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Monitoring of Nitrate and Pesticides in Water in Chickasaw Nation Lands,
Southern Oklahoma
 |
In cooperation with
the Chickasaw Nation |
Figure 1. Extent of the Chickasaw Nation
jurisdictional area, with locations of sampled wells.
Background and Problem
The Chickasaw Nation, with a population of about 39,000 people (Chickasaw
Nation, 2000), is concerned about the quality of ground water in its
jurisdictional area, about 7,648 square miles in south-central Oklahoma (fig.
1). Agriculture is the predominant land use in the area, and the Nation needs
to know about the occurrence of pesticides and nitrate and nitrite in ground
water to formulate a management plan.
Objective
The objective of this study was to conduct ground-water reconnaissance sampling for nitrate plus nitrite and common pesticides for wells in the Chickasaw
Nation. The study will determine if there is evidence of nutrient or pesticide contamination, which may have originated from household
and agricultural activities (Verstraeten and others, 2004; Gilliom and Hamilton, 2006). The study also provided a range of physical parameter values for ground water such as specific conductance, pH, water
temperature, and dissolved oxygen. The analysis results are of direct importance to the well owners and will benefit the residents of the surrounding
area when a pesticide management plan is adopted within the Nation’s jurisdictional area.
Relevance and Benefits
This study provided the Chickasaw Nation with new data on the occurrence
of nitrate plus nitrite and pesticides in ground water and susceptibility of
water resources to contamination by household and agricultural activities in
the Nation's jurisdictional area. It also addressed the USGS priority issue
(Hirsch, 2001) of water quality by providing information to better define and
manage the quality of the Chickasaw Nation's water resources. Furthermore,
the study provided information on pesticide occurrence in an area which the
USGS has never before sampled for pesticides.
Approach
Figure 3. Well house with spigot. |
Seventeen existing wells with powered pumps were selected for sampling by
USGS and Chickasaw Nation staff. Fifteen of these wells were used for
domestic water supply and two were property of the Chickasaw Nation. Sixteen
samples were collected from active wells with spigots (fig. 3) to which
sampling lines could be directly connected to minimize atmospheric contact
and possible contamination during sampling. An additional sample, ADAW2K2,
was collected from an inactive hand-dug well using a portable Grundfos®
pump. Sample bottles were filled inside a sampling chamber consisting of
thick, uncontaminated plastic draped over a PVC pipe framework. Before
sampling, wells were purged until field parameter measurements stabilized.
These measurements were taken with calibrated meters in a sealed flow-through
cell and included specific conductance, pH, temperature, and dissolved oxygen
concentration.
One-liter pesticide sample bottles and 0.25-liter nitrate sample bottles were
sent to the USGS National Water Quality Lab (NWQL) in Lakewood, Colorado. All
17 pesticide samples were tested using analytical schedule 2001 (Zaugg and
others, 1995). Thirteen of the 17 samples also were analyzed using analytical
schedule 2050 (Werner and others, 1996). The remaining four field samples
were analyzed using schedule 2060, which tests for the same pesticides as
schedule 2050, as well as several additional compounds. Pesticides analyzed
and reporting limits are listed in tables 1, 2 and 3. Nitrate analyses, which
were reported as the total concentration of dissolved nitrate and nitrite in
milligrams per liter as nitrogen, were performed using NWQL labcode 1975
(Fishman and others, 1994). |
Table 3. Additional hydrophobic
pesticides and metabolites with reporting limits, USGS Schedule 2060
[reporting limits in parentheses, in micrograms per liter; italics indicate
metabolite or other non-pesticide compound]
| 2,4-D methyl ester (0.0086) |
2-Hydroxyatrazine (0.008) |
3(4-Chlorophenyl)-1-methyl urea (0.024)
|
| 3-Ketocarbofuran (1.5) |
Bendiocarb (0.025) |
Benomyl (0.0038) |
| Bensulfuron-methyl (0.015) |
Caffeine (0.0096) |
Chlorimuron-ethyl (0.0096) |
| Cycloate (0.013) |
Deethyldeisopropylatrazine (0.01) |
Deisopropylatrazine (0.044) |
| Diphenamid (0.026) |
Flumetsulam (0.011) |
Imazaquin (0.016) |
| Imazethapyr (0.017) |
Imidacloprid (0.0068) |
Metalaxyl (0.02) |
| Metsulfuron methyl (0.025) |
Nicosulfuron (0.013) |
Propiconazole (0.021) |
| Siduron (0.016) |
Tribenuron-methyl (0.0088) |
--- |
Results
- Detectable concentrations of nitrate plus nitrite (reported as
nitrogen) were observed in 13 of 17 wells (figs. 2 and 3). One of these
wells, C15MR, had a concentration of about 47 milligrams per liter (as
nitrogen), which exceeds the Maximum Contaminant Level of 10 milligrams
per liter.
