Scientific Investigation Report 2013–5023

U.S. Department of the Interior

U.S. Geological Survey

Methods, Quality Assurance, and Data for Assessing 

Atmospheric Deposition of Pesticides in the Central Valley of 

California
Cover. Photograph of Central Valley on front cover from istockphoto.com.
Methods, Quality Assurance, and Data 

for Assessing Atmospheric Deposition 

of Pesticides in the Central Valley of 

California

By Celia Zamora, Michael S. Majewski, and William T. Foreman

Scientific Investigations Report 2013-5023

U.S. Department of the Interior

U.S. Geological Survey
U.S. Department of the Interior

KEN SALAZAR, Secretary

U.S. Geological Survey

Suzette M. Kimball, Acting Director

U.S. Geological Survey, Reston, Virginia: 2013

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Suggested citation:

Zamora, Celia, Majewski, M.S., and Foreman, W.T., 2013, Methods, quality assurance, and data for assessing atmospheric deposition of pesticides in the Central Valley of California: U.S. Geological Survey Scientific Investigations 

Report 2013-5023, 180 p.
iii

Acknowledgments

The California Department of Pesticide Regulation and the California Regional Water 

Quality Control Board provided funding for this study. 

Connie Clapton, Henry Miyashita, and Patricia Orlando (USGS California Water 

Science Center) helped collect and process samples for this study. Serena Skaates, 

James Madsen, Max Stroppel, and Frank Wiebe (USGS National Water Quality 

Laboratory) helped with methods development and sample analysis. Jo Ann 

Gronberg and Donna Knifong assisted with figures and compilation of pesticide 

application data.
iv

Contents

Acknowledgments........................................................................................................................................iii

Abstract...........................................................................................................................................................1

Introduction.....................................................................................................................................................2

Study Areas............................................................................................................................................2

Sacramento Valley.......................................................................................................................2

San Joaquin Valley ......................................................................................................................4

Study Objective and Design................................................................................................................5

2001 Study Design........................................................................................................................5

2002–04 Study Design..................................................................................................................5

Purpose and Scope ..............................................................................................................................5

Methods of Monitoring .................................................................................................................................5

Field Sampling Methods ......................................................................................................................5

Cleaning Procedures for Sampling Media ..............................................................................5

Storm-Drain Runoff .....................................................................................................................9

Wet Deposition.............................................................................................................................9

Dry Deposition..............................................................................................................................9

Bulk Deposition (Bulk Wet Deposition and Bulk Dry Deposition)......................................10

Deposition to Soil Box ..............................................................................................................10

Soil-Box Runoff (Aqueous Phase and Suspended Sediment)...................................10

Surficial Soil.......................................................................................................................11

Laboratory Analytical Methods........................................................................................................11

2001 Study Period.......................................................................................................................11

2002–04 Study Period ................................................................................................................12

Reporting Levels.........................................................................................................................12

Laboratory and Field Quality Control ........................................................................................................16

Laboratory Quality-Control Methods...............................................................................................16

Dry-Deposition and Bulk Dry-Deposition Samples ..............................................................17

Soil-Box Suspended Sediment................................................................................................17

Soil-Box Surficial Soil ...............................................................................................................17

Field Quality-Control Methods..........................................................................................................28

2001 Study Period.......................................................................................................................31

2002–04 Study Period ................................................................................................................31

Equipment and Field Blanks............................................................................................31

Split Replicates .................................................................................................................31

QA for Soil-Box Samples .................................................................................................31
v

Contents—Continued

Results of Monitoring..................................................................................................................................32

2001 Study Period (Rainfall and Storm-Drain Runoff)...................................................................32

2002–04 Study Period .........................................................................................................................33

Wet-Deposition Sample Type ..................................................................................................35

Bulk Wet-Deposition Sample Type .........................................................................................35

Dry-Deposition Sample Type....................................................................................................42

Bulk Dry-Deposition Sample Type...........................................................................................42

Soil-Box Runoff Sample Types (Aqueous Phase and Suspended Sediment)..................42

Soil-Box Surficial-Soil Sample Type.......................................................................................47

Summary and Conclusions.........................................................................................................................57

2001 Study Period................................................................................................................................57

2002–04 Study Period .........................................................................................................................60

References Cited..........................................................................................................................................61

Appendix 1. Sample Preparation and Instrumental Analyses .........................................................65

Sample Preparation Methods...........................................................................................................65

Dry and Bulk Dry-Deposition Samples (NWQL Research Method LS8054).....................65

Suspended Sediment Sample (NWQL Research Method LS7503)....................................65

Surficial-Soil Samples (NWQL Research Method LS5503) ................................................66

Instrumental Analysis (All Sample Types) ......................................................................................66

References Cited..........................................................................................................................................67

Appendix 2. Analytical Results for Wet Deposition (Rainfall) in Micrograms Per Liter (μg/L)

for Samples With at Least One Detection Collected at Four Urban and Agricultural

Sites, and Storm Run-Off Samples at the McHenry Storm Drain in Modesto,

California, January 23–26, 2001....................................................................................................68

Appendix 3. Calculated Flux Values Presented in Micrograms Per Square Meter Per Day

(μg/m2/day) for Wet-Deposition Samples With at Least One Detection Collected

During the 2002–04 Study Period at Eight Sites in the Central Valley, California ................73

Appendix 4. Calculated Flux Values Presented in Micrograms Per Square Meter Per Day

(μg/m2

/day) for Bulk Wet-Deposition Samples With at Least One Detection Collected

During the 2002–04 Study Period at Eight Sites in the Central Valley, California ..............132

Appendix 5. Calculated Flux Values Presented in Micrograms Per Square Meter Per Day

(μg/m2/day) for Dry-Deposition Samples With at Least One Detection Collected

During the 2002–04 Study Period at Seven Sites in the Central Valley, California ............146

Appendix 6. Calculated Flux Values Presented in Micrograms Per Square Meter Per Day

(μg/m2/day) for Bulk Dry-Deposition Samples With at Least One Detection Collected

During the 2002–04 Study Period at Eight Sites in the Central Valley, California ..............157
vi

Contents—Continued

Appendix 7. Analytical Results Presented in Micrograms Per Liter (μg/L) for Compounds

With at Least One Detection Collected as Soil-Box Runoff (Aqueous Phase) Samples

From Two Sites in the San Joaquin Valley and One Site in the Sacramento Valley,

California, November 2002–March 2004...................................................................................163

Appendix 8. Analytical Results Presented in Micrograms Per Liter (μg/L) for Compounds

With at Least One Detection From the Soil Box as Soil-Box Runoff (Suspended

Sediment) Samples Collected at Two Sites in the San Joaquin Valley and One Site in

the Sacramento Valley, California, November 2002–March 2004 ........................................169

Appendix 9. Analytical Results Presented in Micrograms Per Kilogram (μg/Kg) for

Compounds With at Least One Detection From the Soil Box as Surficial-Soil Samples

Collected at Two Sites in the San Joaquin Valley and One Site in the Sacramento

Valley, California, November 2002–March 2004 ......................................................................174
vii

Figures

1. Figure showing the Central Valley of California and its four hydrographic subregions ...3

2. Graph showing monthly rainfall totals from the rainfall gage at Oroville Dam

(site 15) in California, 2001–04.....................................................................................................4

3. Graph showing monthly rainfall totals from the City of Modesto rainfall gage in

downtown Modesto, California (site 4), 2001–04 ....................................................................4

4. Figure showing study area, land use, and sampling sites for the 2001 and 2002–04

sampling periods in the Central Valley of California...............................................................6

5. Photo showing funnel sampler at the Newman rain gage site at wasteway levee

near Draper Road (site 11) in the Central Valley of California...............................................9

6. Photo showing autosampler at Gridley, California (site 16).................................................10

7. Photos showing soil box at the Modesto Irrigation District gage at Albers Road

(site 5) in the Central Valley of California................................................................................11

8. Photograph of surficial soil box sampling array....................................................................11

9. Bar graph showing concentrations of diazinon and chlorpyrifos in rainfall

measured at the four urban and four agricultural sites during the January 25–26,

2001, storm event in the area of Modesto, California ...........................................................33

10. Bar graph showing measured discharge and concentration of insecticides

diazinon and chlorpyrifos detected in the hourly storm-drain runoff samples

collected during the January 25–26, 2001, storm event in Modesto, California...............34

11. Figure showing distribution of calculated wet-deposition fluxes for the five most

frequently detected compounds collected from the San Joaquin Valley and

Sacramento Valley, California, sites during the 2002–04 study period ..............................37

12. Graphs showing comparison of concentrations of chlorpyrifos, dacthal, and

diazinon collected from the autosampler and funnel sampler for the same sampling

events at sites in the Central Valley of California during 2002–04......................................39

13. Figure showing distribution of calculated bulk wet-deposition fluxes for the most

detected compounds collected from the San Joaquin Valley and Sacramento

Valley sites during the 2002–04 study period ........................................................................41

14. Figure showing distribution of calculated dry-deposition fluxes for the top five most

detected compounds collected from the San Joaquin Valley compared to

detections in the Sacramento Valley of California during the 2002–04 study period......43

15. Figure showing distribution of calculated bulk dry-deposition fluxes for the top five

most detected compounds collected from the San Joaquin Valley compared to

detections in the Sacramento Valley, California, during the 2002–04 study period.........45

16. Figure showing comparison of the distribution of concentrations of the most

detected compounds collected from the San Joaquin Valley, California, soil-box

sites 4 and 5 as aqueous-phase and suspended-sediment sample types during the

2002–04 study period..................................................................................................................48

17. Figure showing comparison of the distribution of concentrations of the most

detected compounds collected from the Sacramento Valley, California, soil-box site

16 as aqueous-phase and suspended-sediment sample types during the 2002–04

study period .................................................................................................................................50
viii

Tables

1. Site number, site name, study period, sampling equipment, location setting, and

sample type collected during the 2001 and 2002–04 sampling periods in the Central

Valley of California........................................................................................................................7

2. Predominant land-use classification within a 4-kilometer radius surrounding each

of the 2001 rainfall sampling sites in the area of Modesto, California.................................8

3. Predominant land-use classification within a 4-kilometer radius surrounding each

of the 2002–04 rainfall sampling sites in the Central Valley of California............................8

4. Laboratory analytical method by sample type and study period........................................12

5. Pesticides analyzed and the laboratory reporting limits for samples collected in the

Central Valley of California during the 2001 and 2002–04 study periods ...........................13

6. Minimum, maximum, and median percentage recoveries for laboratory surrogates

prepared and analyzed with all environmental-sample types submitted to the

National Water Quality Laboratory (NWQL)...........................................................................16

7. Minimum, maximum, median, and standard deviation of percentage recoveries for

laboratory reagent spikes extracted along with the dry-deposition and bulk

dry-deposition environmental samples...................................................................................18

8. Total number and detection mass for the laboratory reagent blanks extracted along

with the dry deposition and bulk-dry deposition environmental samples ........................20

9. Minimum, maximum, median, and standard deviation of percentage recoveries for

laboratory-reagent spikes in the soil-box suspended-sediment samples........................22

10. Concentration in micrograms per kilogram (μg/Kg) of duplicate environmental

aliquots of soil-box mix 1, mix 2, mix 3, and mix 4, and the relative percentage

difference between each of the duplicate sets.....................................................................24

11. Ambient concentrations, spike concentrations, calculated recoveries for the

laboratory matrix spike and laboratory reagent spike, and the relative percentage

difference between recoveries of the soil-box surficial-soil samples ..............................29

12. Environmental and field quality-control sample types and totals collected during

the 2001 and 2002–04 study periods in the Central Valley of California.............................31

13. Minimum, maximum, and median relative percentage difference values for

compounds detected in at least one sample of the replicate set ......................................32

14. Median concentrations of compounds detected in samples collected from the

urban and agricultural rainfall collection sites in Modesto, California, during the

January 25–26, 2001, sampling event......................................................................................33

15. Comparison of median concentrations and the physical and chemical properties of

detected pesticides in rainfall (sites 3 and 4) and storm-drain runoff (site 9) during

the January 25–26, 2001, sampling event in Modesto, California.......................................34

16. Total number of samples analyzed and detection frequency for compounds

analyzed in wet deposition and that had at least one detection during the 2002–04

study period in the Central Valley of California......................................................................36

17. Detection frequency, and percentiles for the most frequently detected compounds

collected as wet, bulk wet, dry, bulk dry deposition and soil box runoff collected in

the San Joaquin Valley and Sacramento Valley, California, during the 2002–04 study

 period...........................................................................................................................................38

18. Comparison of wet and dry-deposition pesticide amounts detected in discrete

samples collected from the autosampler at site 4 during the April 9–May 21, 2002,

sampling event in the Central Valley of California and the physical and chemical

properties of the pesticides ......................................................................................................40
ix

19. Detection frequency for compounds analyzed as bulk-wet deposition with at least

one detection during the 2002–04 study period in the Central Valley of California .........41

20. Detection frequency for compounds analyzed as dry deposition with at least one

detection during the 2002–04 study period in the Central Valley of California.................43

21. Comparison of compounds detected in dry-deposition samples collected from

funnel and autosamplers at San Joaquin Valley, California, urban site 4, and

agricultural site 5 during two composite sampling periods in 2002 and 2003 ..................44

22. Detection frequency for compounds analyzed as bulk-dry deposition with at least

one detection during the 2002–04 study period in the Central Valley of California .........45

23. Detection frequency for samples collected as soil-box runoff (aqueous-phase and

suspended-sediment sample types) from the San Joaquin Valley and Sacramento

Valley, California, soil-box sites during the 2002–04 study period......................................46

24. Comparison of detection frequencies and median concentrations of detected

compounds common to aqueous-phase and suspended-sediment soil-box runoff

samples collected from the San Joaquin Valley and Sacramento Valley, California,

soil-box sites during the 2002–04 study period......................................................................49

25. Comparison of concentrations of compounds detected in the aqueous-phase

sample type to those detected in wet deposition for the same sampling periods

during the 2002–04 study in the Central Valley of California................................................51

26. Detection frequency and comparison of concentrations of compounds detected

before and after atmospheric exposure for the surficial soil-box sample type

collected from the San Joaquin Valley and Sacramento Valley, California, soil-box

sites during the 2002–04 study period .....................................................................................58

Tables—Continued
x

Multiply By To obtain

Length

centimeter (cm) 0.3937 inch (in.)

millimeter (mm) 0.03937 inch (in.)

meter (m) 3.281 foot (ft) 

kilometer (km) 0.6214 mile (mi)

Area

square meter (m2

) 10.76 square foot (ft2) 

square kilometer (km2

) 0.3861 square mile (mi2)

Volume

liter (L) 0.2642 gallon (gal)

liter (L) 61.02 cubic inch (in3

) 

Mass

gram (g) 0.03527 ounce, avoirdupois (oz)

kilogram (kg) 2.205 pound avoirdupois (lb)

Loading Rate

micrograms per square meter per day

[(μg/m2

)/day]

0.00324 pounds per acre per year

[(lb/acre)/yr]

Conversion Factors

SI to Inch/Pound

Temperature in degrees Celsius (°C) may be converted to degrees Fahrenheit (°F) as follows:

°F=(1.8×°C)+32

Altitude, as used in this report, refers to distance above the vertical datum.

Vertical coordinate information is referenced to North American Vertical Datum of 1988 (NAVD 

88).

Horizontal coordinate information is referenced to North American Datum of 1983 (NAD 83).

*Transmissivity: The standard unit for transmissivity is cubic foot per day per square foot times 

foot of aquifer thickness [(ft3/d)/ft2]ft. In this report, the mathematically reduced form, foot 

squared per day (ft2/d), is used for convenience.

Specific conductance is given in microsiemens per centimeter at 25 degrees Celsius (μS/cm at 

25°C).

Concentrations of chemical constituents in water are given either in milligrams per liter (mg/L) 

or micrograms per liter (μg/L).
xi

B-H biased-high

B-L biased-low

CAWSC California Water Science Center

CDPR California Department of Pesticide Regulation

D-U value deleted by NWQL because compound could not be determined due to matrix 

interference

E estimated reported laboratory value

(E) estimated compound concentration due to recognized laboratory performance issues

EPA Environmental Protection Agency

GC-MS gas chromatography-mass spectrometry

H Henry’s Law constant

log Koc soil-organic carbon partition coefficient

LRB laboratory reagent blank

LRL laboratory reporting limit

LRS laboratory reagent spike

LT-MDL long-term method detection limit

MDL method detection limit

MID Modesto Irrigation District

NEMI National Environmental Methods Index

NWQL National Water Quality Laboratory

OP organophosphate

PBW pesticide-grade blank water

PL sub-cooled liquid vapor-phase pressure

QA quality assurance

QC quality control

QMS Quality management system

RPD relative percent difference

SJR San Joaquin River

SL water solubility

SPE solid phase-extraction

ss-IRL sample-specific interim reporting limit

USGS U.S. Geological Survey

Abbreviations
Abstract 1

Abstract

The U.S. Geological Survey monitored atmospheric 

deposition of pesticides in the Central Valley of California 

during two studies in 2001 and 2002–04. The 2001 study 

sampled wet deposition (rain) and storm-drain runoff in the 

Modesto, California, area during the orchard dormant-spray 

season to examine the contribution of pesticide concentrations to storm runoff from rainfall. In the 2002–04 study, the 

number and extent of collection sites in the Central Valley 

were increased to determine the areal distribution of organophosphate insecticides and other pesticides, and also five more 

sample types were collected. These were dry deposition, bulk 

deposition, and three sample types collected from a soil box: 

aqueous phase in runoff, suspended sediment in runoff, and 

surficial-soil samples. This report provides concentration data 

and describes methods and quality assurance of sample collection and laboratory analysis for pesticide compounds in all 

samples collected from 16 sites. Each sample was analyzed 

for 41 currently used pesticides and 23 pesticide degradates, 

including oxygen analogs (oxons) of 9 organophosphate 

insecticides. Analytical results are presented by sample type 

and study period.

The median concentrations of both chloryprifos and 

diazinon sampled at four urban (0.067 micrograms per liter 

[μg/L] and 0.515 μg/L, respectively) and four agricultural 

sites (0.079 μg/L and 0.583 μg/L, respectively) during a 

January 2001 storm event in and around Modesto, Calif., 

were nearly identical, indicating that the overall atmospheric 

burden in the region appeared to be fairly similar during the 

sampling event. Comparisons of median concentrations in the 

rainfall to those in the McHenry storm-drain runoff showed 

that, for some compounds, rainfall contributed a substantial percentage of the concentration in the runoff; for other 

compounds, the concentrations in rainfall were much greater 

than in the runoff. For example, diazinon concentrations in 

rainfall were about 70 percent of the diazinon concentration in the runoff, whereas the chlorpyrifos concentration in 

the rain was 1.8 times greater than in the runoff. The more 

water-soluble pesticides—carbaryl, metolachlor, napropamide, 

and simazine—followed the same pattern as diazinon and had 

lower concentrations in rain compared to runoff. Similar to 

chlorpyrifos,compounds with low water solubilities and higher 

soil-organic carbon partition coefficients, including dacthal, 

pendimethalin, and trifluralin, were found to have higher 

concentrations in rain than in runoff water and were presumed 

to partition to the suspended sediments and organic matter on 

the ground. 

During the 2002–04 study period, the herbicide dacthal 

had the highest detection frequencies for all sample types 

collected from the Central Valley sites (67–100 percent). The 

most frequently detected compounds in the wet-deposition 

samples were dacthal, diazinon, chlorpyrifos, and simazine 

(greater than 90 percent). The median wet-deposition amounts 

for these compounds were 0.044 micrograms per square meter 

per day (μg/m2/day), 0.209 μg/m2/day, 0.079 μg/m2/day, and 

0.172 μg/m2/day, respectively. For the dry-deposition samples, 

detection frequencies were greater than 73 percent for the 

compounds dacthal, metolachor, and chlorpyrifos, and median 

deposition amounts were an order of magnitude less than for 

wet deposition. The differences between wet deposition and 

dry deposition appeared to be closely related to the Henry’s 

Law (H) constant of each compound, although the mass 

deposited by dry deposition takes place over a much longer 

time frame. 

Pesticides detected in rainfall usually were detected in the 

aqueous phase of the soil-box runoff water, and the runoff concentrations were generally similar to those in the rainfall. For 

compounds detected in the aqueous phase and suspended-sediment samples of soil-box runoff, concentrations of pesticides 

in the aqueous phase generally were detected in low concentrations and had few corresponding detections in the suspended-sediment samples. Dacthal, diazinon, chlorpyrifos, and 

simazine were the most frequently detected pesticides (greater 

than 83 percent) in the aqueous-phase samples, with median 

concentrations of 0.010 μg/L, 0.045 μg/L, 0.016 μg/L, and 

0.077 μg/L, respectively. Simazine was the most frequently 

detected compound in the suspended-sediment samples 

(69 percent), with a median concentration of 0.232 μg/L.

Methods, Quality Assurance, and Data for Assessing 

Atmospheric Deposition of Pesticides in the Central Valley 

of California

By Celia Zamora, Michael S. Majewski, and William T. Foreman
2 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides

Results for compounds detected in the surficial-soil 

samples collected throughout the study period showed that 

there was an increase in concentration for some compounds, 

indicating atmospheric deposition of these compounds onto 

the soil-box surface. In the San Joaquin Valley, the compounds chlorpyrifos, dacthal, and iprodione were detected at 

higher concentrations (between 1.4 and 2 times greater) than 

were found in the background samples collected from the 

San Joaquin Valley soil-box sites. In the Sacramento Valley, 

the compounds chlorpyrifos, dacthal, iprodione, parathionmethyl, and its oxygen analog, paraoxon-methyl, were 

detected in samples collected during the study period in low 

concentrations, but were not detected in the background concentration of the Sacramento Valley soil mix. 

Introduction

California is one of the world’s leading agricultural areas, 

and many thousands of metric tons of pesticides are used each 

year on many different crops (Majewski and Baston, 2002). 

Pesticides have been recognized as potential air pollutants 

since 1946 (Daines, 1952), and a wide variety have been 

detected in California air (Baker and others, 1996; Majewski 

and Baston, 2002; Zamora and others, 2003; Majewski and 

others, 2005). In most cases, pesticides in agriculture are 

applied by spraying an aqueous suspension. As a result, a portion of the sprayed compound does not reach the target area, 

but is transported by wind beyond the application site as direct 

drift. The droplets transported by the drift are either deposited 

on soil or plants close to the treated area or are transported in 

the atmosphere over longer distances, depending on their size. 

A loss of pesticide after application caused by volatilization 

or wind erosion of soil to the atmosphere is called “indirect 

drift.” These direct and indirect sources to drift are the main 

input paths of pesticides in the atmosphere (Epple and others, 

2002). Post-application volatilization from treated surfaces 

is often a major dissipation pathway for many pesticides 

(Glotfelty, 1978; Cliath and others, 1980; Glotfelty and others, 

1990; Risebrough, 1990; Majewski, 1991; Majewski and others, 1993; Majewski and Capel, 1995; Seiber and Woodrow, 

1995, Wania and Mackay, 1996; Majewski and Baston, 2002). 

Atmospheric transport and subsequent deposition of 

pesticides can affect the quality of streams and other surface 

waters adversely. Residues of pesticides in surface waters 

of the Central Valley have been evaluated in many previous studies (Kuivala and Foe, 1995, Domagalski, 1997a, b; 

Domalgalski and others, 1997; Panshin and others, 1998; 

Kratzer, 1998; Kratzer, 1999; Kratzer and others, 2002). 

Under section 303(d) of the 1972 Clean Water Act, states 

are required to develop lists of impaired waters that do not 

meet the water-quality standards set by states. The 303(d) 

list shows that several streams in the Central Valley are 

impaired because of pesticides (U.S. Environmental Protection 

Agency, http://www.epa.gov/region09/water/tmdl/303d-pdf/

ca-06-303d-list-final-06-28-07-combined.pdf, accessed August 

2012). The most frequent impairments have been attributed to 

the organophosphate (OP) insecticides diazinon and chlorpyrifos. Most of the agricultural applications of diazinon and 

chlorpyrifos take place from December through February. 

They are applied to dormant orchards of several stone fruits 

and nuts in the San Joaquin Basin, primarily almonds (Panshin and others, 1998). These insecticides are applied during 

extended dry periods during the dormant-spray period, and 

then rainfall events after spraying cause most of the unintentional transport of pesticides from fields to streams with 

rainfall-induced runoff. Atmospheric transport and subsequent 

deposition of pesticides are most likely to affect stream water 

quality when rain and direct surface runoff are major sources 

of streamflow. 

Study Areas

The Central Valley is a large flat valley that dominates 

the central portion of California and is one of California’s 

most productive agricultural regions. It is about 400 miles 

long, averages 50 miles in width, and is composed of four 

hydrographic subregions or drainage basins named for the 

major natural surface-water feature in each subregion (fig. 1). 

Sacramento Valley, the northernmost third of the Central 

Valley, has an area of about 4,400 square miles (mi2) and is 

drained by its namesake, the Sacramento River. San Joaquin 

Valley, the southern two-thirds of the Central Valley, has two 

subregions: the San Joaquin Basin and, at the southern end, 

a basin of interior drainage called the Tulare Basin after a 

Pleistocene lake that occupied most of the area. The fourth 

hydrographic subregion is the delta, a low lying area that 

drains directly to the Sacramento–San Joaquin Delta rather 

than to either river. The lower part of the delta subregion consists of wetlands interspersed with hundreds of miles of channels and numerous islands (Bertoldi and others, 1991). In this 

report, the study area only includes the San Joaquin Valley and 

Sacramento Valley, and results are summarized by the respective geographic region.

Sacramento Valley

The Sacramento Valley is geographically contiguous 

with the San Joaquin Valley to the south, but is defined by its 

distinct drainage basin. The generally flat valley floor covers 

about 5,000 mi2, and its elevation decreases from about 300 ft. 

at its northern end to near sea level in the delta. The major 

land uses in the watershed are forestry, agriculture, urban, and 

mining. Agriculture is the dominant land use on the valley 

floor, followed by urban development. Orchards—principally, 

walnut, almond, prune, and peach—are found along the river 

channels where they take advantage of well-drained soils. 

The hot summer and temperate winter climate, combined with 

the availability of water for irrigation during the normally dry 

summer months, allows for a variety of crops to be grown. 
Introduction 3

0 50 100 25 MILES

0 50 100 25 KILOMETERS

EXPLANATION

Sacramento Basin Valley floor

San Joaquin Basin Valley Floor

Tulare Basin Valley Floor

Sacramento–San Joaquin Delta

42°

124° 122° 120°

40°

38°

36°

34°

Figure 1. The Central Valley of California and its four hydrographic subregions.
4 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides

The predominant land use on the valley 

floor is agriculture. The distribution of 

crops in the valley generally reflects 

the distribution of soil texture and 

chemistry, a long growing season, and 

supply of water for irrigation (Kratzer 

and others, 2011). Orchards and vineyards primarily are grown on the welldrained alluvial-fan soils of the eastside. 

Cotton, a salt tolerant crop, is the principal crop grown on the basin deposits 

at the southern end of the basin. Row 

crops, such as beans, are primarily 

grown on the well-drained alluvial fans 

of the westside. Land along the eastside of San Joaquin River is primarily used for corn, alfalfa, pasture, and 

dairies (Kratzer and others, 2011). 

The San Joaquin Valley has an arid-tosemiarid climate that is characterized by 

hot summers and mild winters. Annual 

precipitation on the valley floor ranges 

from 7 inches (in.) in the south to 15 in. 

in the north (National Center for Atmospheric Research, 

2003). The eastern slopes of the Coast Ranges and the valley 

are in the rain shadow of the Coast Ranges. The major source 

of water entering the basin is wet deposition, or rainfall and 

snow, on the western slope of the Sierra Nevada. The overall long-term average annual rainfall for the basin is 28 in. 

(13 inches in the valley portion only), which mostly falls from 

November through March (National Center for Atmospheric 

Research, 2003). Figure 3 depicts the monthly rainfall totals 

for the study period taken from a City of Modesto rainfall 

gage in downtown Modesto, California (site 4).

Figure 2. Monthly rainfall totals from the rainfall gage at Oroville Dam (site 15) in 

California, 2001–04.

sac12-0461_fig 02

0

2001

Jan.

Feb.

March 

April

May

June

July

August

Sept.

Oct. 

Nov.

2002

Dec.

2003

Jan.

Feb.

March 

April

May

June

July

August

Sept.

Oct. 

Nov.

Dec.

2004

Jan.

Feb.

March 

Jan.

Feb.

April

May

March 

April

May

June

July

August

Sept.

Oct. 

Nov.

Dec.

1

2

3

4

Rainfall totals, in inches per month

0

2001

Jan.

Feb.

March 

April

May

June

July

August

Sept.

Oct. 

Nov.

2002

Dec.

2003

Jan.

Feb.

March 

April

May

June

July

August

Sept.

Oct. 

Nov.

Dec.

2004

Jan.

Feb.

March 

Jan.

Feb.

April

May

March 

April

May

June

July

August

Sept.

Oct. 

Nov.

Dec.

5

10

15

Rainfall totals, in inches per month

Figure 3. Monthly rainfall totals from the City of Modesto rainfall gage in downtown 

Modesto, California (site 4), 2001–04.

The major crops are rice, fruits and nuts, tomatoes, sugar 

beets, corn, alfalfa, and wheat. Dairy products also are important agricultural commodities. The soils of the Sacramento 

Valley are mostly clay with very slow to slow infiltration rates 

(Soil Conservation Service, 1993). Because of the widespread 

presence of clay soils and associated slow infiltration rates, 

and the availability of sufficient irrigation water from the 

Sacramento River, rice farming is possible. Rice production 

includes the seasonal creation of temporary wetlands.

The Sacramento Valley has an arid-to-semiarid climate 

characterized by hot summers and mild winters, and average 

precipitation ranges from 14 to 25 in. Most rain falls in the 

watershed from November through 

April, and the largest amount, on average, falls during the month of January. 

Mean annual rainfall on the valley 

floor tends to increase with latitude 

and elevation, ranging from 17.9 in. 

at Sacramento to 28.8 in. at Oroville 

(http://cdo.ncdc.noaa.gov/cgi-bin/

climatenormals/climatenormals.pl, 

accessed May 27, 2008). Figure 2

depicts the monthly rainfall totals for 

the study period from the Oroville 

Dam rainfall gage (site 15).

San Joaquin Valley

The San Joaquin Valley floor 

is about 3,750 mi2, and the altitude 

ranges from about 1,000 ft in the south 

to near sea level in the north at the 

Sacramento–San Joaquin Delta (fig. 1). 
Methods of Monitoring 5

Study Objective and Design

The data and methods presented in this report are from 

two separate studies that took place over a 3.5-year sampling 

period. For the 2001 study, the objective was to determine 

if agricultural pesticides applied to crops during the orchard 

dormant-spray season (January through February 2001) were 

drifting into urban areas and being deposited, resulting in 

pesticides introduced to urban storm runoff. For the 2002–04 

study, the objective was to determine the areal distribution 

of OP insecticides and other pesticides through wet and dry 

atmospheric deposition and to further investigate contribution 

of pesticides in rainfall to pesticides in runoff from soil surfaces. Figure 4 depicts the study area, land use, and sampling 

sites for the 2001 and 2002–04 sampling periods in the Central 

Valley. The sampling media, location setting, and sample type 

collected during the respective study periods are presented in 

table 1.

2001 Study Design

Wet deposition (rainfall) from a single storm event 

in January 2001 was sampled, and concentrations in rainfall were measured at four urban and four agricultural sites 

(fig. 4, sites 1–8) to examine the overall atmospheric burden 

in the Modesto, Calif., region. At the same time, storm-runoff 

samples were collected from a Modesto storm drain (site 9) 

to examine the contribution of pesticide concentrations to 

storm runoff from rainfall. The storm drain and two of the 

urban sites (sites 3 and 4) were located in a small, urban 

watershed (McHenry storm drain watershed). The major land 

use within a 4-km radius of each of the rainfall sampling site 

is given in table 2. The sites were distributed spatially to be 

representative of the predominant land uses in the study area. 

The urban sampling sites were located on rooftops of buildings to reduce the possibility of ground-level contamination 

and to secure them from public access. Each of the urban sites 

had varying degrees of agricultural activities within a 4-km 

radius (table 2). The agricultural sites were predominately 

surrounded by orchards or other land use (row crops, pasture, 

and native vegetation), and only one agricultural sampling 

location (site 5) was located on a rooftop. 

2002–04 Study Design

For the 2002–04 study, the collection sites were extended 

throughout the Central Valley to determine the areal distribution of OP insecticides and other pesticides. Six sites were 

located in the San Joaquin Valley: two on the west side of the 

San Joaquin River (SJR) in an area of row crops and orchards 

(fig. 4, sites 10 and 11), one in a rural residential area (site 12), 

and another at a small rural airport in an agricultural area 

(site 13). Two of the sites sampled in 2001 (sites 4 and 5) 

were retained for the 2002–04 study period. The locations of 

sites 4 and 5 represented an urban and agricultural setting, 

respectively. In addition, two additional sites were sampled 

in the adjacent northern Sacramento Valley hydrologic basin: 

an urban site located in Gridley, Calif. (site 16), and a downwind site in the Sierra-Nevada foothills (site 15). Table 3

presents the major land use within a 4-km radius of each of 

the 2002–04 sampling sites for both Sacramento and San 

Joaquin Valley study areas. The sample collection period for 

the 2002–04 study began in January 2002 and ended in August 

2004.

The samples collected during this study period included 

wet-deposition, dry-deposition, and bulk-deposition samples. 

In addition, a soil box was added to the 2002–04 study to compare the pesticide concentrations in rainfall to that in runoff 

(aqueous phase and suspended sediment) from the soil, the 

concentrations in aqueous phase with those on the surface soil 

mobilized by the rainfall runoff (suspended sediment), and the 

concentrations of dry deposition collected on the surficial soil.

Purpose and Scope

The purpose of this report is to describe sampling and 

analytical methods used to measure the concentrations of 

pesticide compounds in wet deposition, dry deposition, and 

bulk-deposition samples collected from 16 sites in the Central 

Valley of California. The sampling and analytical methods 

also are presented for samples collected from soil boxes at 

three sites. The pesticide concentration data for each of these 

sample types are presented for the 2001 study and the 2002–04 

study. The two studies were part of a larger U.S. Geological 

Survey (USGS) project designed to identify all sources of pesticides in the San Joaquin and Sacramento River watersheds 

(Majewski and others, 2005; Zamora and others, 2003). 

Methods of Monitoring

Description of methods includes information about field 

collection of the different sample types, sample analyses, and 

quality-control procedures in the laboratory and the field.

Field Sampling Methods

Seven types of samples were collected over the combined 

3.5-year sampling period of the two studies (January 25, 2001, 

to August 7, 2004). The seven sample types collected during 

the two studies are defined and presented separately. 

Cleaning Procedures for Sampling Media

The cleaning procedure for the funnels, collection bottles, 

stainless steel buckets, and the soil box sampling spoon was 

as follows: sampling equipment was rinsed with American 

Society for Testing and Materials (ASTM) II quality deionized 

water (source: California Water Science Center Laboratory, 
6 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides

sac12-0462_fig 04

0 10 20 MILES

0 10 20 KILOMETERS

CALIFORNIA

Study

area

Westley rain gage at pump building 

near lateral 6 North

10.

Newman rain gage at wasteway 

levee near Draper Road

11.

12. Turlock rain gage near Idaho Road

13. Turlock Airport rain gage

Oroville Dam precipitaiton gage at 

spillway

15.

Gridley High School precipitation 

gage at Gridley

16.

2002–04 Sampling Sites

Modesto Irrigation District gage 

rooftop at Modesto

 4.

Modesto Irrigation District gage at 

Albers Road

 5.

Land Use

Citrus

Orchards

Field crops

Grain and hay

Pasture

Rice

Row crops

Vineyard

Water

Urban

2001 Sampling Sites

Sampler Type 

Funnel sampler

Autosampler, soil box, and funnel 

sampler

Soil-control box

Storm drain

EXPLANATION

Waste Water Treatment Plant rooftop 

at Modesto

 1.

 2. Cadoni Road lift station at Modesto 

 3. Bowen and Aloha Street at Modesto 

Modesto Irrigation District gage 

rooftop at Modesto

 4.

Modesto Irrigation District gage at 

Albers Road

 5.

 6. Modesto Irrigation District lateral #4

 7. Turlock Irrigation District lateral #3

 8. Tully Road near Modesto

 9. McHenry storm drain at Bodem Street

14. Soil control box at California State 

University Sacramento Placer Hall 

at Sacramento 8

3

5

7

9 6 4

10 1 2

12 13

11

14

15

16

39°

38°

122° 121°

Figure 4. Study area, land use, and sampling sites for the 2001 and 2002–04 sampling periods in the Central Valley of California.
Introduction 

7

Table 1. Site number, site name, study period, sampling equipment, location setting, and sample type collected during the 2001 and 2002–04 sampling periods in the Central Valley of California.[Abbreviations: CSUS, California State University, Sacramento]

Site

number Site name

Site 

identification 

number

Study 

period Sampling equipment

Sampler

location 

setting

Sample type

1 Waste Water Treatment Plant rooftop at Modesto 373637121004601 2001 Teflon-lined funnel Urban Wet deposition.2 Cadoni Road lift station at Modesto 373725120543701 2001 Teflon-lined funnel Urban Wet deposition.3 Bowen and Aloha Street at Modesto 374028120594301 2001 Teflon-lined funnel Urban Wet deposition.4 Modesto Irrigation District gage rooftop at 

Modesto

373834121000601 2001, 

2002–04

Teflon-lined funnel and automatic 

wet-dry sampler and soil box1

Urban Wet, dry, and bulk deposition2, soil 

runoff (aqueous phase and suspended sediment), and surficial soil.

5 Modesto Irrigation District gage rooftop at Albers 

Road

373841120504801 2001, 

2002–04

Teflon-lined funnel and automatic 

wet-dry sampler and soil box1

Agricultural Wet, dry, and bulk deposition2, soil 

runoff (aqueous phase and suspended sediment), and surficial soil.

6 Modesto Irrigation District lateral #4 373750121092601 2001 Teflon-lined funnel Agricultural Wet deposition.

7 Turlock Irrigation District lateral #3 373228120551201 2001 Teflon-lined funnel Agricultural Wet deposition.8 Tully Road near Modesto 374351121004701 2001 Teflon-lined funnel Agricultural Wet deposition.9 McHenry storm drain at Bodem Street 373847120590801 2001 ISCO sampler3 Urban Storm-drain runoff.

10 Westley rain gage at pump building near lateral 

6 North

373335121143001 2002–04 Teflon-lined funnel Agricultural Wet, dry, and bulk deposition2.

11 Newman rain gage at wasteway levee near Draper 

Road

371735121031201 2002–04 Teflon-lined funnel Agricultural Wet, dry, and bulk deposition2.

12 Turlock rain gage near Idaho Road 372713120534901 2002–04 Teflon-lined funnel Agricultural Wet, dry, and bulk deposition2.13 Turlock Airport rain gage 372857120414001 2002–04 Teflon-lined funnel Agricultural Wet, dry, and bulk deposition2.14 Soil control box at CSUS Placer Hall at Sacramento 383343121252501 2002–04 Soil-box control Urban Surficial soil.

15 Oroville Dam precipitation gage at spillway 393234121292701 2002–04 Teflon-lined funnel Agricultural Wet, dry, and bulk deposition2.

16 Gridley High School precipitation gage at Gridley 392205121410201 2002–04 Teflon-lined funnel and automatic 

wet-dry sampler and soil box

Urban Wet, dry, and bulk deposition2, soil 

runoff (aqueous phase and suspended sediment), and surficial soil.

1Soil boxes added to the existing 2001 site during the 2002–04 study period.2Bulk deposition includes bulk wet and bulk dry-deposition samples as defined in text.3Storm-drain samples collected by using an ISCO automated sampler (Teledyne ISCO Company, Lincoln, Nebr.) that was programmed to collect hourly samples in 1-liter glass collection bottles.
8 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides

Table 2. Predominant land-use classification within a 4-kilometer radius surrounding each of the 2001 rainfall sampling sites in the 

area of Modesto, California.

[Urban land-use classification includes residential, commercial, industrial, and other areas. Agricultural land-use classification includes orchards, vineyards, and 

other areas. Other land use includes corn and other row crops, pasture, and native vegetation]

Site

number Site name Percentage urban

Percentage

orchard

Percentage

vineyards

Percentage

other

Urban sites

1 Waste Water Treatment Plant rooftop at Modesto 56.0 23.5 3.9 16.8

2 Cadoni Road lift station at Modesto 38.8 38.4 2.1 22.1

3 Bowen and Aloha Street at Modesto 88.3 4.9 1.6 5.3

4 Modesto Irrigation District rooftop at Modesto 89.7 3.4 2.4 4.4

Agricultural sites

5 Modesto Irrigation District gage rooftop at Albers Road 6.3 45.8 10.3 43.9

6 Modesto Irrigation District lateral #4 0.5 11.9 0.5 87.1

7 Turlock Irrigation District lateral #3 10.9 49.2 10.1 29.8

8 Tully Road near Modesto 12.3 61.7 3.8 22.3

Table 3. Predominant land-use classification within a 4-kilometer radius surrounding each of the 2002–04 rainfall sampling sites in the 

Central Valley of California.

[Urban land-use classification includes residential, commercial, industrial, and other areas. Agricultural land-use classification includes orchards, vineyards, 

corn/alfalfa/vegetables, and other areas. Other land use includes corn and other row crops, pasture, and native vegetation]

Site

number Site name Percentageurban

Percentage

orchard

Percentage

vineyards

Percentage 

corn/alfalfa/

vegetables

Percentage

other

4 Modesto Irrigation District gage rooftop at Modesto 91.4 2.06 2.25 1.02 3.30

5 Modesto Irrigation District gage rooftop at Albers Road 8.27 40.9 12.8 10.3 27.7

10 Westley rain gage at pump building near lateral 6 North 3.83 31.6 0.44 27.9 36.2

11 Newman rain gage at wasteway levee near Draper Road 8.61 36.0 None 27.4 28.0

12 Turlock rain gage near Idaho Road 5.90 15.2 0.89 58.4 19.7

13 Turlock Airport rain gage 3.1 52.2 2.50 13.1 29.1

15 Oroville Dam precipitation gage at spillway 11.9 0.64 0.01 None 87.4

16 Gridley High School precipitation gage at Gridley 20.9 54.9 0.01 2.39 21.8
Methods of Monitoring 9

CAWSC Laboratory) followed by a thorough wash with a 

dilute Liquinox solution and a sterilized sponge; the wash 

solution was then rinsed by using deionized water, followed 

by a methanol rinse, and then a final rinse of pesticide-grade 

blank water (PBW) purchased and quality assured through the 

National Water Quality Laboratory (NWQL). 

Storm-Drain Runoff 

Urban storm runoff samples were collected from a city 

storm drain in Modesto on an hourly basis beginning on 

January 25, 2001, at 6 p.m. and ending on January 26, 2001, 

at 2 a.m. by using a ISCO (Teledyne ISCO Company, Lincoln 

Nebr.) automated sampler outfitted with a pressure transducer 

that measured water depth. Discharge was determined from 

the collected water-depth data by using a depth-discharge 

relation provided by the City of Modesto. The storm sampling 

at this location was designed to determine the presence and 

concentrations of pesticides in samples collected from the 

urban storm-water runoff and to allow for comparison of these 

results with results from the wet-deposition samples collected 

from agricultural sites during the same storm event. 

Wet Deposition

For this study, a wet-deposition sample is defined as 

having fewer than 5 days of dry-deposition exposure—that is, 

periods during the composite sample-collection period when 

it was not raining. For example, a sample collected at the 

Newman rain gage (site 11) has a sample composite time of 

15 days (February 4–19, 2004) and is considered a wet-deposition sample (rainfall) because there were five rain events during that period (approximately every 2.5 days). Wet-deposition 

(rain) samples were collected by using either a Teflon-coated 

funnel (funnel sampler) or an automated wet-dry sampler 

(autosampler). The funnel sampler collected rainfall by using 

a funnel-bottle assembly consisting of a 32-centimeter (cm) 

diameter funnel placed in the opening of a cleaned, 4-L amber 

glass bottle (collection bottle). The funnel-bottle assembly 

was supported by an appropriate length of plastic irrigation 

pipe attached to a small wooden table (fig. 5). Chicken wire 

covered each funnel to intercept large debris and to keep birds 

and other wildlife from entering the collection area, but one 

or more small insects (flies, bees, and spiders) were present in 

many samples. During the 2001 study period, the wet deposition was collected from a funnel sampler at sampling sites 1–8. 

During the 2002–04 study period, the funnel sampler collected 

wet-deposition, dry-deposition, and bulk-deposition samples at 

sampling sites 4, 5, 10–13, 15, and 16. (fig. 4 and table 1).

Clean funnels and collection bottles were placed at each 

sampling site for no more than 24 hours before a rain event. 

The samples were collected at the end of the rain event. 

The samples were immediately stored on ice and transported to the California Water Science Center Laboratory in 

Sacramento, Calif., for processing. There, the samples were 

weighed in the collection bottle to the nearest 0.1 gram and 

poured into 1-liter (L) glass amber bottles, packed in ice, 

and shipped to the USGS NWQL in Denver, Colo., within 

24 hours of field collection. 

The autosamplers used 27-cm diameter stainless-steel 

buckets to collect the wet-deposition samples during the 

2001 study period and wet deposition, dry deposition, and 

bulk deposition during the 2002–04 study period (fig. 6). 

The sampler was controlled by a moisture sensor. During dry 

periods, a moveable lid covered the “wet” collection bucket, 

and the “dry” collection bucket remained open to collect 

dry deposition from the atmosphere. At the onset of rainfall, 

the moisture sensor activated a motor that moved the lid from 

the “wet” collection bucket to the “dry” collection bucket, 

which enabled the collection of rain and kept the collected 

dry deposition free of moisture. Wet-deposition samples were 

collected from the autosampler at the end of a rain event and 

poured into a clean collection bottle and processed by using 

the same procedures as the funnel-collected samples. 

Dry Deposition

Dry-deposition samples were collected by using a funnel 

sampler and the autosampler during the 2002–04 study period. 

The funnels were exposed to the atmosphere for periods of 

3 weeks to approximately 3 months. At collection, the wire 

screen was removed, and approximately 50 milliliters (mL) of 

PBW from a Teflon squeeze bottle was used to rinse deposited 

material off the sides of the funnel into the collection bottle, 

followed by a rinse composed of approximately 50 mL of an 

equal part mixture of hexane and ethyl acetate (the primary 

extraction solvent mixture used for dry-deposition samples 

collected prior to November 2003) to transfer any remaining 

particles into the sample-collection bottle. 

sac12-0461_fig 05

Figure 5. Funnel sampler at the Newman rain gage site at 

wasteway levee near Draper Road (site 11) in the Central Valley 

of California. Photograph by Michael Majewski, U.S. Geological 

Survey.
10 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides

The method for sample extraction and subsequent extract 

processing of the collected dry deposition, and bulk drydeposition samples (see next section) was modified during 

the study in an effort to improve laboratory method performance (see details under NWQL research method LS8054 in 

appendix 1). These modifications necessitated a change in the 

solvents used for field-rinsing of the collection funnel or autosampler bucket. Samples collected prior to November 2003 

contained at least one or more organic solvents from point of 

collection through any storage period prior to sample preparation. Samples with begin dates of November 2003 or later 

were collected by rinsing the funnel with less than 50 mL of 

PBW (no organic solvent rinse) or with PBW and a small volume (less than or equal to 17 mL) of a 25-percent ethyl acetate 

in hexane solution. All rinses were collected in the collection bottle on which the funnel rested and drained. The same 

rinse procedure was applied to the stainless-steel buckets of 

the autosampler, with each collected sample poured into a 

clean 4-L glass amber collection bottle. All collected samples 

were immediately stored on ice and shipped to NWQL within 

24 hours. For samples with begin dates of November 2003 or 

later, a 50-mL aliquot of dichloromethane was added to each 

sample immediately upon sample receipt at the NWQL as the 

primary extraction solvent and as a preservative. 

Bulk Deposition (Bulk Wet Deposition and Bulk 

Dry Deposition)

Bulk deposition samples are defined as samples that 

contained both wet and dry atmospheric deposition. Two types 

of bulk-deposition samples are presented and discussed 

separately in this report. The first type, a bulk wet-deposition 

sample, was intended to be a dry-deposition sample only; 

however, for these sample types, one of the following was 

true: (1) there were several small storm events during a composite sample time, which resulted in periods of wet deposition along with periods of dry deposition that were greater 

than 5 days; (2) there was a large storm event at the end of a 

long dry period that compromised an intended dry-deposition 

sample; or (3) the autosampler failed to cover the “wet” or 

“dry” collection bucket, and the autosampler collected both 

wet and dry deposition over an extended period. Because of 

the larger volume of water collected (median volume was 

1.04 L for 38 bulk wet samples), these samples were analyzed 

by using two laboratory analytical methods for pesticides and 

degradates in filtered water: methods O-1126-95 (Zaugg and 

others, 1995) and O-2002-01 (Sandstrom and others, 2001) 

with pesticide isolation by C-18 solid phase-extraction (SPE) 

and analysis by gas chromatography-mass spectrometry 

(GC-MS).

The second type of bulk-deposition sample, referred to as 

a bulk dry-deposition sample is defined as a sample that was 

intended to be only a dry-deposition sample; however, there 

was an unpredicted rain event and some wet deposition was 

collected also. Because of the small volume of wet deposition 

collected (median volume was 0.541 L for 26 samples), the 

samples were prepared and analyzed by using the dry-deposition analytical method (NWQL research method LS8054, 

appendix 1). 

Deposition to Soil Box 

Each soil box was approximately 1-meter (m) square 

and divided in half. The inside of each section was lined with 

aluminum sheeting and filled with a composite mixture of 

soil. The composite soil mixture was composed of soil collected near site 10 (mix 1), site 11 (mix 2), and site 9 (mix 3). 

The collected soil from each of the sites was composited and 

placed in the soil boxes located in the San Joaquin Valley 

(fig. 4, sites 4 and 5). The soil in the Sacramento Valley soil 

box (mix 4) was a well-mixed sample collected from one location in an agriculture field adjacent to Gridley High School 

(site 16).

Soil-Box Runoff (Aqueous Phase and Suspended 

Sediment)

Each soil box was set up in a north-south orientation 

and inclined slightly in the southerly direction to direct and 

facilitate collection of surface runoff. The runoff samples were 

collected from only one half of the box into a clean collection bottle secured to one of the sampler legs (fig. 7). Sample 

bottles containing soil-box runoff were collected at the end of 

a rain event that had sufficient intensity and volume to produce 

surficial runoff. Collected samples were immediately stored on 

ice. Runoff samples were processed at the CAWSC Laboratory 

by first weighing the volume of sample collected, then, after 

shaking, filtering the sample through one or more 142-millimeter (mm) diameter 0.7-micron glass-fiber filters (GFFs) 

ac12-0461_fig 06

Figure 6. Autosampler at Gridley, California (site 16). Photograph 

by Michael Majewski, U.S. Geological Survey.
Methods of Monitoring 11

and recorded in the field notes so that the same locations on 

the soil surface would not be resampled during subsequent 

sampling events (fig. 8). The soil in the side of the box where 

the runoff was collected was left undisturbed (not sampled) for 

the duration of the study. Collected soil samples were stored 

in a freezer (–15°C) at the CAWSC Laboratory and shipped to 

NWQL at the end of the study period (August 2004). Laboratory sample preparation and analysis details are provided in 

appendix 1 (NWQL research method LS5503).

A control soil box was set up outdoors on a building rooftop (site 14) to examine the transformation or degradation of 

compounds that were not exposed to sunlight or atmospheric 

deposition. This soil box contained a composite mixture of the 

soils collected in the San Joaquin Valley (mix 1, mix 2, and 

mix 3), and one side was covered with a piece of plywood. 

The covered side had an 0.5 inch gap to allow for soil-air 

exchange and indirect particle deposition (particle deposition 

from the side). Three times during the study, the cover was 

removed, and surficial samples were collected for laboratory 

analysis.

Laboratory Analytical Methods

All samples types were analyzed at the USGS NWQL in 

Denver, Colo. Laboratory analytical methods are presented 

by study period and sample type (table 4). Some methods 

used in the report can be found in the National Environmental 

Methods Index (NEMI) at http://www.nemi.gov/.

2001 Study Period

The wet-deposition and storm-drain runoff samples were 

analyzed for pesticides in water by C-18 SPE and GC-MS 

according to laboratory analytical method O-1126-95 (Zaugg 

and others, 1995).

sac12-0461_fig 07

Soil-box runoff collection bottle

Surficial-soil sample collection side

Soil-box runoff side 

Figure 7. Soil box at the Modesto Irrigation District gage at 

Albers Road (site 5) in the Central Valley of California. Photograph 

by Michael Majewski, U.S. Geological Survey.

sac12-0461_fig 08

Figure 8. Surficial soil box sampling array. Photograph by 

Michael Majewski, U.S. Geological Survey.

as described by Sandstrom (1995). Prior to use, the GFFs 

were precleaned by baking at 400 degrees Celcius (°C) for 

3 hours, and then they were weighed to the nearest 0.1 gram. 

The number of GFFs required for filtration ranged from 1 

(for 17 samples) to 38, depending on volume filtered and the 

amount and particle size of the suspended sediment. Following sample filtration, GFFs were folded in half (particles 

inward), wrapped in aluminum foil, placed in a resealable 

plastic storage bag, and stored at –15°C both prior to shipping 

to the NWQL on ice and after receipt at the NWQL, until they 

were prepared for analysis. The two sample types, the aqueous 

phase (filtered sample volume) and suspended sediment (filters), were shipped to NWQL within 24 hours of field sample 

collection. Laboratory sample preparation and analysis details 

are provided in appendix 1 (NWQL research method LS7503).

Surficial Soil

Surficial-soil samples were taken from one side of the soil 

box three times during the study and analyzed for the same 

suite of pesticides as the rain samples. No runoff samples were 

collected from this side of the box. Subsamples of the soil 

were carefully scooped with a solvent-rinsed spoon from the 

top layer (approximately 0.5–1 cm) of soil. These subsamples 

were collected across the surface of the soil and composited as 

one sample into a 500-mL wide mouth glass jar with Teflonlined lid and stored on ice after collection. The sample configuration used to sample the soil surface was photographed 
12 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides

Table 4. Laboratory analytical method by sample type and study period.

[Abbreviations: NWQL, National Water Quality Laboratory]

Sample type

Laboratory 

analytical 

method

Study 

period Citation

Storm-drain runoff O-1126-95 2001 Zaug and others, 1995; Lindley and others, 1996.

Wet deposition, bulk wet deposition O-1126-95 2001 Zaug and others, 1995; Lindley and others, 1996.

Wet deposition, bulk wet deposition O-1126-95 and O-2002-O 2002–04 Zaug and others, 1995; Lindley and others, 1996; 

Sandstrom and others, 2001.

Wet deposition, bulk wet deposition O-1126-95 and O-2002-O 

and O-1126-02

2002–04 Zaug and others, 1995; Lindley and others, 1996; 

Sandstrom and others, 2001; Madsen and others, 2003.

Dry deposition, bulk dry deposition NWQL research analytical 

method LS8054

2002–04 Described in this report, appendix 1.

Soil-box runoff (aqueous phase) O-1126-95 and O-2002-O 

and O-1126-02

2002–04 Zaug and others, 1995; Lindley and others, 1996; 

Sandstrom and others, 2001; Madsen and others, 2003.

Soil-box runoff (suspended sediment) NWQL research analytical 

method LS7503

2002–04 Described in this report, appendix 1.

Soil-box surficial soil NWQL research analytical 

method LS5503

2002–04 Described in this report, appendix 1.

2002–04 Study Period

The wet-deposition, bulk wet-deposition, and filtered 

soil-box runoff (aqueous phase) sample types collected 

between January 25, 2002, and April 29, 2004, were analyzed 

for pesticides in water by using analytical method O-1126-95 

(Zaugg and others, 1995) and for moderate-use pesticides 

and selected degradates in water by using analytical method 

O-2002-01 (Sandstrom and others, 2001) with C-18 SPE and 

GC-MS. These sample types were also analyzed for concentrations of acetochlor in water by automated SPE and GC-MS 

(Lindley and others, 1996). Samples collected between 

November 7, 2002, and April 29, 2004, were analyzed for 

fipronil and fipronil degradates in water by using GC-MS, 

according to analytical method O-1126-02 (Madsen and 

others, 2003).

The dry-deposition, bulk dry-deposition, surficial-soil, 

and the suspended-sediment sample types were analyzed for 

the same compounds as the wet-deposition samples collected 

during the 2002–4 study period by using NWQL analytical 

research methods. The dry and bulk-dry sample types were 

analyzed by using NWQL research analytical method LS8054. 

The surficial-soil and suspended-sediment sample types were 

analyzed by using NWQL research analytical methods LS7503 

and LS5503, respectively. Each of these analytical methods 

are described by sample type in appendix 1.

