WATER QUALITY CONDITIONS
 GRAND LAKE, SHADOW MOUNTAIN LAKE, LAKE GRANBY





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          ENVIRONMENTAL PROTECTION AGENCY
               WATER QUALITY OFFICE
PACIFIC SOUTHWEST REGION
SAN FRANCISCO, CALIFORNIA
                                           CLEA
                                            /ATE]
                  DECEMBER 197O

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           WATER QUALITY CONDITIONS

                      in

GRAND LAKE, SHADOW MOUNTAIN LAKE, LAKE GRANBY
       ENVIRONMENTAL PROTECTION AGENCY
             Water Quality Office
           Pacific Southwest Region
          San Francisco, California

                December 1970

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                 TABLE   OF   CONTENTS


Chapter                                                              Page

       TABLES	       ii

       FIGURES	      iii

   I.  INTRODUCTION	        1

  II.  HISTORY AND STATEMENT OF THE PROBLEM	        4

 III.  OBJECTIVES	        7

  IV.  SUMMARY AND CONCLUSIONS 	        8

   V.  RECOMMENDATIONS	       13

  VI.  DESCRIPTION OF STUDY AREA	       15

 VII.  METHOD OF SURVEY	       21

VIII.  DISCUSSION OF FINDINGS	       25

            EXISTING WATER QUALITY IN THE LAKES	       26
            EFFECTS OF NATURAL INFLOWS UPON THE WATER
                 QUALITY OF THE LAKES	       38
            EFFECTS OF WASTEWATER DISCHARGES UPON NUTRIENT
                 LEVELS IN THE LAKES	       40

       BIBLIOGRAPHY	       45

       APPENDIX:   A:   PHYSICAL AND CHEMICAL DATA FOR LAKE
                           STATIONS	       46
                  B:   COLORADO WATER QUALITY STANDARDS 	       50
                  C:   GLOSSARY	       57

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                           TABLES
No.                             Title

   I.   Annual Operations Summary,  Colorado-Big Thompson
        Project	       17

  II.   Average Monthly Summaries,  1953-68,  Colorado-Big
        Thompson Project	       18

 III.   Sampling Station Locations, Sampling Dates  and  Types  .  .       23

  IV.   Summary of Nutrient Concentrations,  Grand Lake,
        Shadow Mountain Lake,  Lake  Granby.  	       27

   V.   Physical Measurements  at Selected Lake Stations	       30

  VI.   Sedgwick-Rafter Analyses of Plankton Samples  	       34

 VII.   Net Plankton Sample Analyses 	       36

VIII.   Flow and Nutrient Concentrations Measured at  Tributary
        Stations	       39

  IX.   Flow and Nutrient Concentrations Measured in  the Grand
        Lake Sewage Treatment  Plant Outfall, Station  1-16.  ...       41

   X.   Measured Nutrient Input (Lbs/Day) to the Lakes  from
        Natural and Wastewater Flows 	       42

 A-l.   Physical and Chemical  Data  for Lake  Stations	       47
                                 11

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                          FIGURES
No.                                Title                           Page

  1     Grand Lake, Shadow Mountain Lake,  Lake Granby
        Study Area	       2
        Average Monthly Inflow and Outflow-Grand Lake,  Shadow
        Mountain Lake and Lake Granby	      19

        Dissolved Oxygen and Temperature Profiles at Selected
        Stations	      29
                                 iii

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                         I.  INTRODUCTION






     This survey was carried out under the provisions of Section 1(3)




and (5) of Executive Order 11288, "Prevention, Control and Abatement of




Water Pollution by Federal Activities," which states:




     "Pollution caused by all other operations of the Federal




     Government, such as water resources projects and operations




     under Federal loans, grants, or contracts, shall be reduced to




     the lowest level practicable," and "The Secretary of the Interior




     shall, in administering the Federal Water Pollution Control Act,




     as amended, provide technical advice and assistance to the heads




     of other departments, agencies, and establishments in connection




     with their duties and responsibilities under this order,"




     respectively.




     The Superintendent, Rocky Mountain National Park, Midwest Region,




National Park Service, in a letter dated April 19, 1968, requested the




assistance of the Federal Water Pollution Control Administration to




determine the measures necessary to prevent the pollution of Lake Granby,




Shadow Mountain Lake and Grand Lake (Figure 1).  Shadow Mountain Lake




and Lake Granby are within the Shadow Mountain National Recreation Area




which is part of his jurisdiction.  However, the survey included all




three lakes since their water quality is interdependent.




     In response to this request, the Colorado River-Bonnevilie Basins




Office, Federal Water Pollution Control Administration, conducted a




preliminary survey from August 28-September 6, 1969, of Shadow Mountain




Lake, Grand Lake, Lake Granby and their tributaries.

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                     SCALE  IN MILES
Figure  I. Grand Lake, Shadow  Mountain  Lake,  Lake  Cranbv Study  Area

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Acknowledgments




     Principal Authors:  Christopher M. Timm




                         Charles M. Seeley




     We acknowledge the assistance provided by personnel of the National




Park Service and the Bureau of Reclamation during this survey.

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            II.  HISTORY AND STATEMENT OF THE PROBLEM






     The establishment of the Rocky Mountain National Park in 1915 began




the development of this important recreational area.  The proximity of




Grand Lake, which is the largest natural body of water in Colorado, to




the National Park made the region around the lake a popular summer home




and resort area.  Then, in the late 1940's, the U. S. Bureau of Recla-




mation, as part of the Colorado-Big Thompson Project, constructed Granby




Dam and Shadow Mountain Dam forming Lake Granby and Shadow Mountain Lake




respectively.  The primary purpose for the construction of these dams




was to supply irrigation water for eastern Colorado.  Today, the water




of these lakes serve myriad purposes on both sides of the Rockies such




as power production, public water supplies, fishing, boating, and body




contact sports.  The three lakes and the surrounding area on the western




slope have become one of the most popular recreational spots in Colorado




and are visited by tens of thousands of people annually.




     The sewage treatment systems that serve these thousands of visitors




are primarily pit or vault toilets or septic tanks.  There are two collec-




tion and treatment systems in the area.  The Shadow Mountain Government




Camp is sewered and treatment is provided by septic tanks, subsurface




contact filters and chlorination.  This system was constructed in 1939




and enlarged in 1949.  The effluent is discharged directly into Shadow




Mountain Lake.  Part of the Community of Grand Lake is served by a




trickling filter plant built in 1951 which discharges to Shadow Mountain




Lake.  The population served by this plant varies from approximately 150




people during the winter to 4,000 people during the summer  (recreation

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season).  The remainder of the community is served by individual dis-




posal systems.




     Partially treated wastewater has been discharged into Shadow




Mountain Lake for more than 20 years, but evidence of pollution has not




become apparent until recent years.  On October 2, 1967,  the Public




Health Service consultant to the National Park Service surveyed Shadow




Mountain Lake at the request of the National Park Service.  This survey




resulted from the complaints of local residents and businessmen located




on the west side of Shadow Mountain Lake.  The nature of  the complaints




were varied but were along the following general lines:




     1.  Large accumulations of persistent foam.




     2.  Algae formations along the shoreline and on boats anchored in




         docking areas.




     3.  Floating solids and sludge deposits.




     4.  Turbidity caused by sludge in water.  (This was  subsequently




         identified as algae bloom.)




     The observed conditions in Shadow Mountain Lake were:




     1.  Light to moderate algae growth along the west shoreline from the




         Headquarters area to Grand Lake.




     2.  Some small accumulations of persistent foam at various points




         along the shoreline.




     3.  Moderate algae bloom along the west shoreline.




     4.  Generally heavy turbidity in the western portions of the Lake




         apparently caused by sludge accumulations.




     From these observations, the Public Health Service consultant in a




letter to the Superintendent, Rocky Mountain National Park, dated October 5,

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1967, stated that, "Results of the investigation, while not conclusive




due to lack of quantitative evidence, do indicate the presence of domes-




tic pollution of sufficient strength to create public health hazards."




     In May 1968, the Colorado Water Pollution Control Commission




adopted general standards applicable to all waters of the state.  In




addition, the three lakes have been classified as suitable for potable




water supplies (Class A) and for cold water fisheries (Class B^) .  The




specific standards for these uses include dissolved oxygen not less than




6.0 mg/1, pH between 6.5 and 8.5, and temperature not to exceed 70F




(21.1C). The complete water quality standards for these waters are




reproduced in Appendix B.




     The Secretary of the Interior in approving the Colorado Water Quality




Standards requested that the three lakes also be classified for body




contact sports (63) based upon the existing recreational uses.  The




Commission has conducted some sampling of the lakes over the past two




years to obtain background data for adding this classification.  The




addition of a Bo classification would make the bacteriological criteria




for the lakes more stringent.  The specific standards applicable to




recreational waters classified for body contact sports are also repro-




duced in Appendix B.




     The increasing recreational use of this area, the occurrence of




nuisance algae growths, and the apparent pollution of these lakes brought




about the National Park Service request to the Federal Water Pollution




Control Administration for assistance in defining the effects of waste-




water on these lakes and in developing the necessary corrective measures.

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                           III.  OBJECTIVES






     The primary objective of this survey was to develop the water pollu-




tion control measures necessary to protect and preserve the recreational




and other uses of these lakes.  To accomplish this, the following specific




objectives were pursued:




     1.  To determine the existing physical, chemical, and biological




         conditions in the lakes and tributaries.




     2.  To determine the nutrient inputs to the lakes from natural




         runoff.




     3.  To locate and identify the wastewater inflows to the lakes and




         measure their nutrient loads.




     4.  To evaluate the pollution potential from increased recreational




         use in the surrounding area.




     5.  To recommend the actions necessary to abate the present pollution




         and protect the lakes from accelerated eutrophication.

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                      IV.   SUMMARY AND CONCLUSIONS






1.  The laboratory analyses of samples collected from Grand Lake,  Shadow




    Mountain Lake, and Lake Granby show that the inorganic nitrogen con-




    centrations were uniform throughout the lakes and averaged 0.107 mgN/1




    over the survey period.  This concentration is approximately one-third




    of that considered necessary to initiate an algae bloom (0.30 mgN/1).




