,
DOE/EA-0254, July 1985

Handbook, "Remedial Action at Waste Disposal Sites." USEPA, EPA
625/6-82-006

Handbook, "Leachate Plume Management." USEPA, EPA 5-40/2-85/004

Jacobs Engineering Group, "Aquifer Protection and Restoration
Alternatives and Cost Considerations"

Lauch, R.P., and Cuter, G.A., "Ion Exchange for the Removal of
Nitrate From Well Water." Journal AWWA, 78:5:83, May 1986

Montgomery, James M. "Water Treatment Principles and Design",
John Wiley & Sons, Inc., 1985.

Sorg, T.J., "Treatment Technology to Meet the Interim Primary
Drinking Water Regulations for Inorganics," Journal AWWA,
70:2:105, February 1978

Summary Report, "Remedial Response at Hazardous Waste Sites,"
USEPA, EPA 540/2-84-002 A & B

Thompson, Bruce, Personal Communication, University of New
Mexico, May 1987.

Wagner, K., and Z. Kosin.  1985. In situ treatment.  In:  The
Sixth National Conference on Management of Uncontrolled
HazardoustWaste Sites, November 4-6, 1985, Washington, D.C.
Hazardous Materials Control Research Institute, Silver Spring,
MD.

Roy F. Weston, "Installation Restoration General Environmental
Technology Development," Report No.  DRXTH-TE-CR-83249, December
1983.

Roy F. Weston, "Solvent and Heavy Metals Removal from
Groundwater," Report No. DRXTH-TE-CR-82176, January 1983.
                              5-19

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                            CHAPTER 6

        COSTS OF GROUND WATER RESTORATION  AND  MONITORING
The costs of ground water  restoration  can  vary  greatly among
sites, as discussed in the previous  chapter.  The  purpose of
this chapter is to consider  the  major  capital and  operation cost
components to arrive at a  single  estimate  of the  total ground
water cleanup cost for all 24  sites.   The  major cost components
are the amount of contaminated ground  water, the  amount of
contaminated ground water  that must  be removed  from below the
surface, and any treatments  that  must  be given  the contaminated
ground water.  Costs are also  estimated  for monitoring of ground
water and at water treatment plants.

6.1  AMOUNT OF CONTAMINATED  GROUND WATER

The volume of ground water that  is contaminated is estimated
from well data and the geological structure  in  the locale of the
tailings pile.  Well data  indicate the area of  the contaminated
plume and also provide some  characteristics of  the local
geology.  The presence of  confining  layers (aquitards) limits
the vertical spread of the contamination,  unless  there are
interconnections with other  aquifers.   The vertical distance
between confining layers when  combined with  the area of the
contaminated plume yields  the  volume of  the contaminated
aquifer.  The volume of water  is determined  using the porosity
of the rocks in the aquifer.

The many variables in this determination lead  to  uncertainty.
Estimated uncertainties in the amount  of contaminated water
shown in Table 5.1 range from  +_  17%  to _+ 40%  from the midpoint
values.  Since there is no evidence  that these  volumes are
skewed  (i.e., purposefully over- or  under-estimated), the
midpoint values are used to  estimate total costs.   The volumes
of contaminated ground water are listed in Table  6.1.

6.2  AMOUNT OF GROUND WATER  TO BE REMOVED

The total cost of ground-water restoration is  directly
proportional to the total  amount of  ground water  that must be
processed.  Typically, this  total quantity of  water is expressed
as the number of volumes of  contaminated ground water that must
be removed  to restore ground-water  quality.   For  example, the
amount of contaminated ground  water  at Ambrosia Lake is 650
million gallons  (Mgal).  If  the  total  amount  of ground water to
be processed is five volumes,  the total amount  is 3250 Mgal.
                               6-1

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                Table 6.1  Aquifer Restoration Cost  Estimates
Site
Amount of
Contaminated
Water
(106 gal)
Pumping
Cost
(106 $)
Trenching
Cost
(106 $)
Treatment
Cost
(106 $)
Containment
Cost
(106 *)
Ambrosia Lake     650
Canonsburg        100
Durango           500

Palls City       4000
Grand Junction    700
Gunnison         2000

Lakeview         3000
Maybell           180
Monument Valley  3000

Rifle - New       700
Riverton         1000
Salt Lake City   1600

Shiprock         1250
Slick Rock - NC    30
Slick Rock - DC    23

Spook             180
Tuba City        1250
                         Install  Operate
2.50    7.50

3.75   11.25

3.75   11.25
                2.44
                0.38
                1.88
                2.63
                2.63
                3.75
                6.00

                4.69
                0.11
                0.09

                0.68
                          Install  Operate
1.56
4.69
                    0.62
                    0.10
                    0'.48
0.67
1.90

2.85

2.85

0.67
0.95
1.52

1.19
0.03
0.02

0.25
1.19
         2.47
         0.38
         1.90
                             2.66
                             7.60

                            11.40

                            11.40
                              ,66,
                              ,80
6.08

4.75
0.11
0.09

0.86
4.75
       1.4(0
(a)  Cost estimates  are  for processing  five  volumes of contaminated water over
     15 years.  Unit costs are  $15/sq.  ft. for  containment,  $l,000/Mgal for
     pumping, $750/Mgal  for trenching  and  $950/Mgal for treatment.
(b)  Assumes all water is treated.   These  costs may be much  less for some sites
     if effluent limitations  guidelines are  met for direct discharges to rivers,
     or if land disposal is feasible.
(c)  Containment area  is 62,500 sq.  ft.
(d)  Containment area  is 35,000 sq.  ft.
                                       6-2

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Estimating the number of volumes to  be  extracted  on  a  generic
basis is uncertain.  Restoration is  greatly  dependent  on the
chemical characteristics of the aquifer  rock,  which  can  be
expected to vary widely among  sites.  In a  review ;of in  situ
uranium mining at eight sites  (NUREG86),  considerable
variability was found in the number  of  volumes needed  to
significantly reduce hazardous constituents  in the ground
water.  Restoration of the ground  water  at  these  sites was
complicated due to the processing  solvent (lixiviant)  that  was
used to dissolve the uranium.  An  important  finding  was  that,
for those cases where significant  restoration  was achieved,
almost all the cleanup occurred in the  first few  volumes removed.

Based on the discussion in Chapter 5, a  value  of  five  volumes of
contaminated ground water  is selected as the best quantity  for
estimating costs of restoration.   Selective  chemistry  may be
used at some sites to enhance  restoration,  as  well as  injection •
of treated (clean) water to flush  (sweep) contaminants from the
aquifer.  Such actions are site specific and not  amenable to
assessment in this generic analysis.

6.3  TREATMENT OF CONTAMINATED GROUND WATER

Treatment costs vary from  $500.00  to $1,400.00 per Mgal  treated
(See Table 5.2).  Since seven  treatment methods are  available
for application at any particular  site,  it  appears  likely that
the midpoint of the cost  range can be  achieved when  averaged
over all sites.  Therefore, the midpoint value of $950.00 per
Mgal of water treated  is  selected  for  use in this assessment.

6.4  ESTIMATED COST OF RESTORATION TREATMENT

The estimated cost of  ground water restoration is .shown  in Table
6.1 for the sites for which sufficient  data are available.   The
procedure  includes:

     o  A choice is made  whether  trenches or wells would be the
        preferred method  of groundwater removal.   Then the unit
        cost  range  is  applied  for  the  chosen method.

     o  Cut-off wall costs are estimated for the  two sites where
        river inflow may  need  to  be controlled.

     o  Site-specific  treatment methods are not specified
        because the unit  cost  ranges do not vary  significantly
        between the various  treatment  methods.  A treatment cost
        of $950 is  used for  all  sites.

     o  It is assumed  that  five  times  the volume  of  contaminated
        ground water  needs to  be  extracted to restore adequate
        ground water quality.
                                6-3

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The cost estimates  include, the  major  items required in ain
aquifer restoration program and assume that all ground water
must be restored  at all  sites by treatment.   Some of the items
not included  in  the cost estimates  are:

     - monitoring equipment

     - data collection

     - discharge  or reinjection facilities and operations

     - removal amd  remediation  of facilities

     - final  revegetation and well  abandonment.

Pumping costs and treatment plant operating costs are costs that
will occur over  a period of 5 to 53 years  (DQE'88c).  Therefore,
estimating the operating costs  separately  will allow the present
value of these costs to  be estimated.   The values for the
operating costs  and present worths  at  5% and 10% are presented
in Table 6.2.                                   •           ,

6.5  ESTIMATED COST OF MONITORING

Monitoring costs will be incurred both at  the" treatment plants
and for ground-water sampling at wells.  The cost estimates for
monitoring are developed separately in this section.

6.5.1  Estimated Monitoring Costs at Treatment Plants

Monitoring at the treatment plant consists of collecting
composite samples of the inflow water  and  the outflow water on a
routine schedule.   These samples are analyzed for indicator
nuclides or chemicals that denote that the process is working
efficiently and that discharge  quantities  are.within
specifications.  The frequency  of these  analyses varies due to
several factors, including the  rate of change in inflow
concentrations and  process upsets in the plant.

