EVALUATION OF     IMPACT
MINES DEVELOPMENT, IMC. MIL
 ITY CONDITIONS IN THE CHEYENNE RIVER
   ONMENTAL,PHDTECTI
        Regffon VIII
      Denser,  Colorado
       September 1971


-------
           EVALUATION OF THE IMPACT

                    OF THE

         MINES DEVELOPMENT, INC. MILL

                      ON

WATER QUALITY CONDITIONS IN THE CHEYENNE RIVER
       ENVIRONMENTAL PROTECTION AGENCY
                 Region VIII
               Denver,  Colorado

                September 1971

-------
                      TABLE OF CONTENTS
Section                     Title                      Paqe
               LIST OF FIGURES                          ii

               LIST OF TABLES                           ii

   I           INTRODUCTION                              1

  II           SUMMARY                                   7

 III           RECOMMENDATIONS                          12

  IV           WASTE MANAGEMENT PRACTICES               14

   V           PREVIOUS WATER QUALITY STUDIES           18

  VI           1971 FIELD STUDY                         37
                 Study Procedures                       37
                 Sample Processing Procedures           41
                 Results                                42

-------
                       LIST OF FIGURES


Figure No.                  Title                      Page

    1        Location  Map                              3
             Mines, Development, Inc. Uranium Mill
               Process Ponds and Tailings Piles
                        LIST OF TABLES


Table No.                   Title                      Page

    I        Radioactivity Standards                    10

   II        Mill Process and Retention Ponds           15

  III        Cheyenne River and Cottonwood Creek        19
               Sampling Stations

   IV        Dissolved Radioactivity in Cheyenne        20
               River and Cottonwood Creek Water
               Samples

    V        Chemical and Physical Characteristics       23
               of Cheyenne River and Cottonwood
               Creek Water Samples

   VI        Physical and Radiological Characteristics   27
               of Seepage Samples

  VII        Radioactivity Chemical Contents  Of Bottom   32
               Sediments From The Cheyenne River and
               Cottonwood Creek

-------
                 LIST OF TABLES (Continued)
Table No.                   Title                      Page

  VIII       Radium-226 Concentrations in               36
               Angostura Reservoir Fish -
               September,  1966

    IX       Cottonwood Creek and Cheyenne River        38
               Sampling Stations - 1971

     X       Dissolved Radioactivity in the Cheyenne    43
               River,  Cottonwood Creek, Hat Creek,
               and Cascade Springs
                             111

-------
                       I.  INTRODUCTION


     An intensive water quality study of the Cheyenne River

and the tributary stream, Cottonwood Creek, in the environs

of the Mines Development Mill located at Edgemont, South

Dakota, was conducted by EPA personnel!/ during July 26-30,

1971.  The objectives of the study were to determine and

evaluate:

     1.  Water quality conditions in Cottonwood Creek and the

         Cheyenne River during a period of dry weather flow.

     2.  Chemical and radioactivity loadings (mass/day)  on

         Cottonwood Creek and the Cheyenne River as the re-

         sult of seepage from mill ponds.

     3.  Radioactivity levels in the water, biota and bottom

         sediment of Angostura Reservoir.

The July study was conducted at the request of the South Dakota

State Department of Health.  In this respect,  the study repre-

sented a continuation of the support provided to the State in

its long-term program to monitor and assess the environmental

impact of mill operations.   Mines Development personnel  were
I/  Radiological Activities Section,  Division of Technical
    Support, Office of Water Programs,  Cincinnati,  Ohio

-------
 most  cooperative  in providing the  field team with unlimited




 access  across mill property and bench space in the mill labora-




 tory.




      The  "Edgemont" mill is operated by Mines Development, Inc.,




 a  subsidiary of the Susquehanna Corporation,  As shown in Figure




 I, the  mill is located in the southwest corner of South Dakota




 on the  south bank of the Cheyenne  River.  A tributary to the




 Cheyenne  River, Cottonwood Creek,  traverses the mill property




 and is  flanked on both sides by inactive sand tailings piles




 (Figure 2).  Angostura Reservoir,  a recreational lake, is




 located about thirty-five miles downstream near the city of Hot




 Springs.




     Mineral processing operations carried out at the mill in-




 volve the recovery of uranium, vanadium, and molybdenum (a




 contaminant in the uranium ore).  Recovery and extraction




 operations for vanadium and uranium are housed in separate




buildings.  However, the two circuits are connected with the




 slime tailings -effluent from the uranium circuit becoming the




 feed solution to the vanadium circuit after clarification in




 the mill ponds.  Uranium ore is locally obtained from shaft and




open-pit mines.  A foreign source of ore is used as the dry feed




 to the vanadium circuit to supplement the soluble vanadium feed




 from the uranium circuit.   During the July study,  the average



                              2

-------
                                                                HOT SPRINGS
                                                                  AIRPORT
                                                                  ANGOSTUKA
                                                                   R£S>£R.VOi
W£BRASKA STATE
                       LOCATION MAP
                         FIGURE 1

-------
                  CHEYENNE  RIVER
SAND  TAILINGS PILE •*!
                               MINES  DEVELOPMENT, INC:
                                    URANIUM MILL
                          PROCESS PONDS AND TAILINGS PILES
                                       FIGURE 2

-------
ore  feeds to the uranium and vanadium circuits were 400 and




15.5  tons/day,  respectively.  For uranium, this corresponded to




operation at approximately sixty percent of plant capacity,




650 tons/day.




      Pre-operational surveillance of the Cheyenne River was per-




formed during February, 1956, by personnel of the South Dakota




Department of Health and U. S. Public Health Service.  Four




stations were sampled:  (1) upstream from the mill site at the




State Highway 18 bridge,  (2) approximately 1.5 miles downstream




from  Edgemont,  {3) at Falls Canyon and  (4) just upstream from




the confluence  with Tepee Creek.  Unfortunately, since the




mechanics of environmental surveillance were in the develop-




mental stages at that time, radioactivity analysis was limited




to gross procedures instead of the more definite, analysis for




specific radionuclides.  Water samples contained 10 to 40




picocuries per  liter (pCi/1) of dissolved alpha activity and




10 to 120 pCi/1 of dissolved beta activity; suspended radio-




activity was negligible.  In retrospect, dissolved gross alpha




and beta concentrations at the upper limits of the observed




ranges now seem unusually high for natural background conditions.




Bottom sediment samples showed an average content of 10 and 15




picocuries per gram (pCi/g)  of dry solids of alpha and beta




activity,  respectively.   All the biological samples (algae.

-------
insects, minnows and plankton) showed corresponding low con-




centrations of gross radioactivity.  The initial post-opera-




tional monitoring effort (June 1957) did not show levels of




dissolved radioactivity in either the Cheyenne River or Cotton-




wood Creek greater than background levels, despite a low flow




drainage from the sand tailings pond to the creek containing



1400 and 1800 pCi/1 of dissolved alpha and beta activity, re-




spectively.