- Pesticides were detected in four of the 17 wells (fig. 4). Three of the
four wells had only one detection. The other well, ADAW1BP, had two
detections.
- Though C15MR had the highest nitrate plus nitrite
concentration, it was one of the deeper wells sampled (perforated from
262 to 282 feet).
- Sampled well locations, measured field parameters, nitrate plus nitrite
concentrations, and detected pesticides are listed in table 4.
- Values of specific conductance, pH, dissolved oxygen, and nitrate plus
nitrite concentration are summarized in boxplots in figure 5.
Table 4. Field and laboratory
water-quality measurements for ground-water wells in the Chickasaw Nation
jurisdictional area
[< = less than reporting limit; E = estimated at a
concentration less than reporting limit]
| Field ID |
Date sampled |
Time |
Specific conductance (microsiemens per
centimeter at 25°C) |
pH (standard units) |
Water temperature (Celcius degrees)
|
Dissolved oxygen (milligrams per
liter) |
Dissolved oxygen saturation (percent)
|
Nitrate plus nitrite, dissolved
(milligrams per liter as nitrogen) |
Detected pesticides |
| C14MS |
7/22/2002 |
1700 |
476 |
6.60 |
18.7 |
3.5 |
37.6 |
2.27 |
None |
| ADAW2K2 |
7/30/2002 |
1400 |
221 |
5.98 |
19.9 |
1.3 |
14.7 |
<0.05 |
2-4-DB |
| ADAW1BP |
7/30/2002 |
1000 |
196 |
6.13 |
18.7 |
1.7 |
18.3 |
0.58 |
Carbaryl, Tebuthiuron |
| C107JB |
7/25/2002 |
1400 |
747 |
7.04 |
18.7 |
1.1 |
8.0 |
2.73 |
None |
| C106TP |
7/25/2002 |
1000 |
1,291 |
7.08 |
18.6 |
<0.1 |
0.3 |
0.28 |
Deethylatrazine |
| C5CB |
7/22/2002 |
1500 |
510 |
7.20 |
18.4 |
1.0 |
11.1 |
0.46 |
None |
| C13JU |
7/22/2002 |
1100 |
744 |
7.01 |
19.1 |
3.0 |
34.0 |
1.10 |
None |
| C2DK |
7/26/2002 |
1100 |
757 |
7.05 |
19.9 |
0.2 |
26.1 |
0.12 |
Prometon |
| C16PGJ |
7/24/2002 |
1700 |
709 |
8.03 |
17.4 |
<0.1 |
<0.1 |
E0.04 |
None |
| C108SF |
7/25/2002 |
1700 |
736 |
7.73 |
19.4 |
<0.1 |
<0.1 |
0.85 |
None |
| C8CM |
7/23/2002 |
1100 |
1,196 |
9.31 |
18.9 |
<0.1 |
<0.1 |
<0.05 |
None |
| C105DS |
7/24/2002 |
1400 |
1,683 |
8.83 |
18.5 |
0.4 |
5.4 |
0.08 |
None |
| C11SM |
7/23/2002 |
1300 |
2,160 |
8.87 |
18.2 |
0.1 |
1.1 |
<0.05 |
None |
| C12MH |
7/24/2002 |
1100 |
1,711 |
8.82 |
18.4 |
<0.1 |
<0.1 |
<0.05 |
None |
| C17DB |
7/23/2002 |
1600 |
1,151 |
9.34 |
19.4 |
<0.1 |
<0.1 |
<0.05 |
None |
| C109VM |
7/26/2002 |
1200 |
1,683 |
7.18 |
18.6 |
0.1 |
1.2 |
0.82 |
None |
| C15MR |
7/25/2002 |
1200 |
2,956 |
6.97 |
18.0 |
0.1 |
1.1 |
46.85 |
None |
 
Figure 2. Wells sampled in Garvin and
McClain Counties.
