Minnesota National Lakes Assessment:
Pesticides in Minnesota Lakes
This report is part of a series based on Minnesota’s
participation in U.S. Environmental Protection Agency’s
2012 National Lake Assessment
January 2014
MAU-14-102
Minnesota Department of Agriculture
625 Robert Street North
Saint Paul, MN 55155-4194
http://www.mda.state.mn.us/index.htm
651-201-6000 or 800-967-2474
TTY: 1-800-627-3529 -800-627-3529
651-201-
Authors and Contributors
Minnesota Department of Agriculture
Pesticide and Fertilizer Management Division
Monitoring and Assessment Unit
David Tollefson
Hydrologist
Matthew Ribikawskis
Hydrologist
Bill VanRyswyk
Hydrologist
ACKNOWLEDGEMENTS
The following agencies and individuals were critical to the collection of samples,
laboratory analysis, and report review.
MDA Laboratory Water Analysis Unit
Minnesota’s 2012 National Lakes Assessment was led by MPCA’s Lake and Stream
Monitoring Unit. Team leads for the survey, which included responsibility for field
reconnaissance, assembling and purchasing needed equipment, office logistics, and
sampling of the lakes was led by Pam Anderson, Jesse Anderson, Kelly O’Hara, Lee
Engel, Dereck Richter, and Steve Heiskary. Amy Garcia and Courtney Ahlers-Nelson
(Lake and Stream Monitoring Unit), Mike Kennedy and Andrew Swanson (Duluth
Watershed Unit), and student workers Will Long and Ben Larson also assisted with the
sampling.
Report Review: Loretta M. Ortiz-Ribbing (MDA), Heather Johnson (MDA), Brennon
Schaefer (MDA) & Steve Heiskary (MPCA)
In accordance with the Americans with Disabilities Act, this information is available in alternative forms of communication upon
request by calling 651/201-6000. TTY users can call the Minnesota Relay Service at 711 or 1-800-627-3529.
The MDA is an equal opportunity employer and provider.
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Contents
Abstract ............................................................................................................................ 1
1.0 Introduction ............................................................................................................... 1
2.0 Background ............................................................................................................... 2
3.0 Previous Investigations ............................................................................................. 3
3.1 Lake and Reservoir Pesticide Monitoring Studies ................................................ 3
3.2 Precipitation Pesticide Monitoring Studies ............................................................... 6
3.3 Pesticide Persistence in Lakes .................................................................................. 8
3.3.1 Seasonality of Pesticides in Lakes ..................................................................... 8
3.3.2 Annual Variation of Pesticide Detections within a Specific Lake ................... 10
4.0 Methods................................................................................................................... 11
4.1 Lake Selection ..................................................................................................... 11
4.2 Sampling Protocol ................................................................................................... 13
4.3 Analytical Methods ................................................................................................. 14
4.3.1 MDA Laboratory GC-MS and LC-MS/MS Methods ...................................... 14
4.3.2 Atrazine ELISA Method .................................................................................. 14
4.3.3 USEPA Triazine Screen ................................................................................... 15
4.4 Data Analysis .......................................................................................................... 15
4.4.1 Comparing Lakes with Rivers and Streams Monitoring.................................. 15
4.4.2 Dominant Land Use ......................................................................................... 15
5.0 Results and Discussion ........................................................................................... 16
5.1 Detected Compounds and Frequency of Detection ............................................ 16
5.2 Comparison between 2007 and 2012 NLA results ............................................. 20
5.3 Comparison between Atrazine ELISA and GC-MS Method Results ................. 21
5.4 Comparing Lake Results with Rivers/Streams Results by Region ..................... 22
5.5 Land Use Results ................................................................................................ 23
6.0 Conclusions ............................................................................................................. 25
References: .................................................................................................................... 26
Appendix 1:................................................................................................................... 28
Table A1: 2007 NLA Detected Pesticide Compounds ............................................. 28
Appendix 2 .................................................................................................................... 30
Table A2: 2012 NLA Detected Pesticide Compounds ............................................. 30
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Figures
Figure 1. Minnesota sales information for selected pesticides, 1996-2011. ....................... 3
Figure 2. Median monthly pesticide concentration in precipitation samples collected
from Crystal Springs (1998-2005) in southeast Minnesota, Little Cobb (20082012) in south central Minnesota, and Rochester MDA office (2009-2012) in
southeast Minnesota. ............................................................................................ 8
Figure 3. Pesticide concentration seasonality from lakes sampled early (May and June)
and late (October) in the 2009 open water season. ............................................ 10
Figure 4. Annual variation in concentrations of selected herbicide compounds from three
lakes sampled in 2009, 2010, and 2011. Please note differences in y-axes. ...... 11
Figure 5. Lake pesticide monitoring locations for 2012 NLA in Minnesota. ................... 13
Figure 6. Total number of pesticide compounds detected (6a) and total concentrations
(µg/L) (6b) using MDA GC-MS and LC-MS/MS methods. ............................. 18
Figure 7. 2012 NLA atrazine concentration (µg/L) levels for 125 lakes using the ELISA
screening method. .............................................................................................. 19
Figure 8. Comparison of detection frequencies for herbicide compounds between 2007
and 2012 NLA in Minnesota.............................................................................. 20
Figure 9. Maximum concentrations of pesticide compounds from the 2007 and 2012
NLA in Minnesota. Note Maximum concentrations that were reported as
"Present below MRL" are shown graphically as one-half of the MRL.............. 21
Figure 10. Comparison of ELISA and GC-MS atrazine results as part of the 2012 NLA
in Minnesota....................................................................................................... 22
Figure 11. Median concentration of atrazine in NLA lakes compared with rivers and
streams sampled in 2012 by pesticide monitoring region (PMR). Note:
Medians that were reported as “Present below MRL” are shown graphically
as one-half of the MRL (0.025 µg/L). ................................................................ 22
Figure 12. Number of pesticide compound (parent and /or degradate) detections by the
dominant land use category in each lakeshed. ................................................... 23
Figure 14. Mean, minimum, and maximum total pesticide (parent + degradate)
concentration by the dominant land use category in each lakeshed. ................. 24
Figure 15. Maximum atrazine concentration by the domainant land use category in each
lakeshed.............................................................................................................. 24
Tables
Table 1. Detection limits and frequency of selected herbicide analytes in pretreated water
sampled from Midwest lakes and reservoirs (Acetochlor Registration
Partnership; ARP). ............................................................................................... 4
Table 2. Pesticide detection concentration distribution and applicable water quality
reference values for detected pesticide compounds, 2007 NLA in Minnesota.... 5
Table 3. Minnesota lake distribution and 2012 NLA lake selection by PMR. ................. 12
Table 4. MDA GC-MS and LC-MS/MS analytical methods laboratory analyte list........ 15
Table 5. 2012 NLA pesticide detections, concentrations, water quality standards, and
reference values using GC-MS and LC-MS/MS for detected compounds. ....... 17
Table 6. 2012 NLA summary detection statistics for atrazine ELISA lake sampling. ..... 19
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Abbreviations
µg/L
ARP
BMP
ELISA
GC-MS
LC-MS/MS
MDA
MN DNR
MPCA
MRL
n
nd
NLA
OPP
P
PMR
ug/L
USDA
USEPA
USGS
WEAL
WI DATCP
Microgram per liter (equivalent to one part per billion of water sample or ppb)
Acetochlor Registration Partnership
Best Management Practice
Enzyme-Linked Immunosorbent Assay
Gas Chromatography with Mass Spectrometry
Liquid Chromatography with tandem Mass Spectrometry
Minnesota Department of Agriculture
Minnesota Department of Natural Resources
Minnesota Pollution Control Agency
Method Reporting Limit
Number of samples collected
Not detected
National Lake Assessment
Office of Pesticide Products
Present but below the Method Reporting Limit
Pesticide Monitoring Region
Microgram per Liter (the same as µg/L and equivalent to parts per billion or ppb)
United States Department of Agriculture
United States Environmental Protection Agency
United States Geological Survey
Water and Environmental Analysis Laboratory (University of Wisconsin –
Stevens Point)
Wisconsin Department of Agriculture, Trade, and Consumer Protection
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Abstract
In 2012, as part of the National Lakes Assessment (NLA), the Minnesota Department of
Agriculture (MDA) cooperated with the Minnesota Pollution Control Agency (MPCA) in
a statewide assessment of pesticides in Minnesota lakes. Fifty-two lakes were analyzed
using the MDA laboratory’s gas chromatography-mass spectrometry (GC-MS) and liquid
chromatography-tandem mass spectrometry (LC-MS/MS) advanced methods for onehundred and thirty-two different pesticide compounds. Nineteen different pesticide
compounds were detected, with atrazine being discovered most frequently in 67 percent
of samples. All pesticide compound detections were herbicides. Pesticides and/or
degradates were detected in 85 percent of the samples collected. An atrazine enzymelinked immunosorbent assay (ELISA) method was utilized to analyze samples collected
from an additional 122 lakes. All pesticide detections were well below established state
water quality standards or United States Environmental Protection Agency (USEPA)
reference values. Pesticide detections were widespread and included lakes in nonagricultural areas of the state, however, lakes in agricultural areas of the state tended to
have more compounds detected at higher concentrations. Atmospheric deposition of
pesticides was suspected as the primary transport mechanism in non-agricultural areas.
1.0 Introduction
Minnesota, known as “The Land of 10,000 Lakes,” has a history and heritage linked to its
abundant water resources. These valued natural resources are used and promoted by a
vibrant tourism industry. Minnesota, a major agricultural state, ranked fourth nationally
in the production of corn and third nationally in the production of soybeans in 2012
(USDA, 2013). Both water-based recreation and agriculture are key contributors to
Minnesota’s economy.
Over the last several years, in the western Corn Belt of the United States, there has been
an increase in the amount of acres used in corn and soybean production (Wright, 2013).
For the purpose of this report, it was assumed that these additional acres, transitioned into
row crop production from grassland, had pesticide applications consistent with existing
cropping systems. In 2008, two surface water impairments caused by a corn herbicide
(acetochlor) were identified and placed on the 303(d) list of the state’s impaired waters
maintained by the Minnesota Pollution Control Agency (MPCA). In 2012, an additional
pesticide water quality impairment was identified in Minnesota for chlorpyrifos, an
organophosphate insecticide (MPCA, 2013). All pesticide water quality impairments
have occurred on rivers and/or streams; no Minnesota lakes are listed on the impaired
waters list for pesticides. Acetochlor and chlorpyrifos, along with atrazine, have been
identified as “surface water pesticides of concern” by the Minnesota Commissioner of
Agriculture.
The objective of this report is to 1) provide background and discuss previous research
related to pesticide monitoring in lakes and reservoirs in the United States Corn Belt, 2)
provide an overview of methods used in the 2012 National Lakes Assessment (NLA), and
3) present results and conclusions of the 2012 NLA with previous studies. This report of
145 randomly surveyed lakes was completed in conjunction with the United States
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Environmental Protection Agency’s NLA. The NLA is part of US EPA’s National
Aquatic Resources Surveys (NARS). NARS is intended to allow for statistically based
condition assessments for lake, stream, wetland, and coastal resources across the Nation.
Surveys are conducted on a rotating five-year basis. Lakes were first included in 2007
and 2012 represented the second national assessment for lakes. The Minnesota
Department of Agriculture provided laboratory analytical services and data analysis for
the pesticide samples. In 2012, two different pesticide methods were used by MDA to
analyze samples and each will be presented separately.
2.0 Background
The MDA has been monitoring pesticides in Minnesota groundwater since 1985 and
surface water since 1991. Annually, MDA collects approximately 600 to 800 samples
from rivers, streams, and lakes across the state. In general, MDA targets pesticides that
were widely used and/or posed the greatest risk to water resources. The purpose of
MDA’s pesticide monitoring program is to determine the presence and concentration of
pesticides in Minnesota waters from routine use. Samples are collected statewide when
the greatest potential for pesticide occurrence in surface water exists.
The surface water portion of MDA’s pesticide monitoring program has historically
focused on streams and rivers, specifically systems which drain from agricultural areas of
Minnesota. Based on historic pesticide monitoring data, streams and rivers were the
focus of MDA pesticide monitoring efforts because they were generally regarded to be at
greater risk from land-applied pesticides than lakes. Annually, approximately 60 river
and stream locations are sampled with varying levels of intensity. Statewide lake
pesticide monitoring in Minnesota began in conjunction with the 2007 NLA. MDA also
conducted limited statewide lake monitoring from 2008 through 2011.