Reporting Levels

Two types of reporting levels were used in this study: a 

laboratory reporting limit (LRL) for approved analytical methods and a sample-specific interim reporting level (ss-IRL) for 

research analytical methods. The NWQL uses an extension of 

the Environmental Protection Agency (EPA) method detection 

limit (MDL) procedure to determine the LRL of compounds 

with approved analytical methods (U.S. Environmental Protection Agency, 1992). Updates to the NWQL’s MDLs and 

LRLs based on a statistical Levene’s-test analysis are made 

only if a new long-term method detection level (LT-MDL) 

for a compound differs from the preceding year’s LT-MDL or 

if a compound exhibits poor recovery (Childress and others, 

1999). As a result, the LRLs for a number of compounds differed during the study period (table 5). 

The ss-IRL was applied to the suspended-sediment samples and surficial-soil samples collected from the soil box, and 

sample results are presented as μg/L and μg/Kg, respectively 

(table 5). The ss-IRL for the suspended-sediment sample type 

was calculated by dividing the mass of compound detected 

in the suspended-sediment sample by 0.63 L, which was the 

median volume of soil-box runoff from samples collected during the study period (sample number of 30). The dry and bulk 

deposition data are presented with respect to limited method 

performance quality-control data obtained for the applied 

research methods. For some compounds, this performance 

data indicated likely greater quantitative uncertainty and, thus, 

are reported as estimated concentrations, and no ss-IRL was 

applicable. 

For all mass-spectrometry analysis, concentrations of a 

compound less than the laboratory reporting level or lowest calibration standard (whichever is higher) are reported as 

estimated or having a higher degree of uncertainty (coded with 

an E preceding laboratory value). In these cases, the presence of the pesticide has been verified, but the concentration 

is estimated because it falls below the range of the calibration 

standards. Some compounds (table 5) are always reported 

as estimated (E) regardless of the concentration because of 

recognized performance issues (Childress and others, 1999; 

Sandstrom and others, 2001). In the remainder of this report, 

estimated concentrations are treated as normal detected concentrations for all sample types for the purpose of interpreting 

the concentration data. 
Methods of Monitoring 13

Table 5. Pesticides analyzed and the laboratory reporting limits for samples collected in the Central Valley of California during the 2001 

and 2002–04 study periods.—Continued

[Abbreviations: (E), estimated compound because of poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); 

D,Degradate; F, Fungicide; H, Herbicide; I, Insecticide; LRL, Laboratory Reporting Limit; NA, not applicable; ss-IRL, sample specific-Interim Reporting Limit; 

*, current LRL limit; μg/L, microgram per liter; μg/Kg, micrograms per kilogram; –, compound not analyzed for given sample type]

Compound

Chemical 

Abstract 

Service 

Registry 

Number

Type of 

compound

Sample types

Storm-drain runoff, wet deposition, 

bulk wet deposition, and soil-box

runoff (aqueous phase)

Soil-box 

runoff 

(suspended 

sediment)

Surficial soil 

(soil box)

LRL, μg/L ss-IRL, μg/L ss-IRL, μg/kg

Acetochlor 34256-82-1 H 0.006*, 0.1 0.08 1

Alachlor 15972-60-8 H 0.004*, 0.005 0.08 1

2-Chloro-2,6-diethylacetanilide 6967-29-9 D 0.005 0.08 1

2,6-Diethylaniline (E) 579-66-8 D 0.006 2.38 30

alpha-Hexachlorocyclohexane (HCH) 319-84-6 I 0.005 – –

2-Amino-N-isopropylbenzamide 30391-89-0 D 0.005 – –

Atrazine 1912-24-9 H 0.007*, 0.008, 0.01, 0.031, 0.2 0.08 1

Deethylatrazine, CIAT 6190-65-4 D 0.005. 0.006* 0.16 2

Azinphos-methyl (E) 86-50-0 I 0.05 0.4 5

Azinphos-methyl-oxon (E) NA D 0.02*, 0.03 0.24 30

Benfluralin 1861-40-1 H 0.01 0.08 1

Bifenthrin 82657-04-3 I 0.005 – –

Butylate 2008-41-5 H 0.002 – –

Carbaryl (E) 63-25-2 I 0.041*, 0.045 0.16 2

1-Naphthol (E) 90-15-3 D 0.09 0.79 10

1,4-Naphthoquinone 130-15-4 D 0.05 – –

Carbofuran 1563-66-2 H 0.02 – –

4-Chloro-2-methylphenol (E) 1570-64-5 D 0.006*, 0.007, 0.008, 0.009 0.79 10

Chlorpyrifos 2921-88-2 I 0.005*, 0.006, 0.011 0.08 1

Chlorpyrifos, oxon (E) 5598-15-2 D 0.06*, 0.03, 0.01 2.38 30

Cyanazine 21725-46-2 H 0.018 – –

Cycloate 1134-23-2 H 0.005 – –

Cyfluthrin (E) 68359-37-5 I 0.008*, 0.07 1.59 20

Cyhalothrin-lambda 91465-08-6 I 0.009 – –

Cypermethrin (E) 52315-07-8 I 0.009*, 0.015 1.59 20

Dacthal 1861-32-1 H 0.003 0.08 1

p,p’-Dichlorodiphenyldichloroethylene (DDE) 72-55-9 D 0.003*, 0.004, 0.007, 0.021, 0.03 – –

Diazinon 333-41-5 I 0.005*, 0.006, 0.015 0.08 1

Diazoxon (E) 962-58-3 D 0.006 0.4 5

2,5-Dichloroaniline 95-82-9 D 0.03 – –

4,4-Dichlorobenzophenone 90-98-2 D 0.003 – –

Dichlorvos (E) 62-73-7 I 0.01*, 0.03 2.38 30

Dicrotophos (E) 141-66-2 I 0.08 0.24 3

Dieldrin 60-57-1 I 0.005*, 0.009, 0.01 0.16 2

Dimethoate 60-51-5 I 0.006*, 0.007, 0.01, 0.015, 0.01 0.16 2

(E)-Dimethomorph 110488-70-5 F 0.02 – –

(Z)-Dimethomorph 110488-70-5 F 0.05 – –

Disulfoton 298-04-4 I 0.02 – –

Disulfoton sulfone 2497-06-5 D 0.02 – –

Disulfoton sulfoxide 2497-07-6 D 0.002 – –

Endosulfan-alpha 959-98-8 I 0.005 – –

Endosulfan-beta 33213-65-9 I 0.01 – –

Endosulfan ether 3369-52-6 D 0.004 – –

Endosulfan sulfate 1031-07-8 D 0.006 – –

EPTC 759-94-4 H 0.002 – –

Ethalfluralin 55283-68-6 H 0.009 – –

Ethion 563-12-2 I 0.004*, 0.006 0.16 2

Table 5. Pesticides analyzed and the laboratory reporting limits for samples collected in the Central Valley of California during the 2001 

and 2002–04 study periods.
14 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides

Table 5. Pesticides analyzed and the laboratory reporting limits for samples collected in the Central Valley of California during the 2001 

and 2002–04 study periods.—Continued

[Abbreviations: (E), estimated compound because of poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); 

D,Degradate; F, Fungicide; H, Herbicide; I, Insecticide; LRL, Laboratory Reporting Limit; NA, not applicable; ss-IRL, sample specific-Interim Reporting Limit; 

*, current LRL limit; μg/L, microgram per liter; μg/Kg, micrograms per kilogram; –, compound not analyzed for given sample type]

Compound

Chemical 

Abstract 

Service 

Registry 

Number

Type of 

compound

Sample types

Storm-drain runoff, wet deposition, 

bulk wet deposition, and soil-box

runoff (aqueous phase)

Soil-box 

runoff 

(suspended 

sediment)

Surficial soil 

(soil box)

LRL, μg/L ss-IRL, μg/L ss-IRL, μg/kg

Ethion monoxon 17356-42-2 D 0.03*, 0.01 0.16 2

Ethoprop 13194-48-4 I 0.005 – –

O-Ethyl-O-methyl-S-propylphosphorothioate 76960-87-7 D 0.008 – –

Fenamiphos (E) 22224-92-6 N 0.03 2.38 30

Fenamiphos sulfone (E) 31972-44-8 D 0.008*, 0.01, 0.012, 0.031, 0.312 0.79 10

Fenamiphos sulfoxide (E) 31972-43-7 D 0.03*, 0.12 0.79 10

Fenthion 55-38-9 I 0.02 – –

Fenthion sulfoxide 3761-41-9 D 0.008 – –

Fipronil (E) 120068-37-3 I 0.02 0.08 1

Fipronil sulfide 120067-83-6 D 0.013 0.08 1

Fipronil sulfone 120068-36-2 D 0.024 0.08 1

Friponil, desulfinyl (Desulfinylfipronil) NA D 0.012 0.08 1

Friponil amide, desulfinyl 

(Desulfinylfipronil amide) (E)

NA D 0.029 0.08 1

Flumetralin 62924-70-3 Plant growth 

regulator

0.004 – –

Fonofos 944-22-9 I 0.003 0.08 1

Fonofos, oxon NA D 0.002*, 0.007, 0.011 0.4 5

Hexazinone 51235-04-2 H 0.013 0.08 1

Iprodione (E) 36734-19-7 F 1*, 0.035 0.79 10

3,5-Dichloroaniline 626-43-7 D 0.005 – –

Isofenphos 25311-71-1 I 0.003 0.16 2

Lindane 58-89-9 I 0.004 – –

Linuron 330-55-2 H 0.035 – –

3,4-Dichloroaniline (E) 95-76-1 D *0.004, 0.006, 0.007, 0.009, 0.011 5.95 75

Malathion 121-75-5 I 0.027 0.16 2

Malaoxon (E) 1634-78-2 D 0.008*, 0.01, 0.015, 0.025, 0.125, 

0.312

0.4 5

Metalaxyl 57837-19-1 F 0.005*, 0.007, 0.125 0.6 1

Methidathion 950-37-8 I 0.006*, 0.007, 0.008, 0.021 0.16 2

Metolachlor 51218-45-2 H 0.013 0.08 1

2-Ethyl-6-methylaniline (E) 24549-06-2 D 0.001*, 0.004 2.38 30

Metribuzin 21087-64-9 H 0.006*, 0.125, 0.312 0.32 4

Molinate 2212-67-1 H 0.002 – –

Myclobutanil (E) 88671-89-0 F 0.008*, 0.011, 0.015 0.025, 0.031 0.08 1

Napropamide 15299-99-7 H 0.007*, 0.01 – –

Oxyfluorfen 42874-03-3 H 0.007*, 0.011 – –

Parathion 56-38-2 I 0.01 – –

Paraoxon 311-45-5 D 0.008 – –

Parathion-methyl 298-00-0 I 0.006*, 0.015, 0.01 0.16 2

Paraoxon-methyl (E) 950-35-6 D 0.03 0.4 5

Pebulate 1114-71-2 H 0.004 – –

Pendimethalin 40487-42-1 H 0.022*, 0.021, 0.031 0.11 1

cis-Permethrin 54774-45-7 I 0.006*, 0.007, 0.021, 0.01, 0.07, 

0.08, 0.2

0.4 5

trans-Permethrin NA I – 0.4 5

cis-Propiconazole NA F 0.008 – –
Methods of Monitoring 15

Table 5. Pesticides analyzed and the laboratory reporting limits for samples collected in the Central Valley of California during the 2001 

and 2002–04 study periods.—Continued

[Abbreviations: (E), estimated compound because of poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); 

D,Degradate; F, Fungicide; H, Herbicide; I, Insecticide; LRL, Laboratory Reporting Limit; NA, not applicable; ss-IRL, sample specific-Interim Reporting Limit; 

*, current LRL limit; μg/L, microgram per liter; μg/Kg, micrograms per kilogram; –, compound not analyzed for given sample type]

Compound

Chemical 

Abstract 

Service 

Registry 

Number

Type of 

compound

Sample types

Storm-drain runoff, wet deposition, 

bulk wet deposition, and soil-box

runoff (aqueous phase)

Soil-box 

runoff 

(suspended 

sediment)

Surficial soil 

(soil box)

LRL, μg/L ss-IRL, μg/L ss-IRL, μg/kg

trans-Propiconazole NA F 0.01 – –

Phorate (E) 298-02-2 I 0.011 0.4 5

Phorate, oxon (E) 2600-69-3 D 0.1*, 0.12 0.56 7

Phosmet 732-11-6 I 0.008*, 0.01, 0.015, 0.025, 0.2 2.38 30

Phosmet oxon 3735-33-9 D 0.06 0.79 10

Phostebupirim 96182-53-5 I 0.005 – –

Profenofos 41198-08-7 I 0.006 – –

Prometon (E) 1610-18-0 H 0.01 0.22 2

Prometryn 7287-19-6 H 0.005*, 0.007 0.16 2

Pronamide (Propyzamide) 23950-58-5 H 0.004*, 0.005, 0.006, 0.01 0.16 2

Propachlor 1918-16-7 H 0.01 – –

Propanil 709-98-8 H 0.011 – –

Propargite 2312-35-8 I 0.02 – –

2-(4-tert-Butylphenoxy)-cyclohexanol 1942-71-8 D 0.01*, 0.02, 0.03 – –

Propetamphos 31218-83-4 I 0.004 – –

trans-Propiconazole NA F 0.01 – –

Simazine 122-34-9 H 0.005*, 0.006, 0.007, 0.01, 0.021, 

0.04

0.16 2

Sulfotepp 3689-24-5 I 0.003 – –

Sulprofos 35400-43-2 I 0.02 – –

Tebupirimphos, oxon NA D 0.006 – –

Tebuthiuron (E) 34014-18-1 H 0.02 0.24 3

Tefluthrin 79538-32-2 I 0.008 – –

Temephos 3383-96-8 I 0.3 – –

Terbacil 5902-51-2 H 0.034 – –

Terbufos 13071-79-9 I 0.02 0.24 1

Terbufos-oxon-sulfone (E) 56070-15-6 D 0.07*, 0.12 0.4 5

Terbuthylazine 5915-41-3 H 0.01 0.72 1

Thiobencarb 28249-77-6 H 0.005 – –

Triallate 2303-17-5 H 0.002 – –

Tribuphos 78-48-8 Plant growth 

regulator

0.004 – –

3-(Trifluoromethyl)aniline 98-16-8 D 0.01 – –

Trifluralin 1582-09-8 H 0.009*, 0.01 0.08 1
16 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides

Table 6. Minimum, maximum, and median percentage recoveries 

for laboratory surrogates prepared and analyzed with all 

environmental-sample types submitted to the National Water 

Quality Laboratory (NWQL).

[All compounds were analyzed by gas chromatography-mass spectrometry 

(GC-MS), at the U.S. Geological Survey NWQL]

Sample type alpha-HCH-d6 Diazinon-d10

Storm run off

Minimum percentage recovery 76.8 97.4

Maximum percentage recovery 118 153

Median percentage recovery 91.9 105.5

Wet-deposition samples

Minimum percentage recovery 58.4 77.8

Maximum percentage recovery 112 127

Median percentage recovery 91 102

Dry-deposition samples

Minimum percentage recovery 42 60

Maximum percentage recovery 99 111

Median percentage recovery 80 89

Bulk-depositions samples

Minimum percentage recovery 7.1 8.7

Maximum percentage recovery 112 120

Median percentage recovery 77.4 85.6

Surficial-soil samples

Minimum percentage recovery 81.4 117

Maximum percentage recovery 102 167

Median percentage recovery 97.2 140

Suspended sediment

Minimum percentage recovery 11.1 16.9

Maximum percentage recovery 66.5 100.9

Median percentage recovery 47.9 73.2

Soil run off

Minimum percentage recovery 75.7 86.7

Maximum percentage recovery 103 109

Median percentage recovery 87.2 98.6

Laboratory and Field Quality Control

Data obtained from quality-control (QC) samples are 

used to estimate the variability and bias from sample collection, processing, and laboratory analysis. Variability is defined 

as random error in independent measurements that can result 

with repeated application of the process under specified conditions. Bias refers to a systematic error manifested as a consistent positive or negative deviation from the known or true 

value. The results of the laboratory and field quality-control 

measurements are presented separately.

Laboratory Quality-Control Methods

The NWQL uses a quality management system (QMS) 

that provides a consistent system of protocols and procedures 

for carrying out required quality assurance (QA) and QC in 

compliance with the standards set by the National Environmental Laboratory Accreditation Conference (Maloney, 2005). 

As part of the QMS system, three types of laboratory qualitycontrol measurements are prepared and analyzed with each 

group of environmental samples to monitor method performance. The three types are defined as follows:

• Laboratory Reagent Spike (LRS). A LRS is a sample 

where known concentrations of the compounds of 

interest are added, most commonly, into a synthetic 

matrix (usually blank water or clean sand). An evaluation of the LRS yields information about the method 

performance. The LRS analytical results are compared 

to acceptable criteria for each method to assess potential bias of environmental sample results. The calculation for spike recovery is as follows:

C C

C

( ) spike e − nvironmental 















× =

expected

100 percent percent recovery

where

C is the concentration of analyte foun spike d

ple in g/L

is the concent

, , μ

Cenvironmental ration of analyte in environmental 

background sample, n i g/L and

is the concentration of analyte expe

μ ,

Cexpected c

e.

“ ”

(1)

• Laboratory Reagent Blank (LRB). A LRB is prepared by using an appropriate matrix (typically blank 

water or clean sand) and is processed in the same way 

as the accompanying environmental sample. It is used 

to monitor random contamination introduced from 

laboratory processing.

• Laboratory Surrogates. A surrogate is a compound 

that is expected to perform similarly to the compound 

being analyzed in a laboratory method. The surrogate 

is not normally found in the environment and, therefore, can be used to monitor the recovery efficiency 

of analytical processes (U.S. Geological Survey, 

1998). Two surrogate compounds, α-HCH-d6 and 

diazinon-d10, were added to all sample types submitted in this study. 

The LRS and LRB data for the wet deposition, bulk wet 

deposition, and aqueous phase of the soil runoff samples are 

not presented because these methods are established, and 

the NWQL performs the data assessment and assesses the 

potential bias of an environmental sample result (http://bqs.

usgs.gov/ltmdl/, accessed February 22, 2011). The minimum, 

maximum, and median percentage recoveries for laboratory 

surrogates prepared and analyzed with all the environmental 

sample types collected in during the entire study period are 

presented in table 6. The percentage recoveries for the LRSs, 
Laboratory and Field Quality Control 17

and the detections found in the LRBs, are discussed in the following sections by sample type 

for the dry-deposition, bulk dry-deposition, suspended-sediment, and surficial-soil sample 

types. These sample types are considered research methods and, therefore, required an evaluation of the laboratory QA and QC data. Median percentage recoveries greater than 50 percent 

for the LRSs were considered acceptable for the study.

Dry-Deposition and Bulk Dry-Deposition Samples

Nine LRSs and seven LRBs were analyzed with the dry-deposition and the bulk drydeposition environmental samples. Table 7 describes the minimums, medians, maximums, and 

standard deviations of percentage recoveries for LRSs. Because the analytical techniques used 

to analyze these sample types were being developed and refined during the study, LRS recoveries for many compounds were lower and more variable than LRS recoveries for similar compounds in other media that were obtained by using approved analytical methods (table 4). As a 

result, only 29 of the 64 compounds analyzed had median percentage recoveries greater than or 

equal to 50 percent. For compounds with median percent of recoveries less than 50 percent, the 

concentrations in the environmental samples are considered usable but qualified as biased-low 

(B-L) on the basis of low and variable recovery (table 7). For compounds that are biased low, it 

is possible that small concentrations present in a sample could escape detection and be reported 

as less than the reporting level (appendix 5 and 6).

Two compounds (azinphos-methyl and phosmet) were detected in the LRBs. These detections were likely a result of laboratory analysis carryover. A LRB was run at the end of each set 

of environmental samples (seven sets total). For each set of environmental samples, concentrations in the associated LRBs were approximately an order of magnitude less than the concentrations observed in environmental samples with detections of the same compounds (table 8). 

Soil-Box Suspended Sediment

Four LRSs and two LRBs were analyzed along with the environmental samples for the 

suspended-sediment samples. The minimums, medians, maximums, and standard deviations 

of percentage recoveries for the LRSs are presented in table 9. Median percentage recoveries greater than or equal to 50 percent were found for 44 of the 63 compounds analyzed. The 

remaining 19 compounds had percentage recoveries of less than 50 percent and are qualified 

as B-L. Malaoxon had spike recoveries of zero percent and was qualified as B-L (appendix 8); 

however, this compound was detected in an environmental sample (site 16, December 18–23, 

2003) despite the low bias. No compounds were detected in the suspended-sediment LRBs. 

Soil-Box Surficial Soil

Duplicate environmental aliquots were extracted and analyzed from the soil-box 

mix 1, 2, 3, and 4 samples to examine laboratory method performance. Table 10 presents the 

concentration in micrograms per kilogram (μg/Kg) for the environmental aliquot, the duplicate 

environmental aliquot, and relative percentage difference (RPD) of duplicates. The RPD was 

calculated as follows: 

(2) environmental aliquot duplicate environmentalaliquot RPD 100 percent mean of environmentalaliqout and duplicate environmental aliquot

−  =  ×

 

Overall, the RPD for compounds with detections in both samples was less than 25 percent. 

For compounds with a RPD greater than 25 percent, the greater variability was presumed to be 

a result of the inherent heterogeneity of the soil matrix, an indication of the variability of the 

compound in the soil matrix, or both. 

The quality-control samples analyzed along with the environmental surficial soil-box 

samples included a laboratory matrix spike (LMS), an LRS, and an LRB. The LMS was performed on an aliquot of soil-box mix 2, and the LRS and LRB were performed on aliquots of 
18 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides

Table 7. Minimum, maximum, median, and standard deviation of percentage recoveries for laboratory reagent spikes extracted along 

with the dry-deposition and bulk dry-deposition environmental samples.—Continued

[Abbreviations: B-L, biased low based on low and variable recoveries; na, none applied; (E), estimated compound because of known performance issues by 

applied method (Childress and others, 1999; Sandstrom and others, 2001); ±, plus or minus]

Compound (common name)

Minimum

percentage

recovery

Median

percentage

recovery

Maximum

percentage

recovery

Standard

deviation

Detection

qualifier

1-Naphthol (E) 0 5.83 27.4 ±10.1 B-L

2,6-Diethylanaline1

 (E) 0 31.7 86.5 ±23.6 B-L

2-[(2-ethyl-6-methylphenyl)-amino]-1-propanol1 0 32.6 45.5 ±19.45 B-L

2-chloro-2,6-diethylacetanilide 32.7 83.9 92.3 ±19.2 na

2-ethyl-6 methylaniline1 0 36.3 86.3 ±24.5 B-L

3,4-Dichloroaniline (E) 5.7 47.5 80.9 ±25.3 B-L

Acetochlor 38.1 70.3 106 ±18.3 na

Alachlor 37.6 68.2 88.6 ±14.7 na

Atrazine 36.7 85.4 91.9 ±17.4 na

Azinphos-methyl (E) 0 39.3 69.9 ±23.7 B-L

Azinphos-methyl-oxon (E) 0 7.3 61.2 ±23.0 B-L

Benfluralin1 14.4 27.3 56.6 ±13.2 B-L

Carbaryl (E) 41.8 53.0 83.1 ±15.3 na

Chlorpyrifos 42.3 71.4 95.3 ±16.0 na

Chlorpyrifos, oxon (E) 0 38.8 64.3 ±24.7 B-L

Cyfluthrin (E) 20.0 80.8 91.2 ±25.7 na

Cypermethrin (E) 30.0 76.3 82.8 ±20.9 na

Dacthal 49.4 76.4 109 ±16.5 na

Deethylatrazine, CIAT 19.8 45.3 84.0 ±20.2 B-L

Diazinon 41.8 68.8 97.1 ±18.0 na

Diazoxon (E) 2.3 40.2 83.6 ±24.6 B-L

Dichlorvos 0 36.4 82.7 ±32.6 B-L

Dicrotophos1

 (E) 0 0 70.0 ±24.5 B-L

Dieldrin 44.8 87.6 157 ±30.9 na

Dimethoate 4.9 20.2 74.0 ±22.3 B-L

Ethion 30.2 66.5 149 ±33.2 na

Ethion monoxon 6.9 56.5 97.1 ±28.3 na

Fenamiphos sulfone1

 (E) 2.0 26.3 67.0 ±21.8 B-L

Fenamiphos sulfoxide (E) 0 52.9 140 ±49.5 na

Fenamiphos1

 (E) 0 10.8 69.8 ±24.2 B-L

Fipronil1

 (E) 20.3 34.2 75.0 ±17.7 B-L

Fipronil sulfide 37.1 71.6 79.8 ±17.4 na

Fipronil sulfone1 0 34.5 70.1 ±21.5 B-L

Desulfinylfipronil 38.1 74.1 94.3 ±19.4 na

Desulfinylfipronil amide1 8.2 48.2 93.4 ±30.4 B-L

Fonofos 36.0 63.8 76.6 ±15.2 na

Fonofos oxon1 0 42.2 73.3 ±27.9 B-L

Hexazinone 16.6 22.6 68.7 ±22.5 B-L

Iprodione (E) 0 31.7 87.6 ±23.1 B-L

Isofenphos 39.2 60.2 90.8 ±18.2 na

Malathion 34.9 66.8 94.7 ±21.4 na

Malaoxon (E) 0 28.5 72.7 ±24.4 B-L

Methidathion 29.8 67.8 123 ±24.7 na

Metolachlor 2.0 70.8 95.2 ±25.4 na

Metribuzin 10.9 22.9 75.4 ±22.7 B-L

Myclobutanil 9.0 66.9 118 ±31.3 na

Table 7. Minimum, maximum, median, and standard deviation of percentage recoveries for laboratory reagent spikes extracted along 

with the dry-deposition and bulk dry-deposition environmental samples.
Laboratory and Field Quality Control 19

Table 7. Minimum, maximum, median, and standard deviation of percentage recoveries for laboratory reagent spikes extracted along 

with the dry-deposition and bulk dry-deposition environmental samples.—Continued

[Abbreviations: B-L, biased low based on low and variable recoveries; na, none applied; (E), estimated compound because of known performance issues by 

applied method (Childress and others, 1999; Sandstrom and others, 2001); ±, plus or minus]

Compound (common name)

Minimum

percentage

recovery

Median

percentage

recovery

Maximum

percentage

recovery

Standard

deviation

Detection

qualifier

Parathion-methyl 25.3 45.6 69.6 ±14.9 B-L

Paraoxon-methyl (E) 0 24.1 63.3 ±23 B-L

Pendimethilan 12.1 33.9 77.1 ±19.4 B-L

cis-permethrin 39.5 90.1 110 ±23.6 na

trans-permethrin 32.7 75.6 95.6 ±22.8 na

Phorate oxon1

 (E) 0 15.8 62.2 ±19.3 B-L

Phorate1 0 22.4 72.7 ±19.8 B-L

Phosmet (E) 0 8.4 40.0 ±13.1 B-L

Phosmet oxon (E) 0 0 29.0 ±10.3 B-L

Prometon (E) 7.0 71.0 91.7 ±25.6 na

Prometryn 2.0 51.6 89.4 ±22.6 na

Pronamide 32.2 67.0 80.4 ±15.4 na

Simazine 31.9 69.0 96.9 ±19.6 na

Tebuthiuron (E) 0 27.2 93.0 ±26.9 B-L

Terbufos-oxon-sulfone (E) 0 26.9 63.9 ±22.7 B-L

Terbufos1 0 49.8 73.2 ±23.7 B-L

Terbuthylazine 42.0 82.2 97.8 ±16.3 na

Trifluralin 15.5 29.9 74.0 ±17.7 B-L

1

Compound was not detected in environmental samples and is not presented in appendix 5 and 6 for the dry and bulk dry deposition sample types, respectively, as there are no reporting limits for these sample types; however, it is possible that small concentrations of these compounds may be present in a sample 

and were not detected based on the low and variable laboratory reagent spike recovery.
20 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides

Table 8. Total number and detection mass for the laboratory reagent blanks extracted along with the dry deposition and bulk-dry 

deposition environmental samples.—Continued

[Abbreviations: (E), estimated compound because of known performance issues by applied method (Childress and others, 1999; Sandstrom and others, 2001); 

E, estimated; <, actual value is known to be less than value shown; μg/ sample, microgram per sample; –, no detection for given compound]

Compound Number

of blanks

Number of

detections

Detection in

laboratory blank

(μg/sample)

Detection in

environmental sample

(μg/sample)

1-Naphthol (E) 7 0 – –

2,6-Diethylanaline 7 0 – –

2-[(2-ethyl-6-methylphenyl)-amino]-1-propanol 7 0 – –

2-chloro-2,6-diethylacetanilide 7 0 – –

2-ethyl-6 methylaniline 7 0 – –

3,4-Dichloroaniline 7 0 – –

Acetochlor 7 0 – –

Alachlor 7 0 – –

Atrazine 7 0 – –

Azinphos-methyl (E) 7 2 E0.008, E0.006 <0.06

Azinphos-methyl-oxon (E) 7 0 – –

Benfluralin 7 0 – –

Carbaryl (E) 7 0 – –

Chlorpyrifos 7 0 – –

Chlorpyrifos oxon (E) 7 0 – –

Cyfluthrin (E) 7 0 – –

Cypermethrin (E) 7 0 – –

Dacthal 7 0 – –

Deethylatrazine, CIAT 7 0 – –

Diazinon 7 0 – –

Diazoxon (E) 7 0 – –

Dichlorvos (E) 7 0 – –

Dicrotophos (E) 7 0 – –

Dieldrin 7 0 – –

Dimethoate 7 0 – –

Ethion 7 0 – –

Ethion monoxon 7 0 – –

Fenamiphos (E) 7 0 – –

Fenamiphos sulfone (E) 7 0 – –

Fenamiphos sulfoxide (E) 7 0 – –

Fipronil (E) 7 0 – –

Fipronil sulfide 7 0 – –

Fipronil sulfone 7 0 – –

Desulfinylfipronil 7 0 – –

Desulfinylfipronil amide 7 0 – –

Fonofos 7 0 – –

Fonofos oxon 7 0 – –

Hexazinone 7 0 – –

Iprodione (E) 7 0 – –

Isofenphos 7 0 – –

Malathion 7 0 – –

Malaoxon (E) 7 0 – –

Methidathion 7 0 – –

Metolachlor 7 0 – –

Metribuzin 7 0 – –

Myclobutanil (E) 7 0 – –

Parathion-methyl 7 0 – –

Paraoxon-methyl (E) 7 0 – –

Pendimethilan 7 0 – –

cis-permethrin 7 0 – –

trans-permethrin 7 0 – –

Table 8. Total number and detection mass for the laboratory reagent blanks extracted along with the dry deposition and bulk-dry 

deposition environmental samples.
Laboratory and Field Quality Control 21

Table 8. Total number and detection mass for the laboratory reagent blanks extracted along with the dry deposition and bulk-dry 

deposition environmental samples.—Continued

[Abbreviations: (E), estimated compound because of known performance issues by applied method (Childress and others, 1999; Sandstrom and others, 2001); 

E, estimated; <, actual value is known to be less than value shown; μg/ sample, microgram per sample; –, no detection for given compound]

Compound Number

of blanks

Number of

detections

Detection in

laboratory blank

(μg/sample)

Detection in

environmental sample

(μg/sample)

Phorate (E) 7 0 – –

Phorate oxon (E) 7 0 – –

Phosmet (E) 7 1 E0.005 E0.05

Phosmet oxon (E) 7 0 – –

Prometon (E) 7 0 – –

Prometryn 7 0 – –

Pronamide 7 0 – –

Simazine 7 0 – –

Tebuthiuron (E) 7 0 – –

Terbufos 7 0 – – 

Terbufos-oxon-sulfone (E) 7 0 – –

Terbuthylazine 7 0 – –

Trifluralin 7 0 – –
22 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides

Table 9. Minimum, maximum, median, and standard deviation of percentage recoveries for laboratory-reagent spikes in the soil-box 

suspended-sediment samples.—Continued

[Abbreviations: B-L, biased low; na, none applied; (E), estimated compound because of known performance issues by applied method (Childress and others, 

1999; Sandstrom and others, 2001); ±, plus or minus]

Compound

Minimum

percentage

recovery

Median

percentage 

recovery

Maximum

percentage

recovery

Standard

deviation

 Environmental

detection 

qualifier code

1-Naphthol (E) 3.9 4.0 4.2 ±0.2 B-L

2,6-diethylaniline (E) 23.2 52.5 56.9 ±15.5 na

2-chloro-2,6-diethylacetanilide 56.6 63.5 70.3 ±9.60 na

2-ethyl-6-methylaniline (E) 20.3 36.7 53.2 ±23.3 B-L

3,4-dichloroaniline (E) 23.8 34.8 45.8 ±15.5 B-L

4-chloro-2-methylphenol (E) 13.0 29.8 46.7 ±23.8 B-L

Acetochlor 52.5 71.1 82.7 ±14.8 na

Alachlor 45.3 61.6 70.6 ±12.4 na

Atrazine 46.2 63.8 71.1 ±11.3 na

Azinphos-methyl (E) 40.7 50.2 52.9 ±5.5 na

Azinphos-methyl-oxon (E) 22.1 23.6 25.0 ±2.0 B-L

Benfluralin 52.8 60.8 65.7 ±5.50 na

Carbaryl (E) 0 2.8 19.6 ±9.3 B-L

Chlorpyrifos 46.0 59.5 63.2 ±7.9 na

Chlorpyrifos oxon (E) 43.6 45.8 48.1 ±3.2 B-L

Cyfluthrin (E) 0 22.3 44.6 ±31.5 B-L

Cypermethrin (E) 0 28.7 57.5 ±40.6 B-L

Dacthal 56.5 73.5 85.2 ±13.3 na

Deethylatrazine, CIAT 53.6 82.3 101.1 ±23.5 na

Diazinon 46.4 60.5 70.1 ±10.3 na

Diazoxon (E) 49.7 53.4 57.0 ±5.2 na

Dichlorvos (E) 36.3 36.9 37.4 ±0.8 B-L

Dicrotophos (E) 53.3 61.3 69.3 ±11.3 na

Dieldrin 59.6 79.0 92.5 ±17.3 na

Dimethoate 40.2 48.5 56.9 ±11.8 B-L

Ethion 55.0 58.3 61.7 ±4.7 na

Ethion monoxon 52.1 52.1 52.1 ±0.01 na

Fenamiphos (E) 26.4 33.2 40.0 ±9.6 B-L

Fenamiphos sulfone (E) 67.5 70.1 72.7 ±3.7 na

Fenamiphos sulfoxide (E) 101.9 103.0 104.1 ±1.6 na

Fipronil (E) 49.1 64.6 73.7 ±12.6 na

Fipronil sulfide 51.4 75.3 90.9 ±19.0 na

Fipronil sulfone 35.8 60.7 83.3 ±25.0 na

Desulfinylfipronil 44.0 61.0 68.6 ±10.8 na

Desulfinylfipronil amide (E) 63.7 86.5 98.4 ±16.5 na

Fonofos 40.4 56.8 64.1 ±11.1 na

Fonofos oxon 53.2 58.3 63.5 ±7.3 na

Hexazinone 62.3 69.3 76.3 ±9.9 na

Iprodione (E) 7.1 8.0 8.8 ±1.2 B-L

Isofenphos 48 53.8 59.6 ±8.2 na

Malathion 0 6.7 19.2 ±9.7 B-L

Malaoxon (E) 0 0 0 0 B-L

Metalaxyl 49.8 57.7 65.5 ±11.1 na

Methidathion 51.4 53.1 54.8 ±2.5 na

Metolachlor 45.7 63.4 72.4 ±12.0 na

Metribuzin 50.5 69.5 87.9 ±19.8 na

Myclobutanil (E) 60.1 64.4 68.7 ±6.1 na

Parathion-methyl 49.3 63.0 76.4 ±13.6 na

Paraoxon-methyl (E) 49.0 50.3 51.6 ±1.8 na

Pendimethalin 49.4 72.4 93.3 ±23.1 na

cis-permethrin 62.5 82.4 95.6 ±13.9 na

Table 9. Minimum, maximum, median, and standard deviation of percentage recoveries for laboratory-reagent spikes in the soil-box 

suspended-sediment samples.
Laboratory and Field Quality Control 23

Table 9. Minimum, maximum, median, and standard deviation of percentage recoveries for laboratory-reagent spikes in the soil-box 

suspended-sediment samples.—Continued

[Abbreviations: B-L, biased low; na, none applied; (E), estimated compound because of known performance issues by applied method (Childress and others, 

1999; Sandstrom and others, 2001); ±, plus or minus]

Compound

Minimum

percentage

recovery

Median

percentage 

recovery

Maximum

percentage

recovery

Standard

deviation

 Environmental

detection 

qualifier code

trans-permethrin 55.5 71.3 87.2 ±22.4 na

Phorate (E) 32.6 45.7 60.0 ±11.2 B-L

Phorate oxon (E) 27.1 37.2 47.4 ±14.4 B-L

Prometon (E) 54.0 70.2 80.3 ±12.9 na

Prometryn 47.0 52.4 57.7 ±7.6 na

Pronamide 46.3 58.3 70.8 ±11.9 na

Simazine 52.2 75.9 89.7 ±18.3 na

Tebuthiuron (E) 45.8 69.4 90.2 ±24.5 na

Terbufos 19.4 36.8 38.7 ±9.1 B-L

Terbufos-oxon-sulfone (E) 32.8 33.4 34.1 ±0.9 B-L

Terbuthylazine 59.3 66.4 73.5 ±10.0 na

Trifluralin 51.4 63.9 76.5 ±11.1 na
24 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides

Table 10. Concentration in micrograms per kilogram (μg/Kg) of duplicate environmental aliquots of soil-box mix 1, mix 2, mix 3, and mix 

4, and the relative percentage difference between each of the duplicate sets.—Continued

[Mix 1 collected near site 10, Westley rain gage at pump house, San Joaquin Valley; mix 2 collected from near site 11, Newman rain gage at wasteway levee, 

San Joaquin Valley; mix 3 collected from near site 5, Modest Irrigation District at Albers Road, San Joaquin Valley; mix 4 collected near site 16, Gridley High 

School precipitation gage, Sacramento Valley. Abbreviations: E, estimated reported laboratory value; (E), estimated compound because of poor performance by 

applied method (Childress and others, 1999; Sandstrom and others, 2001); RPD, relative percentage difference; <, less than laboratory reporting value; μg/kg, 

micrograms per kilogram; –, not calculated because compound was not detected in environmental and duplicate sample; NA, not applicable to calculate]

Compound

Mix 1 Mix 2

Environmental

sample

(μg/kg)

Duplicate

environmental 

sample

(μg/kg)

RPD of

duplicates

(in percent)

Environmental

sample

(μg/kg)

Duplicate

environmental 

sample

(μg/kg)

RPD of

duplicates

(in percent)

1-Naphthol (E) <10 <10 – <10 <10 –

2,6-Diethylaniline (E) <30 <30 – <30 <30 –

2-Chloro-2,6-diethylacetanilide <1 <1 – <1 <1 –

2-Ethyl-6-methylaniline (E) <30 <30 – <2 <2 –

3,4-Dichloroaniline (E) 5.4 3.6 38.2 <30 <30 –

4-Chloro-2-methylphenol (E) <10 <10 – 6.10 4.08 39.4

Acetochlor <1 <1 – <10 <10 –

Alachlor <1 <1 – <1 <1 –

Atrazine <1 <1 – <1 <1 –

Azinphos-methyl (E) <5 <5 – <5 <5 –

Azinphos-methyl-oxon (E) <30 <30 – <30 <30 –

Benfluralin <1 <1 – <1 <1 –

Carbaryl (E) 1.5 1.6 9.84 2.10 1.94 8.40

Chlorpyrifos <1 <1 – E 0.68 E 0.63 7.90

Chlorpyrifos oxon (E) <30 <30 – <30 <30 –

Cyfluthrin (E) <20 <20 – <20 <20 –

Cypermethrin (E) <20 <20 – 0.59 0.53 9.81

Dacthal E 0.56 E 0.54 4.91 <1 <1 –

Deethylatrazine , CIAT <2 <2 – <5 <5 –

Diazinon <1 <1 – 3.70 3.38 7.95

Diazoxon (E) <5 <5 – <2.8 0 –

Dichlorvos (E) <30 <30 – <6.1 <6.5 –

Dicrotophos (E) <3 <3 – <30 <30 –

Dieldrin 3.1 E 1.91 47.2 <10 <10 –

Dimethoate E 18 E 15.2 16.3 <10 <10 –

Ethion <2 <2 – <1 <1 –

Ethion monoxon <3.1 <3.3 – <1 <1 –

Fenamiphos (E) <30 <30 – 1.20 1.11 7.79

Fenamiphos sulfone (E) <10 <10 – 0.62 0.56 9.80

Fenamiphos sulfoxide (E) <10 <10 – <1 <1 –

Fipronil (E) <1 <1 – <1 <1 –

Fipronil sulfide <1 <1 – <5 <5 –

Fipronil sulfone 1.2 1.92 50.2 <1 <1 –

Desulfinylfipronil E 0.61 E 0.59 2.17 <30 <30 –

Desulfinylfipronil amide (E) <1 <1 – <3 <3 –

Fonofos <1 <1 – E 8.9 E 7.51 16.49

Fonofos oxon <5 <5 – <2 <2 –

Hexazinone <1 <1 – 25.0 24.4 2.83

Iprodione (E) 5.4 6.44 17.9 <5 <5 –

Isofenphos <2 <2 – <1 <1 –

Malathion 18 17.8 2.22 <2 <2 –

Malaoxon (E) <5 <5 – 130 128 0.00

Metalaxyl <1 <1 – E 23 E 24.1 3.81

Methidathion <2 <2 – E 14 E 13.7 3.58

Metolachlor 58 68.9 18.0 <2 <2 –

Metribuzin E 15 E 15.5 4.62 <5 <5 –

Table 10. Concentration in micrograms per kilogram (μg/Kg) of duplicate environmental aliquots of soil-box mix 1, mix 2, mix 3, and mix 

4, and the relative percentage difference between each of the duplicate sets.
Laboratory and Field Quality Control 25

Table 10. Concentration in micrograms per kilogram (μg/Kg) of duplicate environmental aliquots of soil-box mix 1, mix 2, mix 3, and mix 

4, and the relative percentage difference between each of the duplicate sets.—Continued

[Mix 1 collected near site 10, Westley rain gage at pump house, San Joaquin Valley; mix 2 collected from near site 11, Newman rain gage at wasteway levee, 

San Joaquin Valley; mix 3 collected from near site 5, Modest Irrigation District at Albers Road, San Joaquin Valley; mix 4 collected near site 16, Gridley High 

School precipitation gage, Sacramento Valley. Abbreviations: E, estimated reported laboratory value; (E), estimated compound because of poor performance by 

applied method (Childress and others, 1999; Sandstrom and others, 2001); RPD, relative percentage difference; <, less than laboratory reporting value; μg/kg, 

micrograms per kilogram; –, not calculated because compound was not detected in environmental and duplicate sample; NA, not applicable to calculate]

Compound

Mix 1 Mix 2

Environmental

sample

(μg/kg)

Duplicate

environmental 

sample

(μg/kg)

RPD of

duplicates

(in percent)

Environmental

sample

(μg/kg)

Duplicate

environmental 

sample

(μg/kg)

RPD of

duplicates

(in percent)

Myclobutanil (E) 18 12.7 32.3 48.0 57 18.0

Parathion-methyl <2 <2 – <7 <7 –

Paraoxon-methyl <5 <5 – <5 <5 –

Pendimethalin 58 47.1 20.4 <30 <30 –

cis-Permethrin E 11 E 5.8 64.5 <20 <20 –

trans-Permethrin 6.1 E 4.04 40.0 135 140 3.98

Phorate (E) <5 <5 – <42 <35 –

Phorate oxon (E) <7 <7 – 1.40 1.49 3.41

Phosmet <30 <30 – <2 <2 –

Phosmet oxon <29 <34 – <5 <5 –

Prometon (E) 1.2 1.2 2.53 <5 <5 –

Prometryn <2 <2 – <2 <2 –

Pronamide <2 <2 – 70.0 71.5 2.12

Simazine 99 83.5 16.8 <3 <3 –

Tebuthiuron (E) <3 <3 – <5 <5 –

Terbufos <3 <3 – <1 <1 –

Terbufos-oxon-sulfone (E) <5 <5 – 31.0 33.4 7.78

Terbuthylazine <1 <1 – 101 100 1.17

Trifluralin 17 19.3 10.4 42.2 45.0 NA

alpha-HCH-d6 93.0 86.9 6.86 <1 <1 –

Diazinon-d10 135 127 5.76 26.0 29 12.1

Sample amount, sched 5503, solid, grams 40.9 45.1 NA <3 <3 –
26 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides

Table 10. Concentration in micrograms per kilogram (μg/Kg) of duplicate environmental aliquots of soil-box mix 1, mix 2, mix 3, and mix 

4, and the relative percentage difference between each of the duplicate sets.—Continued

[Mix 1 collected near site 10, Westley rain gage at pump house, San Joaquin Valley; mix 2 collected from near site 11, Newman rain gage at wasteway levee, 

San Joaquin Valley; mix 3 collected from near site 5, Modest Irrigation District at Albers Road, San Joaquin Valley; mix 4 collected near site 16, Gridley High 

School precipitation gage, Sacramento Valley. Abbreviations: E, estimated reported laboratory value; (E), estimated compound because of poor performance by 

applied method (Childress and others, 1999; Sandstrom and others, 2001); RPD, relative percentage difference; <, less than laboratory reporting value; μg/kg, 

micrograms per kilogram; –, not calculated because compound was not detected in environmental and duplicate sample; NA, not applicable to calculate]

Compound

Mix 3 Mix 4

Environmental

sample

(μg/kg)

Duplicate

environmental 

sample

(μg/kg)

RPD of

duplicates

(in percent)

Environmental

sample

(μg/kg)

Duplicate

environmental 

sample

(μg/kg)

RPD of

duplicates

(in percent)

1-Naphthol (E) <10 <10 – <10 <10 –

2,6-Diethylaniline (E) <30 <30 – <30 <30 –

2-Chloro-2,6-diethylacetanilide <1 <1 – <1 <1 –

2-Ethyl-6-methylaniline (E) <2 <2 – <2 <2 –

3,4-Dichloroaniline (E) <30 <30 – <30 <30 –

4-Chloro-2-methylphenol (E) 4 4.07 2.99 0.9 1.09 19.9

Acetochlor <10 <10 – <10 <10 –

Alachlor <1 <1 – <1 <1 –

Atrazine <1.2 <1 – <1.1 <1.2 –

Azinphos-methyl (E) <5 <5 – <5 <5 –

Azinphos-methyl-oxon (E) <30 <30 – <30 <30 –

Benfluralin <1 <1 – <1 <1 –

Carbaryl (E) 1.6 1.23 27.4 1.9 2.6 30.6

Chlorpyrifos E 0.86 <1 – <1 <1 –

Chlorpyrifos oxon (E) <30 <30 <30 <30 –

Cyfluthrin (E) <20 <20 – <20 <20 –

Cypermethrin (E) 0.79 0.62 23.9 <1 <1 –

Dacthal <1 <1 – <1 <1 –

Deethylatrazine , CIAT <5 <5 – <5 <5 –

Diazinon 3.1 3.02 2.29 E 0.43 E 0.60 30.0

Diazoxon (E) <2 <2 – <2 <2 –

Dichlorvos (E) <4.4 <3.8 – <2 <2 –

Dicrotophos (E) <30 <30 – <30 <30 –

Dieldrin <10 <10 – <10 <10 –

Dimethoate <10 <10 – <10 <10 –

Ethion <1 <1 – <1 <1 –

Ethion monoxon <1 <1 – <1 <1 –

Fenamiphos (E) 1.6 1.31 21.8 <1 <1 –

Fenamiphos sulfone (E) 0.83 <1 200 <1 <1 –

Fenamiphos sulfoxide (E) <1 <1 – <1 <1 –

Fipronil (E) <1 <1 – <1 <1 –

Fipronil sulfide <5 <5 – <5 <5 –

Fipronil sulfone <1 <1 – <1 <1 –

Desulfinylfipronil <30 <30 – <30 <30 –

Desulfinylfipronil amide (E) <3 <3 – <3 <3 –

Fonofos E 7.9 E 6.2 23.3 <10 <10 –

Fonofos oxon <2 <2 – <2 <2 –

Hexazinone 27 23.2 13.7 <2 <2 –

Iprodione (E) <5 <5 – <5 <5 –

Isofenphos <1 <1 – <1 <1 –

Malathion <2 <2 – <2 <2 –

Malaoxon (E) 110 95.8 12.0 <1 <1 –

Metalaxyl E 25 E 17.9 31.9 <4 <4 –

Methidathion E 13 E 13.4 6.95 <1 <1 –

Metolachlor <2 <2 – <2 <2 –

Metribuzin <5 <5 – <5 <5 –
Laboratory and Field Quality Control 27

Table 10. Concentration in micrograms per kilogram (μg/Kg) of duplicate environmental aliquots of soil-box mix 1, mix 2, mix 3, and mix 

4, and the relative percentage difference between each of the duplicate sets.—Continued

[Mix 1 collected near site 10, Westley rain gage at pump house, San Joaquin Valley; mix 2 collected from near site 11, Newman rain gage at wasteway levee, 

San Joaquin Valley; mix 3 collected from near site 5, Modest Irrigation District at Albers Road, San Joaquin Valley; mix 4 collected near site 16, Gridley High 

School precipitation gage, Sacramento Valley. Abbreviations: E, estimated reported laboratory value; (E), estimated compound because of poor performance by 

applied method (Childress and others, 1999; Sandstrom and others, 2001); RPD, relative percentage difference; <, less than laboratory reporting value; μg/kg, 

micrograms per kilogram; –, not calculated because compound was not detected in environmental and duplicate sample; NA, not applicable to calculate]

Compound

Mix 3 Mix 4

Environmental

sample

(μg/kg)

Duplicate

environmental 

sample

(μg/kg)

RPD of

duplicates

(in percent)

Environmental

sample

(μg/kg)

Duplicate

environmental 

sample

(μg/kg)

RPD of

duplicates

(in percent)

Myclobutanil (E) 47 51.9 9.27 <1 <1 –

Parathion-methyl <7 <7 – <7 <7 –

Paraoxon-methyl <5 <5 – <5 <5 –

Pendimethalin <30 <30 – <30 <30 –

cis-Permethrin <20 <20 – <20 <20 –

trans-Permethrin 136 127 6.74 155 119 26.2

Phorate (E) <33 < 30 – <10 <10 –

Phorate oxon (E) 1.6 1.21 25.3 2.1 2.48 14.7

Phosmet <2 <2 – <2 <2 –

Phosmet oxon <5 <5 – <5 <5 –

Prometon (E) <5 <5 – <5 <5 –

Prometryn <2 <2 – <2 <2 –

Pronamide 130 74.9 52.3 10 11.1 7.48

Simazine <3 <3 – <3 <3 –

Tebuthiuron (E) <5 <5 – <5 <5 –

Terbufos <1 <1 – <1 <1 –

Terbufos-oxon-sulfone (E) 25 24.8 2.39 0.11 0.08 38.6

Terbuthylazine 98.0 92.9 5.29 81.4 86.5 6.05

Trifluralin 34.6 40.7 NA 28.3 30.1 NA

alpha-HCH-d6 <1 <1 – <1 <1 –

Diazinon-d10 E 23 E 23.9 4.71 <2 <2 –

Sample amount, sched 5503, solid, grams <3 <3 – <3 <3 –
28 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides

laboratory-grade Ottawa Sand (clean dry sand). The average 

ambient concentration from the duplicate analysis performed 

on the soil-box mix 2 matrix was compared to the matrix-spike 

concentration that was recovered (table 11).

Substantially lower recoveries for some compounds in the 

soil-box mix 2 LMS compared to the LRS prepared by using 

clean, dry sand appeared largely influenced by the presence 

of ambient or “background” concentrations in the unspiked 

soil-box mix 2 sample (unspiked mix 2) that were subtracted 

from the determined LMS concentration in the LMS recovery 

calculation. Spike recoveries for a number of compounds from 

the soil-box mix 2 LMS and the LRS exhibited reasonable 

agreement, which is defined as a relative percent difference 

(RPD) in recoveries that is less than or equal to 25 percent 

(table 11). For some compounds, however, the spike recoveries from the soil-box mix 2 LMS were substantially greater or 

less than from the LRS. As a result of the bias, variability, or 

both, as indicated by the recoveries in both the LMS and LRS 

matrices, the compounds are designated with the following 

qualifier codes in table 11 and appendix 9:

• Acceptable Data—Data for environmental samples 

were considered acceptable and were not qualified for 

compounds with LMS and LRS recoveries between 

50–150 percent. Likewise, environmental data were 

considered acceptable and were not qualified for those 

compounds that had (1) LMS recoveries that were 

coded U-R, which is defined as unable to calculate 

a recovery value because the concentration in the 

unspiked mix 2 sample was equivalent to or greater 

than the fortification concentration, or (2) unspiked 

mix 2 sample concentrations that were at least 

25percent of the LMS fortification concentration (for 

example, dieldrin), but that had LRS recoveries greater 

than 50 percent.

• Biased Low—Environmental-sample data were qualified as possibly being biased low (B-L) if the LRS or 

LMS recovery was less than 50 percent and the low 

LMS recovery was not a result of having an unspiked 

mix 2 sample concentration that was greater than 

25 percent of the LMS fortification concentration. For 

compounds coded B-L, it was assumed that the analytical method probably would not adequately recover the 

compound as a result of matrix interference, adsorptive 

losses on the dry sand, or other procedural problems. 

For compounds that were qualified as biased low, it 

is possible that small, true concentrations present in 

a sample near the detection level were not detected 

because of low bias method recovery and, thus, were 

reported as less than the reporting level. Those compounds exhibiting low-biased method performance 

are included in appendix 9 nevertheless. For example, 

dichlorvos was not detected in the environmental 

samples; its recoveries in the LMS and LRS were 

45.1 and 24.6 percent, respectively.

• Biased High—Environmental sample data were 

qualified as possibly biased high (B-H) for those 

compounds with an LMS recovery greater than 

150 percent. Cyfluthrin is an example for which the 

determined concentration from the LMS (190 percent 

recovery) was nearly twice the fortification concentration and substantially greater than from the LRS 

(82 percent).

• Unable to Determine—D-U, for unable to determine, was assigned to those compounds for which 

the analytical method did not determine the LMS or 

sample concentration successfully because of matrix 

interference or other method limitations. Phosmet oxon 

is an example of a compound that was not detected 

(0 percent recovery) in the LRS and for which there 

was interference in the LMS, and a recovery could 

not be determined. Results for phosmet oxon are not 

presented in appendix 9.

No compounds were detected in the laboratory reagent 

blank sample. This could be a consequence of the substantially low recoveries for some compounds in the spiked clean, 

dry sand (the LRS). For the majority of compounds, the LRS 

recoveries were substantially lower than those from the soilbox mix 2 LMS (table 11). These low LRS recoveries are 

believed to be due to strong adsorption to active sites on the 

dry sand on the basis of separate method testing (unpublished 

results). This was especially the case for chlorpyrifos oxon, 

diazoxon, iprodione, phorate, phorate oxon, and prometon. 

Although there could be active sites on the soil box mix 2 

matrix, their numbers could be substantially less than in the 

dry sand as a result of residual moisture in this environmentalsample matrix. A small amount of moisture can dramatically 

alter the adsorptive capacity for organic compounds because 

water strongly binds to active sorptive sites on the mineral surface, thereby deactivating those sites from strong adsorption of 

the organic compounds (Chiou, 2002). In addition, the recoveries for the two surrogates, α-HCH-d6 and diazion-d10, were 

lower in the clean, dry sand compared to the soil-mix 2 matrix, 

indicating overall lower recoveries in the dry sand because 

of more procedural losses relative to the soil-mix 2 matrix 

(table 11). The method applied to this study was subsequently 

modified to improve recovery performance by prewetting 

the reagent sand matrix with a small amount of PBW prior 

to spiking. This change resulted in acceptable recoveries for 

more method compounds (Mast and others, 2006).