-------
                        II.  SUMMARY






     Uranium and vanadium recovery operations carried out at




the Edgemont mill generate liquid wastes and spent ore solids




which are discharged to a system of ponds.  These ponds retain




the fine (slimes) and coarse (sand tailings) ore solids on the




mill property.  However, due to the permeability of the soil




in which the ponds are excavated, liquid wastes are lost to the




ground and eventually reach the Cheyenne River and Cottonwood




Creek in the form of seepage.  The impact of this seepage in




the water environment is the following:




     1.   Unsightly discoloration of stream bank and channel




         areas by the accumulation and/or deposition of "iron-




         rich" solids.




         Although the areas so affected are rather extensive




         during low flow conditions,  the only area which is




         readily visible from the State Highway 18 bridge is




         the seepage zone adjacent to Pond No.  2.




     2.   Increases chemical and radioactivity concentrations




         in Cottonwood  Creek and, to  a much lesser extent,  the




         Cheyenne River.




         The 1964 study showed  dissolved uranium and radium-

-------
           226 concentrations in Cottonwood Creek substantially




           in excess of background concentrations (30 and 100X




           greater, respectively).  In subsequent studies,




           radium and uranium concentrations were lower; approxi-




           mately one order of magnitude greater than back-




           ground levels.




           Consistent with the findings for Cottonwood Creek,




           the maximum radioactivity concentrations in the




           Cheyenne River were obtained in the 1964 study.  At




           a location about 1.5 miles below the mill, dissolved




           radium-226 and uranium concentrations were 2.5 pCi/1




           and 130 pg/1, respectively.  These values corre-




           sponded to a ten-fold increase above background.  The




           results for other studies at this same sampling




           station and other downstream stations were substan-




           tially lower - values less than 1.0 pCi/1 of radium-




           226 and 50 pg/1 of uranium.




Flow data  for the 1971 study indicated that Hat Creek has a




decided impact on Cheyenne River water quality conditions, at




least during low flow periods.   During the 1971 study,  Hat




Creek was responsible for 80 percent of the Cheyenne River




flow at the State Highway 71 bridge.





                              8

-------
     Increased radioactivity levels in the Cheyenne River down-




stream  from  the mill do not pose a health hazard from excessive




exposure to  radiation.  Obviously, the non-use of the Cheyenne




River for domestic water supply makes this conclusion a fact.




However, a comparison of the observed concentrations of radium-




226 and uranium with currently accepted standards (Table  I)




also shows that the radiological quality of the Cheyenne River




is acceptable for drinking water purposes.  Based on the radium-




226 concentrations observed during low flow conditions, it




seems possible that the annual average concentration of radi-




um-226 does not exceed 1.0 pCi/1.  If the Cheyenne River was




used as a regular source of drinking water, the resultant in-




take would be only 5% of the transient rate of daily intake for




the general population, as recommended by the Federal Radiation




Council (upper limit of Range II).  The fact that the maximum




radium concentration observed in the Cheyenne River was less




than the current Public Health Service guideline for radium-




226 in drinking water also demonstrates the absence of a poten-




tial health hazard from this radionuclide.  Similarly, the dis-




solved uranium concentrations in the river have not approached




levels of public health significance.   The maximum concentration

-------
                          TABLE I  RADIOACTIVITY STANDARDS
               Drinking Water
Radionuclide      Standard
Radium-226
Uranium
700 ug/1
                 22 mg/l(c)
                 Limiting Rate Of
                   Daily Intake
                 From All Sources
                 (Annual Average)
3.0 pCi/l      20 pCi/day
                                 0  to  2 pCi/day-Range  I
                                 2  to  20 pCi/day-Range II
                                 20 to 200 pCi/day-Range III
0.7 ing/day
                 22 mg/day(d)
                                Recommendi ng
                                  Authority

                                U.S. Public Health Service

                                Federal Radiation Council
International Commission
on Radiological Protection
(ICRP)

National Committee on
Radiation Protection  (NCRP)
 (a)  The limit may be exceeded if the  radioactivity intake from all sources in addition to
     that from water does not exceed intake  levels  recommended by the Federal Radiation
     Council for control action (the upper limit  of Range II).
 (b)  Action required:
     Range I - Periodic confirmatory surveillance as necessary.
     Range II - Quantitive surveillance and  routine control.
     Range III - Evaluation and application  of conditional control measures as necessary.
 (c)  Calculated from the limiting rate of daily intake by assuming a daily intake from
     drinking water of 1 liter/day and no intake  from other sources.
 (d)  Based on 1/30 of the maximum permissible concentration for natural uranium for con-
     tinuous occupational exposure,  the specific  activity for uranium-238» an activity
     ratio (uranium-234/uranium-238) equal to unity,  and a daily water intake of 2.2
     liters/day from all sources.

-------
of dissolved uranium observed in Cheyenne River was about 20%




of the ICRP standard; negligible in comparison to the NCRP




standard.   (Note;  To date, the more restrictive ICRP standard




has not been formally adopted by the NCRP.)




     The contaminated reach of Cottonwood Creek lies wholly




within the mill property with access to the general public re-




stricted.  Therefore, the creek is not a direct source of




radiation exposure to the general public.




     Based on visual observations, sand tailings from the three




storage areas (Pile No. 1, Pile No. 2, and Pond No. 2) are




entering the water environment by wind and/or water errosion.




Such off-site losses of these high-radioactivity solids is most




undesirable and should be curtailed at an early date.
                             11

-------
                    III.  RECOMMENDATIONS






1.  The bottom and sidewalls of the retention ponds should be




    sealed to eliminate seepage into Cottonwood Creek and the




    Cheyenne River.




2.  A two phase program providing for the stabilization and




    ultimate disposal of sand tailings should be developed with




    a reasonable timetable for implementation.  As a first




    phase, immediate action should be taken to stabilize the




    huge bulks of sand tailings stored in Pile No. 1,  Pile




    No. 2, and Pond No. 2 against wind and/or water errosion.




    The most desirable alternative for the second phase of the




    program,  ultimate disposal, seems to be storage in the ex-




    cavated portions of the open-pit uranium mine operated by




    Mines Development,  Inc.




3.  Monitoring stations should be established on Cottonwood




    Creek (at the mouth)  and the Cheyenne River (downstream




    from the mill)  to determine the extremes in chemical and




    radioactivity concentrations as well as the annual average




    radioactivity concentrations.   As a minimal effort,  weekly




    grab samples should be collected with analyses performed




    on monthly composites.   Monitoring should be continued






                               12

-------
    after recommendation (1),  above, has been implemented to




    show the sustained integrity of the sealed ponds.  Dur-




    ing this stage, the frequency of sample collection could




    be reduced to monthly grabs.