    The orthophosphate concentration in the three lakes averaged 0.0255




    mgP/1 and ranged from 0.0084 mgP/1 in Grand Lake to 0.0526 mgP/1 in




    Shadow Mountain Lake.   This average concentration greatly exceeds the




    minimum level of orthophosphate considered by authorities in the field




    as necessary to sustain an algae "bloom" (0.010 mgP/1).  In addition,




    the orthophosphate concentration at the bottom of Lake Granby ranged




    from two to thirteen times greater than surface concentrations indica-




    ting the possibility that anaerobic respiration may take place in the




    benthic regions.




2.  The average inorganic  nitrogen, orthophosphate, and total soluble




    phosphorus concentrations in the natural runoff from the surrounding




    watershed were 0.07 mgN/1, 0.007 mgP/1, and 0.064 mgP/1 respectively.




    The inorganic nitrogen and orthophosphate concentrations are much lower




    than the suggested limits of 0.30 mgN/1, and 0.010 mgP/1 respectively,




    but the total soluble phosphorus concentrations exceeded the suggested




    limit of 0.05 mgP/1.




3.  The domestic wastewater sources in the three lakes area are the Grand




    Lake wastewater treatment facility, the Shadow Mountain Government Camp




    wastewater treatment facility and the numerous individual subsurface

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                                                                     9




    disposal systems serving homes and businesses along the shores.   Efflu-




    ents from the two treatment facilities are the largest point sources of




    nutrients entering the lakes.   Analyses of the Grand Lake wastewater




    treatment facility effluent,  the largest wastewater discharge,  showed




    average inorganic nitrogen, orthophosphate and total soluble phosphorus




    concentrations of 13.43 mgN/1, 5,21 mgP/1 and 6.14 mgP/1 respectively.




    In terms of total load, this  plant provided only 0.28 percent of the




    total inflow to the lakes but supplies 36.0 percent of the inorganic




    nitrogen, 68 percent of the orthophosphate and 21.5 percent of total




    soluble phosphorus loads to the lakes during this survey.  Therefore,




    advanced waste treatment methods including at least 80 percent ortho-




    phosphate removal, wastewater export, or total containment of effluents




    in ponds will be required to  preserve the present water quality and re-




    duce the nutrient concentrations in the lakes.




4.  The concentration of orthophosphate, the phosphorus form most readily




    available for biological growth, is sufficiently high that any one or




    all three of the lakes could  sustain nuisance algae blooms.  Waste-




    waters contributed the major  portion of orthophosphate to the lakes




    with the Grand Lake wastewater treatment facility alone contributing




    68 percent of the measured orthophosphate load.   It is estimated, based




    upon data obtained in this survey, that the combined wastewater flows




    contribute more than 80 percent of the annual orthophosphate load.  The




    low inorganic nitrogen concentrations existing in the lakes and inflows




    and the presence of Aphanizomenon flos-aquae and Anabaena sp.,  both




    atmospheric nitrogen fixers,  indicate that the lake waters are nitrogen




    deficient and the phytoplankton growth is nitrogen limited.

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                                                                    10




5.   Temperature measurements showed that Lake Granby and  Grand  Lake  had




    thermally stratified layers although thermoclines,  as defined in the




    glossary, were not in evidence.  Shadow Mountain Lake was generally




    isothermal as expected because of its shallow depth and the effects




    of mixing.




6.   The dissolved oxygen concentration in the near surface waters of all




    three lakes exceeded the 6.0 mg/1 standard for cold water fisheries at




    all stations except for Station L-5 on Shadow Mountain Lake.   The dis-




    solved oxygen concentration at this sampling  station, which is located




    near the west shore of the Lake between two marinas,  was 5.6 and 5.2




    mg/1 on September 1 and 3, 1969, respectively.  The dissolved oxygen




    concentrations were 3.0 mg/1 or greater throughout  the depths of all




    three lakes.  Grand Lake and Shadow Mountain  Lake had dissolved  oxygen




    profiles approximating an orthograde pattern,  but the profile in Lake




    Granby approached a clinograde pattern with concentrations  of less than




    6.0.mg/1 in the hypolimnion.   This oxygen deficit is  caused by a natural




    deposition of oxidizable organic material in  Lake Granby during  spring




    runoff.   Because much of the organic material is probably either suspended




    in natural .runoff or photosynthesized in  the  lakes, the depletion of dis-




    solved oxygen in the hypolimnion of Lake  Granby is  not readily correct-




    able and will worsen with time.  There is no  data available which re-




    flects the effects of this organic material upon the  dissolved oxygen




    concentration of Lake Granby during other periods of  the year.  Since




    this lake is stocked regularly with game  fish, the  combined effects




    of the organic matter and ice cover on the dissolved  oxygen concen-




    trations and game fishery should be investigated.

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                                                                     11  .




7.  The Secchi Disk transparency measurements indicate that the euphotic




    zone extended through the epilimnion into or below the zone of greatest




    temperature change in the three lakes.   In addition,  the Sedgwick-Rafter




    analyses of plankton samples did not show any variation between total




    plankton counts with depth.   This indicates that the  entire epilimnion




    receives sufficient light energy to support photosynthesis.   Total




    phytoplankton analyses by the Sedgwick-Rafter method  gave maximum counts




    of 527 organisms/ml in Grand Lake,  272  organisms/ml in Shadow Mountain




    Lake,  and 221 organisms/ml in Lake  Granby.   Eight of  sixteen phyto-




    plankton samples had less than 200  organisms/ml which indicate low




    to moderate biological productivity in  all the lakes.   Numerically,




    Dinobryon sp.,  a yellow-green algae which causes taste and odor problems




    when present in high concentrations, was the most abundant organism.




    The blue-green algae Aphanizomenon  flos-aquae which is capable of fixing




    atmospheric nitrogen was discernable in the surface waters of all three




    lakes  and was the predominant organism  recovered in net plankton samples.




8.  The biological results showed no evidence of an algal "bloom" during  this




    survey.   On the basis of dissolved  oxygen and nutrient concentrations,




    depth  of the euphotic zone,  and plankton populations,  none of the three




    lakes  could be considered eutrophic. The productivity of Granby and




    Grand  Lakes is such that their classifications are between oligotrophic




    and mesotrophic.  Shadow Mountain Lake  was the most productive and




    could  be classed as a mesotrophic lake.




9.  The existing water quality of the three lakes is equal to or better than




    the standards established for the classified uses of  the three lakes  ex-




    cept that the dissolved oxygen concentrations in the  hypolimnion of Lake

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                                                                        12
Granby were less than the established standards of 6.0 mg/1.  It is




possible that natural sources of organic material are the major cause




of the depressed dissolved oxygen.  The limited scope and duration of




the study, however, did not permit a complete evaluation of this situ-




ation, and further study is indicated to provide a basis for remedial




action.

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                                                                         13






                         V.  RECOMMENDATIONS






     In order to protect and/or enhance water quality and water uses of




Grand Lake, Shadow Mountain Lake, and Lake Granby, it is recommended:




     1.  That the classification, 63, Body Contact Recreation, be added




         to the water uses established for the three lakes.




     2.  That the Colorado Water Pollution Control Commission establish




         water quality standards for the three lakes and their tribu-




         taries containing nutrient criteria and required waste treatment




         and other control measures which will not only prevent further




         enrichment of these waters but enhance their quality.




     3.  That immediate action be taken to control and treat all wastewaters




         in the three-lakes watershed by either, (a) total containment,




         (b) advanced waste treatment which will limit the flow weighted




         inorganic nitrogen, orthophosphate and total phosphorus concen-




         trations of the combined natural and wastewater inflows to




         the lakes of less than 0.30 mgN/1, 0.010 mgP/1 and 0.050 mgP/1,




         respectively, or  (c) secondary waste treatment with discharge to




         the Colorado River below Lake Granby.




     4.  That the Federal  agencies immediately implement recommendation




         number 3 in order to control the contribution to water pollution




         from their activities or facilities.  In conjunction with this,




         the Federal agencies must cooperate with and assist the local




         government in the development and implementation of an adequate




         regional wastewater treatment system.

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                                                                   14






5.  That a comprehensive plan for water pollution control and quality




    management be developed for the three-lakes watershed.  This




    plan should include a regional wastewater collection, treatment




    and disposal system to be fully implemented no later than 1975.




    The plan must also provide the controls necessary to insure




    that future development will not degrade the water quality of




    the three lakes.




6.  That the water quality of the lakes, natural inflow and waste




    sources be monitored periodically to determine seasonal changes




    in nutrient loads, and to evaluate the effectiveness of any




    improvements or additions made to the present wastewater treat-




    ment facilities.  The National Park Service, the Bureau of




    Reclamation, and the State of Colorado should make arrangements




    to accomplish this monitoring.

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                                                                          15





                    VI.  DESCRIPTION OF STUDY AREA






     Lake Granby and Shadow Mountain Lake are manmade reservoirs linked




by channels to Grand Lake, the largest natural body of water in Colorado.




The three lakes are located on the headwaters of the Colorado River




(Figure 1) .




     Grand Lake is a glacial lake naturally impounded by the terminal




moraines of the glaciers that created the present valleys of the North




Inlet and East Inlet (5).  It has steep sides along the northern and




eastern shores and is shallow along the southern and western shores formed




by the terminal moraines.  The lake has a maximum depth of greater than




200 feet (69.9M), a surface area of 504 acres (2 sq.Km), and a normal




water surface elevation of 8367 feet (2548M) (11).




     Shadow Mountain Lake is impounded by a low dam across the Colorado




River below Grand Lake and provides passage and flow regulation for water




being diverted to the eastern slope of the Colorado Rockies through the




Alva B. Adams Tunnel.  This lake lies wholly within the Shadow Mountain




National Recreation Area with the eastern shore forming  the boundary for




the Rocky Mountain National Park.  Most of the land along the west and




north shores is privately owned and has been developed as summer home




sites, resorts and marinas.  Shadow Mountain Lake has a maximum capacity




of 18,359 acre-feet (22 .6x10^) , an active storage of 1850 acre-feet




(2.3x10 M ), and a maximum surface area of 1852 acres (7.5 sq.Km.).  The




average and maximum depths are 10 (3M.) and 37 feet (11.3M.), respectively.




