EPA-660/3-75-003
FEBRUARY 1975
Ecological Research Series
Eutrophication of Surface Waters -
Lake Tahoe's Indian Creek Reservoir
national Environmental Research
Office of Research and Development
U.S. Environmental Protection Agency
Corvallis, Oregon 97330
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RESEARCH REPORTING SERIES
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U.S. Environmental Protection Agency, have been grouped into
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2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
This report has been assigned to the ECOLOGICAL RESEARCH STUDIES
series. This series describes research on the effects of pollution
on humans, plant and animal species, and materials. Problems are
assessed for their long- and short-term influences. Investigations
include formation, transport, and pathway studies to determine the
fate of pollutants and their effects. This work provides the technical
basis for setting standards to minimize undesirable changes in living
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EPA REVIEW NOTICE
This report has been reviewed by the Office of Research and
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EPA-660/3-75-003
FEBRUARY 1975
EUTROPHICATION OF SURFACE WATERS ---
LAKE TAHOE'S INDIAN CREEK RESERVOIR
by
Lake Tahoe Area Council
Grant No. 801003
Program Element IBA.031
ROAP/TaskNo. 21AIZ15
Project Officer
Thomas E. Maloney, Chief
Eutrophication and Lake Restoration Branch
Pacific Northwest Environmental Research Laboratory
National Environmental Research Center
Corvallis, Oregon 97330
NATIONAL ENVIRONMENTAL RESEARCH CENTER
OFFICE OF RESEARCH AND DEVELOPMENT
U. S. ENVIRONMENTAL PROTECTION AGENCY
CORVALLIS, OREGON 97330
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ABSTRACT
From April 1969 to October 1974 field and laboratory analyses and ob-
servations were made at approximately -weekly intervals to evaluate the
relationship between the quality of water impounded at Indian Creek
Reservoir (ICR) and the reclaimed water exported by the South Tahoo
Public Utility District. The reclaimed water comprised from 70 to 80
percent of the annual impoundment. On the average the reclaimed water
contained 0. 1 to 0. 2 mg/H of phosphorus and 15-24 mg/4 of ammonia,
the latter making it toxic to fish implanted in ICR. However, as the
reservoir matured, nitrification-denitrification removed most of the
nitrogen from the system and by March 1970 the reservoir had become
an excellent trout fishery. Excess N in comparison with P evidently
precluded blooms of blue green algae but low phosphorus did not prevent
the impoundment from becoming typical of a highly productive environ-
ment, with vascular plants invading to considerable depths because of
the high degree of clarity of the reclaimed water. By 1974 the biosystem
was at an approximately steady state. This state may not remain be-
cause of the appearance of epiphytic blue green algae which caused taste
and odor problems in the water and in the fish. It is concluded that the
reservoir responds to more complex factors than are measurable by
analysis of reclaimed water. The results show why a system of waste-
water reclamation must be designed on the basis of the natural as well
as the man-controlled components of the system, and points the way to
the necessary parameters and institutional concepts if water is to be
reclaimed for a specific purpose.
This report was submitted in fulfillment of Grant No. 801003 by the
Lake Tahoe Area Council under the sponsorship of the Environmental
Protection Agency. Work was completed as of October 31, 1974.
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TABLE OF CONTENTS
Page
Abstract
List of Figures
List of Tables
Acknowledgements
Sections
I Conclusions 1
II Recommendations 8
III Introduction 10
IV Project Design and Methodology 19
V Results of Study 27
VI Discussion and Evaluation of Results 108
VII References 115
VIII Publications and Patents 119
IX Glossary 120
X Appendices 123
111
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LIST OF FIGURES
No. Page
1 Geographical Relationships, Indian Creek Reservoir
and Export Line from Lake Tahoe Basin 13
2 Location of Sampling Stations at Indian Creek Reservoir 20
3 Composite Aerial Photographs of Indian Creek Reservoir,
November 2, 1972 34
4 Temperature, Lndian Creek Reservoir 41
5 COD, Indian Creek Reservoir 43
6 Suspended Solids, Indian Creek Reservoir 44
7 VSS, Indian Creek Reservoir 46
8 Chloride, Indian Creek Reservoir 48
9 Conductivity, Indian Creek Reservoir 49
10 Calcium, Indian Creek Reservoir 51
11 pH, Indian Creek Reservoir 52
12 Alkalinity, Indian Creek Reservoir 54
13 Inorganic Carbon, Indian Creek Reservoir 57
14 Orthophosphate, Indian Creek Reservoir 59
15 Total Phosphorus, Indian Creek Reservoir 60
iv
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LIST OF FIGURES (Continued)
No. Page
16 Ammonia, Indian Creek Reservoir 62
17 Nitrate 81 Nitrite, Indian Creek Reservoir 64
18 Organic Nitrogen, Indian Creek Reservoir 66
19 Total Nitrogen, Indian Creek Reservoir 68
20 Iron, Indian Creek Reservoir 70
21 Dissolved Oxygen, Indian Creek Reservoir 74
22 Increased Dissolved Oxygen at Low Depths Due to
Benthic Vegetation Photosynthesis 77
23 Food Web in ICR in Simple Form 81
24 Growth of Aufwuchs on Glass Slides in ICR,
August 6-20, 1973 84
25 Variation in Bioassay Algal Growth Response in
Impounded Water, ICR 86
26 The Variation in Maximum Specific Growth Rate Batch
as a Function of Orthophosphate Concentration in the
Bioassays, STPUDEffluent (III) Impounded Water (ICR-C) 88
27 Apparent Non-limiting Relationship Between Inorganic Nitro-
gen Concentration in STPUD Effluent 89
28 Photographs of Indian Creek Reservoir, August 1973 91
i
29 Estimated Distribution of Vegetation and Water Level
in ICR August 13, 1974 97
30 Estimated Seasonal Changes in Reservoir Area Covered
by Aquatic Vascular Plants and Benthic Algae 98
31 Oscillatoria Epiphytic on Dying Myriophyllum at shallow
southern end of ICR, September 1974 100
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LIST OF TABLES
No. Page
1 Weekly Observations of Environmental Data, Indian
Creek Reservoir 28
2 Estimations of Annual Water Balances for Indian
Creek Reservoir 37
3 Annual Arithmetic Mean Concentrations of Inorganic
Carbon, Inorganic Nitrogen, and Orthophosphate in
ICR and STPUD Tertiary Effluent 56
4 Annual Arithmetic Mean Concentrations of Nitrogen
and Phosphorus Compounds, Indian Creek Reservoir 67
5 Annual Nutrient Inventory Estimation for Indian
Creek Reservoir 72
6 Concentrations of Nutrient Elements in Sediments of
Indian Creek Reservoir 79
7 Concentrations of Algae and Protozoons in Indian
Creek Reservoir 82
8 Changes in Zooplankton Populations since Summer, 1970 101
9 Summary of Benthic Organisms Collected from Indian
Creek Reservoir Sediments in October 103
10 The Trout Fishery in Indian Creek Reservoir 106
VI
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ACKNOWLEDGMENTS
The Lake Tahoe Area Council (LTAC) acknowledges with sincere thanks
the cooperation of many agencies and. the assistance of numerous in-
dividuals, both outside and within its own staff, who have contributed to
the study of the limnological history of Indian Creek Reservoir since
its inception in 1968.
During the report period herein presented (1971-1974), project manage-
ment of an engineering and scientific nature continued under the guid-
ance of P. H. McGauhey, Project Director, who also donated a portion
of his time to the project as a public service. Field observations and
sampling, laboratory and microscopic analyses, bioassays, and data
tabulation and plotting were performed by Mr. John D. Archambault
and Mrs. Nancy M. Deliantoni, the latter assuming full responsibility
during the final three months of the project. The biological and limno-
logical aspects of the project, special field studies, final data and
analysis, and preparation of the final report were guided by Dr. Donald
B. Porcella, Utah State University (formerly Project Limnologist on
the project), serving as a consultant on an "as needed" basis. Budget-
ary control and accounting were maintained by Mrs. Lorrene Kashuba
and Mrs. Katharine Belyea of the LTAC staff.
A special underwater photographic survey of the benthic conditions of
the reservoir was made by Dr. Thomas Walsh, Environmental Quality
Analysts, Inc. , with the assistance of Dr. Porcella, Dr. Gordon L.
Dugan, University of Hawaii (formerly project Engineer-Biologist), and
Mr. Peter A. Cowan, Utah State University (formerly project research
biologist), and the resident staff of the project. An examination of
benthic invertebrates was made during the report period by Dr. Arthur
W. Noble (Environmental Quality Analysts, Inc. ), extending data he
had previously observed while employed by the Alameda laboratory of
VII
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the EPA. Zooplankton identification counts were made by Dr. J. Anne
Holman, Utah State University. Aerial surveys via infrared and color
photography to reveal the extent of underwater weed growth were made
by Natural Resources Consultants, Reno, Nevada.
Data on the quality and quantity of reclaimed water exported to ICR and
on discharges from the reservoir were furnished by the South Tahoe
Public Utility District through Mr. Russell L. Gulp, General Manager.
John Gonzales, Engineer at STPUD, was extremely helpful. The
California Department of Fish and Game contributed facilities as well
as data on fish population, fish catches, and the suitability of the
reservoir environment for fishes. Russ Wickwire, Fish and Game
Biologist, contributed his special knowledge about ICR as well as time.
The University of California at Davis and Berkeley contributed expert
advice and loaned equipment when needed. Professor Erman A. Pear-
son, University of California (one of the original LTAC Board of Con-
sultants which conceived and guided the study), loaned personally owned
sampling equipment to the project.
Graphic work on the final report was done by Mr. Peter Bray; tables
were prepared by Mrs. Flora Orsi; and manuscript typing was per-
formed by Barbara South, Betty Hansen, and Gretta Curless, D. Anderson.
To all of these and others who participated in the project, the Lake
Tahoe Area Council is deeply grateful.
The financial support of the project by the Environmental Protection
Agency is acknowledged with sincere thanks. Especial appreciation is
expressed to Dr. Thomas E. Maloney, Chief, Eutrophication and Lake
Restoration Branch of the EPA Pacific Northwest Environmental
Research Laboratory, who served as Grant Project Officer throughout
the study, and to Mr. Paul DeFalco, Administrator of the Regional
Office of EPA, and members of his staff, whose approval made the ICR
study possible.
Vlll
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the EPA. Zooplankton identification counts were made by Dr. J. Anne
Holman, Utah State University. Aerial surveys via infrared and color
photography to reveal the extent of underwater weed growth were made
by Natural Resources Consultants, Reno, Nevada.
Data on the quality and quantity of reclaimed water exported to ICR and
on discharges from the reservoir were furnished by the South Tahoe
Public Utility District through Mr. Russell L. Gulp, General Manager.
John Gonzales, Engineer at STPUD, was extremely helpful. The
California Department of Fish and Game contributed facilities as well
as data on fish population, fish catches, and the suitability of the
reservoir environment for fishes. Russ Wickwire, Fish and Game
Biologist, contributed his special knowledge about ICR as well as time.
The University of California at Davis and Berkeley contributed expert
advice and loaned equipment when needed. Professor Erman A. Pear-
son, University of California (one of the original LTAC Board of Con-
sultants which conceived and guided the study), loaned personally owned
sampling equipment to the project.
Graphic work on the final report was done by Mr. Peter Bray; tables
were prepared by Mrs. Flora Orsi; and manuscript typing was per-
formed by Barbara South, Betty Hansen, and Gretta Curless, D. Anderson.
To all of these and others who participated in the project, the Lake
Tahoe Area Council is deeply grateful.
The financial support of the project by the Environmental Protection
Agency is acknowledged with sincere thanks. Especial appreciation is
expressed to Dr. Thomas E. Maloney, Chief, Eutrophication and Lake
Restoration Branch of the EPA Pacific Northwest Environmental
Research Laboratory, -who served as Grant Project Officer throughout
the study, and to Mr. Paul DeFalco, Administrator of the Regional
Office of EPA, and members of his staff, whose approval made the ICR
study possible.
IX
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SECTION I
CONCLUSIONS
HYDROLOGIC AND PHYSICAL
MEASUREMENT
1. The flow of STPUD effluent into ICR is seasonally variable but
shows an increasing trend paralleling that of population growth in the
Lake Tahoe Basin.
2. As might be expected from the tendency of STPUD effluent to
increase with time, estimates of water inputs and outputs show that
reclaimed water from the STPUD is an increasing percentage of the
total impounded at ICR at any time and, consequently, of the discharges
to irrigation; the water budget estimates are deemed reasonably accurate
because percolation rates (estimated by difference) are comparable to
values measured in other similar impoundments of water.
3. Maximum Secchi disc readings were 8.8m (28. 5 feet), indi-
cating a high clarity for water which normally would be treated as a
waste. Generally the clarity is greatest in spring and fall; intermedi-
ate clarity is found during mid-summer and minimum clarity during
February through March during peak phytoplankton populations.
i
4. After a time lag, temperature in the reservoir follows air
temperatures. Temperatures range from freezing (0°C) to about 22°C
during July and August. Generally ice cover is only partial and occurs
during December and January.
OBSERVATIONS OF MACROCHEMICALS
5. Difference between STPUD effluent and impounded water for
COD were ascribed primarily to an increase resulting from algal growth.
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6. SS and VSS were generally less in ICR than in STPUD effluent;
this was probably caused by a settling of SS materials in the reservoir.
When levels in ICR were greater, the difference was ascribed primarily
to wind action suspending bottom sediments; during the spring high VSS
values were ascribed to phytoplankton.
7. Chloride, the conservative tracer of STPUD effluent, has
consistently increased in the reservoir as a result of the concentrating
effects of evaporation.
8. Conductivity in ICR also has increased with time because of
evaporation. Conductivity is significantly less in ICR than in STPUD
effluent. This is ascribed to removal of ions such as Ca++ and HCO^ .
The conductivity levels in ICR indicate a high quality for irrigation pur-
poses.
9. Calcium and alkalinity both decreased significantly in ICR
from values measured in the STPUD effluent. Precipitation of CaCO,
is responsible for some of this decrease.
10. pH in ICR water is extremely constant at about 8. 0, being
similar to that of STPUD effluent; higher values, however, occur during
the late spring, reflecting the onset of increased photo synthetic activity.
11. About 10 percent of the influent alkalinity is removed as a result
of inorganic carbon utilization in photosynthesis.
NUTRIENT FATE AND UTILIZATION
AND EFFECTS ON OXYGEN
12. Bicarbonate carbon is significantly reduced primarily by photo-
synthesis.
13. Little organic phosphorus was measured in ICR during the
last year of study.
14. Orthophosphate concentration is higher during winter than sum-
mer; minimum values were less than 1 fig P/-2 except when phosphorus
loadings were intentionally increased by the STPUD for experimental
purposes in 1972-1973.
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15. Phosphorus concentrations in the reservoir showed an immedi-
ate response to higher input phosphorus. The concentration of phos-
phorus increased markedly in the reservoir, reversing an apparent
earlier trend of gradual diminution of phosphorus in the aqueous phase
during periods of high plant growth.
16. High quantities of inorganic nitrogen as ammonium (18-24 mg
N/2) have entered ICR, resulting in high inorganic nitrogen concentra-
tions in the reservoir--10 mg N/# in 1974 of which 50 percent is NH4-N
and 50 percent NO3-N.
17. Ammonium acts as an oxygen sink (nitrification) and a nitrogen
source in plant growth. The high nitrogen availability insures that
nitrogen is not limiting to plant growth.
18. Inorganic nitrogen concentration in ICR responds rapidly to high
inputs of ammonium nitrogen, increasing in scale with the input concen-
tration increase.
19. Iron is relatively low in concentration, which may indicate that
it could be limiting to plant growth relative to other nutrients measured.
20. Estimates of the nitrogen and phosphorus inventories support
previous estimates that 40-50 percent of the nitrogen and about 60 per-
cent of the phosphorus is removed from the aquatic system; previous
studies showed nitrogen was removed principally by nitrification-denitri-
fication and phosphorus transferred principally into the sediments.
21. Dissolved oxygen largely coincides with saturation calculations
except during periods of high photosynthetic activity: phytoplankton dur-
ing the winter and aquatic vascular plants during the early summer and
in the fall.
22. High dissolved oxygen concentrations at all depths indicate a
change from previous results which showed a large oxygen deficit in
the bottom layers of the reservoir. Because of the high oxygen con-
centration throughout all reservoir depths, it is possible that denitri-
fication is not as significant as previously. Nitrification is apparently
not such a significant sink for oxygen that an oxygen deficit occurs.
23. During the fall season marked increases in dissolved oxygen
were seen in bottom layers, apparently due to benthic oxygen production.
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24. Significant quantities of organic carbon, nitrogen and phosphorus
are in the upper layers of the sediments. Lower layers of sediments
have essentially the same quantity of these elements as soil in the ICR
basin.
25. Ratios of organic carbon, nitrogen and phosphorus indicate ap-
preciable removal by settling of plant material; however, phosphorus
ratios are indicative of precipitation--probably as calcium and iron
phosphates.
BIOLOGICAL OBSERVATIONS
26. Plankton microorganisms show a diversity typical of relatively
high productivity ecosystems.
27. Aufwuchs growth measured on glass slides had a maximum
specific growth rate of 0.4 days~l- This approximates what would be
estimated from laboratory algal bioassays for the nutrient levels in the
reservoir.
28. Algal bioassays integrate the independent variations in concen-
trations of specific nutrients. Results implicated phosphorus as the
limiting nutrient in ICR relative to nitrogen. Growth rates in bioassays
appeared inversely related to the biological growth cycle of the reser-
voir.
29. STPUD effluent is toxic to algal cultures used in bioassays.
30. Because high growth rates were obtained in ICR samples yet
phytoplankton concentrations were relatively low and transparency high,
it was reasoned that predation prevented phytoplankton blooms. The
types of phytoplankton present would have a great influence on the pos-
sible role of predation in controlling algal blooms.
31. Benthic vegetation was primarily Cladophora in deeper waters
and Myriophyllum in shallower waters. The expansion of flora over
greater areas occurred as drawdown of the reservoir during the irri-
gation season increased light transmission in deeper waters.
32. Extensive aquatic vascular plant production is interfering with
recreational uses in the reservoir and represents a control cost to STPUEL
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33. Epiphytic blue-green algae (Oscillatoria) have been observed
growing on the aquatic weeds and are responsible for a developing taste
and odor problem at ICR observed in September 1974.
34. The diversity of zooplankton populations is typical of productive
impoundments. The trend in zooplankton populations is for greater
stability than earlier samplings showed.
35. Benthic fauna measurements support previous results showing
that the further from Station 1 (adjacent to the STPUD effluent outfall
in ICR), the greater the diversity.
36. Snails are quite evident in ICR and form a large part of trout
diet; numbers approach 500/square meter in dried aquatic weed beds
along exposed shoreline.
37. Trout survive very well in ICR except for an episode of toxicity
(apparently caused by free ammonia) observed in March 1972.
38. Rapid growth rates and large fish are typical of the trout popu-
lation. Fishing success is not too high, and this has been ascribed to
the high amount of feed and interference with fishing caused by the dense
aquatic weed growths.
39. Taste and odor problems from the epiphytic Oscillatoria growth
have affected the flavor of the trout flesh.
SOME IMPLICATIONS OF FINDINGS
40. The STPUD wastewater reclamation plant is a highly efficient
system for removing phosphorus, and the impoundment at ICR is an
effective system for removing nitrogen from domestic sewage.
41. Although the STPUD plant successfully performed its design
function in demonstrating the ability of known processes to produce a
highly clarified, low phosphorus effluent meeting drinking water stand-
ards, the suitability of its effluent for fish life and associated recre-
ational values has resulted from further changes in water quality by
limnological phenomena in the ICR system for which no design criteria
are available.
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42. The results of the ICR studies indicate clearly that purifying
wastewater to the highest degree possible by current technology does
not insure its optimum suitability for all further purposes; but rather
that design parameters must eventually include the entire system. The
study suggests what some of these relationships may be and points the
direction for necessary further studies.
43. The findings of the study indicate that the relative nitrogen
surplus resulting from phosphorus removat at the STPUD plant and the
transformations occurring in ICR was sufficient to prevent blooms of
nitrogen-fixing blue green algae. Further studies are needed before
anyone can say whether a greater or lesser degree of phosphorus re-
moval, and consequent changes in cost-effectiveness, would achieve
this same goal.
44. The high degree of clarity achieved by the STPUD plant al-
though enhancing the initial aesthetic quality of the reclaimed water re-
sults in light penetration and, consequently, aquatic weed growth in
greater depths of water.
45. Gentle slopes, a relatively shallow reservoir, great clarity,
and the fill and draw operating schedule of ICR all contribute to a large
percentage of bottom area supportive of vascular plants, a condition
increasingly destructive of the recreational value of ICR.
46. Apparently, phosphorus is not limiting to weed growth in ICR.
Neither has weed cutting and removal proved effective as a control
method for weeds.
47. From the foregoing factors, together with data presented in
detail in the report, it is evident that a wastewater treatment system
in the STPUD/ICR situation, if designed for a recreational impoundment
and winter storage for summer drawdown in irrigation, would involve a
deep reservoir with a minimum, of shallow water under all conditions of
operation, fed with an effluent in which phosphorus concentrations were
no less than necessary, and clarity no greater than that which nature
will dictate in the reservoir.
48. The ICR studies have pioneered along the road to wastewater
treatment processes appropriately divided between man-controlled and
natural reactors to achieve the objectives of an overall system; but
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much is yet to be done to define the system parameters and to insti-
tutionalize the concepts required for accurate engineering design to meet
society's environmental goals.
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SECTION II
RECOMMENDATIONS
The results of studies of Indian Creek Reservoir made by the Lake
Tahoe Area Council under a series of grants from the Environmental
Protection Agency reveal, perhaps for the first time, the limnological
changes which might be expected in an impoundment of water reclaimed
from domestic wastewater flows. In late 1968 when impoundment of
tertiary effluent from the South Tahoe Public Utility District was begun
at Indian Creek Reservoir, the quality characteristics of the reservoir
water closely resembled that of the influent reclaimed water and was
incapable of supporting fish life. Thereafter it changed rapidly and
progressively to a system more clearly complex and highly productive
of aquatic life, including trout which were planted in it in great numbers.
Details of these changing characteristics and of the underlying phenom-
ena were reported in 1971 [5]. The results suggested that some of the
processes applied in the tertiary treatment of sewage were of question-
able utility in conditioning wastewater for use in recreational ponds.
To evaluate this suggestion and to monitor further changes in the char-
acteristics of impounded reclaimed water, studies were continued
through the years 1972, 1973, and 1974. The results, herein reported,
show further changes in the quality of reservoir water which indicate
that the impoundment has not yet reached maturity and that the system
is even more complex than previously revealed. In fact, there is evi-
dence that management techniques both in terms of wastewater treat-
ment and reservoir management may yet require further refinement if
•water quality is not to decline.
Therefore, it is recommended that federal and state agencies concern-
ed with water quality control should continue a program to monitor
seasonal and yearly changes in the quality of ICR for the purpose of
evaluating both the resolving power of wastewater treatment processes
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and the management of recovered water as a .resource. It is further
recommended that studies beyond the scope of the Indian Creek Res-
ervoir study herein reported, but suggested by its findings, be con-
ducted for the purpose of determining: 1) the feasibility of utilizing
intermediate size ponds to reduce the nitrogen content of a phosphate-
stripped water, and 2) the optimum nutrient levels and morphological
relationships for impoundments to be used for recreational or other
specific benefits, with the intent of establishing more rational param-
eters of treatment plant design.
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SECTION HI
INTRODUCTION
ORIGIN OF INDIAN CREEK RESERVOIR
Indian Creek Reservoir is the terminus of a system designed to export
from the Lake Tahoe Basin the final effluent from the domestic waste
water treatment facilities of the South Tahoe Public Utility District
(STPUD). The concept that sewage should be removed from the Tahoe
Basin developed during the early nineteen sixties. At that time it was
becoming widely apparent throughout the U. S. A. that the growing
population pressure on the nation's water resources was leading to
overfertilization of surface waters with consequent algal blooms that
interfered -with normal beneficial use of such resources. In many
instances losses were identifiable in economic terms as well as in
depreciated aesthetic and recreational values.
In the specific case of Lake Tahoe, discharge of waste water effluents
directly into the lake had never been considered an acceptable alter-
native. However, prior to about the year I960 disposal on land within
the basin was generally considered adequate to overcome the public
health and aesthetic objections to discharge into surface waters of the
region. Nevertheless, it was recognized by water quality control
authorities and others that the clarity and beauty of Lake Tahoe was a
consequence of an extremely low productivity resulting from its oligo-
trophic (nutrient poor) characteristics. Moreover, it was evident that
the Lake Tahoe Basin is essentially a closed system subject to human
imports of nutrients but to only limited export of nutrients, principally
via the Truckee River and some selective logging. Thus the lake is
the ultimate nutrient sink in the basin. In such a situation in I960,
sewage disposal was considered the most critical unsolved problem.
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Under a grant from the Max C. Fleischmann Foundation of Reno,
Nevada, the Lake Tahoe Area Council conducted a comprehensive study
on protection of the water resources in the Lake Tahoe Basin through
management of wastes. The resulting report [1] recommended export
as one of the three feasible alternatives. At about the same time (196l)
the STPUD retained consulting engineers to develop a long-range per-
manent solution to its disposal problems.
The idea of export as a practical solution to the waste management
problem of the Lake Tahoe Basin, however, developed slowly. No
community was willing to be the terminus of any waste export scheme.
The concept that water is forever "sewage" once it has been used to
transport wastes proved to be too deeply ingrained in the minds of
citizens to be overcome by simple persuasion. "If it is not good enough
for you, it is not good enough for me" was the ultimate attitude. This
rationale precluded both export by way of the Truckee River and by
pipeline as well, although the latter offered more possible alternatives.
Matters were finally brought to a head as a result of a. growing national
concern over eutrophication. This initiated a review of water quality
criteria that has increasingly led in the direction of nutrient removal
as an obligatory objective of waste water treatment. A series of
demonstration grants to the STPUD were made under the Advanced
Waste Water Treatment program of the series of federal agencies
•which culminated in the Environmental Protection Agency. These
grants led to the development on a plant scale of processes for nutrient
removal and for upgrading waste water in quality to drinking water
standards. Thereafter to make export feasible it was only necessary
for people to understand that what constitutes acceptable high quality
water almost anywhere is not adequate to protect Lake Tahoe from
eutrophication because of the lake's sensitivity to nitrogen at levels
far below those acceptable for drinking water.
The Indian Creek Reservoir site -was selected as a logical place to
impound reclaimed water because it offered an agricultural use of
water without release to surface streams.
CHARACTERISTICS OF INDIAN CREEK RESERVOIR
Indian Creek Reservoir is located in Alpine County, California on the
eastern side of the Sierra Nevadas on a tributary of Indian Creek in
11
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Diamond Valley. Figure 1 shows its general relationship to Lake
Tahoe, Luther Pass, and other geographical features of the area, as
well as the profile of the 43. 5 km (27 miles) reclaimed water export
line from South Lake Tahoe.
The reservoir was formed in 1968 by the construction of a rockfill dam,
20.7 m (68 feet) in height, across the tributary to Indian Creek, together
with a smaller saddle dam of the same type to prevent overflow of the
reservoir into a shallow and little used impoundment known as Stevens
Lake. In preparing the reservoir site the original vegetation, com-
prising mostly scrub brush and pinon pine, was removed and the exist-
ing shallow soil stripped down to a stratum of quite impervious hardpan
and rock which characterizes the area. In this manner it was intended
to minimize the organic matter initially present on the bottom of the
reservoir which might subsequently become a nutrient for organic
growth in the overlying water. The reservoir has a maximum depth
of 17 m (56 feet) and maximum mean depth of 6 m (19. 5 feet).
The spillway crest of the main dam was established at an elevation of
1707 in (5600 feet) above mean sea level. Thus it is about 190. 5 m (625
feet) below the water surface elevation of Lake Tahoe and some 640 m
(2100 feet) below the summit of Luther Pass. At maximum water sur-
face elevevation (5600 feet) the surface area of the reservoir is approxi-
mately 64.8 hectares (ha) (160 acres), or about 9 percent of the 688 ha
(1700 acres) of drainage area above the dam. The maximum volume of
impounded water is about 3,860,000 cubic meters (3130 acre feet).
Although the reclaimed water from the STPUD is essentially of drinking
water quality, its disposal to the Carson River system is not permitted
under standards established to preserve the exceptionally low dissolved
solids content of the west Carson River. Therefore the reservoir is
operated -without overflow by releasing to irrigated agriculture during
the growing season the water impounded during the previous winter.
This results in a maximum variation in water surface elevation between
1707 and 1701 meters (5600 and 5582 feet) and a volume variation
between 3,860,000 and 1,230,000 cubic meters (3130 and 1000 acre
feet). Such an extreme variation, however, is not expected to occur
until after the year 2000, at which time the anticipated export from
South Lake Tahoe will approach the 1701 meters (14, 000 acre feet) of
water that agriculture in the immediate area can probably accept at its
full potential. Thus it is evident that the operational schedule of Indian
Creek Reservoir will have some seasonal effects on the quality of the
12
-------
8,000
*". 7,000
1
5J 6,000
u
w 5,000
X
'Treatment
-Plant
Luther Pass
Pumping Station
Indian Creek
Reservoir
J
10 15 20
DISTANCE, miles
25
30
FIGURE I. GEOGRAPHICAL RELATIONSHIPS, INDIAN CREEK
RESERVOIR AND EXPORT LINE FROM LAKE TAHOE
BASIN (2,3 )
13
-------
impounded water. Since the reservoir reached maximum capacity, the
annual fluctuation in volume of water stored in the reservoir has ranged
between 1.2 to 1. 6 million m3 (1000 to 1300 acre feet).
Other factors governing the quality of stored water, beyond the degree
of treatment of the water exported by the STPUD, include the climato-
logical and hydrological characteristics of the reservoir area. As
shown in Figure 2 (Section IV) the long axis of the reservoir lies along
the meridian. Thus it parallels roughly the adjacent Sierra Nevadas to
the west. The mountain range in turn protects the reservoir from the
prevailing winds but guides local winds along the axis of the reservoir
on a generally south to north path. Cover on the drainage area varies
from pinon pine on the east to a stand of timber intermingled with scrub
brush on the west. This cover varies in density from quite heavy brush
to isolated stands of timber. Slopes are steepest on the west; on the
order of 10 to 20 percent at lakeside. To the east the slopes are more
moderate, averaging about one-half the values cited.
The climate of the Indian Creek area is typical of that of the eastern or
"rain shadow" side of the Sierras at altitudes in the 1520 to 1830 m
(5000 to 6000 feet) range. Average annual precipitation at the reservoir
is reported [2] to be about 51 cm (20 inches), with 70 percent of this
total occurring during the winter, November through April, season of
the year. Although snowfall is substantial during the -winter, rainfall
accounts for much of the precipitation. Average monthly records from
the U.S. Weather Bureau gage at Woodfords, California, some 4. 8 km
(3 miles) northwest of Indian Creek Reservoir, show a variation from
0. 86 cm (0. 34 inches) in the months of July and August, to 10. 9 cm
(4. 28 inches) in January, when prevailing storms occur. In spite of
the small amount of summer rainfall it is likely to be intense. Rapid
rise of heated air up the face of the mountains occasions thunderstorms
and, because the soil in the Indian Creek area is shallow and on appre-
ciable slopes, some of the summer precipitation can be expected to run
off into the reservoir. At times of more seasonal rainfall or of snow-
melt on frozen ground, however, considerably more input of meteo-
rological water is to be expected. In contrast with natural runoff,
inputs to the reservoir through the export pipeline of the STPUD are
continuous the year around, being greatest during the summer 'season
when the transient population of the Lake Tahoe Basin is greatest. Thus
the effect of surface runoff on the nature of water reaching the reservoir
is less in summer than would normally result from climatological vari-
ation in the Indian Creek area. An estimate of the nature of this vari-
ation reported in 1970 [4] was as follows:
14
-------
1. Maximum monthly runoff of surface water to reservoir, approxi-
mately 49 times the minimum.
2. Maximum input of reclaimed -water: approximately 6.4 times the
minimum.
3. Minimum ratio of reclaimed water to surface runoff: 1/2. 66
(January).
4. Maximum ratio of reclaimed water to surface runoff: 118/1 (July,
August, September).
5. Anticipated composition of impounded water of annual influent basis:
Meteorological water 30 percent
Reclaimed water 70 percent
As of April 1974 the influent composition has changed due to the increase
in reclaimed water inflow:
Meteorological water 22 percent
Reclaimed water 78 percent
Evaporation from the surface of Indian Creek Reservoir is a factor in
water quality. Rates of evaporation in the area are greatest during
the period, May to October. At this time the daytime temperatures
are highest, leading to a convective rise of air mass up the face of the
adjacent Sierra Nevadas which rise to elevations of from 2380 to 2750
meters (7800 to more than 9000 feet). Nighttime cooling of the air mass
at higher elevations due to back-radiation through the relatively thin
atmospheric cover contributes to a subsidence of cool air at night,
resulting in a day to night temperature change -which may range from
14 to 22°C (25 to 40°F). Thus although the reservoir is sheltered from
prevailing winds, there is a considerable movement of air which scav-
enges the water surface of its overlying blanket of moist air and so
encourages evaporation. Evaporation losses during the four warmest
months may average some 61 cm (24 inches), 18 cm (7 inches) of which
occurs in July. During the period of study herein reported the annual
evaporative loss from Indian Creek Reservoir was estimated at 76 cm
(30 inches).
Because of the relatively small percentage of surface water in com-
parison with reclaimed water and the operating schedule which calls
for withdrawing by discharge to irrigation and by evaporative and
percolative losses the entire reservoir input each year, it may be
expected that the water impounded in Indian Creek Reservoir -will
resemble reclaimed water more closely as time goes on.
15
-------
NEED FOR STUDY
Need for the study herein reported has both utilitarian and practical
scientific aspects. Inasmuch as the process of tertiary treatment of
waste water is far from its ultimate technological and economic opti-
mum, the creation and utilization of Indian Creek Reservoir raised
a number of important questions, including:
1. How effective is tertiary treatment at present levels of develop-
ment in controlling algal growth in impoundments of effluents from
such treatment?
2. What limnological developments in impounded tertiary effluents
will affect beneficial uses of such impoundments?
3. What degree of treatment would be necessary to permit retention
of reclaimed water in the Lake Tahoe Basin without posing a threat to
the quality of JLake Tahoe water?
4. Given recreational or other beneficial uses as objectives of water
reclamation, what treatment processes are required to produce water
of optimum quality characteristics?
Answers to the first two of these questions are badly needed in order to
evaluate the processes currently classed as "advanced" or "tertiary"
treatment in relation to their objectives.
The third question should be answered because it may not be assumed
that tradeoffs between exports from Lake Tahoe via the Truckee River
and via pipelines will not some day have to be adjudicated; nor that
present social, cultural, and aesthetic attitudes toward reclaimed water
will endure forever. Conceivably, water of a quality equal to that of
Lake Tahoe may eventually be produced routinely from waste water and
be in demand by people living in the Basin at that point in time.
The fourth question is of particular importance in the economic manage-
ment of the environment. In contrast with the current practice of add-
ing new unit processes to waste treatment as rapidly as they are de-
veloped in the belief that the more the treatment the less the pollution,
this question envisions the possibility that an optimum balance of water
quality factors might be established for the specific beneficial uses
16
-------
desired and waste water treatment processes tailored to produce that
desired product.
Interwoven in the need to answer questions such as the foregoing is the
need, and the opportunity, to trace the biological and ecological history
of an impoundment of highly treated waste water created on previously
vegetated dry land. The manner in which such an impoundment matures
with time is all important to answering the four questions cited. More-
over, it affords an opportunity never before presented to collect scien-
tific data of exceptional pertinence to the problem of control of eutrophi-
cation of surface waters.
OBJECTIVES OF STUDY
The general objective of the study was to collect and evaluate data
needed in answering questions such as outlined in the Need For Study.
Specific objectives included:
1. To relate the biological, physical, and chemical characteristics
of Indian Creek Reservoir to the corresponding characteristics of
reclaimed water from the STPUD Wastewater Reclamation Plant.
2. To trace the seasonal and temporal changes in the biological,
physical, and chemical characteristics of Indian Creek Reservoir.
3. To relate the observed characteristics of the reservoir water to
the nutrient concentrations and biostimulatory characteristics of the
influent reclaimed water.
4. To evaluate the relative contribution of biostimulants contributed
by the reclaimed water and by exchange from the underlying soil and
sediments.
NATURE AND SCOPE OF REPORT
The report herein presented covers work done on the Indian Creek
Reservoir pursuant to the objectives of the study during the period
December 1, 1968 through May 31, 1971 under Demonstration Grant
16010 DNY. The report draws also upon findings of other cooperating
agencies (see Acknowledgments) which are either published elsewhere
or included herein in the Appendix.
17
-------
Because the work was conducted over three consecutive grant periods
which ended on May 31 of each year, the data were analyzed and evalu-
ated at the end of each of three study periods (April 1969 through March
1970, April 1970 through May 1971, and June 1971 through April 1974).
In preparing this report the results of these three study periods were
compared for the reason that filling of the reservoir and acclimating
of the newly inundated land occurred during the first year, whereas
normal operating plans were in effect during the second; continued
maturation of the reservoir continued throughout the third study period
and it is primarily that period which is discussed herein. Thus the
results obtained during 1969-70 might reveal important limnological
factors in the development of the reservoir which might become either
more or less critical in the more established impoundment of 1970-74.
Such a consideration is especially important wherever averages are
used in the report to describe the physical, chemical, or biological
responses of the reservoir.
This report draws upon and extends figures and tables previously
published in other progress reports [4, 5]. It is a final report sum-
marizing studies from the initial years of the reservoir's existence
to the spring and summer of 1974.
18
-------
SECTION IV
PROJECT DESIGN AND METHODOLOGY
PROJECT DESIGN
The project -was designed around a program of sampling, analysis, and
evaluation and interpretation in terms of the objectives of the study.
The scope and details of the sampling and analytical aspects were de-
signed to determine, within budgetary and climatological limitations,
1) the amount of nutrients entering the reservoir; 2) the effect of such
nutrients on the level of productivity of the reservoir; and 3) the en-
vironmental fate of these nutrients. It was particularly desired to
learn whether nutrients are sequestered in the reservoir sediments or
biota, escape to the surrounding environment via the atmosphere, or
pass through the reservoir with outflowing water.
Sampling stations were chosen at the locations indicated in Figure 2.
Initially, the reclaimed water influent to the reservoir (herein desig-
nated by the symbol, III) was sampled at the STPUD plant at the inlet
to the pressure outfall line, some 43. 5 km (27 miles) from Indian Creek
Reservoir. Beginning in July 1969, however, this influent sampling
was made at the Luther Pass pumping station (see Figure 1, Section
III), some 16 km (10 miles) closer to the reservoir. Discharge from
the reservoir (herein designated by the symbol, B) was sampled and
measured in rate at a valved outlet pipe in the main dam from which
water is discharged in significant amounts during the irrigation season.
At other times continuous leakage occurs at a rate of about 57 i /minute
(15 gpm) due to poor seating of the valve. By June 1970 it was evident
from analytical results that the chemical quality of the discharge (B)
was no different than that of the reservoir water because of the high
degree of mixing of the impounded water. Therefore sampling of the
discharge was discontinued. A composite sample of the impounded
water (herein designated by the symbol, C) was made up of several
19
-------
(Collected at STPUD
or Luther Pass
Pumping Station)
Spillway
Snow
Sample
Runoff
FIGURE 2. LOCATION OF SAMPLING STATIONS AT INDIAN
CREEK RESERVOIR
20
-------
portions collected around Station 1 (Figure 2). Comparison of analyses
of samples from this and other stations in the reservoir showed that
Station 1 yielded a good estimate of the levels of nutrients and other
constituents of the impounded reservoir water.
SAMPLING PROGRAM AND METHODS
Beginning in April 1969 the influent (III) and composite sample (C) of
the reservoir were collected in one-gallon lots (3. 8 8.) as often as
weather conditions permitted, but generally on approximately a weekly
schedule. Normally, reservoir sampling was made by use of a trailer-
mounted 3. 7 m (12-foot) aluminum outboard motor boat. Of necessity
this equipment had to be stored at the Lake Tahoe Area Council Labora-
tory some 96 km (60 miles) from the reservoir, hence when road con-
ditions made transfer of the boat difficult, a one-man inflatable rubber
boat was used to collect reservoir samples.
Bottom sediments, benthic invertebrates, phyto- and zooplankton were
sampled at intervals to study the aquatic community of Indian Creek
Reservoir. A composite sample of the soil from 20 stations around the
impoundment was collected in the zone above the water line from which
vegetation had been stripped in preparing the site in order to get some
idea of the probable organic content of the reservoir bottom initially.
Temperatures were measured using a laboratory thermometer (-10 to
110 C). The Secchi depth was determined as the average point of dis-
appearance for an ascending and descending 20. 3 cm (8 inch) diameter
white, flat, circular, metal plate. Reservoir depth was read from a
staff gage installed at the main dam.
The influent, discharge, and reservoir composite water samples were
collected directly in polyethylene bottles used as sample containers.
Samples at different depths below the water surface were collected with
a plastic Kemmerer sampler and transferred to polyethylene bottles.
Bottom sediments were sampled with an Ekman or Ponar dredge. Al-
though rocks and sticks interfered with operation of the dredge in some
shoreline areas, it was generally not too difficult to collect adequate
lake sediment (as opposed to the soil stratum constituting the reservoir
bottom). Usually a depth of 2-5 cm (1-2 inches) of silty-clay was col-
lected at each sampling site. This was screened (U. S. No. 30) when
collection and analysis of benthic invertebrates was the objective, or
mixed and placed in a sample container for later chemical analysis.
2.1
-------
Phytoplankton samples were collected as water samples. Zooplankton
were counted directly in water samples or collected by either surface
tows (30 m, 100 foot tow near Station 1) or vertical tows (bottom of
reservoir to surface) using a Wisconsin Style Plankton net (No. 20
mesh nylon, 117 mm opening) and bucket.
Records of climate and of the flora and fauna observed in the Indian
Creek Reservoir Basin were also collected during the sampling trips
to Indian Creek Reservoir. For example, wind direction and speed,
cloud cover, and unusual climatological conditions were recorded
regularly in a permanent log book. Also, visitations to the lake of
deer and migratory waterfowl (principally, ducks and grebes) were
observed and recorded. The location of developing vascular plant
communities, floating algal material, and similar phenomena which
would be expected to indicate changes in the reservoir conditions were
noted. Data on the developing fish population were obtained, princi-
pally from the Department of Fish and Game.
In addition to the regular program of sampling of influent and impounded
waters, samples of surface runoff were collected when such runoff was
observed. However, because of the dry environment, very little runoff
occurred during the summer months. As a rule summer precipitation
takes place during a relatively short period of time and is rapidly
absorbed or drained into the reservoir. This decreased the likelihood
of personnel being on the site to obtain samples when runoff occurred.
Data obtained from studies conducted by the Environmental Protection
Agency, the California Department of Water Resources and of Fish and
Game, and the South Tahoe Public Utility District were also used to
supplement direct observations made by the project staff.
TREATMENT OF SAMPLES
Methods of field and laboratory treatment, as well as storage, of
sample were designed to maintain continuity of the work load in the
laboratory without sacrificing accuracy of the results of analyses for
such characteristics as: DO, COD, BOD, SS, VSS, nitrogen series,'
orthophosphate, total phosphorus, iron, chlorides, calcium, alkalinity,
pH, conductivity, and the bio stimulatory properties of various con-
centrations of the sample.
22
-------
Water samples were normally transported to the laboratory and stored
overnight in a refrigerator (< 5 C) for chemical analysis the following
day. When it was not possible to begin analysis on such a schedule,
the water samples were filtered and the filtrate frozen for analysis at
a later time. Analysis for DO and BOD was begun in the field (re-
agents added up to and including the concentrated P^SO^.). Initially pH
and alkalinity were determined in the field; however, no differences
due to the time involved in transporting samples to the laboratory were
observed and so all other analyses of the regular weekly water samples
were performed in the laboratory.
Phytoplankton were placed in brown glass jars and preserved in the
field in a 5 percent Na2CO3 neutralized formalin solution. Zooplankton
were preserved in 5-10 percent neutralized formalin in brown glass
jars. The benthic invertebrates were placed in glass jars after having
been screened and rinsed with reservoir water and 15 percent neutral-
ized formalin was added for preservation. Bottom sediment samples
were placed in brown glass jars and brought back to the laboratory for
later analysis.
ANALYTICAL PROCEDURES
Preparation of Samples
Preliminary preparation of samples for physical and chemical analyses
and bioassays varied somewhat depending on the specific method chosen
for each assay. Water samples selected for flask bioassays, including
Lake Tahoe water used for dilution, were filtered through Whatman
glass fiber filters (GF/C) and finally through Millipore(5) filters (HA,
0. 45|i pore size). They were then stored in tightly stoppered poly-
ethylene containers and frozen, unless the test was to begin within five
days. For chemical analyses aliquots of the samples, both the un-
filtered and those passed through the previously described glass fiber
and Millipore(5/ filters, were kept in tightly capped 2-i. polyethylene
containers and stored in a refrigerator at temperatures approaching
0 C until all chemical determinations were completed. It was deter-
mined that no significant difference existed between chemical analyses
of nutrients measured in unfiltered or filtered samples.
23
-------
Chemical Assays
Chemical analyses of the filtered and unfiltered water samples were
made according to Standard Methods [6] in determining biochemical
oxygen demand (BOD), chemical oxygen demand (COD), pH, alkalinity,
organic nitrogen, ammonia, chlorides, total phosphorus, calcium, and
conductivity. Methods described by Strickland and Parsons [?] were
considered more suitable for iron, nitrite, nitrate, and reactive in-
organic phosphorus at the low concentrations prevailing in the Tahoe
samples. Details of individual analyses are presented in Appendix G in
[4]. All laboratory chemical determinations were subjected to repli-
cate analyses on aliquots of the same sample [8, 9] to determine the
precision of results attainable by the project staff by the analytical
procedure used. The results showed that with the exception of organic
nitrogen and total phosphorus in Lake Tahoe water, where concentrations
are extremely small, the chemical analytical work is of good precision
in terms of the coefficient of variation. A statistical analysis of the
two methods of laboratory filtration (0. 45|j. HA Millipore and GF/C
Whatman glass fiber filter paper) indicated that there is no essential
difference in the accuracy of the two methods.
Sediment chemical composition on a dry weight basis (available P,
organic carbon, total N, and particle size) was determined according
to methods described by Porcella et al. [lO],
The technique for measuring total suspended solids (SS) and volatile
suspended solids (VSS) was patterned from a combination of the pro-
cedures outlined in Standard Methods [6]; Strickland and Parsons [?];
and Maciolek [ll]. Whatman glass fiber filters (GF/C) were used in
solids preparation. The filters were prepared by soaking in distilled
water to wash the fibers free of salts. They were then placed in a
103°C hot air oven overnight. Thereafter they were placed in a muffle
furnace for 30 minutes at 450°C to destroy any organic matter present
without fusing the glass fibers. After cooling, the filters were dried
in a hot air oven at 103°C and tared quickly on a Mettler semimicro
balance, to avoid error due to the hydroscopic nature of the dried
filter. In making the solids determinations the sample was applibd 1:o
the filter until the volume of sample had passed through, or until the
filter was completely clogged. The volume of filtrate was then re-
corded. The filters with their load of suspended solids were dried
overnight at 103°C and the dry weight recorded to the nearest 0. 01 mg.