4.  The classification of Cottonwood Creek should be resolved




    in regard to applicable standards, i.e., effluent limits




    or receiving water standards.  Upstream from the mill the




    creek is an intermittent stream whereas flow in the reach




    traversing mill property is maintained by seepage,  possible




    spring flow, and drainage  from an abandoned railroad well.
                             13

-------
                IV.  WASTE MANAGEMENT PRACTICES







     The waste management program conducted by Mines Develop-




ment essentially provides for the on-site retention of liquid




and solid wastes with no direct release to the water environ-




ment.  Briefly, liquid wastes from the uranium and vanadium




extraction circuits are discharged to a system of process ponds




wherein volume reduction occurs by evaporation and seepage.




Seepage losses are the result of pond excavation in a zone of




permeable soil.  In order to control the total volume of re-




quired ponding, water is recycled for use as process water.




Sand tailings are stored in two unstabilized piles and two re-




tention ponds.  An areal schematic showing the locations of the




ponds and the sand tailings piles is presented in Figure 2.




     Operational functions of the various ponds are summarized




in Table II.  The flow scheme for the pond system is the follow-




ing;




     1.  Slime tailings and sand tailings from the uranium cir-




         cuit are discharged to Pond No.  7,  a pond functioning




         as a retention and sedimentation basin.




     2.  Clarified vanadium-bearing liquor (blue liquor)  is




         pumped to Pond No.  3.







                              14

-------
                      TJffiLE II  MILL PROCESS & RETENTION  PONDS
                                           Pond Use
Pond
          Current
             Past
No 1
No 2
No 3
No 4
No 7
No 8

No 9

No 10
Disposal of raffinate from
the vanadium extraction circuit,

Sand tailings storage.
Storage basin for vanadium-
bearing liquor (blue liquor)

Not in use.
Retention and storage of" slime
tailings and sand tailings;
sedimentation basin to pro-
duce clarified blue liquor.

Contingency.

Not in use.

Contingency.
Retention of slime tailings from
the uranium circuit.

Disposal of vanadium raffinate and
retention of slime tailings.

Retention of slime tailings.
"Polishing" sedimentation basin for
vanadium-bearing liquor.

Same as current use except for the
storage of sand tailings.

-------
     3.  Clarified blue liquor is pumped from Pond No. 3 to




         the head-end of the vanadium extraction circuit.




     4.  Vanadium raffinate is discharged to Pond No. 1.




There is sufficient flexibility built into the pumping system




to transfer liquid between any two ponds, including the two ponds




which are in standby condition.




     Until the weekend of August 27-28, 1966, Pond No. 2 was




used for the storage and retention of slime tailings and




vanadium raffinate.  At that time, the discharge of repulped




sand tailings was diverted from Pile No. 2 to this pond.  This




was an attempt to seal the bottom of Pond No. 2 with ore solids;




thereby stopping the seepage into the Cheyenne River at the base




of the bank.  The resultant mass of sand tailings stored in this




area rises above the original elevation of the pond surface.




Based on visual observations, the tailings appear to be drifting




toward Highway 18 and down the river bank with perhaps some




level of entry into the Cheyenne River.  This was anticipated



when it was noted in the report on the 1966 study that "storage




of sand tailings in Pond No.  2 does present this somewhat un-



desirable feature of placing the sand directly on the bank of the




Cheyenne River."




     Sand tailings Pile No. 1 is contiguous with Cottonwood




Creek for a distance of several hundred feet (conservatively





                              16

-------
estimated).  Therefore, there is undoubtedly some loss of




solids to the creek as the result of errosion during a period




of high runoff and wind transport.  Although the bulk of sand




tailings Pile No. 2 is located at much higher elevation than




the channel of Cottonwood Creek, there appears to be sloughing




of material from the pile onto the flood plain.  In essence,




sand tailings from the inactive piles are probably reaching




the Cheyenne River with subsequent transport downstream into




Angostura Reservoir.
                              17

-------
               V.  PREVIOUS WATER QUALITY STUDIES


     Short-term field studies to monitor water quality condi-

tions in the Cheyenne River and Cottonwood Creek have been con-

ducted on five occasions since the initial 1957 post-operational

study;  October 17-18, 1962; August 6-7, 1964; September 7-9,

1966; early December, 1967; August 15, 1968.  These have been

cooperative investigations between the South Dakota State De-

partment of Health and the Environmental Protection Agency'3'.

For all studies, the radiochemical analyses were performed in

EPA laboratories.  In the case of 1966 study, water and bottom

sediment sampling was a cooperative undertaking.  State personnel

were solely responsible for sample collection in the other

studies.  A list of the stations at which water and bottom sedi-

ment samples have been collected in the course of these studies

is given in Table III.

     The results of the physical and chemical analyses of water

samples are summarized in Tables IV and V.    Similar data for

the seepage samples collected during the 1966 study are pre-
(a)   Organizational predecessors of the Office of Water Programs,
     Environmental Protection Agency.   That is,  the U.S.  Public
     Health Service {Division of Water Supply and Pollution Con-
     trol) , the Federal Water Pollution Control Administration
     and the Federal Water Quality Administration.
                              18

-------
            TABLE III CHEYENNE  RIVER AND COTTONWQOD CREEK  SAMPLING STATIONS

Station                               Description

  1       Cheyenne River  just upstream from  the Highway  18 bridge outside of  Edgemont.

  2       Cottonwood Creek at the  pedestrian bridge;  200 feet  above sand tailings  Pile
          No.  1 and just  south  of  the fence  that forms the south boundry of mill property.

  3       Cottonwood Creek several hundred feet upstream from  its confluence  with  the
          Cheyenne River;  downstream from sand tailings  Pile No. 2.

  4       Cheyenne River  between the Cottonwood Creek confluence and Pond No.  1.

  5       Cheyenne River  about  1.5 miles downstream from the mill.

  6       Cheyenne River  at the Highway 71 bridge.

  7       Cheyenne River  in the headwaters of Angostura  Reservoir; 0.5  miles  downstream
          in Tepee Canyon.

  8       Central portion of Angostura Reservoir.

  9       Cheyenne River  about  0.25 miles below Angostura  Dam.

-------
                      TABLE  IV  DISSOLVED RADIOACTIVITY  IN CHEYENNE RIVER
ro
O
Station

1 - 1962
    1964
    1966
    1967
    1968

2 - 1962
    1964
    1966
    1967
    1968

Cottonwood
Creek at the
seepage zone
adjacent to
Pond No. 7
(1968)


AND



COTTONWOOD CREEK WATER SAMPLES
Dissolved Radioactivity
Gross Alpha
(pCi/1)
12
—
15
— —
—
9
—
17
Gross Beta
(pCi/1)
55
—
61
—
—
_ _
_—
163
Radium- 2 26
(DCi/1)
	
0.26
0.25
0.10
0.10
____
0.26
0.10
Lead- 210
(pCi/1)
__.
	