The estimated cost  of monitoring at the  treatment plants is    '
based on information supplied by DOE  (DOE  88b).  DOE estimated
that ground water would  require treatment  at 17 sites,  that the
period of operation of treatment plants  would vary from less
than 5 years to 53  years,  that  the  monitoring frequency schedule
could be reduced over the operating lifetime as:
                               6-4

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       Table 6.2  Ground-Water Restoration Cost Estimates
        at 17 Sites Chosen by DOE for Active Restoration
Operating
Site Time
(years)
Ambrosia
Canonsburg
Durango
Falls City
Grand June
Gunnison
Lakeview
Maybell
Monument V
Naturita
Rifle-New
Riverton
Shiprock
Slick-NC
Slick-UC
Spook
Tuba City


10
5
5
53
5
5
5
5
23
5
5
13
5
5
5
32
22




Cost ( $M)
(a)
Install Operate
3,06
.48
2.36
15.00
3.30
4.40
6.60
.93
6.60
.36
3.30
4.70
5.88
.11
.09
.93
2.75
60.85
170
2.47
.38
1.90
(b) 19.00
2.66
15.10
22.65
(b) .86
22.65
(b) .45
2.66
3.80
4.75
(b) .14
(b) .11
(b) .86
9.44
109.88
.73
at
5%
Operate Total
1.91
.33
1.65
6.63
2.30
13.08
19.61
.74
13.28
.39
2.30
2.75-'
4.11
.12
.10
.42
5.65


4.97
.81
4.01
21.63
5.60
17.48
26.21
1.67
19.88
.75
5.60
7.45
9.99
.23
.19
1.35
8.40

136.22
at
10%
Operate Total
1.52
.29
1.44
3.56
2.02
11.45
17.17
.65
8.75
.34
2.02
2.08
3.60
.11
.08
.26
3.76


4.58
.77
3.80
18.56
5.32
15.85
23.77
1.58
15.35
.70
5.32
6.78
9.48
.22
.17
1.19
6.51

119.95
(a).  Costs are from Table 6.1
(b)  Assumes trenching used to collect contaminated ground water
                               6-5

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        Percent of
        operating
         period

           10,
           20
           30
           20
           20
Monitoring
frequency
schedule

daily
3 days/week
weekly
semimonthly
monthly
 Samples
(analyses)
 per year

   730
   312
   104
    48
    24
and that the analysis cost per  sample  would  be  $600.   E^or  a
treatment plant operating 10 years,  the  total number  of  samples
would be 730 + 624 + 312 + 96 + 48  = 1810  and the  estimated cost
of monitoring would be $1,086,000 at $600  per sample.  The total
estimated monitoring cost for the 17 plants  operating for
various periods would be $23 million.  This  cost at a 5% present
worth rate is about $17 million and at 10%,  is  about  $13 million.

6.5.2  Estimated monitoring costs of ground  water

Monitoring of the contaminated  ground  water  consists  of
collecting ground water from wells  that  terminate  in  the
uppermost aquifer and any other aquifers that are  hydraulically
connected to the uppermost aquifer.  The number of wells must  be
sufficient to adequately define the contaminated plume,
Guidance is available for estimating the number of wells
(EPA 86), but for these cost estimates the number  of  wells
already in use is used.  For those  sites where  no  information  is
available, the average of 25 wells  per site  is  used.

Frequency of sampling is quarterly,. consistent  with the  40 CFR
264.99 rule.  The cost of analyzing each sample is $600  (DOE
88b).  The length of time that  compliance  monitoring  must  be
conducted is assumed to be during the  operating period of  the
treatment and for a 5-year period after  standards  are achieved
in ground water (after shutdown of  the treatment plant).  These
times vary from 10 years to 58  years in  these estimates.

The total estimated cost of monitoring ground water  is $21
million at the 17 sites that DOE currently identifies as
requiring ground-water restoration.  The estimated present value
of ground-water monitoring at a 5%  rate  is about $11  million and
at a 10% rate, is about $8 million.

6.6  TOTAL ESTIMATED COSTS

The total estimated cost for ground-water restoration including
monitoring is $214 million at the 17 sites that DOE currently
projects require restoration.   The  cost  of ground-water
monitoring is estimated by DOE  (DOE 88c) as  $24 million  at the
remaining 7 sites.  The grand total for  all  24  sites  is  then
about $240 million.  The present worth of this  grand  total at  5%
is about $190 million.  The present worth of the  grand total at
10% is about $160 million.
                               6-6

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 Using  a  combination of cleanup and natural cleansing will also
 reduce costs.   In this instance, partial cleanup, which appears
 to  be  most  efficient (see Section 6.2), is performed to reduce
 contamination  to levels that will be cleansed by natural
 processes within the extended remedial period limit.  This can
 significantly  reduce costs by reducing the amount of water
 requiring processing to perhaps two or three times the
 contaminated volume (rather than five times).  The
 implementation of institutional controls is not costly.

 Costs  could also be reduced if permission could be obtained to
 discharge contaminated ground water to rivers or to land      :  ..
 treatment  (land farming) facilities (e.g., Christmas tree farm),
 rather than treat it.   For example, if the uranium concentration
 is  less  than 2 mg per liter, which is the effluent limitations  ;
 guidelines  for the discharge of waste water from uranium mines
 (40 CFR  440),  and if all other numerical limits in the
 guidelines  and BADT requirements are met, it appears it may be
 possible to discharge the contaminated water to a river.
 Likewise, it may be possible to discharge contaminated ground
 water  to land  treatment facilities provided that the^   :,.•-..  -
 requirements of 40 CFR 268 are met.  However,, these
 possibilities  are site specific to the extent that cost cannot
 be  estimated on a generic basis.

 6.7 REVIEW OF DOE COST ESTIMATES

 6.7.1  DOE  Cost Estimates

 DOE submitted  comments on the proposed rule during January
 1988.  These included  an appendix presenting cost estimates for
 restoration and monitoring of contaminated ground water (DOE
 88a).  During  May 1988,  DOE provided EPA with additional cost
 estimates that were called "Attachment A  Reestimation of
 Aquifer  Restoration Costs" (DOE 88b).   Further,  DOE submitted a
 report entitled "U.S.  Department of Energy Final Response to
 Standards for  Remedial Actions at Inactive Processing Sites"
'during November 1988 which included a table with an estimated
 groundwater  restoration  project cost (DOE 88c).

 The DOE  January 1988 estimate was based on information on the
 extent of groundwater  contamination at five sites.   These
 estimates were then extrapolated to all 24 sites using a
 "similar site"  approach.   The total volume to be pumped and
 treated  or  discharged  was estimated by adding to the current
 contaminated water  volume,  the volume  that would be needed to
 flush  10% of the contaminants that are adsorbed  on soils.   DOE
 estimated the  base  cost  as $746 million.   DOE applied a "project
 factor"  of  2.3 to obtain their total  cost estimate of J51,715
 million.
                               6-7

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The DOE May 1988 submittal included nine  additional  cost
estimates.  The base cost for  restoring ground  water at all  24
sites combined ranged from a total of  $393.71 million to  $745.68
million.  For some of these estimates, DOE  reduced  the "project
factor" from 2.3 to 1.424 and  reduced  the estimate  for one  site
as discussed below, yielding a new total  cost range  of $560.65
million to $1,715.07 million.

The DOE November 1988 submittal  included  an estimated project
base cost of $664 million and  an  estimated  base plus contingency
cost of ฃ760 million, both in  1989 dollars.   This  report  also
provided an escalated project  cost of  $985  million  after
applying standard federal escalation  rates  through  1994 with no
escalation beyond 1994.

6.7.2  Evaluation of DOE Cost  Estimates

In the DOE January 1988 estimate, one  site,  Falls  City, Texas,
accounts for 47%  ($348 million of ฃ746 million) of  the total
base cost.  The volume of contaminated ground water  at Falls
City is large.  The principal  hazardous  contaminants are
uranium, molybdenum, chromium, nitrate,  and radium-226.   In
fact, the estimated mass of uranium-contaminated ground water at
Falls City is 98% of the total mass  from  all 24 sites. Also,
the quantity of uranium adsorbed on  soil  is among  the four
greatest at the 24 sites.  Likewise,  the  estimated  mass of
molybdenum in ground water is  93% and  of  chromium  is 95%  of the
total from all 24 sites.

In the DOE May 1988 material,  the costs  were reestimated  by
varying 3 different factors:   the number  of water  treatment
plants needed at  the Falls City  site,  the monitoring frequency
of ground water and of the inflow and  outflow of the water
treatment plant,  and the project factor.   The results of  this
reestimation are  summarized in Table  6-3.