The maximum water surface elevation is 8367 feet (2548M) above sea level




and the maximum drawdown head is 20 feet (6.1M.).  A check structure is

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                                                                          16



located between Shadow Mountain and Grand Lake so the water surface eleva-


tion of Shadow Mountain Lake can be lowered without affecting Grand Lake.


However, the usual operating practice is to maintain Shadow Mountain Lake


at the same elevation as Grand Lake. (11)


     Lake Granby, which stores the majority of the water supply for the


Colorado-Big Thompson Project, is formed by Granby Dam and four dikes which


impound the waters of the Colorado River and the water pumped from Willow


Creek Reservoir.  This lake lies wholly within the Shadow Mountain National


Recreation Area and forms part of the boundary for the Rocky Mountain


National Park.  Most of the establishments along the shores of Lake Granby


are boat launching areas, parks, and campgrounds for the summer tourists.


Lake Granby has a maximum capacity of 540,000 acre-feet (666xlOT4 ), and an


active storage of 466,000 acre-feet (575xl0^r).  The lake covers a surface


area of 7,260 acres (29.4 sq.Km.) at the maximum water surface elevation


of 8,280 feet (2521M) above mean sea-level.  The average and maximum depths


are 74 (22.5M) and 200 feet (60.9M), respectively.  The outlet at the face


of Granby Dam is set between elevations 8150 (2481.7M) and 8190 feet (2493.8M),


but active storage is considered to extend downward to elevation 8186 feet


(2492.6M) providing a maximum drawdown head of 94 feet (28.6M) (11).


     The annual operation summary and average monthly summaries for the


Colorado-Big Thompson Project are shown in Tables I and II respectively.


Analysis of the average monthly inflows and outflows, which are plotted on


Figure 2, shows two general flow patterns through the lakes.  Sixty percent


of the average annual inflow generally occurs in May and June.  The average


diversion through the Adams Tunnel during these same months was about 24,900

                  6 ^
acre-feet (30.7x10 M ).  The basic flow pattern is from Grand Lake and

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                    TABLE I  Annual Operations Summary. Western Slope Features
of the Colorado-Big Thompson Proiect








End of Year Storage

Year

1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
Total
Inflow
AFl'
200,756
147,918
204,082
266,737
446,151
243,797
251,832
287,785
297,763
317,878
193,674
221,953
375,316
166,014
283,981
248,630
Lake
Granby
AF!/
427,335
230,050
168,436
188,398
418,061
387,444
352,567
365,772
460,852
437,977
306,412
190,117
346,635
214,714
236,878
259,640
Shadow
Mtn.Lake
AFl/
18,149
18,111
18,111
17,780
17,542
17,725
17,578
17,707
17,854
17,872
17,872
17,670
17,651
17,633
17,651
17,578
1953-1968

Pumped to
Shadow
Mtn.Lake
AFi/
164,919
278,644
195,386
188,783
161,792
228,916
214,261
207,912
130,025
173,072
239,452
253,022
141,021
221,362
196,016
167,418


0 u t f
Adams
Tunnel
AF-i'
205,247
320,794
237,108
220,735
188,541
243,416
257,920
244,871
173,562
237,105
297,426
310,074
188,371
271,091
232,666
196,213


lows
Colorado
River
AF!/
25,767
25,738
25,712
25,745
25,573
25,218
25,660
25,683
24,426
98,931
24,617
27,074
28,846
24,971
28,064
28,673




Seepage
AF!/
6,701
3,446
854
726
2,594
5,588
3,906
3,895
3,756
5,419
3,178
1,302
1,600
1,892
1,069
1,075
AVG.
259,642
311,956
17,780
197,625
239,032
30,669
2,938
I/  To convert to M  multiply by 1233.5.

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                    TABLE II  Average Monthly Summaries. Western Slope Features
of the Colorado -Big Thompson Proiect








End of Month Storage

Month

Jan.
Feb.
Mar.
Apr.
May
June
July
Aug.
Sept.
Oct.
Nov.
Dec.
Total
Inflow
AF!/
3,725
3,206
3,700
14,052
64,574
97,246
36,848
12,643
7,815
6,655
5,093
4,085
Lake
Granby
AF!/
295,782
282,662
252,796
253,582
297,200
380,158
392,470
381,529
368,546
352,906
334,141
311,956
Shadow
Mtn. Lake
AF!/
17,827
17,819
17,869
17,465
17,451
17,527
17,673
17,706
17,715
17,689
17,739
17,780
1953-1968

Pumped to
Shadow
Mtn. Lake
AF!/
24,275
21,838
23,312
13,240
3,838
1,386
11,152
17,346
17,834
18,150
21,247
24,007






Outflows
Adams
Tunnel
AF!/
25,070
22,512
24,304
17,015
16,072
8,781
17,558
20,809
19,078
20,719
22,332
24,782
Colorado
River
AF!/
1,212
1,110
1,614
2,614
4,933
5,274
6,564
2,432
1,233
1,288
1,187
1,208

Seepage
AF!/
258
213
205
178
171
199
276
312
300
300
274
252
I/  To convert to M3 multiply by 1233.5.
                                                                                                       00

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                                                        19
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	 TOTAL OUTFLOW




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JAN  FEB  MAR  APR  MAY  JUN  JUL ' AUG* SEP* OCT* NOV  DEC
                         MONTHS

   Figure 2. Average Monthly Inflow & Outflow, Grand  Lake,
         Shadow Mountain Lake &  Lake  Cranby

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                                                                           20
Shadow Mountain Lake into Lake Granby during this time.



     During the period August through April, the flow through the Adams



Tunnel greatly exceeds the areal runoff into the lakes and water must be



pumped from Lake Granby for diversion to the eastern slope.  During this



time, the flow pattern can generally be described as being from Lake Granby



through Shadow Mountain Lake and Grand Lake into the Adams Tunnel.



     To protect the existing fisheries in the Colorado River, the U. S.



Bureau of Reclamation maintains minimum flow below both Shadow Mountain and



Granby Dams.  The minimum releases from Shadow Mountain Dam are 25 cfs


     3                                                    3
(.7 M /Sec) during October through April and 50 cfs (1.4 M /Sec) during



May through September.  The minimum releases from Granby Dam are 20 cfs



(.6M3/Sec) during September through April, 75 cfs (2.1 M3/Sec) during May



through July, and 40 cfs (l.lM3/Sec) during August.

-------
                                                                           21
                        VII.  METHODS OF SURVEY






     The survey of existing water quality conditions was accomplished in




two phases.  The physical and chemical survey was conducted from August 28,




to September 3, and the biological survey on September 5 and 6, 1969.




During the physical and chemical survey, 14 stations on the three lakes




and 12 stations on tributaries and waste sources were sampled to estab-




lish the existing physical and chemical quality parameters (Figure 1) .




     The Grand Lake wastewater treatment facility effluent (1-16) and




Shadow Mountain Reservoir near the channel to Grand Lake (L-4) were sampled




daily and the Grand Lake Stations (L-l, L-2, L-3) were sampled every other




day.  All other stations were sampled as shown in Table III.  Water quality




samples and measurements were taken at mid-depth from all inflow and out-




flows.  At the lake stations, water quality samples and measurements were




taken at the surface and the bottom except where the total depth was 20




feet (6.1M) or less.  In the latter cases, water quality samples and




measurements were taken at mid-depth.




     Temperature, conductivity, dissolved oxygen concentration and pH were




measured at each point where a sample was collected for nutrient analyses.




The samples were analyzed using standard procedures:




     1.  Nitrate - soluble inorganic nitrogen.




     2.  Ammonia - evidence of organic pollution.




     3.  Total Kjeldahl nitrogen - total organic nitrogen.




     4.  Orthophosphates - Phosphorus available for instant biological use.




     5.  Total soluble phosphates - total phosphorus available for biolo-




         gical use.

-------
                                                                          22
These analyses were performed by the Services Branch,  Colorado River-




Bonneville Basins Office, Federal Water Pollution Control Administration.




     During the biological survey, nine lake stations, three on each lake,




were sampled to establish the biological quality of the lakes.  During




the biological sampling, light penetration was measured using the Secchi




Disk;  water samples were collected for phytoplankton analysis; and net




drags or vertical hauls were made at selected stations for a qualitative




phytoplankton analysis.  In addition, the temperature and dissolved oxygen




concentrations at various depths were measured in all three lakes.  The




biological analyses were performed by personnel of the Services Branch,




California-Nevada Basins Office, Federal Water Pollution Control Admini-




stration.




     The survey areas and sampling station locations are depicted in




Figure 1.  The location, dates and types of sampling for each station are




listed in Table III.

-------
                                                                           23
TABLE III   Station Location,  Dates and Type of Samples  Collected,  1969

No.
1-1
1-2
1-3
1-4
1-5
1-6
1-7
1-9
1-10
1-11
>
1-13
I-16I/
L-l
L-2
L-3
STATION
Location
Arapaho Creek at Bridge
Roaring Fork at Mount
Twin Creek at Mouth
Columbine Creek at Mouth
East Inlet at Mouth
North Inlet at Grand Ave .
Bridge
Little Columbine Creek at
Gaging Station
Colorado River at Gaging
Station near Mouth
Soda Creek at Hwy 34 Crossing
Stillwater Creek at Gaging
Station
Colorado River below Lake
Granby at Bridge
Grand Lake Wastewater Treat-
ment Facility Outlet
Grand Lake about 100 yards
east of west portal
Grand Lake between the two
marinas on Grand Beach
Grand Lake about 50 yards
out from house with slide
DATES AND TYPE OF SAMPLES COLLECTED
Physical
Aug. 28
Aug. 28
Aug. 28
Aug. 28
Aug. 28
Aug. 28
Sept. 2
Aug. 28
Aug. 28
Sept. 2
Aug. 28
Aug. 28
Sept. 2
Aug. 28
Aug. 28
through
Sept. 3
Aug. 28&30
Sept. 1&3
Aug. 28&30
Sept. 1&3
Aug. 28&30
Sept. 1&3
Chemical
Aug. 28
Aug. 28
Aug. 28
Aug. 28
Aug. 28
Aug. 28
Sept. 2
Aug. 28
Aug. 28
Sept. 2
Aug. 28
Aug. 28
Sept. 2
Aug. 28
Aug. 28
through
Sept. 3
Aug. 28&30
Sept. 1&3
Aug. 28&30
Sept. 1&3
Aug. 28&30
Sept. 1&3
Biological