Sales (in pounds) of one insecticide and selected herbicides in Minnesota from 1996
through 2011 (MDA, 2013b) remained relatively steady (Figure 1). However, glyphosate
showed a steady increase in the amount of product sold in Minnesota. With the increased
use of corn herbicides formulated with glyphosate as their active ingredient, sales of
historically popular corn herbicides, such as those containing atrazine and acetochlor as
their active ingredients, have declined slightly since the early 2000’s.
MDA conducted an expanded outreach and regulatory effort to educate Minnesota
pesticide applicators on pesticide product label requirements and voluntary Best
Management Practices (BMPs) for water-quality protection targeted specifically towards
the use of herbicides containing atrazine and acetochlor. These outreach efforts have
been expanded to include insecticides (e.g., chlorpyrifos). Chlorpyrifos has not been
detected in any Minnesota lake by MDA.
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Figure 1. Minnesota sales information for selected pesticides, 1996-2011.
3.0 Previous Investigations
3.1 Lake and Reservoir Pesticide Monitoring Studies
From 1992 through 1995, the MDA cooperated with the Minneapolis Park and
Recreation Board, United States Geological Survey (USGS) and the Minnesota Grey
Freshwater Institute in a study of Lake Harriet, an urban lake located in Minneapolis,
Minnesota. The purpose of the study was to evaluate the presence of 26 commonly used
urban and agricultural pesticides in the watershed. Herbicides detected in Lake Harriet
included 2,4-D, MCPP and atrazine. Rainfall samples collected within the watershed in
1993 indicated detectable levels of alachlor, atrazine, cyanazine, and metolachlor in 54
percent, 71 percent, 42 percent, and 46 percent of the samples collected, respectively.
Atmospheric deposition was identified as the primary transport mechanism of the
agricultural pesticides detected in the urban area evaluated.
One of the largest studies of pesticides in lakes and reservoirs of the Corn Belt region of
the United States was conducted by the Acetochlor Registration Partnership (ARP). In
1995, the ARP implemented a multi-year, multi-analyte monitoring program to satisfy
the conditions of the USEPA acetochlor registration. The ARP study sampled surface
water bodies used as drinking water sources throughout the Midwest and included lakes
and reservoirs in Illinois, Indiana, Iowa, Kansas, Nebraska, Missouri, Ohio, and
Wisconsin. Results indicate that detection frequencies for these compounds ranged from
100 percent for atrazine to 21 percent for acetochlor (Table 1). In addition, there are three
years of monitoring data available for their primary degradates (1999-2001). Watershed
sizes for these 31 sites varied from 208 acres to more than 28 million acres. Land in corn
production ranged from 13 percent to 45 percent in these watersheds. Fourteen samples
were collected annually from each site, biweekly through the spring and summer months,
and quarterly during the fall and winter (Gustafson, 2008).
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Table 1. Detection limits and frequency of selected herbicide analytes in pretreated water sampled from
Midwest lakes and reservoirs (Acetochlor Registration Partnership; ARP).
Analyte (years monitored)
Acetochlor (1995-2001)
Atrazine (1995-2001)
Metolachlor (1995-2001)
Acetochlor-ESA (1999-2001)
Acetochlor-OXA (1999-2001)
Metolachlor-ESA (1999-2001)
Metolachlor-OXA (1999-2001)
Limit of Detection (µg/L)
0.03
0.03
0.03
0.2
0.1
0.2
0.1
Detection Frequency
21%
100%
61%
32%
58%
70%
77%
In 2005, the Wisconsin Department of Agriculture, Trade and Consumer Protection
(WI DATCP) completed a survey of atrazine in 53 lakes in agricultural areas of
Wisconsin using enzyme linked immunosorbent assay (ELISA) methods. Atrazine was
detected in more than 90 percent of the lakes with concentrations ranging from nondetect (<0.10 µg/L) to 0.40 µg/L. Concentrations were greater where agriculture
represented greater than 75 percent of the surrounding land use (Allen, 2006).
In 2007, MDA worked cooperatively with MPCA and USEPA to conduct pesticide
monitoring for the 2007 NLA. During this study, 53 lakes were sampled in a manner
similar to the methods used for the 2012 NLA, which are discussed in this report.
Additional information on the location of lakes, methods, and results are available in the
2008 report, “Pesticides in Minnesota Lakes” (MDA, 2008). Of the 55 samples collected
as part of the 2007 NLA, four pesticides and seven pesticide degradate compounds (all
herbicides) were detected at concentrations well below the applicable water quality
standards (Table 2). Atrazine was the most frequently detected compound in 2007, being
detected in 87 percent of samples. Acetochlor and metolachlor were detected in only 2
and 4 percent of the samples respectively; however, the degradates of these two
pesticides were detected more frequently and at higher concentrations than the parent
compound. The 2007 NLA detection statistics and current aquatic life reference values
are presented in Table 2. Appendix 1 contains the 2007 NLA results for all detected
compounds.
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Table 2. Pesticide detection concentration distribution and applicable water quality reference values for detected pesticide compounds, 2007 NLA in Minnesota.
Detection Concentration Distribution (µg/L)
Pesticide Name
Pesticide
Type
Detects
Total
Samples
Detection
Frequency
Median
75th
%-tile
90th
%-tile
Acetochlor
Herbicide
1
55
2%
nd*
nd
nd
Acetochlor ESA
Degradate
9
55
16%
nd
nd
0.146
Acetochlor OXA
Degradate
10
55
18%
nd
nd
0.14
Alachlor ESA
Degradate
9
55
16%
nd
nd
0.106
Atrazine
Herbicide
48
55
87%
P
0.05
0.06
Deisopropylatrazine
Degradate
1
55
2%
nd
nd
nd
Desethylatrazine
Degradate
36
55
65%
P
P
0.05
Dimethenamid
Herbicide
2
55
4%
nd
nd
nd
Metolachlor
Herbicide
2
55
4%
nd
nd
nd
Metolachlor ESA
Degradate
15
55
27%
nd
0.075
0.196
Metolachlor OXA
Degradate
4
55
7%
nd
nd
nd
* “nd” indicates non-detect or the median concentrations were below the method reporting limit (MRL).
** “P” indicates the compound was present but at a concentration below MRL presented in Table 3
95th
%-tile
Maximum
nd
0.277
0.258
0.144
0.076
nd
0.05
nd
nd
0.287
0.1
P**
0.71
1.02
0.22
0.68
P
0.18
P
P
0.88
0.28
Water Quality Standards and/or Reference Values (µg/L)
MPCA Lake
Water
Chronic
Standard2
3.6 T
─
─
─
3.4 H; 10 T
─
─
─
23 T
─
─
MPCA
Maximum
Standard3
EPA Acute Value
Aquatic Life
Benchmark (μg/L)1
EPA Chronic Value
Aquatic Life
Benchmark (μg/L)1
─
─
─
─
─
─
─
─
271 T
─
─
na
> 62,500 (i)
─
52,000 (f)(i)
na
8,500 (f)
─
3,150 (f)
na
24,000 (f)
7,700 (i)
na
9,900 (n)
─
─
na
2,500 (n)
1,000 (n)
5.1 (v)
na
> 95,100 (v)
57,100 (n)
Table 2 key to value types and symbols in surface water reference values
(─ ) – For some analytes, reference values have not been identified or evaluated
(n) – USEPA/OPP benchmark value for nonvascular plants
na – not applicable
(v) – USEPA/OPP benchmark value for vascular plants.
(f) – USEPA/Office of Pesticide Products (OPP) benchmark value for fish.
(H) – “H” Chronic Standard values are human health-based and protective for an exposure duration of 30 days.
(i) – USEPA/OPP benchmark value for invertebrates.
(T) – “T” Chronic Standard values are toxicity-based for aquatic organisms and protective for an exposure duration of 4 days.
1
Aquatic Life Benchmarks based on toxicity values derived from data available to the USEPA OPP supporting registration of the pesticide are provided only when an MPCA value is not available.
Current values posted by the USEPA’s OPP may differ from those of previous MDA reports. See USEPA’s web site for more detailed information and definitions.
2
Chronic Standard as defined in Minn. Rule Chap. 7050. “H” value is human health-based and is protective for an exposure duration of 30 days. Human health-based values are shown only when
they are less than toxicity-based values. “T” value is toxicity-based for aquatic organisms and is protective for an exposure duration of 4 days.
3
Maximum Standard Value for Aquatic Life & Recreation as defined on MPCA’s web site and Minn. Rule Chap. 7050. Values are the same for all classes of surface waters.
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3.2 Precipitation Pesticide Monitoring Studies
An interesting characteristic of the lake pesticide data collected in Minnesota since 2007
was the presence of pesticides in lakes that were located long distances (greater than 100
miles) from areas of intensive row crop agricultural activity. Previous studies (Sun et al.,
2006, Carlson et al., 2004 and Vogel et al., 2008) have indicated that pesticides can be
transported long distances in the atmosphere. Sun et al. (2006) also suggested that there
were local and regional influences on pesticide concentrations in precipitation. These
studies highlight the presence of pesticides in precipitation, and provide context for
remote lakes that had a pesticide compound detected.
In association with the Lake Harriett study (discussed above), the MDA cooperated with
the USGS in evaluating wet atmospheric deposition of pesticides in Minnesota between
1989 and 1994 (Capel et al., 1998). More than 350 precipitation samples were collected
from several random sites across Minnesota. During the study, all precipitation samples
had detectable concentrations of at least one pesticide compound. The most frequently
detected compounds were alachlor, atrazine, cyanazine and metolachlor, all of which
were active ingredients of corn herbicides. Acetochlor was detected in precipitation in
1994, which was also the first year acetochlor was registered for use in Minnesota.
Pesticide concentrations in precipitation indicated a seasonal peak following the pesticide
application periods and concentrations were highest in agricultural areas.
A USGS study conducted in the late 1990’s examined the atmospheric transport and
deposition of commonly used herbicides in the “Corn Belt” of the United States. This
study analyzed 6,230 rainfall samples collected from random sites located throughout the
Midwest and Northeast United States. ELISA results of 5,927 samples found that
30.1 percent of samples had triazines (i.e., atrazine, etc.) and/or acetanilides (i.e.,
acetochlor, metolachlor, etc.) present. Atrazine was present in 30.2 percent and alachlor
was present in 19.2 percent of the samples (n=2,085 samples) screened by ELISA and
analyzed by gas chromatography with mass spectrometry (GC/MS) methods. These two
compounds were detected most frequently. The concentrations of each pesticide
measured in rainfall varied with climatic conditions, but ultimately increased during
periods of pesticide applications and were greatest in rain that occurred during small
rainfall events. Overall, rainfall-weighted average concentrations during the application
period of mid-April through mid-July yielded concentrations of both atrazine and
alachlor in rainfall of 0.2 to 0.4 µg/L. Higher concentrations of atrazine and alachlor
were reported in areas of higher use (Iowa, Illinois, and Indiana) indicating a decrease in
the amount of pesticides in the atmosphere as the distance from the source increased
(Goolsby, 1997). Goolsby (1997) concluded “herbicides can be transported into the
atmosphere by volatilization and entrainment on dust particles and then dispersed by air
currents for possible re-deposition on watersheds at considerable distances from their
application.”
A 2000 study conducted by the University of Maryland and the United States Department
of Agriculture (USDA) in the Chesapeake Bay area, examined atmospheric deposition of
pesticides into the Choptank River. The study concluded that 3 to 20 percent of
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metolachor in the Choptank River was deposited via wet atmospheric deposition. In
addition to metolachor, pesticide compounds including chlorothalonil, atrazine, simazine,
endosulfan, and chlorpyrifos were detected in both dry and wet deposition. The
concentration of these chemicals and their usage in the local area of this study, predicted
atmospheric deposition was a significant source of agricultural pesticides in surface
waters (Kuang et al., 2003).
