xvEPA
United States
Environmental Protection
Agency
Robert S. Kerr Environmental Research
Laboratory
Ada OK 74820
EPA-6 00/2-78-131a
June 1978
Research and Development
Sewage Disposal on
Agricultural Soils:
Chemical and
Microbiological
Implications
(Volume I
Chemical Implications)
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
7. Interagency Energy-Environment Research and Development
8. "Special" Reports
9. Miscellaneous Reports
This report has been assigned to the ENVIRONMENTAL PROTECTION TECH-
NOLOGY series. This series describes research performed to develop and dem-
onstrate instrumentation, equipment, and methodology to repair or prevent en-
vironmental degradation from point and non-point sources of pollution. This work
provides the new or improved technology required for the control and treatment
of pollution sources to meet environmental quality standards.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/2-78-131a
June 1978
SEWAGE DISPOSAL ON AGRICULTURAL SOILS:
CHEMICAL AND MICROBIOLOGICAL IMPLICATIONS
VOLUME I
CHEMICAL IMPLICATIONS
by
L. R. Hossner, Chun-Wei Kao, R. W. Weaver, and J. A. Waggoner
Soil and Crop Sciences Department
Texas A&M University
College Station, Texas 77843
Grant No. R803281
Project Officer
Lowell E. Leach
Wastewater Management Branch
Robert S. Kerr Environmental Research Laboratory
Ada, Oklahoma 74820
ROBERT S. KERR ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
ADA, OKLAHOMA 74820
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DISCLAIMER
This report has been reviewed by the Robert S. Kerr Environmental Research
Laboratory, U.S. Environmental Protection Agency, and approved for publication.
Approval does not signify that the contents necessarily reflect the views and policies
of the U.S. Environmental Protection Agency, nor does mention of trade names
or commercial products constitute endorsement or recommendation for use.
ii
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FOREWORD
The Environmental Protection Agency was established to coordinate administra-
tion of the major Federal programs designed to protect the quality of our environ-
ment.
An important part of the agency's effort involves the search for information
about environmental problems, management techniques, and new technologies
through which optimum use of the nation's land and water resources can be
assured and the threat pollution poses to the welfare of the American people can
be minimized.
EPA's Office of Research and Development conducts this search through a
nationwide network of research facilities.
As one of these facilities, the Robert S. Kerr Environmental Research
Laboratory is responsible for the management of programs to: (a) investigate
the nature, transport, fate and management of pollutants in groundwater; (b)
develop and demonstrate methods for treating wastewaters with soil and other
natural systems; (c) develop and demonstrate pollution control technologies for
irrigation return flows; (d) develop and demonstrate pollution control technologies
to prevent, control or abate pollution from the petroleum refining and petrochemical '
industries; and.(f) develop and demonstrate technologies to manage pollution re-
sulting from combinations of industrial wastewaters or industrial/municipal waste-
waters .
This report contributes to the knowledge essential if the EPA is to meet the
requirements of environmental laws that it establish and enforce pollution
control standards which are reasonable, cost effective and provide adequate
protection for the American public.
*i
ft
William C. Galegar
Director
Robert S. Kerr Environmental Research Laboratory
ill
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ABSTRACT
The city of San Angelo, Texas has used sewage effluent, which has
undergone primary treatment, for irrigation of the same agricultural land
since 1958. The impact of 18 years of sewage effluent irrigation on the
soil and water quality of the 259 hectare sewage farm was studied from 1975
to 1977. The volume of sewage arriving at the sewage treatment plant ranged
from 0.219 to 0.351 nrVsec. In 1976, sewage effluent contributed from 3.4
to 31.2 percent of the total flow of the Concho River, which borders the
sewage farm.
The fate of applied nitrogen, phosphorus, and selected heavy metals in
the so11-water-plant ecosystem was examined. Nitrogen and phosphorus were
being applied to the farm in large amounts. The average concentrations of
nitrogen and phosphorus in lagoon No. 4 effluent were 22.2 yg N/ml and
9.83 yg p/ml, respectively. The concentration of Zn, Cu, Ni, Cd, Cr and
Pb in the incoming sewage effluent was low.
f
There was evidence of some NO--N accumulation in the soil profiles and
in the Concho River. No accumulation of NH.-N was found in the soil
profiles. Some organic nitrogen accumulated at the surface of the soil.
After 18 years of continuous irrigation with sewage wastewater there was
a net loss of total nitrogen in the soil profile. Phosphorus accumulated in
the soil profile. It is apparent that most of the phosphorus was retained
in the upper 200 cm of soil. Significant increases in water soluble
phosphorus in the upper 200 cm of soil indicates a buildup of soluble forms
to that depth. There was a slight accumulation of certain heavy metals in
the surface of the soils. Generally, heavy metal contamination is not a
serious problem on the sewage farm.
Water from deep wells located on the sewage farm had a nutrient com-
position similar to wells located in the surrounding area of Tom Green
County. The results indicate that land disposal of municipal sewage efflu-
ent combined with a forage and cattle production system can be considered a
practical long-term treatment scheme.
This report was submitted in fulfillment of Grant No. R803281 by
Texas A&M University under the sponsorship of the U.S. Environmental
Protection Agency. This report covers the period April 28, 1975, to
June 27, 1977, and work was completed as of June 27, 1977.
xv
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CONTENTS
Foreword ill
Abstract iv
List of Figures vii
List of Tables ix
Acknowledgments
Sections
1. Introduction 1
2. Summary and Conclusions 3
3. Recommendations 5
4. General Project Characteristics 6
Topography 6
Geology 8
Groundwater 8
City Population and Industrial Input 10
Wastewater Characteristics 10
Vegetation on Farm 11
Animal Population and Crop Production 13
5. Methods and Materials 16
Hydrology and Meteorology 16
Water Analysis 16
Water Sampling Locations 16
Chemical Analysis 20
Soil Analysis 20
Field Plot Experiment and Plant Analysis 20
Statistical Analysis 23
6. Results and Discussion 24
Hydrology and Meteorology 24
Meteorology 24
Hydrology 24
Water Analysis 30
Temperature 33
pH 33
Nitrogen 33
Phosphorus 61
Heavy Metals 63
BOD and COD 65
TFR and TNFR 65
Statistical Relationships between Water Parameters 66
Plant Analysis and Field Plot Experiment 70
* (continued)
v
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Soil Analysis
Introduction 74
Initial Characterization of Physical and
Chemical Properties „ 76
Texture 76
Soil pH 76
Organic Matter 78
Carbonate 78
Cation Exchange Capacity 78
Soil Salinity 80
Statistical Relationships between
Surface Soil Properties 80
1 N HC1 Extractable Heavy Metals 80
Nutrient Loading of Soil Profiles 82
Total Nitrogen 86
Exchangeable Inorganic Nitrogen 86
Total Phosphorus 97
Water Soluble Phosphorus 98
Total Heavy Metals 101
Cadmium 102
Chromium 102
Copper 105
Lead 105
Nickel 107
Zinc 107
7. References 112
vi
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FIGURES
Number Page
/
1 General topography and location of study site at
San Angelo , Texas .................................... 7
2 Cross section of the geologic strata of Tom Green
County , Texas ........ . ...............................
3 Cross sections of three different types of levees
present on the San Angelo sewage farm ................ 12
4 San Angelo sewage farm with blow up on Coastal
bermudagrass fenced plot area ........................ 17
5 Average monthly precipitation for the years 1936-1975
and monthly precipitation in 1976 at the San Angelo
sewage farm, Tom Green County, Texas ................. 25
6 Daily mean temperatures of air and soil at 10 cm and 40
cm depths at the San Angelo sewage farm in 1976 ......... 26
7 Water flow rates of three seepage creeks monitored
on the San Angelo sewage farm ........................ 27
8 Well water sampling locations in Tom Green County, Texas 31
9 Surface and well water sampling locations at the
San Angelo sewage farm and Concho River .............. 32
10 Sampling locations for soil cores taken from the sewage
farm and for soil cores taken from the control area
outside the sewage farm (A = Angelo, M = Mereta,
R = Rioconcho) .................................. ..... 84
11 The effect of sewage effluent irrigation on total
nitrogen content of the top 200 cm of soil from
the sewage farm compared to the control area ......... 87
12 The effect of sewage effluent irrigation on exchangeable
soil ammonium nitrogen content of the top 200 cm
of soil from the sewage farm compared to the control
area ... .............................................. 94
(continued)
vii
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Number Pagj
13 The effect of sewage effluent irrigation on exchangeable
soil nitrate nitrogen content of the top 200 cm of
soil from the sewage farm compared to the control
area 95
14 The effect of sewage effluent irrigation on exchangeable
nitrite nitrogen content of the top 200 cm of soil
from the sewage farm compared to the control area ... 96
15 The effect of sewage effluent irrigation on total soil
phosphorus content of the top 200 cm of soil from
the sewage farm compared to control area 99
16 The effect of sewage effluent irrigation on water-soluble
soil phosphorus content of 200 cm of soil taken from
the sewage farm compared to the control area 100
17 The effect of sewage effluent irrigation on total soil
cadmium content of 200 cm of soil taken from the
sewage farm compared to the control area 103
18 The effect of sewage effluent irrigation on total soil
chromium content of 200 cm of soil taken from the
sewage farm compared to the control area 104
19 The effect of sewage effluent irrigation on total soil
copper content of the top 200 cm of soil taken from
the sewage farm compared to the control area 106
20 - The effect of sewage effluent irrigation on total soil
lead content of the top 200 cm of soil taken from the
sewage farm comparted to the control area 108
21 The effect of sewage effluent irrigation on total soil
nickel content of the top 200 cm of soil taken from
the sewage farm compared to the control area 109
22 The effect of sewage effluent irrigation on total soil
zinc content of the top 200 cm of soil taken from
the sewage farm compared to the control area Ill
viii
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TABLES
Number Page
1 San Angelo city Population increase with time 10
2 Cattle present on the San Angelo city sewage farm in 1975 .. 14
3 Cattle present on the San Angelo city sewage farm in 1976 .. 14
4 Gross income of San Angelo city sewage farm 15
5 Water sampling locations on the San Angelo sewage
farm and Concho River 18
6 Location and depth of water sampling sites outside
sewage farm 19
7 Methods used for chemical analysis of waters 21
8 Equipment and methods used in soil analysis 22
9 Water flow rates of Concho River upstream and downstream
from the sewage farm in 1976 28
10 Average water flow rates of the Concho River upstream
and downstream from the sewage farm and of three
seepage creeks at the sewage farm for 1976 29
11 Chemical anlaysis of raw sewage from Feburary 18, 1976,
to November 11, 1976, collected from the sewage
farm treatment plant 34
12 Chemical analysis of water samples from November 18, 1975,
to November 11, 1976, taken from lagoon no. 1 located on
the San Angelo sewage farm 35
13 Chemical analysis of water samples from November 18, 1975,
to November 11, 1976, taken from lagoon no. 4 located on
on the San Angelo sewage farm 36
14 Chemical analysis of water samples from November 18, 1975»
to November 11, 1976, taken from seepage creek no. 1 on
the San Angelo sewage farm 37
(continued)
ix
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Number Page
15 Chemical analysis of water samples from November 18, 1975,
to November 11, 1976, taken from seepage creek no. 2
located on the Concho River adjacent to the San Angelo
sewage farm 38
16 Chemical analysis of water samples from November 18, 1975,
to November 11, 1976, taken from seepage creek no. 3
located on private land on the Concho River adjacent
to the San Angelo sewage farm 39
17 Chemical analysis of water samples from November 18, 1975}
to November 11, 1976, taken from Concho River sampling
site no. 1 located upstream from the San Angelo
sewage farm 40
18 Chemical analysis of water samples from November 18, 1975,
to November 11, 1976, taken from Concho River sampling
site no. 2 located downstream from the San Angelo
sewage farm ; 41
19 Chemical analysis of water samples from domestic deep
wells and shallow ground wells at the sewage farm 42
20 Chemical analysis of water samples taken from Tom Green
County deep wells 55
21 Average COB, BOD, TFR, and TNFR analysis of water
samples from the Concho River, sewage farm lagoons,
seeps and wells , and Tom Green County wells 59
22 Recommended surface and irrigation water quality
criteria for heavy metals 64
23 Correlation coefficients and significant probability
level of daily air and soil temperatures vs.
concentrations of three seepage creek waters 67
24 Correlation coefficients of temperature and nutrient
concentrations vs. nutrient concentrations of waters
in the sewage farm 69
25 Nutrient composition and yield for single cuttings of
NK37 bermudagrass, forage sorghum, rescuegrass and
Coastal bermudagrass at the San Angelo sewage farm ~j\
26 Yield and nutrient composition of Coastal bermudagrass as
influenced by N and P fertilization 73
(continued)
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Number Page
27 Statistical analysis showing the effect of N and P
fertilization on plant composition and yields of
Coastal bermudagrass grown in the sewage farm 75
28 Chemical and physical properties of the top 40 cm
of three soil series from the San Angelo sewage farm ... 77
29 Statistical analysis of surface soil chemical
characteristics by F test 79
30 Average concentrations of IN HC1 extractable Cd, Cr,
Cu, Pb, Ni, and Zn in three soil series from the
San Angelo sewage farm and the control area 81
31 Partial correlation coefficients and significant
probability level of chemical characteristics of
surface soils (0- 20 cm) in the sewage farm and
the control area 83
32 Distribution of bulk density with depth in three soil
series from the San Angelo sewage farm and the
control area 85
33 Statistical relationships between soil nutrients as
related to soil series, treatment, core and depth
as determined by F test 88
34 Distribution of nutrients with depth in Rioconcho soil
cores taken from the sewage farm and from an adjacent
control area 89
35 Distribution of nutrients with depth in Angelo soil cores
taken from the sewage farm and from an adjacent control
area 90
36 Distribution of nutrients with depth in Mereta soil cores
taken from the sewage farm and from an adjacent
control area 91
37 Total nutrient contents of the top 20 cm of soil taken from
the San Angelo sewage farm and their relative change
after 18 years of irrigation with sewage effluent
compared to an adjacent control area 92
i.
xi
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ACKNOWLEDGMENTS
The full cooperation of the Environmental Protection Agency was
received throughout the study period. Field installations and work plans
were thoroughly reviewed by EPA personnel and procedures for chemical
analyses of water, plants , and soil were periodically reviewed to insure
that the methods and quality control would fulfill the requirements of EPA.
Preparation of the report received full guidance and support of the EPA
office at Ada, Oklahoma. Seventy-six percent of the funding for the
research study was provided by EPA. The remainder was provided by the
Texas Agricultural Experiment Station.
This report would not have been possible without the complete support
and cooperation of the city of San Angelo, Texas. Free access to the farm
and assistance from surrounding landowners was obtained through the city
offices. We wish to express our appreciation to Mr. Harry Behrend, farm
manager, and to Mr. Bob Pryor, San Angelo Municipal Sewage Division, for
their continued assistance and counsel during the study. Mr. Clarence
Wiedenfeld, soil Scientist with the Soil Conservation Service, assisted in
classification and identification of major soil series on the farm.
The cooperation of those landowners in Tom Green County who allowed
us to periodically sample their domestic wells is appreciated.
xii
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SECTION 1
INTRODUCTION
Man and his environment must be protected from pollution caused by his
products and wastes. Disposal of human waste has been one of the most
interesting and persistent problems since the beginning of civilization.
Recently, the practice of land disposal has received much attention as a
modern technique for advanced wastewater treatment. Public Law 92-500
enacted on October 18, 1972, requires increased treatment of municipal
wastewater to reduce water pollution. By 1977 all publicly owned wastewater
treatment plants are required to meet the secondary treatment effluent
standard.
/
The city of San An£p.lo, Texas, has been using the same agricultural
land for disposal of municipal wastewater since 1958. A primary treatment
involving settling and screening of solids has been used before application
of the sewage wastewater to a 259 hectare farm. The wastewater has never
been chlorinated or intentionally disinfected. Much of the applied waste-
water reaches the Concho River, which borders the sewage farm, by underground
seepage. Direct surface runoff of sewage wastewater from the farm does not
occur because the land has been terraced and borders built to retain the
wastewater. The soils on the farm are rather shallow clays or clay loams
and have been used for forage and cattle production. Some hay is removed
from the land and sold. Much of the land has been planted to Coastal
bermudagrass and is grazed by cattle.
Land has a great capacity for receiving and decomposing human wastes.
The soil-water-plant system plays an important role in the renovation of
wastewater. To date, one of the unknown factors in land disposal is the
potential contamination and accumulation of wastes in the field, especially
the long-term effect. The objectives of this study are as follows:
1. Determine the fate of applied nitrogen, phosphorus, and selected
heavy metals in the soil-water-plant ecosystem.
2. Compare the concentrations of nitrogen, phosphorus, and heavy metals in
soil, water, and plant samples taken from the sewage farm with those
taken from adjacent control areas.
3. Measure the chemical characteristics of sewage farm surface soils and
evaluate their relationship to the concentrations of nitrogen, phospho-
rus, and heavy metals in the soils.
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4. Make recommendations for the disposal of sewage wastewater on the land
in view of the effect of nitrogen, phosphorus, and heavy metals on the
environmental quality.
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SECTION 2
SUMMARY AND CONCLUSIONS
The 259 hectare sewage farm had been in operation for 18 years and
received all the sewage from the city of San Angelo at the time this study
was conducted. San Angelo is located in a semi-arid region of Texas and
receives an average of 53 cm of rainfall per year. The average annual
temperature is 19.0°C. The population in 1975 was 67,000.
Gross yields of forage was much higher than on adjacent areas where
irrigation was not practiced. Stocking rate of cattle on the sewage farm
was 2.7 head/ha in 1976. This was twenty times higher than the stocking
rate of surrounding rangeland. In addition, 21,600 bales of hay were sold.
Total gross income from the farm in 1976 was $57,576.
Daily flow of sewage to the farm ranged from 0.22 to 0.35 m-Vsec. The
effluent was separated from solids in a settling tank. It was then either
pumped directly to the land or passed through one to three storage lagoons
before being distributed to various parts of the farm. Water from the
lagoons was distributed through a gravity flow underground pipe system where
it was used for irrigation. Surface irrigation, using bordered terraces, was
used to prevent surface runoff and provide even distribution of water.
Water moved vertically through the soil until it reached relatively
impermeable soil layers. The water then moved laterally and surfaced as
seepage creeks or seeps which eventually flowed into the Concho River which
borders the sewage farm. Seeps along the bank of the Concho River were
observed in the soil profile above the Permian red clay beds.
The San Angelo sewage farm contributed from 3.7 to 31 percent of the
total flow of the Concho River during 1976. The average flow contribution
was 0.14 m^/sec (12.5 percent).
Nitrogen and phosphorus in the effluent were being applied to the farm
in large amounts. The concentration of N in the water (from lagoon no. 4)
was 29.8 yg N/ml, primarily as NH, and organic N. The concentration of
phosphorus in the irrigation water was 18.45 yg P/ml and was in the ortho-
or organic phosphate forms.
Nitrogen present in the seepage waters was in the NO., form. Mean NO«-N
concentrations in three seepage creeks flowing into the Concho River ranged
from 10 to 21 yg/ml.
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There was no accumulation of NHt-N or NC-I-N in the soil profiles. Some
organic N accumulated at the surface of the soil, and there was evidence of
N07-N accumulation in the profiles of the Angelo and Mereta soils. Oxida-
tion of NH, to NO- must have been very rapid to prevent appearance of NOl-
After 18 years of continuous irrigation with sewage effluent there was a
net loss of total N in the soil profile.
Phosphorus accumulated in the soil profile. There was a significant
increase in water soluble phosphorus in the upper 200 cm of soil. Movement
of phosphorus into well waters and seepage creeks 2 and 3 was 0.06 yg P/ml.
The concentration of phosphorus in seepage creek no. 1, which runs through
the farm, reached a high of 3.80 yg P/ml during the month of June. The
average concentration of P in seepage creek 1 was 0.79 "jag P/ml. The average
concentration of P in the Concho River below the sewage farm was 0.078 yg/
ml.
Application of fertilizer nitrogen and phosphorus to Coastal bermuda-
grass did not increase production. The test was conducted on a replicated
field plot experiment on the Angelo soil series. The quantity of nitrogen
and phosphorus in the irrigation water was adequate for maximum production.
Heavy metal contamination was not a problem on the San Angelo sewage
farm. There appeared to be some (accumulation of Cd, Cr, Cu, Pb,, and Zn in
the surface horizons of the Mereta soil which was located adjacent to the
effluent lagoons. There was also a light accumulation of Pb in the surface
of the Angelo soil. Consistently higher concentrations of Cr throughout
the Rioconcho profile was probably due to natural variation between sample
sites. In general, the heavy metal concentration of the sewage was low
because of the general lack of industry in the San Angelo area that would
contribute heavy metals.
Soils nearest to the sewage effluent lagoons have received significantly
more effluent than those located some further distance away. The total soil
content of phosphorus, nitrogen, and heavy metals were considerably higher
in Mereta and Angelo soils.
Water from wells located on the sewage farm had a nutrient composition
similar to wells located in Tom Green County. The average nitrate concen-
tration in domestic deep wells at the sewage farm and surrounding Tom Green
County was 15.7 and 22.0 yg NOl-N/ml, respectively. The average nitrate
concentration in shallow groundwater wells at the sewage farm was 5.8 yg
NO~-N/ml. More than 60 percent of the well water samples analyzed had
nitrate concentrations greater than 10 yg NO»-N/ml. High NCC-N concentra-
tions, exceeding 50 ppm in some wells, should be considered a serious
problem. The unusually high N0» concentrations appear to be a result of
natural distribution and contamination of the aquifer and not due to the
sewage farm.
The primary contributions to the Concho River from the San Angelo
sewage farm appear to be an increased flow rate of the river and a slightly
higher NOl-N concentration in the river below the sewage farm.
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SECTION 3
RECOMMENDATIONS
Land disposal of municipal wastewater at San Angelo, Texas, combined
with a forage crop and cattle production system, can be considered a prac-
tical long-term wastewater treatment scheme. Minimal alteration of the
water quality of surrounding surface streams and' groundwaters has occurred
as a result of the sewage farm operation. Increased levels of NO--N in the
Concho River appear to be the primary concern and will warrant continued
monitoring.
Based on the current daily volume of incoming sewage wastewater to the
sewage plant and the present acreage of the sewage farm, it will be neces-
sary in the near future to expand the sewage farm acreage to effectively
dispose of the increasing volume of sewage wastewater. Disposal of waste-
water over a larger acreage will also eliminate and/or reduce the chances
of direct discharge of sewage wastewaters into surrounding surface streams.
An expanded acreage would'lower the annual loading rate of the soil and
allow more recovery time between applications of sewage effluent. Lower
annual loading rates of the soil would also extend the useful life of the
farm as a sewage effluent disposal site.
Nitrogen and phosphorus inputs from sewage effluent are adequate to
meet the nutritional requirements of the crops. Therefore, additional
applications of these elements as fertilizer are not recommended. Chemical
and/or biological processes which can reduce the high nitrate concentration
in domestic deep wells at the sewage farm and surrounding Tom Green County
should be considered since these waters are used as a domestic water supply.
Irrigation with wastewater effluent on the sewage farm for the past
18 years has significantly changed the concentrations of some of the
chemical elements in the soils. Of those elements determined in this
study, none were present in what would be considered as toxic amounts.
However, as industry expands or the chemical composition of sewage effluent
changes, further investigations and periodic monitoring of the site are
recommended.
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SECTION 4
GENERAL PROJECT CHARACTERISTICS
TOPOGRAPHY
Hilly areas, plains, and river valleys are the three types of topog-
raphy present in Tom Green County where San Angelo, Texas is the county
seat (Willis, 1954). Hilly remnants of a northward extension of the
Edwards Plateau cover much of the northern, western, and southern parts
of the county. Plains lie east of San Angelo from the northern boundary
of the county southward to the base of the hills of the Edwards Plateau.
That portion of the plains south of the Concho River is known as Lipan
Flat. River valley flats lie along the Concho River and its tributaries—
the North, Middle, and South Concho Rivers—which join before reaching
the San Angelo sewage farm land 8 km east of the city limits on Farm
Road 380. The highest point in the county is near the southwest corner,
located 40 km southwest of the sewage farm where the altitude is approxi-
mately 778 m. The lowest point is the bed of the Concho River at the
Tom Green-Concho County line, 19 km down river from the sewage farm where
the altitude is approximately 503 m. The location of the San Angelo area
is shown in Figure 1.
The San Angelo sewage farm is located on the plains bordering the
north bank of the Concho River. The land is slightly sloping from 0 to
3 percent southward toward the river or to a drainage creek in the northern
area of the farm which flows into the Concho River east of the sewage
farm.
Adjacent land to the west and north is cleared rangeland, typical of
the arid region. The land on the eastern border of the sewage farm is
cultivated in wheat and irrigated with water pumped from the river. This
land gently slopes toward the river and has very productive soil. The
private land on the river surrounded by the sewage farm is similar to the
rangeland located west and north of the sewage farm, except for that
portion that is productive river valley soil and is cultivated in grain
sorghum and wheat.
The moderate annual rainfall, gently sloping terrain, and properly
managed grasslands keep erosion in check on the lands adjacent to the
sewage farm. Flooding is not a problem due to the three large reservoirs—
Twin Buttes, 0. C. Fisher, and Lake Nasworthy—which are located on the
river and its main tributaries west of San Angelo.
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Scat'
Source: Adapted from Erwin Raisz, Land forms of the United States, 1957.
Figure 1. General topography and location of study site at San Angelo,
Texas.
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Rangeland adjacent to the sewage farm has been chained and pushed with
bulldozers for brush control and optimum native forage production. Culti-
vated land was root plowed and broken from mechanized row cropping.
The land on the San Angelo sewage farm, which was initially row
cropped, has now been established in permanent pasture except for three
cultivated fields which are used to produce forage sorghum or small
grains for grazing and haying. Due to water disposal requirements which
keep the soil very wet, the grass fields are seldom disturbed by farming
equipment. The cultivated fields are plowed in early spring and fall for
seedbed preparation prior to planting.
GEOLOGY
Rock formations exposed in Tom Green County are of sedimentary origin.
The oldest of these belong to the Permian system and are exposed along the
Concho River (Barnes 1974). The regional dip of the Permian rocks is
westward at a rate of approximately 9.5 m to the km. The hilly remnants of
the Edwards Plateau are composed of rocks in the Cretaceous system which
dip southeastward at a very low angle. Older Quaternary alluvium (the
Leona Formation) covers the Permian rocks in most of the plains area.
Younger Quaternary alluvium is present in the stream valleys. A cross
section of the geologic strata of Tom Green County is presented in Figure 2.
The land in the sewage farm area is located on the Leona formation
which is typified by the conglomerate along the Concho River. The conglo-
merate is classified as Pleistocene and Pleistocene alluvium and is derived
from rocks of the Edwards Plateau. The alluvium was deposited on the
eroded surfaces of the Permian rocks over about 1036 square km in the
plains areas of the county. The thickness of the alluvium ranges from
1 m to about 38 m. The alluvium is composed of discontinuous beds of
poorly sorted, rounded to subangular gravel, conglomerate, sand, silty
clay, and caliche. The upper 20 m of soil is predominately clay and clay
loam. The particles of gravel are composed of limestone and flint, some
of which contain fragments of Cretaceous fossils. Rocks in the county
which are older than those exposed are not known to contain potable water.
Water wells in the county do not penetrate these older rocks. Most of
the irrigation wells in the county draw water from the more permeable
layers of gravel and creviced conglomerate.
GROUNDWATER
Groundwater in the area is derived strictly from precipitation on the
land surface, except for the immediate sewage farm area and the Lipan
Flat where irrigation has contributed to water tables. The non-precipita-
tion contribution to groundwater in the sewage farm area is the municipal
sewage effluent from the city of San Angelo which is used for irrigation
and, in the Lipan flat, the water from the irrigation canal from Lake
Nasworthy-
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VO
SOUTH CONCHO RIVER
CRETACEOUS, UNDIFFERENTIATED
STANDPIPE LIMESTONE MEMBER
10
_J
400
METERS
KILOMETERS
Figure 2. Cross section of the geologic strata of Tom Green County, Texas
-------
The Texas Board of Water Engineers in cooperation with the U. S.
Geological Survey have found that most water wells in the area are in the
Leona formation and range to about 30.5 m in depth.
CITY POPULATION AND INDUSTRIAL INPUT
The city of San Angelo is a steadily growing community with a 1975
population estimated at 67,000.- Daily sewage rates to the treatment
plant are from 0.219 to 0.241 m /sec with a minimum flow of 0.153-0.175
and a maximum flow of 0.307 to 0.351 m /sec. Sewage inputs are
dominately domestic. Industrial flow in 1977 accounted for 0.0162 m /sec
according to the city water department. Major industries involve a
creamery with the greatest input, 4 packing plants, 2 large commercial
laundries, 1 bottling plant, and 2 foundaries which contribute recycled
cooling water.
Population growth of the city of San Angelo from 1910 to 1975 is
listed in Table 1.
TABLE 1. SAN ANGELO CITY POPULATION INCREASE WITH TIME
Year Population
1910
1920
1930
1940
1950
1960
1970
1975a
10,321
10,050
25,308
25,802
52,093
58,815
63,884
67,000
o
estimated
WASTEWATER TREATMENT FACILITIES
The sewage treatment plant of the city of San Angelo, Texas was designed
for primary treatment by screening, sedimentation, skimming, and separate
digestion of sludge. Digested sludge was to be mixed into settled sewage
or placed on a designated area and plowed into soil by mechanized farm
equipment. During this project a new sewage treatment plant was
under construction and the original method of handling had to be altered.
The method used during the time this project was underway was simply primary
treatments of sewage and piping both solids and liquids to lagoon .1, lagoon
2, or occasionally flooding land directly with the primary treated sewage.
3
Presently the sewage plant handles 0.219 to 0.263 m /sec of incoming
sewage. The sewage enters the plant by a 0.76 m diameter line. After
10
-------
passing through a bar screen the sewage was lifted to a clarifier (18.3 m
in diameter x 0.61 m deep) by alternating 0.372 and 0.456 nrVsec electric
pumps. Sometimes sediment from the clarifier was pumped into an adjacent
6.19^ha surface area sludge lagoon, and sewage effluent was pumped from the
clarifier to the first of a series of three lagoons located at the opposite
end of the farm. Other times both effluent and sludge were pumped into
lagoon 1 or lagoon 2. The total surface area of the three lagoons was 17.68
ha. In these three lagoons the sewage was subjected to oxidation and further
settling. Effluent overflowed from the second lagoon to the third lagoon
and from the third lagoon to the fourth lagoon. Water for irrigation was
used directly from each lagoon.
Irrigation was accomplished by distribution from underground mains into
level borders of approximately 0.2 ha each. The borders were separated by
levees not less than 0.25 m high, and each field had a perimeter levee on
its lower side, built to a minimum height of 0.46 m, to insure that sewage
effluent did not flow directly from the field to a water course. Specifica-
tions for the three types of levees present on the farm are shown in Figure
3.
VEGETATION ON FARM
There were approximately 259 ha of the sewage farm that received sewage
effluent and were used for hay production and grazing. Coastal bermudagrass,
Kentucky 31 fescue, and NK 37 bermudagrass were the forage grasses in the
permanent pastures. There were approximately 127 ha of Coastal bermudagrass
(Cynodon dactylon). The growing season at the sewage farm for Coastal ber-
mudagrass is from March through September. Kentucky 31 fescue (cool season
perennial) grew from November through June and there were approximately 40
ha of the farm in this grass. NK 37 is a hybrid bermudagrass variety of the
Northrup King seed company. It is a warm season bermudagrass. There were
approximately 77 ha of cultivated land on the sewage farm. A warm season
annual forage sorghum was utilized for hay and grazing in the spring and
summer. Following the last harvest of the forage sorghum in the early fall
the cultivated land was plowed and planted in oats. The oats receive strong
competition from rescuegrass (Bromus wildenowii), a cool season annual
native, which was very prolific. Rescuegrass could be found growing any-
where on the farm by late winter, and if the bermudagrass sod was plowed in
the fall, an excellent stand of rescuegrass occurred.
All the grasses on the sewage farm were utilized for hay. Hay fields
were cut frequently and provided a primary source of income for the farm.
Frequency of cutting depended on weather limitations, grazing intensities,
and flooding frequency as dictated by sewage accumulations. In 1975 ap-
proximately 27,800 bales of hay were sold despite the yearly average grasing
intensity of 2.08 head of cattle per ha. In 1976 approximately 21,600 bales
of hay were sold during a grazing intensity of 2.69 head of cattle per ha.
For native range the 508 mm rainfall average restricted stocking rates to
one animal unit per 8 ha on good cleared range and to one animal unit per
20 ha on poor brushy range.
11
-------
1.22m
1.83m
compacted
earth fill
8.53m
Typical section of holding pond levee
1.22m
Border levee
.25m (minimum)
2.44 m
Field perimeter levee
t«
.46m (minimum)
Figure 3. Cross sections of three different types of levees present on
the San Angelo sewage farm.
12
-------
Natural vegetation in the area is greatly dependent on grazing
practices. Although very little native vegetation occurred on the farm,
other than weeds such as pigweed (Atnaranthus retroflexus), nightshade
(Solanum sp.)> or mesquite trees (Prosopis sp.)> the immediate area sur-
rounding the farm is inhabited by grasses, brush, and short trees. The
predominant warm season grasses are sideoats grama (Bouteloua cutipendula),
cane bluestem (Andropogon barbinodis), buffalo grass (Buchloe dactyloides),
vine mesquite (Panicum obtusum), plains bristlegrass (Stefai leucopila),
purple threeawn (Aristida purpurea), and other arid area species. The
predominate cool season grasses are rescue grass (Bromus wildenosii),
Canada wildrye (Elymus canadensis), and Texas wintergrass (Stopa leuotricha)
Trees in the area are predominately mesquite (Prosopis juliflora) and are
seldom over 6 meters tall.