Figure 3. Wells sampled in Pontotoc County.
Figure 4. Frequency of detection of
pesticides in water from wells in Chickasaw Tribal Lands, July 2002.
| Specific Conductance |
Dissolved Oxygen |
 |
 |
| pH |
Nitrate plus Nitrite |
 |
 |
Figure 5. Boxplots of field
measurements and nitrate plus nitrite concentration.
Quality Assurance
This study was conducted in accordance with "A Quality-Assurance Plan for
District Ground-Water Activities of the U.S. Geological Survey" (Brunett and
others, 1997), which addresses methods of collection, processing, analysis,
storage, review, and publication of ground-water data. In addition to the 17
field samples, one duplicate sample was taken to measure the reproducibility
of sample results. An equipment blank, consisting of deionized, distilled
water pumped through the sampling apparatus in a laboratory environment, also
was collected. This type of sample tests the quality of apparatus
decontamination. Finally, another duplicate environmental sample was spiked
with a carefully prepared solution with known concentrations of pesticides to
check for sorption, flocculation, interferences, or other types of
degradation between sample collection and analysis. The spiked pesticide
samples were analyzed using USGS schedules 2001 and 2050. Recovery of
pesticide compounds from the spiked sample are summarized below. No
quality-assurance samples were analyzed using pesticide schedule 2060.
Quality Assurance Summary
- Equipment blank returned no detections of any pesticides.
- No pesticides were detected in the field sample and the duplicate
sample.
- No trace of pesticide was found in the field sample collected
immediately after collection of field spikes.
- Percent recovery of pesticides in field spikes ranged from 10 to 129
percent for USGS schedule 2001 and from 13 to 85 percent for USGS
schedule 2050. A percentile summary of pesticide recoveries can be found
in table 5. Individual pesticide recoveries are reported in table 6.
Pesticides with field spike recoveries near 100 percent are more likely
to be reported accurately in water-quality analyses.
Table 5. Summary of pesticide field
spike recovery for USGS schedules 2001 and 2050
|
Analysis of Pesticide Field Spike Recovery
(%) |
|
USGS Schedule 2001 |
USGS Schedule 2050 |
| MAXIMUM |
128.9 |
85.3 |
| 75th PERCENTILE |
100.8 |
71.1 |
| MEDIAN |
88.8 |
59.2 |
| 25th PERCENTILE |
71.2 |
50.8 |
| MINIMUM |
10.0 |
12.7 |
Table 6. Individual pesticide field
spike recoveries for USGS schedules 2001 and 2050
| USGS pesticide schedule
2001 |
USGS pesticide schedule
2050 |
| Name |
Recovery,
in percent |
Name |
Recovery,
in percent |
| 2,6-Diethylaniline | 97.3 |
2-(2,4,5-Trichlorophenoxy)propionic
acid | 70.3 |
| Acetochlor |
127.3 |
2,4,5-T |
65.2 |
| Alachlor |
102.2 |
2,4-D | 82.1 |
| alpha-HCH |
81.4 |
2,4-DB | 58.4 |
| Atrazine |
90.1 |
3 Hydroxycarbofuran | 19.8 |
| Azinphos-methyl | 65.3 |
4,6-Dinitro-2-methylphenol | 54.0 |
| Benfluralin |
75.8 |
Acifluorfen |
76.5 |
| Butylate |
103.4 |
Aldicarb |
51.0 |
| Carbaryl |
32.4 |
Aldicarb Sulfone | 32.8 |
| Carbofuran |
75.1 |
Aldicarb Sulfoxide | 48.4 |
| Chlorpyrifos |
94.2 |
Bentazon |
78.2 |
| cis-Permethrin | 73.4 |
Bromacil |
66.8 |
| Cyanazine |
99.7 |
Bromoxynil |
85.3 |
| Dacthal |
92.9 |
Carbaryl |
13.4 |
| Deethylatrazine | 42.4 |
Carbofuran |
50.6 |
| Diazinon |
96.7 |
Chloramben, methyl | 19.0 |