Field Quality-Control Methods

The field quality-control methods for the project included 

the collection and processing of equipment blanks, field 

blanks, and split replicates. There was no QC performed on 

surficial-soil samples collected from the soil boxes. It was 

impractical to collect field blanks or apply field spikes to soils 

because of the inherent heterogeneity of the soil matrix used 

in the soil boxes and the lack of appropriate “blank” matrix 
Laboratory and Field Quality Control 29

Table 11. Ambient concentrations, spike concentrations, calculated recoveries for the laboratory matrix spike and laboratory reagent 

spike, and the relative percentage difference between recoveries of the soil-box surficial-soil samples.—Continued

[Laboratory reagent spikes were extracted along with the environmental surficial soil samples. Abbreviations: B-H, biased high; B-L, biased low; D-U, compound deleted due to matrix interference; na, none applied; (E), estimated compound due to poor performance by applied method (Childress and others, 1999; 

Sandstrom and others, 2001); LMS, Laboratory Matrix Spike; LRS, Laboratory Reagent Spike; RPD, relative percent difference; U-R, unable to determine 

recovery because the concentration in the unspiked sample is comparable to or higher than the fortification concentration; μg/kg, microgram per kilogram; –, 

compound not detected]

Compound

(common name)

Average ambient

concentration 

of soil mix 2 and 

duplicate, 

(μg/kg)

 LMS

concentration

recovered,

(μg/kg)

LMS,

percentage

recovery

LRS,

clean dry sand,

percentage 

recovery

RPD between 

LRS and LMS 

recoveries,

less than 25 

percent

Environmental

detection

qualifer code

1-Naphthol (E) – 1.02 19.4 16.7 14.9 B-L

2,6-Diethylaniline (E) – 0.41 7.9 7.6 3.5 B-L

2-Chloro-2,6-diethylacetanilide – 7.05 134.0 80.4 – na

2-Ethyl-6-methylaniline (E) – 0.35 6.7 0 – B-L

3,4-Dichloroaniline (E) 5.08 5.21 U-R 12.6 – na

4-Chloro-2-methylphenol (E) – 3.58 68.1 0 – B-L

Acetochlor – 7.19 136.7 92.3 – na

Alachlor – 6.08 115.6 81.8 – na

Atrazine – 5.08 96.6 102.5 6.0 na

Azinphos-methyl (E) – 9.23 175.5 54.4 – B-H

Azinphos-methyl-oxon (E) – 0.00 0 63.4 – B-L

Benfluralin – 7.44 141.4 78.3 – na

Carbaryl (E) 2.03 10.1 151.9 113.4 – B-H

Chlorpyrifos 0.66 6.00 101.1 82.2 20.6 na

Chlorpyrifos oxon (E) – 5.08 96.6 0 – B-L

Cyfluthrin (E) – 9.98 189.7 82.4 – B-H

Cypermethrin (E) – 8.78 166.9 100.4 – B-H

Dacthal 0.56 3.72 59.5 85.3 – na

Deethylatrazine (CIAT) – 7.59 144.3 89.6 – na

Diazinon – 5.85 111.2 74 – na

Diazoxon (E) – 5.50 104.6 0 – B-L

Dichlorvos (E) – 2.37 45.1 24.6 – B-L

Dicrotophos (E) – 0.00 0.0 77.2 – B-L

Dieldrin 3.52 6.08 48.6 92.8 – na

Dimethoate 27.4 23.6 U-R 95.7 – na

Ethion – 6.49 123.4 101.3 19.7 na

Ethion monoxon – 10.1 192.0 98.2 – B-H

Fenamiphos (E) – 5.19 98.7 21 – B-L

Fenamiphos sulfone (E) – 5.49 104.4 99.6 4.7 na

Fenamiphos sulfoxide (E) – 2.89 54.9 79.3 – na

Fipronil – 10.2 193.9 102.8 – B-H

Fipronil sulfide – 9.99 189.9 118.3 – B-H

Fipronil sulfone 1.16 4.38 60.5 116.2 – na

Desulfinylfipronil 0.59 6.70 115.6 89.2 – na

Desulfinylfipronil amide (E) – 9.98 189.7 104.6 – B-H

Fonofos – 4.02 76.4 61.7 21.3 na

Fonofos oxon – 7.11 135.2 69.5 – na

Hexazinone – 4.82 91.6 103.3 12.0 na

Iprodione 8.19 12.5 69.2 2 – B-L

Isofenphos – 10.1 192.0 106 – B-H

Malathion 24.8 28.7 68.4 111.1 – na

Malaoxon (E) – 9.22 175.3 55.3 – B-H

Table 11. Ambient concentrations, spike concentrations, calculated recoveries for the laboratory matrix spike and laboratory reagent 

spike, and the relative percentage difference between recoveries of the soil-box surficial-soil samples.
30 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides

Table 11. Ambient concentrations, spike concentrations, calculated recoveries for the laboratory matrix spike and laboratory reagent 

spike, and the relative percentage difference between recoveries of the soil-box surficial-soil samples.—Continued

[Laboratory reagent spikes were extracted along with the environmental surficial soil samples. Abbreviations: B-H, biased high; B-L, biased low; D-U, compound deleted due to matrix interference; na, none applied; (E), estimated compound due to poor performance by applied method (Childress and others, 1999; 

Sandstrom and others, 2001); LMS, Laboratory Matrix Spike; LRS, Laboratory Reagent Spike; RPD, relative percent difference; U-R, unable to determine 

recovery because the concentration in the unspiked sample is comparable to or higher than the fortification concentration; μg/kg, microgram per kilogram; –, 

compound not detected]

Compound

(common name)

Average ambient

concentration 

of soil mix 2 and 

duplicate, 

(μg/kg)

 LMS

concentration

recovered,

(μg/kg)

LMS,

percentage

recovery

LRS,

clean dry sand,

percentage 

recovery

RPD between 

LRS and LMS 

recoveries,

less than 25 

percent

Environmental

detection

qualifer code

Metalaxyl – 5.05 96.0 83.6 13.8 na

Methidathion – 8.02 152.5 101 – B-H

Metolachlor 128 140 U-R 100.3 – na

Metribuzin 23.7 25.8 49.4 121.9 – na

Myclobutanil (E) 14.0 19.6 102.7 93.2 9.7 na

Parathion-methyl – 7.80 148.3 101 – na

Paraoxon-methyl – 5.83 110.8 112.7 1.7 na

Pendimethalin 52.3 45.4 U-R 91.2 – na

cis-Permethrin – 9.48 180.2 117.5 – B-H

trans-Permethrin – 9.51 180.8 105.3 – B-H

Phorate (E) – 4.96 94.3 16.9 – B-L

Phorate oxon (E) – 4.68 89.0 12.8 – B-L

Phosmet – 5.35 101.7 0 – B-L

Phosmet oxon – 36.0 D-U 0 – D-U

Prometon (E) 1.47 6.35 93.3 47 – na

Prometryn – 4.51 85.7 67.9 23.2 na

Pronamide – 6.48 123.2 72.5 – na

Simazine 70.8 D-U U-R 79.5 – na

Tebuthiuron (E) – 7.87 149.6 75.4 – na

Terbufos – 6.62 125.8 0 – B-L

Terbufos-oxon-sulfone (E) – 12.3 233.8 50.7 – B-H

Terbuthylazine – 5.03 95.6 73.1 – na

Trifluralin 32.15 26.1 U-R 63.4 – na

alpha-HCH-d6 100.6 97.8 97.8 55.2 – na

Diazinon-d10 137.3 116.0 116.0 67.3 – na

Sample amount, grams 43.6 38.0 38.0 50 Not applicable na
Laboratory and Field Quality Control 31

material. Instead, two types of QC samples were collected and 

used for comparison with environmental samples, which are 

discussed separately. All QC samples collected and reported 

in this study were analyzed at the NWQL and are presented by 

study period. 

2001 Study Period

One equipment blank and two field blanks were processed during the 2001 study period with no detections on 

the ISCO (Teledyne ISCO Company, Lincoln, Nebraska) 

automated sampler and collection bottles. The equipment 

blank was processed prior to field deployment, and two field 

blanks were collected during storm-drain runoff sampling 

(appendix 2).

2002–04 Study Period

Equipment and Field Blanks

Equipment blanks were run on the sample collection 

equipment prior to deployment in the field to confirm the 

suitability of equipment to provide samples within the dataquality objectives of the project. Field blanks were used to 

evaluate bias resulting from contamination of environmental 

samples by the compounds of interest during sample collection, processing, shipping, or analysis. There were no 

compounds detected in the 24 equipment blanks and 19 field 

blanks processed and collected during the 2002–04 study 

period (table 12).

NWQL PBW was used as the blank solution to assess 

the degree of potential contamination introduced during field 

processing and handling, as well as laboratory handling of 

samples and equipment. The field-blank procedure for the 

funnel sampler was to place the funnel on top of the samplecollection bottle in the funnel-bottle assembly, following the 

standard cleaning procedure, and then to pour approximately 

1-L of blank solution into the funnel and collection bottle. 

The collected blank solution was then poured into a 1-L 

amber glass bottle and sent to NWQL with the environmental 

samples. Field equipment blanks on the autosampler collection 

pots were done in the same manner, following the standard 

cleaning procedure, except that the PBW was poured directly 

into the collection pot, swirled around, and then poured into 

a 1-L amber glass bottle. 

The equipment blanks were processed in the same manner but at the CAWSC Laboratory. Each site had a dedicated 

funnel and 4-L sample collection bottle. The equipment blanks 

were completed prior to the initial deployment at a site and 

periodically throughout the study period to reduce the possibility of contamination of the environmental samples by 

the equipment as the funnel and collection bottle were reused 

throughout the study period. Individual equipment blanks were 

processed and submitted for the funnel and the 4-L samplecollection bottle (two equipment blanks total per site). 

Split Replicates

Replicate samples were used to identify and quantify 

the variability inherent to sampling and analysis. Replicate 

samples were split from the environmental samples at various sites to characterize the reproducibility of the complete 

sample processing and analytical process. The sample split 

from the environmental sample was considered the QC sample 

or the split replicate. Both samples (environmental and split 

replicate) were defined as the replicate set. RPD was used 

to describe the variability within the replicate set. In at least 

one sample of the replicate sets, 28 compounds were detected 

(table 13). With the exception of metalaxyl and dichlorovos, 

the median RPD ranged from 0 to 17.7 percent. The higher 

median percentage values for metalaxyl (72.8 percent) and 

dichlorovos (66.7 percent) were a result of a non-detection in 

the replicate set. If one value in a replicate pair was reported 

as a non-detection and the other value was greater than the 

laboratory reporting limit, then the non-detection value was set 

to one-half of the LT-MDL, and an RPD was calculated. 

QA for Soil-Box Samples

There were no QC samples collected from the soil 

boxes. It was impractical to collect field blanks or do field 

spikes because of the heterogeneity of the soil used for the 

soil boxes. Samples of native soil were analyzed to determine 

background levels of compounds of interest in the native soil. 

Aliquots of 30–40 grams from each mix (mix 1, mix 2, mix 3, 

and mix 4) were analyzed prior to exposure and compared 

Table 12. Environmental and field quality-control sample types 

and totals collected during the 2001 and 2002–04 study periods in 

the Central Valley of California.

[Abbreviations: –, no field quality control collected]

2001 Study period

Environmental

sample type

Environmental

sample total

Blanks Split

replicates Field Equipment

Storm-drain samples 10 2 1 0

Wet deposition 8 0 0 0

2002–04 Study period

Environmental

sample type

Environmental

sample total

Blanks Split

replicates Field Equipment

Wet deposition 184 12 16 19

Bulk wet deposition 38 –1 –1 –1

Dry deposition 37 5 6 0

Bulk dry deposition 26 –2 –2 –2

Soil-box run off samples 30 2 2 1

Suspended sediment 30 0 0 0

Surficial-soil samples 8 0 0 0

1

No field quality control collected for bulk wet-deposition sample because it 

was collected on the intended sample type: wet deposition.

2

No field quality control collected for bulk dry-deposition sample because it 

was collected on the intended sample type: dry deposition.
32 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides

to environmental samples collected during the study period. 

In addition, a separate soil box was assembled to serve as a 

source of “control samples” (fig. 4, site 14). The control soil 

box was set up outdoors on a building rooftop to examine the 

transformation or degradation of compounds with no exposure 

to sunlight or atmospheric deposition. This soil box contained 

a composite mixture of the soils collected in the San Joaquin 

Valley (mix 1, mix 2, mix 3), and one side was covered with 

a piece of plywood. The covered side had a 0.5 inch gap to 

allow air flow, but minimize atmospheric deposition (both 

wet and dry). Three times during the study, the cover was 

removed, and surficial samples were collected for laboratory analysis. The results of these analyses are presented 

in appendix 9 with the environmental data for comparison. 

Concentrations of detections in the control were nearly 

identical to the background concentrations, indicating there 

was no photolysis or hydrolysis over the 2-year period. The 

concentrations of some compounds, however, decreased over 

time, possibly as a result of volatilization or biodegradation. 

Simazine is an example of a compound for which the initial 

concentration collected from the control was the greatest, and 

concentrations decreased in subsequent samples. The halflife of simazine in aerobic soil conditions is approximately 

90 days (http://sitem.herts.ac.uk/aeru/footprint/en/index.htm, 

accessed April 5, 2011).

Results of Monitoring

2001 Study Period (Rainfall and Storm-Drain 

Runoff)

A single storm event on January 25–26, 2001, was 

sampled, with rainfall collected at four urban and four agricultural sites in the Modesto, Calif., region (fig. 4, sites 1–8), 

while simultaneously hourly storm-drain runoff samples 

were collected from a Modesto storm drain (site 9). The average rainfall at the urban and agricultural sites was about 

0.52 inches. Appendix 2 presents the measured concentrations 

of compounds with at least one detection during the storm 

sampling event for the urban sites, agricultural sites, and urban 

storm drain. Detected pesticide concentrations in rainfall at the 

urban sites were fairly uniform, with the exception of site 1, 

which was located immediately downwind of a recent orchard 

pesticide application of diazinon that probably influenced the 

results. Registered agricultural diazinon application data from 

the California Department of Pesticide Regulation (CDPR) 

indicated approximately 100–200 kilograms of active ingredient was applied within 3 kilometers (km) of site 1 (Majewski 

and others, 2005; http://pubs.usgs.gov/of/2005/1307/, accessed 

April 19, 2011). Detected pesticide concentrations at the agricultural sites were variable, but correlated with proximity to 

orchards and recent pesticide applications. 

Chlorpyrifos, dacthal, diazinon, pendimethalin, and simazine were detected in all rainfall samples collected from urban 

and agricultural sites. Median concentrations of chlorpyrifos 

and diazinon in agricultural and urban rainfall were similar, 

indicating that the overall atmospheric level of these pesticides in the region was fairly evenly distributed during the 

sampling event (fig. 9). The median concentrations of chlorpyrifos, diazinon, and simazine collected from the agricultural 

sites (0.079 μg/L, 0.583 μg/L, and 0.051 μg/L, respectively) 

were slightly greater than the median concentrations collected 

from the urban sites (0.067 μg/L, 0.515 μg/L, and 0.031 μg/L, 

respectively; table 14). Metolachlor and napropamide had 

higher detection frequencies in samples collected from the 

Table 13. Minimum, maximum, and median relative percentage 

difference values for compounds detected in at least one sample 

of the replicate set.

[If one value in a sample pair was reported as a non-detection and the other 

value was greater than the laboratory reporting limit, then the non-detection 

value was set equal to one-half of the laboratory reporting limit and the 

relative percent difference (RPD) calculated.]

Compound 

detected in

split replicate 

sets

Total number 

of replicate 

sets with 

detections

Minimum 

RPD,

in percent

Maximum 

RPD,

in percent

Median 

RPD,

in percent

 1-Naphthol 12 0.0 85.7 0.0

 3,4-Dichloroaniline 7 0.0 120.0 6.9

 4-Chloro-2-

methylphenol

6 0.0 63.6 0.0

 Azinphos-methyl 5 0.0 13.3 8.4

 Carbaryl 14 0.0 127.0 10.8

 Chlorpyrifos 18 0.0 104.0 2.6

 Chlorpyrifos oxon 9 0.0 40.0 0.0

 Dacthal 20 0.0 35.3 2.4

 Diazinon 20 0.0 52.6 5.2

 Diazoxon 12 0.0 40.0 0.0

 Dichlorvos 3 0.0 75.0 66.7

 Hexazinone 6 0.0 28.9 5.4

 Iprodione 12 0.0 125.3 13.2

 Malathion 10 0.0 37.8 7.7

 Malaoxon 6 0.0 57.1 6.1

 Metalaxyl 2 0.0 145.7 72.8

 Methidathion 9 0.0 131.8 6.3

 Metolachlor 12 0.0 150.0 5.0

 Myclobutanil 12 0.0 113.7 10.2

 Parathion-methyl 5 0.0 5.0 3.4

 Paraoxon-methyl 3 0.0 0.0 0.0

 Pendimethalin 16 0.0 152.0 9.8

 Phosmet 5 10.5 81.0 13.3

 Phosmet oxon 2 0.0 0.0 0.0

 Prometryn 6 0.0 61.1 0.0

 Pronamide 5 0.0 22.2 0.0

 Simazine 15 0.0 148.2 8.7

 Trifluralin 12 0.0 107.7 17.7
Results of Monitoring 33

urban sites than those collected from the agricultural sites 

(100 percent compared to 50 percent, appendix 2). Pesticides 

applied in agricultural areas could have drifted into the urban 

environment, but it is unknown how many, if any, urban applications took place during this study that contributed to the 

observed urban concentrations.

Many of the same pesticides detected in rainfall samples 

collected in the McHenry urban watershed (sites 3 and 4) were 

detected in the storm-drain runoff samples from the urban 

watershed also (appendix 2). The median concentrations of 

these compounds detected in both rainfall and storm drain runoff samples are presented in table 15. Comparison of median 

concentrations in the rainfall to those in the McHenry storm 

drain runoff indicates that rainfall contributed to a substantial 

percentage of the concentration found in the runoff for some 

compounds, whereas for other compounds, the concentrations 

in rainfall were much greater than in the runoff. The median 

diazinon concentration in rain was 69 percent of the median 

in runoff, whereas the median chlorpyrifos concentration in 

rain was 194 percent of the median in runoff. Other watersoluble pesticides—carbaryl, metolachlor, napropamide, and 

simazine—were similar to diazinon, with rainfall containing 

less than 100 percent of the median concentration in runoff. 

Malathion was detected in the storm-drain runoff water, but 

not in any rainfall sample. The results are explained by the 

physical and chemical properties of these pesticides. Table 15

includes the water solubility (SL), subcooled liquid vaporphase pressure (PL), and soil organic-carbon partition coefficient (log Koc) for the compounds detected (greater than 

50 percent detection frequency) in both the rainfall and storm 

drain runofff samples (Worthing and Walker, 1987; Wauchope 

and others, 1992; Mackay and others, 1997; Suntio and others, 

1998; U.S. Department of Agriculture, 2005; U.S. Environmental Protection Agency, 2005). Diazinon is much more 

water soluble than chlorpyrifos, whereas chlorpyrifos has a 

higher organic-carbon partition coefficient. Since the runoff 

samples were filtered, and the filters were not analyzed, it is 

likely that most of the chlorpyrifos had been sorbed onto the 

suspended particulate matter and was removed by filtration, 

whereas diazinon stayed in solution (fig. 10). 

2002–04 Study Period

The wet-deposition, bulk wet-deposition, dry-deposition, 

and bulk-dry-deposition samples collected during the 2002–04 

study period were analyzed and presented as flux in micrograms per square meter per day (μg/m2

/day) in appendix 3

through 6, respectively. These sample types are presented 

as a flux for this study period to further examine the areal 

distribution of atmospheric loading rates (mass/area/time) of 

pesticides to the Central Valley, Calif. Compounds with nondetections were not calculated and are not presented.

sac12-0461_fig 09

Site 3, (Bowen and Aloha Street)

Site 4, (Modesto Irrigation District at Modesto)

MedianMedian

Site 5, (Modesto Irrigation District at Albers Road)

Site 6, (Modesto Irrigation District lateral # 4)Site 7, (Modesto Irrigation District lateral # 3)

Site 8, (Tully Road)

Site 1, (Waste Water Treatment Plant)

Site 2, (Cadoni Road)

Urban Sites

EXPLANATION

Agricultural Sites

0.07

0.52

0.58

0.08

Diazinon

Chlorpyrifos

1

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0

Concentration, in imicrogram per liter

Figure 9. Concentrations of diazinon and chlorpyrifos in rainfall 

measured at the four urban and four agricultural sites during 

the January 25–26, 2001, storm event in the area of Modesto, 

California.

Table 14. Median concentrations of compounds detected 

in samples collected from the urban and agricultural rainfall 

collection sites in Modesto, California, during the January 25–26, 

2001, sampling event.

[Abbreviations: E, estimated reported laboratory value; μg/L, micrograms per 

liter; <, less than]

Compound

Median concentrations for

storm sampling event, μg/L

Urban sites Agricultural sites

Carbaryl <0.1 <0.09

Chlorpyrifos 0.067 0.079

Dacthal 0.01 0.009

Diazinon 0.515 0.583

Metolachlor E0.004 <0.013

Pendimethalin 0.122 0.170

Napropamide 0.016 1

0.032

Simazine 0.031 0.051

Trifluralin 1

0.036 0.008

1

Concentration represents detections in 50 percent of samples.
34 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides

Insecticide concentration, in micrograms per liter

0

10

20

30

40

50

60

70

80

0.2

0.4

0.6

0.8

1

1.2

0

1800 1900 2000 2100 2200

Hour

2300 0000 0100 0200

Storm-drain discharge, in cubic feet per second

Diazinon

EXPLANATION

Chlorpyrifos

Discharge

Figure 10. Measured discharge and concentration of insecticides diazinon and chlorpyrifos detected in the hourly storm-drain runoff 

samples collected during the January 25–26, 2001, storm event in Modesto, California.

Table 15. Comparison of median concentrations and the physical and chemical properties of detected pesticides in rainfall (sites 3 

and 4) and storm-drain runoff (site 9) during the January 25–26, 2001, sampling event in Modesto, California.

[Abbreviations: E, estimated reported laboratory value; Pa, Pascals; mg/L, milligrams per liter; μg/L, micrograms per liter]

Compound

Median rain

concentration

(sites 3 and 4),

(μg/L)

Median storm-drain 

runoff concentration 

(site 9),

(μg/L)

Water

solubility,

SL

(mg/L)

9

Subcooled liquid 

vapor pressure,

PL

(Pa)

Soil-organic carbon 

partition coefficient, 

log KOC

Carbaryl 1<0.1 E0.18 2120 0.003 82.36

Chlorypyrifos 0.06 0.031 3

0.73 0.002 23.78

Dacthal 0.011 0.009 6

0.5 0.007 63.75

Diazinon 0.515 0.742 2

60 0.008 82.76

Metolachlor E0.004 E0.005 4

530 0.002 22.30

Napropamide 0.011 0.019 5

74 0.002 53.74

Pendimethalin 0.122 0.061 6

0.275 0.008 64.13

Simazine 0.026 0.053 4

5 0.001 22.11

Trifluralin 1

0.025 0.006 70.05–40 0.010 84.14

1

Concentration represents detections in 50 percent of samples.

2

Wauchope and others, 1992 (referenced from compilation in Mackay and others, 1997).

3

Bowman and Sans, 1983 (referenced from compilation in Mackay and others, 1997).

4

Worthing and Walker, 1987 (referenced from compilation in Mackay and others, 1997).

5

U.S. Environmental Protection Agency, 2005.

6

U.S. Department of Agriculture, 2005.

7

According to Mackay and others, 1997, “the reported values for this quantity vary considerably.”

8

Howard and others, 1991 (referenced from compilation in Mackay and others, 1997).

9

Calculated using δ water solubility values of 56 joules per mole Kelvin from Suntio and others, 1988.
Results of Monitoring 35

Wet-Deposition Sample Type

A total of 184 wet-deposition samples were analyzed 

for 41 currently used pesticides and 23 pesticide degradates, 

including oxygen analogs (oxons) of 9 organophosphate 

insecticides. Fifty-three compounds were detected, and detection frequencies ranged from of 0.5 percent (representing 

one detection) for four compounds to 97.8 percent for dacthal. The most frequently detected compounds in both the 

San Joaquin and Sacramento Valleys were dacthal, diazinon, 

chlorpyrifos, simazine, and pendimethalin (table 16). The 

median wet-deposition flux for these compounds was greater 

in samples collected from the San Joaquin Valley (between 1.2 

and 4.0 times more), than samples collected from the Sacramento Valley (fig. 11 and table 17).

In the San Joaquin Valley, the compounds with the greatest wet-deposition rates were chlorypyrifos (10.1

μg/m2/day, 

site 5), iprodione (77.6 μg/m2/day, site 10), simazine 

(48.9μg/m2/day, site 13), and trifluralin (29.0μg/m2/day, 

site 11; appendix 3). The greatest wet-deposition rates in 

the Sacramento Valley were for diazinon, at 50.6 μg/m2/day 

and 45.6 μg/m2/day, which were collected from the funnel 

and autosampler, respectively, at urban site 16 following the 

February 7–14, 2003, storm event (appendix 3). Diazinon and 

dacthal were detected in every sample collected from this site 

(February 7, 2003, to February 20, 2004), with median deposition amounts of 0.225 and 0.033 μg/m2

/day, respectively. 

At the Sierran-Nevada foothills site 15, located downwind 

from the urban site 16, dacthal also was detected in every 

sample and had a slightly greater median deposition amount at 

0.044 μg/m2/day. 

Wet-deposition samples collected in the San Joaquin 

Valley following the January 9–14, 2003, storm event 

resulted in similar rates of diazinon wet-deposition at urban 

site 4, located in downtown Modesto, and the agricultural 

site 5, located in rural Modesto adjacent to agricultural land 

(appendix 3). At the downtown Modesto site, 12.0μg/m2/day 

and 12.7μg/m2/day were collected from the funnel and autosampler, respectively. At the agricultural site, 14.4

μg/m2/day 

and 11.7 μg/m2/day were collected from the funnel and autosampler, respectively. These samples were collected during the 

orchard dormant-spraying season and indicate that atmospheric levels and deposition in the region could have been 

fairly constant for the compound throughout the sampling 

event.

Measured concentrations of chlorpyrifos, dacthal, and 

diazinon collected from the autosampler and the funnel 

sampler during the same sampling events were compared to 

examine differences in concentrations between the samplers 

(fig. 12). Measured concentrations collected from the funnel 

were expected to be slightly greater than from the autosampler 

because the funnel was exposed to the atmosphere between 

rain events for a sampling period equal to or less than 5 days, 

whereas the autosampler lid closed following a rain event, and 

therefore, the sample was not exposed to potential dry-deposition. For the San Joaquin Valley sites, concentrations for the 

samplers at site 5 were similar (fig. 12B); however, at site 4, 

concentrations of chlorpyrifos and dacthal collected from 

the funnel sampler were greater than from the autosampler 

(fig. 12A). Higher concentrations were also collected from the 

funnel sampler than the autosampler in the Sacramento Valley 

from site 16 for chlorpyrifos and dacthal (fig. 12C). The land 

use surrounding site 16 is predominately orchards, corn, 

alfalfa, and vegetables (table 3). It is likely that, because these 

samples were predominately collected during the orchard 

dormant-spraying season, dry deposition contributed to the 

higher concentrations measured in samples collected from the 

funnel sampler compared to the autosampler. In addition, dacthal and chlorpyrifos are less water soluble and have greater 

log Koc values compared to diazinon (table 15).

Bulk Wet-Deposition Sample Type

A total of 38 bulk-wet-deposition samples were collected 

during the 2002–04 study period (appendix 4). Table 18 compares wet and dry deposition amounts in mass per area (μg/m2

) 

for compounds detected in both sample types collected from 

the Modesto Irrigation District rooftop autosampler (site 4) as 

discrete samples during the April 9–May 21, 2002, composite 

sample period. For some compounds (chlorpyrifos, simazine, 

and myclobutanil), the dry-deposition amount is between 3.4 

and 6.8 times greater than deposition amounts measured in the 

wet-deposition sample type, whereas for the compound phosmet, the dry deposition was substantially greater (17 times 

greater). These differences could be a result of pesticide use 

during the sample period and the predominant deposition 

phase of the detected compounds.

The predominant deposition phase is related to the physical and chemical properties of a pesticide (table 18). Henry’s 

Law describes partitioning properties with respect to a compound’s potential to partition into the gas phase or the aqueous 

phase on the basis of vapor pressure. For compounds with low 

Henry’s Law (H) constants and high water solubility, such as 

diazinon, rainfall was a more significant source of depositional 

loading to the ground than dry deposition. For compounds 

with high H constants and low water solubility, such as chlorpyrifos, dry deposition was more important.

Thirty-two compounds were detected in the samples 

collected as bulk-wet deposition. Detection frequencies for 

the bulk-wet-deposition samples ranged from one detection (2.6 percent) for eight compounds to 100 percent for 

dacthal (table 19). The most detected compounds in the San 

Joaquin Valley and Sacramento Valley were dacthal, diazinon, 

chlorpyrifos, and simazine (fig. 13). The median deposition 

amounts for the compounds dacthal and chlorpyrifos were 

comparable for the San Joaquin Valley and Sacramento Valley 

(table 17), but the median diazinon deposition amount was 
36 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides

Table 16. Total number of samples analyzed and detection frequency for compounds analyzed in wet deposition and that had at least 

one detection during the 2002–04 study period in the Central Valley of California.

[Concentrations can be calculated from additional information listed in appendix 3]

Compound Total number of samples analyzed Detection frequency, in percent

Dacthal 184 97.8

Diazinon 184 97.3

Chlorpyrifos 184 92.4

Simazine 184 91.8

Pendimethalin 184 85.9

Trifluralin 184 64.7

Carbaryl 184 56.5

Metolachlor 184 56.5

Iprodione 184 49.5

Malathion 184 48.4

Myclobutanil 184 47.8

Chlorpyrifos oxon 184 46.2

1,4-Naphthoquinone 184 43.2

Carbofuran 37 43.2

cis-Propiconazole 37 43.2

trans-Propiconazole 37 43.2

Methidathion 37 37.5

Diazoxon 184 35.9

Oxyfluorfen 37 35.1

Prometryn 184 33.7

EPTC 38 29.7

Napropamide 38 29.7

3,4-Dichloroaniline 183 27.2

Malaoxon 183 27.2

3,5-Dichloroaniline 37 27.0

1-Naphthol 184 22.3

Propyzamide 184 17.9

Azinphos-methyl 184 16.8

Dichlorvos 184 16.3

Parathion-methyl 184 13.0

Phosmet 184 12.5

4-Chloro-2-methylphenol 184 10.9

2-(4-tert-Butylphenoxy)-cyclohexanol 37 8.1

p,p’-DDE 37 8.1

Metribuzin 184 5.4

4,4’-Dichlorobenzophenone 37 5.4

Cycloate 37 5.4

lambda-Cyhalothrin 37 5.4

cis-Permethrin 184 3.8

Alachlor 184 3.3

Dimethoate 184 3.3

Cyanazine 37 2.7

Molinate 37 2.7

Metalaxyl 184 2.2

Paraoxon-methyl 184 2.2

Atrazine 184 1.6

Phosmet oxon 184 1.2

Cyfluthrin 184 1.1

Terbufos-oxon-sulfone 184 1.1

Benfluralin 184 0.5

Cypermethrin 184 0.5

Fonofos oxon 184 0.5

Fonofos 184 0.5
Results of Monitoring 37

sac12-0462_fig 11 Wet Deposition Flux, in microgram per square meter per day

Chlorpyrifos Simazine

7.52 8.41 10.1

Dacthal

45.6 50.6

Diazinon Pendamethalin

Diazinon

27.2 48.9

0

1

2

3

0

1

2

0.0

0.1

0.2

0.3

0.4

0.5

18.4

0

5

10

15

0

1

2

3

Chlorpyrifos

0

1

2

Dacthal

0.0

0.1

0.2

0.3

0.4

0.5

0

5

10

15

Pendamethalin Simazine

0

1

2

0

1

2

3

EXPLANATION

San Joaquin Valley (n=145)

Sacramento Valley (n=39)

Outliers beyond 

Value outside of 1.5

90th percentile

10th percentile

n = sample number

75th percentile

25th percentile

Median

times the interquartile

scale

range (IQR)

Figure 11. Distribution of calculated wet-deposition fluxes for the five most frequently detected compounds collected from the San 

Joaquin Valley and Sacramento Valley, California, sites during the 2002–04 study period.
38 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides

Table 17. Detection frequency, and percentiles for the most frequently detected compounds collected as wet, bulk-wet, dry, bulkdry deposition and soil box runoff collected in the San Joaquin Valley and Sacramento Valley, California, during the 2002–04 study 

period.—Continued

[For computation of percentiles, all non-detections were assumed to be less than the lowest detection. Abbreviations: E, estimated compound; NA, not applicable as there were not enough detections to calculate percentiles; μg/L, microgram per liter; μg/m2

/day, microgram per square meter per day]

Compound

Detection 

frequency

(in percent)

Maximum 90th 

percentile

75th 

percentile

50th 

percentile

25th

percentile

10th

percentile

Wet deposition, μg/m2

/day

San Joaquin Valley

Chlorpyrifos 95.2 10.1 0.565 0.237 0.079 0.034 0.021

Dacthal 97.2 0.409 0.170 0.110 0.048 0.025 0.015

Diazinon 97.2 18.4 2.51 0.613 0.216 0.089 0.048

Pendimethalin 89.0 2.70 0.793 0.437 0.187 0.079 Non-detections

Simazine 95.9 48.9 1.04 0.449 0.219 0.079 0.045

Sacramento Valley

Chlorpyrifos 82.1 1.56 0.508 0.200 0.066 0.023 Non-detections

Dacthal 100.0 0.149 0.109 0.078 0.035 0.021 0.013

Diazinon 97.4 50.6 6.39 2.06 0.134 0.051 0.034

Pendimethalin 74.4 1.40 0.433 0.212 0.103 0.013 Non-detections

Simazine 76.9 1.43 0.248 0.106 0.055 0.013 Non-detections

Bulk wet deposition, μg/m2

/day

San Joaquin Valley

Chlorpyrifos 80.0 0.948 0.168 0.100 0.032 0.014 Non-detections

Dacthal 100.0 0.187 0.082 0.045 0.032 0.020 0.016

Diazinon 96.0 2.48 0.70 0.365 0.130 0.630 0.042

Simazine 100.0 7.46 1.16 0.724 0.295 0.145 0.083

Sacramento Valley

Chlorpyrifos 76.9 3.73 0.12 0.058 0.025 0.002 Non-detections

Dacthal 100.0 0.207 0.091 0.058 0.042 0.020 0.012

Diazinon 76.9 8.63 0.308 0.179 0.064 0.003 Non-detections

Simazine 38.0 0.278 NA NA NA NA NA 1

Dry deposition, μg/m2/day

San Joaquin Valley

Carbaryl 64.7 E0.186 E0.036 E0.019 E0.004 Non-detections Non-detections

Chlorpyrifos 73.5 E0.233 E0.052 E0.018 E0.004 E0.001 Non-detections

Dacthal 91.2 E0.009 E0.005 E0.002 E0.001 E0.001 Non-detections

Metolachlor 76.5 E0.153 E0.038 E0.011 E0.002 E0.001 Non-detections

Phosmet 61.8 E0.188 E0.056 E0.019 E0.009 Non-detections Non-detections 1

Bulk dry deposition, μg/m2/day

San Joaquin Valley

Chlorpyrifos 95.0 E0.268 E0.220 E0.143 E0.011 E0.005 E0.004

Dacthal 95.0 E0.012 E0.009 E0.008 E0.006 E0.005 E0.003

Diazinon 75.0 E1.81 E1.56 E0.690 E0.008 E0.003 Non-detections

1-Naphthol 80.0 E0.011 E0.008 E0.004 E0.003 E0.002 Non-detections

Simazine 90.0 E0.099 E0.087 E0.071 E0.047 E0.024 E0.011

San Joaquin Valley soil-box runoff, μg/L

Aqueous phase

Dacthal 94.4 0.047 0.024 0.016 0.012 0.009 0.008

Diazinon 88.9 1.62 0.521 0.147 0.070 0.022 Non-detections

Metolachlor 94.4 0.309 0.228 0.140 0.048 0.021 0.010

Myclobutanil 88.9 1.02 0.127 0.073 0.051 0.030 Non-detections

Simazine 94.4 1.01 0.816 0.498 0.248 0.078 0.047

Suspended sediment

Diazinon 50.0 E0.810 E0.622 E0.490 E0.078 Non-detections Non-detections

Simazine 64.3 E0.930 E0.813 E0.679 E0.121 Non-detections Non-detections

Table 17. Detection frequency, and percentiles for the most frequently detected compounds collected as wet, bulk wet, dry, bulk 

dry deposition and soil box runoff collected in the San Joaquin Valley and Sacramento Valley, California, during the 2002–04 study 

period.
Results of Monitoring 39

Table 17. Detection frequency, and percentiles for the most frequently detected compounds collected as wet, bulk-wet, dry, bulkdry deposition and soil box runoff collected in the San Joaquin Valley and Sacramento Valley, California, during the 2002–04 study 

period.—Continued

[For computation of percentiles, all non-detections were assumed to be less than the lowest detection. Abbreviations: E, estimated compound; NA, not applicable as there were not enough detections to calculate percentiles; μg/L, microgram per liter; μg/m2

/day, microgram per square meter per day]

Compound

Detection 

frequency

(in percent)

Maximum 90th 

percentile

75th 

percentile

50th 

percentile

25th

percentile

10th

percentile

Sacramento Valley soil-box runoff, μg/L

Aqueous phase

Chlorpyrifos 100.0 0.057 0.041 0.026 0.012 0.005 0.004

Dacthal 100.0 0.014 0.010 0.009 0.006 0.004 0.003

Diazinon 100.0 1.75 0.730 0.091 0.046 0.020 0.010

Simazine 91.7 0.141 0.058 0.031 0.025 0.019 0.014

Suspended sediment

Chlorpyrifos 66.7 E0.570 E0.563 E0.492 E0.180 Non-detections Non-detections

Dacthal 66.7 E0.49 E0.260 E0.253 E0.125 Non-detections Non-detections

Simazine 75.0 E0.96 E0.729 E0.623 E0.250 E0.158 Non-detections

1

 Statistical summaries for the dry and bulk-dry deposition sample types are only presented for the San Joaquin Valley sites as there were too few samples collected in the Sacramento Valley. See figures 14 and 15 for comparison of detections in the Sacramento Valley to compounds presented above as dry and bulk-dry 

deposition.

Site 4- Modesto Irrigation District at 

downtown Modesto

Site 5- Modesto Irrigation District at 

Albers Road

Site 16- Gridley High School

Concentrations, micrograms per liter, collected from the funnel sampler

Concentrations, in micrograms per liter, collected from the autosampler

A

A

A

B

B

B

C

C

C

0.0

0.5

1.0

1.5

0 0.5 1.0 1.5

Chlorpyrifos

1:1 line

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.00 0.05 0.10 0.15 0.20 0.25 0.30

Dacthal

1:1 line

0

2

4

6

8

10

12

14

0 2 4 6 8 10 12 14

Diazinon

1:1 line

0.0

2.0

4.0

6.0

8.0

0 2 4 6 8 10

Chlorpyrifos

1:1 line

0.00

0.04

0.08

0.12

0.16

0.20

0.00 0.04 0.08 0.12 0.16 0.20

Dacthal

1:1 line

0

2

4

6

8

10

12

14

16

0 2 4 6 8 10 12 14

0.0

0.5

1.0

1.5

2.0

0 0.5 1 1.5 2

Chlorpyrifos

1:1 line

0.00

0.05

0.10

0.15

0.00 0.05 0.10 0.15

Diazinon

1:1 line

0

10

20

30

40

50

60

0 20 40 60

Diazinon

1:1 line

Dacthal

1:1 line

Figure 12. Comparison of concentrations of chlorpyrifos, dacthal, and diazinon collected from the autosampler and funnel sampler 

for the same sampling events at sites in the Central Valley of California during 2002–04: (A) site 4, MID at downtown Modesto; (B) site 5, 

MID at Albers Road; and (C) site 16, Gridley High School rooftop.
40 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides

Table 18. Comparison of wet and dry-deposition pesticide amounts detected in discrete samples collected from the autosampler at 

site 4 during the April 9–May 21, 2002, sampling event in the Central Valley of California and the physical and chemical properties of the 

pesticides.

[Abbreviations: E, estimated reported laboratory value; KOC, soil-organic carbon partition coefficient; m3/mol, cubic meters per mole; mg/L, milligram per liter; 

Pa, Pascals; μg/m2, micrograms per square meter; –, not detected]

Compound

Wet 

deposition,

(μg/m2)

Dry 

deposition,

(μg/m2)

Henry’s Law 

constant,

H (Pa m3/mol)

Water 

solubility,

SL (mg/L)

10 Subcooled 

liquid

vapor 

pressure,

PL

 (Pa)

Soil-organic 

carbon

partition 

coefficient,

log KOC

Azinphos-methyl E0.858 E1.82 10.0003 130 0.00009 43.00

Carbaryl E0.456 E0.586 1

0.0012 4120 0.003 82.36

Chlorpyrifos 0.132 E0.456 1

1.753 50.73 0.002 43.78

Dacthal 0.078 E0.081 2

0.2213 70.5 0.0003 73.75

Diazinon –9 –9 1

0.0641 460 0.008 82.76

Malathion 0.18 E0.042 1

0.0022 1145 0.0006 43.26

Metolachlor 1.14 E0.378 3

0.0009 6530 0.002 42.30

Myclobutanil E0.174 E1.18 1

0.0004 7142 0.074 72.69

Pendimethilan 0.168 E0.042 3

3.751 70.275 0.008 74.13

Phosmet 0.168 E2.86 1

0.001 125 0.0002 42.91

Simazine 0.264 E1.39 10.0003 65 0.0009 42.11

1

Suntio and others, 1988.

2

Wauchope and others, 1992.

3

Worthing and Walker, 1987.

4

Wauchope and others, 1992 (referenced from compilation in Mackay and others, 1997).

5

Bowman and Sans, 1983 (referenced from compilation in Mackay and others, 1997).

6

Worthing and Walker, 1987 (referenced from compilation in Mackay and others, 1997).

7

U.S. Department of Agriculture, 2005.

8

Howard, 1991 (referenced from compilation in Mackay and others, 1997).

9

Diazinon was not detected in this sample but the physical and chemical properties are included for discussion purposes with respect to figure 10.

10Calculated using δ water solubility values of 56 joules per mole Kelvin from Suntio and others, 1988.
Results of Monitoring 41

Table 19. Detection frequency for compounds analyzed as bulk-wet deposition with at least one detection during the 2002–04 study 

period in the Central Valley of California.

[Abbreviations: n, total number of samples]

Compound Detection frequency

in percent (n=38) Compound Detection frequencyin percent (n=38)

Dacthal 100.0 Diazoxon 26.3

Diazinon 89.5 Prometryn 26.3

Chlorpyrifos 78.9 Propyzamide 21.1

Simazine 78.9 Azinphos-methyl 18.4

1-Naphthol 65.8 4-Chloro-2-methylphenol 15.8

Carbaryl 65.8 Phosmet 13.2

Metolachlor 65.8 Parathion-methyl 7.9

Pendimethalin 65.8 Metribuzin 7.9

Trifluralin 65.8 2,6-Diethylaniline 2.6

Myclobutanil 63.2 Alachlor 2.6

Iprodione 55.3 Atrazine 2.6

Malathion 42.1 Azinphos-methyl-oxon 2.6

Malaoxon 34.2 Cypermethrin 2.6

Methidathion 34.2 Dichlorvos 2.6

3,4-Dichloroaniline 31.6 Metalaxyl 2.6

Chlorpyrifos oxon 28.9 Paraoxon-methyl 2.6

Bulk wet-deposition flux, in micrograms per square meter per day

Chlorpyrifos Dacthal Diazinon Simazine

Chlorpyrifos Dacthal Diazinon Simazine

4.68 7.46

3.73 8.63

0

0.5

1

1.5

2

0

0.1

0.2

0.3

0

0.5

1

1.5

2

2.5

3

0.278

0.176

0.151

0.025

0

0.1

0.2

0.3

0

0.2

0.4

0.6

0.8

1.0

0

0.1

0.2

0.8

1

0.5

2.5

3

0

San Joaquin Valley (n=26)

Sacramento Valley (n=12)

EXPLANATION

Outliers beyond 

scale

Value outside of 1.5

times the interquartile

range (IQR)

90th percentile

10th percentile

n = sample number

75th percentile

25th percentile

Median

Figure 13. Distribution of calculated bulk wet-deposition fluxes for the most detected compounds collected from the San Joaquin 

Valley and Sacramento Valley sites during the 2002–04 study period.
42 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides

twice as much in the San Joaquin Valley. Maximum bulk 

wet-deposition amounts in the San Joaquin Valley were found 

for the compounds iprodione (13.1 μg/m2/day) and simazine 

(7.46 μg/m2/day) at the Turlock Airport raingage (site 13; 

appendix 4). Dacthal was detected in all bulk-wet-deposition 

samples collected from the San Joaquin Valley and the 

Sacramento Valley sites. In the San Joaquin Valley, the median 

and maximum deposition amounts were 0.032μg/m2/day 

and 0.187μg/m2/day, respectively. In the Sacramento 

Valley, the median and maximum deposition amounts were 

0.042μg/m2/day and 0.207μg/m2/day, respectively (table 17).

Dry-Deposition Sample Type

For the dry-deposition (and bulk dry) sample types, 

all detections were reported as estimated (E code preceding 

value) and have a greater, but unknown, degree of uncertainty. 

Additionally, the calculated dry-deposition and bulk drydeposition flux values for 35 of the 64 compounds analyzed 

were biased low because the laboratory reagent spike recoveries were less than 50 percent for these compounds (table 7) 

and, therefore, could be present in the environment at higher 

concentrations than reported. A total of 37 dry-deposition 

samples were analyzed during the study period (appendix 5). 

Thirty-two compounds were detected with detection frequencies that ranged from 2.7 percent (representing one detection) 

for five compounds to 86.5 percent for the compound dacthal (table 20). Carbaryl, chlorpyrifos, dacthal, metolachlor, 

and phosmet were the most frequently detected compounds 

in the San Joaquin Valley (table 17) and were compared to 

the same compounds for the three samples collected from 

the Sacramento Valley at urban site 16 (fig. 14) because 

there were only three dry-deposition samples collected from 

site 16. Although there were few dry-deposition detections in 

the Sacramento Valley (chlorpyrifos, dacthal, and phosmet), 

these detections corresponded to the median flux values collected from the San Joaquin Valley for the same compounds 

(fig. 14 and table 17). In the San Joaquin Valley, the greatest 

dry-deposition amounts collected were for the compounds 

simazine (E 0.245μg/m2/day, site 5) and chlorpyrifos 

(E 0.233 μg/m2/day, site 12; appendix 5). In the Sacramento 

Valley, the greatest dry-deposition amounts collected were for 

the compounds iprodione (E 0.078 μg/m2/day) and simazine 

(E 0.025μg/m2/day; appendix 5).

Dry deposition computed for detections in both the funnel and autosampler from the San Joaquin Valley urban site 4, 

located in downtown Modesto, and the agricultural site 5, 

located in rural Modesto adjacent to agricultural land, were 

compared during two separate composite-sample periods: 

October–November 2002, and May–July 2003 (table 21). In 

general, the dry-deposition amounts collected from the funnel 

and autosampler were comparable for the respective sampling 

periods and sampling locations (urban vs. agricultural), but 

there were a few notable exceptions. During the October–

November 2002, sampling period, chlorpyrifos at the urban 

site was more than twice the dry deposition at the agricultural 

site, and, conversely, simazine was about three times greater 

at the agricultural site compared to the urban site. During the 

May–July 2003, sampling period, the dry deposition of chlorpyrifos was greater at the agricultural site (six times greater 

for the sample collected from the autosampler and more than 

twice for the funnel sampler), which was likely a result of its 

use on row crops during the summer. Detections of chlorpyrifos, diazinon, and dacthal were common to both sampling 

periods.

Bulk Dry-Deposition Sample Type

A total of 26 bulk-dry-deposition samples were analyzed 

for 64 compounds during the study period (appendix 6). 

Thirty-three compounds were detected with detection frequencies ranging from of 3.8 percent (representing one detection) 

for two compounds to 96.2 percent for dacthal (table 22). 

Chlorpyrifos, dacthal, diazinon, 1-napthol, and simazine were 

the most frequently detected compounds collected as bulkdry deposition in the San Joaquin Valley (fig. 15) and were 

compared to the same compounds for the six samples collected from the Sacramento Valley at urban site 16. With the 

exception of simazine, the median bulk dry-deposition fluxes 

in the San Joaquin Valley were comparable to the median 

bulk-dry deposition collected from the Sacramento Valley 

(fig. 15) The compounds with the greatest bulk-dry deposition 

amounts collected in the San Joaquin Valley were iprodione 

(E 0.700μg/m2/day, site 5), methidathion (E 0.426μg/m2/day, 

site 4), and chlorpyrifos (E 0.268μg/m2/day, site 5; appendix 6). At the Gridley High School site (site 16) in the 

Sacramento Valley, diazinon and its oxon, diazoxon, had 

the greatest bulk dry-deposition amounts collected at 

E 5.26μg/m2/day and E 0.203 μg/m2/day, respectively (appendix 6). The Sacramento Valley bulk dry-deposition amounts 

were collected during the January 7–27, 2004, sampling event 

and coincided with the orchard dormant-spray season.

Soil-Box Runoff Sample Types (Aqueous Phase 

and Suspended Sediment)

Soil-box runoff samples (fig. 7) were submitted and 

analyzed as a filtered sample (aqueous phase) along with the 

corresponding suspended-sediment sample collected on one or 

more GFFs during filtration. A total of 30 aqueous-phase soilbox runoff samples (appendix 7) and 30 suspended-sediment 

samples (appendix 8) were submitted for analysis from the 

2 sites in the San Joaquin Valley (urban site 4 and agricultural 

site 5) and one in the Sacramento Valley (urban site 16) during 

the 2002–04 study period. 

In the San Joaquin Valley, 22 compounds were detected 

in the aqueous phase, and 11 compounds were detected in the 

suspended sediment samples (table 23). Detection frequencies 

for the aqueous phase in the San Joaquin Valley were greater 

than 88 percent for the top five most commonly detected 

compounds (dacthal, metolachlor, simazine, diazinon, and 
Results of Monitoring 43

Dry-deposition flux, in micrograms per square meter per day

E 0.004 E 0.001 E 0.009

not detected not detected

0.000

0.002

0.004

0.006

0.008

0.010

Dacthal

0.05

0

0.10

0.15

0.20

Carbaryl

0.00

0.05

0.10

0.15

0.20

0.25

Chlorpyrifos Phosmet

0.00

0.05

0.10

0.15

0.20

0.00

0.05

0.10

0.15

0.20

Metolachlor

Carbaryl Chlorpyrifos Dacthal Metolachlor Phosmet

n = sample number

E = estimated

San Joaquin Valley (n=34)

Sacramento Valley (n=3)

EXPLANATION

Value outside of 1.5

times the interquartile

range (IQR)

90th percentile

10th percentile

75th percentile

25th percentile

Median

Figure 14. Distribution of calculated dry-deposition fluxes for the top five most detected compounds collected from the San Joaquin 

Valley compared to detections in the Sacramento Valley of California during the 2002–04 study period.

Table 20. Detection frequency for compounds analyzed as dry deposition with at least one detection during the 2002–04 study period 

in the Central Valley of California.

[Abbreviations: n, total number of samples]

Compound Detection frequency

in percent (n=37) Compound Detection frequencyin percent (n=37)

Dacthal 86.5 Paraoxon-methyl 24.3

Chlorpyrifos 70.3 Dimethoate 21.6

Metolachlor 70.3 Malathion 18.9

Simazine 64.9 Pendimethilan 18.9

Carbaryl 59.5 Phosmet oxon 18.9

Phosmet 59.5 Dichlorvos 16.2

Trifluralin 59.5 3,4-Dichloroaniline 13.5

Myclobutanil 56.8 Chlorpyrifos oxon 13.5

Diazinon 51.4 Diazoxon 10.8

Azinphos-methyl 43.2 Metribuzin 5.4

Parathion-methyl 43.2 Prometryn 5.4

Malaoxon 40.5 Alachlor 2.7

trans-Permethrin 40.5 Cypermethrin 2.7

1-Naphthol 37.8 Hexazinone 2.7

cis-Permethrin 35.1 Methidathion 2.7

Iprodione 32.4 Pronamide 2.7
44 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Table 21. Comparison of compounds detected in dry-deposition samples collected from funnel and autosamplers at San Joaquin Valley, California, urban site 4, and agricultural site 5 during two composite sampling periods in 2002 and 2003.

[Abbreviations: E, estimated reported laboratory value; μg/m2/day, microgram per square meter per day]

Site

number Site name Composite sampling date Sampler type Chlorpyrifos (μg/m2/day) Diazinon (μg/m2/day) Dacthal (μg/m2/day) Simazine (μg/m2/day)

4 Modesto Irrigation District gage rooftop at Modesto October 4–November 6, 2002 Autosampler E0.020 E0.006 E0.006 E0.079

October 4–November 6, 2002 Funnel E0.013 E0.016 E0.008 E0.077

5 Modesto Irrigation District gage rooftop at Albers Road October 4–November 6, 2002 Autosampler E0.009 E0.007 E0.009 E0.245

October 4–November 6, 2002 Funnel E0.006 E0.004 E0.005 E0.218

Site

number Site name Composite sampling date Sampler type Chlorpyrifos (μg/m2/day) Diazinon (μg/m2/day) Dacthal (μg/m2/day) Parathion-methyl (μg/m2/day)

4 Modesto Irrigation District gage rooftop at Modesto May 5–July 22, 2003 Autosampler E0.009 E0.001 E0.001 E0.009

May 5–July 22, 2003 Funnel E0.016 E0.002 E0.002 E0.007

5 Modesto Irrigation District gage rooftop at Albers Road May 9–July 22, 2003 Autosampler E0.054 E0.001 E0.001 E0.032

May 9–July 22, 2003 Funnel E0.039 E0.002 E0.001 E0.017

Site

number Site name Composite sampling date Sampler type Paraoxon- methyl (μg/m2/day) Metolachlor (μg/m2/day) Dichlorvos (μg/m2/day) cis- permethrin (μg/m2/day) trans- permethrin (μg/m2/day)

4 Modesto Irrigation District gage rooftop at Modesto May 5–July 22, 2003 Autosampler E0.006 E0.002 E0.002 E0.004 E0.006

May 5–July 22, 2003 Funnel E0.006 E0.002 E0.004 E0.003 E0.005

5 Modesto Irrigation District gage rooftop at Albers Road May 9–July 22, 2003 Autosampler E0.017 E0.006 E0.006 E0.004 E0.006

May 9–July 22, 2003 Funnel E0.005 E0.011 E0.003 E0.006 E0.005
Results of Monitoring 45

Bulk Dry-Deposition Flux, in micrograms per square meter per day

E 0.002

E 0.003

E 0.008

E 0.235

E 0.008

E 0.011

E 0.012

E 0.005

0.001

E 0.002

E 0.005

E 0.030

E 0.038

E 0.104

E 0.024

E 5.26

0.003

0.009

0.092

0.002

n = sample number

E = estimated

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.000

0.005

0.010

Chlorpyrifos Dacthal

median = 

E 0.011 μg/m2/day

median = 

E 0.006 μg/m2/day

0.00

0.01

0.02

1-Naphthol

median = 

E 0.003 μg/m2/day

Simazine

median = 

E 0.047 μg/m2/day

0.00

0.02

0.04

0.06

0.08

0.10

Diazinon

Chlorpyrifos Dacthal 1-Naphthol Simazine Diazinon

median = 

E 0.008 μg/m2/day

0.0

0.5

1.0

1.5

2.0

median = 

E 0.001 μg/m2/day

median = 

E 0.010 μg/m2/day

median = 

E 0 .002 μg/m2/day

median = 

E 0.027 μg/m2/day

median = 

E 0.006 μg/m2/day

San Joaquin Valley (n=20)

Sacramento Valley (n=6)

EXPLANATION

Value outside of 1.5

times the interquartile

range (IQR)

90th percentile

10th percentile

75th percentile

25th percentile

Median

Figure 15. Distribution of calculated bulk dry-deposition fluxes for the top five most detected compounds collected from the San 

Joaquin Valley compared to detections in the Sacramento Valley, California, during the 2002–04 study period.

Table 22. Detection frequency for compounds analyzed as bulk-dry deposition with at least one detection during the 2002–04 study 

period in the Central Valley of California.

[Abbreviations: n, total number of samples]

Compound Detection frequency

in percent (n=26) Compound Detection frequencyin percent (n=26)

Dacthal 96.2 Parathion-methyl 42.3

Chlorpyrifos 92.3 Diazoxon 34.6

Simazine 92.3 Malathion 34.6

1-Naphthol 84.6 Chlorpyrifos oxon 26.9

Diazinon 76.9 Prometryn 26.9

Metolachlor 73.1 Dichlorvos 19.2

3,4-Dichloroaniline 69.2 Phosmet 19.2

Iprodione 61.5 Dimethoate 15.4

Carbaryl 57.7 Azinphos-methyl 11.5

Methidathion 57.7 Pronamide 11.5

Pendimethilan 53.8 Metribuzin 7.7

Malaoxon 50.0 Paraoxon-methyl 7.7

Myclobutanil 50.0 Phosmet oxon 7.7

cis-Permethrin 50.0 Deethylatrazine, CIAT 3.8

trans-Permethrin 50.0 Cyfluthrin 3.8

Trifluralin 50.0 Fipronil sulfone 3.8

Hexazinone 42.3
46 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides

Table 23. Detection frequency for samples collected as soil-box runoff (aqueous-phase and suspended-sediment sample types) from 

the San Joaquin Valley and Sacramento Valley, California, soil-box sites during the 2002–04 study period.