Sept. 6
Sept. 6
Sept. 6
I/ Bacteriological Quality determined by Colorado State Health Department (2)

-------
                                                                           24
TABLE III (Continued) Station Location, Dates and Type of Samples Collected
1969

No.
L-4


L-5


L-6i/

L-7

L-&1/


L-9


L-10


L-ll

L-12^

L-131/

L-lO/

STATION
Location
Shadow Mountain Lake between
entrance to Grand Lake
channel and marina.
Shadow Mountain Lake between
Lake Kove and Shadow Mountain
Marina.
Shadow Mountain Lake at
center of lake ,
Shadow Mountain Lake about
50 yards from east shore.
Shadow Mountain Lake at
National Park Service boat
dock.
Lake Granby 100 yards out from
Stillwater Campground boat
launch.
Lake Granby in Rainbow Bay
midway between boat ramp and
Lochleven Cove.
Lake Granby at Center

Lake Granby 300 yards north
of Twin Creek in Grand Bay.
Lake Granby about 400 yards
south of Twin Pines Point.
Lake Granby in the middle of
Arapaho Bay .
DATES AND TYPE OF SAMPLES COLLECTED
Phys ical
Aug. 28
through
Sept. 3
Aug. 29
Sept. 1&3

Aug. 29
Sept. 2
Aug. 29
Sept. 2
Aug. 29&30


Aug. 29
Sept. 2

Aug. 29
Sept. 2

Aug. 29
Sept. 2
Aug. 29
Sept. 2
Aug. 29

Aug. 29
Sept. 2
Chemical
Aug. 28
through
Sept. 3
Aug. 29
Sept. 1&3

Aug. 29
Sept. 2
Aug. 29
Sept. 2
Aug. 29&30


Aug. 29
Sept. 2

Aug. 29
Sept. 2

Aug. 29
Sept. 2
Aug. 29
Sept. 2
Aug. 29

Aug. 29
Sept. 2
Biological
Sept. 5





Sept. 5



Sept. 5








Sept. 6

Sept. 6

Sept. 6



\l Bacteriological Quality determined by Colorado State Health Department (2)

-------
                                                                          25






                      V.  DISCUSSION OF FINDINGS






     The intent of this survey was to evaluate the existing water quality




conditions, define the effects of wastewaters, and recommend remedial




measures to protect the lakes.  To accomplish this, the analytical results




of this survey were compared with established water quality standards where




applicable and with the recommended limits for those parameters for which




standards have not been set.




     With the exception of nutrient concentrations, the Colorado Water




Quality Standards established limits for all the physical and chemical




parameters measured during this survey.  The limiting values for the




former, which are discussed below, are based on previous work reported in




the literature.




     Several investigators (3,6)  have concluded that concentrations of




inorganic nitrogen exceeding 0.30 mgN/1 in lakes could be expected to




produce nuisance algae blooms, although it has also been shown that many




blue-green algae species, particularly Anabaena and Aphanizomenon, can fix




sufficient amounts of atmospheric nitrogen to sustain high productivity.




For evaluation of the data obtained in this survey, an inorganic nitrogen




limit of 0.30 mgN/1 in Lakes appears reasonable.  The limiting value is




also 0.30 mgN/1 for all tributary streams sampled.




     Although much has been written about the effects of phosphorus upon




algae growth, the level of phosphorus necessary to sustain a nuisance algae




growth has yet to be quantified.  From the results of previous investigations




(6,7,8), it appears that the orthophosphate concentration in a lake must be




limited to 0.01 mgP/1 to prevent algae blooms.  With respect to the

-------
                                                                           26


concentrations in streams, Mackenthun (7) has recommended that the total


soluble phosphorus concentrations be limited to 0.05 mgP/1.  However, this

limit is considered applicable only during low-flow conditions and the

average annual orthophosphate concentration in the stream should not exceed

the limit proposed earlier for the lakes.


EXISTING WATER QUALITY IN THE LAKES

     Individual results of the nutrient samples collected from the lakes

for analysis are shown in Table A-l in the Appendix.  These data have been

summarized and the high, low and average orthophosphate and total soluble

phosphate and inorganic nitrogen concentrations are shown in Table IV.

Comparing the summary of data with the nutrient criteria discussed above,

all three lakes are nitrogen deficient but contain sufficient phosphorus

concentrations to support algae "blooms."  In such circumstances, only

those algae species capable of providing their own nitrogen by atmospheric

nitrogen fixation can cause "blooms."


     The nutrient levels in Grand Lake (Station L-l, L-2, L-3) and Shadow


Mountain Lake (Station L-4 through L-8) did not vary appreciably with depth.


The only exception is Station L-8 where the inorganic nitrogen, orthophos-

phate and total soluble phosphate concentrations measured on August  29,

1969, were approximately four times the lake averages shown in Table IV.

One possible explanation is that the effluent from the Shadow Mountain

Government Camp wastewater treatment facility   may have been flowing


across this sampling station as a density current at the time of sampling.


     The samples from Lake Granby showed orthophosphate concentrations two
 ,
to thirteen times greater at the lake bottom than at the surface, and

dissolved oxygen content and pH were consistently lower at the lake bottom.

-------
     TABLE IV  Summary of Nutrient Concentrations - Grand Lake,  Shadow Mountain  Lake,  Lake  Granby


                                                                                           Total
                               Inorganic Nitrogen           Orthophosphate           Soluble  Phosphorus
Grand Lake

Shadow Mountain Lake

Lake Granby

All Three Lakes
High
mgN/1
.12
.62
.29
.62
Low
mgN/1
.06
.07
.06
.06
Avg
mgN/1
.082
.145
.096
.107
High
mgP/1
.0293
.1565
.0880
.1565
Low
mgP/1
.0032
.0064
.0032
.0032
Avg
mgP/1
.0084
.0526
.0154
.0255
High
mgP/1
.109
.254
.111
.254
Low
mgP/1
.013
 .013
.013
.013
Avg
mgP/1
.043
.065
.070
.059

-------
                                                                     28






From these facts, it would appear that organic decomposition in the




hypolimnion was converting organic phosphate to soluble polyphosphates




and reducing the dissolved oxygen concentration.  Since pH generally



                                            (3)
parallels the dissolved oxygen concentration   , the hypolimnion may




become acidic during the course of the summer; thereby, increasing the




rate of hydrolysis of polyphosphates to orthophosphates^  ^.  Since



these physical phenomena were not present in either Grand Lake or Shadow




Mountain Lake, it is reasonable to assume that Lake Granby has the highest




organic content.  This may be the result of either the failure to properly




clear the lake bed prior to impoundment or the transportation of the




organics deposited in the upper lakes into Lake Granby during the spring




runoff period or both.




     Although a true thermocline was not found in any of the lakes, both




Grand Lake and Lake Granby have two distinct temperature zones and could




be classified as thermally stratified (Table V, Figure 3).  The use of




the terms, epilimnion and hypolimnion, therefore, will be used in dis-




cussing the waters above and below that zone of greatest temperature




change.  In Shadow Mountain Lake, the shallow nature of the reservoir,




the mixing due to wind action, and the pumping of colder water from the




depths of Lake Granby into Shadow Mountain Lake prevent thermal stratifi-




cation.




     The dissolved oxygen concentrations measured during the first phase




of this survey are shown in Table A-l in the Appendix.  Dissolved oxygen




profiles were measured at selected stations during the biological phase




of the survey as shown in Table V and Figure 3.  The dissolved oxygen

-------
               10
          DISSOLVED OXYGEN -  MG/L
10     0     5    10         0	   5
                     10
                                     10     0
                               10
                                             TEMPERATURE -  C
         10    20    0     10    20    0     10    20         0     10    20    0     10    20    0    10   20
   10
  20
   30
  40
H- 50
^ 60
  70
  80
  90
  100
                l-l
  L-2
1-3
L-11
1-12
                                            LEGEND
                                            DISSOLVED OXYGEN
                                            TEMPERATURE
L-13
                      GRAND LAKE
                                                                         LAKE GRANBY
                 Figure  3.  Dissolved  Oxvgen  and Temperalure Profiles at Selected Stations

-------
                              TABLE V  Physical Measurements at Selected Lake Stations
Station
Number
L-l









L-2






L-3


L-4
L-6
L-8
Date
and Time
Sept. 6
1530









Sept. 6
1715






Sept. 6
1500


Sept. 5
1330
Sept. 5
1245
Sept. 5
1145
Sample . ,
Depth Ft.-'
2
10
20
30
40
50
60
70
80
90
100
2
10
20
30
40
60
80
100
2
10
20
30
0
7
0
16
0
8
Temperature
C
16.6
16.6
15.0
10.5
8.3
7.8
7.2
6.7
6.0
5.5
5.5
16.0
16.0
13.9
11.6
8.3
7.2
6.1
5.5
15.5
15.5
12.7
9.4
15.0
15.0
15.2
15.0-
15.0
14.5
Dissolved
Oxygen
tng/1
7.6
7.6
7.3
6.6
7.0
7.4
7.6
7.6
	
6.9
6.4
7.6
7.6
6.6
6.4
7.0
7.6
7.2
	
7.6
7.6
6.4
6.4
7.6
7.3
7.2
7.7
7.4
7.2
DJD xlOO
Saturation
104
104
97
80
80
84
85
83
	
74
68
103
103
86
79
80
84
78
	
102
102
81
81
101
97
97
103
99
95
Secchi Disk . ,
Transp. Ft. Euphotic Zone Ft.-=-'
13.5 36.4









12.5 33.5









7 Depth of Lake
7.2 Depth of Lake
8.0 Depth of Lake
!_/ To convert to meters,  multiply by .3046.
US
o

-------
                        TABLE V  (Continued)  Physical Measurements  at  Selected  Lake Stations
Station Date
Number and Time
L-ll Sept. 6
1245







L-12 Sept. 6
1140


L-13 Sept. 6
1020






Sample
Depth Ft.!/
2
10
20
30
40
50
70
80
102
2
10
25
50
2
10
20
30
40
50
60
90
Temperature
C
19.4
17.7
17.7
17.1
14.4
12.1
8.9
8.3
8.3
18.2
17.7
17.7
11.0
18.2
17.7
18.2
17.7
13.5
12.1
10.5
8.3
Dissolved
Oxygen
mg/1
7.0
7.1
	
6.4
___
5.0
___
___
4.0
6.8
6.8
6.6
3.0
6.85
6.8
6.75
6.85
4.55
	
5.0
3.95
D.O.
D.O. Secchioisk
Saturation Transp . Ft. Euphotic Zone Ft.!'
102
100 12.5 33.5
	
89
_._
62
	
___
46
96
97 14.5 39.1
93
36
97
96 17.0 45.9
96
99
58
	
60
45
_!/ b  convert to meters  multiply by .3046.