0.6
0.9
	
_ __
	
0.7
Uranium
(ucr/1)
._
17
12
13
7
__
7
18
Thorium
(ucr/1)
____
	
	
N.D.
N.D.
____
	
	
                                                 0.11
   18
N.D.
                                                 0.86
100-200
                                                                            (a)
     (a)   Analytical difficulty prevented reporting of a specific concentration.
     N.D.  - Not detectable,  i.e.  net counting rate less than two standard deviations counting rate

-------
            TABLE IV  (Continued)   DISSOLVED RADIOACTIVITY IN CHEYENNE RIVER
                                                    AND
                                        COTTONWOOD CREEK WATER SAMPLES
                                          Dissolved Radioactivity
ISJ
Station

Cottonwood
Creek at the
seepage zone
adjacent to
sand tailings
Pile No. 2
(1967)

3 - 1962
    1964
    1966
    1967
    1968

Cheyenne River
adj acent to
Pond No. 2
seepage zone
    1964
    1966
    1967
    1968
                     Gross Alpha
                       (pCi/1)
Gross Beta
 (pCi/1)
                         48

                          1
                         14
Radium-226
 (pCi/1)
Lead-210
 (pCi/1)
Uranium
 (uq/1)
                                                  0.60
                0.26
                0.50
                0.10
                0.27
                             N.D,
                4.7
                0.2
                          53
              4
              18
              26
              15
Thorium
 (uq/1)
                        2.3
180
—
53
— —
— —
	
24
1.6
0.60
0.46
	
— _
1.2
N.D.
___
—
550
49
64
12
	
	
_-_
5.7
5.0

-------
             TABLE IV  (Continued)  DISSOLVED RAD10ACTIVITY IN CHEYENNE RIVER
M
AND
COTTONWOOD CREEK WATER SAMPLES
Dissolved Radioactivity
Station
4 -
5 _


6 -



7 .

8 -
9 _
1966
1967
1968
1962
1964
1966
1962
1964
1966
1967
1962
1966
1966
1966
Gross Alpha
(pCi/1)
- 15
11
—
9
20
__
5
—
3
5
5
3
Gross Beta
(pCi/1)
50
56
— —
127
mmmm
	
101
—
37
51
23
29
Radium- 2 26
(pCi/1)
0.29
0.44
2.5
0.50
_ •««.*
0.44
0.30
0.40
____
0.26
0.14
0.28
Lead-210
(pCi/1)
	
	
0.2
«_.
	
N.D.
N.D.
___
0.1
	
0.1
Uranium Thorium
(uq/1) (uq/1)
10 N.D.
130 	
26 	
__ ____
8 	
13 	
19 8.5
__ ____
Q __ — _
	 	
13 	

-------
                         TABLE V   CHEMICAL AND PHYSICAL CHARACTERISTICS  OF
                              CHEYENNE RIVER AND COTTONWOOD CREEK WATER SAMPLES
NJ
U)
Station

1 - 1962
    1964
    1966
    1967
    1968

2 - 1962
    1964
    1966
    1967
    1968

Cottonwood
Creek at the
seepage zone
adj acent to
Pond No. 7
(1968)
                    Dissolved
                      Solids
                      (mq/1)

                       3552

                       3098
                       4160
                       4112
Susp.
Solids
(mq/1)
  28
Total
Iron
(mq/1)
           36
Sulfates   Nitrates
 (mq/1)      (mq/1)
           2140
                                                                       PH
                     7.8 - 8.0
                                           20
                    2350
  39
                                   7.0
                                   7.3
Vanadium
                                                                                       <100
                                                                                        <20
                                                                                        <20
                                                                                        <20

-------
      TABLE  V (Contined)  CHEMICAL AND PHYSICAL CHARACTERISTICS OF
                       CHSYEHME RIVER AND COTTONWOOD CREEK WATER SAMPLES
Station

Cottonwood
Creek at the
seepage zone
adjacent to
sand tailings
Pile No. 2
(1967)
Dissolved
  Solids
  (mg/1)
Susp.
Solids
(mq/1)
Total
Iron
(mg/l)
Sulfates
 (mq/1)
Nitrates
 (mq/1)
                                                                       pH
Vanadium
 (uq/1)
                                                                  <100
3 -
1962
1964
1966
1967
1968
5328
	
6286
	
.._ —
                                      67
                                2400
                               0.29
                            268
                                   6.4
                                   6.3
                                                                                 <100
                                                                                  <20
Cheyenne River
adjacent to
Pond No. 2
seepage zone
    1964
    1966
    1967
    1968
                      196
                    3240
                      0.36
  19500
 178
                          6.0
                          6.5
                                                                  <100
                                                                   <20

-------
              TABLE  V (Continued)   CHEMICAL AND  PHYSICAL CHARACTERISTICS  OF
in
Station
4 -
5 -
6 -
7 -
8 -
9 -
1966
1967
1968
1962
196'4
1966
1962
1964
1966
1967
1962
1966
1966
1966
CHEYENNE RIVER AND COTTONWOOD CREEK WATER SAMPLES
Dissolved Susp. Total
Solids Solids Iron -Sul fates Nitrates pH Vanadium
(mq/1) (mq/1) (mq/1)* ' (mq/1) (mq/1) (uq/1)
3D DO 4&X <-» — mmmmmmm* mm ****** mm mm mum mm mm mm
" i
	 	 — <20
3624 — — 	 	 — 	
	 — 42 3667 1.52 7.4 	
3538 6 — 	 	 — 	
3084 — — 	 	 — r 	
	 — 47 1593 0.10 7.8 	
2664 5 ~ 	 	 — 	
	 „ __ 	 	 — <100
824 — ' — 	 	 	 — 	
1558 37 — 	 	 — 	
1656 2 - ~ 	 ^ 	 ~ —
looo 3 **™ ——«-... ____ __ __ _

-------
sented in Table VI.  Although data for the 1962, 1964, and 1966




studies were the subject of a previous report, these data are




included herein to maintain continuity and to present the com-




plete historical record, particularly for comparative purposes.




     As shown in Table  IV   seepage into Cottonwood Creek re-




sults in significant degradation of water quality.  The specific




reductions in chemical, physical and radiological quality were




the following:




     1.  Significant increases in the concentration of dissolved




         gross alpha and beta radioactivity,  radium-226,  urani-




         um, and lead-210.   The maximum concentrations of




         radium-226 and uranium were observed in 1964.  These




         values, 550 pg/1 of uranium and 24 pCi/1 of radium-




         226 were approximately 30 and 100 times the respective




         background levels.




     2.  Increases in the dissolved solids and total iron (dis-



         solved) concentrations.




     3.  pH decrease.