ANIMAL POPULATION AND CROP PRODUCTION
Cattle are the only livestock grazed on the sewage farm. All animals
are rotated from field to field to permit haying, flooding, planting^ or
any other operation and are not grazed specifically in any one field or
combination of fields. All classes of cattle are grazed on the farm and
grazing records are kept according to animal grazing days (AGO). One
animal grazing day is defined as the presence of one cow, cow and calf,
or a bull grazing on the sewage farm for one day. Yearling cattle are
listed as cows in the farm records since they consume approximately the
same amount of forage.
Approximately 259 ha of the farm are flood irrigated with sewage
effluent, grazed, and hayed. The data in Tables 2 and 3 show livestock
numbers on the farm for 1976 and 1976. The average number of cattle per
month and the livestock grazing intensity (head/ha) are also shown.
Since 1976 was a wet year, it was not a good year for hay production
because cut hay was rained on, and rainfall interrupted other forms of
haying. The sewage farm may realize more income by intensifying haying
operations and decreasing livestock numbers, especially during the warm
season of the year when hay production is greatest. The gross income of
sewage farm in 1975 and 1976 are shown in Table 4.
13
-------
Animal Grazing Days
Month
Jan.
Feb.
Mar.
Apr.
May
June
July
Aug.
Sept.
Oct.
Nov.
Dec.
Cows
7863
6120
7452
7500
12054
21146
19170
21644
20640
17874
17640
13524
Pairs
1830
1830
1830
1830
1740
1740
1740
1740
1740
1140
1140
780
Bulls
367
330
330
330
180
180
120
150
150
150
150
120
Total
10060
8280
9612
9660
13974
23066
21030
23534
22530
19164
18930
14424
Head per
Month
335
276
320
322
466
769
701
784
751
639
631
481
Total 6475
Average head per month (1975) 540
Grazing intensity (head/ha) 2.08
TABLE 3. CATTLE PRESENT ON THE
SAN ANGELO CITY SEWAGE FARM IN 1976
Animal Grazing Days
Month
Jan.
Feb.
Mar.
Apr.
May
June
July
Aug.
Sept ,
Oct.
Nov.
Dec.
Cows
9210
12330
17220
34287
23640
23640
23640
22500
11570
21870
20566
15135
Pairs
780
780
780
780
780
780
780
780
780
1050
1050
300
Bulls
120
210
210
240
180
180
180
180
180
180
150
150
Total
10110
13320
18210
35307
24600
24600
24600
23460
16530
23100
21766
15585
Head Per
Month
337
444
607
1177
820
820
820
782
551
770
726
520
Total 8374
Average head per month (1976) 698
Grazing intensity (head/ha) 2.69
14
-------
TABLE 4- GROSS INCOME OF SAN ANGELO CITY SEWAGE FARM
Year
Item
Unit Price
Income
1975
1976
27,828 bales
294,264 AGD
21,632 bales
251,188 AGD
$
1.50
0.10
1.50
0.10
$
41,742.00
29,426.40
Total 71,168.70
32,448.00
25,118.80
Total 57,567.30
AGD is animal grazing days.
15
-------
SECTION 5
METHODS AND MATERIALS
HYDROLOGY AND METEOROLOGY
Water flow of three seepage creeks in the sewage farm was continuously
monitored over a one year period by installation of weirs in conjunction
with a water level recording device (Stevens type F recorder, model 68).
A 90-degree V-notch weir was installed in seepage creek 1. A 60-degree
V-notch was installed in seepage creeks 2 and 3. This weir design permitted
accurate measurement over a wide range of water flow. Measurement of
water flow of the Concho River was determined by the area-velocity method
with a F583 Pygmy-type water current meter on the Concho River at
sampling sites above and below the sewage farm. These measurements pro-
vided an estimate of water contribution of the sewage farm to the Concho
River. Irrigation flow of sewage' effluent to the fenced Coastal bermudar
grass area was determined with a commercial type Badger magnetic drive
irrigation meter. The location of weirs, Concho River sample sitesy, and
the fenced plot area in relation to the effluent lagoons are shown in
Figure 4.
A temperature recording device (Weathermeasure Corp. model T603, three
point thermograph) was installed in the fenced Coastal bermuda/grass area.
Air temperature and soil temperatures at 10 cm and 40 cm depths were
monitored hourly. Precipitation was recorded at the fenced plot area with
a weighing rain gauge made by Belfort Instrument Company.
WATER ANALYSIS
Water Sampling Locations
Sewage Farm Locations—
The on-farm water sampling sites were located across the entire area.
These locations were selected to permit monitoring of sewage effluent from
the time it entered the treatment plant until it flowed into the Concho
River adjacent to the sewage farm through seepage creeks. Ground water
was sampled from shallow (1.5-9.1 m) wells and from deep (21.3-36.6 m)
wells located within the sewage farm boundary (Table 5).
Non Sewage Farm Locations—
Water samples were collected from domestic wells in Tom Green County,
Texas on an irregular basis. These sampling sites are located within a
16
-------
Shallow grou
water wells
O
O
O
O
•=}
Fenced I
plot area
Weir
Pond
Seepage creek
No. I
Sewage/
effluent lagoons
Seep No. 3
weir
Figure 4. San Angelo sewage farm with blow up
of Coastal bermudagrass fenced plot area.
17
-------
TABLE 5. WATER SAMPLING LOCATIONS
ON THE SAN ANGELO SEWAGE FARM AND CONCHO RIVER
Sampling
Number Location
1 Upstream Concho River: on the west bank of the river 0.64
km south of the bridge over the river on farm road 380
2 Downstream Concho River: 0.84 km down the river from the
sewage farm
3 Lagoon #1: on the east side of lagoon directly west of the
old clarifier
4 Lagoon #4: on the east side of lagoon where the water over-
flows from the lagoon into the irrigation mains
5 Seepage creek #1: the large seepage creek on the eastern
border of the farm. Sample was taken from the pond created by
the weir and on the south side 30 feet upstream from the weir
6 Seepage creek #2: The spring as it flows from the river bank
into a pond created by the river weir
7 Seepage creek #3: The spring that flows from the river bank
on Mika private land on the north side of the river 2.01
km down river from sampling site #1
8 Shallow well (2.1 m) on the south side of the seepage creek
#1 on the bank just above the creek about 180 meters above
the weir at sampling site #5
9 Deep well (29.0 m) at the sewage treatment plant
10 Deep well £30.5 m) at the hay barn
11 Deep well (33.6 m) on the west edge of the Carson Farm on the
east border of the city farm
12 Deep well (36.6 m) at the cattle pens just north of the sludge
lagoon
13 Deep well (27.5 m) at the southeast corner of lagoon #4
14 Deep well (21.4 m) at the earth dammed pond approximately
0.8 km
16 Deep well (30.5 m) at the house 137 m west of sampling site
# 11
(continued)
18
-------
TABLE 5i (continued)
Sampling
Number
17
18
19
20
21
22
TABLE 6.
Sampling
JQ umber
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
Location
Shallow well (1.2 m) on the north side of seepage creek #1
36.6 m above sampling site #5
Shallow well (7.6 m) at the top of the Coastal bermudagrass
field in the northeast corner of the sewage farm
Shallow well (6.3 m) four borders below sampling site #18
and in the same field.
Shallow well (7.8 m) five borders below sampling site #19
and in the same field
Shallow well (9.3 m) six borders below sampling site #20 and
in the same field
The incoming sewage effluent at the sewage treatment plant
LOCATION AND DEPTH OF WATER SAMPLING SITES OUTSIDE SEWAGE FARM
Distance and direction
Location from sewage farm well depth
Air km m
Veribest NE 6.4 18
Veribest NE 5.3 24
Veribest SE 6.1 46
Veribest SW 1.6 61
San Angelo N 2.1 37
San Angelo N 2.4 37
Red Creek N 3.2 28
San Angelo NW 10.1 34
San Angelo SW 9.7 18
San Angelo SW 9.7 29
San Angelo SW 7.2 20
Wall S , 12.6 42
Wall SE 15.3 41
Eula SE 8.8 46
San Angelo S 4.8 64
Wall SE 14.5 41
Eula SE 11.3 43
Veribest E 5,6 43
19
-------
16 km radius of the sewage farm. The samples were analyzed and used
as background information to compare with that of the sewage farm (Table 6).
Chemical Analysis
Beginning November 18, 1975 waters in the sewage farm were sampled
regularly over a one year period for chemical analysis. Samples were
taken initially on a weekly schedule and later on a biweekly schedule.
Collecting, handling, and analysis of water samples conformed to the general
procedures outlined by the U. S. Environmental Protection Agency (197?,
1973, 1974). Analytical procedures used for analysis of water samples are
presented in Table 7.
Temperature and pH values were determined on site at the sewage farm.
Ammonia-N, nitrate-N, nitrite-N, total Kjeldahl-N, total phosphorus, dis-
solved orthophosphate, and total heavy metals (Cd, Cr, Cu, Ni, Pb, and Zn)
were determined at the College Station laboratory. Forms of nitrogen and
phosphorus were determined within 24 hours of collection. Water samples
were analyzed on two different dates for total filterable residue, total
nonfilterable residue, biochemical oxygen demand, and chemical oxygen
demand.
SOIL ANALYSIS
Three major soil series (Angelo, Mereta, and Rioconcho) were identified
in the San Angelo sewage farm. A total of 15 soil cores were taken from
each major soil series with a stainless steel auger (available from Arts
Machine Shop, American Falls, Idaho); 10 cores in the sewage farm and 5
cores in an adjacent control area. Soils were taken to a depth of 200 cm,
except where a gravel or hard caliche layer existed in the soil profile.
The control areas have never been irrigated with sewage effluent. Each core
was subdivided into 10 subsamples in varying depth increments. A subsample
of each soil was stored in a freezer under field moisture conditions and
used immediately for chemical analysis of NH.-N, NO~-N, and NOl-N. The rest
of the soil was air-dried and ground to pass a 1-mm sieve (2-mm for texture
analysis) using a mortar and pestle (Table 8).
FIELD PLOT EXPERIMENT AND PLANT ANALYSIS
2
Twenty-seven experimental plots (1.830 x 4.575 m ) were established in
a fenced Coastal bermudagrass plot area in the sewage farm. The area was
fenced to exclude animal movement into the plots but not to exclude
irrigation with sewage effluent. These plots were used for biological and
chemical tests where recycling of organisms and nutrients through animals
was to be avoided.
A factorial experiment (3x3x3) where combinations of three rates
of nitrogen (0, 112.2, and 224.4 kg N/ha as NH.NOJ and phosphorus (0, 56.1,
and 112.2 kg P_05/ha as 0-20-0) and three replications was designed. These
plots were completely randomized in the field. Forage was clipped from the
20
-------
TABLE 7. METHODS USED FOR CHEMICAL ANALYSIS OF WATERS
Measurement
1.
2.
3.
4.
5.
Temperature
pH
NH. -N
4
NOg-N
NO;-N
Method
Thermometer
Corning model 7 pH meter
Distillation with MgO and
collected in HoB03
Brucine sulfate
Diazotation of sulfanilamide
Reference
EPA 1974
EPA 1974
Bremner 1965 b
EPA 1974
EPA 1974
6. Total Kjeldahl
nitrogen
Hot, concentrated
digestion and distillation
with NaOH
EPA 1974
7. Total
Phosphorus
8. Dissolved
orthophosphate
9. Heavy metals
HNQ3-HC104 digestion and
antimony-phospho-molybdate
complexation
Antimony-phospho-molybdate
complexation
HNO. digestion and HC1
dissolution
APHA 1976
Murphy & Riley 1962
EPA 1974
Murphy & Riley 1962
EPA 1974
10. COD
11. BOD
12. Total
filterable
residue
13. Total
nonfilterable
residue
Digestion with potassium
dichromate and back titration
with ferrous ammonium sulfate
Incubation for 5 days at 20°C
followed by 02 analysis with
Yellow Springs model 57
dissolved oxygen meter
Filtering through 0.45 V-
millipore filter paper and
dried at 180°C
Filtering through 0.45 U
millipore filter paper and
dried at 105°C
APHA 1976
APHA 1976
EPA 1974
EPA 1974
21
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TABLE 8. EQUIPMENT AND METHODS USED IN SOIL ANALYSIS
Measurement
Method
Reference
1.
2.
3.
4.
Texture
Bulk density
pH
Carbonate
Bouyoucous hydrometer
Core method
Metrohm/Brinkmann model
pH-103 pH meter
Acid-neutralization
Day 1965
Blake 1965
Peech 1965
Allison and
Moodie 1965
5. Organic matter
6. Cation exchange
capacity
7. Soluble salts
8. Total phosphorus
9. Water soluble
Phosphorus
10. Total nitrogen
11. NO;-N
12. NHj-N
13. N02-N
14. acid-extractable
heavy metals
15. Total heavy
metals
Walkley-Black method
pH 7.0 IN NH^OAc extraction
and Kjeldahl distillation
Industrial Instruments Inc.
Model RC 16B2 conductivity
bridge
digestion and vanadate
molybdate color method
1:10 soil-water extraction
and ascorbic acid method
Jackson 1958
Keeney and
Bremner 1969
Bower and
Wilcox 1965
Kao and Blancher
1975, Tandon,
et al, 1968
Olsen and Dean
1965, Murphy
and Riley 1962
Kjeldahl digestion and distillation Bremner 1965 a.
Bremner 1965 b.
EPA 1974
Bremner 1965 b.
1:10 soil-2N KC1 extraction
and brucine sulfate color method
1:10 soil 2N KC1 extraction
and kjeldahl distillation
with MgO
1:10 soil-2N KC1 extraction
and diazotation of sulfanilamide
1:2 soil-lN HC1 extraction and
determination by using a Perkin-
Elmer Model 403 atomic adsorption
spectrophotometer
HNO-j-HClO, digestion and determina- Kao and Blanchar
tion using a Perkin-Elmer model 403 1973
atomic ab'sorption spectrophotometer
22
Bremner 1965 b.
EPA 1974
Lagerwerff 1971
-------
experimental plots twice during the active growing season. Yield of
forage grass was calculated from the plot weights. Yield of major grass
crops in other areas of the sewage farm was also determined. Once dry
matter yield was measured, the plant tissue was used for chemical analysis.
Plant tissue was dried at 75 C for 24 hours and ground with a T-Jiley Mill to
pass through a 40 mesh sieve prior to analysis.
Total phosphorus was determined by the procedure reported by Kao and
Blanchar (1973) and Tandon et al. (1968). The semimicro Kjeldahl method
was used to determine the total nitrogen concentration (Bremner, 1965a).
Heavy metals were determined by digesting a suitable amount of plant tissue
in hot, concentrated HNO, and HC10, in a micro-Kjeldahl flask (Perkin-
Elmer Corp. 1971) and analyzed with a Perkin-Elmer Model 403 Atomic
Adsorption Spectrophotometer.
STATISTICAL ANALYSIS
All field and laboratory data were processed and analyzed by the
Statistical Analysis System (Barr et al., 1976) on an IBM 370 computer at
Texas A & M University.
23
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SECTION 6
RESULTS AND DISCUSSION
HYDROLOGY AND METEROLOGY
Meteorology
The climate of San Angelo, Texas is semiarid to subhumid. The average
annual precipitation is 52.78 cm with about 85 percent of the precipitation
falling between mid-March and mid-November. On the average, rain or snow
falls during all or parts of 42 days a year. Freezing temperatures occur
at intervals between mid-November and mid-March (Willis 1954). The data
presented in Figure 5 show average monthly precipitation from 1936 to
1975 and monthly precipitation in 1976 at the sewage farm. The precipitation
was 64.29 cm in 1976, about 22 percent higher than the average of the last
40 years.
Temperatures of air, soil at 10 cm depth, and soil at 40 cm depth are
shown in Figure 6. Soil temperatures fluctuated less than the air
temperature. There was little difference between the soil temperature at
10 cm and at 40 cm. Soil temperatures at 40 cm ranged from a high of 30 C
to a low of +5 C. Air temperatures fluctuated between a high of 31 C to a
low of -1 C. Maximum soil temperatures at 10 and 40 cm depths are about
50 days behind the maximum air temperature. Both the soil temperature at
10 cm depth and soil temperature at 40 cm depth show the same pattern.
Hydrology
Water flow rates of the Concho River measured on 32 separate days in
1976 upstream and downstream from the sewage farm are shown in Table 9. The
mean water flow rates upstream and downstream from the sewage farm were
U0007 and 1.1436 m /sec. This indicates a net contribution of 0.1429
m /sec from the sewage farm to the Concho River. It was calculated that, on
the average, the San Angelo sewage farm contributed about 12.5 percent of the
total water flow of the Concho River downstream from the sewage farm in
1976 (Table 10). Data presented in Figure 7 show the water flow rates
of the three seepage creeks monitored on the sewage farm. Seepage creek
no. 1 had a daily mean flow rate of 1,009.5 liters per minute. Flow rates
ranged from 53.0 to 3,225.1 liters per minute with a daily mean standard
deviation of 465.9 liters per minute. Seepage creek no. 2 had a daily
mean flow rate of 166.6 liters per minute and ranged from 2.5 to 550.0
liters per minute with a daily mean standard deviation of 33.5 liters per
minute. The mean flow rate of seepage creek no. 3 was 97.6 liters per
minute with a range of 17.9 to 525.0 liters per minute and a daily mean
24
-------
20"
1976
avg. 1936-1975
E
u
Z
o
Q.
O
UJ
OC
Q.
15"
5 •
Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec
MONTH
Figure 5, Average monthly precipitation for the years 1936 - 1975 and monthly precipitation
in 1976 at the San Angelo sewage farm, Tom Green County, Texas.
-------
30
25
20-
15-
10"
5"
30-
25- •
20-•
TEMPERATURE 15
"C
10- •
S'-
30-
25-
20-
15-
10"
5"
AMBIENT
SOIL- 10 cm
SOIL -40 cm
0-1 1 1 1 1 1-
JAN FEB MAR APR MAY JUN JUL AU6 SEP OCT NOV DEC
DATE
Figure 6. Daily mean temperatures of air,
soil at 10 cm and 40 cm depths at
San Angelo sewage farm in 1976.
26
-------
700-
600' •
500"
400"
300--
200
100-
0
90
80
70
60
FLOW RATE 50
GPM
40 •
30
20
10
SEEPAGE CREEK NO. I
SEEPASE CREEK NO. 2
-I 1-
H H-
80"
70-
so-
50"
40-
30-
20--
10-
SEEPAGE CREEK NO. 3
-H
NOV DEC JAN FEB MAR APR MAY JUN JUL AUS SEP OCT
DATE
Figure 7. Water flow rates of three seepage creeks
monitored on the San Angelo sewage farm.
27
-------
TABLE 9. WATER FLOW RATES OF CONCHO RIVER UPSTREAM AND DOWNSTREAM
FROM THE SEWAGE FARM IN 1976
Water flow rate
Date
760129
760205
760212
760219
760226
760304
760311
760316
760325
760401
760408
760415
760422
760430
760511
760527
760610
760623
760708
760719
760728
760813
760830
760908
760922
761001
761014
761022
761025
761103
761124
mean
Downstream
1.2899
0.7399
0.8899
1.0599
0.5900
0.7799
0.8999
0.8500
0.8059
0.6920
0.9570
1.1419
0.9590
2.3429
1.2659
0.9789
0.4910
0.3750
0.7500
2.1858
1.4569
0.7759
1.7859
1.5500
1.1930
0.8580
1.1790
1.2739
1.4619
1.6669
1.3289
2.0229
1.1436
Upstream
- m /sec —
1.2299
0.6700
0.7199
0.9499
0.5300
0.6300
0.7599
0.6999
0.7629
0.5870
0.8980
0.9699
0.8770
2.1548
0.9759
0.8170
0.3380
0.3510
0.6159
1.8399
1.1609
0.6669
1.5539
1.4901
0.9961
0.7520
1.0361
1.2159
1.1369
1.5079
1.1739
1.9548
1 . 0007
Difference
0.0600
0.0699
0.1700
0.1100
0.0600
0.1499
0.1400
0.1501
0.0430
0.1050
0.0590
0.1720
0.0820
0.1881
0.2900
0.1619
0.1530
0.0240
0.1341
0.3459
0.2960
0.1090
0.2320
0.0599
0.1969
0.1060
0.1429
0.0580
0.3250
0.1590
0.1550
0.0681
0.1429
Difference , ni
T. X 10'
Downstream
4.65
9.46
19.11
10.38
10.17
19.23
15.56
17.65
5.33
15.17
6.16
15.06
8.55
8.02
22.91
16.54
31.16
6.41
17.87
15.83
20.31
14.05
12.99
3.87
16.51
12.35
12.13
4.55
22.23
9.54
11.66
3.36
12.50
28
-------
TABLE 10. AVERAGE WATER FLOW RATES OF THE CONCHO RIVER
UPSTREAM AND DOWNSTREAM FROM THE SEWAGE FARM
AND OF THREE SEEPAGE CREEKS AT THE SEWAGE FARM FOR 1976
Location
Concho River upstream
from sewage farm
Concho River downstream
from sewage farm
A
Sewage farm output
Seepage creek no. 1
Seepage creek no. 2
Seepage creek no. 3
Sum of three seepage creeks
Average percentage contribution
to sewage farm output.
Average percentage contribution
to downstream Concho River.
GPM
15861.0
18127.0
2266.0
266.7
44.0
25.7
336.4
of three
of sewage
Flow rate
MGD
22.840
26.103
3.263
0.384
0.063
0.037
0.484
seepage creeks
farm output
m /sec
1.0007
1.1436
0.1429
0.0168
0.0028
0.0016
0.0212
14.85%
12.50%
*Difference from upstream to downstream
29
-------
standard deviation of 24.1 liters per minute. It was calculated that
these three seepage creeks contributed about 14.85 percent of the water
flowing into the Concho River from the sewage farm (Table 10). Approximately
100 active seeps have been observed discharging water to the Concho River
(Texas Water Quality Board 1973).
The wastewater that is being constantly applied to the sewage farm is
apparently percolating to the shallow bedrock layer and moving laterally
to the Concho River. Discharge measurements made on October 24, 1973 in
the Concho River above and below the sewage farm by Texas Water Quality-
Board indicated that on that date 0.2747 m /sec entered the river. This
volume made up approximately 43 percent of the flow in the river downstream
from the sewage farm. The highest percentage contribution of water from
the sewage farm to the Concho River measured in 1976 was 31.2 percent on
June 10, whereas the lowest value was 3.4 on December 10 (Table 9).
The Concho River originates in central Tom Green County at the
confluence of the north and south forks and flows through Tom Green and
Concho Counties in an eastward direction to its mouth with the Colorado
River, a distance of approximately 85 km. The city of San Angelo's sewage
treatment plant has a permitted discharge volume of 0.2234 m /sec (Texas
Water Quality Board 1973). The discharge of treated sewage effluent from
the city of San Angelo's sewage treatment plant is significantly increasing
the flow of the Concho River. At the present time a new activated sludge
wastewater treatment plant that will discharge an average of 0.3198 m /sec
of treated domestic sewage to the farm is being constructed.
WATER ANALYSIS
One of the purposes of this portion of the study was to evaluate the
environmental impact of the city of San Angelo's sewage treatment plant
discharge on the water quality of the receiving Concho River. At the
present time no absolute water quality criteria values are available.
Water quality criteria, published by U. S. Environmental Protection Agency
in 1976, were based on the concentration-effect relationship of a partic-
ular water quality constituent upon a particular aquatic species within
the limits of experimental investigation. However, those water quality
criteria published by the U. S. Environmental Protection Agency (EPA 1976)
will be used to evaluate the waters in the sewage farm and in Tom Green
County. As stated in that publication, those water quality criteria levels
should provide for the protection and propagation of fish and othe'r aquatic
life and for recreation in and on water in accord with the 1983 goals of
Public Law 92-500. Water quality criteria published by the National
Technical Advisory Committee (NTAC) to the secretary of the Interior
(NTAC, 1968) will also be used. Furthermore, water quality criteria from
states having the most stringent standards will be also used as a reference
(Lykins and Smith, 1976).
Water sampling locations at the sewage farm and in Tom Green County
are shown in Figures 8 and 9.
30
-------
SAN ANGELO CITY
To Eden
Figure 8. Well water sampling locations in Tom Green County, Texas.
-------
To Son
RocK
Figure 9. Surface and well water sampling locations at the San Angelo
sewage farm and Concho River.
32
-------
Data presented in Tables 11 through 18 summarize water analyses
of the incoming sewage effluent, effluent lagoons 1 and 4, seepage creeks
1, 2 and 3, and the concentration of nutrients in the Concho River above
and below the sewage farm. The chemical composition of water from shallow
and domestic wells on the sewage farm is summarized in Table 19. Eighteen
domestic wells were monitored on an irregular basis outside the perimeter
of the sewage farm during 1976. These data are presented in Table 20.
Finally, biological oxygen demand (BOD) and chemical oxygen demand (COD)
are presented for all sampling sites in Table 21.
\
Temperature
Solution temperatures varied with the time of year of sampling. Sample
temperatures were as low as 3.8°C on January 3, 1976 at lagoon number 1
and as high as 32.6°C on July 7, 1976 at lagoon no. 4. Temperature
fluctuations of water from seepage creeks 2 and 3 were very small, ranging
from 18.9 to 21.5°C for the duration of the study (Tables 15 and 16).
The discharge of water from the sewage farm into the Concho River had
no effect on the pH values of the Concho River below the sewage farm
(Tables 17 and 18). A r:s £.11 increase in pH value and ammonia-nitrogen
concentration was observed in the incoming sewage effluent at the sewage
treatment plant and lagoon no. 4. Ammonification of organic nitrogen and
dissolution of ammonia in wastewater increase both the pH and ammonia-
nitrogen in wastewater. All three seepage creeks, shallow ground wells,
domestic deep wells at the sewage farm, and Tom Green County deep wells had
pH values of 7.2 ± 0.2.
Nitrogen
Ammonium (Nilt) , nitrate (N0~) , nitrite (N0~) , and organic nitrogen^
are the most important forms of nitrogen in the nitrogen cycle. The NH^
ion is either released from proteinaceous organic matter and urea (Ammonifi
cation) , or is synthesized in industrial processes involving atmospheric
nitrogen fixation. The NOl ion is formed by the biochemical oxidation of
NH, to N0~ (nitrification); NOg is an intermediate produc£ of the
nitrification process. The NOl ion is formed from the NH^ or the NO- ions
by certain biochemical processes (nitrification) . In an aerobic condition
N0~ is rapidly oxidized to N0~. Plants can take up both NH^ and N0~ ions
and convert them, to protein. When nitrogen in sewage effluent whicfi is
mostly in the NH, form is applied to an aerobic soil, the NH^ will be
converted to N0«. Some of the nitrogen may be used by plants, some may
be lost by denitrification as molecular nitrogen and nitrogen oxides or
volatilization as ammonia (NHO, and some may be leached down to the
ground water as NO,.
A limit of 10 yg/ml of nitrogen as NOZ plus NOg ion is recommended
as a domestic water supply standard (EPA 1976) . Waters containing N03 plus
33
-------
CO
TABLE 11. CHEMICAL ANALYSIS OF RAW SEWAGE FROM FEBRUARY 18, 1976 TO NOVEMBER 11, 1976, COLLECTED
FROM THE SEWAGE TREATMENT PLANT
Date
760218b
750225
760303
760310
760315
760324
760331
760407
760414
760421
760510
760526
760609
760624
760707
7C0722
760805
760331
760916
760928
761019
761103
761111
Mean
Maximum
Minimum
Standard
Annual ii
Time
850
903
920
935
1020
845
930
945
1000
820
825
915
855
948
940
1015
945
915
900
1012
1012
905
1005
Deviation
iput* 103
Temp
°C
19.0
18.4
20.8
14.0
19.3
20.4
19.3
20.5
22.7
21.8
23.0
25.0
26.0
27.8
26.5
26.8
28.2
23.0
27.9
26.0
23.9
19.8
20.6
22.9
28.2
14.0
3.9
Kg/year
PH
7.4
7.0
7.1
7.6
7.3
7.2
7.2
7.3
7.1
7.4
7.1
7.2
7.3
7.0
7.3
7.1
7.0
7.2
7.3
7.4
7.1
7.1
7.4
7.2
7.6
7.0
0.2
•NHj-N
/ig/nl
18.2
18.0
17.1
29.2
16.2
18.1
17.7
16.0
13.2
17.1
18.8
15.7
15.5
13.8
13.7
16.3
13.6
12.9
14.5
15.1
15.8
12.0
15.5
16.3
29.2
12.0
3.4
112.6
NOj-N
;ug/ml
0.1
0.1
ND
Nt>
ND
ND
ND
ND
0.1
ND
ND
1.5
0.2
0.1
0.2
0.3
0.1
0.5
0.3
0.1
0.4
0.2
0.2
0.2
1.5
<0.1
0.3
1.4
NOj-N
ng/ml
ND0
ND
7
9
ND
6
8
7
11
9
19
21
ND
19
7
10
11
8
30
53
32
11
11
13
53
< 5
12
0.090
Kjeldahl
N
Dissolved
Ortho-P
Total
P
Zn Cu
Tig/ml •
24.6
27.0
27.4
36.4
23.8
24.9
23.7
23.0
20.0
23.9
26.6
20.7
22.5
19.2
17.0
19.2
22.2
16.9
16.6
17.6
20.2
17.2
19.6
22.2
36.4
16.6
4.6
153.3
5.25
5.48
5.25
13.30
5.63
5.50
5.75
5.38
4.25
7.33
5.58
5.00
4.75
4.13
4.37
4.37
4.25
3.75
3.75
3.13
3.55
1.28
3.75
5.08
13.30
3.13
2.05
35.1
12.00
11.25
10.25
22.25
11.25
14.00
31.63
12.38
8.00
14.13
1Q.75
9.63
7. 03
8.88
7.00
8.00
6.90
5.88
5.25
7.50
7.68
6.75
7.75
9.83
22.25
5.25
3.71
67.9
110 120
200 130
170 120
48 64
130 100
115 92
325 100
155 83
178 87
109 92
191 80
117 108
190 87
79 78
94 76
90 93
140 73
142 78
96 87
190 81
87 76
70 82
120 70
137 89
325 130
43 64
59 17
0.946 0.615
Hi Cd
ng/ml — ---
ND 8
ND 7
15 ND
IV ND
15 ND
15 ND
10 5
20 5
15 SD
20 8
15 ND
25 8
30 ND
12 5
10 ND
33 ND
19 4
«D 14
ND ND
ND ND
12 5
14 5
17 5
14 ^4
33 14
<10 <4
9 4
0.097 ~
Cr Pb
375 ND
320 80
225 230
80 100
140 ND
150 170
205 100
540 ND
440 50
420 ND
660 ND
400 ND
400 ND
140 ND
210 ND
200 KD
ND ND
330 50
ND 50
425 50
200 ND
200 ND
145 ND
272 <50
660 230
<. 5 <50
169 62
0.188 ~
a Assume 5 mgd (6.908 x 10' liters/year) incoming sewage effluenc.