-------
                                                                          32






profiles in Grand Lake approximate an orthograde rather than a clinograde




pattern with the lowest measured concentration (6.4 mg/1 at 5.5C and 100




feet) equal to 68 percent of saturation.  Percentages as high as this




obtained from the hypolimnion of a thermally stratified lake late in the




summer suggest that the amount of oxidizing organic material is not great




and that Grand Lake is only moderately productive.




    In Lake Granby, oxygen depletion in the hypolimnion is more severe.




Dissolved oxygen concentrations as low as 3.0 mg/1 (36 percent saturation)




were found at the 50-foot depth of Station L-12.  This suggests that, while




not extreme, the oxygen pattern is more clinograde than orthograde and that




summer-long accumulations of oxygen-demanding organic materials are more




concentrated in Lake Granby than in Grand Lake.  In the well-mixed waters of




the epilimnion, the oxygen content remained close to saturation.  The absence




of very high values here indicates only a moderate rate of photosynthesis.




    In Shadow Mountain Lake, the oxygen concentrations remain uniformly




near saturation values throughout the depths showing that the effects of




the physical processes of atmospheric reaeration and deaeration override




any tendency for oxygen to reach either extreme highs or lows.  This is




to be expected in such a shallow exposed lake containing moderately produc-




tive water.




    In Grand Lake and Lake Granby the surface dissolved oxygen values




were equal to or greater than 6.0 mg/1, the established dissolved oxygen




standard for Class B^ waters.  However, dissolved oxygen concentrations




as low as 5.2 mg/1 were observed at Station L-5 in  Shadow Mountain Lake.




Since this station is located on the west side of the lake between two




marinas, it is possible that this dissolved oxygen depletion resulted

-------
                                                                           33
from the increased recreational use in this area during the Labor Day




weekend.




     The depth of light penetration into a lake is of biological impor-




tance since all rooted, suspended, and floating aquatic plants require




light energy for photosynthesis.  While light penetration is exceedingly




variable in different lakes, it can generally be stated that higher




quality water permits greater light.penetration.




     At the selected lake stations where light penetration was measured




(Table V) , the euphotic zone, which is calculated from the Secchi Disk




transparency measurements, extended through the well mixed upper water




into or below the depths of greatest temperature change.  Therefore,




sufficient light existed throughout the epilimnion for photosynthesis.




Shadow Mountain Lake, because of the shallow depths, is entirely within




the euphotic zone.  The fact that the depth of light penetration was




greater than 30 feet in all the lakes is indicative of generally high-




quality waters.




     Although the blue-green algae, Aphanizomenon flos-aquae, was abun-




dant enough to be discerned visually in the surface water, examination




of the Sedgwick-Rafter analyses of water samples (Table VI) indicates




that the algae "bloom" conditions found during the October 2, 1967,




survey were not present at this time.  For this survey, an algae "bloom"




is defined as a count of an individual organism exceeding 500/ml (4).




The maximum density was observed at Station L-3 in Grand Lake where a




count of 527 organisms/ml was recorded at a depth of two feet.  Overall,




the productivity of the lakes can be considered low since one-half of the

-------
TABLE VI.  Sedgwick-Rafter Analyses  of Plankton Samples
Location



HTanrl
T akp




Shadow
Reservoir




Station
& Depth
L-1 9 '
L-i in1
T _0 0 '
T _9 in1
T _9 QO '
L_o 0 1
J > ^
T _Q 1 0 1
T -^ *}o '

L-4, 21
T _f> 9 '
L-8, 2'
L-11,21
L-11,101
L-i i ^n '
T _1 0 01
L-i "^ 9n '

Blue-Green Green
Coccoid Coccoid
______ ^i
______ "\L
------ f>8
------ f>8
______ 17
______ 11Q
______ 170


	 17
17
17 17
17

______ ^A

Green
Flagellates

f.0
si

SI
QC



--
34
34
34
70/L
QC
1 1 Q

Other
Flaggellates
i r>9
QC
QS

JA
991
110
OA

17
1 ^6
102
	



Diatoms
1 7f>
T/,
QS
1 09
(.a
1 O9
110
9fiQ

102
SI
119
85
34
OA
1 7

Total
Plankton
Counts
OAfi
991
oaq
i 70
1 7O
S97
408
Q O*3

136
1 R7
272
153
85
991
1 1 Q
i 70


-------
                                                                            35
 plankton samples  had  less  than  200  organisms/ml,  total  count.   Numerically




 the most abundant organism in any sample  was  Dinobryon  sp.,  a  yellow-green




 algae which causes taste and  odor problems  when present in high concen-




 trations (9) .




     The net plankton sample  analyses  (Table  VII)  provide a  different




 qualitative picture.   It is emphasized, however,  that net samples  are not




 quantitative because  (1) they are biased  toward the  larger forms,  (2)  the




 efficiency  increases  as  the meshes  become clogged, and  (3) the volume




 filtered is difficult to control.   Notwithstanding these shortcomings,




 plankton net samples  permit the examination of  a  much larger volume  of




 water  than  that  collected  for the Sedgwick-Rafter analysis.




     At  those  stations where  net plankton hauls were made, Aphanizomenon




 flos-aquae  was the dominant organism as shown in  Table  VII.  Although the




 Sedgwick-Rafter  analyses revealed low  numbers of  this organism, calcu-




lations based on  the amounts of  water filtered,  the amount of plankton




 concentrate obtained,  and  the number of organisms in that concentrate




 indicate that  the densities obtained from both  Sedgwick-Rafter and net




 plankton analyses are comparable.   Aphanizomenon  flos-aquae  was easily




 seen in  the lakes even though present  in  low numbers because of its  habit




 of forming  large  aggregates.  Similarly,  copepods and cladocerans  could




 easily be seen in the lakes though  only a few organisms were present.  The




 presence of the  blue-green algae Aphanizomenon  flos-aquae and  Anabaena




 which are both capable of  fixing atmospheric  nitrogen  (converting  molecular




 nitrogen to ammonia)  supports the hypothesis  discussed  earlier that  the




 phytoplankton  are nitrogen limited. In many  bodies  of  water,  these  forms




 become abundant  during the late summer and early  fall months particularly

-------
Genera Species
Rotifers
Asplanchia sp.
Kellicottia sp.
Synchaeta sp .
Cladocerans
Bosmina sp .
Daphnia spp.
Copepods
Cyclops sp .
Diaptomus spp.
Water Mite
Blue Greens
Aphanizomenan flos -aquae
Oscillatoria sp .
Anabaena sp .
Greens
Volvox sp .
Scenedesmus sp .
Dictyosphaerium sp .
Oedogonium sp .
Pandorina sp.
Pediastrum sp .
Carteria sp.
Closterium sp.
Unknown coccoid form
Other
Dinobryan sp.
TABLE VII
Grand Lake
L-3
Oblique
Hand Tow

3
1


48
121

11
18


14,586

3

101


2
85






Net Plankton
Sample Analyses

Shadow Mountain Lake
L-4
Oblique
Hand Tow

19



3
88

6
8


19,320

5

22


70

1




210
L-6
Vert. Haul
From 20' Deep

26
1
6

3
88

28
6
1

9,905
35


8
35
17







70
L-8
Surface
Tow

10



55
322

13
78


74,690

70

95





70
70
280

350
Lake Granby
L-12 L-13
Vert. Haul Vert. Haul
From 25 ' Deep From 17 ' Deep

56 59
1
106 72


104 31

13 . 20
127 47


201,460 167,160



8











-------
                            TABLE VII (Continued)   Net  Plankton Sample Analyses
     Genera Species
Grand Lake
    L-3
  Oblique
  Hand Tow
                                                      Shadow Mountain Lake
                                              Lake Granby
  L-4
Ob 1ique
Hand Tow
    L-6
 Vert. Haul
From 20' Deep
 L-8
Surface
  Tow
    L-12
 Vert. Haul
From 25' Deep
    L-13
 Vert. Haul
From 17' Deep
Diatoms
   Navicula sp.
   Fragilaria sp.
   Asterionella sp.
   Cymbella sp.
   Cyclotella sp.
   Melosira spp.
   Fragilaria Crotonensis
   Cyclotella Bodanica
   Nitzschia sp.
   Tabellaria sp.
   Stephanodiscus sp.
                   70
                1,610
                  210
                3,780
                3,990

                   70
                  560
                  210
                  70
                  70
                 105
                  35
                 105
                 490
                   9,380
                     910
                     350

                   8,120
          Totals
   15,065
 30,252
   11,087
 94,863
    201,867
    167,397

-------
                                                                          38






if high phosphorus to nitrogen ratios prevail.  Therefore, reduction of




the phosphorus concentration in the lake is necessary to prevent "blooms"




by the nitrogen-fixing blue-green algae.  Since the natural removal of




phosphorus by outflows and combination with consolidated bottom sediments




is a slow process, a reduction in the phosphorus inflows to the lakes is




the logical control measure.




     While bottom vegetation was not sampled in any of the lakes, it was




observed in relative abundance in Shadow Mountain Lake.  The bottom




growth was particularly thick along the west shoreline of Shadow Mountain




Lake.  This same area was reported to  have light to moderate growth during




the October 2, 1967,  survey.