A large reduction in costs  is  achieved by using one treatment ,,
plant at Falls City instead of three.   Four different aquifers
are contaminated  at Falls City.   In  the  initial estimate  DOE
extrapolated cost estimates from other sites,  including a   } ia
treatment plant for each of  the  three major contaminated   :,\
aquifers  (the contaminated water from the fourth aquifer  was to
be treated at one of  these  three).   Since the cost of extracting
ground water at Falls  City  is  low (it can all be done by
trenching), the major  costs  are  for  installing, operating,  and
monitoring the treatment plants.  In fact,  almost 95% of  the,, .
cost is associated with  these  tasks.   The reason for the  high
operating and monitoring costs is the projected 80 to 100 years
that the  treatment plants will have  to operate.
                                6-8

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 Table  6-3   Summary  table  -  Aquifer  restoration costs (DOE 88b)
   Option
where:
                                   Cost (Millions $)
                            Base
                             Project
Current*
1
2
3
4
5
6
7
8
9
745.68
393.71
538.44
593.60
453.73
745.68
393.71
538.44
593.60
453.73
1,715.07
905.54
1,238.41
1,365.28
1,043.58-
1,061.85
560.65
766.74
845.29
646.11
Number of
Option
Current*
1
2
3
4
5
6
7
8
9
treatment Plant
plants at sampling
Falls City frequency
3
1
3
3
1
3
1
3
3
1
daily
schedule
schedule
schedule
schedule
daily
schedule
schedule
schedule
schedule

A
A
B
B

A
A
B
B
Well
sampling
frequency
daily
schedule
schedule
schedule
schedule
daily
schedule
schedule
schedule
schedule
Project
factor

C
C
C
C

C
C
C
C
2.
2.
2.
2.
2.
1.
1.
1.
1.
1.
3
3
3
3
3
424
424
424
424
424
where schedules are presented in percentage of  the  restoration
or monitoring time which varies from  site  to  site.   For  example,
if restoration is estimated to take 10 years, under  schedule A
sampling would occur on a daily basis for  1 year, on a 3 day per
week basis for 20 years, on a weekly  basis for  3 years,  on  a
semimonthly basis for 2 years and on  a monthly  basis for 2  years.
   Schedule A
Daily        10%
3 days/week  20%
Weekly       30%
Semimonthly  20%
Monthly      20%

*DOE 88a
   Schedule B
Daily        20%
3 days/week  30%
Weekly       20%
Semimonthly  30%
   Schedule C
Quarterly    20%
Annually     70%
Quarterly    10%
                               6-9

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Only one treatment plant is needed at  Falls  City.   The
contaminated ground water extends less  than  three  miles  and  can
be pumped inexpensively to a central treatment plant.  Use of
one plant instead of  three reduces construction  costs from $28
million to $10 million, operating costs  from $179  million to $63
million, and monitoring costs  from $123  million  to $44 million.
Reducing the plant monitoring  schedule  from  daily  to monthly
gradually over the 100-year operating  period further reduces
monitoring costs from $44 million to $11 million.   When  the
reduced monitoring schedule is  extended  to all sites, the low
end of the range of the total  base cost  estimate is $394 million.

The "project factor"  reflects  the difference in  cost between
industry doing the job and the  government  (DOE)  doing the job.
Although the 1.424 factor appears more  reasonable  than the 2.3
factor, especially considering  the routine nature  of the job,  it
is not clear that EPA is required to consider this additional
cost in promulgating  standards.  Basically,  the-cost of  actively
restoring ground water quality  at all  24 sites,"  according to DOE
estimates, is $394 million.  However,  DOE has identified 7 sites
that will not require active restoration,  This  is consistent
with EPA's projection in the draft BID  (EPA  87).   Reducing the
DOE base cost by the  active restoration  costs for  these  7 sites
results in a total estimated base cost  of $325 million.  This
cost estimate includes monitoring costs  over a period that
extends to 100 years  at some sites.  This estimate can then  be
compared to EPA's cost estimate of $240  million  (see Table 6-1
and Section 6.5).

A comparison of DOE and EPA total cost  estimates is presented  in
Table 6-4.  The low estimate from the  May 1988 DOE submittal is
used since this appears to be  the most  reasonable  estimate.   The
estimated costs for ground-water monitoring  at the 7 sites where
cleanup is unlikely are from the November 1988 DOE submittal.
The EPA costs are from Table 6.1.  The  two estimated total costs
are within about 30%  of each other, which is acceptable
agreement, given the preliminary nature  of the data.

DOE appears to use unusual conservatism  in estimating some of
these costs for ground-water restoration.  An example of this  is
found in the estimate for the  Falls City site.   The latest DOE
projection indicates  it will take 53 years to restore the ground
water at Falls City using a treatment  plant  with a capacity  of
100,000 gallons per day (DOE 88c).  DOE  estimates  the installed
cost of a treatment plant of this size  to be $2  million.  With
an assumed plant lifetime of 20 years,  3 new plants are  assumed
to be needed over the 53-year  restoration period,  for a  total
installation cost of $6 million.  The  EPA estimate for the total
installed cost of 3 treatment  plants is  $1 to $2 million, after
increasing 1975 costs by a factor of 3  to account  for inflation
(EPA 77).  Operating  the treatment plant for 53  years is
estimated by DOE to cost $33 million.   This  may  be compared  to
EPA's estimate of operating costs of $11 million (EPA 77).   The

                               6-10

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Table 6-4  Comparison of DOE and EPA Cost Estimates
           for  Restoration  of  Ground  Water  at  the
           Inactive  Uranium Mill  Tailings Sites
DOE estimates
Site
Ambrosia
Belf ield
Bowman
Canonsburg
Durango
Falls City
Grand Junction
Green River
Gunnison
Lakeview
Lowman
Maybell
Mexican Hat
Monument Valley
Naturita
Rifle - old
Rifle - new
Riverton
Salt Lake City
Shiprock
Slick Rock - NC
Slick Rock - UC
Spook
Tuba City
Totals
Similar Base cost
site (DOE 88b)
Lakeview 25.58
Lakeview
Lakeview
Riverton 8.32
Gunnison 8.50
Falls City 103.02
Riverton 5.98
Lakeview
Gunnison 18.3
Lakeview 9.8
Lakeview
Tuba City 4.7
Tuba City
Tuba City 20.6
Riverton 4.2
Riverton
Riverton 3.93
Riverton 14.53
Riverton
Riverton 6.04
Riverton 3.88
Riverton 4.16
Tuba City 40.92
Tuba City 18.68
301
Monitoring
cost only
(DOE 88c)
2.8
3.8




3.8


2.8

2.8


3.8


3.8





23.6
EPA
cost
estimates
7.74

2.38
5.31
46.71
6.98

20.67
30.51

2.93

33.56
1.95

7.01
10.82

11.77
1.39
1.34
7.48
15.36
214
                        6-11

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primary cause of this difference is due to the size of the
operating crew, estimated as 15 person-days per  day by DOE  and
as .4 person-days per day by EPA.  We do not believe, it is
necessary to maintain a full crew for all three  8-hour shifts.
One is sufficient for two of these, since repairs and manpower
intensive maintenance can be scheduled for a  normal daytime
workday shift.

6.8  REVIEW OF TOTAL URANIUM VALUE

An estimate of the total value of the uranium produced at the
inactive sites was made to provide a perspective on the  costs of
remediation of ground water contamination.  The  total quantity
of tailings at the inactive sites is about 25 million tons  (see
Chapter 3).  The average uranium content of the  ore was
estimated to be 0.25%.  We were unable to determine the  price
actually paid for uranium at these inactive sites.  However,
uranium production and prices were summarized by DOE in  their
1982 report on commingled uranium tailings (DOE  82).  The report
contains data for the licensed, or to be licensed, sites that
were operating during the 1949 through 1971 period, including
the quantity of uranium purchased and the purchase price.   Most
of the uranium from these sites was purchased in the 1960s. It
is reasonable to assume that uranium from the inactive sites was
purchased earlier or in any case no later than that from the
licensed sites.  Based on this data and assuming a mean  year of
production of 1965, the price of the uranium  varied over a
narrow range with a mean of about 10 dollars  per pound.

Using the above values, it is estimated that  the value of
uranium produced at the inactive sites was $1.2  billion  1965
dollars.  Using the producer price index for  crude materials for
further processing (GPO 89) to escalate this  value to the
estimated 1989 value yields $3.9 billion.  The estimated present
value of the cost of cleanup of the ground water at the  inactive
sites is $214 million, or less than 6% of the total value of the
uranium produced at these sites, in constant  dollars.

6.9 REFERENCES

DOE 82   Commingled Uranium Tailings Study, DOE/DP-0011, U.S.
         Department of Energy, Washington, D.C.  20545  (June
         1982).

DOE 88a  U.S. Department of Energy, letter to EPA docket, number
         R-87-01, from Theodore J. Garrish, Assistant Secretary
         for Nuclear Energy, January 26, 1988.

DOE 88b  U.S. Department of Energy, material  provided to Tom
         Loomis, EPA contractor, entitled "Attachment A,
         Re-estimation of Aquifer Restoration Costs, May 17,
         1988."

                              6-12

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DOE 88c  U.S. Department of Energy, "Final Response to'Standards
         for Remedial Actions at Inactive Uranium Processing
         Sites," November 1988.

EPA 77   U.S. Environmental Protection Agency, "Costs of Radium
         Removal from Potable Water Supplies,"
         EPA-600/2-77-073.  Municipal Environmental Research
         Laboratory, Office of Research and Development, U.S.
         EPA, Cincinnati, Ohio 45268.

EPA 86   U.S. Environmental Protection Agency, "RCRA Ground
         Water Monitoring Technical Enforcement Guidance
         Document (TEGD)," OSWER-9950.1, September 1986.

EPA 87   U.S. Environmental Protection Agency, "Ground-Water
         Protection Standards for Inactive Uranium Tailings
         Sites - Background Information for Proposed Rule," EPA
         520/1-87-014, Office of Radiatio'n Programs, Washington,
         D.C. 20460.

GPO 89   Economic Report of the President, U.S. Government
         Printing Office, Washington, D.C. (January 1989).

