ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF ENFORCEMENT
EPA-330/2-76-037
Herbicide Contamination
Water Supplies
Kimball, Nebraska
NATIONAL ENFORCEMENT INVESTIGATIONS CENTER
DENVER, COLORADO
<°*>
AND />>• £^
REGION VII KANSAS CITY, MISSOURI
DECEMBER 1976
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ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF ENFORCEMENT
EPA-330/2-76-037
HERBICIDE CONTAMINATION IN WATER SUPPLIES
KIMBALL, NEBRASKA
December 1976
National Enforcement Investigations Center - Denver, Colorado
and
Region VII - Kansas City, Missouri
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CONTENTS
I INTRODUCTION 1
Objectives 1
II SUMMARY AND CONCLUSIONS 3
III RECOMMENDATION 4
IV BACKGROUND ,
V STUDY AREA 7
VI RESULTS AND DISCUSSION’ 12
Field Studies 12
Laboratory Studies 13
VII METHODS 16
Picloram Analyses 16
Plant Bioassays 18
REFERENCES 19
TABLES
1 Comparison of Historical Results of
Picloram Analyses 6
2 ,Picloram Concentrations in
Water Samples 11
FIGURES
1 Lodgepole Valley Area 9
2 Sampling Stations 10
111
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I. INTRODUCTION
In 1968, use of the weed-killing herbicide picloram contaminated
the ground water near Kimball, Nebraska. When the ground water was used
for irrigation, major plant damage occurred in gardens, croplands, and
commercial greenhouses in Kimball.
In 1975, commercial greenhouses in Kimball again experienced severe
plant damage. Greenhouse owners contacted the Cooperative Extension
Service in Scottsbluff, Nebraska and requested agronomists to examine
damaged greenhouse plants. The opinion of the agricultural experts was
that the plant injuries were caused by herbicides. In view of the 1968
picloram-contaniination problem, the greenhouse owners contacted the
Environmental Protection Agency, Region VII, to request an investigation
of the Kimball water supplies.
On February 23, 1976, the EPA Region VII Pesticide Branch in Kansas
City requested technical assistance from the National Enforcement
Investigations Center (NEIC) to investigate the Kimball water supply
problem.
OBJECTIVES
The objectives of the study were:
1 . Determine the occurrence of picloram contamination in the
water supplies of Kimball, Nebraska.
2. Determine the effects of picloram on selected broadleaf
plants.
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2
3. Compare morphological effects induced by picloram with plant
damage observed at Kimball greenhouses.
Field studies and bioassays were conducted by NEIC from March to
July 1976. Water samples were collected from city wells, irrigation
wells, and various surface water sites. Aliquots of selected water
samples were sent to Dow Chemical Company (picloram manufacturer) and
to NEIC (EPA laboratory) for picloram analyses.
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II. SUMMARY AND CONCLUSIONS
1 . Of the thirty-eight water samples collected and analyzed by the
National Enforcement Investigations Center and Dow Chemical Company
in 1976, picloram was detected in two surface water samples and in
eight wells. One irrigation well contained 4.3 pg/i picloram; the
other nine surface and ground water samples contained trace quantities
of picloram (<1 j.ig/l).
2. Study results strongly suggest that the picloram contamination of
ground water is a result of the sewage lagoon spraying that occurred
in the 1960’s and more recent applications of picloram such as
those along the Union Pacific Railroad tracks in 1975.
3. In laboratory bioassay studies conducted with ornamental plants and
field beans, morphological changes were caused by 1 pg/i of the
herbicide, picloram. The morphological changes caused by picloram
were similar to the symptoms observed at the greenhouses in Kimball,
Nebraska.
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III. RECOMMENDATION
Based on the results of this study and a history of picloram
contamination of Kimball, Nebraska water supplies, NEIC recommends that
Administrative action be initiated by EPA to restrict the use of herbicides
containing picloram pursuant to the Federal Insecticide, Fungicide, and
Rodenticide Act, as amended (7 usc 135, et seq.).
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IV. BACKGROUND
Picloram, 4-amino-3,5,6-trichloropicolonic acid, is a herbicide
effective in the control of many broadleafed weeds and woody plants.