[Abbreviations: n, total number of samples; (E), estimated compound because of poor performance by applied method (Childress and others, 1999; Sandstrom 

and others, 2001); NWQL, National Water Quality Laboratory]

San Joaquin Valley soil-box runoff

(urban site 4 and agricultural site 5)

Sacramento Valley soil-box runoff 

(urban site 16)

Compound Aqueous-phase detection

frequency, in percent (n=18) Compound Aqueous-phase detectionfrequency, in percent (n=12)

Dacthal 94.4 Chlorpyrifos 100.0

Metolachlor 94.4 Dacthal 100.0

Simazine 94.4 Diazinon 100.0

Diazinon 88.9 Simazine 91.7

Myclobutanil 3

88.9 Pendimethalin 66.7

Chlorpyrifos 83.3 Carbaryl 58.3

3,4-Dichloroaniline 3

82.4 Parathion-methyl 50.0

Pendimethalin 72.2 Prometon 3

36.4

Methidathion 55.6 3,4-Dichloroaniline 33.3

Metribuzin 55.6 Diazoxon 33.3

Prometryn 3

47.1 1-Naphthol (E) 430

Diazoxon 38.9 Methidathion 25.0

Trifluralin 27.8 Myclobutanil 25.0

Carbaryl 22.2 Prometryn 25.0

Parathion-methyl 3

22.2 Iprodione 16.7

Iprodione 3

17.6 Metolachlor 16.7

Malathion 16.7 Azinphos-methyl 8.3

Pronamide 16.7 Hexazinone 8.3

Hexazinone 6

14.3 Malathion 8.3

Azinphos-methyl 11.1 Malaoxon 8.3

Dimethoate 3

5.9 Paraoxon-methyl 8.3

Prometon 3

5.9

Compound Suspended-sediment detection

frequency, in percent (2

n=14) Compound Suspended-sediment detection frequency, in percent (n=12)

Simazine 64.3 Simazine 75.0

3,4-Dichloroaniline1

 (E) 50.0 Chlorpyrifos1 66.7

Diazinon 50.0 Dacthal 66.7

Myclobutanil 28.6 Carbaryl1

 (E) 50.0

Dacthal 21.4 Paraoxon-methyl 50.0

Pendimethalin 21.4 Pendimethalin 50.0

Chlorpyrifos1 14.3 Diazinon 33.3

Trifluralin 14.3 3,4-Dichloroaniline1

 (E) 25.0

1-Naphthol1

 (E) 7.1 Malaoxon1 (E) 512.5

Fipronil 7.1 Fipronil 8.3

Iprodione1

 (E) 7.1 Iprodione1 (E) 8.3

Myclobutanil 8.3

Trifluralin 8.3

1

Compound is biased low because it is assumed that the analytical method might not adequately recover the compound because of matrix interference, adsorptive losses on the dry matrix, or other procedural problem for this sample type. See table 11 and corresponding text for laboratory reagent spike recoveries.

2

Four samples were ruined during laboratory preparation of these sample types, therefore the total number of samples does not equal the aqueous-phase 

sample type. See appendix 8 for site specific samples.

3

 Total samples equal n–1, results of one sample deleted by NWQL because compound could not be determined because of matrix interference.

4

 Total samples equal n–2, results of two samples deleted by NWQL because compound could not be determined because of matrix interference.

5

 Total samples equal n–4, results of four samples deleted by NWQL because compound could not be determined because of matrix interference.

6

 Total samples equal n–11, results of eleven samples deleted by NWQL because compound could not be determined because of matrix interference.
Results of Monitoring 47

myclobutanil), whereas only three compounds had detection 

frequencies greater than 50 percent for suspended sediment 

(simazine, 3,4-Dichloroaniline, and diazinon). Figure 16

shows the distribution of concentrations for the most detected 

compounds in the aqueous phase compared to the most 

detected compounds in suspended-sediment samples from the 

urban and agricultural soil-box sites in the San Joaquin Valley 

during the study period. The suspended-sediment sample type 

was analyzed by using a laboratory research method (NWQL 

research method LS750, appendix 1) to determine concentrations of pesticides, and in some cases, the LRL was above 

reported detections. For example, 3,4-Dichloroanaline was 

detected in 50 percent of the suspended-sediment sample types 

collected from the San Joaquin Valley; however, all the detections were below the LRL value of 5.9 μg/L and were reported 

as estimated concentrations and, therefore, assumed a greater 

degree of uncertainty (fig. 16 and appendix 8). With the exception of 3,4-Dichloroanaline and simazine collected in the San 

Joaquin Valley, the LRL for the most detected compounds 

collected from suspended sediment from the soil-box runoff, 

depicted in figures 16 and 17, was at or below the 50th percentile (median).

Nine compounds were detected in both the aqueousphase and suspended-sediment sample types collected from 

the San Joaquin Valley soil-box sites (table 24). For compounds common to both sample types, concentrations of 

pesticides in the aqueous phase generally were detected in low 

concentrations and had few corresponding detections in the 

suspended-sediment sample type. Exceptions to this were the 

compounds simazine, 3,4-Dichloroaniline, and diazinon, for 

which concentrations in the aqueous phase were at least twice 

those in the suspended-sediment sample type. The highest 

concentrations detected in the aqueous phase for a given compound did not always correspond with the highest concentrations detected in corresponding suspended-sediment sample 

type because the physical and chemical properties of the 

pesticides vary (table 15), as did the timing and application of 

pesticides in the Central Valley during the study period. A soilbox runoff sample collected after the January 14–21, 2003, 

storm event from agricultural site 5 in the San Joaquin Valley 

had the highest concentrations of iprodione (E 3.52 μg/L), 

myclobutanil (1.02 μg/L), and simazine (1.01 μg/L) detected 

in the aqueous-phase sample type (appendix 7). The highest 

concentration of diazinon in the aqueous phase (1.62 μg/L) 

was collected from the same site after the previous storm event 

(January 9–14, 2003). The highest concentrations detected 

in suspended-sediment samples from the same site were for 

the compounds pendamethalin (0.96 μg/L) and myclobutanil 

(E 0.89 μg/L) following the November 7–10, 2002, storm 

event (appendix 8).

At site 16 at Gridley High School in the Sacramento 

Valley, 21 compounds were detected in the aqueous phase 

and 13 compounds were detected in the suspended-sediment sample type (table 23). Detection frequencies for the 

aqueous-phase sample type were greater than 91 percent for 

simazine, diazinon, dacthal, and chlorpyrifos, and only greater 

than 66 percent for simazine, chlorpyrifos, and dacthal for the 

suspended-sediment sample type. Figure 17 depicts the distribution of concentrations for the most detected compounds in 

the aqueous-phase sample type compared to the most detected 

compounds in suspended-sediment sample type collected from 

the urban and agricultural soil-box sites in the San Joaquin 

Valley during the study period. Concentrations of pesticides in 

the aqueous phase generally were detected in low concentrations, with the exception of diazinon at 1.75 μg/L (January 27–

February 6, 2004 composite-sample time; table 24, appendix 7). Ten compounds were detected in both sample types 

collected from the Sacramento Valley soil box (table 24), and 

concentrations of pesticides in the aqueous phase generally 

were detected in low concentrations compared to the median 

concentrations detected in the suspended-sediment sample 

type for the same compound. In the Sacramento Valley at 

site 16, the highest concentrations of pesticides detected in 

suspended sediment were for the compounds methyl parathion (0.92 μg/L), chlorpyrifos (0.72 μg/L), and diazinon 

(0.52 μg/L; appendix 8).

When comparing concentration of compounds in the 

aqueous-phase sample type to concentrations in the rainfall 

(wet-deposition sample type collected from the autosampler 

and funnel sampler) collected during the same sampling event, 

pesticides present in the aqueous phase also were detected in 

the rainfall at similar concentrations, with the exception of 

metalachlor, myclobutanil, and simazine (table 25). In general, 

the aqueous-phase concentrations of metolachlor, myclobutanil, and simazine were an order of magnitude greater than 

concentrations detected in rainfall. The compound diazinon 

exhibited higher concentrations in rainfall than were detected 

in the aqueous phase for samples collected from the urban 

San Joaquin Valley soil-box at site 4 during the January 9–14, 

2003, composite sample period (between 3 and 14 times 

greater). Conversely, the aqueous-phase concentration was 

twice the detected diazinon concentration in the rainfall at the 

San Joaquin Valley agricultural soil-box at site 5 collected 

during the same period (table 25). The differences were likely 

due to proximity of the sampler to the pesticide application 

areas as well as the timing and amount of pesticide used in 

conjunction with the physical and chemical properties of the 

pesticides. 

Soil-Box Surficial-Soil Sample Type

Results for soil-box soil mixes prior to exposure (mix 1, 

2, 3, and 4) and for samples collected from the soil boxes 

after exposure to the atmosphere during the study period are 

presented together for comparison purposes (appendix 9). Soil 

mix 1, 2, 3 was collected near specific sites in San Joaquin 

Valley (see appendix 9 header for locations), composited 

together, and placed in the San Joaquin Valley urban site 4 and 
48 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides

sac12-0462_fig 16 Soil runoff (aqueous phase and suspended sediment), in microgram per liter (mg/L)

Diazinon 3,4-Dichloroanaline

LRL= 0.16 μg/L

LRL= 0.08 μg/L

E 0.36

E 0.69

E 0.78

E 0.87

E 0.40

E 0.14

E 0.31

LRL= 5.9 μg/L

LRL= 0.003 μg/L LRL= 0.005 μg/L LRL= 0.013 μg/L LRL= 0.008 μg/L LRL= 0.005 μg/L

n = sample number

LRL = laboratory reporting limit

Dacthal Diazinon Metolachlor Myclobutanil Simazine

0.0

0.2

0.4

0.6

0.8

1.0

0.0

0.5

1.0

1.5

0.0

0.1

0.2

0.3

0.4

0.5

0.00

0.02

0.04

0.06

0.08

0.10

0.0

0.5

1.0

1.5

2.0

0.0

0.5

1.0

1.5

2.0

Simazine

0.0

0.2

0.4

0.6

0.8

1.0

San Joaquin Valley soil-box runoff (aqueous phase) n=18

San Joaquin Valley soil-box runoff (suspended sediment) n=14

EXPLANATION

Value outside of 1.5

times the interquartile

range (IQR)

90th percentile

10th percentile

75th percentile

25th percentile

Median

Figure 16. Comparison of the distribution of concentrations of the most detected compounds collected from the San Joaquin Valley, 

California, soil-box sites 4 and 5 as aqueous-phase and suspended-sediment sample types during the 2002–04 study period.
Results of Monitoring 49

Table 24. Comparison of detection frequencies and median concentrations of detected compounds common to aqueous-phase and 

suspended-sediment soil-box runoff samples collected from the San Joaquin Valley and Sacramento Valley, California, soil-box sites 

during the 2002–04 study period.

[Abbreviations: n, total number of samples; (E), estimated compound because of poor performance by applied method (Childress and others, 1999; Sandstrom 

and others, 2001); NWQL, National Water Quality Laboratory; μg/L, microgram per liter; <, less than]

San Joaquin Valley soil-box runoff (urban site 4 and agricultural site 5)

Compound

Suspended-sediment

detection frequency,

in percent (2

n=14)

Aqueous-phase

detection frequency,

in percent (n=18)

Median suspendedsediment concentration, 

μg/L

Median aqueousphase concentration,

μg/L

Simazine 64.3 94.4 0.121 0.248

3,4-Dichloroaniline (E) 50.0 3

82.4 13.38 0.033

Diazinon 50.0 88.9 0.118 0.07

Myclobutanil 28.6 3

88.9 5<0.08 0.052

Dacthal 21.4 94.4 5

<0.08 0.012

Pendimethalin 21.4 72.2 5

<0.11 0.033

Chlorpyrifos 14.3 83.3 1,5<0.08 0.017

Trifluralin 14.3 27.8 5

<0.08 5<0.009

Iprodione (E) 7.1 3

17.6 1,5<0.079 5<1.42

Sacramento Valley soil-box runoff (urban site 16)

Compound

Suspended-sediment 

detection frequency,

in percent (n=12)

Aqueous-phase

detection frequency,

in percent (n=12)

Median suspendedsediment concentration, 

μg/L

Median aqueousphase concentration,

μg/L

Simazine 75.0 91.7 0.25 0.025

Chlorpyrifos 66.7 100.0 1

0.18 0.012

Dacthal 66.7 100.0 0.13 0.006

Carbaryl (E) 50.0 58.3 1,5<0.16 5

<0.041

Paraoxon-methyl 50.0 8.3 0.10 5

<0.03

Diazinon 33.3 100.0 5

<0.08 0.039

3,4-Dichloroaniline (E) 25.0 33.3 1,5<5.9 0.005

Malaoxon1

 (E) 412.5 8.3 1,5<0.40 5<0.008

Iprodione1

 (E) 8.3 16.7 1,5<0.79 5<1.42

Myclobutanil 8.3 25.0 5

<0.08 5<0.008

1

Concentration result is biased low for given compound and sample type because it is assumed that the analytical method might not adequately recover the 

compound because of matrix interference, adsorptive losses on the dry matrix, or other procedural problem for this sample type. See table 11 and corresponding 

text for LRS recoveries.

2

Four samples were ruined during laboratory preparation of these sample types, therefore the total number of samples does not equal the aqueous phase 

sample type. See appendix 8 for site specific samples.

3

 Total samples equal n–1, results of one sample deleted by NWQL because compound could not be determined because of matrix interference.

4

 Total samples equal n–4, results of four samples deleted by NWQL because compound could not be determined because of matrix interference.

5

 Concentration value given is the laboratory reporting limit for that compound and is considered a non-detection.
50 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides

Soil-box runoff (aqueous phase and suspended sediment), in micrograms per liter (mg/L)

Chlorpyrifos Dacthal Diazinon

0.0

0.5

1.0

1.5

2.0

LRL= 0.08 μg/L

LRL= 0.16 μg/L

LRL= 0.08 μg/L

LRL= 0.08 μg/L

0.0

0.2

0.4

0.6

0.8

1.0

0.0

0.2

0.4

0.6

0.8

1.0

E 0.29

E 0.52

E 0.31

E 0.13

0.0

0.2

0.4

0.6

0.8

1.0

LRL= 0.005 μg/L LRL= 0.003 μg/L LRL= 0.005 μg/L LRL= 0.005 μg/L

n = sample number

0.00

0.05

0.10

0.15

Simazine

0.000

0.005

0.010

0.015

0.00

0.05

0.10

Chlorpyrifos Dacthal Diazinon Simazine

San Joaquin Valley soil-box runoff (suspended sediment) n=12

Sacramento Valley soil-box runoff (aqueous phase) n=12

EXPLANATION

Value outside of 1.5

times the interquartile

range (IQR)

90th percentile

10th percentile

75th percentile

25th percentile

Median

LRL = laboratory reporting limit

Figure 17. Comparison of the distribution of concentrations of the most detected compounds collected from the Sacramento Valley, 

California, soil-box site 16 as aqueous-phase and suspended-sediment sample types during the 2002–04 study period.
Results of Monitoring 51

Table 25. Comparison of concentrations of compounds detected in the aqueous-phase sample type to those detected in wet deposition for the same sampling periods during the 2002–04 study in the Central Valley of California.—Continued[Compounds presented are for those with detection frequencies greater than 50 percent; all compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). Abbreviations: AS, autosampler; E, estimated reported laboratory value; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; L, liters; mm/dd/yyyy, month/day/year; μg/L, micrograms per liter; <, less than laboratory reporting value]

Site name

Sample 

begin date

(mm/dd/yyyy)

Start

time

(hh:mm)

Sample

end date

(mm/dd/yyyy)

End

time

(hh:mm)

Volume

collected,

(L)

Sample type

 3,4-Dichloroaniline (E),

(μg/L)

Site 4

Modesto Irrigation District gage rooftop at Modesto 11/07/2002 02:00 11/10/2002 03:10 0.422 Aqueous phase—soil-box runoff E0.04

Modesto Irrigation District gage rooftop at Modesto 11/07/2002 02:00 11/10/2002 03:00 4.1 Wet deposition—funnel <0.004

Modesto Irrigation District gage rooftop at Modesto 11/07/2002 02:00 11/10/2002 03:05 3.39 Wet deposition—AS <0.004

Modesto Irrigation District gage rooftop at Modesto 12/23/2002 09:30 01/09/2003 15:35 0.7 Aqueous phase—soil-box runoff E0.014

Modesto Irrigation District gage rooftop at Modesto 12/23/2002 09:30 01/09/2003 15:30 1.3 Wet deposition—funnel E0.011

Modesto Irrigation District gage rooftop at Modesto 12/23/2002 09:30 01/09/2003 15:40 0.58 Wet deposition—AS E0.017

Modesto Irrigation District gage rooftop at Modesto 01/09/2003 15:30 01/14/2003 10:40 0.66 Aqueous phase—soil-box runoff E0.013

Modesto Irrigation District gage rooftop at Modesto 01/09/2003 15:30 01/14/2003 10:20 0.91 Wet deposition—funnel E0.017

Modesto Irrigation District gage rooftop at Modesto 01/09/2003 15:30 01/14/2003 10:30 0.66 Wet deposition—AS <0.025

Modesto Irrigation District gage rooftop at Modesto 12/11/2003 13:20 12/16/2003 15:20 0.12 Aqueous phase—soil-box runoff <0.004

Modesto Irrigation District gage rooftop at Modesto 12/11/2003 13:10 12/16/2003 15:40 0.81 Wet deposition—funnel E0.024Modesto Irrigation District gage rooftop at Modesto 12/11/2003 13:00 12/16/2003 15:30 0.37 Wet deposition—AS E0.082Modesto Irrigation District gage rooftop at Modesto 12/23/2003 12:20 12/31/2003 09:40 0.325 Aqueous phase—soil-box runoff <0.004

Modesto Irrigation District gage rooftop at Modesto 12/23/2003 13:00 12/31/2003 09:30 2.81 Wet deposition—funnel <0.004

Site 5

Modesto Irrigation District gage rooftop at Albers Road 11/07/2002 02:00 11/10/2002 03:10 0.389 Aqueous phase—soil-box runoff E0.043

Modesto Irrigation District gage rooftop at Albers Road 11/07/2002 02:00 11/10/2002 03:00 4.18 Wet deposition—funnel <0.004

Modesto Irrigation District gage rooftop at Albers Road 11/07/2002 02:00 11/10/2002 03:05 3.6 Wet deposition—AS <0.004

Modesto Irrigation District gage rooftop at Albers Road 12/16/2002 12:00 12/23/2002 10:40 0.45 Aqueous phase—soil-box runoff E0.041

Modesto Irrigation District gage rooftop at Albers Road 12/16/2002 12:00 12/23/2002 10:20 1.9 Wet deposition—funnel E0.028

Modesto Irrigation District gage rooftop at Albers Road 12/16/2002 12:00 12/23/2002 10:30 1.44 Wet deposition—AS E0.018

Modesto Irrigation District gage rooftop at Albers Road 01/09/2003 14:30 01/14/2003 11:50 1.07 Aqueous phase—soil-box runoff E0.033Modesto Irrigation District gage rooftop at Albers Road 01/09/2003 14:30 01/14/2003 11:30 1.2 Wet deposition—funnel 0.074Modesto Irrigation District gage rooftop at Albers Road 01/09/2003 14:30 01/14/2003 11:40 0.86 Wet deposition—AS 0.038Modesto Irrigation District gage rooftop at Albers Road 12/11/2003 14:00 12/16/2003 14:30 0.64 Aqueous phase—soil-box runoff E0.027Modesto Irrigation District gage rooftop at Albers Road 12/11/2003 14:05 12/16/2003 14:40 0.76 Wet deposition—funnel E0.022Modesto Irrigation District gage rooftop at Albers Road 12/11/2003 14:10 12/16/2003 14:35 0.67 Wet deposition—AS <0.004

Table 25. Comparison of concentrations of compounds detected in the aqueous-phase sample type to those detected in wet deposition for the same sampling periods during the 2002–04 study in the Central Valley of California.
52 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Table 25. Comparison of concentrations of compounds detected in the aqueous-phase sample type to those detected in wet deposition for the same sampling periods during the 2002–04 study in the Central Valley of California.—Continued [Compounds presented are for those with detection frequencies greater than 50 percent; all compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). Abbreviations: AS, autosampler; E, estimated reported laboratory value; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; L, liters; mm/dd/yyyy, month/day/year; μg/L, micrograms per liter; <, less than laboratory reporting value] Site name Sample begin date (mm/dd/yyyy) Start time (hh:mm) Sample end date (mm/dd/yyyy) End time (hh:mm) Metolachlor, (μg/L) Myclobutanil (E), (μg/L) Pendimethalin, (μg/L) Simazine, (μg/L) Site 4 Modesto Irrigation District gage rooftop at Modesto 11/07/2002 02:00 11/10/2002 03:10 0.309 E0.064 0.094 0.765 Modesto Irrigation District gage rooftop at Modesto 11/07/2002 02:00 11/10/2002 03:00 E0.006 <0.008 0.033 0.01 Modesto Irrigation District gage rooftop at Modesto 11/07/2002 02:00 11/10/2002 03:05 E0.005 E0.008 0.033 0.017 Modesto Irrigation District gage rooftop at Modesto 12/23/2002 09:30 01/09/2003 15:35 0.193 E0.047 0.029 0.297 Modesto Irrigation District gage rooftop at Modesto 12/23/2002 09:30 01/09/2003 15:30 E0.007 <0.008 0.071 0.04 Modesto Irrigation District gage rooftop at Modesto 12/23/2002 09:30 01/09/2003 15:40 E0.01 <0.008 0.044 0.068 Modesto Irrigation District gage rooftop at Modesto 01/09/2003 15:30 01/14/2003 10:40 0.143 E0.049 0.03 0.246 Modesto Irrigation District gage rooftop at Modesto 01/09/2003 15:30 01/14/2003 10:20 E0.004 <0.008 0.048 0.022 Modesto Irrigation District gage rooftop at Modesto 01/09/2003 15:30 01/14/2003 10:30 E0.006 <0.008 0.062 0.025 Modesto Irrigation District gage rooftop at Modesto 12/11/2003 13:20 12/16/2003 15:20 0.05 <0.008 <0.095 <0.005 Modesto Irrigation District gage rooftop at Modesto 12/11/2003 13:10 12/16/2003 15:40 E0.006 <0.008 0.025 0.015 Modesto Irrigation District gage rooftop at Modesto 12/11/2003 13:00 12/16/2003 15:30 E0.011 <0.008 <0.022 0.037 Modesto Irrigation District gage rooftop at Modesto 12/23/2003 12:20 12/31/2003 09:40 E0.01 E0.026 0.039 0.027 Modesto Irrigation District gage rooftop at Modesto 12/23/2003 13:00 12/31/2003 09:30 <0.013 <0.008 0.043 0.014 Site 5 Modesto Irrigation District gage rooftop at Albers Road 11/07/2002 02:00 11/10/2002 03:10 0.132 E0.067 0.071 0.388 Modesto Irrigation District gage rooftop at Albers Road 11/07/2002 02:00 11/10/2002 03:00 E0.004 E0.006 E0.015 0.017 Modesto Irrigation District gage rooftop at Albers Road 11/07/2002 02:00 11/10/2002 03:05 E0.004 E0.006 E0.016 0.035 Modesto Irrigation District gage rooftop at Albers Road 12/16/2002 12:00 12/23/2002 10:40 0.154 E0.053 0.06 0.324 Modesto Irrigation District gage rooftop at Albers Road 12/16/2002 12:00 12/23/2002 10:20 <0.013 <0.008 0.028 0.012 Modesto Irrigation District gage rooftop at Albers Road 12/16/2002 12:00 12/23/2002 10:30 <0.013 <0.008 0.027 0.01

Modesto Irrigation District gage rooftop at Albers Road 01/09/2003 14:30 01/14/2003 11:50 0.066 E0.039 0.033 0.146

Modesto Irrigation District gage rooftop at Albers Road 01/09/2003 14:30 01/14/2003 11:30 <0.013 <0.008 0.035 0.015

Modesto Irrigation District gage rooftop at Albers Road 01/09/2003 14:30 01/14/2003 11:40 <0.013 <0.008 0.027 0.007

Modesto Irrigation District gage rooftop at Albers Road 12/11/2003 14:00 12/16/2003 14:30 0.023 E0.034 0.032 0.076

Modesto Irrigation District gage rooftop at Albers Road 12/11/2003 14:05 12/16/2003 14:40 <0.013 <0.008 0.035 0.033

Modesto Irrigation District gage rooftop at Albers Road 12/11/2003 14:10 12/16/2003 14:35 <0.013 <0.008 E0.019 0.019
Results of Monitoring 53

Table 25. Comparison of concentrations of compounds detected in the aqueous-phase sample type to those detected in wet deposition for the same sampling periods during the 2002–04 study in the Central Valley of California.—Continued[Compounds presented are for those with detection frequencies greater than 50 percent; all compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). Abbreviations: AS, autosampler; E, estimated reported laboratory value; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; L, liters; mm/dd/yyyy, month/day/year; μg/L, micrograms per liter; <, less than laboratory reporting value]

Site name

Sample 

begin date

(mm/dd/yyyy)

Start

time

(hh:mm)

Sample

end date

(mm/dd/yyyy)

End

time

(hh:mm)

 Carbaryl (E),

(μg/L)

 Chlorpyrifos,

(μg/L)

Dacthal,

DCPA,

(μg/L)

 Diazinon,

(μg/L)

Site 4

Modesto Irrigation District gage rooftop at Modesto 11/07/2002 02:00 11/10/2002 03:10 E0.012 0.009 0.018 0.026Modesto Irrigation District gage rooftop at Modesto 11/07/2002 02:00 11/10/2002 03:00 E0.026 0.007 0.009 0.03Modesto Irrigation District gage rooftop at Modesto 11/07/2002 02:00 11/10/2002 03:05 E0.011 0.009 0.008 0.025Modesto Irrigation District gage rooftop at Modesto 12/23/2002 09:30 01/09/2003 15:35 E0.007 0.016 0.009 0.154

Modesto Irrigation District gage rooftop at Modesto 12/23/2002 09:30 01/09/2003 15:30 E0.097 0.056 0.014 0.785

Modesto Irrigation District gage rooftop at Modesto 12/23/2002 09:30 01/09/2003 15:40 E0.087 0.109 0.019 2.22

Modesto Irrigation District gage rooftop at Modesto 01/09/2003 15:30 01/14/2003 10:40 <0.041 0.039 0.009 0.304

Modesto Irrigation District gage rooftop at Modesto 01/09/2003 15:30 01/14/2003 10:20 E0.01 0.072 0.008 0.962

Modesto Irrigation District gage rooftop at Modesto 01/09/2003 15:30 01/14/2003 10:30 E0.011 0.052 0.013 1.18

Modesto Irrigation District gage rooftop at Modesto 12/11/2003 13:20 12/16/2003 15:20 <0.041 0.053 0.031 0.101

Modesto Irrigation District gage rooftop at Modesto 12/11/2003 13:10 12/16/2003 15:40 <0.041 0.013 0.008 0.032

Modesto Irrigation District gage rooftop at Modesto 12/11/2003 13:00 12/16/2003 15:30 E0.052 0.023 0.008 0.064

Modesto Irrigation District gage rooftop at Modesto 12/23/2003 12:20 12/31/2003 09:40 <0.041 0.015 0.009 0.124

Modesto Irrigation District gage rooftop at Modesto 12/23/2003 13:00 12/31/2003 09:30 E0.009 0.019 0.004 0.074

Site 5

Modesto Irrigation District gage rooftop at Albers Road 11/07/2002 02:00 11/10/2002 03:10 <0.041 0.011 0.009 0.012

Modesto Irrigation District gage rooftop at Albers Road 11/07/2002 02:00 11/10/2002 03:00 E0.005 0.009 0.005 0.013

Modesto Irrigation District gage rooftop at Albers Road 11/07/2002 02:00 11/10/2002 03:05 E0.006 0.01 0.006 0.016

Modesto Irrigation District gage rooftop at Albers Road 12/16/2002 12:00 12/23/2002 10:40 <0.041 0.028 0.01 0.043

Modesto Irrigation District gage rooftop at Albers Road 12/16/2002 12:00 12/23/2002 10:20 <0.041 0.035 0.007 0.024

Modesto Irrigation District gage rooftop at Albers Road 12/16/2002 12:00 12/23/2002 10:30 <0.041 0.037 0.01 0.029

Modesto Irrigation District gage rooftop at Albers Road 01/09/2003 14:30 01/14/2003 11:50 E0.004 0.544 0.005 1.62

Modesto Irrigation District gage rooftop at Albers Road 01/09/2003 14:30 01/14/2003 11:30 <0.041 0.458 0.004 0.879

Modesto Irrigation District gage rooftop at Albers Road 01/09/2003 14:30 01/14/2003 11:40 <0.041 0.601 0.005 0.834

Modesto Irrigation District gage rooftop at Albers Road 12/11/2003 14:00 12/16/2003 14:30 <0.041 0.015 0.011 0.096

Modesto Irrigation District gage rooftop at Albers Road 12/11/2003 14:05 12/16/2003 14:40 <0.041 0.015 0.007 0.06

Modesto Irrigation District gage rooftop at Albers Road 12/11/2003 14:10 12/16/2003 14:35 <0.041 0.012 0.007 0.059
54 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Table 25. Comparison of concentrations of compounds detected in the aqueous-phase sample type to those detected in wet deposition for the same sampling periods during the 2002–04 study in the Central Valley of California.—Continued [Compounds presented are for those with detection frequencies greater than 50 percent; all compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). Abbreviations: AS, autosampler; E, estimated reported laboratory value; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; L, liters; mm/dd/yyyy, month/day/year; μg/L, micrograms per liter; <, less than laboratory reporting value] Site name Sample begin date (mm/dd/yyyy) Start time (hh:mm) Sample end date (mm/dd/yyyy) End time (hh:mm) Volume collected, (L) Sample type 3,4-Dichloro- aniline (E), (μg/L) Site 16 Gridley High School precipitation gage at Gridley 11/04/2003 10:15 11/12/2003 10:20 1.03 Aqueous phase—soil-box runoff E0.01 Gridley High School precipitation gage at Gridley 11/04/2003 10:00 11/12/2003 10:15 2.05 Wet deposition—AS <0.004 Gridley High School precipitation gage at Gridley 12/03/2003 12:30 12/12/2003 11:00 4.2 Aqueous phase—soil-box runoff E0.008 Gridley High School precipitation gage at Gridley 12/03/2003 12:50 12/12/2003 11:20 3.885 Wet deposition—funnel E0.006 Gridley High School precipitation gage at Gridley 12/03/2003 12:40 12/12/2003 11:10 2.13 Wet deposition—AS <0.006 Gridley High School precipitation gage at Gridley 12/12/2003 11:00 12/18/2003 10:10 2 Aqueous phase—soil-box runoff E0.009 Gridley High School precipitation gage at Gridley 12/12/2003 11:20 12/18/2003 10:30 1.19 Wet deposition—funnel <0.004 Gridley High School precipitation gage at Gridley 12/12/2003 11:10 12/18/2003 10:20 0.57 Wet deposition—AS <0.004 Gridley High School precipitation gage at Gridley 12/18/2003 10:00 12/23/2003 08:00 1.22 Aqueous phase—soil-box runoff <0.004 Gridley High School precipitation gage at Gridley 12/18/2003 10:30 12/23/2003 08:10 1.72 Wet deposition—funnel <0.004 Gridley High School precipitation gage at Gridley 12/23/2003 08:00 12/30/2003 09:45 3 Aqueous phase—soil-box runoff <0.005 Gridley High School precipitation gage at Gridley 12/23/2003 08:10 12/30/2003 09:40 4.3 Wet deposition—funnel <0.004 Gridley High School precipitation gage at Gridley 02/06/2004 10:30 02/17/2004 14:20 0.11 Aqueous phase—soil-box runoff <0.004 Gridley High School precipitation gage at Gridley 02/06/2004 10:20 02/17/2004 14:00 3.4 Wet deposition—funnel <0.004 Gridley High School precipitation gage at Gridley 02/17/2004 14:20 02/20/2004 10:30 1.28 Aqueous phase—soil-box runoff <0.004 Gridley High School precipitation gage at Gridley 02/17/2004 14:00 02/20/2004 10:30 3.1 Wet deposition—funnel <0.004 Gridley High School precipitation gage at Gridley 02/20/2004 10:30 03/02/2004 11:00 4.18 Aqueous phase—soil-box runoff <0.004 Gridley High School precipitation gage at Gridley 02/20/2004 10:30 03/02/2004 10:40 4.28 Wet deposition—funnel <0.004
Results of Monitoring 55

Table 25. Comparison of concentrations of compounds detected in the aqueous-phase sample type to those detected in wet deposition for the same sampling periods during the 2002–04 study in the Central Valley of California.—Continued[Compounds presented are for those with detection frequencies greater than 50 percent; all compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). Abbreviations: AS, autosampler; E, estimated reported laboratory value; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; L, liters; mm/dd/yyyy, month/day/year; μg/L, micrograms per liter; <, less than laboratory reporting value]

Site name

Sample 

begin date

(mm/dd/yyyy)

Start

time

(hh:mm)

Sample

end date

(mm/dd/yyyy)

End

time

(hh:mm)

 Metolachlor,

(μg/L)

 Myclobutanil (E),

(μg/L)

 Pendimethalin,

(μg/L)

Simazine,

(μg/L)

Site 16

Gridley High School precipitation gage at Gridley 11/04/2003 10:15 11/12/2003 10:20 <0.013 <0.008 E0.014 0.025

Gridley High School precipitation gage at Gridley 11/04/2003 10:00 11/12/2003 10:15 <0.013 <0.008 <0.022 0.006Gridley High School precipitation gage at Gridley 12/03/2003 12:30 12/12/2003 11:00 <0.013 <0.008 E0.013 0.019

Gridley High School precipitation gage at Gridley 12/03/2003 12:50 12/12/2003 11:20 <0.013 <0.008 E0.018 0.009

Gridley High School precipitation gage at Gridley 12/03/2003 12:40 12/12/2003 11:10 <0.013 <0.008 <0.022 0.011

Gridley High School precipitation gage at Gridley 12/12/2003 11:00 12/18/2003 10:10 <0.013 <0.008 0.023 0.026

Gridley High School precipitation gage at Gridley 12/12/2003 11:20 12/18/2003 10:30 E0.004 <0.008 0.026 0.009

Gridley High School precipitation gage at Gridley 12/12/2003 11:10 12/18/2003 10:20 <0.013 <0.008 E0.02 0.012

Gridley High School precipitation gage at Gridley 12/18/2003 10:00 12/23/2003 08:00 <0.013 <0.008 0.022 0.024

Gridley High School precipitation gage at Gridley 12/18/2003 10:30 12/23/2003 08:10 <0.013 <0.008 0.027 <0.01

Gridley High School precipitation gage at Gridley 12/23/2003 08:00 12/30/2003 09:45 <0.013 <0.008 E0.015 0.028

Gridley High School precipitation gage at Gridley 12/23/2003 08:10 12/30/2003 09:40 <0.013 <0.008 E0.017 0.009

Gridley High School precipitation gage at Gridley 02/06/2004 10:30 02/17/2004 14:20 <0.013 <0.008 <0.022 0.06

Gridley High School precipitation gage at Gridley 02/06/2004 10:20 02/17/2004 14:00 <0.013 <0.008 0.027 0.043

Gridley High School precipitation gage at Gridley 02/17/2004 14:20 02/20/2004 10:30 E0.002 E0.003 E0.022 0.014

Gridley High School precipitation gage at Gridley 02/17/2004 14:00 02/20/2004 10:30 <0.013 E0.006 E0.023 0.01

Gridley High School precipitation gage at Gridley 02/20/2004 10:30 03/02/2004 11:00 <0.013 E0.008 <0.022 0.021

Gridley High School precipitation gage at Gridley 02/20/2004 10:30 03/02/2004 10:40 <0.013 E0.022 E0.015 0.01
56 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Table 25. Comparison of concentrations of compounds detected in the aqueous-phase sample type to those detected in wet deposition for the same sampling periods during the 2002–04 study in the Central Valley of California.—Continued [Compounds presented are for those with detection frequencies greater than 50 percent; all compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). Abbreviations: AS, autosampler; E, estimated reported laboratory value; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; L, liters; mm/dd/yyyy, month/day/year; μg/L, micrograms per liter; <, less than laboratory reporting value] Site name Sample begin date (mm/dd/yyyy) Start time (hh:mm) Sample end date (mm/dd/yyyy) End time (hh:mm) Carbaryl (E), (μg/L) Chlorpyrifos, (μg/L) Dacthal, DCPA, (μg/L) Diazinon, (μg/L) Site 16 Gridley High School precipitation gage at Gridley 11/04/2003 10:15 11/12/2003 10:20 E0.023 0.005 0.008 0.012 Gridley High School precipitation gage at Gridley 11/04/2003 10:00 11/12/2003 10:15 E0.006 E0.005 0.006 0.009 Gridley High School precipitation gage at Gridley 12/03/2003 12:30 12/12/2003 11:00 E0.024 0.005 0.006 0.01 Gridley High School precipitation gage at Gridley 12/03/2003 12:50 12/12/2003 11:20 E0.011 0.006 0.005 0.007 Gridley High School precipitation gage at Gridley 12/03/2003 12:40 12/12/2003 11:10 <0.041 <0.005 0.005 0.007 Gridley High School precipitation gage at Gridley 12/12/2003 11:00 12/18/2003 10:10 <0.055 E0.004 0.004 0.013 Gridley High School precipitation gage at Gridley 12/12/2003 11:20 12/18/2003 10:30 E0.033 0.007 0.004 0.008 Gridley High School precipitation gage at Gridley 12/12/2003 11:10 12/18/2003 10:20 E0.021 0.054 0.004 0.036 Gridley High School precipitation gage at Gridley 12/18/2003 10:00 12/23/2003 08:00 E0.034 0.009 0.005 0.031 Gridley High School precipitation gage at Gridley 12/18/2003 10:30 12/23/2003 08:10 E0.007 0.011 0.003 0.037 Gridley High School precipitation gage at Gridley 12/23/2003 08:00 12/30/2003 09:45 E0.012 0.018 E0.003 0.022 Gridley High School precipitation gage at Gridley 12/23/2003 08:10 12/30/2003 09:40 E0.005 0.017 E0.003 0.008 Gridley High School precipitation gage at Gridley 02/06/2004 10:30 02/17/2004 14:20 E0.043 0.042 0.014 0.796 Gridley High School precipitation gage at Gridley 02/06/2004 10:20 02/17/2004 14:00 E0.007 0.03 0.005 0.311 Gridley High School precipitation gage at Gridley 02/17/2004 14:20 02/20/2004 10:30 <0.041 0.014 0.004 0.131 Gridley High School precipitation gage at Gridley 02/17/2004 14:00 02/20/2004 10:30 <0.041 0.018 0.005 0.097 Gridley High School precipitation gage at Gridley 02/20/2004 10:30 03/02/2004 11:00 <0.041 0.007 0.004 0.07 Gridley High School precipitation gage at Gridley 02/20/2004 10:30 03/02/2004 10:40 <0.041 0.011 0.004 0.051
Summary and Conclusions 57

agricultural site 5 soil-boxes. Soil mix 4 was collected from 

the Sacramento Valley near site 16 and placed in soil box at 

urban site 16 on the Gridley High School rooftop. Therefore, 

background concentrations of some compounds were detected 

only in the San Joaquin Valley mix, whereas others were only 

detected in the Sacramento Valley soil mix, and some in both. 

No soil-box runoff samples were collected from the side of the 

box from which the surficial-soil samples were collected. 

In the San Joaquin Valley, 19 compounds were detected 

in the background concentrations of the composite soil mix 

placed in the urban and agricultural soil boxes (table 26). 

The highest background concentrations were detected for the 

compounds simazine (99 μg/Kg), metolachlor (98μg/Kg), 

trifluralin (24.3 μg/Kg ), and malathion (23.3 μg/Kg). For surficial-soil samples collected throughout the study period from 

the San Joaquin urban soil box, 16 of the 19 compounds 

detected in background concentrations were detected at lower 

concentrations following atmospheric exposure; of the exceptions were chlorpyrifos, dacthal, and iprodione (table 26). 

At the San Joaquin Valley agricultural soil-box site 5, carbaryl, chlorpyrifos, dacthal, iprodione, and myclobutinil also 

were detected at higher concentrations than the background 

concentrations of the composite soil mix, indicating atmospheric deposition of these compounds onto the soil-box 

surface. For chlorpyrifos, the concentration was twice that of 

background in at the urban soil-box site (1.6 μg/Kg compared 

to E 0.8μg/Kg), whereas at the agricultural soil-box site, the 

concentration was nearly an order of magnitude more than 

background (6 μg/Kg compared to E 0.8 μg/Kg). The oxygen 

analog of chlopyrifos was not detected in the background 

concentrations of soil mix 1, 2, 3, but was detected at low 

concentrations in samples collected from both the urban and 

agricultural soil-box sites in July 2004. Detections of chlorpyrifos oxon could be attributed to the use of its parent compound, chlorpyrifos, on row crops during the summer in the 

San Joaquin Valley.

In the Sacramento Valley, six compounds were detected 

in background concentrations of soil mix 4 (table 26). These 

compounds also were detected in samples collected following 

atmospheric exposure at the same or slightly higher concentrations. Simazine had the highest concentration detected in 

both the background concentration and samples collected after 

atmospheric exposure at 10 μg/Kg and 11 μg/Kg, respectively. 

Chlorpyrifos, dacthal, iprodione, methyl parathion, and methyl 

paraoxon were detected in low concentrations in samples 

collected during the study period, but were not detected 

in the background concentration of soil mix 4, indicating 

atmospheric deposition of these compounds onto the soil-box 

surface.

Summary and Conclusions

2001 Study Period

A single storm event on January 25–26, 2001, was 

sampled, and concentrations in rainfall were measured at 

four urban and four agricultural sites in the Modesto, Calif., 

region, while simultaneously collecting hourly storm-drain 

runoff samples from a Modesto storm drain. Chlorpyrifos, 

dacthal, diazinon, pendimethalin, and simazine were detected 

in all rainfall samples collected from urban and agricultural 

sites. During a January 2001 storm event, the median concentrations of both chloryprifos and diazinon sampled at four 

urban (0.067 μg/L and 0.515 μg/L, respectively) and four 

agricultural sites (0.079 μg/L and 0.583 μg/L, respectively) in 

and around the Modesto, Calif., region were nearly identical, 

indicating that the overall atmospheric burden in the region 

could have been fairly evenly distributed during the sampling 

event. The median concentrations of chlorpyrifos, diazinon, 

and simazine collected from the agricultural sites (0.079 μg/L, 

0.583 μg/L, and 0.051 μg/L, respectively) were greater than 

the median concentrations collected from the urban sites 

(0.067 μg/L, 0.515 μg/L, and 0.031 μg/L, respectively). 

Metolachlor and napropamide had higher detection frequencies in samples collected from the urban sites than those 

collected from the agricultural sites (100 percent compared to 

50 percent). It is unknown how many, if any, urban applications there were during this study that could have contributed 

to the observed urban concentrations.

It is likely that rainfall can contribute significantly to 

pesticide concentrations in storm runoff for some compounds, 

depending on their physical and chemical properties. Many 

of the same pesticides detected in rainfall samples collected in the McHenry urban watershed also were detected 

in the storm-drain runoff samples from the urban watershed. 

When comparing the median concentrations in the rainfall to 

those in the McHenry storm drain runoff, it was found that for 

some compounds rainfall contributed a substantial percentage 

of the concentration found in the runoff, whereas for other 

compounds, the concentrations in rainfall were much greater 

than in the runoff. Diazinon is an example for which concentrations in rainfall likely contributed about 70 percent of the 

diazinon in the runoff, whereas the chlorpyrifos concentration 

in the rain was 1.8 times higher than in the runoff. Diazinon is 

much more water soluble than chlorpyrifos, whereas chlorpyrifos has a higher soil absorption coefficient. Since the runoff 

samples were filtered, and the filters were not analyzed, it can 

be inferred that most of the chlorpyrifos had been sorbed onto 

the suspended particulate matter, whereas diazinon stayed in 

solution. 
58 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides

Table 26. Detection frequency and comparison of concentrations of compounds detected before and after atmospheric exposure for 

the surficial soil-box sample type collected from the San Joaquin Valley and Sacramento Valley, California, soil-box sites during the 

2002–04 study period.—Continued

[See appendix 1 for background concentrations and sample weight of mix 1 collected near site 10 (Westly raingage), mix 2 collected near site 11 (Newman 

raingage), Mix 3 collected near site 5 (Modesto Irrigation District at Albers Road), and mix 4 collected near site 16 (Gridley High School); total area of soil box, 

0.374 cubic meters. Abbreviations: E, estimated reported laboratory value; n, total number of samples analyzed for given sample type; NA, not applicable as 

there was only one detection for given compound; μg/Kg, micrograms per Kilogram; –, not detected]

Compound

3

Surficial-soil average 

background concentration 

(μg/Kg) (n=3)

Surficial-soil 

detection frequency 

(in percent) (n=3)

Median surficialsoil concentration

(μg/Kg)

Maximum surficialsoil concentration

(μg/Kg)

San Joaquin Valley surficial soil (urban site 4)

Chlorpyrifos 6

E0.8 100 1.6 2

Dacthal1 E0.7 100 1 1

Dieldrin1 3.3 100 2.3 3

Fipronil sulfone 1.3 100 1 1

Desulfinylfipronil (E) E0.7 100 E0.7 E0.8

Iprodione (E) E7.3 100 E10 E15

Metolachlor 98 100 23 55

Myclobutanil (E) E14.7 100 E9.6 E10

Pendimethalin 51 100 E32 E40

Simazine 99 100 22 53

Trifluralin 24.3 100 12 17

Carbaryl2

 (E) E1.7 66.6 6E0.7 E0.8

Metribuzin1 E21 66.6 6

E7 E12

3,4-Dichloroaniline1

 (E) E5 33.3 5E2 NA

Chlorpyrifos oxon (E) – 33.3 5

E3 NA

Dimethoate E22.3 33.3 5

9 NA

Malathion 23.3 33.3 5

10 NA

cis-Permethrin 5

E11 – – –

trans-Permethrin 5

6 – – –

Prometon (E) E1.3 – – –

San Joaquin Valley surficial soil (agricultural site 5)

Carbaryl2

 (E) E1.7 100 E0.73 E1

Chlorpyrifos 6

E0.8 100 6 10

Dacthal1 E0.7 100 E0.93 E1

Dieldrin1 3.3 100 2.3 3

Fipronil sulfone 1.30 100 1.3 2

Desulfinylfipronil (E) E0.7 100 E0.73 E0.9

Iprodione (E) E7.3 100 E18.6 E28

Metolachlor 98 100 28.3 66

Metribuzin1 E21 100 E8.5 E12

Myclobutanil (E) E14.7 100 E16 E17

Pendimethalin 51 100 E39.6 E62

Simazine 99 100 34.6 72

Trifluralin 24.3 100 10.6 17

3,4-Dichloroaniline1

 (E) E5 66.6 6E2.5 3

Chlorpyrifos oxon (E) – 33.3 5

E5 NA

Dimethoate E22.3 33.3 5

E6 NA

Malathion 23.3 33.3 5

12 NA

Paraoxon-methyl – 33.3 5

E4 –

cis-Permethrin 5

E11 – – –

trans-Permethrin 5

6 – – –

Prometon (E) E1.3 – – –

Table 26. Detection frequency and comparison of concentrations of compounds detected before and after atmospheric exposure for 

the surficial soil-box sample type collected from the San Joaquin Valley and Sacramento Valley, California, soil-box sites during the 

2002–04 study period.
Results of Monitoring 59

Table 26. Detection frequency and comparison of concentrations of compounds detected before and after atmospheric exposure for 

the surficial soil-box sample type collected from the San Joaquin Valley and Sacramento Valley, California, soil-box sites during the 

2002–04 study period.—Continued

[See appendix 1 for background concentrations and sample weight of mix 1 collected near site 10 (Westly raingage), mix 2 collected near site 11 (Newman 

raingage), Mix 3 collected near site 5 (Modesto Irrigation District at Albers Road), and mix 4 collected near site 16 (Gridley High School); total area of soil box, 

0.374 cubic meters. Abbreviations: E, estimated reported laboratory value; n, total number of samples analyzed for given sample type; NA, not applicable as 

there was only one detection for given compound; μg/Kg, micrograms per Kilogram; –, not detected]

Compound

3

Surficial-soil average 

background concentration 

(μg/Kg) (n=3)

Surficial-soil 

detection frequency 

(in percent) (n=3)

Median surficialsoil concentration

(μg/Kg)

Maximum surficialsoil concentration

(μg/Kg)

Sacramento Valley surficial soil (urban site 16)

3,4-Dichloroaniline1

 (E) E0.9 100.0 E1 E1

Chlorpyrifos – 100.0 0.95 1

Dacthal1 – 100.0 E0.8 E0.8

Dieldrin1 E0.4 100.0 E0.5 0.6

Iprodione (E) – 100.0 E0.95 1

Simazine 10 100.0 6.5 11

Trifluralin E0.1 100.0 E0.45 E0.6

Carbaryl2

 (E) E2 50.0 5E2 NA

Parathion-methyl – 50.0 5

E6 NA

Paraoxon-methyl – 50.0 5

E4 NA

Prometon (E) E2 50.0 5

E2 NA

1

Compound is biased low (B-L) because of low laboratory matrix and reagent spike recoveries, see table 11. Compounds with non-detections are not presented in appendix 9 but could be present in low concentrations in the environment.

2

Compound is biased high (B-H) because laboratory matrix and reagent spike recoveries were greater than 150 percent, see table 11.

3

Values represent the average of the background individual concentrations found in soil mix 1, soil mix 2, soil mix 3 (San Joaquin Valley) prior to exposure to 

the atmosphere and subsequent compositing of soil mixes for placement in the soil box.

4

Values represent the background concentration found in soil mix 4 (Sacramento Valley) prior to exposure to the atmosphere and placement in the soil box.

5

Value represents only one detection, n=1.

6

Value represents two detections, n=2.
60 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides

2002–04 Study Period

Throughout the 2.5-year study period, a wide variety of 

pesticides were detected in the wet, bulk wet, dry, and bulk dry 

atmospheric-deposition sample types. Each sample type was 

analyzed for 41 currently used pesticides and 23 pesticide degradates, including oxygen analogs (oxons) of 9 organophosphate insecticides. The suite of pesticides detected in the wet 

deposition during this study period was similar to that of the 

2001 study. The differences in pesticide concentrations found 

in wet deposition (and bulk wet) compared to dry deposition 

(and bulk dry) appeared to be closely related to the Henry’s 

Law value of each compound, although the mass deposited 

by dry deposition takes place over a much longer time frame. 

For those compounds characterized by low Henry’s Law (H) 

values and high water solubility, such as diazinon, rainfall 

was a more significant source of depositional loading to the 

ground than dry deposition. For those compounds having high 

Henry’s Law values and low water solubility, such as chlorpyrifos, dry deposition was more important. 

Detection frequencies for the wet-deposition sample 

type collected from the San Joaquin Valley and Sacramento 

Valley were greater than 90 percent for the compounds 

dacthal, diazinon, chlorpyrifos, and simazine and greater 

than 78 percent for samples collected as bulk-wet deposition. 

For wet-deposition samples collected from the San Joaquin 

Valley and Sacramento Valley, the median wet-deposition 

flux values were comparable for the compounds dacthal 

(0.048 μg/L and 0.035 μg/L, respectively) and chlorpyrifos 

(0.079 μg/L and 0.066 μg/L, respectively). Dacthal concentrations also were comparable for bulk-wet deposition 

collected from the San Joaquin Valley and Sacramento Valley 

at 0.032 μg/L and 0.042 μg/L, respectively. In contrast, the 

median wet-deposition flux values for the compounds diazinon 

and simazine were 1.6 and 4.0 times greater, respectively, in 

samples collected from the San Joaquin Valley. The highest 

wet-deposition flux measured was for the compound diazinon 

at 50.64 μg/m2/day and 45.61 μg/m2/day, collected from the 

funnel and autosampler, respectively, in the Sacramento Valley 

at the Gridley High School rooftop site 16 during the 2003 

orchard dormant-spray season. 

The compounds most detected in the dry-deposition sample type were metolachlor, chlorpyrifos, and dacthal (detection 

frequencies greater than 70 percent). Detection frequencies 

were greater than 90 percent in samples collected as bulk-dry 

deposition for the compounds simazine, chlorypyrifos, and 

dacthal. Dry-deposition fluxes measured in the Sacramento 

Valley were two orders of magnitude less than many of the 

same compounds detected in the San Joaquin Valley. In the 

San Joaquin Valley, the largest dry deposition fluxes measured 

were for the herbicide simazine (E 0.244μg/m2/day) and 

insecticide chlorpyrifos (E 0.233μg/m2/day). The compounds 

with the highest bulk dry-deposition rates measured in the San 

Joaquin Valley were diazinon (E 1.81 μg/m2/day) and iprodione (E 0.70 μg/m2

/day). During the January 2004 orchard 

dormant-spray season, diazinon and its oxygen analog, 

diazoxon, had the highest bulk dry-deposition rates measured 

at E 5.26 μg/m2/day and E 0.203 μg/m2/day, respectively, at 

the Gridley High School rooftop site 16 in the Sacramento 

Valley .

The soil-box results showed that many of the pesticides 

present in the soil-box runoff (aqueous phase) also were 

detected in the rainfall at similar concentrations, with the 

exception of the aqueous phase of metolachlor, myclobutanil, 

and simazine, which were found in concentrations an order of 

magnitude greater than those detected in rainfall. Compounds 

detected in aqueous-phase and suspended-sediment samples 

collected from the soil-box runoff were compared. In the San 

Joaquin Valley, detection frequencies for the aqueous-phase 

sample type were greater than 88 percent for the compounds 

myclobutanil, diazinon, simazine, metolachlor, and dacthal. In 

the Sacramento Valley, detection frequencies for the aqueousphase sample type were 100 percent for the compounds diazinon, dacthal, and chlorypyrifos and 92 percent for simazine. 

In contrast, few pesticides were detected in the soil-box runoff 

suspended-sediment sample type collected from the San Joaquin Valley and Sacramento Valley, with the exception of the 

herbicide simazine (median concentration of E 0.121 μg/L and 

E 0.250 μg/L, respectively). Detection frequencies for simazine in the suspended-sediment sample type were 64 percent 

in the San Joaquin Valley and 75 percent in the Sacramento 

Valley.

Prior to atmospheric exposure, background concentrations for 19 compounds were measured in the composite soil 

mix placed in the San Joaquin Valley urban and agricultural 

soil boxes, and 6 compounds were detected in the soil mix 

placed in the urban Sacramento Valley soil box. Results for 

compounds detected after atmospheric exposure in the surficial-soil samples collected during the study period indicated 

that for some compounds concentration (μg/Kg) increased, 

which indicated atmospheric deposition of these compounds 

onto the soil-box surface. In the San Joaquin Valley, for samples collected from both the urban and agricultural soil-box 

sites, the compounds chlorpyrifos, dacthal, and iprodione were 

detected at higher concentrations than were found in the background samples. The remaining compounds also were detected 

in samples collected following exposure to the atmosphere 

during the study period, but at lower concentrations than the 

measured background concentrations. In the Sacramento 

Valley, the six compounds detected in the background concentration of soil-box mix were also detected throughout the study 

period, but at much lower concentrations. Conversely, chlorpyrifos, dacthal, iprodione, parathion-methyl, and its oxygen 

analog, paraoxon-methyl, were detected in low concentrations 

in samples collected during the study period, but were not 

detected in the background concentration of soil mix 4.
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64 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides

Appendix 1. Sample Preparation and Instrumental Analyses
Appendix 1 65

This appendix provides more details about the sample 

preparation methods and instrumental analysis methods. 

Sample preparation methods varied by sample type; however, after the samples were prepared, all underwent the same 

instrumental analysis method.

Sample Preparation Methods

All samples were shipped to the National Water-Qulaity 

Laboratory (NWQL) on ice. Upon receipt by the laboratory, 

samples were stored at 4 degrees Celsius (°C) until prepared 

for analysis. 