NUREG86  U.S. Nuclear Regulatory Commission, "An Analysis of
         Excursions at Selected In Situ Uranium Mines in Wyoming
         and Texas," NUREG/CR-3967 (ORNL/TM-9956), 1986.
                              6-13

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                            CHAPTER 7

                      OTHER CONSIDERATIONS

7.1  CONCENTRATION LIMITS FOR MOLYBDENUM, URANIUM,  RADIUM AND
     NITRATES

Molybdenum, uranium, radium and  nitrates  have  been  found  in
tailings and in ground water that  is  contaminated by  tailings.
While these substances have not  been  listed  as hazardous  under
the Resource Conservation and Recovery  Act  (RCRA),  which  amended
the Solid Waste Disposal Act (SWDA),  they have been identified
as hazardous or controlled in other EPA rules  using different
authorities.  However, quantitative limits  that are useful for
this rulemaking have not, as yet,  been  determined for  uranium
and molybdenum.  The proposed concentration  limits  for each  of
these four substances are discussed in  this  section.

7.1.1  Molybdenum

Molybdenum was added to the hazardous constituents  for the
licensed tailings since it was found  in high concentrations  at
some sites and had caused molybdenosis  in cattle  (48FR45926,
Do72).  No concentration limit was established at that time,
however, because only sparse data  were  available  on human
toxicity.  Listing molybdenum, but not  issuing a  concentration
limit, means it must be controlled to background  levels,  to  be
consistent with RCRA standards.

     A concentration limit of 50 ppb  was proposed for  molybdenum
in the proposed standards for inactive  tailings (46FR2556).
This proposed groundwater standard was  not promulgated, however,
because as stated in the Federal Register notice, "We  do  not
believe that the existing evidence indicates that ground  water
contamination from inactive mill tailings is or will be a matter
of regulatory concern" (48FR590).  The  Court remanded  this to
the Agency in 1985.

     The Agency has proposed National Primary  Drinking Water
Regulations for Inorganic Chemicals,  among others (50FR46936).
While the Agency decided not to  propose a Recommended  Maximum
Concentration Limit (RMCL) [This is now being  called a Maximum
Concentration Limit Goal (MCLG).] for molybdenum  because  of
inadequate data on toxicity of the compound, a provisional
adjusted acceptable daily intake (AADI) was determined.   This
provisional AADI was based upon  an epidemiological  study  in
which only one dose was examined and  no effects were noted.
                               7-1

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The Agency asked for  comments  on  the  question,  "Should a Health
Advisory be developed for  molybdenum  or  is  there sufficient
health effects  information upon which to base  an RMCL?"  While
the Agency has  not  made  a  final decision on molybdenum, it
appears unlikely that a  Health Advisory  will be issued for
molybdenum based on the  NAS consideration (NAS80) that
molybdenum in drinking water,  except  from highly contaminated
sources (molybdenum mining waste  water), is not likely to
constitute a significant portion  of the  total  human daily intake
of the element.

An analysis of  toxic substances  in tailings was included in the
Final EIS for Remedial Action  Standards  for Inactive Uranium
Processing Sites  (EPA82),  Appendix C.  This analysis included
consideration of molybdenum in tailings  and of molybdenum
toxicity in humans, livestock, and crops.

Molybdenum in tailings is  found  at levels greater than 100 times
its  levels in typical or local soils.  Uranium, selenium,
arsenic, and vanadium are  the  only other metallic elements found
at similarly high  levels.   However,  data show wide variations of
element concentrations among different piles.   The ratio of an
element's concentration  in tailings to that in the spil
surrounding the tailings is a  measure of both its potential
hazard and its  potential for contaminating ground water.

Molybdenum is essential  in trace  quantities for human
nutrition.  There  are no data  for acute toxicity of molybdenum
following ingestion by humans, but the animal data (Ve78) show
that  toxicity results from intakes of around hundreds of
milligrams per  kilogram  of body  weight.

Chronic toxicity symptoms  have been reported in 18 percent to 31
percent of a group  of Armenian adults who consumed 10 to 15
milligrams of molybdenum per day  and  in 1 percent to 4 percent
,of a  group consuming 1 to  2 milligrams of molybdenum per day
 (Cha79),  (NAS80).   Clinical signs of  the toxicity were a high
incidence of a  gout-like disease  with arthralgia and joint
deformities, and increased urinary excretion of copper and uric
acid.   Increased urinary copper  excretion has been observed in
persons who consumed 0.5 to 1.5  milligrams of molybdenum per day
and  in persons  drinking  water  containing 0.15 to 0.20 ppm of
molybdenum but  not  in persons  drinking water containing up to
0.05  ppm of molybdenum (Cha79).   The  significance of the
increased copper excretion is  not known.  Recent reports have
associated molybdenum deficiency and  esophageal cancer
 (Lu80a,b).  Until  these  reports  are confirmed and evaluated, the
minimum molybdenum  requirements  are uncertain.
                                7-2

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The ratio of toxic intake to the recommended daily  allowance  for
humans is narrow for molybdenum, ranging  from  10  to 40  (NAS80).
Using the NAS80 value for Adequate and Safe Daily Intake  of  0.15
to 0.50 mg and this ratio leads to an estimated potentially
toxic daily intake of 2 to 20 mg of molybdenum,
In livestock,
toxicity were
most critical
dairy cattle,
lactating cows
water that is
,ppm  (EPA82).
molybdenum in
estimates of molybdenum concentrations  leading  to
made for both ruminants and nonruminants.  The
receptor for molybdenum in the water pathway was
because of the large water consumption  of
   The estimated concentration of molybdenum in
potentially toxic to dairy cattle is 0.51  to 2.6
This led to a recommended maximum concentration of
water of 0.05 ppm (EPA82).
In crops, estimates were made  of  molybdenum  concentrations in
irrigation water that might  be toxic  to  agricultural  crops grown
using such water.  Based on  an NAS  publication  (NAS72),
irrigation water at 1 ppm molybdenum  could be  immediately toxic
to crops  if the  irrigation water  is applied  at  3-acre foot per
acre per  year  (8.13 Ibs of molybdenum per acre  per  year).

7.1.2  Uranium

The National Interim Primary Drinking Water  Regulation
(40CFR141, EPA76) provide no maximum  contaminant level (MCL)  for
uranium.  In fact, uranium along  with radon  is  explicitly
excluded  from  the MCL for gross alpha particle  activity
(40CFR141) which is 15 pCi per liter.  These were excluded
because data were inadequate to determine  if there  was a need
for such  regulations  (i.e.,  the levels of  uranium and radon in
water were not well-known) and the  cost  of  removal  of uranium
and radon from drinking water was not established.   The  Agency
has issued an  advance notice of proposed rulemaking (51FR34836)
stating that MCLGs and MCLs  are being considered for radium-226,
-228, natural  uranium, radon,  gross alpha,  and  gross beta and
photon emitters.

At  the uranium mill tailings sites, natural  uranium is present
and consists of  three isotopes, 234U, 0.0057% abundance  by
weight; 235U,  0.7196% abundance;  and  238g,  99.276%
abundance.  Their half-lives are, respectively, 2.47 x 105
years, 7.1 x 108 years, and  4.51  x  109 years.   Each decays
by  emitting an alpha  particle; uranium-234  and 235 also  emit
gamma  rays.  Although uranium-238 is  the most abundant isotope
in  natural uranium by weight, it  accounts for only half  of the
total  radioactivity of natural uranium.
                                7-3

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Uranium  can  damage human health two ways, chemically and
radiologically.   Uranium ingested above ,a certain concentration
is  chemically  toxic to humans and thus has a threshold below
which chemical  toxicity does  not exist.  The National Academy of
Sciences (NAS  83)  reviewed the toxicity level of uranium and
issued a suggested No-Adverse-Response, Level (SNARL) of 35 ppb
(23 pCi/1) for  chronic exposure.  The NAS report states,,
"Because of  its  low specific  activity, natural uranium dose'not
pose a problem  of  radiotoxicity in drinking water.   Assessment
of uranium toxicity in drinking water should be based on its
chemical toxicity  and  not on  radiation toxicity.  However, when
the specific activity  of uranium in drinking water  has been
altered  so that  it is  greater than that of natural  uranium,
potential radiotoxicity should be given, attention equal to that
of  the chemical  toxicity.   The committee also recommends that
toxicological assessment of uranium in water be based solely on
its renal toxicity in  all instances except when industrial
processes result  in., a  marked  enrichment of shorter-lived uranium
isotopes."

