WATER POLLUTION CONTROL RESEARCH SERIES •16060 OCO 10/70
POTENTIAL POLLUTION OF OGALLALA BY
RECHARGING PLAYA LAKE WATER
-PESTICIDES-
ENVIRONMENTAL PROTECTION AGENCY
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WATER POLLUTION CONTROL RESEARCH SERIES
The Water Pollution Control Research Series describes the
results and progress in the control and abatement of pollution
in our Nation's waters. They provide a central source of
information on the research, development and demonstration
activities in the Environmental Protection Agency, through
inhouse research and grants and contracts with Federal,
State, and local agencies, research institutions, and
industrial organizations.
Inquiries pertaining to Water Pollution Control Research
Reports should be directed to the Chief, Publications Branch
(Water), Research Information Division, R&M, EnvirdiMlental
Protection Agency, Washington, D^C. 20^60.
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POTENTIAL POLLUTION OF THE OGALLALA
BY RECHARGING PLAYA LAKE WATER
-pesticides-
by
Dan M. Wells,
Ellis W. Huddles ton,
and Robert G. Rekers
Texas Tech University
Water Resources Center
Lubbock, Texas 79409
for the
ENVIRONMENTAL PROTECTION AGENCY
Project #16060 DCO
October 1970
For sale by the Superintendent of Documents, U.8. Government Printing Office, Washington, D.C. 2M02 - Price 40 cents
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EPA Review Notice
This report has been reviewed by the Water
Quality Office, EPA, and approved for publv
cation. Approval does not signify that the
contents necessarily reflect the views and
policies of the Environmental Protection
Agency, nor does mention of trade names or
commercial products constitute endorsement
or recommendation for use.
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ABSTRACT
Twenty-four playa lakes in Lubbock County were sampled on a routine
basis following runoff-producing rainfall for a period of approximate-
ly eighteen months to determine whether or not recharging of water
collected in these lakes might be a hazard to the quality of water
contained in the underlying Ogallala aquifer. In addition, fifteen
lakes lying within a triangle bounded by Plainview, Canyon, and
Hereford, Texas, were sampled during the summer of 1969 to provide
additional data regarding the extent of the potential problem.
Based on results of the detailed analyses of approximately 220 samples
of water collected in the lakes and an equal number of sediment sam-
ples collected from the lakes, it appears that the quality of water
collected in High Plains playa lakes is generally superior to the
quality of water contained in the underlying aquifer in terms of the
amount of dissolved materials. The amounts of suspended solids,
organic material, and microorganisms is subject to wide variation and
is highly dependent upon the recent history or treatment of the
drainage basin.
m
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CONTENTS
Page
CONCLUSIONS AND RECOMMENDATIONS 1
INTRODUCTION 3
Purpose 4
Scope 4
MATERIALS AND METHODS 5
Lake Selection 5
Sampling Methods .... 5
Pesticide Use on Watershed 5
Rainfall Runoff and Lake Levels 8
PESTICIDE ANALYTICAL PROCEDURES 11
Analytical Procedure for Water 13
Analytical Procedure for Sediment 16
Analytical Difficulties 18
RESULTS AND INTERPRETATIONS 21
ACKNOWLEDGMENTS 33
GLOSSARY OF TERMS 35
IV
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TABLES
Paqe
1 LAKE CLASSIFICATION, WATERSHED ACREAGE AND
PESTICIDE USE ON WATERSHEDS OF LAKES INCLUDED
IN STUDY 7
2 RETENTION TIMES FOR THE NON-POLAR COLUMN 14
3 INSECTICIDE CONCENTRATION IN MUD SAMPLES 22
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FIGURES
1 LOCATION OF LAKES SAMPLED 6
2 INUNDATION PERIODS FOR LAKES INCLUDED IN
THE STUDY 10
3 SCHEMATIC DIAGRAM OF GAS CHROMATOGRAPH 12
4 TYPICAL CHROMATOGRAM OBTAINED FROM SOIL EXTRACT .... 15
5 CHROMATOGRAM OBTAINED FROM ANALYSIS OF PURE
COMPOUNDS AS INDICATED 15
6 CHROMATOGRAM OF SAMPLE CONTAMINATED BY HIGH
CONCENTRATION OF "TRASHY COMPLEX" 19
7 CONCENTRATIONS OF DDT AND DIELDRIN IN SEDIMENT
LAYERS OF AN URBAN LAKE 28
8 CONCENTRATION OF DIELDRIN IN SEDIMENT LAYERS IN
AN URBAN LAKE 29
9 VARIATION OF DIELDRIN CONCENTRATION WITH DEPTH
OF SEDIMENT, LAKES 11 AND 12 32
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CONCLUSIONS AND RECOMMENDATIONS
1. It is concluded that playa lake water is of sufficiently good
quality that its recharge into the Ogallala formation is not
likely to be deleterious to the quality of water in the forma-
tion.
It is recommended that all levels of government take immediate
steps to encourage farmers to recharge playa lake water to the
Ogallala by all feasible means.
2. It is concluded that playa lake water is generally superior to
water contained in the Ogallala in terms of dissolved solids,
but that from the standpoints of suspended solids and bacterio-
logical quality^ playa lake water quality is generally inferior
to groundwater quality.
It is therefore recommended that, as recharge practices increase
in the future, water quality monitoring programs be instituted
to monitor the quality of playa lake water and of water collected
both from recharge wells and from observation wells in the
vicinity of recharge wells.
3. It is concluded that present farming practices in the High Plains
area do not pose a significant threat to the quality of water in
the Ogallala aquifer or in surface runoff from the area.
It is recommended that research into improved methods of recharge
of playa lake water be initiated by all levels of government at
the earliest possible time.
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INTRODUCTION
A large quantity of water—estimates vary from one to three million
acre-feet--is collected annually in the twenty thousand playa lakes
on the High Plains of West Texas as a result of runoff from precipi-
tation. Historically, much of this water has been evaporated to the
atmosphere rather than being put to beneficial use. Recently, however,
as the water table in the Ogallala formation has declined, increasing
interest has been focused on finding economically feasible means of
utilizing playa lake water. The direct use of this water for irri-
gation of the adjacent land has become fairly widespread, but utili-
zing the water for this purpose is inherently inefficient. When the
lakes are fullest, the adjacent farm land is saturated or nearly
saturated with moisture, and by the time the land requires additional
water, a significant portion of the lake water has been lost to
evaporation.
A more efficient method of utilizing playa lake water, and one that
has been practiced to a limited extent for a number of years, is the
practice of using the water for recharge of the Ogallala aquifer.
Increasing concern for conservation of water by farmers and by govern-
mental agencies in recent years has made it likely that increasing
quantities of playa lake water will be used for recharge water in
coming years.