24
-------
To determine the VSS present in suspended solids the loaded filters
were then redried and reweighed to verify the SS value. They were
then ignited at 560°C for 1 hour, soaked with a few drops of distilled
water to rehydrate the mineral matter, dried overnight at 103°C and
weighed. The loss in weight was recorded as VSS in
In some cases it was necessary to revise the suggested methods in
order to expand the scope of the analysis to encompass the wide range
of nutrient concentrations encountered in the various samples assayed.
The procedure was to prepare two standard curves for the Beckman
Model B spectrophotometer, one using a 1-cm pathway cuvette and the
other a 5 -cm cuvette. The range of concentration for N, P, and Fe
using the two pathway cells was from 1 |o.g/^ to 200 \i.g/2 . Samples in
which the level of the constituent exceeded the maximum range of con-
centration were diluted to the concentration range of the cells by a
measured volume of deionized water.
Flask Bioassays
Reservoir samples (C) and reservoir influent water (III) were assayed
by the flask bioassay technique [8, 9] both undiluted and diluted to 10
percent and 1 percent concentrations in Lake Tahoe water,
In making the assay the filtered sample was first diluted to the desired
concentration with filtered Lake Tahoe water. One hundred and fifty
m£ of this solution was then placed in each of three sterile 250 mtf
Erlenmeyer flasks. Glassware used in assays was dry heat sterilized.
Cells of Selenastrum capricornutum in good physiological condition
were centrifuged and washed twice in Lake Tahoe water to minimize
the chance of nutrient carry over from the stock culture to the test
flasks. An equal volume of the suspended cells was then added to each
test flask, so that the concentrations of cells in the 150 mf. of liquid
was approximately 50 cells /mm .
Loose fitting plastic beakers were inverted over the tops of the inocu-
lated test flasks, prior to being placed in a 20°C constant temperature
room and incubated on a gently moving (30 cycles /min) shaker table
for a period of five days. Illumination of approximately 550 ft-c (5920
lux) intensity was provided by four 40 watt G. E. fluorescent lamps,
No.. F40-CW, Coolwhite, four ft in length.
25
-------
The cell concentration in the test flasks was determined by cell counts
at the end of 1, 3, and 5 days during the five week period of incubation.
After the final counts were completed, suspended solids and pH mea-
surements were made on a composite of the liquid in the five replicate
flasks.
The basic culture of Selenastrum capricornutum. was maintained at a
constant growth rate by the continuous culture method (9 = 5 days)
using a nutrient solution of 10 percent Skulberg's medium [12] (Appen-
dix 7).
Algal Counting Procedures
The Model B Coulter counter was used for cell counts. The method
used in the Coulter counter technique involved removing a 10 m^
aliquot from each flask. The aliquot was then diluted with a saline
solution so that the final concentration was from a maximum of 50
percent to the concentration that will provide a final count of less than
100, 000 particles (counting capacity of the Coulter counter) for a 0. 5
mi diluted sample. The maximum time required for each count is
13 sec. A mean value was obtained for the five replicate flasks.
Reliability, Sensitivity, and
Precision of Cell Counting
The Coulter counter records each time a particle passes between two
electrodes. A coincidence correction coefficient is multiplied by the
number of particles recorded by the Coulter counter, thereby, pro-
viding a statistical correction for the possibility of superimposed cells
passing between the electrodes at the same time. Thus it is obvious
that the Coulter counter should provide a much higher degree of sensi-
tivity and reliability as well as the added benefit of a considerable
time saving over the hand counting technique. The reliability of the
Coulter counter was emphasized when the same sample was introduced
to the Coulter counter several times in succession and the difference
in the numerical results was found to be insignificant (< < 1 percent
coefficient of variation).
26
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SECTION V
RESULTS OF STUDY
INTRODUCTION
Pursuant to the objectives and the program outlined in Section III,
physical, chemical, and biological observations were made of the pro-
gressive changes in the water budget and in water quality in Indian
Creek Reservoir (ICR). The results of these observations are here-
inafter presented and discussed, and further evaluated in Section VI.
The data presented and analyzed were collected by members of the
project staff and by the South Tahoe Public Utility District as a part
of their normal operating procedures. Estimates by Clair A. Hill and
Associates for the STPUD [2] were also used in computing the water
budget of the reservoir.
The data for the earlier years of the project are contained in previous
reports (April 1968 to March 1970 [4]; April 1970 to March 1971 [5])
and are contiguous with the data presented in this report (April 1971 to
October 13, 1974, Appendix 8; graphical presentations are for April
1971 to April 1974 only). Where appropriate, the data from the prev-
ious reports are summarized herein. Missing data resulted from
interrupted findings, limited access to the sampling sites, or to strong
winds which prevented the launching of a sampling boat.
GENERAL, OBSERVATIONS
Observations of the reservoir (Table 1) indicate an increase in recre-
ational use, chiefly by fishermen and campers, and in irrigation use
because flows of reclaimed water have increased in scale with popula-
tion increase in the area served by the STPUD. The continued increase
27
-------
TABLE 1. WEEKLY OBSERVATIONS OF ENVIRONMENTAL DATA,
INDIAN CREEK RESERVOIR (JUNE 1971 MAY 1974)
1
D»te
J^ 1971
2
14
21
Jol
7
19
21
Am
2
9
16
23
30
7
20
27
Oct
4
11
18
27
Nor
1
8
15
22
30
J«n 1972
10
24
Mjr
27
Apr
3
10
17
25
2
Time
el
D.T
(hour.)
12:00
12:30
12:10
11:30
12:35
12:10
13:00
13:00
12:45
12:00
12:10
11:45
12:00
12:00
11:20
12:50
1:15
11:00
12:15
11:45
12:10
11:50
11:45
11:35
12:15
9:15
11:25
10:45
11:15
11:00
3
Depth
(meter*)
3."
2.4
5.3
3.9
4. 0
5.2
5.2
3.0
2.8
3.8
3.7
3.4
4.4
4. 1
5.1
5.2
4.8
"
S.8
5.4
4.3
5.3
5.5
--
-
1. 1
1.2
--
4. 9
6.1
4
Depth
(ftl
53. 1
53.1
53.3
53.7
53.9
53.9
53.9
53.9
53.6
52.9
52.9
52.0
51.4
51.5
51.7
SI. 8
52.0
-
52.1
52.3
52.8
52.9
53.0
--
--
51.0
5...
--
51.6
52.0
5
Temp.
<°c>
13.5
18. 0
18.7
19.8
21. 1
22.0
23.5
23.5
21. 0
21.0
20.0
17.8
17.0
14.5
12.0
14. 0
11.0
--
7.0
6.8
5.0
4.0
4.0
I 9
3.5
9.0
10. 0
9.0
9.0
10. 5
4
Temp.
• °C>
11.0
25.0
2J.5
22,0
21.0
23.0
29.5
28. 0
24.0
22. 1
20.8
20.0
14. 0
19.0
22.0
11. 0
—
17.0
12.0
2,0
13.0
3. 5
9. 0
a, 2
I.O
19.0
14.0
9.5
13.0
7
Remarks
Blue, partly cloudy, relocated ata. No. 3 approximately 100' S- in deeper location
Blue, flying insects a slight nuisance near shore
Blue, approximately 20 fishermen. 4 boats, flying insects still present
Blue, approximately 20-30 anglers, abundant pop- mayflies and night hawks
Blue, partly cloudy, numerous fishermen. 3 boats, insects still present
Blue, approximately 20 fishermen fishing reported poor, greenish cast
Blue, partly cloudy, aquatic growth heavy in near shore areas -- 2 swimmers
Blue, partly cloudy, approximately six vehicles with fishermen. 1 boat, no water
fowl* observed
Blue, partly cloudy, no fishermen, no wildlife observed, strange
Blue, approximately 18 anglers, one reported a 10'' catch, calm
Blue, large masses floating marine flora
Blue, approximately 25 fishermen, heavy amounts el* aquatic growth
Blue, prolific aquatic growth, gusty surface choppy
Blue, several hundred American Coots in bay
Blue, approximately 11 cars and 3 boats
Blue, beautiful day. Lake surface glassy
Blue to partly cloudy. Coot population diminishing
Partly cloudy, 50 A mph winds, impossible to launch
Blue, bent hie study
Blue to partly cloudy, extremely green cast, abundant aquatic growth
Cloudy, ground snow covered, aerators operating
Blue, fishing season closed 11-15
Snow, one to 2 inches snow and light snow falling
Blue, samples taken through approximately 9" ice. Lake entirely frozen
Blue to partly cloudy. Lake 75% frozen approximately 6" tee, aerators operating
Blue to partly cloudy, aerators operating, several hundred gulls and smaller birds
Blue to partly cloudy, millions of black gnat-like flying Iniecta. aerators operating
Partly cloudy, approximately 40 mph 5W wind, too windy to launch, well mixed
Blue, black flying insects a nuisance, moderate SW winds
Partly cloudy, deepest secchi thus far, checked by two observers
28
-------
TABLE 1 (continued)
1
Date
1
8
15
22
30
Jon
5
26
Jnl
10
17
25
31
AUB
8
14
21
28
Sej*
5
11
18
25
Oct
I
9
16
20
30
Nor
6
13
20
27
2
Time
of
(hour*)
11:20
11:20
11:15
11:45
11:15
11:40
11:00
11:20
11:00
11:00
11:25
11:15
11:40
11:10
11:05
11:10
11:15
10:55
11:22
11:25
11:45
11:45
11:05
11:25
11:30
11:45
11:05
10:45
3
Secchi
Depth
(meter,)
6. 1
4.5
2.7
3.0
6. 1.
f.S
4.5
3.2
4. 5
3. 1
3.3
4.3
3.4
4. y
5.5
6.6
4.4
t. t
6. B
7.3
4.4
5.5
6.0
5.4
3.7
3.5
6.1
7.3
4
Water
Depth
(ft)
52.1
52.1
52.1
52.2
S2.4
52.4
52.5
52.3
51.8
51.0
50.5
47.5
47.2
46.0
44.2
42.3
42.0
41.4
41.9
43.0
43.1
43.2
43.7
44.1
44.5
44.8
45.2
45.7
5
Water
Temp-
(°CJ
11. £
12.6
15.5
14.2
19. 0
19. 0
19.2
20.0
22.0
20.0
21.0
21.2
19.2
18.2
19.0
18.0
16.9
16.0
14.0
13.2
14.0
12.0
10.8
8.7
7.9
5.9
4.5
3.9
6
Air
Temp.
<"C>
17.0
15.0
22.0
15.0
25.0
21. u
24.0
26. 5
26.0
24.0
24. 0
22.0
17.0
19. 5
19.0
19.5
14.0
16.0
13.0
15. 5
8.0
7.0
4.0
7. 1
7. 0
3.0
4.5
7
Remark*
Blue. ftBhing opening day. 1/4 ii,h per hour
Partly cloudy. swallow, feeding on flying black inflects
Partly cloudy, approximately 24 fi,hermen, aoutherly wind* guattog
Partly cloudy, very calm. 2 boats. 14 aaglera
Blue, no aquatic growth viBible. enail population increased
Partly cloudy, aquatic growth now apparent near launch are*
Partly cloudy. Blight northerly. 2 boats, 12 fishermen
Blue, reservoir level down 0. 2'
Blue, prolific aquatic growth breaking lurface
Blue, approximately 24 anglers. 11/4 fish/hr reported
Partly cloudy, marine flora now extending approximately 30' around entire perimeter1
Blue, brisk southerly, wave 4 - 6". 3 fishing boat*
Partly cloudy, STPUD harvesting aquatic growth with mechanical sickle device
Partly cloudy, BLM Const, crews working on South perimeter road to California
Cloudy, rain, cutting discontinued, aesthetically unsuccessful
Partly cloudy. STPUD unsuccessfully trying to burn aquatic debris
Partly cloudy aerators operating approximately 10 fishermen mostly in boats
Cloudy, large population of American Coots, several hundred
Cloudy, 3 boats. 10 angler*, benethic study made, aerators not operating
Partly cloudy, BLM Contractors working on recreation facilities
Cloudy, bacteriological survey conducted with Don PorcclU
Partly cloudy northerly wind gustlng wave 2 - 4". 2 boat*
Partly cloudy. SW wave 5 - 8". 2 boats. 4 car*
Cloudy, snow, wind from S approximately 2$ * 30 mph, approximately tOOCoots
2 fishermen
Blu«. aeration greatly Improved. BLM Contractors out for winter
Blue. elec. Into a*rators4 Coots still abundant, calm, glassy
29
-------
TABLE 1 (continued)
1
Date
Dec
5
11
26
Jan 1973
2
8
IS
22
29
Feb
5
13
20
26
Mar
5
12
19
26
**»
9
16
23
30
MIT
7
»
21
26
Jun
4
11
18
25
Jul
Z
9
17
23
Z
Time
of
Day
(hour.)
12:30
11:20
11:12
11:05
10:50
11:15
11:40
11:30
11:30
11:30
11:45
11:20
11:34
11:45
10:55
11:15
11:10
11:35
11:30
11:15
11:10
10:50
11:15
11:20
11:55
10:50
11:30
11:20
11:05
11:40
11:10
11:30
12:30
3
SeccM
Depth
(meteri)
Ice
Ice
Ice
Ice
Ice
Ice
Ice
Ice
Ice
Ice
Ice
Ice
Ice
--
-
1.2
1.6
--
8.'
7.6
7.6
6.0
4.5
4.5
2.6
4.9
5.4
4. 9
5.3
4. 3
4. 5
4. 7
4
Water
Depth
(ft)
--
-
—
--
--
--
--
--
--
--
--
--
--
--
--
54.5
„
55.0
--
55.7
55.9
56.0
56.3
56.5
56.3
56.3
56.6
56.4
56.3
56.4
55.9
54.0
52.8
5
Water
Temp.
(°C)
2.5
1.0
2.0
2.0
2.0
2.5
2.5
3.0
2.2
4.5
7.0
7. 1
4. 1
6.5
7.2
6.2
8.0
9.5
10.2
10.8
12.1
14. 0
15.0
16.5
17.2
17.8
19.5
17. Z
18.5
19.0
21.0
21.0
20.2
6
Air
Temp.
<°C)
3.0
-1 1. £
5.5
5.2
2.0
8.0
0.0
1.0
2.8
5.0
5.0
10.0
6.0
6.8
9. 1
12.0
11.0
13.9
9.0
14.8
13.0
16.0
17.3
16.2
18. 8
13.2
19.0
14.5
19.6
23.0
22.0
20.5
24.6
7
Remark*
Partly cloudy, approximately 15% frozen with 1/2 to 1 1/2" Ice, 2 - 3" .cow
Blue, approximately 3" ice covering 99% Lake. 6 - B" anew
Partly cloudy, blue, approximately 75% frozen with 1" ice, open over aeration line.
Blue, approximately 85% frozen, 1 to 1 1/2". toad .lippery, .trong .outherly
Cloudy, 65% frozen, 1 1/2 to 2 1/2" ice cover, .now expected
Blue, partly cloudy, 50% frozen with lemm than 1" ice, mixing
Blue, 85% frozen, approximately 1 dozen bird, netting on the ice
Cloudy, .now. 80% frozen approximately 1" of *now on ground
Partly eloudy, 1/2 to 1" ice covering 75% .orface
Blue, 70% ice cover, approximately 12" .now, road not plowed
Blue, 50% Ice, road extremely muddy
Cloudy, 40% ice, 35 mph wind, flock of water fowl
Blue. 30% ice cover, PUD aerating with 90 p.i compreiaor
Cloudy, completely unfrozen, PUD aerating at launch
Cloudy, 1 to 2" wave, 3 car.. 4 fi.hermen, 1 boat
Blue, partly cloudy, 4 vehicle*. 8 fishermen, filh jumping apparently under .tree*
Partly cloudy, slight northerly. PUD aerating with portable unit
Cloudy, approximately 26 fishermen. Hying gnat-like insect, a problem
Partly cloudy, 20 mph wind. SE. approximately 12 fishermen, PUD aerating
Blue, approximately 20 vehicle.. 4 campers, green filamentous algae
Partly cloudy, overnight campers, several M swallows diving at surface
Blue, approximately 28 fishermen, slight northerly breeze
Blue, partly cloudy, approximately 6 ree. vehicles, mayflies hatching
Blue, noticeable burnt odor near North dam, floating clumps algae
Blue,approximately 50 fishermen, 17 boats, 49 boats previous Saturday
Blue, floating algal chimps East of boat launch
Partly cloudy, northerly wind, 8-10 mph, approximately IB fishermen
Blue, approximately 16 vehicles, 24 fishermen and 6 boats
Blue, approximately 10 fishermen, abundant snail population, floating algae
Blue, brisk SW wind, approximately 24 fishing, 4 boats. 9 ree. vehicle.
Blue, increased algal bloom, near boat launch
Partly cloudy, approximately 10 boats. 24 fishermen, 4 ree. vehicle.
Blue, wind, from S at 2 to 5 mph, wave 3 to 6" ,
__ , _ _ — •" '
30
-------
TABLE 1 (continued)
1
D*te
6
13
20
26
Sag
4
10
17
24
1
1
15
22
29
Nev
13
19
26
Dec
4
17
26
Jin 1974
14
21
2B
2
Time
of
(hoari)
11:20
12:20
11:45
11:10
11:00
11:00
11:31
11:15
11:30
11:10
11:00
11:05
11:05
10:40
11:45
12:00
11:50
11:45
11:30
11:45
12:05
11:15
3
Secchl
Depth
Imeter*)
5.7
0. 1
5.5
7.3
6.2
5.2
5.7
--
>6. 7
6.0
6.6
--
4.7
. 5.2
--
"
--
--
--
—
-
4
W.ter
Depth
(ftl
51.0
49.3
48.0
45.8
44.6
42.4
40.9
41.3
41.9
42.0
42.6
43.0
43.4
45. 1
-
"
..
-
--
-
"
5
W.ter
Temp,
(°CI
21.5
20.2
19. 5
17. 0
17.0
17.0
17.2
1 5. 3
14.6
II. 2
16.8
12.2
10.0
7.5
4.2
i.a
--
4.0
4.0
4.0
6.0
6.5
6
Air
Temp.
("0
29.0
22.5
19. 8
18.9
19.2
11. «
19.5
12.7
IB. 4
8.9
18.5
14. 1
8.5
6.4
4.0
3. 1
1.0
a.4
11.0
3.5
1.5
9. 1
7
Remarks
Blue, partly cloudy, extremely warm water level going down rapidly
Blue, wind guitlng to 10 mph, wave 3 to 6"
Blue, nmtherly winds to 20 mph
Blue, winds from N, wave 3 to 5", 3 boats
Blue, partly cloudy. 14-16 angler t, 7 boat*, slight northerly
Cloudy, PUD dragon harvesting, aquatic weed growth
Partly cloudy, otrong (35—45 mph) S. W. winds, toe windy to launch
Cloudy, Secchl resting on bottom etlll visible
Cloudy. BOutherly> large population of Coots
Partly cloudy. 4 fishermen. 3 cara, southerly winds
Partly cloudy, brtik southerly 15" white raps, no launch
Blue, alight N. wind, wave 1 - 2", a ma 11 flock of Coots
Cloudy, strong SVf wind 30 -- 35 mph, no launch
Blue, calm, road muddy. Coot population Into thousands
Partly cloudy, 1/4" Ice around shallows, light snow, calm
Partly cloudy, 15% tee-cover 1/2 to 3/4", no Inflow due to power outage
Cloudy. vtrong SW, Coot population dlmlnshlng
Cloudy, thin layer Ice, early a. m. broken up by wind
Cloudy, approximately 60% frozen. 2 fishermen, no wind
Partly cloudy, no Ice cover, approximately 1" new snow. 4 fishing
B)u«, slight SW wind, no lea. approximately 6 rUhermcn
31
-------
TABLE 1 (continued)
1
Date
Feb
4
11
20
25
4
12
18
25
2
1
i;
22
29
".
2
Time
ol
Day
(hour,)
11:15
11:15
11:10
11:30
12:30
11:15
12:00
11:20
12:00
11:15
11:40
11:15
11:10
11:25
3
Secchl
Depth
(meter.)
--
--
--
--
..
--
5.2
-•
._
--
--
--
3.3
6.1
4
Water
Depth
<«>
--
--
up
--
..
--
54.6
»P
up
up
up
np
57.0
57.0
5
Water
Temp.
<°C>
5.9
5.5
5.3
9.0
8. 1
r. i
6.3
8.2
9.0
10. a
10. 1
13. 1
11.2
13. a
6
Air
Temp.
I°CI
7.2
12.0
1.5
13.8
8.0
8.2
12.0
6. 1
2.0
9.6
8.2
9.2
10.0
,4,
7
Remarks
Blue. • light SW wind, catch 3 . 18" rainbows 3 to 4 Ib In 1 hr
Blue, southerly wind gutting to 20 mph, 12 to 16" whltecaps
Blue, no Ice, 2" enow. level up considerably
Partly cloudy, brisk SW. 4 vehicle*, 8 to 10 fishing, no snow or Ice
Blue. 8 to 10" new enow, alight NW wind. • now shoe Into reservoir
Partly cloudy. SW winds gnat Ing to 40 mph, whlteeap* to 16"
Cloudy, no wind, boat launched, water very green, 4 fishing
Cloudy, snow, wind southerly at 10 mph. fishing poor
Partly cloudy, slight southerly, large flock black birds
Blue, partly cloudy, strong southerly guitlng to 50 mph. 20" wave
Blue, strong winds from couth, whltecapplng
Partly cloudy, strong southerly, overnight campers, soaring gulls
Partly cloudy, approximately 20 angler*, mass of floating clumps, soaring gulls
Blue, approximately 16 anglers* approximately 40 gulls, mayflies hatched,
•light north wind.
32
-------
in aquatic weed growth with aging of the reservoir has been a major
observable trend.
Simple quantitative methods for heterogenous and complex systems
often are incomplete and photographs can convey better understanding
of the total system than other kinds of measurements. The aerial
photograph (Figure 3) was taken to illustrate the accumulated aquatic
vegetation in littoral areas of the reservoir at the low water mark in
reference to the high water mark as of November 2, 1972 (see Figure
2 for schematic description of reservoir). The dirt road can be
clearly seen as it circles the lake. Also there is a sharp outline of
the water's edge as well as the greyish border of grass above the
shoreline as it meets the white of the exposed lake bottom (Figure 3A).
The aquatic weeds (Figure 3B) show up as greyish areas in the shallows
of the lake.
The picture (Figure 3) illustrates a segment of the typical ICR annual
cycle, i. e. , attaining the low water volume during the fall as a result
of the irrigation season. The reservoir fills during the winter months.
Thus, as spring begins and water is discharged for irrigation, aquatic
vascular plants begin to bloom in shallow areas. These weeds are
limited in their areal expansion most probably by light intensity.
Higher turbidity with the spring phytoplankton bloom and other suspend-
ed solids interferes with light transmission (refer to Secchi disc meas-
urements in Figure 4) and restricts weed growth to shallow water areas
along the edge of the reservoir. This is followed by increased water
clarity hence light transmission during the early summer months
allows penetration of weed growth into deeper waters.
Irrigation water use causes a marked decrease in water level leaving
banks of weeds dying on the exposed shores but also allowing expansion
of the weed population into deeper waters. This pattern allows expan-
sion of the aquatic weed community to expand into deeper waters and
cover greater areas of ICR each year.
Reservoir management practices at ICR began with the installation of
aeration apparatus in 1970 for destratification purposes. Aeration has
been more or less continuous, maintaining relatively isothermal con-
ditions but not saturation with DO nor biological mixing; biological
populations of plankton remain unevenly distributed.
33
-------
A. Color photograph in black and white; north to south reads left to
right.
B. Infrared in black and white. Note plant growth in shallow south
area and along west shore.
Figure 3. Composite aerial photographs of Indian Creek Reservoir
November 2, 1972.
34
-------
In the summer of 1972 aquatic weeds became a significant nuisance in
ICR and a rented mechanical weed harvester was used to remove some
of the shoreline growth; burning of the dried, exposed weeds was also
undertaken as a means of control but apparently had little effect on
weed growth during the following years. The rented harvester was
utilized again in summer, 1973; in summer, 1974, beginning after
July 4 and finishing about the middle of August. A harvester, the
"Dragon, " designed and built by STPUD was utilized for harvesting and
reportedly removed more than 300-400 cubic yards of plant material
from ICR [13]. The effects of this harvesting were not readily appar-
ent at the time of this reporting (September 1974). A diminution in
ICR. nutrient concentrations occurred but weeds were still abundant in
September 1974 and interfered with bank fishing. At that time weeds
had covered a larger area of the reservoir as the water level dropped
during the summer irrigation season.
During the latter half of summer 1974 a significant population of blue
green algae, Oscillatoria (rubescens) was observed growing on de-
tached Cladophora clumps and on attached weeds, principally Myrio-
phyllum. The blue green algae imparted a significant earthy odor [14]
which apparently tainted the fish flavor in addition to producing a strong
shoreline odor observed by the project staff on September 4, 1974. It
is unclear what conditions influenced the development of the large
bloom of this alga.
Insects flying around the lake and over its surface are plentiful in
summer and include damselflies, dypterans and mayflies. Bird popu-
lations vary chiefly with the migratory season.
Weather conditions at ICR remain fairly typical; brisk winds and
breezes occur in the fall through winter and during mid-day (11 a.m.
to 3 p.m. ) during summer. Clear skies are more common during the
summer when minimal precipitation occurs.
Wind direction seems to be heavily influenced by the adjacent mountain
range, with southwesterly or northwesterly winds most common. Only
on rare occasions was the water surface free of ripples or waves due
to wind, a fact which undoubtedly reduced the clarity as measured by
the Secchi disk. The roughest water observed resulted from strong
southwesterly winds in October and December, and from northerly
winds in March.
35
-------
Wind movement across the reservoir undoubtedly has an important
effect on mixing of the reservoir. From Figure 2 (Section IV) it may
be seen that a southerly wind roughly parallels the long axis of the
reservoir, moving from the shallowest water towards the dam. Waves
induced by such wind action then tend to stir up sediments in the shal-
lows and, if of any duration, to pile up water at the deepest end of the
reservoir. Subsequent movement of water is therefore from the re-
claimed water inlet (near the dam) to the shallow southerly end of the
pool. A northerly wind, of course, develops a seiche that results in a
return flow to the dam when calm is restored. Southwesterly winds
blow toward the lake shore northeast of the dam (see Figure 2) and,
because of the protection of a high ridge at the west abutment of the
dam, can be expected to initiate a counterclockwise movement of the
surface water in the reservoir. This should have a mixing effect, at
least in the deeper portion of the impoundment north of an east-west
line passing through the saddle dam. It is concluded that the well
mixed condition found to exist in Indian Creek Reservoir is to no small
degree a result of wind movement and direction.
Water Budgets of ICR
Because the chief purpose of this report is to catalog biological changes
with respect to reservoir maturation, chemical changes, and biological
succession, analysis of hydrologic events is limited to a brief review
of data in previous reports (4, 5) and to a brief analysis and listing of
recent flows into ICR from STPUD (see Appendix 6).
Filling of Indian Creek Reservoir was begun on March 31, 1968. Table
2 summarizes five 12-month periods (April through March, 1969-1974)
in developing a water budget for Indian Creek Reservoir. The values
for use in the water balance equation, E + P = I + RO + P - D - V
- AS, were estimated as hereinafter outlined.0 Definition ofeach sym-
bol in the equation is noted in column 2 of Table 2.
An obvious development with time has been the increase in flow from
STPUD into the ICR system and the increase in use of the reclaimed
effluent as irrigation water. The reclaimed water inflow is not yet
equivalent to that estimated in the planning study (see Appendix 2).
Evaporation from the reservoir surface (E) was computed from the
reservoir water surface corresponding to the average gage height ob-
served for each month of the year, multiplied by the average
36
-------
Table Z. ESTIMATIONS OF ANNUAL WATER BALANCES FOR INDIAN CREEK RESERVOIR
[SEE 4, 5 FOR METHODS]
Symbols
for Water
Budget
Equation
Ia
RO
PL
Eb
PC
o
3,
D
voe
AS
Explanation
STPUD reclaimed
water influent (+)
Sub-basin drainage
into ICR (+)
Precipitation on
ICR surface" (+)
Evaporation from
reservoir surface (-)
Percolation
throu,gh reservoir
bottom (- )
Discharges (-)
Leakage through ICR
outlet (-)
Change in volume of
water impounded during
period of calculation (i)
3
Volumes and Flows During Period of Estimation, m (ac ft)
Apr. 1969
Mar. 1970
2674
1145
340
387
2426
522
24
+800
Apr. 1970
Mar. 1971
2687
815
225
450
1375
2448
24
-570
Apr. 1971
Mar. 1972
3021
723d
229d
368
1051
2530
24
+200
Apr. 1972
Mar. 1973
3184
728d
213d
309
1864
1640
24
+288
Apr. 1973
Mar. 1974
3608
727d
270d
322
846
3413
24
0
Total
4/69-3/74
15174
4138
1277
1836
7562
10553
120
718
f-Data released from STPUD [15].
Based on Clair Hill Associates data [2],
cEstimated from assumed water balance; see [4, 5] for methods.
"Based on average annual rainfalls; Woodfords Precipitation Station Closed [see 2, 4,
Estimated using a single measurement of 15 gpm.
5].
-------
evaporation rate for free water surfaces in the Indian Creek area for
the corresponding month. Depth-Area and Monthly Evaporation Curves
developed by Clair A. Hill and Associates [2, 4, 5] were used in this
computation (see Appendix 4).
Precipitation on the ICR drainage area, and directly on the reservoir
surface (P ), was taken from the U. S. Weather Bureau records at
Woodfords which shows 28. 02 inches for the 1969-70 12-month period.
For the 1970-74 period the long-term average value of 20 inches [2,4]
was used; the Woodfords station is no longer operating.
Runoff (RO) was computed from monthly precipitation values (observed
or average) multiplied by monthly runoff factors estimated by Clair A.
Hill and Associates [2,4]. However, the estimated annual input to the
reservoir from runoff and direct precipitation is decreasing ranging
from 34 down to 22 in 1974, as compared to the anticipated average
annual value of 30 percent (Appendix 2).
Leakage through the reservoir outlet (V ) was determined by measure-
ments made by the project staff, which showed about 15 gallons per
minute as an average value.
Percolation losses through the reservoir bottom. (P ) were obtained by
differences, using the water balance equation. Thus the value for per-
colation reported in line 5 of Table 2 represents actual percolative
losses from the reservoir, plus or minus the net error in assumption
in evaluating other items in the water balance equation. In exploring
the inherent error resulting from the foregoing approach it was pre-
viously reported [4] that during the summer months of 1969-70 the
apparent loss of water by percolation was around 0. 035 feet of water
per day. Such a value has been shown [16] to be within the range which
might be expected in tight soils continuously inundated for more than a
year. The apparent percolative loss rates for the full five year period
(assuming an annual average area of 135 acres) was 0. 048, 0. 028,
0. 021, 0. 038, and 0. 017 feet of water per day for each of the years
1969-1974, respectively. None of these values take into consideration
the greater percolative capacity of soils that are drained when the
depth of water in the reservoir is decreased during discharge--a re- ,
finement that is impossible to achieve with the available data. Neverj-
theless, the values are reasonable and consistent with the well-known
fact that the rate of infiltration into a continuously inundated soil de-
creases with time. Consequently in very rough terms the percolative
38
-------
rate results appear to support the general conclusion that the water
balance shown in Table 2 is a reasonable estimate.
PHYSICAL, PARAMETERS OF ICR
Such detailed data as clarity (Secchi depth), air and water temperature
variations throughout the day and with depth below the water surface
are of particular importance in evaluating the quality of water in the
reservoir and its relationship to observed biological changes. In the
context of the physical characteristics of the reservoir, however, Table
1 is adequate to reveal the magnitude and variation in water and air
temperatures, and in the clarity of the water as measured by the Secchi
disk.
Clarity of Water
During the period May 1969 to May 1971 the clarity of the water in
Indian Creek Reservoir varied from 0. 8 to 6. 5 meters (2. 3 to 21. 5
feet). As the reservoir became more mature there was a marked ten-
dency for the clarity to increase. For example, during 1969 the maxi-
mum clarity occurred in December when the Secchi disk reading ex-
ceeded 3.4 m. However, in 1970 values in the5. 8 to 6.4 meter range
appeared in April and July, and again in the October to December per-
iod. In both years a period of high clarity appeared in the month of
July, with minimum values occurring in February and March. It is
difficult to document the exact causes of the winter decline in clarity.
The greatest surface runoff occurred in winter. This might be expec-
ted to bring in appreciable suspended solids from surface wash. Con-
siderable algal growth occurs in the February-March period, giving a
green cast to the water and quite obviously reducing its clarity.
In the years since 1972 the reservoir has remained in a relatively
stable pattern of low clarity during the months of February and March,
with a trend to high clarity during April, May, and June, decreasing
to intermediate values in July and August and reaching high clarity
during September, October and November (Table 1). December and
January measurements were seldom obtained because of thin ice cover
and winds which interfered with boat launching. The maximum Secchi
depth of 8. 7 m (28. 5 feet) was observed on April 23, 1973.
A possible explanation for the observed pattern of water clarity is that
algal blooms developing in late winter are removed by increased
39
-------
zooplankton (Daphnia magna and other herbivores) grazing as water
temperature increases during the spring. Summer winds increase the
turbidity of the lake by mixing which affects deeper sediments as the
lake level falls due to irrigation use. Fall clarity increases as less
phytoplankton grow in the lake due to decreasing light intensity. In
general the clarity of ICR was typical of shallow impoundments of
good quality water.
Temperature
From Table 1 it is evident that water temperature in the surface zone
followed ambient air temperature in a normal manner, with less re-
sponse to transient climatological phenomena. Of greatest significance
to the water quality and biological productivity of the reservoir is the
fact that the near-surface water temperature maintained levels in the
18-22°C range over essentially a four-month period each year. Figure
4 shows that the water temperature pattern was essentially repeated
for each year studied. Data presented in Appendix 8 show that some
(> 1. 0°C) thermal stratification was evident from late May to mid-July.
In September there was little (< 0. 5°C) temperature difference between
the surface sample and the sample 1/2 meter off the lake bottom, in-
dicating good vertical mixing. That this was not simply the effect of
the aeration turnover system is evidenced by the thermal profile which
existed in previous months under similar aeration.
CHEMICAL OBSERVATIONS MACROCONSTITUENTS
Daily observations of the chemical and bacteriological quality of re-
claimed water exported to Indian Creek Reservoir by the South Tahoe
Public Utility District were compiled by the District from the begin-
ning of export March 31, 1968 and reported on a monthly basis there-
after. Analyses of the impounded water were begun by the LTAC Lab-
oratory on October 3, 1968, prior to the beginning of the EPA Indian
Creek Reservoir Demonstration Grant, as a part of ongoing studies of
eutrophication of surface waters likewise supported by the EPA [l?].
Beginning in April 1969, analysis of the exported reclaimed water was
made also by the LTAC Laboratory as a part of its weekly sampling
program at Indian Creek Reservoir [4, 5]. Analysis of surface and
ground waters in the vicinity of the reservoir made by the California .
Department of Water Resources have been reported [see 4].
40
-------
20 -
15
10
. 0
UJ
I20
.
I
15
10
IT
LJ
0
20
15
10
-I—: *
l__—l_^—I——)
AugSept Oct NovDec
Jon ftb Mar
1971
1972
Aug Sept Oct Nov
0 I L
Apr May ' June ' July ' Aug ' Sept ' Oct ' Nov ' Dec Jan ' Feb ' Mar ' Apr
1973
1974
FIGURE 4. TEMPERATURE, INDIAN CREEK RESERVOIR
41
-------
COD
From results of BOD analyses obtained during the first year of study
[4] it was evident that the Biochemical Oxygen Demand of the reclaimed
water exported to Indian Creek Reservoir (III) was extremely low,
averaging only about one mg/-0. Therefore routine BOD examinations
of reservoir influent were discontinued in March 1970.
Values of COD as a measure of organic matter in the influent and im-
pounded water of ICR are reported in Appendix 8. From Figure 5 it is
evident that there was little difference in influent and impounded water
in terms of COD; influent waters have slightly higher concentrations of
COD. There is, however, a slight tendency for the impounded water
to be higher in COD, especially during the spring growing season when,
as noted in relation to clarity (Table 1), the presence of algae in the
impounded water was evident. Some of the influent COD must decom-
pose as there is a slight decrease from influent levels and the impound-
ed water also contains algal cells which contribute to COD,
Suspended Solids (SS)
Previously, SS was related to clarity [5], The correlation coefficient
for suspended solids versus reciprocal clarity was found to be 0. 88 and
the regression coefficient was 25 ft. mg SS/-2 Secchi disk depth. When
the data on SS were segregated into two groups (> 50% VSS, and < 50%
VSS) it was found that although the correlation coefficients were com-
parable (0. 93 and 0.87, respectively), the regression coefficients were
quite different, varying from 31 ft. mg SS/t for the > 50% VSS material
to 21 ft. mg SS/Ji for the < 50% VSS material. Thus considerable effect
of the presence of algae as VSS on the relationship between SS and
Secchi depth occurs, probably because of the absorption of the longer
wave lengths of light (red) by the chlorophyll in the algae.
The variation in SS concentrations in reclaimed water is relatively con-
stant except for an occasional peak (Figure 6). The peak values (nearly 10
mg/^) are about double the peak values presented previously [5]. The
excess of SS in impounded water over that in reclaimed water is most
impressive in the early growing season (January to April) of each year.
The effect of climatological factors on the suspended solids in the
reservoir is evident in the data for September through November, par-
ticularly in 1973. Strong winds are largely responsible for the high SS
values during that time (see clarity data in Table 1).
42
-------
25
20 -
15
10
5
25
20
0< 15
O 10
5
25
20
15
10
C - Impounded Water
IK - Influent Reclaimed Water
4-
Apr May June July Aug Sept
Oct
Nov
Dec
1973
Jan Feb
Mar Apr
1974
FIGURES. COD, INDIAN CREEK RESERVOIR
43
-------
15
10
in
Q 10
15
10
1 1 1 1
C - Impounded Water
HI - Influent Reclaimed Water
Apr May June July Aug Sept Oct Nov ' Dec
1973
Jan Feb Mar Apr
1974
FIGURE 6. SUSPENDED SOLIDS, INDIAN CREEK RESERVOIR
44
-------
Volatile Suspended Solids (VSS)
Figure 7 shows a tendency for the VSS in the impounded water to be
like that of the influent reclaimed water except during the spring grow-
ing season and on a few other less obviously explainable occasions.
Thus VSS, as might be expected in a situation such as Indian Creek
Reservoir, tends to follow the same pattern as the total suspended
solids (SS). A comparison of Figure 7 with Figure 6 shows this gen-
erally to be the case. Peak values of SS seem to be associated with
winds while VSS values peak during bloom conditions. Inasmuch as
wind conditions at Indian Creek Reservoir are unpredictable and no
continuous wind records are available, and the VSS levels involved are
only in the 1 to 2 mg/^ range, there is nothing implausible about the
observed variation in SS/VSS ratio although its causes are not fully
identified.
Chlorides
Previous results show that the chloride concentrations of the reclaimed
water generally exceeded that of the impounded water prior to about
September 1970 as the reservoir was filled and became somewhat stab-
ilized [5], In September the two were essentially equal and remained
so until the spring of 1971 when the impounded water concentration
curve became slightly the higher of the two. In numerical terms the
chloride concentration of influent reclaimed water averaged 27 mg/f.
during the first period (April 1969 through March 1970), and increased
to 29 mg/i (April 1970 through March 1971), 32.4 mg/l (April 1971
through March 1972), 35. 8 rag ft. (April 1972 through March 1973), and
39. 3 (April 1973 through March 1974). Peak values were observed dur-
ing October and November and increased from 29. 9 mg/-2 (October
1969), 32.4mg/i (October 1970), 40. 0 mg/^ (November 1971), 42.4
rag/f. (October 1972), to 47. 8 mg/^ (November 1973); illogically high
values were excluded. The incremental percent increase in chloride
concentration for each year following the first year (April 1969 through
March 1970) was 7.4, 11.7, 9.5, 10.9. The average increment over
the four years was 9. 9 percent per year; the calculated evaporation
rate (1449 evap/16030 inflow from Table 2) over the same four years
was 9 percent. Thus, the increase in chlorides apparently results
from the concentrating effects of evaporation with time.
In general the trends in chloride concentration with time support the
idea that evaporation will increase chlorides and other conservative
45
-------
C ~ Impounded Water
Iff - Influent Reclaimed Water
Apr May June July Aug Sept Oct Nov Dec , Jan Feb Mar Apr
FIGURE 7. VSS, INDIAN CREEK RESERVOIR
46
-------
substances (Figure 8). Reclaimed water is remaining relatively con-
stant. Inasmuch as chloride is a conservative material in most bio-
logical and chemical systems, the observed difference in concentration
of the reclaimed and impounded water is presumably due to a combina-
tion of surface runoff and evaporation after the initial leaching from
underlying soil. It is difficult to estimate how much chloride may have
leached from the disturbed soil during the initial reservoir filling op-
eration. However, in the Tahoe basin the chloride concentration in
precipitation and surface runoff from undisturbed land is less than 2
mg/-^ [17]. Therefore, it appears that the chloride concentration of
the impounded water is principally a function of that of the reclaimed
water plus the concentrating effect of evaporation.
Note that the extremely low value observed in February 1973 probably
represents a sampling error. Low concentrations of alkalinity and con-
ductivity were also observed. Ice cover was still observed at ICR
(Table 1) and it may be that the sample contained water from icemelt
which would have lower concentrations of impurities than a completely
mixed sample.
Conductivity
Values of conductivity observed during April 1971 through April 1974
are summarized in Figure 9. The same slight tendency for an increase
with time previously noted in relation to chlorides is evident in the con-
ductivity of both reclaimed and impounded water. However, a consist-
ent drop in conductivity is apparent throughout the period of study as
reclaimed water was mixed with the impounded water which included
both surface runoff and effluent from the STPUD plant. Appendix 8
shows that the conductivity of impounded water ranged from 229 to 530
(j. mhos/cm at 25°C. This is within the 0. 25 to 0. 75 m. mhos/cm range
reported by Eldridge [18] to characterize about half of the irrigation
waters used in the western U. S. It is also in the range where the sal-
inity effects are reported by the USDA [19] to be mostly negligible on
field, vegetable, and forage crops.
It is therefore concluded that in terms of conductivity, water impounded
in Indian Creek Reservoir is of good quality for its current use in irri-
gated agriculture.
47
-------
40
C - Impounded Water
HI - Influent Reclaimed Water
New Dec Jan
1971 1972
10
Apr1 May June July Aug ' Sept ' Oct Nov ' Dec
1973
Jan Feb Mar Apr
1974
FIGURE 8- CHLORIDE, INDIAN CREEK RESERVOIR
48
-------
650
550
450
350
250
w 650
E
P 550
>"
t 450
Q
350
250
650
550
450
350
250
C - Impounded Water
HT - Influent Reclaimed
Water
Apr May Jun« July Aug ' S«pt Ocl Nov Dec , Jan Feb Mar Apr
197311974
FIGURE 9. CONDUCTIVITY, INDIAN" CREEK RESERVOIR
49
-------
Calcium.
Figure 10 summarizes the concentration of calcium observed in re-
claimed and impounded water at Indian Creek Reservoir during the per-
iod herein reported. As in the case of other quality factors observed,
transient fluctuations in the influent concentration are damped out in
the mass of impounded water. The influent concentration is character-
istically high, and the impounded water and discharged water curves
are close together except when some unusual event occurred, i. e. , in
August and September 1969 when water was released for irrigation use
at a rate of some four times the influent rate.
The question of whether dilution alone, or dilution plus precipitation of
calcium carbonate or calcium phosphate, accounted for the difference
in calcium concentration in influent and impounded water (about 71 per-
cent of influent) was explored previously [4]. The conclusion, based on
hydrologic calculations, was that dilution rather than precipitation of
calcium was the major factor. This does not mean that precipitation
of CaCO and Ca (PO )y was not occurring; it was possible to observe
layers of CaCO on exposed rocks and along the shoreline. However,
dilution accounted for most of the change in calcium averaging 26 per-
cent (over the April 1969 to April 1974 period) of the total inflow to ICR
(Table 2).
CaCO_ precipitation would depend primarily on temperature (solubility)
and pH. The concentration of the carbonate species of the alkalinity
system which essentially buffers the lake is very pH dependent. The
pH was high enough to allow for measureable quantities of carbonates
only during the summer (pH rise probably caused by photosynthesis);
thus, precipitation of CaCO was probably the reason for the slight
lowering of calcium concentration observed during the summer, par-
ticularly in 1973 and 1974 (Figure 10).
2H
Variations in the pH of reclaimed and impounded water reported in
Appendix 8 are shown graphically in Figure 11. In general, the two
waters showed very little difference in pH. However, because pH is
the negative logarithm of the hydrogen ion concentration it requires a
tenfold concentration difference to change the pH by one unit. There-
fore, the parameter is much less sensitive than other chemical par-
ameters.
50
-------
Ul
o
80
60
40
20
0
80
60
40
20
0
80
60
40
20
C - Impounded Water
n- Influent Reclaimed Water
Sept ' Oct ' Nov Dec
Apr1 May ' June ' July ' Aug ' Sept 'Oct ' Nov ' Dec
1973
Jan ' Feb ' Mar Apr
1974
FIGURE |Q CALCIUM, INDIAN CREEK RESERVOIR
51
-------
9 -
C - Impounded Water
II - Influent Reclaimed Water
May June July Aug Sept Oct Nov Dec Jan Feb Mar Apr
May June July
Aug Sept Oct
Dec I Jan
1972 1973
-T: 1—• 1———I—
Apr May June July Aug Sept Oct Nov Dec , Jan Fab Mar Apr
e -
7 -
FIGURE II. pH, INDIAN CREEK RESERVOIR
52
-------
It is to be expected that during periods of extensive algal growth, free
carbon dioxide will be utilized at such a rapid rate that the pH will show
an increase. Such an increase is evident in Figure 11 during the Febru-
ary to April 1971 and 1972 period. Previous results [5] showed a more
marked increase during that period. The pH seems to have stabilized
around 8. 3 where all of the alkalinity is present as bicarbonate; thus
little free CO is present in ICR.
£i
Alkalinity
Variation in the alkalinity of ICR waters is summarized in Figure 12.
Variability of the influent reclaimed and impounded water is minimal.
Although previous results indicated an upward trend in alkalinity with
time over the period of study [5], the alkalinity seems to have reached
a maximum level and stabilized.