     4.  Discoloration to the extent that the creek has been




         described as "running red" on occasion.  This was con-




         sidered to be attributable to a chemical reaction be-




         tween the natural  water and the iron-bearing seepage.
                              26

-------
             TABLE VI PHYSICAL AND RADIOLOGICAL CHARACTERISTICS OF SEEPAGE SAMPLES
NJ
                                     Dissolved Radioactivity
     Description

     Seepage from
     bank of Cotton-
     wood Creek
     adjacent to
     Sand Tailings
     Pile No. 2
Seepage from
bank of Cheyenne
River upstream
from Pond No. 1
                    Gross
                    Alpha
                   (pCi/1)
 Gross
 Beta
(pCi/1)
Radium-226
 (pCi/1)
                     148
  187
   32
                           35
  342
    1.4
Lead-210
(PCi/1)
  0.8
  0.4
Uranium
 (ocr/1)
Dissolved
  Solids
  (mg/1)
   175
  8212
    89
21,800
6.3 to
6.7
5.7

-------
        Presumably,  iron-bearing precipitate was formed which




        gave the stream a red to reddish-brown appearance when




        suspended  and transported in the liquid phase.




Although the flow  in Cottonwood Creek is intermittent in nature




upstream from the  mill, seepage or a combination of seepage and




spring flow apparently maintain flow in the creek throughout




the reach on mill  property.  Intermittent flow appears to be




the reason for the finding of maximum concentrations during the




1964 study.  There was no observable flow upstream from the see-




page zone in 1964  -  the only study period for which such a con-




dition was noted.  Correspondingly, the differences in concentra-




tion increases indicated by the five studies are considered to be




more a function of specific flow conditions and the dilution




provided rather than differences in seepage flow or quality.




     Several factors indicated the process and retention ponds




were a major source of the seepage entering Cottonwood Creek:




the extension of the zone of active seepage to bank height(s)




substantially above the water surface,  accumulation of reddish-




brown deposits in  the seepage fcone considered to be indicative




of high iron content in the seepage,  and the physical and




radiological characteristics of the seepage samples.   The high




radium-226 and uranium concentrations (Table VI) low pH,  and
                              28

-------
implied high iron content of the seepage samples were consis-




tent with the physical and chemical composition of the vanadium




raffinate and vanadium-bearing liquors held in the ponds.  These




ponded liquors were characterized by low pH values (2.0 to 2.5),




dissolved radium-226 concentrations in the range of 60 to 300




pCi/1, and dissolved iron concentrations in excess of 500 mg/1.




     Another possible source of seepage in 1966 was drainage




from sand tailings Pile No. 2 since the pumping of repulped




tailings  (50% slurry) was terminated only two weeks before the




study.  Moreover, mill personnel believed that as far as bulk




flow into the creek was concerned, an underground spring rather




than pond seepage or tailings pile drainage was the causative




agent.  If an underground spring is responsible for sustained




flow in the creek, the water quality conditions in the creek in-




dicate that the spring flow is contaminated by pond seepage.




     The adverse effect of seepage from Pond No. 2 into the




Cheyenne River was the unsightly discoloration of the stream




bed at the base of the bank and for some distance downstream.




Although the 1966 water samples from this location showed in-




creased radioactivity levels (Table iv) ,  the results were




judged to be representative of partially diluted seepage perco-
                              29

-------
 lating up through the stream bed;  not stream quality.   These




 samples were collected from a channel of flowing water adjacent




 to the dike, but separated from the main channel by a  sand bar.




 As such,  the indicated change in radiological water quality rep-




 resented only a minute fraction of the Cheyenne River  flow at




 this site.




      Seepage into the Cheyenne River at a point just upstream




 from Pond No.  1 contained concentrations of  dissolved  radium




 and uranium in excess of surface water background levels  (Table




VT) .  However,  the concentrations were much lower than  those




 found in  the seepage flowing into  Cottonwood Creek - an order




 of magnitude less for radium-226.   The seepage had no  effect




 on Cheyenne River water  quality because the  observed flow  was




 only trickle.




      Downstream from the confluence with Cottonwood Creek,  the




 Cheyenne  River showed recovery to  nominal or background levels




 in the  vicinity of Station 5 or 6.   Consistent with the find-




 ings for  Cottonwood  Creek,  the maximum results for dissolved




 radium-226  and uranium concentrations  in the Cheyenne  River  were




 observed  in the 1964 study -2.5 pCi/1 of  radium-226 and 130 ug/1




of  uranium.  This  is in  contrast to the  results of the  other




 studies which  have shown radium-226 and  uranium concentrations






                              30

-------
 in the river to be only slightly  in  excess of background




 levels.   For example,  with  exception of  the  2.5 pCi/1 result,




 the maximum radium-226 concentration was 0.5 pCi/1  at Station




 5  during the 1966  study.




     Chemical and  radioactivity results  for bottom  sediment




 samples  are presented  in Table VII.  Although the vanadium re-




 sults  indicated somewhat higher levels in the seepage zone of




 Cottonwood  Creek,  the  finding was not considered definitive in




 terms  of providing positive identification of vanadium liquors




 as a major  source  of seepage.  This  was  due to the  limited num-




 ber of samples  analyzed and the relative insensitivity of the




 analytical  procedure.   Similarly, the iron data did not provide




 a  quantitive-type  illustration of the bank and channel discolora-




 tion.  This was, in part, attributable to the method of sample




 collection.   Sediment  samples were collected in a manner such




 that they were  representative of the  average condition at each




 location  and were  not  limited to the  collection of obviously




 discolored  material (unless  the discoloration was distributed




 across the  channel width).




     Radium-226 and uranium  concentrations in the bottom sedi-




ments  showed  the same contamination pattern as that exhibited




by  the corresponding results for water samples.   That is,  the






                               31

-------
                           TABLE VII  RADIOACTIVITY CHEMICAL CONTENTS OF
to
BOTTOM SEDIMENTS
FROM THE


CHEYENNE RIVER AND COTTONWOOD CREEK


Station
1




2




- 1962
1964
1966
1967
1968
- 1962
1964
1966
1967
1968
Gross Alpha
(pCi/g)
7
—
5
—
—
70
—
7
—
— —
Gross Beta
(pCi/g)
37
—
18
__
—
195
—
41
—
—
Radium- 2 26
(pCi/g)

1.4
1.2
__ _
1.2
__ _
4.4
2.0
	
2.3
Uranium
(uq/q)

2.4
	
___
0.6
_____
5.6
	
	
2.2
Vanadium
(uq/q)

	
	