The Ogallala aquifer serves as a source of supply for municipal, in-
dustrial, and domestic use, as well as for irrigation water. It is
therefore essential that its usefulness for these purposes be pro-
tected.
The quantities of agricultural chemicals—insecticides, herbicides,
and fertilizers—used in the High Plains area are increasing as
farmers in the area adopt more efficient farming techniques. All of
these chemicals are soluble to some extent in water, and any runoff
from treated areas can be expected to be contaminated to some extent
by them. Since practically all runoff on the High Plains is ulti-
mately collected in playa lakes, it seems to be apparent that the
water in playa lakes will generally be contaminated to some extent
by these chemicals.
Because playa lake water has always been allowed to evaporate or has
been utilized for irrigation of the adjacent land, and because the
quality of playa lake water is adequate for use as irrigation water,
very few people have been interested in determining the concentration
of agricultural chemicals in the playa lake water. Thus, practically
no data are available concerning the concentration of agricultural
chemicals in these waters.
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Purpose
This research program was undertaken for the purpose of determining
whether or not the concentrations of insecticides and herbicides in
playa lake waters are sufficiently high to adversely affect the
quality of water in the Ogallala aquifer if the playa lake water
were recharged. Additional funds were made available from the Texas
Water Quality Board to allow supplemental analyses for nitrates and
phosphates.
Lakes selected for this study were chosen to represent the widest
possible variation of test conditions. These lakes include some that
receive only urban runoff, some that receive both urban and agricul-
tural runoff and are routinely treated for mosquito control, some
that receive only runoff from agricultural lands, and some that have
been recently modified and that had not been inundated prior to the
start of the study. Additional lakes designed for recharge and
equipped with observation wells which permit samples to be taken from
the aquifer at various distances from the recharge well were also
included in this study.
The chlorinated hydrocarbon insecticides, especially DDT, Toxaphene,
Endrin, Dieldrin, and Aldrin, were given first priority in this study
because of their toxicity and proven long residual time. Conversely,
the organophosphate insecticides, such as Parathion, Malathion, and
Di-Syston, were not given immediate attention because of their rela-
tively rapid decomposition.
In the herbicide field, Treflan, because of its recently greatly ex-
panded market and stable nature, was included in analytical studies.
The second most commonly used herbicide, Propazine, was given the
same priority as the organophosphate pesticides. A critical problem
and one that greatly complicated the research was the identification
of the decomposition products of the pesticide compounds. These
products are not well known and they may be as hazardous as the parent
compounds.
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MATERIALS AND METHODS
Lake Selection
Playa lakes sampled in this study were selected to represent the major
land use patterns on playa watersheds. Categories selected were:
(1) cropland; (2) pasture land; (3) urban areas; and (4) combinations
of these. In addition, two lakes which had been extensively modified
were selected because a new basin had been created which had never
been inundated prior to the initiation of this study. Two additional
lakes located in Hale County, Texas, and used for studies of recharge
of the Ogallala formation were included in the sampling scheme.
Twenty-four lakes located in Lubbock County and two in Hale County
were selected for intensive study which required sampling after each
major rainfall period. An additional fifteen lakes were sampled
once during the summer of 1969. These lakes were located in a tri-
angle between Plainview, Hereford, and Amarillo, Texas, and they were
primarily cropland watersheds.
A stratified selection technique was used to assure that the inten-
sive study sites would be well distributed throughout Lubbock County,
Figure 1. Detailed data on land use on the watershed, size of the
watershed, and cropping practices are given in Table 1.
Sampling Methods
A one-gallon sample of water and a one-gallon sample of sediment were
taken from each lake on each sampling date. One-gallon, brown glass
jars which had been thoroughly cleaned in a chromic acid solution and
thoroughly rinsed were used for sample containers. These containers
were closed with a bakelite screw cap lined with sheet aluminum foil.
Samples collected for analysis were retained in a refrigerator at
approximately 2° C until analyzed. Water samples were taken by com-
positing one-half pint samples from each of sixteen locations within
a lake. A one-half pint dipper was used to obtain the sub-samples
which were composited directly into the sample jar. Mud (sediment)
samples penetrated approximately the top one inch of sediment below
the water-sediment interface, and they were taken with the same
dipper technique.
Pesticide Use on Watershed
Although exact quantities of pesticide and fertilizer used on each
watershed could not be obtained, certain generalizations can be
given. Almost all cropland is fertilized with both nitrogen and
phosphorus in one of several forms. The total amount of each element
applied is fairly uniform from watershed to watershed. Average ap-
plication rates are eighty pounds of nitrogen and sixty pounds of
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LUBBOCK COUNTY
ABERNATHY
o No. 16
SHALLOWATER
No. 10
No. 21
LEVELLAND HWY.
LUBBOCK
No. 5
No. 13
No. 22 /
No.23 No. 6 «
WOLFFORTH
Figure I. Location of Lakes Sampled.
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TABLE 1. LAKE CLASSIFICATION, WATERSHED ACREAGE AND PESTICIDE USE ON WATERSHEDS OF LAKES INCLUDED
IN STUDY.
Acres
in
Lake
No.
1
2
3
4
6
7
8
9
10
11
12
13
14
15
19
20
21
22
23
24
*
**
Type*
P-U
C-U
U
C-U
U
C
C-U
C-U
C
C
C
P
C
C-P
C
C
U
C
R
C
Watershed Acreage in Various Crops
Lake
Bed
6
8
15
8
4
4
2
6
2
10
8
6
15
8
35
35
10
6
15
10
P-Pasture
Acreat
36S f
Cotton
350
0
0
800
0
900
100
160
400
320
320
0
640
800
200
500
0
320
0
320
Milo
0
0
0
320
0
900
0
160
400
320
640
0
640
600
240
600
0
400
0
640
Land, U-Urban
^eoorted t
Dased
Fallow
0
360
0
0
0
0
320
0
80
320
0
200
0
0
100
0
200
0
320
Land,
on the
Soy-
beans
0
0
0
0
0
0
0
400
0
640
320
0
400
0
100
40
0
0
0
160
C-Crop
assumt
Wheat
0
0
0
0
0
0
0
0
0
80
0
0
0
0
0
0
0
0
0
0
Land,
)tions
Pasture
0
0
0
0
0
0
0
0
0
0
0
1280
0
400
0
40
0
0
0
0
Urban Total
500 850
400 760
700 700
600 1720
800 800
300 2100
1000 1420
800 1520
0 800
0 1340
0 1600
0 1280
0 1980
0 1800
0
0
1000 1000
300 1220
1200 1200
0 1440
Pesticide Used
Acreage Treated** Lb/Watershed***
Insecti
cide
35
0
0
240
0
540
10
96
240
192
352
0
384
380
140
350
0
232
0
352
- Herbi-
cide
280
0
0
896
0
1440
80
576
640
1024
1024
0
1344
1120
432
912
0
576
0
896
- Insecti-
cide
17.5
0
0
80
0
157
5
18
70
56
96
0
112
115
40
100
0
66
0
96
Herbi-
cide
140
0
0
448
0
720
40
288
320
512
512
0
672
560
216
456
0
288
0
448
R-Urban-Residential
that 10?