Dry and Bulk Dry-Deposition Samples (NWQL 

Research Method LS8054)

The methods for preparing and analyzing dry and bulkdry-deposition samples were modified several times during 

the study in an effort to improve performance. All dry and 

bulk-dry samples were fortified with 100 nanograms (ng) of 

surrogate compounds α-HCH-d6 and diazinon-d10 before 

performing extractions at the NWQL. Samples collected from 

April 2002 through October 2003 were extracted by adding 

250 milliliters (mL) of reagent water (if no water was already 

present) to aid in mixing and shaking the sample in a separatory funnel with two sequential 100-mL portions of 25-percent 

ethyl acetate in hexane. These extracts were combined, were 

dried with sodium sulfate, and then were concentrated as an 

azeotrope by using Kuderna-Danish (K-D) distillation at 85°C 

followed by nitrogen gas evaporation to about 1 mL. Samples 

collected from November 2003 through April 2004 were 

extracted by adding 250 mL of reagent water (if needed) and 

shaking with 50-mL of dichloromethane (DCM). The DCM 

extract was isolated from the water fraction by using a polytetrafluoroethylene membrane (DryDisk, Horizon Technologies, 

Inc., Salem, N.H.). The water fraction was returned to the 

sample bottle, shaken with another 50-mL aliquot of DCM, 

and this second DCM extract was isolated from the water fraction by using the membrane. The DCM extracts were combined, were dried further with sodium sulfate, and then were 

concentrated and solvent-exchanged to ethyl acetate by using 

Kuderna-Danish distillation at 65°C, followed by nitrogen gas 

evaporation to about 1 mL. 

Extracts of samples collected in 2002 were cleaned 

by using a 0.5-gram (g) C-18 solid-phase extraction (SPE) 

column positioned over a 1-g Florisil® SPE column (International Sorbent Technologies; now Biotage, LLC, Charlotte, 

N.C.). Analytes were eluted from each of the columns with 

6 mL of ethyl acetate, and the resulting eluents were reduced 

in volume and exchanged to toluene by nitrogen gas evaporation and then transferred to gas chromatography (GC) vials 

with a toluene rinse to achieve a 0.5 mL final volume for 

instrument analysis. The use of combined C-18/Florisil® 

SPE columns provided cleaner extracts, but some analytes, 

especially diazinon oxon, chlorpyrifos oxon, and malathion 

oxon, had poor recoveries with this approach. 

 For samples collected in 2003 and 2004, each extract 

was introduced to a 0.5-g CarboPrep® 90 (Restek Corp., 

Belefonte, Pa.) graphitized-carbon SPE column, and the 

analytes were eluted with 13 mL of a 50-percent DCM in ethyl 

acetate solution. The resulting eluents were reduced to 1–2 mL 

by using micro-Kuderna-Danish distillation at 85°C. A procedural internal standard solution of perdeuterated polycyclic 

aromatic hydrocarbons was added to these extracts before final 

solvent reduction and exchange to toluene by using nitrogen 

gas evaporation. The extracts were transferred to vials with 

toluene rinse to achieve a 0.5-mL final volume for instrumental analysis. 

 Laboratory reagent blanks and spiked samples were prepared by using solvents and reagent water in amounts comparable to typical field samples for the set of prepared samples. 

Spiked samples were fortified with 100 ng of method analytes. 

These quality-control (QC) samples were prepared subsequent 

to and analyzed along with (and by using the same methods 

as) the field samples. Bulk-deposition samples collected at 

Modesto Irrigation District (MID) at MID, MID at Albers 

Road, Turlock Airport, and Turlock near Idaho Road from 

January 14 to February 14, 2003, were ruined during sample 

preparation.

Suspended Sediment Sample (NWQL Research 

Method LS7503)

The glass-fiber filters (GFFs) containing suspended 

sediment were extracted by using an Accelerated Solvent 

Extraction (ASE) system model 200 (ASE-200) or model 

300 (ASE-300) instrument (Dionex, Sunnyvale, Calif.). 

The samples of suspended sediment collected on the GFFs 

were folded (particles inward), and each of the samples was 

placed inside a pre-weighed glass-fiber thimble (prebaked 

at 450 °C for 4 hours) and pre-positioned inside a 22-mL 

ASE-200 stainless-steel extraction cell. For samples with multiple GFFs, the GFFs were composited by placing the folded 

filters inside a 100-mL ASE model 300 extraction cell that also 

contained a pre-weighed 30-millimeter (mm) diameter GFF 

positioned as a support above the cell’s bottom cap (thimbles 

were not used in the 100-mL cells). The composite samples 

collected on December 3, 2003, and February 20, 2004, from 

site 16 required 2 cells to extract the 9 GFFs and 6 cells for 

the 38 GFFs, respectively. All samples (including laboratory blanks and spiked samples) were fortified with 100 ng 

of α-HCH-d6 and diazinon-d10 surrogates by addition on 

top of the GFF. For the two samples requiring multiple cells 

(site 16), surrogate addition was proportioned between cells. 

All samples were extracted with 25-percent acetone in DCM 

at 100°C and 10,342 kilopascals (kPa) of pressure by using 

Appendix 1. Sample Preparation and Instrumental Analyses
66 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides

three 10-minute static cycles on the ASE model 200 or 300 

instruments to isolate the analytes in organic solvent. 

Quality-control samples extracted along with the field 

samples included laboratory reagent blanks and spiked 

samples prepared by using one GFF each for the ASE-200 and 

four GFFs each for the ASE-300 extractions. The GFFs for 

quality-control samples were moistened with reagent water 

prior to loading in extraction cells to simulate field samples. 

Spiked samples were fortified with 100 ng of all method 

analytes. These QC samples were subsequently prepared 

and analyzed along with (and by using the same methods 

as) the field samples. Suspended-material samples from site 

4 on November 7, 2002, and site 5 on November 14, 2002, 

December 16, 2002, and January 14, 2004, were ruined during 

sample preparation at the NWQL.

 Following extraction, the contents of each ASE cell were 

placed in beakers and dried at 120°C for 24 hours, then cooled 

in a desiccator for 1 hour, and finally weighed. The mass 

of suspended material isolated on the GFFs was calculated 

by subtracting the initial GFF and thimble or cap-filter tare 

weights from the post-ASE final weights. Masses ranged from 

a maximum of 21.8 g for the site 16 sample from February 

20, 2004, to a minimum of negative or 0 g for samples with 

low particle loading, where either pieces of filter were lost or 

the initial GFF tare to the nearest 0.1 g was not precise enough 

to distinguish small mass loadings to the GFF. 

For samples requiring multiple cells, ASE extracts were 

combined prior to further sample preparation. Residual water 

was removed from ASE extracts by reaction with sodium 

sulfate. Extracts were reduced in volume and exchanged to 

ethyl acetate by using Kuderna-Danish (K-D) distillation 

at 75°C and nitrogen gas evaporation to about 1 mL. Each 

extract was introduced to a 0.5-g Carboprep® 90 SPE column, 

and the analytes were eluted with 13 mL of a 50-percent DCM 

in ethyl acetate solution. Eluents were reduced to 1–2 mL by 

using micro-Kuderna-Danish distillation at 85°C. A procedural internal-standard solution of perdeuterated polycyclic 

aromatic hydrocarbons was added to the extracts before final 

solvent reduction and exchange to toluene by using nitrogen 

gas evaporation. The extracts were transferred to vials with 

toluene rinse to achieve a 0.5-mL final volume for instrumental analysis.

Surficial-Soil Samples (NWQL Research Method 

LS5503) 

Each surficial soil sample was stirred by using a precleaned stainless-stell spoon to break up any clumps, and its 

dry weight as a percentage of its original mass (ranging from 

81– 8 percent) was determined on a high-temperature drying 

balance. Aliquots of 28 to 46-g dry-weight equivalent of the 

soil samples were mixed with up to 2 g of pelletized diatomaceous earth (Hydromatrix from Varian, Inc., now Agilent 

Technologies, Santa Clara, Calif.) to separate the particles 

in the soil matrix and bind any residual moisture. The soil 

samples were then transferred to 33-mL extraction cells, 

followed by fortification with 100 ng of the surrogate compounds αHCH-d6 and diazinon-d10, and finally extracted with 

25-percent acetone in DCM at 100°C and 10,342 kilopascals 

(kPa) by using three 10-min static cycles on the ASE-200 to 

isolate the analytes in organic solvent. 

Quality-control samples extracted along with the field 

samples included laboratory reagent blanks and reagent spiked 

samples, which were both prepared by using dry Ottawa Sand. 

The spiked samples were fortified with 100 ng of all method 

analytes. A laboratory matrix spike sample was prepared by 

adding 200 ng of all method analytes to an aliquot of soil mix 

2 sample. Duplicate aliquots were extracted and analyzed for 

the July 21, 2003, sample from Gridley High School, and for 

soil mix 1, 2 and 3 samples.

Residual water was removed from the ASE extracts by 

adding sodium sulfate. Extracts were reduced in volume, 

and the solvent-exchanged to ethyl acetate byusing K-D 

distillation at 75 °C and nitrogen gas evaporation to about 

1 mL. Each extract was introduced to a 0.5-g CarboPrep® 

90graphitized-carbon SPE column, and the analytes were 

eluted with 13 mL of 50-percent DCM in ethyl acetate solution. Eluents were reduced by using micro-K-D distillation 

at 85°C and nitrogen gas evaporation, if needed, to about 

2.5 mL. Analytes were further isolated from elemental sulfur 

and some unwanted coextractants by gel-permeation chromatography (GPC; Waters Corp., Milford, Mass.) of a 1.4-mL 

aliquot of the extract, with separation on a 300-mm long by 

7.5-mm internal diameter GPC column containing 5-micrometer diameter particles of polymeric styrene-divinylbenzene 

with 50-angstrom pores (Polymer Laboratories Ltd., now 

Agilent Technologies) by using a 1-mL/minute ethyl acetate 

mobile phase. The 9-mL collected GPC fractions were reduced 

as hexane/ethyl acetate azeotropes by micro-K-D distillation 

at 75°C to 1–2 mL. A procedural internal-standard solution of perdeuterated polycyclic aromatic hydrocarbons was 

added to each of the extracts before final solvent reduction 

and exchange to toluene by using nitrogen gas evaporation. 

The extracts were transferred to GC vials with toluene rinses 

to achieve a 0.5-mL final volume. The extracts were transferred to vials with toluene rinse to achieve a 0.5-mL final 

volume for instrumental analysis.

Instrumental Analysis (All Sample Types)

Analytes of interest in the extracts were determined by 

capillary-column gas chromatography/electron-impact mass 

spectrometry (GC-MS) operated in the selected-ion monitoring mode as described in Sandstrom and others (2001). 

The analytes of interest included selected pesticides and degradates that typically are determined by the method described 

in Madsen and others (2003) and additional compounds 

determined by similar methods described by Zaugg and others 

(1995) and Madsen and others (2003). 
Appendix 1 67

References Cited

Madsen, J.E., Sandstrom, M.W., and Zaugg, S.D., 2003, Meth-

ods of analysis by the U.S. Geological Survey National 

Water Quality Laboratory—A method supplement for the 

determination of fipronil and degradates in water by gas 

chromatography/mass spectrometry: U.S. Geological Sur-

vey Open-File Report 02–462, 11 p.

Sandstrom, M.W., Stroppel, M.E., Foreman, W.T., and Schro-

eder, M.P., 2001, Methods of analysis by the U.S. Geologi-

cal Survey National Water Quality Laboratory–Determina-

tion of moderate-use pesticides and selected degradates in 

water by C-18 solid-phase extraction and capillary-column 

gas chromatography/mass spectrometry with selected-ion 

monitoring (methods 2002/2011): U.S. Geological Survey 

Water-Resources Investigations Report 01–4098, 70 p.

Zaugg, S.D., Sandstrom, M.W., Smith, S.G., and Fehlberg, 

K.M., 1995, Methods of analysis by the U.S. Geological 

Survey National Water Quality Laboratory–Determination 

of pesticides in water by C-18 solid phase extraction and 

capillary-column gas chromatography with selected-ion 

monitoring: U.S. Geological Survey Open-File Report 

95–181, 49 p.
68 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides

Appendix 2. Analytical Results for Wet Deposition 

(Rainfall) in Micrograms Per Liter (μg/L) for Samples 

With at Least One Detection Collected at Four Urban 

and Agricultural Sites, and Storm Run-Off Samples 

at the McHenry Storm Drain in Modesto, California, 

January 23–26, 2001
Appendix 2 69

Appendix 2. Analytical results for wet deposition (rainfall) in micrograms per liter (μg/L) for samples with at least one detection collected at four urban and agricultural sites, and storm run-off samples at the McHenry storm drain in Modesto, California, January 23–26, 2001.[All compounds were analyzed by gas chromatography/mass spectrometry (GC/MS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Abbreviations: E, estimated reported laboratory 

value; hh:mm, hour:minute; Jan, January; [-], no Chemical Abstract Service Number available for given compound; <, less than laboratory reporting limit; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001)]

Site 

number Site name

Site 

identification 

number

Date Time (hh:mm) Atrazine [1912-24-9] (39632) Benfluralin [1861-40-1] (82673) Carbaryl (E) [1563-66-2] (82680) Chlorpyrifos [2921-88-2] (38933) Dacthal [1861-32-1] (82682) p’p’-DDE [72-55-9] (34653) 

Urban sites

1 Waste Water Treatment Plant rooftop at Modesto 373637121004601 Jan 26, 2001 07:30 <0.007 <0.01 <0.041 0.086 0.011 <0.003

2 Cadoni Road lift station at Modesto 373725120543701 Jan 26, 2001 08:30 <0.007 <0.01 E0.074 0.071 0.009 <0.003

3 Bowen and Aloha Street at Modesto 374028120594301 Jan 26, 2001 08:00 <0.007 <0.01 <0.1 0.057 0.009 <0.003

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Jan 26, 2001 08:30 <0.007 <0.01 E0.085 0.063 0.013 <0.003

Agricultural sites

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Jan 26, 2001 09:50 <0.007 <0.01 E0.087 0.148 0.005 <0.003

6 Modesto Irrigation District lateral #4 373750121092601 Jan 26, 2001 07:10 <0.007 <0.01 <0.041 0.034 0.013 <0.003

7 Turlock Irrigation District lateral #3 373228120551201 Jan 26, 2001 13:40 E0.003 <0.01 <0.09 0.052 0.009 E0.0068 Tully Road near Modesto 374351121004701 Jan 26, 2001 09:10 <0.007 <0.01 E0.081 0.105 0.01 <0.003

Urban storm drain

9 McHenry storm drain at Bodem Street 373847120590801 Jan 23, 2001 23:50 <0.007 <0.01 E0.015 0.007 <0.003 <0.003

9 McHenry storm drain at Bodem Street 373847120590801 Jan 25, 2001 18:00 <0.007 <0.01 E0.411 <0.05 0.004 <0.003

9 McHenry storm drain at Bodem Street 373847120590801 Jan 25, 2001 19:00 <0.007 <0.01 E0.297 0.023 0.006 <0.003

9 McHenry storm drain at Bodem Street 373847120590801 Jan 25, 2001 20:00 <0.007 <0.01 E0.015 0.035 0.009 <0.003

9 McHenry storm drain at Bodem Street 373847120590801 Jan 25, 2001 21:00 <0.007 E0.004 E0.034 0.033 0.009 <0.003

9 McHenry storm drain at Bodem Street 373847120590801 Jan 25, 2001 22:00 <0.007 <0.01 E0.045 0.031 0.009 <0.003

9 McHenry storm drain at Bodem Street 373847120590801 Jan 25, 2001 23:00 <0.007 <0.01 E0.179 0.033 <0.003 <0.003

9 McHenry storm drain at Bodem Street 373847120590801 Jan 26, 2001 00:00 <0.007 <0.01 E0.181 0.018 <0.003 <0.003

9 McHenry storm drain at Bodem Street 373847120590801 Jan 26, 2001 01:00 <0.007 <0.01 E0.209 0.023 <0.003 <0.003

9 McHenry storm drain at Bodem Street 373847120590801 Jan 26, 2001 02:00 <0.007 <0.01 E0.207 0.033 <0.003 <0.003

Equipment blank

9 McHenry storm drain at Bodem Street 373847120590801 Jan 23, 2001 23:58 <0.007 <0.01 <0.041 <0.005 <0.003 <0.003

Field blank

9 McHenry storm drain at Bodem Street 373847120590801 Jan 25, 2001 13:08 <0.007 <0.01 <0.041 <0.005 <0.003 <0.003

9 McHenry storm drain at Bodem Street 373847120590801 Jan 25, 2001 21:08 <0.007 <0.01 <0.041 <0.005 <0.003 <0.003
70 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 2. Analytical results for wet deposition (rainfall) in micrograms per liter (μg/L) for samples with at least one detection collected at four urban and agricultural sites, and storm run-off samples at the McHenry storm drain in Modesto, California, January 23–26, 2001.—Continued [All compounds were analyzed by gas chromatography/mass spectrometry (GC/MS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Num- ber is given below each compound name in brackets. The five digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Abbreviations: E, estimated reported laboratory value; hh:mm, hour:minute; Jan, January; [-], no Chemical Abstract Service Number available for given compound; <, less than laboratory reporting limit; (E), estimated compound due to known poor perfor- mance by applied method (Childress and others, 1999; Sandstrom and others, 2001)] Site number Site name Site identification number Date Time (hh:mm) Diazinon [333-41-5] (39572) Ethalfluralin [55283-68-6] (82663) Malathion [121-75-5] (39532) Metolachlor [51218-45-2] (39415) Napropamide [15299-99-7] (82684) Pendimethalin [40487-42-1] (82683) Urban sites—Continued

1 Waste Water Treatment Plant rooftop at Modesto 373637121004601 Jan 26, 2001 07:30 0.908 <0.009 <0.025 E0.004 0.024 0.18

2 Cadoni Road lift station at Modesto 373725120543701 Jan 26, 2001 08:30 0.472 <0.009 <0.027 E0.004 0.018 E0.118

3 Bowen and Aloha Street at Modesto 374028120594301 Jan 26, 2001 08:00 0.486 <0.009 <0.027 E0.004 0.014 0.121

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Jan 26, 2001 08:30 0.544 <0.009 <0.027 E0.004 0.008 E0.122

Agricultural sites—Continued

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Jan 26, 2001 09:50 0.87 <0.009 <0.027 <0.013 <0.007 0.083

6 Modesto Irrigation District lateral #4 373750121092601 Jan 26, 2001 07:10 0.188 <0.009 <0.027 <0.013 <0.007 0.02

7 Turlock Irrigation District lateral #3 373228120551201 Jan 26, 2001 13:40 0.491 E0.002 E0.015 E0.004 0.028 E0.2928 Tully Road near Modesto 374351121004701 Jan 26, 2001 09:10 0.675 <0.009 <0.027 E0.005 0.037 E0.257

Urban storm drain—Continued

9 McHenry storm drain at Bodem Street 373847120590801 Jan 23, 2001 23:50 0.334 <0.009 <0.027 <0.013 0.019 0.034

9 McHenry storm drain at Bodem Street 373847120590801 Jan 25, 2001 18:00 0.506 <0.009 <0.15 E0.009 0.051 <0.075

9 McHenry storm drain at Bodem Street 373847120590801 Jan 25, 2001 19:00 0.947 <0.009 E0.065 E0.008 0.035 E0.1059 McHenry storm drain at Bodem Street 373847120590801 Jan 25, 2001 20:00 0.922 <0.009 0.051 E0.005 0.02 0.0929 McHenry storm drain at Bodem Street 373847120590801 Jan 25, 2001 21:00 0.708 <0.009 0.04 E0.004 0.017 0.0979 McHenry storm drain at Bodem Street 373847120590801 Jan 25, 2001 22:00 0.691 <0.009 E0.022 E0.004 0.019 0.129 McHenry storm drain at Bodem Street 373847120590801 Jan 25, 2001 23:00 0.727 <0.009 <0.027 <0.013 0.011 0.061

9 McHenry storm drain at Bodem Street 373847120590801 Jan 26, 2001 00:00 0.756 <0.009 <0.027 <0.013 <0.02 0.033

9 McHenry storm drain at Bodem Street 373847120590801 Jan 26, 2001 01:00 0.761 <0.009 <0.027 <0.013 0.023 0.047

9 McHenry storm drain at Bodem Street 373847120590801 Jan 26, 2001 02:00 0.823 <0.009 <0.03 <0.013 <0.01 0.059

Equipment blank—Continued

9 McHenry storm drain at Bodem Street 373847120590801 Jan 23, 2001 23:58 <0.005 <0.009 <0.027 <0.013 <0.007 <0.01

Field blank—Continued

9 McHenry storm drain at Bodem Street 373847120590801 Jan 25, 2001 13:08 <0.005 <0.009 <0.027 <0.013 <0.007 <0.01

9 McHenry storm drain at Bodem Street 373847120590801 Jan 25, 2001 21:08 <0.005 <0.009 <0.027 <0.013 <0.007 <0.01
Appendix 2 71

Appendix 2. Analytical results for wet deposition (rainfall) in micrograms per liter (μg/L) for samples with at least one detection collected at four urban and agricultural sites, and storm run-off samples at the McHenry storm drain in Modesto, California, January 23–26, 2001.—Continued[All compounds were analyzed by gas chromatography/mass spectrometry (GC/MS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Abbreviations: E, estimated reported laboratory 

value; hh:mm, hour:minute; Jan, January; [-], no Chemical Abstract Service Number available for given compound; <, less than laboratory reporting limit; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001)]

Site 

number Site name

Site 

identification 

number

Date Time (hh:mm) cis-Permethrin [54774-45-7] (82687) Propargite [2312-35-8] (82685) Simazine [122-34-9] (04035) Terbacil [5902-51-2] (82665) Trifluralin [1582-09-8] (82661)

Urban sites—Continued

1 Waste Water Treatment Plant rooftop at Modesto 373637121004601 Jan 26, 2001 07:30 <0.006 <0.02 0.034 <0.034 <0.009

2 Cadoni Road lift station at Modesto 373725120543701 Jan 26, 2001 08:30 <0.006 <0.02 0.037 <0.034 0.048

3 Bowen and Aloha Street at Modesto 374028120594301 Jan 26, 2001 08:00 <0.006 <0.02 0.028 <0.034 0.025

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Jan 26, 2001 08:30 <0.006 <0.02 0.025 E0.087 <0.009

Agricultural sites—Continued

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Jan 26, 2001 09:50 <0.006 <0.02 0.036 <0.034 E0.006

6 Modesto Irrigation District lateral #4 373750121092601 Jan 26, 2001 07:10 <0.006 <0.02 0.013 <0.034 E0.007

7 Turlock Irrigation District lateral #3 373228120551201 Jan 26, 2001 13:40 0.007 E0.01 0.066 E0.018 0.01

8 Tully Road near Modesto 374351121004701 Jan 26, 2001 09:10 <0.006 <0.02 0.172 <0.034 0.03

Urban storm drain—Continued

9 McHenry storm drain at Bodem Street 373847120590801 Jan 23, 2001 23:50 <0.006 <0.02 0.051 <0.034 E0.006

9 McHenry storm drain at Bodem Street 373847120590801 Jan 25, 2001 18:00 <0.006 <0.02 0.111 <0.034 <0.0099 McHenry storm drain at Bodem Street 373847120590801 Jan 25, 2001 19:00 <0.006 <0.02 0.105 <0.034 <0.009

9 McHenry storm drain at Bodem Street 373847120590801 Jan 25, 2001 20:00 <0.006 <0.02 0.061 <0.034 E0.006

9 McHenry storm drain at Bodem Street 373847120590801 Jan 25, 2001 21:00 <0.006 <0.02 0.042 <0.034 E0.008

9 McHenry storm drain at Bodem Street 373847120590801 Jan 25, 2001 22:00 <0.006 <0.02 0.045 <0.034 E0.007

9 McHenry storm drain at Bodem Street 373847120590801 Jan 25, 2001 23:00 <0.006 <0.02 0.051 <0.034 E0.006

9 McHenry storm drain at Bodem Street 373847120590801 Jan 26, 2001 00:00 <0.006 <0.02 0.055 <0.034 <0.0099 McHenry storm drain at Bodem Street 373847120590801 Jan 26, 2001 01:00 <0.006 <0.02 0.034 <0.034 <0.0099 McHenry storm drain at Bodem Street 373847120590801 Jan 26, 2001 02:00 <0.006 <0.02 0.054 <0.034 0.005

Equipment blank—Continued

9 McHenry storm drain at Bodem Street 373847120590801 Jan 23, 2001 23:58 <0.006 <0.02 <0.011 <0.034 <0.009

Field blank—Continued

9 McHenry storm drain at Bodem Street 373847120590801 Jan 25, 2001 13:08 <0.006 <0.02 <0.011 <0.034 <0.009

9 McHenry storm drain at Bodem Street 373847120590801 Jan 25, 2001 21:08 <0.006 <0.02 <0.011 <0.034 <0.009
72 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides References Cited Childress, C.J.O., Foreman, W.T., Connor, B.F., and Maloney, T.J., 1999, New reporting procedures based on long-term method detection levels and some consid- erations for interpretations of water-quality data provided by the U.S. Geological Survey National Water Quality Laboratory: U.S. Geological Survey Open-File Report 99–193, 19 p. Sandstrom, M.W., Stroppel, M.E., Foreman, W.T., and Schroeder, M.P., 2001, Methods of analysis by the U.S. Geological Survey National Water Quality Labora- tory–Determination of moderate-use pesticides and selected degradates in water by C-18 solid-phase extraction and capillary-column gas chromatography/mass spec- trometry with selected-ion monitoring (methods 2002/2011): U.S. Geological Survey Water-Resources Investigations Report 01–4098, 70 p.
Appendix 3 73

Appendix 3. Calculated Flux Values Presented in 

Micrograms Per Square Meter Per Day (μg/m2/day) for WetDeposition Samples With at Least One Detection Collected 

During the 2002–04 Study Period at Eight Sites in the Central 

Valley, California
74 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 2002–04 study period at eight sites in the Central Valley, California.—Continued [All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler (AS)= 0.0614 m2) and sample composite time in days. Abbrevia- tions: E, estimated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; –, compound not detected; [-], no Chemical Abstract Service Number available for given compound] Site number Site name Site identification number Start date Start time (hh:mm) End date End time (hh:mm) Composite sample time, days Rain events during composite sample time, days Sample type Sampler type 11 Newman rain gage at wasteway levee near Draper Road 371735121031201 Feb 9, 2002 09:00 Feb 11, 2002 10:45 2 1 wet Funnel 11 Newman rain gage at wasteway levee near Draper Road 371735121031201 Feb 15, 2002 11:15 Feb 18, 2002 12:30 3 2 wet Funnel 11 Newman rain gage at wasteway levee near Draper Road 371735121031201 Mar 5, 2002 10:15 Mar 8, 2002 10:15 3 2 wet Funnel 11 Newman rain gage at wasteway levee near Draper Road 371735121031201 Mar 15, 2002 10:00 Mar 19, 2002 10:20 4 3 wet Funnel 11 Newman rain gage at wasteway levee near Draper Road 371735121031201 Mar 22, 2002 09:40 Mar 24, 2002 13:20 2 1 wet Funnel 11 Newman rain gage at wasteway levee near Draper Road 371735121031201 Nov 7, 2002 02:00 Nov 10, 2002 03:00 3 2 wet Funnel 11 Newman rain gage at wasteway levee near Draper Road 371735121031201 Dec 9, 2002 10:15 Dec 16, 2002 09:50 7 5 wet Funnel 11 Newman rain gage at wasteway levee near Draper Road 371735121031201 Dec 16, 2002 09:50 Dec 22, 2002 13:00 6 6 wet Funnel 11 Newman rain gage at wasteway levee near Draper Road 371735121031201 Jan 8, 2003 14:00 Jan 14, 2003 10:10 6 1 wet Funnel 11 Newman rain gage at wasteway levee near Draper Road 371735121031201 Mar 13, 2003 10:20 Mar 18, 2003 10:15 5 3 wet Funnel 11 Newman rain gage at wasteway levee near Draper Road 371735121031201 Mar 18, 2003 10:15 Mar 27, 2003 10:20 9 2 wet Funnel 11 Newman rain gage at wasteway levee near Draper Road 371735121031201 Nov 5, 2003 10:50 Nov 10, 2003 10:30 5 4 wet Funnel 11 Newman rain gage at wasteway levee near Draper Road 371735121031201 Jan 29, 2004 14:00 Feb 4, 2004 12:30 6 2 wet Funnel 11 Newman rain gage at wasteway levee near Draper Road 371735121031201 Feb 4, 2004 12:30 Feb 19, 2004 13:00 15 5 wet Funnel 11 Newman rain gage at wasteway levee near Draper Road 371735121031201 Feb 19, 2004 13:00 Feb 24, 2004 14:30 5 3 wet Funnel 11 Newman rain gage at wasteway levee near Draper Road 371735121031201 Feb 24, 2004 14:30 Feb 27, 2004 14:50 3 3 wet Funnel 12 Turlock rain gage near Idaho Road 372713120534901 Jan 25, 2002 12:00 Jan 29, 2002 12:00 4 3 wet Funnel 12 Turlock rain gage near Idaho Road 372713120534901 Feb 7, 2002 09:30 Feb 9, 2002 13:00 2 2 wet Funnel 12 Turlock rain gage near Idaho Road 372713120534901 Feb 15, 2002 14:15 Feb 18, 2002 11:00 3 2 wet Funnel 12 Turlock rain gage near Idaho Road 372713120534901 Mar 5, 2002 16:00 Mar 8, 2002 10:45 3 2 wet Funnel

12 Turlock rain gage near Idaho Road 372713120534901 Mar 9, 2002 14:20 Mar 11, 2002 09:30 2 1 wet Funnel

12 Turlock rain gage near Idaho Road 372713120534901 Mar 17, 2002 07:00 Mar 18, 2002 13:00 1 1 wet Funnel

12 Turlock rain gage near Idaho Road 372713120534901 Mar 22, 2002 10:00 Mar 24, 2002 08:30 2 1 wet Funnel

12 Turlock rain gage near Idaho Road 372713120534901 Nov 7, 2002 02:00 Nov 10, 2002 03:00 3 2 wet Funnel

12 Turlock rain gage near Idaho Road 372713120534901 Dec 9, 2002 11:15 Dec 16, 2002 10:50 7 5 wet Funnel

12 Turlock rain gage near Idaho Road 372713120534901 Dec 16, 2002 10:40 Dec 22, 2002 13:30 6 6 wet Funnel

12 Turlock rain gage near Idaho Road 372713120534901 Jan 8, 2003 14:40 Jan 14, 2003 11:00 6 1 wet Funnel

12 Turlock rain gage near Idaho Road 372713120534901 Feb 14, 2003 09:20 Feb 21, 2003 11:00 7 3 wet Funnel

12 Turlock rain gage near Idaho Road 372713120534901 Mar 13, 2003 11:00 Mar 18, 2003 11:00 5 3 wet Funnel

12 Turlock rain gage near Idaho Road 372713120534901 Mar 18, 2003 11:00 Mar 27, 2003 11:20 9 2 wet Funnel

Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 

2002–04 study period at eight sites in the Central Valley, California.
Appendix 3 75

Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 

2002–04 study period at eight sites in the Central Valley, California.—Continued

[All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler (AS)= 0.0614 m2) and sample composite time in days. Abbreviations: E, estimated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, 

hour:minute; –, compound not detected; [-], no Chemical Abstract Service Number available for given compound]

Site 

number Site name

Site 

identification 

number

Start date

Start 

time

(hh:mm)

End date

End 

time

(hh:mm)

Composite 

sample 

time, 

days

Rain events 

during 

composite 

sample time, 

days

Sample 

type

Sampler 

type

12 Turlock rain gage near Idaho Road 372713120534901 Apr 29, 2003 10:30 May 9, 2003 17:00 10 3 wet Funnel

12 Turlock rain gage near Idaho Road 372713120534901 Nov 5, 2003 11:30 Nov 10, 2003 11:10 5 4 wet Funnel

12 Turlock rain gage near Idaho Road 372713120534901 Jan 29, 2004 13:00 Feb 4, 2004 11:30 6 2 wet Funnel

12 Turlock rain gage near Idaho Road 372713120534901 Feb 4, 2004 11:30 Feb 19, 2004 11:50 15 5 wet Funnel

12 Turlock rain gage near Idaho Road 372713120534901 Feb 19, 2004 11:50 Feb 24, 2004 13:40 5 3 wet Funnel

12 Turlock rain gage near Idaho Road 372713120534901 Feb 24, 2004 13:40 Feb 27, 2004 14:00 3 3 wet Funnel

12 Turlock rain gage near Idaho Road 372713120534901 Mar 25, 2004 13:35 Mar 26, 2004 13:45 1 1 wet Funnel

13 Turlock Airport rain gage 372857120414001 Jan 25, 2002 12:00 Jan 29, 2002 09:40 4 3 wet Funnel

13 Turlock Airport rain gage 372857120414001 Feb 6, 2002 15:40 Feb 11, 2002 10:55 5 2 wet Funnel

13 Turlock Airport rain gage 372857120414001 Feb 15, 2002 12:00 Feb 18, 2002 13:50 3 2 wet Funnel

13 Turlock Airport rain gage 372857120414001 Mar 5, 2002 11:30 Mar 8, 2002 11:15 3 2 wet Funnel

13 Turlock Airport rain gage 372857120414001 Mar 8, 2002 11:15 Mar 11, 2002 11:25 3 2 wet Funnel

13 Turlock Airport rain gage 372857120414001 Mar 15, 2002 12:00 Mar 19, 2002 12:00 4 3 wet Funnel

13 Turlock Airport rain gage 372857120414001 Mar 22, 2002 10:30 Mar 24, 2002 10:30 2 1 wet Funnel

13 Turlock Airport rain gage 372857120414001 Nov 7, 2002 02:00 Nov 10, 2002 03:00 3 2 wet Funnel

13 Turlock Airport rain gage 372857120414001 Dec 9, 2002 12:00 Dec 16, 2002 11:30 7 5 wet Funnel

13 Turlock Airport rain gage 372857120414001 Dec 16, 2002 11:30 Dec 22, 2002 14:00 6 6 wet Funnel

13 Turlock Airport rain gage 372857120414001 Jan 9, 2003 13:50 Jan 14, 2003 11:40 5 1 wet Funnel

13 Turlock Airport rain gage 372857120414001 Feb 12, 2003 08:00 Feb 14, 2003 10:15 2 2 wet Funnel

13 Turlock Airport rain gage 372857120414001 Feb 14, 2003 10:00 Feb 21, 2003 11:40 7 3 wet Funnel

13 Turlock Airport rain gage 372857120414001 Mar 12, 2003 10:00 Mar 18, 2003 11:50 6 3 wet Funnel

13 Turlock Airport rain gage 372857120414001 Apr 26, 2003 13:00 Apr 29, 2003 11:15 3 1 wet Funnel

13 Turlock Airport rain gage 372857120414001 Apr 29, 2003 11:15 May 5, 2003 10:40 6 3 wet Funnel

13 Turlock Airport rain gage 372857120414001 Nov 5, 2003 12:10 Nov 10, 2003 11:40 5 4 wet Funnel

13 Turlock Airport rain gage 372857120414001 Jan 29, 2004 12:00 Feb 4, 2004 10:30 6 2 wet Funnel

13 Turlock Airport rain gage 372857120414001 Feb 19, 2004 10:10 Feb 24, 2004 11:40 5 3 wet Funnel

13 Turlock Airport rain gage 372857120414001 Feb 24, 2004 11:40 Feb 27, 2004 10:40 3 3 wet Funnel

13 Turlock Airport rain gage 372857120414001 Mar 25, 2004 12:30 Mar 26, 2004 13:00 1 1 wet Funnel
76 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 2002–04 study period at eight sites in the Central Valley, California.—Continued [All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler (AS)= 0.0614 m2) and sample composite time in days. Abbrevia- tions: E, estimated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; –, compound not detected; [-], no Chemical Abstract Service Number available for given compound] Site number Site name Site identification number Start date Start time (hh:mm) End date End time (hh:mm) Composite sample time, days Rain events during composite sample time, days Sample type Sampler type 10 Westley rain gage at pump building near lateral 6 North 373335121143001 Jan 25, 2002 09:45 Jan 29, 2002 11:20 4 3 wet Funnel 10 Westley rain gage at pump building near lateral 6 North 373335121143001 Feb 15, 2002 10:30 Feb 18, 2002 11:45 3 2 wet Funnel 10 Westley rain gage at pump building near lateral 6 North 373335121143001 Mar 5, 2002 09:30 Mar 8, 2002 09:30 3 2 wet Funnel 10 Westley rain gage at pump building near lateral 6 North 373335121143001 Mar 8, 2002 09:30 Mar 11, 2002 09:45 3 2 wet Funnel 10 Westley rain gage at pump building near lateral 6 North 373335121143001 Mar 15, 2002 09:30 Mar 19, 2002 09:30 4 3 wet Funnel 10 Westley rain gage at pump building near lateral 6 North 373335121143001 Mar 22, 2002 08:45 Mar 24, 2002 12:45 2 1 wet Funnel 10 Westley rain gage at pump building near lateral 6 North 373335121143001 Nov 7, 2002 02:00 Nov 10, 2002 03:00 3 2 wet Funnel 10 Westley rain gage at pump building near lateral 6 North 373335121143001 Dec 9, 2002 09:15 Dec 16, 2002 09:00 7 5 wet Funnel 10 Westley rain gage at pump building near lateral 6 North 373335121143001 Dec 16, 2002 09:00 Dec 22, 2002 12:00 6 6 wet Funnel 10 Westley rain gage at pump building near lateral 6 North 373335121143001 Jan 8, 2003 13:15 Jan 14, 2003 09:20 6 1 wet Funnel 10 Westley rain gage at pump building near lateral 6 North 373335121143001 Feb 15, 2003 11:45 Mar 1, 2003 11:00 14 4 wet Funnel 10 Westley rain gage at pump building near lateral 6 North 373335121143001 Mar 13, 2003 09:30 Mar 18, 2003 09:30 5 3 wet Funnel 10 Westley rain gage at pump building near lateral 6 North 373335121143001 Nov 6, 2003 12:30 Nov 11, 2003 10:30 5 4 wet Funnel 10 Westley rain gage at pump building near lateral 6 North 373335121143001 Feb 19, 2004 14:30 Feb 24, 2004 15:30 5 3 wet Funnel 10 Westley rain gage at pump building near lateral 6 North 373335121143001 Feb 24, 2004 15:30 Feb 27, 2004 16:00 3 3 wet Funnel

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Jan 25, 2002 12:00 Jan 29, 2002 14:00 4 3 wet AS

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Feb 7, 2002 14:00 Feb 11, 2002 12:50 4 2 wet AS

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Mar 5, 2002 13:00 Mar 8, 2002 12:30 3 2 wet AS

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Mar 8, 2002 12:30 Mar 11, 2002 12:30 3 2 wet AS

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Mar 15, 2002 11:00 Mar 19, 2002 12:30 4 3 wet AS

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Mar 22, 2002 12:00 Mar 24, 2002 09:45 2 1 wet AS

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Apr 9, 2002 10:30 May 21, 2002 13:20 42 6 wet AS

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Nov 7, 2002 02:00 Nov 10, 2002 03:00 3 2 wet Funnel

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Nov 7, 2002 02:00 Nov 10, 2002 03:05 3 2 wet AS

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Dec 9, 2002 14:00 Dec 16, 2002 12:50 7 5 wet Funnel

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Dec 9, 2002 14:00 Dec 16, 2002 13:00 7 5 wet AS

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Dec 16, 2002 12:50 Dec 23, 2002 09:30 7 6 wet Funnel

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Dec 16, 2002 12:50 Dec 23, 2002 09:40 7 6 wet AS

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Dec 23, 2002 09:30 Jan 9, 2003 15:40 17 6 wet AS

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Jan 9, 2003 15:30 Jan 14, 2003 10:20 5 1 wet Funnel
Appendix 3 77

Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 

2002–04 study period at eight sites in the Central Valley, California.—Continued

[All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler (AS)= 0.0614 m2) and sample composite time in days. Abbreviations: E, estimated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, 

hour:minute; –, compound not detected; [-], no Chemical Abstract Service Number available for given compound]

Site 

number Site name

Site 

identification 

number

Start date

Start 

time

(hh:mm)

End date

End 

time

(hh:mm)

Composite 

sample 

time, 

days

Rain events 

during 

composite 

sample time, 

days

Sample 

type

Sampler 

type

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Jan 9, 2003 15:30 Jan 14, 2003 10:30 5 1 wet AS

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Jan 14, 2003 10:30 Feb 14, 2003 14:10 31 6 wet AS

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Feb 14, 2003 14:00 Feb 21, 2003 14:40 7 3 wet Funnel

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Feb 14, 2003 14:10 Feb 21, 2003 14:30 7 3 wet AS

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Mar 13, 2003 11:40 Mar 18, 2003 16:15 5 3 wet Funnel

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Mar 13, 2003 11:40 Mar 18, 2003 16:25 5 3 wet AS

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Mar 18, 2003 16:25 Mar 27, 2003 15:00 9 2 wet AS

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Mar 27, 2003 15:00 Apr 8, 2003 13:15 12 3 wet AS

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Apr 29, 2003 14:30 May 5, 2003 09:15 6 3 wet Funnel

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Nov 5, 2003 14:20 Nov 10, 2003 13:15 5 4 wet AS

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Dec 11, 2003 13:00 Dec 16, 2003 15:30 5 5 wet AS

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Dec 11, 2003 13:10 Dec 16, 2003 15:40 5 5 wet Funnel

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Dec 16, 2003 15:40 Dec 23, 2003 13:00 7 3 wet Funnel

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Dec 23, 2003 13:00 Dec 31, 2003 09:30 8 5 wet Funnel

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Dec 31, 2003 09:30 Jan 6, 2004 08:40 6 3 wet Funnel

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Jan 29, 2004 09:55 Feb 4, 2004 08:00 6 2 wet Funnel

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Jan 29, 2004 10:00 Feb 4, 2004 08:10 6 2 wet AS

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Feb 19, 2004 08:10 Feb 24, 2004 09:10 5 3 wet Funnel

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Feb 24, 2004 09:10 Feb 27, 2004 09:15 3 3 wet Funnel

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Mar 25, 2004 10:00 Mar 26, 2004 10:20 1 1 wet Funnel

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Jan 25, 2002 12:00 Jan 29, 2002 13:15 4 3 wet AS

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Feb 7, 2002 13:00 Feb 11, 2002 12:15 4 2 wet AS

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Feb 15, 2002 15:40 Feb 18, 2002 14:25 3 2 wet AS

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Mar 5, 2002 12:00 Mar 8, 2002 11:45 3 2 wet AS

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Mar 8, 2002 11:45 Mar 11, 2002 12:00 3 2 wet AS

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Mar 22, 2002 11:00 Mar 24, 2002 10:30 2 1 wet AS

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Nov 7, 2002 02:00 Nov 10, 2002 03:00 3 2 wet Funnel

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Nov 7, 2002 02:00 Nov 10, 2002 03:05 3 2 wet AS

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Dec 9, 2002 12:15 Dec 16, 2002 12:00 7 5 wet Funnel

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Dec 9, 2002 12:15 Dec 16, 2002 12:10 7 5 wet AS
78 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 2002–04 study period at eight sites in the Central Valley, California.—Continued [All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler (AS)= 0.0614 m2) and sample composite time in days. Abbrevia- tions: E, estimated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; –, compound not detected; [-], no Chemical Abstract Service Number available for given compound] Site number Site name Site identification number Start date Start time (hh:mm) End date End time (hh:mm) Composite sample time, days Rain events during composite sample time, days Sample type Sampler type

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Dec 16, 2002 12:00 Dec 23, 2002 10:20 6 6 wet Funnel

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Dec 16, 2002 12:00 Dec 23, 2002 10:30 7 6 wet AS

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Dec 23, 2002 10:30 Jan 9, 2003 14:20 17 6 wet AS

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Jan 9, 2003 14:30 Jan 14, 2003 11:30 5 1 wet Funnel

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Jan 9, 2003 14:30 Jan 14, 2003 11:40 5 1 wet AS

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Jan 14, 2003 11:40 Feb 14, 2003 13:00 31 6 wet AS

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Feb 14, 2003 12:50 Feb 21, 2003 13:20 7 3 wet Funnel

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Feb 14, 2003 13:00 Feb 21, 2003 13:15 7 3 wet AS

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Mar 12, 2003 14:00 Mar 18, 2003 14:50 6 3 wet Funnel

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Mar 12, 2003 14:00 Mar 18, 2003 15:10 6 3 wet AS

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Mar 18, 2003 15:10 Apr 8, 2003 12:10 21 5 wet AS

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Apr 8, 2003 13:00 Apr 29, 2003 13:40 21 4 wet AS

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Apr 29, 2003 13:30 May 9, 2003 17:45 10 3 wet Funnel

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Apr 29, 2003 13:40 May 9, 2003 17:50 10 3 wet AS

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Nov 5, 2003 13:30 Nov 10, 2003 12:20 5 4 wet Funnel

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Nov 5, 2003 13:40 Nov 10, 2003 12:30 5 4 wet AS

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Dec 11, 2003 14:05 Dec 16, 2003 14:40 5 2 wet Funnel

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Dec 11, 2003 14:10 Dec 16, 2003 14:35 5 2 wet AS

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Dec 16, 2003 14:40 Dec 23, 2003 13:00 7 1 wet Funnel

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Dec 23, 2003 13:00 Dec 31, 2003 10:30 8 5 wet Funnel

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Dec 31, 2003 10:30 Jan 6, 2004 09:35 6 3 wet Funnel

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Jan 29, 2004 10:50 Feb 4, 2004 09:10 6 2 wet Funnel

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Jan 29, 2004 11:00 Feb 4, 2004 09:20 6 2 wet AS

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Feb 4, 2004 09:10 Feb 19, 2004 09:20 15 5 wet Funnel

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Feb 19, 2004 09:10 Feb 24, 2004 10:30 5 3 wet Funnel

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Feb 24, 2004 10:30 Feb 27, 2004 09:55 3 3 wet Funnel

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Mar 25, 2004 11:00 Mar 26, 2004 11:00 1 1 wet Funnel

16 Gridley High School precipitation gage at Gridley 392205121410201 Feb 7, 2003 09:15 Feb 14, 2003 11:50 7 2 wet Funnel

16 Gridley High School precipitation gage at Gridley 392205121410201 Feb 7, 2003 09:45 Feb 14, 2003 12:00 7 2 wet AS

16 Gridley High School precipitation gage at Gridley 392205121410201 Feb 14, 2003 11:50 Feb 20, 2003 14:00 6 3 wet Funnel
Appendix 3 79

Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 

2002–04 study period at eight sites in the Central Valley, California.—Continued

[All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler (AS)= 0.0614 m2) and sample composite time in days. Abbreviations: E, estimated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, 

hour:minute; –, compound not detected; [-], no Chemical Abstract Service Number available for given compound]

Site 

number Site name

Site 

identification 

number

Start date

Start 

time

(hh:mm)

End date

End 

time

(hh:mm)

Composite 

sample 

time, 

days

Rain events 

during 

composite 

sample time, 

days

Sample 

type

Sampler 

type

16 Gridley High School precipitation gage at Gridley 392205121410201 Feb 14, 2003 11:50 Feb 20, 2003 14:10 6 3 wet AS

16 Gridley High School precipitation gage at Gridley 392205121410201 Mar 11, 2003 11:40 Mar 19, 2003 10:00 8 5 wet AS

16 Gridley High School precipitation gage at Gridley 392205121410201 Mar 11, 2003 11:40 Mar 19, 2003 10:10 8 5 wet Funnel

16 Gridley High School precipitation gage at Gridley 392205121410201 Apr 9, 2003 14:00 Apr 28, 2003 12:10 19 11 wet Funnel16 Gridley High School precipitation gage at Gridley 392205121410201 Apr 28, 2003 12:10 May 9, 2003 10:30 11 6 wet Funnel

16 Gridley High School precipitation gage at Gridley 392205121410201 Apr 28, 2003 12:10 May 9, 2003 10:40 11 6 wet AS

16 Gridley High School precipitation gage at Gridley 392205121410201 Nov 4, 2003 10:00 Nov 12, 2003 10:15 8 3 wet AS

16 Gridley High School precipitation gage at Gridley 392205121410201 Nov 12, 2003 10:15 Nov 17, 2003 12:00 5 2 wet AS

16 Gridley High School precipitation gage at Gridley 392205121410201 Nov 17, 2003 12:00 Dec 3, 2003 12:40 16 4 wet AS

16 Gridley High School precipitation gage at Gridley 392205121410201 Dec 3, 2003 12:40 Dec 12, 2003 11:10 9 7 wet AS

16 Gridley High School precipitation gage at Gridley 392205121410201 Dec 3, 2003 12:50 Dec 12, 2003 11:20 9 7 wet Funnel

16 Gridley High School precipitation gage at Gridley 392205121410201 Dec 12, 2003 11:10 Dec 18, 2003 10:20 6 3 wet AS

16 Gridley High School precipitation gage at Gridley 392205121410201 Dec 12, 2003 11:20 Dec 18, 2003 10:30 6 3 wet Funnel

16 Gridley High School precipitation gage at Gridley 392205121410201 Dec 18, 2003 10:30 Dec 23, 2003 08:10 5 3 wet Funnel

16 Gridley High School precipitation gage at Gridley 392205121410201 Dec 23, 2003 08:10 Dec 30, 2003 09:40 7 5 wet Funnel

16 Gridley High School precipitation gage at Gridley 392205121410201 Dec 30, 2003 09:40 Jan 7, 2004 11:00 8 7 wet Funnel

16 Gridley High School precipitation gage at Gridley 392205121410201 Jan 27, 2004 10:00 Jan 30, 2004 09:30 3 3 wet Funnel

16 Gridley High School precipitation gage at Gridley 392205121410201 Jan 27, 2004 10:10 Jan 30, 2004 09:40 3 3 wet AS

16 Gridley High School precipitation gage at Gridley 392205121410201 Jan 30, 2004 09:30 Feb 6, 2004 10:20 7 4 wet Funnel

16 Gridley High School precipitation gage at Gridley 392205121410201 Jan 30, 2004 09:40 Feb 6, 2004 10:10 7 4 wet AS

16 Gridley High School precipitation gage at Gridley 392205121410201 Feb 6, 2004 10:20 Feb 17, 2004 14:00 11 3 wet Funnel

16 Gridley High School precipitation gage at Gridley 392205121410201 Feb 17, 2004 14:00 Feb 20, 2004 10:30 3 2 wet Funnel

16 Gridley High School precipitation gage at Gridley 392205121410201 Feb 20, 2004 10:30 Mar 2, 2004 10:40 11 7 wet Funnel

15 Oroville Dam precipitation gage at spillway 393234121292701 Dec 19, 2002 11:00 Dec 23, 2002 10:30 4 4 wet Funnel

15 Oroville Dam precipitation gage at spillway 393234121292701 Jan 7, 2003 10:30 Jan 13, 2003 09:50 6 5 wet Funnel

15 Oroville Dam precipitation gage at spillway 393234121292701 Jan 23, 2003 11:30 Jan 31, 2003 12:45 8 4 wet Funnel

15 Oroville Dam precipitation gage at spillway 393234121292701 Feb 14, 2003 10:30 Feb 20, 2003 15:20 6 3 wet Funnel

15 Oroville Dam precipitation gage at spillway 393234121292701 Mar 11, 2003 11:40 Mar 19, 2003 11:00 8 5 wet Funnel

15 Oroville Dam precipitation gage at spillway 393234121292701 Apr 9, 2003 12:30 Apr 28, 2003 13:10 19 11 wet Funnel

15 Oroville Dam precipitation gage at spillway 393234121292701 Apr 28, 2003 13:10 May 9, 2003 13:10 11 6 wet Funnel
80 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 2002–04 study period at eight sites in the Central Valley, California.—Continued [All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler (AS)= 0.0614 m2) and sample composite time in days. Abbrevia- tions: E, estimated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; –, compound not detected; [-], no Chemical Abstract Service Number available for given compound] Site number Site name Site identification number Start date Start time (hh:mm) End date End time (hh:mm) Composite sample time, days Rain events during composite sample time, days Sample type Sampler type 15 Oroville Dam precipitation gage at spillway 393234121292701 Dec 3, 2003 12:00 Dec 18, 2003 11:40 15 9 wet Funnel 15 Oroville Dam precipitation gage at spillway 393234121292701 Dec 30, 2003 10:40 Jan 7, 2004 12:30 8 7 wet Funnel 15 Oroville Dam precipitation gage at spillway 393234121292701 Jan 27, 2004 11:15 Jan 30, 2004 10:40 3 3 wet Funnel 15 Oroville Dam precipitation gage at spillway 393234121292701 Jan 30, 2004 10:40 Feb 6, 2004 11:50 7 4 wet Funnel 15 Oroville Dam precipitation gage at spillway 393234121292701 Feb 17, 2004 15:00 Feb 20, 2004 11:30 3 2 wet Funnel 15 Oroville Dam precipitation gage at spillway 393234121292701 Feb 20, 2004 11:30 Mar 2, 2004 11:40 11 7 wet Funnel
Appendix 3 81

Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 

2002–04 study period at eight sites in the Central Valley, California.—Continued

[All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: 

E, estimated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; –, compound not detected; [-], no Chemical Abstract Service Number available for given compound]

Site 

number Site name

Site 

identification 

number

Total sample 

volume collected, liters

 1,4-Naphthoquinone 

[130-15-4]

(61611)

 1-Naphthol 

(E) 

[90-15-3]

(49295)

 2-(4-tertButylphenoxy)-cyclo-hexanol

[1942-71-8]

(61637)

 3,4-

Dichloroaniline (E)

[95-76-1]

(61625)

 3,5-

Dichloroaniline

[626-43-7]

(61627)

 4,4'-

Dichlorobenzo-phenone

[90-98-2]

(61631)

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 0.323 E0.13 – – – – –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 0.339 E0.02 – – – – –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 0.294 – – – – – –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 0.895 – – – – – –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 0.316 – – – – – –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 3.52 na – na – na na

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 2.225 na – na – na na

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 3 na – na E0.096 na na11 Newman rain gage at wasteway levee near Draper Road 371735121031201 0.87 na – na E0.155 na na

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 1.39 na – na – na na

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 0.32 na – na – na na

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 0.52 na – na – na na

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 1 na E0.02 na E0.062 na na

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 3.1 na – na E0.17 na na

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 0.16 na – na E0.052 na na

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 2.2 na – na – na na

12 Turlock rain gage near Idaho Road 372713120534901 0.855 E0.08 – – – – –

12 Turlock rain gage near Idaho Road 372713120534901 0.241 E0.05 – – – – –

12 Turlock rain gage near Idaho Road 372713120534901 0.636 E0.02 – 0.04 – – –12 Turlock rain gage near Idaho Road 372713120534901 0.394 – – – – – –

12 Turlock rain gage near Idaho Road 372713120534901 0.419 – – – – – –

12 Turlock rain gage near Idaho Road 372713120534901 0.779 E0.11 – – – – –

12 Turlock rain gage near Idaho Road 372713120534901 0.465 – – – – – –

12 Turlock rain gage near Idaho Road 372713120534901 2.78 na – na – na na

12 Turlock rain gage near Idaho Road 372713120534901 3.6 na – na – na na

12 Turlock rain gage near Idaho Road 372713120534901 1.8 na – na E0.057 na na12 Turlock rain gage near Idaho Road 372713120534901 1.32 na – na E0.271 na na12 Turlock rain gage near Idaho Road 372713120534901 0.44 na E0.04 na – na na12 Turlock rain gage near Idaho Road 372713120534901 1.6 na – na – na na
82 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 2002–04 study period at eight sites in the Central Valley, California.—Continued [All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: E, estimated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; –, compound not detected; [-], no Chemical Abstract Service Number available for given compound] Site number Site name Site identification number Total sample volume col- lected, liters 1,4-Naphtho- quinone [130-15-4] (61611) 1-Naphthol (E) [90-15-3] (49295) 2-(4-tert- Butyl- phenoxy)-cy- clo-hexanol [1942-71-8] (61637) 3,4- Dichloro- aniline (E) [95-76-1] (61625) 3,5- Dichloro- aniline [626-43-7] (61627) 4,4'- Dichloro- benzo-phe- none [90-98-2] (61631) 12 Turlock rain gage near Idaho Road 372713120534901 0.4 na E0.03 na – na na 12 Turlock rain gage near Idaho Road 372713120534901 0.61 na E0.03 na – na na 12 Turlock rain gage near Idaho Road 372713120534901 0.66 na – na – na na 12 Turlock rain gage near Idaho Road 372713120534901 1.34 na E0.04 na – na na 12 Turlock rain gage near Idaho Road 372713120534901 2 na E0.03 na E0.049 na na 12 Turlock rain gage near Idaho Road 372713120534901 0.165 na E0.02 na E0.010 na na 12 Turlock rain gage near Idaho Road 372713120534901 1.28 na – na – na na 12 Turlock rain gage near Idaho Road 372713120534901 0.22 na – na E0.057 na na 13 Turlock Airport rain gage 372857120414001 1.958 E0.18 – – – – – 13 Turlock Airport rain gage 372857120414001 0.24 E0.03 – – – – – 13 Turlock Airport rain gage 372857120414001 0.692 E0.05 – – – – – 13 Turlock Airport rain gage 372857120414001 0.698 – – – – 0.057 – 13 Turlock Airport rain gage 372857120414001 0.312 – – – – 0.030 – 13 Turlock Airport rain gage 372857120414001 0.52 – – – – 0.014 – 13 Turlock Airport rain gage 372857120414001 0.239 – – – – – – 13 Turlock Airport rain gage 372857120414001 4.12 na – na – na na 13 Turlock Airport rain gage 372857120414001 3.88 na – na – na na 13 Turlock Airport rain gage 372857120414001 1.5 na – na – na na 13 Turlock Airport rain gage 372857120414001 1.2 na – na E0.099 na na