Radiotoxcity can  be the basis for establishing a limit for
uranium  in drinking water  by  using the recommendations of the
International Commission on Radiological Protection (ICRP 78).
By allowing the  same level of risk for uranium as for radium
(0.7 to  3.0 fatal  cancers per year per million persons exposed)
a natural uranium  concentration limit of 23 pCi/1 is calculated
by using ratios  of the ICRP annual limits on intake (ALIs) for
stochastic (non-threshold)  effects.   Using the ICRP ALIs for
nonstochastic  (toxic)  effects^ for protection of workers yields a
natural  uranium concentration limit  of 30 pCi/1, assuming the
same risk from uranium as  from radium.  This approach, therefore
leads to limits for  natural uranium  in .drinking wate.r that are,
for all  practical  purposes the same  as the NAS recommended
limits.
                                  , '      ' ' < -    •  : '
A review of the uranium concentrations in ground water at the 14
sites for which data are  available (see Chapter 4)  is presented
in Table 7.1.  This  review indicates that when uranium
contamination of ground water occurs at uranium mill sites
con'centrations of  uranium  increase substantially.  Large
percentages of the  ground  water  samples that were measured for
uranium  exceed 100  pCi/1  at most sites.   Based on these limited
data,  ground water  is  contaminated at 12 of  the 14  sites at
either the 30 pCi/1  or  the  100 pCi/1 limit.   From this it can be
concluded that the  choice  of  a limit in the  range under
consideration (10  to 100 pCi/1)  will not make a difference in
determining whether or  not  ground water  is  contaminated at a
site.   However, the  choice  of a  limit may make a difference in
the extent of cleanup-of ground  water,  should cleanup be
necessary.
                               7-4

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               Table  7.1   Summary of  Uranium Concentrations in
                       Ground Water at Inactive Uranium
                              Mill Tailing Sites
    Site

Ambrosia Lake
Canonsburg
Durango

Grand Junction
Green.River
Gunnison
Lakeview
   Number of Samples
Analyzed for Uranium (a)

             30
             55
             64

            140
            156
             59
             70
Percent of Samples Greater Than
   15 ppb (b)  44 ppb   150 ppb
Mexican Hat
Monument Valley
Rifle
Riverton

Salt Lake City
Shiprock
Tuba City
             15
             57
             34
             26

             81
             19
             15
     77
     49
     78

     79
     47
     64
      4

     53
     18
     94
     92

     51
     95
    100
60
40
45

74
37
42
 1

47
 0
82
88

37
79
87
47
35
20

31
30
32
 1

40
 0
47
73

21
68
53
 (a) For  some  sites  samples  are  from both  down gradient
 and background  aquifers.  For other sites samples  are
 from  known  contaminated  ground  water.   No conclusions
 should be drawn from  these  data regarding the need for
 cleanup.

 (b) 1.47 ppb  =  0.00147 mg/1 = 1 pCi/1
                               7-5

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 7.1.3  Radium

 Radium is  present  in  mill  tailings at levels in the hundreds of
 pCi per gram range  and  has been  found in elevated concentrations
 in ground  water  near  tailings sites.   The National Interim
 Primary Drinking Water  Regulation  for radium is 5 PCi  per liter
 combined radium-226 and radium-228.   Since the standards are
 required by UMTRCA  to be consistent  with RCRA standards and
 since RCRA standards  have  adopted  drinking water regulations as
 standards  for ground  water,  the  same  procedure is used in this
 rulemaking. Thus,  the standard for radium is 5 pCi per liter
 combined radium-226 and radium-228.

 7.1.4  Nitrates

 Nitrates have been  found in elevated  concentrations in ground
 water near tailings piles.   The  National Interim Primary
 Drinking Water Regulation  for nitrates is 10 mg per liter as
 nitrogen.  Using the  same  rationale  as above for radium, the
 standard for nitrates is 10 mg per liter as nitrogen.

 7.2  INSTITUTIONAL  CONTROL

 The Agency has been considering  institutional control  for over
 ten years.  Public  workshops and a public forum were conducted
 in 1977 and 1978 to develop insight  for the objectives of
 radioactive waste disposal (EPA77a,  EPA77b,  EPA78).  These
 efforts resulted in 1978 with the  publication of proposed
 Criteria for Radioactive Wastes:   Recommendations for  Federal
 Radiation Guidance  (43  F.R.  53262).   The subject of
 institutional control was  a  major  factor in these
 recommendations:

 "Proposed Criterion No. 2.   The  fundamental goal for controlling
 any type of radioactive waste should  be complete isolation over
 its hazardous lifetime.  Controls  which are based on
 institutional functions should not be  relied upon for  longer
 than 100 years to provide  such isolation; .radioactive  wastes
with a hazardous lifetime  longer than  100 years should be
controlled by as many engineered and  natural barriers  as are
necessary."  And,

 "Proposed Criterion No. 6.   Certain additional  procedures and
techniques should also  be  applied  to  waste  disposal systems
which otherwise satisfy these criteria if use of these
additional procedures and  techniques  provide a  net  improvement
in environmental and  public  health protection.   Among  these
are:   a.  Procedures or  techniques  designed  to enhance  the
retrievability of the waste;  and   b.  Passive methods of

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communicating to future people the potential  hazards  which  could
result from an accidental or intentional  disturbance  of  disposed
radioactive wastes."

These proposed criteria were further  discussed:

"Issue No. 2.  Control of Radioactive waste.   The  management  of
radioactive wastes  represents potential  exposure  of  individuals
and populations and the possible contamination of  the general
environment.  These potential impacts require definitive
controls to be established.  Further, because of  the  trustee
responsibility each generation has to succeeding  ones,
contamination of the general environment  should be avoided
regardless of whether humans will actually  contact the waste
directly.  It is important  to prevent both  human  and
environmental adverse impacts.  Therefore,  the fundamental  goal
for controlling any type of  radioactive  waste should  be  complete
isolation over its  hazardous lifetime.

"Controls for radioactive wastes are  of  three general types:
Engineered barriers, natural barriers,  and  institutional
mechanisms.  Engineered barriers such as  containers or
structures generally can be  considered  only as interim measures
for containment, despite the fact that  some structures have
survived  intact through the  ages.  Stable geologic media are  an
example of natural  barriers.  Institutional controls  are those
which depend on some social  order to  prevent humans from coming
in contact with wastes, such as controlling site  boundaries,
guarding  a structure, land  use policies,  record-keeping,
monitoring,  etc.

"It generally is accepted  that  long-term isolation should depend
on stable natural  barriers.   Institutional  mechanisms, which  are
essential in the early  stages of management of any waste, are
short-term processes because  of practical limitations.
Institutional means can be  very  effective i-n isolating
radioactive  wastes from humans  if  they  can  be maintained.  Since
society's basic  structure  and concern about waste may change,  it
is reasonable to  rely on  such controls  for  only limited periods.

"The  choice  of  a  time period for  relying on institutional
control  is completely a matter  of  judgment, but is basic to a
determination of  when use  of such  controls is proper.  During
the developmental  stages  of this  criteria document,  it was
proposed  that  100  years  should  be  the maximum time period for
such  controls to  be depended upon  with  any degree of assurance.
The public  forum  participants  recommended deleting the time
period  because  it  appeared  to  be  arbitrary; however,  they left
the  issue unaddressed  in  any other  form.

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 "Because  there  are  a number of current mechanisms for disposing
 of  various  types  of wastes  which are based on institutional
 care/  the Agency  believes that guidance is required to assure
 that institutional  controls are relied upon only ,to the extent
 they are  appropriate.   There are numerous types of radioactive
 wastes of such  hazard  potential that they will require the
 adoption  of stricter control methods than currently practiced
 and will  require  the development of new disposal technologies
 which  will  assure better  isolation [than] that afforded by
 institutional control  mechanisms.   For this reason, when
 disposal  decisions  are made they should recognize that
 institutional controls are  only of limited use, and if the
 wastes will be  hazardous  longer than 100 years, other means of
 control will need to be found.

 "This  means that  in selecting control options for wastes whose
 hazards extend  beyond  100 years decisions makers cannot rely on
 restrictions on customary uses of  land and of ground or surface
 waters.   This does  not mean that institutional controls are
 required  for 100  years, or  that they must stop at that point if
 society can still maintain  them; only that people making the
 initial disposal  decision should not plan on their use to
 maintain  protection beyond  100 years.   The judgment that 100
 years  is  the most appropriate time interval will be further
 examined  throughout the public comment period."

 "Issue No.  6    Supplementary Protection Goals.  A number of
 other  subjects  pertinent  to protection of the public from
 radioactive wastes  were discussed  in the development of the
 criteria.   Among>  these, most attention centered on monitoring,
 provision of ret'rievability,  and passive communication of the
 nature of the possible hazard to future generations.   In
 general,  it  was,determined  that,  while each has positive aspects
 for control  of  radiological hazards,  their application might
 undermine the goal  of  providing permanent isolation for wastes.
 It is difficult to  maintain retrievability or conduct a
 monitoring  program  without  compromising the ability to provide
 isolation.   Furthermore,  in many disposal situations which will
 satisfy the  five  criteria discussed above, the residual risk
 will mainly be  attributable to  potential failure mechanisms
 involving eventual  intrusion by humans.   Passive methods of
communicating the hazard, such  as  markers which call attention
 to the waste, may sometimes be  judged  to provide a net reduction
 of risk.  Other passive methods,  such  as creating records
describing  the  waste,  or  setting aside of the land title to the
 disposal  site,  have  value in  reducing  the likelihood of
 intrusion for some  limited  time.

 "An example of  a  circumstance where land title transfer is
 reasonable  is a current site  that  has  been in use for some time
where optimal environmental  isolation  is no longer a practicable

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alternative, such as an abandoned mill tailings site, a nuclear
test facility site, etc.  In these cases, Federal  ownership  of
the land beyond the normal period of institutional control would
be reasonable to minimize potential  intrusion.  Such  decisions
should be made on a case-by-case basis and provision  for
specifically treating such exceptions should  be addressed  in
standards and regulations which are  promulgated for these  types
of wastes.

"It is not appropriate  to depend upon methods such as these  or
other similar ones for  long-term control; nonetheless, when  such
methods would enhance overall protection  from wastes, it  is
prudent to use them.  This is particularly the case for
retrievability and passive communication.  Monitoring was  judged
by the Public Forum participants to  be generally a part of early
institutional controls  prior to completion of disposal, and  thus
it is not included in the criterion  for  supplementary controls."