EFFECTS OF NATURAL INFLOWS UPON THE WATER QUALITY IN THE LAKES




     The chemical and physical data for all tributary stations are contained




in Table VIII.  The natural runoff into the lakes (Station 1-1 through 1-11)




had a flow-weighted average inorganic nitrogen concentration of 0.07 mgN/1,




orthophosphate concentration of 0.007 mgP/1, and total soluble phosphorus




concentration of 0.064 mgP/1.  Comparing this with the criteria established




earlier, it is apparent that the total soluble phosphorus concentrations in




the natural inflows is greater than the upper limit of 0.05 mgP/1 suggested




for low flow conditions while the orthophosphate concentration is less




than the suggested limit of 0.010 mgP/1.  At the time of this survey, the




tributary inflow approached low flow conditions which is generally associ-




ated with higher mineral concentrations.  Therefore, the average annual




natural orthophosphate and total soluble phosphorus inputs from the natural




inflows are believed to be less than 0.010 mgP/1 and 0.050 mgP/1 respec-




tively, but a short-term water quality surveillance program to collect

-------
                                                                         39
        TABLE  VIII   Flow and Nutrient Concentrations Measured
Station
Number
1-1

1-2

1-3

1-4

1-5

1-6

1-7

1-9

1-10

1-11

Flow Weighted
Date &
Time
Sampled
Aug. 28
0840
Aug. 28
0905
Aug. 28
1015
Aug. 28
1000
Aug. 28
1600
Aug. 28
1615
Aug. 28
1640
Aug. 28
1335
Aug. 28
1250
Aug. 28
1235

Average 1-1 through 1-11
	 i
at Tributary Stations
Nitrogen
Gage Inor-
Ht/Flow N03- NH3- ganic
Cfs.I/ mgN/1 mgN/1 mgN/1
4.00 .05 .02 .07
38.80
4.17 .05 .02 .07
4.50
0.97 .05 .01 .06
1.70
3.25 .05 .02 .07
1.80
0.78 .05 .01 .06
17.00
7.69 .05 .02 .07
26.70
0.45 .05 .04 .09
2.20
3.49 .05 .01 .06
28.00
4.60 .05 .03 .08
0.10
0.62 .05 .02 .07
3.60

.05 .02 .07
Phosphates
Ortho Total-Sol
mgP/1 meP/1
.003 .062

.003 .059

.003 .082

.003 .039

.003 .062

.003 .065

.023 .072

.006 .055

.110 .166

.091 .144


.007 .064
I/  To convert to M /Sec.  multiply  by .02832.

-------
                                                                           40
flow and quality data during all flow cycles should be conducted to




affirm this assumption.




EFFECT OF WASTEWATER DISCHARGES UPON NUTRIENT LEVELS IN THE LAKES




     Two sources of treated wastewater enter the lakes studied.  The major




sources are the Grand Lake and the Shadow Mountain Government Camp waste-




water treatment facilities which serve approximately 4,000 people during




the summer months and about 450 people the remainder of the year.  The




residences and businesses which use septic tank and subsurface disposal




fields for wastewater treatment and disposal constitute the other sources.




According to personnel of the Colorado State Health Department (5), there




are approximately 300 residences and businesses served by individual




systems.  On a typical summer weekend, these individual systems probably




receive the wastes of 1,500 or more people.




     The quality of the effluent from the Grand Lake wastewater treatment




facility is believed to be similar to the quality of the effluents from




the Shadow Mountain Government Camp system and the individual systems




and representative of the nutrient inflows from wastewater.  Therefore,




the effects of wastewater on the lakes were evaluated by sampling the




Grand Lake wastewater treatment facility effluent.  The results of the




chemical analyses in Table IX show that the concentrations of ammonia,




orthophosphates and total soluble phosphates averaged 13.38 mgN/1, 5.21




mgP/1 and 6.14 mgP/1 respectively, and are two to three orders of magni-




tude greater than the concentrations determined in natural runoff.




     A more realistic view of the impact of domestic wastewater nutrients




on the lakes can be presented by conversion of the nutrient concentrations




from mg/1 to Ibs/day as shown in Table X.  Analysis of this data shows

-------
                                                                          41
               TABLE IX  Flow and Nutrient Concentrations
Measured in the Grand Lake Wastewater Treatment Facility Outfall,  Station 1-16
Date
and
Time
Aug. 28
1030
Aug. 29
1310
Aug. 30
1515
Aug. 31
1630
Sept. 1
1325
Sept. 2
1625
FloY
gptn '
30
202
150
202
202
175
N I
Nitrate
maN/1
.05
.05
.05
.05
.05
.09
T R 0 G
Ammonia
mgN/1
9.7
11.0
13.0
16.0
18.0
8.7
E N
Inorganic
mgN/1
9.75
11.05
13.05
16.05
18.05
8.79
PROS
Ortho
mgP/1
6.20
4.57
4.57
5.55
5.55
5.55
PRATES
Total Soluble
meP/1
7.18
5.87
5.55
6.85
6.20
5.87
Flow Weighted
AVERAGE              160     .06       13.38  13.43       5.21        6.14
 I/ To convert to M /Sec. multiply by  .63x10
                                           -4

-------
                                                                           42
        TABLE X  Measured Nutrient Input (Lbs/Day) to the Lakes
From Natural and Wastewater




Sta.Flow
No. AcFt/Day-'
1-1
1-2
1-3
1-4
1-5
1-6
1-7
1-9
1-10
1-11
77.0
8.9
3.4
3.6
33.7
53.0
4.4
55.5
0.2
7.1

N
Nitrate .
IbsN/Day-
10.5
1.2
0.5
0.5
4.6
7.2
0.6
7.5
0.3
1.0

I T R 0 G E N


Flows

P H 0 S
Ammonia Inorganic. Ortho
IbsN/Day-' IbsN/Day-' IbsP/Day-2-'
4'. 2
0.5
0.1
0.2
0.9
2.9
0.5
1.5
0.2
0.4
14.7
1.7
0.6
0.7
5.5
10.1
1.1
9.0
0.5
1.4
0.69
0.08
0.03
0.03
.0.30
0.48
0.28
0.98
0.06
1.76


P H A T E S
Total Soluble
IbsP/dayl'
12.99
1.43
0.76
0.38
5.68
9.37
0.86
8.30
0.09
2.78
                   33.9
            11.4
45.3
4.69
42.64
1-16-    0.7
WASTEWATER   FLOWS

 0.1        25.5        25.6
             9.92
             11.69
I/  To convert to M /Sec. multiply by .01428.
2/  To convert to Kg/Day multiply by .4536.
3_/  Flow-Weighted Average.

-------
                                                                           43






that the Grand Lake wastewater treatment facility effluent, while contribu-




ting only 0.28 percent of the total inflow, contributed 36 percent of the




inorganic nitrogen, 68 percent of the orthophosphates, and 21.5 percent of




the total soluble phosphates as compared to the natural runoff contributions




of 97.72 percent of the flow, 64 percent of the inorganic nitrogen, 32 per-




cent of the orthophosphates, and 78.5 percent of the total soluble phosphates.




     Phosphorus is the element most often limiting to aquatic plant growth.




However, when present in abundance in conjunction with other environmental




conditions, phosphorus can stimulate algae growths that produce nuisance




tastes and odors, fish kills and otherwise impair water uses.  Unlike




nitrogen, phosphorus cannot be fixed from the atmosphere by plants and is




added to the lakes by natural runoff or wastewater discharges (7).  For




biological growth, the orthophosphate ion is the most readily available




source of phosphorus (8).  As shown above, the Grand Lake wastewater treat-




ment facility contributed 68 percent of the orthophosphates entering the




lakes during the time of this survey.  Considering this and the additional




quantity and quality of wastewater entering the lakes from other sources,




the evidence is that wastewater, the major contributor of orthophosphates,




is the cause of nutrient pollution of these lakes.




     The natural runoff provided 99.7 percent of the inflow with an ortho-




phosphate concentration of 0.007 mgP/1.  Therefore,  to restrict the flow-




weighted average orthophosphate concentration entering the lake to 0.010




mgP/1, the suggested maximum, the orthophosphate concentration in waste-




waters discharged to the lake cannot exceed 1.054 mgP/1.  Since the measured




orthophosphate concentration in the Grand Lake wastewater treatment facility

-------
                                                                      44




effluent was 5.21 mgP/1, an additional 80 percent reduction in orthophos-




phate is required.  This can only be accomplished by advanced waste




treatment methods.




     Beyond nutrient inputs, it has been shown that organic matter is also




an important factor affecting the growth of algae, although the specific




amount of organic matter necessary to sustain growth has not been quanti-




fied (8).  Hinman (2) presents data showing that the Grand Lake wastewater




treatment facility only achieved a 45 percent suspended solids reduction




during August 1969, and the sludge accumulations noticed during the




October 2, 1967, survey were also observed by Federal Water Pollution Con-




trol Administration personnel during this survey.  Therefore, the organic




matter necessary for algae growth is probably present in the lakes and is




contributed primarily by wastewater inflows.




     In addition to phosphorus removal, an increase in the removal of




organic matter from wastewaters is also necessary to prevent water quality




degradation.  However, the contribution of organic matter by natural run-




off is unknown and must be evaluated as part of water pollution control




programs for the lakes.




     No information is available regarding the quality of spring runoff,




the effects of ice cover on water quality, etc.  Development of a compre-




hensive plan for water quality control in the three lakes area will require




that these factors be evaluated.

-------
                                                                           45
                             BIBLIOGRAPHY
 1.   American Public Health Association, American Water Works Association
     and Water Pollution Control Federation,  1967,  "Standard Methods for
     the Examination of Water  and Wastewater,"  12th Edition, American
     Public Health Association,  76a p.

 2.   Hinman, H. Fred,  1969,  "Sanitary Survey  Report, Grand Lake, Shadow
     Mountain Reservoir, Lake  Granby,"  Colorado Department of Health,
     Water Pollution Control Division,  7 p  plus appendix.  (Mimeo)

 3.   Hutchinson,  G. Evelyn,  1957, "A Treatise on Limnology," Vol.  1, John
     Wiley and Sons, New York,  1015 p.

 4.   Lackey, J. B., 1949, "Plankton as  Related  to Nuisance Conditions  in
     Surface Water,"  "Limnological Aspects of  Water Supply and Waste
     Disposal," American Association for the  Advancement of Science, pp 56-63,

 5.   Lee, Willis  T., 1917,  "The  Geologic Story  of the Rocky Mountain
     National Park, Colorado,"  USDI, National  Park Service, 89 p.

 6.   Mackenthun,  Kenneth M.  and  Ingram, William M., 1967, "Biological
     Associated Problems in Freshwater  Environments, Their Identification,
     Investigation and Control," USDI,  FWPCA, 287 p.