That this was a function of treatment plant operations in precipitating
phosphorus with lime and re stabilizing the water, was shown in data
on raw sewage at the STPUD plant. Here, for example, an increase in
alkalinity from 192 mg/^ in the raw sewage to 221 mg/^ in the reclaimed
water was reported for June 25, 1968; on January 18, 1969 this increase
through the treatment plant was from 84 rag/l in raw sewage to 208 mg/^
in the plant effluent [9].
As in the case of both chlorides and calcium, there is an appreciable
difference between the influent alkalinity curve and that for the im-
pounded water; impounded water alkalinity is about 60 percent of the
influent water. Again, this brings up the question of the role of dilution
in reducing concentration. As stated before about 26 percent of the
reduction could be accounted for on the basis of dilution. A small frac-
tion might be removed through precipitation (3 percent ? ). The remain-
ing quantity of alkalinity removed (about 10 percent of the influent) must
be caused by the utilization of inorganic carbon during photosynthesis.
CHEMICAL OBSERVATIONS PLANT NUTRIENTS
The quality of ICR is primarily a function of the concentration of plant
nutrients (principally N, P, C, Fe) because other water quality param-
eters indicate good quality water. Little dilution (about 22 percent) of
the plant nutrients in STPUD effluent occurs and since those waters are
classified as eutrophic in terms of nutrient concentrations, the lake
53
-------
300
200
100
^
E
" 300
o"
o
o
O 200
CO
>- 100
C - Impounded Water
1 - Influent Reclaimed Water
May vbne July Aug Sept Oct Nov Dec . Jan Feb Mar Apr
May June July Aug 'Sept Ocf
+-= r
"' Feb ' Mar ' Apr
Nov Dec Jan
1972 1973
300
200
100
H
Apr May June July Aug Sept Oct Nov ' Dec Jan ^ FW> ' Mar Apr
197311974
FIGURE 12. ALKALINITY, INDIAN CREEK RESERVOIR
54
-------
waters are eutrophic and plant productivity of the lake is high. As will
be shown in the section on biology of ICR, the algal productivity at least
does not interfere with beneficial uses as much as would be expected
because of the types of plant organisms present, an apparent conse-
quence of succession.
The nutrient concentration in the reservoir is a function of the con-
centration in waters entering ICR and removal processes operating
within the reservoir. The effect of the in-reservoir removal processes
is reflected in the concentration differences between the III effluent
•waters pumped into the reservoir and the concentration actually in the
reservoir (Table 3). Although long term trends are not discernible
either in the reservoir or in the effluent from STPUD, higher in-
reservoir concentrations of inorganic carbon and nitrogen and of ortho-
phosphate are observed with higher STPUD effluent concentrations.
The concentrations are considerably higher than are necessary to define
eutrophic waters [20]. In the following paragraphs individual nutrients
will be considered in more detail.
Inorganic Carbon
Figure 13 shows the inorganic carbon content of reclaimed and im-
pounded waters. Inorganic carbon values were computed on the basis
that inorganic carbon is present as the bicarbonate radical of alkalinity
[2l]. The computed values, therefore, are not only a function of alka-
linity but also vary with the pH and temperature. As in the case of
alkalinity the difference in concentration of inorganic carbon (Figure
13) between influent and impounded water cannot be attributed to dilu-
tion alone. The difference between the observed and the computed
inorganic carbon in the impounded water leads to the inescapable con-
clusion that bicarbonate alkalinity was used as a source of carbon by
the flora of Indian Creek Reservoir during the period of study.
I
Phosphorus
Because of its chemistry, phosphorus is the nutrient to which most
removal processes are directed. At STPUD, carbonaceous BOD re-
moval and phosphorus removal are extremely efficient (Appendix 9).
The role of phosphorus in limiting algal blooms is well documented
elsewhere. The most available form of phosphorus to algae is as ortho-
phosphate; other forms may require dissolution, enzymatic conversion,
or complex metabolic sequences to become available for algal growth.
55
-------
Table 3. ANNUAL, ARITHMETIC MEAN CONCENTRATIONS OF
INORGANIC CARBON, INORGANIC NITROGEN, AND
ORTHOPHOSPHATE IN ICR AND STPUD
TERTIARY EFFLUENT
Period -
Parameter April Through
March, Year
Inorganic Carbon
Inorganic Nitrogen
Ortho phosphate P
1970
1971
1972
1973
1974
1970
1971
1972
1973
1974
1970
1971
1972
1973
1974
Arithmetic Mean Concentration, (J.g/1
In ICR(C) In STPUD Effluent HI
29000
35000
38000
32000
33000
6300
7200
9600
13000
9700
37
14
36
46
26
52000
62000
62000
58000
59000
19000
20000
23000
26000
22000
126
86
181
168
99
56
-------
90
70
50
30
10
90
§ 7°
o:
C - Impounded Water
M - Influent Reclaimed Water
O---O--O..Q.
—cr
'*-—- -..
May June July Aug Sept ' Oct Nov Dec
1971
Jan Feb Mar Apr
1972
O
O
50
30
10
90
70
50
30
10
\ A
* / ^=
May June July Aug ' Sept Oct Nov ' Dec
1972
Jan ' Feb ' Mar ' Apr
1973
H 1 1 h
1 r-
May June July Aug Sept Oct Nov Dec i Jan Feb Mar Apr
197311974
FIGURE 13. INORGANIC CARBON, INDIAN CREEK RESERVOIR
57
-------
Consequently, most attention was directed toward orthophosphate as P
(Figure 14). Also, total inorganic phosphorus [6] was analyzed (Total
P in Figure 15). During the last year of the project, total phosphorus
was measured by the persulfate technique and essentially no difference
between the two methods was obtained. Thus little organic phosphorus
was detected in the lake.
Phosphorus removal at the STPUD plant is a highly efficient process,
which can reduce the concentration in the reclaimed water to a level
which seldom exceeds 300 [ig/£ • Removal is achieved by lime precipi-
tation followed by recarbonation to precipitate the excess calcium car-
bonate. During the first period of study (April 1969 March 1970) the
total inorganic phosphorus content of the reclaimed water averaged 148
\Lgll and orthophosphate (PO4-P) averaged 126 p.g/-2; for the second
period of study (April 1970 March 1971) these same constituents
averaged 119 a-nd 86p.g/£, respectively. Thus it appears, assuming
that the raw sewage was of approximately of the same quality over the
two study periods, that the efficiency of phosphorus removal improved
at the STPUD plant as time progressed. However, in the third and
fourth periods of study (April 1971 March 1972), nutrient removal
processes were altered to increase orthophosphate concentrations in
the effluent in an attempt to chemically manage ICR to cause higher
nitrification-denitrification and possibly weed control (Figures 14 and
15). This resulted in higher nutrient levels in ICR but did not achieve
the desired effects on the aquatic ecosystem.
The difference in phosphorus concentration in reclaimed and impounded
water is only partially accounted for by dilution. Phosphorus is a non-
conservative material in that it enters into life cycles and essentially
enters a sink in the benthic sludge or in living cells; hence it cannot be
accurately traced by the dilution approach applied to conservative
elements. From Figure 14 there appears to have been more ortho-
phosphate in the impounded water during the winter than during the
summer seasons, especially in the second period of study. This is
explainable because winter temperatures and light conditions limit the
ability of biota to increase and thus they cannot utilize the available
phosphorus as completely.
It had previously been considered that orthophosphate concentrations in
the reservoir would decrease with time as long as influent to ICR did
not increase [5], The relatively high concentrations of phosphorus in
58
-------
400 -
C - Impounded Water
TSL - Influent Reclaimed Water
Apr May June July
Dec Jon
1973 1974
Mar Apr
FIGURE 14. ORTHOPHOSPHATE, INDIAN CREEK RESERVOIR
59
-------
400 -
300 -
ZOO -
0_
eo
cr
o
a.
V)
O
o
rr
o
LL)
HI ~ Influent Reclaimed Water
100 -
Apr May June July Aug Sept Oct Nov Dec
1973
Jan Feb Mar Apr
1974
FIGURE 15. TOTAL PHOSPHORUS, INDIAN CREEK RESERVOIR
60
-------
STPUD effluent (III) observed in the third and fourth years of study
(April 1971 to April 1973) resulted in high concentrations of phosphorus
in the reservoir during those years. An example of this effect can be
seen from the minimum orthophosphate concentrations observed during
those years and succeeding years. Minimum nutrient concentrations
indicate the quantity of nutrient still in solution for uptake and utilization
in further growth and as such gives an indication of the relative limiting
factor. Because of "luxury uptake" zero minimum concentrations do not
confirm nutrient limitation. The minimum concentrations typically -were
observed during May and June (Figure 14) when the phytoplankton bloom
had essentially reached its maximum. During 1971, 1972, and most of
1973, 4(ig/£ of PC>4-P was the minimum concentration observed in ICR.
However, as input of phosphorus was reduced in early 1973 a low of 1
|o.g/-2 PC>4-P was observed during September, October, and November
1973 (Figure 14).
Ammonium
The inorganic forms of nitrogen (nitrate and ammonium) appear to be
most available for algal and plant growth; however, ammonia has the
additional environmental problem of being an oxygen sink and apparently
being toxic to fish when significant concentrations exist and the pH is
high enough (> 8. 0) to result in toxic levels of free ammonia. Because
most of the effluent nitrogen discharged from STPUD is in the ammonium
form (Figure 16), it can cause problems in ICR in several ways: 1)
oxygen utilization as nitrogenous BOD, 2) toxicity, and 3) nutrient for
growth of plants. The ammonium ion is apparently nitrified to a great
extent and plant growth and, more importantly, denitrification act as
sinks for the nitrate formed by nitrification; nitrite is an important
intermediate in nitrification but is not found in large quantities in ICR
(less than 10 percent of nitrate).
1
The ammonium nitrogen concentration in the STPUD tertiary effluent
averaged 18, 20, 22, 24, and 22 mg N/f annually over the five years of
study resulting in ICR concentrations of 3. 4, 3. 8, 5. 3, 5. 0, and 4. 6
mg N/i. for the same years. A sharp increase in ammonium nitrogen
concentration in summer 1972 (Figure 16), surprisingly did not affect
the impounded water concentrations. The "biological buffering capacity"
of ICR for ammonium ion can be thought of as a homeostatic device for
the aquatic ecosystem.
61
-------
30,000 -
C - Impounded Water
I - Influent Reclaimed Water
10,000 -
4,000 L
Apr May June July
Jan
197311974
Mar Apr
FIGURE 16. AMMONIA, INDIAN CREEK RESERVQIF^
62
-------
As in the case of most other water quality factors discussed in pre-
ceding paragraphs, the transient fluctuations in concentration character-
istic of the influent water are damped out in the impounded water in the
reservoir. From Figure 16 and the above comparison, it is obvious
that only a minor fraction of the difference in ammonium concentration
between influent and impounded water can be accounted for by dilution.
The mechanisms by which ammonium is so drastically reduced in Indian
Creek Reservoir from influent to resident impounded water are perhaps
the most important phenomena in the quality of ICR water. They repre-
sent the difference between a water definitely inimical to fish life and
one in which fish have flourished for more than 2 years. They are dis-
cussed herein in greater detail in relation to the biological observations
at Indian Creek Reservoir.
Nitrite Plus Nitrate Nitrogen
Appendix 8 shows that the values for nitrite nitrogen averaged less than
10 percent of those for nitrate nitrogen. Consequently, the two forms
of nitrogen are combined for presentation in Figure 17. As was the case
with ammonium nitrogen, biological activity more than overwhelmed the
dilution effect; thus in the reservoir the influent nitrate-nitrite nitrogen
was only a small fraction of that present in the reservoir. These vastly
greater concentrations appearing in the impounded water are largely due
to the oxidation of ammonium by biological activity in the reservoir.
This may also be a pathway by which nitrogen is removed from the res-
ervoir via nitrification-denitrification phenomena.
The typical situation of low concentrations of oxidized inorganic nitrogen
and high concentrations of ammonium nitrogen in the effluent discharged
by STPUD was not maintained during spring and early summer 1972.
Just prior to the time that ammonium nitrogen increased to 35-40 mg
N/.£ , nitrate plus nitrite increased from a typical value of about 0. 6
mg N/-0 to as much as 14 mg N/& . Although no measureable effect of
increased influent concentrations on ICR concentrations of ammonium
nitrogen was observed, the combined effect of the high inputs of total
inorganic nitrogen was to result in an approximate doubling of total
inorganic nitrogen in ICR over the whole year (4. 4 increased up to 8.2
mg N/^ ) and in a tripling to 12-14 mg N/l during the period of high
nitrogen input (April through November, 1972).
63
-------
8,000 -
I 1 1 1 1
C ~ Impounded Water
ffi - Influent Reclaimed Water
2,000 -
May June July Aug Sept Oct Nov Dec
1973
Jan Feb Mar Apr
1974
FIGURE 17. NITRATE NITRITE, INDIAN CREEK RESERVOIR
64
-------
Organic Nitrogen
Organic nitrogen is the only major quality factor herein discussed in
which the concentration in the impounded water fluctuated as wildly as
did that in the influent reclaimed water (Figure 18). Biological pro-
cesses are used in the reclamation process. They are followed by
precipitation, filtration, and carbon adsorption. Nevertheless, the
reclaimed water is far from a uniform product in terms of organic
nitrogen content. Higher organic nitrogen content was observed during
the same period that higher inorganic nitrogen forms were discharged
from STPUD. This coincided particularly with the period of nitrification
at STPUD (May and June, 1972). At all other times the concentration
of organic nitrogen was significantly higher than in the STPUD effluent.
This may result from decay of the large amount of attached vegetation
in the reservoir (see Biological Parameters of ICR, Section V) but no
definitive correlations were made.
On the basis of Figure 18 it must be concluded that although there is
nothing unexplainable in the behavior of the organic nitrogen curves,
organic nitrogen is not a good parameter by which to describe the lim-
nology of Indian Creek Reservoir.
Total Nitrogen
Table 4 shows that the total nitrogen in title influent reclaimed water
is comprised mostly of ammonia, -whereas in the impounded water the
total is only about 50 percent ammonia. In both cases the average has
increased slightly with time; a trend, which if continued over a period
of years in parallel with a decreasing concentration of phosphorus,
could have a profound influence on the biota of Indian Creek Reservoir.
Beginning in 1972 and continuing halfway through 1973 a marked in-
stability in concentrations of total nitrogen in ICR resulted from the
higher inputs which were observed particularly in the summer of 1972
(Figure 19). When the high inputs of nitrogen were moderated, the
concentrations in ICR apparently stabilized at 10-11 nag N/S. . It is
obvious that nitrogen available for plant growth in ICR is more than
adequate for bloom conditions.
Iron
In the first two years of study [5], the iron content of influent reclaimed
water averaged higher than that of the impounded water. Because iron
65
-------
1,400 -
C - Impounded Water
II - Influent Reclaimed Water
Sept ' Oct Nov
V" Wu
200 -
Apr May June July Aug
Mar Apr
FIGURE 18. ORGANIC NITROGEN, INDIAN CREEK RESERVOIR
66
-------
Table 4. ANNUAL ARITHMETIC MEAN CONCENTRATIONS OF NITROGEN AND
PHOSPHORUS COMPOUNDS, INDIAN CREEK RESERVOIR
Sample
STPUD Effluent III
Indian Creek
Reservoir (C)
STPUD Effluent III
Indian Creek
Reservoir (C)
STPUD Effluent III
Indian Creek
Reservoir (C)
STPUD Effluent III
Indian Creek
Reservoir (C)
STPUD Effluent III
Indian Creek
Reservoir (C)
Period
April
Through
March, Year
1970
1971
1972
1973
1974
Mean Concentrations of Nitrogen Compounds, (J-g/1
NH -N
17942
3439
19588
3810
22078
5253
23624
5021
22040
4608
(N02+N03)-N
664
2893
295
3349
610
4353
2393
8209
188
5125
Total
Inorg N
18606
6322
19883
7159
22688
9606
26017
13230
22228
9733
Total N
19313
7241
20395
8094
23111
10640
26946
14377
22684
10730
po4-p
126
37
86
14
181
36
168
46
99
26
Total
-P
148
51
119
27
211
69
193
63
114
37
-------
30.000 h
C - Impounded Water
ffi - Influent Reclaimed Water
10.000 \-
4,000 I-
Apr' May ' June ' July
FIGURE 19. TOTAL NITROGEN, INDIAN CREEK RESERVOIR
68
-------
was measured in filtered samples, such a condition could result from
the taking up of influent iron by living cells or by precipitation of iron
from the impounded water. The former would indicate that iron is an
important factor in the production of biota in the reservoir, whereas
the latter would be of little significance.
The concentration of iron in influent and impounded water was variable,
particularly on a seasonal basis, being higher during the summer months
when the visitor load on the Lake Tahoe Basin is greatest [5]. Analysis
of raw sewage at the STPUD plant (Appendix 9) shows clearly that the
STPUD effluent is much more concentrated in summer than in winter.
Previous results showed that from June to November 1969 there was a
tendency for the impounded (C) and reservoir discharge water (B) curves
to parallel each other, but little tendency to follow the pattern of influent
iron (III) [5], The greatest concentration of iron in the reservoir water
was observed in June 1969 coincident with similar high concentrations
in SS and VSS. Again in the spring and summer of 1970 the concentration
of iron tended to follow the same pattern as that of suspended solids.
This indicates that the presence of iron was related to the solids. How-
ever, because iron was measured in a filtered sample, the measured
value could not have been incorporated in algal cells. The correla'tion
may have resulted from turbulence and increased movement of iron
from the bottom layers of the reservoir where solids are higher and
dissolved iron (Fe ) exists to the upper layers where the sample C
is collected.
Figure 20 shows a closer correlation between STPUD effluent and im-
pounded water than previously reported [5], The iron in filtered water
is apparently developing a. pattern with low concentrations in the summer
and higher concentrations in the fall and winter. The relationship be-
tween iron and biological productivity is unclear; the low concentration
in STPUD effluent during June, July, and August appears responsible
for the low levels in ICR at that time. Generally, the iron concentration
in ICR appears to lag behind the previous measurement of iron in STPUD
effluent; this temporal relationship indicates the present, influence of
STPUD effluent on iron levels in ICR.
In regard to other heavy metals, STPUD has had a sample analyzed at
Battelle Laboratories (Appendix 10) and the results indicate that none
of the metals were at toxic levels. The iron concentration listed is
about 2 orders of magnitude less than typical values measured by
69
-------
C - Impounded water
1 - Influent Reclaimed Water
10 -
Apr May June July Aug
Dec . Jan
1973 1974
Mar Apr
. FIGURE 20. IRON, INDIAN CREEK RESERVOIR
70
-------
project staff for both STPUD effluent and ICR samples (typically 10-15
(ig Fe/t, filtered samples). This discrepancy may represent a differ-
ence in samples or be caused by differences in analytical technique.
Staff analyses seem reasonable in light of results presented by other
laboratories on similar waters. Note: iron will not be studied in the
following nutrient inventory because of such data uncertainties.
Inventory of Nitrogen and Phosphorus in ICR
Aninventory of nutrients is presented in Table 5 for the two periods of
study herein reported. Hydrologic data were previously summarized
in Table 2. Loss by evaporation was omitted becasue the amount of
chemicals transported by evaporation is insignificant in comparison
with the amounts present in the reclaimed or impounded water. The
arithmetic signs shown in the An columns of Table 5 pertain to the inven-
tory equation expressed in the form: An = I + RO + FT - D - Po Vo -AS,
in which An is the difference in the factor inventoried. A positive
value of An indicates that more material went into the reservoir than is
accounted for by the combination of observations, estimates, and
assumptions available for evaluating its fate when making the inventory
(Table 5). Other symbols used in the equation are as defined in relation
to Table 2 but refer to mass flows in this context. By multiplying the
respective concentration by the appropriate water flow in the inventory
equation to obtain mass flows, An is expressed in terms of the nutrients,
nitrogen and phosphorus. Influent values (I) are concentrations of N and
P in STPUD effluent; rainfall (PL) and runoff (RO) values are from a
previous report [5] assumed to apply to all 5 years; all subtractive values
are from concentrations measured in the reservoir. Only annual flow
(Table 2) and total nutrient (Table 4) values are used. Several other
assumptions were assumed to hold:
1. Only oxidized forms of nitrogen (NO3, NX^) were assumed to
leave the reservoir via percolation; ammonium and organic nitrogen
were assumed held in the sediments.
2. No phosphorus was assumed to leave the reservoir via percolation
but was assumed to be retained in the sediments.
Thus of the calculated output 41. 4 metric tons of nitrogen and 0. 47
metric tons of phosphorus entered the sediment phase via percolation.
Probably they would remain there until chemical conditions in the over-
lying water were to change enough to allow their release to the overlying
waters.
71
-------
Table 5. ANNUAL NUTRIENT INVENTORY ESTIMATION FOR INDIAN CREEK RESERVOIR
Year of
Study Ending
March 1970
March 1971
March 1972
March 1973
March 1974
Annual Values, metric tons (1000 kg)
Input
64.0
67.9
86.3
106. 1
101.2
Nitrogen
Output
33.8
32.7
49.9
67.7
56.7
Phosphorus
An (%)a
30.2 (47)
35.2 (52)
36.4 (42)
38.4 (36)
44. 5 (44)
Input
.527
.422
.810
.783
.533
Output
.238
. 110
.326
.296
.195
An (%)a
0.289 (55)
0.312 (74)
0.485 (60)
0.487 (62)
0.338 (63)
aPercent values refer to nutrients which are unaccounted for each year by simple hydrologic-
al relationships arid hence reflect nutrient utilization in chemical-biological systems.
-------
As is obvious in Table 5 considerably more nitrogen is lost from the
system than can be accounted for by biological and sediment sinks.
Using previous results of the first two study periods, it was estimated
using more detailed results that phosphorus loss in ICR was into bio-
logical and sediment (primarily) sinks [5]. An estimate of concomitant
nitrogen loss explained a small fraction of the unaccounted nitrogen.
The remaining unaccounted nitrogen was ascribed to nitrification-deni-
trification using rate measurements of those functions and mass balance
estimates to lend support to that explanation [5, also see 22]. The rel-
ative constancy of the unaccounted for nitrogen and the system at ICR
suggests that similar patterns of the fates of nitrogen and phosphorus
are still ongoing at present and that nitrification-denitrification is the
important sink for nitrogen.
The decreasing percentage of unaccounted for nitrogen indicates that the
capacity of ICR to denitrify is fixed by some environmental factor (too
much oxygen or organic energy source? ) and that modification of some
parameter related to the factor might lead to a lowering of nitrogen
content of the water and reverse the apparent trend to higher nitrogen
content in the reservoir. However, the consequences of such a modifi-
cation might lead to higher ammonia content and thus a greater oppor-
tunity for ammonia toxicity to the fish.
CHEMICAL OBSERVATIONS DISSOLVED OXYGEN
Dissolved oxygen is one of the more indicative and affected parameters
of biological interactions in aquatic systems and this is well illustrated
at ICR. Dissolved oxygen data for Indian Creek Reservoir waters
throughout the period of study are presented in Appendix 8. Variation
in DO with depth below the water surface has been shown for periodic
sampling dates during the 1969-70 study period and at approximately
weekly intervals since then. From Appendix 8 it may be observed that
the dissolved oxygen content of the influent reclaimed water was gener-
ally less than or equal to 2 mg/^ except on a few occasions which may
well be in error due to problems of sampling from a pressure outfall
line without aerating the sample.
Figure 21 shows that throughout nearly the entire period of observation
the impounded water in the top half-meter was near or above saturation
(calculated from table in [6] at 576 mm pressure), varying normally
with water temperature. Those samples which apparently exhibit under-
saturation may represent sampling error or bias in calculation but even
if those values are correct, the conclusion would be that generally ICR
remains well oxygenated. The low values seen in spring and early
73
-------
16 r-
C - Impounded Water
DOSAT- Dissolved OxygenSATuRATED
1 - Influent Reclaimed Water
.-O&^^Y t>
I f*-L I kl T
Dec j Jan
197211973
Apr' May ' June July ' Auq ' Sepl ' Oct ' Nov ' Dec | Jan ' Feb ' Mar ' Apr
FIGURE 21. DISSOLVED OXYGEN, INDIAN CREEK RESERVOIR
74
-------
summer 1972 apparently resulted from the high ammonium nitrogen
loadings which occurred then.
Supersaturation probably resulted from photosynthesis and generally
occurred during three periods of time: winter, early summer, and
fall. The winter period of super saturation has become more marked
with time, occurring earlier each year. This coincided with the phyto-
plankton bloom described in Table 1 and the loss of clarity as inter-
preted from decreasing Secchi disc readings. The early summer period
of supersaturation coincided with increased aquatic vascular plant
growth and expansion of these weeds into deeper water along with in-
creased water clarity. The fall period of supersaturation again was
caused by the weeds as maximum clarity was observed at this time.
Apparently suspended sediments interfered with light transmission
during July and August because clarity decreased (Table 1) and sus-
pended sediments increased (Figure 6) at that time.
Generally the reservoir showed a well mixed condition in terms of
dissolved oxygen during the spring and fall. In the summer and winter
slight gradients occurred which the artificial aeration of ICR could not
completely overcome. Low benthic concentrations commonly were
observed during early summer until conditions had improved to allow
near vertical saturation: 0.7 mg/-0 on 6/21-71; 2.5 vag/f. on 6/5-72;
6.2 mg/Ji on 8/2-73.
The maturation of ICR is reflected in the development of more complete
distribution of dissolved oxygen within the reservoir. Previously, long
periods of benthic anaerobiosis existed [5]. For example, in July 1969
the dissolved oxygen in the vertical profile of the reservoir ranged from
7. 6 mg/i at 0. 5 meters below the water surface to 0 rag/f. at 0. 5 meters
above the reservoir bottom. By September 1969, however, the dissolved
oxygen profile at all three of the sampling stations (Figure 2 [5]) re-
vealed a well mixed water mass both vertically and horizontally, with a
reduction in concentration of oxygen in the upper strata as a result of
mixing with underlying oxygen-poor water.
Part of this improvement may have been due to the long term effects of
artificial aeration. In March of 1970 mechanical aeration was initiated
but was interrupted after only about 10 days of operation until June 23.
In the interval, in May 1970, an oxygen profile began to develop. By
early June it showed a DO range of from 11.1 mg/^ at -0. 5 meters to
1. 4 mg/i at -10 meters. However, a well mixed condition developed
75
-------
by June 16, before the artificial aeration system was restored. There-
after, as the weather warmed up and aeration was practiced, oxygen
profiles were less pronounced until mid-July when the steep oxygen
profile of the preceding July was essentially repeated, albeit with, a low
of 1. 5 mg/i instead of 0 mg/^ as before. A second period of low oxy-
gen in the bottom stratum occurred in August. Then from September
1970 to the end of the report period in May 1971 the DO in impounded
water was at or above saturation throughout the vertical profile.
From the data observed, the exact effect of artificial aeration of Indian
Creek Reservoir is obscure. Both before and after installation of the
system, periods of complete mixing and strong stratification occurred.
In general it appears that the oxygen depletion at the bottom of the
reservoir was less severe and DO concentrations under well mixed
conditions were somewhat higher after operation of the aerator began.
Problems in aerator operation and general improvement in the reservoir
oxygen regime (aquatic plant photosynthesis, etc. ) as well as maturation
of the system have made it difficult to interpret exactly the role of aera-
tion.
An interesting observation was the typical fall reversal of dissolved
oxygen so that the highest concentration was observed at the bottom of
the reservoir. The pattern is illustrated in Figure 22 for those dates
where the phenomenon is most obvious. The events leading to the
development of the plant growth responsible for this observation are
discussed in the section on Biology of ICR.
CHEMICAL OBSERVATIONS - SEDIMENT ANALYSES
Sediments consist of materials deposited on the original substratum
of the reservoir and as such represent minerals, sorbed materials
on silts and clays, chemical precipitates, organic detritus, and living
plants and animals. Sediment concentrations of organic carbon (C),
total nitrogen (N), and total (P) and available phosphorus (AP) indicate
the probable sources of lake sediments. If the ratios of C/P and N/P
are less than typical values for organisms {e. g., Cx0N7P, on a weight
basis calculated from [23]), one would expect a greater effect from
chemical removal (sorption and precipitation) than from biological
mechanisms or a change in yield relationships due to changes in limit-
ing factors. Because such yield ratios are only indicative of actual
relationships, only speculations can be made and hypotheses derived
for later studies.
76
-------
o
2
4
6
8
IO
12
CT II
— MAXIMUM DEPTH
. I . I i I . I . I i I i I . I .
O 2 4 6 8 IO 12 14 16 18 2O
r
Ml
O 8
IO
O
2
4
6
8
IO
I | I
FALL 1972
SEPT 25
OCT 2-
-MAXIMUM DEPTH
I I I I I I I I I I I I I
I I I
O 24 6 8 IO 12 14 16 18 2O
— FALL 1973
SEPT 17
•MAXIMUM DEPTH
-i I i I i I i I i I J i I i I i I
O 2 4 6 8 IO 12 14 16 18 2O
DISSOLVED CONCENTRATION(mg/l)
Figure 22. Increased dissolved oxygen at low depths due to benthic
vegetation photo synthe sis.
77
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Analyses of Ekman dredge samples collected on October 20, 1972 from
Indian Creek Reservoir show distinct changes with either distance from
the source of tertiary effluent to the reservoir (Station 1) or with depth
since these two factors are not separable (Table 6). One would expect
higher concentrations of nutrients with depth because easily resuspended
material such as organic detritus would tend to accumulate in the deepest
part of the lake. Although lower diversity in benthic samples from ICR,
collected closer to the source of tertiary effluent, has been observed
[22], greater benthic biomass (numbers) occurred in the deeper por-
tions.
The higher P concentrations in relation to N and C indicate chemical
removal mechanisms or that P was not limiting the microbial popu-
lations. Because the C/N ratio for the samples was high (10-13 as
compared to 5. 7 for Stumm and Leckie [23]) and the AP, a measure of
inorganic phosphorus (see [lO]), was low, it appears that some other
factor yet unexplained affected the nutrient relationships.
The shoreline sample showed the highest P and N concentration and
the second highest C concentration reflecting the high addition of or-
ganic matter as considerable aquatic vascular plant growth had taken
place in the sampling area.
Essentially similar results •were obtained for analyses performed on
samples obtained on August 6, 1973 (Table 6). Because the shoreline
sample was highest in October a core sample, collected by diver (Tom
Walsh), was collected and analyzed. This showed a pattern which
would be expected along the shoreline; the aquatic vegetation dies,
decays and collects in the shallow area producing relatively high C/N
and C/P ratios in the upper sediment layers. A calculated completely
mixed core on a weighted depth basis would have about 20 mg organic
C/g sediment, 1. 6 g N/g, and 0. 36 g P/g or a weight ratio of C55N4P.
The low phosphorus content in the shallow waters of the east shore
produces a different ratio than obtained in the October sample from
the west shore. Note that soil in the ICR basin (described in [5])
showed a similar composition to the lower strata of the core sample
having 11 mg organic C/g and 0. 6 mg N/g of soil.
78
-------
Table 6. CONCENTRATIONS OF NUTRIENT ELEMENTS
IN SEDIMENTS OF INDIAN CREEK RESERVOIR
(Nutrients,b mg/g dry weight (103°C)
a
Station
Total Total
Available Phos-
Phosphorus phorus
Organic Total
Carbon Nitrogen
Element
Weight
Ratios,
CxNyPl
October 20, 1972
1
2
3
4
5
Shoreline
West of 5
1
2
0.042
0.030
0.028
0.029
0.037
0.039
Samples
-
-
3 South Trans
North Transect
1000 foot
1200 foot
Core
Samples
-
-
0.66
0. 62
0.50
0.70
0.75
1.20
Collected on
0.80
0.38
0.71
0.74
0.77
Sample Collected near
August 6,
23
18
14
18
14
22
August 6,
30
13
20
22
7
Shore East
1973
1.8
1.5
1.3
1.8
1.3
2.0
1973
3.7
1.0
1.7
1.8
0. 6
of Station
C35N3P
C29N2P
C28N3P
C26N3P
C19N2P
C18N2P
C38N5P
C33N3P
C27N2P
C30N2P
C10N8P
3
Core Depth, cm
0 - 1
1 - 2
2-3
3-5
5-7
7-12
12 - ~ 15
-
-
-
-
_
-
-
0.86
0.67
0.40
0.34
0.28
0.27
0.27
64
43
21
29
23
9.0
4.5
7.2
3.5
1.4
1.8
1.6
0.7
0.5
C75N8P
C64N5P
C53N4P
C87N5P
C82N£,P
C33N2P
C17N2P
See Figure 2.
Analyses performed according to procedures in [24].
79
-------
BIOLOGICAL OBSERVATIONS
Introduction
Because many of the nutrients are affected by the aquatic food chain in
the ways in which they are distributed and transferred throughout the
various phases of the aquatic ecosystem, it is necessary to obtain some
measurements of the different members of the food chain and attempt
to relate them to various distributions of nutrients in the reservoir.
To simplify relationships, different species in the reservoir community
are grouped into particular functional groups which relate to energy and
nutrient transfer and utilization. Heterotrophic microorganisms would
include all organisms which utilize organic carbon compounds as a
source of energy while autotrophic organisms utilize sunlight as a source
of energy and furthermore are the ultimate basis for the growth of the
heterotrophic group. Primary consumers include those organisms
which prey on the producing organisms; because primary consumers
are usually filter feeders (zooplankton) or other herbivores (e.g.,
snails) their food at ICR is made up of particulate matter (debris,
heterotrophic and autotrophic microorganisms) and vascular plants,
respectively. Higher consumers would include the trout planted at
ICR which feed on insects, zooplankton, and snails. A simplified
schematic of the food web at ICR and its relationships to nutrient flow
is shown in Figure 23. The measurements of the different levels in
this system (Figure 23) will be made in the following paragraphs.
Microorganisms
Bacteria, algae, and protozoans are included in any discussion of
microorganisms. These groups occur in both planktonic and attached
forms. The attached forms include "slimes" as well as filamentous
growths. Filamentous attached algae will be discussed in the para-
graphs on Benthic Vegetation.
Plankton counts of algae and protozoa are based on samples collected
with a modified "Hale's Sampling Bottle" [25] which collects an inte-
grated sample throughout the depth sampled. A 500 ml sample 'could
be collected from a 10 meter depth of water by steadily pulling the
bottle through the water for about 90 seconds. Plankton counts were
made with a Sedgewick-Rafter cell and a calibrated Whipple eyepiece.
These estimates are necessarily relatively crude both in terms of
80
-------
ATMOSPHERE
LIGHT
oo
GREBES, LOONS*
FISHERMEN
DUCKS*
COOTS
AIRBORNE
PARTICULATE
EPIPHYTIC ALGAE
& AQUATIC PLANTS
ZOOPLANKTON* ) FILTER \
INSECTS \ FEEDERS /
RESERVOIR
OUTFLOW
HETEROTROPHIC \
MICROORGANISMS )
(DECOMPOSERS)*/
AQUEOUS PHASE
/INSECTS
(PREDATORS)
EFFLUENT &
RUNOFF
PARTICULATE
MATERIAL*
DETRITUS
& SOLUBLE
ORGANIC
MATTER
BENTHIC DECOMPOSERS
BENTHIC CONSUMERS*
* Denotes Estimates
or Measurement of
Standing Crop Made
BOTTOM SEDIMENTS
Figure 23. Food web in ICR in simple form.
-------
frequency of sampling and in the sophistication of the measurements
of standing crop and diversity.
The results of these analyses are in Appendix 11 and are summarized
in Table 7. Generally the results show very little pattern in terms of
either numbers, species present or of the estimate of planktonic diver-
sity. Apparently either the free living suspended microorganisms do
not follow a pattern which relate simply to season or other parameters,
or the measures are too crude to make good correlations. Undoubtedly
both reasons are involved.
Table 7. CONCENTRATIONS OF ALGAE AND PROTOZOONS
IN INDIAN CREEK RESERVOIR (DATA IN APPENDIX 11)
Sampling
Date
1972
May 30
June 19
June 26
July 16
July 31
Aug . 1 4
Aug. 28
Sept. 11
Sept. 18
Sept. 25
Oct. 9
Oct. 16
Oct. 30
Nov. 13
Nov. 27
1973
Mar. 24
Apr. 23
May 7
May 21
June 4
June 18
July 2
July 17
Total
Organisms
per ml
272
48
580
880
2820
1160
2125
1175
scana
765
1330
5985
601
683
609
2566
463
890
840
2481
772
840
424
Diatoms,
Percent of
Number
32
a
37
16
1
12
1
12
_
28
27
_
17
34
31
4
7
6
2
1
4
3
3
Number of
Species
Represented
14
9
15
15
23
15
30b
19
11
24
17
31
20
20
20
17
8
17
17
16
18
16
12
Estimated
Diversity0
2.32
2.07
2.20
2.06
2.77
1.98
3.79
2.55
_
3.46
2.22
3.45
2.97
2.91
2.96
2.04
1. 14
2.36
2.38
1.92
2.56
2.23
1.82
82
-------
Table 7 (continued). CONCENTRATIONS OF ALGAE AND
PROTOZOONS IN INDIAN CREEK RESERVOIR
(DATA IN APPENDIX 11)
Sampling
Date
Aug.
Aug.
Sept.
Sept.
Oct.
Oct.
Oct.
Nov.
Nov.
Dec.
1974
Jan.
Feb.
Mar.
Mar.
20
27
10
17
1
15
29
13
26
4
14
4
4
18
Total Diatoms, Number of
Organisms Percent of Species
per ml Number Represented
1053
623
377
324
381
349
1637
scan
374
scan
i
scan
scan
scan
384
8
33
20
25
29
31
4
-
23
-
-
-
-
34
19
20
12
16
15
18
17
23
16
11
15
15
9
15
Estimated
Diversity0
2.59
2.95
1.85
2.59
2.36
2.90
2. 16
_
2.53
-
-
-
-
2.35
Dashes indicate no data; scan indicates that only a quick genera count
was made.
Includes 7 ciliates; only 2 genera of ciliates noted on the 21 other
occasions were observed.
CD = (S - l)/log N, S = Species number and N = total population. From
[26] p. 55. e
It is obvious that the planktonic numbers are more than sufficient to
draw the conclusion that ICR is eutrophic. However, the diversity and
the high clarity (Table 1) of the water at certain seasons of the year
indicate that a well balanced planktonic producer level of organisms
exists. Thus the initial energy level of the food web would be passed
quickly to the consumer level. According to Margalef [27] the values
are typical of low diversity ecosystems of relatively high productivity.
83
-------
Bacterial estimates were made using plate counts on Plate Count Agar
with sterile samples collected on October 20, 1972. The values, as do
all plate counts, only give a rough indication of heterotrophic patterns
in the reservoirs. Counts of colony forming units (cfu) ranged between
376 and 1273 cfu/ml! at Station 3 and highest numbers were measured
at the 0. 5 meter depth and decreasing with depth to 6. 5 m; no samples
were collected near the bottom to prevent sediment bacteria from being
counted. Two different colors of colonies were seen, yellow and cream,
but the colonies were otherwise smooth edged and undistinguished. A
surface sample collected at Station 1 had only 230 cfu/m0 . Either depth
or residual toxicity remaining in STPUD effluent reduced bacterial con-
centrations relative to Station 3.
Aufwuchs (mostly algal) were measured using glass slides placed in
ICR during the period August 6-20, 1973. These results give an esti-
mate of the maximum growth rate of aufwuchs (Figure 24). Over a
two week period the growth apparently was still increasing. The maxi-
DENOTES RANGE OF THREE
MEASUREMENTS WHEN GREATER
THAN SIZE OF SYMBOL;
3 SLIDES/DATA POINT
IO
TIME (Days)
15
Figure 24. Growth of aufwuchs on glass slides in ICR, August 6-20,
1973.
84
-------
mum growth rate (p.b = (I/At) In (Xj/Xi.i)) was estimated at 0.4 days"1
(values for day 1 not utilized in calculation). Continuously lighted
agitated flask cultures in the laboratory at about the same temperature
as ICR generally have values of about 0. 7 for ICR during times of high
productivity (see next section, Algal Bioassays). If lighting conditions
are taken into account, these results indicate that the attached organisms
(mostly algae) are increasing in mass at about the same rate as would
occur under laboratory conditions. Thus, aufwuchs as of August 1973
at ICR are at near maximum potential growth rates for the particular
environmental conditions at ICR.
Algal Bioassays
Algal bioassays are used to estimate the biological effects of biostimu-
lants and toxicants on potential algal growth and growth rates. Bio-
stimulants for the test alga in this bioassay, Selena strum capricornutum,
essentially are all inorganic nutrients. The procedures have been
described in Section IV and previously [4, 5, 8, 17], The data for the
bioassays are in Appendix 12.
As can be seen in Figure 25 the maximum specific algal growth rate
in batch cultures (£b = I/At In (X2/X1) or = I/At In (X3/X2), which-
ever is greater) shows considerable variation with time in filtered ICR
samples. With few exceptions little or no response was obtained with
STPUD effluent (not graphed), a pattern which has been consistent
throughout the study and which indicates residual toxicity. The toxicity
is probably due to chlorine and chlorine compounds as the plant effluent
is chlorinated when leaving the plant (see Appendix 9).
The particular pattern of response in the algal cultures is dependent on
available nutrients. Thus the low growth rates in impounded water
(Figure 25) observed in March through June 1972, September-October
1972, and September-October 1973 japparently correspond to periods
of low nutrients.
One method of detecting whether the decrease in growth rate is caused
by decreased nutrient content or by toxicity is to bioassay dilutions of
the sample. If toxicity is present, dilutions will produce greater growth
than the 100 percent sample as the toxicants become diluted. If no
toxicity is present, dilutions will have less growth than the 100 percent
sample as the nutrients become diluted. When toxicants and nutrients
are both effectively decreased by dilution, the change in growth rate
85
-------
0.9
oo
o--
I I I I III! I I I I I I I I I I I I
I I I I I I I I I I I I I I
I I I I I I I I I
I I I I I I I I I I I
JO.I —
MAMJ J ASOND J F M A M J J ASONDJFMAMJ JASONOJF M
1971 1972 1973 1974
TIME
Figure 25. Variation in bioassay algal growth response in impounded water, ICR.
-------
will lie in between the above two situations and some indication of
toxicity can usually be determined.
The bioassay results of dilutions ([5], Appendix 12) indicate that STPUD
effluent is almost invariably toxic as usually more growth was obtained
with more dilution. The dilutions of impounded water have always
indicated no observable toxicity; less growth was always obtained with
greater dilution. Because the pattern of bioassay response seemed
stable, dilution bioassays were discontinued at the beginning of 1972
and hence, the low responses for impounded water during the periods
listed previously cannot be checked for toxicity. However, unless
some unique happening were to have occurred, one would suspect that
nutrient levels were low during those periods. The three periods noted
do not correspond to other measurements within the system but visual
observations suggest that high productivity, algae in the spring and
vascular plants in the fall may have occurred and resulted in sufficient
removal of nutrients to cause lower bioassay response.
An attempt to relate growth rates to nutrient concentrations is shown in
Figures 26 and 27. The algal response to both STPUD effluent and ICR
samples and their dilution are shown as a function of the nutrient con-
centrations in the sample. It is obvious that algal response to nutrients
in STPUD effluent is low, indicating toxicity.
The algal response to impounded water samples has been fit with a
Monod type line [8, 9]. The relationship between growth rate and phos-
phorus (PO^-P) seems reasonable (Figure 26), while the relationship
with inorganic nitrogen has an x-axis intercept of about 8000 [ig N/-0
(Figure 27) indicating that nitrogen was not limiting. Thus the algal
bioassays indicate that phosphorus was probably a more limiting
nutrient than nitrogen in ICR. Other factors such as light, turbidity, and
predation probably control the phytoplankton population more than phos-
phorus. Trace metals and iron may be in short supply and help control
the quantity and type of algae present. The high nitrogen levels prevent
nitrogen from being limiting and thus no competitive advantage exists
for nitrogen-fixing blue greens in ICR. The presence of other attached
algae in large quantities Cladophora and Oscillatoria (just observed in
quantity in 1974) seem to indicate that predation and not nutrients is a
major factor in keeping phytoplankton at the observed relatively low
densities. These algae will be discussed in the following section
(Benthic Vegetation).
87
-------
oo
oo
O.9
0.8
A
A.A ^A A
«>a AAA I ^
y^frt F\ I |
MAY 17,1971 THRU APRILI5.I974
o ICR
AHC
A
A A
A
A A
A
AA
.A
A
5O
IOO I5O
2OO 250 3OO 350 4OO 45O 5OO 55O
CONCENTRATION^ PO4-P/D
Figure 26. The variation in maximum specific growth rate batch (|j.b) as a function of.
orthophosphate concentration in the bioassays, STPUD effluent (HI)
impounded water (ICR-C).
-------
00
0.9
0.8
0.7
0.6
O.5
O4
O.3
O.2
O.I
A
MAY 17,1971 THRU APRIL 15,1974
0 ICR
A m
A
A^A"
AA P A A I A *%
i
I
O 5OOO IO.OOO I5.OOO 2O.OOO 25.OOO 30.OOO 35.OOO 4O.OOO 45.OOO 5O.OOO 63.OOO
CONCENTRATION fj.q (NO3-»NO2+NH4)-N/I
Figure 27. Apparent non-limiting relationship between inorganic nitrogen concentration
in STPUD effluent (III) and impounded water (1CR-C) and maximum specific
growth rate batch (jj. b) in algal bioassays.
-------
Benthic Vegetation
The growth of benthic and attached (epiphytic to benthic rooted plants)
vegetation in ICR has developed into one of the most serious reservoir
management problems. Aquatic weeds, periphyton, and algae growing
on the mud surfaces of the bottom of the lake cover extensive areas of
the lake. The vegetation interferes with recreational (fishing and boat-
ing) and aesthetic pursuits, contributes considerable organic matter
which later degrades and decomposes affecting the dissolved oxygen
balance in ICR, and probably has an impact on nutrient utilization and
plant succession in the reservoir.
Vegetation types observed in ICR include: 1) aquatic weeds: Myriophyl-
lum, Ceratophyllum, and Potamogeton as the principal weeds; also
there have been observations of Salvinia, grasses and cattails; 2) peri-
phyton; and 3) mud surface algae, almost entirely Cladophora. Photo-
graphs of the reservoir, various weeds, and some of the algae with
notes on depth and location and distribution are shown in Figure 28.
The photographs are of two types, either taken above the water surface
by project staff or below the water surface by a diver employed by the
project during July-August 1973 (Appendix 13).
The above water pictures vividly point out the effect of the aquatic weeds
on the aesthetic value and uses of the ICR ecosystem (Figure 28A). As
the water receded due to decreasing water levels dried mats of weeds,
algae, snails and other organisms accumulated on the exposed shore
(Figure 28B, C, D). Immediately offshore, mats of weeds and algae
had built up because the water depth was insufficient to support the
mass of plant material which previously had been actively growing there.