13 Turlock Airport rain gage 372857120414001 0.29 na – na E0.048 na na13 Turlock Airport rain gage 372857120414001 0.42 na E0.02 na – na na13 Turlock Airport rain gage 372857120414001 1.59 na – na – na na

13 Turlock Airport rain gage 372857120414001 0.78 na E0.11 na – na na

13 Turlock Airport rain gage 372857120414001 1.075 na – na – na na

13 Turlock Airport rain gage 372857120414001 0.715 na – na E0.029 na na13 Turlock Airport rain gage 372857120414001 1.39 na – na – na na

13 Turlock Airport rain gage 372857120414001 0.465 na E0.02 na E0.013 na na

13 Turlock Airport rain gage 372857120414001 2.22 na – na – na na

13 Turlock Airport rain gage 372857120414001 0.85 na E0.12 na E0.105 na na
Appendix 3 83

Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 

2002–04 study period at eight sites in the Central Valley, California.—Continued

[All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: 

E, estimated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; –, compound not detected; [-], no Chemical Abstract Service Number available for given compound]

Site 

number Site name

Site 

identification 

number

Total sample 

volume collected, liters

 1,4-Naphthoquinone 

[130-15-4]

(61611)

 1-Naphthol 

(E) 

[90-15-3]

(49295)

 2-(4-tertButylphenoxy)-cyclo-hexanol

[1942-71-8]

(61637)

 3,4-

Dichloroaniline (E)

[95-76-1]

(61625)

 3,5-

Dichloroaniline

[626-43-7]

(61627)

 4,4'-

Dichlorobenzo-phenone

[90-98-2]

(61631)

10 Westley rain gage at pump building near lateral 6 North 373335121143001 0.371 E0.05 – 0.03 – – –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 0.759 E0.05 – – – – –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 0.152 – – – – 0.061 –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 0.205 – – – – 0.041 E0.006

10 Westley rain gage at pump building near lateral 6 North 373335121143001 1.125 – – – – E0.02 –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 0.616 – – – – 0.051 E0.025

10 Westley rain gage at pump building near lateral 6 North 373335121143001 3.08 na – na – na na

10 Westley rain gage at pump building near lateral 6 North 373335121143001 2.94 na – na E0.040 na na

10 Westley rain gage at pump building near lateral 6 North 373335121143001 1.82 na – na – na na

10 Westley rain gage at pump building near lateral 6 North 373335121143001 0.68 na – na E0.214 na na

10 Westley rain gage at pump building near lateral 6 North 373335121143001 1.06 na – na – na na

10 Westley rain gage at pump building near lateral 6 North 373335121143001 1.76 na – na – na na

10 Westley rain gage at pump building near lateral 6 North 373335121143001 2.53 na – na – na na

10 Westley rain gage at pump building near lateral 6 North 373335121143001 0.12 na – na E0.041 na na

10 Westley rain gage at pump building near lateral 6 North 373335121143001 2.52 na – na – na na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.346 E0.06 – 0.06 – – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.212 E0.02 – – – – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.331 – – – E0.024 – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.571 na na na na na na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.719 – – – – – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.614 – – – – – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.21 – – – – – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 4.1 na E0.28 na – na na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 3.39 na – na – na na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 4 na – na – na na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 3.6 na – na – na na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 1.9 na – na – na na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 1.64 na – na – na na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.58 na E0.03 na E0.027 na na
84 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 2002–04 study period at eight sites in the Central Valley, California.—Continued [All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: E, estimated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; –, compound not detected; [-], no Chemical Abstract Service Number available for given compound] Site number Site name Site identification number Total sample volume col- lected, liters 1,4-Naphtho- quinone [130-15-4] (61611) 1-Naphthol (E) [90-15-3] (49295) 2-(4-tert- Butyl- phenoxy)-cy- clo-hexanol [1942-71-8] (61637) 3,4- Dichloro- aniline (E) [95-76-1] (61625) 3,5- Dichloro- aniline [626-43-7] (61627) 4,4'- Dichloro- benzo-phe- none [90-98-2] (61631)

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.91 na E0.37 na E0.212 na na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.66 na – na – na na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.56 na – na E0.035 na na4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.62 na E0.06 na – na na4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.54 na E0.03 na – na na4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 2.24 na E0.1 na – na na4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 1.8 na – na – na na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.35 na – na – na na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.62 na E0.03 na – na na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.56 na – na – na na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.9 na – na – na na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.37 na – na E0.099 na na4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.81 na – na E0.053 na na4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 2.81 na – na – na na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 2.81 na – na – na na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 1.115 na – na – na na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 1.4 na E0.04 na – na na4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 1.26 na – na – na na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.3 na E0.01 na E0.025 na na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 2.39 na E0.04 na – na na4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.3 na E0.08 na E0.119 na na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 1.184 E0.19 – – – – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.229 E0.06 – – – – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.781 E0.06 – – – – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.15 – – – – 0.094 –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.347 – – – E0.051 0.045 –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.375 – – – – 0.073 –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 4.18 na – na – na na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 3.6 na – na – na na
Appendix 3 85

Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 

2002–04 study period at eight sites in the Central Valley, California.—Continued

[All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: 

E, estimated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; –, compound not detected; [-], no Chemical Abstract Service Number available for given compound]

Site 

number Site name

Site 

identification 

number

Total sample 

volume collected, liters

 1,4-Naphthoquinone 

[130-15-4]

(61611)

 1-Naphthol 

(E) 

[90-15-3]

(49295)

 2-(4-tertButylphenoxy)-cyclo-hexanol

[1942-71-8]

(61637)

 3,4-

Dichloroaniline (E)

[95-76-1]

(61625)

 3,5-

Dichloroaniline

[626-43-7]

(61627)

 4,4'-

Dichlorobenzo-phenone

[90-98-2]

(61631)

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 4 na – na E0.219 na na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 3.25 na – na E0.074 na na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 1.9 na – na E0.121 na na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 1.44 na – na E0.070 na na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.7 na – na E0.245 na na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 1.2 na – na E1.215 na na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.86 na – na 0.532 na na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.34 na – na – na na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.42 na – na E0.038 na na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.25 na – na – na na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 1.61 na – na E0.066 na na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 1.42 na – na – na na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 1.4 na – na – na na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 1.64 na – na – na na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.71 na – na – na na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.38 na – na – na na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.64 na – na E0.024 na na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.82 na – na – na na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.76 na – na E0.114 na na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.67 na – na – na na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.89 na – na – na na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 2.82 na – na – na na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.24 na – na – na na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.98 na – na E0.255 na na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.67 na – na E0.142 na na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 1.7 na E0.02 na E0.745 na na5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.42 na E0.02 na E0.556 na na5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 1.5 na – na E0.068 na na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.82 na E0.11 na E0.247 na na
86 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 2002–04 study period at eight sites in the Central Valley, California.—Continued [All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: E, estimated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; –, compound not detected; [-], no Chemical Abstract Service Number available for given compound] Site number Site name Site identification number Total sample volume col- lected, liters 1,4-Naphtho- quinone [130-15-4] (61611) 1-Naphthol (E) [90-15-3] (49295) 2-(4-tert- Butyl- phenoxy)-cy- clo-hexanol [1942-71-8] (61637) 3,4- Dichloro- aniline (E) [95-76-1] (61625) 3,5- Dichloro- aniline [626-43-7] (61627) 4,4'- Dichloro- benzo-phe- none [90-98-2] (61631) 16 Gridley High School precipitation gage at Gridley 392205121410201 4 na E0.55 na – na na 16 Gridley High School precipitation gage at Gridley 392205121410201 4 na – na – na na 16 Gridley High School precipitation gage at Gridley 392205121410201 2.56 na E0.12 na – na na 16 Gridley High School precipitation gage at Gridley 392205121410201 1.16 na – na – na na 16 Gridley High School precipitation gage at Gridley 392205121410201 0.85 na E0.03 na – na na 16 Gridley High School precipitation gage at Gridley 392205121410201 2.96 na E0.08 na – na na 16 Gridley High School precipitation gage at Gridley 392205121410201 4.24 na E0.05 na – na na 16 Gridley High School precipitation gage at Gridley 392205121410201 3.7 na E0.08 na – na na 16 Gridley High School precipitation gage at Gridley 392205121410201 1.09 na – na – na na 16 Gridley High School precipitation gage at Gridley 392205121410201 2.05 na – na – na na 16 Gridley High School precipitation gage at Gridley 392205121410201 0.43 na – na E0.039 na na 16 Gridley High School precipitation gage at Gridley 392205121410201 1.67 na – na – na na 16 Gridley High School precipitation gage at Gridley 392205121410201 2.13 na – na – na na 16 Gridley High School precipitation gage at Gridley 392205121410201 3.885 na – na E0.046 na na 16 Gridley High School precipitation gage at Gridley 392205121410201 0.57 na – na – na na 16 Gridley High School precipitation gage at Gridley 392205121410201 1.19 na E0.02 na – na na 16 Gridley High School precipitation gage at Gridley 392205121410201 1.72 na – na – na na 16 Gridley High School precipitation gage at Gridley 392205121410201 4.3 na – na – na na 16 Gridley High School precipitation gage at Gridley 392205121410201 4.03 na – na – na na 16 Gridley High School precipitation gage at Gridley 392205121410201 0.75 na – na E0.017 na na

16 Gridley High School precipitation gage at Gridley 392205121410201 0.48 na – na E0.013 na na16 Gridley High School precipitation gage at Gridley 392205121410201 1.43 na E0.02 na – na na16 Gridley High School precipitation gage at Gridley 392205121410201 1.42 na E0.02 na – na na

16 Gridley High School precipitation gage at Gridley 392205121410201 3.4 na E0.06 na – na na16 Gridley High School precipitation gage at Gridley 392205121410201 3.1 na – na – na na

16 Gridley High School precipitation gage at Gridley 392205121410201 4.28 na – na – na na

15 Oroville Dam precipitation gage at spillway 393234121292701 4 na – na – na na

15 Oroville Dam precipitation gage at spillway 393234121292701 4 na – na – na na

15 Oroville Dam precipitation gage at spillway 393234121292701 0.38 na E0.03 na – na na
Appendix 3 87

Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 

2002–04 study period at eight sites in the Central Valley, California.—Continued

[All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: 

E, estimated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; –, compound not detected; [-], no Chemical Abstract Service Number available for given compound]

Site 

number Site name

Site 

identification 

number

Total sample 

volume collected, liters

 1,4-Naphthoquinone 

[130-15-4]

(61611)

 1-Naphthol 

(E) 

[90-15-3]

(49295)

 2-(4-tertButylphenoxy)-cyclo-hexanol

[1942-71-8]

(61637)

 3,4-

Dichloroaniline (E)

[95-76-1]

(61625)

 3,5-

Dichloroaniline

[626-43-7]

(61627)

 4,4'-

Dichlorobenzo-phenone

[90-98-2]

(61631)

15 Oroville Dam precipitation gage at spillway 393234121292701 1.78 na E0.08 na – na na15 Oroville Dam precipitation gage at spillway 393234121292701 2.725 na E0.07 na – na na15 Oroville Dam precipitation gage at spillway 393234121292701 4.27 na E0.03 na – na na15 Oroville Dam precipitation gage at spillway 393234121292701 3.4 na – na – na na

15 Oroville Dam precipitation gage at spillway 393234121292701 1.55 na E0.01 na – na na15 Oroville Dam precipitation gage at spillway 393234121292701 2.8 na – na – na na

15 Oroville Dam precipitation gage at spillway 393234121292701 0.91 na E0.02 na E0.021 na na

15 Oroville Dam precipitation gage at spillway 393234121292701 2.535 na – na E0.312 na na15 Oroville Dam precipitation gage at spillway 393234121292701 3.12 na – na – na na

15 Oroville Dam precipitation gage at spillway 393234121292701 4.22 na – na – na na
88 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 2002–04 study period at eight sites in the Central Valley, California.—Continued [All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L mul- tiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: E, esti- mated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; –, compound not detected; [-], no Chemical Abstract Service Number available for given compound] Site number Site name Site identification number 4-Chloro- 2-methyl- phenol (E) [1570-64-5] (61633) Alachlor [15972-60-8] (46342) Atrazine [1912-24-9] (39632) Azinphos- methyl (E) [86-50-0] (82686) Benfluralin [1861-40-1] (82673) Carbaryl (E) [63-25-2] (82680) Carbofuran [1563-66-2] (82674) 11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – – – – E0.813 – 11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – – – – – – 11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – – – – – – 11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – – – – – E0.053 11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – – – – – – 11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – – E0.29 – E0.120 na 11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – – E0.05 – E0.024 na 11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – – – – – na 11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – – – – E0.048 na 11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – 0.082 – – – E0.032 na 11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – – – – E0.050 na 11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – – E0.03 – E0.023 na 11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – – – – – na 11 Newman rain gage at wasteway levee near Draper Road 371735121031201 E0.017 – – – – – na 11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – – – – E0.024 na 11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – E0.040 – – – – na 12 Turlock rain gage near Idaho Road 372713120534901 – – – – – E0.062 – 12 Turlock rain gage near Idaho Road 372713120534901 – – – – – E0.157 – 12 Turlock rain gage near Idaho Road 372713120534901 E0.07 – – – – – – 12 Turlock rain gage near Idaho Road 372713120534901 E0.035 – – – – E0.035 E0.089

12 Turlock rain gage near Idaho Road 372713120534901 – – – – – – E0.310

12 Turlock rain gage near Idaho Road 372713120534901 – – – – – – E0.149

12 Turlock rain gage near Idaho Road 372713120534901 – – – – – – E0.465

12 Turlock rain gage near Idaho Road 372713120534901 – – – E0.27 – E0.247 na

12 Turlock rain gage near Idaho Road 372713120534901 – – – E0.06 – E0.049 na

12 Turlock rain gage near Idaho Road 372713120534901 – – – E0.04 – – na

12 Turlock rain gage near Idaho Road 372713120534901 E0.036 – – – – E0.145 na

12 Turlock rain gage near Idaho Road 372713120534901 – – – – – E0.026 na

12 Turlock rain gage near Idaho Road 372713120534901 E0.036 0.044 – – – E0.044 na

12 Turlock rain gage near Idaho Road 372713120534901 – – – – – E0.112 na
Appendix 3 89

Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 

2002–04 study period at eight sites in the Central Valley, California.—Continued

[All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: E, estimated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; 

–, compound not detected; [-], no Chemical Abstract Service Number available for given compound]

Site 

number Site name

Site 

identification 

number

 4-Chloro2-methylphenol (E) 

[1570-64-5]

(61633)

 Alachlor

[15972-60-8]

(46342)

 Atrazine

[1912-24-9]

(39632)

 Azinphosmethyl (E)

[86-50-0]

(82686)

 Benfluralin

[1861-40-1]

(82673)

Carbaryl (E)

[63-25-2]

(82680)

Carbofuran

[1563-66-2]

(82674)

12 Turlock rain gage near Idaho Road 372713120534901 – – E0.017 E0.21 – E0.359 na

12 Turlock rain gage near Idaho Road 372713120534901 – – – E0.03 – E0.029 na

12 Turlock rain gage near Idaho Road 372713120534901 E0.037 – – – – E0.064 na

12 Turlock rain gage near Idaho Road 372713120534901 E0.011 – – – – E0.104 na

12 Turlock rain gage near Idaho Road 372713120534901 E0.005 – – – – E0.039 na

12 Turlock rain gage near Idaho Road 372713120534901 – – – – – – na

12 Turlock rain gage near Idaho Road 372713120534901 – – – – – – na

13 Turlock Airport rain gage 372857120414001 – – – – – E0.116 –

13 Turlock Airport rain gage 372857120414001 – – – – – E0.158 –

13 Turlock Airport rain gage 372857120414001 E0.052 – – – – E0.071 –

13 Turlock Airport rain gage 372857120414001 – – – – – E0.153 –

13 Turlock Airport rain gage 372857120414001 – – – – – – E2.109

13 Turlock Airport rain gage 372857120414001 – – – – – – E0.505

13 Turlock Airport rain gage 372857120414001 – – – – – – –

13 Turlock Airport rain gage 372857120414001 – – – E0.39 – E0.254 na

13 Turlock Airport rain gage 372857120414001 E0.042 – – E0.07 – E0.042 na

13 Turlock Airport rain gage 372857120414001 – – – – – – na

13 Turlock Airport rain gage 372857120414001 E0.049 – – – – E0.082 na

13 Turlock Airport rain gage 372857120414001 E0.032 – – – – – na

13 Turlock Airport rain gage 372857120414001 – – – – – E0.015 na

13 Turlock Airport rain gage 372857120414001 – – – – – E0.065 na

13 Turlock Airport rain gage 372857120414001 – – – – – E0.673 na

13 Turlock Airport rain gage 372857120414001 – – – E0.29 – E0.270 na

13 Turlock Airport rain gage 372857120414001 – – – E0.03 – E0.034 na

13 Turlock Airport rain gage 372857120414001 – – – – – E0.105 na

13 Turlock Airport rain gage 372857120414001 – – – – – – na

13 Turlock Airport rain gage 372857120414001 – – – – – E0.030 na

13 Turlock Airport rain gage 372857120414001 E0.023 – – – – E0.151 na
90 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 2002–04 study period at eight sites in the Central Valley, California.—Continued [All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L mul- tiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: E, esti- mated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; –, compound not detected; [-], no Chemical Abstract Service Number available for given compound] Site number Site name Site identification number 4-Chloro- 2-methyl- phenol (E) [1570-64-5] (61633) Alachlor [15972-60-8] (46342) Atrazine [1912-24-9] (39632) Azinphos- methyl (E) [86-50-0] (82686) Benfluralin [1861-40-1] (82673) Carbaryl (E) [63-25-2] (82680) Carbofuran [1563-66-2] (82674) 10 Westley rain gage at pump building near lateral 6 North 373335121143001 – – – – – – – 10 Westley rain gage at pump building near lateral 6 North 373335121143001 – – – – – – – 10 Westley rain gage at pump building near lateral 6 North 373335121143001 – – – – – E0.063 E10.173 10 Westley rain gage at pump building near lateral 6 North 373335121143001 – – – – – E0.045 E5.205 10 Westley rain gage at pump building near lateral 6 North 373335121143001 – – – – – E0.046 E0.082 10 Westley rain gage at pump building near lateral 6 North 373335121143001 – – – – – E0.076 E0.169 10 Westley rain gage at pump building near lateral 6 North 373335121143001 – – – E0.38 – E0.169 na 10 Westley rain gage at pump building near lateral 6 North 373335121143001 – – – E0.06 – – na 10 Westley rain gage at pump building near lateral 6 North 373335121143001 – – – – – E0.037 na 10 Westley rain gage at pump building near lateral 6 North 373335121143001 – – – – – E0.074 na 10 Westley rain gage at pump building near lateral 6 North 373335121143001 – – – – – E0.040 na 10 Westley rain gage at pump building near lateral 6 North 373335121143001 – 0.112 – – – – na 10 Westley rain gage at pump building near lateral 6 North 373335121143001 – – – E0.09 E0.04 E0.061 na 10 Westley rain gage at pump building near lateral 6 North 373335121143001 – – – – – – na 10 Westley rain gage at pump building near lateral 6 North 373335121143001 – E0.023 – – – – nana

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – – – E0.034 –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – – – E0.302 –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – – – – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – – – E0.237

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – – – E0.031 E0.995

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – – – – E1.330

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – E0.14 – E0.076 –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – E0.39 – E0.729 na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – E0.41 – E0.304 na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – E0.09 – E0.077 na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – E0.07 – – na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – – – E0.035 na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – – – – na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.028 – – – – E0.137 na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.037 – – – – E0.125 na
Appendix 3 91

Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 

2002–04 study period at eight sites in the Central Valley, California.—Continued

[All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: E, estimated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; 

–, compound not detected; [-], no Chemical Abstract Service Number available for given compound]

Site 

number Site name

Site 

identification 

number

 4-Chloro2-methylphenol (E) 

[1570-64-5]

(61633)

 Alachlor

[15972-60-8]

(46342)

 Atrazine

[1912-24-9]

(39632)

 Azinphosmethyl (E)

[86-50-0]

(82686)

 Benfluralin

[1861-40-1]

(82673)

Carbaryl (E)

[63-25-2]

(82680)

Carbofuran

[1563-66-2]

(82674)

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.054 – – – – E0.118 na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.012 – – – – – na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – – – E0.037 na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.012 – – – – – na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – – – E0.061 na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – – – E0.029 na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – – – E0.043 na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – – – E0.377 na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – E0.39 – E0.623 na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – E0.05 – E0.051 na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – – – E0.063 na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – – – – na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – – – E0.282 na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – – – E0.069 na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – – – – na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – – – E0.086 na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – – – E0.082 na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – – – E0.031 na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – – – E0.305 na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – – – E0.209 na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – – – E0.154 –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – – – E0.179 –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – – – E0.127 –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – – – E0.109 E0.243

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – – – – E1.181

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – – – – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – E0.49 – E0.143 na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – E0.29 – E0.176 na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – – – E0.044 na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – – – – na
92 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 2002–04 study period at eight sites in the Central Valley, California.—Continued [All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L mul- tiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: E, esti- mated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; –, compound not detected; [-], no Chemical Abstract Service Number available for given compound] Site number Site name Site identification number 4-Chloro- 2-methyl- phenol (E) [1570-64-5] (61633) Alachlor [15972-60-8] (46342) Atrazine [1912-24-9] (39632) Azinphos- methyl (E) [86-50-0] (82686) Benfluralin [1861-40-1] (82673) Carbaryl (E) [63-25-2] (82680) Carbofuran [1563-66-2] (82674)

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – – – – na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – – – – na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – – – E0.010 na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – – – – na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – – – – na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – – – – na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – – – – na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – E0.019 – – – na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – – – – na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – – – – na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – – – E0.160 na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – 0.033 – E0.07 – E0.301 na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – E0.41 – E0.392 na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – – – – na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – E0.02 – E0.037 na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – E0.04 – – na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – – – – na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – – – – na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – – – E0.207 na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – – – – na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – – – – na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – – – E0.034 na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – – – – na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E0.009 – – – – E0.033 na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E0.004 – – – – E0.027 na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – – – – na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – – – E0.157 na
Appendix 3 93

Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 

2002–04 study period at eight sites in the Central Valley, California.—Continued

[All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: E, estimated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; 

–, compound not detected; [-], no Chemical Abstract Service Number available for given compound]

Site 

number Site name

Site 

identification 

number

 4-Chloro2-methylphenol (E) 

[1570-64-5]

(61633)

 Alachlor

[15972-60-8]

(46342)

 Atrazine

[1912-24-9]

(39632)

 Azinphosmethyl (E)

[86-50-0]

(82686)

 Benfluralin

[1861-40-1]

(82673)

Carbaryl (E)

[63-25-2]

(82680)

Carbofuran

[1563-66-2]

(82674)

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – – – – na

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – – – – na

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – – – – na

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – – – – na

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – – – – na

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – – – – na

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – E0.72 – E0.169 na

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – E0.19 – E0.135 na

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – – – E0.024 na

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – – – E0.067 na

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – – – E0.046 na

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – – – E0.048 na

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – – – – na

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – – – E0.084 na

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – – – E0.065 na

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – – – E0.179 na

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – – – E0.055 na

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – – – E0.059 na

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – – – – na

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – – – – na

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – – – – na

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – – – – na

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – – – E0.035 na

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – – – E0.109 na

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – – – – na

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – – – – na
94 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 2002–04 study period at eight sites in the Central Valley, California.—Continued [All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L mul- tiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: E, esti- mated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; –, compound not detected; [-], no Chemical Abstract Service Number available for given compound] Site number Site name Site identification number 4-Chloro- 2-methyl- phenol (E) [1570-64-5] (61633) Alachlor [15972-60-8] (46342) Atrazine [1912-24-9] (39632) Azinphos- methyl (E) [86-50-0] (82686) Benfluralin [1861-40-1] (82673) Carbaryl (E) [63-25-2] (82680) Carbofuran [1563-66-2] (82674) 15 Oroville Dam precipitation gage at spillway 393234121292701 – – – – – – na 15 Oroville Dam precipitation gage at spillway 393234121292701 – – – – – – na 15 Oroville Dam precipitation gage at spillway 393234121292701 – – – – – – na 15 Oroville Dam precipitation gage at spillway 393234121292701 – – – – – – na 15 Oroville Dam precipitation gage at spillway 393234121292701 – – – – – – na 15 Oroville Dam precipitation gage at spillway 393234121292701 – – – E0.13 – E0.080 na 15 Oroville Dam precipitation gage at spillway 393234121292701 – – – – – – na 15 Oroville Dam precipitation gage at spillway 393234121292701 – – – – – – na 15 Oroville Dam precipitation gage at spillway 393234121292701 – – – – – – na 15 Oroville Dam precipitation gage at spillway 393234121292701 – – – – – – na 15 Oroville Dam precipitation gage at spillway 393234121292701 – – – – – – na 15 Oroville Dam precipitation gage at spillway 393234121292701 – – E0.085 – – – na 15 Oroville Dam precipitation gage at spillway 393234121292701 – – – – – E0.025 na
Appendix 3 95

Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 

2002–04 study period at eight sites in the Central Valley, California.—Continued

[All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: E, estimated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; 

–, compound not detected; [-], no Chemical Abstract Service Number available for given compound]

Site 

number Site name

Site 

identification 

number

 Chlorpyrifos

[2921-88-2]

(38933)

Chlorpyrifos 

oxon (E)

[5598-15-2]

(61636)

 Cyanazine

[21725-46-2]

(04041)

Cycloate

[1134-23-2]

(04031)

 Cyfluthrin (E)

[68359-37-5]

(61585)

Cypermethrin 

(E)

[52315-07-8]

(61586)

Dacthal 

(DCPA) 

[1861-32-1]

(82682)

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 0.040 – – – – – 0.119

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 0.035 – – – – – 0.016

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 0.062 – – 0.107 – – 0.048

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 0.073 E0.04 – – – – –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 0.048 E0.09 – 0.095 – – 0.195

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 0.193 – na na – – 0.409

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – na na – – 0.091

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 E0.027 – na na – – 0.075

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 0.274 – na na – – 0.286

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 0.159 E0.06 na na – – 0.082

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 0.020 – na na – – 0.018

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 0.037 – na na – – 0.053

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 0.041 E0.07 na na – – 0.123

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 0.085 E0.08 na na – – 0.093

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 0.015 – na na – – 0.015

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 0.120 – na na – – 0.130

12 Turlock rain gage near Idaho Road 372713120534901 0.207 – – – – – 0.031

12 Turlock rain gage near Idaho Road 372713120534901 0.056 E0.07 – – – – 0.030

12 Turlock rain gage near Idaho Road 372713120534901 0.044 – – – – – 0.044

12 Turlock rain gage near Idaho Road 372713120534901 0.410 E0.05 – – – – 0.032

12 Turlock rain gage near Idaho Road 372713120534901 0.430 E0.06 – – – – –

12 Turlock rain gage near Idaho Road 372713120534901 0.213 E0.11 – – – – –

12 Turlock rain gage near Idaho Road 372713120534901 0.121 E0.06 – – – – 0.102

12 Turlock rain gage near Idaho Road 372713120534901 0.133 – na na – E0.209 0.133

12 Turlock rain gage near Idaho Road 372713120534901 0.079 – na na – – 0.089

12 Turlock rain gage near Idaho Road 372713120534901 0.062 – na na – – 0.037

12 Turlock rain gage near Idaho Road 372713120534901 0.632 – na na – – 0.108

12 Turlock rain gage near Idaho Road 372713120534901 – – na na – – E0.016

12 Turlock rain gage near Idaho Road 372713120534901 0.569 E0.22 na na – – 0.161

12 Turlock rain gage near Idaho Road 372713120534901 0.049 – na na – – 0.011

12 Turlock rain gage near Idaho Road 372713120534901 0.022 – na na – – 0.019
96 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 2002–04 study period at eight sites in the Central Valley, California.—Continued [All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L mul- tiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: E, esti- mated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; –, compound not detected; [-], no Chemical Abstract Service Number available for given compound] Site number Site name Site identification number Chlorpyrifos [2921-88-2] (38933) Chlorpyrifos oxon (E) [5598-15-2] (61636) Cyanazine [21725-46-2] (04041) Cycloate [1134-23-2] (04031) Cyfluthrin (E) [68359-37-5] (61585) Cypermethrin (E) [52315-07-8] (61586) Dacthal (DCPA) [1861-32-1] (82682) 12 Turlock rain gage near Idaho Road 372713120534901 0.020 – na na – – 0.056 12 Turlock rain gage near Idaho Road 372713120534901 0.504 E0.18 na na – – 0.092 12 Turlock rain gage near Idaho Road 372713120534901 0.246 E0.16 na na – – 0.038 12 Turlock rain gage near Idaho Road 372713120534901 0.047 E0.05 na na – – 0.012 12 Turlock rain gage near Idaho Road 372713120534901 0.374 E0.06 na na – – 0.035 12 Turlock rain gage near Idaho Road 372713120534901 0.066 – na na – – 0.078 13 Turlock Airport rain gage 372857120414001 0.232 E0.18 – – – – 0.071 13 Turlock Airport rain gage 372857120414001 0.026 – – – – – 0.021 13 Turlock Airport rain gage 372857120414001 0.038 E0.05 – – – – 0.047 13 Turlock Airport rain gage 372857120414001 0.115 – – – – – 0.110 13 Turlock Airport rain gage 372857120414001 0.062 – – – – – 0.019 13 Turlock Airport rain gage 372857120414001 0.026 E0.02 – – – – – 13 Turlock Airport rain gage 372857120414001 – – – – – – 0.105 13 Turlock Airport rain gage 372857120414001 0.226 – na na – – 0.169 13 Turlock Airport rain gage 372857120414001 0.064 – na na – – 0.074 13 Turlock Airport rain gage 372857120414001 0.044 – na na – – 0.021 13 Turlock Airport rain gage 372857120414001 0.361 – na na – – 0.082 13 Turlock Airport rain gage 372857120414001 0.024 – na na – – 0.022 13 Turlock Airport rain gage 372857120414001 0.021 E0.02 na na – – 0.036 13 Turlock Airport rain gage 372857120414001 0.225 E0.07 na na – – 0.044 13 Turlock Airport rain gage 372857120414001 E0.021 – na na – – 0.171

13 Turlock Airport rain gage 372857120414001 0.029 – na na – – 0.025

13 Turlock Airport rain gage 372857120414001 0.076 – na na – – 0.054

13 Turlock Airport rain gage 372857120414001 0.618 E0.38 na na – – 0.105

13 Turlock Airport rain gage 372857120414001 0.078 E0.06 na na – – 0.025

13 Turlock Airport rain gage 372857120414001 0.132 E0.10 na na – – 0.061

13 Turlock Airport rain gage 372857120414001 0.326 – na na – – 0.186

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – – – – – – 0.014

10 Westley rain gage at pump building near lateral 6 North 373335121143001 0.042 E0.05 – – – – 0.187

10 Westley rain gage at pump building near lateral 6 North 373335121143001 0.028 E0.03 – – – – 0.023
Appendix 3 97

Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 

2002–04 study period at eight sites in the Central Valley, California.—Continued

[All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: E, estimated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; 

–, compound not detected; [-], no Chemical Abstract Service Number available for given compound]

Site 

number Site name

Site 

identification 

number

 Chlorpyrifos

[2921-88-2]

(38933)

Chlorpyrifos 

oxon (E)

[5598-15-2]

(61636)

 Cyanazine

[21725-46-2]

(04041)

Cycloate

[1134-23-2]

(04031)

 Cyfluthrin (E)

[68359-37-5]

(61585)

Cypermethrin 

(E)

[52315-07-8]

(61586)

Dacthal 

(DCPA) 

[1861-32-1]

(82682)

10 Westley rain gage at pump building near lateral 6 North 373335121143001 1.950 E0.41 0.06 – – – 0.022

10 Westley rain gage at pump building near lateral 6 North 373335121143001 0.144 E0.05 – – – – E0.015

10 Westley rain gage at pump building near lateral 6 North 373335121143001 0.177 E0.17 – – – – 0.076

10 Westley rain gage at pump building near lateral 6 North 373335121143001 0.169 – na na – – 0.400

10 Westley rain gage at pump building near lateral 6 North 373335121143001 0.040 – na na – – 0.153

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – – na na – – 0.025

10 Westley rain gage at pump building near lateral 6 North 373335121143001 0.112 – na na – – 0.186

10 Westley rain gage at pump building near lateral 6 North 373335121143001 0.105 E0.04 na na – – 0.036

10 Westley rain gage at pump building near lateral 6 North 373335121143001 0.241 E0.08 na na E0.136 – 0.136

10 Westley rain gage at pump building near lateral 6 North 373335121143001 0.164 – na na E0.104 – 0.173

10 Westley rain gage at pump building near lateral 6 North 373335121143001 0.014 E0.03 na na – – 0.015

10 Westley rain gage at pump building near lateral 6 North 373335121143001 0.092 E0.11 na na – – 0.172

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.079 – – – – – 0.021

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.022 – – – – – 0.033

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.043 – – – – – 0.030

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.326 – 0.0424 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.148 E0.12 – – – – E0.0124 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – E0.2 – – – – 0.290

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.022 E0.1 – – – – 0.013

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.196 – na na – – 0.253

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.248 – na na – – 0.221

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.307 – na na – – 0.131

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.176 – na na – – 0.106

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.078 E0.04 na na – – 0.048

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.053 – na na – – 0.049

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.172 E0.06 na na – – 0.030

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.897 E0.12 na na – – 0.100

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.559 – na na – – 0.140

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.041 – na na – – 0.014

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.034 E0.03 na na – – 0.048

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.029 – na na – – 0.032
98 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 2002–04 study period at eight sites in the Central Valley, California.—Continued [All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L mul- tiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: E, esti- mated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; –, compound not detected; [-], no Chemical Abstract Service Number available for given compound] Site number Site name Site identification number Chlorpyrifos [2921-88-2] (38933) Chlorpyrifos oxon (E) [5598-15-2] (61636) Cyanazine [21725-46-2] (04041) Cycloate [1134-23-2] (04031) Cyfluthrin (E) [68359-37-5] (61585) Cypermethrin (E) [52315-07-8] (61586) Dacthal (DCPA) [1861-32-1] (82682)

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.623 E0.31 na na – – 0.184

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.322 E0.10 na na – – 0.137

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.020 – na na – – 0.029

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.040 – na na – – 0.024

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.020 E0.03 na na – – 0.033

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.033 – na na – – 0.059

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.028 – na na – – 0.010

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.029 – na na – – 0.018

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.526 – na na – – 0.115

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.146 – na na – – 0.031

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.056 – na na – – 0.025

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.987 E0.19 na na – – 0.134

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.872 E0.31 na na – – 0.123

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.034 E0.05 na na – – 0.018

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.207 E0.11 na na – – 0.076

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.062 – na na – – 0.066

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.270 – – – – – 0.032

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.024 E0.06 – – – – 0.034

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.197 E0.13 – – – – 0.159

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.034 E0.06 – – – – 0.037

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.057 E0.06 – – – – 0.048

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.110 E0.86 – – – – 0.110

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.257 – na na – – 0.143

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.293 – na na – – 0.176

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.142 – na na – – 0.066

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.138 – na na – – 0.074

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.152 – na na – – 0.030

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.145 – na na – – 0.039

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.893 E0.04 na na – – 0.017

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 7.522 E0.33 na na – – 0.066

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 8.418 E0.14 na na – – 0.070
Appendix 3 99

Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 

2002–04 study period at eight sites in the Central Valley, California.—Continued

[All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: E, estimated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; 

–, compound not detected; [-], no Chemical Abstract Service Number available for given compound]

Site 

number Site name

Site 

identification 

number

 Chlorpyrifos

[2921-88-2]

(38933)

Chlorpyrifos 

oxon (E)

[5598-15-2]

(61636)

 Cyanazine

[21725-46-2]

(04041)

Cycloate

[1134-23-2]

(04031)

 Cyfluthrin (E)

[68359-37-5]

(61585)

Cypermethrin 

(E)

[52315-07-8]

(61586)

Dacthal 

(DCPA) 

[1861-32-1]

(82682)

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.041 – na na – – 0.006

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.048 – na na – – 0.029

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E0.018 – na na – – 0.029

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.301 E0.15 na na – – 0.110

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.224 E0.08 na na – – 0.100

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.064 – na na – – 0.032

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E0.033 E0.07 na na – – 0.114

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.023 E0.03 na na – – 0.019

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – na na – – 0.010

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.020 – na na – – 0.026

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.033 – na na – – 0.020

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.078 – na na – – 0.036

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.065 – na na – – 0.038

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 10.122 E1.83 na na – – 0.110

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 1.312 E0.23 na na – – 0.031

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.090 E0.03 na na – – 0.005

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 1.381 E0.47 na na – – 0.067

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.938 E0.11 na na – – 0.065

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.554 E0.28 na na – – 0.023

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.084 E0.11 na na – – 0.021

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.219 E0.14 na na – – 0.055

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.303 – na na – – 0.123

16 Gridley High School precipitation gage at Gridley 392205121410201 0.931 E0.27 na na – – 0.082

16 Gridley High School precipitation gage at Gridley 392205121410201 1.564 E0.65 na na – – 0.130

16 Gridley High School precipitation gage at Gridley 392205121410201 0.853 – na na – – 0.128

16 Gridley High School precipitation gage at Gridley 392205121410201 0.044 E0.06 na na – – 0.044

16 Gridley High School precipitation gage at Gridley 392205121410201 0.066 E0.03 na na – – 0.039

16 Gridley High School precipitation gage at Gridley 392205121410201 0.154 E0.08 na na – – 0.081

16 Gridley High School precipitation gage at Gridley 392205121410201 E0.021 – na na – – 0.032

16 Gridley High School precipitation gage at Gridley 392205121410201 E0.034 – na na – – 0.084

16 Gridley High School precipitation gage at Gridley 392205121410201 E0.006 – na na – – 0.018
100 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 2002–04 study period at eight sites in the Central Valley, California.—Continued [All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L mul- tiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: E, esti- mated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; –, compound not detected; [-], no Chemical Abstract Service Number available for given compound] Site number Site name Site identification number Chlorpyrifos [2921-88-2] (38933) Chlorpyrifos oxon (E) [5598-15-2] (61636) Cyanazine [21725-46-2] (04041) Cycloate [1134-23-2] (04031) Cyfluthrin (E) [68359-37-5] (61585) Cypermethrin (E) [52315-07-8] (61586) Dacthal (DCPA) [1861-32-1] (82682) 16 Gridley High School precipitation gage at Gridley 392205121410201 E0.056 – na na – – 0.067 16 Gridley High School precipitation gage at Gridley 392205121410201 0.032 – na na – – 0.021 16 Gridley High School precipitation gage at Gridley 392205121410201 – – na na – – 0.020 16 Gridley High School precipitation gage at Gridley 392205121410201 – – na na – – 0.025 16 Gridley High School precipitation gage at Gridley 392205121410201 0.046 – na na – – 0.038 16 Gridley High School precipitation gage at Gridley 392205121410201 0.167 E0.06 na na – – 0.012 16 Gridley High School precipitation gage at Gridley 392205121410201 0.038 – na na – – 0.022 16 Gridley High School precipitation gage at Gridley 392205121410201 0.086 E0.08 na na – – 0.024 16 Gridley High School precipitation gage at Gridley 392205121410201 0.200 E0.12 na na – – E0.035 16 Gridley High School precipitation gage at Gridley 392205121410201 0.276 E0.08 na na – – 0.032 16 Gridley High School precipitation gage at Gridley 392205121410201 0.681 E0.10 na na – – 0.017 16 Gridley High School precipitation gage at Gridley 392205121410201 0.266 E0.08 na na – – 0.013 16 Gridley High School precipitation gage at Gridley 392205121410201 0.431 E0.10 na na – – 0.020 16 Gridley High School precipitation gage at Gridley 392205121410201 0.162 E0.17 na na – – 0.023 16 Gridley High School precipitation gage at Gridley 392205121410201 0.465 E0.31 na na – – 0.078 16 Gridley High School precipitation gage at Gridley 392205121410201 0.382 – na na – – 0.106 16 Gridley High School precipitation gage at Gridley 392205121410201 0.092 E0.08 na na – – 0.033 15 Oroville Dam precipitation gage at spillway 393234121292701 – – na na – – 0.068 15 Oroville Dam precipitation gage at spillway 393234121292701 – – na na – – 0.044 15 Oroville Dam precipitation gage at spillway 393234121292701 0.009 – na na – – E0.003 15 Oroville Dam precipitation gage at spillway 393234121292701 0.073 – na na – – 0.122

15 Oroville Dam precipitation gage at spillway 393234121292701 0.157 E0.07 na na – – 0.082

15 Oroville Dam precipitation gage at spillway 393234121292701 – – na na – – 0.037

15 Oroville Dam precipitation gage at spillway 393234121292701 – – na na – – 0.070

15 Oroville Dam precipitation gage at spillway 393234121292701 – – na na – – E0.007

15 Oroville Dam precipitation gage at spillway 393234121292701 0.038 – na na – – 0.027

15 Oroville Dam precipitation gage at spillway 393234121292701 0.029 E0.04 na na – – E0.012

15 Oroville Dam precipitation gage at spillway 393234121292701 0.087 E0.09 na na – – 0.026

15 Oroville Dam precipitation gage at spillway 393234121292701 0.107 – na na – – 0.149

15 Oroville Dam precipitation gage at spillway 393234121292701 E0.025 E0.08 na na – – 0.050
Appendix 3 101

Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 

2002–04 study period at eight sites in the Central Valley, California.—Continued

[All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: E, estimated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; 

–, compound not detected; [-], no Chemical Abstract Service Number available for given compound]

Site 

number Site name

Site 

identification 

number

p,p'-DDE

[72-55-9]

(34653)

 Diazinon

[333-41-5]

(39572)

 Diazoxon (E)

[962-58-3]

(61638)

Dichlorvos (E)

[62-73-7]

(38775)

 Dimethoate

[60-51-5]

(82662)

 EPTC

[759-94-4]

(82668)

 Fonofos 

[944-22-9]

(04095)

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – 0.199 na – – – –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – 0.160 na – – – –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – 0.074 na – – – –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – na – – – –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – 0.065 na – – – –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 na 0.747 na E0.06 E0.819 na –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 na 0.049 na – E0.067 na –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 na – – – – na –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 na 0.988 – – – na –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 na 0.140 E0.06 – – na –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 na 0.037 – – E0.074 na –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 na 0.048 – E0.04 E0.027 na –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 na 1.28 E0.41 – – na –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 na 0.526 E0.17 – – na –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 na 0.064 E0.04 – – na –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 na 0.462 E0.20 E0.10 – na –

12 Turlock rain gage near Idaho Road 372713120534901 – 6.55 na – – – –

12 Turlock rain gage near Idaho Road 372713120534901 – 0.744 na – – – –

12 Turlock rain gage near Idaho Road 372713120534901 – 0.487 na – – 0.039 –

12 Turlock rain gage near Idaho Road 372713120534901 – 0.089 na – – 0.027 –

12 Turlock rain gage near Idaho Road 372713120534901 – 0.080 na – – 0.132 –

12 Turlock rain gage near Idaho Road 372713120534901 – 0.064 na E0.04 – – –

12 Turlock rain gage near Idaho Road 372713120534901 – 0.102 na – – 0.064 –

12 Turlock rain gage near Idaho Road 372713120534901 na 0.266 na E0.19 – na –

12 Turlock rain gage near Idaho Road 372713120534901 na 0.325 na – – na –

12 Turlock rain gage near Idaho Road 372713120534901 na 0.033 – – – na –

12 Turlock rain gage near Idaho Road 372713120534901 na 0.921 – – – na –

12 Turlock rain gage near Idaho Road 372713120534901 na 0.151 – na – na –

12 Turlock rain gage near Idaho Road 372713120534901 na 0.307 – – – na –

12 Turlock rain gage near Idaho Road 372713120534901 na 0.126 – – E0.041 na –

12 Turlock rain gage near Idaho Road 372713120534901 na 0.031 – – – na –
102 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 2002–04 study period at eight sites in the Central Valley, California.—Continued [All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L mul- tiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: E, esti- mated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; –, compound not detected; [-], no Chemical Abstract Service Number available for given compound] Site number Site name Site identification number p,p'-DDE [72-55-9] (34653) Diazinon [333-41-5] (39572) Diazoxon (E) [962-58-3] (61638) Dichlorvos (E) [62-73-7] (38775) Dimethoate [60-51-5] (82662) EPTC [759-94-4] (82668) Fonofos [944-22-9] (04095) 12 Turlock rain gage near Idaho Road 372713120534901 na 0.099 – E0.02 – na – 12 Turlock rain gage near Idaho Road 372713120534901 na 2.77 E0.64 E0.04 – na – 12 Turlock rain gage near Idaho Road 372713120534901 na 0.345 E0.11 – – na – 12 Turlock rain gage near Idaho Road 372713120534901 na 0.090 E0.05 – – na – 12 Turlock rain gage near Idaho Road 372713120534901 na 0.146 E0.06 E0.01 – na – 12 Turlock rain gage near Idaho Road 372713120534901 na 0.120 E0.15 E0.03 – na – 13 Turlock Airport rain gage 372857120414001 – 5.01 na – – – – 13 Turlock Airport rain gage 372857120414001 – 0.376 na – – – – 13 Turlock Airport rain gage 372857120414001 – 0.421 na – – – – 13 Turlock Airport rain gage 372857120414001 – 0.272 na – – 0.086 – 13 Turlock Airport rain gage 372857120414001 – 0.060 na – – 0.034 – 13 Turlock Airport rain gage 372857120414001 – 0.021 na – – – – 13 Turlock Airport rain gage 372857120414001 – 0.111 na – – – – 13 Turlock Airport rain gage 372857120414001 na 0.536 na – – na – 13 Turlock Airport rain gage 372857120414001 na 0.096 – – – na – 13 Turlock Airport rain gage 372857120414001 na 0.065 – – – na – 13 Turlock Airport rain gage 372857120414001 na 9.85 E0.99 – – na – 13 Turlock Airport rain gage 372857120414001 na 0.617 – – – na – 13 Turlock Airport rain gage 372857120414001 na 0.240 – – – na – 13 Turlock Airport rain gage 372857120414001 na 0.326 E0.07 – – na – 13 Turlock Airport rain gage 372857120414001 na 0.117 – – – na –

13 Turlock Airport rain gage 372857120414001 na 0.054 – – – na –

13 Turlock Airport rain gage 372857120414001 na 0.046 – – – na –

13 Turlock Airport rain gage 372857120414001 na 1.62 E0.38 – – na –

13 Turlock Airport rain gage 372857120414001 na 0.129 E0.06 – – na –

13 Turlock Airport rain gage 372857120414001 na 0.192 E0.10 – – na –

13 Turlock Airport rain gage 372857120414001 na 0.081 0.233 E0.04 – na –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – 0.530 na – – – –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – 1.29 na E0.16 – 0.057 –10 Westley rain gage at pump building near lateral 6 North 373335121143001 – 0.086 na – – – –
Appendix 3 103

Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 

2002–04 study period at eight sites in the Central Valley, California.—Continued

[All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: E, estimated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; 

–, compound not detected; [-], no Chemical Abstract Service Number available for given compound]

Site 

number Site name

Site 

identification 

number

p,p'-DDE

[72-55-9]

(34653)

 Diazinon

[333-41-5]

(39572)

 Diazoxon (E)

[962-58-3]

(61638)

Dichlorvos (E)

[62-73-7]

(38775)

 Dimethoate

[60-51-5]

(82662)

 EPTC

[759-94-4]

(82668)

 Fonofos 

[944-22-9]

(04095)

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – 0.038 na – – 0.032 –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 E0.041 – na E0.05 – – 0.015

10 Westley rain gage at pump building near lateral 6 North 373335121143001 0.025 0.110 na – – 0.034 –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 na 0.927 na E0.08 – na –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 na E0.056 – – – na –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 na – – – – na –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 na 1.08 – – – na –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 na 0.352 – – – na –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 na 0.273 E0.08 – – na –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 na 0.208 – E0.09 – na –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 na 0.057 E0.05 – – na –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 na 0.609 E0.23 E0.01 – na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – 2.78 na – – – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – 1.11 na – – – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – 0.348 na – – – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – 0.237 na na na 0.070 –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – 0.074 na – – – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.030 0.330 na – E0.15 – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – 0.029 na E0.06 – – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 na 0.842 na E0.07 – na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 na 0.690 na E0.12 – na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 na 0.526 – – – na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 na 0.399 na – – na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 na 0.256 na – – na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 na 0.138 – – – na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 na 3.50 na – – na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 na 12.0 E0.87 – – na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 na 12.7 E1.29 – – na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 na 1.40 E0.46 – – na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 na 0.269 E0.14 – – na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 na 0.202 – – – na –
104 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 2002–04 study period at eight sites in the Central Valley, California.—Continued [All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L mul- tiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: E, esti- mated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; –, compound not detected; [-], no Chemical Abstract Service Number available for given compound] Site number Site name Site identification number p,p'-DDE [72-55-9] (34653) Diazinon [333-41-5] (39572) Diazoxon (E) [962-58-3] (61638) Dichlorvos (E) [62-73-7] (38775) Dimethoate [60-51-5] (82662) EPTC [759-94-4] (82668) Fonofos [944-22-9] (04095)

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 na 0.828 – – – na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 na 0.645 E0.10 – – na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 na 0.083 – – – na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 na 0.088 E0.03 – – na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 na 0.115 – – – na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 na 0.216 E0.04 E0.07 – na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 na 0.077 E0.06 – – na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 na 0.071 – – – na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 na 5.03 E0.64 E0.26 – na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 na 0.569 E0.08 – – na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 na 0.188 E0.05 E0.03 – na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 na 5.38 E0.77 – – na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 na 5.86 E0.92 E0.03 – na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 na 0.093 E0.05 – – na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 na 0.349 E0.11 – – na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 na 0.123 E0.12 E0.04 – na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – 2.90 na – – – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – 0.895 na – – – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – 1.41 na – – 0.038 –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – 0.210 na – – – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – 0.153 na – – – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – 0.183 na – – – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 na 0.372 na – – na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 na 0.469 na – – na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 na 0.120 – – – na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 na 0.116 na – – na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 na 0.104 – – – na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 na 0.113 – – – na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 na 0.378 na – – na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 na 14.4 E0.99 – – na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 na 11.7 E0.56 – – na –
Appendix 3 105

Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 

2002–04 study period at eight sites in the Central Valley, California.—Continued

[All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: E, estimated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; 

–, compound not detected; [-], no Chemical Abstract Service Number available for given compound]

Site 

number Site name

Site 

identification 

number

p,p'-DDE

[72-55-9]

(34653)

 Diazinon

[333-41-5]

(39572)

 Diazoxon (E)

[962-58-3]

(61638)

Dichlorvos (E)

[62-73-7]

(38775)

 Dimethoate

[60-51-5]

(82662)

 EPTC

[759-94-4]

(82668)

 Fonofos 

[944-22-9]

(04095)

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 na 0.149 – – – na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 na 0.188 – na – na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 na 0.152 – na – na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 na 0.499 E0.07 – – na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 na 0.586 – – – na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 na 0.073 E0.05 E0.01 – na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 na 0.100 – – – na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 na 0.052 – – – na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 na 0.017 – – – na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 na 0.031 – – – na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 na 0.037 – – – na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 na 0.312 E0.16 – – na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 na 0.322 – – – na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 na 18.4 E0.97 E0.12 – na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 na 0.795 E0.15 E0.02 – na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 na 0.066 E0.01 E0.00 – na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 na 2.12 E0.40 – – na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 na 1.04 E0.11 – – na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 na 0.521 E0.14 – – na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 na 0.418 E0.10 – – na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 na 0.246 E0.07 – – na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 na 0.191 E0.11 E0.03 – na –

16 Gridley High School precipitation gage at Gridley 392205121410201 na 50.6 E1.64 – – na –

16 Gridley High School precipitation gage at Gridley 392205121410201 na 45.6 E6.52 – – na –

16 Gridley High School precipitation gage at Gridley 392205121410201 na 9.78 – na – na –

16 Gridley High School precipitation gage at Gridley 392205121410201 na 2.99 – na – na –

16 Gridley High School precipitation gage at Gridley 392205121410201 na 0.058 E0.03 – – na –

16 Gridley High School precipitation gage at Gridley 392205121410201 na 0.559 E0.08 – – na –

16 Gridley High School precipitation gage at Gridley 392205121410201 na 0.106 – – – na –

16 Gridley High School precipitation gage at Gridley 392205121410201 na 0.160 – – – na –

16 Gridley High School precipitation gage at Gridley 392205121410201 na 0.033 – – – na –
106 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 2002–04 study period at eight sites in the Central Valley, California.—Continued [All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L mul- tiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: E, esti- mated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; –, compound not detected; [-], no Chemical Abstract Service Number available for given compound] Site number Site name Site identification number p,p'-DDE [72-55-9] (34653) Diazinon [333-41-5] (39572) Diazoxon (E) [962-58-3] (61638) Dichlorvos (E) [62-73-7] (38775) Dimethoate [60-51-5] (82662) EPTC [759-94-4] (82668) Fonofos [944-22-9] (04095) 16 Gridley High School precipitation gage at Gridley 392205121410201 na 0.100 – – – na – 16 Gridley High School precipitation gage at Gridley 392205121410201 na 0.056 – – – na – 16 Gridley High School precipitation gage at Gridley 392205121410201 na 0.048 – – – na – 16 Gridley High School precipitation gage at Gridley 392205121410201 na 0.035 – – – na – 16 Gridley High School precipitation gage at Gridley 392205121410201 na 0.053 – – – na – 16 Gridley High School precipitation gage at Gridley 392205121410201 na 0.111 E0.03 – – na – 16 Gridley High School precipitation gage at Gridley 392205121410201 na 0.043 – – – na – 16 Gridley High School precipitation gage at Gridley 392205121410201 na 0.290 – – – na – 16 Gridley High School precipitation gage at Gridley 392205121410201 na 0.094 – – – na – 16 Gridley High School precipitation gage at Gridley 392205121410201 na 0.134 E0.08 – – na – 16 Gridley High School precipitation gage at Gridley 392205121410201 na 6.19 E0.44 – – na – 16 Gridley High School precipitation gage at Gridley 392205121410201 na 7.17 E0.65 – – na – 16 Gridley High School precipitation gage at Gridley 392205121410201 na 2.33 E0.24 – – na – 16 Gridley High School precipitation gage at Gridley 392205121410201 na 6.19 E0.52 – – na – 16 Gridley High School precipitation gage at Gridley 392205121410201 na 4.82 E0.78 – – na – 16 Gridley High School precipitation gage at Gridley 392205121410201 na 2.06 E0.21 – – na – 16 Gridley High School precipitation gage at Gridley 392205121410201 na 0.427 E0.08 E0.02 – na – 15 Oroville Dam precipitation gage at spillway 393234121292701 na E0.055 na – – na – 15 Oroville Dam precipitation gage at spillway 393234121292701 na E0.044 na – – na – 15 Oroville Dam precipitation gage at spillway 393234121292701 na 0.702 E0.07 – – na – 15 Oroville Dam precipitation gage at spillway 393234121292701 na 0.439 – na – na –

15 Oroville Dam precipitation gage at spillway 393234121292701 na 0.559 – – – na –

15 Oroville Dam precipitation gage at spillway 393234121292701 na 0.032 – – – na –

15 Oroville Dam precipitation gage at spillway 393234121292701 na 0.047 – – – na –

15 Oroville Dam precipitation gage at spillway 393234121292701 na – – – – na –

15 Oroville Dam precipitation gage at spillway 393234121292701 na 0.060 – – – na –

15 Oroville Dam precipitation gage at spillway 393234121292701 na 0.050 E0.04 – – na –

15 Oroville Dam precipitation gage at spillway 393234121292701 na 0.278 E0.09 – – na –

15 Oroville Dam precipitation gage at spillway 393234121292701 na 0.235 E0.09 – – na –

15 Oroville Dam precipitation gage at spillway 393234121292701 na E0.033 – E0.03 – na –
Appendix 3 107

Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 

2002–04 study period at eight sites in the Central Valley, California.—Continued

[All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: E, estimated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; 

–, compound not detected; [-], no Chemical Abstract Service Number available for given compound]

Site 

number Site name

Site 

identification 

number

Fonofos 

oxon

[-]

(61649)