 7.   Mackenthun,  Kenneth M., 1968,  "The Phosphorus  Problem," Journal of
     the American Water Works  Association,  Vol. 60, No. 9, pp 1047-54.

 8.   Nesbitt, John B., 1966, "Removal of Phosphorus from Municipal Sewage
     Plant Effleunts," Engineer  Research Bulletin B-93, The Pennsylvania
     State University, College Park, Maryland,  54 p.

 9.   Palmer, C. M., 1959, "Algae in Water Supplies," U. S. Public Health
     Service, Publication #657,  88p.

10.   Sawyer, Glair N,  and McCarty,  Perry L.,  1967,  "Chemistry for Sanitary
     Engineers," McGraw-Hill Book Company,  New  York 518 p.

11.   U. S. Department of the Interior,  Bureau of Reclamation, 1962, "The
     Story of the Colorado-Big Thompson Project," Bureau of Reclamation,
     56 p.

-------
                                                     46
     APPENDIX   A







PHYSICAL AND CHEMICAL DATA




   FOR LAKE STATIONS

-------
Table A-l Physical-Chemical Data  for Lake Stations
Date & Sample Tempera-
Station Time Depth ture
Number Sampled Feet C
L-l







L-2







L-3







L-4





8/28/69
1015&1000
8/30/69
1120
9/1/69
0945
9/3/69
1005
8/28/69
1045
8/30/69
1135
9/1/69
1005
9/3/69
1025
8/28/69
1115
8/30/69
1110
9/1/69
1015
9/3/69
0955
8/28-0930
8/29-1250
8/30-1150
8/31-1535
9/1-1135
9/3-0945
0.0
60.0
0.0
120.0
0.0
120.0
0.0
135
0.0
130.0
0.0
70.0
0.0
80.0
0.0
70.0
0.0
30.0
0.0
40.0
0.0
40.0
0.0
40.0
2.5
2.5
5.0
5.0
5.0
4.0
16.0
17.0
15.5
8.5
14.5
9.0
15.5
11.5
17.0
9.0
15.0
8.5
15.5
7.5
15.5
13.0
17.0
17.0
15.0
12.0
15.0
10.5
15.5
10.5
13.0
14.5
14.0
15.0
14.0
15.0
PH
7.4
7.6
7.5
7.3
7.6
7.6
7.4
6.9
7.6
6.8
7.3
7.1
7.6
7.3
7.5
7.3
...
7.1
8.3
7.4
7.3
6.9
7.0
7.2
7.2
7.8
7.2
8.5
7.5
7.4
Specific
Cond. D. 0.
pmhos mg/1
..
--
50
^50
<50
00
<50
<50
__
--

-------
Table A-l(Continued)  Physical-Chemical Data for Lake Stations
Date & Sample
Station Time Depth
Number Sampled Feet
L-5



L-6



L-7


L-8

L-9



L-10



L-ll



8/29/69
1300
9/1-1115
9/3-0930
8/29/69
1240
9/2
1345
8/29-1225
9/2/69
1330
8/29-1340
8/30-1500
8/29/69
1130
9/2/69
1135
. 8/29/69
1110
9/2/69
1115
8/29/69
1100 ;
9/2/69
1100
0.0
20.0
6-12
5-10
0.0
20.0
0.0
20.0
7.5-15
0.0
20.0
2.5-5
2.5-5
0.0
36.0
0.0
34.0
0.0
50.0
0.0
66.0
0.0
76.0
0.0
110.0
Tempera-
ture
C PH
14.0
14.0
13.0
13.5
15.0
13.0
15.0
12.0
15.0
16.0
12.0
17.0
17.5
19.0
14.0
18.5
14.5
18.0
11.0
18.0
11.0
18.0
10.0
18.0
11.0
7.5
7.1
6.8
7.1
7.5
7.4
7.3
7.1
7.5
7.7
7.0
7.7
8.0
7.5
7.3
7.6
7.0
7.9
7.1
7.3
7.0
7.1
6.5
7.7
7.2
Specific
Cond. D. 0.
^mhos mg/ 1
63
62
60
^50
63
60
60
63
52
60
63
70
^-50
55
50
55
60
55
55
60
55
55
60
60
55
7.8
6.0
5.6
5.2
7.8
6.3
7.2
5.8
8.0
6.8
5.6
8.3
7.5
7.6
6.4
6.6
4.8
7.8
5.1
6.6
4.1
7.5
5.2
7.5
4.1

N03-
mg/1
as N
 .05
2.05
 .05
.05
..05
* .05
f .05
.05
i.05
*.05
Z.Q5
.Q5
.05
^.05
i.05
-i.,05
i.05
..05
.11
.05
.13
i.05
.14
i.05
i.05
NIT
NH3
mg/1
as N
.03
.19
.05
.02
.02
.05
.02
.03
.03
.02
.02
.57
.06
* .01
.10
.01
.03
<. .01
^ .01
.02
.02
.01
.03
.01
.24
R 0 G E N
Organic
mg/1
as N
.43
.29
.35
.13
.20
.32
.23
.14
.24
.15
.17
.39
.38
.10
.14
.11
.18
.15
.15
.18
.23
.15
.17
.13
.28
Total
Kjeldahl
mg/1 as N
.46
.48
.40
.15
.22
.37
.25
.17
.27
.17
.19
.96
.44
.11
.24
.12
.21
.16
.16
.20
.25
.16
.20
.14
.52
PHOSPHATES
Ortho
mg/1
PO&
.02
.02
.02
.03
.02
.03
.02
.11
.39
.03
.09
.48
.19
.02
.10
.02
.04
.01
.08
.02
.14
.01
.05
.02
.27
Total Soluble
mg/1 mg/1
PO/, P
.06
.10
.05
.06
.04
.06
.03
.17
.43
.06
.10
.78
.25
.22
.31
.08
.08
.26
.27
.04
.14
.15
.33
.04
.28
.020
.033
.016
.020
.013
.020
.010
.055
.140
.020
.033
.254
.082
.072
.101
.026
.026
.085
.088
.013
.046
.099
.108
.013
.091

-------
                           Table A-1(Continued)  Physical-Chemical Data for Lake Stations
NITROGEN
Date &
Station Time
Number Sampled
L-12

L-13

L-14

8/29/69
0930
8/29/69
1025
8/29-1010
9/2-1020
Sample
Depth
Feet
0.0
40.0
0.0
34.0
7.5-15
5-10
Tempera-
ture
C PH
18.0
12.0
19.0
13.0
18.0
17.0
8.5
6.8
6.9
6.3
7.6
7.1
Specific
Cond. D. 0.
umhos mg/1
55
60
55
55
55
52
7.2
4.4
7.6
5.0
7.1
6.1
N03-
mg/1
as N
.05
.08

-------
                                                         50
       APPENDIX   B
WATER QUALITY STANDARDS FOR COLORADO

-------
                                                                                  51
COLORADO DEPARTMENT OF HEALTH
Water Pollution Control  Commission
^210 East 11th Avenue
Denver, Colorado 80220
Adopted May  15, 1968


                     WATER QUALITY STANDARDS FOR COLORADO


          The Second Session of the Forty-Fifth General  Assembly of the State
of Colorado  passed Water Pollution Control  Legislation for the State of Colorado
as set out in Chapter 4*4, Session Laws 1966.  In adopting this legislation,
the following legislative declaration was made:

          "Whereas the pollution of the waters of this state constitutes
          a  menace to public health and welfare, creates public nuisances,
          is harmful to wildlife, fish and other aquatic life,and impairs
          domestic, agricultural, industrial,recreational, and other
          beneficial uses of water; and whereas the problem of water
          pollution of this state is closely related to the problem of
          water pollution in adjoining states; and whereas it is the public
          policy of this state to conserve the waters of the state and to
          protect, maintain, and improve the quality thereof for public
          water supplies, for the propagation  of wildlife, fish and other
          aquatic life,  and for domestic, agricultural,  industrial,
          recreational,  and other beneficial uses, and to provide that
          no wastes be discharged into any waters of the state without
          first being given the degree of treatment necessary to protect
          the beneficial uses of such water, it is hereby declared that
          the prevention, abatement, and control of the pollution of
          the waters of this state are affected with a public interest,
          and the provisions of this act are enacted in the exercise of the
          police powers of this state for the  purpose of protecting the
          health, peace, and safety, and general welfare of the people
          of this state."

          These standards are the foundation for the classification of the
waters of the State of Colorado.

          Standards are subject to revision as technical data, surveillance
programs, and technological  advances make such revisions desirable.

          For purposes of enforcement of these standards, sampling will be
done at a point where these standards can be evaluated.

          For purposes of enforcement of water classification standards,
sampling of  the waters will  be done at any point, except for areas immediately
adjacent to  outfalls and except as may be noted in the text of the standards.
In such areas, cognizance will be given to the opportunity for admixture of
waste effluents with receiving water.

-------
                                                                                 52
Water Quality Standards For Colorado
Adopted May 15, J_9j>8	


          Tests or analytical procedures to determine compliance with standards
will, insofar as practicable and applicable, be made in accordance with the
methods given in the latest edition of "Standard Methods For The Examination
Of Water And Waste Water" published by the American Public Health Association,
or in accordance with tests or analytical procedures that have been found to be
equal or more applicable and satisfactory and accepted and approved by the
Commission.

           In areas where a body of water is classified for more than one use,
the standards applicable to each use shall apply and in case of a conflict,
the more restrictive standards shall prevail in each instance.

          Where and when additional waters become available, hearings will be
held on the possible classification or reclassification of such waters for
further enhancement.  The quality of water will  be maintained as high as possible
and in no case shall stream standards be violated.

           It is expected that the present uses of the waters of Colorado will
continue but if other uses develop, streams may be classified or reclassified
after public hearings.


I.  BASIC STANDARDS APPLICABLE TO ALL WATERS:

    A.  All wastes capable of treatment or control prior to discharge into any
        waters of the state, shall receive secondary treatment with disinfection
        or its industrial waste equivalent, as determined by the State Water
        Pollution Control Commission.  Lesser degrees of treatment or control
        may be permitted only where it can be demonstrated that the standards
        applicable to the classified use of the water can be attained.
        Greater degrees of treatment or control  will be required where it
        can be demonstrated that it is necessary to comply with the standards
        applicable to the classified use of the water.