(, of cotton,
50% of g
rain sore
jhum treated
with
***
insecticides, 80% of cotton, grain sorghum, and soybeans treated with herbicides.
Quantities based on application rates of 0.5 pounds of insecticide per acre of cotton, 0.25 pounds
per acre of grain sorghum, 0.5 pounds of herbicide per acre of cotton, grain sorghum, and soybeans.
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phosphorus per acre on cotton, and 120 pounds of nitrogen and sixty
pounds of phosphorus per acre on grain sorghum. On grain sorghum,
however, only about fifty percent of the acreage receives phosphorus
fertilizer. Almost all urban lawns are also fertilized, mainly with
nitrogen, but occasionally with some phosphorus.
Herbicides are used on seventy-five to eighty percent of the cropland
in Lubbock County. Approximately three-fourths of the cotton and
soybean acreage is treated with a pre-plant application of Treflan
(Trifluralin). Other herbicides used on cotton not treated with
Treflan are Planavin, Karmex, and Caparol. Ami ben and Tenoran
are used on soybean. Atrazine and Propazine are the main herbicides
used on the seventy-five to eighty percent of the acreage of grain
sorghum that is treated.
Insecticides are normally used on cotton and grain sorghum only in
response to specific insect problems that arise. In 1969, little of
the cotton acreage was treated. Some farmers treated the seed with
low rates of an organophosphate systemic insecticide, either Di-Syston
or Thimet. Grain sorghum, on the other hand, was subjected to severe
infestations of aphids. As a result, almost all of the acres in this
crop were treated at least once. Parathion or Di-Syston were the
primary insecticides used, with about seventy-five percent of the
crop being treated with Parathion.
Rainfall, Runoff and Lake Levels
When the first sampling run was made on February 11, 1969, most of
the lakes selected for sampling were dry. Samples were obtained from
Lakes 4, 8, and 9 only. A heavy snow of approximately ten inches in
March produced a considerable amount of runoff, but Lakes 1, 7, 11,
12, 14, and 16 remained dry. The water level in Lakes 4, 8, and 9
rose considerably. A one-inch rain in April raised the levels in
most of the lakes which had been sampled previously and allowed an
initial sample to be taken from Lake 14.
General rains of almost four inches in the first half of May, 1969
produced runoff to all lakes except Lake No. 17. All lakes except
No. 17 caught additional water following a rainfall of about one and
one-half inches in the middle of June.
Three lakes had gone dry when a sampling run was made early in July,
but a two and one-half inch rain on July 21 produced additional run-
off to all lakes except No. 17.
Heavy general rains in September produced runoff to all lakes except
Lakes 11, 15, 16, 17, and 24. These lakes lost water quickly and
stayed dry most of the time.
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Samples were taken again in November, 1969 following a moderate rain-
fall in the area. Several of the lakes were dry at this time and
they remained dry throughout the winter.
Samples were obtained from five of the ten lakes that contained water
following a moderate rainfall in March, 1970. The other five lakes
containing water were sampled in April.
Two sampling runs were made in June, and two additional runs in July,
1970. No more than ten to twelve lakes contained water at the same
time in either June or July, and the water contained in some of the
lakes was believed to be derived from irrigation tailwater rather
than from runoff from precipitation.
All lakes not sampled more than once either dried up after the first
sample was taken or were included in the random samples taken before
and during the period in which specific lakes were regularly sampled.
Figure 2 indicates the period during which each lake contained water.
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1969 1970
Lake No. JFMAMJJASONDJFMAMJJASOND
I ^MM^™
O _____ ___
4 •—
5 (I)
6
7
8
9 (2)
10 —
II
12
13
14
15 —
16
17 (3)
18 (2) (4)
19 (2)
20
21
22
23
24
Figure 2. inundation Periods for Lakes Included in
the Study
(I) Sampled only one time because not incorporated into regular sampling
program.
(2) Condition not known as of February, 1969 because not included in
the study until March, 1969.
(3) Never caught water.
(4) Sampled only once because owner requested sampling be stopped.
10
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PESTICIDE ANALYTICAL PROCEDURES
Approximately 220 samples each of water and sediments were analyzed
in performing this research. In general, very low concentrations of
pesticides were found in sediments, and water samples were found to
be free of concentrations detectable with the equipment used.
The analytical procedures used generally consisted of three separate
parts:
1. The extraction of pesticides from the water or soil, both of
which may contain or have previously contained plants.
2. Cleanup or separation of the pesticide residues from the extract.
3. Identification and quantitative determination of the concentra-
tion of pesticides.
The extraction and cleanup procedures are usually the limiting and
time-consuming factors when there is organic contamination of the
samples. Most of the contamination found is thought to be caus-ed
by living or decomposing plant material contained in the water and
sediments.
After extraction and cleanup as required, all samples were analyzed
on a Varian Aerograph Model 600 C Gas Chromatograph equipped with a
Tritium Electron Capture Detector and a Leeds and Northrup Speedomax
H 1 millivolt recorder. A schematic diagram of the system is shown
in Figure 3.
Detection of a particular pesticide in an unknown sample requires
that the response of the instrument to that sample be compared to the
response of the instrument to a known standard pesticide. Provided
all variables such as gas flow rate, temperature, electronic variables,
type of absorbent column, etc. remain constant, a particular compound
passes through the chromatograph at a particular time.
Since all variables involved could not be held absolutely constant
from day to day, a procedure was adopted to minimize errors resulting
from uncontrolled variables. The procedure adopted was based on the
fact that, while the absolute retention time of different compounds
may vary from day to day as test conditions vary slightly, the re-
lative retention time of all compounds will remain constant under
any particular set of test conditions. The instrument was therefore
calibrated each day with hexane solution containing a standard con-
centration of Aldrin, and all other peaks observed were recorded in
terms of their retention times relative to Aldrin. Thus,
RTA _ Time unknown peak comes off
Time Aldrin peak comes off
11
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ELECTROMETI
RECORDER
ELECTRON
CAPTURE
DETECTOR
SYSTEM KEPT
AT 190° C
COLUMN FILLED
WITH ABSORBENT
GAS
RUBBER GASKET
* NEEDLE
(MICROSYRING)
Figure 3. Schematic Diagram of Gas Chromatograph
12
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Hence, the relative retention time for Aldrin is 1.00. Substances
with longer retention times than Aldrin have RTA's greater than 1.00,
and substances with shorter stays in the chromatographic column have
RTA's less than 1.00. Relative retention times of several pesticides
and of some unidentified compounds are shown in Table 2 along with
standard deviations as determined over a period of approximately five
months.