The MDA has continued to conduct precipitation monitoring as part of their routine
pesticide monitoring program, reporting the median monthly concentrations for the three
most frequently detected pesticides (acetochlor, atrazine and metolachlor) in rainfall
(Figure 2). Data collected from three different locations and monitoring periods (Crystal
Springs near Altura, MN from 1998-2005, Little Cobb near Mankato, MN from 20082012, and Rochester, MN from 2009-2012) showed strong seasonality in the relative
concentration of these pesticides, generally associated with the pesticide’s application
period in Minnesota. In addition, the results showed some variation in median monthly
concentrations among the sites that were likely related to local land use differences. For
example, the Little Cobb location is located in an agricultural area and has higher
monthly median acetochlor concentrations in April and May than the Rochester location,
located in the city of Rochester. Generally pesticides that were frequently detected in
Minnesota surface waters were also detected in precipitation collected across southern
Minnesota. These data indicated that pesticides moved through the atmosphere and were
deposited with precipitation in Minnesota. In some lakes this may be an important
transport pathway. Further information regarding the current precipitation monitoring
stations can be found within the MDA Monitoring and Assessment Unit’s annual reports
(MDA 2009, MDA 2010, MDA 2011, MDA 2012, and MDA 2013a) at:
http://www.mda.state.mn.us/monitoring.
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Figure 2. Median monthly pesticide concentration in precipitation samples collected from Crystal Springs (19982005) in southeast Minnesota, Little Cobb (2008-2012) in south central Minnesota, and Rochester MDA office
(2009-2012) in southeast Minnesota.
3.3 Pesticide Persistence in Lakes
Following the 2007 NLA, MDA continued to monitor for pesticides in a limited number
of lakes from 2008 through 2011. MDA worked cooperatively with several agencies
including the Minnesota Department of Natural Resources (MN DNR), MPCA, and
USGS to select lakes that were part of on-going research studies including the Sentinel
Lakes Program, MPCA’s Intensive Watershed Assessment program, and multiple
endocrine disruptor studies. Due to the differences between the NLA random survey
design, and the targeted approach of these other studies, the 2008-2011 data are included
in this section only. All of these pesticide data are available within the MDA Monitoring
and Assessment Unit’s annual reports (MDA 2009, MDA 2010, MDA 2011, MDA 2012,
and MDA 2013a) available online at: http://www.mda.state.mn.us/monitoring
3.3.1 Seasonality of Pesticides in Lakes
The stability or persistence of pesticide parent compounds once they enter a lake system
is not well understood. Persistence is influenced by the conditions of the aquatic
environment primarily temperature and sunlight, the presence of various microorganisms
and the chemical and physical properties of the particular pesticide. The NLA study
design consisted of randomly selected lakes, with a single sample collection event for
most lakes, during the summer of each NLA sample year. The NLA design did not allow
for MDA to examine if pesticide concentrations within a particular lake varied across the
open water season. MDA’s stream monitoring program indicated strong seasonality with
respect to pesticide concentration and presence throughout the spring and summer with
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peak concentrations following the primary pesticide application periods in May and June
(MDA 2009, MDA 2010, MDA 2011, MDA 2012, and MDA 2013a).
To further evaluate seasonality of pesticides in lakes, six lakes were sampled twice, in
2009, in conjunction with the Minnesota Sentinel Lakes Program. For each lake, the first
sample was collected in May or June and the second sample was collected in September
or October. These two periods represented typical pre- and post- pesticide application
timings. Although these data were not collected with a NLA survey, the results were
valid for understanding pesticide occurrence and degradation dynamics in Minnesota
lakes throughout the open water season.
Of the six lakes that were sampled, only four lakes had a pesticide compound detected.
For the analysis completed for this paper, the concentrations of the parent compounds of
acetochlor and atrazine and the degradate compounds of acetochlor ESA and metolachlor
ESA where compared from the two lake sampling events in 2009 (Figure 3). Acetochlor
and atrazine results that were reported as “Present but below the method reporting limit
(MRL)” are shown graphically as one-half the MRL (0.025 µg/L). Acetochlor was
detected at very low concentrations in three lakes in the early open water season sample
and was not detected in any of the late open water season samples. Atrazine was also
detected at very low concentrations in all four lakes in the early open water season
sample, but was only detected in a single lake (St. Olaf Lake) in the late open water
season sample (0.06 µg/L). St. Olaf Lake also had the highest atrazine concentration
(0.08 µg/L) in the early season sample. For the pesticide degradates acetochlor ESA and
metolachlor ESA, all concentrations were lower in the late season than the early season
sample. The acetochlor ESA concentrations were 3 percent to 10 percent lower, and
metolachlor ESA concentrations were 15 percent to 30 percent lower between sampling
periods. All compounds detected in Minnesota lakes in 2009 were also detected in
Minnesota lakes in the 2007 and 2012 NLA.
Based on these results, it appears degradation of the pesticide compounds occurred
throughout the summer; however, all concentrations were low relative to applicable
surface water reference values. These results bracket the open water season in Minnesota
and provide evidence that, under normal conditions, sampling lakes once for pesticides
during the months of June, July or August, will result in data that represents the entire
open water season.
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Pesticides in MN Lakes 11/2013
Minnesota Department of Agriculture
9
Figure 3. Pesticide concentration seasonality from lakes sampled early (May and June) and late (October) in the
2009 open water season.
3.3.2 Annual Variation of Pesticide Detections within a Specific Lake
The year-to-year annual pesticide detection variability in a specific lake is not well
understood. The NLA was conducted on a five year rotation and different lakes were
selected in each sampling round. The MDA was interested in the annual differences in
pesticide detections within a specific lake. Therefore, between 2009 and 2011, returning
to some of the same lakes for repeated sampling over multiple years provided value for
determining whether the five year NLA cycle was adequate to use as a statewide
assessment of pesticides in Minnesota lakes. Significant laboratory resources are
required for pesticide analysis and this annual variability review was used to guide MDA
pesticide lake sampling efforts between NLA surveys.
Three lakes were included in this analysis: Artichoke, Carrie, and St. Olaf. These lakes
were all sampled in 2009, 2010, and 2011. In 2009, to examine the seasonality of
pesticides in these three lakes, samples were collected twice per year; one in late spring
and one in the fall. For the analysis completed for this paper, only the spring sample
from 2009 will be included to be consistent with the timing of the 2010 and 2011
sampling. Atrazine, acetochlor, acetochlor ESA, and metolachlor ESA were the primary
chemicals detected in these three lakes (Figure 4). Acetochlor and atrazine results that
were reported as “Present but below the MRL” are shown graphically as one-half of the
MRL (0.025 µg/L). In general, when comparing each herbicide compound, the
occurrence and concentrations were similar for all compounds in all lakes. For
compounds with quantifiable concentrations, it was likely that the compound was
detected each year. In terms of concentrations, there was some variability over the years;
however, all the concentrations were extremely low when compared to applicable water
quality standards.
Given the results in Section 3.3, the MDA will likely rely primarily on the NLA in future
lake pesticide water quality assessments.
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Pesticides in MN Lakes 11/2013
Minnesota Department of Agriculture
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Figure 4. Annual variation in concentrations of selected herbicide compounds from three lakes sampled in 2009,
2010, and 2011. Please note differences in y-axes.
4.0 Methods
4.1 Lake Selection
Lake selection was completed by the USEPA and MPCA using a stratified random
approach. The NLA was a national study that included 904 natural lakes, ponds, and
reservoirs from each of the lower 48 states. Water bodies had to be at least 1 meter deep,
and have a surface area of at least 2.5 acres to be included. Lakes were selected to
represent the USEPA eco-region where they were located. Minnesota had 51 lakes
selected by the USEPA to be included in the NLA. In addition, the MPCA sampled an
additional 96 lakes to collect Minnesota specific eco-region information. As part of the
2012 NLA, a total of 147 Minnesota lakes were sampled for pesticides (Figure 5).
2012 NLA lake selection was completed by the USEPA using a stratified random
approach and was intended for the assessment at the national and aggregated ecoregion
level. The 2012 design used a minimum surface area of one hectare (2.5 acres) and depth
of 1 meter (~ 3.3 feet).Study design also allowed for comparisons with the 2007 study.
At the national scale, approximately one-half of the lakes included in 2012 were included
in the 2007 NLA and the remainder of the lakes were not sampled in 2007, which
resulted in about 910 lakes being selected across the lower 48 states. As a part of the
national draw, Minnesota received 42 lakes and added 8 lakes to allow for a state-based
assessment of lake condition. In addition, the MPCA sampled an additional 100 lakes
from the “overdraw” list from the survey to allow for state ecoregion-based assessment of
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Pesticides in MN Lakes 11/2013
Minnesota Department of Agriculture
11
water chemistry, zooplankton, and related parameters. As part of the 2012 NLAP, a total
of 147 Minnesota lakes were sampled for pesticides (Figure 5).
The Pesticide Monitoring Regions (PMRs) developed by MDA for collecting, assessing,
and reporting monitoring data were used by MDA to coordinate monitoring efforts and
analyze pesticide data in broad geographical areas of similar agricultural management,
soil and geologic characteristics; however, PMR designation was not used for lake
selection. At least one lake was sampled in nine of the ten PMRs (Figure 5). No lakes
within PMR 9 were sampled. PMR 9 generally represents a more mature geologic
landscape with karst terrain. Table 3 presents Minnesota lake distribution and 2012 NLA
lake selection distribution by PMR.
Table 3. Minnesota lake distribution and 2012 NLA lake selection by PMR.
PMR
Total Number of Lakes
1
2
3
4
5
6
7
8
9
10
Total
1160
1949
2994
5704
857
581
188
1183
140
1332
16088
Number of lakes
included in 2012 NLA
20
14
15
53
6
12
6
16
0
5
147
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Pesticides in MN Lakes 11/2013
Minnesota Department of Agriculture
12
Figure 5. Lake pesticide monitoring locations for 2012 NLA in Minnesota.
4.2 Sampling Protocol
The MDA provided pre-labeled, lake-specific sampling kits to the MPCA for sample
collection. These kits included bottles, gloves, and a paper chain of custody form used
for laboratory submission. A grab sample, consisting of two - 1000 mL amber bottles
and/or a 40 mL centrifuge tube, was collected from the lake surface over the deepest part
of the lake from the bow of the boat facing upwind. MDA provided sampling materials
for field replicates and field blanks targeting five percent quality control/quality
assurance for both replicates and blanks. All quality control/quality control samples were
collected from randomly selected lakes. The samples were transported on ice for the
duration of the sampling trip and refrigerated until delivered to the MDA laboratory.
Samples had a maximum 10-day holding time. The samples were transferred by MPCA
staff to the MDA laboratory for analysis. GC-MS and liquid chromatography with
tandem mass spectrometry (LC-MS/MS) samples were collected from June 6ththrough
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13
September 6th, , 2012. Atrazine ELISA samples were collected from June 7th through
September 6th, 2012. Twenty-nine lakes were sampled in replicate utilizing both the
GC-MS and atrazine ELISA method to compare atrazine results.
More information on the NLA field methods is available in the 2012 NLA Field
Operations Manual (USEPA, 2012).
4.3 Analytical Methods
Three laboratory analytical methods were used to analyze samples collected in this study
including the MDA laboratory’s GC-MS and LC-MS/MS in both positive and negative
modes, along with an atrazine ELISA screen. The GC-MS and LC-MS/MS methods
included a target analyte list of 132 different pesticide compounds (Table 4). In this
report, the results from the GC-MS and LC-MS/MS were presented together. Of the 147
lakes, 52 lake samples (from 51 lakes) received the GC-MS and LC-MS/MS analytical
methods. In addition, 125 lake samples (from 122 lakes) were analyzed for the atrazine
ELISA at the University of Wisconsin Stevens Point Water and Environmental Analysis
Laboratory (WEAL).
4.3.1 MDA Laboratory GC-MS and LC-MS/MS Methods
Lake water samples were analyzed at the MDA’s laboratory using GC-MS and/or
LC-MS/MS analytical methods. Due to limited resources, the MDA carefully selected
which agricultural chemicals to include in its monitoring program. A pesticide may be
included in MDA’s target analyte list based on several factors. The following criteria were
used to guide the development of the “target analyte” list. To be included, the pesticide must:
 Be used in Minnesota or neighboring states;
 Have environmental fate characteristics or use patterns that could potentially
result in adverse water resource impacts;
 Have a laboratory analytical method that can achieve reasonable results given
prevailing resource limitations; and
 Have available a risk guidance for human health and aquatic life toxicity.