 Iprodione (E)

[36734-19-7]

(61593)

Cyhalothrinlambda

[91465-08-6]

(61595)

Malathion

[121-75-5]

(39532)

Malaoxon (E)

[1634-78-2]

(61652)

 Metalaxyl

[57837-19-1]

(61596)

 Methidathion

[950-37-8]

(61598)

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – – – – – –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – – – – – –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – E2.66 – 1.490 E0.243 – –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – E1.12 E0.033 E0.033 E0.049 – –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – E1.76 E0.082 0.203 E0.221 – –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – E0.217 na E0.434 E0.337 – –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – E0.110 na – – – –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – na – – – –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – na – – – E0.060

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – E2.85 na E0.076 E0.108 – –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – E0.495 na 0.092 E0.186 – –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – na 0.052 E0.089 – –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – na – – – 0.370

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – E0.127 na – – – 0.280

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – E2.73 na – – – 0.032

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – E3.47 na – – – 0.090

12 Turlock rain gage near Idaho Road 372713120534901 – – – E0.043 – – 0.094

12 Turlock rain gage near Idaho Road 372713120534901 – – – – – – –

12 Turlock rain gage near Idaho Road 372713120534901 – – – – – – –

12 Turlock rain gage near Idaho Road 372713120534901 – E4.75 – 0.456 E0.119 – 0.01612 Turlock rain gage near Idaho Road 372713120534901 – – – E0.086 – 0.034 –12 Turlock rain gage near Idaho Road 372713120534901 – E1.14 – E0.053 – – –12 Turlock rain gage near Idaho Road 372713120534901 – E2.52 – 2.49 E0.223 – –12 Turlock rain gage near Idaho Road 372713120534901 – – na E0.285 E0.285 – –

12 Turlock rain gage near Idaho Road 372713120534901 – – na E0.049 – – –

12 Turlock rain gage near Idaho Road 372713120534901 – – na – – – –

12 Turlock rain gage near Idaho Road 372713120534901 – – na E0.09 – – 0.199

12 Turlock rain gage near Idaho Road 372713120534901 na E0.755 na – – – –

12 Turlock rain gage near Idaho Road 372713120534901 – E4.17 na E0.131 E0.102 – –12 Turlock rain gage near Idaho Road 372713120534901 – E0.586 na E0.071 E0.112 – –12 Turlock rain gage near Idaho Road 372713120534901 – E0.042 na E0.022 – – –
108 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 2002–04 study period at eight sites in the Central Valley, California.—Continued [All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L mul- tiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: E, esti- mated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; –, compound not detected; [-], no Chemical Abstract Service Number available for given compound] Site number Site name Site identification number Fonofos oxon [-] (61649) Iprodione (E) [36734-19-7] (61593) Cyhalothrin- lambda [91465-08-6] (61595) Malathion [121-75-5] (39532) Malaoxon (E) [1634-78-2] (61652) Metalaxyl [57837-19-1] (61596) Methidathion [950-37-8] (61598) 12 Turlock rain gage near Idaho Road 372713120534901 – – na E0.032 E0.056 – – 12 Turlock rain gage near Idaho Road 372713120534901 – – na – – – 0.110 12 Turlock rain gage near Idaho Road 372713120534901 – E0.252 na – – – E0.027 12 Turlock rain gage near Idaho Road 372713120534901 – E4.23 na – – – 0.020 12 Turlock rain gage near Idaho Road 372713120534901 – E3.94 na – – – – 12 Turlock rain gage near Idaho Road 372713120534901 – E3.34 na 0.352 E0.190 – – 13 Turlock Airport rain gage 372857120414001 – – – E0.08 – – – 13 Turlock Airport rain gage 372857120414001 – – – – – – – 13 Turlock Airport rain gage 372857120414001 – – – – – – – 13 Turlock Airport rain gage 372857120414001 – E9.27 – 1.46 E0.177 – E0.024 13 Turlock Airport rain gage 372857120414001 – E3.65 – – – – – 13 Turlock Airport rain gage 372857120414001 – E1.013 – E0.057 E0.047 – – 13 Turlock Airport rain gage 372857120414001 – E3.34 – 0.710 E0.167 – – 13 Turlock Airport rain gage 372857120414001 – E0.507 na E0.479 E0.620 – 0.197 13 Turlock Airport rain gage 372857120414001 – – na – – – – 13 Turlock Airport rain gage 372857120414001 – – na – – – – 13 Turlock Airport rain gage 372857120414001 – – na – – – 5.206 13 Turlock Airport rain gage 372857120414001 – E6.83 na E0.016 – – 0.054 13 Turlock Airport rain gage 372857120414001 – E14.1 na E0.019 – – 0.031 13 Turlock Airport rain gage 372857120414001 – E5.81 na E0.196 E0.116 – – 13 Turlock Airport rain gage 372857120414001 – E0.374 na – – – –

13 Turlock Airport rain gage 372857120414001 – E0.191 na – – – –

13 Turlock Airport rain gage 372857120414001 – E0.091 na 0.284 E0.061 – –13 Turlock Airport rain gage 372857120414001 – – na – – – 0.457

13 Turlock Airport rain gage 372857120414001 – E11.9 na – – – 0.028

13 Turlock Airport rain gage 372857120414001 – E4.90 na – – – –

13 Turlock Airport rain gage 372857120414001 – E10.5 na E0.314 E0.279 – 0.09310 Westley rain gage at pump building near lateral 6 North 373335121143001 – – – E0.036 – – 0.171

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – – – – – – 0.047

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – E8.55 – 0.265 E0.111 – 0.024
Appendix 3 109

Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 

2002–04 study period at eight sites in the Central Valley, California.—Continued

[All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: E, estimated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; 

–, compound not detected; [-], no Chemical Abstract Service Number available for given compound]

Site 

number Site name

Site 

identification 

number

Fonofos 

oxon

[-]

(61649)

 Iprodione (E)

[36734-19-7]

(61593)

Cyhalothrinlambda

[91465-08-6]

(61595)

Malathion

[121-75-5]

(39532)

Malaoxon (E)

[1634-78-2]

(61652)

 Metalaxyl

[57837-19-1]

(61596)

 Methidathion

[950-37-8]

(61598)

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – E3.02 – 0.370 E0.059 – 0.018

10 Westley rain gage at pump building near lateral 6 North 373335121143001 E0.036 E1.72 – E0.046 E0.056 – –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – E3.69 – 0.135 E0.16 – –10 Westley rain gage at pump building near lateral 6 North 373335121143001 – E0.569 na E0.422 E0.759 – –10 Westley rain gage at pump building near lateral 6 North 373335121143001 – E0.113 na – – – –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – – na – – – –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – – na E0.074 – – 0.084

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – E77.6 na E0.029 – – –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – E10.3 na E0.112 E0.088 – –10 Westley rain gage at pump building near lateral 6 North 373335121143001 – E0.121 na E0.139 E0.19 0.078 –10 Westley rain gage at pump building near lateral 6 North 373335121143001 – E3.64 na – – – –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – E3.48 na – – – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – E0.032 – – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – – – – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – E1.36 – 0.084 E0.051 – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 na na na E0.051 na na na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – E0.105 E0.051 – 0.031

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – E3.37 – 1.830 E0.41 – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – 0.030 E0.056 0.013 –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – na E0.477 – – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – na E0.469 E1.27 – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – na E0.088 – – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – na E0.059 – – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – na E0.022 – – E0.017

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – na – – – 0.067

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – na E0.038 E0.068 – 0.350

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – na E0.112 – – 0.436

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – na E0.15 – – 0.462

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – E0.341 na E0.021 – – 0.242

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – E4.33 na E0.034 – – 0.034

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – E0.478 na – – – 0.021
110 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 2002–04 study period at eight sites in the Central Valley, California.—Continued [All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L mul- tiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: E, esti- mated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; –, compound not detected; [-], no Chemical Abstract Service Number available for given compound] Site number Site name Site identification number Fonofos oxon [-] (61649) Iprodione (E) [36734-19-7] (61593) Cyhalothrin- lambda [91465-08-6] (61595) Malathion [121-75-5] (39532) Malaoxon (E) [1634-78-2] (61652) Metalaxyl [57837-19-1] (61596) Methidathion [950-37-8] (61598)

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – E1.21 na E0.194 E0.153 – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – E0.195 na E0.098 – – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – E0.105 na E0.048 – – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – E0.057 na 0.353 E0.108 – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – E0.054 na E0.049 – – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – na 0.114 E0.143 – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – E0.047 na – – – 0.043

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – na – – – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – E0.295 na – – 0.449 0.2694 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – na – – – E0.038

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – na – – – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – na – – – 0.872

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – na – – – 0.523

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – E5.12 na – – – 0.022

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – E4.13 na – – – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – E2.04 na 0.312 E0.131 – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – – – – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – – – – 0.035

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – E0.025 – – 0.051

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – E9.55 – 0.768 E0.167 – 0.0545 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – E2.59 – 0.102 – – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – E3.37 – 0.800 E0.299 – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – E0.486 na E0.257 – – E0.143

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – E0.44 na E0.293 E0.322 – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – na – – – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – E0.095 na – – – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – na – – – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – na – – – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – na – – – 0.032

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – na – – – 0.706

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – na – – – 0.406
Appendix 3 111

Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 

2002–04 study period at eight sites in the Central Valley, California.—Continued

[All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: E, estimated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; 

–, compound not detected; [-], no Chemical Abstract Service Number available for given compound]

Site 

number Site name

Site 

identification 

number

Fonofos 

oxon

[-]

(61649)

 Iprodione (E)

[36734-19-7]

(61593)

Cyhalothrinlambda

[91465-08-6]

(61595)

Malathion

[121-75-5]

(39532)

Malaoxon (E)

[1634-78-2]

(61652)

 Metalaxyl

[57837-19-1]

(61596)

 Methidathion

[950-37-8]

(61598)

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – E0.132 na – – – 0.010

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 na E7.43 na – – – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 na E0.149 na – – – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – E4.36 na E0.066 E0.088 – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – E0.100 na – – – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – E0.178 na 0.771 E0.100 – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – E0.047 na E0.147 E0.114 – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – E0.065 na – – – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – na – – – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – na E0.024 E0.044 – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – na E0.040 E0.050 – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – na – – – 0.458

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – na – – – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – na – – – 0.914

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – na – – – 0.093

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – na – – – 0.071

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – na – – – 1.06

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – na – – – 0.180

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – E0.368 na E0.084 E0.074 – 0.2935 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – E22.2 na – – – 0.094

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – E6.60 na – – – 0.075

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – E3.70 na 0.37 E0.191 – 0.123

16 Gridley High School precipitation gage at Gridley 392205121410201 – E3.23 na – – – 0.246

16 Gridley High School precipitation gage at Gridley 392205121410201 – E5.44 na – – – 1.66

16 Gridley High School precipitation gage at Gridley 392205121410201 E1.24 na – – – –

16 Gridley High School precipitation gage at Gridley 392205121410201 – na – – – –

16 Gridley High School precipitation gage at Gridley 392205121410201 – E0.102 na E0.039 – – –16 Gridley High School precipitation gage at Gridley 392205121410201 – E0.284 na E0.057 – – –16 Gridley High School precipitation gage at Gridley 392205121410201 – – na E0.037 – – –

16 Gridley High School precipitation gage at Gridley 392205121410201 – – na – – – –

16 Gridley High School precipitation gage at Gridley 392205121410201 – – na – – – –
112 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 2002–04 study period at eight sites in the Central Valley, California.—Continued [All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L mul- tiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: E, esti- mated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; –, compound not detected; [-], no Chemical Abstract Service Number available for given compound] Site number Site name Site identification number Fonofos oxon [-] (61649) Iprodione (E) [36734-19-7] (61593) Cyhalothrin- lambda [91465-08-6] (61595) Malathion [121-75-5] (39532) Malaoxon (E) [1634-78-2] (61652) Metalaxyl [57837-19-1] (61596) Methidathion [950-37-8] (61598) 16 Gridley High School precipitation gage at Gridley 392205121410201 – – na E0.067 E0.111 – – 16 Gridley High School precipitation gage at Gridley 392205121410201 – – na E0.056 – – – 16 Gridley High School precipitation gage at Gridley 392205121410201 – – na – – – – 16 Gridley High School precipitation gage at Gridley 392205121410201 – – na E0.040 E0.059 – – 16 Gridley High School precipitation gage at Gridley 392205121410201 – – na – – – – 16 Gridley High School precipitation gage at Gridley 392205121410201 – – na E0.043 – – – 16 Gridley High School precipitation gage at Gridley 392205121410201 – – na – – – – 16 Gridley High School precipitation gage at Gridley 392205121410201 – – na – – – E0.039 16 Gridley High School precipitation gage at Gridley 392205121410201 – – na – – – – 16 Gridley High School precipitation gage at Gridley 392205121410201 – – na – – – 0.055 16 Gridley High School precipitation gage at Gridley 392205121410201 – – na E0.031 – – 0.058 16 Gridley High School precipitation gage at Gridley 392205121410201 – – na E0.034 – – 0.091 16 Gridley High School precipitation gage at Gridley 392205121410201 – – na – – – 0.044 16 Gridley High School precipitation gage at Gridley 392205121410201 – – na E0.035 – – 0.064 16 Gridley High School precipitation gage at Gridley 392205121410201 – – na E0.093 – – 0.171 16 Gridley High School precipitation gage at Gridley 392205121410201 – E0.276 na – – – – 16 Gridley High School precipitation gage at Gridley 392205121410201 – E1.57 na – – – 0.075 15 Oroville Dam precipitation gage at spillway 393234121292701 – E0.301 na – – – – 15 Oroville Dam precipitation gage at spillway 393234121292701 – – na – – – – 15 Oroville Dam precipitation gage at spillway 393234121292701 – – na – – – – 15 Oroville Dam precipitation gage at spillway 393234121292701 E0.853 na – – – –

15 Oroville Dam precipitation gage at spillway 393234121292701 – E0.462 na E0.052 – – 0.09015 Oroville Dam precipitation gage at spillway 393234121292701 – – na – – – –

15 Oroville Dam precipitation gage at spillway 393234121292701 – – na E0.023 – – –

15 Oroville Dam precipitation gage at spillway 393234121292701 – – na – – – –

15 Oroville Dam precipitation gage at spillway 393234121292701 – – na – – – 0.033

15 Oroville Dam precipitation gage at spillway 393234121292701 – – na – – – –

15 Oroville Dam precipitation gage at spillway 393234121292701 – – na – – – –

15 Oroville Dam precipitation gage at spillway 393234121292701 – E0.235 na – – – –

15 Oroville Dam precipitation gage at spillway 393234121292701 – E4.34 na – – – –
Appendix 3 113

Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 

2002–04 study period at eight sites in the Central Valley, California.—Continued

[All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: E, estimated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; 

–, compound not detected; [-], no Chemical Abstract Service Number available for given compound]

Site 

number Site name

Site 

identification 

number

Metolachlor

[51218-45-2]

(39415)

Metribuzin

[21087-64-9]

(82630)

 Molinate

[2212-67-1]

(82671)

 Myclobutanil 

(E)

[88671-89-0]

(61599)

Napropamide

[15299-99-7]

(82684)

Oxyfluorfen

[42874-03-3]

(61600)

 Parathionmethyl

[298-00-0]

(61664)

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – – – – – –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – – – – 0.053 –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – – E0.095 – – –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – – E0.114 – – –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – – E0.099 – – –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 E0.265 – na E0.289 na na 0.62611 Newman rain gage at wasteway levee near Draper Road 371735121031201 E0.049 0.049 na E0.049 na na –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 E0.034 – na – na na –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 E0.083 – na – na na –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 E0.070 – na E0.120 na na –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 E0.026 – na E0.074 na na –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 0.085 0.055 na E0.053 na na 0.08011 Newman rain gage at wasteway levee near Draper Road 371735121031201 E0.021 – na – na na –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 E0.059 – na E0.170 na na –11 Newman rain gage at wasteway levee near Draper Road 371735121031201 0.023 – na E0.141 na na –11 Newman rain gage at wasteway levee near Draper Road 371735121031201 E0.030 – na E0.221 na na –

12 Turlock rain gage near Idaho Road 372713120534901 E0.031 – – – 0.070 – –

12 Turlock rain gage near Idaho Road 372713120534901 0.038 – – – – – –

12 Turlock rain gage near Idaho Road 372713120534901 E0.017 – – – 0.044 0.078 –

12 Turlock rain gage near Idaho Road 372713120534901 E0.019 – – E0.639 0.043 – –12 Turlock rain gage near Idaho Road 372713120534901 – – – E0.075 – – –

12 Turlock rain gage near Idaho Road 372713120534901 – – – – – – –

12 Turlock rain gage near Idaho Road 372713120534901 E0.025 – – E0.153 – – –12 Turlock rain gage near Idaho Road 372713120534901 E0.114 – na E0.114 na na –

12 Turlock rain gage near Idaho Road 372713120534901 E0.039 – na – na na –

12 Turlock rain gage near Idaho Road 372713120534901 E0.016 – na – na na –

12 Turlock rain gage near Idaho Road 372713120534901 E0.054 – na – na na –

12 Turlock rain gage near Idaho Road 372713120534901 E0.008 – na na na na –

12 Turlock rain gage near Idaho Road 372713120534901 E0.066 – na E0.204 na na –12 Turlock rain gage near Idaho Road 372713120534901 E0.022 – na E0.093 na na –12 Turlock rain gage near Idaho Road 372713120534901 0.159 – na E0.198 na na –
114 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 2002–04 study period at eight sites in the Central Valley, California.—Continued [All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L mul- tiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: E, esti- mated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; –, compound not detected; [-], no Chemical Abstract Service Number available for given compound] Site number Site name Site identification number Metolachlor [51218-45-2] (39415) Metribuzin [21087-64-9] (82630) Molinate [2212-67-1] (82671) Myclobutanil (E) [88671-89-0] (61599) Napropamide [15299-99-7] (82684) Oxyfluorfen [42874-03-3] (61600) Parathion- methyl [298-00-0] (61664) 12 Turlock rain gage near Idaho Road 372713120534901 E0.023 – na E0.027 na na 0.038 12 Turlock rain gage near Idaho Road 372713120534901 – – na – na na – 12 Turlock rain gage near Idaho Road 372713120534901 E0.027 – na E0.071 na na – 12 Turlock rain gage near Idaho Road 372713120534901 0.017 – na E0.425 na na – 12 Turlock rain gage near Idaho Road 372713120534901 E0.023 – na E0.333 na na – 12 Turlock rain gage near Idaho Road 372713120534901 0.060 – na E0.111 na na – 13 Turlock Airport rain gage 372857120414001 – – – – 0.125 0.143 – 13 Turlock Airport rain gage 372857120414001 – – – – 0.053 – – 13 Turlock Airport rain gage 372857120414001 – – – – 0.047 0.071 – 13 Turlock Airport rain gage 372857120414001 – – – E0.750 – – – 13 Turlock Airport rain gage 372857120414001 – – – E0.092 – – – 13 Turlock Airport rain gage 372857120414001 – – – E0.081 – – – 13 Turlock Airport rain gage 372857120414001 – – – – – – – 13 Turlock Airport rain gage 372857120414001 – – na – na na 0.282 13 Turlock Airport rain gage 372857120414001 E0.032 – na – na na – 13 Turlock Airport rain gage 372857120414001 – – na – na na – 13 Turlock Airport rain gage 372857120414001 – – na – na na – 13 Turlock Airport rain gage 372857120414001 E0.006 – na E0.224 na na – 13 Turlock Airport rain gage 372857120414001 E0.013 – na E0.471 na na – 13 Turlock Airport rain gage 372857120414001 E0.036 – na E0.247 na na – 13 Turlock Airport rain gage 372857120414001 E0.032 – na E0.470 na na –

13 Turlock Airport rain gage 372857120414001 0.064 – na E0.304 na na –13 Turlock Airport rain gage 372857120414001 E0.020 – na E0.046 na na 0.04913 Turlock Airport rain gage 372857120414001 – – na – na na –

13 Turlock Airport rain gage 372857120414001 – – na E0.861 na na –

13 Turlock Airport rain gage 372857120414001 – – na E0.354 na na –

13 Turlock Airport rain gage 372857120414001 E0.081 – na E0.314 na na –10 Westley rain gage at pump building near lateral 6 North 373335121143001 0.027 – – – 0.071 0.088 –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 E0.026 – – – – 0.467 –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 0.016 – – E1.14 – 0.062 –
Appendix 3 115

Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 

2002–04 study period at eight sites in the Central Valley, California.—Continued

[All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: E, estimated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; 

–, compound not detected; [-], no Chemical Abstract Service Number available for given compound]

Site 

number Site name

Site 

identification 

number

Metolachlor

[51218-45-2]

(39415)

Metribuzin

[21087-64-9]

(82630)

 Molinate

[2212-67-1]

(82671)

 Myclobutanil 

(E)

[88671-89-0]

(61599)

Napropamide

[15299-99-7]

(82684)

Oxyfluorfen

[42874-03-3]

(61600)

 Parathionmethyl

[298-00-0]

(61664)

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – – – E0.819 0.034 0.052 –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – – – E0.067 – – –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 0.067 – – E0.523 – 0.388 –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 0.400 1.12 na E0.316 na na 1.391

10 Westley rain gage at pump building near lateral 6 North 373335121143001 E0.072 0.233 na E0.048 na na 0.056

10 Westley rain gage at pump building near lateral 6 North 373335121143001 E0.025 0.029 na – na na –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 0.177 0.121 na – na na –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 E0.036 0.025 na E0.754 na na –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 E0.072 – na E0.128 na na 0.096

10 Westley rain gage at pump building near lateral 6 North 373335121143001 0.130 6.84 na E0.061 na na 0.277

10 Westley rain gage at pump building near lateral 6 North 373335121143001 0.028 – na 0.089 na na 0.019

10 Westley rain gage at pump building near lateral 6 North 373335121143001 E0.034 – na 0.149 na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – – 0.056 0.062 –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.043 – – – 0.568 0.074 –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – E0.210 – – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – na – na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – E0.051 – – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – E0.180 – – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.190 – 0.095 E0.029 – – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.168 – na – na na 0.309

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.138 – na E0.221 na na 0.414

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.044 – na – na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.035 – na – na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.017 – na – na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.022 – na – na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.016 – na – na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.050 – na – na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.064 – na – na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.011 – na E0.058 na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.017 – na E0.614 na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.015 – na E0.141 na na –
116 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 2002–04 study period at eight sites in the Central Valley, California.—Continued [All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L mul- tiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: E, esti- mated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; –, compound not detected; [-], no Chemical Abstract Service Number available for given compound] Site number Site name Site identification number Metolachlor [51218-45-2] (39415) Metribuzin [21087-64-9] (82630) Molinate [2212-67-1] (82671) Myclobutanil (E) [88671-89-0] (61599) Napropamide [15299-99-7] (82684) Oxyfluorfen [42874-03-3] (61600) Parathion- methyl [298-00-0] (61664)

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.061 – na E0.102 na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.049 – na – na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – na E0.037 na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.020 – na E0.040 na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.161 – na E0.281 na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.04 – na – na na 0.158

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.013 – na – na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.013 – na – na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – na – na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – na – na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – na – na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – E0.038 na – na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – na – na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.016 – na E1.10 na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – na E0.491 na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.086 – na E0.152 na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – – 0.064 – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – – – 0.086 –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E0.013 – – – – 0.191 –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.022 – – E0.685 – – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – E0.413 – – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E0.031 – – E0.305 – – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E0.114 – na E0.172 na na 0.858

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E0.117 – na E0.176 na na 0.821

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E0.033 – na – na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E0.021 – na E0.032 na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – na – na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – na – na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E0.008 – na E0.011 na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – na – na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – na – na na –
Appendix 3 117

Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 

2002–04 study period at eight sites in the Central Valley, California.—Continued

[All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: E, estimated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; 

–, compound not detected; [-], no Chemical Abstract Service Number available for given compound]

Site 

number Site name

Site 

identification 

number

Metolachlor

[51218-45-2]

(39415)

Metribuzin

[21087-64-9]

(82630)

 Molinate

[2212-67-1]

(82671)

 Myclobutanil 

(E)

[88671-89-0]

(61599)

Napropamide

[15299-99-7]

(82684)

Oxyfluorfen

[42874-03-3]

(61600)

 Parathionmethyl

[298-00-0]

(61664)

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E0.005 – na E0.020 na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E0.008 – na E0.538 na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – na E0.069 na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E0.022 – na E0.397 na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E0.023 – na E0.108 na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E0.018 – na E0.059 na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E0.047 – na E0.060 na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.055 – na E0.292 na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E0.023 – na E0.033 na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E0.011 – na E0.013 na na 0.120

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – na – na na 0.107

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – na – na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – na – na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – na – na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – na – na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E0.004 – na – na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – na – na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – na – na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E0.019 – na E4.18 na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E0.017 – na E1.09 na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – na E0.684 na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E0.067 – na E0.202 na na –

16 Gridley High School precipitation gage at Gridley 392205121410201 – – na E0.328 na na –

16 Gridley High School precipitation gage at Gridley 392205121410201 – – na E1.99 na na –

16 Gridley High School precipitation gage at Gridley 392205121410201 – – na na na na –

16 Gridley High School precipitation gage at Gridley 392205121410201 – – na na na na –

16 Gridley High School precipitation gage at Gridley 392205121410201 E0.017 – na – na na –

16 Gridley High School precipitation gage at Gridley 392205121410201 E0.032 – na – na na –

16 Gridley High School precipitation gage at Gridley 392205121410201 E0.032 – na – na na –

16 Gridley High School precipitation gage at Gridley 392205121410201 E0.068 – na – na na –

16 Gridley High School precipitation gage at Gridley 392205121410201 E0.015 – na – na na –
118 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 2002–04 study period at eight sites in the Central Valley, California.—Continued [All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L mul- tiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: E, esti- mated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; –, compound not detected; [-], no Chemical Abstract Service Number available for given compound] Site number Site name Site identification number Metolachlor [51218-45-2] (39415) Metribuzin [21087-64-9] (82630) Molinate [2212-67-1] (82671) Myclobutanil (E) [88671-89-0] (61599) Napropamide [15299-99-7] (82684) Oxyfluorfen [42874-03-3] (61600) Parathion- methyl [298-00-0] (61664) 16 Gridley High School precipitation gage at Gridley 392205121410201 – – na – na na 0.657 16 Gridley High School precipitation gage at Gridley 392205121410201 E0.028 – na – na na 0.193 16 Gridley High School precipitation gage at Gridley 392205121410201 – – na – na na 0.204 16 Gridley High School precipitation gage at Gridley 392205121410201 – – na – na na – 16 Gridley High School precipitation gage at Gridley 392205121410201 – – na – na na 0.084 16 Gridley High School precipitation gage at Gridley 392205121410201 – – na – na na 0.050 16 Gridley High School precipitation gage at Gridley 392205121410201 E0.022 – na – na na 0.043 16 Gridley High School precipitation gage at Gridley 392205121410201 – – na – na na – 16 Gridley High School precipitation gage at Gridley 392205121410201 – – na – na na – 16 Gridley High School precipitation gage at Gridley 392205121410201 – – na – na na – 16 Gridley High School precipitation gage at Gridley 392205121410201 – – na – na na – 16 Gridley High School precipitation gage at Gridley 392205121410201 – – na – na na – 16 Gridley High School precipitation gage at Gridley 392205121410201 – – na – na na – 16 Gridley High School precipitation gage at Gridley 392205121410201 – – na – na na – 16 Gridley High School precipitation gage at Gridley 392205121410201 – – na – na na 0.062 16 Gridley High School precipitation gage at Gridley 392205121410201 – – na E0.127 na na – 16 Gridley High School precipitation gage at Gridley 392205121410201 – – na E0.184 na na – 15 Oroville Dam precipitation gage at spillway 393234121292701 – – na – na na – 15 Oroville Dam precipitation gage at spillway 393234121292701 – – na – na na – 15 Oroville Dam precipitation gage at spillway 393234121292701 – – na – na na – 15 Oroville Dam precipitation gage at spillway 393234121292701 – – na na na na –

15 Oroville Dam precipitation gage at spillway 393234121292701 E0.022 – na – na na –

15 Oroville Dam precipitation gage at spillway 393234121292701

M – na – na na –

15 Oroville Dam precipitation gage at spillway 393234121292701 E0.039 – na – na na –

15 Oroville Dam precipitation gage at spillway 393234121292701 – – na – na na –

15 Oroville Dam precipitation gage at spillway 393234121292701 – – na – na na –

15 Oroville Dam precipitation gage at spillway 393234121292701 – – na – na na –

15 Oroville Dam precipitation gage at spillway 393234121292701 – – na – na na –

15 Oroville Dam precipitation gage at spillway 393234121292701 E0.043 – na E0.107 na na –15 Oroville Dam precipitation gage at spillway 393234121292701 – E0.033 na E0.322 na na –
Appendix 3 119

Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 

2002–04 study period at eight sites in the Central Valley, California.—Continued

[All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: 

E, estimated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; –, compound not detected; [-], no Chemical Abstract Service Number available for given compound]

Site 

number Site name

Site 

identification 

number

 Paraoxonmethyl (E)

[950-35-6]

(61664)

Pendimethalin

[40487-42-1]

(82683)

cis-Permethrin

[54774-45-7]

(82687)

cis-Propiconazole

[-]

(79846)

transPropiconazole

[-]

(79847)

Phosmet

[732-11-6]

(61601)

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – – – – –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – 0.079 – – – –11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – 0.278 – E0.010 0.02 –11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – – – – –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – 0.177 – 0.043 E0.04 –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – 2.67 – na na E0.24111 Newman rain gage at wasteway levee near Draper Road 371735121031201 – 0.621 – na na –11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – – na na –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – 0.774 – na na –11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – 0.380 – na na E0.13311 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – – na na –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – 0.091 – na na E0.025

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – E0.308 – na na –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – E0.560 – na na –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – 0.069 – na na –11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – E0.361 – na na –

12 Turlock rain gage near Idaho Road 372713120534901 – 0.160 E0.02 – – –

12 Turlock rain gage near Idaho Road 372713120534901 – 0.110 – – – –

12 Turlock rain gage near Idaho Road 372713120534901 – 0.422 – – – –

12 Turlock rain gage near Idaho Road 372713120534901 – – – 0.040 0.11 –

12 Turlock rain gage near Idaho Road 372713120534901 – – – – – –

12 Turlock rain gage near Idaho Road 372713120534901 – – – – – –

12 Turlock rain gage near Idaho Road 372713120534901 – 0.172 – 0.057 0.06 E0.20412 Turlock rain gage near Idaho Road 372713120534901 – 0.628 – na na E0.17112 Turlock rain gage near Idaho Road 372713120534901 – 0.483 – na na –

12 Turlock rain gage near Idaho Road 372713120534901 – 0.094 – na na –

12 Turlock rain gage near Idaho Road 372713120534901 – 0.506 – na na –

12 Turlock rain gage near Idaho Road 372713120534901 na E0.086 – na na –

12 Turlock rain gage near Idaho Road 372713120534901 – 0.438 – na na E0.07312 Turlock rain gage near Idaho Road 372713120534901 – – – na na –

12 Turlock rain gage near Idaho Road 372713120534901 – E0.056 – na na E0.042
120 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 2002–04 study period at eight sites in the Central Valley, California.—Continued [All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: E, estimated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; –, compound not detected; [-], no Chemical Abstract Service Number available for given compound] Site number Site name Site identification number Paraoxon- methyl (E) [950-35-6] (61664) Pendimethalin [40487-42-1] (82683) cis-Permethrin [54774-45-7] (82687) cis-Propi- conazole [-] (79846) trans- Propiconazole [-] (79847) Phosmet [732-11-6] (61601) 12 Turlock rain gage near Idaho Road 372713120534901 – E0.038

– na na E0.027

12 Turlock rain gage near Idaho Road 372713120534901 – E0.394 E0.04 na na –

12 Turlock rain gage near Idaho Road 372713120534901 – E0.153 – na na –

12 Turlock rain gage near Idaho Road 372713120534901 – 0.036 – na na –

12 Turlock rain gage near Idaho Road 372713120534901 – E0.187 – na na –

12 Turlock rain gage near Idaho Road 372713120534901 – 0.072

– na na na

13 Turlock Airport rain gage 372857120414001 – E0.152 E0.04 – – –

13 Turlock Airport rain gage 372857120414001 – – – – – –

13 Turlock Airport rain gage 372857120414001 – 0.137 – – – –

13 Turlock Airport rain gage 372857120414001 – 0.215

– 0.096 0.14 –

13 Turlock Airport rain gage 372857120414001 – – – 0.019 0.04 E0.337

13 Turlock Airport rain gage 372857120414001 – – – 0.047 0.07 –

13 Turlock Airport rain gage 372857120414001 – 0.157 – 0.062 0.07 –

13 Turlock Airport rain gage 372857120414001 – 0.818 – na na E0.33813 Turlock Airport rain gage 372857120414001 – 0.340 – na na –

13 Turlock Airport rain gage 372857120414001 – E0.065 – na na –

13 Turlock Airport rain gage 372857120414001 – E0.279 – na na –

13 Turlock Airport rain gage 372857120414001 – 0.113 – na na –

13 Turlock Airport rain gage 372857120414001 – 0.086

– na na –

13 Turlock Airport rain gage 372857120414001 – 0.276 – na na E0.08713 Turlock Airport rain gage 372857120414001 – E0.107 – na na –

13 Turlock Airport rain gage 372857120414001 – E0.078 – na na E0.09313 Turlock Airport rain gage 372857120414001 – E0.037 – na na E0.03913 Turlock Airport rain gage 372857120414001 – E0.561 – na na –

13 Turlock Airport rain gage 372857120414001 – 0.182 – na na –

13 Turlock Airport rain gage 372857120414001 – E0.122 – na na –

13 Turlock Airport rain gage 372857120414001 – 0.349 – na na na

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – 0.262 – – – –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – 1.13 – – – –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – 0.200 – 0.087 0.11 –
Appendix 3 121

Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 

2002–04 study period at eight sites in the Central Valley, California.—Continued

[All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: 

E, estimated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; –, compound not detected; [-], no Chemical Abstract Service Number available for given compound]

Site 

number Site name

Site 

identification 

number

 Paraoxonmethyl (E)

[950-35-6]

(61664)

Pendimethalin

[40487-42-1]

(82683)

cis-Permethrin

[54774-45-7]

(82687)

cis-Propiconazole

[-]

(79846)

transPropiconazole

[-]

(79847)

Phosmet

[732-11-6]

(61601)

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – 0.146 – 0.083 0.11 –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – 0.221 – E0.021 E0.05 –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – 0.750 – E0.059 E0.08 –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – 1.79 – na na E0.316

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – 1.09 – na na –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – 0.158 – na na –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – 0.791 – na na –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – 0.352 – na na –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – 0.795 – na na E0.128

10 Westley rain gage at pump building near lateral 6 North 373335121143001 E0.087 0.329 E0.05 na na E0.08710 Westley rain gage at pump building near lateral 6 North 373335121143001 – 0.227 – na na –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – E2.70 – na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – 0.165 – – – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – 0.326 – – – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – 0.367 – – – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 na 0.237 – na na na

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – 0.191 – – – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – 0.610 – E0.07 E0.10 –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – 0.028 – – – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – 0.926 – na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.552 0.911 – na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – 0.580 – na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – 0.375 – na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – 0.299 – na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – E0.085 – na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – 0.069 – na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – 0.598 – na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – 0.666 – na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – 0.120 – na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – 0.187 – na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – 0.132 – na na –
122 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 2002–04 study period at eight sites in the Central Valley, California.—Continued [All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: E, estimated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; –, compound not detected; [-], no Chemical Abstract Service Number available for given compound] Site number Site name Site identification number Paraoxon- methyl (E) [950-35-6] (61664) Pendimethalin [40487-42-1] (82683) cis-Permethrin [54774-45-7] (82687) cis-Propi- conazole [-] (79846) trans- Propiconazole [-] (79847) Phosmet [732-11-6] (61601)

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – 0.961 – na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – 0.450

– na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – 0.071 – na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – 0.094 – na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – 0.102 – na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.073 E0.059 – na na E0.0734 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – 0.055

– na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – 1.01 – na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – 0.331

– na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – E0.107 – na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – E1.11 – na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – E0.8 – na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – 0.073 – na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – E0.436 – na na –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – 0.094 – na na na

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – 0.199 – – – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – 0.145 – – – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – 0.897

– – – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – 0.193 0.18 –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – E0.062 E0.11 –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – 0.171 – 0.140 2.20 –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – E0.429 – na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – E0.469 – na na E0.235

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – 0.328 – na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – 0.392

– na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – 0.121 – na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – 0.106 – na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – 0.061

– na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – 0.575 – na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – 0.378 – na na –
Appendix 3 123

Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 

2002–04 study period at eight sites in the Central Valley, California.—Continued

[All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: 

E, estimated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; –, compound not detected; [-], no Chemical Abstract Service Number available for given compound]

Site 

number Site name

Site 

identification 

number

 Paraoxonmethyl (E)

[950-35-6]

(61664)

Pendimethalin

[40487-42-1]

(82683)

cis-Permethrin

[54774-45-7]

(82687)

cis-Propiconazole

[-]

(79846)

transPropiconazole

[-]

(79847)

Phosmet

[732-11-6]

(61601)

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – 0.058 – na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 na E0.057 – na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 na E0.049 – na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – 0.639 – na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – 0.971 – na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – 0.210 – na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – E0.087 – na na E0.053

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – 0.104 – na na E0.049

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – E0.031 – na na E0.053

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – na na E0.033

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – 0.182 – na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – E0.104 – na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – 0.694 – na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – 0.255 – na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – E0.018 – na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – E0.577 E0.03 na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – E0.338 E0.02 na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – E0.321 – na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – 0.094 – na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – E0.260 – na na –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – 0.561 – na na na

16 Gridley High School precipitation gage at Gridley 392205121410201 – 1.40 – na na –

16 Gridley High School precipitation gage at Gridley 392205121410201 – 0.880 – na na –

16 Gridley High School precipitation gage at Gridley 392205121410201 na 0.549 – na na –

16 Gridley High School precipitation gage at Gridley 392205121410201 na – – na na –

16 Gridley High School precipitation gage at Gridley 392205121410201 – E0.055 – na na –

16 Gridley High School precipitation gage at Gridley 392205121410201 – 0.267 – na na –

16 Gridley High School precipitation gage at Gridley 392205121410201 – E0.063 – na na –

16 Gridley High School precipitation gage at Gridley 392205121410201 – E0.169 – na na –

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – na na –
124 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 2002–04 study period at eight sites in the Central Valley, California.—Continued [All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: E, estimated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; –, compound not detected; [-], no Chemical Abstract Service Number available for given compound] Site number Site name Site identification number Paraoxon- methyl (E) [950-35-6] (61664) Pendimethalin [40487-42-1] (82683) cis-Permethrin [54774-45-7] (82687) cis-Propi- conazole [-] (79846) trans- Propiconazole [-] (79847) Phosmet [732-11-6] (61601) 16 Gridley High School precipitation gage at Gridley 392205121410201 E0.111 – – na na E0.078 16 Gridley High School precipitation gage at Gridley 392205121410201 – – – na na – 16 Gridley High School precipitation gage at Gridley 392205121410201 – – – na na na 16 Gridley High School precipitation gage at Gridley 392205121410201 – – – na na – 16 Gridley High School precipitation gage at Gridley 392205121410201 – E0.137 – na na – 16 Gridley High School precipitation gage at Gridley 392205121410201 – E0.062 – na na – 16 Gridley High School precipitation gage at Gridley 392205121410201 – 0.141 – na na – 16 Gridley High School precipitation gage at Gridley 392205121410201 – 0.212 – na na – 16 Gridley High School precipitation gage at Gridley 392205121410201 – E0.200

– na na –

16 Gridley High School precipitation gage at Gridley 392205121410201 – 0.205 – na na –

16 Gridley High School precipitation gage at Gridley 392205121410201 – 0.140

– na na –

16 Gridley High School precipitation gage at Gridley 392205121410201 – 0.089 – na na –

16 Gridley High School precipitation gage at Gridley 392205121410201 – E0.103 – na na –

16 Gridley High School precipitation gage at Gridley 392205121410201 – E0.064 – na na –

16 Gridley High School precipitation gage at Gridley 392205121410201 – 0.419 – na na –

16 Gridley High School precipitation gage at Gridley 392205121410201 – E0.488 – na na –

16 Gridley High School precipitation gage at Gridley 392205121410201 – E0.126 – na na –

15 Oroville Dam precipitation gage at spillway 393234121292701 – E0.260 – na na –

15 Oroville Dam precipitation gage at spillway 393234121292701 – – – na na –

15 Oroville Dam precipitation gage at spillway 393234121292701 – – – na na –

15 Oroville Dam precipitation gage at spillway 393234121292701 na 0.179 – na na –

15 Oroville Dam precipitation gage at spillway 393234121292701 – 0.254 – na na –

15 Oroville Dam precipitation gage at spillway 393234121292701 – – – na na –

15 Oroville Dam precipitation gage at spillway 393234121292701 – E0.070 – na na –

15 Oroville Dam precipitation gage at spillway 393234121292701 – E0.026 – na na –

15 Oroville Dam precipitation gage at spillway 393234121292701 – E0.104

– na na –

15 Oroville Dam precipitation gage at spillway 393234121292701 – – 0.04 na na –

15 Oroville Dam precipitation gage at spillway 393234121292701 – E0.069 – na na –

15 Oroville Dam precipitation gage at spillway 393234121292701 – E0.278 – na na –

15 Oroville Dam precipitation gage at spillway 393234121292701 – E0.091 – na na –
Appendix 3 125

Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 

2002–04 study period at eight sites in the Central Valley, California.—Continued

[All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: 

E, estimated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; –, compound not detected; [-], no Chemical Abstract Service Number available for given compound]

Site 

number Site name

Site 

identification 

number

Phosmet 

oxon

[3735-33-9]

(61668)

Prometryn

[7287-19-6]

(04036)

Pronamide

[23950-58-5]

(82676)

Simazine

[122-34-9]

(04035)

Terbufos-oxonsulfone

[56070-15-6]

(61674)

Trifluralin

[1582-09-8]

(82661)

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – 0.053 – 0.482 – –11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – – 0.104 – 0.049

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – – 0.217 E0.06 29.0

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – – 0.045 – 0.429

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – – 0.082 – 0.753

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – 0.193 0.145 0.530 – 0.578

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – 1.407 0.073 2.57 – 0.152

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – 0.096 – 0.055 – 0.07511 Newman rain gage at wasteway levee near Draper Road 371735121031201 – 0.155 0.143 0.274 – 0.310

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – – 0.881 – 0.184

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – – 0.092 – 0.026

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 na 0.101 0.025 0.044 – 0.060

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – – 0.342 – E0.096

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 E0.08 E0.042 0.042 1.84 – 0.195

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – 0.019 0.055 – 0.011

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – E0.030 – 0.221 – 0.271

12 Turlock rain gage near Idaho Road 372713120534901 – 0.043 – 0.324 – E0.023

12 Turlock rain gage near Idaho Road 372713120534901 – 0.020 – 0.193 – –12 Turlock rain gage near Idaho Road 372713120534901 – 0.030 – 0.270 – –12 Turlock rain gage near Idaho Road 372713120534901 – – – 0.351 – 0.043

12 Turlock rain gage near Idaho Road 372713120534901 – – – – – 0.052

12 Turlock rain gage near Idaho Road 372713120534901 – – – – – E0.053

12 Turlock rain gage near Idaho Road 372713120534901 – – – 0.242 E0.127 –12 Turlock rain gage near Idaho Road 372713120534901 – 0.285 – 0.209 – E0.152

12 Turlock rain gage near Idaho Road 372713120534901 – 0.581 0.059 0.256 – E0.079

12 Turlock rain gage near Idaho Road 372713120534901 – 0.086 – 0.057 – E0.029

12 Turlock rain gage near Idaho Road 372713120534901 – 0.090 E0.072 0.397 – E0.09

12 Turlock rain gage near Idaho Road 372713120534901 na – – 0.112 na –

12 Turlock rain gage near Idaho Road 372713120534901 – – – 0.226 – 0.080

12 Turlock rain gage near Idaho Road 372713120534901 – – – 0.205 – –12 Turlock rain gage near Idaho Road 372713120534901 – – – 0.078 – –12 Turlock rain gage near Idaho Road 372713120534901 na 0.113 0.025 0.047 – 0.025
126 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 2002–04 study period at eight sites in the Central Valley, California.—Continued [All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: E, estimated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; –, compound not detected; [-], no Chemical Abstract Service Number available for given compound] Site number Site name Site identification number Phosmet oxon [3735-33-9] (61668) Prometryn [7287-19-6] (04036) Pronamide [23950-58-5] (82676) Simazine [122-34-9] (04035) Terbufos-oxon- sulfone [56070-15-6] (61674) Trifluralin [1582-09-8] (82661) 12 Turlock rain gage near Idaho Road 372713120534901 – – – 1.27 – E0.165 12 Turlock rain gage near Idaho Road 372713120534901 – – – 1.18 – 0.077 12 Turlock rain gage near Idaho Road 372713120534901 – – – 0.064 – E0.002 12 Turlock rain gage near Idaho Road 372713120534901 – – – 0.292 – 0.053 12 Turlock rain gage near Idaho Road 372713120534901 na – 0.057 0.319 – 0.072 13 Turlock Airport rain gage 372857120414001 – – – 0.456 – E0.045 13 Turlock Airport rain gage 372857120414001 – – – 0.442 – – 13 Turlock Airport rain gage 372857120414001 – 0.038 – 0.256 – – 13 Turlock Airport rain gage 372857120414001 – – – 0.845 – 0.043 13 Turlock Airport rain gage 372857120414001 – – – 0.199 – – 13 Turlock Airport rain gage 372857120414001 – – – 0.074 – – 13 Turlock Airport rain gage 372857120414001 – – – 0.167 – – 13 Turlock Airport rain gage 372857120414001 – 0.197 0.141 0.902 – E0.197 13 Turlock Airport rain gage 372857120414001 – 0.287 0.074 0.584 – E0.064 13 Turlock Airport rain gage 372857120414001 – 0.048 – 0.075 – – 13 Turlock Airport rain gage 372857120414001 – – – 0.427 – E0.082 13 Turlock Airport rain gage 372857120414001 – – – 0.536 – E0.016 13 Turlock Airport rain gage 372857120414001 – – – 0.123 – 0.029 13 Turlock Airport rain gage 372857120414001 – – – 48.9 – 0.073 13 Turlock Airport rain gage 372857120414001 – – – 1.59 – E0.043 13 Turlock Airport rain gage 372857120414001 – – – 0.706 – E0.039 13 Turlock Airport rain gage 372857120414001 na 0.071 0.027 0.188 – E0.017

13 Turlock Airport rain gage 372857120414001 – – – 1.59 – E0.076

13 Turlock Airport rain gage 372857120414001 – – – 0.180 – E0.004

13 Turlock Airport rain gage 372857120414001 – – – 0.456 – E0.03

13 Turlock Airport rain gage 372857120414001 – 0.081 1.06 – 0.151

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – 0.054 – 0.076 – 0.020

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – 0.026 0.021 0.239 – 0.104

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – – – 0.157 – –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – – – 0.123 – –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – – – 0.031 – E0.041
Appendix 3 127

Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 

2002–04 study period at eight sites in the Central Valley, California.—Continued

[All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: 

E, estimated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; –, compound not detected; [-], no Chemical Abstract Service Number available for given compound]

Site 

number Site name

Site 

identification 

number

Phosmet 

oxon

[3735-33-9]

(61668)

Prometryn

[7287-19-6]

(04036)

Pronamide

[23950-58-5]

(82676)

Simazine

[122-34-9]

(04035)

Terbufos-oxonsulfone

[56070-15-6]

(61674)

Trifluralin

[1582-09-8]

(82661)

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – 0.059 – 0.143 – 0.059

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – 0.211 0.169 0.443 – 0.35810 Westley rain gage at pump building near lateral 6 North 373335121143001 – 0.756 0.089 0.330 – 0.11310 Westley rain gage at pump building near lateral 6 North 373335121143001 – 0.050 – 0.079 – E0.033

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – 0.112 0.112 0.270 – 0.09310 Westley rain gage at pump building near lateral 6 North 373335121143001 – – – 0.210 – 0.03310 Westley rain gage at pump building near lateral 6 North 373335121143001 – 0.048 – 0.257 – 0.120

10 Westley rain gage at pump building near lateral 6 North 373335121143001 na 0.130 0.078 0.104 – 0.338

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – 0.015 0.030 0.059 – E0.00210 Westley rain gage at pump building near lateral 6 North 373335121143001 – – – 0.057 – 0.218

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – 0.201 – 0.019

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – 0.314 – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – – – –4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 na na – – na E0.033

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – 0.051 – E0.020

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – 0.240 – 0.080

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – 0.044 – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – 0.253 – 0.281 – 0.253

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – 0.166 – 0.469 – E0.166

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – 0.438 0.066 0.219 – E0.099

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – 0.563 E0.047 0.141 – E0.07

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – 0.052 0.030 0.039 – E0.035

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – 0.058 – – – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – 0.028 – 0.107 – E0.011

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – 0.274 – E0.075

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – 0.269 – E0.064

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – 0.201 – 0.020

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – 0.110 – 0.031

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – 0.073 – 0.029

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – 0.378 – 0.112

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – 0.225 – E0.049

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – 0.060 – –
128 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 2002–04 study period at eight sites in the Central Valley, California.—Continued [All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: E, estimated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; –, compound not detected; [-], no Chemical Abstract Service Number available for given compound] Site number Site name Site identification number Phosmet oxon [3735-33-9] (61668) Prometryn [7287-19-6] (04036) Pronamide [23950-58-5] (82676) Simazine [122-34-9] (04035) Terbufos-oxon- sulfone [56070-15-6] (61674) Trifluralin [1582-09-8] (82661)

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – 0.057 – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – 0.066 – 0.028

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 na 0.125

– 0.172 – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – 0.052

– 0.045 – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – 0.098

– 0.033 – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – 0.500 0.167 1.06 – E0.077

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – E0.015

– 0.108 – E0.031

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – – – E0.015

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – E0.038 – 1.42 – E0.077

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – 1.047 – E0.062

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – 0.097 – E0.005

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – 0.382 – E0.065

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 na – – 0.805 – –5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – 0.225 – E0.0395 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – 0.196 – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – E0.025 0.623 – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – 0.743 – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – 0.398 – 0.0315 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – 0.641 – 0.055

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – 0.143 – 0.486 – E0.143

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – E0.147

– 1.03 – E0.147

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – 0.208 0.044 0.405 – E0.055

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – 0.201 E0.042 0.328 – E0.0535 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – 0.056 – 0.052 – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – 0.051 0.043 0.039 – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – 0.023 0.013 0.067 – E0.0115 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – E0.049 0.246 – E0.066

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – 0.098 – E0.07

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – 0.055 – 0.012

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 na – – 0.192 na –5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 na – – 0.058 na –5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – 1.40 – E0.044
Appendix 3 129

Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 

2002–04 study period at eight sites in the Central Valley, California.—Continued

[All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: 

E, estimated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; –, compound not detected; [-], no Chemical Abstract Service Number available for given compound]

Site 

number Site name

Site 

identification 

number

Phosmet 

oxon

[3735-33-9]

(61668)

Prometryn

[7287-19-6]

(04036)

Pronamide

[23950-58-5]

(82676)

Simazine

[122-34-9]

(04035)

Terbufos-oxonsulfone

[56070-15-6]

(61674)

Trifluralin

[1582-09-8]

(82661)

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – 0.455 – E0.046

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – 0.141 – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – 0.040 0.147 – E0.033

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – 0.489 – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – 0.118 – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 na 0.118 – 0.081 – E0.011

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 na 0.037 0.020 0.043 – E0.020

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – 0.078 – 0.172 – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – 0.060 – 0.104 – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – 0.268 – 27.2 – 0.158

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – 0.309 – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – 0.023 – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – 2.31 – E0.1345 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – 0.518 – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E0.047 – – 1.01 – 0.051

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – 0.385 – E0.002

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – 0.356 – E0.0415 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 na – – 1.98 – E0.045

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – 0.794 – 0.958

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – 1.43 – E0.228

16 Gridley High School precipitation gage at Gridley 392205121410201 na – – – na E0.093

16 Gridley High School precipitation gage at Gridley 392205121410201 na – – 0.069 na E0.025

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – 0.299 – E0.019

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – 0.089 – 0.105

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – – – 0.058

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – – – E0.034

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – – – –

16 Gridley High School precipitation gage at Gridley 392205121410201 na – – 0.067 – –

16 Gridley High School precipitation gage at Gridley 392205121410201 na – – 0.081 – –16 Gridley High School precipitation gage at Gridley 392205121410201 na 0.041 – 0.150 – –16 Gridley High School precipitation gage at Gridley 392205121410201 – 0.030 – 0.055 – –16 Gridley High School precipitation gage at Gridley 392205121410201 – 0.046 – 0.068 – –
130 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 3. Calculated flux values presented as micrograms per square meter per day (μg/m2/day) for wet-deposition samples with at least one detection collected during the 2002–04 study period at eight sites in the Central Valley, California.—Continued [All compounds were analyzed by gas chromatography/mass spectrometry (GCMS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five-digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in μg/L multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 m2, Autosampler= 0.0614 m2) and sample composite time in days. Abbreviations: E, estimated reported laboratory value; na, not applicable; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; –, compound not detected; [-], no Chemical Abstract Service Number available for given compound] Site number Site name Site identification number Phosmet oxon [3735-33-9] (61668) Prometryn [7287-19-6] (04036) Pronamide [23950-58-5] (82676) Simazine [122-34-9] (04035) Terbufos-oxon- sulfone [56070-15-6] (61674) Trifluralin [1582-09-8] (82661) 16 Gridley High School precipitation gage at Gridley 392205121410201 – 0.034

– 0.037 – –

16 Gridley High School precipitation gage at Gridley 392205121410201 – 0.054

– 0.049 – –

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – – – –

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – 0.106 – –

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – E0.039 – –

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – 0.079 – –

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – 0.052 – –

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – 0.078 – 0.049

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – 0.104 – –

16 Gridley High School precipitation gage at Gridley 392205121410201 – – 0.078 0.667 – E0.016

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – 0.212 – E0.064

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – 0.084 – –

15 Oroville Dam precipitation gage at spillway 393234121292701 – – – E0.055 – E0.055

15 Oroville Dam precipitation gage at spillway 393234121292701 – – – – – –

15 Oroville Dam precipitation gage at spillway 393234121292701 – – – 0.018 – –15 Oroville Dam precipitation gage at spillway 393234121292701 na – – – na E0.024

15 Oroville Dam precipitation gage at spillway 393234121292701 – – – 0.164 – 0.082

15 Oroville Dam precipitation gage at spillway 393234121292701 – – – – – –15 Oroville Dam precipitation gage at spillway 393234121292701 – – – – – –15 Oroville Dam precipitation gage at spillway 393234121292701 – 0.026 – E0.009 – –

15 Oroville Dam precipitation gage at spillway 393234121292701 – – – E0.016 – –

15 Oroville Dam precipitation gage at spillway 393234121292701 – – – E0.017 – –15 Oroville Dam precipitation gage at spillway 393234121292701 – – – 0.052 – –15 Oroville Dam precipitation gage at spillway 393234121292701 – – – 0.235 – –15 Oroville Dam precipitation gage at spillway 393234121292701 – – – 0.149 – –
Appendix 3 131

References Cited

Childress, C.J.O., Foreman, W.T., Connor, B.F., and Maloney, T.J., 1999, New reporting procedures based on long-term method detection levels and some considerations for interpretations of water-quality data provided by the U.S. Geological Survey National Water Quality Laboratory: U.S. Geological Survey Open-File Report 

99–193, 19 p.