A typical chromatogram of a sediment extract is shown in Figure 4.
Figure 5 is a chromatogram obtained from a sample containing pure
compounds as indicated.
Compounds were occasionally detected with an RTA very close to a
known standard. In order to determine whether or not the compound
was, in fact, the standard compound, a mixture of the standard and
the unknown was introduced into the chromatograph. A larger, smooth
curve across the unknown then indicated that the unknown and the
standard were the same compound, while a slight difference in RTA's
was indicated by a shoulder on the curves as suggested by the values
of 1.00 to 1.07 in Figure 4.
It is possible that a compound could have an RTA exactly equal to
the standards used, yet be a different compound. The RTA's used were
dependent on the specific absorbents and other conditions in the
separation and in the system. While all reasonable precautions were
taken to avoid the possibility of such an error, instrumentation
available did not permit absolute confirmatory tests to be made.
Analytical Procedure for Water
The determination of pesticide concentrations in water was a fairly
straightforward process usually involving no cleanup procedure. The
extraction procedure used required that 600 ml of water and 50 ml of
n-Hexane be agitated by magnetic stirring for twenty minutes in a
1000 ml Erlenmeyer flask at a rate that resulted in the formation of
n-Hexane droplets in the water, but not in emulsification of the mix-
ture. The mixture was then poured into a 1000 ml separatory funnel
and allowed to separate into two layers. After separation, the lower
water layer was discarded. Tests showed that a single extraction by
this method removed 99%+ of the pesticides present in the water, thus
eliminating further time-consuming extractions of the sample. The
hexane layer was separated and reduced in volume by evaporation at
room temperature, after being passed through a small column contain-
ing powdered anhydrous sodium sulfate on a glass wool plug. The
column had been rinsed previously with n-Hexane. The elutant was
collected in a 50 ml amber bottle with a foil-lined screw cap.
Most samples were then ready for immediate injection into the gas
chromatograph. However, if organic contamination was found to be
present, the sample was put through a Florisil cleanup procedure
which will be described later.
13
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TABLE 2. RETENTION TIMES FOR THE NON-POLAR COLUMN
Pesticide
Standards
Lindane
Retention
Times
Minutes
1.3 i 0.2
Relative
Retention
Times
(To Aldrin)
0.44 - .01
Relative
Retention
Times
Samples
(To Aldrin)
Accepted
Retention Times
5% Dow II on
Chromosorb W
.44
Heptachlor
2.4 - 0.4
0.78 - .01
.80
Al dri n
Dieldrin
Endrin
3.0 - 0.4
6.2 - 0.3
6.6 i 1 .1
1.00 - .00
2.00 - .03
2.19 - .05
1.00
1.07*
1.50*
2.00
2.15*
1.00
1.94
2.18
2.50*
pp1 DDT
10.0 - 1.8
3.28 - 0.11
3.29
Unidentified peaks.
Experimental values reported were calculated from chromatograms which
were run over a 5^ month period.
Column Conditions
Support: Chromosorb W 60/80 mesh
Coating: 5% Dow II
Length: 6 ft.
Diameter: 1/8" I.D.
14
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1 U 1
0 1
— 1 —
2
— I —
3
— i —
4
I
5
1
6
1
7
1
8
I
9
T 1
10 1
TIME (minutes)
Figure 4. Typical Chromatogram Obtained
from Soil Extract.
I
2
I
5
8
10
6 7
TIME (minutes)
Figure 5. Chromatogram Obtained from Analysis
of Pure Compounds as Indicated.
15
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In the early testing stages of the program, the hexane solutions were
transferred and diluted to 25 ml. Later, the analytical procedures
for the lake waters were changed so that more hexane was recovered in
the extraction and cleanup procedure and made up to smaller final
volumes. The detectable range for each pesticide was established by
the introduction of known quantities of the pesticide in a series of
duplicated water samples, so that the range of linear response of
the chromatograph could be established, the lower detectable limit
shown, and the effectiveness of the extraction process demonstrated.
The introduction of 1 ug of pesticide into the 600 ml water sample
was approximately the least quantity detectable with certainty above
the various high trash backgrounds and corresponds to a pesticide
concentration of 1.6 ppb. Non-trashy water samples allowed this
detection limit to be reduced ten fold to the 0.1 ppb limit.
Recoveries of 95% - 100% ± 3% have been obtained using the method
described above. Pesticides were usually detected in the water as
trace quantities only at the beginning of the mosquito season when
spraying for insects was most intensive. Even then, pesticides were
normally found in trace concentrations only if the rainfall had been
light enough that extensive dilution had not occurred.
The main problem encountered in extraction of water samples was the
problem of emulsification during the extraction process. This prob-
lem was most pronounced during the spring and early summer months
when there was a profuse growth of plants in the watersheds because
of rainfall. This problem was less severe in samples taken during
dry weather, and it disappeared completely during the winter months.
It was therefore concluded that the "trashy" or contaminated chromato-
grams obtained when cleanup was omitted resulted from organic by-
products of plants. The Florisil procedure described later did not
always remove this contamination. A solution to this problem is
discussed under the analytical procedure for sediment.
Analytical Procedure for Sediment
The extraction of soil samples was more difficult than was the ex-
traction of water samples. It was also more productive in terms of
number and amounts of pesticides detected.
Three methods of extraction were tested as follows:
1. A 25 gm sample of sediment saturated with water was stirred in a
125 ml Erlenmeyer flask for twenty minutes with 50 ml n-Hexane.
2. A 15 gm sample of sediment that had been air-dried and ground to
a fine powder was extracted by allowing 25 ml of n-Hexane to
gravity filter through the sample.
16
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3. A 25 gin sample of sediment that had been air-dried and ground to
a fine powder was extracted by magnetic stirring for twenty
minutes with 50 ml of n-Hexane in a 125 ml Erlenmeyer flask.
In all cases, the n-Hexane was collected and passed through a small
column containing powdered anhydrous sodium sulfate. The extract was
then ready for analysis on the gas chromatograph if it was free of
interfering organic contaminants.
When the sample was found to contain organic interferences, it was
run through a Florisil cleanup process. In this process, the sample
extract was concentrated to approximately 10 ml by evaporation over
a 70° C water bath equipped with an aspirated air stream to pull off
vapors and speed up evaporation. A 15 gm charge of activated Flori-
sil was placed in a 5/16 I.D. column over a glass wool plug topped by
1/2 in. of anhydrous sodium sulfate. After the Florisil was tapped
in place in the column, an additional 1/2 in. of anhydrous sodium
sulfate was added to the top of the column. After cooling, the
column was pre-eluted with 30 ml n-Hexane and the pre-elutant was
discarded. The sample extract was transferred to the column just
before the top layer of anhydrous sodium sulfate was exposed to air.