Year, month, day
0 Not detectable
-------
TABLE 12. CHEMICAL ANALYSIS OF WATER SAMPLES FROM NOVEMBER 18, 1975 TO NOVEMBER 11, 1976
TAKEN FROM LAGOON NO. 1 LOCATED ON THE SAN ANGELO SEWAGE FARM
Date
751118s
751125
751202
751209
751216
751222
760101
760103
760112
760121
760128
760204
760211
760218
760225
760303
760310
760315
760324
760331
760407
760414
760421
760510
760526
760609
760624
760707
760722
760805
760831
760916
760928
75 1019
761103
761111
Mean
Maximum
Minimum
Standard
Time
415
845
1000
925
915
900
1014
1050
1245
1013
1100
900
845
840
930
855
905
950
830
945
1030
945
845
800
845
910
1015
905
940
920
850
845
950
948
845
915
deviation
Temp
°C ~
18.0
12.0
10.0
9.5
11.0
8.9
8.2
3.8
9.1
8.8
8.2
11.0
13.0
13.2
11.2
1S.O
14.2
13.0
15.9
15.8
18.0
22.2
20.0
19.0
24.4
24.3
25.8
26.6
26.2
27.8
26.0
24.7
22.1
15.8
13.0
19.2
16.3
27.8
3.8
6.6
PH
7.2
7.2
7.3
7.4
7.4
7.3
7.2
7.3
7.4
7.5
7.5
7.4
7.6
7.4
7.2
7.0
7.1
7.3
7.2
7.2
7.3
7.1
7.3
7.3
7.6
7.2
7.5
7.5
7.1
7.1
7.1
7.2
7.4
6.3
7.5
7.0
7.3
7.6
7.0
0.2
I
NHj-N
jug/ml
29.7
27.8
28.1
30 1
28.6
28.8
30.8
30.0
32.5
33.8
32.6
33.4
33.2
33.4
34.0
30.7
32.3
33.0
32.3
35.1
40.3
37.3
36.5
33.5
23.7
24.0
21.1
20.1
18.5
19.3
18.1
19.0
17.5
18.7
18.6
20.3
23.2
40.3
17.5
6.6
NO^-N
,ug/i»l
NDb
0.4
0.5
0.4
0.2
0.2
0.1
0.2
0.1
0.2
0.3
0.2
ND
ND
ND
0.1
NT)
0.2
0.1
0.1
0.1
0.1
0.1
0.2
0.7
0.3
0.3
0.7
0.3
0.3
0.4
0.5
0.2
0.2
0.3
0.2
0.2
0.7
< 0.1
0.2
NO~-N
ng/ml
5
NP
6
5
4
ND
9
23
ND
15
5
ND
ND
ND
8
S
8
ND
It
8
19
20
11
9
13
13
5
29
29
23
10
34
45
8
16
16
12
45
< 5
11
Kjeldahl
34.9
39.9
40.1
40.7
39.9
39.3
37.2
29.1
40.1
35.4
39.9
38.0
35.7
41.1
46.5
45.3
42.8
45.9
42.8
47.8
44.0
48.4
55.3
45.6
45.2
47.2
57.5
44.2
33.8
36.4
36.4
24.0
35.2
37.9
31.7
36.1
40.7
57.5
24.0
6.6
Dissolved
Ortho-P
11.25
11.50
11.98
10.20
13.00
13.30
14.00
15.30
14.50
15.50
15.75
16.25
15.75
14.75
16.48
16.00
15.50
16.03
15.00
13.75
15.00
13.75
13.25
9.00
8.00
6.63
1.25
2.00
4.75
6.63
7.75
7.50
6.45
7.75
5.50
6.75
. 11.35
16.48
1.25
4.36
Total
P
Zn
Cu Ni
Cd
Cr Pb
14.63
40.63
19.00
30.00
21.13
13.80
25.00
58.80
18.25
29.80
29.30
24.88
22.73
28.75
26.25
27.50
32.50
27.50
28.13
29.38
27.50
26.25
21.25
18.75
21.87
21.25
29.75
23.03
24.00
22.00
21.00
18.25
19.50
19.00
18.40
20.00
24.94
58.80
13.80
8.02
350
330
240
450
220
170
80
80
100-
150
140
120
180
100
150
230
246
140
165
105
111
111
245
130
111
135
130
73
1540
80
93
106
118
62
62
150
194
1540
62
246
110 ND
•140 40
200 ND
110 20
103 20
80 ND
60 ND
50 ND
50 20
50 20
60 ND
20 30
70 20
70 20
60 20
110 20
130 13
57 20-
92 45
70 20
65 25
58 15
95 20
49 20
51 ND
54 20
57 15
56 16
8060 2200
50 42
48 10
64 10
50 10
37 12
60 20
118 20
296 77
8060 2200
20 <10
1331 364
ND
ND
ND
ND
15D
ND
ND
ND
ND
ND
ND
ND
ND
12
8
5
ND
ND
ND
6
5
5
10
6
7
6
ND
ND
ND
4
ND
ND
5
5
ND
5
<4
12
<4
3
200 150
150 100
150 150
300 200
150 150
100 100
80 150
70 ND
70 KD
80 ND
100 ND
80 ND
100 ND
140 50
140 ND
210 230
190 230
80 70
120 170
95 70
102 ND
105 ND
230 120
88 70
90 ND
88 50
80 50
70 ND
65 ND
66 50
150 50
240 100
120 175
90 ND
95 ND
180 ND
124 69
300 230
65 <50
57 75
* Year, month, day
Not detectable
-------
TABLE 13. CHEMICAL ANALYSIS OF WATER SAMPLES FROM NOVEMBER 18, 1975 TO NOVEMBER 11, 1976
TAKEN FROM LAGOON NO. 4 LOCATED ON THE SAN ANGELO SEWAGE FARM
UJ
Date
7511188
751125
751202
751209
751218
751222
760101
760103
760112
760121
760128
760204
760211
760218
760225
760303
760310
760315
760324
760331
760407
760414
760421
760510
760326
760609
760624
760707
760722
760805
760831
760916
760928
761019
761103
761111
Mean
Maximum
Minimum
Standard
Time
405
130
230
150
155
1225
155
315
415
310
415
1245
120
135
230
120
215
340
1000
1045
230
415
1115
925
1035
1000
1130
320
1135
140
1035
1100
1118
207
1030
1135
deviation
Temp
°C
18.0
10.5
17.0
14.5
14.4
10.8
8.8
6.5
9.2
11.0
11.2
15.0
15.0
19.5
14.5
21.0
17.0
21.7
17.0
17.0
22.0
26.0
22.8
20.3
23.0
24.8
27.9
32.6
27.8
30.0
28.0
26.3
22.2
17.3
15.0
16.0
18.7
32.6
6.5
6.5
PH
8.0
8.2
7.8
7.3
8.2
7.9
7.2
8.0
7.7
7.7
7.6
7.8
7.9
7.6
7.5
7.7
7.9
7.7
7.6
7.5
7.8
7.9
8.0
7.6
7.1
7.6
_..|_
7.6
7.2
7.4
8.2
7.5
7.8
7.4
8.0
7.8
7.7
8.2
7.1
0.3
4
NH4-N
;ug/ml
19.4
20.8
23.4
25.7
26.4
30.3
26.0
26.2
26.9
27.7
27.6
26.6
27.7
26.5
25.7
24.6
24.6
24.9
22.5
24.0
21.7
11.7
19.1
ia.fi
17.5
16.3
14.4
11.8
13.4
12.8
11.7
13.4
15.0
14.5
15.2
17.9
21.1
30.3
11.7
5.5
NOj-N
/ig/ml
M,"
0.3
0.5
0.7
0.2
0.7
0.2
0.3
0.1
0.1
0.1
0.2
ND
0.1
ND
0.1
ND
0.1
ND
ND
0.1
0.1
0.2
0.3
2.5
0.4
0.3
0.3
0.6
0.3
0.4
0.2
0.3
0.3
0.4
0.3
0.3
2.5
<0.1
0.4
NOj-N
ng/ol
5
5
16
5
13
6
6
8
9
9
ND
6
6
13
17
6
18
6
56
10
17
19
11
23
125
20
ND
50
26
34
5
19
14
18
15
14
18
125
<5
22
Kjeldahl
29.9
29.0
31.6
28.8
31.7
33.6
31.5
32.0
32.2
28.5
32.3
29.1
22.6
33.5
33.8
33.7
32.9
35.4
34.1
33.6
28.8
31.2
30.9
28.8
35.4
32.7
39.3
25.2
24.1
24.6
20.4
26.1
23.7
26.2
22.0
23.0
29.8
39.3
20.4
4.4
Dissolved
Ortho-P
3.34
8.75
8.13
8.60
10.00
11.00
10.50
11.30
12.30
12.00
9.50
12.75
12.75
12.25
12.50
12.00
12.00
11.00
11.00
11.50
9.38
4. ^0
2.00
1.50
5.50
4.88
4.00
0.13
2.15
6.00
5.00
0.17
3.75
1.88
3.45
5.38
7.58
12.75
0.13
4.16
Total
P
9.63
50.00
20.00
22.50
18.40
12.50
21.30
21.30
12.50
25.00
25.00
20.38
20.13
23.13
17.50
18.60
22.50
21.30
18.13
20.63
19.75
12.50
15.00
13.75
23.12
13.75
21.50
16.00
17.50
14.50
13.00
11.75
15.10
12.50
12.00
12.00
18.45
50.00
9.63
6.92
Zn
110
90
110
280
140
80
70
60
70
120
110
40
140
70
20
180
258
720
77
92
410
238
290
150
74
175
160
440
72
.320
120
85
92
207
53
160
163
720
20
138
Cu
120
80
80
80
60
60
50
ND
40
30
60
ND
70
70
50
50
54
54
51
54
46
42
46
40
40
42
37
38
76
160
25
31
36
31
58
46
53
160
-------
TABLE 14. CHEMICAL ANALYSIS OF WATER SAMPLES FROM NOVEMBER 18, 1975 TO NOVEMBER 11, 1976
TAKEN FROM SEEPAGE CREEK NO. 1 ON THE SAN ANGELO SEWAGE FARM
U>
Date
751118*
751125
751202
751209
751216
751222
760101
760108
760112
760121
760128
760204
760211
760218
760225
760303
760310
760315
760324
760331
760407
760414
760421
760510
760526
760609
760624
760707
760722
760805
760831
760916
760928
761019
761103
761111
Mean
Maxijnuni
Minimum
Standard
Time
210
1125
1235
1200
1130
1030
1157
105
230
1215
140
1045
1050
1115
1225
1150
1150
115
200
100
1200
400
1000
1155
1110
1115
225
1155
110
130
1135
1145
100
1248
1230
120
deviation
Temp
__
\j
21.0
12.5
16.0
14.0
13.0
14.0
14.7
13.0
16.2
13.0
13.8
14.5
14.5
13.5
14.8
20.2
16.4
19.5
19.0
20.0
18.8
28.8
17.2
23.5
21.7
21.6
26.9
24.4
23.1
30.7
26.5
25.8
20.9
7.0
zO.4
17.4
18.8
30.7
12.5
4.9
PH
7.5
7.4
7.6
7.6
7.3
7.4
7.4
7.5
7.6
7.7
7.4
7.7
7.3
7.5
7.0
7.4
7.3
7.5
7.6
7.7
7.2
7.6
7.3
7.7
7.5
8.0
7.5
7.6
7.1
7.6
7.7
7.4
7.5
7.7
7.5
7.6
7.5
8.0
7.0
0.2
T +.»
^Jg/ull
b
ND
8S
ND
ND
ND
ND
ND
2.7
ND
ND
ND
0.3
ND
ND
ND
2.1
1.7
1.4
0.6
ND
1.0
ND
3.5
0.7
ND
ND
3.6
0.6
ND
ND
ND
ND
ND
ND
ND
ND
0.5
3.6
< 0.3
1.0
NOj-N
^Jg/raJ.
6.9
10.3
9.4
12.8
7.4
11.2
4.6
15.4
11.8
11.8
12.4
12.0
9.6
9.4
8.6
8.0
10.2
9.8
9.4
10.0
9.8
10.2
11.4
15.6
12.6
11.2
6.4
11.6
12.8
9.8
J2.2
15,0
10.2
13.2
8.2
8.S
10.6
15.6
4.6
2.4
NOj-N
us/mi
55
44
18
41
58
51
90
73
101
75
115
148
148
160
160
275
193
33
163
225
188
36
1325
275
613
200
288
169
187
281
156
153
150
73
113
143
183
1325
18
224
Kjeldahl
1.1
1.2
1.9
0.9
1.1
2.0
0.6
4.3
0.8
0.6
1.3
0.7
0.9
0.9
2.8
2.7
3.2
2.7
1.7
1.0
1.0
1.2
4.9
1.6
2.1
1.0
6.3
2.2
1.3
1.4
0.6
0.7
0.8
0.7
-
0.4
1.7
6.3
0.4
L.3
Dissolved
Ortho-P
0.15
0.11
0.15
0.19
0.27
0.18
0,20
0.81
0.43
0.16
0.16
0.09
0.00
0.14
0.85
0.51
0.89
0.81
0.11
0.14
0.29
0.19
0.34
0.33
0.65
0.51
1.80
0.65
0.57
0.30
0.10
0.13
0.13
0.07
0.30
0.32
0.36
1.80
< 0.01
0.35
Total
P
0.19
0.21
0.37
0.20
0.33
0.18
0.28
0.48
0.48
0.63
0.50
0.24
1.03
0.45
1.43
1.90
1.90
0.81
0.14
0.48
0.60
0.43
2.60
0.60
1.83
1.00
3.80
1.30
0.95
0.55
0.15
0.13
0.23
0.76
0.37
0.58
0.79
3.80
0.13
0.78
Zn
30
20
90
70
110
30
70
ND
20
180
20
30
20
20
100
60
28
120
135
78
56
214
64
155
73
220
205
120
110
400
162
84
112
82
65
170
98
400
< 10
79
Cu
30
ND
30
20
30
30
20
20
20
20
20
ND
20
20
ND
ND
15
15
ND
11
16
20
18
10
16
13
14
14
30
20
10
13
14
31
20
20
17
31
<10
9
Nt
ND
110
20
ND
30
ND
ND
20
ND
30
ND
30
30
30
30
15
13
20
30
15
30
25
25
25
15
30
16
20
46
24
20
13
20
20
26
26
22
110
<10
19
Cd
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
8
14
10
ND
ND
ND
ND
5
5
6
6
6
a
10
ND
ND
ND
4
ND
5
ND
5
5
7
< 4
14
< 4
4
Cr
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
7
5
5
ND
ND
ND
ND
ND
ND
ND
5
11
ND
9
5
ND
ND
5
6
ND
10
ND
< 5
11
< 5
3
Pb
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
70
ND
ND
ND
ND
ND
ND
ND
ND
50
ND
ND
ND
ND
ND
ND
50
ND
ND
ND
< 50
70
< 50
16
Year, month, day
Not detectable
-------
TABLE 15. CHEMICAL ANALYSIS OF WATER SAMPLES FROM NOVEMBER 18, 1975 TO NOVEMBER 11, 1976
TAKEN FROM SEEPAGE CREEK NO. 2 LOCATED ON THE CONCHO RIVER ADJACENT TO THE SAN ANGELO SEWAGE FARM
oo
Date
751118*
751125
751202
751209
751216
751222
760101
760108
760112
760121
760128
760204
760211
760218
760225
760303
760310
760315
760324
760331
760407
760414
760i21
760510
760526
760609
760624
760707
760722
760805
760831
760916
760928
761019
761103
761111
Mean
Maximum
Minimum
Standard
Time
150
1245
215
1245
1225
1104
1245
200
310
125
215
1130
1135
1145
100
1035
1050
200
1245
1230
100
330
1015
1140
1215
120
310
130
220
220
1215
1245
1246
1235
1145
1240
deviation
Temp
°C
21.5
20.0
20.0
20.0
19.9
19.7
20.0
19.0
19.5
19.7
19.5
19.0
18.8
18.8
17.8
21.0
18.4
18.9
18.4
13.5
19.0
19.3
18.2
18.0
18.4
18.9
18.4
19.6
19.6
19.5
19.3
19.7
19.8
20.8
19.0
20.0
19.3
21.5
17.8
0.8
PH
7.9
7.1
7.1
7.1
7.2
7.7
7.1
7.0
7.2
7.3
7.6
7.4
7.3
7.3
7.0
7.3
7.3
7.3
7.4
7.2
7.0
7.2
7.1
7.3
7.6
7.5
7.1
7.3
7.2
7.4
7.5
7.2
7.1
7.2
7.5
7.1
7.3
7.9
7.0
0.2
-1-
NH ,-N
4
/is/ml
NT,"
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
< 0.3
<0.3
<0.3
0
NOj-N
,Ug/ml
10.5
10.5
13.6
14.8
12.0
16.2
16.2
30.0
17.0
10.6
18.4
17.4
15.4
16.5
16.0
14.0
17.5
16.0
15.5
14.0
15.5
15.5
15.0
15.0
14.5
16.5
17.5
18.0
21.0
14.5
20.0
20.5
16.0
20.0
19.0
16.5
16.3
30.0
10.5
3.5
N02-N
ng/ml
ND
ND
5
5
ND
ND
ND
ND
ND
8
ND
ND
ND
ND
ND
5
8
ND
6
13
ND
5
7
6
16
ND
5
5
9
6
ND
10
6
6
7
ND
< 5
16
< 5
4
Kjeldahl
N
ND
0.4
ND
0.4
ND
1.2
0.3
ND
ND
ND
0.3
ND
ND
0.4
ND
ND
ND
1.0
ND
ND
ND
ND
0.3
0.3
ND
0.3
0.4
0.4
ND
0.4
ND
0.4
0.5
0.6
ND
ND
< 0.3
1.2
< 0.3
0.3
Dissolved
Ortho-P
-/is/ml
0.02
0.05
0.04
0.04
0.04
0.04
0.05
0.06
0.05
0.06
0.06
0.04
ND
0.05
0.05
ND
0.05
0.04
0.03
0.03
0.04
0.04
0.04
0.03
O.C6
0.05
0.04
0.02
0.03
0.04
0.03
0.02
0.01
0.04
0.01
SO
0.04
0.06
< 0.01
0.02
Total
P
Zn
Cu
Ni
Cd
Cr Pb
0.05
0.05
0.05
0.06
0.06
0.04
0.05
0.06
0.05
0.07
0.06
0.04
0.04
0.05
0.05
ND
0.05
0.04
0.03
0.03
0.04
0.04
0.04
0.03
0.07
0.05
0.04
0.02
0.03
0.04
0.03
0.02
0.01
0.04
0.01
ND
0.04
0.07
< 0.01
0.02
40
30
20
70
60
20
10
20
30
40
20
40
20
10
90
20
10
330
80
120
96
188
66
150
108
315
215
315
175
350
222
163
75
68
54
140
105
350
10
100
ND
ND
ND
30
40
20
ND
30
ND
ND
20
ND
ND
30
ND
ND
ND
11
19
ND
ND
18
18
10
ND
10
11
17
32
14
10
13
14
SD
20
10
11
40
< 10
11
ND
ND
ND
ND
30
ND
ND
ND
40
20
ND
ND
20
ND
20
ND
17
20
15
10
20
25
20
25
15
20
15
16
37
24
10
ND
17
20
23
20
14
40
< 10
11
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
12
14
6
ND
ND
ND
ND
ND
ND
5
6
6
7
5
ND
ND
ND
ND
ND
ND
ND
5
ND
5
< 4
14
< 4
4
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
7 ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
m ND
ND ND
ND ND
ND ND
ND 50
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
< 5 < 50
7 50
< 5 < 50
1 8
" Year, month, day
° Not detectable
-------
OJ
TABLE 16. CHEMICAL ANALYSIS OF WATER SAMPLES FROM NOVEMBER 18, 1975 to NOVEMBER 11, 1976
TAKEN FROM SEEPAGE CREEK NO. 3 LOCATED ON PRIVATE LAND ON THE CONCHO RIVER ADJACENT
TO THE SAN ANGELO SEWAGE FARM
Date
7511183
751125
751202
751209
751216
751222
760101
760108
760112
760121
760128
760204
760211
76021S
760225
760303
760310
760315
760324
760331
760407
760414
760421
760510
760525
760609
760624
760707
760722
760805
760831
760916
760928
761019
761103
761111
Mean
Maximum
Minimum
Standard
Time
1035
940
1040
1015
945
920
1050
1125
115
1040
1140
935
920
945
1000
950
1005
1050
930
1015
1030
200
905
900
955
935
1050
1030
1050
1030
1000
1000
1051
1042
940
1050
deviation
Temp
"C
19.5
18.5
19.0
19.0
18.2
18.0
18.9
18.6
18.0
18.8
18.8
19.0
19.0
19.0
13.9
19.0
19.0
19.9
18.2
18.5
18.1
20.2
18.8
19.0
18.0
19.1
19.0
19.5
19.6
19.4
19.8
19.6
19.2
18.9
19.3
18.8
18.9
20.2
18.0
0.5
pH
7.1
7.1
7.2
7.4
7.1
7.2
7.1
7.0
7.2
7.3
7.0
7.6
7.2
7.4
7.0
7.1
7.4
7.4
7.3
7.1
7.0
7.1
7.2
7.7
7.6
7.5
7.2
7.5
7.5
7.1
7.5
7.1
7.2
7.0
7.1
7.3
7.2
7.7
7.0
0.2
NH^-N
4
pg/ml
ND*
ND
ND
KD
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
<0.3
<0.3
<0.3
0
NOj-N
jug/ml
17.6
13.6
17.0
20.8
15.2
19.4
20.5
6.0
24.0
24.5
22.5
20.0
21.5
22.5
20.5
21.0
24.5
20.5
22.5
22.5
24.0
22.5
23.0
21.5
25.0
24.0
24.5
22.5
23.5
20.0
23.0
21.0
19.0
25.5
19.0
21.5
21.0
25.5
6.0
3.7
M>2-N
ng/ml
9
ND
5
5
ND
ND
ND
ND
ND
5
ND
ND
ND
ND
ND
ND
ND
6
ND
10
7
8
9
9
6
5
ND
5
9
6
5
12
6
6
7
ND
< 5
12
< 5
4
K.ji:ldahl
M
ND
0.4
ND
0.4
ND
1.2
0.5
ND
ND
ND
ND
ND
0.5
0.4
0.5
ND
ND
ND
0.3
ND
SD
ND
ND
0.4
NH
0.3
ND
ND
SD
ND
SD
0.4
ND
0.4
0.5
ND
<0.3
1.2
<0.3
0.3
Dissolved
Ortho-P
0.02
0.03
0.02
0.03
0.03
0.03
0.04
0.02
0.02
0.03
0.04
0.02
0.02
0.03
C.03
0.02
O.i12
0.05
NP
0.05
0.02
• 0.03
0.03
0.03
0.04
0.03
XD
0.01
0.02
0.03
0.02
ND
ND
0.01
0.01
ND
0.02
0.05
<0.01
0.01
Total
P
0.02
0.03
0.02
0.03
0.03
0.03
0.04
0.03
0.04
0.04
0.04
0.02
0.02
0.03
0.07
0.02
0.04
0.05
ND
0.05
0.02
0.03
0.03
0.03
0.04
0.06
0.03
0.01
0.02
0.05
0.03
Nl>
ND
0.01
0.01
ND
0.03
0.07
<0.01
0.02
Zn
40
50
50
90
60
60
20
40
60
100
150
90
130
20
70
20
58
99
69
120
35
119
23
97
60
135
71
77
45
115
84
44
55
77
31
96
71
150
20
35
Cu
20
ND
30
40
50
30
ND
ND
ND
ND
20
ND
20
20
ND
ND
11
ND
ND
11
10
18
10
10
ND
ND
17
14
50
14
ND
13
18
ND
17
10
13
50
<10
14
Hi
Hj
ND
ND
20
ND
20
ND
ND
20
20
20
ND
ND
20
ND
20
10
10
ND
20
15
25
20
20
25
25'
30
16
20
37
15
13
10
10
17
26
20
15
37
<10
10
Cd
!/nl
ND
ND
ND
ND
ND
ND
ND
Ml
ND
ND
ND
ND
12
12
8
ND
ND
5
5
5
5
5
12
8
10
5
ND
ND
ND
4
ND
ND
ND
6
ND
7
<4
12
< 4
4
Cr
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
6
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
5
ND
ND
ND
ND
ND
ND
ND
ND
<5
6
<5
1
Pb
ND
HD
ND
ND
ND
ND
' ND
ND
SO
ND
HP
ND
ND
ND
ND
ND
ND
ND
ND
ND
SD
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
<50
<50
<50
0
Year, month, day
b Not detectable
-------
TABLE 17. CHEMICAL ANALYSIS OF WATER SAMPLES FROM NOVEMBER 18, 1975 TO NOVEMBER 11, 1976 TAKEN
FROM CONCHO RIVER SAMPLING SITE NO. 1 LOCATED UPSTREAM FROM THE SAN ANGELO SEWAGE FARM
-Date
751118b
751125
751202
751209
751216
751222
760101
760108
760112
760121
760128
760204
760211
760218
760225
760303
760310
760315
760324
760331
760407
760414
760421
760510
760526
760609
760624
760707
760722
760S05
760?31
760916
760928
761019
761103
761111
Mean
Maximum
Minimum
Standard
Time
945
815
920
830
840
750
940
1030
1030
940
1045
845
830
825
845
840
850
935
815
840
915
930
805
745
240
825
925
845
915
900
830
830
934
932
822
900
Deviation
Temp
°C
16.5
9.5
9.5
10.0
9.3
8.7
8.0
4.0
6.7
7.5
8.2
10.0
13.0
13.0
10.7
18.8
13.8
14.0
15.3
14.2
18.0
21.2
19.4
18.5
28.0
25.2
28.0
27.0
26.4
28.0
25.3
26.0
21.7
15.9
13.3
15.0
15.8
28.0
4.0
7.0
PH
8.1
8.2
8.1
8.1
8.2
8.2
8.2
8.1
8.0
8.2
8.1
8.2
8.2
8;2
7.9
8.1
8.'2
8.1
8.0
8.0
8.1
8.1
8.4
8.2
8.3
8.1
8.4
8.0
7.9
8.0
8.2
7.8
7.8
7.8
7.8
8.2
8.1
8.4
7.8
0.2
NH*-N
Aig/ral
NDC
ND
ND
ND
ND
ND
0.3
ND
ND
ND
ND
0.7
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
1.0
ND
ND
ND
<0.3
1.0
<0.3
0.2
NO~-N
.Ug/ml
1.0
2.4
2.6
2.4
1.9
2.8
2.1
4.8
2.8
2.6
1.6
2.0
1.9
1.5
2.8
2.5
1.3
1.3
1.3
1.3
0.8
0.9
0.7
0.6
0.7
0.6
0.8
0.3
0.7
0.9
0.8
0.8
0.9
1.5
1.1
1.4
1.6'
4.8
0.3
0.9
NO^-N
ng/nl
19
18
28
15
14
19
25
25
20
23
25
18
20
25
34
28
34
26
28
43
31
43
14
18
71
26
44
15
30
28
28
32
26
22
20
16
27
71
14
11
Kjeldahl
rl
0.5
0.4
0.6
0,7
0.4
1.7
0.8
!O
0.5
0.3
0.5
1.1
0.8
0.7
0.6
to
0.6
1,0
0.3
0.4
0.6
0.5
0.4
0.8
1,1
0.8
1.7
0.9
0.6
0.4
1.0
0.5
0.8
0.8
0.5
0.6
0.7
1.7
<0.3
0.4
Dissolved
Ortho-P
'--- /ig/ml — -
ND
0.03
0.02
0.01
0.02
0.02
0.01
0.02
ND
0.01
0.03
0.02
0.02
0.06
0.02
ND
0.02
0.03
0.03
0.01
0.02
0.02
0.02
0.02
0.01
0.01
ND
0.03
0.04
ND
0.01
0.01
ND
0.01
0.01
0.01
0.017
0.060
<0.010
0.013
Total
P
0.06
0.06
0.09
0.01
0.06
0.03
0.05
0.05
0.06
0.08
0.05
0.05
0.07
0.06
0.06
0.05
0.07
0.04
0.03
0.06
0.07
0.14
0.12
0.07
0.09
0.10
0.10
6.04
0.04
0.08
0.03
0.01
0.03
0.06
0.04
0.02
0.060
0.140
<0.010
0.029
Zn
40
50
30
70
80
30
10
20
30
120
10
90
30
20
80
10
23
10
12
35
24
64
29
76
380
63
27
24
30
42
32
22
19
23
18
40
48
380
10
63
Co
130
20
ND
50
40
20
30
30
ND
20
20
30
20
20
ND
ND
15
ND
21
11
32
12
18
21
ND
10
17
ND
66
14
ND
10
12
ND
23
ND
20
130
< 10
24
Ni
ng,
40
ND
40
20
ND
ND
ND
ND
30
ND
ND
ND
ND
ND
ND
ND
13
ND
ND
ND
15
ND
10
20
ND
15
ND
ND
87
ND
NI)
ND
ND
ND
10
10
<10
87
{ 10
18
Cd
/ml
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
5
5
5
5
ND
ND
ND
5
ND
ND
ND
ND
ND
ND
<4.0
5.0
<4.0
1.8
Cr Pb
ND ND
20 ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND 70
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND' ND
ND ND
ND ND
5 ND
ND ND
ND ND
ND ND
<5.0 <50
20.0 70
<5.0 <50
3.4 12
a Significantly different from downstream water samples
b Year, month, day
c Not detectable
-------
TABLE 18. CHEMICAL ANALYSIS OF WATER SAMPLES FROM NOVEMBER 18, 1975 TO NOVEMBER 11, 1976 TAKEN
FROM CONCHO RIVER SAMPLING SITE NO. 2 LOCATED DOWNSTREAM FROM THE SAN ANGELO SEWAGE FARM
Date
751118b
751125
751202
751209
751216
751222
760101
760108
760112
760121
760128
760204
760211
760218
760225
760303
760310
760315
760324
760331
760407
760414
760421
760510
760526
760609
760624
760707
760722
760805
760831
760916
760928
761019
761103
761111
Mean
Maximum
Minimum
Standard
Time
310
115
150
130
1240
1117
100
215
325
140
230
1145
1215
1220
120
1205
1205
205
1115
1145
115
345
1030
1045
125
135
325
155
235
240
1245
100
110
103
1255
135
Deviation
Temp
°C
18.0
12.0
13.0
13.0
13.0
10.0
10.9
7.2
10.9
10.3
11.0
13.0
15.0
16.5
14.8
21.0
16.2
17.1
17.8
16.9
20.0
25.0
20.6
19.9
25.8
26.9
27.4
28.8
26.4
30.8
26.6
27.2
22.1
17.2
17.8
15.8
18.2
30.8
7.2
6.3
pH
8.0
7.9
8.0
8.0
8.2
8.0
7.9
8.0
7.9
8.1
8.2
8.1
8.0
7.9
7.9
7.8
8.0
8.1
7.9
8.0
7.9
8.0
8.2
8.1
8.2
8.1
8.0
7.8
7.9
8.1
8.0
7.8
7.3
7.7
7.9
7.9
8.0
8.2
7.7
0.1.
/ug/ml
NDC
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
0.4
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
0.3
ND
ND
ND
ND
0.7
ND
ND
ND
<0.3
0.7
<0.3
0.1
NOJj-N
jug/ml
3.9
6.0
6.6
6.0
5.7
7.3
6.3
14.0
8.2
8.2
5.6
6.6
6.0
5.1
6.3
5.8
6.5
5.9
6.3
6.1
3.3
3.4
5.1
3.4
4.3
5.0
7.1
3.1
3.6
6.3
3.5
4.5
4.5
5.4
3.9
5.1
5. f
14.0
3.1
2.0
NOI-N
rig/ml
24
33
38
16
19
23
29
31
31
31
24
25
31
38
45
50
59
44
50
80
50
78
75
80
185
•75
120
45
65
93
30
56
60
29
24
33
51
185
16
33
KJeldahl
H
ND
0.6
0.6
0.6
0.5
1.3
0.5
0.5
0.7
0.7
0.6
0.9
0.9
0.8
0.6
ND
0.6
1.4
1.0
0.7
0.5
0.7
0.7
0'.9
1.0
1.8
1.7
1.0
0.9
0.3
ND
0.6
0.7
0.9
ND
0.4
0.7
1.8
<0.3
0.4
Dissolved
Ortho-P
jug/ml— — •
0.02
0.02
0.19
ND
0.02
0.01
0.01
0.05
0.01
0.01
0.02
0.02
0.02
0.02
0.05
0.03
0.03
0.05
0.02
0.03
0.02
0.03
0.02
0.02
0.03
0.01
ND
0.01
0.02
ND
0.01
ND
ND
0.02
0.04
0.01
0.024
0.190
< 0.010
0.031
Total
P
0.06
0.06
0.19
0.10
0.06
0.04
0.06
0.06
0.14
0.14
0.07
0.06
0.08
0.07
0.06
0.08
0.07
0.05
0.03
0.09
0.08
0.11
0.18
0.14
0.10
0.12
0.12
0.05
0.05
0.06
0.03
0.03
0.05
0.04
0.07
0.01
0.078
0.1SO
0.010
0.042
Zn
40
50
60
80
60
40
20
20
30
50
20
40
40
20
110
90
119
290
60
125
157
215
89
185
150
235
275
200
140
500
236
181
95
82
102
210
123
500
20
101
Cu
20
ND
40
30
30
ND
ND
ND
ND
20
30
20
ND
ND
ND
ND
ND
ND
11
15
15
15
13
13
10
10
19
12
20
17
10
16
18
11
15
ND
12
40
4.10
11
Nl
20
20
ND
ND
ND
ND
ND
ND
20
ND
ND
ND
ND
ND
ND
KD
ND
20
ND
10
15
15
15
20
ND
20
10
10
24
19
ND
ND
ND
ND
ND
14
<10
24
< 10
9
Cd
-ng/ml--
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
8
ND
ND
ND
ND
5
ND
ND
ND
5
12
5
10
ND
ND
7
ND
ND
ND
ND
5
ND
ND
< 4.0
12.0
<4.0
3.2
Cr
ND
ND
ND
ND
ND
10
ND
ND
ND
ND
ND
ND
ND
ND
ND
5
TO
5
ND
ND
ND
ND
ND
ND
ND
7
ND
ND
5
ND
ND
ND
5
ND
ND
ND
<5.0
10,0
<5.0
2.5
Pb
KD
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
<50
<50
<50
ND
Significantly different from upstream water samples.
b Year, month, day
c Not detectable
-------
TABLE 19. CHEMICAL ANALYSIS OF WATER SAMPLES FROM DOMESTIC DEEP WELLS
AND SHALLOW GROUND WELLS AT THE SEWAGE FARM
Date
Time
Temp.
°C
pH
NHt-N
/ig/ml
NO~-N
Jig/ml
NOj-N
ng/ml
Shallow Ground Well -
751118 a
751125
751202
751209
751216
751222
760101
760108
760112
760121
760128
760204
760211
760218
760225
760303
760310
760315
760324
760331
760407
760414
760421
760510
760521
760609
760624
760707
760722
760805
760831
760916
760928
761019
761103
761111
230
1055
1200
1120
1105
1005
1138
1240
150
1145
115
1025
1020
1045
1055
1120
1120
1205
115
130
1130
1030
945
1220
1050
1050
155
1140
1245
105
1115
1130
1152
1137
1115
100
18.5
16.0
16.5
15.5
15.0
14.5
14.1
12.3
13.7
12.2
13.2
11.3
13.5
14.0
12.3
16.4
16.6
16.5
17.2
16.0
16.6
23.1
16.8
19.7
21.9
20.4
21.8
23.9
23.2
22.0
23.0
25.3
22.0
17.9
17.0
15.3
7.4
7.3
7.6
7.6
7.3
7.1
7.5
7.5
7.4
7.8
8.1
7.7
7.5
7.6
7.4
7.4
7.2
7.4
7.1
7.2
7.1
7.0
7.3
7.0
7.9
7.7
7.3
7.6
7.1
7.2
7.7
7.5
7.6
7.1
7.5
7.3
NDb
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
0.6
1.0
ND
ND
ND
6.2
8.4
1.7
1.1
0.8
4.4
0.9
1.3
0.2
0.7
0.7
0.5
1.9
0.2
0.3
0.1
1.5
0.9
3.4
2.8
3.0
12.8
4.6
0.8
6.7
2.2
2.2
6.9
6.4
4.2
0.6
0.5
0.3
2.2
2.1
4.1
26
8
5
8
ND
28
ND
10
13
6
ND
ND
17
ND
ND
5
725
20
363
40
88
43
700
125
575
150
215
323
537
75
10
20
15
111
75
78
Kjeldahl
N
Dissolved
Ortho-P
..*. /~i
Total
P
Zn
Cu
Nl
«« /
Cd
'_1
Cr
Pb
Location No.