___
<50
_____
___
<50
	
60
Iron
(uq/q)
i —
	
	
____
4720
_____
_____
>2500
	
8180
     Cottonwood
     Creek at the
     seepage zone
     adjacent to
     Pond  No. 7
     (1968)
7.9
2.7
<50
9530

-------
        TABLE VII (Continued)   RADIOACTIVITY CHEMICAL CONTENTS OF
                                    BOTTOM SEDIMENT FROM THE
                               CHEYENNE RIVER AND COTTONWOOD CREEK
Station

Cottonwood
Creek at the
seepage zone
adjacent to
sand tailings
Pile No. 2
    1966
    1967
           Gross Alpha
              (pCi/g)
         Gross Beta
           (pCi/g)
                55
             61
          Radium-226
           (pCj/g)
             12
             15
Uranium
 (uq/q)
                                                    9.5
Vanadium
 (pg/gl
Iron
(uq/g)
                                                310
                      >2500
3 -
1962
1964
1966
1967
1968
124
                    55
195
             61
             74
             12
             45
             31
                                                       62
                                                        6.5
                                                        8.5
                                                190
                                                 90
                      >2500
                        6350
Cheyenne River
at base of
Pond No. 2
dike
    1964
    1966
    1967
    1968
                            24
                          1.1
                          1.0
                          1.8
                          1.1
                         9.3

                         1.9
                         0.6
             <50
             <50
             <50
              1550
            >2500
              1890

-------
TABLE VII  (Continued)  RADIOACTIVITY CHEMICAL CONTENTS OF
BOTTOM SEDIMENTS FROM THE
Station
4 -
5 -
6 -
7 -
8 -
9 -
1966
1967
1968
1962
1964
1966
1968
1962
1964
1966
1967
1962
1966
1966
1966
Gross Alpha
(pCi/g)
11
14
15
13
7
11
8
6
4
CHEYENNE
Gross Beta
(pCi/q)
33
64
25
91
24
47
31
32
17
RIVER AND COTTONWOOD CREEK
Radium- 2 26
(pCi/a)
2.9
3.7
2.7
3.9
2.7
2.1
0.9
1.7
0.9
1.7
1.5
1.3
Uranium Vanadium Iron
(uq/q) (uq/q) (uq/q)
	 <50 1875
2.2 <50 1970
1.6 60 3010
11 __ 	
1.5 <50 3150
1.4 ~ 	
	 <50 1075
0.9 <50 825
	 — 	
	 — 	
___ __ ____

-------
highest  level  of contamination occurred in Cottonwood Creek




with  concentrations  ranging  from 12 to 74 pCi/gram  for radium-




226 and  7 to 85 pg/gram  for  uranium  (Table VII  -Station 3).




These values are in  comparison to background concentrations on




the order of 1.0 to  2.0  pCi  of radium-226 and 1.0 to 2.0 pg of




uranium.  In the Cheyenne River, the sediment concentrations




decreased to background  levels in the reach between Stations 5




and 6.   Radium-226 and uranium concentrations at the pedestrian




bridge across Cottonwood Creek (Station 2) were slightly greater




than  background levels.  A possible explanation is periodic




contamination of this location by windblown sand tailings  from




Pile  No. 1  (located  several hundred feet downstream).




      Radium-226 results  for  fish collected from Angostura  Reser-




voir  during the September, 1966,  study are shown in Table  VIII.




Based on a comparison with similar results for fish collected at




locations upstream from uranium mills in the Colorado River




Basin, the Angostura fish were at typical background levels.




This was consistent with the background level of dissolved ra-




dium-226 in Angostura Reservoir.
                              35

-------
              TABLE VIII  RADIUM-226 CONCENTRATIONS IN ANGOSTURA RESERVOIR FISH
                                             SEPTEMBER, 1966
                                  Radium-226 in Flesh
     Species
             (a)
     Black Crappie
     (3)

     Bluegill
     (6)

     Ringed Perch
     (48)
 Live Weight of
Composite Sample
	(gram)	
      105
      151
      727
 pCi/gram
Ash Weight
   0.06
   0.04
   0.47
                            (b)
pC i/kilogr am
 Wet Weight
    0.75
    0.52
    5.3
                      (b)
Radium-226 in Bone

    pCi/gram
   Ash Weight
      0.08
      0.07
      0.10
U)
      (a)  Number in parentheses refers to the number of fish in the composite sample
      (b)  Probably high as the result of the fusion of the sample with the  porcelain dish
          during dry ashing.

-------
                    VI    1971 FIELD STUDY






     The July  1971  field  study was conducted by personnel of the




Environmental  Protection  Agency  (Radiological Activities Sec-




tion, Office of Water Programs)  in cooperation with the South




Dakota State Department of Health.  Sampling extended over the




five day period of  July 26-30.




STUDY PROCEDURES




     Sampling  stations on the Cheyenne River and three tribu-




taries, Cottonwood  Creek, Hat Creek, and Cascade Springs, are




listed in Table IX,    Water samples were collected daily at




the Cheyenne River  and Cottonwood Creek stations (excluding




Stations 9 and 10)  whereas single grab samples were collected




from Hat Creek and  Cascade Springs.  Bottom sediment samples




were collected once at each station during the study period.




     Staff gages  (rated with a pygmy current meter) were used




to meter the flow in Cottonwood Creek at each of the three




sampling stations.  The permanent gaging stations of the U. S.




Geological Survey were used to obtain the flows in the Cheyenne




River above the Edgemont mill and downstream at the State High-




way 71 bridge.   Flow in Hat Creek was also obtained from a




U.S.G.S.  gaging station.





                              37

-------
Ul
CD
                    TABLE IX    COTTONWOOD CREEK AM3 CHEYENNE RIVER
                                     SAMPLING STATIONS - 1971

 Station                                   Description

 1              Cheyenne River just upstream from the State Highway 18 bridge outside
                of Edgemontj at the railroad bridge.

 2              Cottonwood Creek upstream  from mill property  at the county road bridge;
                off State Highway 52.

 3              Cottonwood Creek at the road culvert? downstream  from sand tailings
                Pile Mo. 2.

 4              Cottonwood Creek at confluence with the Cheyenne  River.

 5              Cheyenne River about 1.5 miles downstream from the mill.

 6              Cheyenne River about 6 miles downstream from  the  mill; at Gull Hill Park,

 7              Cheyenne River at ford on  County Road 11.

 8              Cheyenne River at State Highway 71 bridge.

 9              Cheyenne River in the headwaters of Angostura Reservoir.

10              Cheyenne River below Angostura Dam.

11              Hat Creek.

12              Cascade Springs.

-------
      In  addition to the collection of samples at the main




stations on Cottonwood Creek and the Cheyenne River, bottom




sediment samples were also collected in the following areas:




      (a)  Cottonwood Creek:




          Six  locations between the pipeline suspension bridge




          immediately upstream from sand tailings Pile No. 2




          and  the pedestrian footbridge.  Sampling locations




          were selected to assess the variations in radio-




          activity concentrations throughout this previously




          unsampled reach.