The extract was followed with 50 ml n-Hexane and the total volume of
elutant was collected and evaporated over a 70° C water bath to a
volume of approximately 5 ml. The concentrated extract was then
diluted back to the pre-Florisil treatment volume and injected into
the gas chromatograph.
In extraction method (1), the presence of water tended to produce
emulsions which presented a barrier to the passage of pesticides from
the soil to the Hexane. The emulsions did not break up upon standing
nor could they be destroyed by centrifuging. Recoveries by this
method were therefore very low, and it was rejected as an unacceptable
procedure.
Of the last two methods, the former gave slightly better recoveries
of pesticides. However, since method (2) required more time for
gravity filtration and precise collection of the first 25 ml of n-
Hexane passing through the filter, method (3) was used for most of
the work. Recoveries by method (3) are comparable to those obtained
using method (2). Recoveries of 84% ± 7% to 35% ± 4% were obtained,
depending upon the type of pesticide and the texture of the soil.
An additional problem was encountered when the Florisil cleanup
procedure failed to remove all of the interferences present in some
of the soil samples. In these cases, extracts produced chromatograms
with large contamination peaks that were able to mask pesticides
present. A recent publication in the Journal Analytical Chemistry
42-2, p. 282, 1970, described a procedure which was being tested.
Preliminary results indicated it would be useful in removing many of
the organic contaminants before the extract is put through the
Florisil cleanup.
17
-------
Concentrations of pesticides in sediment samples which were inter-
ference-free generally exceeded the concentrations found in water
samples by a factor of 100 to 1000. Most pesticide concentrations
detected in sediment samples range from .01 to 1 ppm. Three sediment
samples taken from two lakes in the City of Lubbock contained Dieldrin
in concentrations of 1.06, T.87, and 2.82 ppm.
Analytical Difficulties
From the beginning, extraction of muds and soils was a problem because
of the appearance of trashy substances in the Hexane phase. The
typical range of most of the trouble encountered is illustrated in
Figure 4. Often the trashy complex was much more intense, producing
a record such'as that shown in Figure 6.
Various cleanup procedures were tried using such absorbents as Flori-
sil, Attaclay, and Norit. These procedures were frequently unsuccess-
ful, since the absorbents removed pesticides as well as the trashy
substances. A cleanup method that removed the trashy complex without
also removing pesticides was finally found. This method is as follows:
1. Pipet a 10 ml aliquot of trashy Hexane into a 125 ml separatory
funnel.
2. Add 10 ml saturated KOH solution of absolute ethanol to the
separatory funnel; shake for two minutes.
3. Leach the ethanol-KOH out of the Hexane with 20 ml distilled water,
shaking for about one minute. Allow phases to separate.
4. Remove and discard water phase from separatory funnel. Repeat
procedure in step 3 above three times, or until Hexane layer is
optically clear.
5. Add a small quantity of powdered anhydrous Na^SO. to remove any
water in contact with Hexane.
6. The Hexane solution is now ready for analysis on the gas chromato-
graph.
This procedure made possible quantitative detection of Aldrin with an
RTA within the typical trashy range shown in Figure 6 (note dotted
line result of cleanup where Aldrin is present). This procedure was
found to remove the Lindane and p, p-DDT, and to reduce the concen-
trations of Treflan. However, since it did not affect Aldrin,
Heptachlor, Dieldrin, or Endrin, it was used in conjunction with these
pesticides. Other trashy complexes appeared occasionally at higher
retention times, and certain water samples also contained these same
interfering substances.
18
-------
Ul
o
CO
TIME
Figure 6. Chromatogram of Sample Contaminated
by High Concentration of "Trashy Complex".
19
-------
One procedure was found to be successful in confirmation of apparent
pesticides. This procedure was used in conjunction with the gas
chromatograph. It involves extraction p-values (Analytical Chemistry,
37 > 2, Feb. 1965), where p-values are defined as follows:
1 s Amount of pesticide in upper phase (2nd analysis)
p Total amount of pesticide (1st analysis)
This method is based on the distribution of the pesticide between two
immiscible phases. A given pesticide will have its own specific p-
value for the same phase system, i.e., its own distribution ratio.
Thus a suspected pesticide can be checked by determining whether its
p-value is the same as that of a known standard pesticide.
20
-------
RESULTS AND INTERPRETATIONS
None of the water samples analyzed contained measurable concentrations
of any of the herbicides or insecticides commonly used in the area.
Aldrin, Dieldrin, and DDT were the only insecticides found in sedi-
ment samples in the lakes, and no measurable concentrations of herbi-
cides were found in any sediment samples. Measurable concentrations
of Dieldrin were found in the sediments in about eighty percent of
the lakes. Aldrin was found to be detectable in sediments in less
than ten percent of the Takes, and, surprisingly, DDT was present in
detectable concentrations in only three of the samples analyzed.
These results are shown in detail in Table 3.
As noted earlier, all sediment samples were obtained from the top
one inch of sediment in the lakes. Because of the generally negative
results obtained for analyses of sediment samples taken in this
manner, it was decided to obtain core samples from a few lakes to
determine whether or not pesticides had been carried deeper into
lake sediments by percolation of water over a period of several years.
Core samples were therefore taken from the bottoms of four lakes
that were included in the study, with two of the cores being taken
from lakes at which mosquito control programs had been in operation
for several years, and the other two being in farming areas not
subject to mosquito control programs. Core samples were taken at
one-inch increments from the sediment surface to a depth of twelve
inches. Each sample obtained was analyzed in the same manner as
were other sediment samples.
A substantial difference was found in the four lakes cored. Although
Dieldrin was found in all four lakes and DDT was found in the sedi-
ments in one of them, the two rural lakes contained low concentrations
of Dieldrin that remained fairly constant in the twelve samples
analyzed. The two urban lakes, however, contained higher concentra-
tions of Dieldrin that apparently varied with the depth of the sam-
ples. Although the concentration of Dieldrin varied in Lakes 2 and
3 for the first four to five inches, a definite trend was indicated
later, Figures 7 and 8. Starting with the five inch sample on both
lakes, there was a steady decrease in pesticide concentration until
the seven to eight inch level was reached. After the lowest concen-
tration was reached at the eight inch level, a sharp increase in
concentration values throughout the remaining four inches was indi-
cated. This increase may be an indication of heavier treatments for
mosquito control in past years.