1.5
0.7
ND
0.5
ND
1.2
0.7
ND
ND
SD
ND
ND
NP
0.4
ND
IID
ND
ND
0.3
ND
ND
ND
ND
ND
0.7
0.7
ND
0.3
ND
ND
ND
ND
1.3
ND
0.7
ND
8
0.04
ND
0.01
0.01
0.01
0.01
0.04
ND
0.02
ND
0.02
0.02
0.02
0.01
0.01
0.02
ND
0.04
0.03
0.02
0.02
0.03
0.02
0.03
0.03
0.02
ND
0.01
0.02
ND
ND
H>
ND
0.01
0.02
0.01
0.59
0.22
0.14
0.01
0.19
0.30
0.08
0.07
0.03
0.06
0.07
0.04
0.20
0.02
0.02
0.03
0.08
0.04
0.03
0.02
0.05
0.03
0.02
0.03
0.04
0.04
0.03
0.01
0.02
0.02
0.02
to
ND
0.01
0.02
0.01
50
280
500
200
150
90
110
30
120
240
250
200
240
70
140
120
228
160
235
275
155
105
165
355
195
295
341
255
220
470
286
166
190
157
48
352
20
230
100
120
120
90
70
30
80
120
100
50
140
80
70
210
145
120
70
212
150
36
340
177
165
280
242
275
102
110
158
92
230
120
120
116
ND
ND
20
20
30
ND
40
20
30
ND
ND
ND
20
ND
20
ND
ND
25
10
10
25
25
20
25
25
20
18
16
46
19
13
10
10
20
26
20
ND
ND
10
ND
ND
ND
ND
ND
ND
ND
ND
ND
6
12
7
ND
ND
ND
5
5
•6
5
8
8
10
6
ND
ND
ND
5
ND
ND
ND
8
ND
5
ND
ND
20
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
8
6
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
TO
ND
ND
ND
ND
ND
ND
150
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
Year, month, day
Not detectable
(continued)
-------
TABLE 19. (continued)
UJ
Date
751118s
751125
751202
751209
751216
751222
760101
760108
760112
760121
760128
760204
760211
760218
760225
760303
760310
760315
760324
760331
760407
760414
760421
760510
760526
760609
760624
760707
760722
760805
760831
Tine
245
1110
1220
1135
1120
1021
1147
115
220
1200
130
1035
1035
1100
1110
1135
1135
100
100
115
1145
1100
955
1205
1100
1105
215
1210
100
120
1125
Temp.
°C
18.5
16.2
15.5
16.0
15.1
15.0
16.0
13.2
16.1
14.6
19.2
15.6
16.1
11.2
15.3
18.8
16.6
16.8
17.3
19.3
18.0
23.5
18.3
20.0
19.8
21.0
21.9
22.9
22.0
24.0
22.5
pH
6.9
7.3
7.7
7.1
7.7
7.0
7.2
7.7
7.5
8.0
7.6
7.5
7.4
7.2
7.4
7.1
7.1
7.2
7.1
7.1
7.1
7.2
7.1
7.1
7.6
7.5
7.0
7.3
7.2
7.2
7.5
NH+-N
Jig /ml
NDb
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
6.3
NOj-N
/ig/ml
Shallow
8.1
9.2
2.6
12.7
11.8
13.8
9.2
14.4
6.2
2.0
4.9
8.6
5.5
4.0
5.0
5.5
10.8
10.0
2.6
11.1
10.2
12.6
U.4
3.8
14.0
12.2
13.8
13.0
10.6
10.0
6.6
NOj-N
ng/ml
Ground Well
25
25
10
10
14
23
20
33
36
8
9
28
26
37
21
250
46
10
50
63
60
50
75
300
238
350
350
400
525
388
30
Kjel.iahl
N
- Location
ND
0.7
1.1.
0.3
0.4
1.1
0.7
1.0
0.5
ND
0.3
BD
0.5
1.3
M)
iV
ND
i..l
ND
IID
HD
ND
0.4
NT*
HD
KD
0.3
:ro
:JD
3.5
6.6
Dissolved
Ortho-P
No. 17
0.08
0.10
0.04
0.06
0.05
0.04
0.05
0.06
0.01
0.03
0.02
0.03
0.03
0.02
0.01
ND
0.02
0.02
0.03
0.01
0.05
0.06
0.05
0.05
0.04
0.03
0.01
0.03
0.05
0.02
0.06
Total
P
0.09
0.35
0.07
0.07
0.08
0.04
0.24
0.15
0.05
0.04
0.04
0.05
0.16
0.03
0.03
0.02
0.04
0.02
0.03
0.01
0.05
0.15
0.08
0.05
0.04
0.07
0.09
0.03
0.05
0.04
0.07
Zn
60
240
10
270
130
50
210
70
120
190
270
110
180
50
100
80
156
210
165
125
112
140
180
340
180
225
325
225
190
480
232
Cu
40
230
ND
140
280
100
310
40
100
60
100
190
340
60
60
60
94
290
92
162
125
71
350
238
190
195
347
115
130
160
142
Nl
ND
40
ND
ND
20
ND
20
ND
30
ND
ND
20
20
ND
ND
10
ND
10
20
10
25
25
25
25
38
15
22
20
46
24
ND
Cd
no /ml ...
ND
10
ND
ND
ND
ND
ND
ND
ND
ND
ND
HD
8
ND
8
ND
ND
ND
ND
6
6
6
8
6
12
6
14
ND
5
4
ND
Cr
10
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
8
ND
6
5
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
Pb
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
70
ND
ND
ND
ND
ND
50
ND
a Year, month, day
b Not detectable
(continued)
-------
TABLE 19. (continued)
Date
751216s
751222
760101
760108
760112
760121
760128
760204
760211
760218
760225
760303
760310
760315
760324
760331
760407
760414
760421
760510
760526
760609
760624
760707
760722
760805
760831
760916
760928
761019
761103
761111
Time
110
1140
120
230
335
155
300
1200
1235
1235
135
1220
115
230
1015
1100
130
1130
1045
950
145
150
340
220
250
255
100
115
200
121
115
150
Temp
°C
19.0
18.5
12.6
12.0
18.1
11.8
16.5
16.8
16.2
18.5
17.6
17.8
16.0
16.3
16.8
16.5
17.5
20.2
17.5
17.3
19.0
19.2
19.7
21.5
21.0
20.1
19.8
21.6
20.0
20.7
20.0
18.5
pH
7.4
7.4
7.1
7.0
7.4
7.3
7.0
7.6
7.0
7.0
7.0
7.1
7.1
7.1
7.2
7.0
7.0
7.4
7.3
7.6
7.2
7.3
7.1
7.2
7.2
7.0
7.4
7.0
7.1
7.0
7.0
7.0
NH+-N
>ig,'«il
ND*
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
NO~-N
ml
Shallow
0.8
1.4
0.7
1.4
0.7
1.3
1.6
1.8
0.9
1.3
1.0
0.8
10.8
2.0
0.3
1.6
0.8
0.8
0.2
0.8
1.9
1.1
0.7
1.1
2.1
1.3
0.8
0.5
0.5
1.3
0.4
0.3
SO^-N
ng/ml
Ground
5
8
20
7
13
28
ND
15
11
5
8
11
47
9
12
14
13
29
37
45
26
5
9
9
8
11
ND
12
14
11
7
ND
Kjeldahl
N
Well - Location
0.6
1.4
0.5
0.4
0.4
ND
0.3
0.5
0.4
0.5
0.5
N3
NO
O.o
ND
ND
ND
1.0
0.4
0.6
0.8
0.4
0.5
NO
N3
NO
N'3
0.4
NO
S3
0.5
N3
Dissolved
Ortho-P
— -/jg/ml
No. 18
0.05
0.09
0.10
0.10
0.13
0.15
0.11
0.10
0.09
0.10
0.10
.14
0.02
0.13
0.09
0.08
0.14
0.16
0.11
0.12
0.15
0.16
0.13
0.10
0.13
0.11
0.14
0.07
0.08
0.05
0.10
0.01
Total
P
0.05
0.09
0.12
0.15
0.14
0.15
0.13
0.10
0.09
0.10
0.10
0.14
0.04
0.13
0.09
0.08
0.14
0.17
0.11
0.12
0.16
0.16
0.13
0.10
0.13
0.11
0.14
0.07
0.08
0.13
0.10
0.10
Zn
180
60
70
60
90
110
120
80
110
70
180
120
132
310
125
225
202
275
258
248
245
550
465
370
370
650
400
320
192
197
206
330
Cu
310
90
110
80
130
100
90
60
160
150
90
90
87
92
140
173
135
234
490
257
165
670
147
160
180
102
122
142
180
100
145
140
Nl
ng/ml
20
ND
20
20
40
ND
ND
ND
ND
ND
ND
15
ND
10
15
15
20
25
15
15
25
30
16
10
42
15
ND
101
10
29
29
26
Cd
ND
ND
ND
ND
ND
10
ND
ND
10
ND
ND
ND
ND
ND
ND
5
5
9
6
6
8
5
ND
ND
5
ND
ND
ND
ND
6
7
7
Cr
ND
ND
ND
ND
ND
ND
ND
ND
6
ND
7
ND
ND
ND
5
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
Pb
BD
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
b Year, month, day
Not detectable
(continued)
-------
TABLE 19.. (continued)
Date
7512168
751222
760101
760108
760112
760121
760128
760204
760211
760218
760225
760303
760310
760315
760324
760331
760407
760414
760421
760510
760526
760609
760624
760707
760722
760805
760831
760916
760928
761019
761103
Time
120
1155
125
240
345
1200
310
1210
1245
1245
150
1235
130
245
1030
1110
145
1145
1050
1000
1155
200
350
230
305
310
115
130
205
130
130
Temp
°C
19,0
17.0
16.3
11.5
17.4
14.6
16.0
15.0
15.7
18.7
16.2
17.2
17.7
16.8
16.8
16.2
16.9
21.2
16.8
17.0
18.2
17.7
18.4
20.1
21.0
21.7
19.2
20.3
19.9
20.3
18.7
PH
7.1
6.9
7.0
7.0
7.1
7.2
7.0
7.3
7.0
7.0
7.0
6.9
7.0
7.0
7.0
7.0
6.3
7.2
7.0
7.3
7.4
7.0
7.0
7.2
7.0
7.0
7.0
7.0
7.0
7.0
7.1
NH+-N
jig/ml
**
ND
ND
ND
m
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
NO^-N
^Jg/ral
Shallow
1.6
4.0
1.3
2.3
0.8
1.7
1.7
1.5
1.6
1.1
1.2
1.1
1.1
0.4
0.4
1.4
1.5
2.0
2.2
2.4
3.7
3.9
4.2
2.9
4.7
6.0
6.0
8.5
6.6
7.4
1.4
NOj-N
ng/ral
Ground Well
ND
ND
10
5
9
5
14
ND
ND
ND
ND
5
39
11
6
16
7
11
15
43
10
6
14
9
12
13
13
12
11
9
19
Kjeldahl
S
- Location I
ND
0.9
0.7
ND
ND
ItD
0.3
ND
tro
0.4
;ro
ND
ND
0.5
1JD
:n>
iffi
KD
HD
0.4
KD
:m
ai>
SD
ND
D.5
SC
D.3
:XD
TO
0.5
Dissolved
Ortho-P
---- *ig/ml-----
(o. 19
0.03
0.03
0.03
0.18
0.02
0.04
0.04
ND
0.02
0.02
0.02
0.02
0.03
ND
0.02
0.01
0.03
0.02
0.03
0.04
0.03
0.04
0.02
0.03
0.02
0.01
0.03
ND
0.01
0.03
0.18
Total
P
0.03
0.03
0.05
0.18
0.04
0.04
0.04
0.02
0.03-
0.02
0.02
0.02
0.07
ND
0.03
0.01
0.03
0.02
0.03
0.04
0.03
0.05
0.02
0.03
0.02
0.01
0.03
0.01
0.01
0.05
0.18
Zn
150
140
90
50
100
120
130
70
110
60
150
120
218
410
86
130
257
215
270
247
170
580
475
435
390
970
446
273
181
187
246
Cu
170
400
90
40
240
150
120
50
100
60
70
60
83
150
135
200
157
74
420
210
125
400
3J2
150
215
102
122
142
180
100
145
Nl
30
ND
40
20
50
ND
ND
ND
ND
20
20
25
10
10
20
20
25
25
20
20
38
35
18
16
50
15
ND
13
ND
26
35
Cd
ng/ml--— •
ND
ND
ND
ND
ND
ND
ND
ND
12
ND
9
ND
ND
5
ND
6
5
6
6
6
12
6
8
ND
5
4
ND
KD
ND
6
11
Cr
ND
ND
ND
ND
ND
10
ND
ND
7
6
7
5
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
6
Pb
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
50
ND
50
ND
ND
a Year, month, day
b Not detectable
(continued)
-------
TABLE 19 . (continued)
Date
76Ulf
751216
751222
760101
760108
760112
760121
760128
760204
760211
760218
760225
760303
760310
760315
760324
760331
760407
760414
760421
760510
760526
760609
760624
760707
760722
760805
760831
760916
76092S
761019
761103
761111
Time
205
130
1200
130
250
355
230
320
1220
1255
100
155
1250
145
310
1045
1120
200
1200
1055
1010
205
210
400
245
320
325
130
145
211
133
145
220
Temp
°C
18.0
19.0
19.0
18.6
17.0
18.6
18.3
17.7
18.0
18.1
17.9
19.2
19.1
18.0
19.8
16.8
17.0
18.7
20.4
15.9
16.8
18.1
17.9
18.0
22.1
19.8
20.2
20.8
20.1
19.0
20.9
20.0
18.0
pH
7.0
7.0
6.9
7.0
7.1
7.1
7.1
7.0
7.3
7.0
7.0
6.9
7.0
7.0
7.1
7.0
6.9
6.8
7.0
7.0
7.0
7.2
7.0
7.0
7.0
7.0
7.2
7.1
7.0
7.0
7.0
7.3
7.0
NH*-N
(Jg/ml
b
ND
ND
ND.
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
NO"-N
.ug/ml
Shallow
4.4
4.4
6.6
5.2
7.2
5.1
4.3
4.9
5.0
4.3
3.8
3.9
3.8
4.1
2.4
0.7
4.2
3.9
5.0
5.1
4.2
8.0
7.3
7.4
7.0
10.1
6.8
10.0
9.5
7.6
10.8
8.2
7.6
NO"-N
ng/ml
Ground
11
11
6
6
8
5
8
ND
ND
ND
ND
13
5
8
6
7
13
7
14
16
23
16
5
20
7
15
21
6
13
10
13
5
ND
KJeldahl
N
Well - Location
ND
0.3
0.7
0.4
ND
ND
HD
ND
0.5
0.4
0.4
0.4
KD
ND
0.6
ND
ND
ND
J;D
ND
ND
ND
ND
NO
ND
ND
ND
ND
0.3
ND
0.3
ND
ND
Dissolved
Ortho-P
/ig/ro.l
No. 20
0.01
0.02
0.03
0.03
0.02
0.01
0.03
0.02
ND
0.01
0.03
0.02
KD
0.02
0.04
0.02
0.03
0.02
0.02
0.04
0.04
0.04
0.04
ND
0.01
0.02
0.01
0.02
0.01
KD
0.02
0.03
KD
Total
P
0.01
0.02
0.03
0.03
0.05
0.03
0.03
0.02
0.01
0.01
O.Q3
0.02
ND
0.05
0.04
0.07
0.03
0.02
0.02
0.04
0.04
0.08
0.07
0.01
0.01
C.02
0.03
0.02
ND
0.03
0.02
0.07
ND
Zn
525
180
50
90
50
70
150
190
80
100
80
180
120
168
540
125
170
275
178
270
235
330
515
465
600
340
660
402
360
235
207
216
365
Cu
140
190
100
120
70
70
150
170
70
100
130
90
60
74
60
120
185
120
36
350
210
320
235
187
120
81
225
128
104
166
105
110
175
Ni
ng/ml
26
20
ND
40
20
40
ND
ND
ND
ND
20
20
25
20
15
20
20
40
30
30
20
38
35
18
20
42
15
ND
16
10
20
20
26
Cd
8
ND
ND
ND
ND
ND
ND
ND
ND
12
8
10
ND
ND
8
ND
8
6
6
11
6
10
ND
5
ND
5
ND
ND
ND
ND
6
11
8
Cr
ND
10
ND
ND
ND
ND
10
ND
ND
8
6
7
5
ND
ND
5
ND
ND
tJD
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
Pb
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
70
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
50
ND
ND
ND
ND
Year, month, day
Not detectable
(continued)
-------
TABLE 19, (continued)
Kjeldnhl Dissolved
Date
751216*
751222
760101
760108
760112
760121
760128
760X04
760211
760218
760225
760103
760110
760U5
760324
760331
760'.07
760414
760121
760110
760526
760f,016
760928
761019
761103
761111
Time
140
1215
140
300
405
250
345
1230
105
115
210
105
200
325
1100
1130
215
1215
1100
1020
215
220
410
300
335
340
145
200
222
144
200
235
Temp
o
C
18.0
18.0
18.8
18.5
18.1
17.7
17.8
18.0
17.7
18.8
18.6
21.2
17.2
17.2
16.8
16.8
18.1
21.1
16.5
17.2
19.3
18.9
19.5
21.0
20.8
19.8
19.7
20.5
19.3
20.9
19.5
16.6
pH
7.0
7,0
7,0
7.3
7.1
7.3
7. 1
7.2
7.0
7.3
7.0
7.0
7.1
7.1
7.1
7.2
7,2
6,8
6.9
7.2
7.2
7.2
7.0
7.1
7.1
7.1
7.1
7.1
7.1
7.1
7.4
7-2
NH+-N
fig/ml
b
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
KD
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
NOj-N
/Jg/nii
Shallow
10.2
12.0
8.4
18.0
14.4
15.6
12.0
8.4
11.2
13.0
13.6
16.0
8.8
4.8
8.2
11.6
12.2
12.2
13.2
15.6
17.4
18.8
15.0
16.0
17.4
10.8
16.2
20.0
16.5
25.0
11. 0
14.0
NOj-N
ng/ml
Ground
6
6
6
8
8
9
ND
ND
ND
ND
6
8
8
6
ND
8
9
20
15
16
31
11
6
36
238
ND
20
13
24
14
5
SD
N
• •— -- .
Ortho-P
. — jUg/ml •
Total
p
Zn
Cu
Ni
Cd
ng/ml---
Cr
Pb
Well - Location no. 21
ND
1.0
0.5
ND
ND
ND
0.3
ND
ND
0.7
ND
ND
ND
ND
ND
NO
SD
(TO
SD
0.7
ND
0.5
ND
ND
0.6
ND
NO
0.3
0.4
1.5
ND
ND
~ SIJAUJOW r.F.OlINTT
All Sainpl«s (N
Mean
Maxinum
MinlTTMm
Standard
* Vear.
deviation
month, day
18.1
25.3
11.2
2.6
7.2
8.1
6.8
0.2
<0.3
6.3
<0.3
0.5
5.8
25.0
0.1 <
5.2
49
725
5
118
< 3.3
6.6
<: 0.3
0.6
0.01
0.03
0.02
ND
0.02
0.02
0.02
ND
0.01
0.02
0.02
ND
0.02
ND
0.01
0.03
0.03
0.03
0.02
0.04
0.02
0.03
ND
ND
0.02
0,01
0.02
0.01
ND
0.03
0.01
ND
'WEES " ~~~
• 195)
0.04
0.18
<0.01
0.04
0.02
0.03
0.03
0.04
0.03
0.03
0.02
0.02
0.01
0.02
0.02
ND
0.06
ND
0.01
0.03
0.02
0.03
0.02
0.04
0.02
0.09
0.02
ND
0.02
0.02
O.'.O
0.01
0.01
0.04
0.01
ND
0.06
0'.59
<0.0i
0.07
180
40
70
50
100
110
120
70
100
80
170
140
208
740
115
125
310
175
310
210
335
920
465
740
500
710
400
445
210
402
316
3 HO
233
970
10
165
20
50
70
60
130
70
100
50
110
120
60
70
64
90
115
150
180
31
565
225
230
310
222
94
150
295
78
224
144
94
181
145
149
670
< 10
97
20
ND
40
ND
30
ND
ND
Nn
20
20
30
25
13
10
20
15
20
20
25
15
38
35
18
16
42
29
ND
16
10
20
23
23
17
50
<10
13
ND
ND
ND
ND
ND
ND
ND
ND
12
6
8
ND
ND
ND
ND
8
6
6
8
6
12
ND
6
ND
7
ND
5
ND
ND
8
7
7
<4
14
<4
4
20
ND
ND
ND
ND
10
SD
ND
u
6
8
NO
ND
ND
5
ND
ND
NO
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
<5
20
<5
3
ND
NP
ND
ND
ND
ND
ND
ND
ND
ND
ND
70
70
ND
ND
ND
ND
NT)
ND
ND
ND
ND
ND
ND
ND
ND
ND
K>
ND
ND
ND
ND
<50
150
<50
16
Not detectable /___*-,•„ i\
-------
TABLE 19. (continued)
oo
Date
751118"
751125
751202
751209
751216
751222
760101
760108
760112
760121
760128
760204
760211
760218
760225
760303
760310
760315
760324
760407
760414
760421
760510
760526
760609
760624
760707
760722
760805
760831
760916
760928
761019
761103
761111
Time
1010
835
945
905
900
852
1004
1045
1230
955
1115
915
855
900
915
910
920
1005
900
930
1015
855
815
900
840
1000
955
955
1000
930
915
1026
1022
915
1025
Temp.
°C
22.0
13.0
19.0
19.5
18.5
19.6
21.0
18.2
17.2
8.3
19.0
19.0
14.5
20.5
13.0
20.3
14.0
19.6
21.5
16.8
20.5
19.0
20.2
2A.O
25.0
25.4
26.0
24.2
26.3
25.0
26.8
21.2
19.0
20.5
20.7
PH
7.3
7.3
7.3
7.2
7.4
7.3
7.2
7.1
7.4
7.7
7.2
7.4
7.0
7.4
7.0
7.3
7.3
7.3
7.2
7.1
7.2
7.6
7.5
7.6
7.6
7.4
7.5
7.5
7.3
7.4
7.3
7.2
7.0
7.2
7.5
NH+-N
/ig/ml
ND»
ND
ND
•ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
NO~-N
/ig/ml
Domestic
4.8
9.3
7.6
9.0
5.8
11.2
3.6
14.0
9.6
10.0
9.4
8.4
8.6
8.4
8.0
6.8
8.6
7.8
8.2
6.2
8.8
8.8
8.0
9.6
8.4
9.2
7.4
10.8
8.2
10.2
10.8
8.6
14.4
9.0
10.4
NO~-N
ng/ml
Deep Well
ND
ND
5
5
ND
ND
ND
5
ND
13
ND
ND
11
ND
ND
ND
5
ND
ND-
ND
5
40
9
6
ND
10
ND
5
ND
ND
12
8
8
9
5
Kjeldahl
N
- Location
1.1
ND
ND
ND
0.4
1.0
0.3
ND
ND
ND
ND
ND
0.5
ND
ND
ND
ND
ND
ND
ND
ND
ND
0.3
ND
ND
ND
ND
ND
ND
ND
0.3
0.3
ND
ND
ND
Dissolved
Ortho-P
.... — pg/iol- --
No. 9
ND
ND
ND
ND
0.01
0.01
0.02
ND
0.01
0.03
0.02
0.01
ND
0.03
ND
ND
ND
0.02
0.03
0.01
0.02
0.02
ND
0.02
0.01
ND
0.02
0.02
0.01
0.03
ND
ND
0.01
ND
ND
Total
P
ND
ND
ND
ND
0.02
0.01
0.03
ND
0.03
0.04
0.02
0.01
0.03
0.03
0.01
ND
0.01
0.02
0.03
0.01
0.02
0.02
0.03
0.03
0.01
0.01
0.02
0.02
0.01
0.03
ND
ND
0.01
ND
ND
Zn
120
120
100
140
90
110
60
310
70
120
140
160
180
70
150
70
48
117
93
118
200
175
160
155
200
120
140
110
250
190
180
262
377
66
138
Cu
50
ND
60
40
30
ND
20
»
ND
20
20
ND
20
30
ND
20
15
15
21
30
28
13
13
16
45
35
30
66
40
16
34
30
15
24
22
Hi
ng/ml
40
ND
40
ND
ND
ND
170
ND
30
20
ND
ND
ND
ND
ND
ND
10
15
20
25
20
20
25
45
15
18
16
42
24
10
10
17
20
20
20
Cd
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
10
6
6
ND
ND
5
ND
9
5
6
6
8
6
19
ND
ND
8
ND
ND
ND
6
ND
5
Cr
10
ND
10
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
6
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
5
5
ND
ND
ND
ND
ND
ND
ND
m
Pb
ND
ND
ND
SD
ND
ND
ND
ND
ND
ND
150
ND
ND
ND
ND
ND
70
SO
70
ND
ND
ND
70
ND
50
ND
ND
50
50
ND
ND
ND
ND
ND
ND
* Year, month, day
b Not detectable
(continued)
-------
TABLE 19. (continued)
-o
VO
Date
Time
Temp
°C
PH
<*
/ig/ml
NOj-N
Jig /in I
NOJ-N
ng/ml
Domestic Deep Well
751118 a
751125
751202
751209
751216
751222
760101
760108
760112
760121
760204
760211
760218
760225
760303
760310
760315
760324
760331
760407
760414
760421
760510
760526
760609
760624
760707
760722
760805
760831
760916
760928
761019
761103
761111
h Year,
1025
920
1025
1000
935
825
1035
1115
105
1030
925
910
930
945
935
950
1035
915
1000
1015
145
900
850
940
925
1035
1015
1030
1015
950
940
1044
1032
920
1040
month, day
20.0
18.5
19.5
19.5
19.2
19.4
19.7
13.0
19.5
17.7
19.1
19.6
19.8
19.2
18.6
19.2
20.6
19.0
19.5
18.7
20.5
19.3
20.0
21.0
19.0
20.8
20.5
20.5
21.1
21.0
21.7
19.8
19.1
19.0
19.0
7.0
6.9
7.0
7.1
7.0
7.0
7.1
7.1
7.2
7.3
7.3
7.0
7.0
7.0
7.2
7.2
7.3
7.0
7.2
7.0
7.1.
7.0
7.5
7.2
7.2
7.2
7.5
7.8
7.2 ,
7.1
7.1
7.1
7.2
7.1
7.0
NDb
ND
ND
ND
ND '
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND.
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
15.8
13.6
15.4
18.0
15.0
22.0
21.0
22.0
24.0
21.5
19,0
21.0
23.5
23.5
24.0
23.0
23.0
24.5
22.0
24.5
25.0
23.5
19.0
25.0
23.5
24.0
23.0
27.0
20.0
26.0
30.0
22.5
30.5
20.0
25.4
5
ND
5
5
ND
ND
5
8
ND
11
ND
ND
ND
13
10
9
ND
6
7
9
11
9
11
16
8
9
5
7
12
ND
12
10
6
4
ND
Kjeldahl
N
- Location No
0.4
ND
ND
0.3
ND
1.1
0.3
ND
ND
ND
ND
ND
0.3
0.3
ND
NO
NO
0.3
ND
ND
ND
ND
ND
0.4
ND
ND
ND
ND
ND
ND
ND
0.5
ND
NO
NO
Dissolved
Ortho-P
— -- jig/ml----
. 10
0.03
0.03
0 02
0 04
0.03
0.03
0.02
6.01
0.02
0.03
0.02
0.02
ND
0.01
0.03
0.02
0.03
ND
0.01
0.03
0.05
0.04
0.02
0.04
0.03
ND
0.02
0.02
0.02
0.02
ND
ND
0.01
0.01
0.01
Total
P
Zn
Cu
Ni
Cd
Cr
Pb
... — , . ng/ml
0.03
0.03
0.02
0.04
0.04
0.03
0.05
0.05
0.03
0.04
0.02
0.03
0.01
0.01
0.03
0.02
0.03
N)
0.01
0.03
0.05
0.04
0.02
0.05
0.04
0.02
0.02
0.02
0.02
0.02
ND
ND
0.01
0.01
0.01
0.5
150.0
80.0
270.0
200.0
190.0
280.0
20.0
190.0
300.0
280.0
300.0
180.0
300.0
200.0
241.0
350.0
225.0
240.0
255.0
275.0
145.0
255.0
250.0
295.0
102.0
182.0
190.0
225.0
162.0
163.0
180.0
147.0
123.0
255.0
50
70
20
20
20
20
20
20
ND
ND
ND
ND
ND
ND
ND
24
ND
ND
ND
10
23
13
10
ND
13
14
17
91
22
19
ND
20
ND
17
20
ND
ND
ND
ND
20
ND
20
ND
40
20
ND
ND
ND
20
10
10
10
10
20
20
20
20
20
25
15
16
16
46
19
10
13
17
20
25
23
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
6
10
10
ND
ND'
5
5
5
ND
5
8
5
8
5 .