At the same time that the reservoir water level decreased, peak Secchi
depths were observed (Table 1). The resultant of those phenomena was
that more light reached the reservoir substrate at deeper depths and
the vegetation was able to colonize and grow at greater depths and over
greater areas. Thus, the area covered by weeds and benthic algae
probably increases each year as clarity improves and as colonization
of deeper areas occurs.
In July and August 1973 an underwater survey of bottom conditions in
ICR was made with the aid of a diver and underwater photography equip-
ment (Appendix 13). The results of the survey resulted in a series of
35 mm color slides. Typical examples of these are reproduced as
black and white prints (Figure 28). Also the vegetation on the reservoir
bottom was analyzed resulting in the estimate of areas of vegetation as
90
-------
A. ICR, dam and milieu.
B. West Shoreline of ICR showing exposed and dried aquatic weeds.
Figure 28. Photographs of Indian Creek Reservoir, August 1973.
91
-------
w^^'ssa*.
C. Close up of dried weeds with dead snail shells.
D. Shallow water on west shore showing Myriophyllum in foreground,
floating algae, and rocks having periphyton (< 1 m).
Figure 28 (continued). Photographs of Indian Creek Reservoir,
August 1973.
92
-------
a function of depth shown in Figure 29. The observed sharp interfaces
of algae and silt (9 meters, 30 feet, deep) and weeds and no weeds (6
meters, 20 feet, deep) led to further analysis of the weed-algae distri-
bution in ICR.
The August 8, 1973 survey showed that the aquatic weed populations
extended to approximately the typical Secchi depth (Figure 28E, F).
Cladophora extended into deeper waters approximating 1. 5 times the
typical Secchi depth (Figure 28G, H). Four zones were differentiated
on the basis of depth and area (Figure 29): 1) exposed reservoir bottom
(equals zero when the reservoir is full); 2) aquatic weed zone which
extends from the shoreline to the Secchi depth; 3) the Cladophora zone
which extends from the Secchi depth to 1. 5 times the Secchi depth; and
4) the nonvegetated or silt zone. The interfaces between these zones
are shown in Figure 28B, C, D, E, F, G, H for zones 1 and 2, 2 and 3,
3 and 4, respectively. Note that one of the aerator tubes (Figure 281)
is in deep water (silt bottom) and that the scale of the underwater pic-
tures is about 50 cm (20 inches) (Figure 28J).
Obviously many assumptions and approximations are involved in such
an analysis. For example, the bottom surface area is approximated
based on the water surface area at the specific water depth. Because
of temperature and instabilities in the Secchi depth (hence light pene-
tration) during the late spring and early summer, the values are prob-
ably reasonable only during late summer and in fall when water temper-
atures and water clarity are fairly constant and sufficient to allow
reasonable growth. These considerations become more evident in
viewing the results shown in Figure 30 where the estimated area where
extensive weed growth would likely occur is plotted as a function of
time.
In late spring and early summer for all three years the weed area in-
creases rapidly and then decreases as wind storms increase turbidity
(also see data on Secchi disc in Table 1). Then a relatively stable
period of maximum development of weed areas develops during summer
and fall. Not only did the area available for weed growth increase from
1971 to 1973 but the time of maximum expected area of weed growth
came earlier in the year; as would be expected from an analysis based
on Secchi depth this coincided with the overall improvement in clarity
as time progressed and with the earlier in the year that maximum
clarity occurred as time progressed. Although these estimates are
very approximate, visual observations and the increased need for weed
93
-------
E. Myriophyllum and some Cladophora; interface at about Secchi depth
(20 - 25 ft, 6. 1 - 7. 6 m).~~
F. Myriophyllum and some Cladophora; interface at about Secchi depth
(20-25 ft, 6. 1 - 7. 6 m).
Figure 28 (continued). Photographs of Indian Creek Reservoir,
August 1973.
94
-------
G. Cladophora and silt interface. Note extremely short stalked
Myriophyllum invasion (30-35 ft, 9. 2 - 10. 8 m).
H. Cladophora and silt interface (30 - 35 ft, 9. 2 - 10. 8 m).
Figure 28 (continued). Photographs of Indian Creek Reservoir,
August 1973.
95
-------
I. Aerator line at 10. 8 meters (35 ft). Note lack of plant growth.
J. Scale of underwater pictures; length of frame is 0. 5 meters (20
inches).
Figure 28 (continued). Photographs of Indian Creek Reservoir,
August 1973.
96
-------
EXPOSED
RESERVOIR
BOTTOM ZONE
AQUATIC WEED ZONE
2O FEET DEEP
(SECCHI DEPTH)
CLADOPHORA ONLY ZONE
3O FEET DEEP
NON-VEGETATED (SILT) ZONE
MAXIMUM SHORE LINE
OUTLET TO
RESERVOIR
® INLET TO RESERVOIR
NUMBERS INDICATE ELEVATIONS
Figure 29. Estimated distribution of vegetation and water level in
ICR August 13, 1974.
97
-------
I6O
I2O
SO
40
I I I I I I I I I I I I I I I I I I I I I I I I I I I I
OCTOBER 4,
1971
(SECCHI DEPTH, 17 ft)
I I I I I I I I I I I I I I I I I I I I I I I I I I I I
1971
5O
IOO
ISO 2OO 25O 3OO
•S)160
< ISO
UJ
a:
LJ 8O
a:
SEPTEMBER 25,
1972
(SECCHI DEPTH, >22ft)
I I I I I I I I I I I I I l_
1972 '
I I I I I I I I I I I I I I I I I 81 I I I I I I I I I I
5O
IOO ISO 2OO 25O 3OO
I6O —
I2O
I I I I I I I I I I I I I I I I I I I I I I I I I I I I
MAXIMUM AREA
COVERED BY WATER
EXPOSED LAND
AUGUST 13,
1973
-^ (SECCHI DEPTH,
2O ft) "CLADQEtfORA
ON
AREA COVERED
BY WATER
©O
BENTHIC
AUSAE,
PERIPHYTON
AQUATIC
WEED
3OO
TIME(Days)
Figure 30. Estimated seasonal changes in reservoir area covered by
aquatic vascular plants and benthic algae.
98
-------
harvesting tend to confirm the analysis. Although the apparent maxi-
mum area of active weed growth occurred in May-June during all three
years, this value was rejected as occurring over too short an interval
and when temperatures would be low enough (16°C) to inhibit weed growth
as compared to temperatures (20°C) later in the summer and fall
(August, September, October).
Weed harvesting by the STPUD began in 1972 and continued through 1973
using a mechanical harvester rented from Dillingham Corporation. How-
ever, the most extensive harvesting occurred beginning right after July
4, 1974 and'continuing until the middle of August. Using a mechanical
weed harvester designed by STPUD (the "Dragon"), reportedly [28],
over 100 truckloads (3-4 cubic yard capacity) of wet weeds were re-
moved. However, extensive weed beds are still present both dried on
exposed reservoir bottom and as weed banks along the shoreline.
At present (September 1974) these weeds are decomposing and creating
a mechanical nuisance to fishermen and possibly supporting a dense
growth of epiphytic blue-green algae, Os cilia to ria (Figure 31). The
algae in turn are leading to a noticeable taste and odor problem both
in the air, the water and the flesh of trout caught by fishermen (see
section on the trout fishery). The implications of the large blooms
of Oscillatoria on the weeds, principally Myriophyllum, are that at
least future taste and odor problems will occur. Whether or not cells
will break off and become "planktonic" in high enough concentrations
to interfere •with existing food chains will only become apparent with
further observation. If it does occur, the use of the eutrophic waters
of ICE. for recreation and irrigation will probably be severely inhibited.
Zooplankton
I
Although data are scattered, there has been an apparent general increase
in population density (organisms ji ), biomass (dry weight, mg/-2 ), mean
size (fig/organism), and diversity in Indian Creek Reservoir (see Table
8). The results indicate a gradual maturation of the reservoir although
the diversity (D = 2 (n^/N) In (nj/N))[26] remains typical of highly
productive impoundments. Sampling during the spring, 1972 indicates
a higher stability in the zooplankton community with less variation in
the diversity index than in previous years. The number of species
detected reflect this increased diversity, being relatively constant.
99
-------
A. Mats of dying algae - -Myriophyllum.
B. Tube-like structures formed by Oscillatoria growing on dying
Myriophyllum.
Figure 31. Oscillatoria epiphytic on dying Myriophyllum at shallow
southern end of ICR, September 1974.
100
-------
TableS. CHANGES IN ZOOPLANKTON POPULATIONS SINCE SUMMER, 1970
Sampling
Date
7/30-70
10/1- 70
10/14-70
12/9-70
3/24-71
6/2 - 71
6/12-71
7/7 - 71
4/17-72
5/8 - 72
5/31-72
7/10-72
7/25-72
8/8 - 72
Total
a
Tow Number of
Organisms /I
V
V
H
V
H
V
H
V
V
H
V
H
V
V
H
V
H
V
H
V
H
V
H
V
H
2.89
0. 64
0. 14
,_c
-
0.88
0.046
0.40
0.43
0.80
0.45
2.93
0.37
1.98
1.52
2. 13
2.02
2.09
0.82
1. 11
1.09
1.44
1.22
0.91
0.71
Cone entration
Dry Wt mg/1
0.243
0.216
0.014
0.447
0.013
0.342
0.027
0. Ill
0.063
0.067
0.367
0.374
0. 152
1.521
0. 161
1. 129
0.390
1. 135
0. 616
0.315
0.080
0.248
0. 107
0.258
0.065
,., „. Number
Mean Size
(Jig/Organism
Species
84
338
100
-
_
389
587
278
147
84
816
128
411
768
106
530
193
543
751
284
73
172
88
284
92
6
7
5
-
_
3
4
6
6
14
6
5
7
9
11
10
10
14
5
6
9
5
6
3
9
Number
of
Daphnia
67
46
4
-
-
113
10
30
45
115
17
100
10
113
61
192
375
180
204
30
4
5
10
28
66
(%of
Total)
(18)
(55)
(9)
-
-
(99)
(67)
(59)
(80)
(44)
(29)
(10)
(21)
(44)
(14)
(70)
(57)
(67)
(76)
(21)
(1)
(3)
(2)
(24)
(28)
Diversity
Index [2 6]
0.78
1. 53
1. 18
-
-
0. 66
1.21
1.23
0.98
1.79
1.43
0. 68
1.23
1. 38
1.27
1. 34
1.39
1. 30
1. 09
1. 35
0.44
0. 30
0.28
0. 61
0. 96
Vertical (V) Tow collected near Station 1 from reservoir bottom to surface through a column
of 10-14 m depth (calculations based on mean of 12 m); Horizontal (H) Tow collected near
Station 1 just beneath reservoir surface through distance of about 30. 5 m.
Daphnia magna and Daphnia pulex.
cDashcs indicate no analysis.
-------
Generally, vertical tows had higher population densities, biomass, and
mean size. This would indicate that considerable grazing (filter feeders,
such as daphnids and ostracods) and predatory (copepods) activity occur-
red below the surface meter where the horizontal tows were made.
The diversity of both tows were about the same value generally. The
phytoplankton diversity was slightly greater than for the zooplankton
community but both values indicated productive aquatic systems.
Note that Daphnia appear to be most dominant during times when Secchi
depths (Table 1) increase, indicating a possible cause-effect relation-
ship, where Daphnia are filter-feeding and removing algae which have
caused turbidity and decreased Secchi depth.
Invertebrates in ICR
Although many estimates of invertebrate organisms (egg masses, larval,
and adult forms) were made in the progress of the study, the only quanti-
tative measurements (excluding the protozoa and zooplankton results
above) were made using bottom samples collected by a dredge. Samples
collected in 1969 and 1970 were presented previously [5] and those col-
lected in 1972 are in Appendix 14; the results are summarized in Table
9.
In the early project years an Ekman dredge was used for sampling.
This type of dredge often loses many of the smaller organisms which
float out as excess water drains from the dredge as it is returned to
the surface. A Ponar dredge was used for the last set of samples. As
can be seen in Table 9 for Station 1, the apparent effect of the two
dredges was for the Ponar to increase the number of organisms but
little difference was detected in the diversity estimated by the two
sample types (for more data see Appendix 14). More careful analyses
of the differences between the two dredges have been described else-
where and the Ponar judged superior.
Because of this difference in sampling effect on numbers, conclusions
cannot be drawn about the annual trends in population density of benthic
invertebrates. If the ratio 620/290 for Station 1 in 1972 were to be
correct, then it would be reasonable to assume that population density
in 1972 would be about 300-350 thus indicating an approximation of
steady state for the density of bottom organisms.
102
-------
Table 9. SUMMARY OF BENTHIC ORGANISMS COLLECTED FROM INDIAN
CREEK RESERVOIR3" SEDIMENTS IN OCTOBER
Number
Station of Dredge
Number Satnples
Collected
1 (3), (5 in 1972)
2 (3)
3 (3)
4 (3)
5 (3)
6 (1)
7 (1)
Mean
Average Number
per Square Foot
1969
412
588
528
648
268
364
176
428
1970
588
160
392
260
160
120
__c
280
1972
290 (620)
(490)
(920)
(920)
(490)
(1400)
(150)
(713)
Diversity
1969
0. 35
0.70
0. 72
0. 36
1. 05
1. 22
1. 02
0. 94
1970
0. 93
1. 2
1.4
1.4
1.9
0. 8
c
1. 5
b
1972
0.96 (0.96)
(1.4)
(1.3)
(1.3)
(1.4)
(0. 88)
(1.89)
(1.3)
Copepods and Cladocera not included in calculations. All samples collected with Ekman
dredge except 1972 samples in parentheses collected by Ponar dredge (see Appendix 14).
>~. ^ ni
Diversity = - S _
—
in which, n. = number of
individuals in a particular species and
N = the total number of individuals in
all species [26].
'No sample collected.
-------
This argument is supported by approximately the same diversity for the
different stations. Station 6 has a low diversity primarily because about
one-half the number of organisms is the planorbid snail, Gyraulus
parvus. Station 7 has high density which might be expected because of
its location in a shallow shoreline area having many aquatic vascular
plants, algae, and also wave turbulence to introduce oxygen. This
hypothesis is supported by counts of organisms obtained from rock
scrapings, Station 8, and from the reservoir outlet stream, Indian
Creek, where high population densities and diversities were seen (Ap-
pendix 14).
As in all previous years the results show that both numbers and diversity
increase with distance from Station 1. This observation could result
from moving from deep to 'shallow waters but it is likely that toxicity
and lack of dissolved oxygen are involved in limiting Station 1 popu-
lations near the outfall of the STPUD effluent.
Large numbers of ephippia were collected in the dredge samples. In
the reservoir, estimates varied between 51, 667 to 441. 324 per m (4800
to 41, 000 per square foot) and averaged 17Z, 224 per m (16, 000 per
square foot). These wintering egg estimates of densities indicate a
great amount of daphnid zooplankton productivity.
Several invertebrates new to ICE. have been detected in 1972 which were
not found previously. These include most notably the amphipod, Hyallela
azteca, and the gastropods, Gyraulus parvus and Planorbella sub-
crenatum. It is not likely that the gastropods at least were detected
only because the Ponar dredge was used.
The role of snails in aquatic weed control and in the ecosystem generally
is not clear. There are extremely large numbers of snails in the system
and counts of snail shells in dried weeds along the exposed shoreline
were in the range of 200-400/m2 in 1971 [5] and about 500/m in August
of 1973. It is not known if the snails represent a significant drain on
the weed productivity but because of the nutrient excess in the lake, this
is unlikely. The snails do represent a significant part of the feed for
larger trout as evidenced by fish stomach analyses [5, 29].
Trout in Indian Creek Reservoir
The history of fish plantings in Indian Creek Reservoir reveals much
information concerning the maturing of the reservoir with time. During
the summer of 1968 trout were placed in test boxes in the reservoir
104
-------
water but failed to survive for longer than 24 hours, some dying within
30 minutes. To test the reservoir environment further 2,080 rainbow
trout fingerlings 7. 6-10. 2 cm (3-4 inches) long were planted in the
reservoir on October 16, 1968, some 6 months after filling of the res-
ervoir began. No mortality was observed during the fall months but by
springtime no fish apparently remained. Fish mortality was presumed
to be due to a lack of dissolved oxygen caused by prolonged heavy ice
cover of the water surface during the winter of 1968-69, although this
presumption was not fully proven.
On August 8, 1969, 3, 600 hybrid (rainbow and cutthroat) trout 4. 3 cm
(1. 7 inches) in length were planted in the reservoir. Three days later
4,400 trout of the Hat Creek (Mono County) rainbow strain were planted.
These were some 11.4 cm (4. 5 inches) in length. An overnight gill
netting operation on October 1969 produced a catch of 130 of these fish.
By that time the small fingerlings had grown to 15. 2 cm (6 inches) in
length and the second group averaged 22. 6 cm (8. 9 inches) long. Sub-
sequently, in March 1970, a one-day gill net setting yielded 18 fish
most of which were 27. 9 cm (11 inches) long, the smallest being 24. 5
cm (10 inches). Thus, the reservoir food chain resulted in excellent
growth rates of the trout and indicated that the reservoir was very pro-
ductive. Plantings and fishing success are summarized for available
data in Table 10. Only trout have been planted at ICR and no other
species have ever been reported.
Obviously something occurred during the reservoir's development which
made it compatible to trout. Although the exact cause of mortality of
fish in the 1968 tests is not known, some toxic factor was evidently
present. Inasmuch as the recommended limit for ammonium at normal
outdoor values of pH is 2. 5 mg/-2 for trout, free ammonia toxicity seems
the most logical cause of fish mortality at that time [30], the influent to
the reservoir having an ammonium concentration of from 12 to 20 mg/i.
The most important factor in fish survival must then be the phenomenon
which reduced the concentration of ammonium in the impounded water
from these high values to values ranging from 2. 5 to 7. 0 mg/^ in sub-
sequent months, a level which will apparently not affect fish at the pH's
common in the reservoir. As previously noted, dilution alone was not
the cause of nitrogen reduction but rather nitrification.
The effect of ammonia-ammonium toxicity is extremely important in
discussing the disposal of wastes in east slope Sierra waters [30] and if
the balance is upset in some way, the trout population shows a rapid
response. The Tahoe Daily Tribune (South Lake Tahoe, Calif. ) of March
105
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Table 10. THE TROUT FISHERY IN INDIAN CREEK RESERVOIR0
Fish Stocked Creel Census
_. Catchable Success Days An- Num- _. . ,
Finger- , „ Anglers J Size, inches
Year . and Sub- Rate, ° Sur- gling ber -
ingS catchable Number/hr Boat Shore veyed Hours Caught Range Ave.
6.4 to
1971 Totals 117,696 33,600 0.15 139 647 9 2627 402 18.5 11.6
No./day - - - 15 72 - 314 45 - -
10. 2 to
1972 36,700 0 0.23 75 176 9 736 169 19.6 13.1
£ 8 20 - 82 19
1973 37,280 119 (spawning) no data
1974 65,000 0 no data
Totals 256,676 33,719
a
Data courtesy of Russ Wickwire, Fishery Biologist, Calif. Dept. of Fish and Game [29].
-------
13, 1972 reported that about 5, 500 trout some of which weighed up to
1. 8-2. 3 kg (4-5 Ibs) each had died and this coincided with the beginning
of the higher than normal discharges of ammonium in spring and summer
1972 (see Figure 16). Unfortunately the laboratory was temporarily
closed at this time, being between funding periods. The California Fish
and Game judged that fish kill was probably caused by free ammonia
(Appendix 15).
Thus, two conclusions are supported by the experience with trout in
Indian Creek Reservoir:
1. That the establishment of a balanced ecosystem in which ammonia
toxicity was not a problem was necessary before the water became a
suitable environment for trout.
2. The control of free ammonia through limitation of the amount of
ammonium nitrogen discharged and productivity control to prevent high
pH (ammonia and pH relationships are shown in 31) are necessary to
prevent further occurrences of this type.
At present the trout fishery at ICR is going well and many fishermen are
present at all seasons (see Table 1). The aquatic weed growth is causing
problems by physically interfering with fishing. In September 1974 it
was observed that a significant earthy odor was present at the reservoir
and it was observed that trout were tainted with an earthy taste. This
taste and odor problem is apparently due to the presence of epiphytic
Qscillatoria blooms; this problem will undoubtedly interfere with rec-
reation especially fishing at ICR.
107
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SECTION VI
DISCUSSION AND EVALUATION OF RESULTS
Evaluation of specific findings of environmental, chemical, and bio-
logical observations of Indian Creek Reservoir is included in Section V
as a part of the interpretation and discussion of the individual subjects
therein presented. Conclusions are drawn in that section as deemed
appropriate by the authors. These are summarized and extended in
Section I, and recommendations are summarized in Section II. There-
fore it seems appropriate to consider in this section what the Indian
Creek Reservoir study has thus far shown concerning the reclamation
of water from domestic wastes for recreational use and its import in
the context of eutrophication of surface waters, as well as the changes
observed with time in the impounded water itself.
In evaluating the results of the study herein reported it must be borne
in mind that although Indian Creek Reservoir was providing recreational
opportunity in the form of sport fishing and development for contact
sports is contemplated, it was adapted rather than designed for such
purpose. This is to say that the processes to be applied to secondary
waste water effluent at the South Tahoe Public Utility District Plant
were not originally selected with the objective of producing a water
quality ideally suited to the multiple beneficial uses which are com-
patible in a wilderness. Instead they were the outgrowth of concern
on the part of water quality control officials for the consequences of
fertilizing surface waters with nutrients added by domestic use of
water - nutrients which are only stabilized and not removed by the
best, or even perfect, sewage treatment plants of the conventional type.
Overriding even this national problem, and the national objective of its
solution, was the unique situation existing in the Lake Tahoe Basin.. ,
Here it was deemed unacceptable, and on good evidence, to discharge
into Lake Tahoe even water which meets U. S. drinking water quality
standards, because in the matter of nutrients such standards exceed
by some two orders of magnitude the concentrations presently found
in the lake.
108
-------
The factors underlying process design were therefore based on a number
of rational concepts, not all of which were necessarily- explicit in the
decisions which followed:
1. The time is at hand when in many circumstances conventional
waste water treatment processes must be extended to include nutrient
removal or reduction.
2. Phosphorus is capable of triggering objectional algal growths
when low oxygen concentrations encourage algal species capable of
utilizing nitrogen from the atmosphere .
3. We know how to remove phosphorus, therefore in the course of
"pollution control" it should be removed as an act of faith if not of
scientific necessity.
4. Nitrogen removal, although not immediately technologically
developed, must in the future likewise be applied to waste water
effluents.
5. At the present state of technology and knowledge of the sensitiv-
ity of Lake Tahoe, even the most highly treated waste water cannot be
allowed to enter the lake, either directly or indirectly. Therefore, ex-
port from the basin is a practical necessity.
6. Given present aesthetic attitudes of people, exported effluents
must be good enough to be acceptable to the exporter himself under
normal conditions, i.e. , were it not for the unique quality of Lake
Tahoe.
7. Emerging standards of both surface and ground water quality
must be met by any process o,f water reclamation.
8. A pioneering task of process development has to be undertaken
if other concepts of water quality are to be achieved.
Given objectives, constraints, and problems such as the foregoing, and
the political climate in which they must be resolved, the objectives of
process design were necessarily different than might have been the
case had the creation of a recreational reservoir been the water quality
objective. This fact is extremely important in understanding what has
been observed at Indian Creek Reservoir; and in considering what
109
-------
observations are required for the future.
The data herein presented show quite clearly that the reclaimed water
delivered to Indian Creek Reservoir during its first three years of op-
eration were so low in phosphorus as a result of purposeful phosphate
removal by the South Tahoe Public Utility District as apparently to be
phosphate limited with reference to nitrogen, as an algal growth medi-
um. That is, it contained nitrogen in excess of phosphorus in some 10
times the N/P ratio at which algae utilize these two nutrients, while at
the same time approaching the concentration (0. 10 mg/-2 ) of phosphorus
at which less than eutrophic conditions might be expected to occur.
Moreover, in its undiluted state STPUD effluent was toxic to both trout,
in the early years, and the test alga (Selena strum) used inbioassays
of its growth potential. It was tentatively concluded early in the study
that free ammonia was the toxic factor for the trout. Later it became
apparent that in the impoundment this same water lost ammonium-
nitrogen from its initial 15 to 20 mg/£ concentration in STPUD effluent
to a level generally less than 4- 6 mg/i .
That the observed profound change in ammonium content was not due to
simple dilution was shown by a hydrological balance which revealed the
reservoir input to be increasingly reclaimed water from STPUD (up to
80%) and decreasing surface runoff (down to 20%) and rainfall directly
on the reservoir water surface. That it was not due to nitrification
alone was likewise evidenced by the failure of nitrates to reach any
sustained levels above about 6
Loss of nitrogen from the reservoir by nitrification- denitrification was
early suspected as the cause of the observed nitrogen imbalance. From
the evidence developed in the study there is no doubt but that nitrifica-
tion in the hypolimnion and denitrification in the benthic zone is the major
mechanism. Analysis of the benthic sludge in 1971 [5] revealed the
presence of denitrifying bacteria in numbers characteristic of a healthy
denitrifying sludge. Similarly, direct experiments showed nitrification
activity in the hypolimnion during the summer months sufficient to ac-
count for the nitrogen lost by denitrification [s]. Aeration of the reser-
voir by mechanical means, however, gives reason to believe that the
benthos is the site of denitrification activity.
The efficiency of removal of phosphorus by the STPUD reclamation
plant varied during the study as did ammonia removal; but high N/P
ratios were observed at all times in the reservoir. Other possible
110
-------
sources of phosphorus include the original soil on which the reservoir
was constructed, animal and plant wastes washed in from the small
(1700-acre) drainage area, and such allochthnous material as wind
blown dust and pollens. Although these sources might conceivably be
considered minor, they could add to a buildup in the benthic sludge.
The extent to which phosphate limitation is responsible for the apparent
good quality of Indian Creek Reservoir should be further studied in re-
lation to sources of phosphorus in order that the true value of phosphate
removal as a waste water treatment process may be determined. In the
specific case of the Indian Creek Reservoir, where the annual discharge
represents a large percentage of the reservoir capacity, biological re-
cycling may be either more or less important than in larger lakes, de-
pending upon where the phosphorus is in the system at the time of water
releases. The loss of phosphorus largely to benthic sludge indicates
that phosphorus cycling is not too important.
Biologically, Indian Creek Reservoir showed important changes over
the five year study period. From an initial situation in which it appar-
ently would not support fish life, it developed into an excellent trout
fishery. However, the fish production, as measured by early season
catches, appeared to have declined. Gill netting studies indicated that
this might not be the case. In view of somewhat contradictory, albeit
fragmentary evidence, such as the nitrogen increase and the question
of over availability of feed for the fish and the fish population itself,
it is clear that ICR should be monitored for a longer period to determine
whether the reservoir fishery will support the large number of fisher-
men interested in the reservoir.
Evidence that with time the reservoir increased rather than decreased
in biological health is to be found in an increase in the diversity of
benthic invertebrates. This diversity was the more convincing because
of a decline in the predominance of low oxygen tolerant species of chir-
nomids. The extent to which this was the result of mechanical aeration
of the water is uncertain but it is well established that such aeration of
water will not preclude an anaerobic zone in the underlying sludge or
soil. This is further specifically evidenced in Indian Creek Reservoir
by denitrification activity traceable to the benthic sludge.
Plankton in the impounded water, as well as the emergence of a normal
cycle of algae and grazers (Daphnia) in the impounded water likewise
suggests an improving limnological situation.
Ill
-------
Bioassays of impounded and reclaimed water were especially revealing
of the maturation of Indian Creek Reservoir. The cyclical nature of
growth response, as measured by the specific growth rate (JJLK) of
Selenastrum, showed that the growth potential of the impounded water
decreased during the growing season -when the biota of the reservoir
were utilizing the nutrients. In contrast, no such cyclical response
was clear in the reclaimed water and toxicity to algae masked the effects
of high nutrient content as shown by the dilution bioassays.
This cyclic finding is logical and is particularly important because it
differentiates between the growth potential and the residual growth
potential of a water. This is to say that a bioassay of a waste water
(filtered) may reveal its true algal growth potential (within the limits
of capability of the test), whereas in an outdoor body of water it can
only measure the residual potential in the water. In wintertime more
of the total potential of an impounded water might be in undecomposed
organic matter in the benthic sludge than in the water, whereas in the
summer time the reverse may be the case. But in any case a bioassay
must be interpreted with caution when applied to a natural body of water.
Conceivably, an extremely highly eutrophied body of water could show
little response because the test utilizes only that fraction of the nutrients
currently being recycled between decomposing and growing biota. In
contrast, a filtered waste water, or the reclaimed water influent to
Indian Creek Reservoir, harbors no nutrient sinks such as those in a
lake or reservoir. In this circumstance the lesser growth shown by
reclaimed water than by the impounded water indicates clearly that
Indian Creek Reservoir as a limnological entity is influenced by many
factors not implicit in the mere quality of its principal source of in-
fluent. For example, apparently there is a detoxification mechanism
in ICR which removes the toxicity in STPUD effluent.
Productive biological systems represent complex interactions between
physical, chemical, and biological phenomena, ICR is a productive
reservoir with waters containing high nutrient concentrations which can
only be defined as being at eutrophic levels.
Because of its large area of relatively shallow waters the reservoir has
extensive areas covered by aquatic vascular plants, i.e. weeds. The
weed problem has important ramifications for the expansion of recrea-
tional uses in the reservoir; however, fu.tu.re such reservoirs could
avoid this weed problem by morphological design changes to produce
an overall deeper reservoir. In general the reservoir water is of high
112
-------
quality to the casual viewer and this is because of the high water clarity.
This observation generates the question of why there are not greater
algal populations in ICR which would cause a readily apparent problem
to the average recreationalist.
Obviously, the types of algae does not include the typical nuisance algae
found in eutrophic lakes, i.e. , blue-green algae. Nitrogen-fixing blue-
green algae do not occur in ICR probably because there would be no
competitive advantage for nitrogen fixers in the high nitrogen environ-
ment of ICR. In addition, nitrogen fixation is inhibited by high concen-
tration of nitrogen [32], However, populations of other blue-greens
are not developing either [33]. Probably other algal groups are more
subject to predation than most blue-green algae and it appears that
predation is preventing the development of algal blooms in ICR. Then
the central question about ICR is why are large populations of blue-
green algae not present in ICR?
Observations about nutrients and other chemicals in ICR suggest
several possible reasons for the lack of blue-green algal blooms:
1) There is an unusual nutrient relationship in ICR where inorganic
nitrogen concentrations are 300-400 times the orthophosphate con-
centrations in the reservoir, does the high N/P ratio select for other
algae over blue-greens?; 2) Are the high ammonium concentrations
toxic to blue-greens? ; 3) Apparently metals concentrations are rel-
atively low and these may be limiting to blue-greens; and 4) Organic
carbon concentrations entering the reservoir are quite low when com-
pared to typical eutrophic reservoirs receiving sewage effluents and
organics maybe necessary for blue-greens; the presence of the blue-
green alga, Oscillatoria, as an epiphyte on the aquatic weed,
Myriophyllum , suggests that the Qscillatoria may require organic
compounds secreted by Myriophyllum. Obviously other factors than
the presence of Myriophyllurq are involved, but until September 1974
no large populations of blue-green algae had been observed in ICR.
The implications of the possible incipient blue-green bloom in ICR
for algal succession and for the development of ICR as a recreational
resource are extremely important to water quality management.
Other interactions of interest to other investigators concern nutrient
cycling where the question of phosphorus-iron (and other metals),
calcium precipitation should be considered in more detail. Nitrification-
denitrification, although originally having a significant effect on dis-
solved oxygen, does not affect it at present, however, the process
113
-------
apparently prevents even greater buildups of nitrogen compounds than
occur there at present.
The role of nutrient cycling in maintaining succession and productivity
in ICR is not clear and although the reservoir is clearly eutrophic,
the nutrient ratios must be involved in the types of organisms present
and thus be involved in control of the phytoplankton standing crop.
In an overall evaluation of Indian Creek Reservoir it might be said that
the impoundment affords an unprecedented opportunity to observe, for
practical as well as scientific reasons, what may be expected from a
ponding of water reclaimed from domestic return flows. As noted in
the opening paragraphs, no attempt was made originally to design the
waste water reclamation plant at South Tahoe to produce a -water of
optimum quality for recreational purposes, if indeed such an optimum
could be defined. Eventually, however, the data from Indian Creek
Reservoir should indicate whether such an optimum process would be
appreciably different than that presently installed at STPUD. In the
meantime it may be said that the STPUD plant is a very efficient system
for removing phosphorus, and Indian Creek Reservoir is a good system
for removing nitrogen. Whether or not the level of phosphorus removal
is presently effective, is the controlling factor, or is of little consequence
is an important practical and economic question.
The blue-green algal and aquatic weed problems as they affect quality
in ICR and its recreational - aesthetic use still remain to be evaluated.
Unless these current problem trends reverse it is apparent that the
reservoir will not be as useful for recreation as previously supposed.
This observation should not be taken to imply that the STPUD - ICR
project has failed; the development of irrigation downstream of ICR
has shown the value of reclaimed water and the necessity of recycling -
taking and using a product which previously society discarded.
114
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SECTION VII
REFERENCES
1. McGauhey, P. H. , E. A. Pearson and G. A. Rohlich. Compre-
hensive Study on Protection of Water Resources of Lake Tahoe
Basin. Lake Tahoe Area Council, South Lake Tahoe, Calif. ,
95705. 1963.
2. South Tahoe Public Utility District. Feasibility Report on Indian
Creek Reservoir. Clair A. Hill and Assoc. , Consulting Engineers,
Redding, Calif. 1968.
3. South Tahoe Public Utility District. South Lake Tahoe Water
Reclamation System. Brochure. Undated - obtained in 1969-
4. McGauhey, P. H. , D. B. Porcella, G. L. Dugan and E. J.
Middlebrooks. Eutrophication of Surface Waters--Indian Creek
Reservoir. FWQA First Progress Report for Grant No. 16010
DNY, LTAC, South Lake Tahoe, Calif. , 95705, 141 p. 1970.
5. McGauhey, P. H. , D. B. Porcella and G. L. Dugan. Eutrophi-
cation of Surface Waters--Lake Tahoe: Indian Creek Reservoir.
EPA- 16010 DNY 07/71, U.S. Supt. of Documents, Washington,
D.C., 115 p. 1971.
6. American Public Health Association. Standard Methods for the
Examination of Water and Waste water. 12th Ed. , New York.
1965.
i
7. Strickland, J. D. H. and T. R. Parsons. A Manual of Sea Water
Analysis. Bulletin No. 125, Fisheries Research Board of Canada,
Ottawa. 1965.
8. McGauhey, P. H. , G. A. Rohlich, E. A. Pearson, M. Tunzi,
A. Adinarayana and E. J. Middlebrooks. Eutrophication of Sur-
face Waters—Lake Tahoe: Bioassay of Nutrient Sources. FWPCA
Progress Report for Grant No. WPD 48-01 (Rl), 178 p. 1968.
115
-------
9. McGauhey, P. H. , G. A. Rohlich, E. A. Pearson, E. J.
Middlebrooks, D. B. Porcella, A. Aleti and M. Tunzi. Eutrophi-
cation of Surface Waters--Lake Tahoe: Laboratory and Pilot Pond
Studies. FWPCA Second Progress Report for Grant No. WPD 48-
02, LTAC, South Lake Tahoe, Calif., 95705, 180 p. 1969.
10. Porcella, D. B., J. S. Kumagai and E. J. Middlebrooks. Bio-
logical Effects on Sediment-Water Nutrient Interchange. J. San.
Eng. Div. ASCE, 96:911. 1970.
11. Maciolek, J. A. Limnological Organic Analyses by Quantitative
Bichromate Oxidation. Bureau of Sport Fisheries and Wildlife,
Research Report 60, Washington, D.C., 61 p. 1962.
12. Skulberg, O. M. Algal Cultures as a Means to Assess the Fer-
tilizing Influence of Pollution, Advances in Water Pollution Re-
search. Water Poll. Cont. Fed., Washington, D. C. 1:113. 1967.
13. Gonzales, J. Personal Communication. STPUD, South Lake Tahoe,
Calif. 1974.
14. Medsker, L. L. , D. Jenkins and J. F. Thomas. Odorous Com-
pounds in Natural Waters. Env. Sci. and Tech., 2:461-464.
1968.
15. Culp, Russell L. Monthly Reports to the Lahontan Regional Water
Quality Control Board. STPUD, South Lake Tahoe, Calif. 1968-
1974.
16. McGauhey, P. H. and R. B. Krone. Soil Mantle as a Waste-water
Treatment System. Final Report, Sanit. Eng. Res. Lab. Report
No. 67-11, Berkeley, California. 1967.
17. McGauhey, P. H. , G. L. Dug an and D. B. Porcella. Eutrophi-
cation of Surface Waters--Lake Tahoe. FWQA, Final Report for
Grant No. 16010 DSW. LTAC, South Lake Tahoe, Calif., 95705,
141 p. 1971.
18. Eldridge, E. F. Return Irrigation Water--Characteristics and
Effects. DREW, U.S. PHS Region IX, Portland, Oregon, 119 p.
I960.
19. Bernstein, L. Salt Tolerance of Plants. Agricultural Information
Bulletin 283, U.S. Department of Agriculture. 1964.
116
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20. Sawyer, C. N. Fertilization of Lakes by Agricultural and Urban
Drainage. J. New England Water Works Assoc. , 61:109. 1947.
21. Saunders, G. W. , F. B. Trama and R. W. Bachman. Evaluation
of a Modified * C Technique for Shipboard Estimation of Photo-
synthesis in Large Lakes. Great Lakes Res. Div. , inst. Sci. and
Tech., Univ. Mich. Publ. No. 8:1-61. 1962.
22. Porcella, D. B., P. H. McGauhey and G. L. Dugan. Response
to Tertiary Effluent in Indian Creek Reservoir. Journal WPCF,
44:2148-2161. 1972.
23. Stumm, W. and J. O. Leckie. Phosphate Exchange with Sedi-
ments; Its Role in the Productivity of Surface Waters. Presented
at the 5th International Water Poll. Res. Conf. , San Francisco,
16 p. 1970.
24. Cowan, P. A. and D. B. Porcella. Analytical Methods at UWRL.
Unpublished. Utah State University, Logan, Utah. 1972.
25. Whipple, G. C. The Microscope of Drinking Water. John Wiley
and Sons, Inc., N. Y. 1927.
26. Margalef, R. Perspectives in Ecological Theory. Univ. of
Chicago Press, 109 p. 1968.
27. Margalef, R. Correspondence Between the Classic Types of Lakes
and the Structural and Dynamic Properties of Their Populations.
Verh. Intern. Verein. Limnol. , 15:169-175. 1964.
28. Gonzales, J. Personal Communication. South Tahoe Public
Utilities District, South Lake Tahoe, Calif. 1974.
l
29. Wickwire, Russ. Personal Communication and Unpublished Data.
California Fish and Game Department, Tahoe City, Calif. 1974.
30. Skarheim, H. P., T. R. Galloway, R. E. Selleck, A. J. Home
and W. J. Kaufman. Assessment of Biological Effects of Treated
Wastewater on the Truckee River. SERL Rept. No. 73-2, Univ.
of Calif. , Berkeley, 129 p. 1973.
31. Stumm, W and J. J. Morgan. Aquatic Chemistry. Wiley Inter-
science, N. Y. , p. 241. 1970.
117
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32. Home, A. J. and C. R. Goldman. Nitrogen Fixation in Clear
Lake, Calif. I. Seasonal Variation and the Role of Heterocysts.
Lamnol. and Oceanogr. , 17:678-692. 1972.
33. Whitton, B. A. Freshwater Plankton. _In: The Biology of Blue-
Green Algae (Carr and Whitton, Eds.). Botanical Monogr. 9,
Univ. of Calif. Press, Berkeley. 1973.
118
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SECTION VHI
PUBLICATIONS AND PATENTS
No patents were produced in the course of the project. Three publi-
cations were released by the Lake Tahoe Area Council pursuant to
the terras of the initial grant. These are:
1. Eutrophication of Surface Waters--Indian Creek Res-
ervoir. First Progress Report (FWQA Grant No.
16010 DNY). Lake Tahoe Area Council, South Lake
Tahoe, Calif. 141 p. May 1970.
2. Eutrophication of Surface Waters — Lake Tahoe:
Indian Creek Reservoir. EPA 16010 DNY 07/71.
115 p. July 1971.
3. Response to Tertiary Effluent in Indian Creek
Reservoir. Journal WPCF, 44:2148-2161. 1972.
119
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SECTION IX
GLOSSARY
The following list represents the sense or context in -which various
terms and symbols are used in this report, without specific regard to
generalized or standard definitions.
Benthic Sludge - Accumulated organic and organic sediment on the bot-
tom of the reservoir.
Benthic Invertebrates - Invertebrate organisms living in or upon the
benthic sludge.
Bioassay - Laboratory measurements of the effect of nutrients or other
factors on the rate of growth of a test alga under specified conditions.
Bio stimulation - Increase in the expected or normal response of an
organism as a result of the presence of some growth stimulating factor.
Conservative Element - Chemical element not significantly removed or
increased by chemical, physical, or biological processes.
J3enitrification - Reduction of nitrate or nitrite to nitrogen gas by aero-
bic bacteria living under anaerobic conditions.
Discharged, or Released, Water Water purposefully released from
Indian Creek Reservoir for irrigation use.
Eutrophic - Nutrient rich condition of water.
Grazers - Aquatic animals which eat plant material, e. g. , herbivorous
zooplankton such as Daphnia.
Hypolimnion Region below the thermocline in a body of water.
Impounded Water Mixture of influent reclaimed water and surface run-
off plus precipitation stored in Indian Creek Reservoir.
Infiltration - Movement of water downward into the soil through the soil-
water interface, or bottom, of the reservoir.
120
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Influent Reclaimed Water - Domestic sewage effluent exported to
Indian Creek Reservoir after advanced treatment at the South Tahoe
Public Utility District's reclamation plant.
Limnology - The study of physical, chemical, biological, and environ-
mental interrelationships infresh water, particularly lakes and ponds.
Mechanical Aeration Bubbling or air through the impounded water with
the purpose of saturating it with oxygen in equilibrium with the atmo-
sphere.
Mixing The intermingling of water masses in Indian Creek Reservoir
so that passive materials such as chemical constituents are uniformly
distributed horizontally and vertically when the reservoir is well mixed.
Nitrification - Oxidation of ammonia to nitrate or nitrite by specific
bacteria, called nitrifiers.
Nutrient Budget The algebraic sum of the effect of all factors which
add or subtract a specific plant nutrient, such as nitrogen or phosphorus,
in the reservoir, i. e., an accounting for all inputs and outputs of a
particular nutrient.
Nutrient Recycling - Movement of nutrients through the natural cycle
of growth and decay of organic matter.
Oli go trophic - Nutrient poor condition of water.
Plankton - The host of free living microscopic plants (phytoplankton) and
animals (zooplankton) in water.
Productivity - The rate of change of biomass with time in a system, ex-
pressed in amount per unit area or unit volume, e.g. , Ibs fish per acre
per year.
Secchi Disc - An 8-inch diameter white disc used to measure the clarity
of water in terms of depth below the water surface at which it disappears
from sight of the observer.
Seiche - An oscillating wave motion in the reservoir caused by winds.
Toxicity - The presence of factors which decrease or inhibit the expect-
ed or normal response of an organism.
121
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|\ - Maximum rate of increase in algal cell numbers or mass during a
5-day flask bioassay.
X_ - Algal cell counts performed at days 1, 3, 5.
SS5 - Dry weight of suspended solids in flask at end of 5-day bioassay.
122
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SECTION X
APPENDICES
No. Page
1. Contour Map of Indian Creek Reservoir 124
2. Reclaimed Water as Percentage of Input to Indian Creek
Reservoir 125
3. Indian Creek Reservoir Area and Capacity 126
4. Indian Creek Reservoir Evaporation by Month in Acre Feet 127
5. Aerial Photo of Indian Creek Reservoir Site with Overlay
of Reservoir and Proposed Improvements 128
6. Measured Water Inputs and Withdrawals, Indian Creek
Reservoir 129
7. Modified Skulberg Nutrient Medium (1967) 131
8. Analyses--Indian Creek Reservoir 132
9. Maximum, Minimum, and Average Values of Quality
Factors in Reclaimed Water 146
10. Ionic Analyses for Metals in Reclaimed Water 148
11. Phytoplankton Counts of Samples Collected at Station C,
ICR 149
12. Algal Bioassays of IOR and STPUD Effluent: Counts,
pH and Suspended Solids Measurements 150
13. Report by Thomas Walsh (E Q A, Inc. ) to LTAC on
Underwater Photography 172
14. Benthic Survey--Indian Creek Reservoir (by Environ-
mental Quality Analysts Inc. ) 174
15. California Fish and Game, Department of—Progress Report
on Indian Creek Reservoir--Field Survey 184
123
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IS)
APPENDIX I. CONTOUR MAP OF INDIAN CREEK RESERVOIR (2)
-------
APPENDIX 2
KECIAIMED WATER AS PERCENTAL OF INPUT TO
IHDIAJST CREEK RESERVOIR (ESTIMATED)
Year
1970
1975
1980
1985
1990
1995
2000
2005
2010
2015
2018
Reclaimed
Water
Inflow
(acre -ft)
3,68V
4,912
6,l4o
7,368
8,596
10,131
11,666
12,89^
13,815
14,122
14,276
Runoff
Inflow
From 1700
Acres
(acre -ft)
815
8l5
815
815
815
815
815
,815
815
815
815
Percent
Reclaimed
Water
Annual
(*)
72.0
86.0
88.0
90.0
91-5
92.5
93-5
94.0
94.0
94-5
94-5
T, . a
Percent
Reclaimed
Water
Maximum
3 -Months
<*)
99
99-3
99-5
99-5
99-5
99-7
99-7 +
99.8 -
99.8
99-8
99-8
aComputed from data [z] not shown in this table.
125
-------
AREA, acres
0 20 40 60 SO 100 120 140 160 180
56IO
5600
5590
5580
5570
UJ
5560
5550
5540
VOLUME-ACRE
MINIMUM POOL
FE
ET-
"—AREA
MAX
-ACRES
MUM
POOL
56
46
36
to
Ul
UJ
16
600 1200 1800 2400
VOLUME, acre feet
3000 360O
APPENDIX 3- INDIAN CREEK RESERVOIR AREA AND CAPACITY (2)
126
-------
100
10 20 30 40 90 60 70 80 90 100 110 120 130 140 ISO 160
SURFACE AREA, acres
APPENDIX 4. INDIAN CREEK RESERVOIR EVAPORATION BY MONTH IN ACRE FEET (2)
-------
00
APPENDIX 5. AERIAL PHOTO OF INDIAN CREEK RESERVOIR SITE WITH OVERLAY
OF RESERVOIR AND PROPOSED IMPROVEMENTS (2)
-------
APPENDIX 6
MEASURED WATER INPUTS AND WITHDRAWALS,
INDIAN CREEK RESERVOIR (15)
Month
1971
April
May
June
July
August
September
October
November
December
Monthly
Reclaimed
Water Inflow
3 3
10 M (Acre feet)
104 (84.5)
101 (82.1)
102 (82.6)
121 (98.4)
129 (104.5)
103 (83.9)
89 (71.8)
84 (67.7)
95 (77.1)
Withdrawn
for
10 M
10
70
212
138
25
38
Irrigation
(Acre feet)
(8.0)
(57.0)
-
(172.1)
(111.8)
-
(20.0)
(310.0)
Runoff
Factors
(from 2)
1972
January
February
March
April
May
June
July
August
September
October
November
December
94
95
98
95
97
100
126
136
106
97
89
113
(75.9)
(76.7)
(79.8)
(76.9)
(78.8)
(81.0)
(102.4)
(110.0)
(86. 1)
(78.3)
(71.94)
(91.6)
123
179
344
100
(100.0)
-
-
(145.0)
(279.0)
(81.0)
-
0.4
0.4
0.4
0.