The Lubbock City-County Health Department has indicated that, from
1956 through 1962, Dieldrin was sprayed on lakes within the City for
mosquito control during the summer with concentrations of one-half
21
-------
TABLE 3. INSECTICIDE CONCENTRATION IN MUD SAMPLES
N.D. = Not detectable
Lake Location Number Date
Number of
Sample
1 Airport 20
145
213
2 4th & Quaker 23
43
49
77
251
331
351
3 24th & Vicksburg 24
27
45
51
79
105
117
249
289
4 Old Slaton 12A
ISA
33
53
67
99
137
179
225
239
265
315
335
363
5 50th & Avenue A 12
6 66th & University 8
47
55
3/14/69
6/20/69
7/22/69
3/14/69
3/25/69
4/12/69
5/ 6/69
9/19/69
5/14/70
6/ 2/70
3/14/69
3/18/69
3/25/69
4/12/69
5/ 6/69
5/29/69
6/17/69
9/19/69
11/28/69
12/23/68
2/11/69
3/18/69
4/12/69
5/ 3/69
5/28/69
6/18/69
7/10/69
7/23/69
9/15/69
11/22/69
4/23/70
5/15/70
6/ 5/70
12/23/68
12/23/68
12/23/68
4/12/69
Apparent
Aldrin
PPM
N.D.
N.D.
Trace
.11
N.D.
.022
.087
.031
.085
N.D.
.034
.0092
.029
.072
.038
.053
N.D.
N.D.
.063
N.D.
.19
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
.015
Apparent Apparent
Dieldrin DDT
PPM PPM
.11
.25
.33
1.87
.23
.11
.76
.42
.034
.071
.27
.27
1.06
2.82
.21
.19
.27
.07
.394
.08
.11
.06
.01
.04
.05
.16
.065
.067
.065
.008
Trace
Trace
Trace
.034
.047
.27
.27
N.D.
N.D.
.49
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
.11
.38
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
22
-------
TABLE 3. INSECTICIDE CONCENTRATION IN MUD SAMPLES - Continued
N.D. = Not Detectable
Lake Location Number
Number of
Sample
81
109
125
195
217
245
293
301
323
359
7 New Slaton 65
95
135
177
227
237
263
297
333
8 Strip Lake 16
31
57
83
107
119
219
255
271
299
337
361
9 Loop 289 & 29
73
N. Quaker 123
201
209
241
291
Date Apparent Apparent Apparent
Aldrin Dieldrin DDT
PPM PPM PPM
5/ 6/69
5/30/69
6/17/69
7/12/69
7/23/69
9/19/69
11/28/69
3/17/70
5/13/70
6/ 2/70
5/ 3/69
5/28/69
6/18/69
7/10/69
7/23/69
9/15/69
11/22/69
3/17/70
5/15/70
2/11/69
3/18/69
4/12/69
5/ 6/69
5/30/69
6/17/69
7/22/69
9/19/69
11/26/69
3/17/70
5/15/70
6/ 5/70
3/18/69
5/ 6/69
6/17/69
7/16/70
7/22/69
9/19/69
11/28/69
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
.039
.32
.10
.11
.010
.016
.029
.016
.032
.038
N.D.
.054
N.D.
.030
.067
.061
.007
N.D.
.027
.088
.33
.39
.098
.050
.16
.053
.024
.050
.055
.053
.065
.083
.15
.29
.14
.30
.11
.065
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
23
-------
TABLE 3. INSECTICIDE CONCENTRATION IN MUD SAMPLES - Continued
N.D. = Not Detectable
Lake Location Number
Number of
Sample
305
339
349
10 North University 2
14
35
61
75
91
115
203
211
253
279
309
325
347
11 Huddleston 21
101
121
191
235A
283
311
327
343
12 Abernathy #2 22
103
129
183
233
257
277
13 Yellowhouse 37
63
69
93
133
Date
4/ 4/70
5/15/70
6/ 2/70
12/23/69
2/11/69
3/18/69
4/12/69
5/ 6/69
5/28/69
6/17/69
7/16/69
7/22/69
9/19/69
11/17/69
4/23/70
5/14/70
6/ 2/70
3/14/69
5/30/69
6/18/69
7/11/69
7/24/69
11/28/69
4/23/70
5/14/70
6/ 2/70
3/14/69
5/29/69
6/18/69
7/11/69
7/24/69
9/20/69
11/17/69
3/20/69
4/12/69
5/ 3/69
5/28/69
6/18/69
Apparent
Aldrin
PPM
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
Apparent Apparent
Dieldrin DDT
PPM PPM
.065
.121
.062
.27
.16
.11
.14
.21
.15
.052
.082
.058
.12
.030
.056
.032
.074
.53
.15
.034
.061
.26
.075
.15
.027
Trace
.022
.081
.11
.063
.060
.073
.020
N.D.
N.D.
N.D.
N.D.
.21
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
24
-------
TABLE 3. INSECTICIDE CONCENTRATION IN MUD SAMPLES - Continued
N.D. = Not Detectable
Lake Location Number
Number of
Sample
14 Shall owater
15 Woodrow #2
16 Culpepper
17 Woodrow #1
18 Hufstedler
19 Halfway-North
Halfway-North
Observ. Well N-l
North Well Lake
North Well after
Recharge
North Well
Pumping
181
223
235B
267
295
341
6
38
85
87
143
193
231A
258
275
41S
97
139
268
40
39S
89
205
204
204
204
204
204
Date Apparent
Aldrin
PPM
7/10/69
7/23/69
9/15/69
11/22/69
3/17/70
6/ 2/70
12/23/68
3/20/69
5/ 6/69
5/28/69
6/20/69
7/12/69
7/24/69
9/20/69
11/17/69
3/20/69
5/28/69
6/16/69
11/26/69
3/20/69
3/20/69
5/28/69
11 4/69
8/20/69
8/20/69
8/20/69
10/ 2/69
4/ 6/70
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
.038
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
Apparent Apparent
Dieldrin DDT
PPM PPM
N.D.
N.D.
.46
N.D.
N.D.
N.D.
Trace
.067
.090
.067
.12
N.D.
.084
.067
N.D.
.011
.064
.052
.015
.060
Trace
.12
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
20 Halfway-South
Well 205
South Well Lake 205
South Well
after Recharge 205
II 4/69
II 4/69
I.D.
I.D.