While these criteria were never enacted  in final  form,  they
served as the basis for the assurance requirements (40  CFR
191.14) which the Agency  issued as  final  standards in 1985:
Environmental Standards for the Management and Disposal of Spent
Nuclear Fuel, High-Level  and Transuranic  Radioactive  Wastes  50
F.R.  38066.  These standards culminated  the  above  consideration
of institutional control  in this context.  Specifically:

      40 CFR 191.14   (a) Active  institutional  controls over
          disposal sites  should be  maintained for  as  long a
          period of  time  as is  practicable after  disposal;
          however, performance  assessments  that  assess  isolation
          of the wastes from the accessible  environment shall
          not consider  any contributions from active
          institutional controls for more than 100 years  after
          disposal.

           (b) Disposal  systems  shall be  monitored after disposal
          to detect  substantial  and detrimental  deviations from
          expected  performance.   This monitoring  shall  be done
          with  techniques that  do  not jeopardize  the  isolation
          of  the wastes and  shall  be conducted until  there are
          no  significant  concerns  to be  addressed by  further
          monitoring.

           (c)  Disposal  sites  shall  be designated  by  the most
          permanent  markers,  records, and other passive
           institutional controls  practicable  to indicate the
           dangers  of the  wastes and their location.

Where the following terms are  defined as:

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     40 CPR 191.12   (a)  "Disposal  system"  means  any combination
          of engineered  and  natural  barriers  that  isolate  spent
          nuclear fuel or  radioactive  waste  after  disposal.

          (d) "Barrier"  means  any  material or structure  that
          prevents  or substantially  delays movement of water or
          radionuclides  toward  the accessible environment.   For
          example/  a barrier may be  a  geologic structure,  a
          canister, a waste  form with  physical and chemical
          characteristics  that  significantly  decrease  the
          mobility  of radionuclides, or  a  material placed  over
          and around waste,  provided that  the material or
          structure substantially  delays movement  of water or
          radionuclides.

          (e) "Passive institutional control" means:   (1)
          Permanent markers placed at  a  disposal site,  (2)
          public records and archives,  (3) government  ownership
          and regulations  regarding  land or  resource use,  and
          (4) other methods  of  preserving  knowledge about  the
          location, design,  and contents of a disposal system.

          (f) "Active institutional  control"  means:  (1)
          Controlling access to a  disposal site  by any means
          other than passive institutional controls; (2)
          performing maintenance operations or remedial  actions
          at a site, (3) controlling or  cleaning up releases
          from a site, or  (4) monitoring parameters  related  to
          disposal  system  performance.

And the following guidance for  implementation is given:

          40 CFR 191 Appendix B  Institutional Controls.   To
              comply with  section  191.14(a),  the implementing
              agency will  assume that  none of the  active
              institutional controls prevent  or  reduce
              radionuclide releases for  more  than  100 years
              after disposal.  However,  the Federal Government
              is committed to retaining  ownership  of all
              disposal sites for spent nuclear fuel and
              high-level and transuranic radioactive wastes  and
              will establish appropriate markers and records,
              consistent with section  191.14(c).   The Agency
              assumes that, as long as such passive
              institutional controls endure and  are understood,
              they:  (1)  can be effective  in  deterring
              systematic or persistent exploitation of these
              disposal sites; and  (2)  can reduce  the likelihood
              of inadvertent, intermittent human intrusion to a
              degree to be determined  by the  implementing

                              7-10

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          agency.  However, the Agency believes  that  passive
          institutional controls can never be  assumed to
          eliminate the chance of inadvertent  and  intermittent
          human intrusion into these disposal  sites.

The statement of considerations for this  regulation  (50 F.R.
38066) includes the following discussion:

"Approach Toward Institutional Controls.  The  Agency
particularly sought comment on its proposed approach  to reliance
on institutional controls.  The proposed  rule  limited reliance
on 'active institutional controls' (such  as controlling access
to a disposal site, performing maintenance operations, or
cleaning up releases) to a reasonable period of  time  after
disposal, described as on the order of a  'few  hundred years.'
On the other hand, 'passive institutional controls'  (such as
permanent markers, records, archives, and other  methods of
preserving knowledge) were considered to  be at least  partially
effective for a longer period of time.

"Pew commenters argued with the distinction between  active  and
passive institutional controls, or with the amount of reliance
the proposed rule envisioned for passive  controls.   However,
many commenters felt that  'a few hundred  years'  was  too long  a
period to count on active controls.  Accordingly,  the final rule
limits reliance on active institutional controls to  no more than
100 years after disposal.  This was the time period  the Agency
considered in criteria for radioactive waste disposal that  were
proposed for public comment in 1978 (43 P.R. 53262),  a period
that was generally supported by the commenters on  that
proposal.  After this time, no contribution from any  of the
active institutional controls can be projected to  prevent or
limit potential releases of waste from a  disposal  system.

"The concept of passive institutional controls has now been
incorporated into the definition of 'controlled  area'  that  is
used to establish one of the boundaries for applicability of  the
containment requirements and the individual protection
requirements in the final rule.  Because  the assumptions made
about the effectiveness of passive institutional controls can
strongly affect implementation of the containment  requirements,
the Agency's intent has been elaborated in the "guidance for
implementation" section.  The Federal Government is  committed  to
retaining control over disposal sites for these  wastes as long
as possible.  Accordingly  (and in compliance with  one of the
assurance requirements), an extensive system of  explanatory
markers and records will be instituted to warn future
                               7-11

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generations about the  location  and  dangers  of  these  wastes.
These passive controls  have  not been  assumed  to  prevent  all
possibilities of inadvertent  human  intrusion,  because  there  will
always be a realistic  chance  that  some  individuals will  over
look or misunderstand  the markers  and  records.   (For example,
exploratory drilling operations occasionally  intrude into areas
that clearly would have  been  avoided  if  existing information had
been obtained and properly evaluated.)   However, the Agency
assumed that society in  general will  retain knowledge  about
these wastes and that  future  societies  should  be able  to deter
systematic or persistent exploitation  of  a  disposal  site.

"The Agency also assumed that passive  institutional  controls
should reduce the chance of  inadvertent  intrusion compared to
the likelihood if no markers  and records  were  in place.
Specific judgments about the  chances  and  consequences  of
intrusion should be made by  the implementing  agencies  when more
information about particular  disposal  sites'and  passive  control
systems is available.   The parameters  described  in the "guidance
for implementation" represent the  most  severe  assumptions  that
the Agency believed were reasonable to  use  in  its analyses to  •
evaluate the feasibility of compliance  with this rule  (analyses
that are summarized in  the BID).   The  implementing agencies  are
free to use other assumption  if they  develop  information
considered adequate to  support  those  judgments.

"The role envisioned for institutional  controls  in this  •
rulemaking has been adapted  from the  general  approach  the  Agency
has followed in its activities  involving  disposal of radioactive
wastes since the initial public workshops conducted  in 1977  and
1978.  The Agency's overall objective  has been to protect  public
health and the environment from disposal  of "radioactive  wastes
without relying upon institutional controls for  extended periods
of time—because such  controls  do  not  appear  to  be reliable
enough over the very long periods  that  these wastes  remain
dangerous.  Instead the Agency  has pursued  standards that  call
for isolation of the wastes through the physical characteristics
of disposal system siting and design,  rather  than through
continuing maintenance 'and surveillance.  The principle  was
enunciated in the general criteria published  for public  comment
in 1978 (43 F.R. 53262), and  it has been  incorporated  into the
Agency's standards for  disposal of uranium  mill  tailings (48
F.R. 590, 48 F.R. 45926).

"This approach has been  tailored  to fit  two circumstances
associated with mined geologic  repositories.  First, 40  CFR  Part
191 places containment  requirements on  a  broad range of
                              7-12

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potential unplanned releases as well  as  the  expected  behavior  of
the disposal system.  Therefore,  determining compliance  with  the
standards involves performance assessments  that  consider the
probabilities and consequences of a variety  of disruptive
events, including potential human intrusion.  Not  allowing
passive institutional controls to be  taken  into  account  to some
degree when estimating  the consequences  of  inadvertent  human
intrusion could lead to less protective  geologic media  being
selected for repository sites.  The Agency's analyses indicate
that repositories in salt formations  have particularly  good
capabilities to isolate the wastes from  flowing  groundwater and,
hence, the accessible environment.  However, salt  formations  are
also relatively easy to mine and  are  often  associated with other
types of resources.  If performance assessments  had  to  assume
that future societies will have no way  to ever  recognize and
limit the consequences  of inadvertent intrusion Jfrom solution
mining of salt, for example), the scenarios  that would  have to
be studied would be more likely to eliminate salt  media  from
consideration than other rock types.  Yet this c.ould  rule out
repositories that may provide the best  isolation,  compared to
other alternatives, if  less pessimistic  assumptions  about
survival of knowledge were made.

"The second circumstance that the Agency considered  in
evaluating the approach towards institutional controls  taken  in
this rule is the fact that the mined  geologic repositories
planned for disposal of the materials covered by 40  CFR Part  191
are different from the  disposal systems  envisioned for  any other
type of waste.  The types of inadvertent human activities that
could lead to significant radiation exposures or releases of
material from geologic  repositories appear  to call for  much more
intensive and organized effort than those which  could cause
problems at, for example, an unattended  surface  disposal site. ..
It appears reasonable to assume that  information regarding the
disposal system is more likely to reach  (and presumably deter).
people undertaking such organized efforts than  it  is  to inform
individuals involved in mundane activities.