      (b)  Cheyenne River:




          Along the edge of the river channel extending from




          the  downstream edge of Pond No. 1 for a distance of




          approximately one mile downstream (seven samples).




          This area was characterized by reddish-brown discolora-




          tion.




Thirteen soil  samples were collected from the bank and dry stream




bed adjacent to Pond No. 2.




     Seepage samples were collected at four locations by ex-




cavating small collection basins in the bank proper:




      (1)  Cottonwood Creek just upstream from the pipeline sus-




          pension bridge (at the bank-stream bed interface).
                              39

-------
      (2)  Cottonwood Creek  several hundred yards upstream from




          the pipeline  suspension bridge  (approximately six




          feet  above the water level in the creek).




      (3)  Cheyenne River just upstream from Pond No. 1  (approxi-




          mately two feet above the stream water level).




      (4)  Cheyenne River about 1 1/2 miles downstream from the




          mill  (just above  the stream water level).




The collection basins were  allowed to flush overnight and the




samples collected the following morning with a polyethlene




beaker or glass pipette.  At the base of the Cheyenne River bank




adjacent to Pond No, 2, seepage was collected from a natural




depression in the dry steam bed.




     Water and bottom sediment samples were collected from




Angostura Reservoir at  thirteen locations, providing complete




coverage of the impoundment.  At each station, the water column




was sampled at the surface  and near the bottom.  Fish samples




for radiological analysis were obtained from the fish sampling




study conducted earlier in  the year  by the Division of Field




Investigations - Denver, Environmental Protection Agency.




     To assess the chemical and radiological characteristics




of ground water in the mill environs,  grab samples of well




water were collected from the Edgemont reservoir well,  Edgemont






                               40

-------
park well, Edgemont airport well, Mines Development process




water well, an abandoned railroad well  (next to Pond No. 2),




and the Cheyenne River campground well  (across the river from




the mill).




SAMPLE PROCESSING PROCEDURES




     Surface water samples and seepage samples were filtered on




the day of collection.  Well water samples were not filtered.




All pH measurements were performed in the field or in the mill




laboratory (within a few hours of collection) with a Yellow




Springs portable meter.




     Chemical and radiochemical analyses will be performed on




the daily water samples collected at the Cottonwood Creek and




Cheyenne River stations as well as 5-day composite samples.




In the case of seepage in the vicinity of Pond No. 1,  analyses




will be performed on a composite sample prepared from the




samples collected on two consecutive days.




     Due to the large number of samples requiring analysis,




the time required for a radium-226 determination, and the com-




plexities of preparing sediment samples for radiochemical




analysis, the quantitive data to be reported herein are largely




limited to pH,  dissolved uranium,  and total alpha radium (dis-




solved)  for water samples.   A complete compilation of the







                               41

-------
 radioactivity results will be the subject of a supplemental




 report.




     Spectrographic metals analysis of the seepage samples was




 performed by the EPA Analytical Duality Control Laboratory,




 Cincinnati, Ohio.




 RESULTS




     Flows in Cottonwood Creek during the study period averaged




 0.1 cfs at the upstream stations, 0.4 cfs at the road culvert,




 and 0.5 cfs at the mouth.  The small increase between the




 culvert and the mouth might represent the drainage into the




 creek from the abandoned railroad well.  However, the small




 difference is within the limits of metering error.  Flow in the




 Cheyenne River was about 5 cfs at the upstream railroad bridge




 and approximately 132 cfs at the State Highway 71 bridge.  The




 increase was largely attributable to Hat Creek (100 cfs)  and




Cascade Springs.  All other tributaries were dry.




     The limited results on water quality conditions in Cotton-




wood Creek and the Cheyenne River are presented in Table X.




These data show the same pattern of water quality degradation




 as observed in past studies.   That is,  due to seepage,  the




dissolved uranium concentration in Cottonwood Creek approached




 a level in excess of 10X the natural level.   In contrast, there





                             42

-------
Station

   1
   2
   3
   4
   5
   6
   7
   8
   9
  10
  11
  12
       TABLE  X    DISSOLVED RADIOACTIVITY
                            IN THE
               CHEYENNE RIVER, COTTONWOOD CREEK,
                HAT CREEK, AND CASCADE SPRINGS

	Dissolved Radioactivity'5'	
Total Alpha
  Radium            Uranium        Thorium
  (pCi/1)
    0.11
    0.67
    0.75
    0.09
    0.17
    0.32
    0.11
    0.10
    0.14
    0.11
    0.08
    0.08
Uranium
 (ug/1)

   16
   26
  147
  177
   28
   14
   19
   14
   10
   12
   24
    5
4
3
2
1
7
5
3
3
3
                                                                            pH
8.
7.
6.
6.
7.
8.
7.
7.

0
0
4
7
8
1
9
9

- 8
- 7
- 6
- 7
- 8
- 8
- 8
- 8
7.7
6.8
.2
.1
.8
.1
.0
.4
.2
.2

(a)   With the exception of single grab samples for Stations  11  and  12,  the values refer
     to 5-day composite samples.

-------
was a negligible concentration increase in the Cheyenne River
downstream  from the mill.  This finding is consistent with the
flow data which showed the dilution capacity afforded by the
Cheyenne River was on the order of 50 times.
     The total alpha radium analysis is commonly used as a
quick guide to the probable radium-226 concentration.  However,
the analysis is not particularly sensitive and should not be
depended upon completely to demonstrate small differences.
For example, the results for the total alpha concentrations in
the Cottonwood CreeTc samples indicated essentially no increase
in the dissolved radium-226 concentration in the reach receiv-
ing seepage, a finding which was not consistent with the urani-
um results.  However, radium-226 determinations on the composite
samples for Stations 2 and 3 showed dissolved concentrations of
0.26 and 3,1 pCi/1, respectively.  This was in complete accord
with the uranium results.
     By visually inspecting the reach of Cottonwood Creek ex-
tending from the pipeline bridge to the pedestrian bridge, the
occurence of seepage from mill ponds was observed to extend
at least as far upstream as a point opposite the north edge of
Pond No. 7.  In this area,  the high bank was observed to be
moist {and "dripping")  to heights of over six feet above the
water surface.   Further,  pooled sections of the creek were
                            44

-------
observed to have the same yellowish-green color as the seepage




samples.  Quantitative support for the conclusion that the mill




ponds were a significant source of seepage was the high concen-




trations of molybdenum (5 to 25 mg/1) in the seepage samples.




Molybdenum is a mill byproduct and dissolved concentrations in




the ponds ranged from 20 to 75 mg/l^aJ.  The seepage samples




also showed traces of iron and manganese «2 mg/1) and, in one




case, chromium, nickel and lead concentrations in the range of




5 to 25 mg/1.