5
ND
ND
4
ND
ND
ND
6
5
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
6
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
5
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
100
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
NO
ND
ND
ND
ND
ND
50
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
0 Not detectable /„„„*. ,'«.,^J\
-------
TABLE 19. (continued)
Ul
o
Date
751118°
751125
751202
751209
751216
751222
760101
760108
760112
760121
760128
760204
760211
760218
760225
760303
760310
760315
760324
760331
760407
760414
760421
760510
760526
760609
760624
760707
760722
760805
760831
760916
760928
761019
761103
Time
200
1210
130
110
1140
1041
1210
130
245
1255
155
1100
1105
1130
1140
1105
1205
130
1130
1200
1215
300
1005
1100
1145
1125
240
1225
1230
145
1230
1200
1202
1152
1200
Temp
°C
19.5
18.0
19.0
19.0
19.1
19.0
19.1
17.3
19.8
18.9
18.8
19.5
18.5
18.5
18.6
19.8
19.8
20.1
19.6
16.9
18.2
19.7
18.7
17.9
20.2
19.0
19.8
13.8
19.0
19.8
19.0
19.8
19.3
18.8
19.5
PH
7.0
7.1
7.0
7.2
7.1
7.0
7.0
7.1
7.2
7.0
7.1
7.3
7.0
7.1
6.9
7.0
7.2
7.1
7.0
7.0
7.0
7.1
7.0
7.2
7.3
7.3
7.1
7.4
7.2
7.1
7.3
7.0
7.3
7.1
7.0
NH£-N
pg/ml
NDb
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
NO
ND
SD
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
NOJ-N
*ig/ml
Domestic
8.1
9.6
11.8
12.0
8.8
13.6
11.6
18.6
15.6
15.6
13.8
13.8
13.0
12.6
12.2
13.2
14.2
12.6
13.6
13.6
14.4
15.0
14.2
17.8
16.4
15.8
15.0
14.0
16.4
12,4
14.8
17.0
10.8
16.6
11.2
NOJ-N
ng/ml
Deep Well
6
ND
5
5
ND
ND
13
7
ND
8
ND
ND
ND
ND
ND
11
8
8
8
11
ND
6
17
11
29
9
5
ND
9
11
ND
13
11
9
5
Kjeldahl
N
____..«___..
- Location
0.5
0.6
NI>
NH
KI>
1.1
0.4
Nt
Nt'
NT'
0.3
0.4
NT
0.4
NT
Nt
KC
RE
NE
NE
Nt
NE
NE
KC
NC
NE
NE
ND
ND
NE
1C
0.5
0.3
0.4
ND
Dissolved
Ortho-P
pg/ml
No. 11
0.02
0.02
0.02
0.03
0.03
0.03
0.03
0.02
0.01
0.03
0.04
0.03
0.03
0.02
0.02
0.01
0.04
0.02
ND
0.02
0.04
0.04
0.04
0.03
0.04
0.05
0.01
0.01
0.02
0.02
0.02
Nil
0.01
0.03
0,02
Total
P
*"*"*""" -
0.07
0.06
0.02
0-03
0.03
0.03
0.04
0.09
0.04
0.04
0.04
0.03
0.03
0.02
0.02
0.02
0.04
0.02
SD
0.02
0.04
0.06
0.08
0.04
0.04
0.05
0.01
0.01
0.02
0.02
0.02
ND
0.01
0.04
0.03
Zn
*.___
100
120
80
170
80
30
40
30
30
50
60
90
10
30
100
80
91
330
88
97
81
215
81
285
83
225
215
182
88
380
290
107
67
67
63
Cu
"*"""""*"
30
20
40
40
40
ND
ND
ND
ND
ND
20
ND
ND
KD
ND
ND
11
ND
NH
11
22
15
18
18
13
13
17
17
30
25
10
16
18
ND
20
Hi
KD
ND
ND
ND
30
ND
ND
20
30
20
ND
ND
ND
ND
20
15
10
10
10
15
25
20
20
20
32
15
16
10
37
15
10
13
20
20
20
Gd
ng/ml
ND
ND
ND
TO
KD
ND
ND
ND
SD
ND
ND
ND
11
14
6
ND
ND
ND
ND
5
5
6
6
6
12
8
ND
ND
ND
4
ND
ND
ND
5
9
Cr
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
6
6
ND
ND
ND
ND
ND
ND
SD
ND
ND
ND
ND
ND
9
ND
ND
ND
ND
ND
ND
ND
Pb
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
KD
ND
SD
ND
70
ND
ND
KD
1TD
ND
KD
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
Year, month, day
Not detectable
(continued)
-------
TABLE 19, (continued)
Date
Time
Temp
°C
pH
NH*-N
4
jig/ml
N05-N
/ig/ml
NOJ-N
ng/ml
Domestic Deep
751118a
751125
751202
751209
751216
751222
760101
760108
760112
760121
760128
760204
760211
760218
760225
760303
760310
760315
760324
760331
760407
760414
760421
760510
760526
760609
760624
760707
760722
760805
760831
760916
760928
761019
761103
761111
1100
955
1100
1030
1000
935
1104
1140
125
1100
1220
950
935
1000
1015
1005
1020
1120
945
1030
1045
215
915
915
1005
945
1115
1050
1105
1045
220
1015
1104
1055
955
1105
20.0
20.0
21.0
20.5
21.0
20.0
20.9
19.2
20.3
19.7
20.3
20.0
19.9
19.3
19.1
18.8
19.0
19.1
19.0
18.9
19.0
19.9
18.7
18.8
18.2
18.8
18.8
19.6
19.2
20.2
20.5
20.0
19.0
19.4
19.9
19.6
7.1
7.0
7.2
7.1
7.1
7.2
7.2
7.1
7.2
7.4
7.1
7.6
7.0
7.0
7.0
7.2
7.2
7.2
7.3
7.2
7.1
7.0
7.1
7.1
7.6
7.3
7.0
7.4
7.3
7.2
7.1
7.2
7.2
7.1
7.1
7.2
NDb
ND
ND
;JD
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
5ID
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
10.8
15.5
23.0
20.5
21.0
26.0
26.0
37.0
25.5
28.5
24.5
21.4
24.0
22.5
23.5
24.5
24.5
21.5
24.5
21.5
23.0
23.0
21.5
16.5
20.5
19.0
20.0
21.0
25.5
21.0
25.2
27.5
22.0
31.0
19.0
22.0
5
ND
5
5
ND
SD
9
ND
5
5
ND
ND
ND
ND
ND
ND
8
ND
6
11
7
11
ND
18
6
6
5
ND
9
6
ND
12
10
9
9
ND
Kjeld.ihl
N
Well - Location
ND
0.6
ND
0.4
0.4
1.0
0.3
ND
ND
ND
ND
ND
ND
0.3
ND
ND
ND
ND
ND
SD
ND
MD
ND
ND
ND
ND
0.4
ND
ND
0.3
ND
0.3
0.5
0.3
0.3
ND
Dissolved
Ortho-P
^g/ml
No. 12
0.03
0.02
0.02
0.03
0.06
0.01
0.04
0.01
0.02
0.03
0.02
0.02
0.02
0.62
0.01
ND
ND
0.03
0.02
0.02
0.02
0.01
0.02
0.01
0.03
0.03
SD
0.01
0.02
0.02
0.02
ND
ND
0.01
0.02
ND
Total
P
0.03
0.02
0.05
0.03
0.06
0.01
0.04
0.04
0.02
0.03
0.02
0.02
0,02
0.02
0.01
ND
ND
0.03
0.02
0.02
0.02
0.01
0.02
0.01
0.03
0.05
ND
0.01
0.02
0.02
0.02
ND
ND
0.01
0.03
ND
Zn
20
90
80
110
80
70
40
60
40
140
180
60
120
30
110
40
10
85
41
52
40
208
33
93
77
101
88
74
55
155
540
50
39
55
29
170
Cu
ND
30
40
20
30
ND
ND
ND
ND
20
20
ND
20
ND
ND
ND
11
15
11
ND
22
18
13
10
10
10
11
14
40
22
10
22
18
13
17
15
Ni
ND
ND
ND
ND
ND
ND
ND
20
20
30
ND
ND
ND
ND
20
10
13
10
15
15
20
20
20
25
32
KD
17
16
42
24
10
13
ND
20
23
20
Cd
ng/ml
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
10
7
4
ND
ND
ND
ND
5
5
5
100
8
10
ND
ND
ND
ND
4
6
ND
ND
5
ND
7
Cr
ND
ND
HI)
ND
ND
ND
ND
KD
ND
ND
ND
ND
ND
6
7
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
Pb
ND
ND
ND
ND
KD
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
KD
Year, month, day
b Not detectable
(continued)
-------
TABLE 19_ (continued)
Ui
ho
^ Kjeldahl Dissolved
Date
751118"
751125
751209
751216
751222
760101
760108
760112
7C-0121
760128
760204
760211
760218
760225
760303
760310
760315
760324
760331
760407
760414
760421
760510
760526
760609
760624
760707
760722
760805
760831
760916
760928
761019
761103
761111
' Year,
Time
1130
1015
1045
1030
945
1112
1215
130
1115
1240
1005
950
1015
1030
1020
1035
1135
145
200
1100
230
925
1250
1020
1020
1145
1105
1120
1115
1015
1040
1111
1110
1035
1120
month, day
Temp
°C
20.0
19.0
19.5
17.2
19.5
12.1
12.5
19.9
19.1
19.4
20.0
19.1
19.3
17.9
20.7
18.3
19.9
19.5
19.3
17.3
20.1
18.4
19.3
19.0
19.7
19.4
22.2
21.6
24.7
20.0
19.5
18.3
19.2
19.1
18.7
pH
7.0
7.0
7.0
7.0
7.2
7.1
7.0
8.0
7.0
7.1
7.1
7.0
7.0
7.0
6.9
7.4
7.2
7.0
6.9
6.9
7.0
7.0
7.0
7.1
7.3
7.0
7.5
7.2
7.0
7.0
7.0
7.2
7.1
7.0
7.1
NHA-N
Jttg/nl
NDb
ND
ND
ND
M>
ND
ND
ND
ND
ND
ND
ND
ND
NI>
ND
ND
ND
KD
ND
ND
ND
ND
ND
W
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
N03-N
/Jg/ml
Domestic
5.1
9.8
14.8
8.2
11.8
13.6
16.2
14.4
17.2
16.6
16.0
8.8
13.8
7.8
8.4
11.4
12.2
12.0
10.2
7.2
15.2
10.2
16.6
19.0
17.5
14.0
16.0
20.0
14.5
10.0
12.5
20.5
22.0
13.0
20.5
N02-N
ng/ml
Deep Well
10
ND
5
9
6
103
35
ND
23
13
22
6
8
9
9
36
14
16
29
39
14
23
23
54
26
16
89
42
46
36
38
8
53
16
8
H
- Location No.
HD
0.4
0.5
KD
1.0
0.7
M>
fD
M)
>D
fiD
0.3
0.4
KD
ND
KD
ND
ND
ND
ND
0.4
ND
ND
ND
ND
0.3
0.3
N3
ND
N3
0.4
NO
10
Hi)
n>
Ortho-P
•-yug/ml-- — •
13
0.04
0.02
0.01
0.01
0.04
0.06
0.02
0.01
0.03
0.03
0.02
0.03
0.03
0.02
0.03
0.02
0.04
0.02
ND
0.02
0.02
0.03
0.04
0.03
0.03
ND
0.04
0.02
0.02
0.02
ND
ND
ND
0.03
KD
Total
P
0.04
0.05
0.01
0.03
0.04
0.06
0.10
0.04
0.04
0.03
0.02
0.03
0.03
0.02
0.03
0.03
0.12
0.04
ND
0.02
0.02
0.03
0.04
0.03
0,07
0.02
0.05
0.02
0.02
0.02
ND
ND
ND
0.03
ND
Zn
50
10
110
90
10
120
2250
40
150
180
170
130
20
90
40
44
62
250
90
68
173
50
305
75
175
104
160
120
240
125
49
92
80
96
238
Cu
30
20
20
40
20
40
ND
ND
30
20
20
20
ND
ND
ND
19
31
360
58
35
39
49
18
20
22
14
38
46
59
25
16
30
140
22
20
Ni
ND
ND
ND
20
ND
20
ND
40
ND
ND
ND
ND
ND
ND
15
ND
10
10
10
20
20
20
20
32
15
18
16
33
29
ND
13
10
23
26
23
Cd
•ng/ml---
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
8
8
7
ND
ND
ND
ND
ND
5
6
6
5
8
5
ND
5
ND
4
ND
ND
ND
5
ND
7
Cr Pb
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND 100
ND 40
7 ND
6 ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND 70
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND 50
ND NE
ND ND
ND ND
ND ND
b Not detectable .
(continued)
-------
TABLE 19. (continued)
01
Date
751118s
751125
751202
751209
751216
751222
760101
760108
760112
760121
760128
760204
760211
760218
760315
760324
760331
760407
760414
760421
760510
760526
760609
760624
760707
760722
760805
760831
760916
760928
761019
761103
761111
Time
1155
1030
1125
1100
1050
957
1125
1225
140
1130
1255
1015
1005
1030
1150
130
145
1115
245
935
1235
1035
1035
'140
1125
1150
1245
1055
1115
1140
1120
1100
1150
Temp
n
°C
19.5
19.0
19.5
19.0
18.0
18.6
18.0
14.0
18.8
18.4
18.6
18.5
18.2
19.3
19.1
18.6
18.2
19.0
20.3
17.6
21.0
20.3
19.5
21.2
23.7
20.5
21.0
22.0
20.3
18.8
17.8
18.9
18.3
pH
6.9
7.0
7.1
7.0
7.3
7.0
7.0
7.7
7.2
7.1
7.0
7.2
7.0
7.2
7.0
7.0
6.9
7.0
6.9
7.2
7.2
7.4
7.5
7.1
7.6
7.2
7.3
7.3
7.2
7.2
7.0
7.1
7.2
NHj-N
TOb
ND
TO
ND
ND
TO
ND
TO
TO
ND
TO
TO
ND
TO
TO
ND
ND
ND
ND
TO
ND
TO
TO
TO
TO
TO
TO
ND
TO
ND
TO
ND
ND
NO"-N
I1O" /Tftl
A* (5 '
Domestic
10.8
10.8
10.6
9.6
9.2
11.4
12.2
24.0
14.8
14.4
11.6
9.6
11.2
11.6
8.4
2.6
11.8
9.8
11.0
11.0
18.0
19.0
19.5
16.5
17.0
20.0
16.0
17.5
18.5
13.0
18.0
13.0
14.0
NO"-N
f\n /inl
Ug/ HlL
Deep Well
24
13
63
15
19
20
31
105
26
34
23
36
23
20
18
16
40
19
23
16
60
69
13
13
18
19
9
8
12
8
9
13
TO
-------
TABLE 19. (continued)
Ui
+ Kjeldahl Dissolved
Date
Tine
Temp
°C
pH
NH. -N
4
Jig/ml
NO"-N
*lg/ml
NOj-N
ng/ral
Domestic Deep
751118*
751125
751202
751209
751216
751222
170108
760112
760121
760128
760i04
760211
7C0218
760225
760103
760310
760315
760324
760331
760407
760414
760421
760510
760526
760609
760624
760707
760722
760805
760831
760916
760928
761019
761103
761111
125
1150
125
1230
1200
1050
145
300
110
400
1115
1120
1235
1210
10SO
1105
145
1145
1245
1230
315
1010
1110
1200
105
250
1240
125
200
1150
1230
1235
1221
1130
1205
20.5
19.5
20.0
20.0
19.7
19.0
18.0
19.9
19.6
19.7
19.5
19.2
18.5
18.7
20.5
20.5
19.0
19.5
17.2
18.9
20.9
19.0
18.9
21.7
19.3
19.9
20.1
19.6
19.5
19.4
19.5
20.0
18.8
19.0
18.6
6.9
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.5
7.0
7.2
7.0
7.4
7.0
7.0
7.1
7.1
7.0
7.0
7.1
7.0
7.3
7.1
7.6
7.2
7.0
7.4
7.0
7.0
7.2
7.1
7.1
7.0
7.1
7.1
NDb
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
V)
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
NO
ND
ND
5.4
8.8
11.8
12.0
11.0
13.2
22.0
15. u
16.4
15.8
14.0
13.4
13.6
13.0
15.8
16.6
14.0
8.8
15.0
14.2
16.0
14.2
17.8
17.0
15.0
13.0
17.5
21.0
14.5
17.0
15.5
13.5
18.0
10.0
12.0
10
ND
5
5
ND
ND
10
6
8
ND
6
ND
ND
ND
9
19
6
9
16
11
14
ND
13
14
9
5
7
11
6
ND
12
6
6
0
ND
N
Well - Location no
2.6
0.4
NH
0.3
NP
0.9
W
HD
NH
ND
ND
0.5
0.3
0.4
HI'
NIi
0.5
KD
NTi
HD
NIi
ND
NIi
ND
HI'
MI
NT.
ND
HI'
Nl.'
0.4
NC
0.6
NC
NT
Ortho-P
«/•!
. 16
0.06
0.02
0.02
ND
0.02
0.02
0.02
0.01
0.04
0.03
0.03
0.02
0.02
0.03
0.01
0.03
ND
0.03
0.02
0.02
0.03
0.01
0.03
0.03
0.05
ND
0.02
0.02
0.01
0.02
ND
ND
0.02
0.01
MD
Total
P
0.06
0.02
0.02
ND
0.02
0.02
0.07
0.07
0.04
0.03
0.03
0.02
0.02
0.03
0.02
0.03
ND
0.03
0.02
0.02
0.03
0.01
0.03
0.05
0.07
0.03
0.02
0.02
0.02
0.02
ND
0.04
0.04
0.01
ND
Zn
60
30
50
100
70
60
60
20
50
100
80
30
30
110
60
33
220
130
103
109
133
67
180
150
285
265
225
205
510
252
190
63
102
136
225
Cu
20
ND
20
40
30
50
50
20
20
30
30
40
20
30
ND
19
15
15
19
19
23
18
10
23
10
17
17
50
25
12
16
14
11
20
15
Ni
20
ND
ND
ND
ND
ND
ND
40
ND
ND
ND
30
ND
ND
15
10
10
10
10
20
20
20
20
32
15
18
16
42
15
10
13
ND
23
23
23
Cd.
ND
10
ND
ND
ND
ND
ND
ND
ND
ND
ND
8
7
7
ND
ND
ND
ND
5
5
5
6
5
12
6
6
ND
ND
4
ND
ND
ND
5
5
7
Cr
10
ND
ND
ND
10
ND
ND
ND
ND
ND
ND
ND
6
6
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
Pb
ND
ND
ND
100
ND
ND
ND
SD
ND
SD
ND
ND
ND
ND
ND
70
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
50
ND
ND
SD
~ " DOMKSTIC DKF,:? WE11S
Mean
Maxlnura
Mini*™
Standard
h Year'
deviation
month, day
19.4
26.8
8.3
2.0
7.2
8.0
6.9
0.2
<0.3
<0.3
<0.3
<0.3
15.7
37.0
2.6
5.9
All
11
105
< 5
15
Samples (N - 249)
<0.3
2.£
<0.2
0.3
0.02
0,06
<0.01
0.01
0.03
0.12
<0.01
0.02
199
2250
< 10
264
21
360
<10
28
15
170
<10
16
<4
100
<4
7
<5
10
<5
2
<50
150
<50
21
Not detectable
-------
TABLE 20. CHEMICAL ANALYSIS OF WATER SAMPLES TAKEN FROM TOM GREEN COUNTY DEEP WELLS
Ui
Oi
Date
7603293
760520
760628
760714
760812
760921
761005
761122
760329
760520
760628
760329
760520
760628
760714
760812
760921
761005
761122
760329
760520
760628
760714
760812
760921
761005
761122
760329
760520
760628
760714
760812
760921
761005
761122
Tine
825
930
825
840
725
805
810
830
900
950
855
915
1005
910
910
800
835
835
900
940
255
920
950
815
900
849
930
1100
1125
945
1010
840
935
1001
950
Tenp.
18.4
21.0
23.3
22.7
24.5
21.5
19.0
16.0
21.3
21.8
21.5
17.2
20.8
22.0
24.2
25.8
20.8
20.5
18.4
19.6
23.8
24.5
24.1
26.0
23.0
21.9
15.6
22.0
28.8
24.8
22.6
22.5
22.2
21.5
19.0
PH
7.0
7.1
7.4
7.2
7.0
7.3
7.3
7.2
7.0
7.1
7.7
7.0
7.0
7.5
7.2
7.1
7.1
7.4
7.6
7.0
7.2
7.4
7.1
7.5
7.2
7.3
7.3
7.1
7.0
7.7
7.1
7.2
7.2
7.3
7.4
«£*
f-SI
N3Jb
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
NO^-N
/Ig/Ettl
7.0
4.7
4.9
3.8
4.2
6.5
10.5
8.8
22.5
25.0
26.5
35.5
26.5
23.5
34.5
35.5
45.5
80.0
45.0
10.0
26.5
11.5
22.5
12.5
29.5
38.0
29.5
2.4
2.5
2.4
1.3
2.9
4.1
7.0
5.6
NOj-fc
rig/ in j
ND
ND
ND
ND
ND
KD
ND
ND
ND
ND
ND
ND
9
41
39
8
ND
ND
ND
KD
ND
ND
ND
ND
8
5
18
ND
9
45
ND
20
ND
ND
ND
I Kjeldahl
N
LOCATION NO. 31
ND
ND
ND
ND
ND
ND
ND
ND
LOCATION NO. 32
ND
ND
ND
LOCATION NO. 33
ND
ND
0.5
ND
ND
ND
ND
ND
LOCATION NO. 34
ND
0.6
ND
ND
ND
0.4
ND
ND
LOCATION NO. 35
ND
ND
ND
ND
ND
ND
ND
ND
Dissolved
Ortho-P
0.05
0.04
0.02
0.02
ND
ND
0.01
ND
0.04
0.02
0.03
KD
0.03
0.01
0.01
ND
ND
0.01
ND
0.02
0.02
0.01
ND
ND
ND
0.01
ND
ND
0.02
0.01
0.01
0.01
ND
0.01
ND
Total
P
0.05
0.06
0.02
0.02
KD
ND
0.01
ND
0.04
0.02
0.03
ND
0.03
0.01
0.01
0.03
,ND
0.03
ND
0.03
0.03
0.01
ND
ND
ND
0.02
ND
ND
0.02
0.01
0.02
0.05
ND
0.03
ND
Zn
105
77
58
118
56
57
47
140
130
77
58
320
340
225
643
240
240
283
285
680
1600
438
783
302
1020
503
1210
460
1190
850
413
594
515
483
790
Cu
15
20
12
22
27
16
ND
14
15
20
12
11
13
12
11
ND
ND
ND
10
15
23
15
19
12
28
14
20
15
10
17
14
12
16
16
20
Ni
20
25
15
16
10
10
14
14
10
25
15
30
38
18
20
20
10
17
17
15
58
15
20
15
33
23
30
30
38
18
16
20
28
23
21
Cd
/ml ' .»
fmi •""
ND
ND
5
ND
ND
ND
5
7
ND
ND
5
ND
5
5
6
ND
ND
6
5
5
10
ND
6
ND
6
6
10
6
5
10
5
6
5
5
7
Cr
5
ND
5
ND
KD
5
ND
ND
ND
ND
5
5
ND
ND
5
ND
ND
ND
5
5
5
ND
ND
ND
9
9
5
5
5
ND
ND
ND
9
ND
5
Pb
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
100
50
ND
ND
ND
ND
ND
ND
120
ND
ND
ND
ND
ND
ND
70
100
50
ND
ND
50
ND
ND
Year, month, day
Not detectable
(continued)
-------
TABLE 20. (continued)
Date
760329 a
760520
760628
760714
760312
760921
761005
761122
760329
760520
760628
760714
760812
760921
761005
761122
760329
760520
760628
760714
760812
760921
761005
761122
760329
760520
760628
760714
760812
760921
761005
761122
Time
1125
1140
1010
1030
850
955
954
1005
1150
1155
1020
1050
910
1015
945
1025
1215
1220
1045
1115
925
.1040
916
1045
125
115
1125
1115
955
1110
1124
1115
Temp
"C
20.8
24.0
26.5
24.0
28.0
22.8
17.9
10.1
21.5
25.8
27.3
24.0
27.0
22.4
20.2
13.0
20.8
21.8
26.8
22.9
25.0
22.4
16.2
9.3
20.4
22.0
27.5
22.9
27.0
21.0
19.9
8.2
PH
7.0
7.0
7.7
7.1
7.0
7.1
7.4
7.2
7.1
7.0
8.0
7.8
7.6
7.5
7.8
7.8
7.0
7.1
7.3
7.6
7.3
7.2
7.5
7.3
6.5
6.9
7.3
7.6
7.0
7.1
7.0
7.1
NH+-M
jug/ml
NDb
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
NO
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
NO~-N
^Jg/ml
27.0
26.5
26.5
25.5
25.0
18.5
20.0
33.0
1.7
1.8
2.2
1.9
1.7
0.3
2.5
1.7
7.2
6.0
10.0
7.8
7.8
7.6
13.8
7.0
11.5
7.5
12.5
7.8
13.0
12.5
18.0
11.0
NOl-N Kjcldahl
N
ng/ml — • --- -----
LOCATION NO. 36
ND ND
5 ND
ND ND
10 ND
8 ND
350 0.7
33 0.6
SD ND
LOCATIOB KO. 37
ND ND
ND ND
ND ND
ND ND
ND ND
5 ND
8 ND
ND ND
LOCATION NO. 38
ND ND
ND ND
6 ND
ND ND
6 0.4
5 ND
11 ND
ND NO
LOCATION NO. 39
ND ND
ND ND
ND ND
KD ND
90 ND
240 0.7
22 0.6
119 SD
Dissolved
Ortho-P
— /jg/ml — —
ND
0.02
0.01
0.02
0.01
0.04
ND
ND
0.05
0.01
0.01
0.01
ND
0.01
0.01
0.01
0.02
0.02
0.01
0.01
0.02
HD
0.01
ND
ND
0.01
ND
0.01
0.01
ND
ND
ND
Total
P Zn
ND 140
0.03 75
0.01 49
0.02 168
0.01 98
0.08 61
0.05 49
ND 90
0.05 460
0.02 315
0.01 266
0.01 618
ND 300
0.01 750
0.02 653
0.01 520
0.02 720
0.03 820
0.09 544
0.01 2083
0.02 800
ND 2310
0.01 1870
0.02 5170
0.02 290
0.13 410
0.01- 6809
0.01 16940
0.02 9202
ND 19118
0.01 21175
ND 12100
Cu
44
74
41
86
30
26
22
22
15
ND
ND
11
ND
ND
ND
ND
31
ND
ND
11
ND
10
ND
ND
15
16
17
30
21
22
16
26
Ni
ng
15
45
22
25
20
44
29
23
15
ND
ND
ND
ND
ND
10
17
10
ND
10
ND
10
ND
17
14
55
70
40
56
51
88
63
54
Cd
/ml
5
5
8
7
4
9
6
9
ND
ND
ND
ND
ND
ND
ND
5
7
ND
5
ND
ND
ND
5
7
ND
10
12
12
10
18
13
16
Cr
5
5
9
ND
ND
9
5
5
ND
ND
ND
ND
ND
ND
ND
5
5
ND
ND
ND
ND
5
ND
ND
ND
7
15
11
10
15
14
8
Pb
70
100
50
80
ND
100
ND
ND
ND
80
ND
ND
ND
50
ND
ND
ND
80
ND
ND
ND
ND
ND
ND
130
100
100
105
100
175
100
100
? Year, month, day
Not detectable
(continued)
-------
TABLE 20. (continued)
Date
«
760329
760520
760628
760714
760812
760329
760520
760628
760714
760812
760921
761005
761122
760329
760520
760628
760714
760812
760921
761005
761122
760329
760520
760329
760520
Time
145
140
1130
1255
1010
215
200
1105
120
945
1050
1135
1100
240
215
1140
135
1020
1130
1100
1145
305
235
320
255
Temp
°C
20.0
21.0
21.4
22.8
25.0
21.5
21.6
20.8
21.0
21.5
22.4
20.9
10.8
20.8
20.7
21.0
20.5
21.0
23.0
21.9
12.8
22.7
22.3
20.5
21.0
pH
6.7
7.0
7.0
7.2
7.2
7.0
7.0
7.5
7.0
7.4
7.2
7.3
7.2
7.0
7.1
7.2
7.2
7.2
7.6
7.4
7.4
7.4
7.0
7.0
7.2
NrfJ-N
>ig/ml
NDb
ND
ND
ND
ND
ND
ND
ND
ND
ND
N£
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
NO'-N
^g/ml
10.0
15.5
15.0
13.5
10.5
24.0
27.0
29.5
27.5
24.5
25.5
37.5
24.0
18.0
24.0
24.0
26.0
27.5
31.5
42.0
27.0
2.1
2.3
46.5
25.0
Dissolved
NOl-N Kjeldahl Ortho-P
M
ND
9
ND
6
6
6
11
6
10
ND
8
ND
11
5
21
6
35
6
23
ND
ND
10
5
13
44
LOCATION NO. 40
ND
0.4
ND
ND
ND
LOCATION NO. 41
ND
ND
ND
ND
ND
ND
ND
ND
LOCATION NO. 42
ND
ND
ND
ND
ND
ND
ND
ND
LOCATION NO. 43
ND
ND
LOCATION NO. 44
ND
1.1
- /ig/ml --
ND
ND
ND
0.01
ND
ND
0.01
0.01
0.01
0,03
KD
0.01
ND
ND
0.02
0.01
0.01
0.01
ND
0.01
ND
0.02
0.01
' ND
0.01
Total
P
Zn
Cu
Hi
Cd
Cr
Fb
ND
ND
0.01
0.01
ND
ND
'0.03
0.01
0.01
0.03
ND
0.01
ND
ND
0.02
0.01
0.01
0.01
ND
0.01
ND
0.03
0.11
ND
0.01
175
100
59
19
140
230
275
50
213
99
145
273
370
210
121
88
283
107
412
383
610
390
515
255
160
11
13
25
47
12
19
29
28
37
12
16
ND
10
11
13
12
ND
12
10
ND
NS
84
135
19
13
45
52
45
383
42
25
32
22
25
24
17
26
23
15
15
15
16
20
17
20
17
10
25
25
88
11
7
13
10
7
KD
5
6
6
4
5
8
9
ND
7
6
5
4
ND
8
10
ND
ND
ND
10
ND
7
12
ND
KD
5
5
ND
ND
ND
8
ND
5
ND
5
9
ND
ND
8
ND
5
ND
ND
ND
5
100
100
70
80
50
ND
60
50
ND
ND
50
ND
250
ND
ND
50
ND
ND
50
ND
ND
ND
ND
ND
ND
Tear, month, day
Not detectable
(continued)
-------
TABLE 20. (continued)
Ln
00
Date
760329 a
760520
760628
760714
760812
760921
761005
761122
760714
760312
760921
761005
761122
760714
760812
760921
761005
761122
760312
760921
761005
761122
Mean
Minimum
Maximum
Standard
Time
335
325
1225
235
1005
100
1020
1245
155
1035
1145
1045
1205
215
1050
1230
1037
1230
745
820
830
845
deviation
Temp
°C
19.8
19.5
21.5
23.0
23.0
23.6
21.2
11.6
23.7
31.0
22.5
20.5
9.0
22.7
23.0
23.0
17.3
16.4
23.2
18.2
20.2
9.3
pH
7.1
7.1
7.6
7.3
7.3
7.4
7.5
7.3
7.1
7.5
7.5
7.5
7.3
7.2
7.3
7.3
7.4
7.1
7.4
7.2
7.4
7.2
7.3
6.5
8.0
0.2
^
NH^-N
^E/ml
t
NDb
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
< 0.3
<0.3
<0.3
0
NO~-N
>.g/ml
39.0
49.5
54.0
61.0
47.0
57.0
67.0
45.0
1.9
1.8
2.6
3.2
2.3
36.5
45.0
38.0
57.0
36.0
60.0
48.5
84.0
49.0
22.0
0.3
84.0
18.4
NO~-N
ng/ml
ND
103
13
625
75
38
23
23
10
ND
ND
ND
ND
10
6
5
5
ND
6
13
ND
14
AI:
20
< 5
625
72
Kjeldalil
10
LOCATION NO. 45
ND
0.4
HD
ND
ND
KD
ND
0.5
LOCATION NO. 46
iro
HD
ND
KD
HD
LOCATION NO. 47
ND
ND
SD
ND
ND
LOCATICM NO. 48
:SD
tfD
HD
•JTO
L Samples CN=114)
< 0.30
< 0.30
1.10
0,19
Dissolved
Ortho-P
0.02
0.01
0.01
0.01
0.01
ND
0.01
ND
0.01
ND
0.01
0.01
ND
0.01
ND
ND
0.01
ND
ND
ND
0.01
ND
< 0.010
< 0.010
0.050
0.011
Total
P
0.02
0.03
0.01
0.11
0.05
ND
0.03
ND
0.02
ND
0.01
0.01
0.02
0.09
ND
ND
0.01
ND
ND
ND
0.01
0.02
0.018
< 0.010
0.130
0.024
Zn
650
4950
1848
1753
570
2101
1595
2772
5273
4125
4400
4735
5555'
7583
330
630
483
1000
350
1540
203
700
1572
19
21175
3497
Cu
11
ND
15
14
ND
ND
ND
ND
ND
ND
10
ND
ND
ND
ND
19
ND
ND
15
34
10
12
16
<10
135
19
Ni
— ng/ml
15
38
10
10
ND
10
14
11
10
ND
ND
10
ND
10
10
17
14
ND
10
10
14
14
25
< 10
383
38
Cd
ND
8
5
KD
ND
ND
6
7
5
4
ND
5
5
5
ND
ND
6
ND
ND
ND
5
5
5
< 4
18
4
Cr
ND
ND
ND
ND
ND
8
ND
5
ND
ND
ND
ND
5
ND
ND
6
ND
5
ND
5
ND
ND
< 5
< 5
15
4
Pb
ND
60
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
< 50
< 50
250
46
Year, month, day
Not detectable
-------
TABLE 21. AVERAGE COD, IOD, TFR, AND TNFR ANALYSIS OF WATER
SAMPLES FROM THE CONCHO RIVER, SEWAGE FARM LAGOONS, SEEPS
AND WELLS AND TOM GREEN COUNTY WELLS
Sample
Number
Location
BOD
Total
Filterable
COD Residue
Total
Nonf ilterable
Residue
SEWAGE FARM
1
2
3
4
5
6
7
8
9
10
12
13
14
16
18
19
20
21
22
Concho River - upstream
Concho River - downstream
Effluent Lagoon 1
Effluent Lagoon 4
Seepage Creek no. 1
Seepage Creek no. 2
Seepage Creek no. 3
Shallow Well
Domestic Well
Domestic Well
Domestic Well
Domestic Well
Domestic Well
Domestic Well
Shallow Well
Shallow Well
Shallow Well
Shallow Well-
Sewage Treatment Plant
3.8
3.1
148.0
89.0
9.2
0.6
0.6
0.7
1.6
1.3
0.1
0.6
0.9
0.5
1.0
1.3
0.7
1.6
146.0
65
58
400
280
80
58
62
100
64
38
38
48
52
38
102
62
74
54
502
965
975
1298
1382
1630
1438
2200
1648
2245
1660
1691
1625
1763
1673
1803
1222
1933
2110
1528
30
25
968
1060
70
33
30
40
73
57
68
63
72
93
92
83
110
102
605
TOM GREEN COUNTY WELLS
31
33
34
35
36
37
38
39
41
42
45
46
>47
48
Domestic Well
Domestic Well
Domestic Well
Domestic Well
Domestic Well
Domestic Well
Domestic Well "
Domestic Well
Domestic Well
Domestic Well
Domestic Well
Domestic Well
Domestic Well
Domestic Well
1.6
1.2
1.3
0.5
0.8
1.8
1.5
0.1
2.3
0.1
2.1
1.1
0.6
1.5
46
6
15
11
<10
<10
<10
34
28
11
<10
<10
42
25
1528
1240
3200
2770
2445
485
808
5088
1603
1485
1025
470
1198
1035
78
105
100
115
130
100
152
43
<23
20
<21
20
21
30
59
-------
NO™ nitrogen higher than 10 yg/ml may result in a high potential risk of
methemogloginemic. to bottle-fed infants. Waters with a NO~-N concentration
over 1 yg/ml should not be used for infant feeding. A limit of 0.02 yg/ml
of nonionized NH_ has been recommended as the water quality criteria for
freshwater aquatic life (EPA 1976). A chemical equilibrium exists between
nonionized NH3 and NH4 ion. At 20°C and a pH of 8.0 only 3.8 percent of the
nitrogen is present as nonionized NH_ in aqueous solution. The other 96.2
percent is present as NH, ions. There is no water quality criteria for
N0~ or NH_ for livestock water supplies. Campbell and others (NTAC, 1968)
have reported methemoglobinemia in cattle receiving water containing
2,790"yg/ml of N03-N.
In ruminant animals, NO,, may be reduced to tK^ by microflora in the
rumen. Nitrite may then exert toxic effects on the animal. High concen-
trations of NO- and/or NH, in waters may also stimulate growth of undesir-
able plants and decrease recreation uses. The toxicity of ammonia is
dependant upon pH, temperature, the concentration of total ammonia
(NH- + NH,), and ionic strength. The concentration of NH~ increases with
increasing temperature and decreases with increasing ionic strength.
Lykins and Smith (1976) reported that Missouri has the most stringent
standard of NH_ (0.1 yg/ml) for streams. Nevada and California have the
lowest NO--N value (1.0 yg/ml), and Delaware has the lowest total nitrogen
value (3.0 yg/ml).
Nitrogen entered the sewage treatment plant primarily as NH,-N (Table
11). The 12 month mean was 16.3 yg NH,-N/ml but fluctuated between 12.0 and
29.2 yg/ml over the year. In addition, an average of 5.9 yg/ml organic N
entered the treatment plant (difference between Kj eldahl-N and NH,-N). A
trace of NOj-N and small but variable quantities of NO--N were present in
the incoming effluent.
Ammonium nitrogen was the predominant form in the sewage effluent
lagoons (Tables 12 and 13) with mean values of 28.2 and 21.1 yg NH,-N/ml
found in effluent lagoons 1 and 4, respectively. Total Kjeldahl-N also
tended to increase in concentration in the lagoons while NOl-N and NO--N
concentration remained fairly constant.