"These considerations led the Agency  to  conclude that a limited
role for passive institutional controls  would be appropriate
when projecting the long-term performance of mined geologic
repositories to judge compliance  with these  standards."
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The Agency is continuing its consideration  of  institutional
control with emphasis on its effectiveness.  There  is  a  need  for
guidance on the role for institutional control  in developing
corrective action policies for Subtitles C  and  D under the
Resource Conservation and Recovery Act (RCRA),  in designing the
alternate concentration limit  (ACL) program under RCRA,  and in
developing policies and achieving consistency  for Superfund,
especially in view of the Superfund Amendments  and
Reauthorization Act of 1986 (SARA).

Institutional controls can be  ranked  in terms  of their
effectiveness although it must be recognized that such ordering
is not objective.  There are many shifting  perceptions about  the
effectiveness of each control, most of which are based on
societal behavior.  Nevertheless, the following ranking  of
institutional controls in roughly decreasing order  of
reliability may be useful in a broad, albeit arbitrary,  context:

              Monument (marble, granite, etc.)

              Security program (guards and  fences)

              Government ownership

              Government controlled easements  on property
                 adjacent to government-owned property

              Restrictive covenant (deed restriction)

              Deed notice

              Professional licensing  (licensing of  well
                 drillers)

              Permitting programs (well construction
                 permits)

              Environmental standards (for  well
                 construction and location)

              Water quality testing

              Zoning (regulation of new development and
                 property transactions)

              Health advisories
                              7-14

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The institutional controls with the  greatest  effectiveness are
permanent and attention-gathering monuments,  a security program
involving guards, fences, etc., and  government ownership.
The second group involves land records  and  includes  easements,
deed restrictions, and deed notices.  This  second  group is
considered more effective than the third  group since it involves
less human activity and what human activity it does  entail is
primarily performed early (soon after a decision  is  made to use
institutional controls).  The third  group includes
regulatory/licensing actions similar  to those applied to
regulated operating activities.  This third group  involves more
human activity than the second group.   The  fourth  group involves
a variety of general controls which  are considered the least
effective of this list.                              •  •  •

There are three important points evident  in this  ranking.
First, some of the institutional controls are active in that
continuing actions are required by persons  and some  are passive
in that no continuing actions are required  by persons.  Since
active institutional controls are effective only  as  long as
persons take action, selecting the period over which they  retain
effectiveness is crucial for health  and environmental protection,

This timing question became the focus of  the  Agency's
considerations of institutional control for providing protection
from radioactive waste.  There is no  general  consensus off the^-
length of time human institutions will  remain effective s^.-^^
reliable to continue such active measures.   In this  regard,
failure of institutional controls does  not  necessarily imply a
complete breakdown of societal structure.   The more  likely
situation would be failure of institutional controls through
program reductions, reorganization,  changes in priorities, or^ ,
through the failure of special funding  mechanisms.   .-- "  --  "~

The timing question is most applicable  to hazardous^onstituents
at uranium mill sites since metals are  the  primary p'roblem and
no radioactive decay or organic decomposition takes  place  with
metals.  Dispersion of the metals in  the  ground water or
adsorption in the aquifer matrix are  the  only natural  cleansing
processes.

Second, certain active institutional  controls can  be effective
for as long as they last.  A security program,  for example,
might well be the best institutional  control  method  available
for a short period.  As such, active  controls may  be the best
solution at a contaminated ground water site,  if  predictions of
ground water cleansing by natural processes reliably project
decontamination within a period during  which  the  active   "
institutional controls are highly effective.   Another  benefi-fe—ฉ€-

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this approach is a reduction  in  both  economic  and  environmental
costs.  An active institutional  control  solution  is  generally
less expensive than a  restoration program.   Further,  less
environmental harm results  from  an  active  institutional  control
than from restoration  activities.   Restoration of  ground water
uses considerable energy  and  can contaminate large land  areas
for impoundments, processing  plants,  and associated
appurtenances.

Third, institutional controls can be  considered voluntary or
involuntary, based on  whether people  comply  with  controls on
their own accord or are forced to comply.  A permanent  marker is
considered a voluntary control since  it  indicates  the presence
of hazardous wastes at a  site but does not restrict  actions
which might disturb such  wastes.  A security program is
considered an involuntary control since  guards would prevent
people from intruding  into  such  wastes.  Controls  -that  prohibit
new well construction  or  that prevent certain  uses of the land
can be voluntary or involuntary  depending 'on the  statutory
authorities and implementing  philosophy  or practice  of  the local
or state agency.

Institutional controls may  be useful  when  combined with  limited
restoration of ground  water quality.  As discussed in Chapter 6,
most of the decontamination appears to be  achieved in the early
stages of ground water pumping.  If this initial  efficiency of
pumping is found to be the  general  case  or can be  reliably
predicted, it may be feasible to combine limited  pumping with
institutional controls.   This could be especially  attractive if
the initial pumping can reduce contaminant concentrations to
levels where natural cleansing will reduce concentrations to
standards levels within the life time of   institutional  controls,

Since wide variations  exist in contamination and  site
characteristics and since local  and state  laws vary  with regards
to institutional control  mechanisms,  it  is difficult to  develop
a generally applicable limit  for a  combined  cleanup  and
institutional control  effort.  Nevertheless,  it might be
possible to establish  a concentration, limit  at a  particular site
that is a few times the MCL and  at  which consideration  of
institutional control  is  warranted.
                               7-16

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7.3  POST-REMEDIATION GROUNDWATER CONTAMINATION

Existing plumes of contaminated groundwater have  been
identified and evaluated at the various  sites.  These  plumes
have been characterized and estimates made as  to  both  the  time
frame and efficacy of natural flushing to  reduce  the various
contaminates to acceptable levels, either  MCLs or,  in  some
cases, background levels.  Where it did  not appear  that  these
levels would be attained through natural flushing,  estimates
were made of the time and costs for alternative treatment  of
the contaminated groundwater.  These estimates are  presented
elsewhere in this BID.

Following stabilization of the piles there are three possible
mechanisms by which the tailings may serve as  sources  of new or
continued contamination of the local groundwater:   seasonal
intrusions of local groundwater into the tailings piles,
seepage of precipitation through the cover and*the  tailings,
and drainage of moisture added during the  remediation
construction process to aid in tailings  compaction  during
consolidation, relocating, and/or regrading of-the  piles.  As
discussed below, infiltration or seepage of precipitation  into
and through the tailings has been identified as the most
serious long-term groundwater concern at the Title  I UMTRA
sites and designs for the pile covers are  being evaluated  on a
site-specific basis to address this possibility.


7.3.1  Groundwater Intrusion

Studies identified groundwater intrusion as a  potential  problem
at three sites: Grand Junction, Riverton,  and  Salt  Lake  City.
The tailings have been relocated from the  Salt Lake City site
to Clive, the tailings at Riverton are in  the  process  of being
relocated to a Title II site, and it is  planned to  move  the
Grand Junction tailings to Cheney Reservoir site.   Relocation
of the tailings and contaminated soils will eliminate  the
source of contamination at the original  site;  care  is  taken  in
selection of alternate disposal sites and  design  of the
disposal cells to avoid this problem at  the new sites.(Ca88)

Groundwater intrusion is not considered  to be  a possibility  at
the sites identified for stabilization-in-place (SIP)  or
stabilization-on-site (SOS).  At the SIP sites it has  been
determined that the base of the existing tailings pile  is  above
the fluctuation range of the water table.  At  the SOS  sites,
where some or all of the tailings are to be relocated  on the
site, designs call for the tailings to be  sited so  that  the
base of the pile will be above the water table fluctuation
range.
                               7-17

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7.3.2  Precipitation

Precipitation which lands  on  the  pile  may  infiltrate  through
the cover and the tailings, leaching contaminants  from  the
tailings and carrying  them into the groundwater  thus  augmenting
groundwater contamination.  Even though the  average  annual
precipitation exceeds  the  average annual evaporation  at all  of
the sites except Canonsburg,  this has  been  identified as a
concern because of the  rock erosion barrier capping the piles.
It appears 'that the unvegetated riprap or broken rock layer
capping the pile and armoring  the sides to  prevent  erosion will
significantly reduce evaporation,  allowing  more  infiltration.

Field studies carried  out  on  completed piles at  Clive and
Shiprock, both sites having precipitation of about  6  inches
annually, indicated that these piles are operating  under
unsaturated conditions.  Measurement showed the  compacted clay
radon barrier to be operating  at  a hydrologic transmissivity in
excess of 10~9 rather  than the designed 10~7.  Measured
conductivity ranged between 10~9  to 10~12 at Shiprock and
1Q-10 to 10~14 at Clive.   At  the  Burrell vicinity  property
near Canonsburg, moisture  levels  remain at  construction levels
and the pile may be operating  under saturated conditions with a
hydrologic conductivity of 10~7 for the clay radon  barrier.
Additional field studies of the hydrologic  conductivity of the
clay layer are to be made  at  sites having precipitation of 10
to 16 inches annually.(Ti88)


7.3.3  Construction Water

During remediation work some  water is  added to the  tailings  and
contaminated soil to control  dust and  assist compaction and
grading as the tailings are consolidated on site or moved to
another site.  Subsequently,  most of this added  water will
drain from the tailings carrying  leached contaminants with it.
This dischargeซof contaminated water will be a one-time "slug"
occurring during and for a period after construction
activities.