The MDA laboratory updated its analytical methods from including 37 pesticide
compounds in 2007, to 132 pesticide compounds in 2012. Most of the compounds had
lower MRL’s in 2012 than 2007. There were pesticide compounds detected in 2012 that
were not included as a target analyte in the 2007 NLA (Table 4). This is a function of
analytical method improvement and not necessarily a reflection of environmental water
quality condition changes.
4.3.2 Atrazine ELISA Method
In addition to the GC-MS analysis discussed above, which included atrazine, additional
lakes were evaluated for atrazine utilizing an ELISA method. Analysis of these samples
was completed at the University of Wisconsin-Stevens Point WEAL. The atrazine
ELISA method was performed using the Modern Water RaPID Assay® for atrazine (part
number A00071). This atrazine ELISA screen reported a single value and had a MRL of
0.1 µg/L. In order to compare atrazine detection results between the MDA GC-MS and
the WEAL ELISA methods, samples from 29 randomly selected lakes were collected and
analyzed. The atrazine ELISA method was not completed with the 2007 NLA.
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Pesticides in MN Lakes 11/2013
Minnesota Department of Agriculture
14
4.3.3 USEPA Triazine Screen
As part of the 2012 NLA effort, the USEPA included a triazine ELISA analysis for all
904 lakes and reservoirs included in the NLA. The atrazine ELISA method performed by
MDA, and the USEPA triazine screen utilized the same analytical method and test kit
manufacturer. The difference in naming was related to agency preference. These data
were unavailable at the time of publication. When these data become available, an
addendum to this report will be completed to provide context to the lake pesticide
monitoring results in Minnesota, as well as nationally.
4.4 Data Analysis
4.4.1 Comparing Lakes with Rivers and Streams Monitoring
In an effort to evaluate the differences in pesticide detections between lake with rivers
and streams monitoring within the same PMR, the MDA compared median atrazine
concentrations. PMR based lake atrazine results were compared to Tier 1 and 2 level
river and stream monitoring within MDA’s routine stream monitoring program. MDA
has focused on sampling rivers and streams since 1991 as opposed to lakes due to the
higher likelihood of pesticide transport in streams. Median atrazine values were used due
to right skewed data set. For more information on Tier 1 and 2 level river and stream
monitoring locations, please see MDA, 2013a.
4.4.2 Dominant Land Use
In an effort to evaluate the effects of local land use, agricultural pesticide detections and
concentrations were compared between lakes with similar lakeshed land use
characteristics. Land use information for each lakeshed was provided by the MPCA, and
MDA classified each lake in this study into one of three categories (agricultural,
forest/water/wetland, or urban) based on the dominate land use within the lakeshed.
Land use was examined for 51 lakes that were analyzed with the MDA laboratory’s GCMS and LC-MS/MS methods and 125 lakes that were analyzed with the atrazine ELISA
method in 2012.
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Pesticides in MN Lakes 11/2013
Minnesota Department of Agriculture
15
Table 4. MDA GC-MS and LC-MS/MS analytical methods laboratory analyte list.
Common Name
Type
MRL
(µg/L)
2,4,5-T
2,4,5-TP
2,4-D
2,4-DB
Acetamiprid
Acetochlor
Acetochlor ESA
Acetochlor OXA
Alachlor
Alachlor ESA
Alachlor OXA
Aldicarb Sulfone
Aldicarb Sulfoxide
Atrazine
DEDI Atrazine
Deisopropylatrazine
Desethylatrazine
Hydroxyatrazine
Azoxystrobin
Benfluralin
Bensulfuron-methyl
Bentazon
Bifenthrin
Boscalid
Bromacil
Carbaryl
Carbendazim
Carbofuran
Chlorantraniliprole
Chlorimuron-ethyl
Chlorothalonil
Chlorpyrifos
Chlorpyrifos Oxon
Clomazone
Clopyralid
Clothianidin
Cyanazine
Cyfluthrin
Diazinon
Diazinon Oxon
Dicamba
Dichlobenil
Herbicide
Herbicide
Herbicide
Herbicide
Insecticide
Herbicide
Degradate
Degradate
Herbicide
Degradate
Degradate
Degradate
Degradate
Herbicide
Degradate
Degradate
Degradate
Degradate
Fungicide
Herbicide
Herbicide
Herbicide
Insecticide
Fungicide
Herbicide
Insecticide
Degradate
Insecticide
Insecticide
Herbicide
Fungicide
Insecticide
Degradate
Herbicide
Herbicide
Insecticide
Herbicide
Insecticide
Insecticide
Degradate
Herbicide
Herbicide
0.05
0.05
0.0083
0.02
0.025
0.05
0.03
0.0333
0.05
0.0416
0.0333
0.015
0.05
0.05
0.05
0.2
0.05
0.0067
0.01
0.15
0.0167
0.005
0.1
0.3
0.03
0.0025
0.01
0.0133
0.05
0.02
0.12
0.04
0.04
0.1
0.0416
0.025
0.2
0.5
0.1
0.15
0.05
0.05
Analyzed
in 2007
NLA
X
X
X
X
X
X
X
X
X
X
X
X
X
Common Name
Type
MRL
(µg/L)
Dichlorprop
Dichlorvos
Dicrotophos
Difenoconazole
Dimethenamid
Dimethenamid ESA
Dimethenamid OXA
Dimethoate
Dinotefuran
Disulfoton
Disulfoton Sulfone
Diuron
EPTC
Esfenvalerate
Ethalfluralin
Ethofumesate
Flufenacet OXA
Flumetsulam
Fonofos
Halosulfuron-methyl
Hexazinone
Imazamethabenz-methyl
Imazamethabenz Acid
Imazamox
Imazapic
Imazapyr
Imazaquin
Imazethapyr
Imidacloprid
Isoxaflutole
Isoxaflutole DKN
lambda-Cyhalothrin
Linuron
Malathion
MCPA
MCPB
MCPP
Mesotrione
Metalaxyl
Methoxychlor
Metolachlor
Metolachlor ESA
Herbicide
Insecticide
Insecticide
Fungicide
Herbicide
Degradate
Degradate
Insecticide
Insecticide
Insecticide
Degradate
Herbicide
Herbicide
Insecticide
Herbicide
Herbicide
Degradate
Herbicide
Insecticide
Herbicide
Herbicide
Herbicide
Degradate
Herbicide
Herbicide
Herbicide
Herbicide
Herbicide
Insecticide
Herbicide
Degradate
Insecticide
Herbicide
Insecticide
Herbicide
Herbicide
Herbicide
Herbicide
Fungicide
Insecticide
Herbicide
Degradate
0.05
0.09
0.025
0.025
0.05
0.0067
0.01
0.22
0.025
0.15
0.02
0.0133
0.23
0.2
0.15
0.1
0.0083
0.05
0.1
0.03
0.01
0.005
0.01
0.0133
0.01
0.0083
0.0167
0.0067
0.02
0.04
0.05
0.2
0.02
0.09
0.005
0.02
0.05
0.05
0.0083
0.15
0.07
0.01
Analyzed
in 2007
NLA
X
X
X
X
X
X
X
X
X
Common Name
Metolachlor OXA
Metribuzin
Metribuzin DA
Metribuzin DADK
Metribuzin DK
Metsulfuron-methyl
Myclobutanil
Neburon
Nicosulfuron
Norflurazon
Norflurazon-desmethyl
Oxadiazon
Oxydemeton-methyl
Parathion-methyl
Parathion-methyl Oxon
Pendimethalin
Phorate
Picloram
Prometon
Prometryn
Propachlor
Propachlor ESA
Propachlor OXA
Propazine
Propiconazole
Saflufenacil
Siduron
Simazine
Sulfometuron-methyl
Tebuconazole
Tebuprimiphos
Tembotrione
Terbufos
Tetraconazole
Thiamethoxam
Thifensulfuron-methyl
Thiobencarb
Triallate
Triasulfuron
Triclopyr
Trifluralin
zeta-Cypermethrin
Type
MRL
(µg/L)
Degradate
Herbicide
Degradate
Degradate
Degradate
Herbicide
Fungicide
Herbicide
Herbicide
Herbicide
Degradate
Herbicide
Insecticide
Insecticide
Degradate
Herbicide
Insecticide
Herbicide
Herbicide
Herbicide
Herbicide
Degradate
Degradate
Herbicide
Fungicide
Herbicide
Herbicide
Herbicide
Herbicide
Fungicide
Fungicide
Herbicide
Insecticide
Fungicide
Insecticide
Herbicide
Herbicide
Herbicide
Herbicide
Herbicide
Herbicide
Insecticide
0.01
0.1
1
1
1
0.0233
0.2
0.01
0.0266
0.02
0.05
0.05
0.02
0.12
0.025
0.08
0.12
0.0416
0.1
0.0033
0.1
0.03
0.01
0.1
0.2
0.15
0.0067
0.1
0.0083
0.2
0.1
0.05
0.19
0.15
0.025
0.0167
0.0083
0.1
0.0233
0.05
0.17
0.5
Analyzed
in 2007
NLA
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
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Pesticides in MN Lakes 11/2013
Minnesota Department of Agriculture
15
5.0 Results and Discussion
5.1 Detected Compounds and Frequency of Detection
5.1.1 MDA Laboratory GC-MS and LC-MS/MS Methods
All herbicide detections were well below applicable surface water quality reference
values. No insecticides or fungicides were detected in Minnesota lakes. A total of 10
parent herbicide compounds were found in at least one of the 52 Minnesota lake samples
(Table 5) including the herbicides 2,4-D, acetochlor, atrazine, bentazon, dimethenamid,
flumetsulam, MCPA, MCPP, metolachlor and saflufenacil. Atrazine and 2,4-D were
detected most frequently at 67 and 54 percent, respectively. Bentazon, dimethenamid,
flumetsulam, MCPA, MCPP, and saflucfenacil were detected only once or twice out of
the 52 samples. Median atrazine concentrations were present but below the MRL
(0.05 µg/L) and median 2,4-D concentrations were 0.009 µg/L.
Atrazine and hydroxyatrazine, a degradate of atrazine, were both found in 67 percent of
samples. The degradates of acetochlor, alachlor, dimethenamid, and metolachlor were
detected more frequently than their associated parent herbicide compound. The
degradates of acetochlor and alachlor were detected at a higher concentration than the
parent herbicide, while the degradates of dimethenamid and metolachlor were detected at
a lower concentration than their associated parent. All herbicide degradate detections
were well below applicable surface water quality reference values (Table 5). All
pesticide detections in the 2012 NLA are presented in Appendix 2.
These results indicate that both parent herbicide and their associated herbicide degradate
compounds may be present in a particular lake; however, it is unknown if the degradation
of the parent occurred within the lake or prior to transport to the lake via runoff,
groundwater discharge, or atmospheric deposition.
The total number of pesticide detections and total pesticide concentration were calculated
for each individual lake (Figure 6a and 6b). Neither the total number of pesticide
compounds detected nor their total concentration values have applicable water quality
reference values or standards; however, a spatial representation of relative occurrence and
magnitude of pesticide detections was provided. The lakes in far northeastern Minnesota
did not have any type of pesticide compounds detected; most lakes in the remainder of
Minnesota had at least one pesticide compound detected. Forty-three of the 52 lake
samples had total herbicide concentrations less than 0.5 µg/L, while only three lakes had
total herbicide concentrations greater than 1.0 µg/L. Lakes found in central Minnesota
had both the highest number of compounds detected, as well as the highest total
concentrations (Figure 6a and 6b).
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Pesticides in MN Lakes 11/2013
Minnesota Department of Agriculture
16
Table 5. 2012 NLA pesticide detections, concentrations, water quality standards, and reference values using GC-MS and LC-MS/MS for detected compounds.