Once sewage effluent water was applied to the soils, oxidation of
NH.-N occurred, and the nitrogen species found in seepage creeks was
N0~—N (Tables 14, 15, and 16). The exception was seepage creek no. 1 where
significant quantities of NH.-N and Kjeldahl-N were measured. Seepage
creek no. 1 originates within the boundary of the farm and flows through it.
Cattle drink and excrete into the stream. On several occasions effluent
was detected flowing directly from the irrigation lines into seepage creek
no. 1. These two factors probably largely account for the levels of NH.-N,
Kjeldahl-N and NO--N measured in the seepage creek no. 1 compared to
seepage creeks 2 and 3 (Tables 15 and 16). The latter two seeps were
discharging from the bank of the Concho River. They were fenced to exclude
cattle from drinking from them. There was no possibility of surface flow
into these seeps, so all of the water had to pass through the soil profile.
Consequently, NH.-N, NO»-N and Kjeldahl-N were detected sporadically and in
60
-------
small quantities. Except for the high NO.--N concentration (16.3 and 21.0
yg/ml) in seeps 2 and 3, the water was of good quality.
The mean NO,-N value of water from all three seepage creeks is higher
than 10 yg/ml. The lower the water flow rate of these three seepage creeks,
the higher the nitrate value found in the waters (Tables 14, 15 and 16).
The average value of 183 ng NO^-N/ml in seepage creek no. 1 was much higher
than values in seepage creeks no. 2 and 3.
There was a significant increase in the nitrate concentration of Concho
River waters below compared to that above the sewage farm (Tables 17 and 18).
The discharge of treated sewage effluent from the sewage farm into the
Concho River (via seepage and some surface runoff) increased the nitrate
concentration of river waters from a mean value of 1.6 - 1.0 to 5.7 - 2.0
yg/ml NO~-N. Because the NO,-N value of downstream waters is less than
the standard of 10 yg/ml (except on January 8, 1976, a value of 14.0 yg/ml
was observed), a minimal environmental impact is expected. No significant
increase in Kjeldahl-N, NH.-N, and NOl-N concentrations was observed in the
Concho River below the sewage farm.
The nitrate values of shallow ground wells and domestic deep wells
in the sewage farm are 5,8 ± 5.2 and 15.7 ± 5.9 yg N03-N/ml, respectively
(Table 19). Both the NH.-N and Kjeldahl-N concentrations are below the
detection limit. Waters of high concentration of NOv-N are not suitable
for drinking, but they do make a good source of plant nutrients. Most
deep well water in Tom Green County has a high concentration of NQ,-N.
At sampling locations no. 33, 45, 47, and 48, the concentration^
NO~-N is higher than 50 yg/ml (Table 20). Comparison of the NO~-N
concentration of deep wells in the sewage farm and that of Tom Green county
wells indicated that application of sewage wastewater to the farm did not
increase the NO~-N concentration. The average NO.,-N concentration of deep
well water from the sewage farm was 15.7 (Table 19) while that of the deep
wells located in Tom Green county was 22.0 (Table 20).
In a study to determine the source of N0_ in ground water using N
isotope, Kreitler (1975) found that the major source of nitrate in ground
water in the San Angelo area is from natural soil nitrate, which was derived
from the mineralization of organic nitrogen in the soil. He indicates that
the Permian carbonate aquifers and the tertiary gravel aquifer have no
downdip portion so the entire aquifer has been polluted. He concluded that
the oxidation of part of the humus of semiarid grassland soils and the
subsequent leaching of the N0_ to the saturated zone by extensive terracing
in the 1950fs resulted in the high NO, concentration in the ground waters
in this area.
Phosphorus
Phosphorus is one of the major essential elements for plant growth.
In general, evidence indicates that high phosphorus concentrations are
associated with accelerated eutrophication of waters, when other growth-
promoting factors are present. Phosphorus is not the sole cause of
eutrophication but there is substantiating evidence that frequently it is
61
-------
the key element required by freshwater plants. Because it is present in
the least amount relative to need, phosphorus is one of the most easily
controlled elements required for plant growth by man's activity. Under
normal soil and water conditions plants take up phosphorus in the H^PO^
forms. It is well-known that phosphorus concentrations critical to noxious
plant growth vary, and nuisance growths may result from a particular
phosphorus concentration in one geographical area but not in another.
A level of 100 yg/1 total P has been suggested by MacKenthum (1973) as
the desired water quality criteria for the prevention of plant nuisance in
streams or other flowing waters not discharging directly into lakes or
impoundments. At the time of the spring turnover total phosphate concentra-
tions in excess of 25 yg P/l may occasionally stimulate excessive or
nuisance growths of algae and other aquatic plants and interfere with water
treatment (EPA 1976). Lykins and Smith (1976) reported that Hawaii has
the most stringent total phosphate phosphorus standard (20 yg P/l) for
streams. At present no national criterion is presented for phosphate
phosphorus for the control of eutrophication (EPA 1976).
The sewage farm is receiving about 67,900 kg total P/year from the city
of San Angelo if an average value of 0.219 m /sec of raw sewage is assumed.
The phosphorus is present as about 50 percent dissolved orthophosphate and
50 percent organic phosphorus (Table 11). The average orthophosphate
concentration in 1976 was 5.08 yg/ml and the average total phosphorus
concentration was 9.83. Considerable fluctuation in phosphate concentration
was apparent during the year ; however, the ratio of ortho- to total phospho-
rus remained about ^he same. As the sewage effluent passed through the
lagoons the ortho- and total phosphorus concentration tended to increase
somewhat. The average total phosphate concentration of effluent water at
the sewage treatment plant, lagoon no. 1 and lagoon no. 4 were 9.83 ± 3.71,
24.94 ± 8.02, and 18.45 ± 6.92 yg P/ml, respectively (Tables 11, 12 and 13).
The dissolved orthophosphate concentrations of the effluent at these three
locations were 5.08 ± 2.05, 11.35 ± 4.36, and 7.58 ± 4.16 yg P/ml,
Both the dissolved orthophosphate and total phosphorus of water
sampled at seepage creek no. 1 exceeded 100 yg P/l (Table 14). From the
middle of February to early July, the total phosphorus concentration of
seepage creek no. 1 water often exceeded 1,000 yg P/l. In the spring of the
year, total phosphorus concentrations of seepage creeks no. 2 and 3 were
higher than 25 yg P/l (Tables 15 and 16). All three seepage creeks had
high total phosphorus concentration in the spring time and produced thick,
dense algae growth. Algal growth interfered with water flow through weirs
installed at the three seepage creeks and required frequent cleaning of the
weirs to obtain accurate data.
Comparison of the dissolved orthophosphate and total phosphate between
domestical deep wells at the sewage farm and Tom Green County wells indica-
ted that no significant difference in phosphorus concentrations is found
(Table 19 and 20). Apparently the application of sewage effluent to the
soil does not increase the dissolved orthophosphate or total phosphorus
concentrations in underground water. Because no downdip portion existed in
the carbonate and gravel aquifers, water moves laterally rather than
62
-------
vertically in the soil profile. This water movement apparently results in
higher phosphorus concentrations in surface flow waters (Concho River and
seepage creeks), but not in deep well groundwater. Control measures to
prevent the development of excessive vegetative growth within the water ways
are necessary for the long-term operation of the sewage farm.
A slight increase was found in the total phosphate in the Concho River
waters below the San Angelo sewage farm (Tables 17 and 18). Total phos-
phorus concentration above the sewage farm was 0.060 yg P/ml. The concen-
tration below the farm was 0/078 yg P/ml. Dissolved orthophosphate
increased from 0.017 to 0.019 yg P/ml. Waters flowing from the seepage
creeks are probably representative of those flowing from the sewage farm
in terms of P concentration. Total phosphorus ranged from 0.03 yg P/ml
in seepage creek 3 to 0.79 yg P/ml in seepage creek 1. Dissolved ortho-
phosphate ranged from 0.02 to 0.36 yg P/ml for the same two sites.
Heavy Metals
Excessive concentrations of heavy metals in water may constitute a
very serious form of pollution. Heavy metals form relatively stable
compounds and are not readily removed by natural processes. A character-
istic feature of heavy metal pollution is its persistence in time as well
as in space for years after the pollution practices have ceased (NTAC 1968).
Living organisms can take up heavy metals from a solution against a concen-
tration gradient and concentrate them above that level normally found in
the medium. The order of affinity of cations for plankton generally is
Zn>Pb>Cu>Mn>Ni>Cdi and for algae is Pb>Mn>Zn>Cu,Cd>Co>Ni. It is clear that
the heavier metals tend to be more readily taken up than the lighter ones,
which have a higher degree of hydration. The uptake of heavy metals by
living organisms is clearly linked with metabolic activities within the
cell. Many environmental factors (such as temperature, oxygen, light)
can affect the active uptake process of heavy metals by living organisms.
Heavy metals cause toxic action on the growth and metabolism of an
organism even at very low concentration. Many mechanisms of toxic action
have been observed; such as the poisoning of enzyme systems, formation of
antimetabolites catalyzing the decomposition of essential metabolites,
alteration of cell membrane permeability, and replacing important elements
in the cell which affect their ability to function. Living organisms
exhibit rather marked differences in tolerance to levels of heavy metals
in its environment. One of the potential hazards in applying sewage
effluent to: land is the contamination of groundwater and receiving streams
by heavy metals, and the subsequent uptake of heavy metals by aquatic
organisms.
The data presented in Table 22 show the water quality criteria for
heavy metals for domestic water supply and irrigation use. The values of
the National Academy of Science (NAC 1973) refer to recommended maximum
concentrations of trace elements in irrigation waters used for sensitive
crops on coarse-textured soils with low capacities to retain heavy metals.
Lykins and Smith (1976) listed states having most stringent water quality
criteria of streams and the concentration of each heavy metal.
63
-------
Table 22- RECOMMENDED SURFACE AND IRRIGATION WATER QUALITY CRITERIA FOR
HEAVY METALS
Stream Domestic Water Irrigation Water
Elements (Lykins and Smith) Supplies (NTAC 1968) (NAS 1973)
1976 (EPA 1976)
Cd
Cr
Cu
Ni
Pb
Zn
0.
0.
0.
1.
0.
—
005
010
010
000
040
(Ohio)
(Ohio)
(Minn.)
(111.)
(Ohio)
1 I rt
— yg
0.
0.
i.
-
0.
5.
/ml
01
05
00
05
00
0.
5.
0.
0.
5.
5.
005
000
200
500
000
000
0.
0.
0.
0.
5.
2.
01
10
20
20
00
00
Data in Tables 11, 12, and 13 show the heavy metals concentration of
incoming sewage effluent at the sewage treatment plant lagoon no. 1 and
lagoon no. 4, respectively. The heavy metals concentration of lagoon no. 4
waters, which is irrigated directly to the land, is less than that
suggested by the National Technical Advisory Committee (1968) and by the
National Academy of Science (1973) for irrigation water (Table 13). The
chromium concentration of water decreases from 0.272 ± 0.169-yg/ml at the
sewage treatment plant to 0.064 ± 0.021 yg/ml at lagoon no. 4; whereas no
significant change was observed in the Cd, Cu, Ni, Pb, and Zn concentra-
tions. The heavy metal concentration of three seepage creeks, the shallow
ground wells, and the deep wells for domestic use located within the
sewage farm are below the water quality criteria for either domestic water
supply or irrigation use (Tables 14, 15, 16 and 19). Most Tom Green
County deep well waters have low concentrations of heavy metals for
drinking and irrigation purposes (Table 20). Waters sampled at Tom Green
County well locations no. 38, 39, 45, 46, and 47 have high zinc concen-
trations which exceeded the water quality standard for either domestical
drinking or irrigation. The zinc concentration of water at sampling site
no. 39 increased from 0-29 yg Zn/ml in March to 21.18 yg Zn/ml in October,
then dropped to 12.10 yg Zn/ml in November in 1976. It is not clear what
causes this high zinc concentration in these waters. Corrosion and con-
tamination of the water by galvanized well pipe is probably the main
factor.
No significant difference in Cu, Ni, Cd, Cr, and Pb concentrations in
Concho River waters above and below the sewage farm was found (Tables 17
and 18). The average zinc concentration (0.123 ± 0.101 yg/ml) of Concho
River water below the sewage farm is higher than that (0.050 ± 0.065 yg/ml)
above the sewage farm. The concentrations of heavy metals in the Concho
River above and below the sewage farm do not exceed the water quality
criteria recommended by the U. S. Environmental Protection Agency (1976)
for domestic water supplies. It is clear that the discharge of sewage
farm water into the Concho River does not change the water quality of the
Concho River with respect to the heavy metals.
64
-------
BOD and COD
The biochemical oxygen demand (BOD) indicates the relative oxygen re-
quirements of wastewaters, effluents, and polluted waters. It also can be
used in evaluating the efficiency (BOD removal) of wastewater treatment
systems. The measurement of chemical oxygen demand (COD) provides the
oxygen equivalent of that portion of the organic matter in water that is
susceptible to oxidation by potassium dichromate. With wastewater con-
taining toxic substances, the COD test may be the only measurement for
evaluating the organic load. The BOD and COD values of water at the sewage
farm and Tom Green County are listed in Table 21.
The BOD values of incoming sewage wastewater at the sewage treatment
plant and effluent lagoon no. 1 are almost the same, 146 and 148 yg/ml,
respectively. It drops to 89 yg/ml at effluent lagoon no. 4. The COD
value of incoming sewage wastewater is 502 yg/ml. It decreases to 400 and
280 yg/ml at the effluent lagoon no. 1 and 4, respectively. There was
essentially no difference between the BOD and COD values of Concho River
waters above and below the sewage farm. Therefore, it can be inferred that
sewage farm operation has no effect on the BOD arid COD values of the Concho
River on the dates measured. Considerable reduction in BOD and COD values
are apparent between the applied wastewater and the three seepage creek
waters. The BOD values of well waters in the sewage farm are similar to
those of well waters in Tom Green County. However, well waters in the
sewage farm generally had higher values of COD than domestic wells in
Tom Green County. Infiltration of applied sewage wastewater into and
through the sewage farm soils decrease the BOD and COD values of the
wastewater. The soils act as a living filter. In the United States,
Nevada has the most stringent BOD criteria level of 1.0 yg/ml for streams
(Lykins and Smith 1976). The highest BOD values for deep well waters in
this study were 2.1 and 2.3 yg/ml and came from domestic wells located in
Tom Green County.
Total Filterable Residue (TFR) and Total Ndnfiltefable Residue (TNFR)
Waters yielding a high value of residue are generally inferior with
respect to palatability, or they may induce an unfavorable physiological
reaction in the transient consumer. A limit of 500 yg/ml total filterable
residue (TFR) is the permissible criteria^, and a limit of less than 200
yg/ml is the desirable level for public drinking water (NTAC 1968;. The
value of 500 yg/ml TFR is also the recommended level for farmstead use.
The state of Illinois has the most stringent total nonfilterable residue
(TNFR) level of 5.0 yg/mlj whereas Nevada has the most stringest TFR level
of 60 yg/ml (Lykins and Smith 1976). High TNFR values are objectionable
because of physiological effects, abnormal taste, or economic effect
(corrosion damage in water systems by high concentrations of sulfates
and chlorides).
The data presented in Table 21 show TFR and TNFR values of waters
from the sewage farm and Tom Green County wells. All waters in the
sewage farm and most well waters in Tom Green County have values of TFR
greater than 1000 yg/ml. The Concho River waters above and below the
65
-------
sewage farm have values of 965 and 975 yg/ml, respectively. The deep well
located near the treatment plant had the highest value (2245 yg/ml) of TFR
in the sewage farm while water sampling site no. 39, located in the city of
San Angelo, has the highest value (5088 yg/ml) of TFR in the Tom Green
County wells sampled. Comparison of TFR and TNFR values between sewage
farm well waters and those from Tom Green County wells indicates that
application of sewage wastewater to the soil does not increase the TFR and
TNFR values in ground waters in the sewage farm. The high values of TFR in
Tom Green County are probably the result of dissolution of salts from
underground rocks which are sedimentary origin. The principal ions in
the well waters are calcium, bicarbonate, and sulfate, and, in general, the
water is excessively hard (Willis, 1954).
There was no apparent difference in TFR and TNFR in Concho River waters
sampled upstream or downstream from the sewage farm (Table 21).
Statistical Relationships between Water Parameters
Correlation coefficients between the air and soil temperatures and
nutrient concentrations of three seepage creeks are calculated and listed
in Table 23. At seepage creeks no. 1 and 2 the zinc concentration is
linearly correlated with the air and soil temperatures. The location of
the temperature measuring equipment was at the fenced bermudagrass area,
adjacent to seepage creek no. 1. No linear correlation is observed between
the zinc concentration of seepage creek no. 3 and the measured air and
soil temperatures. Waters sampled at seepage creek no. 3 are located in a
dense mesquite tree area along the Concho River bank. The temperature of
the water at seepage creek no. 3 was usually cooler than that of seepage
creeks no. 1 and 2 at the same time of the day. The air and soil tempera-
tures measured at the fenced bermudagrass area are not representative of
the air and soil temperature of seepage creek no. 3. A highly significant
linear correlation existed between the NO^-N concentration of seepage creek
no. 3 and the soil temperature at 10 and 50 cm depth.
Linear correlation coefficients between the nutrient concentrations
and the temperature of water at the sampling location at the sewage farm
were calculated. Furthermore, linear correlation coefficients between
nutrient species were also calculated. Only those linear correlation
coefficients with an absolute value greater than 0.600 are listed in Table
24. Highly significant linear correlation coefficients between total
phosphorus and dissolved orthophosphorus are found at the three seepage
creeks and most of the shallow and deep wells at the sewage farm. Water
temperature and nitrate concentration of Concho River waters were negatively
correlated. Water temperature and dissolved orthophosphate concentration
of incoming sewage effluent at the sewage treatment plant, lagoon no. 1,
and lagoon no. 4 are also negatively correlated. At the sewage treatment
plant the water temperature is negatively correlated with the total
phosphorus, total Kjeldahl nitrogen, NH.-N, and dissolved orthophosphorus
concentrations. Highly significant positive linear correlation coefficients
between total phosphorus, dissolved orthophosphorus, NH.-N and total
Kjeldahl nitrogen are found in water samples taken at the sewage treatment
66
-------
TABLE 23. CORRELATION COEFFICIENTS AND SIGNIFICANT PROBABILITY LEVEL OF DAILY AIR AND SOIL
TEMPERATURES VS. NUTRIENT CONCENTRATIONS OF THREE SEEPAGE CREEK WATERS
Temperature
Air
Soil at 10 cm
Soil at 40 cm
<-»
yg/n
-0.002
0.992
-0.008
0.967
-0.050
0.798
N03~-N
,1
-0.251
0.188
0.086
0.656
0.151
0.434
N02~-N
ng/ml
See
0.188
0.328
0.225
0.241
0.194
0.314
Kjl-N
Ortho-P
Total-P
Zn
Cu
Ni
page creek
0.081
0.685
0.045
0.820
0.012
0.952
Seepage creek
Air
Soil at 10 cm
Soil at 40 cm
0.000
1.000
0.000
1.000
0.000
1.000
-0.227
0.236
-0.100
0.605
-0.011
0.095
0.223
0.245
0.378
0.043
0.385
0.039
0.170
0.378
0.269
0.158
0.302
0.111
no. 1
0.199
0.300
0.135
0.485
0.120
0.534
no. 2
-0.357
0.058
-0.250
0.191
-0.235
0.219
0.287
0.132
0.191
0.322
0.140
0.468
-0.404
0.030
-0.315
0.096
-0.315
0.096
0.540
0.003
0.577
0.001
0.583
0.001
0.667
0.000
0.675
0.000
0.693
0.000
-0.251
) 0.189
-0.037
0.848
0.057
0.770
0.031
0.874
0.125
0.520
0.181
0.348
0.210
0.275
0.164
0.397
0.141
0.467
0.150
0.436
0.171
0.376
0.176
0.361
(continued)
-------
TABLE 23. (continued)
ON
QO
Temperature
NH4+-N
N03~-N
yg/ml
Air
Soil at 10 cm
Soil at 40 cm
0.000
1.000
0.000
1.000
0.000
1.000
-0.227
0.236
-0.100
0.605
-0.011
0.095
N02~-N
ng/ml
See
0.223
0.245
0.378
0.043
0.385
0.039
Kjl-N
Ortho-P
page creek no. 3
0.170
0.378
0.269
0.158
0.302
0.111
-0.357
0.058
-0.250
0.191
-0.235
0.219
Total-P
-0.404
0.030
-0.315
0.096
-0.315
0.096
Zn
0.667
0.000
0.675
0.000
0.693
0.000
Cu
0.031
0.874
0.125
0.520
0.181
0.348
Ni
0.150
0.436
0.171
0.376
0.176
0.361
-------
TABLE 24. CORRELATION COEFFICIENTS OF TEMPERATURE AND NUTRIENT CONCENTRATIONS
VS. NUTRIENT CONCENTRATIONS OF WATERS IN THE SEWAGE FARM a
Sampling Sampling
Location Location
Number Correlation Coefficient Number Correlation Coefficient
1
2
3
4
5
6
7
9
10
NO~-N
Zn
N02-N
NO^-N
NH4-N
Temp
NO^-N
Ortho-P
NHJ-N
NO^-N
Ortho-P
NH4-N
Total-P
Ortho-P
Total-P
total-P
Temp
Ortho-P
Total-P
Total-P
Total-P
Total-P
vs.
vs.
vs.
vs.
vs.
vs.
vs.
vs.
vs.
vs.
vs.
vs.
vs.
vs.
vs.
vs.
vs.
vs.
vs.
vs.
vs.
vs.
Temp
Temp
Temp
Temp
Ortho-P
Ortho-P
Ortho-P
NH4-N
Temp
NOji-N
Temp
Kjl-N
Kjl-N
Kjl-N
Ortho-P
NHj-N
Zn
NHj-N
Ortho-P
Ortho-P
Ortho-P
Ortho-P
-0
0
0
-0
0
-0
-0
0
-0
0
-0
0
0
0
0
0
0
0
0
0
0
0
.800 12
.754 13
.624
.601 14
.845 17
.718
.616
.875 18
.777
.743 19
.645
20
.896
.800 22
.796
.778
.730
.683
.657
.852
.774
.755
.784
Total-P
Total-P
Total-P
Kjl-N
N02-N
Total-P
Total-P
Total-P
Total-P
Total-P
Ortho-P
Total-P
Kjl-N
Total-P
Ortho-P
Total-P
Kjl-N
NH^-N
Ortho-P
vs.
vs.
vs.
vs.
vs.
vs.
vs.
vs.
vs.
vs.
vs.
vs.
vs.
vs.
vs.
vs.
vs.
vs.
vs.
Ortho-P
Ortho-P
Ortho-P
NH4-N
Temp
Ortho-P
Ortho-P
Ortho-P
Ortho-P
Ortho-P
NH4-N
NH^-N
NH-4--N
Kjl-N
Kjl-N
Temp
Temp
Temp
Temp
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
-0.
-0.
-0.
-0.
857
607
661
933
683
663
797
972
671
924
917
898
896
882
866
772
735
677
644
a Correlation coefficients of NH4-N, N03-N, N02-N, Kjl-N, Total-P, Ortho-P
Zn, Cu, and Ni versus NO^-N, NO^-N, Kjl-N, Ortho-P, Total-P, and
temperature were calculated for all water sampling locations at the
sewage farm. Any coefficient not listed in this table has an absolute
value of less than 0.600.
Significant at 1% level
69
-------
plant and seepage creek no. 1. It is apparent that water temperature
influences the concentration of certain nutrients in waters.
PLANT ANALYSIS AND FIELD PLOT EXPERIMENT
One of the major concerns of land disposal of sewage wastes is the
cycling of chemical elements in sewage treated soils by the soil-plant
system. Sixteen elements have been shown to be essential for plant growth.
Four other elements are essential for some plants. Some elements may have
little or no effect on plant growth, whereas others may be toxic. Many
factors affect the toxicity of an element to a plant including plant
species and variety, plant growth stage, soil solution concentration, soil
availability and competition^ and balance of other elements. Generally, the
concentration of a chemical element in plant tissue increases as the
concentration and availability of that element in the soil increases if
other growth factors are the same. Plant species, even varieties within
species, exhibit natural variability and vary markedly in their tolerance
to concentrations of specific elements. Balance and competition of other
elements are also important in determining plant requirements and toxicity
for a particular element. Whenever the concentration of a given element in
a plant or the amount of that element supplied by the soil exceeds that
needed for sufficient and optimum growth, accumulation or toxicity of that
element may occur. The accumulation of toxic elements will in turn deter-
mine the long-term loading limits of sewage waste disposal on a land. One
of the objectives of this study is to examine the effect of long-term
sewage wastewater irrigation on plant growth and crop quality.
The data in Table . show the chemical composition and yield of four
forage crops grown at tJ ^ewage farm. Each set of data comes from a
sample taken from a dif nt part of the field. Coastal bermudagrass was
harvested on two diffen dates. The nitrogen concentration of individual
plant tissues ranged fr' .80 percent for Coastal bermudagrass on the first
cutting to 1.62 percent the second cutting. This corresponds to 17.50
and 10.13 percent crude protein in plants, respectively. The phosphorus
concentrations of plant tissue range from an average of 0.199 percent for
the first cutting of Coastal bermudagrass to an average of 0.343 percent
for forage sorghum. The yield of the second harvest of Coastal bermuda-*-
grass was the highest (6000 Kg/ha), whereas the yield of NK37 bermudagrass
was the lowest (2146 Kg/ha). Generally, the nutrient concentration in .the
first cutting of Coastal bermudagrass is higher than that of the second
cutting.
Both zinc and copper are required for normal plant growth. The con-
centration of copper in plant tissues varies from 3.8 Ug/g for the second
cutting of the Coastal bermudagrass to 9.1 Ug/g for forage sorghum. Allaway
(1968) indicated that the normal range of copper in plants is 4-15 Ug/g and
the toxicity level is 20 ug Gu/g. All the plants1 tissues contain less than
200 Ug/g Zn, the toxicity level suggested by Allaway (1968). Melstead (1973)
considered 300 Ug/g Zn in plant tissues as the maximum concentration value
for plants. Cadmium, chromium, and nickel are not considered as essential
for plant growth. Melstead (1973) suggested that the maximum .concentrations
70
-------
TABLE 25. NUTRIENT COMPOSITION AND YIELD FOR SINGLE CUTTINGS OF NK37 BERMUDAGRASS,
FORAGE SORGHUM, RESCUEGRASS AND COASTAL BERMUDAGRASS AT THE SAN ANGELO SEWAGE FARM
Sampling
Crop Acreages Data
ha
KK37 bermudagrass 14.2 750902
Forage Sorghum 75.9 750902
Pvescuegrass 40.5 760513
Coastal 127.5 760728
beraiudagrass
Coastal 127.5 760810
bermudagrass
Cd
0.2
0.3
0.5
0.2
0.3
0.2
0.4
0.3
0,3
0.4
0.3
0.3
0.4
0.5
0.3
Cr
*
0.5
1.2
0.8
0.8
0.8
-------
of Cd and Cr in plants are 3 and 2 yg/g, respectively. None of the plant
tissue taken from the sewage farm had concentrations of Cd and Cr greater
than that. The concentration of Ni of plant tissues was far less than 50
yg/g, the toxicity level suggested by Allaway (1968).
Several studies have shown the accumulation of trace elements in plants
grown in sewage waste treated soils. In his investigation of trace element
concentrations of plants grown on soil treated with sewage sludge over a
period of 19 years, Le Riche (1968) found no adverse effects on crop yields,
but the plants accumulated abnormally large amounts of certain trace
elements. John et al. (1972) investigated the factors affecting plant up-
take and phytotoxicity of Cd added to soils. They found that Cd may reaaily
be taken up from the soil and may result in potentially hazardous accumula-
tion of Cd in plants. Page et al. (1972) reported that plant leaves were
capable of accumulating excessive amounts of Cd when the culture solution
concentration was a few tenths of 1 ppm. Day and Kirkpatrick (1973) showed
that wastewater generally produced equal or somewhat higher yields of grain
or forage than well water with N, P, and K added equal to the N, P, and K of
the wastewater. Hodgson (1970) found that the ratio of cadmium concentration
in plants to that in the corresponding soil was about 10 to 1. He also
showed that the ratio of total chromium in plants to that in soil was 0.02.
Allaway (1968) indicated that plants may grow normally but contain levels of
Cd, Mo, Ni, and Se which are toxic to animals. Plants may exclude As, Be, I,
F, Zn, Ni, and others by only minimal adsorption of these trace elements
from soils.
Sewage wastewaters contain certain amounts of nitrogen, phosphate,
carbon, and other chemical species as well as heavy metals. The inter-
actions between the heavy metals and all other chemical species play an
important role in the fate of applied chemical elements in the soil. Agboala
and Corey (1973) stated that soil phosphate level is one of four major
factors which affect the availability of zinc to plants. Giordano and
Mortvedt (1976) found that application of nitrogen fertilizer did not affect
the downward movement of heavy metals in soil but enhanced uptake of these
metals by plants. Miller et al. (1976) investigated the relationship
between uptake of cadmium by soybeans and available soil phosphorus and
found cadmium accumulation increased with increasingly available soil
phosphorus. Williams and David (1976) reported that in a field experiment
uptake by wheat of both native soil cadmium and cadmium residue from super-
phosphate was substantially increased by the application of ammonium nitrate.
They also showed that at high levels of application, phosphate significantly
affected the uptake of cadmium by plants. Caro (1974) showed the normal
range of concentration of several trace elements formed in average super-
phosphate as follows: Cd, 50-170 ppm; Cr, 66-243 ppm; Cu, 4-79 ppm; Ni, 7-32
ppm; and Zn, 50-1430 ppm. Ozanne et al. (1976) found that phosphatic fer-
tilizers contain appreciable amounts of zinc and play an important part in
meeting the zinc requirements of plants on some Zn-deficient Australian
soils.
The effects of nitrogen and phosphate fertilization and cutting on the
chemical composition and yields of Coastal bermudagrass grown in the
fenced plot area are listed in Table 26. The date of the first cutting of
72
-------
TABLE 26. YIELD AND NUTRIENT COMPOSITION OF COASTAL BERMUDAGRASS AS INFLUENCED BY N AND P FERTILIZATION
CO
PloC
Mo.
Bate of
fertilizer
Cutting
H
S
CH
Cr
PUnt
Cu
Composition
HI
Zn
N
Xg/lia PK'g
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
f ^
if
18
19
20
21
22
23
24
25
26
27
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2.
2
2
2
2
224.4
224.4
0.0
0.0
112.2
112.2
112.2
0.0
224.4
224.4
0.0
112.2
0.0
0.0
224.4
112.2
*t"JL A
£ ***. *t
112.2
224.4
0.0
0.0
224.4
112.2
0.0
112.2
224.4
112.2
224.4
224.4
0.0
0.0
112.2
112.2
112.2
0.0
224.4
224.4
0.0
112.2
0.0
0.0
224.4
112.2
224.4
112.2
224.4
0.0
0.0
22'.. 4
112.2
0.0
112.2
224.4
112.2
112.2
56.1
0.0
56.1
112.2
56.1
0.0
112.2
o o
112.2
112.2
112.2
56.1
0.0
0.0
56.1
56 1
JO . 1
0.0
56.1
0.0
112.2
0.0
0.0
56.1
112.2
112.2
56.1
112.2
56.1
0.0
56.1
112.2
56.1
0.0
112.2
0.0
112.2
112.2
112.2
56.1
0.0
0.0
56.1
56.1
0.0
56.1
0.0
112.2
0.0
0.0
56.1
112.2
112.2
56.1
0.3
0.4
0.4
0.2
0.3
0.3
0.3
0.4
0.4
0.3
0.3
0.2
0.3
0.3
0.2
0.3
0.2
0.2
0.2
0.3
0.3
0.3
0.2
0.3
0.3
0.3
0.4
0.1
0.1
0.1
0.2
0.1
0.
0.
0,
0.
0.
0.
0.
0.
0.
0.2
0.1
0.0
0.2
0.2
0.2
0.1
0.4
0.2
0.5
0.1
0.1
0.1
0.7
0.3
0.4
0.7
0.6
0.6
0.6
0.7
0.7
0.4
0.3
1.0
1.0
1.0
1.0
1.3
1.8
1.8
1.8
1.6
1.8
1.8
1.6
1.2
1.4
0.7
0.8
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.3
0.3
0.5
0.8
0.5
0.5
0.1
0.1
0.5
0.3
0.8
6.7
5.6
5.6
5.6
6.4
7.0
6.0
6.4
6.7
5.4
10.0
5.0
6.7
5.6
5.0
5.4
5.6
6.0
7.0
5.6
6.0
6.4
6.8
5.4
8,2
8.2.
7.0
6.7
6.7
6.3
6.3
5.7
5.9
6.5
5.9
6.1
5.9
5.9
7.1
5.7
5.7
5.7
5.7
7.9
8.9
5.7
7.6
5.7
5.7
7.1
7.1
7.5
7.6
2.8
2.0
1.2
1.2
1.6
1.2
2.0
1.2
2.0
1.2
1.2
1.2
2.4
2.0
2.4
1.2
1.2
1.2
1.2
4.0
3.2
2.8
3.0
2.8
4.0
2.8
3.0
3.4
3.7
3.4
2.8
2.8
4.0
3.1
3.1
3.1
2.5
3.7
3.4
3.1
4.0
3.1
4.0
3.1
3.1
3.1
4.0
4.3
3.1
4.0
3.4
4.0
3.4
35
28
30
26
31
35
31
27
40
36
35
32
37
21
37
30
30
28
33
28
26
24
25
21
33
33
60
40
37
34
56
38
38
48
62
44
51
40
44
40
40
38
36
48
47
37
33
33
86
93
45
42
66
2.690
2.834
2.683
2.583
2.753
2.695
2.650
2.624
2.352
2.578
2.476
2.588
3.003
2.655
2.683
2.593
2£ 1 •)
• Ol*
2.767
2.841
2.869
2.650
2.593
2.514
2.962
2.576
2.979
2.151
2.451
2.051
2.354
2.236
1.995
1.883
1.976
2.054
1.941
1.952
2.113
2.057
2.067
2.531
2.526
2.464
2.585
2.577
2.612
2.365
2.378
2.665
2.337
2.494
2.553
2.467
2.644
P
1,
0.278
0.278
0.243
0.256
0.270
0.316
0.313
0.266
0.313
0.300
0.323
0.280
0.233
0.266
0.280
0.260
0.2SO
0.280
0.300
0.266
0.260
0.260
0.300
0.266
0.350
0.330
0.286
0.256
0.264
0.233
0.233
0.233
0.249
0.276
0.236
0.256
0.263
0.256
0.268
0.279
0.276
0.276
0.286
0.316
0.303
0.276
0.286
0.268
0.279
0.276
0.299
0.286
0.303
Protein
*
16.81
17.71
16.77
16.14
17.20
16.84
16.56
16.40
14.70
16.11
15.47
16.17
13.77
16.59
16.77
16.20
1 f -If
lu . $£.