0.
0. 1
0. 1
0. 1
0.
0.
0.
3
1
0.3
129
-------
APPENDIX 6 (continued). MEASURED WATER INPUTS AND WITHDRAWALS,
INDIAN CREEK RESERVOIR (15)
Month
Monthly
Reclaimed
Withdrawn
Water Inflow
3 3
10 M (Acre feet)
1973
January
February
March
April
May
June
July
August
September
October
November
December
1974
January
February
March
April
118
99
105
110
110
115
138
145
134
98
101
109
153
107
128
130
(95.9)
(80.5)
(85.0)
(89.5)
(89.1)
(93.5)
(112.2)
(117.8)
(108.9)
(79.4)
(82.0)
(88.3)
(124.2)
(86.9)
(104.0)
(105.6)
for Irrigation Runoff
ir.^T.,3 /A r t\ Factors
10 M Acre feet ., _.
(from 2)
-
75 (61.0)
115 (93.5)
395 (320. 1)
459 (372.0)
252 (204.0)
-
-
-
_
-
-
78 (63.0)
130
-------
APPENDIX 7
MODIFIED SKULBERG NUTRIENT MEDIUM (1967)
Macronutrients
NaNO3
Ca(NO3)2 • 4H2O
K2HP04
MgSO4 ' 7H2O
Na2CO3
Fe EDTA (FeSO4 + Na2 EDTA)
Final
C oncentr ation
(mg/1)
46. 7
5.9
3.1
2.5
2. 1
0= 2 as Fe
Micronutrients
(Adopted
from Myers,
1951)*
CO(NO3)2 ' 6H2O
(NH4)6 M0?024 ' 4H20
CuSO4 ' 5H2)
Zn(C2H3O2)
MnCl2 ' 4H2O
H3BO3
Final
Concentration
(mg/1)
0. 0012
0. 0122
0.0200
0.0382
0. 050
0. 50
^Myers, J. (1951). "Physiology of the Algae, " Ann. Rev..Microbiology, 6:165- 180.
-------
APPENDIX 8
ANALYSES - INDIAN CREEK RESERVOIR
D.I.
1971
6/2
6/14
6/21
7/7
7/19
7/26
8/2
8/9
8/16
8/23
Samplt
Typ«
C
in
0.5 m
3. 5 m
6. 5 m
9. 5 m
C
III
0.5m
3. 5 m
6. 5 m
9.5 m
C
m
0. 5 m
3. 5 m
6. 5 m
10.0 m
C
m
0. 5 m
3. 5 m
6. 5 m
10.5 m
C
III
0. 5 m
3. 5 m
t. 5 m
10.0 m
C
III
0. 5 m
3. 5 m
6. 5 m
8. 0 m
C
m
0.5
3.5
6.5
10.5
C
in
0.5
3.5
6.5
8.5
C
m
0. 5
3. 5
6.5
8.5
C
in
0.5
3.5
6.5
8.0
R.i.
D«plh
(I
53.1
53.1
53. 3
53.7
53.9
53.9
53.9
53.9
53.6
52.9
Secehl
DLck
(t
12.0
7. 8
17.5
12.9
13.0
17.0
17.0
10.0
9.2
12.5
Temperature
Water
•C
1J. 5
U. 5
12.9
12.6
12. 5
18.0
18.0
16.5
IS. 1
14.2
18. 7
18.7
18.5
16.8
14.7
19.8
19. 8
19.6
19.0
18. 2
21. 1
21. 1
21.0
20.0
19.2
22.0
22.0
22.0
21.0
20.5
23.5
23.5
22.5
22.2
20.4
23.5
23.5
22. 1
21.9
21. 8
21.0
21.0
21.0
21.0
20.5
20.0
20.0
Air
•C
11.0
25.0
21.5
22.0
21.0
23.0
29.3
28.0
24.0
Unaltered Sample.
So. p.
Solid.
mj/l
2.18
1.70
3.39
0.94
1.29
2. 20
1.94
1.76
2.02
1.46
I. 24
0.53
. 13
.51
. 17
.58
. 19
.02
. 14
.03
1. 27
3.95
2.44
2.10
1.77
2.25
1.29
1.13
Vol.
Sulp.
Solid!
mj/f
1.42
0.82
2. 34
0.80
1. 68
1.33
1.53
1. 12
I. 15
0. 81
0.52
0.79
1.45
0.88
1.33
0.84
0.13
0.93
1.29
0. 76
2. J7
1.34
1.20
1. 12
1. 14
0.78
0.85
COD
mg/l
14.8
13. 3
16.1
6. 6
17. 4
17. 1
10.2
17. 8
12. 2
5.9
9.2
7. 7
1
11.6
11.6
11. 3
12.6
11. 1
IS. 2
DO
mg/l
7.4
1.0
7.4
.:,
6.0
9. 3
3. 6
9.3
10. 1
6. 8
3.6
10. 3
10.3
9.0
5.4
0.7
10.8
1.4
10.8
9.3
6.7
5.0
10.2
1.5
10.2
11.8
6.8
4.2
6.9
0.4
6.9
6.6
5.6
3.0
7.8
1.4
7.8
7.0
7.2
1.5
7.1
0.7
7. 1
7.6
6.7
4.6
7. 7
0.6
7. 7
7.8
7. 3
6.7
7.8
2.1
7.8
8.3
8.6
7.9
Inorg.
C
mg It
40.9
58. 1
40.9
40.7
41.2
40.7
39.2
58. 3
40.4
40.4
41.2
42.7
39.4
58.0
39.7
39.4
40.9
43.7
39.4
63.3
39.7
40.7
41.2
40.9
40.7
62.5
40.2
69.6
40.9
40.7
41.4
42.7
39.4
71.8
39.9
39.2
41.7
43.5
36.7
67.5
40,2
39.4
38.9
40. 7
38.9
62.5
40.4
40.4
40.2
39.4
38.7
62.8
39.7
39.2
39.2
39.7
045 |i MUllpore Filtered Simple.
Nitrogen •• N
Or«.
n«/i
1055
368
1165
317
997
497
820
342
52
<1
794
889
1181
533
994
1051
972
781
452
230
852
600
948
939
1018
983
1118
838
NH,
|i>/<
5572
12540
5187
19939
5200
16460
6505
26900
5615
17500
4115
24280
5202
4941
6050
7811
6115
5833
24374
4789
24287
6289
5398
5833
5463
6050
26020
NO, * NO,
ft»
1942
182
2200
268
1797
94
4220
365
2232
630
2746
904
2978
2920
2848
2297
1884
2848
187
4039
1986
3460
3468
3782
3681
4251
4390
Total
»8/t
8569
13096
8552
20524
7994
17051
11545
27607
7899
18130
7655
26073
9361
8855
9949
11080
8780
9133
24791
9680
26873
10697
10105
10633
10127
11439
31248
PhOKphorui
a. P
PO,
»(/'
11
99
7
307
4
90
13
366
24
446
15
366
30
23
27
74
120
21
34
68
494
68
70
64
60
68
231
Total
,ig/l
148
142
32
349
28
119
53
444
41
478
41
433
88
88
89
167
175
57
41
104
529
114
89
90
77
92
264
C«
mg/<
48. 1
59. 1
47.2
54.0
48.2
53. 8
47.8
48.8
45. 8
49.6
44.4
54.4
46. 2
45.8
45. 8
45.8
46.8
46.2
55.4
49. 6
50.6
49.8
49.8
49.6
49.4
50.4
59.6
Cl"
rat/I
26.70
26.91
26.57
26.50
26.70
26.29
25.79
25.65
27.29
26.63
26.77
26. 77
29.54
34.58
28.46
30.84
31.56
28.03
28.78
28.52
27.83
27.75
28.95
28.18
29.38
31.54
29.63
30.56
29.29
27.78
31.25
28. 55
30. 32
29.98
30.66
30.24
30.77
28.80
28.48
28.40
28.64
28.49
29.74
33.45
29.14
28.97
29.40
29.14
32.61
35.71
33.65
33.27
33.55
33.36
29. 63
34.09
29.89
29.46
29.89
29. 72
Te
Mg/'
R«Bume
Iron
8/2
1
1
1
16
PH
7.9
7.8
8.0
8.0
8.0
8.0
8.2
7.6
8.3
8. 2
8.0
7.8
8.2
7. 9
8.2
8.2
8.2
8.7
8.0
7.9
8.1
8. 1
8. 1
8. 1
8. 1
8. 1
8.2
7.9
8. 2
8.2
8.2
8.0
8. 1
7. 8
8.0
8.0
7.9
7.9
8.2
8.0
8. 1
8. 1
8.0
8.2
8. 1
7.9
8. 1
8. 1
8.0
8. 1
9.0
7.8
7.9
8.0
8.0
7.9
Alk.
&•
CaCO,
mg/l
167.1
237.8
167. 1
166.1
168. 1
166.1
159.9
237.8
165.0
165.0
168. I
174.3
160.9
236. 8
161.9
160.9
167. 1
178.3
160.9
258.3
162.0
166.1
168. 1
167. 1
166.1
255.2
164.0
283.9
167. 1
166. 0
169. 1
174. 3
160.9
293.2
163.0
159.9
170.2
177. 3
157.8
275.7
164.0
160.9
158.9
166.1
158.9
255.2
165.0
165.0
164.0
160.9
157.9
256.3
162.0
159.9
159.9
162.0
Cond.
lio-')
mhot
464
572
512
495
490
490
440
616
430
30
51
06
60
33
83
83
495
506
550
682
533
506
506
503
488
668
514
509
509
514
466
700
498
509
511
530
516
692
494
493
515
515
504
688
504
504
499
506
520
683
504
502
502
504
507
700
-------
APPENDIX 8. Continued
ANALYSES - INDIAN CREEK RESERVOIR
Data
8/30
9/7
9/14
9/20
9/27
10/5
10/11
10/16
10/27
ll/l
11/8
11/15
Simple
Typ«
c
III
0.5
3.5
6.5
8.0
C
III
0.5
3.5
6.5
C
III
0.5
3.5
6. 5
C
III
0.5
1.5
6.5
C
in
o.s
1.5
6.5
C
III
0.5
3.5
6.5
C
in
0.5
1. i
6.5
C
III
0.3
1.5
6.5
C
III
C
III
o.s
1.5
6.5
C
III
0.5
1.5
6.5
C
III
O.S
1, J
6.5
Ree.
Depth
ft
52.9
52.0
51.5
51.4
51.5
51.7
51. 9
52.0
Crib
Simple
52. 1
52. 3
52. 8
SeceU
Dl.k
ft
12. 1
11.0
11.2
14.5
13.4
16. 8
16.9
15.9
17. «
14.0
Temperature
Water
•c
20. 0
20. 0
19.5
19.5
19.2
17.8
17.8
17. 1
17.0
19.0
19.0
18.0
18.0
17.0
17.0
16.8
16.8
14.5
14.5
14.0
13.9
12.0
12.0
11.8
11.5
14.0
14.0
13.0
12.8
11.0
II. 0
10.8
10.8
7.0
k. 5
6.2
6.8
6.8
6.2
6.0
5.0
S.O
5.0
5.0
Air
•c
22. 1
20.8
22. 1
20.0
14.0
19.0
22.0
11.0
12.0
2.0
Unftltered Sample!
Su.p.
Solid!
mg/l
1.56
0.64
1.82
2.16
1.67
2.71
1. 18
0.60
1.04
0.41
2.51
1. 17
2.44
2.21
6.49
2.09
1.40
2.23
1.01
4.82
1. 30
1.46
1. 70
1.57
6. 78
0. 77
4.26
1. 70
2.21
I. 75
1. 11
4. 52
16.92
3.40
1.94
6.09
5. 00
2.08
5.91
4. 12
1.69
2.49
25.99
4.59
1.86
1.33
2. 39
2.95
2. 68
4. 38
Vol.
S».p.
Solid!
mg/J
0.82
0. 52
1.61
1.29
1.40
0.62
0.56
0.79
0.25
2. 12
1.54
0.90
2.00
1. 27
1. 13
1.29
0. 69
2.43
1. 14
1. 35
1. 23
2.65
1 77
1. 17
1. 69
1.26
0.63
1.86
4.40
1. >1
1. 25
1. 77
1.91
1. 14
1. 72
2. 11
0.74
1.78
5.56
1.88
1.64
0.67
1. 74
1. 34
1. 16
1.58
COD
itii/l
13.7
12. 3
14. 3
10.6
10.9
9.9
7.2
11. 5
II. 2
9.2
11.9
11.2
10.9
11.9
10. 6
10.1
11. 3
14. 4
3,4
11.4
11.4
12.0
7.1
11. 7
4.9
16. 8
11. 1
11.0
8. 6
21. 1
9.6
9. 1
15.4
18.6
13.8
II. 6
17.8
17. 8
12. 5
11. 8
IS. 1
12. 8
16.5
11.4
10.6
10.6
11.4
13.7
DO
mg/«
8.4
0.4
8.2
8.4
7.8
8.6
1.0
8.6
9.6
10.6
11.3
0.8
11.1
11.8
8.6
9.8
1.0
9.8
10.1
9.8
9.7
1.0
9.7
10.8
10.7
10.7
12.9
14. 1
11.4
0. 6
11. 1
12.9
11. 1
0.2
II. 1
13.4
9.0
9.4
0.6
9.4
10. 1
9.8
1.4
9. a
11.2
12. 1
10.2
0.6
10.2
II. 0
loorg.
C
mg/J
40.4
61.8
37.7
18. 2
16.9
36.9
65.3
37.4
36.9
36.9
36.4
65. 1
37.9
36.8
36.8
37.2
62.8
36.9
36.7
36.2
36.8
65.2
36.5
35.3
35.0
64.9
35.0
35.0
35.0
36.0
65.2
35.5
35.8
34.5
62.0
35.5
34.8
35.0
36.0
69. 1
34.8
58.6
36.5
35. 1
36.0
53.9
36.3
36.0
35.5
045 |i MUltpore Filtered Sample*
Nitrogen a! N
Org.
Hit
1101
42
1050
811
1211
1000
142
789
150
1261
1142
1311
1215
876
997
1011
867
865
360
813
691
605
1263
137
1081
295
1 169
1134
1060
60
1068
10S6
973
1190
S21
1257
1357
1407
1100
485
1480
1185
1555
1138
512
1157
1162
1522
NH,
l»g/< .
2985
2985
3245
1876
2615
5202
21418
1940
13852
2050
5158
2485
5I3S
15418
5094
5115
4595
4115
20374
4376
5200
3898
4375
18113
3900
17760
4660
4155
3680
20374
1811
4311
J463
4583
36110
5531
6583
580B
5158
29530
69SB
5433
6288
4783
33130
5708
5011
5911
NO, *NO,
ft/I
3448
3869
4492
4332
4609
391!
5
2016
5
2064
5536
5145
4319
46
5290
4911
5188
5797
301
5638
6203
5621
5200
247
5348
174
6320
4960
5840
6594
195
6348
6201
6638
6507
214
8522
6261
6896
5436
757
6768
6680
7088
5116
562
5840
5652
6436
Total
ft"
7534
7948
8787
7019
8435
10115
21565
6745
14207
5177
11816
8941
10669
16340
11181
11059
10650
10777
20975
10827
12094
10126
10833
18497
10329
18229
11915
10789
11329
1 1 334
20629
11227
11600
11074
12280
27065
15312
14201
141 II
13409
11694
30772
15206
13298
11237
34404
12705
12047
13891
PhoephorU!
ai P
PO.
fg/<
75
54
60
61
52
60
96
2V
77
10
41
51
44
85
43
41
40
49
42
14
35
34
28
15
32
14
30
29
30
31
8
34
35
37
54
40
158
51
40
47
122
45
44
19
99
29
39
43
Total
fg/<
85
80
80
92
81
74
114
57
90
(4
72
70
98
61
60
61
247
96
67
61
132
54
32
41
20
51
51
54
47
12
55
46
44
141
61
185
7!
59
58
132
(1
60
62
131
t.0
60
64
Ca
mg/<
48.6
40.6
47.4
48.2
48.4
48.2
47.6
41.4
46. 8
36. 8
46. 6
47.4
47. 6
53.4
46.8
46.8
46.4
49.4
55.0
48.2
47. 6
43. 2
47.0
57.6
49.8
59.8
49.0
48.2
47.4
48.4
55. 8
47.0
47.2
49.2
72.0
45.4
66.8
45.6
47. 8
50.6
72.8
51.2
51.6
50; 6
60.4
50.4
49.8
49.6
Cl"
nig /I
32.34
28. 17
30.97
30.55
30. 55
30. 72
28. 67
27.99
28. 67
29. 01
28. 84
33.95
33. 16
33. 60
33.87
34.33
33.27
33.89
34.33
35. 12
34.23
30. 64
32. 71
32.80
33.42
10.96
28.83
30.87
31.14
31.23
36.25
31.75
33.74
34.00
32.53
33.21
31.61
31.61
32.05
11.62
59.74
15. 79
62.32
15. 97
35.43
35. 89
72.77
28.63
14.24
36.07
45.85
34. 63
14.61
14. 10
Fe
v-tlt
3
16
11
14
10
4
<1
10
1 1
8
8
6'
9
10
1
6
6
5
7
8
4
7
8
13
7
12
8
13
6
10
1
13
10
3
3
14
16
15
10
8
a
a
14
27
5
21
18
43
pH
8.2
8.5
a. i
3.2
8.2
8.2
8.0
8.2
8.2
8.2
8. 1
a. 3
a. 3
a. i
8. 1
8.2
8. 2
8. 3
a. 2
8.2
8. 0
7.9
8. 0
a. o
8. 0
8. 2
8. 1
8. 2
8.2
8. 2
3. 1
7. 9
a. i
a. i
a. i
7. 9
7. 8
8.0
8.0
8.0
7. 9
8.0
7. 9
8.0
8. 1
a. o
7. 7
a. o
a. o
Alk.
ai
CaCO,
mg/»
165.0
252.2
153.8
151.8
155.8
150.7
150.7
266.5
152.7
150.7
150.7
148. 6
265. 5
154.8
150. 2
151.7
256, 1
150.7
149.7
147.6
150. 0
266.0
149. 0
147. 0
144. 0
143.0
265.0
143.0
143.0
143.0
147.0
266.0
143.0
145.0
146. 0
141. 0
253.0
142. 0
143. 0
147.0
282.0
142.0
239.0
149. 0
144. 0
147.0
220. 0
148. 0
147.0
Coud.
Kihoi
SOI
600
491
512
512
491
513
667
502
508
508
499
662
520
520
545
596
545
682
550
522
668
504
525
528
510
668
519
514
514
497
650
497
513
508
518
637
524
540
524
512
765
596
765
594
578
890
93!
742
793
917
451
476
-------
APPENDIX 8. Continued
ANALYSES - INDIAN CREEK RESERVOIR
Date
11/22
11/30
15.72
1/10
1/24
3/27
4/3
4/10
4/17
4/25
5/1
5/8
Sample
Type
c
III
0.5
3.5
«. 5
C
III
0.5
3.5
6.5
C
III
0.5
3.5
«-5
C
III
0.5
3.5
6.5
C
III
0.5
3.5
6.5
C
III
0.5
3.5
6.5
C
in
c
in
o.s
J. 5
6.5
9.5
C
in
0.5
3.5
6.5
9.5
C
in
o.s
4.5
6. 5-
9.0
C '<
in
0.5 '
3.5
6.5
Rei.
Depth
(1
52.9
53.0
Frozen
Frozen
51.0
51.1
51.3
51.5
52.0
52. 1
51.1
Secchl
Dills
ft
17.5
17.9
3. 7
4. I
16.0
20.0
19.9
14.9
Temperature
W.ter
•c
4.0
4.0
4.0
4.0
4.0
4.0
4.0
4.0
2.9
2.9
3.0
3.2
3.5
3.5
3.2
2.8
9.0
9.0
8.8
8.2
10.0
10.0
9.2
8.9
9.0
9.0
9.0
9.0
8.4
8. 1
10.5
10.5
9.6
9.4
9.0
11.2
11.2
11.0
10.9
10.9
12.8
12.8
12.8
12.5
Air
•c
13.0
3.5
9.0
8.2
1.0
19.0
14.0
9.5
13.0
17. 0
15.0
Unaltered Sample!
Su.p.
Solid.
mg/1
1. 13
7. 31
15.08
3. 1 1
1. 11
1.53
3.69
5.68
4. 14
4.09
2.68
2.00
2.25
3.68
3.81
1.36
1.80
1.67
1.64
4.86
2.65
6. 19
4.02
3.36
5.38
3. 11
7. 12
7.50
7.73
5.83
2.56
1. 17
1.47
2.04
3.35
2.54
3.24
I. 32
3.22
1.94
2.90
3.36
7.25
1.07
2.56
1.44
3. 30
2.34
2.85
3.23
3.43
1.34
1.16
Vol.
Suip.
Solid!
mg/(
0.63
3. 84
2.48
1.63
0. 55
. 20
.35
.96
.94
.22
. 83
. 18
.02
. 29
1. 37
0.99
0.98
0.92
0.92
4.03
1.49
5.35
3.40
2. 72
2. 16
6.49
7.36
7.07
3. 10
1.61
0.65
0.94
1. 19
2.61
1.43
2.25
0. 63
2.25
1. 17
1.89
2. 06
3.57
0.69
1. 88
1. 11
1.94
1.45
1.74
0.80
1. 19
1.41
1.72
COO
mg/1
12.8
20.7
10. 7
11.9
11.8
10.0
10. 3
9.7
16.8
11.0
17.5
11. 7
11.0
13. 6
7. 3
7.9
10, 6
7.9
6.7
16.0
11.6
17. 2
13.2
28.0
32.0
23. 2
15.0
8.5
13.4
6.9
15.0
16.3
14.6
17. 5
11. 2
10. 8
15.2
14.8
11. 6
18.0
12. 0
9.2
16.4
13.2
13.2
14.0
15.0
9.7
16.2
13.8
17.8
DO
mg/<
10.8
10.8
11.4
10. 6
10.5
0.6
10.5
10.6
10.8
9.8
0.7
9.8
9.8
9.8
11.6
11.6
10.0
9.8
13. 0
0.6
13.0
12. 1
12.3
9.0
0.6
7. 3
7. 3
8. 3
7. fr
7.6
1. 1
7. 6
7. 2
6. 8
5.3
7.6
0.6
7.6
7. 5
6.5
6.2
7.8
1.4
7.8
8.6
9.0
Inorg.
C
mg/1
36.3
36.5
36.5
36.0
35.3
58. 1
35.5
36.3
36.0
31.4
55.9
32.8
31.9
34.5
40.4
63.7
43.6
41.6
41.9
40.9
53.7
39.2
38.5
38.5
37. 2
53.9
39.7
37. 7
38.2
37.5
59.8
37.5
55.6
38.0
37.5
39.0
37.2
36.7
54.9
37.5
37. 0
37. 0
37.0
36.5
45.6
36.7
36.7
37.0
36.5
33.3
38.5
31.8
31. 1
0.45 H Mllllpore Filtered S.mplei
Nitrogen *• N
Org.
t>g/<
1527
997
1177
1187
1514
734
1439
1469
1389
1416
486
1321
1361
1321
1152
981
2015
1101
929
1178
1509
1235
1350
1190
1360
1252
1085
1805
1657
1346
1309
1292
1096
1393
1393
1273
1762
1525
942
1274
1277
1205
1277
1594
1516
13(2
1526
1596
NH,
»g/<
4858
7382
6333
6783
633}
36830
6158
5:3)
6783
6583
22320
9458
8883
10633
7133
25330
11208
9708
11208
7175
21840
7065
8230
10115
6890
16696
7630
7888
8203
6000
17268
6269
14640
7631
8232
6917
8146
6600
14410
7889
8115
6660
7775
5289
11440
6660
7374
6003
7230
4745
7668
5315
5174
NO, 4 NO,
flit
6636
7000
6636
7796
7944
415
7388
7560
10120
610
7200
4640
5720
4880
170
6316
5040
6044
3908
3846
4446
3677
3846
4152
3624
4768
5540
5540
7640
325
1944
1609
1596
1652
1580
1652
6112
3682
6600
6264
8200
7364
6400
6320
6252
7366
6672
6672
9712
11606
8296
8328
Total
Mg/(
13021
24938
15379
14146
15766
15791
37979
14985
14382
11119
23426
17979
14884
17874
12235
26667
13546
13008
14890
12220
21829
13633
14778
14933
15000
18845
9318
16254
10884
11232
9805
11090
13808
19465
15882
15652
16642
16664
12631
19034
14189
15947
13952
15496
15973
26638
15139
15098
Photphorui
• e P
PO4
l>g/<
53
203
60
79
51
52
95
47
46
46
80
428
95
101
121
118
350
118
98
114
9
132
II
12
12
8
71
8
13
11
4
59
18
86
24
24
21
23
35
73
30
33
26
40
41
172
43
43
46
SO
43
86
36
43
Total
M«
65
225
79
101
69
68
107
68
62
70
101
462
106
114
132
126
385
147
133
135
25
154
30
33
29
•44
89
26
32
20
22
74
33
99
41
38
38
39
52
84
51
a
4
1 2
2
8
7
66
66
65
63
104
68
68
Ca
mg/I
50.2
56.2
50.6
49.4
48.8
46.6
53.8
48.8
46.4
48.6
45.4
53.0
40.2
40.6
40. 6
54.0
66.0
58.2
55.4
56.0
57.2
66.4
52. 7
77.9
53.6
54.8
54. 8
54.4
81.4
54. 5
80. 7
58.4
55. 3
54.8
54.8
55. 6
81.2
56.2
55.8
55.0
55.0
56.4
66.0
55. 6
55.0
55.0
54.3
57.9
67.6
52.8
51.4
Cl"
mg/1
40.05
32.22
37.59
37.41
37.76
39.06
29.86
37. 33
38.02
36.87
40.36
35.07
37.15
37.76
36.98
36.82
31.00
36.91
35.09
36.00
38.57
27.47
33. 10
29.55
32.61
33.20
32.51
35.97
30.76
33.51
29.30
33.16
33.33
32.81
32.02
35.26
28.49
33.40
33.30
32.74
32.74
33.93
32.24
34.23
33.83
34. 13
33.83
32.16
32.71
31.69
31.78
Fe
M/'
13
13
10
8
8
9
4
8
12
16
14
6
10
10
8
38
48
34
40
34
7
10
10
12
13
15
3
18
18
14
6
<1
17
<1
7
11
7
20
11
-------
APPENDIX 8. Continued
ANALYSES - INDIAN CREEK RESERVOIR
Date
5/15
5/22
5/30
6/5
6/12
6/19
6/26
tit
7/10
7/17
Sample
Type
C
m
0.5
3.5
6.5
9.5
C
in
0.5
3.5
6.5
9.5
C
111
0.5
3.5
6.5
9.5
C
III
0.5
3.5
6.5
9.5
C
III
0.5
3.5
6.5
9.5
C
III
0.5
3.5
6.5
9.5
C
III
0.5
3.5
6.5
9.5
C
III
0,5
3.5
6.;
9.5
C
in
0.5
3.5
6.5
9.5
C
III
0.9
9.9
4.9
9.9
Re*.
Depth
H
52.1
52.2
52.4
52.4
52. 5
52.5
52.5
52.5
52.3
51. a
Secchl
Dl.k
11
9.0
9. »
21.7
180
15. 8
16.4
24.0
16.2
10.9
14. 7
Temperature
Water
•C
15.5
15.5
15.0
13.5
13.0
14. 2
14. 2
13. 8
13. 5
13. 0
19. 0
19. 0
18. 0
15.0
14. 0
19. 0
19.0
18. 2
16. 3
14. 5
16.0
16.0
16. 8
16.5
17. 0
19. 2
19.2
18. 8
18.0
16.2
19. 2
19. 2
19.0
18. 7
17. 8
21.5
21. 5
21.2
21.0
19. 5
20. 0
20.0
19. 8
19.8
19.2
22. 0
22. 0
21.5
20. 8
20,2
Air
•C
22.0
15.0
25. 0
2L 0
22.0
22.0
24.0
27.0
26. 5
26.0
Uiflltered Simple.
Su*p.
Solid.
mg//
4.66
2.77
4. 30
5.61
2. 82
3. 17
3.63
3. 91
3. 55
5.00
4. 33
3.94
1. 19
1.99
1.50
1. 88
1. 86
1. 21
1.02
1.40
1. 13
1. 29
1. 36
1.09
1.24
4. 14
1.52
1.81
1. 76
0.98
0. 75
1.36
2.28
1.23
1.69
1.20
0.60
1. 72
2.00
2.23
2.37
1. 58
3.05
3.76
1.48
1.45
3.26
3.04
4.76
2.09
2. 31
6. 70
8.50
1.00
3.46
1. 45
1. 36
2. 52
2. 58
Vol.
Su.p.
Solid*
mg/l
1. 11
3.79
4, 73
2. 16
1. 94
3. 13
2. 50
3. 38
4. 56
3. 86
3 25
0. 68
1 29
1. 13
1. 72
1. 66
1. 08
0. 82
1. 30
1. 19
1. 26
0. 80
1. 19
1. 81
1. 36
1.65
1. 21
0. 85
0. 73
1. 14
1. 11
0. 75
0.53
1.66
0. 89
1. 55
1. 61
0. 88
2. 32
2.02
1.45
1. 39
2. 42
1.05
3 29
1. 27
I 49
2. 12
2. 62
0. 66
2. 39
I. 35
1. 45
1.67
1.63
COD
mg/<
12.6
19. 6
19.2
15. 6
14.0
17. 1
14. 1
15. 6
22. 8
16.7
17. 5
17.7
12. 8
18. 8
15.8
15.4
15.4
17. 5
7. 1
10. 0
17. 5
6. 7
15. 2
7.4
12.6
12.6
18. 5
12.2
11.0
4. 4
13.2
13.2
14.0
13. 2
14. 6
9. 1
13.9
15. 3
11. 7
11.7
10.2
19.0
4. 1
II. 1
9.0
5.4
18.5
24. 8
13. 3
13. 3
13. 6
12. 2
13. 1
18.4
16.0
II. 0
18. 1
9.9
DO
mg/l
11.4
1.0
11.4
12.9
9.2
6.2
1 1. 5
2.0
II. 5
11. 9
10. 9
10. 2
10. 1
1. 4
10. 1
10. 6
9.2
6.4
8.9
0.4
8.9
8.9
2.5
5.3
0.6
5.3
7.0
8. 1
7.6
11.4
1.0
10.4
11. 8
7.8
3. 8
9.5
0.5
9.5
9.0
7.6
4.8
4. 1
1.0
12.3
15. 1
91.2
9.2
7.5
10.3
7 5
7.4
7.8
8.7
6.7
0. 5
6.7
6.4
5. 1
4. 1
Inorg.
C
mg/f
35.5
45.6
35.5
35.8
37.0
37. 2
35.5
48.0
35.8
36.0
35.8
35.6
34. 3
55. 1
35.0
35.0
36. 3
36.7
33. 8
51 4
33. 6
33. 8
37. 7
34 3
53.2
35.5
34. 3
34 5
34.8
!2 6
53. 2
33. 3
32.6
33.8
37.0
29.4
26. 1
32. 1
31. 6
32. 8
36.3
27. 8
57.8
30. 7
28. 8
34. 3
35.0
28. 6
56.4
28. 6
29. 3
30.7
27.8
26.9
57. 4
27. 1
27. 8
32.2
10. 5
045 |i MllUpore Filtered Sample*
Nitrogen a* N
Org.
M/l
1162
1266
1671
1677
1603
1471
1605
1994
1223
1497
1588
1434
745
1 85
1 34
1 34
1 85
1 03
1432
2015
1426
1926
1244
1132
969
1406
1246
1505
1406
1109
1544
1355
1452
1367
1424
1188
1296
1325
1130
1279
1125
948
1268
1422
1250
1462
1222
860
1025
1 160
1095
1000
1215
988
928
1513
973
1163
1483
NH,
l-g/<
4745
13268
6174
5090
860
830
717
1 554
831
000
974
5135
2346
22400
4517
4574
4803
6145
5280
11289
6980
6640
7896
2750
9634
3666
4460
1831
4460
2860
13500
3375
3375
3145
4974
2844
19554
4031
4317
5030
4232
2175
28700
5060
2915
5374
5774
3060
37250
3563
3060
3238
3413
3488
30750
3512
3812
5138
3738
NO, *NO,
I-!/'
6900
4100
7020
5590
7860
7610
9707
5185
9740
9460
9320
9390
9770
3510
9460
10400
0394
10550
13900
9850
8696
7825
7059
9200
6685
8130
8550
9350
9670
12460
4365
7930
3030
7930
6990
60990
32700
64350
63815
69570
67470
11136
1580
8280
9986
8383
9986
1805
6000
6360
6252
6400
20304
8200
16680
16400
16960
16960
Total
Mg/<
12807
18634
14865
12357
14323
1491 1
15029
18713
15794
15957
15882
15959
12861
27295
15311
16308
15582
18208
20612
21 154
17102
16391
16044
16109
12082
17308
13202
14256
14686
15536
164:0
19400
12660
12857
12442
13388
65022
53550
69706
68762
7587
7282
1425
3154
1476
1415
15210
161 K2
40060
10723
10515
10490
11028
24780
39878
21705
21185
23261
22181
Phoiphorua
ae P
PO,
l>S/<
13
132
21
18
54
68
6
128
0
6
1 1
14
4
105
4
4
»
18
3
129
5
5
15
68
16
73
38
24
17
4
104
6
4
16
83
12
60
12
12
21
79
13
74
55
23
51
84
37
34
40
45
34
136
34
30
60
64
Total
fflt
29
130
43
37
73
85
140
24
20
27
27
48
138
30
32
30
53
20
166
23
26
97
98
30
146
61
43
35
18
125
19
21
38
99
26
89
33
29
45
104
31
85
68
40
73
105
50
46
55
59
46
138
44
40
69
77
Ca
mg/J
54. 8
55. 0
55. 7
56.4
56.4
55. 9
67. 8
56. 9
55. 2
56. 9
56. 6
53. 1
61. 7
54. 5
53.6
55. 5
56. 0
51.9
67.4
53. 1
52. 1
54.8
56. 0
52. 8»
68. 3
52.9
52.9
52. 8
53. 1
50. 5
65.5
50. 9
50. 9
52.4
56.9
48.4
64.5
48.4
47.9
49. 7
52. 6
43. 1
61. 7
47. a
44.5
49. 1
50.9
45.9
45.0
45.5
44. 8
42.8
64.
42.
42.
44.
44.
cr
mg//
38.23
35. 12
35. 12
34.73
34.73
34. 51
32. 67
33.81
33.81
33. 90
34. 19
38.05
30.75
34.22
34. 12
33. 94
33.76
34.08
27.07
32. 10
31.56
31. 38
30. 04
14.45
27.77
33.01
33.30
33.40
33 11
35. 73
28.45
33.72
33.81
33.81
33. 14
34. 00
29.26
33. 71
34.47
34. 09
33. 62
34.59
31. 34
62. 16
32.53
62.67
33. 30
1 . 87
3 ,96
J . 34
3 . 87
6. 90
3. 79
4. 71
4. 62
4.52
4.07
Fe
Pg/<
4
4
5
5
5
4
<1
1
I
1
<1
-------
APPENDIX 8. Continued
ANALYSES - INDIAN CBEEK RESERVOIR
Date
7/23
7/31
8/8
8/14
8/21
8/28
9/5
9/11
9/18
9/25
10/2
10/9
Sample
Type
C
HI
0.5
3.5
6.5
C
III
0.5
3.5
6. 5
C
III
0.5
3.5
6.5
C
III
0.5
3.5
6.5
C
III
0.5
3.5
6.5
C
III
0.5
3.5
6.5
C
111
0.5
3. S
6.5
C
III
0.5
3.5
5.5
C
III
0.5
3.5
6.5
C
III
0.5
3.5
.6.5
C
in
0.5
3.5
6.5
C
m
0.5
3.5
6.5
Ret.
Depth
n
51.0
50.5
48.5
47.2
46.0
44. 2
42. 3
42.0
41.4
41.9
43.0
43. 1
Seceht
Dllfc
ft
10.2
10. 7
14.0
11.2
15.5
18. 1
21.5
14. 5
21. 5
22. i
23.9
14. 3
Tcmpcxatore
Water
•C
20.0
20.0
20.0
20.0
21.0
21.0
21. 0
20.2
21.2
21.2
20.6
20.6
19.2
19.2
19. 1
19.0
18.2
18.2
18.0
17.9
19.0
19.0
19.0
19.0
18.0
18.0
17.9
17.9
16.9
16.9
16.5
16.5
16.0
16.0
15.5
15.0
14. 0
14.0
13.7
n. o
13.2
13.2
13. 2
13.2
14.0
14.0
13.8
13. 8
Alt
•C
24.0
24.0
22.0
17.0
19. 5
19.0
19.5
14. 0
16.0
10.0
13.0
15.5
UniUtered Sample*
Suip.
Solldi
mg/l
2.42
4. 23
2. 52
3. 15
3. 31
1.41
7.06
2. 13
2.64
1.43
1. 79
1.42
1.60
3.09
3.06
2.48
1.98
2.55
I. 18
5. 12
1.41
1.91
0.99
0.86
3.93
1.00
0. 95
0. 77
0. 49
1. 03
0. 85
0.97
1.35
1.37
1.65
1.53
4.35
1. 11
3. 76
1. 33
1. 18
2. 66
1.32
0.67
1. 60
1. 27
1.51
1. 50
4.29
1.36
1.26
1.90
1.05
2. 26
1.36
1.41
Vol.
Susp.
Solid!
m«//
1.08
2.98
2. 21
1.50
1. 50
0.99
5.08
1.67
1.53
0. 69
1.27
1. 17
1. 39
1.09
2.24
1.52
1.45
1. 58
0. 67
3. 59
1. 31
1.57
0.95
0. 54
2. 57
0. 45
0.87
D. 98
1.04
0.75
1.24
1.25
1.26
1.77
0.83
1.49
1.58
1.59
2. 66
0.68
0.55
1.27
1. 24
I. 19
0. 76
3.47
0.88
1.02
0.92
0.63
0.70
1.04
1. 17
COD
mg/l
13,9
19. 1
14.6
18. 7
14. 2
12.5
19.8
15. 8
14.2
12.5
14. 2
13.2
12.2
10.2
14.8
13.8
13. 1
12. a
11.6
18.7
15. 7
14. 3
12. 2
14.2
16.8
13 9
14. 5
16.8
10.8
11.8
12. 1
11.4
10.2
n. a
10.5
io. a
14 1
11.0
15.2
4.0
1. 6
3. 1
3.4
2.5
3. 1
4. 9
4.9
12. 1
10. 3
13.0
13.9
13.9
13.9
11. a
13. 3
12. 7
13.0
DO
mg/l
7.6
0.8
7.6
6.4
7.9
9. 1
0.8
9. 1
7. 7
9. 0
9. 0
9.8
10.6
8. 3
1. 7
8. 3
8. 3
10.2
8.8
0.9
8.8
9. 8
12.4
9.0
1.6
9.0
10.5
11.0
7. 9
7. 9
8. 2
9.9
9.3
1.4
9.3
9.2
9.6
10. 1
2. 3
10. 1
12. 2
11.9
8.4
1.8
8.4
11. 7
12. 7
10.3
1.8
10.3
11.6
13.4
11.2
1.4
11.2
11.9
14.5
Inorg.
C
mg/l
29.8
65. 1
30.0
30 0
28.8
28. 6
65.3
28.8
29. 3
28.8
29.5
28. 6
28.6
28.5
64. 3
30.0
27.4
29.5
28.6
55.0
28. 3
28.6
27. 6
29. 8
65.3
30.2
28. 6
27. 6
28. 8
57. 8
30.0
28. 1
28. 8
59.3
29.0
28.6
28.6
28. 1
55.4
29.3
28. 1
28.6
28. 1
62.4
30. 3
27. 4
28.5
28.3
56.9
27. I
26.6
27.4
30.5
71.8
30.2
30.0
M. 2
0.45 V Mtlllpore Filtered Sample*
Nitrogen a* N
Org.
»
34
41
209
35
32
33
38
117
38
37
49
Ca
mg/(
42.6
64.3
42.7
42.2
42.2
41.2
58. 1
41.4
42. 1
40. 5
51.2
42. 1
41.0
40.5
55. 3
40.2
40.5
40.2
39. 7
52.6
40.2
40. 7
39. 5
41.0
57.9
41. 4
40. 1
40. 9
40.2
40. 5
40.7
41.8
53.0
42.4
41. 6
41.8
41.9
19. 1
40. 5
40. 7
40. 0
40. 2
56. 6
41.0
39.8
40.2
59. 3
40.2
40.0
40.0
40. 2
54. 3
40.5
40. 5
40.5
cr
mg/l
37.62
40.31
39.86
41.05
41.21
3 .56
3 . 40
3 .48
3 .21
37.64
33.70
34. 43
35.07
35.61
32.84
36.07
35.33
35.70
35.73
33.55
38.27
35.82
36.09
39. 37
34.61
35.54
36. 29
39.98
35.50
36.64
36.07
35.97
35.51
30.92
33.98
33. 37
33.67
36.84
31.67
35. 53
35. 18
36.40
33.76
29.50
34.65
34.97
37.54
30.63
36.25
36.73
36.33
42.69
33. 10
38.74
38.74
38.93
Fe
fill
<1
21
9
9
9
6
6
5
2
4
<1
11
5
12
9
10
10
6
21
15
14
19
9
13
16
37
20
33
15
18
15
9
14
13
15
12
12
11
6
8
13
12
9
23
27
23
22
8
16
12
16
14
34
42
22
19
35
pH
8.5
8.5
a. 4
a. 4
a. 4
8. 4
a. 4
8.4
a. 4
e. 3
a. 2
a. i
8.2
e. i
8.2
8.4
a. 4
a. 2
7. 9
a. 2
8. 3
8.3
8.3
8. 3
8.2
8. 3
8.2
8. 4
8.2
8.2
8. 1
8. 1
8.0
8. 1
6. 1
8.2
8. 3
8.2
8.2
8.2
8.2
8. 3
8.2
8.2
8. I
8.2
8. 3
8. 1
8.0
8. 1
8. 1
8.1
8.0
8.0
8.0
6. 3
8.2
8.0
8.0
A I*.
a*
CaCO,
mg/(
124.0
271.0
125.0
125.0
120.0
119.0
272.0
120.0
120.0
122.0
120.0
261.0
123.0
119.0
119.0
1 14. 0
257.0
120.0
114.0
ne. o
119.0
229.0
118.0
1 19. 0
115.0
124.0
272.0
126.0
119.0
115.0
120.0
241.0
120.0
117.0
117.0
120.0
247.0
121. 0
m.o
119.0
117.0
231.0
122.0
117. 0
119.0
117.0
260.0
114.0
114.0
120.0
237.0
113.0
111.0
114.0
122. 0
299.0
126. 0
120.0
125.0
Cond.
(lO-'l
mho*
471
701
455
461
455
456
684
457
454
456
486
626
481
506
484
504
667
531
489
535
497
586
496
496
562
497
626
481
464
486
496
621
483
480
480
495
644
506
495
492
439
538
491
515
497
483
673
472
466
470
582
470
459
454
508
664
508
496
521
-------
APPENDIX 8. Continued
ANALYSES - INDIAN CREEK RESERVOIR
Date
10/16
10/20
10/30
16/6
11/13
11/20
11/27
12/5
w
c
m
0.5
3.5
6.5
C
in
0.5
3.5
6.5
C
III
0.5
3.5
C
ID
0. S
3.5
6.5
C
m
0.5
3.5
6.5
C
m
0.5
3. S
6.5
C
III
0.5
3.5
6.5
Crab C
in
Rea.
Depth
ft
43.2
43. 7
44. 1
44. 5
44.8
45.2
45. 7
Secchl
Diek
ft
18.0
19.7
17. 7
12.0
11.4
20.0
23.9
Temperature
Water
•c
12.0
12.0
11. 2
10.8
10. 8
lo.a
10. 5
8. 7
8. 7
8. 7
8. 5
7.9
7. 9
7.9
7. 9
5.9
5.9
5.5
5.5
4. 5
4.5
4. 5
4. 5
3.9
3. 9
3.9
3.9
2. 5
Air
•C
8.0
7. 0
4. 0
7. 1
V.O
3.0
4. 5
3.0
Unfl.tered Samplea
Suep.
Solldi
mg/l
1.5)
7. 45
2. 19
1.72
1.76
3. 57
0. 79
3.41
1. 32
2.02
i.n
1. 14
4. 34
1.64
2.83
3.90
1.38
1.74
2.25
3.55
2.35
0.83
2. 19
1.87
2. 14
2.21
0.87
9.31
1. 11
1.42
2.58
2.23
1.45
Vol.
Suep.
Sollda
mg/l
0.73
5.8)
1. 26
1.09
1. 10
2. ai
0.49
2. 70
1.20
1. 81
2.01
0. 73
3.27
1. 35
2.09
1. 61
0.65
1.45
1. SI
1.89
1. 35
0. 65
1. 60
1. 18
1.63
1.49
0.55
6.82
0.97
1. 10
2.02
1. 12
1. 19
COD
mg/l
14. 3
14. 6
13. 4
13. 1
13.8
11. 8
14.2
13. 8
14.5
14. 3
15.0
14.6
13. 2
13.6
14. 6
15. 0
15.0
13.5
13.9
17. 8
11.4
13.2
11.7
13.9
IS. 1
23.4
12. 6
10. 1
8. 3
13. 7
35. 2
13. 7
13.0
27.0
11. 3
14.9
DO
m,//
10.6
2.6
11. 4
13.4
10.5
2. 3
10.5
10.6
11.4
11.8
2.3
11. 8
15.3
15. 6
9.4
1.2
9.4
8.6
B. 9
10.4
1.3
10.4
10. 7
10. 6
9. 8
1.8
9.8
10.5
13.0
10. 1
1. 1
10. 1
10.6
13.6
Inorg.
C
mg/(
29.0
70.0
29.8
28.6
26.9
71. 5
32.0
)D. 8
31.0
28.6
68.6
31.2
30.5
30. 2
29.5
62.2
29.3
30.7
30.9
28. 1
71.5
31. 6
33.0
32.8
)1.9
66.5
3.2.4
)2. 4
32.2
31.9
66.5
31.9
)2. 4
)4. 0
)l.4
67. )
045 H Mllllpore Fill. red Samplea
Nitrogen aa N
Org.