     Areas of reddish-brown (reddish-orange) channel discolora-




tion were observed in Cottonwood Creek as far upstream as the




pedestrian bridge and on both sides of the channel.  This




suggested the possibility that natural sources (springs, etc.)




were partly responsible for the channel discoloration effect.




However, the magnitude of discoloration within the mill proper




indicates that seepage intensifies the problem and the overall




situation is undoubtedly much worse than it would be in the




absence of seepage from the ponds.




     Based on the discoloration of the dry stream channel




adjacent to Pond No.  2,  seepage from the pond has not been corn-
fa)   Analysis of samples collected from the ponds.
                              45

-------
pletely stopped despite the fact that the pond is an inactive




repository for uranium sand tailings.  The pond was not com-




pletely dry but contained a small pool of water in the end




nearest the mill.  Presumably, drainage from the abandoned rail-




road well is entering the pond.




     The impact of seepage in the area of Pond No. 1 was sub-




stantially greater than that observed in 1966.  During the




1966 study, the seepage caused only a small localized effect.




However, in this most recent study, the impact of the seepage




as measured by channel discoloration was observed for a dis-




tance of over one mile downstream.  It was not determined




whether this was the result of differences in Cheyenne River




flow or increased seepage flow.




     Dissolved uranium concentrations in the Angostura Reser-




voir samples were at natural background levels.  The overall




concentration range was 6 to 13 ug/1 with no significant




differences between the surface and "bottom1,1 samples.
                             46

-------
                       ADDENDUM  I

                            TO

            "EVALUATION OF THE IMPACT OF THE
               MINES DEVELOPMENT,  INC. HILL
                            ON
     WATER QUALITY CONDITIONS IN THE CHEYENNE RIVER"
          DISSOLVED MERCURY IN CHEYENNE RIVER,
         COTTONWOOD CREEK, AND SEEPAGE SAMPLES-
                                                  Dissolved Hg
Station                                               (uq/1)

1.  Cheyenne River just upstream from the State       2.1
    Highway 18 bridge outside of Edgemont.

2.  Cottonwood Creek upstream from mill  property      3.5
    at the county road bridge; off State Highway
    52.

3.  Cottonwood Creek at the road culvert; down-       4.2
    stream from sand tailings Pile No. 2.

4.  Cottonwood Creek at confluence with the           1.8
    Cheyenne River.

5.  Cheyenne River about 1.5 miles downstream         0.6
    from the mill.

6.  Cheyenne River about 6 miles downstream from      3.0
    the mill; at Gull Hill Park.

7.  Cheyenne River at ford on County Road II.         3.2

8.  Cheyenne River at State Highway 71 bridge.        0.8

9.  Cheyenne River in the headwaters of Angostura     1.8
    Reservoir.

Seepage into Cottonwood Creek just upstream from the  1.0
pipeline suspension bridge.

Seepage into Cottonwood Creek several hundred yards   2.3
upstream from the pipeline suspension bridge.

-------
                                                  Dissolved Hg
Station                                               (ug/1)

Seepage into the Cheyenne River just upstream from    2.2
Pond No.  1.
NOTE:  Analyses performed on field-filtered samples by the
Division of Field Investigations - Cincinnati, Environmental
Protection Agency.   With the exception of the seepage samples,
the dissolved mercury values refer to 5-day composite samples.

-------
                       ADDENDUM  II

                            TO

            "EVALUATION OF THE IMPACT OF THE
               MINES DEVELOPMENT, INC. MILL
                            ON
     WATER QUALITY CONDITIONS IN THE CHEYENNE RIVER"


1.  Page 1:  In the fourth line, change the superscript ]_/
    to a/.  Similarly, change the footnote designation from
    I/ to a/.

2.  Page 6:  Insert the superscript 1 after the last word on
    this page.

3.  Page 7, Item 2:  "Increases11 should be changed to "In-
    creased".

4.  Page 10, Table I:  Insert superscripts 2,3,4, & 5 after
    U. S. Public Health Service, Federal Radiation Council,
    International  Commission on Radiological Protection (ICRP),
    and the National Committee on Radiation Protection (NCRP),
    respectively.

5.  Page 11:  The  following paragraph is to be added after the
    second paragraph:

          Despite  the fact that the increased radioactivity
    concentrations in Cottonwood Creek and the Cheyenne River
    do not pose a  public health hazard, steps should be taken
    to eliminate or substantially reduce the radioactivity of
    the seepage entering Cottonwood Creek and the Cheyenne
    River.  This is consistent with a policy of minimizing
    the release of radioactive materials to man's environment
    insofar as  is  practicable.  That is, the waste management
    program should be the best available provided the specific
    practices  are  technologically feasible and economically
    reasonable.  Moreover, elimination of the aesthetically
    displeasing discoloration of bank and channel areas re-
    quires curtailment of the seepage from the retention ponds
    (or substantial reduction thereof).

    In the fourth  line of the third paragraph, Insert the super-
    script a/  after "... high-radioactivity solids,.11.  This
    change is  accompanied by the following footnote at the bottom
    of the page:

-------
      a/  A Sample of drained sands from Pile No.  2
          collected during the 1966 study contained
          230 pCi  of radium-226 per gram dry weight.

Page 26:  In the second sentence, insert the superscript
6 after "report".

A section listing  references, Section VII, should  be added
as the last page of the report and noted in the Table of
Contents.

                  VII.  REFERENCES

1.  Tsivoglou, E.  C.f Kalda, D. C.» and Dearwater, J. R.f
    "The Resin-In-Pulp Uranium Extraction Process.  Mines
    Development Company, Edgemont, South Dakota",  Technical
    Report W62-17, U. S, Public Health Service, R. A. Taft
    Sanitary Engineering Center, Cincinnati, Ohio  (1962)

2.  U. S. Public Health Service, "Drinking Water Standards-
    1962", Publication No. 956.

3,  Federal Radiation Council, "Background Material for
    the Development of Radiation Protection Standards",
    Staff Report No. 2 (September, 1961).

4.  International  Commission on Radiological Protection,
    "Recommendations of the International Commission on
    Radiological Protection, as Amended 1959 and Revised
    1962", ICRP Publication No. 6, Pergamon Press, New
    York, New York (1964).

5.  National Committee on Radiation Protection,"Maximum
    Permissible Body Burdens and Maximum Permissible Con-
    centrations of Radionuclides in Air and Water  for
    Occupational Exposure", Handbook 69 (including Adden-
    dum I), U. S.  Department of Commerce, National Bureau
    of Standards (August 1963).

6.  Federal Water  Pollution Control Administration, "Evalua-
    tion of the Radioactivity Levels in the Vicinity of the
    Mines Development, Inc. Uranium Mill at Edgemont, South
    Dakota, 1966", Technical Advisory and Investigations
    Branch, Physical and Engineering Sciences Section,
    Cincinnati, Ohio (May 1967).

-------