17.29
17.75
18.05
16.56
16.20
15.71
18.51
16.10
18.62
13.44
15.32
12.82
14,71
13.98
12.47
11.80
12.35
12.84
12.13
12.20
13.20
12.85
12.92
15.82
15.79
15.40
16.15
16.10
16.32
14.78
14.86
16.66
14.31
15.58
15.95
15.42
16.52
Yield
Kg/h«
9913
14085
10970
12202
11268
15656
12907
15263
14139
15087
11647
12893
12040
9101
8S57
10401
10266
10130
11078
7855
10469
7882
11444
9792
12717
7787
5647
6121
5959
6677
5893
8694
7841
7286
7950
8193
6365
7367
7625
5638
2532
4103
3724
4239
4117
5146
4469
6162
4753
5078
3914
4347
3927
-------
Coastal bermudagrass was July 20, 1976 and the second cutting September
15, 1976. The nitrogen concentration of plant tissues of Coastal bermuda-
grass ranged from 1.89 to 2.98 percent. This corresponds to 11.8 and 18.6
percent crude protein in plants. The phosphorus concentration of Coastal
bermudagrass varied from 0.233 to 0.350 percent. Fertilization with
nitrogen and/or phosphate has no significant effect on the chemical compo-
sition and yield of Coastal bermudagrass grown in the sewage farm plots
(Table 27).
San Angelo city employees have annually applied 40,000 pounds of
N (as NILNO-) to the forage crops. In view of the total nitrogen in the
sewage effluent and high fertility of the soil from past effluent appli-
cations the practice of applying additional fertilizer N would seem highly
questionable. Applications as high as 224 kg N/ha and 112 kg P-O^/ha did
not significantly increase yield or nutrient composition of Coastal
bermudagrass.
The concentrations of heavy metals (Cd, Cr, Cu, Ni, and Zn) in plants
are all in the normal range reported by Allaway (1968) as discussed before.
No evidence of accumulation of heavy metals in Coastal bermudagrass is
observed (Table 26). There are highly significant (at 1 percent level)
correlation coefficients between cutting and Cd, Cr, Ni, Zn, and N
concentrations and between cutting and yields (Table 27). Cutting has a
significant effect on the Cd, Cr, Ni, Zn, and N concentrations, and yields
of Coastal bermudagrass (Table 27). Application of average amounts of N
and P fertilizers on the sewage farm do not increase the forage yield.
There was no evidence to show that accumulation of heavy metals in plants
was related to impurities in the N and P fertilizers.
SOIL ANALYSIS
Introduction
Soils on the San Angelo sewage farm are from three major soil series
(Angelo, Mereta, and Rioconcho). These soils belong to the great group
Calciustolls which are characterized by a distinct lime (CaCO~) accumu-
lation within 1.3 m of the soil surface. Appreciable amounts of mont-
morillonite and mixed clay minerals are found in the soils. These red to
brown soils, formed in outwash, clayey to silty red bed, or over limestone
in the Rolling Plains in Central Texas, are classified as Mollisols
(suborder).
The Angelo soil is well drained, and surface runoff is slow. This
calcareous soil has a distinct zone of calcium carbonate accumulation at
a depth of about 70 cm. The permeability is moderately slow, and the
available water capacity is high. The soil profile can be distinguished
by the following horizons: Ap, B21, B22, B23 , and C. The Angelo
solum thickness is 150 to 300 cm. Angelo soils are deeper than the Mereta
soils but lack an indurated zone of calcium carbonate accumulation. These
are productive soils when used for crops and as rangeland.
74
-------
TABLE 27. STATISTICAL ANALYSIS SHOWING THE EFFECT OF N AND P FERTILIZATION
ON PLANT COMPOSITION AND YIELDS OF COASTAL BERMUDAGRASS GROWN IN THE SEWAGE FARM
-•j
Ui
Effect
N fertilizer
P fertilizer
Cutting
N
A.
0.0236
0.865
-0.0944
0.497
—0.6293
0.000
P
r
Correlation
0.1556
0.261
0.0724
0.602
-0.2215
0.107
Cd
coefficients
0.0198
0.886
0.15S5
0.252
-0.5985
0.000
Cr
Cu
Ni
Zn
Yield
and significant probability level
0.0048
0.972
-0.1151
0.407
—0.5561
0.000
B. Values of F
Cutting
N fertilizer
P fertilizer
N and P fertilizers
Cutting and N
Cutting and P
Cutting and N and P
29.47*
0.68
0.53
0.63
0.40
0.49
0.55
2.39
0.67
0.20
1.19
0.28
0.18
0.72
25.35a
o.::4
1.19
O.L9
0.30
0.52
0.80
18.313
0.00
0.55
0.18
0.03
0.70
0.40
-0.0934
0.501
0.2325
0.090
0.1173
0.398
test
0.67
0.33
1.49
0.77
0.36
0.22
1.04
0.0985
0.478.
0.0022
0.986
0.7019
0.000
43.82a
0.85
0.24
0.97
0.02
0.61
0.45
0.0182
0.895
-0.0066
0.961
0.6041
0.000
25.34a
0.12
0.01
0.81
0.58
0.06
0.82
-0.0248
0.858
0.1002
0.470
-0.8143
0.000
77.S43
0.08
0.60
0.36
0.19
0.14
0.01
significant at 1% level
-------
The Mereta soils are well drained, and the surface runoff is slow. The
available water capacity is low and limits vegetative production. They have
indurated caliche at less than 50 cm depth. The surface layer is dark
brown or dark grayish brown clay loam about 30.48 cm thick. The Mereta
series is located in the level to gently sloping parts of the outwash
plains of Tom Green County. The soil profile can be distinguished by the
following horizons: Ap, A12, A13, CI^san, C2Ca, and C3. The indurated
caliche is located in the C, horizon (45 to 54 cm depth). . The indurated '
caliche horizon may have roots and a little soil in the cracks and between
plates. It contains a few to 10 percent by volume of caliche fragments
less than 2.54 cm in diameter. The Mereta solum thickness ranges from
35 to 50 cm. Land leveling, terracing, and depth of plowing are limited
by the shallow depth of hard caliche.
The Rioconcho soils are well drained, and surface runoff is slow. The
permeability is moderately slow, and the available water capacity is high.
The Rioconcho series is located in the alluvial flood plain of streams
draining limestone areas. The surface layer is dark grayish brown clay
loam about 95 cm thick. The thickness of Rioconcho soils over gravel, sand,
or limestone ranges from 180 to 600 cm. Only three soil horizons (All,
A12, and C) can be distinguished in the Rioconcho soil profile. The
thickness of the Dark A horizon ranges from 51 to 127 cm. These soils are
well suited for cropland and are frequently irrigated. Flooding occurs
once in 3 to 20 years but seldom lasts for more than 1 day.
Initial Characterization of Physical and Chemical Properties
Initially a total of 180 surface soil samples were analyzed for organic
matter, carbonate, cation exchange capacity, total phosphorus, water
soluble phosphate, total nitrogen, and IN HC1 extractable Cd, Cr, Cu, Ni,
Pb, and Zn. These surface samples were taken from the 3 soil series
located on the sewage farm.
The chemical and physical properties of these three sewage farm soil
series compiled from samples taken to a depth of 30 cm are listed in
Table 28.
Texture
Rioconcho and Angelo soils had more than 38 percent clay in the upper
40 cm of the soil profile. Mereta soil had a clay content ranging from
27 to 35 percent. Angelo and Mereta soils are classified as clay loams
and Rioconcho as clay.
Soil pH
The pH value of all three soils in 1:1 soil-water solution is greater
than 7.6.
76
-------
TABLE 28. CHEMICAL AND PHYSICAL PROPERTIES OF THE TOP 40 CM OF THREE MAJOR SOIL SERIES
FROM THE SAN ANGELO SEWAGE FARM
Soil
Series Depth
en
Aloconcho 0-5
5-10
10-20
20-30
30-40
Angelo 0-5
5-10
10-20
20-30
30-40
Har.t. 0-5
5-10
10-20
20-30
30-40
Sand
20.8
19.7
17.2
18.8
18.3
36.2
37.5
36.2
33.7
36.2
45.8
43.1
45,9
43.2
39.2
Silt
" *
36.2
34.4
36.4
34.1
34.4
26.0
24.7
26.1
26.3
24.5
27.1
28,5
25.2
25.9
26.2
Clay
42.9
45.8
46.3
46.9
47.3
37.8
37.8
37.7
40.0
39.3
27.1
28.4
28,9
30.9
34.6
Texture
Clan
clay
clay
clay
clay
clay
clay loan
clay loam
clay loan
clay loam
clay loam
clay loan
clay loan
clay loan
clay loan
clay loaa
Bulk
Density
gin/cor*
1.37
1.31
1.20
1.21
1.22
1.32
1. 15
1.23
1.23
1.21
1.37
1.58
1.45
1.44
1.43
P
V
7.64
7.70
7.67
7.75
7,84
8.17
8.34
8.54
8.75
8.33
7.87
8.02
8.10
8.06
«. 30
H
0,01 M
CaClj
7.20
7.08
7.05
7.05
7.11
7.65
7.67
7.75
7.82
7.88
7.45
7.53
7.85
7.59
7.71
Carbonate
COj-C
X
2.59
2.72
2.76
1.94
2.09
1.81
1.90
2.01
2.54
4.22
1.33
1.55
1.50
1.79
5.50
Organic
Matter
*
3.16
1.91
1.39
1.18
1.18
2.53
2.44
1.94
1.40
1.13
3.36
2.25
1.85
1.67
1.16
Cation
Exchange
Capacity
B«J./100g
17.43
16.25
15.87
16.61
16.49
23.12
24.22
21.50
17.26
15.52
20.90
17.29
16.00
16.53
10.91
Soluble
Salt
Jlmhot/ca
720
620
770
710
660
273
252
200
179
183
399
315
273
252
252
-------
Organic Matter
The organic matter content of all three soils in the upper 5 cm ranges
from 2.5 to 3.4 percent and drops to about 1.1 percent below 30 cm depth.
Prasad et al. (1976) found that in alkaline and calcareous soils natural
chelating agents play an important role in the self-diffusion of zinc. In
his study of 75 pasture soils of Spain, Macias (1973) found a significant
positive correlation (5 percent level) between organic matter and total
zinc and between organic matter and IN NH.OAc extractable Cu. He found a
negative correlation, significant at the 5 percent level, between organic
matter and 0.1 Ni HC1 extractable Cu. Martens (1968) suggested that Cu
bonded to organic matter is the main source of plant available Cu.
John (1972) reported that extractable zinc in soil is increased with higher
organic matter and is one of the important soil properties in predicting the
zinc content of corn and oat plants.
Carbonate
All three sewage farm soils have free CaCO- throughout the profile.
Angelo and Mereta soils have high carbonate content (4.22 and 5.50 percent
CO--C, respectively) at a soil depth between 30 to 40 cm. The average
carbonate content of 120 sewage farm surface soils is 1.78 ± 0.68 percent
as CO~-C. In their study of zinc adsorption by calcareous soils, Udo et al.
(1970; found that the carbonate equivalent and organic matter content of
the soil influenced the Langmuir adsorption maxima of zinc by calcareous
soils. Griffin and Shrimp (1976) reported that both cation exchange
capacity and carbonate precipitates were the principal mechanisms
affecting metal attraction by clay minerals in landfill leaching. Ellis
(1974) stated that after prolonged wastewater applications most of the
heavy metals will be expected to precipitate as a hydroxide or a car-
bonate in the soil with a pH greater than 7.0.
Cation Exchange Capacity
The cation exchange capacity of Mereta soil ranges from 20.90 meq/100 g
at the surface to 10.95 meq/100 g at the 30-40 cm depth. Angelo soils
have the highest average cation exchange capacity (ranging from 24.22 to
15.52 meq/100 g) of the three soils. The cation exchange capacity of
Rioconcho soils ranges from 17.43 to 16.49 meq/100 g. The cation exchange
capacity of 120 surface soils at the sewage farm was 18.4 ± 4.1 meq/100 g.
The cation exchange capacity is significantly different at the 1 percent
level from that of 60 surface soils from the control area (20.2 ± 3.6
meq/100 g) as shown in Table 29. Haghiri (1974) found the plant uptake of
cadmium could be influenced by several factors such as organic matter and
cation exchange capacity. Korte et al. (1976) studied the influence of
soil chemical properties on trace element movement in soils of 7 major
orders. They found significant correlations between cation exchange
capacity and adsorption of Ni and Zn by soils. No significant correlation
between cation exchange capacity and adsorption of Cd and Cr was observed.
They concluded that the value of cation exchange capacity for predictive
purposes with natural soils is limited. There was a highly significant
difference at the 1 percent level in cation exchange capacity of surface
78
-------
TABLE 29. STATISTICAL ANALYSIS OF SURFACE SOIL CHEMICAL CHARACTERISTICS BY F TEST
Cation
Organic Exchange Water
Effect matter Carbonate Capacity Soluble Total Total IN HC1 extractable
P P N Cd Cr Cu Pb Ni Zn
Soil
Series (A) 0.26 18.52C 9.32C 6.69° 2.54a 1.45 10.86C 5.63C 3.89 1.77 23.24C 2.38a
Wastewater
treatment (B)0.03 3.30a 9.20C 417.78C 118.23° 0.27 14.28C 4.46 0.15 1.89 0.46 1.54
Soil
Depth (C) 11.83 7.32° 2.91b 1.06 18.58C 10.49° 3.62b 5.82° 2.46a 2.37a 1.82 1.78
A, B
interaction 2.61a 40.23° 0.01 0.69 12.17° 3.04a 8.89° 4.15b 2.21 0.71 16.44° 1.10
A, C
interaction 0.49 1.73 0.40 0.62 0.93 0.62 1.43 0.96 0.99 1.25 0.29 1.50
B, C
interaction 2.57& 0.12 1.73 0.17 8.50° 2.63a 1,32 2.49a 0.75 1.06 0.89 0.86
A, B, C
interaction 0.55 0.46 0.84 0.28 0.79 0.62 1.44 0.50 0.42 0.56 0.97 0.73
Significant at 10 percent level
significant at 5 percent level
Significant at 1 percent level
18C surface soil samples are used for calculation
-------
soils among three soil series. The difference in cation exchange capacity
at varying soil depths is significant at the 5 percent level.
Soil Salinity
The amount of soluble salt in all three soils is low, and no salinity
effect on plants is expected. The conductivity of a saturated paste
extract was less than 1 mmho/cm.
Statistical Relationships Between Surface Soil Properties
The effects of soil series, wastewater treatment, and soil depth on
the soil chemical characteristics were analyzed statistically and are
listed in Table 29. Partial correlation coefficients among the 12 soil
chemical parameters are calculated and listed in Table 30. These partial
correlation coefficients will be used to evaluate the best relationships
among all 12 soil characteristics.
It was found that wastewater treatment and soil series have no effect
on the soil organic matter content; whereas soil depth has a significant
effect at the 5 percent level. Partial correlation coefficients among
soil organic matter and total nitrogen, total phosphorus, and cation
exchange capacity are highly significant at the 0.1 percent level (Yp =
0.985, 0.585, and 0.569, respectively).
There was a significant difference at the 10 percent level between
the carbonate content of soils in the sewage farm and that of the control
area. It was found that soil series, soil depth, and interaction of soil
series and wastewater treatment have a highly significant (at the 1 percent
level) effect on the carbonate content of these surface soils (Table 29).
A highly significant negative partial correlation at the 1 percent level
between carbonate content and HCl extractable Ni, Cu, Cr (Yp = -0.504,
-0.233, and -0.337^ respectively), and between carbonate content and cation
exchange capacity (Yp = -Q.213) was found.
IN HCl Extractable Heavy Metals
Lagerwerff (1971) showed that a chemical ind6x using IN HCl as an
extractant could be used to examine the availability of heavy metals to the
plants. He found that increasing the soil pH from 5.9 to 7.2 resulted in
decreases in yield and heavy metal content of the radish plant. Average
concentrations of 111 HCl extractable Cd, Cr, Cu, Ph, Ni and Zn are presented
in Table 30 for the San Angelo sewage farm and the control area soil.
Data presented in Table 29 show that irrigation of land with sewage
wastewater can significantly affect the acid extractable Cd and Cr in the
surface soils. No significant effect of wastewater irrigation on IN HCl
extractable Cu, Pb, Ni, and Zn of soils is observed. The average IN HCl
extractable Cd and Cr concentration of 120 surface soils at the sewage farm
was 0.48 ± 0.22 and 0.49 ± 1.09 yg/g, respectively, and that of 60 surface
soils in the control area was 0.38 ± 0.07 and 0.21 ± 0.22 yg/g, respectively.
Application of sewage wastewater on land significantly increased the acid
80
-------
TABLE 30. AVERAGE CONCENTRATIONS OF IN HC1 EXTRACTABLE Cd, Cr, Cu, Pb, Ni, and Zn
IN THREE SOIL SERIES FROM THE SAN ANGELO SEWAGE FARM AND THE CONTROL AREA
CO
Rioconcho v
Elements
Cd Mean
Standard Deviation
Maximum
Minimum
Cr Mean
Standard Deviation
Maximum
Minimum
Cu Mean
Standard Deviation
Maximum
Minimum
Pb Mean
Standard Deviation
Maximum
Minimum
Hi Mean
Standard Deviation
Maximum
Minimum
Zn Mean
Standard Deviation
Maximum
Minimum
Sewage*1
farm
0.38
0.07
0.50
0.28
0.13
0.21
0.81
0.00
0.55
0.07
0.78
0.47
4.76
1.44
8.67
3.09
2.04
0.27
2.89
1.79
0.73
0.63
2.89
0.37
Control
farm
0.38
0.06
0.45
0,17
0.11
0.05
0.14
0.00
0.50
0.06
0.52
0.25
4.68
0.76
5.69
2.28
1.71
0.20
1.80
0.87
0.41
0.07
0.47
0.21
.Angelo ,_
Sewage"
farm
• *••• *tm* Ml* » w ••••• 1 I Cf i
0.46
0.05
0.54
0.36
0.90
1.40
7.05
0.00
1.13
1.09
5.22
0.47
17.75
34.17
208.64
3.12
2.46
0.58
3.33
1.62
5.48
8.26
39.02
0.33
Control
farm
fa — -
0.41
0.04
0.48
0.36
0,09
0.11
0.26
0.00
0.52
0.12
1.02
0.47
5,38
1.07
8.99
4.71
2.01
0.42
3.12
1.66
0.48
0.39
1.97
0.31
Mereta
Sewage "*
farm
0.60
0.34
2.40
0.36
0.43
1.15
6.56
0.00
1.04
2.45
15.83
0.45
36.81
133.90
833.36
4.09
2.38
0.67
5.05
1.74
45.72
178.56
1096.60
0.35
Control15
farm
0.35
O.C8
0.46
0.21
0.42
0.26
0,65
0.00
1.48
0.74
2.51
0.46
7.03
2.76
16.67
4,15
3.00
0.72
4.19
1.37
1.64
1.06
4.C4
0.29
from a total of 40 samples.
from a total .of 20 samples.
-------
extractable Cd and Cr concentrations in these soils. There is a highly
significant partial correlation at the 1 percent level between any one of
these acid extractable heavy metals (Cr, Cd, Cu, Pb, Ni and Zn) and other
heavy metals (Table 31). The partial correlation coefficients (a total of
15 Yp) between these six IN HC1 extractable heavy metals ranges from
0.427 to 0.970. The IN HCl extractable Zn, Pb, and Cd are highly corre-
lated with total soil nitrogen. There is significant partial correlation
(at 5 percent level) between acid extractable Cd and total soil phosphorus,
and between acid extractable Cu and total soil nitrogen. Water soluble
phosphorus is significantly correlated at the 1 percent level with acid
extractable Cd, Cr,. Cu, Ni, Pb, and Zn.
A highly significant partial correlation was found between organic
matter content and IN HCl extractable Zn and Cd concentrations (Yp - 0.206
and 0.290, respectively). Some heavy metals are expected to be retained
in the soil by organic matter. Many organic materials are capable
chelating the heavy metals and increase their concentration in soil
solution. This will result in increased uptake by plants and increased
leaching through the soil profile into the groundwater (Ellis 197'
There was a highly significant positive partial correlation ^. the
1 percent level between cation exchange capacity and HCl-extractable Ni
(Yp = 0.205), total N(Yp = 0.546), total P(Yp = 0.440), and water
soluble phosphorus (Yp = 0.260 (Table 31).
NUTRIENT LOADING OF SOIL PROFILES
Soil cores were taken from the sewage farm and from a control area
adjacent to the farm. Sampling areas were chosen that represented the
major s-oil series (Angelo, Mereta and Rioconcho) . Ten cores were taken
on the farm where sewage effluent has been applied for the past 18 years.
Five cores were taken from the control area which had been grazed but had
not been cultivated or received sewage effluent. Soils were taken to a
depth of 200 cm, except where a gravel or hard caliche layer existed in
the soil profile. The location of cores from the sewage farm and from
the control area is shown in Figure 10. The cores were sectioned and
each section analyzed for total nitrogen, NH,-N, NOl-N, NO~-N, total P,
water-soluble P and total heavy metals (Cd, Cr, Cu, Pb, Ni, and Zn). A
comparison of the two sets of profile samples were used to assess the
nutrient loading which occurred as a result of sewage effluent irrigation.
The total nutrient contents were calculated using the concentration of
total nutrients and soil bulk density at each depth. Because only two
soil profiles, one in the sewage farm and another one in the control
area, from each soil series have been used for the determination of bulk
density and that value of bulk density has been used for all soil profiles
of the same soil series, the total soil nutrient contents are only an
estimate. The bulk densities of three soil series from the San Angelo
sewage farm and the control area are shown in Table 32.
82
-------
TABLE 31. PARTIAL CORRELATION COEFFICIENTS AND SIGNIFICANT PROBABILITY LEVEL OF CHEMICAL
CHARACTERISTICS OF SURFACE SOILS .(0 - 20 cm) IN THE SEWAGE FARM AND THE CONTROL AREA *
00
HCl-Zn
HC1-S1
HCl-Pb
HCl-Cu
HCl-Cr
HCl-Cd
Total-N
Total-P
H,0-P
Cation
Exchange
Capacity
Carbonate
Organic
Matter
0.20625
0.009
0.07681
O.J38
0.16246
0.042
0.15778
0.048
0.12401
0.121
0.28989
0.000
0.9S547
0.000
0.53451
0.000
0.24841
0.001
0.56912
0.000
-0.02237
0.780
Carbonate
—0.09328
0.245
-0.50388
0.000
-0.13023
0.104
-0.23309
0.003
-0.33724
0.000
0.03603
0.654
-0.02288
0.776
0.15205
0.057
-0.11978
0.135
—0.21312
0.007
Cation
Exchange
Capacity
-0.04209
0.600
0.20542
0.009
-0.03111
0.69S
0.05980
0.456
0.16261
0.041
-0.07230
0.368
0.54626
0.000
0.44030
0.000
0.26001
0.001
H20-P
0.38285
0.000
0.27360
0.000
0.39035
0.000
0.40938
0.000
0.33240
0.000
0.30061
0.000
0.27291
0.000
0.25942
0.001
Total-P Total-N HCl-Cd HCl-Cr HCl-Cu HCl-Ri HCl-Pb
0.06J.23 0.26073 0.90283 0.54849 0.90141 0.96953 0.46173
0.42.'. 0.001 0.000 0.000 0.000 0.000 0.000
-0.10004 0.08934 0.42692 0.63813 0.6123t- 0.49921
0.213 0.265 0.000 0.000 0.000 0.000
0.05179 0.20327 0.85783 0.69533 0.94989
0.51S 0.010 0.000 0.000 0.000
0.04108 0.19166 0.76194 0.78387
0.60S 0.016 0.000 0.000
0.07566 0.11919 0.44750
0.346 0.137 0.000
0.19S27 0.33983
0.012 0.000
0.60671
0.000
'From 180 soil samples
-------
Figure 10. Sampling locations for soil cores taken from the
sewage farm and for soil cores taken from the control area
outside the sewage farm (A = Angelo, M = Mereta, R = Rioconcho)
84
-------
TABLE 32. DISTRIBUTION OF BULK DENSITY WITH DEPTH IN THREE SOIL
SERIES FROM THE SAN ANGELO SEWAGE FARM AND THE CONTROL
AREA
Location
Sewage
farm
Control
area
Depth
0-5
5-10
10-15
15-20
20-30
30-40
40-50
50-100
0-5
5-10
10-15
15-20
20-30
30-40
40-50
50-100
Rioconcho
1.37
1.31
1.23
1.18
1.21
1.22
1.31
1.31
1.18
1.26
1.20
1.26
1.25
1.28
1.38
1.21
Bulk density3
Angelo
3
1.36
1.58
1.39
1.50
1.44
1.43
1.42
1.38
1.25
1.07
1.10
1.01
1.20
1.14
1.13
1.23
Mereta
1.32
1.15
1.37
1.08
1.23
1.21
1.22
—
1.36
1.34
1.42
1.43
1.49
1.50
1.62
from a single measurement
85
-------
Total Nitrogen
The total nitrogen (N) concentration ranges from 0.06 to 0.5 percent in
the top 15 cm of most cultivated soils. Most of the total N is in the
organic form. Ammonification and nitrification of organic N may signifi-
cantly increase the NH.-N, N02~N, and NOo-N concentrations in the soil
solution. Irrigation with wastewater on land may become a potential
environmental hazard if the crop removal of applied N is small, and the
applied N leaches , into the surface or ground waters.
A study by Johnson et al. (1975) indicated that growing soybeans
resulted in a net removal of N from the soil, especially when the soil
contained residual inorganic N from a preceding crop. Stanford (1973)
reported that with good management the grain and stover of corn could
recover 50 to 70 percent of the applied N. He showed that if optimum rates
of N were applied on corn, all residual N would be immobilized. Immobiliza-
tion of applied N by microorganisms and plants will reduce the potential of
leaching of N and removals of N on cropland in 8 Great Plains and Western
States in the United States. They found that the weighted average of the
ratio N fertilizer applied to nitrogen removed was 0.82 for this region.
This ratio for other states in Central, East, and Southeast regions of the
United States ranged from 0.59 to 4.90.
The distribution of total N concentration with depth in the sewage
farm soils compared to the control area is shown in Figure 11. The
maximum total N concentration was found in the top 0-5 cm layer and
generally decreased with increased soil depth in all soils. There is a
significant difference (at the 1 percent level) in total N concentrations
among the three soil series and among soils at varying depths (Table 33).
No significant difference is found in total N concentration between the
sewage farm soils and the control area soils or among the soil cores
sampled. Irrigation with sewage wastewater did not significantly change
the total N concentration of Rioconcho, Angelo, and Mereta soils. In
Rioconcho soils removal of applied N is greater than the N applied to the
soil. In Angelo and Mereta soils there is an accumulation of total N in
the upper 0-5 cm of surface soil. The total N content at varying soil
depths in the soil profile in Rioconcho, Angelo, and Mereta soils is listed
in Tables 34 , 35 , and 36 , respectively. The average total N content-of
the upper 20 cm of soil increased 38.9 percent in Angelo soils, and 26.6
percent in Mereta soils after 18 years of wastewater irrigation and crop
production (Table 37). This increase was due primarily to an accumulation
in the top 0-5 cm. There was a decrease of 19.6 percent of total N
content in the top 20 cm soil column in Rioconcho soils. Total N content
was less for the Rioconcho soils in the sewage farm at all depths. The
overall average total N content of the top 20 cm of soil in these
three soil series increased 13.4 percent.
Exchangeable Inorganic Nitrogen
Ammonium (NH,) and nitrate (NO,) are the most important forms of N
utilized for plant growth. Generally, only a small proportion of total
soil N is in the inorganic forms, if the nonexchangeable NH. .fixed by soil
86
-------
RIOCONCHO
ANGELO
MERETA
DEPTH
cm
00
1250
2500
TOTAL-N,^g/g
0 12.50 2500
I £50
2500
SEWAGE FARM SOIL
CONTROL SOIL
Figure 11. The effect of sewage effluent irrigation on total nitrogen content of the top
200 cm of soil from the sewage farm compared to the control area.
-------
TABLE 33. STATISTICAL RELATIONSHIPS BETWEEN SOIL NUTRIENTS AS RELATED TO SOIL SERIES,
TREATMENT, CORE AND DEPTH AS DETERMINED BY ? TEST
Effect Total-N NO~-N NOj-N
Soil Series 7.08° 7.86° 1.66
Treatment 0.09 12.05° 0.46
c
00 Core 0.82 5.80 1.28
00
Depth 17.42° 1.04 0.86
KH^-N Total-:?
2.19 5.26':
0.10 127.37°
b ,.
2.14 3.06'-
0.82 22.60°
H20-P Cd Cr Cu Ni Pb Zn
2.25 12.99° 1.19 2.28 126.55° 28.58° 5.31°
528.16° 2.10 5.99b 3.29a 57.61° 11.46° 2.19
c c a c c c a
7.30 2.76 1.71 5.29 3.96 2.49 1.73
13.48° 19.44 1.67* 0.59 24.33° 0.80 1.72*
"significant at 107. level
b
Significant at 57, level
Significant at 1% level
dFrom 408 Soil Samples
-------
TABLE 34. DISTRIBUTION OF NUTRIENTS WITH DEPTH IN RIOCONCHO SOIL CORES TAKEN FROM THE
SEWAGE FARM AND FROM AN ADJACENT CONTROL AREA
oo
Depth
0-5
5-10
10-15
15-20
20-30
30-40
40-50
50-100
0-5
5-10
10-15
15-20
20-30
30-40
40-50
50-100
Total-P
763.77
569.19
486.46
433.65
S61.52
824.72
839.71
3668.00
401.79
412.02
376.20
377.37
696.25
661.76
673.44
3043.15
V*
15.99
14.47
13.06
11.76
22.13
20.38
20.18
63.79
2.25
1.48
0.86
0.72
1.47
1.33
1.25
4.29
Total-N
1298.76
831.85
698.02
600.62
1090.21
883.28
877.70
3530.45
1227.20
1255.59
915.60
869.40
1585.00
1288.96
1188.18
5541.80
NOj-N
7.69
6.39
7.06
5.95
16.28
13.84
11.59
50.56
4.55
5.24
3.27
6.91
10.80
4.50
3.56
17.54
NO~-N
0.07
0.05
0.06
0.04
0.09
0.09
0.09
0.48
0.13
0.24
0.11
0.14
0.22
0.19
0.19
0.87
NH+-N
4
•" Ks/1
SEWAGE
0.54
0.85
0.86
1.00
0.60
0.00
0.52
2.62
CONTR01
0.41
0.00
0.00
1.07
1.62
3.20
0.00
0.00
Cd
la ------
FARM
0.73
0.71
0.65
0.63
1.34
1.41
1.53
8.18
L AREA
0.80
0.84
0.82
0.86
1.73
1.71
1.84
8.77
Cr.