10/10/69 N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
25
-------
TABLE 3. INSECTICIDE CONCENTRATION IN MUD SAMPLES - Continued
N.D. = Not Detectable
Lake
Number
21
22
23
24
25
26
27
Location Number
of
Sample
South Well Lake 205
South Well In-
take Ditch 205
19th & Vicksburg 71
141
197
207
243
287
307
319
353
Petroleum Engr. 113
187
221
261
273
K. N. Clapp 185
215
247
281
303
321
Biology 127
189
229
285
313
329
345
Experiment
Station 10
South of Idalou 4
Hereford (3 mi
Date Apparent
Aldrin
PPM
10/31/69
4/ 6/70
5/ 5/69
6/20/69
7/16/69
7/22/69
9/19/69
11/28/69
4/23/70
5/13/70
6/ 2/70
6/11/69
7/11/69
7/23/69
9/20/69
11/26/69
7/11/69
7/23/69
9/19/69
11/28/69
3/17/70
5/13/70
6/18/69
7/11/69
7/23/69
11/28/69
4/23/70
5/14/70
6/ 2/70
12/23/68
12/23/68
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
.015
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
Apparent Apparent
Dieldrin DDT
PPM PPM
N.D.
N.D.
.25
.016
.030
.091
.063
.049
.057
.035
.059
.18
.059
.051
.13
.080
N.D.
Trace
N.D.
N.D.
.006
.036
Trace
.13
N.D.
.019
.050
.053
.037
.079
.16
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
SW)
149
II 7/69 N.D.
.17
N.D.
26
-------
TABLE 3. INSECTICIDE CONCENTRATION IN MUD SAMPLES - Continued
N.D. = Not Detectable
Lake
Number
28
29
30
31
32
33
34
35
36
37
38
40
41
42
Location
Summerfield
(1/2 mi)
Summerfield
Summerfield
Happy (6 mi)
Canyon (3 mi)
66th & Sunset
Wil dorado
P.M. 1912 & 287
Amarillo (5 mi
& 1541)
Amarillo (24 mi)
Tulia on 87
(3 mi)
Plainview (3 mi)
Post Lake
Tulia on 87
(8 mi)
Number
of
Sample
151
153
155
157
159
161
163
165
167
169
171
175
231
173
Date Apparent
Aldrin
PPM
11 7/69
11 7/69
11 7/69
11 8/69
11 8/69
11 8/69
11 8/69
11 8/69
11 8/69
11 8/69
11 8/69
11 8/69
8/ 1/69
11 8/69
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
Apparent Apparent
Dieldrin DDT
PPM PPM
Trace
.13
N.D.
N.D.
N.D.
.095
Trace
N.D.
N.D.
N.D.
.12
.027
.094
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
27
-------
E
o.
Q.
cc
LL)
o
z
o
o
UJ
Q
o
I-
V)
UJ
Q.
.17
.16
.15
.14
.13
.12
.11
.(0
.09
.08
.07
.06
.05
.04
URBAN LAKE
LAKE 2
345
DEPTH
678
(inches)
10 II 12
Figure 7. Concentrations of DDT and Dieldrin in
Sediment Layers of an Urban Lake.
28
-------
E
0.
Q.
Q
o
en
UJ
o_
.19
.18
.17
.16
.15
.14
.13
.12
.1 I
.10
09
.08
.07
.06
.05
.04
URBAN LAKE
LAKE 3
2345678
DEPTH (inches)
10 I I 12
Figure 8. Concentration of Dieldrin in Sediment
Layers in an Urban Lake.
29
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pound per acre used for each application. Also, in 1962 and 1963,
three pounds of DDT per acre were sprayed on the lakes. Since 1956,
DDT dust and Malathion have been used as larvicides and insecticides
in conjunction with the other spray programs.
The concentrations of DDT and Dieldrin follow roughly the same pat-
terns from a depth of eight to eleven inches. It therefore appears
that in the seven or eight years since Dieldrin was used extensively
on urban lakes, very little of it has concentrated in the upper
sediment layers of the lakes. The runoff into the lakes since about
1962 has likely carried with it enough silt to deposit the seven or
eight inches of sediment found over the levels containing high con-
centrations of Dieldrin.
The concentrations of DDT in sediments in Lake 2 are of the same
magnitude as are the concentrations of Dieldrin. The erratic values
obtained for concentrations of DDT from the one to six inch depth
levels might be attributed to uneven distribution of the pesticide
resulting from wave action or to water level fluctuations resulting
in different concentrations being applied to the water in different
years.
It is interesting to note that in Lake No. 3, although Dieldrin con-
centrations were found to be consistently higher than the concen-
trations found in Lake No. 2, no DDT was present in a measurable con-
centration, Figure 9.
The concentrations of Dieldrin in rural lakes were found to be
considerably lower than those found in urban lakes, Figure 9. Again,
it is interesting to note that Dieldrin was the only pesticide found
at any depth in the two rural lakes.
Under terms of a parallel contract with the Texas Water Quality
Board, all samples collected for this project were analyzed to
determine the concentrations of nitrates and phosphates in playa
lake water. Nitrates were generally found to be present in concen-
trations ranging from one to six mg/1, and phosphate concentrations
were generally found to range from about 0.01 to a maximum of about
1.0 mg/1.
Lakes 19 and 20 were selected for the specific reason that waters
from these lakes are currently being recharged into the Ogallala.
Although no tables have been given in this report, it appears that
the inorganic elements calcium, phosphate, chloride, and ammonia
are present in lake waters in higher concentrations than in Ogallala
water. The concentration of nitrate in lake water was in all cases
lower than the concentration existing in the groundwater.
After periods of recharge, the concentration of phosphate in well
water tended to be less than that found in playa lake water but
30
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phosphate concentrations in well water tended to change with sampling
time.
A similar phenomenon was observed regarding the concentration of ni-
trate. In one series of tests, water containing 3.4 mg/1 of nitrate
ion was used for recharge. After recharging was complete, a sample
from the well indicated a nitrate concentration of 3.2 mg/1. Two
months later, a sample from the same well showed a nitrate concen-
tration of 0.1 mg/1. This same nitrate concentration was found at
an observation well approximately 200 feet from the "recharge well
both while recharge was taking place and also two months after re-
charge had ceased. These findings suggest that recharged water does
not necessarily stay in the immediate vicinity of the recharge well,
but, under the relatively steep water table gradients induced by
normal recharge operations, recharged water tends to move away from
the point of recharge at a fairly rapid rate.
31
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RURAL LAKES
.10
-g .09
Q.
Q.
~ .08
1 .07
2 .06
UJ
o
z
o
o
Q
O
CO
UJ
Q.
.05
.04
.03
.02
.01
I
LAKE II
-e e-
LAKE 12
-e e-
10 II 12
23456789
DEPTH (inches)
Figure 9. Variation of Dieldrin Concentration
with Depth of Sediment, Lakes II and 12.
32
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ACKNOWLEDGMENTS
The study on which this report is based was supported by the Environ-
mental Protection Agency (formerly the Federal Water Quality Adminis-
tration). The primary purpose of this project was to determine
whether or not the utilization of playa lake water for recharge of
the Ogallala aquifer is likely to result in permanent damage to water
quality in the form of herbicide and insecticide contamination.