7.3.4  Construction of Final  Cover

Originally, the pile cover was designed principally as  a radon
barrier, to control erosion,  and  to deter intrusion by
vegetation and burrowing animals.  Typical  cover designs, shown
in Figure 7.1, included a  compacted clay and silt  radon
barrier, a sand bedding layer, and rock erosion  barrier.  The
low-permeability radon barrier also served  to limit significant
infiltration.  Pile covers similar to  this  design  were
installed at Shiprock, Clive,  and Canonsburg and planned for
Ambrosia Lake. Prior to publication of the  EPA's proposed
groundwater standards, similar pile and cover designs were

                               7-18

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                                             Pool
                                                                   Starter  Dike
BEFORE RECLAMATION
Erosion Barrier
Radon
Barrier
                                         A'

                  Windblown Contaminated Soils

                             Windblown Soils
AFTER RECLAMATION (Section A-A')
      V-2' Erosion Barrier
        • Durable Rock
      6"  Bedding   • Clean  Sand
      3' Radon  Barrier
        • Compacted Clay
          & Silt
      Tailings
        • Sand,  Silt, & Clay
COVER DETAIL
                                           Original Perimeter of  Pile - Tailings
                                           Relocated to  Fill Pond Area
PLAN LAYOUT
                                  FIGURE   7-1
                 TYPICAL UMTRA PROJECT  PILE LAYOUT
                                     7-19

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being considered for most of the other UMTRA Project  sites.
Construction had begun at Lakeview and Durango  and  was
scheduled for Tuba City and Mexican Hat. Project  designs were
significantly advanced at Grand Junction,  Belfield  and  Bowman,
Palls City, and Slick Rock.

As a result of the EPA's proposed groundwater standards the  DOE
decided to relocate the tailings from the  Monument  Valley  site
to the Mexican Hat site; it was determined to be  more
economical to move the tailings than to  stabilize them  at
Monument Valley. Also, the proposed standards have  had  a
significant impact on the decision to relocate  the  Gunnison
tailings to the Landfill site.

DOE has conducted a technology development program  in
conjunction with the UMTRA Project to develop standard
practices for use in carrying, out stabilization of  the  tailing
piles.  A number of special studies were undertaken as  a
consequence of the proposed groundwater  standards,  and
revisions in the disposal pile and cover designs  are  under
consideration.  The studies focused on the use  of geomembranes,
alternate cover materials, alternate cover designs  (including
both composition and configuration), and disposal cell
configuration.  Figure 7.2 illustrates the various  cover
components now under consideration for use as appropriate  on a
site-by-site basis.


The following is a brief summary of the  impact  of the proposed
groundwater standards on the various UMTRA Project  sites.

     -Ambrosia Lake:   The hydraulic conductivity of  the  filter
      has been increased; no significant cost increase,,

     -Belfield/Bowman:   Cover thickness has  been increased  to
      provide frost protection at a cost of about $400,000.

     -Canonsburg:   No impact; stabilization  completed,

     -Durango:   Significant change in cover  design.

     -Falls City:   Detailed evaluations have not been
      completed but it is expected that  significant cell  and
      cover design changes will be required to  achieve
      compliance with the proposed groundwater  standards.

     -Grand Junction:   New cover design formulated.

     -Green River:   Cover design modified by adding a frost
      protection layer and a higher permeability  filter,  and
      adding sodium bentonite to the  radon/infiltration barrier
      to reduce permeability.  Estimated additional cost is
      about $100,000.
                               7-20

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X

c_
UJ
o
cc
t-
UJ

UJ
0.


CO
o
GC

                                               VEGETATION
                                      0-1.0'   ROCK MULCH
                                        3.0'     GROWTH MEDIUM & FROST PROTECTION
                                        1.0'
                                       0.5'
                                               BIOBARRIER: COBBLES (TOP CHOKED OR
                                               FILTERED)

                                               DRAIN:  CLEAN SAND
                                               INFILTRATION BARRIER: CLAYMAX
                                        1.0'     RADON BARRIER: CLAY/SILT
                                   FIGURE   7-2

                                  "CHECKLIST"

                                   TOP  COVER
                                          7-21

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     -Gunnison:   Tailings to be  relocated  to  new  site where
      the constrained cell with very  low permeability cover
      will be constructed.

     -Maybelle:   Evaluation of design changes  required  to meet
      proposed standards has not  been made; some changes  in
      cover design may be needed.

     -Mexican Hat:   Material from Monument Valley will  be
      incorporated at this site.
     -Monument Valley:
      Hat site.
       Tailings to be relocated to Mexican
     -Lakeview:   No significant changes.

     -Lowman:   A frost protection  layer may  be  added  at  a  cost
      of $100,000.
     -Naturita:
      adopted.
The constrained cell design will probably be
     -Riverton:   No effect; the tailings  are  being  relocated
      to a Title II facility.

     -Rifle:  A frost protection layer will  be added  to  the
      cover at an estimated cost of $2 million.

     -Salt Lake City:   No impact; stabilization  nearly
      complete at time proposed standards  published.

     -Shiprock:   No impact; stabilization' completed.

     -Slick Rock:   Detailed design reevaluations  have not been
      done but a frost protection layer will probably have to
      be added; estimated cost is $125,000.

     -Spook:   A layer of CLAYMAX may be placed over  the  pile
      to facilitate demonstrating that ACLs  are not  required.

     -Tuba City:   The infiltration barrier  will  be  placed at
      an hydraulic conductivity of 10~^; on-site  tests show
      that this is feasible.

The most significant impact on disposal cell design  at
individual UMTRA Project sites has been on the cover  design;
the realization that it is imperative to protect  the
infiltration barrier from the freeze/thaw  cycle to maintain  its
low permeability and its ability to comply over the  long-term
with the EPA's proposed groundwater standards.  The  estimated
total cost increase for adding frost protection is about  $10
million.
                               7-22

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Relocation of the Monument Valley tailings will cost about $10
million more than the previous design for stabilization  on site.
The revised cover designs at Durango, Grand Junction, Gunnison,
Falls City, and Maybelle are roughly estimated to  add about  $1
million to the stabilization costs at each site.(Ca88)
7.4 REFERENCES

Ca88   Caldwell, J. A., R. Rager and N.B. Larson,  "The  Impact
       of Proposed EPA Groundwater Standards on UMTRA Project
       Disposal Cell Design," DOE Remedial Action  Program
       Annual Meeting, Oct. 18-28, 1988.

Cha79  Chappell, W. R., et. al., "Human Health Effects  of
       Molybdenum in Drinking Water,"  EPA600/1-79-006,  1979.

Do72   Dollahite, J. W.,  et. al., "Copper Deficiency  and
       Molybdenosis Intoxication Associated with Grazing Near  a
       Uranium Mine,"  The  Southwestern Veterinarian,  Fall  1972.

EPA76  Environmental Protection Agency, "National  Interim
       Primary Drinking Water Regulations," EPA 570/9-76-003,
       1976.

EPA77a Environmental Protection Agency, Proceedings:  A
       Workshop on Policy  and Technical Issues Pertinent to the
       Development of  Environmental  Protection Criteria for
       Radioactive Wastes, ORP/CSD-77-1,  1977.

EPA77b Environmental Protection Agency, Proceedings:  A
       Workshop  on Policy  and Technical Issues Pertinent to the
       Development of  Environmental  Protection Criteria for
       Radioactive Wastes, ORP/CSD-77-2,  1977.

EPA78  Environmental Protection Agency, Proceedings of  a Public
       Forum  on  Environmental Protection  Criteria  for
       Radioactive Wastes, ORP/CSD-78-2,  1978.

EPA82  Environmental Protection Agency, "FEIS for  Remedial
       Action Standards for  Inactive Uranium  Processing Sites
        (40  CFR 192),"  EPA 520/4-82-013-1, Oct 82.

ICRP78  International Commission on Radiological Protection,
        "Limits for Intakes of Radionuclides by Workers,"  ICRP
        Publication 30, Pergamon Press, 1979.

LuSOa ; Luo, X. M., et. al.,  "Molybdenum and Esophageal  Cancer
        in China,"  Southeast-Southwest  Regional American
        Chemical  Society Annual  Meeting Abstracts,  40, 1980.
                               7-23

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LuSOb  Luo, X. M., et. al.,  "Preliminary Analysis of the
       Distribution of the Esophageal Cancer Mortality Rates,"
       Geographical Environment and Chemical Elements in Food
       and Drinking Water in Anyang Administrative Region,
       Honan Province, Chinese J. Oncol. 2:74-80, 1980.

NAS72  National Academy of Science, "Water Quality Criteria,
       1972," EPA-R3-73-033, NAS, Washington, 1972.

NAS80  National Academy of Science, "Drinking Water and Health,
       Volume 3," NAS, National Academy Press, Washington,  1980

NAS83  National Academy of Science, "Drinking Water and Health,
       Volume 5," NAS, National Academy Press, -Washington,  1983

Ti88   Titus, Frank B., Jacobs Engineering Group, Inc., Oral
       presentation at DOE/NRC Hydrology Work Group Meeting,
       Albuquerque, NM, October 27, 1988.

Ve78   Venugopal, B. and T.  D. Luckey,  "Metal Toxicity in
       Mammals, Volume 2: Chemical Toxicity of Metals and
       Metoloids," Plenum Press, New York, 1978.
                               7-24

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