Pesticide Name
Analyzed
in 2007
NLA
Detection Concentration Distribution (µg/L)
Pesticide
Type
Detects
Total
Samples
Detection
Frequency
Water Quality Standards and/or Reference Values (µg/L)
95th
%-tile
Maximum
MPCA Lake
Water Chronic
Standard2
MPCA
Maximum
Standard3
EPA Acute Value
Aquatic Life
Benchmark (μg/L)1
2,4-D
Herbicide
28
52
54%
0.009
0.03
0.073
0.179
Acetochlor
X
Herbicide
8
52
15%
nd
nd
nd
nd
Acetochlor ESA
X
Degradate
13
52
25%
nd
0.01
0.127
0.216
Acetochlor OXA
X
Degradate
14
52
27%
nd
0.04
0.114
0.176
Alachlor ESA
X
Degradate
3
52
6%
nd
nd
nd
0.02
Atrazine
X
Herbicide
35
52
67%
P
0.05
0.080
0.095
Desethylatrazine
X
Degradate
28
52
54%
P
P
P
0.055
Hydroxyatrazine
Degradate
35
52
67%
0.013
0.058
0.1192
0.16
Bentazon
Herbicide
1
52
2%
nd
nd
nd
nd
Dimethenamid
X
Herbicide
2
52
4%
nd
nd
nd
nd
X
Degradate
Dimethenamid ESA
3
52
6%
nd
nd
nd
0.003
X
Degradate
Dimethenamid OXA
2
52
4%
nd
nd
nd
nd
Flumetsulam
Herbicide
1
52
2%
nd
nd
nd
nd
MCPA
Herbicide
2
52
4%
nd
nd
nd
nd
MCPP
Herbicide
1
52
2%
nd
nd
nd
nd
Metolachlor
X
Herbicide
5
52
10%
nd
nd
nd
P
Metolachlor ESA
X
Degradate
19
52
37%
nd
0.042
0.131
0.212
Metolachlor OXA
X
Degradate
12
52
23%
nd
nd
0.049
0.088
Saflufenacil
Herbicide
1
52
2%
nd
nd
nd
nd
* “nd” indicates non-detect or the median concentrations were below the method reporting limit.
** “P” indicates the compound was present but at a concentration below the method reporting limit (MRL) presented in table 3.
0.753
0.32
0.594
0.474
0.117
0.22
0.09
0.295
0.006
0.15
0.111
0.07
0.07
0.027
0.196
0.75
0.295
0.135
0.035
70 H
3.6 T
─
─
─
─
─
─
─
─
─
─
─
─
─
─
─
─
─
─
271 T
─
─
─
12,075 (f)
na
> 62,500 (i)
─
52,000 (f)(i)
na
─
> 1,500 (f)
> 50,000 (f)(i)
3,150 (f)
─
─
125,000 (i)
90 (i)
45,500 (i)
na
24,000 (f)
7,700 (i)
> 49,000 (f)(i)
Median
75th %tile
90th
%-tile
3.4 H; 10 T
─
─
─
─
─
─
─
─
─
23 T
─
─
─
EPA Chronic
Value Aquatic
Life Benchmark
(μg/L)1
13.1 (v)
na
9,900 (n)
─
─
na
1,000 (n)
>10,000 (n)
4,500 (n)
5.1 (v)8
─
─
3.1 (v)
20 (v)
14 (n)
na
> 95,100 (v)
57,100 (n)
42 (n)
Table 4 key to value types and symbols in surface water reference values
(─ ) – For some analytes, reference values have not been identified or evaluated
(n) – USEPA/OPP benchmark value for nonvascular plants
na – not applicable
(v) – USEPA/OPP benchmark value for vascular plants.
(f) – USEPA/Office of Pesticide Products (OPP) benchmark value for fish.
(H) – “H” Chronic Standard values are human health-based and protective for an exposure duration of 30 days.
(i) – USEPA/OPP benchmark value for invertebrates.
(T) – “T” Chronic Standard values are toxicity-based for aquatic organisms and protective for an exposure duration of 4 days.
1
Aquatic Life Benchmarks based on toxicity values derived from data available to the USEPA OPP supporting registration of the pesticide are provided only when an MPCA value is not available. Current values
posted by the USEPA’s OPP may differ from those of previous MDA reports. See USEPA’s web site for more detailed information and definitions.
2
Chronic Standard as defined in Minn. Rule Chap. 7050. “H” value is human health-based and is protective for an exposure duration of 30 days. Human health-based values are shown only when they are less than
toxicity-based values. “T” value is toxicity-based for aquatic organisms and is protective for an exposure duration of 4 days.
3
Maximum Standard Value for Aquatic Life & Recreation as defined on MPCA’s web site and Minn. Rule Chap. 7050. Values are the same for all classes of surface waters.
_____________________________________________________________________________________________________________________________ ________________
Pesticides in MN Lakes 11/2013
Minnesota Department of Agriculture
17
Figure 6. Total number of pesticide compounds detected (6a) and total concentrations (µg/L) (6b) using MDA GC-MS and LC-MS/MS methods.
_____________________________________________________________________________________________________________________________ ________________
Pesticides in MN Lakes 11/2013
Minnesota Department of Agriculture
18
5.1.2 Atrazine ELISA Method
Atrazine was detected in 21 percent of the samples analyze with the atrazine ELISA
screening method (Table 5). The maximum concentration (0.35 µg/L) was much lower
the applicable water quality standard (10 µg/L). The lakes in far northeast Minnesota and
most others across Minnesota did not have atrazine detected with the ELISA screening
method (Figure 7). Detections were more frequent across central and southern
Minnesota. The highest atrazine concentrations occurred in the southern half of the state.
Table 6. 2012 NLA summary detection statistics for atrazine ELISA lake sampling.
Atrazine ELISA
Atrazine ELISA
Detections
(n=125)
Detection
Frequency
Median
(μg/L)
Maximum
(μg/L)
Water Quality Standard or
Reference Value (μg/L)
26
21%
non-detect
0.35
10.0
Figure 7. 2012 NLA atrazine concentration (µg/L) levels for 125 lakes using the ELISA screening method.
______________________________________________________________________________________
Pesticides in MN Lakes 11/2013
Minnesota Department of Agriculture
19
5.2 Comparison between 2007 and 2012 NLA results
The NLA provided a unique opportunity to compare lake water quality using a stratified
random survey design over five years. As discussed above, the MDA laboratory GC-MS
and LC-MS/MS methods have been enhanced since the 2007 NLA (Table 4). This
portion of the report (Section 5.2) will refer only to pesticide compounds that were
detected in both the 2007 and 2012 NLA. Only herbicides were detected in the study
lakes in 2007 and 2012.
Due to laboratory enhancements between 2007 and 2012, many MRL’s were lowered
since 2007. To complete this analysis, all data were censored to the higher MRL for five
compounds: acetochlor ESA (0.07 µg/L), acetochlor OXA (0.07 µg/L), alachlor ESA
(0.07 µg/L), metolachlor ESA (0.07 µg/L), and metolachlor OXA (0.07 µg/L). The
MRL’s for all other compounds in this section were consistent between 2007 and 2012.
2012 data presented in all other sections of this report will not be censored and will be
presented with the MRL’s listed in Table 4.
Comparing detection frequencies for all herbicide compounds detected in both the 2007
and 2012 NLA showed that all atrazine pesticide compounds, alachlor ESA, and
metolachlor ESA were detected less frequently in 2012 compared to 2007 (Figure 8).
Detection frequencies for acetochlor ESA, acetochlor OXA, dimethenamid, and
metolachlor OXA were similar in 2007 and 2012. The detection frequencies for
acetochlor and metolachlor were higher in 2012 than 2007.
Figure 8. Comparison of detection frequencies for herbicide compounds between 2007 and 2012 NLA in
Minnesota.
Maximum herbicide concentrations, from the 2007 and 2012 NLA, although not
statistically reflective of the entire population, provided an indication of the extremes
present during the sampling period (Figure 9). Full percentile concentrations were
previously presented (Tables 2 and 5). All atrazine compounds, along with alachlor ESA,
had lower maximums in 2012 when compared to 2007. Acetochlor, dimethenamid, and
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Pesticides in MN Lakes 11/2013
Minnesota Department of Agriculture
20
metolachlor had higher maximums in 2012, while the acetochlor and metolachlor
degradates were lower in 2012 when compared to 2007.
Figure 9. Maximum concentrations of pesticide compounds from the 2007 and 2012 NLA in Minnesota. Note
Maximum concentrations that were reported as "Present below MRL" are shown graphically as one-half of the MRL.
In general, there appeared to be less atrazine compounds detected in 2012. Also,
acetochlor and metolachlor parent products had an increase in detection frequency and
maximum concentrations. Acetochlor ESA, acetochlor OXA, and metolachlor OXA had
similar detection frequencies, and lower maximum concentrations in 2012 than 2007.
5.3 Comparison between Atrazine ELISA and GC-MS Method Results
As part of the 2012 NLA, 31 lake samples were analyzed for atrazine utilizing both the
atrazine ELISA method and MDA’s GC-MS method (Figure 10). Of these 31 samples,
only eight samples had atrazine detected with the atrazine ELISA method (MRL = 0.10
µg/L), and 19 samples had atrazine detections with the MDA GC-MS method (MRL =
0.05 µg/L). Only two samples detected utilizing the MDA GC-MS method also had
atrazine detected above the atrazine ELISA method, further limiting the comparison. The
atrazine ELISA method had six other atrazine detections above 0.10 µg/L; however, all
associated MDA GC-MS results were less than 0.10 µg/L. All atrazine ELISA detections
over-estimated the MDA GC-MS atrazine results. ELISA kits are often sensitive to
several compounds from a specific class of chemicals (i.e., triazines); however, nontarget compounds often have higher levels of detections and exhibit less reactivity to the
kit than the target compound. Due to these limitations, the atrazine ELISA method was
better utilized as an inexpensive screening tool for atrazine. More advanced methods
(e.g., GC-MS or comparable) should be utilized for precise determination of atrazine
concentrations in lakes.
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Pesticides in MN Lakes 11/2013
Minnesota Department of Agriculture
21
Figure 10. Comparison of ELISA and GC-MS atrazine results as part of the 2012 NLA in Minnesota.
5.4 Comparing Lake Results with Rivers/Streams Results by Region
The median concentration of atrazine, the most commonly detected agricultural pesticide
in Minnesota during the 2007 and 2012 NLA, was compared in lakes and rivers/streams
in the ten PMRs. In general, the median concentration was comparable for both lakes,
and rivers/streams in 2012 (Figure 11).
Figure 11. Median concentration of atrazine in NLA lakes compared with rivers and streams sampled in 2012 by
pesticide monitoring region (PMR). Note: Medians that were reported as “Present below MRL” are shown
graphically as one-half of the MRL (0.025 µg/L).
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Pesticides in MN Lakes 11/2013
Minnesota Department of Agriculture
22
5.5 Land Use Results
5.5.1 Lakes Sampled with MDA GC-MS and LC-MS/MS Methods
Of the 52 lake samples collected, 18 were considered agricultural, 32 were considered
forest and water, and 2 were considered urban. The number of individual pesticide
detections was examined based on dominant land use category of each lakeshed. The
land use category dominated by forest, water and wetlands had the lowest mean number
of detections and agricultural had the highest mean number of detections (Figure 12).
The minimum number of detections by category ranged from zero in the forest, water,
and wetlands category to four in the urban. Lakes in agricultural areas had the most
pesticide compounds detected, however, several lakes in the forest, water, and wetland,
as well as the urban, lakesheds had multiple pesticides detected.
Agricultural pesticides detections in lakes of the urban and forest, water, and wetland
dominated lakesheds may be a result of atmospheric deposition. Pesticide detections in
lakes with agricultural dominated lakesheds were likely a combination of local pesticide
use and atmospheric deposition.
Figure 12. Number of pesticide compound (parent and /or degradate) detections by the dominant land use
category in each lakeshed.
Total pesticide concentrations were summarized for the detected parent and degradate
compounds and then placed into the dominant land use category of the lakeshed from
which they were collected (Figure 13). Lakes within lakesheds dominated by row crop
agriculture had higher total pesticide concentrations than lakes within lakesheds
dominated by forest, water, and wetlands and urban land uses. Higher levels in row crop
areas was generally consistent with the findings of a Wisconsin lake study that found
increased concentrations of atrazine in lakes with greater than 75 percent row crop
agricultural in the lakeshed (Allen, 2006).
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Pesticides in MN Lakes 11/2013
Minnesota Department of Agriculture
23
Figure 13. Mean, minimum, and maximum total pesticide (parent + degradate) concentration by the dominant
land use category in each lakeshed.