The •product is manufactured by Dow Chemical Company and marketed under
the trade name Tordon. There are now eight different formulations
registered for use in control of weeds. Picloram is highly soluble in
water, highly phytotoxic and very persistent. 1 ’ 2 ’ 3 The persistence is
evidenced by the fact that certain species of plants have been injured
as long as five years after an application. Toxicity to mammals is
low; however, the concern of this study is its persistence and effects
on plant growth.
Historically, in Kimball County, picloram has been used to control
weeds along roadways and on non-cropland acreage. In spite of the
precautions taken by farmers, county weed control agents and other
applicators to avoid contamination, a problem occurred in 1968. Well
water used for irrigation in gardens, croplands and commercial greenhouses
became contaminated with a herbicide and caused major plant damage. The
contaminant was picloram. This herbicide had been sprayed around or in
the Kimball city sewage lagoon basin in 1965 and 1968 for weed control.
The chemical apparently entered ground water through abandoned exploration
holes in the lagoon basin. Subsequently, ground water was used for
irrigation of croplands and greenhouse plants and caused damage.
Several incidents of water contamination have been reported in the
Kimball area since 1968. Citizen complaints of well water contamination
stimulated investigations by county, state and federal agencies. Results
of these past studies are presented in Table 1.
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6
Table 1
COMPARISON OF HISTORICAL RESULTS OF PICLORAM ANALYSES
KIMBALL COUNTY, NEBRASKA
Station
No.
Station Description
[ n5N-R55w]
P
icloram in ug/l
-
1968 a 1970 b] 971 c 1974 c
8
11
Sewage Lagoon Sec 28 NE¼ of NW¼
City Well #11 Sec 30 SE¼ of NE¼
NDd
ND ND
-
ND
ND
14
City Well #7 Sec 28 SW¼ of SW¼
<3
ND ND
0.5
16
City Well #3 Sec 32 SW¼ of NW¼
-
0.17 ND
ND
19
Kimball Water Supply @ greenhouse
Sec 32 NW¼ of NE¼
-
0.72 0.6
ND
22
23
Mossberg (Cannon) Well
Sec 28 NW¼ of SW¼
Rasmussen Well Sec 28 NE¼ of NW¼
-
ND
0.16 ND
ND -
ND
ND
25
Strauch Well Sec 28 NE¼ of S [ ¼
3
0.36 0.17
0.4
26
Rodman Well Sec 27 NW¼ of SW¼
<3
P ND
ND
27
34
Underdown (Henson) Well
Sec 27 SW¼ of SW¼
[ bell Well Sec 26 NW¼ of SW¼
-
-
P -
P -
ND
ND
-
City Well #9 Sec 30 NE¼ of SW¼
-
P -
ND
-
-
Strauch Farm Well
Sec 28 NE¼ of SE¼
Rodman Well Sec 27 NW¼ of SW¼
-
-
0.33 0.25
0.69 ND
ND
ND
-
Henson (Stolp) Well
Sec 25 SW¼ of NW¼
-
0.49 ND
ND
-
Kimball Recreation
Sec 34 NW¼ of SW¼
-
.
0.03 ND
ND
a Analysis by University of Nebraska, Lincoln, Neb.
b Analysis by Federal Water Quality Administration
C Analysis by EPA
d ND = not detected
e P = presumptive data, indicative of picloram but not identified
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Seepage and leaching from the soil are believed to be the principal
causes of herbicide contamination of Kimball ground water. During oil
exploration in the early 1960’s, numerous holes were drilled throughout
Kimball County. Additionally, 52 ground water test holes were drilled
in the County in 1969 and 1970. Although most of these abandoned oil
and water exploration holes have since been filled and capped, it is
possible that surface water has leaked into the aquifer. 5 ’ 6
It is also possible that ground water was contaminated by leaching.
The water table in the area is shallow, ranging from near the land
surface to approximately 60 feet. Picloram leaching is greatest when
soils are low in organic materials and clay content, both of which are
characteristic of the Kimball area. 5 ’ 7
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V. STUDY AREA
Kimball County is in the southwest corner of the Nebraska panhandle.