    B.  Free from substances attributable to municipal, domestic, or  industrial
        wastes, or other controllable sources that will either settle to form
        unsightly, putrescent, or odorous bottom deposits, or will interfere
        with the,classified use of the water.

    C.  Free from unsighly floating debris, oil, grease, scum, and other
        floating material attributable to municipal, domestic, or industrial
        wastes, or other controllable sources.

    D.  Free from materials attributable to municipal,  domestic, or industrial
        wastes, or other controllable sources that will produce odor  in the
        water or produce an appreciable change in the existing color, taste,
        turbidity or other conditions that interfere with the classified use
        of the water.

    E.  Free from high  temperatures, biocides, toxic, or other deleterious
        substances attributable to municipal, domestic, or  industrial wastes,
        or other controllable sources in levels, concentrations, or combinations
        sufficient to be harmful to human or animal life.

-------
 Water Quality Standards  For  Colorado
 Adopted May 15,  1968 ___
         Radioactive materials attributable to municipal,  industrial  or other
         controllable sources will  be minimum concentrations that are physically
         and economically feasible  to achieve.  In no case shall  such materials
         in the stream exceed the limits established in the current edition of
         the U.S.  Public Health Service Drinking Water Standards  or the limits
         approved  by the Federal  Radiation Council,  or, in the absence of 'any
         limits specified by the  U.S. Public Healtn  Serv.ice or the Federal
         Radiation Council,  1/30  of the 168-hour-week values for  other radio-
         active substances specified in the National Bureau of Standards
         Handbook  69.
II.  ADDITIONAL WATER QUALITY STANDARDS KOR BODIES OF WATER THAT HAVE BEEN
     CLASSIFIED FOR ANY OF THE FOLLOWING USES:
CLASS A.

     The  following standards shai1  apply to water withdrawn for treatment as a
     potable supply:

     1.   Bacter i a:  The annual  average number of coliform bacteria at any
         sampling station shall  not exceed the historical  average by more
         than 20% and in no case shall the monthly average of the number
         of coliform bacteria exceed 5,000 per 100 milliliter (either MPN or
         MF count).   AM averages  shall  be computed logarithmically.

     2.   Dissolved Oxygen:   Dissolved oxygen shall not  be less than k milligrams
         per 1i ter.

     3.   pH:  The pH shall  be maintained between 6.0  and 9-0.

     k.   Taste and Odor:  Free from materials attributable to municipal, domestic,
         or industrial  wastes,  or  other controllable  sources that will  produce
         taste or odor  in the water.

     5.   Pi ssolved Sol ids:   Total  dissolved solids, annual volume weighted average,
         should be less than 500 milligrams per liter.

     6.   Selected Chemical  Constituents:   The following substances shall not be
         present in  such amounts as to exceed the specified concentrations in a
         potable water  supply according to the mandatory requirements of the
         latest edition of  the U.S. Public Health Service Drrnking Water Standards:

                   Substance                       Concentration - mg/1

                   Arsenic  ----------------0.05
                   Barium  -----------.-----).QO
                   Cadmium  -----------------0.01
                   Chromium (Hexavalent)  --------- 0.05
                   Cyanide  ----------------0.20
                   Lead  -------------	0.05
                   Selenium  --- 	 _______ o.Ol
                   Silver  	 ----- Q.05

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                                                                                 54
Water Quality Standards For Colorado
Adopted Hay 15, 1968	


CLASS B.

     1.  The following standards shall  apply to waters classified for fish and
         wildlife (Cold Water Fishery):

         a.  Dissolved Oxygen:  In cold water fisheries,  the dissolved oxygen
             content shall  in no case go below 6 milligrams per liter.

         b.  pH:   pH shall  be maintained between 6.5 and  8,5-   No controllable
             pH change will be permitted which will  interfere with fish and
             aquat i c 1i fe.

         c.  Turbid i ty:  No turbidity shall  exist in concentrations that will
             impair  natural and developed fisheries.

         d.  Temperature:  In cold water fisheries the temperatures shall  not
             exceed  70  F.   No controllable  temperature change will be permitted
             which will  interfere with, the spawning and other aspects of  fish  life.

         e.  Toxic Material:   Free from biocides, toxic,  or other deleterious
             substances attributable to municipal, domestic, or industrial
             wastes, or other controllable sources in levels,  concentrations,
             or combinations  sufficient to be harmful  to  aquatic life.

         f.  Other Material:   Free from materials attributable to municipal,
             domestic, or industrial wastes, or other controllable sources
             that will produce off-flavor in the flesh of fish.


     2.  The following standards shall  apply to waters classified for fish and
         wildlife (Warm Water Fishery):

         a.  Dissolved Oxygen:  In warm water fisheries,  dissolved oxygen  content
             shall in no case go below 5 milligrams  per liter.

         b.  pH:   pH shall  be maintained between 6.5 and  8.5.   No controllable
             pH change will be permitted which will  interfere with fish and
             aquati c 1i fe.

         c.  Turb i di ty:  No turbidity shall  exist in concentrations that will
             impair  natural and developed fisheries.

         d.  Temperature:  In warm water fisheries the temperatures shall  not
             exceed  90  F.   No controllable temperature change will be permitted
             which will  interfere with spawning and  other aspects of fish  life.

         e.  Toxi c Materi al:   Free from biocides, toxic,  or other deleterious
             substances attributable to municipal, domestic, or industrial
             wastes, or other controllable sources in levels, concentrations,
             or combinations  sufficient to be harmful  to  aquatic life.

         f.  Other Materi al:   Free from materials attributable to municipal,
             domestic, or industrial wastes, or other controllable sources
             that will produce off-flavor in the flesh of fish.

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Water Quality Standards For Colorado
Adopted May 15, 1968'	


CLASS B - continued


     3.  The following standards shall apply to recreational waters classified
         for body contact sports such as, but not limited to, swimming and
         water ski i ng:

         a.  Bacteria:  Total  coliform bacteria shall not exceed 1,000 per
             100 milliliters as a monthly average (either MPN or MF count);
             nor exceed this number in more than 20% of the samples examined
             during any month; nor exceed 2,^00 per 100 mill!liters in a
             single sample.   In addition, the fecal  coliform count shall not
             exceed 100 per 100 mill!liters and the fecal streptococcus count
             shall not exceed  20 per 100 milliliters, both of these limits to
             be an average of  five (5) consecutive samples within a month.

         b.  pH:  pH shall be  maintained between 6.5 and 8.5.


CLASS C:

     The following standards shall  apply to waters classified for industrial  uses:

     1.   Dissolved Oxygen:  Dissolved  oxygen content shall not  go below
         3 mi 111 grams  per liter.

     2.   pH:  pH shall be maintained between 5-0 and 9.0.

     3.   Turbidity:   No turbidity shall  exist in concentrations  that will
         interfere with established levels  of treatment.

     *.   Temperature:   The temperature shall  not exceed 93  F.
CLASS D:

     1.  The following standards shall  apply to waters classified for irrigation:

         a.   Total Dissolved Solids (Salt)Concentration:

             A time-weighted monthly mean at a monitoring station which exceeds
             the time-weighted monthly  mean for a base period established
             by the Commission by more  than two standard  deviations shall be
             subject to review by the Commission.

         b.   Sodium Adsorption Ratio:

             A time-weighted monthly mean at a monitoring station which exceeds
             the time-weighted monthly  mean for a base period established by
             the Commission by more than two standard deviations shall be subject
             to review by the Commission.

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Water Quality Standards For Colorado
Adopted May 15, 1968	
                                                                                56
CLASS D -  continued
         c.   Toxi c Material:

             Free from biocides, toxic, or other deleterious substances
             attributable to municpal, domestic, industrial  wastes, or other
             controllable sources in concentrations or combinations which
             are harmful  to crop life.

     2.  The following standards shall apply to waters classified for livestock
         water!ng:

         a.   Soluble Salts:    The soluble salts shall  not exceed 3,000 milligrams
             per 1i ter.
                                          Betty M.  .Chronic, Secretary
                                          Colorado Water Pollution Control  Commission
Richard T. Eckles, Chairman
Colorado Water Pollution Control Commission

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                                                 57
APPENDIX   C
     GLOSSARY

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                                                                          sa


                                GLOSSARY


ALGAE BLOOM - A concentration of phytoplankton exceeding 500 organisms/ml.

BENTHIC REGION - The bottom of lakes and streams; the substratum that
     supports the bottom dwelling plants and animals.

CLINOGRADE - A distribution of dissolved oxygen in the hypolimnion which
     decreases with depth - approaching zero near the lake bottom.

EPILIMNION - That upper layer of a body of water in which the water
     temperature is virtually uniform.

EUPHOTIC ZONE - The surface layers of a lake in which light provides the
     energy for organic production from mineral substances.

EUTROPHIC WATERS - Waters with a good supply of nutrients; they may support
     rich organic production, such as algal blooms.

EUTROPHICATION - The intentional or unintentional enrichment of water.

HYDROLYSIS - A chemical reaction in which a compound reacts with the ions
     of water to fonfl a weak acid, a weak base, or both.

HYPOLIMNION - The region of a body of water which extends from the thermo-
     cline to the bottom of the lake and has a nearly uniform temperature.

MESOTROPHIC - Waters with a moderate supply of nutrients; they will support
     organic production and will occasionally support algal blooms.

OLIGOTROPHIC WATERS - Waters with a small supply of nutrients; hence, they
     support little organic production.

ORTHOGRADE - A nearly uniform distribution of oxygen in the hypolimnion of
     a lake.

PHOTOSYNTHESIS - The process by which living plant cells, in the presence
     of light, convert organic and inorganic matter to cell material.

PHYTOPLANKTON - Plant microorganisms, such as certain algae, living
     unattached in the water.

PLANKTON - Organisms of relatively small size, mostly microscopic, that
     either have relatively small powers of locomotion or drift in the
     water subject to the action of waves and currents.

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                                                                          59
SECCHI DISC - A circular metal plate, 20 cm in diameter, the upper
     surface of which is divided into four equal quadrants and so painted
     that two quadrants directly opposite each other are black and the
     intervening ones white.

THERMOCLINE - The layer in a body of water in which the drop in temperature
     equals or exceeds one degree centrigrade for each meter or approximately
     three feet of water depth.

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