1347
277
1437
1282
88
37
104
98
114
1284
760
1484
1075
1356
1640
963
1482
1573
1573
1 179
565
1179
1603
1474
1254
907
1292
1135
1412
1612
1321
1297
1297
1283
1162
223
NH,
3762
31750
4775
3297
3780
27550
5575
4125
3125
3848
36340
4205
3657
3372
2787
19152
3420
3800
3895
3395
18248
3157
3324
3110
3810
22960
4095
3 35
3 86
4 86
24 76
4 34
4 48
4 72
3881
2)334
NO, + NO,
7644
274
7992
7620
8204
240
7640
7360
8132
2048
360
1360
2208
2420
9164
399
8432
9152
8860
8880
360
8264
8920
8600
8464
225
7824
8296
8296
8040
2)9
7424
8)20
72)2
6648
152
Total
1275)
32301
14204
12199
12865
28161
14256
12466
12398
7180
37460
7049
6940
7146'
13611
20514
133)4
14525
14248
13454
19173
12600
13847
13184
13528
24092
1)211
12766
12994
26036
1)055
1)665
1)087
2)709
Phoaphorui
ai P
PO.
32
157
31
35
30
35
334
61
41
37
266
49
40
40
42
80
38
43
47
51
60
50
52
48
60
85
62
59
26
60
58
64
189
Total
48
167
43
46
42
39
382
67
49
51
303
62
53
52
62
104
63
63
65
64
ao
64
64
64
73
102
75
75
40
78
80
79
215
C»
mg/l
42.9
73. 3
50.0
42.2
42.4
42.9
43.4
44. 1
42. 1
43.8
7). 1
43.8
44. 7
45. 3
45.0
69.)
45.9
45.0
45.2
45. 7
76.9
45.9
45.2
45. 7
47.9
76.8
56.2
55.2
73. 3
48.4
48. 3
48. 6
7). 3
Cl"
mg/l
)6. 87
31.07
35.27
35.54
36.16
36. 38
28.94
35.48
35.66
36.21
28.83
34.52
35.23
35. 14
34.00
25.72
3 . 16
3 .08
3 .08
3 .41
3 .43
3 .65
35.29
35.20
35.21
30. 81
37.24
38. 12
29. 7
38. a
38. 7
39. 4
31.8
Fe
eg/'
11
33
24
23
22
24
31
33
27
24
12
19
1 1
11
10
15
33
4
8
4
18
20
16
33
16
14
14
23
18
)0
24
26
2)
20
28
pH
8.
8.
7.
7.
8. 1
8.0
8.0
7.9
7. 8
8.3
6. 3
8. 3
8. 3
8.2
8. 3
8.2
8. 3
8.24
8.2
8.2
8. 1
8.2
8. 1
8. 1
a. i
a. o
a. i
a. i
a. o
7.9
a. o
8. 1
7.9
8.0
7. 7
A Ik.
a*
CaCO,
mg/l
121. 0
293.0
122. 0
124. 0
119.0
112.0
286.0
128.0
123.0
124.0
119.0
286.0
130.0
127.0
126.0
123.0
259.0
122.0
128.0
129.0
117.0
270.0
132.0
132.0
1)1.0
1)). 0
266. 0
1)5. 0
1)4. 0
1)). 0
266. 0
1)3. 0
1)5.0
1)6.0
131. 0
269. 0
Cond.
(io-'i
mho>
486
699
477
472
466
488
683
487
477
475
501
698
523
510
514
480
698
485
485
485
SIB
667
508
497
508
525
698
536
525
515
560
700
605
566
560
488
644
-------
APPENDIX 8. Continued
ANALYSES - INDIAN CREEK RESERVOIR
Due
I'm
IZ-ll
12-26
1973
1-1
i-e
1-15
\~"
1-29
2-5
2-11
2.20
2-26
3-5
1-12
3-19
)-26
4-3
4-9
•4-16
4-23
Sample
Type
Crib C
HI
GrabC
III
Crib C
HI
GrabC
III
GrabC
III
Or»b C
111
Grab C
111
Grab C
11!
Crab C
III
Grab C
111
Crab C
111
Grab C
111^
Crab C
III
Crab C
111
Crab C
III
0.5
3.5
6. 5
9.5
Grab C
111
Grab C
III
0.5
3.5
6.5
9.5
Crab C
lit
GrabC
III
O.t
3.5
6.5
8. 5
Reja.
Depth
ft
47.3
54.5
55.0
55. 4._
55.7
—
Secchl
DUk
ft
4. 1
5.3
ia. s
Temperature
Water
°C
1.0
2.0
2.0
2.0
I. 5
2.5
3.0
2. 2
4. S
7.0
7. 1
4. 1
6.5
7. Z
6.2
6. Z
6.0
5.3
5.0
8.0
9.5
9.5
9.0
9.0
8.7
10. Z
10.8
10. B
10. 5
10.0
10.0
Air
°C
11.2
5.5
5.0
2.0
6.0
0.0
I. 0
2.8
5.0
5.0
10.0
6.0
6.8
9.1
12.0
11.0
13.9
9.0
14.8
Unflllered Sample*
SuBp.
Solids
meH
1.61
2.94
1. 18
1.54
5.41
0. 71
1.80
2. 99
3. 32
3.25
1. B7
2.44
7. 39
1. 2)
5. 611
l. to
25. 33
0.88
5.89
1. 18
8.69
1.05
13. 77
1.09
4. 30
0.63
5.92
6.43
4. 77
6.65
6.34
0.65
4. 17
0.75
4.64
6.22
46.80
16.41
1.20
1.38
0.80
1.68
3.58
1.69
5.22
Vol.
SuBp.
Solid!
mg/l
0. 84
0. 78
0. 72
0.80
4.31
0.51
1.54
1.01
1.49
1. 51
1.47
1. 93
1. 13
1. 75
1. 39
4.93
0. 38
4.46
1. II
4. 34
0. 83
4.54
0.96
3. 55
0. 70
4.93
3.83
3.30
3.36
5.49
0.74
3.24
0.67
3.66
5. 17
14.61
3.79
0.94
0. 71
0.64
0. 98
2. 12
1.22
3.07
COD
mg/<
16.0
13.4
16.7
26.9
12.5
18.3
24. 1
20. 1
14.8
13. 3
20. 4
14.3
17. 1
26.0
20.0
13. 1
22. 7
17.0
17.0
17.3
24.0
15.5
25. 7
'.9
DO
mg/l
10. 5
8.9
1. S
12.5
2.4
10. 6
1. 8
13.8
13. 2
0.5
12.9
2. 6
12. 7
2.0
9.3
2.0
11.0
1.9
14.0
1. 8
r..'1
. j. 4
1 : 1. 2
1 ' 7
, '• 2
- ! ' >. 7
3 •' . > 1. 1
0. * \
17. 1
16.8
15.7
18.7
17.5
16.3
15. 1
23.2
17.5
it. 9
12. a
10.2
12. 5
12. 8
14.0
16.4
9. 1
3.0
15.0
3.0
15.0
17.0
15.0
14. 3
11. 7
1. 8
9.4
1.9
9.4
9.4
10.2
9.5
Ir.org.
mg/l
33.8
65.3
32.9
33.8
57.6
34.6
56.9
31.9
60. 3
36.5
36.0
55.9
35.5
57. 4
21. 8
61.2
35.5
65. 3
36.5
62.9
35.8
49.2
34. 1
38.5
33.8
53.0
33.8
60. 5
36.7
36.5
39.6
42.7
36.5
50.6
35.5
49.7
36.0
36.7
36.5
35.3
32.6
46.5
35.8
54.2
36.7
36.7
35.5
35.3
0.45 |i Mllllporo Filtered Samples
Nitrogen aa N
Orj.
PS It
1377
353
1302
1003
870
1048
596
1407
997
1430
1451
780
933
704
1069
773
884
741
1299
627
1229
896
1354
830
1629
1348
1053
744
825
963
1139
839
1063
681
1358
891
1272
1263
1598
1768
1023
695
1102
578
1345
1578
1707
1111
NH,
fS/'
5000
22952
5167
5476
26570
6120
2B100
6000
6215
6950
Z8000
7050
23240
2738
23904
7024
31619
8760
22840
6770
21500
8405
23846
8126
27199
10357
36190
10357
10000
9762
10310
7665
28572
5714
16476
5500
5810
5333
5238
7380
17142
7261
20572
6167
7046
6834
7024
NO, t NO,
ft/I
7016
253
7432
6400
218
5580
183
5124
200
4720
169
5832
211
54B6
173
3210
162
4872
117
5348
197
6016
270
4720
410
5136
532
6600
728
6240
6668
6780
6112
4232
134
4316
183
4092
4512
3952
4428
3212
37
4064
120
3576
4024
3452
4160
Total
fill
13393
21558
13901
12379
27667
12748
28379
12531
24 149
123SS
14233
28991
13469
24117
7017
24839
12780
32477
15407
23664
14015
22666
14479
25086
14891
29079
18010
37662
17422
17631
17681
17261
12960
29387
11388
17550
10864
11585
10883
11434
1 1 615
17874
12427
21270
11088
12650
11993
12295
Phoaphorua
ae P
PO,
ft II
80
366
74
101
154
93
215
97
97
118
108
269
92
101
58
398
106
361
93
225
38
151
51
462
65
419
55
334
51
52
65
69
9
497
9
430
12
20
12
15
36
318
46
185
5!
55
60
59
Total
1»g/<
84
371
82
143
116
105
232
114
110
133
126
296
113
114
68
417
120
398
107
234
65
621
64
462
79
430
71
347
68
70
81
86
34
540
23
462
26
37
Z7
32
46
322
68
199
75
77
80
10
Ca
mg/l
54. 3
69. 1
48. 1
51.2
59. 6
51.9
65.9
51. 7
49. 3
51.4
59. 6
52. 2
69. 8
32. 1
71.2
52. 6
68. 1
54. 5
78.4
52. 1
65. 9
50. 9
76.2
51.0
70. 2
54. 7
81. 9
55.2
55.9
55. 7
55. 7
54.7
; 61.4
53.8
58.3
56.0
55.2
55.2
54. 1
53.6
69.0
55.0
69.3
56.0
55.3
54.8
54.0
Cl"
mg/l
39.69
27.46
36.38
37.68
33.76
34.90
31.27
34.32
33.72
31.51
28. 44
32.61
39.67
17.96
36.60
32.86
37.95
36.45
36. 18
34.32
57.08
35.26
122.46
35.37
56.61
36.47
51.97
33.74
33.55
33.36
33.83
35.56
44.63
35.31
35.89
34.53
33.85
33.07
34.05
32.97
48.82
34.20
37.14
34.29
34.46
34.64
13.39
Fe
fg/<
34
27
34
15
27
23
19
27
29
21
24
28
22
46
26
22
23
24
20
23
26
22
16
8
45
<1
<1
22
16
23
5
24
38
21
33
8
31
22
16
19
26
18
30
28
21
21
24
pH
8. 1
7. 8
8. 1
8. 1
8. 1
7.9
8.0
8.0
8. 2
8. 5
8. 3
8. 3
8. 3
8.3
8. 3
8. 3
8. 4
8. 4
8. 3
8. 3
8. 1
8. 1
8. 1
•7. 9
8. 3
8. 2
8. 1
8. 3
8. 3
8. 3
8.3
8. 3
6. 3
8.2
8.3
8.2
8.4
8.4
8.4
8. 3
8.3
8.2
8. 3
6.3
8.4
8.4
8.4
6.3
A Ik.
as
CaCO,
mg/l
141
261
137
141
240
144
237
133
152
257
150
233
148
239
91
255
148
272
152
262
149
205
142
154
141
221
141
252
153
152
165
178
152
211
148
207
150
153
152
147
136
202
149
226
153
153
148
147
Cond.
(10'')
mhoB
578
664
550
521
672
566
683
527
603
527
675
522
622
540
680
311
676
549
704
523
696
554
736
541
848
545
698
528
693
506
517
506
512
523
612
549
583
523
523
526
616
522
576
528
650
558
529
518
SIS
oo
-------
APPENDIX 8. Continued
ANALYSES - INDIAN CREEK RESERVOIR
Dale
4-30
5-7
5-H
5-21
5-28
6-4
6-11
6-ie
6-25
7-2
SK Triple
Type
CrabC
III
0.5
3.5
6.5
9.5
Crib C
III
0.5
3.5
6.5
9.5
Crab C
III
0.5
3.5
6.5
9.5
GrabC
III
0.5
3.5
6.5
9.5
GrabC
III
0.5
). 5
6.5
9.5
Grab C
III
0.5
3.5
6.5
9.5
Crab C
111
0.5
3.5
6.5
9. 5
CrabC
III
0.5
J. 5
6.5
9.5
CrabC
III
0.5
J. 5
6.5
9,5
Crab C
III
0,5
],)
6,5
9.5
R«!.
Depth
ft
55.9
56.0
56.3
56.4
46.3
56. 3
56.4
56.4
56.3
56.4
Secchl
Dlik
«
24.8
25.0
14. 7
14.6
9. 1
16.0
17.8
16.0
17. 5
Tempe
Water
°C
12. 1
12. 1
12.0
12.0
IZ. 0
14.0
14.0
12.9
12.0
ii. a
15.0
14.9
14.9
14.4
16.5
16. 5
16.2
16.5
16.5
17.2
17.2
16.9
16.0
16. 0
17.8
17.8
17.5
17. 0
16.5
19. 5
19.5
19.0
19.6
13.0
17.2
17.2
17.0
16.5
16.5
18.5
18.5
18.0
17.6
17,2
19.0
19.0
19.0
19.0
18.8
ature
Air
°C
13.0
16.0
16.2
IB. e
13.2
19.0
14.5
19.6
23.0
Undllered Sample!
Suip.
Solids
mg/l
2.08
0.59
2. 19
2.50
1. 80
30. 12
6.27
2.08
1.84
1. 88
2.02
1. 31
1.42
1.97
1. 55
2.29
1.49
1. 31
2.51
2.40
1.91
1.63
1.70
1. 34
3.06.
3. 11
2.76
2.69
2.81
0.51
5.48
5.08
2.72
17.52
1.74
1. 16
1.96
Z. 12
2.34
2.26
0.97
4.03
1. 72
1.57
1.64
3.32
1.23
0.98
2. 35
1 72
1.29
1.23
3 40
I, 24
1.82
1.50
1.52
Vol.
Suap.
Solldi
m« II
0.54
1.59
1. 74
1. 39
8. 60
1. 15
1.25
1. 31
1. 62
1. 69
1. 13
1.39
1.60
1.32
1.91
1.09
0. 91
1.54
1.96
1.41
1.37
1. 11
0.84
1.92
2. 12
2.03
1.76
2.61
0.50
4.56
4.61
2.40
7.76
1.49
1.05
1.96
2.09
2.08
2.11
0.73
3. 15
1. 72
1. 57
1.52
1. 73
0.84
0. 74
2. 14
1. 70
1.28
0. 76
1.72
1.75
1.39
1.20
COD
mg/<
13. 1
18. 5
17. 0
16.4
36. 7
15. 1
14. 3
16.3
16.3
15. 7
13. 7
15.4
15.4
14.0
16.3
11.8
9. 1
12. 1
14. 3
10. 7
14. 5
14.5
17.2
15.0
15.0
15.6
21.2
18.0
23.2
18. 8
18.4
32.0
15. 5
11.0
17. 1
16.7
16.7
17.5
13.4
10. 6
13. 8
12. 6
12. 2
13.4
15. 7
13. 3
18. 9
15. 3
14. 9
15. 3
12.9
13. 3
14. 1
13.7
DO
mg/(
2. 1
7.8
8.2
9.3
10.3
1.9
11.0
12.9
15.9
10.9
8.2
0. 7
8.2
8.0
8. 6
8.0
1. 3
8.0
8.6
II. 0
11.4
II. 0
3. 1
11.0
II 2
10. 6
8.2
10.2
i. e
10.2
II. 0
ii. e
7.9
8.5
1. 9
8. 5
9.2
10. 8
12. 1
9.0
2. 7
9.0
9. 1
10.4
9.4
94
8. 1
10.2
9.6
Inorg.
mg/l
60.5
17. 3
35.8
36.5
35. 5
39.4
41.5
39. 1
40.8
40. 1
65.3
37.4
37.0
36.2
35.8
37.4
64.8
34. 7
36.5
36.7
35.0
53. B
37. 2
37.9
37. 2
36. 7
37. 7
54.5
37.9
37. 7
37.4
38.4
34. 6
56.4
37.7
37. 7
37.2
37.9
'0.0
56.2
39.4
38.6
38.2
37.9
37.0
57.8
38.4
37.7
37.9
36.2
37.4
39.4
38.4
38.4
0.45 t> MUllpo.-c Filtered Sample!
Org.
|tgV<
1592
706
1225
1735
1573
1525
1562
1614
1362
1552
1595
735
1669
1258
1857
1777
1217
803
1327
1298
993
1536
700
1296
1438
1583
1517
1225
839
1453
1829
1648
1610
1480
613
1623
1766
1956
1089
1239
648
1514
1610
1610
1514
1639
748
1672
1782
1596
1391
1336
646
1298
1426
1288
1246
NHj
US"
7154
21618
7630
8024
6595
6310
7143
7500
7929
7143
7070
20998
8214
7334
7262
7025
7619
2)524
7262
7381
7429
8214
24286
7262
7500
7740
6548
9167
31048
8929
9429
9714
9405
6357
23810
6572
6619
6548
6500
6786
23904
7405
7476
6667
6738
6714
23524
7929
7000
7262
7524
6762
27809
7738
7929
7452
6810
NO, t NO,
|ig/'
4228
298
4412
4160
4300
4272
4580
4036
3604
4692
4580
4160
253
3604
4452
4440
3924
6000
995
5416
6196
6416
5692
3952
162
3600
3880
3672
3772
100
2700
3688
6672
4860
3436
2908
3436
3336
3072
3160
169
2476
3256
3188
2516
3590
208
3311
3423
3423
2907
3312
159
2808
3464
3436
2780
Total
l>g/<
13267
13919
12468
12107
13285
13150
12695
13387
13245
11371
21986
13487
13044
13559
12726
14836
25322
15269
15095
141 14
13702
25148
12158
13203
11737
14164
31987
13082
14946
18D34
15875
i 1273
1 1103
IIB2I
1 1840
10661
II 185
24721
11395
12342
11465
10768
1 1943
24480
12281
11822
11410
28614
11844
12819
12176
10636
Phoiphorvi!
as P
PO,
[»g/<
64
66
76
68
52
39
52
51
51
51
126
52
55
57
S7
58
83
49
59
43
138
55
57
61
34
22
24
51
84
23
18
24
30
52
45
95
54
45
47
47
24
95
42
51
62
III
51
51
62
56
Total
W/<
82
85
90
84
74
70
71
68
68
68
148
63
70
71
70
83
97
71
73
64
142
71
68
73
M
43
51
80
109
40
36
40
44
6n
64
101
70
63
64
65
71
108
60
93
93
166
86
90
88
86
Ca
mg//
55. 3
55.2
56. 7
57.4
57. 1
57. 1
57.8
57.2
58.3
58. 1
85.9
60.0
59. 0
57. 9
57. 6
57.9
89.5
60. 0
59. 1
57.8
62. 1
56.6
56.0
57. 6
70.2
59.5
SB. 8
57. 8
57. 1
57.4
57.9
57.2
56.9
57.2
56.2
67. 2
57.9
57. 1
56. 9
56. 7
57.
63.
57.
57. 8
57.2
65.0
58. 3
58. 1
57. 1
57.8
cr
mg/(
35.20
33.61
32.49
33. 42
32. 67
40. 96
39.33
39.84
36.48
36.28
49.90
32.39
46.21
5.64
3.56
9. 96
6. 90
3.23
8. 77
38.70
39. 33
33. 28
31.93
32. 80
32. 56
31. 53
30. 74
37. 16
36.67
36.87
36. 87
37.65
32.94
37.65
38.24
37.75
37.75
33.49
33. 56
33. 74
34.52
34.43
33.48
37. 1
36. 2
37. 2
37.28
38. 58
31.74
39.03
37. 68
37.23
42.36
Fe
hg/l
18
20
19
12
22
20
30
21
14
9
15
8
11
a
3
15
10
<1
<1
. 2
8.4
8.4
8.4
8.3
a. 2
8. 2
8. 2
8.2
8.2
8.2
8. 4
8. 1
8. 3
8. 3
8. 3
8.2
7.9
8.2
8.0
8. 1
8.2
Alk.
aa
CaCO,
mg//
120
252
72
149
152
148
164
173
163
170
167
154
272
156
154
151
149
156
270
156
157
152
153
146
224
155
158
155
153
157
227
158
157
156
160
144
235
157
157
155
158
154
234
164
161
159
158
154
241
160
159
157
158
151
262
156
164
160
160
Cond.
110"*)
mho!
514
694
526
526
526
526
554
566
571
582
591
513
672
538
515
513
504
504
715
556
561
550
578
512
596
528
512
512
528
506
600
517
528
523
523
538
627
526
515
515
515
533
644
533
533
533
544
523
616
528
527
527
527
465
651
521
504
491
491
(Jj
vO
-------
APPENDIX 8. Continued
ANALYSES - INDIAN CREEK RESERVOIR
Date
7-9
7-17
7-23
6-6
(-11
6-20
8-27
9-4
Sample
Type
Crib C
III
0.5
3.5
6.5
9.5
GrabC
III
0.5
3.5
Or«b C
III
0.5
3.5
6.5
9. 5
Grkb C
HI
0.5
3.5
6.5
8.5
Crab C
III
0.5
3.5
6.5
6.5
Gr«b C
111
0.5
3.5
6. 5
8.5
Gr»b C
III
0.5
3.5
6.5
Grab C
III
0.5
3.5
6.5
Ret.
Depth
ft
55.9
54.0
52.8
50. 1
49.3
48.0
45. 8
44. 6
Seech!
Dllk
ft
14.0
14. 6
15. 5
18.8
20. 0
18.1
23.9
20.5
Temperature
Water
°C
21.0
21.0
20.5
20.0
20.0
21.0
21.0
20.5
20. 0
20.2
20.2
20.0
20.0
20.0
19. 7
19. 7
19.2
19.2
19.2
20.2
20. 1
20. 1
20. 1
20.0
19.5
19.5
19.5
19.0
19.0
17.0
17.0
16.9
16.2
17.0
17.0
16.7
16.5
Air
°C
22.0
20.5
24.6
28.0
22. 5
19.0
18.9
19.2
Unflltered Simple*
Su.p.
Solid*
mg/l
1. 15
1. 68
2.02
2. 00
1.03
0.85
1. 15
0.91
1.49
1. 49
1.21
3. 18
1. 17
1.26
1.25
1. 59
2.43
4. 10
1.43
1.66
1.25
0. 79
1. 4H
1.06
1.93
1-. 06
0.82
0. 81
0.87
1. 74
1.03
1. 60
1.21
1.06
0. 76
2.79
1. 14
1.07
1. 36
1.00
1.55
1.01
1. 11
1.97
Vol.
mg«
0.66
1.68
1.69
2.00
1. 11
0.65
0.67
0. 75
1. 31
1.49
0.85
2. 74
1. 17
1.28
1.25
1.35
1.63
2. 60
1.03
1. 47
1. 21
0. 79
0. 89
0.96
0. 77
0.45
0. 36
0. 31
0.64
1.05
0.97
1.44
1. 10
1.06
0. 50
2. 30
1.02
1.08
0.95
0.73
1.23
0.95
1. 11
1. 11
COD
mgrt
16.4
IB. 4
19. 2
16.8
14.0
14.4
17. 8
15.0
13.4
14.2
10. 6
16.7
10. 6
8. 5
B. 1
13. 8
14.9
22.4
15. 7
14. 5
14.9
16. 1
16.5
20. 1
19. 3
19. 3
17. 7
15.0
13. 3
17. 7
14.5
14.5
12.6
14. 9
15. 7
23. 7
13. 3
13. 7
13. 7
28.9
11.7
12.9
12.9
DO
mg/l
8.3
0.4
8.3
9.3
8.6
9.0
7.2
1.3
7.2
6.8
8. 0
1.8
8.0
8.9
9. 1
8.7
7.3
0.9
7.3
7. 5
7. 5
7.6
7.2
1.4
7.2
7.8
7.6
9.0
6.8
1.9
6.8
6.8
6.6
6.2
6.3
2. 1
6.3
6.6
10.5
1.1
10.5
11.0
10.2
Inorg.
C
mg/l
37.4
57.8
38.4
38. 9
37.9
38.6
38.4
62.9
37.9
37.4
33.6
38.4
37. 7
37.4
38.2
35.0
53.5
34.6
36.0
35. 3
35. 5
32.2
60.0
33. 1
33. 1
32.4
33. 1
30. 5
50.4
31.0
31.0
30.7
30.0
28. 1
48. 5
29.5
29. 5
27. 1
54.5
29.0
28.6
28.6
0. 45 11 Mllllpore Filtered Sample!
Nitrogen •< N
Org.
fS/l
1722
575
1432
1803
1622
1670
1636
922
1579
1636
1280
290
1090
1435
1430
1320
810
615
810
870
945
720
770
370
1770
1245
1320
1460
625
290
625
670
860
180
615
535
H70
1020
925
765
810
715
925
NH,
Mg/l
6070
24760
6786
7024
6524
6357
6166
24476
5657
0643
5143
4550
16800
4600
1600
4150
4800
1375
20700
1075
3575
1075
3575
3000
21810
2905
2905
2600
2600
2050
20400
2220
1740
820
1450
2625
22400
1450
750
1350
18260
840
700
660
NO, t NO,
fg/'
3452
121
2692
2768
3576
2976
3668
117
2921
3683
3868
5416
553
3536
4616
3296
3144
4648
100
5864
4512
AOOO
4776
4168
277
4996
6164
6184
4996
7152
661
5952
7232
7736
6368
8680
758
7512
8152
8104
6504
134
6316
6372
5634
Tolal
HI /'
11244
25456
11110
11595
11722
11003
11670
25515
10357
11162
10719
11246
17643
9226
9651
8676
9264
8633
21415
9719
8957
10020
9071
7958
22457
9671
10334
10104
Y P
PO,
n/t
71
160
52
46
65
64
71
143
57
52
55
44
107
46
44
42
42
32
56
29
29
30
32
26
160
22
20
18
20
31
291
24
22
15
19
80
13
12
10
Total
fg/<
73
175
71
76
63
86
76
159
73
71
71
72
175
71
76
7
7
6
13
7
A
5
62
44
126
40
40
44
45
32
160
30
30
24
24
43
298
33
30
35
44
151
42
39
36
Ca
mg/<
57.4
62. 6
58. 1
58. 3
58. 8
57.9
i 57.6
63.4
58.3
57.9
57. 2
72.6
73.4
73.8
74.5
74.0
74.3
69.6
76.6
70.9
70.9
68. 3
72.2
63.3
80. 7
64.0
63. 1
63. 1
63. 1
59.6
64.7
53.6
52.9
52.8
53.4
51.4
57.9
52. 1
51.9
50.3
49.4
62.4
50.3
48.8
46.4
Cl"
mg/l
39.20
35. 13
38.54
39. 70
38.37
38. 12
34. 30
29.44
31.31
32.66
30. 97
34. 34
30.27
35.47
36.37
35.62
35.62
36.64
39. 19
35.89
35.36
36.26
36.71
38.21
39.04
36.86
37. 16
35.06
30. 71
38.51
39.96
32.60
36.57
35.27
35.52
37.30
40.27
35. 69
36.90
35.45
39.22
46.75
39.40
41.64
41.54
Fe
fB/'
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
PH
ft. 4
6. 4
8.3
8. 4
8. 3
8.3
8. 3
8.2
8.4
8.4
8. 3
8.2
8.4
8.4
8.4
8.4
8.3
8.2
8. 3
8.4
8. 3
8. 3
8. 2
8. 3
8. 3
8. 3
8. 3
8. 3
8.2
8.3
8. 2
8.3
8.2
8.2
8.4
8. 3
8. 3
8.4
8.4
8.3
B. 3
6.2
8. 3
8.2
A Ik.
a.
CaCO,
mg/I
156
241
160
162
158
161
160
262
158
156
156
140
160
157
156
159
146
223
144
150
147
148
134
250
138
138
135
138
127
210
129
129
128
125
1 17
202
123
123
122
11)
227
121
119
119
Cond.
(10"')
mho.
593
627
593
593
585
605
535
633
536
536
536
515
571
514
514
514
514
513
653
4S9
89
89
89
18
02
529
529
524
516
503
636
515
512
487
491
504
606
482
482
482
506
660
512
509
516
-------
APPENDIX 8. Continued
ANALYSES - INDIAN CREEK RESERVOIR
Date
9-10
9-17
9-24
10-1
10-S
10-15
10-22
10-29
11.6
11-13
11-19
Sample
Type
GrabC
0.5
6.5
Grab C
III
0.5
).5
5. 5
Grab C
HI
Grab C
III
0.5
3.5
5. 5
Grab C
111
0.5
3.5
6.5
Grab C
III
0.5
3.5
(.5
Grab C
III
Grab C
III
0.5
3.5
6.5
Grab C
III
0.5
3.5
6.5
Crib C
III
GrabC
111
0.5
3.5
4.5
Rei.
Depth
ft
42.4
40.9
41. 3
41. 9
42.0
42.6
43.0
43.4
43.9
44.5
45. 1
Seeehl
Dlik
ft
IT. 0
18.6
22. 0
19. 6
21. 6
15.3
12.0
17.0
Temperature
Water
°C
17.0
17.0
16! 4
17.2
17. 2
16.9
16.6
15.3
14.0
14.0
14.0
14.0
11.2
11.2
11.2
11.2
16.8
16. 8
16.2
16.0
12.2
10.0
10.0
9.5
9. 1
6.4
6. 4
6.2
6.2
7.5
4.2
4.2
4.0
4.0
Air
°C
it. e
19.5
12.7
18.4
e. 9
18.5
14. 1
8.5
13.9
6.4
4.0
Unfiltered Sample*
Su«p.
Solid!
mg/f
0. 75
\'.2H
1.16
3B. 31
0.96
9.21
0. 89
1. 17
1. 48
7. 10
1. 12
1.0)
0. 83
1.36
1.31
4. 73
1.61
0. 92
1.29
1. 17
2. '42
0.83
1.07
0.94
0.97
1.96
16. 34
0.95
1.04
0.28
1. II
2. 68
2.27
2.20
0. 37
2.99
3. 57
2. 79
13. 20
1. 51
0. 61
2.76
2.93
3. 53
Vol.
Su.p.
Solid!
mn«
0.59
1.02
1. 15
7. 13
0. 56
5. 12
0. 69
0. 92
0. 89
1. 76
0.76
0.51
0. 63
0. 91
1.04
1. 78
0.84
0. 70
0. 89
0. 81
0.85
0.51
0.97
0.91
0.88
1.01
3. 80
0.47
0. 67
0.28
0. 94
2. 35
1. 31
0.91
0. 37
1. 33
2. 03
1. 41
1. 51
0. 86
0. 54
1. 23
1. 61
1.64
COD
n.B«
12. 5
1 6. 9
15. 7
15. 7
29. 8
14. 1
14. 9
12. 5
16.0
21. 7
21. 5
17. 5
14. 6
15. 0
15.5
16.7
20. 7
15.5
16.7
15.5
14.4
14.8
14.8
14.4
15.2
16.8
11.6
15.0
12.6
14.6
18.6
16.6
15.8
9. 3
15.4
14.6
14.6
13. 1
11.5
14.6
20. 61
17.8
16.6
17.4
DO
m«/<
12.2
12.2
12. 9
13.4
10. 2
1. 3
10. 2
10.5
13. 1
9. 4
0. 7
10. 7
1. 2
10. 7
9. 7
9. 5
7. 8
1.2
7. 8
7. 5
7. 1
8. 1
2. 3
a. i
9.4
a. 2
8.5
0. 6
7. 7
0.9
7. 7
8.2
8.6
8. 3
1. 1
8. 3
7.9
8.0
1. 1
8. 8
1.0
8.8
8. 3
8. 2
Inorg.
C
mg/l
27.4
28. 1
28. 3
27. 1
31.0
60.7
28. 8
29.5
28. 1
28.6
61.2
28.3
61.0
27.8
25.2
28. 1
30.0
60.7
27. 8
25. 0
32.2
67.0
32.0
31.2
30.2
31.9
69. 1
32.4
31. 7
31.2
27.8
49. 7
26.4
58.6
31.4
31. 7
31. 7
Total
PhoB.
aa P
fell
16
17
1 5
17
26
123
24
40
15
18
38
10
4
1 1
4
5
4
5
13
5
5
5
24
23
5
33
3
4
3
6
34
6
6
6
12
41
6
26
8
8
6
0.45|i MiHiporc Filtered Sample*
Nitrogen aa N
Org.
vs/i
475
650
775
865
675
415
1270
1070
990
310
335
610
345
980
725
895
270
145
1045
995
1215
230
110
970
1180
1200
1154
20
760
188
607
940
802
845
60
1283
1298
1317
1012
136
660
140
526
917
NH,
Kg/'
1475
1250
725
600
2400
20300
2200
2300
1550
975
18700
1500
19100
975
1150
1475
2100
23400
2025
2075
850
1350
18700
1325
875
925
950
13200
2798
30238
3299
2465
2250
2799
25330
3321
2679
2440
1607
16048
2155
27000
2702
2441
2560
NO, + NO»
nil
22 H
6224
6140
6084
155
5024
6252
6184
6392
5834
64
4552
6043
4S94
5292
4176
5832
5804
6043
120
4468
4748
4788
8881
52
5416
11 1
4064
5848
4832
6876
124
6252
6316
302
6531
116
5695
5972
4580
Total
fgl<
201 '13
8124
7605
9159
20X70
H414
9622
8724
7677
7944
19509
6507
7918
6964
7662
23755
7246
3902
7869
7623
18930
6763
6803
6913
10985
13272
8974
30537
7969
9253
7884
10519
25564
10009
8935
16486
9346
27256
8923
8057
Phosphorus
SB P
PO,
1-8"
2 1
3
3
4
22
5
3
4
4
3
1
2
1
3
1
1
2
8
1
I
1
I
9
1
28
1
-------
APPENDIX 8. Continued
ANALYSES-INDIAN CREEK RESERVOIR
Date
11-26
12-4
12-17
12-26
1-14
1-21
1-28
2-4
2-11
2-20
2-25
3-4
3-12
3-18
3-25
4-2
4-8
4-15
Sample
Type
Grab C
III
Grab C
III
111
Orab C
111
Grab C
III
Grab C
III
Grab C
III
Grab C
III
Grab C
[11
Grab C
III
Grab C
III
Grab C
III
Grab C
III
Grab C
III
Grab C
111
0.5
3. 5
6.5
9m
Grab C
III
Grab C
III
Grab C
III
GrabC
III
Rei.
Depth
It
54.6
Secchl
Dlik
ft
17. 1
Temperature
Water
°c
5. a
4.0
4.0
6.0
6.5
5.9
5.5
5.3
9.0
8.2
6.3
B. 2
9.0
10.1
Air
°C
3. 1
2.0
1 1. )
8.4
11.0
-1.5
9. 1
7.2
12.0
1.5
13.5
7.1
12.0
6. 1
2.0
9. a
8.2
Untlltered Sample!
Su.p.
Solid!
mg/(
2.87
0.64
0. 81
1.07
0.54
21.96
2.21
7.23
3.99
1. 16
1. 18
4. 09
1. 35
6.48
24. 14
0.99
1. 63
0. 79
8.27
1. 19
3.57
1. 18
121.20
0.98
1.08
1.88
2.23
1.95
1.86
1.99
9.72
0. 92
1.72
1.33
IB. 43
1.31
10.36
4.47
Vol.
Su!p.
Sol Id !
mg/l
0.85
0.61
0. 47
I'M
3.56
1.50
1.60
2. 76
0.47
0.96
0. 97
1. 01
1. 69
3.54
0. 70
0.57
0.51
1. 74
0.8;
1.22
0.94
12.72
0.69
0.51
1.30
0.95
1.01
1.06
1.09
1.99
0. 69
0.64
1.00
2. 33
0.83
1.88
2.85
COD
mg/l
9.5
14.6
9.5
17.6
9.5
14.2
11.3
13.8
18.0
24.2
12.3
13.5
14.9
17.2
14.3
18.9
16.5
11.3
12.9
12.6
18.3
11.3
12.9
15.9
26.1
11.7
21.6
14.8
18.6
18.2
20. 1
14.8
17. B
14.0
19.3
11.1
11, 1
11.5
19.7
DO
mg/l
9.2
0.6
1.6
11. 1
1.4
10.9
1.9
9.0
0.4
9.6
1.0
10.9
0.7
12.2
0.9
11.9
2.2
12. 1
1.0
9. 3
1.9
1.2
9.8
2.2
9.8
10.6
10.0
9.9
9. 1
0. 7
9.5
0.9
1. 4
1. 1
Inorg.
mg/l
26.9
61.9
30.7
61.0
31.2
61.2
31.0
63. 1
35.6
58.8
34. 8
61.0
32.2
62.2
32.6
35.5
64.6
35.5
60.5
35.8
63.6
33.4
60.7
37.0
61.7
33.8
53.3
37.0
37.7
38.4
37.2
34.3
57.6
32.9
44.4
36^5
31.0
54.2
Total
Phot.
aa P
MB /'
16
131
19
48
21
43
19
41
46
50
26
33
35
101
35
50
38
35
40
31
57
76
95
34
77
37
109
38
33
35
35
24
38
33
86
40
64
124
180
0. 45 |i Mllllpore Filtered Sample I
Nitrogen a! N
Org.
»!/<
817
464
707
502
864
407
898
436
960
498
831
169
1045
474
1279
912
407
1026
192
•)64
307
1088
283
507
260
693
321
1274
1393
1040
807
902
188
712
412
679
212
1189
231
NH,
Mg/<
2274
293BO
2917
15000
2607
26904
2893
27380
5415
23476
5179
21570
5618
16142
5179
61 79
24524
5655
17667
6131
26618
5679
21666
6084
19286
6845
18714
6631
5941
5702
5035
6131
20524
6607
16904
18714
5536
19760
NO, 4 NO,
HI/«
6392
113
5676
6128
107
6000
169
6544
211
5420
9(
5290
67
5264
78
5540
5555
83
5108
90
4968
90
4692
55
4859
79
4580
94
4328
4898
3856
4832
4788
170
4440
125
109
3172
128
Total
HI /I
9483
29957
9500
15609
9471
27480
10335
2B027
11795
24070
11300
21806
11927
16694
11998
12646
25014
11789
17949
12063
27015
11459
22004
1 1449
19624
12318
19129
12233
12222
10598
10674
11821
20882
11759
17441
19035
9896
20119
Phoaphoru!
ai P
P°«
Hg/(
9
126
15
1 7
39
16
39
17
38
26
29
18
20
32
77
28
62
30
32
27
25
20
44
30
54
24
65
34
89
33
32
34
33
24
36
27
61
50
27
83
Total
HJ/«
12
127
16
1 8
39
19
40
18
38
43
47
16
21
32
79
32
64
30
37
32
34
29
49
57
92
31
66
34
89
33
33
34
33
24
38
30
75
64
71
83
Ca
mg/l
51.4
61.2
51. 7
73.3
54. 7
67.9
52.4
71.0
54.3
73.8
51. 7
80.5
53.6
77.9
54. 1
68. 3
55.3
78.6
53. 1
71.4
54. 1
67.2
53.6
69.5
52. 2
67. 8
52. 6
57. 9
52. 2
53. 1
52.4
52.6
52.2
66.9
50.9
49.0
50. 5
36.0
50.7
63.8
cr
mg/l
40.86
29.45
39.90
35.47
36. 43
31. 33
35.43
32. 67
36.56
40.31
55.00
35.26
40. 05
55.99
40. 20
42. 36
39. 36
40. 16
39. 2J
38.08
38.55
33.21
37.00
28.97
38. 38
30. 81
36. 56
31. 16
37. 59
37. 24
36. 91
36.47
34. 97
31. 40
38.40
28.96
36. 74
35.70
37. 11
37.98
Fe
ug/l
16
a
9
23
17
19
13
17
17
40
2e
14
7
41
10
22
12
17
17
7
19
17
10
2
10
4
9
29
17
17
9
7
12
17
10
11
12
16
17
10
PH
8.3
8.3
8.2
8.2
8.2
9.2
8.2
8.2
8. 3
8.3
8. 3
8. 3
9. 3
9.3
8. 3
8. 3
8. 3
8. 3
8.2
8.2
8.2
8.2
8. 2
8.2
8. 3
8.2
8. 1
8. 2
8. 1
8. 1
8. 1
a. i
8.3
8. 3
8.2
8.3
8. 0
a. o
a. 3
8.3
A Ik.
CaCO}
mg/l
112
258
128
254
130
255
129
263
149
245
145
254
134
259
136
262
148
269
148
252
149
265
139
253
1 54
257
141
222
1 54
157
160
155
143
240
137
185
154
152
129
226
Cond.
(io"M
mho!
540
645
538
524
648
543
667
536
661
551
691
528
655
528
693
550
669
539
704
539
689
533
682
528
600
564
649
566
60S
538
547
526
538
521
649
532
549
524
493
538
638
N)
-------
APPENDIX 8. Continued
ANALYSES - INDIAN CREEK RESERVOIR
DMe
4-22
4-29
9-6
5-15
5-20
9-28
6-3
6-10
6-24
Sample
Type
GrabC
III
GrabC
III
0.5
3.5
6.5
9.5
GrabC
HI
0.5
3.5
6.5
9.5
Crib C
til
Grab C
III
0.5
3.5
6.5
9.5
Grab C
111
0. 5
3. 5
6.5
1. 5
Crab C
III
0.5
3. 5
6.5
9. 5
Cr»b C
III
Grab C
III
0.5
3.5
6,5
9.5
Cr.bC
III
0. 5
3. 5
6.5
9.m
Rel.
Depth
ft
57.0
57.0
57.4
57.4
57. 3
56.8
Seeehl
Dlik
ft
10.7
20.0
10.5
1. 1
13.6
19.8
19.5
Temperature
Water
°C
13. 1
M.2
11. 2
10.8
10.3
10. 1
13.8
13.8
13.0
12.8
12. 5
14.2
13.0
13.0
12.9
12,2
12,0
15. 7
15.6
15.6
15.6
16.5
16.5
16.2
16.0
15. 8
20. 5
19. 2
19.2
19. 0
18.8
18. 5
19. 0
19.0
19.0
18.9
18. 8
Air
°C
9.2
10. 0
14.5
14.9
10. 1
18.2
19.2
18.5
24.3
Unflltered Sapiplei
Suip.
Solid!
n>|/<
6.44
0.71
1.82
1.66
2.54
4.06
1.58
3.00
0.94
0.69
0. 10
3. II
3. 10
8.28
18.23
2.25
2. 70
0.49
2.82
J.01
4.24
4.02
0.57
6. 27
6. 15
4. 67
5.22
1. 27
3.05
2.25
2. 36
2 15
1. 28
7.84
0.92
0. 81
0. 65
1.42
2.07
1.35
1. 18
0.62
0.57
1.31
0.92
0.87
1.09
Vol.
Suip.
Solid.
nig /I
1.71
0.63
1.15
0.75
1.89
2.55
1.46
1.58
0.66
0.49
0. 10
1.89
1.86
2.88
2. 82
1.52
2. 13
0.49
2.26
3.46
3. 19
0. 57
5. 50
5. 59
4 Z6
4 41
1.99
1. 87
2.03
1.91
1. 28
6.92
0. 85
0.66
0.56
1.33
1.91
1.33
1.33
0. 64
0. 60
1.21
0.98
0.84
0.92
COD
mg/l
14. 6
14. 2
15.6
13.0
20.5
19.0
14. 5
16.7
14.9
16.0
16.0
17. 1
18. 6
15.0
12.7
18.6
9. 1
16.4
17. 5
mg/l
49.5
65.9
49.8
64. 0
56.7
55.0
56.7
56.7
55. 7
69.8
57.6
56.9
56.7
66.9
57.9
77. 1
60. 2
57.4
56.0
57.4
58. 1
58, 1
57. 4
56, 9
70.0
60.0
59. 1
59. 7
49. 8
69. 1
60.3
54.8
55.0
54. 5
54. 1
48. 6
53.8
54. 3
54. 1
CI"
mg/l
37.32
43.93
39.93
43.86
35. 16
36.24
35. 70
36.09
38. 16
36. 75
36. 56
39.53
46. 32
38.66
38.38
36. IS
36.52
36.24
35.97
38.90
38. 11
37.94
36.89
37.37
30. 96
37. 11
35. 88
35. 7")
37. 68
36. 54
61. 67
40. 24
39. 81
40. 51
39. 90
47. 97
40. 35
40. 83
41.31
Ft
nti
12
13
6
8
5
11
5
16
58
7
3
14
10
20
4
18
<1
3
10
4
11
<1
7
2
3
< 1
16
5
7
2
3
4
1 1
12
9
9
9
24
15
II
10
12
pH
8.2
8. 3
8.2
8.2
8. 1
8. 1
8.0
8. 1
8.0
B. 0
8.0
8. 1
8. 3
8. 3
6.2
8. 3
8. 3
8. 3
8. 3
8. 3
a. 3
8.4
8.4
n. 4
8. 4
n. 2
3.2
8.2
8.2
a. 2
8.5
8. 2
8,
3.
8.
a,
a.
8.
8.
8.
fl.
8.
Alk.
a*
c.co,
mg/l
130
Z33
236
I4Z
154
155
133
242
175
157
153
160
136
199
155
249
193
174
164
163
265
166
165
159
162
151
262
164
163
163
130
250
1 11
IY7
144
147
146
144
190
142
146
145
144
Cond.
do-'i
mho*
535
672
649
558
554
554
545
549
610
532
530
538
562
496
610
554
713
539
S4I
539
i4l
661
SI5
5H
498
515
514
661
515
504
495
495
689
488
688
S04
497
504
497
595
S04
492
492
492
-------
APPENDIX 8. Continued
ANALYSES - INDIAN CREEK RESERVOIR
Date
7-1
7-8
7-15
7-22
7-29
8-4
8-12
8-19
8-26
9-4
Sample
Type
Oral! C
III
0.5
3,5
6.5
9.5
CrabC
III
Crab C
III
0. 5
3.5
6.5
9. 5
Grab C
III
0.5
3.5
6. C
9.0
Crab C
III
0.5
3,5
6.5
9.5
Grab C
III
0.5
3.5
6.5
8.5
Crab C
Crab C
HI
Crab C
III
0.5
3.5
6.5
Crab C
III
0.5
3.5
S.O
Rci,
Depth
II
56.6
56.0
54.7
54.2
46.6
43.6
Secchl
Dirt
«
r. 4
15.7
19.4
14. 1
24.4
20.0
Temperature
Water
°C
21.3
21.3
20.2
19.5
19. 0
IB, B
19.2
19.2
19. 1
19.0
19,0
21.3
21.3
20.8
20. 1
19.9
21.4
21.4
21. 3
21.2
21.2
22.0
22.0
21.1
20.8
20.5
21.0
20. 5
20.2
20.2
20.0
19.5
19.9
19.9
19.8
19.8
Air
°C
24.2
13.0
21.6
26.7
21.0
23.0
22.0
19.5
20. 1
Unllltered Samplei
Suep.