5.5.2 Lakes Sampled with the Atrazine ELISA Method
Of the 128 lake samples, 49 were considered agriculturally dominated lakesheds, 75 were
considered forest and water dominated lakesheds, and four were considered urban
dominated lakesheds. Using the atrazine ELISA method, atrazine was detected in 36
percent of the samples from agricultural lakesheds, 13 percent of the samples from forest,
water, and wetland lakesheds, and 50 percent of the samples from urban lakesheds. The
minimum and mean atrazine ELISA concentrations were less than the MRL for all land
use categories. The maximum concentration occurred in an agricultural lakeshed (Figure
14).
Figure 14. Maximum atrazine concentration by the domainant land use category in each lakeshed.
______________________________________________________________________________________
Pesticides in MN Lakes 11/2013
Minnesota Department of Agriculture
24
6.0 Conclusions















Concentrations of all detected pesticide compounds in lakes were well below
applicable water quality standards and reference values.
Only herbicide compounds were detected in the 2007 and 2012 study lakes.
19 different herbicide compounds were detected in the 2012 NLA in samples
analyzed with MDA’s GC-MS and LC-MS/MS laboratory methods.
Atrazine was detected in 67 percent of the 52 lake samples collected in Minnesota
and analyzed with MDA’s GC-MS laboratory method, including lakes located
outside of agricultural dominated lakesheds.
2,4-D was detected in 54 percent of the 52 lake samples collected in Minnesota
and analyzed with MDA’s LC-MS/MS laboratory method.
A herbicide or a herbicide degradate was detected in 85 percent of the samples
collected from Minnesota lakes and analyzed with MDA’s GC-MS and LCMS/MS laboratory methods.
The degradates of several herbicides were found more frequently and in higher
concentrations than its associated parent compound.
All detected compounds in the 2007 NLA were detected during the 2012 NLA.
All atrazine compounds were detected less frequently in 2012 than 2007.
Acetochlor and metolachlor parent compounds were detected more frequently in
2012 than 2007.
An atrazine ELISA method was determined to be best-suited as a screening tool,
and over-predicted atrazine concentrations in lakes (when compared to the
MDA’s GC-MS results).
In general, the ranges of concentrations detected as well as the frequency of
detection in Minnesota were similar or lower when compared with other studies
of lakes and reservoirs in the Midwest.
The median concentrations of atrazine were similar between samples collected
from the NLA lakes and rivers/streams located within the same Pesticide
Monitoring Region.
Lakes in lakesheds with row crop agriculture as a dominant land use had higher
concentrations of total herbicides. This may be the result of local herbicide use
on adjacent lands and/or from greater atmospheric deposition due to closer
proximity to application areas.
Atmospheric deposition was suspected as the primary method of transport in lakes
where pesticides were detected far from areas of application.
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Pesticides in MN Lakes 11/2013
Minnesota Department of Agriculture
25
References:
Allen, P. "Volunteer Monitoring of Atrazine in Wisconsin Lakes." Lake Tides 31.12
(2006): Print.
Capel, P., M. Lin, and P. Wotzka. Wet Atmospheric Deposition of Pesticides in
Minnesota, 1989-94. Mounds View, MN: U.S. Dept. of the Interior, U.S. Geological
Survey, (1998). Print.
Carlson, D., I. Basu, and R. Hites. "Annual Variations of Pesticide Concentrations in
Great Lakes Precipitation." Environmental Science & Technology 38.20 (2004): 5290296. Print.
Goolsby, D. Herbicides and Their Metabolites in Rainfall: Origin, Transport, and
Deposition Patterns across the Midwestern and Northeastern United States, 1990-1991.
Washington, D.C.: American Chemical Society, (1997). Print.
Gustafson, D. Acetochlor Registration Partnership Data. 23 Sept. (2008). Raw data.
Kuang, Z., .L. McConnell, A. Torrents, D. Meritt, and S. Tobash. "Atmospheric
Deposition of Pesticides to an Agricultural Watershed of the Chesapeake Bay." Journal
of Environment Quality 32.5 (2003): 1611. Print.
MDA (Minnesota Department of Agriculture). Minnesota National Lakes Assessment
Program: Pesticides in Minnesota Lakes. St. Paul. Minnesota Department of Agriculture.
(2008). 20 pages. http://www.mda.state.mn.us/monitoring/
MDA (Minnesota Department of Agriculture). 2008 Water Quality Monitoring Report.
St. Paul. Minnesota Department of Agriculture. St. Paul. Minnesota Department of
Agriculture. (2009). 211 pages. http://www.mda.state.mn.us/monitoring/
MDA (Minnesota Department of Agriculture). 2009 Water Quality Monitoring Report.
St. Paul. Minnesota Department of Agriculture. St. Paul. Minnesota Department of
Agriculture. (2010). 205 pages. http://www.mda.state.mn.us/monitoring/
MDA (Minnesota Department of Agriculture). 2010 Water Quality Monitoring Report.
St. Paul. Minnesota Department of Agriculture. St. Paul. Minnesota Department of
Agriculture. (2011). 262 pages. http://www.mda.state.mn.us/monitoring/
MDA (Minnesota Department of Agriculture). 2011 Water Quality Monitoring Report.
St. Paul. Minnesota Department of Agriculture. St. Paul. Minnesota Department of
Agriculture. (2012). 274 pages. http://www.mda.state.mn.us/monitoring/
______________________________________________________________________________________
Pesticides in MN Lakes 11/2013
Minnesota Department of Agriculture
26
MDA (Minnesota Department of Agriculture). 2012 Water Quality Monitoring Report.
St. Paul. Minnesota Department of Agriculture. St. Paul. Minnesota Department of
Agriculture. (2013a). 184 pages. http://www.mda.state.mn.us/monitoring/
MDA (Minnesota Department of Agriculture). Minnesota Pesticide Sales Database
Search. Retrieved: 18 July 2013. St. Paul. Minnesota Department of Agriculture. (2013b).
http://www.mda.state.mn.us/chemicals/pesticides/useandsales.aspx
MPCA (Minnesota Pollution Control Agency). Minnesota's Impaired Waters and
TMDLs. Retrieved: 18 July 2013. St. Paul. Minnesota Pollution Control Agency. (2013).
< http://www.pca.state.mn.us/index.php/water/water-types-and-programs/minnesotasimpaired-waters-and-tmdls/minnesotas-impaired-waters-and-total-maximum-daily-loadstmdls.html >.
Sun, P., S. Backus, P. Blanchard, and R. Hites. "Temporal and Spatial Trends of
Organochlorine Pesticides in Great Lakes Precipitation." Environmental Science &
Technology 40.7 (2006): 2135-141. Print.
USDA (United States Department of Agriculture). National Agricultural Statistics
Service. By Douglas A. Hartwig and Dan Lofthus. Retrieved 18 July 2013.
http://www.nass.usda.gov/
USEPA (United States Environmental Protection Agency). Survey of the Nation's Lakes.
Field Operations Manual. EPA 841-B-11-003. U.S. Environmental Protection Agency,
Washington, DC. (2012) 234 pages Print.
Vogel, J., M. Majewski, and P. Capel. "Pesticides in Rain in Four Agricultural
Watersheds in the United States." Journal of Environmental Quality 37.3 (2008): 1101115. Print.
Wotzka, P., P. Capel, L. Ma, and J. Lee. “Pesticide Transport and Cycling in the Lake
Harriet Watershed, Minneapolis, Minnesota.” Proceedings of the Sixteenth Annual North
American Lake Management Society International Symposium (1998). Print.
Wright, Christopher K., and Micheal C. Wimberly.. "Recent Land Use Change in the
Western Corn Belt Threatens Grasslands and Wetlands." Proceedings of the National
Academy of Sciences of the United States” 4134-139. (2013) Print.
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Pesticides in MN Lakes 11/2013
Minnesota Department of Agriculture
27
Appendix 1:
Table A1: 2007 NLA Detected Pesticide Compounds
Note: “nd” = non-detect, “P” = Present but below Method Reporting Limit
County
Lake Name
MN
DNR
Lake ID
Sample
Date
Acetochlor ESA
Acetochlor OXA
Alachlor ESA
Atrazine
Deisopropylatrazine
Desethylatrazine
Dimethenamid
Metolachlor
Metolachlor ESA
Metolachlor OXA
Detected Pesticide or Pesticide Degradate Concentration (µg/L)
Acetochlor
Lake and Sample Information
Becker
Straight
03-0010
7/31/2007
nd
nd
nd
0.2
P
nd
P
nd
nd
0.35
nd
Becker
Hungry Man
03-0029
8/8/2007
nd
nd
nd
nd
P
nd
P
nd
nd
nd
nd
Becker
Flat
03-0242
8/7/2007
nd
nd
nd
nd
P
nd
P
nd
nd
nd
nd
Becker
Pickerel
03-0287
7/31/2007
nd
nd
nd
nd
0.05
nd
0.05
nd
nd
nd
nd
Beltrami
Cass
04-0030
8/6/2007
nd
nd
nd
nd
nd
nd
P
nd
nd
nd
nd
Blue Earth
Eagle (North)
07-0060
8/8/2007
nd
0.19
0.21
nd
P
nd
P
nd
nd
0.26
0.1
Cass
Spring
11-0022
8/10/2007
nd
nd
nd
nd
nd
nd
0
nd
nd
nd
nd
Cass
Island
11-0102
8/11/2007
nd
nd
nd
nd
P
nd
0
nd
nd
nd
nd
Cass
Pine Mountain
11-0411
7/11/2007
nd
nd
nd
nd
P
nd
P
nd
nd
nd
nd
Cass
Long
11-0480
7/10/2007
nd
nd
nd
nd
P
nd
P
nd
nd
nd
nd
Clay
North Mayfield
14-0029
8/9/2007
nd
nd
nd
nd
P
nd
nd
nd
nd
nd
nd
Clearwater
Elk
15-0010
8/9/2007
nd
nd
nd
nd
nd
nd
P
nd
nd
nd
nd
Cook
Musquash
16-0104
8/1/2007
nd
nd
nd
nd
P
nd
P
nd
nd
nd
nd
Cook
Vesper
16-0414
7/31/2007
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
Cook
Rickey
16-0643
8/2/2007
nd
nd
nd
nd
P
nd
nd
nd
nd
nd
nd
Crow Wing
Lookout
18-0123
8/13/2007
nd
nd
nd
nd
P
nd
P
nd
nd
nd
nd
Crow Wing
Crow Wing
18-0155
7/30/2007
nd
nd
nd
nd
P
nd
P
nd
nd
nd
nd
Crow Wing
Pelican
18-0308
7/11/2007
nd
nd
nd
nd
P
nd
P
nd
nd
nd
nd
Crow Wing
Mayo
18-0408
7/9/2007
nd
nd
nd
nd
P
nd
P
nd
nd
nd
nd
Douglas
Victoria
21-0054
7/24/2007
nd
nd
nd
nd
0.05
nd
P
nd
nd
nd
nd
Douglas
Darling
21-0080
7/19/2007
nd
nd
nd
nd
0.06
nd
0.05
nd
nd
nd
nd
Douglas
Red Rock
21-0291
7/25/2007
nd
nd
nd
nd
0.05
nd
P
nd
nd
nd
nd
Douglas
Fanny
21-0336
7/11/2007
nd
nd
nd
0.1
0.06
nd
P
nd
nd
0.09
0.11
Hennepin
Nokomis
27-0019
6/27/2007
nd
nd
nd
nd
0.05
nd
nd
nd
nd
nd
nd
Itasca
Long
31-0266
8/15/2007
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
Itasca
Upper Hatch
31-0770
8/14/2007
nd
nd
nd
nd
P
nd
nd
nd
nd
nd
nd
Kanabec
Spring
33-0027
6/27/2007
nd
nd
nd
nd
0.09
nd
nd
nd
nd
0.08
nd
Kandiyohi
Woodcock
34-0141
7/24/2007
nd
nd
nd
nd
0.06
nd
nd
nd
nd
nd
nd
Kandiyohi
Nest
34-0154
8/22/2007
nd
nd
nd
0.12
P
nd
P
nd
nd
0.11
nd
Kandiyohi
Norway
34-0251
8/22/2007
nd
nd
0.07
nd
0.06
nd
0.05
nd
nd
0.07
nd
Lake
Becoosin
38-0472
7/18/2007
nd
nd
nd
nd
0.05
nd
P
nd
nd
nd
nd
Lake
August
38-0691
8/3/2007
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
Le Sueur
Upper Sakatah
40-0002
8/8/2007
nd
0.48
0.37
0.2
0.05
nd
nd
nd
nd
0.88
0.28
Lincoln
North Ash
41-0055
7/10/2007
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
McLeod
South
43-0014
7/23/2007
nd
0.15
0.15
0.07
0.07
nd
nd
nd
nd
nd
nd
______________________________________________________________________________________
Pesticides in MN Lakes 11/2013
Minnesota Department of Agriculture
28
Appendix 1 (continued)
Table A1: 2007 NLA Detected Pesticide Compounds
Note: “nd” = non-detect, “P” = Present but below Method Reporting Limit