15.35
13.78
12.86
12.40
25.05
24.96
26.10
131.00
9.92
11.17
10.12
10.59
21.31
20.31
20.17
97.22
Cu
8.12
7.75
7.76
8.04
16.15
18.62
21.47
219.29
6,33
7.06
6.54
7.16
13.81
13.35
13.09
66.24
Nl
9.35
8.86
8.25
8.02
16.69
17.05
19.00
98.44
8.64
9.75
9.33
9.78
19.63
19.96
20.87
98.61
Pb
15.20
13.87
12.34
11.12
21.93
22.70
25.02
122.94
12.70
13.41
12.83
13.60
27.55
25.12
25.84
122.45
Zn
30.14
26.57
24.65
23.64
46.25
46.61
50.50
303.65
27.09
29.85
26.37
27.09
48.85
53 . 64
54.42
250. S4
-------
TABLE 35. DISTRIBUTION OF NUTRIENTS WITH DEPTH IN ANGELO SOIL CORES TAKEN FROM THE
SEWAGE FARM AND FROM AN ADJACENT CONTROL AREA
Depth
Total-P
H20-P
Total-N
N03-H
NOj-N
Cd
Cr
Cu
Pb
Zn
Kg/ha
SEWAGE FARM
VD
o
0-5
5-10
10-15
•15-20
20-30
30-40
40-50
50-100
1024.76
842.93
548.35
513.75
915.84
898.04
866.20
3346.50
11.27
12.91
12.22
13.62
24.71
22.95
18.80
80.17
1723.12
1231.61
987.59
967.50
1696.32
1468.61
1324.86
4319.40
14.17
7.77
5.11
5.07
9.70
7.65
7.51
26.97
0.10
0.08
0.07
0.08
0.18
0.18
0.15
0.71
1.29
0.23
0.00
1.05
1.58
0.71
2.1.3
6.21
0.55
0.69
0.63
0.67
1.42
1.63
1.86
11.79
16.23
15.71
14.57
14.40
27.87
24.78
25.27
102.60
8.16
8.80
7.51
7.88
14.84
14.85
14.73
66.17
9.73
11.82
10.73
11.56
24.04
26.21
26.83
138.82
25.34
25.58
19.78
18.89
26.79
26.52
28.44
142.55
37.58
39.69
32.40
33.36
58.63
55.02
52.44
226.66
CONTROL AREA
0-5
5-10
10-15
15-20
20-30
30-40
40-50
50-100
247.50
219.88
206.80
181.29
423. 60
384.18
360.47
1906,50
0.50
0.32
0.26
0.33
0.74
0.49
0.35
0.73
1093.75
859.21
799.70
783.25
1452.00
1295.04
1111.92
4040.55
2.66
2.16
2.29
2.85
6.84
7.22
7.07
52.02
0.21
0.23
0.14
0.13
0.38
0.26
0.26
1.46
4.37
3.63
2.42
3.28
8.76
6.15
7.57
27.67
0.74
0.62
0.65
0.64
1.57
1.53
1.71
11.80
9.43
8.20
9.27
9.27
25.06
24.48
22.37
88.31
7.78
6.72
6.12
5.67
13.46
12.22
11.96
62.11
10.59
9.25
9.71
9.46
22.99
22.68
23.53
134.43
11.25
9.15
9.42
8.96
22.04
21.32
21.78
132.77
29.28
23.74
23.75
21.46
51.19
49.12
48.90
218.57
-------
TABLE 36. DISTRIBUTION OF NUTRIENTS WITH DEPTH IN MERETA SOIL CORES TAKEN FROM THE
SEWAGE FARM AND FROM AN ADJACENT CONTROL AREA
Depth
0-5
5-10
10-15
15-20
20-30
30-40
40-50
0-5
5-10
10-15
15-20
20-30
30-40
40-50
Total-P
1180.74
733.70
669.93
438.48
836.40
655.82
642.94
212.84
214.40
250.63
255.97
505.11
535.50
596.16
H20-P
14.66
10.49
12.02
9.04
15.32
14.37
14.56
0.33
0.14
0.19
0.1R
0.4b
0.42
0.37
Total-N
2333.10
980.95
940.50
695.52
2277.96
975.26
810.08
1024.08
982.22
959.92
945.23
1737.34
1638.00
1814.40
NO^-N
20.98
15.08
35.66
11.94
23.37
23.58
24.32
0.88
0.57
1.10
1.24
2.17
2.07
3.28
N02-N
1.37
0.08
8.29
0.08
0.13
0.13
0,16
0.05
0.07
0.22
0.08
0.06
0.14
0.18
NflJ-N
SEWAGE I
26.26
0.46
19.52
0.54
0.00
0.60
1.22
CONTROL
0.40
0.00
0.63
0.00
1.19
1.05
2.43
Cd
'ARM
1.00
0.73
0.80
0.72
2.17
2.27
2.54
AREA.
0.53
0.51
0.57
0.65
1.63
1.89
2.13
Cr
42.27
13.98
13.45
9.48
23.03
16.26
15.15
10.15
10.31
11.16
11.57
24.68
26.38
28.80
Cu
21.33
9.49
9.16
6.81
14.77
10.75
9.79
6.70
7.14
7.40
7.60
14.91
15.51
17.82
Ni
9.39
8.17
10.40
8.62
22.69
22.66
23.42
9.22
9.82
10.74
11.93
25.01
26.34
30.52
Pb
268.75
118.62
135.63
115.50
225.09
438.38
230.58
9.87
8.64
8.97
9.76
21.96
23.20
26.70
Zn
204.07
57.28
41.40
27.01
67.28
40.02
34.41
28.85
26.51
27.48
27.34
53.95
55 77
** ^ " i /
62.03
-------
Table 37. TOTAL NUTRIENT CONTENTS OF THE TOP 20 CM SOIL SOLUMS FROM THE SAN ANGELO SEWAGE
FARM AND THEIR RELATIVE CHANGE AFTER 18 YEARS OF IRRIGATION WITH SEWAGE EFFLUENT
COMPARED TO AN ADJACENT CONTROL AREA
to
RIOCONCHO
Nutrient
Total-P
H20-P
Total-N
KO~-N
SO~-N
K-"
Total-Cd
lotal-Cr
Total-Cu
Total-Ni
Total-Pb
Total-Zn
Sewage
farm
2253.09
55.30
3429.26
27.11
0.24
3.26
2.73
54.41
31.69
34.51
52.56
105.02
Control
area
_« !f«.1
221.9
-52.7
-81.2
-4.5
65.7
22.9
12.3
130.9
45.6
Sewage
farm
3022.85
46.23
4950.08
83.68
9.85
46.79
3.28
79.20
46.81
•36.61
638.51
329.77
MERETA
Control
area
L'o/fia __.
933.84
0.86
3911.45
3.81
0.44
1.05
2.29
43.22
28.85
41.73
37.24
110.20
Difference
2089.01
45.37
1038.63
79.87
9.41
45.74
0.99
35.98
17.96
-5.12
601.27
219'.57
223.7
5275.6
26.6
2096.3
2138.6
4356.2
43.2
83.2
62.3
-12.3
1614.6
199.2
ALL SOILS
Difference
Kg/ha
4849.04
143.94
1574.01
109.14
8.61
36.38
0.26
72.72
28.58
-3.32
652.07
258.97
144.5
1886.5
13.4
323.1
470.5
223.9
3.1
59.7
34.7
-2.8
507.1
81.2
-------
is not included. The amount o£ nitrite (N0~) is generally very small
compared with the amount of NH4 or N0~ Application of high rates of M*
may result in N02 accumulation in alkaline soils (Bremner 1965b).
Wb,en sewage wastewater is applied to a predominantly aerobic soil,
fhe NH4 in the sewage effluent will be converted to N0~ by the nitrification
process. The applied N can be removed by plant uptake; denitrification,
leaching, and ammonia (NH ) volatilization. Denitrification is the most
important process whereby the applied N in excess of plant uptake can be
removed from the soil (Lance 1972). Long periods of flooding with sewage
wastewater can stimulate the denitrification process in the soil. Stefanson
(1973) showed that crops may increase N removal by stimulating denitri-
fication in the root zone due to exudation of organic carbon and the
creation of low oxygen levels. Nitrate, which was neither denitrified nor
taken up by plants, will move down to the ground water. Thomas et al.
(1974) found that a well operated overland flow system could achieve 90
percent N removal in the summer, but N removal may drop substantially in
the winter. 1
The distribution of 2N KCl exchangeable NH4-N, NO~-N, and N02-N with
soil depth in the sewage farm and the control area soil are shown in
Figures 12, 13, and 14, respectively. In Angelo soils the NH.-N concen-
tration sampled from the sewage farm is less than that from the control
area. In Rioconcho and Mereta soils the difference in NH.-N concentration
between the sewage farm soils and the control area soils varies with soil
depth. There is an accumulation of NH.-N in the upper 15 cm soil in Mereta
soils of the sewage farm. There is no significant difference in NH4~N
concentration among three soil series and with soil depth (Table 33).
Irrigation with sewage wastewater did not significantly change the NHt-N
concentration of Rioconcho, Mereta, and Angelo,soils. There is a signifi-
cant difference (at the 5 percent level) in NH.-N concentration among soil
cores sampled. The total exchangeable NH4~N content at varying soil depth
in the soil profile of Rioconcho, Angelo, and Mereta soils is shown in
Tables 34, 35, and 36, respectively. Irrigation with wastewater increased
by 120 and 4356 percent the total NH,-N content in the soil profile of
Rioconcho and Mereta soils (Table 37)+- However, in Angelo soils the total
NH.-N content on the soil profile decreased 81 percent. The overall
average NH/-N content of the top 20 cm soil column of these three soil
series increased 224 percent. Reneau (1977) studied the changes in
inorganic nitrogen compounds from septic tank+effluent in a Virginia coastal
plain soil. He found that the decrease in NH4~N was due to the processes
of adsorption and nitrification.
In both Rioconcho and Angelo soils the N02 concentration of sewage
farm soils is less than that of the control area soils (Figure 14) . The
N0~ concentration of Mereta sewage farm soils is greater than that of the
control area. There are large amounts of N02 in the 0-15 cm layer in the
Mereta soils. There was no statistically significant difference in N02
concentration among_the three soil series, soil cores, or soil depths.
No difference in NO, concentration between the sewage farm soils and the
control area soils is found (Table 33}. The total exchangeable NO -N
content at varying soil depth in the soil profiles in Rioconcho, Angelo
93
-------
RIOCONCHO
ANGELO
MERETA
DEPTH
cm
V£>
JS-
468 10 02468 10
i i . .
024 6 8 10
'/ 39.75 1
0SEWAGE FARM SOIL
IB CONTROL SOIL
Figure 12. The effect of sewage effluent irrigation on exchangeable ammonium
nitrogen content of the top 200 cm of soil from the sewage farm compared to the control area.
-------
RIOCONCHO
ANGELO
MERETA
DEPTH
cm
VO
Ui
10 15 20 25
N03 -
05 10 15 20 25
QSEWAGE FARM SOIL
• CONTROL SOIL
Figure 13. The effect of sewage effluent irrigation on exchangeable soil nitrate nitrogen
content of the top 200 cm of soil from the sewage farm compared to the control area.
-------
RIOCONCHO
AN6ELO
MERETA
DEPTH
cm
250
500
N02-N,ng/g
0 250 500
250
500
QSEWAGE FARM SOIL
•[CONTROL SOIL
Figure 14. The effect of sewage effluent irrigation on exchangeable nitrite nitrogen
content of the top 200 cm of soil from the sewage farm compared to the control area.
-------
and Meireta soils is shown in Tables 34, 35, and 36, respectively.
Irrigation with wastewater decreases the total N0~ content in the soil
profile of Rioconcho and Angelo soils 63 and 53 percent, respectively
(Table 37). In Mereta soils, an increase of 2139 percent in total N0~
content is found after wastewater irrigation. Irrigation with wastewater
can change the NH^-N or NO^-N content in a soil. However, the change may
be positive or negative. There is an increase of 471 percent of NO~-N in
the upper 20 cm soil column of all soils in the sewage farm after 18 years
of wastewater irrigation.
The N03 concentration of Mereta soils at the sewage farm is much
greater than that of the control area soils. There is an accumulation of
N0.j in the upper 50 cm soil in the Mereta soils after sewage irrigation.
In Rioconcho and Angelo soils the difference in NO~-N concentration between
the sewage farm soils and the control area soils varies with soil depth.
Generally, the NO,, concentration of sewage farm soils decreases with in-
creased soil_depth. There is a significant difference .(at.the 1 percent
level) in N03 concentration among three soil series and among soil cores.
No significant difference in NO«-N concentration is found with varying soil
depth. Irrigation with wastewater significantly (at the 1 percent level)
changed the NO- concentration of Rioconcho, Angelo, and Mereta soils (Table
33). Data presented in Tables 34, 35, and 36 show the total NO~--N content
at varying soil depths in the soil profile of Rioconcho, Angelo,_and Mereta
soils, respectively. In Mereta soils the difference in total NO,, content
of the upper 20 cm of soil between the sewage farm and the control area
soils is 79.87 Kg/ha, an increase of 2096 percent based on the control area
soils (Table 37) . In Rioconcho soil the difference in total NO,, content
in the upper 20 cm soil solum between the sewage farm and the control area
is 7.12 Kg/ha, an increase of 36 percent. In Angelo soils an increase of
222 percent (22.2 Kg/ha) of total NO- content in the upper 20 cm soil
solum is found. Frere (1976) reported that soils cultivated for 100 years
can have drainage waters with 5 to 10 ppm NO^-N. Kreitler (1975) found
high NO, concentration in the ground water in central West Texas. His
study snowed that the main source of NO, in this region was the mineral-
ization of organic soil N. Reneau (1977) observed N0~ accumulation in the
plinthic horizon beginning at a distance of 1.27 m from the drainfield
when septic tank effluent is applied.
Total Phosphorus
Total phosphate (P) concentration in soils ranges from 100 to 1300 ppm.
Because of the low soil solution P (ranges from 0.01 to 1 ppm P) and high
degree of fixation, soil P tends not to leach i^_soils.= The applied P
can be precipitated in soils as Fe , Al , Ca , C03> and OH phosphate
compounds. In calcareous soils the calcium phosphate precipitate may
be the main mechanism for P removal from wastewater (Lindsay and Moreno
1960).
Kao and Blanchar (1973) found that soil fertilized with P for 82 years
had nearly double the total P content, but the ability of the soil to
adsorb additional P was the same. No fertilizer P was found below 137 cm
in the soil profile. Beek et al. (1977) studied distribution of soil P
97
-------
in soil from a sewage farm in the Netherlands treated with domestic and
industrial wastewaters. They showed that applied P accumulated in the top
50 cm layer of the soil.
The distribution of total P concentration with depth in the sewage
farm soils and in the control area soils is shown in Figure 15. It is
clear that the maximum total P concentration is found in the top 0-5 cm
layer and decreases with increased soil depth in all three soil series in
the sewage farm. No significant difference in total soil P with soil depth
was found in the soil profiles of the control area. A comparison of the
distribution of total soil P concentration with depth between the sewage
farm and the control area indicates that applied P from sewage wastewaters
had accumulated in the upper 150 cm in both the Rioconcho and Angelo soils
and the upper 100 cm in Mereta soil. The application of sewage wastewater
on land significantly increased (at the 1 percent level) the total P
concentration in the soil profile of these three soil series (Table 33).
There was a significant increase (at the 1 percent level) in total soil
P concentration among three soil series, soil depth, and soil cores sampled.
Data in Tables 34, 35, and 36 show the total P content at varying
soil depths in the soil profile in Rioconcho, Angelo, and Mereta soils,
respectively. The average total soil P content in the whole soil profile
of Rioconcho, Angelo, and Mereta soils is listed in Table 37. An increase
of 44 to 243 percent of total soil P in the soil profile was found in
these three soils after 18 years of sewage wastewater treatment.
Water Soluble Phosphorus
Water soluble P is a useful index of soil P availability for plant
growth. Adsorption of P and growth of plants increase as water soluble
P increases in soils low in P. Many studies have shown significant corre-
lation between soluble soil water P and P uptake by plants (Olsen and Dean
1965).
The distribution of water soluble P content with depth in the sewage
farm soils and in the control area soils is shown in Figure 16. The
Rioconcho and Mereta soils inside the sewage farm have the highest water
soluble P concentration in the top 0-5 cm layer. The P concentration
then decreases with increasing soil depth. The highest water soluble P
concentration is found in the 15-20 cm layer in Angelo soil, located
inside the sewage farm. The water soluble P concentration is about the
same in the whole soil profile of the Angelo and Mereta soils in the
control area. Rioconcho soils from the control area have higher water
soluble P concentration in the surface and decreases with increased soil
depth.
Comparison of the distribution of water soluble P concentration with
depth for the soils located in the sewage farm and control area indicates
that there is an active pool of water soluble P in the soil profile inside
the sewage farm. Irrigation with sewage wastewater significantly increased
(at the 1 percent level) the water soluble P concentration in Rioconcho,
98
-------
RIOCONCHO
ANGELO
MERETA
DEPTH
cm
VO
15Op
TOTAL- P, Mg/g
Q 750 I50C
SEWAGE FARM SOIL
CONTROL SOIL
Figure 15. The effect of sewage effluent irrigation on total soil phosphorus
content of the top 200 cm of soil from the sewage farm compared to control area.
-------
RIOCONCHO
AN6ELO
MERETA
DEPTH
cm
o
o
WATER SOLUBLE P, >ug/g
0 5 1.0 1.5 2.0 35 05 10 15 2p 2.5 0 $ 1.0 15 2.0 %5
SEWAGE FARM SOIL
CONTROL SOIL
Figure 16. The effect of sewage effluent irrigation on water-soluble soil phosphorus
content of 200 cm of soil taken from the sewage farm compared to the control area.
-------
Angelo, and Mereta soils (Table 33). There is a significant difference
(at the 1 percent level) in water soluble soil P concentration among soil
depth and soil cores sampled.
The water soluble P content at varying soil depths in Rioconcho,
Angelo, and Mereta soils is shown in Tables 34, 35, and 36, respectively.
After 18 years of wastewater irrigation, the average total amount of
water soluble P in the soil profile increased 936 percent in the Rioconcho
soil, 3399 percent in the Angelo soil and 5276 percent in the Mereta" soil
The water soluble P increased 1887 percent in the top 20 cm of all soils
in the sewage farm after 18 years of wastewater irrigation. The water
soluble P is greater than 15 yg/g P in the upper 20 cm layer of Rioconcho,
Angelo, and Mereta soils (Figure 16). The percentage of water soluble P
based on the total P content was also increased in all three soils in the
sewage farm.
The distribution pattern with depth and the high concentrations of
water soluble P in the soil profile indicate that the upper 40 cm layer
of Angelo soil may have reached its maximum adsorption potential with
regard to applied P in wastewater. The upper 20 cm layer has been
saturated with respect to water soluble P, in Rioconcho and Mereta soils.
It is clear that the upper 200 cm soil column has been affected to some
degree by the applied P in wastewater. When the P fixation capacity of
the soil is not sufficient to handle the desired volume of wastewater,
the P-containing water will be filtered through the soil profile and
reach the groundwater.
Total Heavy Metals
Heavy metals can influence environmental quality by their potential
hazard and toxicity to man and other living organisms. Heavy metals in
soils and plants are the major link in the heavy metal cycle in the food
chain. One of the unknown factors of land application of wastewater is
the contamination and accumulation of heavy metals in the soil, especially
in regard to long-term effects. Lisk (1972) warned that using sewage
wastes for plant fertilizer might be a dangerous practice. He pointed out
that some edible plants may cpncentrate toxic heavy metals present in
wastes to a level which would not harm plants but which could be toxic to
animals. Reefer and Estepp (1971) found most of the labeled Zn-65 applied
to soils became acid-soluble and/or fixed on the clays. Fuller et al.
(1976) reported that the municipal landfill leachate was relatively low
in heavy metals and that those present did not migrate through the soils
in significant quantities. They found that all soils examined did not
release heavy metals at the same rate. A study at the sewage farm in
Melbourne, Australia showed that large amounts of metals have accumulated
during 70 years of application of raw and settled sewage (Bouwer and
Chaney 1976). It is clear that soil-plant systems play an important
role in the renovation of wastewater.
101
-------
Cadmium
Cadmium (Cd) levels in non-polluted soil are usually below 1 ppm
(Haan and Zwerman 1976). Buchaver (1973) found 1,700 ppm Cd in topsoil
sampled near a zinc smelter. The Cd concentration in phosphate fertilizers
ranges from 1-2 ppm for tertiary calcium phosphate to 50-170 ppm for
superphosphate. Miller et al. (1976) investigated the relationship between
uptake of Cd by soybean and soil available P and found that Cd accumulation
increased with increasing available soil P. Williams and David (1976)
reported that at least 80 percent of the Cd impurities in P fertilizers
applied could be accounted for in the cultivated layers of soil. The
sources of soil Cd are varied but may come from the application of wastes
and P fertilizer, fallout, precipitation, decomposition of plant residues
and microorganisms, and weathering of soil parent materials.
The distribution of total Cd concentration with soil depth in the
sewage farm soils and the control area soils is shown in Figure 17. There
is a highly significant difference in total soil Cd concentration among
the three soil series, among soil cores sampled, and at different soil depths
(Table 33). However, comparison of the total Cd concentration of soils
in the sewage farm and the control area indicates no significant change
in total soil Cd concentration after 18 years of wastewater irrigation. The
average total amount of Cd content in the upper 20 cm soil solum of the
sewage farm changes -19.3 percent in Rioconcho soils, -4.5 percent in
Angelo soils, and +43.2 percent in Mereta soils (Table 37). This amounts
to a 3.1 percent increase of all top 20 cm soils of the sewage farm after
18 years of wastewater treatment.
Chromium
Chromium (Cr) has been considered nonessential for plant growth;
whereas it is essential to animals and man. Chromium plays an important
role in carbohydrate metabolism and prevention of diabetes. Chromium
reaches the soil through sanitary landfills, urban air, snow melting salts,
industrial and sewage wastes, and weathering of soil parent material. The
Cr content of most soils is usually limited to trace amounts. In soils
treated with sewage sludges the Cr concentration can reach up to 50,000
ppm (Walsh et al. 1976). Dowdy and Larson (1975) found that Cr from sewage
sludges is less available to barley plants grown in alkaline soils compared
to those grown in acid soils. Lindsay (1973) reported that Cr is generally
oxidized from Cr(II) or reduced from Cr(VI) to Cr(III) and precipitated as
an insoluble hydroxide. Bartlett and Kimble (1976) showed that the presence
of soil organic matter brought about spontaneous reduction of Cr(VI) to Cr
(III) even at pH's above neutrality.
The distribution of total Cr with soil depth in the sewage farm and
the control area soils is shown in Figure 18. In Mereta soils sampled
at the sewage farm, a small amount of Cr (32.12 Kg/ha) was accumulated in
the top 0-5 cm (Table 36). There is a significant difference (at the
5 percent level) in total Cr concentration between the sewage farm soils
and the control area soils. A significant difference (at the 10 percent
102
-------
RIOCONCHO
ANGELO
MERETA
DEPTH
cm
o.oo
1.25
TOTAL-Cd,
250 0.00 1,25
2,50 0.00
2.50
O SEWAGE FARM SOIL
• CONTROL SOIL
Figure 17. The effect of sewage effluent irrigation on total soil cadmium
content of 200 cm of soil taken from the sewage farm compared to the control area.
-------
RIOCONCHO
ANGELO
MERETA
DEPTH
cm
15 20 25
TOTAL-Cr, flg/g
0 5 10 15 2,0 2,5
5 10 15 2,0 25
QSEWAGE FARM SOIL
•B CONTROL SOIL
Figure 18. The effect of sewage effluent irrigation on total soil chromium
content of 200 cm of soil taken from the sewage farm compared to the control area.
-------
level) in total Cr concentration among soil cores sampled and among soil
depth was found (Table 33). The average total Cr content in the soil
profile of the sewage farm changed 30.1 percent in Rioconcho soil, 65.7
percent in Angelo soil and 83.2 percent in Mereta soil after 18 years of
sewage wastewater irrigation (Table 37). The average increase of total
Cr content of all soils in the top 20 cm was 59.7 percent.
Copper
Copper (Cu) is essential to plant growth and has a normal concentration
in plant tissue ranging from 5 to 20 ppm (Walsh et al. 1976). The con-
centration of Cu in soils ranges from 2 to 100 ppm with an average of 20
ppm (Haan and Zwerman 19 J6.). In neutral and alkaline soils Cu exists in
soil solution as the Cu , and Cu(OH) ions. The Cu in soils may originate
from fertilizer, manure, mine effluents, industrial and sewage wastes, and
soil parent materials. Copper sulfate has been used as either a fungicide
for fruit crops and potatoes or as an additive in swine and poultry feed.
The mobility of Cu in soils is low and Cu tends to accumulate in the top-
soil. Jenne (1968) postulated that the hydrous oxides of Mn and Fe control
the concentration of Cu, Ni, and Zn in soils and water. Stevenson (1977)
studied the nature of the binding of divalent metal ions by soil humic acid.
He showed the stability constant of metals in soils followed the order
Cu>Pb»Cd>Zn.
The distribution of total Cu with soil depth in the sewage farm soils
and the control area soils is shown in Figure 19. In Mereta soils in the
sewage farm, an accumulation of Cu in the 0-5 cm of top soil was observed.
This is a significant increase (at the 10 percent level) in total Cu con-
centration between the sewage farm soils and the control area soils (Table
33 ). Irrigation with wastewater on the sewage farm increased the average total
Cu content in the upper 20 cm soil solum in Rioconcho soils, Angelo soils,
and Mereta soils by 16.8, 22.9, and 62.3 percent, respectively. This
amounts to an average of 34.7 percent increase of total Cu content in
these three soil series (Table 37 )•
Lead
Lead (Pb) is a biologically nonessential heavy metal. The total Pb
concentration of soils ranges from 2 to 200 ppm with an average of about
10 ppm (Allaway 1968). The sources of Pb in soils include pesticides,
insecticides, fertilizer impurities, mining and smelting operations,
engine exhausts,,and industrial and sewage wastes. One of the potential
hazards associated with Pb contamination of soil is animal ingestion of
plants with abnormally high concentrations of Pb, which may be toxic to
the animal. Lagerwerff and Specht (1970) reported that Pb concentrations
reached as high as 24,000 ppm in soils located directly along a roadside
in the Los Angeles metropolitan area. Singer and Hanson (1969) studied
the Pb accumulation in soils near highways and found that PbC03> Pb»(PO^),,
and PbSO. were the insoluble Pb compounds formed in the soil. Walsfi et -al.
(1976) suggested that in calcareous soils in the arid and semi-arid region,
lead carbonate may form and the calcareous soil would then act as a sink
for applied Pb.
105
-------
RIOCONCHO
ANGELO
MERETA
DEPTH
cm
1.0 1.5 2,0 2$
TOTAL-Cu,>ug/g
0 $ Ip 1.5 2.0 2.5
IP
dlSEWAGE FARM SOIL
CONTROL SOIL
Figure 19. The effect of sewage effluent irrigation on total soil copper
content of the top 200 cm of soil taken from the sewage farm compared to the control area.
-------
The distribution of total Pb with soil depth in the sewage farm and the
control area is shown in Figure 20. An accumulation of total Pb in the
upper 50 cm of soil in Mereta soils at the sewage farm was observed. There
is a significant difference at the 1 percent level for total Pb concentra-
tion among three soil series and among soil cores sampled (Table 33)
Irrigation of wastewater on the sewage farm significantly increased (at the 1
percent level) the total lead concentration in the three soil series. The
average increase in total Pb content in soil profiles of the sewage farm are
0.0, 130.9 and 1614.6 percent in Rioconcho, Angelo, and Mereta soils,
respectively (Table 37). The average increase of total Pb content of these
three soil series is 507.1 percent after 18 years of wastewater irrigation.
Nickel
To date nickel (Ni) has no essential function in plant growth. It is
readily absorbed by plants. The total Ni concentration of soil may vary
from 5-500 ppm, with mean values commonly around 40 ppm (Allaway 1968).
Most of the Ni in soils comes from weathering products of basic rocks,
impurities in superphosphate fertilizer, automobile exhausts, and industrial
and sewage wastes. Nickel is considered 8 times as toxic as Zn to plant
growth in the calculation of the "Zn equivalent factor" (Chumbley 1971).
The U. S. Environmental Protection Agency suggests that Ni is 4 times as
toxic to plants as Zn in the calculation of their "metal equivalent".
Hinesly et al. (1972) found 42 to 56 percent of the Ni applied as sewage
sludge is retained in the surface 15 cm of- soil. Anderson and Nilsson
(1972) showed a 140 percent recovery of Ni in the surface 20 cm of soil
treated with 84 metric tons of sewage sludge over a period of 12 years.
The distribution of total Ni with soil depth in the sewage farm soils
and the control area soils is shown in Figure 21. Generally, the total Ni
concentration increased with increased soil depth, and reached a maximum
at the 50-100 cm depth. There is a significant difference (at the 1
percent level) in total Ni concentration among three soil series, among
soil cores sampled, among soil depth, and between the sewage farm soils
and the control area soils (Table 33). Irrigation of sewage wastewater
over a period of 18 years increased the average total Ni content in the
upper 20 cm Angelo soil solutn by 12.3 percent (Table 37) . In Rioconcho
soils and Mereta soils a decrease of 8.0 to 12.3 percent of average total
Ni content in the upper 20 cm soil solum was observed. This amounts to a
decrease of 2.8 percent of total Ni content of these tnree soil series.
Zinc
Zinc (Zn) is an essential element for both plants and animals. It is
an important component of a number of enzyme systems. Zinc reaches the
soils in various chemicals and wastes. The total Zn concentration of
soils under normal conditions ranges from 10-300 ppm, with an average
value of 50 ppm (Allaway 1968). Lindsay (1973) showed that the predominant
Zn series in soils below pH 7.7 is Zn and at higher pH values is Zn(OH) .
Toxic Zn symptoms usually start at about 400 ppm and up for most plant
species. If the Zn content of the animal diet exceeds about 1000 ppm, Zn
toxicity will occur in animals (Haan and Zwerman 1976). Chaney (1973)
107
-------
RIOCONCHO
ANGELO
MERETA
o
oo
DEPTH
cm
0-5
5-10
10-15
15-20
20-30
30-40
40-50
50- 100
100-150
150-200
1.0 2.0 3.0 4.0 5.0
TOTAL Pb,>ug/g
10 20 30 40 5.0
1.0 20 3.0 4.0 50
/I07.22J
C3SEWAGE FARM SOIL
• CONTROL SOIL
Figure 20. The effect of sewage effluent irrigation on total soil lead
content of the top 200 cm of soil taken from the sewage farm compared to the control area.
-------
RIOCONCHO
AN6ELO
MERETA
DEPTH
cm
o
VO
2025
TOTAL-Ni, xtg/g
0 5 10 15 20 25
10 15 20 25
SEWAGE FARM SOIL
CONTROL SOIL
Figure 2J.. The effect of sewage effluent irrigation on total soil nickel
content of the top 200 cm of soil taken from the sewage farm compared to the control area.
-------
recommended that the toxic metal addition should not exceed Zn equivalent
levels equal to 5 percent of the CEC at p'H<6.5. Decreasing the soil pH will
increase the total Zn concentration and its availability to plants.
Cunningham (1975).found that enhancement of soil total Zn to 1,300 ppm by
sludge treatment would cause plant Zn concentrations in excess of 900 ppm
and result in severe reduction of yield.
The distribution of total Zn concentration with soil depth in the
sewage farm soils and the control area soils is shown in Figure 22. There
is an accumulation of total Zn in the upper 10 cm soil in Mereta soil series.
Irrigation with sewage wastewater does not change the Zn concentration of
soils in the sewage farm (Table 33). There is a significant difference in
total Zn concentration among the three soil series, among soil cores
sampled, and among soil depths. The differences in total Zn content between
the sewage farm and the control area in the upper 20 cm soil profile of
Rioconcho, Angelo, and Mereta soils are -4.9, +45.6, and H-199.2 percent,
respectively. Irrigation of wastewater increases 81.2 percent of total Zn
content in the top 20 cm soil profile of these soil series of the sewage
farm.
110
-------
RIOCONCHO
ANGELO
MERETA
DEPTH
cm 0
100
TOTAL- Zn,>qg/g
0 50 100
100
QSEWAGE FARM SOIL
• CONTROL SOIL
Figure 22. The effect of sewage effluent irrigation on total soil zinc
content of the top 200 cm of soil taken from the sewage farm compared to the control area.
-------
SECTION 7
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-------
Frere, M. H. Nutrient Aspects of Pollution from Cropland. In:
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1973. pp. 91-96.
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of Public Law 92-500 on Municipal Pollution Control Technology.
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Melsted, S. W. Soil-plant Relationships (Some Practical Consid-
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by Soybeans as Influenced by Soil Cation Exchange Capacity, pH,
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116
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118
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
REPORT NO.
EPA-600/2-78-131a
2.
3. RECIPIENT'S ACCESSION-NO.
TITLE AND SUBTITLE
SEWAGE DISPOSAL ON AGRICULTURAL SOILS: CHEMICAL
AND MICROBIOLOGICAL IMPLICATIONS (VOLUME I CHEMICAL
IMPLICATIONS)
5. REPORT DATE
June 1978 issuing date^
6. PERFORMING ORGANIZATION CODE
AUTHORCS)
L> R_ Hossner
Chun-Wei Kao
R. W. Weaver
J. A. Waggoner
8. PERFORMING ORGANIZATION REPORT NO,
PERFORMING ORGANIZATION NAME AND ADDRESS
Texas A&M University
Department of Soil & Crop Sciences
College Station, Texas 77843
10. PROGRAM ELEMENT NO.
1BC611
11. CONTRACT/GRANT NO.
R803281
12. SPONSORING AGENCY NAME AND ADDRESS
Robert S. Kerr Environmental Research Lab.
Office of Research and Development
U.S. Environmental Protection Agency
Ada, Oklahoma 74820
- ADA, OK
13. TYPE OF REPORT AND PERIOD COVERED
Final - 1975-1977
14. SPONSORING AGENCY CODE
EPA/600/15
15. SUPPLEMENTARY NOTES
16. ABSTRACT
The city of San Angelo, Texas, has used sewage effluent which has undergone
primary treatment for irrigation of the same 259-hectare sewage farm since 1958.
The impact of 18 years of sewage effluent irrigation on the soil and water quality
was studied from 1975 to 1977. The volume of sewage arriving at the sewage treat-
ment plant ranged from 0.219 to 0.351 m^/sec. and contributed from 3.4 to 31.2
percent of the total flow of the bordering Concho River in 1976. 'The fate of
applied nitrogen, phosphorus, and selected heavy metals in the soil-water-plant
ecosystem were examined. There was evidence of some NO-j-N accumulation in the
soil profile and in the Concho River while no accumulation of NH^ -N was found
in the soil profiles. Some organic nitrogen accumulated at the soil surface,
but after 18 years of operation there was a net loss of total nitrogen in the
soil profile. Phosphorus accumulated in the soil profile to depths of 200 cm
along with a slight build-up of certain heavy metals in the surface soils. Deep
wells appeared to be uncontaminated by the sewage farm operation.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS
c. COS AT I Field/Group
Land use
Sewage treatment
Nutrient
Removal
Land pollution abatement
San Angelo, Texas
Land application
Municipal wastewater
Rural land use
Farmlands
Sewage effluents
pffliipnt- t-ommral
68D
91A
43F
18. DISTRIBUTION STATEMENT
RELEASE TO PUBLIC
EPA Form 2220-1 (9-73)
19. SECURITY CLASS (ThisReport)
131
20. SECURITY CLASS (Thispage)
UNCLASSIFII
22. PRICE
ft U.S. OOVBNMENTPMHTlhG OfFTCL 1978—757 -140/1356
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