The City of Kimball is near the center of the county and lies within
Lodgepole Valley [ Fig. 1]. The major land use is agriculture and the
principal crops are beans, potatoes, sugar beets, alfalfa, corn and
other grains. In the past, crops were irrigated from Oliver Reservoir,
Lodgepole Creek, drainage ditches and wells. In the spring of 1976, the
reservoir was drained because the dam.was in need of repair. As a
result, well usage increased and became the primary source of irrigation
water.
The Ogallala is the aquifer from which the majority of wells in the
Kimball area draw. Ground water is depleted by use of these wells, and
additionally by subsurface outflow and plant transpiration. Hydrologic
records indicate that about one—quarter of the water used for irrigation
and minor contributions from precipitation recharge the ground water. 5 ’ 6
Recharge along Lodgepole Creek locally modifies the direction of ground
water flow; however, movement is primarily easterly with a hydraulic gradient
of about 30 feet per mile.
During presurvey reconnaissance in the spring of 1976, thirty-eight
sites were selected for water quality sampling. Eight sites were surface
water and the remaining thirty were wells. Figure 2 shows the location
of sampling sites. A descriptori of the sampling stations is presented
in Table 2.
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SEWAGE LAGO
BENNETT RES.
e
K IMBAL
—
—
— —
—
— — —
— —
D IX
\ — —
1-80
-. — -.
Kimball Count
Figure I. Lodgepole Valley Area, Kimball County, Nebraska
0
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LOCATION
LEGEND
TOWNSHIP 15N RANGE 55W
UNCONTAMINATED SITE
PICLORAM CONTAMINATED SITE
30 SECTION NUMBER
19
20 21 22 23 24
-l
Figure 2. Sampling Stations Kimball County, Nebraska — 1976 (Stations J ..2,3,4,17,38, not shown)
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Table 2
PICLORAM CONCEWTRATIONS IN WATER SAMPLES
FROM KZ fBALL COUNTY, NEBRASKA
March-July 1976
Station Sample Date Station Description Picloram
No. NEICt
(pg/l)
DOWtt
Surface Water
1 4/27 ‘Lodgepole Creek 8 mouth of Oliver Reservoir ND ND
2 4/27 Oliver Reservoir ND ND
3 4/27 Irrigation ditch 8 Hwy 30W of Kimball,
½ mi. E of Lodgepole Wayside area ND ND
4 4/27 Lodgepole Creek @ Hwy 30 W of Kimball ND ND
5’ 4/27 Lodgepole Creek 8 Hwy 71 N of Kimball ND ND
6 4/28 Bennett Reservoir ND ND
7 4/28 Bennett Canal, S of Station #59 ND 0.1
8 7/15 South Cell of Sewage Lagoon ND 0.2
Well Water
9 4/26 Kimball City Well #8 ND ND
10 4/26 Kimball City.Well #4 NO ND
11 4/26 Kimball City Well #11 ND ND
12 4/26 Kimball City Well #14 ND ND
13 4/26 Kimball City Well #5 ND ND
14 4/26 Kimball City Well #7 ND ND
15 4/26 Kimball City Well #6 ND ND
16 4/26 Kimball City Well #3 ND ND
17 4/26 City of Kimball Storage Tank 8 Hwys 71 & 80 ND ND
18 3/25, 4/27 Vogler Well 15N-55W Sec 32 NW¼ of NE¼ ND ND
19 3/25, 4/27 City of Kimball Water Supply 8 greenhouse ND ND
20 4/28 Stahla Well #2 l5N-55W Sec 29 SW¼ of NW¼ ND ND
21 4/28 Stahia Well #1 15N-55W Sec 29 SW¼ of NW¼. ND ND
22 4/27 Mossberg Well 15N-55W Sec 28 NW¼ of SW¼ 2.9 4.3
23 7/14 Rasmussen Well l5N—55W Sec 28 NE¼ of NW¼ ND 0.5
24 7/14 Strauch Well l5N-55W Sec 28 NW of SE¼ 0.05 0.3
25 4/27 Strauch Well 15N-55W Sec 28 NE½ of SE¼ ND ND
26 7/14 Rodman Well 15N-55W Sec 27 NW¼ of SW½ ND 0.1
27 4/28 linderdowri Well #1 15N-55W Sec 27 SW¼ of SW¼ 0.06 0.6
28 4/28 Henson Well #2 15N-55W Sec 34 NW¼ of NW¼ ND ND
29 ‘ 4/28 Henson Well #1 15N-55W Sec 34 SE¼ of NW¼ ND ND
30 4/28 Underdown Well #2 1 5N 55W Sec 27 SW¼ of SE¼ ND ND
31 4/27 Ebel Well l5N-55W Sec 27 Middle of NE¼ ND ND
32 4/28 Everston Well 1 5N—55W Sec 22 SW¼ of SE¼ ND ND
33 4/27 Ebel Well l5N-55W Sec 26 NW¼ of NW¼ ND ND