Alachlor ESA
Atrazine
Deisopropylatrazine
Desethylatrazine
Dimethenamid
Metolachlor
Metolachlor ESA
Metolachlor OXA
0.12
0.14
nd
0.07
nd
P
nd
nd
nd
nd
nd
nd
nd
P
nd
nd
nd
nd
nd
nd
0.6
0.42
nd
P
nd
nd
nd
nd
0.69
0.1
0.14
0.13
0.11
0.05
nd
P
nd
nd
0.12
nd
nd
nd
nd
0.1
P
nd
P
P
P
0.18
nd
nd
nd
nd
nd
P
nd
P
nd
nd
nd
nd
7/25/2007
nd
nd
nd
nd
P
nd
P
nd
nd
nd
nd
56-0829
7/25/2007
nd
nd
nd
nd
0.06
nd
0.05
nd
nd
nd
nd
56-0829
8/22/2007
nd
nd
nd
nd
0.06
nd
0.05
nd
nd
nd
nd
Unnamed
60-0307
8/8/2007
nd
nd
nd
nd
0.68
P
0.18
nd
nd
0.15
nd
County
Lake Name
MN
DNR
Lake ID
Sample
Date
Acetochlor
Acetochlor OXA
Detected Pesticide or Pesticide Degradate Concentration (µg/L)
Acetochlor ESA
Lake and Sample Information
McLeod
South
43-0014
8/21/2007
nd
Mahnomen
Allen
44-0157
8/7/2007
nd
Martin
Okamanpeedan
46-0051
8/7/2007
nd
Meeker
Jennie
47-0015
8/21/2007
nd
Otter Tail
West Leaf
56-0114
8/1/2007
Otter Tail
Fairy
56-0356
8/6/2007
Otter Tail
Maine (Round)
56-0476
Otter Tail
Pebble
Otter Tail
Pebble
Polk
Ramsey
Snail
62-0073
7/18/2007
nd
nd
nd
nd
0.06
nd
0.05
nd
nd
nd
nd
St. Louis
Alruss
69-0005
7/16/2007
nd
nd
nd
nd
0.05
nd
P
nd
nd
nd
nd
St. Louis
Spring
69-0129
6/28/2007
nd
nd
nd
nd
P
nd
P
nd
nd
nd
nd
St. Louis
Arthur
69-0154
7/17/2007
nd
nd
nd
nd
P
nd
P
nd
nd
nd
nd
St. Louis
Lamb
69-0341
7/19/2007
nd
nd
nd
nd
0.05
nd
P
nd
nd
nd
nd
St. Louis
Lost (Horseshoe)
69-0611
7/20/2007
nd
nd
nd
nd
P
nd
nd
nd
nd
nd
nd
Scott
Fish
70-0069
8/6/2007
nd
0.09
0.1
nd
0.05
nd
nd
nd
nd
0.1
nd
Swift
South Drywood
76-0149
7/12/2007
nd
0.71
1.02
nd
P
nd
nd
nd
nd
0.25
nd
Wright
Long
86-0069
6/26/2007
nd
nd
nd
0.11
0.06
nd
0.05
nd
nd
0.19
nd
Wright
Cokato
86-0263
8/20/2007
P
0.18
0.14
0.22
0.18
nd
0.06
P
P
0.2
nd
______________________________________________________________________________________
Pesticides in MN Lakes 11/2013
Minnesota Department of Agriculture
29
Appendix 2
Table A2: 2012 NLA Detected Pesticide Compounds
Note: “-“ = sample not analyzed for specific compound, “nd” = non-detect, “P” = Present but below Method Reporting Limit
2,4-D
Acetochlor
Acetochlor ESA
Acetochlor OXA
Alachlor ESA
Atrazine
Desethylatrazine
Hydroxyatrazine
Bentazon
Dimethenamid
Dimethenamid
ESA
Dimethenamid
OXA
Flumetsulam
MCPA
MCPP
Metolachlor
Metolachlor ESA
Metolachlor OXA
Saflufenacil
Detected Pesticide or Pesticide Degradate Concentration (µg/L)
Atrazine
ELISA
Lake and Sample Information
Aitkin
Jenkins
01-0100
8/6/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Becker
Unnamed
03-0236
6/12/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Becker
Flat
03-0242
6/12/2012
<0.10
0.016
nd
nd
nd
nd
0.06
P
0.0104
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
Becker
Bear
03-0303
6/28/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Becker
Bear
03-0303
7/18/2012
<0.10
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
Becker
Unnamed
03-0393
6/11/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Becker
Unnamed
03-0393
6/27/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Becker
Granrud
03-0414
6/11/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Becker
Cucumber
03-0571
6/13/2012
<0.10
0.0369
P
nd
nd
nd
0.05
P
0.0529
0.006
nd
nd
nd
nd
0.0271
nd
nd
nd
nd
nd
Becker
Granrud
03-0627
8/1/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Becker
Unnamed
03-0751
8/1/2012
-
nd
nd
nd
nd
nd
0.06
P
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
Beltrami
Popple
04-0014
8/8/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
County
Lake Name
MN
DNR
Lake ID
Sample
Date
Beltrami
Fox
04-0251
6/26/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Big Stone
Bentsen
06-0090
8/22/2012
0.27
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Big Stone
Thielke
06-0102
8/21/2012
0.26
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Big Stone
Big Stone
06-0152
8/7/2012
<0.10
0.242
nd
0.457
0.474
nd
0.09
P
0.111
nd
nd
0.0074
nd
nd
nd
nd
nd
0.0519
0.0442
nd
Big Stone
Unnamed
06-0206
8/22/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Big Stone
Unnamed
06-0266
8/20/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Big Stone
Unnamed
06-0349
8/28/2012
<0.10
nd
nd
0.0766
0.0869
nd
nd
nd
0.161
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
Big Stone
Unnamed
06-0460
7/10/2012
-
nd
nd
nd
nd
nd
P
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
0.294
nd
nd
Blue Earth
Eagle (North)
07-0060
8/14/2012
-
0.0126
nd
0.192
0.167
nd
0.06
P
0.107
nd
nd
nd
nd
nd
nd
nd
nd
0.123
0.0498
nd
Blue Earth
Lieberg
07-0124
7/12/2012
0.27
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
_____________________________________________________________________________________________________________________________ _________________
Pesticides in MN Lakes 11/2013
Minnesota Department of Agriculture
30
Appendix 2 (continued)
Table A2: 2012 NLA Detected Pesticide Compounds
Note: “-“ = sample not analyzed for specific compound, “nd” = non-detect, “P” = Present but below Method Reporting Limit
County
Lake Name
MN DNR
Lake ID
Sample
Date
2,4-D
Acetochlor
Acetochlor ESA
Acetochlor OXA
Alachlor ESA
Atrazine
Desethylatrazine
Hydroxyatrazine
Bentazon
Dimethenamid
Dimethenamid ESA
Dimethenamid OXA
Flumetsulam
MCPA
MCPP
Metolachlor
Metolachlor ESA
Metolachlor OXA
Saflufenacil
Detected Pesticide or Pesticide Degradate Concentration (µg/L)
Atrazine ELISA
Lake and Sample Information
Cass
Pistol
11-0110
7/23/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Cass
Tamarack
11-0150
7/23/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Cass
Tamarack
11-0241
8/6/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Cass
Unnamed
11-0440
8/27/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Cass
Long
11-0480
6/19/2012
-
0.0184
nd
nd
nd
nd
P
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
Cass
Long
11-0480
8/27/2012
-
0.00996
nd
nd
nd
nd
P
P
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
Cass
Diamond Pond
11-1013
7/24/2012
-
nd
nd
nd
nd
nd
nd
nd
0.0103
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
Cass
Unnamed
11-1033
8/6/2012
0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Chisago
Unnamed
13-0061
8/7/2012
0.14
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Clay
Unnamed
14-0081
8/1/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Clay
Unnamed
14-0389
7/30/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Clearwater
Miskogineu
15-0107
6/26/2012
<0.10
nd
nd
nd
nd
nd
P
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
Clearwater
Unnamed
15-0279
6/27/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Clearwater
Unnamed
15-0491
6/27/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Cook
Ball Club
16-0182
9/5/2012
<0.10
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
Cook
Tenor
16-0613
6/28/2012
-
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
Cook
Richey
16-0643
6/25/2012
<0.10
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
Cottonwood
String
17-0024
7/11/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Cottonwood
Talcot
17-0060
8/15/2012
0.18
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Cottonwood
Summit
17-0073
8/20/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Crow Wing
Lookout
18-0123
8/7/2012
<0.10
nd
nd
nd
nd
nd
P
P
0.0114
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
Crow Wing
Crow Wing
18-0155
7/25/2012
-
0.0596
nd
nd
nd
nd
P
P
0.00692
nd
nd
nd
nd
nd
nd
nd
nd
0.0503
0.0121
nd
_____________________________________________________________________________________________________________________________ _________________
Pesticides in MN Lakes 11/2013
Minnesota Department of Agriculture
31
Appendix 2 (continued)
Table A2: 2012 NLA Detected Pesticide Compounds
Note: “-“ = sample not analyzed for specific compound, “nd” = non-detect, “P” = Present but below Method Reporting Limit
MN DNR
Lake ID
Sample
Date
Acetochlor
Acetochlor ESA
Acetochlor OXA
Alachlor ESA
Atrazine
Desethylatrazine
Hydroxyatrazine
Bentazon
Dimethenamid
Dimethenamid ESA
Dimethenamid OXA
Flumetsulam
MCPA
MCPP
Metolachlor
Metolachlor ESA
Metolachlor OXA
Saflufenacil
Lake Name
2,4-D
County
Detected Pesticide or Pesticide Degradate Concentration (µg/L)
Atrazine ELISA
Lake and Sample Information
18-0312
8/28/2012
0.11
0.0318
nd
nd
nd
nd
P
P
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
Crow Wing
Cross Lake
Reservoir
Unnamed
18-0418
6/18/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Crow Wing
Unnamed
18-0527
8/7/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Douglas
Krueger's Slough
21-0060
8/20/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Douglas
Darling
21-0080
8/8/2012
-
0.147
nd
nd
nd
nd
P
P
0.0247
nd
nd
nd
nd
nd
nd
nd
nd
0.0146
nd
nd
Douglas
Crooked(East)
21-0199
9/5/2012
<0.10
0.0144
nd
0.0391
0.0432
nd
nd
nd
0.0559
nd
nd
nd
nd
nd
nd
nd
nd
0.0122
nd
nd
Crow Wing
Douglas
Unnamed
21-0729
8/21/2012
-
nd
nd
nd
0.115
nd
P
P
0.0562
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
Faribault
South Walnut
22-0022
8/15/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Grant
Unnamed
26-0043
7/23/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Grant
Unnamed
26-0205
7/23/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Grant
Unnamed
26-0217
8/21/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Grant
Hodgson
26-0228
7/23/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Hennepin
Nokomis
27-0019
7/12/2012
<0.10
0.0685
nd
nd
nd
nd
0.09
P
0.0384
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
Hennepin
Edina
27-0029
8/9/2012
0.24
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Hennepin
Little Long
27-0179
8/9/2012
0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Hubbard
Sunday
29-0144
8/8/2012
0.11
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Hubbard
Belle Taine
29-0146
6/18/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Hubbard
Lost
29-0303
9/5/2012
<0.10
nd
nd
nd
nd
nd
nd
0.06
0.00846
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
Isanti
Section
30-0060
8/7/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Isanti
Long
30-0072
6/21/2012
-
0.219
P
nd
nd
nd
0.11
0.05
0.00796
nd
nd
nd
nd
nd
nd
nd
nd
0.135
0.0369
nd
Itasca
Unnamed
31-0211
8/9/2012
0.18
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Itasca
Long (Main Bay)
31-0266
7/11/2012
<0.10
0.0283
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
_____________________________________________________________________________________________________________________________ _________________
Pesticides in MN Lakes 11/2013
Minnesota Department of Agriculture
32
Appendix 2 (continued)
Table A2: 2012 NLA Detected Pesticide Compounds
Note: “-“ = sample not analyzed for specific compound, “nd” = non-detect, “P” = Present but below Method Reporting Limit
Sample
Date
2,4-D
Acetochlor
Acetochlor ESA
Acetochlor OXA
Alachlor ESA
Atrazine
Desethylatrazine
Hydroxyatrazine
Bentazon
Dimethenamid