Professional members of the research team were Ellis W. Huddleston,
Robert G. Rekers, and Dan M. Wells. In addition, several graduate
and undergraduate students contributed to and benefited from this
research. Many landowners in the study area cooperated by furnish-
ing information on their farming practices and in permitting samples
to be taken from their playas.
A parallel study involving the same research team was financed by the
Texas Water Quality Board. The primary purpose of this latter pro-
ject is to determine the concentrations of nitrates and phosphates in
playa lake waters. Some of the data presented in this report were
obtained from the TWQB financed project.
33
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GLOSSARY OF TERMS - Herbicides
Alanap N-1-naphthylphthalamic acid
Ami ben 3-amino-2,5-dichlorobenzoic acid
Atrazine 2-chloro-4-ethylamino-6-isopropylami no-1 ,3,
5-triazine
Bandane polychlorodicyclopentadiene isomers
Banvel D 2-methoxy-3, 6-dichlorobenzoic acid
Barban 4-chloro-2-butynyl-N-(3-chlorophenyl )-
carbamate
CIPC isopropyl n-(3-chloro-phenyl) carbamate
Dacthal -dimethyl 2,3,5,6-tetrachloroterephthalate
2,4 D 2,4-dichlorophenoxyacetic acid
2,4, DB dimethyl ami ne salt of 4-(2,4-dichlorophe-
noxy)-butric acid
Dichlobenil 2,6-dichlorobenzonitrile
2,4 D (iso-Octylester) iso-octyl 2,4-dichlorophenoxyacetate
Diuron 3-(3,4-dichlorophenyl)-l, 1-dimethylurea
DNBP 2-(l-methyl-n-propyl)-4,6-dinitrophenyl
2,4 DP acid 2-(2,4-dichlorophenoxy) propionic acid
Eptam ethyl n, n-di-n-propyl thiocarbamate
Erbon 2-(2,4,5-trich1orophenoxy) ethyl 2,
2,2-di chloropropi onate
Falone --tris, B-(2,4-dichlorophenoxy) ethyl phos-
phite
IPC n-phenyl isopropyl carbamate
MCPA 4-chloro-2-methylphenoxyacetic acid
Prometone 2-chloro-4,6-bis(ethylamino)-s-triazine
Propazine 2-chloro-4,6-bis(isopropylamino)-l ,3,
5-triazine
Rogue 3,4 - dichloropropionanilide
Si 1 vex 2-(2,4,5-trichlorophenoxy) propionic acid
2,4,5 T 2,4,5-trichlorophenoxyacetic acid
Till am n-propyl N-ethyl-N-(n-butyl) thiocarbamate
2,4,5 T (iso-Octylester)--iso-Octyl 2,4,5-trichlorophenoxyacetate
Treflan (Trifluralin) a-a-a-trifluoro-2,6-dinitro-n,n-dipropyl-
p-toluidine
Wallop parathion and 2-chloro-N-isopiopylacetani-
lide combination
Zytron o-(2,4-dichlorophenyl) o-methy 1 isopropyl -
phosphoramidothioate
35
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GLOSSARY OF TERMS - Insecticides
Aldrin 1,2,3,4,10,10-hexachloro-l ,4,4,5,8,8a-hexahydro-l,
4-endoexo-5,8-dimethanonaphtha1ene
BHC 1,2,3,4,5,6-hexachlorocyclohexane (mixed isomers)
Chlordane 1,2,4,6,7,8,8-octochloro-3a,4,7,7a-tetrahydro-4,
7-methanoindane
DDT 1,1,1-trichloro-2,2-bis(p-chlorophenyl) ethane
Dieldrin 1,2,3,4,10,"10-hexachloro-6,7-epoxy-l ,4,4,5,6,7,8,
8a-octahydro-l,4-endoexo-5,8-dimethanonaphtha-
lene
Endosulfan 6,7,8,9,10,10-hexachloro-l ,5,5a,6,9,9a-hexahydro-6,
9-methano-2,4,3-benzodioxathiepin-3-oxide
Endrin 1,2,3,4,10,10-hexachloro-6,7-epoxy-l ,4,4a,5,6,7,8,
8a-octahydro-l,4-endo,endo-5,6-dimethanonaphtha-
lene
Heptachlor 1,4,5,6,7,8,8-heptachloro-3a,4,7,7-tetrahydro-4,
7-methanoindene
Lindane gamma-1,2,3,4,5,6-hexachlorocyclohexane
Methoxychlor 1,1 ,l-trichloro-2,2-bis(p-methoxyphenyl)-ethane
Mi rex dodecachloroctahydro-1,3,4-metheno-2H-cyc1obuta
[cd] pentaline
Parathion- --o,o-diethyl-o,p,nitropheny1-phosphorothiolate
Perthane 1,l-dichloro-2,2-bis-(p-ethylphenyl) ethane
Strobane- terpene polychlorinates
TDE 2,2-bis-(p-chloropheny1)-l-chloroethylene
Toxaphene chlorinated camphene isomers
36
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^4 cce.s^ /on Number
Subject Fn-ld & Group
05A
SELECTED WATER RESOURCES ABSTRACTS
INPUT TRANSACTION FORM
Organization
Texas Tech University Water Resources Center, Lubbock, Texas
Title
Potential Pollution of the Ogallala by Recharging Playa Lake Water—Pesticides
10
Authors)
Wells, Dan M.
Huddleston, Ellis W.
Rekers, Robert G.
16
Project Designation
Project No. 16060 DCO
21
Note
22
Citation
23
Descriptors (Starred First)
*Herbicides, *Insecticides, *Runoff, *Playa Lakes, *0gallala
25
Identifiers (Starred First)
27
Abstract
The purpose of this study was to determine the concentrations of herbicides and
insecticides in playa lake water in the High Plains of West Texas. Twenty-four
urban and rural lakes were sampled routinely for the period of eighteen months
following runoff-producing precipitation events. Samples of water and sediment
were analyzed by means of a gas chromatograph to determine concentrations of all
herbicides and insecticides commonly used in the area. Findings of the research
are that runoff water does not contain any measurable concentrations of any of
the commonly used herbicides or insecticides, and that sediment samples contain
very low concentrations of some of the compounds. The compound most commonly
found in sediment samples was Dieldrin, with Aldrin being next most common, and
DDT found in only a few sediment samples.
Abstractor
Dan M. Wells
Institution
Texas Tech llnivprsitv
WR:102 (REV JULY 1969) SEND TO: WATER RES5uRCES SCIENTIFIC INFORMATION CENTER
U S DEPARTMENT OF THE INTERIOR
WASHINGTON. D. C 20240
* GPO: 1969-359-339
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