34 4/27 Ebel Well 15N-55W Sec 26 NW½ of SW¼ 0.1 0.2
35 7/14 Meier Fid Sup Well 15N-55W Sec 26 SW½ of SW¼ ND ND
36 7/14 Robinson Well l5N-55W Sec 26 SW¼ of SE¼ ND 0.2
37 7/15 Vowers Well 15N-55W Sec 25 SE½ of SE¼ ND 0.1
38 4/28 Day Well 15N-57W Sec 32 NW¼ of SW¼ ND ND
t ND = not detected 0 /SIC detection limits ranged 0.05 to 0.2 iig/l)
1-t ND = not detected (Dow Chemical Co. detection limit 0. 1 pg/l)
•11
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VI. RESULTS AND DISCUSSION
FIELD STUDIES
In April and July 1976, field investigations were conducted in
Kimball, Nebraska and the surrounding area to determine the extent of
herbicidal contamination of the water supplies. Thirty-eight water
samples for picloram analyses were collected from the city wells,
irrigation wells and various surface water sources.
The County Weed Control Authority and the County Road Department
spray herbicides on roadsides of thecity and state highways, county
roads, andcity and state parks. Occasionally, they spray picloram on
non-croplands and along county roadsides. Additionally, the Union Pacific
Railroad uses picloram for spot spraying along the railroad tracks.
Picloram was detected in both surface and ground water supplies in
the Kimball area [ Table 2]. Surface water at the Kimball sewage lagoon,
Station 8, contained as much as 0.2 ugh picloram. This is the same
lagoon that was identified as the point source of ground water contamination
in 1968. A review of city and county records revealed no recent application
of picloram near the sewage lagoon and no picloram was detected in the
lagoon from 1968 through 1974 [ Table 1]. Consequently, the picloram
found in the lagoon water during this study is believed to be the result
of picloram—contaminated wastewater entering the lagoon through the
Kimball sewerage system.
The sewage lagoon discharges into Bennett Reservoir which supplies
irrigation water to Bennett Canal. At station 7 in Bennett Canal, as
much as 0.1 pg/i picloram was detected [ Table 2]. In the absence of
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records showing a recent use of picloram near Bennett Canal, it is
assumed that effluent from the sewage lagoon caused this contamination.
Analyses showed well water near Kimball to be contaminated with
picloram. Wells contained concentrations ranging from 0.05 to 4.3 pg/l
[ Table 2]. The source of contamination may be related to the historical
picloram problem, but the continued use of picloram in the Kimball area
is highly suspect. For example, in 1975 the Union Pacific Railroad used
15 pounds of picloram along the right-of-way between Kimball and Dix
(9 miles east of Kimball). In 1976, picloram was detected in eight
wells, seven of which are near the Union Pacific Railroad tracks.
LABORATORY STUDIES
From March to May 1976, bioassays were performed at the NEIC
laboratory in Denver. Ornamental plants (Episcia and Peperornia) and
beans (Phaseolus) were used for the studies. The seven test waters used
in the bioassays were: Kimball city water, which was suspected of
causing the damage at the greenhouses; private well water, now in use at
the greenhouses; Denver city water, as a test reference; and water spiked
with picloram at concentrations of 1,000, 100, 10, and 1 iig/l.
Ornamental plants underwent no unusual morphological changes when
watered with the Kimball water, greenhouse well water, or Denver water.
The plants grew and remained healthy throughout the test.
Bioassays using ornamental plants watered with 1,000 and 100 pg/l
picloram-spiked water showed damage within 20 days. The plants showed’
herbicide damage such as leaf curl and discoloration. Before the end of
the 50-day test the plants died.