Dimethenamid ESA
Dimethenamid OXA
Flumetsulam
MCPA
MCPP
Metolachlor
Metolachlor ESA
Metolachlor OXA
Saflufenacil
Detected Pesticide or Pesticide Degradate Concentration (µg/L)
Atrazine ELISA
Lake and Sample Information
31-0298
8/6/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
31-0407
7/10/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Charlie
31-0419
8/2/2012
0.14
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Itasca
Cottonwood
31-0594
7/10/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Itasca
Lower Pigeon
31-0893
7/10/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Itasca
Unnamed
31-1366
8/9/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
County
Lake Name
MN DNR
Lake ID
Itasca
Walters
Itasca
Hay
Itasca
Itasca
Unnamed
31-1367
8/9/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Kandiyohi
Ella
34-0033
8/9/2012
<0.10
0.0173
nd
0.245
0.188
nd
P
P
0.0724
nd
nd
nd
nd
nd
nd
nd
nd
0.0525
nd
nd
Kandiyohi
Woodcock
34-0141
8/15/2012
0.10
nd
nd
nd
nd
nd
0.05
nd
0.0306
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
Kandiyohi
Norway
34-0251
8/6/2012
-
0.0408
nd
0.0614
0.0388
nd
P
nd
0.068
nd
nd
nd
nd
nd
nd
nd
nd
0.0208
nd
nd
Kandiyohi
Lindgren
34-0294
8/14/2012
-
nd
nd
0.0721
0.0671
nd
0.06
nd
0.157
nd
nd
nd
nd
nd
nd
nd
nd
0.0269
nd
nd
Kandiyohi
Mary
34-0249
8/14/2012
0.23
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Kandiyohi
Swenson
34-0321
8/6/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Lac Qui Parle
Unnamed
37-0026
7/9/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Lac Qui Parle
Unnamed
37-0100
7/9/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Lac Qui Parle
Unnamed
37-0134
7/9/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Lake
Crooked
38-0024
7/30/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Lake
Divide
38-0256
8/28/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Lake
Becoosin
38-0472
6/26/2012
<0.10
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
Lake
Cattyman
38-0510
8/1/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Lake
Spree
38-0623
6/27/2012
-
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
Lake
Two Deer
38-0671
7/23/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
_____________________________________________________________________________________________________________________________ _________________
Pesticides in MN Lakes 11/2013
Minnesota Department of Agriculture
33
Appendix 2 (continued)
Table A2: 2012 NLA Detected Pesticide Compounds
Note: “-“ = sample not analyzed for specific compound, “nd” = non-detect, “P” = Present but below Method Reporting Limit
Metolachlor OXA
Metolachlor ESA
Dimethenamid OXA
Dimethenamid ESA
Hydroxyatrazine
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
nd
nd
nd
P
P
0.0615
nd
nd
nd
nd
nd
nd
nd
nd
0.0195
0.0126
nd
Le Sueur
Savidge
40-0107
7/12/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Lincoln
Popowski
41-0044
7/16/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Lincoln
North Ash
41-0055
7/17/2012
<0.10
nd
nd
0.0665
0.0641
nd
nd
nd
0.12
nd
nd
nd
nd
nd
nd
nd
nd
0.0415
0.0117
nd
Lyon
East Twin
42-0070
8/20/2012
0.11
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
McLeod
South
43-0014
6/7/2012
0.35
0.0737
P
0.129
0.133
nd
0.22
0.09
0.295
nd
P
0.025
nd
0.159
0.135
nd
Saflufenacil
-
nd
Metolachlor
-
nd
MCPP
-
<0.10
MCPA
<0.10
8/9/2012
Flumetsulam
7/12/2012
40-0098
Dimethenamid
40-0098
Unnamed
Bentazon
Unnamed
Le Sueur
Atrazine
Le Sueur
Alachlor ESA
Sample
Date
Acetochlor ESA
MN
DNR
Lake ID
Acetochlor
Lake Name
2,4-D
County
Atrazine ELISA
Desethylatrazine
Detected Pesticide or Pesticide Degradate Concentration (µg/L)
Acetochlor OXA
Lake and Sample Information
McLeod
Bear
43-0076
6/12/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
0.022
2
-
-
0.0096
2
-
-
-
-
-
-
Mahnomen
Circle
44-0140
7/31/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Mahnomen
Unnamed
44-0228
7/19/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Mahnomen
44-0244
8/2/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
46-0098
7/11/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Meeker
Unnamed
Dutton
Slough
Jennie
47-0015
6/12/2012
<0.10
0.0526
P
0.13
0.1
0.0446
0.05
P
0.16
nd
nd
nd
nd
nd
nd
nd
P
0.295
0.0999
nd
Mille Lacs
Unnamed
48-0019
7/23/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Morrison
Unnamed
49-0139
8/10/2012
-
nd
nd
nd
nd
nd
0.014
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
Murray
Summit
51-0068
8/20/2012
0.22
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Murray
Iron
51-0079
7/17/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Murray
Iron
51-0079
8/20/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Nobles
Ocheda
53-0024
8/15/2012
0.14
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Norman
Home
54-0013
8/2/2012
0.17
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Otter Tail
Unnamed
56-0113
7/23/2012
0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Martin
0.0086 nd
0.196 0.75
_____________________________________________________________________________________________________________________________ _________________
Pesticides in MN Lakes 11/2013
Minnesota Department of Agriculture
34
Appendix 2 (continued)
Table A2: 2012 NLA Detected Pesticide Compounds
Note: “-“ = sample not analyzed for specific compound, “nd” = non-detect, “P” = Present but below Method Reporting Limit
Metolachlor OXA
Metolachlor ESA
Dimethenamid OXA
Dimethenamid ESA
Hydroxyatrazine
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
nd
nd
nd
0.07
P
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
Otter Tail
Fiske
56-0430
6/11/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Otter Tail
Maine (Round)
56-0476
8/8/2012
-
0.0175
nd
nd
nd
nd
P
P
0.0136
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
Otter Tail
Horseshoe
56-0492
8/20/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Otter Tail
East Red River
56-0573
7/24/2012
-
0.029
nd
nd
nd
0.0651
0.05
P
0.0129
nd
nd
nd
nd
nd
nd
nd
nd
0.0879
0.0358
nd
Otter Tail
Holbrook
56-0578
7/31/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Otter Tail
South Stang
56-0629
7/25/2012
-
0.00897
nd
nd
nd
nd
nd
nd
0.0513
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
Otter Tail
Unnamed
56-0810
8/21/2012
<0.10
0.00876
nd
0.0736
0.0462
nd
P
nd
0.0639
nd
nd
nd
nd
nd
nd
nd
nd
0.125
0.0786
nd
Otter Tail
Unnamed
56-0853
7/25/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Otter Tail
Unnamed
56-0985
7/30/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Saflufenacil
-
nd
Metolachlor
-
0.011
MCPP
-
-
MCPA
<0.10
7/31/2012
Flumetsulam
7/23/2012
56-0356
Dimethenamid
56-0147
Fairy
Bentazon
Unnamed
Otter Tail
Atrazine
Otter Tail
Alachlor ESA
Sample
Date
Acetochlor ESA
MN DNR
Lake ID
Acetochlor
Lake Name
2,4-D
County
Atrazine ELISA
Desethylatrazine
Detected Pesticide or Pesticide Degradate Concentration (µg/L)
Acetochlor OXA
Lake and Sample Information
Otter Tail
Unnamed
56-1582
8/20/2012
0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Pennington
Unnamed
57-0027
7/12/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Pine
Wilbur
58-0045
7/10/2012
<0.10
0.753
nd
nd
nd
nd
0.08
P
0.0112
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
Polk
Unnamed
60-0078
8/2/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Polk
Unnamed
60-0099
8/22/2012
<0.10
nd
nd
nd
nd
nd
nd
nd
0.0454
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
Polk
Unnamed
60-0129
8/21/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Polk
Unnamed
60-0211
7/30/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Polk
Unnamed
60-0275
8/2/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Polk
Unnamed
60-0281
7/30/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Polk
Unnamed
60-0319
7/31/2012
<0.10
nd
nd
nd
nd
nd
P
P
0.0086
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
Pope
Unnamed
61-0091
8/14/2012
-
nd
nd
nd
nd
nd
P
nd
0.0303
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
Pope
Unnamed
61-0189
8/13/2012
0.12
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
_____________________________________________________________________________________________________________________________ _________________
Pesticides in MN Lakes 11/2013
Minnesota Department of Agriculture
35
Appendix 2 (continued)
Table A2: 2012 NLA Detected Pesticide Compounds
Note: “-“ = sample not analyzed for specific compound, “nd” = non-detect, “P” = Present but below Method Reporting Limit
2,4-D
Acetochlor
Acetochlor ESA
Acetochlor OXA
Alachlor ESA
Atrazine
Desethylatrazine
Hydroxyatrazine
Bentazon
Dimethenamid
Dimethenamid ESA
Dimethenamid OXA
Flumetsulam
MCPA
MCPP
Metolachlor
Metolachlor ESA
Metolachlor OXA
Saflufenacil
Detected Pesticide or Pesticide Degradate Concentration (µg/L)
Atrazine ELISA
Lake and Sample Information
Ramsey
Snail
62-0073
6/7/2012
0.13
0.0758
P
nd
nd
nd
0.1
0.06
0.0204
nd
nd
nd
nd
nd
nd
nd
P
0.042
nd
nd
Redwood
Unnamed
64-0096
7/11/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
St. Louis
Big
69-0050
8/7/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
St. Louis
Spring
69-0129
6/19/2012
-
nd
nd
nd
nd
nd
P
P
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
St. Louis
Little Crab
69-0296
7/31/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
St. Louis
Long
69-0653
7/24/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
St. Louis
Net
69-0757
6/21/2012
-
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
St. Louis
Stuart
Little
Diamond
High Island
69-0920
9/6/2012
0.10
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
nd
71-0044
8/7/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
72-0050
6/13/2012
0.12
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Stearns
Clear
73-0172
6/11/2012
-
0.00967
P
0.113
0.0774
nd
P
P
0.174
nd
nd
nd
nd
nd
nd
nd
nd
0.132
0.0657
nd
Stearns
Black Oak
73-0241
6/11/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Stearns
Unnamed
73-0317
8/7/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Stevens
Silver
75-0164
8/21/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Stevens
Unnamed
75-0205
8/20/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Todd
Unnamed
77-0258
8/20/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Washington
Terrapin
82-0031
6/6/2012
-
0.0107
P
nd
nd
nd
0.08
0.05
0.017
nd
nd
nd
nd
nd
nd
nd
P
nd
nd
nd
Wright
Unnamed
86-0065
8/27/2012
<0.10
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Wright
Cokato
86-0263
6/13/2012
<0.10
0.0646
0.32
0.594
0.409
0.117
0.05
P
0.112
nd
0.15
0.111
nd
nd
0.07
0.276
0.0994
0.0352
County
Sherburne
Sibley
Lake Name
MN
DNR
Lake
ID
Sample
Date
0.0703 0.0702
_____________________________________________________________________________________________________________________________ _________________
Pesticides in MN Lakes 11/2013
Minnesota Department of Agriculture
36