Sollde
mg/1
4.75
0.32
6.04
3.91
2.20
2.30
9.70
0.62
1.71
1.65
2.33
3. 13
2.13
3.38
1.33
1.53
1,82
1.88
1.57
1.81
0:94
1.29
1.82
1.29
1.62
2.35
1.44
1.25
1.44
1.53
1.37
1.40
21.23
28.71
1.23
0.64
1, 10
2.54
1.60
1.92
0.64
4.61
1, 13
1.24
1.2S
Vol.
Suip.
Solldi
mg/1
4.75
0.32
5.63
3.91
2.20
2.22
5. 38
0.56
1.52
1. 31
2.21
2.97
2.13
3.21
1. 11
1.03
1.23
1.57
1.24
1.47
0.77
0.91
1.09
1.07
1.62
1.58
1. 16
0.69
1. 15
1.25
1.03
1.07
4.99
10.75
0.92
0.46
0.91
1. 13
1.05
1. 13
0.49
3.09
0.89
1.09
1.25
COD
mg/1
18.0
22.3
22,4
20.4
19.6
18.8
24.2
25. B
18.4
28.2
18,8
22.9
18.4
19.6
25.3
28. 9
20. 1
20. 1
21. 3
25.2
12. B
21.2
20.0
15.2
14.0
14.0
14.9
22.9
18. 1
14.5
14.5
12.9
16.3
29.4
40.7
29.0
44.4
35. 1
33.9
30.2
11.4
31.5
13.8
14.6
13.8
DO
mg/1
13.5
1. 1
13.5
12.4
10.3
8.6
10.3
0. 7
8. 1
1. 1
8. 1
8.3
7. 8
6.6
5.7
0.4
5.7
5.6
4, 7
3,6
5.2
1.0
5.2
4.8
4.0
3.3
4.0
0.2
4.0
3. 8
3.8
3.4
5.4
3.4
1. 5
7.8
1. 2
7. 8
7.6
7.9
7.1
0.0
7.1
6.9
7.5
tnorg.
mg/1
31. 7
47. 3
31. 7
32.4
32.6
33. 1
29.3
47.8
31.0
42.7
29. 5
29. 8
30.0
30.2
28.8
38.4
29. 5
29.0
29. 3
29. 3
29.0
46.8
29. 3
29.8
29.8
29.3
27.6
38.2
30.2
30.5
30.5
30.2
26.2
27. 1
44.9
27.4
47.8
27.8
27. 1
27. 1
25.4
46.6
26.6
26.4
25.9
Total
Phoi.
ae P
Cg/1
309
752
374
220
231
382
143
467
347
518
131
123
117
149
148
260
164
148
145
151
154
365
160
176
160
160
183
261
207
159
205
201
196
197
667
too
495
102
117
84
151
621
172
138
145
0. 45 |i Mllllpore Filtered Sample!
Nitrogen an N
Org.
ft /I
1358
733
1318
1548
1463
1358
1353
763
2013
908
993
1008
1158
2553
1273
923
1528
1353
1513
1058
I26B
693
1428
I42B
1323
1243
1063
4ia
878
1186
1198
753
IOOB
1213
868
748
963
613
803
1128
1083
1068
94B
1308
813
NH,
\>l/'
4313
28550
3432
3513
4513
3613
2788
37150
2638
34150
2663
2888
2738
2138
2763
25350
2488
2438
2713
1988
2663
32050
3638
2288
3188
1988
3338
25250
3263
3738
2713
2088
1788
1388
28950
1613
29050
1388
1138
1188
1913
29050
1388
1078
1153
NO, 4 NO,
Ml'
5484
85
5152
4972
4984
4928
5552
47
5428
66
5512
5848
5724
5848
5563
71
5960
5848
5820
5836
5404
66
5444
5556
5556
5584
5428
64
5444
5484
5556
5696
5724
5780
81
5680
73
5528
5888
5960
6793
64
5848
5708
6112
Total
UK /I
II 155
29368
9902
10033
10960
9899
9693
37960
10079
35124
9168
9744
9620
10539
9604
26344
9976
9639
10046
8882
9)35
32809
10510
9272
10067
8815
9829
25732
9585
10408
9467
8517
8520
8381
29899
8041
30086
7529
7829
8276
8788
30182
8184
8094
8078
Phoephoru*
ae P
PO,
Hg«
38
677
52
46
101
83
32
396
57
349
57
57
59
65
77
102
77
78
88
89
89
99
83
87
62
86
86
161
98
97
97
92
68
47
438
51
252
55
44
42
42
174
40
38
34
Total
PI/I
261
748
145
145
183
174
74
420
105
42S
120
116
no
122
142
191
1)5
1)3
143
151
141
176
145
176
136
153
159
207
162
157
165
1 74
186
99
666
93
430
120
118
98
86
279
106
87
74
Ca
mg/1
53.1
50.7
52.6
52.9
52.9
53.6
52.9
43.4
52.4
46.4
SI. 9
52.8
52.1
51.9
52.4
60.0
52.2
52.9
52.8
52.8
51,4
48.8
50.5
51.6
51.0
51.9
50. 9
33. 1
50.7
SI. 4
51.2
51.0
51.0
48,4
44,5
50.3
47.5
50.0
50. 0
49.5
49. 5
54. 5
48.8
48. 3
49.1
cr
mill
45.56
45.75
41.22
41.02
41. 12
41.31
44.54
45.98
46.20
48.67
44.30
39.83
39.92
39.83
47.47
84.00
44.84
44.23
43.22
43.62
39.80
44.39
39.98
37.04
38. 97
39.80
48. 66
51.23
46.65
46.43
46.88
43.64
45.77
50.41
51.22
50.92
48. 78
46. 84
46, 43
45.31
52. 27
57. 85
48.04
47. 01
46.28
Fe
|>g/l
6
6
tl
2
7
10
<1
14
-------
APPENDIX 8. Continued
ANALYSES - INDIAN CREEK RESERVOIR (Continued!
Date
9-9
9-15
9-23
9-29
10-6
10-13
Sample
Type
Grab C
III
0.5
3. S
6.5
Grab C
• III
0.5
3.5
6.5
Grab C
III
0.5
3.5
Grab C
in
0. 5
3,5
GrabC
III
0.5
3.5
5.0
OrabC
III
0.5
3.5
9.0
Ree.
Depth
It
43. t
43.5
42.0
39.5
40. 0 ^
40.0
SeeeM
DUX
ft
21.1
20.8
11.0
11.6
18.0
17.6
Temperature
Water
°C
20.1
20. 1
19.5
19.2
18.6
18.6
16.0
17.5
16.7
18, 7
17. 1
17.0
17.0
16.8
15.2
15.2
15.2
14.5
14.4
14.4
13.9
13.0
Air
°C
19.5
"""
16.5
17.0
17. 5
11.3
14.9
Unllltered Sample!
Suap.
Sol Id •
mg/l
1.26
6.50
1.81
1.94
1.53
0.64
1.25
1.54
1.93
0.99
0.88
0.97
2.82
1.94
0.65
1.88
2. II
2. 14
0.95
2. 10
4.01
4.97
3.65
17.42
1.57
2.44
1.51
2.04
V.I.
Suap.
\Solldi
mg/l
1.05
2.66
1.48
1. 89
1.39
0.58
0.98
1.26
1.64
0.99
0.64
0.79
1.76
1.69
0.54
0.20
0.36
0.70
0.86
1.74
3.25
4. 17
1.92
2.80
0.87
1.73
1.07
0.97
COD
mg/l
15. 2
30.8
15.6
15.
31.
16.
25.
17.
16.
18. 8
42.4
41.6
33.6
31.6
11.51
14.2
15.9
15.5
14.5
10.6
16.0
17.6
15.6
22.8
13.5
17.6
17.0
14.7
DO
mg/l
7.8
0.6
7. 8
7.
8.
7.
1.
7.
7.
e.
7.2
2. 0
7.2
7.0
7. 3
1. 6
7. 3
7. }
7. 1
1. 5
7. 1
6.9
7. 8
7.5
1.2
7.5
7.2
8.5
Inorg.
C
mg/(
25.7
46.1
25. 9
26. 6
25.0
26. 6
46.6
26.6
26. 6
25.4
26.2
45. 6
26. 2
26.2
26.4
42.0
26.4
26.2
25.9
40.6
25.9
25.4
25.2
24.2
39.4
25.7
25.2
25.0
Total
Phoi.
aa P
nil
111
159
1 15
163
101
128
354
120
155
105
111
296
123
112
174
130
III
114
101
137
170
96
121
126
133
106
92
90
0. 45|> Mllllpore Flit. red Sample!
Nitrogen aa N f
Org.
nil
1328
808
763
1259
1053
1003
663
1553
943
I07J
1378
308
1487
1655
1143
278
1298
1278
1305
362
1271
1381
1457
910
190
871
1095
643
NH,
M/l
1213
29050
1288
963
788
3188
24050
2413
1 163
1389
2239
34950
1913
1563
2513
19075
799
788
2357
17363
1915
2286
1643
7238
31142
6476
8910
7391
NO, 4 NO,
n't
5876
55
5988
5648
6268
5152
73
5404
5612
4996
3828
67
5012
4996
5680
335
5940
5840
5264
92
5708
5584
5600
5404
166
6044
5904
6016
Total
nil
9417
29913
9039
9069
9109
9343
24786
9370
7716
7457
7444
3S325
8412
3214
9336
19688
7926
7906
8926
17817
8794
9251
8700
13552
31498
13391
15809
14040
Phoephorue
aa P
PO,
nil
44
96
41
37
37
80
l«0
71
61
46
62
96
54
55
39
47
58
47
61
48
127
46
51
56
52
56
58
37
Total
>g/<
98
223
99
89
86
141
248
113
105
69
247
100
102
100
95
101
100
101
81
167
87
89
111
95
92
80
82
Ca
mg/l
48.1
48.4
50.0
48.8
49.8
48.3
45.0
48.6
50.2
48.6
47.6
39.3
49.6
48.6
47.4
45.3
44.5
47.6
47.6
46.2
47.6
46.9
47. 1
47.2
44.3
47.4
46.9
47.8
Cl~
mg/l
48.67
45.71
45. 10
45.51
44.49
51.55
54.43
50.44
51.66
46.89
51.93
33.44
51.42
46.85
75.39
50.29
59.73
47.94
49.64
49.10
49.73
46.49
45. 50
49.46
43. 17
46.49
45.05
44.06
Fe
Cg/<
3
7
6
5
6
31
7
2
6
15
12
25
12
7
15
12
7
14
-------
APPENDIX 9. MAXIMUM, MINIMUM, AND AVERAGE VALUES OF
QUALITY FACTORS IN RECLAIMED WATER (COMPUTED FROM
MONTHLY REPORTS BY THE SOUTH TAHOE PUBLIC UTILITY
DISTRICT). (All values in mg/4 except Turbidity, pH and Coliform)
1971
M.y
June
Ja>y
Auguet
Sept
NOY
Dee
1112
J.n
Fen
M»r
Apr
MMT
June
JtJT
A-I
5.2*
o.ob
1.4*
4.}
0.0
1. 1
2.2
0.4
1.0
2.4
0.4
1. 1
3. 1
0.0
1.0
0.4
1.5
3.3
0.4
1. 1
4.0
0.6
1.2
2.2
0.1
1.2
2.0
1.1
2. fc
1.4
1. £
0.1
1.0
2.7
0.2
1.5
0.2
0.7
7.4
O.I
1.6
3.2
0.0
0.7
*Hlfh
*Low
eA».r
1«. 1
s. i
10.5
16.5
3.8
13. 5
15.7
3.5
8.6
20.1
3. 3
8.1
8.3
2.2
5.6
1.6
6.2
9.6
5.0
7.6
21.5
4.3
11.5
17.2
02.1
11.5
13.1
9.8
14.0
7.9
20.1
2.6
16.0
10.0
1.3
11.3
Z.2
S.S
29.6
e.o
15.1
28.7
4.5
11.5
»«•
Solldi
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0.33
0.06
0. 17
0.31
0.01
0.18
0.27
0.01
0. 15
0.17
0.01
0. 11
0.21
0.01
0. 10
0.01
0.13
0.27
0.04
0.17
1. 10
0.07
0.22
0.23
0.01
0. 14
0.27
0. 18
0.36
0.15
O.JO
0.16
0.27
0.35
0. 11
0.70
0.07
0.20
0.62
0.16
0.35
0.45
0.11
0.21
Tur-
JTU
0.6
0.2
0.3
0.7
0.2
0.36
0.2
0.3
0.5
0.0
0. 3
0.6
0. 1
0.2
0.1
0.2
0.5
0.2
0.25
1.5
0.2
0.6
0. 5
0.3
0.4
8.9
0.5
1.0
0.5
0.6
0.2
0.3
0. 1
0.4
0.1
0.2
1.2
0.3
0.6
0.5
0.2
0.4
pH
7.6
7. 1
7.7
7.0
7.0
8.5
7.0
7. 9
7. 2
7.1
7.5
7. 1
8.1
7.2
8.2
7. 1
8.2
8.0
8.0
6.9
6.8
7.6
6.7
7.9
7.0
8.6
6.9
Chlorine
Re«idu»l
IniUn-
tancou*
3.5
1. J
4.0
1. 1
2.6
1.5
2.3
5.6
0.7
2.2
2. 5
0.7
1.4
0.9
1.6
3. 1
i. i
1.9
1.9
0.9
1.4
4.6
1.0
2.3
3.4
2.2
3.6
1.6
8.7
0.7
2.2
0.6
1.4
2.8
0.6
1.5
3.6
0.4
1.4
Z.2
0.6
1.2
(mpn)
<2. 0
<2. 0
-------
APPENDIX 9. Continued
S.p<
oa
Mov
Sec
1973
J»
r.b
*
Apr
K»v
June
July
A«I
S.pt
Oet
Nor
Dee
UM
J>n
Fib
K.r
2.?'
0.0*
4. 1
0.0
1.1
e.o
0.4
2.1
3.9
O.I
4.4
0.6
2.2
2.4
0. 1
1.2
0.1
I.I
1.1
1.5
1.1
0.0
2.2
0.9S
1.3
0.3
2.0
5.2
0. Z
2.2
7. Z
0.)
2.9
Z. 2
0.4
1.5
2.6
O.I
1.2
1.5
0. «
1. 8
LI
O.S
4.1
4.1
0.4
\.1
5.1
0.2
2.3
19.5
5.4
1«. 0
7.9
17.5
3.4
19.5
2.9
9.0
0.5
It.!
7.1
10. 4
0.0
7.8
15.2
II. 1
11-9
11.2
ta.2
12.0
15. 6
5.1
13.3
19.7
1.4
14.8
21.4
11.2
17.3
23.1
8.4
14.8
22.4
6.3
13.8
20.1
2.7
13.1
40.2
9.6
20. S
20.0
(.3
13.2
3S.2
1. >
17.9
So.p.
SoliJ.
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0. 21
0.00
1.20
0.02
0.20
0.52
0.17
0.40
0.17
0.51
0.25
0.0?
0.04
0.05
0.12
0.15
. 0.15
0.07
0.10
0.06
0.135
0.073
0. HO
0.011
0.1)1
0.62
0.27
0.38
0.07
0.04
0.05
0.82
0.47
0.64
0.14
0.06
0.09
0.06
0.11
0.90
0.36
0.51
0.30
0.07
0.19
0.29
0.15
0.23
Tur-
JTU
0.4
0.)
0.6
0.2
0.3
2.5
0.1
0.6
0.3
1.0
0.2
0.4
0.2
0.3
0. 1
0.2
0.5
0.4
0.7
0.1
0.6
0.4
0.5
0.3
0.4
0.8
0.3
0.4
0.7
0.4
0.5
O.S
0.2
0.3
0.5
0.2
0.3
0.3
0.5
1.2
0.5
0.8
1.0
0.4
0.9
0.8
0.3
0.5
7. 8
7.0
7.4
7.0
7.3
6.8
6.8
7. 6
7. 2
7. 5
6.9
6.3
7. 1
7.4
6.9
~"
7.4
7. S
6.8
7.4
6.8
7.9
6.8
7.1
6.9
7.5
4.7
6.9
7.7
7.2
7. 1
6.8
7.6
6.1
Chlorlni
B..I f.j.l
!«.un-
3.5
1.0
2.0
2.1
0.6
1.2
7.1
0.2
1.6
0.4
1.4
0.2
0.7
3.5
0.5
1.9
0.8
2.17
1.0
1.8
2.7
1.2
2.8
1.4
2.8
*. I
1.4
3.6
1.2
2.0
2.8
o.<
1.8
4.0
1.2
2.1
2.3
l.i
1.5
0.6
1.7
3.0
1.2
2. 1
4. 4
1.2
2.4
4.4
0.5
2.2
(mpni
<2.0
<2.o
<2. 0
a. •
<2. 0
38.0
C2.0
<2.0
38.0
<2. 0
<2.0
<2.0
<2. 0
<2.0
<2.0
<2.0
<2.0
2.6
2.2
<2.0
2.2
-------
APPENDIX 10
IONIC ANALYSES FOE. METALS IN RECLAIMED WATER
South Tahoe Public Utility District - 1971
List Taken from Sept. 24, 1971 Report (15)
(Tests by Battelle - NW Research.)
Concentration in mg/1
Element
Arsenic
Chromium
Copper
Iron
Manganese
Selenium
Silver
Zinc
Bromine
Uranium
Cobalt
Cesium
Mercury
Rubidium
Scandium
Antimony
Reclaimed
Water
less than 0.005
less than 0.0005
0.0116
less than 0.0003
0.002
less than 0.0005
0.0004
less than 0.005
0.065
0.0015
0.00022
0.000006
less than 0.0005
0. 010
0.000001
0.00044
Maximum Allowable
USPHS-DWS
0.05
0.05
1.0
0.3
0.05
0.01
0.05
5.0
--
--
--
--
--
--
--
--
148
-------
APPENDIX 11. PHYTOPLANKTON COUNTS OF SAMPLES COLLECTED AT STATION C, ICR
Dal* uf S*mplln«
foul Count, Organiimi/ml
CDIvlilon, ChlvrephrU (Smith)
Battllario ph»c«»« CDlatoroO
Dlatatn *p.
NavlcuU
FruiMlU
PlnnulkrlB
S/W 6/19 b/2o 7/lt 7/J1 8/14 8/2S 9/11 9/16 9/ZS 10/9 10/16 10/30 MM* II/Z7 3/26 4/23 S/1 5/21 6/4 b/18 7/2 7/17 8/20 8/27 9/10 9/11 10/1 10/15 10/29 ll/U 11/26 12/4 1/14 2/4
272 17fl 413 62t 2007 BZi 1545 858 Sean ?98 9<7 1,260 601 663 609 2,160 4d 890 840 Z48I 772 840 424 1053 623 171 J24 18] 349 1637 Sc»n 174 Stan Scan Stap
3/4 3/6
Scan «•*
Cy ml topi* urn
AfterlOMllt
Meridian
SUpb* odi«t.u
CymlMlU
StmiiruMli
Fr«|lllara
Hh
Chlorella
Oocyilii
Coimarlum
Clu.i.rium
Ankl«lro4«imui
Splrogyr.
CMUiirum
Ulocucyflti
ProiMoccu*
IVcieittlv* e«ll.)
ftotrrococcui
SchluUamr*
Mou|«olU
Microipora
Ulothri.
Chunoahyta ISnulhr
( Mvrabulryt
inoldlrfj IKudal
CwRUM >p,
Eu|J«M *ru*
Hharui »p,
Tr« rh«lw>wn< • ip,
T, ir.W,
Ami«n*/n« fp.
Cli/^n iKurfuf
(Modify* *P>
0*,l/ieh. ^., -,
'.*lpHiUfn
l'l«ur.,n«n,.
' t.lt>»tuMJU
Wpv^ii)lufn
/ in*i',^.fl-Z 37 Id 1 12 1 Ti 28 27% 5 Tl H Jl 4~
x 160 » iJ x IZO x 71 x x X 224 r 107 x * x « « x 113 x K
^tunJitr .,1 .~rnti,,,,,,» ft,
-------
APPENDIX 12
ALGAL B1OASSAYS OF ICR AND STPUD EFFLUENT:
COUNTS, pH AND SUSPENDED SOLIDS MEASUREMENTS.
Duration of Growth
Date Cone 1-Day 3- Day
of Sample of Counts Counts
Sample Type Sample CELLS/mm CELLS/mm
5/17/71 C 1 A
B
C
10 A
B
C
100 A
B
C
III 1 A
B
C
10 A
B
C
100 A
B
C
6/2/71 C 1 A
B
C
10 A
B
C
100 A
B
C
III 1 A
B
C
10 A
B
C
100 A
B
C
62.8
68.4
69.2
67.6
62.0
68.8
69.2
62.4
65.2
71.2
64.8
61.2
54.4
53.2
56.0
52.8
49.6
52.0
47.6
46.4
52.8
43.2
45.2
48.8
39.2
43.6
54.4
45.2
44.0
46.4
52.8
50.0
48.4
43.6
41.6
38.8
129.6
144.4
138.0
152.0
146.4
144.4
112.4
126.4
126.8
143.6
144.4
133.2
92.0
98.0
95.6
50.0
49.6
48.8
70.8
58.4
70.8
92.4
96.4
113.6
151.6
156.8
159-2
102.4
73.6
104.0
71.2
77.2
63.2
41.2
39.2
41.6
5-Day
Counts
CELLS/mm (!
158.0
168.8
166.4
182.0
174.0
177.6
175.6
182.4
176.4
216.8
212.0
209.2
178.0
170.8
167.2
50.8
50.4
51.2
88.0
67.2
83.6
138.0
133.2
142.0
203.6
203.2
214.0
233.6
199.6
229.6
90.8
102.8
83.2
53.2
51.2
53.2
Composite
pH at ^-^>
Day 5
Suspended Solids) Days
7.4 .362
.374
.345
7.4 .405
.430
.371
8.3 .243
.353
.333
7.4 .351
.401
.389
7.5 .330
.305
.280
8.1 .00794
.00800
.024
7.2 .199
.115
. 147
7.7 -380
.379
.422
7.6 .676
.640
.537
7.5 .412
.499
.404
7.4 .149
.217
. 137
77 . 128
. 134
150
-------
APPENDIX 12. Continued
Duration of Growth
Date Cone 1-Day
of Sample of Counts
Sample Type Sample CELLS/mm
6/14/71 C I A
B
C
10 A
B
C
100 A
B
C
III 1 A
B
C
10 A
B
C
100 A
B
C
6/21/71 C 1 A
B
C
10 A
B
C
100 A
B
C
III 1 A
B
C
10 A
B
C
100 A
B
C
7/7/71 C 1 A
B
C
55.2
57.6
60.4
53.2
53.6
57.2
54.8
56.4
72.4
48.4
49.6
45.6
44.0
44.0
43.6
45.2
42.8
43.6
60.0
64.0
61.2
55.2
59.6
60.4
50.0
52.4
57.2
62.0
61.2 i
63.2
55.2
54.8
57.6
52.8
52.0
49.6
52.0
52.8
53.6
3- Day
Counts
CELLS/mm3
70.8
78.0
82.0
72.8
76.0
87.6
104.0
101.6
108.8
61.6
68.8
59.2
43.6
42.8
42.4
43.2
43.6
42.8
84.4
91.2
85.6.
72.0
79.2
76.8
60.4
66.0
65.6
86.8
73.6
83.2
66.4
62.8
64.4
51.2
51.6
50.8
73.6
74.4
74.4
Composite /x
5- Day pH at >^b
Counts Day 5 ,
CELLS/mm3 (Suspended Solids) Days"
78.4
90.4
104.8
94.4
98.0
106.8
129.2
130.4
136.0
90.0
104.0
88.8
43.6
43.6
41.6
42.8
43.6
43.6
97.6
100.0
92.0
82.8
80.0
84.0
64.4
74.4
66.0
134.0
118.4
119.6
74.0
72.0
80.4
52.0
52.0
50.8
89.2
96.4
97.2
7.9
.152
. 188
72. .130
.175
.196
8.3 .320
.294
7.3 -190
.207
.203
8.0 0
.00926
(-)
8.4 (-)
.00926
.00926
7.8 -171
. 177
.168
7.9 -133
.142
.120
8.3 -0945
.115
.0685
8.1 .217
.238
.181
8.0 -0924
.0681
.111
8.5 .00775
.00386
.0313
.174
* .171
.164
151
-------
APPENDIX 12. Continued
Date Cone 1-Day
of Sample of Counts
Sample Type Sample CELLS /mm
7/7/71 10 A
B
C
100 A
B
C
III 1 A
B
C
10 A
B
C
100 A
B
C
7/26/71 C 1 A
B
C
10 A
B
C
100 A
B
C
in i A
B
C
10 A
B
C
100 A
B
C
8/9/71 C 100 A
B
C
51.6
51.2
50.4
46.8
48.8
47.6
52.4
52.8
54.8
52.0
52.0
51.2
48.4
47.2
48.4
98.4
76.0
97.6
38.0
38.4
36.0
50.0
52.0
54.4
39.2
37.6
37.2
30.8
25.6
29.6
28.8
27.6
32.4
33.6
3-Day 5-Day Composite J^^
Counts Counts pH at
CELLS/mm CELLS/mm (Suspended Solids) Days'*
76.4
72.4
78.4
63.2
64.0
64.4
57.6
63.2
66.8
158.4
195.6
192.8
63.2
62.8
72.0
65.6
46.0
42.0
64.4
66.8
53.2
126.8
136.4
137.2
80.8
77.6
70.8
18.0
13.2
16.4
14.4
14.0
9.6
10.0
113.6
111.6
118.4
116.4
116.4
116.4
*
*
*
*
*
94.8
42.4
37.6
51.2
53.6
50.0
332.8
337.6
333.6
128.0
114.0
112.8
86.4
62.8
16.8
15.6
16.4
144.4
206.4
.198
* .216
.221
.305
* .299
.296
Coulter • 0473
counter « 0899
•was not - 0990
operating
.557
.662
.663
.133
.143
.199
7.4 .184
(- )
(-)
7.3 -264
.277
.195
8. 1 • 482
.482
.463
7.4 -362
.362
.322
7 A
.784
.780
8.5 .0120
.0400
.0791
7.8 1.36
(2.94)ss
1.51
152
-------
APPENDIX 12. Continued
Duration of Growth
Date
of Sample
Sample Type
8/9/71 IH
9/7/71 C
III
9/14/71 C
in
9/27/71 C
III
10/4/71 C
III
10/11/71 C
III
10/18/71 C
Cone 1-Day 3-Day 5-Day Composite
of Counts Counts Counts pH at
Sample CELLS/mm CELLS/mm CELLS/mm3 (Suspended Soli
100 A
B
C
100 A
B
C
100 A
B
C
100 A
B
C
100 A
B
C
100 A
B
C
100 A
B
C
100 A
B
C
100 A
B
C
100 A
B
C
100 A
B
C
100 A
B
C
49.6
51.6
52.8
50.8
45.2
46.8
38.8
36.4
38.4
55.2
56.0
62.8
42.0
43.6
37.6
56.8
56.0
60.4
43.2
42.8
45.2
60.8
59.2
56.8
44.0
46.0
44.4
62.0
59.6
61.6
43.6
42.4
39.6
57.2
54.4
55.2
37.6
33.6
42.0
142.0
99.6
104.0
29.2
27.6
29.6
163.6
144.8
227.6
36.8
36.0
35.6
214.8
300.8
334.8
46.0
39.2
39.6
212.0
210.8
210.0
41.6
43.6
42.0
203.2
173.6
179.6
42.8
35.2
34.0
155.2
144.8
154.4
18.4
13.2
12.8
176.4
124.8
130.8
38.4
32.8
34.8
240.4
200.4
328.0
40.0
42.8
38.8
289.2
489.0
526.0
44.8
37.6
38.8
282.8
272.0
267.2
41.6
36.8
250.4
205.2
217.2
44.8
36.0
31.2
165.2
141.2
152.4
8.4
(1.53)
7.2
(5.46
8.0
(1.46)
7.4
(9.83)
8.1
(1.81)
8.1
(9.89)
8.0
(1.50)
7.6
8.37
7.9
1.34
7.4
7.97
7.9
1.40
7.5
7.70
A
./"-b
ds) Days'
(-)
(-)
(-)
.514
.395
.399
.137
.0863
.0809
.475
.644
.0417
.0865
.0430
.665
.841
.856
.0314
(-)
(-)
.624
.635
.654
0
.0311
(-)
.594
.535
.535
.0228
.0112
(-)
.499
.489
.514
153
-------
APPENDIX 12. Continued
Duration of Growth
Date
of Sample
Sample Type
10/18/71 HI
11/1/71 C
III
11/8/71 C
in
11/15/71 C
III
3/27/73 C
III
4/3/72 C
in
4/10/72 C
Cone 1-Day
of Counts
Sample CELLS/mm
100 A
B
C
100 A
B
C
100 A
B
C
100 A
B
C
100 A
B
C
100 A
B
C
100 A
B
C
100 A
B
C
100 A
B
C
100 A
B
C
100 A
B
C
100 A
B
C
46.4
42.8
44.8
52.0
50.8
50.0
48.4
47.2
48.4
50.4
49.6
52.4
48.8
47.2
46.0
52.0
52.8
49.2
48.4
55.6
51.6
56.4
60.0
50.0
50.0
49.6
52.0
50.4
51.6
47.2
49-6
52.4
50.8
51.2
53.2
54.4
3- Day 5- Day
Counts Counts
CELLS/mm3 CELLS/mm
50.8
46.0
45.2
77.6
77.6
80.8
51.2
48.8
52.0
59.6
53.2
55.6
50.0
51.2
49.6
98.0
80.8
74.8
51.6
52.8
54.8
57.6
123.2
104.8
50.0
50.8
53.2
73.2
62.0
88.8
53.2
54.8
52.8
58.4
61.6
64.4
36.0
44.8
45.2
78.4
87.2
83.6
50.0
49.2
49.6
66.8
55.6
56.4
49.6
50.4
48.8
157.2
126.0
112.4
54.8
54.4
52.8
62.0
180.4
144.0
50.4
50.0
50.4
90.8
66.8
128.0
50.0
52.0
50.4
61.6
70.0
70.4
Composite /J,
PH at ^
(Suspended Solids) Days"
8.0
3.26
7.5
2.86
7.9
1.42
7.5
2.33
8.1
1.08
7.8
5.24
8.3
2.11
8.1
6.30
8.6
2.73
8.7
(4.73)
8.7
(4.43)
8.6
(3.65)
.0453
.0361
. 00444
.200
.212
.240
.0281
.0167
.0359
.0838
.0350
.0296
.0121
.0407
.0377
.317
.222
.209
.0320
.0149
.0301
.0368
.360
.370
. 00398
.0120
.0114
.187
.0918
.316
.0350
.0224
.0267
.0733
.0844
154
-------
APPENDIX 12. Continued
Duration of Growth
Date Cone 1-Day 3-Day
of Sample of Counts Counts
Sample Type Sample CELLS/mm CELLS/mm
4/10/72
4/17/72
4/25
5/1
5/8
5/15
5/22
III 100 A
B
C
C 100 A
B
C
III 100 A
B
C
C 100 A
B
C
III 100 A
B
C
C 100 A
B
C
III 100 A
B
C
C 100 A
B
C
in 100 A
B
C
C 100 A
B
C
III 100 A
B
C
C 100 A
B
C
56.0
56.4
52.0
55.6
56.8
57.6
52.8
50.0
50.0
55.6
53.6
54.8
49.6
52.0
53.2
55.6
55.6
54.4
51.2
51.6
50.8
54.8
56.4
55.2
52.4
50.8
52.0
51.6
49.2
52.0
46.0
42.8
48.8
51.6
51.6
50.8
58.4
58.8
59.6
67.2
62.4
69.2
75.2
51.2
52.4
87.2
58.8
68.8
60.8
49.2
55.6
58.8
58.4
74.8
52.0
54.4
54.4
58.4
80.8
64.8
52.8
52.4
50.8
66.4
53.6
68.4
49.2
45.2
46.4
54.8
55.2
60.0
5- Day
Counts ,
CELLS/mm
52.8
52.8
54.4
69.2
60.8
67.2
50.0
50.0
49.2
112.8
60.0
84.4
51.6
47.6
50.0
58.8
60.8
101.6
52.0
50.0
50.8
62.0
122.0
83.6
52.0
47.6
46.4
76.4
56.8
80.8
48.4
47.2
49.2
54.8
55.2
69.2
Composite ju-^
pH at .
(Suspended Solids) Days
8.7
(6. 92)
8.0
(2.91)
8.5
(2.30)
8.2
(2. 74)
8.4
(3.41)
8.2
(2.84)
8.3
(1.22)
8.6
(3.33)
8.7
(1.31)
8.6
(2. 05)
8.6
(0.95)
8.5
(1.81)
.0210
.0208
.0682
.0947
.0470
.0917
.177
.0119
.0234
.225
.0463
.114
.102
(-)
.0221
.0280
.0246
.159
. 00775
.0264
.0342
.0318
.206
.127
.00380
.0155
(-)
.126
.0428
.137
.0336
.0273
.0293
9
.0337
.0832
155
-------
APPENDIX 12. Continued
Duration of Growth
Date
of
Sample
5/22
5/31
6/1
6/12
6/19
6/26
7/5
Cone 1-Day 3-Day 5-Day
Sample of Counts Counts Counts _
Type Sample CELLS/mm CELLS/mm CELLS/mm
III 100 A
B
C
C 100 A
B
C
III 100 A
B
C
C 100 A
B
C
III 100 A
B
C
C 100 A
B
C
III 100 A
B
C
C 100 A
B
C
III 100 A
B
C
C 100 A
B
C
III 100 A
B
C
C 100 A
B
C
47.6
39.6
43.6
51.2
54.4
58.4
46.4
45.2
44.0
46.0
45.2
46.0
52.8
53.2
53.2
48.4
49.2
49.2
44.8
51.2
48.4
51.6
47.2
47.2
46.4
45.2
44.8
49.6
46.4
49.2
44.8
52.8
48.8
53.2
52.0
53.2
46.0
42.0
46.0
52.0
60.8
66.4
45.2
45.6
43.6
61.6
61.2
61.2
46.0
44.4
45.2
49.6
62.8
50.4
45.2
45.6
47.2
57.6
55.6
49.2
44.4
44.4
44.0
64.8
50.8
65.6
48.4
46.8
44.8
74.4
76.0
68.4
45.6
45.2
44.8
53.6
68.0
74.4
44.4
43.6
44.8
63.2
62.0
62.8
46.8
49.2
46.8
56.8
72.8
56.8
44.8
52.8
51.2
65.6
67.6
50.8
49.2
45.6
45.2
87.2
56.0
90.0
48.8
48.8
47.6
97.2
104.0
87.6
. •^
Composite .x^V)
pH at _t
(Suspended Solids) Days""
8.6
(1.62)
8.5
(2.00)
8.7
(1.62)
8.5
(2.22)
.•••__
(1.72)
8.2
(•2. 00)
8.6
(1.29)
8.5
(2.22)
8.7
(1.57)
8.3
(2. 84)
8.7
(2.78)
8.4
(3.80)
(-)
.0367
.0268
.0152
.0560
.0642
(-)
. 00441
.146
.152
.143
.00862
.0513
.0174
.0678
.122
.0598
. 00444
.0733
.0407
.0650
.0977
.0207
.0513
.0133
.0135
.148
.0487
.158
.0386
.0209
.0303
.168
. 190
.126
156
-------
APPENDIX 12. Continued
Duration of Growth
Date
of
Sample
7/5
7/10
7/17
7/25
7/31
8/8
8/14
Cone 1-Day 3- Day 5- Day
Sample of Counts Counts Counts
Type Sample CELLS/mm3 CELLS/mm3 CELLS/mm
III 100 A
B
C
C 100 A
B
C
in 100 A
B
C
C 100 A
B
C
III 100 A
B
C
C 100 A
B
C
III 100 A
B
C
C 100 A
B
C
III 100 A
B
C
C 100 A
B
C
III 100 A
B
C
C 100 A
B
C
III 100 A
B
C
50.0
47.2
49.2
52.8
57.6
52.8
44.4
44.4
48.4
47.6
44.0
47.6
41.6
39.2
39.6
46.8
42.4
43.2
44.0
42.4
43.6
44.0
42.8
45.2
42.4
42.0
42.8
52.0
46.4
45.6
43.6
44.0
41.2
62.0
61.6
45.6
42.8
46.0
38.4
36.8
36.4
104.0
124.0
107.2
46.4
42.4
45.6
.^_
72.8
73.2
34.0
33.2
34.0
90.0
.^_^_
82.0
38.8
34.4
39.6
44.0
44.0
98.4
36.0
37.6
37.6
t—~— iH
85.6
104.0
37.2
38.0
34.0
158.0
170.8
45.2
35.2
37.2
44.8
45.6
44.0
162.4
186.4
150.0
47.6
46.4
47.6
104.8
104.0
34.8
32.4
32.4
120.0
__
120.0
38.8
35.2
38.0
45.6
46.4
137.2
41.6
38.0
39.6
_
109.6
164.8
39.6
43.6
41.6
238.0
252.4
47.2
44.0
43.2
Composite >^V)
pHat
(Suspended Solids) Days
8.7
(1.16)
8.5
(5.56)
8.6
(1.39)
8.3
(3.14)
8.7
(0.97)
8.4
3.83
8.7
1.67
8.3
5.54
8.7
1.68
8.3
4.17
8.6
2.03
8.4
5.86
8.6
2.31
.0771
.107
.0948
.339
.383
.354
.0333
.0451
.0215
.252
.215
.0116
(-)
(-)
.327
.320
0
.0115
(-)
.0179
.0266
.389
.0723
.00529
.0259
.306
.412
.0313
.0687
.101
.468
.510
.0216
.112
.0748
157
-------
APPENDIX 12. Continued
Duration of Growth
Date
of
Sample
R/71
O f £j±
8/28
9/5
9/11
9/18
9/25
Cone 1-Day 3- Day
Sample of Counts , Counts
Type Sample CEULS/mm CEL,LS/mm
c i on A
V_> JL \J U Xi
B
C
III 100 A
B
C
C 100 A
B
C
III 100 A
B
C
C 100 A
B
C
in 100 A
B
C
C 100 A
B
C
in 100 A
B
C
C 100 A
B
C
III 100 A
B
C
C 100 A
B
C
III 100 A
B
C
60.8
64.8
45.6
46.0
47.6
51.6
58.8
53.6
46.0
44.0
43.6
54.4
53.6
64.0
50.0
49.6
50.4
60.8
62.8
64.0
47.2
49.2
49.2
68.4
67.6
74.8
53.2
53.2
56.0
51.6
50.8
53.2
48.4
48.8
49.2
178.0
222.4
48.4
44.8
46.0
101.6
90.0
74.4
50.8
49.6
44.8
170.4
227.6
233.6
52.0
60.8
46.4
264.0
254.4
245.2
49.2
49.2
48.4
173.6
212.0
166.4
77.2
72.0
95.6
87.2
80.8
91.2
46.4
45.6
46.4
5- Day Composite _/-*~^
Counts . pH at .
CELiLS/mm (Suspended Solids) Days"
456.0
534.0
49.6
49.2
46.0
152.4
118.0
397.6
52.8
47.6
44.0
345.0
588.0
546.0
67.2
78.0
57.2
540.0
547.0
529.0
57.6
62.4
53.2
314.0
406.0
294.0
170.4
155.6
206.0
133.6
128.0
141.2
73.6
68.8
65.2
84
. *x
18.23
8.6
2.22
8.5
8.11
8.7
2.08
8.6
15.83
8.6
3.06
8.7
19.26
8.7
2.47
8.5
13.46
8.8
7.03
8.2
4.64
8.7
2.00
.537
.617
.0298
.0468
9
.339
.213
.825
.0496
.0599
.0136
.571
.723
.647
.128
.125
.105
.734
.699
.672
.0788
.119
.466
.571
.400
.396
.385
.384
.262
.232
.269
.231
.206
.170
158
-------
APPENDIX 12. Continued
Duration of Growth
Date Cone 1-Day 3- Day
of Sample of Counts Counts
Sample Type Sample CELLS/mm CELLS/mm3
10/2
10/9
10/18
10/20
10/30
11/6
C 100 A
B
C
III 100 A
B
C
C 100 A
B
C
in 100 A
B
C
C 100 A
B
C
in 100 A
B
C
C 100 A
B
C
in 100 A
B
C
C 100 A
B
C
ni 100 A
B
C
C 100 A
B
C
III 100 A
B
C
52.0
53.2
55.6
49.6
49.6
47.2
57.2
55.6
54.8
47.6
46.8
52.0
52.0
51.2
50.8
44.8
45.2
46.8
50.4
50.4
50.8
47.6
46.4
47.2
53.2
56". 0 .
58.4
49.6
50.0
50.8
54.8
54.4
56.8
46.4
47.6
45.6
108.8
93.2
102.4
44.0
43.6
43.2
56.4
69.2
79.2
42.0
41.6
38.8
108.8
121.6
136.8
46.4
48.4
45.2
66.4
62.0
63.2
65.2
64.4
62.0
176.4
176.4
167.6
70.0
66.4
62.8
195.2
181.2
154.4
41.2
43.6
42.4
5- Day Composite
Counts pH at
CELLS /mm (Suspended Solic
151.6
125.2
146.8
49.2
50.4
47.2
56.8
77.2
79.2
45.6
44.8
48.4
122.8
133.2
155.6
49.2
50.4
46.0
71.2
65.6
65.2
75.2
74.8
71.6
205.6
203.6
199.6
80.8
78.8
64.8
240.4
223.6
188.4
42.4
42.0
39.2
8.1
6.22
8.6
2.46
8.1
3.67
8.6
1.05
8.2
6.71
8.7
3.11
8.3
3.67
8.7
3.65
8.4
8.28
8.7
3.65
8.5
(9.23)
8.6
(2.56)
A
>*b
1
Is) Days
.369
.280
.305
.0559
.0725
.0443
.00353
. 109
.184
.0411
.0371
. Ill
.369
.432
.495
.0293
.0342
.00877
. 138
. 104
.109
.157
. 164
. 136
.599
.574
.527
. 172
.142
. 106
.635
.602
.500
.0144
(-)
(-)
159
-------
APPENDIX 12. Continued
Duration of Growth
Date
of
Sample
11/13
11/20
11/27
12/5
12/11
12/26
Cone 1-Day 3- Day
Sample of Counts Counts
Type Sample CELLS/mm CELLS/mm
C 100 A
B
C
in 100 A
B
C
C 100 A
B
C
ni 100 A
B
C
C 100 A
B
C
III 100 A
B
C
C 100 A
B
C
in 100 A
B
C
C 100 A
B
C
in 100 A
B
C
C 100 A
B
C
in 100 A
B
C
56.0
55.2
55.6
48.8
50.0
49.6
55.2
55.2
52.4
50.4
48.4
49.6
54.4
52.8
56.4
51.3
48.8
49.2
43.6
42.4
45.6
32.4
32.4
32.4
45.2
45.2
44.0
36.4
33.2
36.4
52.4
53.6
53.6
130.4
120.0
120.4
56.8
49.6
48.4
164.8
173.6
129.2
61.2
51.2
52.8
155.6
148.8
156.0
54.4
48.4
46.4
149.6
140.8
142.0
33.6
28.8
31.6
144.0
131.2
103.2
63.2
62.0
58.4
296.8
298.8
272.0
5- Day Composite ^"'U
Counts pH at
CELLS/mm (Suspended Solids) Days"1"
222.0
190.8
201.2
57.2
49.6
48.8
289.2
273.2
225.6
57.6
50.4
48.4
291.2
269.6
272.0
20.8
29.6
46.0
418.8
355.6
339.6
43.2
39.2
35.2
349.6
303.2
190.4
90.8
94.0
86.4
899.0
929.0
846.0
8.6
(8.82)
8.7
(2.67)
8.7
(10.84)
8.7
(3.03)
8.7
(11.81)
8.6
(2.64)
8.4
(13.02)
8.7
(0.92)
8.6
(9.08)
8.7
(2.78)
8.8
(33.09)
.423
.388
.386
.0759
0
.00412
.547
.573
.451
.0971
.0281
.0313
.525
.518
.509
.0293
(-)
(-)
.616
.600
.568
. 126
.154
.0539
.579
.533
.426
.276
.312
.236
.867
.859
.812
160
-------
APPENDIX 12. Continued
Duration of Growth
Date Cone 1-Day 3- Day
of Sample of Counts Counts
Sample Type Sample CELLS/mm CELLS/mm
1973
1/2/73
1/8/73
1/15/73
1/22/73
1/29
2/5
C 100 A
B
C
in 100 A
B
C
C 100 A
B
C
in 100 A
B
C
C 100 A
B
C
in 100 A
B
C
C 100 A
B
C
in 100 A
B
C
C 100 A
B
C
ni loo A
B
C
C 100 A
B
C
ni 100 A
B
C
43.2
46.8
50.4
37.6
42.0
38.4
47.2
49.2
48.4
36.0
35.2
36.4
49.2
54.8
56.0
50.0
50.0
52.4
54.8
55.6
52.8
50.0
51.2
49.2
55.2
55.6
56.0
53.6
52.8
52.8
53.2
52.4
51.2
50.0
50.4
49.6
116.0
182.0
193.2
38.4
37.6
30.8
168.8
176.8
160.4
39.2
31.6
34.0
168.8
182.4
210.4
68.8
69.2
71.2
209.2
228,4
209.6
78.8
79.6
78.0
240.8
250.8
244.8
56.4
52.4
51.6
209.6
197.2
157.2
51.6
51.2
48.8
5-Day Composite J^V.