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Watering with 10 i.ig/1 picloram-spiked water produced less drastic
effects. At the end of 50 days, the ornamental plants were alive, but
they were underdeveloped. Curled leaves and excessive branching, which
made them distinct from the control plants, appeared between days 30 and
45.
Ornamental plants watered with 1 ug/l picloram-spiked water differed
from the control plants also. Excessive branching especially in Episcia
was the most prevalent symptom. Some leaf curl was also observed and
the plants were underdeveloped. The symptoms were not distinct until
after day 40.
Beans were tested for germination and growth using some of the same
test waters as those used for the ornamental plant bioassays. Beans
kept moist with Denver city water were 97% germinated after 5 days. Two
weeks after planting, these beans averaged 25.5 cm in height. However,
beans kept moist with Kimball city water were only 89% germinated after
5 days, 7% less than beans germinated in ‘Denver city water. Two weeks
after planting, beans watered with Kimball city water averaged 23.0 cm
in height or 14% less growth than beans grown in Denver city water.
Beans kept moist in 1,000 ig/l picloram-spiked water were only 48%
germinated after 5 days and the germinated beans had much less root
development than those moistened with Denver or Kimball water. The
germinated beans were planted and of those that grew, their height
averaged 18.4 cm after two weeks, 39% less than beans watered with
Denver city water and 25% less than beans watered with Kimball city
water. The beans germinated and grown in Denver and Kimball city water
for two weeks were then watered with 1,000 pg/l picloram-spiked water
for one week. Growth of these plants was retarded, the leaves curled,
and the plants died within one week.
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Morphological changes induced by picloram applications were similar
to morphological effects observed in Kimball, Nebraska greenhouses.
In summary, the bioassays showed that picloram concentrations of
1 pg/i or higher cause damage to beans and greenhouse ornamental’ plants.
One of the eight wells in which picloram contamination was detected
contained as much as 4.3 pg/i picioram. If used for irrigation of’
broadleaf plants, this contaminated well water would retard plant growth
and cause other plant damage. The, presence of <1.0 pg/i picloram in
other Kimball wells may constitute a problem; the severity of the
problem was not determined because the lowest picloram concentration
tested in the bioassays conducted by NEIC was 1.0 pg/i.
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VII. METHODS
PICLORAM ANALYSES*
Water samples from 38 stations in the City of Kimball and surrounding
area were collected in duplicate. The samples were collected in 1-liter
polyethylene containers, labeled, and stored under dry ice for trans-
portation to the National Enforcement Investigations Center in Denver,
Colorado, and to Dow Chemical Company in Midland, Michigan for picloram
analysis. The samples remained frozen until they were analyzed.
Extraction
Four hundred ml of water was acidified with 20 ml 85% phosphoric
acid and 110 g of salt was added and dissolved. Picloram was extracted
with 100 ml of ethyl ether followed by an extraction with 40 ml ethyl
ether. Both extracts were combined and concentrated by evaporation to a
volume of about 6 ml. The concentrated extract was then passed through
an anhydrous sodium sulfate drying column in a 140 mm long x 5 mm inside
diameter glass pipet. The extract was then concentrated to 1 nil in a 12
ml graduated centrifuge tube and 0.1 ml of methanol was added.
Esteri ficat ion
The sample extract was esterified with diazomethane following
standardized procedures. 8 The esterified sample was diluted to 10 ml
with hexane.
* Analytical methods described are those used by NEIC.
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Alumina Column Cleanup
Impurities were removedfrom samples using an alumina column to
eliminate gross intereference peaks. Samples in 10 ml of hexane were
added to a 2 x 15 cm column of adsorption alumina which had been de-
activated with 10% water and prewetted with hexane. The column was
eluted with 25% ethyl ether in hexane and three 50 ml fractions were
collected. The fractions were concentrated to 10 ml; an aliquot was
injected into an electron capture gas chromatograph (GC).
Typical recoveries of samples spiked with 0.5 pg/i picloram ranged
from 82 to 87%.