| Dieldrin |
85.3 |
Chlorothalonil | 22.6 |
| Disulfoton |
14.6 |
Clopyralid |
67.6 |
| EPTC | 92.2 |
Dacthal monoacid | 72.0 |
| Ethalfluralin | 80.8 |
Dicamba | 76.3 |
| Ethoprophos |
72.6 |
Dichlobenil |
51.5 |
| Fonofos | 20.6 |
Dichlorprop |
76.5 |
| Lindane |
79.1 |
Dinoseb |
78.2 |
| Linuron |
111.0 |
Diuron | 68.4 |
| Malathion |
31.1 |
Fenuron | 55.3 |
| Metolachlor |
101.9 |
Fluometuron |
65.3 |
| Metribuzin |
68.1 |
Linuron | 70.0 |
| Molinate |
96.0 |
MCPA | 65.1 |
| Napropamide |
118.9 |
MCPB | 57.3 |
| p,p'-DDE |
56.8 |
Methiocarb |
12.7 |
| Parathion |
90.0 |
Methomyl |
64.4 |
| Parathion-methyl | 85.3 |
Neburon | 59.2 |
| Pebulate |
92.0 |
Norflurazon |
58.1 |
| Pendimethalin | 73.6 |
Oryzalin |
38.6 |
| Phorate | 10.0 |
Oxamyl | 53.0 |
| Prometon |
88.8 |
Picloram |
77.1 |
| Propachlor |
126.6 |
Propham | 54.2 |
| Propanil |
107.6 |
Propoxur |
48.3 |
| Propargite |
54.5 |
Triclopyr |
80.4 |
| Propyzamide |
106.0 |
--- | --- |
| Simazine |
48.4 |
--- | --- |
| Tebuthiuron |
117.5 |
--- | --- |
| Terbacil |
128.9 |
--- | --- |
| Terbufos |
117.3 |
--- | --- |
| Thiobencarb |
96.2 |
--- | --- |
| Tri-allate |
87.9 |
--- | --- |
| Trifluralin |
69.8 |
--- | --- |
Selected References
Brunett, J.O., Barber, N.L., Burns, A.W., Fogelman, R.P.,
Gillies, D.C., Lidwin, R.A., and Mack, T.J., 1997, A quality-assurance plan
of District ground-water activities of the U.S. Geological Survey: U.S.
Geological Survey Open-File Report 97-11, 41 p.
Chickasaw Nation, 2000, Socio-Geographic Reference and Guide,
accessed February 18, 2000, at URL: http://www.chickasaw.net/government/
socioreference.htm
Fishman, M.J., Raese, J.W., Gerlitz, C.N., and Husband, R.A.,
1994, U.S. Geological Survey approved inorganic and organic methods for the
analysis of water and fluvial sediment, 1954-94: U.S. Geological Survey
Open-File Report 94-351, 55 p.
Gilliom, R.J., and Hamilton, P.A., 2006, Pesticides in the Nation's streams
and ground water, 1992-2001 - a summary: U.S. Geological Survey Fact Sheet 2006-3028, March 2006, 6 p.
Hirsch, R.M., 1995, Avoiding Competition with the Private
Sector: U.S. Geological Survey Water Resources Division Memorandum No.
95.44, July 7, 1995, 3 p.
Hirsch, R.M., 2001, Priority Issues for the Cooperative Water
Program, Fiscal Year 2002: U.S. Geological Survey Water Resources
Discipline Information Memorandum No. 2002.01, October 15, 2001, 4 p.
Verstraeten, I.M, Fetterman, G.S., Sebree, S.K., Meyer, M.T., and Bullen,
T.D., 2004, Is septic waste affecting drinking water from shallow domestic wells along the
Platte River in eastern Nebraska?: U.S. Geological Survey Fact Sheet 072-03, January 2004, 4 p.
Werner, S.L., Burkhardt, M.R., and DeRusseau, S.N., 1996,
Methods of analysis by the U.S. Geological Survey National Water Quality
Laboratory; determination of pesticides in water by Carbopak-B solid-phase
extraction and high-performance liquid chromatography: U.S. Geological
Survey Open-File Report 96-216, 42 p.
Zaugg, S.D., Sandstrom, M.W., Smith, S.G., and Fehlberg, K.M.,
1995, Methods of analysis by the U.S. Geological Survey National Water
Quality Laboratory; determination of pesticides in water by C-18
solid-phase extraction and capillary-column gas chromatography/mass
spectrometry with selected-ion monitoring: U.S. Geological Survey Open-File
Report 95-181, 49 p.
| 
U.S. Department of the Interior |
U.S. Geological Survey