Counts pH at
CELLS/mm (Suspended Solids) Days
-
648.0
707.0
50.8
54.4
45.6
513.0
512.0
436.0
60.4
43.2
50.0
374.8
387.6
669.0
97.6
100.4
94.8
499.0
672.0
493.0
110.8
105.2
98.0
711.0
817.0
812.0
68.4
56.0
54.8
398.8
303.6
227.2
56.4
53.6
50.0
8.7
(21.68)
8.7
(3.06)
8.7
(23.14)
8.7
(4.00)
8.8
(17. 24)
8.6
(5.03)
8.9
(19.94)
8.8
(18.68)
8.9
(30.43)
8.7
(2.66)
8.8
(15.37)
8.8
(2.46)
.494
.679
.672
.140
. 185
.196
.637
.640
.599
.216
.156
— —
.616
.601
.662
.175
.186
.153
.670
.706
.689
.227
.221
.230
.737
.753
.738
.0965
.0332
.0301
.686
.663
.561
.0445
.0229
.0121
161
-------
APPENDIX 12. Continued
Duration of Growth
Date
of
Sample
2/13
2/20
2/26
3/5
3/12
3/19
Cone 1-Day
Sample of Counts
Type Sample CELLS /mm
C 100 A
B
C
in 100 A
B
C
C 100 A
B
C
in 100 A
B
C
C 100 A
B
C
ni 100 A
B
C
C 100 A
B
C
in 100 A
B
C
C 100 A
B
C
in 100 A
B
C
C 100 A
B
C
in 100 A
B
C
56.8
62.0
61.6
52.0
52.8
52.4
63.2
63.2
62.0
56.8
54.4
53.6
64.0
64.0
64.0
48.8
48.4
46.8
59.2
64.4
63.2
54.8
48.4
48.4
64.4
63.2
62.8
53.2
53.2
50.4
64.8
60.4
64.4
53.6
51.6
54.4
3- Day
Counts
CELLS/mm
198.0
234.0
244.8
53.2
52.0
51.2
250.8
264.4
274.0
55.6
52.0
46.0
238.0
296.8
249.2
45.6
46.0
42.8
204.8
227.2
171.6
53.2
46.4
45.2
151.6
139.2
152.4
46.8
45.2
42.8
181.2
195.2
195.6
46.0
45.2
45.6
5 -Day
Counts ,
CELLS/mm
337.0
438.0
453.0
56.8
52.8
55.2
478.0
560.0
627.0
66.8
56.8
53.2
509.0
674.0
546.0
51.6
49.2
45.6
392.0
399.0
301.0
63.2
55.6
50.8
298.4
252.0
329.6
56.4
54.8
50.0
396.0
546.0
516.0
56.0
50.4
51.6
Composite
pH at
(Suspended Soli<
8.4
(15.00)
8.7
(2.84)
8.8
(24.11)
8.7
(3.69)
8.8
(23.85)
8.7
(2.97)
8.7
(14.46)
8.7
(3.11)
7.7
(7.71)
8.5
(2.46)
8.6
(13.97)
8.6
(2.19)
A
^
is) Days""''-
.625
.664
.690
.0327
.00763
.0376
.689
.716
.743
.0918
.0441
.0727
.657
.767
.680
.0618
.0336
.0317
.621
.630
.499
.0861
.0904
.427
.395
.443
.0933
.0963
.0777
.514
.587
.555
.0984
.0544
.0618
162
-------
APPENDIX 12. Continued
Duration of Growth
Date
of
Sample
3/26
4/3
4/9
4/16
4/23
4/30
Cone 1-Day 3- Day
Sample of Counts Counts ,
Sample CELLS/mm CELLS/mm
C 100 A
B
C
III 100 A
B
C
C 100 A
B
C
in 100 A
B
C
C 100 A
B
C
in 100 A
B
C
C 100 A
B
C
III 100 A
B
C
C 100 A
B
C
in 100 A
B
C
C 100 A
B
C
in 100 A
B
C
61.6
67.2
68.4
53.6
55.6
54.8
65.6
66.4
67.6
57.2
57.6
58.8
62.0
65.2
63.2
46.8
50.8
45.6
72.8
68.4
72.0
44.8
45.6
43.2
76.8
76.8
78.0
45.2
44.4
44.8
67.6
66.4
66.8
56.8
50.8
43.2
225.2
266.8
250.0
56.4
53.6
54.4
120.0
105.2
160.4
56.4
57.2
53.6
144.4
159.2
186.4
31.2
31.2
25.6
299.2
292.4
318.4
44.4
35.6
38.8
347.6
380.4
, 385.6
51.6
45.6
39.2
238.4
286.0
216.0
48.8
53.2
37.2
5-Day Composite
Counts pH at
CELLS/mm (Suspended Solic
507.0
600.0
566.0
63.2
61.2
64.0
157.6
148.8
209.6
60.0
61.6
61.2
228.8
240.0
252.4
39.6
34.0
28.4
425.0
416.0
434.0
42.0
37.2
36.8
501.0
543.0
541.0
50.0
42.8
39.6
361.0
489.0
337.0
44.4
45.2
39.2
8.5
(16.14)
8.5
(3.42)
8.6
(7.94)
8.6
(5.03)
8.3
(11.14)
8.4
(3.19)
8.5
(17. 16)
8.5
(3.09)
8.5
(20.0)
8.6
(2.36)
8.5
(12.39)
8.6
(2.05)
/\
S*t>
Is) Days"1
.648
.689
.648
.0569
.0663
.0813
.302
.230
.432
.0309
.0371
.0663
.423
.446
.541
.119
.0430
.0519
.707
.726
.743
(-)
.0220
(-)
.757
.800
.799
.0662
.0133
.00508
.630
.730
.587
(-)
.0231
163
-------
APPENDIX 12. Continued
Duration of Growth
Date
of
Sample
5/7
5/14
5/21
5/28
6/4
6/11
Cone 1-Day 3- Day
Sample of Counts Counts
Type Sample CELLS /mm3 CELLS /mm
C 100 A
B
C
III 100 A
B
c
C 100 A
B
C
III 100 A
B
C
C 100 A
B
C
in 100 A
B
C
C 100 A
B
C
III 100 A
B
C
C 100 A
B
C
HI 100 A
B
C
C 100 A
B
C
in 100 A
B
c
53.2
55.6
56.4
52.0
57.2
55.6
34.8
34.4
35.2
52.8
52.8
50.4
32.8
32.8
33.2
58.8
56.4
53.6
31.2
31.2
33.6
50.0
52.4
52.4
42.4
42.4
41.2
57.2
53.2
50.4
38.8
37.6
38.0
196.4
217.2
214.0
216.8
238.0
159.2
35.6
33.6
35.2
187.6
188.4
170.4
28.0
23.6
26.0
268.8
252.4
204.8
26.0
21.6
22.0
123.2
120.4
109.2
39.6
35.6
32.8
162.8
139.6
114.0
34.0
33.6
32.8
5- Day Composite
Counts _ pH at
CELLS/mm (Suspended Solic
363.2
398.4
398.8
384.0
426.4
308.8
38.8
28.0
31.6
342.4
370.8
308.4
32.0
29.2
27.6
587.0
543.0
407.0
28.0
24.4
24.0
207.6
192.0
179.2
39.6
32.8
25.2
238.4
216.0
173.6
36.8
34.4
32.4
7.9
(12.92)
8.6
(12.78)
8.7
(2.32)
8.7
(14.00)
8.7
(3.47)
8.7
(18.33)
8.7
(3,38)
8.2
(8.80)
8.6
(2.78)
8.3
(7.73)
8.6
(2.00)
A
/%
Is) Days"^-
.653
.681
.667
.714
.713
.526
.0430
(-)
0
.634
.636
.609
.0668
.106
.0299
.760
.749
.670
.0371
.0609
.0435
.451
.416
.367
.146
(-)
(-)
.523
.482
.408
.0396
.0118
.00155
164
-------
APPENDIX 12. Continued
Duration of Growth
Date
of
Sample
6/18
6/26
7/2
7/9
7/16
7/23
Cone 1-Day 3- Day
Sample of Counts Counts
Type Sample CELLS/mm CELLS/mm
C 100 A
B
C
m 100 A
B
C
C 100 A
B
C
in 100 A
B
C
C 100 A
B
C
in 100 A
B
C
C 100 A
B
C
in 100 A
B
C
C 100 A
B
C
in 100 A
B
C
C 100 A
B
C
in 100 A
B
r
62.4
59.6
58.8
47.6
46.0
45.6
62.8
60.4
60.8
37.2
37.2
38.4
45.6
50.8
38.8
37.6
36.4
53.6
50.8
53.2
37.6
36.4
37.2
55.2
52.4
55.2
37.2
37.2
36.0
55.6
54.8
56.4
-
211.6
260.4
245.2
35.2
44.4
29.2
248.4
244.8
222.0
40.0
31.2
27.2
88.0
87.6
37.6
35.6
36.0
114.8
109.2
113.2
36.8
38.4
32.4
140.0
132.4
126.8
36.0
32.8
32.8
136.4
131.2
145.2
5-Day Composite V"1^
Counts pH at .
CELLS/mm3 (Suspended Solids) Days"
348.0
477.0
435.0
44.8
57.2
34.8
540.0
553.0
493.0
34.0
31.6
28.4
136.8
146.9
44.4
44.0
40.0
209.6
187.6
196.8
45.2
42.0
42.4
237,6
193.2
186.8
38.4
38.8
37.6
218.8
228.8
233.2
8.4
(11.13)
8.6
(3.54)
8.4
(15.66)
8.6
(2.53)
8.4
(20.37)
8.6
(2.26)
8.5
(8.69)
8.6
(1.36)
8.5
(5.49)
8.6
(1.50)
8.6
(8.11)
.611
.737
.714
. 121
.127
.0877
.688
.700
.648
.0363
.00637
.0216
.329
.272
.0831
.113
.381
.383
.378
.103
i0448
.134
.465
.463
.416
.0323
.0840
.0683
.449
.437
.473
— ^^~
—
165
-------
APPENDIX 12. Continued
Duration of Growth
Date
of
Sample
8/6
8/13
8/20
8/27
9/4
9/10
Cone 1-Day 3- Day
Sample of Counts Counts _
Type Sample CELLS/mm CELLS/mm
C 100 A
B
C
HI 100 A
B
C
C 100 A
B
C
ni 100 A
B
C
C 100 A
B
C
in 100 A
B
C
C 100 A
B
C
in 100 A
B
C
C 100 A
B
C
ni 100 A
B
C
C 100 A
B
C
in 100 A
B
C
55.6
52.4
53.6
44.4
42.0
44.0
54.4
50.8
50.8
41.6
38.8
42.0
78.0
78.0
80.4
48.4
57.2
54.8
80.0
84.4
78.4
53.6
50.4
52.4
90.8
84.0
84.0
56.8
54.4
51.2
88.8
82.0
84.4
53.6
51.6
52.4
171.2
157.6
190.4
53.2
46.8
51.2
157.6
139.6
130.4
48.4
38.8
41.6
142.0
142.4
192.0
53.6
54.8
54.8
156.8
157.2
149.2
48.8
46.8
47.2
148.8
167.2
152.0
57.6
52.0
59.6
178.0
141.2
143.6
64.8
62.0
68.4
5- Day Composite /^U
Counts pH at
CELLS/mm3 (Suspended Solids) Days"*
355.2
237.2
291.2
42.4
38.8
38.4
219.6
212.4
197.6
51.2
36.8
42.8
257.6
244.0
333.6
66.0
62.0
60.8
230.4
270.4
256.4
54.4
50.4
47.2
212.8
269.2
226.4
71.2
68.0
67.2
275.6
235.2
259.2
77.6
71.6
174.0
8.6
(9.86)
8.6
(2.84)
8.5
(8.22)
8.6
(2.57)
8.4
(9.09)
8.6
(2.78)
8.4
(6.11)
8.6
(2.00)
8.5
(7.46)
8.7
(2.97)
8.4
(7.86)
8.6
(2. 92)
.562
.551
.634
.0904
.0541
.0758
.532
.505
.471
.0757
0
.0142
.300
.301
.435
.104
.0617
.0519
.336
.311
.322
.0543
.0371
0
.247
.344
.297
.106
.134
.0760
.348
.272
.295
.0949
.0918
.133
166
-------
APPENDIX 12. Continued
Duration of Growth
Date Cone 1-Day 3- Day
of Sample of Counts Counts
Sample Type Sample CELLS/mm CELLS/mm3
9/16
9/24
10/1
10/8
10/15
10/22
C 100 A
B
C
III 100 A
B
C
C 100 A
B
C
III 100 A
B
C
C 100 A
B
C
in 100 A
B
C
C 100 A
B
C
ni 100 A
B
C
C 100 A
B
C
in 100 A
B
C
C 100 A
B
C
III 100 A
B
C
70.0
61.6
66.8
54.8
54.8
54.8
60.4
62.0
61.2
52.0
48.4
52.4
60.4
60.8
62.4
55.2
50.8
54.4
66.0
67.6
66.0
58.8
54.8
54.8
57.6
55.2
57.2
52.8
50.4
50.0
56.8
56.4
56.0
50.8
50.4
51.2
65.2
59.6
65.2
48.8
46.0
46.0
51.6
48.4
48.4
42.4
36.8
33.6
47.6
49.2
56.8
32.8
36.4
24.0
93.2
101.2
99.2
39.2
35.2
33.2
64.0
53.2
60.4
44.4
45.6
45.6
57.6
60.0
59.6
43.2
44.4
42.8
5-Day Composite
Counts pH at
CELLS/mm (Suspended Solit
69.2
68.4
77.6
51.6
49.2
46.4
56.8
53.6
57.2
42.4
36.8
33.2
52.4
53.2
63.2
31.2
37.2
24.0
92.8
103.2
96.8
43.6
36.0
30.8
92.4
72.0
72.4
50.0
47.2
46.0
60.8
61.2
58.8
42.4
41.2
42.6
7.7
(1.74)
8.0
(2.16)
7.9
(1.31)
8.0
(2.06)
7.9
(2. 14)
8.0
(1.61)
7.9
(2.79)
8.0
(1.82)
8.1
(3.59)
8.6
(1.46)
8.2
(1.31)
8.7
(1.86)
A
>*b
Is) Days"1
.0298
.0689
.0871
.0279
.0336
.00433
.0480
.0510
.0835
0
9
(-)
.0480
.0391
.0534
(-)
.0109
0
.173
.202
.204
.0532
.0112
(-)
.184
.151
.0906
.0594
.0172
. 00437
.0270
.0309
.0312
<-)
(-)
(-)
167
-------
APPENDIX 12. Continued
Duration of Growth
Date
of
Sample
10/29
11/6
11/13
11/19
11/26
12/4
Cone
Sample of
Type Sample
C 100 A
B
C
in 100 A
B
C
C 100 A
B
C
in 100 A
B
C
C 100 A
B
C
ni 100 A
B
C
C 100 A
B
C
in 100 A
B
C
C 100 A
B
C
in 100 A
B
C
C 100 A
B
C
in 100 A
B
C
1-Day
Counts
CELLS/mm3
56.4
56.0
59.2
50.0
49.2
52.4
56.4
57.6
54.8
48.4
52.8
47.2
90.0
92.0
93.2
65.6
68.0
68.4
88.0
85.2
90.0
66.0
62.4
62.0
93.6
^^_ ^^^
96.0
66.8
65.6
65.6
128.4
126.0
128.0
No
3- Day
Counts
CELLS/mm3
68.8
70.4
71.2
46.0
47.6
41.6
82.0
79.6
72.8
45.6
43.2
38.8
170.0
175.2
172.8
103.6
96.4
95.6
170.0
157.2
168.4
87.6
70.8
68.4
302.0
— ^^^^_
270.8
94.0
76.8
82.8
659.0
646.0
581.0
Sample
5- Day
Counts
CELLS/mm
108.8
111.6
114.4
72.0
70.0
70.8
130.4
128.4
121.2
72.0
64.0
58.8
230.4
238.8
219.2
124.8
121.6
116.8
244.8
215.2
242.8
84.0
77.2
79.6
660.0
^•^•V^K
555.0
123.6
102.8
110.8
1066.0
1014.0
1005.0
Composite
pH at
(Suspended Solids)
8.4
(2.71)
8.7
(1.86)
8.4
(4.03)
8.7
(1.92)
8.2
(7.51)
8.6
(4. 69)
8.4
(10.31)
8.7
(3.47)
8.5
(15.00)
8.7
(5.25)
9.2
(42. 90)
/"b
Days"1
.299
.230
.237
.224
.193
.266
.232
.239
.255
.228
. 197
.208
.318
.322
.309
.228
.174
.329
.306
.313
.142
.0631
.0758
.586
.519
.171
.146
.146
.818
.817
.756
168
-------
APPENDIX 12. Continued
Duration of Growth
Date Cone 1-Day 3- Day
of Sample of Counts Counts
Sample Type Sample CELLS/mm CELLS/mm3
12/17
12/26
1/8/74
1/14
1/21
1/28
C 100 A
B
C
mi nn A
X \J V **
B
C
C 100 A
B
C
ni 100 A
B
C
C 100 A
C
III 100 A
B
C
C 100 A
B
C
in 100 A
B
C
C 100 A
B
C
III 100 A
B
C
C 100 A
B
C
m 100 A
B
C
70.8
76.8
78.8
46.4
47.6
75.2
80.8
77.6
46.8
46.0
45.6
63.2
66.0
68.0
78.4
82.8
79.6
51.6
51.2
53.2
54.8
59.6
55.6
42.0
42.4
41.2
55.2
61.6
58.4
43.6
44.0
42.8
198.4
272.4
318.0
49.6
46.8
246.8
236.4
238.4
47.6
43.2
44.0
90.0
102.4
100.4
199.6
302.4
350.0
66.0
66.4
70.8
226.4
1 274.8
247.6
50.4
49.2
45.6
218.8
234.8
211.6
47.6
46.0
45.6
5 - Day C ompo site
Counts pH
CELLS/mm (Suspended Solii
384.0
689.0
836.0
45.2
49.2
673.0
571.0
584.0
48.4
42.4
45.6
714.0
383.0
386.0
362.0
753.0
877.0
150.4
129.6
167.6
619.0
722.0
572.0
45.6
39.6
37.6
554.0
449.0
508.0
42.8
37.6
38.0
8.5
(22.30)
87
. i
(3.20)
8.8
(23.6)
8.7
(2.84)
8.8
(35.26)
8.9
(28.97)
8.9
(7.94)
8.8
(20.51)
8.7
(2. 14)
8.7
(17.08)
8.7
(2.65)
.A.
/"-b
is) Days'l
.515
.633
.698
.0333
.0250
.594
.537
.561
. 00847
(-)
.0179
1.04
.660
.673
.467
.648
.740
.412
.334
.431
.709
.764
.747
.0912
.0744
.0507
.689
.669
.644
.0439
.0222
.0317
169
-------
APPENDIX 12. Continued
Duration of Growth
Date
of
Sample
2/4
2/11
2/20
2/25
3/4
3/11
Cone 1-Day 3- Day
Sample of Counts Counts
Type Sample CELLS/mm3 CELLS/mm
C 100 A
B
C
in 100 A
B
C
C 100 A
B
C
in 100 A
B
C
C 100 A
B
C
in 100 A
B
C
C 100 A
B
C
III 100 A
B
C
C 100 A
B
C
in 100 A
B
C
C 100 A
B
C
in 100 A
B
C
51.6
51.2
57.2
46.0
43.6
42.4
68.0
66.0
63.2
44.4
44.0
42.8
61.2
64.0
61.2
35.2
34.8
35.2
62.4
62.4
64.0
46.0
46.0
46.8
65.2
64.0
64.8
35.6
36.0
36.0
60.0
61.2
60.0
37.6
36.4
37.2
175,6
167.2
197.6
46.0
44.8
44.8
305.6
295.2
298.4
42.0
36.8
42.0
146.0
198.8
170.0
36.4
36.0
30.4
174.0
192.0
208.0
57.2
49.2
52.8
214.8
198.8
209.2
32.8
31.6
37.6
121.2
151.6
121.6
32.4
34.0
34.4
5- Day Composite
Counts pH at
CELiLS/mm (Suspended Solic
313.6
271.6
376.8
41.6
47.2
38.4
720.0
668.0
583.0
32.8
34.0
39.6
297.2
440.0
332.0
37.2
32.0
26.8
237.2
366.0
421.6
57.2
44.8
46.0
389.2
372.0
372.8
39.2
30.8
29.6
180.4
216.4
180.4
32.8
30.0
27.6
8.7
(15.49)
8.7
(2.29)
8.6
(23.37)
8.6
(3.97)
8.5
(16.40)
8.7
(1.91)
8.7
(18.70)
8.7
(2.49)
8.7
(19.43)
8.7
(1.73)
8.7
(9.65)
8.7
(3.43)
A
Is) Days'1
.612
.592
.620
0
.0261
.0275
.751
.749
.776
(-)
(-)
(-)
.435
.567
.511
.0168
.0170
(-)
.513
.562
.589
. 109
.0336
.0603
.596
.567
.586
.0891
(-)
.0217
.352
.454
.353
.00614
(-)
170
-------
APPENDIX 12. Continued
• __^
Duration of Growth
Date
of
Sample
3/18
3/25
4/3
4/8
4/15
Cone 1-Day 3- Day
Sample of Counts Counts
Type Sample CELLS/mm3 CELLS/mm3
C 100 A
B
C
HI 100 A
B
C
C 100 A
B
C
in 100 A
B
C
C 100 A
B
C
in 100 A
B
C
C 100 A
B
C
III 100 A
B
C
C 100 A
B
C
III 100 A
B
C
84.0
87.6
84.0
51.2
47.6
47.6
74.4
73.2
78.8
46.0
46.0
46.0
74.8
74.4
74.4
57.2
57.2
57.6
77.6
78.4
76.4
50.0
50.8
52.0
79.6
74.8
72.0
46.0
44.0
43.2
323.2
438.4
405.6
52.0
47.2
47.2
212.8
218.4
217.2
52.0
52.0
45.2
253.2
278.4
260.8
93.6
95.6
87.6
255.2
256.8
269.6
59.2
60.0
74.8
319.6
256.0
240.4
41.2
34.8
32.0
5- Day Composite
Counts pH at
CELLS/mm3 (Suspended Solid
585.0
831.0
773.0
36.4
60.0
38.0
352.8
406.4
383.2
54.8
56.8
54.8
439.0
493.0
441.0
232.4
252.0
238.4
440.0
416.0
510.0
114.0
132.4
155.2
744.0
581.0
520.0
96.0
90.0
93.6
8.7
(26.94)
8.7
(3.43)
8.8
(15.90)
8.8
(2.81)
8.8
(21.78)
8.9
(8.78)
8.8
(21.62)
8.8
(6.31)
8.9
(24. 44)
8.8
(2.69)
A
>^b
.s) Days
.674
.805
.787
.00775
. 120
(-)
.525
.547
.507
.0613
.0613
.0963
.610
.660
.627
.455
.485
.501
.595
.593
.630
.328
.396
.365
.695
.615
.603
.423
171
-------
APPENDIX 13
REPORT BY THOMAS WALSH (E Q A, INC. ) TO
LTAC ON UNDERWATER PHOTOGRAPHY
7/25/73
Photographs were taken at 900 ft and 1100 ft mark on T- 1 transect.
General observations of bottom conditions were made along the entire
transect. There was heavy grass growth up to 150 ft offshore at a
depth of approximately 25 ft. The bottom in the middle of the transect
was made up of silt covered with a fine algal mat. The silt layer was
from 2 to 6 inches deep.
7/26/73
Photographs were taken at 100 ft intervals from shore to 700 feet off-
shore along T-2 transect. Observations were made as to the general
bottom conditions along the transect. There was heavy grass growth
to a depth of 20 to 25 ft off both shores. From a depth of approxi-
mately 25 to 40 ft. The bottom consisted of silt with a fine algal mat.
The silt layer was from 1/2 to 1 1/2 inches in depth. The bottom be-
tween a depth of 50 and 60 feet was made up of a silt layer 11/2 inches
thick. There was no algal mat at this depth.
Photographs were taken at 3 different near shore shallow areas. There
was one designated on the area map on pg. 1, 2, & 3.
7/27/73
Photographs were taken at 100 ft intervals from 700 feet offshore to the
far shore along transect T-2. General bottom observations were tne
same as those made on transect T-2 on 7/26/73.
172
-------
8/7/73
Photographs were taken along the main dam area. Interfaces were ob-
served between silt, algae and grass. Growth of tall grass stopped at
a depth of from 20-25 ft. Algal mat growth was observed to a depth of
from 30 to 40 feet. From the 40 ft depth contain to a depth of 55 feet
there was no algal growth.
Photographs and observations were made of the aeration tubes at a
depth of 40 feet. The aeration tubes were free of silt and in good work-
ing condition.
8/2/73
Photographs were taken at station 3 at a depth of from 30 to 35 ft
Photographs were taken depicting the intervals between tall grass,
algal mat, and silt. The interface between tall grass growth and algal
mat-silt bottom was at a depth of between 20 and 25 feet. The interface
between algal mat- silt bottom and silt bottom was at a depth of between
35 and 40 feet«
173
-------
ENVIRONMENTAL
QUALITY
ANALYSTS
INC.
« DIVISION OF BROWN AND CALDWELL
SAN FRANCISCO ALHAMBRA
APPENDIX 14.
J. T. NORGAARO
T. V. LUTGE
M. L. WHITT
M. N. LIPSCHUETZ
C. P. WALTON
R. D. SMITH
President
Vice-President
Environmental Engineer
Laboratories
Ecologist
Oceanographer
April 27, 1973
Mr. P.H. McGauhey
Lake Tahoe Area Council
6819 Snowden Avenue
El Cerrito, California 9*4-530
BENTHIC SURVEY — INDIAN CEEEK RESERVOIR
Dear Mr. McGauhey:
Enclosed are the results of the Indian Creek Reservoir benthos survey conducted
on October 9, 1972. Nine stations were sampled, including eight stations in
Indian Creek Reservoir and one station on Indian Creek as shown in Figure 1.
The methods used in this survey were essentially the same as in previous studies
except that a Ponar dredge was used rather than an Ekman dredge. The Ponar
dredge is a more efficient sampler even though a smaller area is sampled (five
inches by six inches surface area versus six inches by six inches using the
Ekman dredge).
Five samples were collected with each dredge from Station 1 for comparative
purposes (Table 1). Although the mean number of organisms,expressed on a
square foot basis, was more than twice as high when the Ponar dredge was used,
it was not possible to calculate a conversion factor to equate the results of
the present survey with the results of previous surveys. This was due to the
high variation among replicate samples. We recommend the continued use of the
Ponar dredge because of its increased efficiency, but suggest that comparisons
between Ponar dredge sample data and Ekman dredge sample data be qualitative
rather- than quantitative.
The results of the survey (Table 2) showed that the predominant organisms were
midge larva of the genera Frocladius and Chironomus (Chironomus). At Station 1,
located near the outfall, the diversity of species was lower than at stations
located furthest from the outfall, such as Stations 5 and 6. Ephemeroptera,
for example, were found at the latter stations, but not in the vicinity of the
outfall. Although the diversity was lower, the density of organisms was
greatest near the outfall, which is a biological indication of pollution.
WATER QUALITY INVESTIGATIONS AND MARINE STUDIES BIOLOGICAL AND CHEMICAL LABORATORIES
ENVIRONMENTAL QUALITY ANALYSTS INC. 66 MINT STREET SAN FRANCISCO CA 94103 (415)982-24J42
174
-------
Lake Tahoe Area Council
April 27, 1973
Page 2
Table 3 shows the results of a sample collected by scrubbing rocks at Station 6.
A relatively high population of leeches was found along with midge larvae,
snails, and a few other organisms. This assemblage consists mostly of organisms
which feed on the masses of decaying aquatic plants found in the area.
The sample from Station 9 on Indian Creek consisted primarily of tubificid worms
(Table k). This is indicative of organic pollution.
To summarize, the results of this survey showed that the benthos of Indian Creek
Reservoir was predominately midge larvae. The highest density and lowest
diversity of organisms was found nearest the outfall. The shoreline and
Indian Creek samples both contained organisms characteristic of waters with
decaying organic material. A comparison of samples collected by a Ponar dredge
and a Ekman dredge showed that it was not feasible to compare the results on a
quantitative basis.
We appreciate this opportunity to provide services in the water quality field.
If any questions arise regarding this survey, please do not hesitate to contact
us.
Very truly yours,
ENVIRONMENTAL QUALITY ANALYSTS, INC.
C.P. Walton, Ph.D.
eb
encs
WATER QUALITY INVESTIGATIONS AND MARINE STUDIES / BIOLOGICAL AND CHEMICAL LABORATORIES
ENVIRONMENTAL QUALITY ANALYSTS INC. 66 MINT STREET SAN FRANCISCO CA 94103 (415)982-2442
175
-------
APPENDIX 14 (continued).
Table 1*. Sample from Indian Creek
Station 9
Organisms Identified Computed
Number Number Number Number
Organism. Per 0.5$ Per 5.O/& Per Entire Per Entire
Aliquot Aliquot Sample Sample
Oligochaeta
Tubificidae 1»37 — ~ 87^00
Hirudinea
Gloss iphonildae
Helobdella ? 1 1
Hirudidae — 2 2
Amphipoda
Hyalellidae
Hyalellfl azteca — — ^6 *46
Hydraoarina -- 2 2
Ephemeroptera
Baetidee
Baetis sp. — 6 -- 120
Zygoptera
Coenagrionidae
Anphiagrion sp. ~ — 2 2
Argia sp. — — 20 20
Hemiptera
Gerridae
Gerris sp. — — 3 3
Trichoptera
Hydropsycnidae
Hydropsyche sp. — 155 — 3100
Coleoptera
Dytiscidae
Agabus sp. — — 5 5
Coptotomus sp. — — 30 30
Laccodytes Ep. — — 23 23
Diptera
Simuliidae — 1>* — 280
Chironomidae
Tanypodinae
Procladius sp. — 1 ~ 20
Orthocladiinae
Cardiocladius sp. -- U ~ 80
Corynoneura sp. — 10 — 200
Cricotopus sp". — 137 -- 27UO
Manoeladi-us sp. — l6 — 320
Trichocladrus sp. — 1 — 20
Chironominae
Micropsectra sp. — 18 — 360
Unidentified pupae — 12 — 2UO
Tabanidae
Tabanus sp. -- — 1 1
Muscidae
Llmnophora sp. — — 3 3
Unidentified pupae — — 1 1
Ga stropoda
Physidae
Physa sp. — — 5 5
Planorbiidae
Gyraulus parvus — — 1 1
Planorbella suberer.atur. — — 2 2
Total Organisms 1*37 3?U lU? 95027
176
-------
APPENDIX 14 (continued).
Table 2. Samples Collected by Ponar Dredge (Continued)
Station 7
Sample
Organism a
Cladocera
Sphippia* 1000
Hirudinea
Glossiphoniidae
Helobdella 2 U
Hydracarina 2
Zygopfcera
Coena grionida e
Ischnura sp. 6
Diptera
Chironomindae
Tanypodinae
Procladius sp. 5
Orthocladiinae
Metriocnemus sp. 5
Chironominae
Paralauterborniella sp. 1
Tanytarsus sp. 1
Gastropoda
PLanorbidae
Gyraulus parvus 8
Total Organisms 32
Volume (liters) 0.6
Organisms Per Square Foot 150
Table 3. Sample Collected frog Rocks
Station 8
Sample
a
Hirudinea
Glossiphoniidae
Helobdella ? 229
Amphlpoda
Hyalellidae
Hyalella azteca 56
Zygoptera
Coenagrionidae
Ischnura sp. 1
Coleopters
Elmidae
Optioservus sp. 1
Diptera
Chironomidae
Orthocladiina e
Corynon^ura sp. 2
Cricotopus sp. 202
Metriocneir.us sp. 2
Cbironominae
Paralauterborniella sp. ^0
Gastropoda
Pnysidae
Physa sp. 3
Lycnaeidae
Radix aurieularia 11
Planorbidae
Gyraulus parvus 63
Planorbella su'oerenatun 1
Total Organisms
^Estimated number, not included in sample totals.
177
611
-------
APPENDIX 14 (continued).
Table 2. Samples Collected by Ponar Dredge (Continued)
Station 6
Sample
Cladocera
Ephippia* 2000
Coelenterata
Hydrozoo
Hydra sp. U
Ollgochaeta
Tubificidae 1
Hirudlnea
Glosaiphoniidse
Helobdella 7 1
Ephemeroptera
Baetidae
Callibaetis sp. k
Zygqptera
Coenagrionidae
Ischnura sp. 1
Diptera
Chlronomida
Tacypodicae
Proeladius sp. 1.8
Orthocladiinue
Corynoneura sp. 5
Crleotopus sp. 1
KetrioeneEus sp. 17
Chironominae
Baralauterborniella sp. 3
Unidentified pupae 3
Gastropoda
Fbysidae
Hiysa sp. 1
Lymnaeidae
Radix auricularia k
Hianorbidse
Gyraillns parvus 232
Total Organisms 29?
Volume (liters) 0,5
Organisms Per Square Foot lUOO
Estimated number, not included in sample totals.
178
-------
APPENDIX 14 (continued).
Table 2. Samples Collected by Ponar Dredge (Continued)
Station 5_
Organism
Cladocera
Ephippia*
Hirudinea
Glossiphoniidae
Helobdella ?
Amphipoda
Hyalell'.dae
Hyalella azteca
Hydracarina
Ephemeroptera
Baetidae
Callibaetis sp.
Diptera
Chironomidae
Tanypodinae
Pentaneurini
Procladius sp.
Cbironominae
Chironomus
(Chironomus ) sp.
Tanytarsus sp.
Unidentified pupae
Gastropoda
Planorbidae
Gyraulus parvus
Total Organisms
Volume (liters)
Organisms Per Square Foot
a
3000
—
6
2
2
__
23
1
15
—
1
50
0.7
240
b
3000
1
8
1
5
1
10
27
2
—
—
55
0.5
260
Sample
c
2000
--
1
1
15
4
137
8
31
1
1
199
0.9
960
Total
8000
1
15
U
22
5
170
36
1»8
1
2
3CA
a.i
li(6o
Mean
2700
0.3
5.0
1.3
7.3
1.7
56.7
12.0
16.0
0.3
0.7
101.3
0.7
^90
Estimated number, not included in sample totals.
179
-------
APPENDIX 14 (continued).
Table 2. Samples Collected by Ponar Dredge (Continued)
Station 3
Organ! SB
Cladocera
Ephippia*
Coelenterata
Hydrozoa
Hydra sp.
Hlrudinea
Glos s iphoniidae
Helobdella ?
Amphipoda
Hyalellidae
Hyalella azteca
Hydra oarina
Diptera
Chironomidae
Tanypodinae
Prooladlus sp.
Ctironominae
Chironomus
(Chironosus ) sp .
Tanytarsus sp.
Unidentified pupae
Gastropoda
Planorbidae
Gyraulus parvus
Planorbella subcrenatum
Total Organisms
Volume (liters)
Organisms Per Square Foot
a
5000
8
—
—
103
69
—
5
1
1
«
187
0.9
900
b
3000
52
--
2
35
50
9
9
~
—
1
158
0.5
760
Sample
c
Uooo
37
2
2
121
53
2
1
—
—
—
219
0.5
1100
Total
12000
97
2
1»
259
172
11
15
1
1
1
561*
1.9
2760
Mean
Uooo
32.2
0.7
1.3
86.3
57:3
3.6
5.0
0.3
0.3
0.3
188.0
0.6
920
Station U
Organism
Cladocera
Ephippia*
Coelenterata
Hydrozoa
Hydra sp.
Hydra carins
Diptera
Chironomidae
Tanypodinae
Procladius sp.
Chironominae
Chironomus
(Chirononus) sp .
Tanytarsu? sp.
Unidentified pupae
Gastropoda
Flanorbidae
Gyraulus parvus
i
Total Organisms
Volume (liters)
Organisms Per Square Foot
a
2000
15
140
97
ll*
17
3
1
187
0.7
900
b
1*000
23
5
105
1*1
7
—
—
181
0.9
870
Sample
c
2000
«
20
7U
121
1
—
2
218
0.9
1000
Total
8000
38
65
276
176
25
3
3
586
2.5
2770
Mean
2700
12.7
21.7
92.0
58.7
8.3
1.0
1.0
195.3
0.8
920
Estimated number, not included in sample totals.
180
-------
APPENDIX 14 (continued).
Table 2. Samples Collected by Ponar Dredge
Station 1
Sample
Organism
Cladocera
Ephippia*
Hydracarina
Dipt«ra
Chironcmidae
Tanypodinae
Proeladius sp.
Chironcminae
Chironomus (Chironomus) sp.
Polypedilum sp.
Gastropoda
Planorbidae
Gyraulus parvus
Total Organisms
Volume (liters)
Organisms Per Square Foot
Organism
Cladocera
Ephippia*
Coelenterata
Hydrozoa
Hydra sp.
Hirudines
Glossiphoniidae
Helobdella ?
Aqhipoda
Hyalellidae
Hyalella azteca
Hydracarina
Diptere
Chlronomidae
Tanypodinae
Frocladius sp.
Chironominae
Chironomus (Chironomus} sp.
Chironomus
( Cryptoch ironomus ) sp.
Tanytarsus sp.
Total Organisms
Volume (liters)
Organisms Per Square Foot
a
5000
1*3
26
91
—
1
161
1.6
770
a
2000
10
—
6
--
12
1
1
11
1*1
0.7
200
b
20000
80
19
80
—
1
180
1.6
860
Station 2
11
2000
32
2
3
97
33
~
—
8
175
0.7
8UO
c
5000
6
20
1*9
~
2
77
0.5
370
Sample
c
2000
5
1
2
U8
26
1
—
9
92
0.7
UUO
d
8000
6
ll*
92
1
1
11U
0.7
550
Total
6000
1*7
3
11
lit 5
71
2
1
28
308
2.1
lit 80
e
5000
8
12
93
—
113
0.7
5UO
Mean
2OOO
15:7
1.0
3-6
1*8.3
23-7
0.7
0.3
9-3
102.7
0.7
Total Mean
1*3000 8600
1U3 28.6
91 18.2
U05 81.0
1 0.2
5 1.0
61*5 129-0
5.1 1.0
3090 620
Estimated number, not included in sample totals.
181
-------
APPENDIX 14 (continued).
BEHTHIC ORGANISM SURVEY,. IIIPIAH CHEFK RESERVOIR.
October 9, 1972
Table 1. Comparison of Samples Collected by Ponar and Ekman Dredse
Samples
Collected by
the Ponar
Dredge
Sample
Organism
Cladocera
Ephippia*
Hydra carina
Diptera
Chironomidae
Tanypodinae
Frocladius sp.
Chironominae
Chironomus (Chironomus ) sp.
Polypedilum sp.
Gastropoda
PLanorbidae
Gyraulus parvus
Total Organisms
Volume (liters)
Organisms Per Square Foot
a
5000
1*3
26
91
1
161
1.6
770
Samples
b
20000
80
19
80
__
1
180
1.6
860
0
5000
6
20
1*9
2
77
0.5
370
Collected by
d
8000
6
l!+
92
1
1
111*
0.7
550
the Eknan :
e
5000
8
12
93
—
113
0.7
D
Total
1*3000
11*3
91
1*05
1
5
6U5
5.1
3090
Mean
8600
29.6
18.2
81.0
0.2
1.0
129.0
1.0
620
Percent
__
22.9
lU.l
62.8
0.2
0.8
100.8
— —
Sample
Organism
Cladocera
Ephippia*
Coelenterata
Hydrozoa
Hydra sp.
Hirudinea
Gloss iphoniidae
Helobdella ?
Hydra carina
Diptera
ChrLr onomida e
Tanypodinae
Procladius sp.
Chironominae
Chironomus (Chironomus ) sp.
Polypedilum sp.
Total Organisms
Volume (liters)
Organisms Per Square Foot
a
2000
—
1
—
it
31
—
36
0.5
ll*0
b
5000
6
--
12
17
76
—
Ill
0.5
1*1*0
0
2000
7
_.
2
17
29
—
55
0.5
220
d
1*000
1*
—
3
26
78
1
112
0.7
1*50
e
2000
1*
—
—
11*
26
1
1*5
0.7
180
Total
15000
21
1
17
78
2UO
2
359
2-9
1430
Mean
3000
1*.2
0.2
3. >»
15.6
1*8.0
O.U
71.8
0.6
290
Percent
—
5.8
0.3
21.7
66.9
0.6
100.0
—
Estimated number, not included in sample totals.
182
-------
APPENDIX 14 (continued)
STPUD Pipeline
Spillway
-«.V^-.:j-!-'.*- -..• ';"•• . ,
'' ""' • "
Fig. |. Location of Sampling Stations at
Indian Creek Reservoir
183
-------
State of California The Resources Agency
Memorandum APPENDIX is
To : Mr. John D. Archambault Dcrte. March 1, 1973
Lake Tahoe Area Council
Box 575
Tahoe City, Calif.
From : Department of Fish and Game Water Pollution Control Laboratory
Subject: Progress Report on Indian Creek Reservoir — Field Survey
Attached for your information is a laboratory progress
report on a field survey conducted at Indian Creek Reservoir
in March 1972. Further work is planned in the near future,
followed by a more detailed report.
If you have any questions concerning this report, feel
free to contact the Water Pollution Control Laboratory.
Fredric Kopperdahl
Associate Water Quality Biologist
Attachment
184
-------
INDIAN CREEK RESERVOIR -- FIELD SURVEY
During March., 1972, a large dieoff of rainbow trout occurred in Indian
Creek Reservoir, Alpine County. This loss was discovered and moni-
tored closely by the Department of Fish and Games' regional biologist
and personnel from the Nimbus Water Pollution Control Laboratory
(WPCL). Physical and chemical data of the lake water collected dur-
ing the dieoff period indicated that high ammonia levels coupled with
high pH was the probable cause of the fish mortalities. In conjunction
with water chemistry studies, live car and laboratory tests were con-
ducted.
Physical and Chemical Evaluations Vertical profiles of hydrogen ion
concentration (pH), dissolved oxygen (D. O. ) and temperature were re-
corded from five stations covering the period from 0645 in the morn-
ing until 1800 hours in the evening (Table 1, Figure 1). Ammonia
samples were taken on the surface at station 1 and preserved with sul-
furic acid for later analyses at the laboratory.
Live Car Studies Live cars, containing five rainbow trout each, were
placed in the Reservoir at stations 1 & 2. Fish were held at mid-depth,
three feet from the bottom and three feet from the surface. Eighty per-
cent mortality occurred after two days of exposure at all three depths
with 100% mortality occurring within three days.
Laboratory Tests
Ten gallons of lake water was collected from the surface at station 1
and packed in ice for transport to the laboratory. Bioassays, using
rainbow trout, at varying dilutions of lake water and adjusted pH levels
were conducted at the laboratory at temperatures of 15 and 18°
centigrade (°C).
185
-------
TABLE 1
Physical-Chemical Data, Indian Creek Reservoir
(06L,5-l800 March 16, 1972)
Time 06:
Air Temp.
Station
1
2
3
Time 13 :
Air Temp.
1
3
5
2
Time 17 :
Air Temp.
2
5
3
4
i
^ 0
Time
0648
0645
0713
0710
0730 .
0725
00 o
16 C
1303
1300
1315
1310
1345
1340
1430
n.5°o
1720
1715
1725
1738
1735
1745
1800
1755
Sunrise 0600
Clear-Strong Breeze
Death (ft) pH D.O. (mg/1)
Surface
40
Surface
16
Surface
8
Clear and Calm
Surface
40
Surface
8
Surface
22
Surface
8.7 >15
8.6 > 15
8.7 >15
8.7 >15
8.6 >i5
8.6 14.9
9.0 >15
8.9 M5
9.0 >15
9.1 >15
9.2 >15
9.0 >15
9.2 >15
Tenro.°C
Q'.O
8.5
8.5
8.0
8.5
11.0
10.0
12.0
11.0
12.0
11.0
11.0
NHifmg/1)
7.1
7-3
Sunset 1720
Clear-Slight Breeze
Surface
16
Surface
Surface
10
Surface
Surface
40
9.4 >15
9.3 >15
9.4 >i5
9-4 >i5
9.3 >i5
9.2 >l5
9.2 >15
9.1 >15
11.0
9.5
ii.5
14.0
12.0
10.5
9.0
9.0
7.3
186
-------
Main Dam
Saddle Dam
Figure 1. Location of Sampling Stations at Indian Creek Reservoir
187
-------
Results and Conclusions
Little variation was noted in the vertical and horizontal distribution of
the various constituents tested, indicating the reservoir was well mixed.
However, a significant change was noted in the pH with time. The pH
increased from a' low of 8. 6 in the morning to approximately 9. 0 at noon
to 9.4 in the late afternoon. Fish mortalities appeared to coincide with
the increased pH level. Few fish were observed in stress or dead
throughout most of the day; however, during the last sampling period,
1700 to 1800 hours, a large number of fish were observed swimming
close to the surface in tight circles. Dead fish were also noted floating
near the shore line.
This phenomenon! was duplicated under laboratory conditions. In bio-
assay tests of lake water, no mortalities occurred when ammonia levels
were between 7 and 8 mg/1 at a pH of 8. 6. When pH levels were in-
creased above 9.0, signs of stress and eventual death resulted.
Temperatures may also be a factor that should be considered. In
studies conducted at the laboratory using a reservoir water at 15 C
and 6-8 mg/1 ammonia, the critical pH level would be between 9. 0
and 9.1. However, the critical pH level dropped to between 8.6 and
8.8 at 18 C and 3-5 mg/1 ammonia.
188
-------
SELECTED WATER
RESOURCES ABSTRACTS
INPUT TRANSACTION FORM
W
4. Title
EUTROPHICATION OF SURFACE WATERS - INDIAN CREEK
RESERVOIR
P.H. McGauhey, D.B. Porcella, and G. L. Dugan
Lake Tahoe Area Council, South Lake Tahoe, Calif.
EPA,
WQO Grant Nos. 16010
DNY, 16010 DSW
12. -.por.ior.oj; Crew:.:/;Lio;,
16. AbvLjc From April 1969 to October 1974 field and laboratory analyses and observa-
tions were made at approximately weekly intervals to evaluate the relationship between
the quality of water impounded at Indian Creek Reservoir (ICR) and the reclaimed water
exported by the South Tahoe Public Utility District. The reclaimed water comprised
from 70 to 80 per cent of the annual impoundment. On the average the reclaimed water
contained 0. 1 to 0. 2 mg/i of phosphorus and 15-24 mg/£ of ammonia, the latter making
it toxic to fish implanted in ICR. However, as the reservoir matured, nitrification-de-
nitrification removed most of the nitrogen from the system and by March 1970 the reser-
voir had become an excellent trout fishery. Excess N in comparison with P evidently
precluded blooms of blue green algae but low phosphorus did not prevent the impound-
ment from becoming typical of a highly productive environment, with vascular plants
invading to considerable depths because of the high degree of clarity of the reclaimed
water. By 1974 the biosystem was at an approximately steady state. This state may not
remain because of the appearance of epiphytic blue green algae which caused taste and
odor problems in the water and in the fish. It is concluded that the reservoir responds
to more complex factors than are measurable by analysis of reclaimed water. The re-
sults show why a system of wastewater reclamation must be designed on the basis of the
natural ao well ao the man-controlled components of the system, and points the way to
the necessary parameters and institutional concepts if water is to be reclaimed for a
specific purpose.
*Eutrophication, *Nitrification, *Denitrification, *Reclaimed Wastes, *Aquatic Pro-
ductivity, *Density, #Bioassay, *Limnology, *Cycling Nutrients, *Benthos, Aquatic
Microorganisms, Algae, Vascular Plants, Fish Population, Tertiary Treatment, Nu-
trients, Nutrient budget, Biomass
*Indian Creek Reservoir, *Sewage Export, *South Tahoe Public Utility District,
Lake Tahoe Area Council, EPA Demonstration Grant Lake Tahoe
05C
Send To:
WATER RESOURCES SCIENTIFIC INFORMATION CENTER
U.S. DEPARTMENT OF THE INTERIOR
WASHINGTON. D.C. 2024O
P.H. McGauhev
Berkeley
* U.S. GOVERNMENT PRINTING OFFICE: 1975-698-025I9B REGION 10
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