Gas Chromatography/Mass Spectrometry (GC/MS )
The samples were in 10 ml hexane originally, and about 15 to 20% of
the volume of these samples had been expended for GC analysis. To
obtain enough sample for GC/MS analysis (10-20 nanograms), the extracts
were concentrated to 0.05 ml in a 5 ml centrifuge tube on a hot water
bath under a gentle stream of filtered air.
A l-pl sample containing 100 ng of a standard methyl ester of
picloram was analyzed on the GC/MS, and the normal complete mass range
for this compound from 33 to 260 atomic mass units was scanned at optimum
instrument conditions. The atomic mass units of the most prominent ions
in the standard were selected and only these ranges were scanned for a
longer period of time to increase the signal.. This was necessary because
of the very small amounts of sample available. A 4- to 5—pl sample size
was used to increase the signal. The mass spectra generated demonstrated
the presence of the methyl ester of picloram in all positive samples.
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PLANT BIOASSAYS
Healthy cuttings of the ornamental plants Episcia and Peperomia
were divided into seven groups of 6 plants of each type and watered for
50 days with Denver city water, Kimball city water, private well water
used by the greenhouses, or one of four concentrations of picloram-spiked
greenhouse well water.(l, 10, 100, 1,000 pg/l). The Denver water was
tap water from NEIC which was placed in a plastic container and stored
in a refrigerator with the other test waters. The Kimball city water
and private well water were both collected from the greenhouses which had
experienced herbicidal damage, transported to Denver and refrigerated.
During transport and subsequent storage the samples were kept in the
dark to prevent photochemical breakdown of any contaminant. The spiked
test waters were made with picloram (Tordon 22K) purchased from a
Nebraska agricultural chemical company. Each group. of 12 plants
(6 Peperomia and 6 Episcia) was watered with 25 ml every Monday, Wednes-
day, and Friday; fertilized approximately every ten days; incubated at
20°C (68°F); and exposed to 12 hr/day of 300 ft-c incandescent and
fluorescent light.
Great Northern #59 beans were obtained from a Nebraska seed dealer
and used for germination and growth tests. Beans were germinated (100
beans per test) by being kept moist between paper towels soaked with
Denver city water, kimball city water, or greenhouse private well water
spiked with 1,000 pg/I picloram. After five days, germination success
was recorded. Germinated beans were then planted, 2 plants per 2¼-inch
plastic pot or 4 plants per 4-inch plastic pot and watered three times
per week with the water in which they had been germinated. After two
weeks, plant height was measured. Beans watered with Denver and Kimball
city water were then watered with 1,000 ig/l picloram-spiked water for
another week and remeasured. Morphological changes that occurred during
the bioassays were recorded.
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REFERENCES
1. Weidner, Carl W. 1974. Degradation in Groundwater and Mobility of
Herbicides. (Univ. Neb. Lincoln, Dept. of Agronomy.) Nat’l. Tech.
Infor. Serv. PB 239-242. 69 p.
2. Meikel, R. W., C. R. Youngson, R. T,. Hedlung, C. A. I. Goring, J.
W. Hamaker, and W. W. Addington, 1973. Measurement and Prediction
of Picloram Disappearance Rates from Soil. Weed Science, 21 :549-
555.
3. Haas, R. H., C. 3. Scifres, M. G. Merkle, R. R. Hahn, and G. 0.
Hoffman, 1971. Occurrences and Persistence of Picloram in Grassland
Water Sources. Weed Research, ll(1):54-62.
4. National Research Council of Canada, 1972. Picloram: The Effects
of its use as a Herbicide on Environmental Quality. 128 p.
5. Bjorklund, L. 3., 1957. Geology and Groundwater Resources of the
Lower Lodgepole Creek Drainage Basin. Nebraska Geological Water
Supply Paper 1410, 76 p.
6. Smith, F. A., and V. L. Souders, 1971. Occurrence of Groundwater
in Kimball County, Nebraska. Neb. Water Survey Paper No. 29 Univ.
Neb., Lincoln, 133 p.
7. Grover, R., 1973. Movement of Picloram in Soil Columns. Can.
Jour. Soil Sci. 53(3):307-314.
8. 1976 Annual Book of ASTM Standards. Part 31, Water. American
Society for Testing and Materials, Philadelphia, PA. p. 523.
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