Sandstrom, M.W., Stroppel, M.E., Foreman, W.T., and Schroeder, M.P., 2001, Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory–Determination of moderate-use pesticides and selected degradates in water by C-18 solid-phase extraction and capillary-column gas chromatography/mass spectrometry with selected-ion monitoring (methods 2002/2011): U.S. Geological Survey Water-Resources Investigations Report 01–4098, 70 p.
132 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides

Appendix 4. Calculated Flux Values Presented in 

Micrograms Per Square Meter Per Day (μg/m2/day) for 

Bulk Wet-Deposition Samples With at Least One Detection 

Collected During the 2002–04 Study Period at Eight Sites in 

the Central Valley, California
Appendix 4 133

Appendix 4. Calculated flux values presented in micrograms per square meter per day (μg/m2/day) for bulk wet-deposition samples with at least one detection collected during 

the 2002–04 study period at eight sites in the Central Valley, California.—Continued

[All compounds were analyzed by gas chromatography/mass spectrometry (GC/MS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in microgram per liter (μg/L) multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 square meter [m2], Autosampler=0.0614 m2) and sample 

composite time in days. Abbreviations: D-U, value deleted by NWQL because compound could not be determined due to matrix interference; E, estimated reported laboratory value; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; [-], no Chemical Abstract Service Number available for given compound; 

<, less than laboratory reporting limit; –, not detected]

Site 

number Site name

Site 

identification 

number

Start date

Start 

time

(hh:mm)

End date

End 

time

(hh:mm)

Composite 

sample 

time, 

days

Rain events 

during 

composite 

sample time, 

days

Sample 

type

Sampler 

type

Total 

sample volume 

collected, 

liters

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 Dec 22, 2002 13:00 Jan 8, 2003 14:00 17 7 Bulk-wet Funnel 0.78

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 Jan 14, 2003 10:10 Feb 14, 2003 08:30 31 6 Bulk-wet Funnel 0.81

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 Feb 21, 2003 10:15 Mar 13, 2003 10:20 20 2 Bulk-wet Funnel 1.3

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 Mar 27, 2003 10:20 Apr 8, 2003 09:00 12 3 Bulk-wet Funnel 0.7

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 Apr 8, 2003 10:00 Apr 29, 2003 09:40 21 4 Bulk-wet Funnel 0.76

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 Apr 29, 2003 09:40 May 9, 2003 16:00 10 3 Bulk-wet Funnel 0.71

12 Turlock rain gage near Idaho Road 372713120534901 Dec 22, 2002 13:30 Jan 8, 2003 14:40 17 7 Bulk-wet Funnel 0.81

12 Turlock rain gage near Idaho Road 372713120534901 Feb 21, 2003 11:00 Mar 13, 2003 11:00 20 2 Bulk-wet Funnel 0.4512 Turlock rain gage near Idaho Road 372713120534901 Mar 27, 2003 11:20 Apr 8, 2003 09:40 12 3 Bulk-wet Funnel 1.04

12 Turlock rain gage near Idaho Road 372713120534901 Apr 8, 2003 10:40 Apr 29, 2003 10:30 21 4 Bulk-wet Funnel 1.46

13 Turlock Airport rain gage 372857120414001 Dec 22, 2002 14:00 Jan 9, 2003 13:50 18 7 Bulk-wet Funnel 1.26

13 Turlock Airport rain gage 372857120414001 Feb 21, 2003 11:40 Mar 12, 2003 10:00 19 2 Bulk-wet Funnel 0.52

13 Turlock Airport rain gage 372857120414001 Mar 18, 2003 11:50 Apr 8, 2003 10:20 21 5 Bulk-wet Funnel 1.42

13 Turlock Airport rain gage 372857120414001 Apr 8, 2003 11:20 Apr 26, 2003 13:00 18 3 Bulk-wet Funnel 0.76

13 Turlock Airport rain gage 372857120414001 Feb 4, 2004 10:30 Feb 19, 2004 10:10 15 5 Bulk-wet Funnel 2.64

10 Westley rain gage at pump building near lateral 6 North 373335121143001 Dec 22, 2002 12:00 Jan 8, 2003 13:15 17 7 Bulk-wet Funnel 1.05

10 Westley rain gage at pump building near lateral 6 North 373335121143001 Jan 14, 2003 09:20 Feb 15, 2003 11:45 32 6 Bulk-wet Funnel 1.510 Westley rain gage at pump building near lateral 6 North 373335121143001 Mar 27, 2003 09:20 May 2, 2003 09:20 36 7 Bulk-wet Funnel 1.26

10 Westley rain gage at pump building near lateral 6 North 373335121143001 Feb 4, 2004 13:30 Feb 19, 2004 14:20 15 5 Bulk-wet Funnel 0.98

Appendix 4. Calculated flux values presented in micrograms per square meter per day (μg/m2/day) for bulk wet-deposition samples with at least one detection collected during 

the 2002–04 study period at eight sites in the Central Valley, California.
134 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 4. Calculated flux values presented in micrograms per square meter per day (μg/m2/day) for bulk wet-deposition samples with at least one detection collected during the 2002–04 study period at eight sites in the Central Valley, California.—Continued [All compounds were analyzed by gas chromatography/mass spectrometry (GC/MS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in microgram per liter (μg/L) multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 square meter [m2], Autosampler=0.0614 m2) and sample composite time in days. Abbreviations: D-U, value deleted by NWQL because compound could not be determined due to matrix interference; E, estimated reported laboratory value; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; [-], no Chemical Abstract Service Number available for given compound; <, less than laboratory reporting limit; –, not detected] Site num- ber Site name Site identification number Start date Start time (hh:mm) End date End time (hh:mm) Composite sample time, days Rain events during composite sample time, days Sample type Sampler type Total sample volume collected, liters

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Dec 23, 2002 09:30 Jan 9, 2003 15:30 17 6 Bulk-wet Funnel 1.3

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Mar 27, 2003 14:50 Apr 8, 2003 13:10 12 3 Bulk-wet Funnel 0.86

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Apr 8, 2003 14:10 Apr 29, 2003 14:30 21 4 Bulk-wet Funnel 1.45

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Feb 4, 2004 08:00 Feb 19, 2004 08:10 15 5 Bulk-wet Funnel 2.24

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Dec 23, 2002 10:30 Jan 9, 2003 14:30 17 6 Bulk-wet Funnel 0.78

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Mar 27, 2003 13:50 Apr 8, 2003 11:50 12 3 Bulk-wet Funnel 1.41

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Apr 8, 2003 12:50 Apr 29, 2003 13:30 21 4 Bulk-wet Funnel 2.02

16 Gridley High School precipitation gage at Gridley 392205121410201 Mar 28, 2003 12:10 Apr 9, 2003 13:00 12 1 Bulk-wet Funnel 0.85

16 Gridley High School precipitation gage at Gridley 392205121410201 Jul 21, 2003 09:00 Aug 6, 2003 11:30 16 1 Bulk-wet Funnel 1.515

16 Gridley High School precipitation gage at Gridley 392205121410201 Aug 6, 2003 11:30 Aug 29, 2003 09:30 23 2 Bulk-wet Funnel 0.26

15 Oroville Dam precipitation gage at spillway 393234121292701 Nov 14, 2002 12:00 Dec 19, 2002 11:00 35 8 Bulk-wet Funnel 2.28

15 Oroville Dam precipitation gage at spillway 393234121292701 Dec 23, 2002 10:30 Jan 7, 2003 10:30 15 6 Bulk-wet Funnel 4

15 Oroville Dam precipitation gage at spillway 393234121292701 Jan 13, 2003 09:50 Jan 23, 2003 11:30 10 5 Bulk-wet Funnel 3.415 Oroville Dam precipitation gage at spillway 393234121292701 Jan 31, 2003 12:45 Feb 14, 2003 10:30 14 3 Bulk-wet Funnel 1.68

15 Oroville Dam precipitation gage at spillway 393234121292701 Mar 28, 2003 13:20 Apr 9, 2003 11:30 12 1 Bulk-wet Funnel 0.7515 Oroville Dam precipitation gage at spillway 393234121292701 Jul 21, 2003 09:00 Aug 6, 2003 13:00 16 1 Bulk-wet Funnel 0.69

15 Oroville Dam precipitation gage at spillway 393234121292701 Aug 6, 2003 13:00 Sep 2, 2003 11:15 27 2 Bulk-wet Funnel 0.9415 Oroville Dam precipitation gage at spillway 393234121292701 Jan 7, 2004 12:30 Jan 27, 2004 11:15 20 5 Bulk-wet Funnel 1.0115 Oroville Dam precipitation gage at spillway 393234121292701 Feb 6, 2004 11:50 Feb 17, 2004 15:00 11 4 Bulk-wet Funnel 4.27
Appendix 4 135

Appendix 4. Calculated flux values presented in micrograms per square meter per day (μg/m2/day) for bulk wet-deposition samples with at least one detection collected during 

the 2002–04 study period at eight sites in the Central Valley, California.—Continued

[All compounds were analyzed by gas chromatography/mass spectrometry (GC/MS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in microgram per liter (μg/L) multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 square meter [m2], Autosampler=0.0614 m2) and sample 

composite time in days. Abbreviations: D-U, value deleted by NWQL because compound could not be determined due to matrix interference; E, estimated reported laboratory value; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; [-], no Chemical Abstract Service Number available for given compound; 

<, less than laboratory reporting limit; –, not detected]

Site 

number Site name

Site 

identification 

number

 1-Naphthol 

(E)

[90-15-3]

(49295)

2,6-Diethylaniline 

(E)

[579-66-8]

(82660)

3,4-Dichloroaniline 

(E)

[95-76-1]

(61625)

 4-Chloro2-methylphenol (E)

[1570-64-5]

(61633)

 Alachlor

[15972-60-8]

(46342)

 Atrazine

[1912-24-9]

(39632)

 Azinphosmethyl 

(E)

[86-50-0]

(82686)

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – E0.017 – – – –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – E0.131 E0.017 – – –11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – E0.116 – – – –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 E0.03 – – – – – –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 E0.05 – – – – – –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 E0.002 – – – 0.023 – E0.37

12 Turlock rain gage near Idaho Road 372713120534901 E0.02 – – – – – –

12 Turlock rain gage near Idaho Road 372713120534901 – – – – – – –12 Turlock rain gage near Idaho Road 372713120534901 E0.05 – – – – – –

12 Turlock rain gage near Idaho Road 372713120534901 E0.05 – – – – – –

13 Turlock Airport rain gage 372857120414001 E0.02 – E0.017 – – – –

13 Turlock Airport rain gage 372857120414001 – – – – – – –13 Turlock Airport rain gage 372857120414001 E0.04 – – – – – –

13 Turlock Airport rain gage 372857120414001 E0.07 – – – – – E0.0513 Turlock Airport rain gage 372857120414001 E0.04 – E0.137 E0.014 – – –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 E0.02 – E0.043 – – – –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 E0.03 – E0.072 E0.017 – – –10 Westley rain gage at pump building near lateral 6 North 373335121143001 E0.12 – – – – – E0.79

10 Westley rain gage at pump building near lateral 6 North 373335121143001 E0.01 – E0.080 E0.003 – – –
136 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 4. Calculated flux values presented in micrograms per square meter per day (μg/m2/day) for bulk wet-deposition samples with at least one detection collected during the 2002–04 study period at eight sites in the Central Valley, California.—Continued [All compounds were analyzed by gas chromatography/mass spectrometry (GC/MS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in microgram per liter (μg/L) multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 square meter [m2], Autosampler=0.0614 m2) and sample composite time in days. Abbreviations: D-U, value deleted by NWQL because compound could not be determined due to matrix interference; E, estimated reported laboratory value; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; [-], no Chemical Abstract Service Number available for given compound; <, less than laboratory reporting limit; –, not detected] Site num- ber Site name Site identification number 1-Naphthol (E) [90-15-3] (49295) 2,6-Diethylaniline (E) [579-66-8] (82660) 3,4-Dichloroaniline (E) [95-76-1] (61625) 4-Chloro- 2-methylphe- nol (E) [1570-64-5] (61633) Alachlor [15972-60-8] (46342) Atrazine [1912-24-9] (39632) Azinphos- methyl (E) [86-50-0] (82686)

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.06 – E0.033 E0.009 – – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.08 – – – – – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.05 – – – – – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.07 – E0.055 E0.006 – – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E0.02 – E0.630 – – – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E0.06 – – – – – –5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E0.14 – E0.076 – – – E0.08

16 Gridley High School precipitation gage at Gridley 392205121410201 E0.58 – – – – – –

16 Gridley High School precipitation gage at Gridley 392205121410201 E0.62 – – – – – E0.6816 Gridley High School precipitation gage at Gridley 392205121410201 – – – – – – –

15 Oroville Dam precipitation gage at spillway 393234121292701 – – – – – – –15 Oroville Dam precipitation gage at spillway 393234121292701 – – – – – – –15 Oroville Dam precipitation gage at spillway 393234121292701 – – – – – – –15 Oroville Dam precipitation gage at spillway 393234121292701 E0.08 E0.031 – – – – –

15 Oroville Dam precipitation gage at spillway 393234121292701 E0.31 – – – – – –

15 Oroville Dam precipitation gage at spillway 393234121292701 – – – – – – E0.22

15 Oroville Dam precipitation gage at spillway 393234121292701 – – – – – – E0.21

15 Oroville Dam precipitation gage at spillway 393234121292701 – – – – – E0.011 –15 Oroville Dam precipitation gage at spillway 393234121292701 – – – – – – –
Appendix 4 137

Appendix 4. Calculated flux values presented in micrograms per square meter per day (μg/m2/day) for bulk wet-deposition samples with at least one detection collected during 

the 2002–04 study period at eight sites in the Central Valley, California.—Continued

[All compounds were analyzed by gas chromatography/mass spectrometry (GC/MS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in microgram per liter (μg/L) multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 square meter [m2], Autosampler=0.0614 m2) and sample 

composite time in days. Abbreviations: D-U, value deleted by NWQL because compound could not be determined due to matrix interference; E, estimated reported laboratory value; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; [-], no Chemical Abstract Service Number available for given compound; 

<, less than laboratory reporting limit; –, not detected]

Site 

number Site name

Site 

identification 

number

Azinphosmethyl-oxon 

(E)

[-] 

61635

Carbaryl 

(E)

[63-25-2]

(82680)

 Chlorpyrifos

[2921-88-2]

(38933)

Chlorpyrifos 

oxon 

(E)

[5598-15-2]

(61636)

Cypermethrin 

(E)

[52315-07-8]

(61586)

Dacthal (DCPA) 

[1861-32-1]

(82682)

 Diazinon

[333-41-5]

(39572)

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – – – – 0.017 0.05011 Newman rain gage at wasteway levee near Draper Road 371735121031201 – E0.015 0.024 – – 0.013 0.37511 Newman rain gage at wasteway levee near Draper Road 371735121031201 – E0.036 0.080 – – 0.187 0.71211 Newman rain gage at wasteway levee near Draper Road 371735121031201 – E0.172 – – – 0.029 –11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – E0.681 – – – 0.065 0.05211 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – E0.010 – – 0.016 0.032

12 Turlock rain gage near Idaho Road 372713120534901 – E0.010 0.030 – – 0.017 0.041

12 Turlock rain gage near Idaho Road 372713120534901 – E0.028 0.065 – – 0.034 0.206

12 Turlock rain gage near Idaho Road 372713120534901 – E0.289 0.171 – – 0.081 0.138

12 Turlock rain gage near Idaho Road 372713120534901 – E1.19 E0.025 – – 0.045 0.075

13 Turlock Airport rain gage 372857120414001 – E0.020 0.052 E0.02 – 0.025 0.271

13 Turlock Airport rain gage 372857120414001 – – 0.025 – – 0.032 0.085

13 Turlock Airport rain gage 372857120414001 – E0.074 0.035 – – 0.019 0.043

13 Turlock Airport rain gage 372857120414001 – E0.770 – – – 0.031 0.059

13 Turlock Airport rain gage 372857120414001 – – 0.159 – – E0.022 0.361

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – E0.018 0.012 – – 0.045 0.144

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – E0.031 0.024 E0.03 – 0.027 2.48

10 Westley rain gage at pump building near lateral 6 North 373335121143001 E0.02 E1.86 – – – 0.020 0.296

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – – 0.054 E0.05 – 0.027 0.231
138 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 4. Calculated flux values presented in micrograms per square meter per day (μg/m2/day) for bulk wet-deposition samples with at least one detection collected during the 2002–04 study period at eight sites in the Central Valley, California.—Continued [All compounds were analyzed by gas chromatography/mass spectrometry (GC/MS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in microgram per liter (μg/L) multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 square meter [m2], Autosampler=0.0614 m2) and sample composite time in days. Abbreviations: D-U, value deleted by NWQL because compound could not be determined due to matrix interference; E, estimated reported laboratory value; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; [-], no Chemical Abstract Service Number available for given compound; <, less than laboratory reporting limit; –, not detected] Site num- ber Site name Site identification number Azinphos- methyl-oxon (E) [-] 61635 Carbaryl (E) [63-25-2] (82680) Chlorpyrifos [2921-88-2] (38933) Chlorpyrifos oxon (E) [5598-15-2] (61636) Cypermethrin (E) [52315-07-8] (61586) Dacthal (DCPA) [1861-32-1] (82682) Diazinon [333-41-5] (39572)

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – E0.288 0.166 E0.09 E0.030 0.042 2.33

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – E0.757 0.090 E0.04 – 0.039 0.122

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – E1.20 E0.020 – – 0.084 0.1194 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – E0.061 0.208 E0.12 – 0.043 0.423

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – E0.009 0.948 E0.11 – 0.012 0.694

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – E0.367 0.129 – – 0.045 0.109

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – E1.26 0.035 – – 0.097 0.117

16 Gridley High School precipitation gage at Gridley 392205121410201 – – E0.058 – – 0.047 0.163

16 Gridley High School precipitation gage at Gridley 392205121410201 – E5.76 3.73 E1.66 – 0.207 8.6316 Gridley High School precipitation gage at Gridley 392205121410201 – E0.562 0.043 E0.12 – 0.020 0.08

15 Oroville Dam precipitation gage at spillway 393234121292701 – – E0.016 – – 0.020 E0.012

15 Oroville Dam precipitation gage at spillway 393234121292701 – – – – – 0.036 0.046

15 Oroville Dam precipitation gage at spillway 393234121292701 – – E0.028 E0.09 – 0.037 0.158

15 Oroville Dam precipitation gage at spillway 393234121292701 – – E0.023 – – 0.023 0.184

15 Oroville Dam precipitation gage at spillway 393234121292701 – – – – – 0.051 –

15 Oroville Dam precipitation gage at spillway 393234121292701 – E0.699 0.123 – – 0.094 –

15 Oroville Dam precipitation gage at spillway 393234121292701 – – – – – 0.058 –

15 Oroville Dam precipitation gage at spillway 393234121292701 – – E0.008 – – 0.008 0.047

15 Oroville Dam precipitation gage at spillway 393234121292701 – E0.073 E0.058 E0.15 – 0.058 0.321
Appendix 4 139

Appendix 4. Calculated flux values presented in micrograms per square meter per day (μg/m2/day) for bulk wet-deposition samples with at least one detection collected during 

the 2002–04 study period at eight sites in the Central Valley, California.—Continued

[All compounds were analyzed by gas chromatography/mass spectrometry (GC/MS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in microgram per liter (μg/L) multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 square meter [m2], Autosampler=0.0614 m2) and sample 

composite time in days. Abbreviations: D-U, value deleted by NWQL because compound could not be determined due to matrix interference; E, estimated reported laboratory value; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; [-], no Chemical Abstract Service Number available for given compound; 

<, less than laboratory reporting limit; –, not detected]

Site 

number Site name

Site 

identification 

number

Diazoxon 

(E)

[962-58-3]

(61638)

Dichlorvos 

(E)

[62-73-7]

(38775)

Iprodione 

(E)

[36734-19-7]

(61593)

Malathion

[121-75-5]

(39532)

Malaoxon 

(E)

[1634-78-2]

(61652)

Metalaxyl

[57837-19-1]

(61596)

Methidathion

[950-37-8]

(61598)

Metolachlor

[51218-45-2]

(39415)

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – – – – – – 0.03811 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – E1.12 – – – – E0.01711 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – E8.90 – – – 0.053 E0.03611 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – E0.319 E0.029 E0.096 – – E0.01611 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – E0.117 – – – – 0.10411 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – – – – – – 0.149

12 Turlock rain gage near Idaho Road 372713120534901 – – – – – – 0.025 E0.008

12 Turlock rain gage near Idaho Road 372713120534901 – – E3.26 E0.040 – – 0.028 E0.031

12 Turlock rain gage near Idaho Road 372713120534901 E0.05 – E0.864 0.180 E0.256 – – E0.038

12 Turlock rain gage near Idaho Road 372713120534901 – – E0.165 – E0.095 – – 0.075

13 Turlock Airport rain gage 372857120414001 – – – E0.015 – – 0.478 E0.007

13 Turlock Airport rain gage 372857120414001 – – E13.1 – – – 0.039 –

13 Turlock Airport rain gage 372857120414001 – – E0.882 E0.074 E0.109 – – E0.019

13 Turlock Airport rain gage 372857120414001 E0.03 – E0.243 E0.028 E0.087 – – 0.055

13 Turlock Airport rain gage 372857120414001 E0.07 – E0.513 – – – 0.072 –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – – – – – – E0.010 0.035

10 Westley rain gage at pump building near lateral 6 North 373335121143001 E0.44 – E2.23 – E0.062 – 0.027 E0.03810 Westley rain gage at pump building near lateral 6 North 373335121143001 – – E0.126 – E0.039 – – 0.468

10 Westley rain gage at pump building near lateral 6 North 373335121143001 E0.08 – E0.094 – – – – E0.024
140 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 4. Calculated flux values presented in micrograms per square meter per day (μg/m2/day) for bulk wet-deposition samples with at least one detection collected during the 2002–04 study period at eight sites in the Central Valley, California.—Continued [All compounds were analyzed by gas chromatography/mass spectrometry (GC/MS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in microgram per liter (μg/L) multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 square meter [m2], Autosampler=0.0614 m2) and sample composite time in days. Abbreviations: D-U, value deleted by NWQL because compound could not be determined due to matrix interference; E, estimated reported laboratory value; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; [-], no Chemical Abstract Service Number available for given compound; <, less than laboratory reporting limit; –, not detected] Site num- ber Site name Site identification number Diazoxon (E) [962-58-3] (61638) Dichlorvos (E) [62-73-7] (38775) Iprodione (E) [36734-19-7] (61593) Malathion [121-75-5] (39532) Malaoxon (E) [1634-78-2] (61652) Metalaxyl [57837-19-1] (61596) Methidathion [950-37-8] (61598) Metolachlor [51218-45-2] (39415)

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – E0.039 – – 0.305 E0.0214 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.04 – E0.851 1.50 E0.145 – – E0.0274 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – E0.104 E0.074 E0.134 0.089 – 0.139

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.12 – E0.472 E0.049 – – 0.049 E0.025

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – – – – 0.101 –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – E0.482 0.965 E0.161 – – E0.032

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – E0.145 E0.090 E0.145 – 0.055 E0.076

16 Gridley High School precipitation gage at Gridley 392205121410201 – – E0.174 – – – E0.140

16 Gridley High School precipitation gage at Gridley 392205121410201 E0.62 E0.41 E1.49 4.15 E1.908 – – –

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – 0.685 0.471 – – –

15 Oroville Dam precipitation gage at spillway 393234121292701 – – – – – – – –

15 Oroville Dam precipitation gage at spillway 393234121292701 – – – – – – – –

15 Oroville Dam precipitation gage at spillway 393234121292701 – – – – – – – –

15 Oroville Dam precipitation gage at spillway 393234121292701 – – E0.628 – – – – –

15 Oroville Dam precipitation gage at spillway 393234121292701 – – – – – – E0.072

15 Oroville Dam precipitation gage at spillway 393234121292701 – – – 0.331 – – – –

15 Oroville Dam precipitation gage at spillway 393234121292701 – – – – – – – –

15 Oroville Dam precipitation gage at spillway 393234121292701 E0.008 – – – – – E0.011 –

15 Oroville Dam precipitation gage at spillway 393234121292701 E0.15 – – – – – – –
Appendix 4 141

Appendix 4. Calculated flux values presented in micrograms per square meter per day (μg/m2/day) for bulk wet-deposition samples with at least one detection collected during 

the 2002–04 study period at eight sites in the Central Valley, California.—Continued

[All compounds were analyzed by gas chromatography/mass spectrometry (GC/MS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in microgram per liter (μg/L) multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 square meter [m2], Autosampler=0.0614 m2) and sample 

composite time in days. Abbreviations: D-U, value deleted by NWQL because compound could not be determined due to matrix interference; E, estimated reported laboratory value; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; [-], no Chemical Abstract Service Number available for given compound; 

<, less than laboratory reporting limit; –, not detected]

Site 

number Site name

Site 

identification 

number

Metribuzin

[21087-64-9]

(82630)

Myclobutanil 

(E)

[88671-89-0]

(61599)

 Parathionmethyl

[298-00-0]

(61664)

 Paraoxonmethyl 

(E)

[950-35-6]

(61664)

Pendimethalin

[40487-42-1]

(82683)

Phosmet

[732-11-6]

(61601)

Prometryn

[7287-19-6]

(04036)

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – – – 0.043 – –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – E0.070 – – 0.052 – 0.01111 Newman rain gage at wasteway levee near Draper Road 371735121031201 – E0.703 – – 0.338 – –11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – E0.051 – – – E0.032 –11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – E0.075 – – – – –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – E0.110 – – E0.045 – –

12 Turlock rain gage near Idaho Road 372713120534901 – – – – 0.055 – 0.033

12 Turlock rain gage near Idaho Road 372713120534901 – E0.487 – – 0.120 – –

12 Turlock rain gage near Idaho Road 372713120534901 – E0.085 – – 0.133 – –12 Turlock rain gage near Idaho Road 372713120534901 – E0.255 – – E0.085 E0.045 –

13 Turlock Airport rain gage 372857120414001 – – – – 0.096 – 0.042

13 Turlock Airport rain gage 372857120414001 – E0.747 – – 0.093 – –13 Turlock Airport rain gage 372857120414001 – E0.210 – – 0.109 E0.031 –

13 Turlock Airport rain gage 372857120414001 – E0.270 – – – E0.083 –13 Turlock Airport rain gage 372857120414001 – E0.058 – – E0.766 – –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 0.041 E0.010 – – 0.177 – 0.039

10 Westley rain gage at pump building near lateral 6 North 373335121143001 0.192 E0.229 – – 0.920 – 0.089

10 Westley rain gage at pump building near lateral 6 North 373335121143001 0.111 E0.406 – – – – 0.044

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – E0.027 – – E1.221 – 0.032
142 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 4. Calculated flux values presented in micrograms per square meter per day (μg/m2/day) for bulk wet-deposition samples with at least one detection collected during the 2002–04 study period at eight sites in the Central Valley, California.—Continued [All compounds were analyzed by gas chromatography/mass spectrometry (GC/MS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in microgram per liter (μg/L) multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 square meter [m2], Autosampler=0.0614 m2) and sample composite time in days. Abbreviations: D-U, value deleted by NWQL because compound could not be determined due to matrix interference; E, estimated reported laboratory value; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; [-], no Chemical Abstract Service Number available for given compound; <, less than laboratory reporting limit; –, not detected] Site num- ber Site name Site identification number Metribuzin [21087-64-9] (82630) Myclobutanil (E) [88671-89-0] (61599) Parathion- methyl [298-00-0] (61664) Paraoxon- methyl (E) [950-35-6] (61664) Pendimethalin [40487-42-1] (82683) Phosmet [732-11-6] (61601) Prometryn [7287-19-6] (04036)

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – – 0.211 – 0.0334 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – E0.114 – 0.243 – –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – E0.198 – – 0.546 – –4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – E0.472 – – E0.300 – E0.025

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – E0.009 – – 0.093 – 0.016

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – E0.148 – – 0.206 – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – E0.387 – – E0.104 E0.069 –

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – – – – –

16 Gridley High School precipitation gage at Gridley 392205121410201 – E0.228 10.1 E2.49 – – –

16 Gridley High School precipitation gage at Gridley 392205121410201 – – E1.39 – – – –

15 Oroville Dam precipitation gage at spillway 393234121292701 – – – – E0.078 – –

15 Oroville Dam precipitation gage at spillway 393234121292701 – – – – E0.100 – –15 Oroville Dam precipitation gage at spillway 393234121292701 – – – – – – –

15 Oroville Dam precipitation gage at spillway 393234121292701 – E0.169 – – E0.138 – –

15 Oroville Dam precipitation gage at spillway 393234121292701 – – – – – – –

15 Oroville Dam precipitation gage at spillway 393234121292701 – – 0.737 – – – –

15 Oroville Dam precipitation gage at spillway 393234121292701 – – – – – – –

15 Oroville Dam precipitation gage at spillway 393234121292701 – – – – – – –

15 Oroville Dam precipitation gage at spillway 393234121292701 – – – – – – –
Appendix 4 143

Appendix 4. Calculated flux values presented in micrograms per square meter per day (μg/m2/day) for bulk wet-deposition samples with at least one detection collected during 

the 2002–04 study period at eight sites in the Central Valley, California.—Continued

[All compounds were analyzed by gas chromatography/mass spectrometry (GC/MS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in microgram per liter (μg/L) multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 square meter [m2], Autosampler=0.0614 m2) and sample 

composite time in days. Abbreviations: D-U, value deleted by NWQL because compound could not be determined due to matrix interference; E, estimated reported laboratory value; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; [-], no Chemical Abstract Service Number available for given compound; 

<, less than laboratory reporting limit; –, not detected]

Site 

number Site name

Site 

identification 

number

Pronamide

[23950-58-5]

(82676)

Simazine

[122-34-9]

(04035)

Trifluralin

[1582-09-8]

(82661)

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – E0.006 0.01511 Newman rain gage at wasteway levee near Draper Road 371735121031201 – 0.349 0.03311 Newman rain gage at wasteway levee near Draper Road 371735121031201 – 0.801 0.10711 Newman rain gage at wasteway levee near Draper Road 371735121031201 – 0.141 0.03211 Newman rain gage at wasteway levee near Draper Road 371735121031201 – 0.169 0.02911 Newman rain gage at wasteway levee near Draper Road 371735121031201 – 0.071 E0.016

12 Turlock rain gage near Idaho Road 372713120534901 0.014 0.082 E0.010

12 Turlock rain gage near Idaho Road 372713120534901 – 0.394 0.03412 Turlock rain gage near Idaho Road 372713120534901 – 0.859 E0.04312 Turlock rain gage near Idaho Road 372713120534901 – 0.320 E0.03013 Turlock Airport rain gage 372857120414001 0.027 0.190 E0.012

13 Turlock Airport rain gage 372857120414001 – 1.38 –

13 Turlock Airport rain gage 372857120414001 – 7.46 –

13 Turlock Airport rain gage 372857120414001 – 4.68 E0.02113 Turlock Airport rain gage 372857120414001 0.029 0.932 0.072

10 Westley rain gage at pump building near lateral 6 North 373335121143001 0.053 0.084 0.021

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – 0.684 0.038

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – 0.148 0.032

10 Westley rain gage at pump building near lateral 6 North 373335121143001 0.105 0.424 0.064
144 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 4. Calculated flux values presented in micrograms per square meter per day (μg/m2/day) for bulk wet-deposition samples with at least one detection collected during the 2002–04 study period at eight sites in the Central Valley, California.—Continued [All compounds were analyzed by gas chromatography/mass spectrometry (GC/MS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five digit number in parenthesis is a code used by the USGS to uniquely identify the given compound. Flux calculated as the analytical result in microgram per liter (μg/L) multiplied by the total sample volume collected in liters divided by the area of the respective sampler type (Funnel=0.0731 square meter [m2], Autosampler=0.0614 m2) and sample composite time in days. Abbreviations: D-U, value deleted by NWQL because compound could not be determined due to matrix interference; E, estimated reported laboratory value; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); hh:mm, hour:minute; [-], no Chemical Abstract Service Number available for given compound; <, less than laboratory reporting limit; –, not detected] Site num- ber Site name Site identification number Pronamide [23950-58-5] (82676) Simazine [122-34-9] (04035) Trifluralin [1582-09-8] (82661)

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – 0.119 E0.0214 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – E0.180 E0.0314 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – 0.228 E0.0404 Modesto Irrigation District gage rooftop at Modesto 373834121000601 0.031 0.527 0.067

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.016 0.144 E0.009

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – 0.270 0.071

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.035 0.698 E0.028

16 Gridley High School precipitation gage at Gridley 392205121410201 – E0.151 E0.07016 Gridley High School precipitation gage at Gridley 392205121410201 – – –

16 Gridley High School precipitation gage at Gridley 392205121410201 – – –

15 Oroville Dam precipitation gage at spillway 393234121292701 – – –

15 Oroville Dam precipitation gage at spillway 393234121292701 – – –

15 Oroville Dam precipitation gage at spillway 393234121292701 – – –

15 Oroville Dam precipitation gage at spillway 393234121292701 – 0.176 –

15 Oroville Dam precipitation gage at spillway 393234121292701 – – –

15 Oroville Dam precipitation gage at spillway 393234121292701 – – –

15 Oroville Dam precipitation gage at spillway 393234121292701 – – –

15 Oroville Dam precipitation gage at spillway 393234121292701 – 0.025 –

15 Oroville Dam precipitation gage at spillway 393234121292701 – 0.278 –
Appendix 4 145

References Cited

Childress, C.J.O., Foreman, W.T., Connor, B.F., and Maloney, T.J., 1999, New reporting procedures based on long-term method detection levels and some considerations for interpretations of water-quality data provided by the U.S. Geological Survey National Water Quality Laboratory: U.S. Geological Survey Open-File Report 

99–193, 19 p.

Sandstrom, M.W., Stroppel, M.E., Foreman, W.T., and Schroeder, M.P., 2001, Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory–Determination of moderate-use pesticides and selected degradates in water by C-18 solid-phase extraction and capillary-column gas chromatography/mass spectrometry with selected-ion monitoring (methods 2002/2011): U.S. Geological Survey Water-Resources Investigations Report 01–4098, 70 p.
146 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides

Appendix 5. Calculated Flux Values Presented in 

Micrograms Per Square Meter Per Day (μg/m2/day) for DryDeposition Samples With at Least One Detection Collected 

During the 2002–04 Study Period at Seven Sites in the 

Central Valley, California
Appendix 5 147

Appendix 5. Calculated flux values presented in micrograms per square meter per day (μg/m2/day) for dry-deposition samples with at least one detection collected during the 

2002–04 study period at seven sites in the Central Valley, California.—Continued

[All compounds were analyzed by gas chromatography/mass spectrometry (GC/MS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. Flux calculated as the analytical result in microgram per sample (μg/sample) divided by the area of the respective sampler type (Funnel=0.0731 square meter [m2], Autosampler=0.0614 m2) and sample composite time in days. Abbreviations: E, estimated reported laboratory value; hh:mm, hour:minute; [-], no Chemical Abstract Service Number available for 

given compound; –, not detected]

Site 

number Site name

Site 

identification 

number

Start date

Start 

time 

(hh:mm)

End date

End 

time 

(hh:mm)

Sample 

composite 

time, 

days

Sampler 

type

1-Naphthol1

[90-15-3]

3,4-

Dichloroaniline1

[95-76-1]

Alachlor

[15972-60-8]

11 Newman rain gage at wasteway levee near 

Draper Road

371735121031201 Apr 9, 2002 08:50 May 21, 2002 10:30 42 Funnel – – –

11 Newman rain gage at wasteway levee near 

Draper Road

371735121031201 May 21, 2002 10:30 Oct 3, 2002 11:30 135 Funnel – – –

11 Newman rain gage at wasteway levee near 

Draper Road

371735121031201 Oct 3, 2002 11:30 Nov 6, 2002 10:45 34 Funnel – – –

11 Newman rain gage at wasteway levee near 

Draper Road

371735121031201 May 9, 2003 16:00 Jul 18, 2003 09:30 70 Funnel E0.004 – –

11 Newman rain gage at wasteway levee near 

Draper Road

371735121031201 Mar 8, 2004 15:40 Apr 16, 2004 13:30 39 Funnel E0.002 E0.001 –

12 Turlock rain gage near Idaho Road 372713120534901 Apr 25, 2002 12:00 May 21, 2002 11:05 26 Funnel – – E0.004

12 Turlock rain gage near Idaho Road 372713120534901 May 21, 2002 11:05 Oct 3, 2002 12:15 135 Funnel – – –

12 Turlock rain gage near Idaho Road 372713120534901 Oct 3, 2002 12:15 Nov 6, 2002 11:30 34 Funnel E0.005 – –

12 Turlock rain gage near Idaho Road 372713120534901 May 9, 2003 17:00 Jul 18, 2003 10:30 70 Funnel – – –

12 Turlock rain gage near Idaho Road 372713120534901 Mar 8, 2004 12:10 Apr 16, 2004 12:30 39 Funnel E0.004 – –

13 Turlock Airport rain gage 372857120414001 May 21, 2002 12:00 Oct 3, 2002 13:00 135 Funnel – – –

13 Turlock Airport rain gage 372857120414001 Oct 3, 2002 13:00 Nov 6, 2002 12:15 34 Funnel – – –

13 Turlock Airport rain gage 372857120414001 May 5, 2003 10:40 Jul 22, 2003 11:30 78 Funnel – – –

13 Turlock Airport rain gage 372857120414001 Mar 8, 2004 11:20 Apr 16, 2004 11:10 39 Funnel E0.002 E0.003 –

10 Westley rain gage at pump building near 

lateral 6 North

373335121143001 Apr 9, 2002 08:10 May 21, 2002 09:30 42 Funnel – – –

10 Westley rain gage at pump building near 

lateral 6 North

373335121143001 May 21, 2002 09:30 Oct 3, 2002 10:30 135 Funnel – – –

10 Westley rain gage at pump building near 

lateral 6 North

373335121143001 Oct 3, 2002 10:30 Nov 6, 2002 09:45 34 Funnel – – –

10 Westley rain gage at pump building near 

lateral 6 North

373335121143001 May 22, 2003 09:30 Jul 18, 2003 08:45 57 Funnel E0.003 – –

10 Westley rain gage at pump building near 

lateral 6 North

373335121143001 Mar 8, 2004 16:30 Mar 23, 2004 15:15 15 Funnel E0.005 – –

10 Westley rain gage at pump building near 

lateral 6 North

373335121143001 Mar 25, 2004 15:30 Apr 16, 2004 14:50 22 Funnel E0.036 E0.003 –

Appendix 5. Calculated flux values presented in micrograms per square meter per day (μg/m2/day) for dry-deposition samples with at least one detection collected during the 

2002–04 study period at seven sites in the Central Valley, California.
148 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 5. Calculated flux values presented in micrograms per square meter per day (μg/m2/day) for dry-deposition samples with at least one detection collected during the 2002–04 study period at seven sites in the Central Valley, California.—Continued [All compounds were analyzed by gas chromatography/mass spectrometry (GC/MS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. Flux calculated as the analytical result in microgram per sample (μg/sample) divided by the area of the respective sampler type (Funnel=0.0731 square meter [m2], Autosampler=0.0614 m2) and sample composite time in days. Abbreviations: E, estimated reported laboratory value; hh:mm, hour:minute; [-], no Chemical Abstract Service Number available for given compound; –, not detected] Site num- ber Site name Site identification number Start date Start time (hh:mm) End date End time (hh:mm) Sample composite time, days Sampler type 1-Naphthol1 [90-15-3] 3,4- Dichloroaniline1 [95-76-1] Alachlor [15972-60-8]

4 Modesto Irrigation District gage rooftop at 

Modesto

373834121000601 Apr 9, 2002 10:40 May 21, 2002 13:30 42 Autosampler – – –

4 Modesto Irrigation District gage rooftop at 

Modesto

373834121000601 May 21, 2002 12:30 Oct 3, 2002 11:00 135 Autosampler – – –

4 Modesto Irrigation District gage rooftop at 

Modesto

373834121000601 Oct 4, 2002 12:00 Nov 6, 2002 11:50 33 Autosampler – – –

4 Modesto Irrigation District gage rooftop at 

Modesto

373834121000601 Oct 4, 2002 12:10 Nov 6, 2002 12:00 33 Funnel – – –

4 Modesto Irrigation District gage rooftop at 

Modesto

373834121000601 May 5, 2003 09:15 Jul 22, 2003 09:30 78 Funnel E0.003 – –

4 Modesto Irrigation District gage rooftop at 

Modesto

373834121000601 May 5, 2003 09:20 Jul 22, 2003 09:40 78 Autosampler E0.003 – –

4 Modesto Irrigation District gage rooftop at 

Modesto

373834121000601 Mar 8, 2004 10:40 Apr 16, 2004 09:00 39 Funnel E0.003 E0.002 –

5 Modesto Irrigation District gage rooftop at 

Albers Road

373841120504801 Apr 9, 2002 11:20 May 21, 2002 12:30 42 Autosampler – – –

5 Modesto Irrigation District gage rooftop at 

Albers Road

373841120504801 May 21, 2002 12:00 Oct 3, 2002 12:00 136 Autosampler – – –

5 Modesto Irrigation District gage rooftop at 

Albers Road

373841120504801 Oct 4, 2002 11:00 Nov 6, 2002 13:10 33 Autosampler – – –

5 Modesto Irrigation District gage rooftop at 

Albers Road

373841120504801 Oct 4, 2002 11:10 Nov 6, 2002 13:00 33 Funnel – – –

5 Modesto Irrigation District gage rooftop at 

Albers Road

373841120504801 May 9, 2003 17:45 Jul 22, 2003 10:00 74 Autosampler – – –

5 Modesto Irrigation District gage rooftop at 

Albers Road

373841120504801 May 9, 2003 17:50 Jul 22, 2003 10:10 74 Funnel – – –

5 Modesto Irrigation District gage rooftop at 

Albers Road

373841120504801 Mar 8, 2004 11:00 Apr 16, 2004 09:50 39 Funnel E0.003 E0.005 –

16 Gridley High School precipitation gage at 

Gridley

392205121410201 Feb 20, 2003 14:00 Mar 11, 2003 11:40 19 Autosampler – – –

16 Gridley High School precipitation gage at 

Gridley

392205121410201 May 9, 2003 10:30 Jul 21, 2003 09:00 73 Funnel E0.006 – –

16 Gridley High School precipitation gage at 

Gridley

392205121410201 May 9, 2003 10:40 Jul 21, 2003 09:15 73 Autosampler E0.002 – –
Appendix 5 149

Appendix 5. Calculated flux values presented in micrograms per square meter per day (μg/m2/day) for dry-deposition samples with at least one detection collected during the 

2002–04 study period at seven sites in the Central Valley, California.—Continued

[All compounds were analyzed by gas chromatography/mass spectrometry (GC/MS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. Flux calculated as the analytical result in microgram per sample (μg/sample) divided by the area of the respective sampler type (Funnel=0.0731 square meter [m2], Autosampler=0.0614 m2) and sample composite time in days. Abbreviations: E, estimated reported laboratory value; hh:mm, hour:minute; [-], no Chemical Abstract Service Number available for 

given compound; –, not detected]

Site 

number Site name

Site 

identification 

number

Azinphosmethyl1

[86-50-0]

Carbaryl

[63-25-2]

Chlorpyrifos

[2921-88-2]

Chlorpyrifos 

oxon1

[5598-15-2]

Cypermethrin 

[52315-07-8]

Dacthal 

(DCPA)

[1861-32-1]

Diazinon

[333-41-5]

 Diazoxon1

[962-58-3]

11 Newman rain gage at wasteway levee near 

Draper Road

371735121031201 – E0.003 – – – E0.002 – –

11 Newman rain gage at wasteway levee near 

Draper Road

371735121031201 – – E0.002 – – E0.0005 – –

11 Newman rain gage at wasteway levee near 

Draper Road

371735121031201 – – – – – – – –

11 Newman rain gage at wasteway levee near 

Draper Road

371735121031201 E0.116 E0.004 E0.024 – – E0.0004 E0.027 E0.006

11 Newman rain gage at wasteway levee near 

Draper Road

371735121031201 – E0.015 – – – E0.001 – –

12 Turlock rain gage near Idaho Road 372713120534901 E0.108 E0.009 – – – E0.002 – –12 Turlock rain gage near Idaho Road 372713120534901 E0.009 – E0.004 – – E0.002 E0.001 –

12 Turlock rain gage near Idaho Road 372713120534901 – – E0.006 – – E0.003 E0.005 –

12 Turlock rain gage near Idaho Road 372713120534901 – – E0.233 – – – – –

12 Turlock rain gage near Idaho Road 372713120534901 – E0.029 E0.002 – – E0.001 – –13 Turlock Airport rain gage 372857120414001 E0.004 – E0.001 – – E0.0003 – –13 Turlock Airport rain gage 372857120414001 – – E0.004 – – E0.004 E0.008 –13 Turlock Airport rain gage 372857120414001 E0.006 – E0.132 E0.140 – E0.0004 – –13 Turlock Airport rain gage 372857120414001 – E0.019 – – – E0.0005 – –

10 Westley rain gage at pump building near 

lateral 6 North

373335121143001 E0.070 E0.046 – – – E0.001 – –

10 Westley rain gage at pump building near 

lateral 6 North

373335121143001 E0.003 E0.002 E0.001 – – E0.001 – –

10 Westley rain gage at pump building near 

lateral 6 North

373335121143001 E0.017 E0.004 E0.002 – – E0.004 E0.001 –

10 Westley rain gage at pump building near 

lateral 6 North

373335121143001 E0.010 E0.013 – – – E0.001 E0.007 E0.002

10 Westley rain gage at pump building near 

lateral 6 North

373335121143001 – E0.036 – – – – – –

10 Westley rain gage at pump building near 

lateral 6 North

373335121143001 – E0.186 – – – E0.001 E0.010 E0.007
150 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 5. Calculated flux values presented in micrograms per square meter per day (μg/m2/day) for dry-deposition samples with at least one detection collected during the 2002–04 study period at seven sites in the Central Valley, California.—Continued [All compounds were analyzed by gas chromatography/mass spectrometry (GC/MS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. Flux calculated as the analytical result in microgram per sample (μg/sample) divided by the area of the respective sampler type (Funnel=0.0731 square meter [m2], Autosampler=0.0614 m2) and sample composite time in days. Abbreviations: E, estimated reported laboratory value; hh:mm, hour:minute; [-], no Chemical Abstract Service Number available for given compound; –, not detected] Site num- ber Site name Site identification number Azinphos- methyl1 [86-50-0] Carbaryl [63-25-2] Chlorpyrifos [2921-88-2] Chlorpyrifos oxon1 [5598-15-2] Cypermethrin [52315-07-8] Dacthal (DCPA) [1861-32-1] Diazinon [333-41-5] Diazoxon1 [962-58-3]

4 Modesto Irrigation District gage rooftop at 

Modesto

373834121000601 E0.043 E0.014 E0.011 – – E0.002 – –

4 Modesto Irrigation District gage rooftop at 

Modesto

373834121000601 E0.003 E0.003 E0.001 – – E0.001 E0.001 –

4 Modesto Irrigation District gage rooftop at 

Modesto

373834121000601 – E0.010 E0.020 – – E0.006 E0.006 E0.001

4 Modesto Irrigation District gage rooftop at 

Modesto

373834121000601 – – E0.013 – E0.050 E0.008 E0.016 –

4 Modesto Irrigation District gage rooftop at 

Modesto

373834121000601 – – E0.009 – – E0.001 E0.001 –

4 Modesto Irrigation District gage rooftop at 

Modesto

373834121000601 – – E0.016 E0.021 – E0.002 E0.002 –

4 Modesto Irrigation District gage rooftop at 

Modesto

373834121000601 – E0.030 – – – E0.001 – –

5 Modesto Irrigation District gage rooftop at 

Albers Road

373841120504801 – E0.048 E0.018 – – E0.002 – –

5 Modesto Irrigation District gage rooftop at 

Albers Road

373841120504801 E0.008 E0.003 E0.004 – – E0.0004 – –

5 Modesto Irrigation District gage rooftop at 

Albers Road

373841120504801 E0.014 E0.013 E0.009 – – E0.009 E0.007 –

5 Modesto Irrigation District gage rooftop at 

Albers Road

373841120504801 E0.010 E0.009 E0.006 – – E0.005 E0.004 –

5 Modesto Irrigation District gage rooftop at 

Albers Road

373841120504801 E0.015 E0.004 E0.054 E0.104 – E0.001 E0.001 –

5 Modesto Irrigation District gage rooftop at 

Albers Road

373841120504801 – – E0.039 E0.031 – E0.001 E0.002 –

5 Modesto Irrigation District gage rooftop at 

Albers Road

373841120504801 – E0.027 E0.002 – – E0.001 – –

16 Gridley High School precipitation gage at 

Gridley

392205121410201 – – – – – – E0.008 –

16 Gridley High School precipitation gage at 

Gridley

392205121410201 – – E0.004 – – E0.001 E0.001 –

16 Gridley High School precipitation gage at 

Gridley

392205121410201 E0.002 – E0.004 E0.009 – – E0.002 –
Appendix 5 151

Appendix 5. Calculated flux values presented in micrograms per square meter per day (μg/m2/day) for dry-deposition samples with at least one detection collected during the 

2002–04 study period at seven sites in the Central Valley, California.—Continued

[All compounds were analyzed by gas chromatography/mass spectrometry (GC/MS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. Flux calculated as the analytical result in microgram per sample (μg/sample) divided by the area of the respective sampler type (Funnel=0.0731 square meter [m2], Autosampler=0.0614 m2) and sample composite time in days. Abbreviations: E, estimated reported laboratory value; hh:mm, hour:minute; [-], no Chemical Abstract Service Number available for 

given compound; –, not detected]

Site 

number Site name

Site 

identification 

number

Dichlorvos1

[62-73-7]

Dimethoate1

[60-51-5]

Hexazinone1

[51235-04-2]

Iprodione1

[36734-19-7]

Malathion

[121-75-5]

Malaoxon 

[1634-78-2]

Methidathion

[950-37-8]

11 Newman rain gage at wasteway levee near 

Draper Road

371735121031201 – – – – – – –

11 Newman rain gage at wasteway levee near 

Draper Road

371735121031201 – – – – – – –

11 Newman rain gage at wasteway levee near 

Draper Road

371735121031201 E0.017 – – – – – –

11 Newman rain gage at wasteway levee near 

Draper Road

371735121031201 – – – – – E0.008 –

11 Newman rain gage at wasteway levee near 

Draper Road

371735121031201 – – – E0.010 – – –

12 Turlock rain gage near Idaho Road 372713120534901 – – – – – – –

12 Turlock rain gage near Idaho Road 372713120534901 E0.003 – – – – – –

12 Turlock rain gage near Idaho Road 372713120534901 – – – – – – –

12 Turlock rain gage near Idaho Road 372713120534901 – E0.092 – – – – –

12 Turlock rain gage near Idaho Road 372713120534901 – E0.018 – E0.074 – E0.004 –13 Turlock Airport rain gage 372857120414001 – – – – – – –

13 Turlock Airport rain gage 372857120414001 – – – – – E0.022 –

13 Turlock Airport rain gage 372857120414001 – E0.003 – E0.011 – E0.003 –

13 Turlock Airport rain gage 372857120414001 – – – E0.032 – – –

10 Westley rain gage at pump building near 

lateral 6 North

373335121143001 – – – – – – –

10 Westley rain gage at pump building near 

lateral 6 North

373335121143001 – E0.001 – – E0.002 E0.013 –

10 Westley rain gage at pump building near 

lateral 6 North

373335121143001 – – – – E0.003 E0.015 –

10 Westley rain gage at pump building near 

lateral 6 North

373335121143001 – E0.013 – – – E0.045 –

10 Westley rain gage at pump building near 

lateral 6 North

373335121143001 – – E0.007 E0.017 – – –

10 Westley rain gage at pump building near 

lateral 6 North

373335121143001 – E0.014 – E0.032 – E0.012 –
152 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 5. Calculated flux values presented in micrograms per square meter per day (μg/m2/day) for dry-deposition samples with at least one detection collected during the 2002–04 study period at seven sites in the Central Valley, California.—Continued [All compounds were analyzed by gas chromatography/mass spectrometry (GC/MS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. Flux calculated as the analytical result in microgram per sample (μg/sample) divided by the area of the respective sampler type (Funnel=0.0731 square meter [m2], Autosampler=0.0614 m2) and sample composite time in days. Abbreviations: E, estimated reported laboratory value; hh:mm, hour:minute; [-], no Chemical Abstract Service Number available for given compound; –, not detected] Site num- ber Site name Site identification number Dichlorvos1 [62-73-7] Dimethoate1 [60-51-5] Hexazinone1 [51235-04-2] Iprodione1 [36734-19-7] Malathion [121-75-5] Malaoxon [1634-78-2] Methidathion [950-37-8]

4 Modesto Irrigation District gage rooftop at 

Modesto

373834121000601 – – – – – – –

4 Modesto Irrigation District gage rooftop at 

Modesto

373834121000601 – – – – E0.002 E0.006 –

4 Modesto Irrigation District gage rooftop at 

Modesto

373834121000601 – – – – E0.009 – –

4 Modesto Irrigation District gage rooftop at 

Modesto

373834121000601 – – – E0.114 0.058 – –

4 Modesto Irrigation District gage rooftop at 

Modesto

373834121000601 E0.002 – – – – E0.016 –

4 Modesto Irrigation District gage rooftop at 

Modesto

373834121000601 E0.004 – – E0.009 – E0.009 –

4 Modesto Irrigation District gage rooftop at 

Modesto

373834121000601 – – – E0.045 – E0.009 –

5 Modesto Irrigation District gage rooftop at 

Albers Road

373841120504801 – – – – – – –

5 Modesto Irrigation District gage rooftop at 

Albers Road

373841120504801 – – – – 0.004 E0.006 –

5 Modesto Irrigation District gage rooftop at 

Albers Road

373841120504801 – – – – E0.004 – –

5 Modesto Irrigation District gage rooftop at 

Albers Road

373841120504801 – – – – – – –

5 Modesto Irrigation District gage rooftop at 

Albers Road

373841120504801 E0.006 E0.003 – E0.009 – – –

5 Modesto Irrigation District gage rooftop at 

Albers Road

373841120504801 E0.003 E0.065 – – – – –

5 Modesto Irrigation District gage rooftop at 

Albers Road

373841120504801 – – – E0.032 – – –

16 Gridley High School precipitation gage at 

Gridley

392205121410201 – – – E0.078 – E0.014 E0.018

16 Gridley High School precipitation gage at 

Gridley

392205121410201 – – – – – – –

16 Gridley High School precipitation gage at 

Gridley

392205121410201 – – – – – E0.003 –
Appendix 5 153

Appendix 5. Calculated flux values presented in micrograms per square meter per day (μg/m2/day) for dry-deposition samples with at least one detection collected during the 

2002–04 study period at seven sites in the Central Valley, California.—Continued

[All compounds were analyzed by gas chromatography/mass spectrometry (GC/MS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. Flux calculated as the analytical result in microgram per sample (μg/sample) divided by the area of the respective sampler type (Funnel=0.0731 square meter [m2], Autosampler=0.0614 m2) and sample composite time in days. Abbreviations: E, estimated reported laboratory value; hh:mm, hour:minute; [-], no Chemical Abstract Service Number available for 

given compound; –, not detected]

Site 

number Site name

Site 

identification 

number

Metolachlor

[51218-45-2]

Metribuzin1

[21087-64-9]

Myclobutanil 

[88671-89-0]

 Parathionmethyl1

[298-00-0]

 Paraoxonmethyl1

[950-35-6]

Pendimethilan1

[40487-42-1]

cis-Permethrin

[54774-45-7]

11 Newman rain gage at wasteway levee near 

Draper Road

371735121031201 E0.016 – – – – – –

11 Newman rain gage at wasteway levee near 

Draper Road

371735121031201 E0.004 E0.004 – E0.004 – – –

11 Newman rain gage at wasteway levee near 

Draper Road

371735121031201 E0.004 – – – – – –

11 Newman rain gage at wasteway levee near 

Draper Road

371735121031201 E0.065 – – E0.010 E0.006 – E0.014

11 Newman rain gage at wasteway levee near 

Draper Road

371735121031201 E0.003 – E0.003 – – – –

12 Turlock rain gage near Idaho Road 372713120534901 E0.038 – E0.020 – – – –

12 Turlock rain gage near Idaho Road 372713120534901 E0.002 – – – – – –

12 Turlock rain gage near Idaho Road 372713120534901 – – – – – – –

12 Turlock rain gage near Idaho Road 372713120534901 – – – E0.005 – – E0.047

12 Turlock rain gage near Idaho Road 372713120534901 – – E0.004 – – – –

13 Turlock Airport rain gage 372857120414001 – – – – – – –

13 Turlock Airport rain gage 372857120414001 – – – – – – –

13 Turlock Airport rain gage 372857120414001 E0.004 – E0.005 E0.008 E0.006 – E0.124

13 Turlock Airport rain gage 372857120414001 E0.001 – – – – – –

10 Westley rain gage at pump building near 

lateral 6 North

373335121143001 E0.153 – E0.033 – – – –

10 Westley rain gage at pump building near 

lateral 6 North

373335121143001 E0.007 – E0.002 – – E0.001 E0.001

10 Westley rain gage at pump building near 

lateral 6 North

373335121143001 E0.018 E0.004 E0.003 – – E0.020 –

10 Westley rain gage at pump building near 

lateral 6 North

373335121143001 E0.035 – E0.004 E0.074 E0.022 – E0.003

10 Westley rain gage at pump building near 

lateral 6 North

373335121143001 – – E0.007 – – – –

10 Westley rain gage at pump building near 

lateral 6 North

373335121143001 E0.043 – E0.028 – – E0.012 E0.027
154 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 5. Calculated flux values presented in micrograms per square meter per day (μg/m2/day) for dry-deposition samples with at least one detection collected during the 2002–04 study period at seven sites in the Central Valley, California.—Continued [All compounds were analyzed by gas chromatography/mass spectrometry (GC/MS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. Flux calculated as the analytical result in microgram per sample (μg/sample) divided by the area of the respective sampler type (Funnel=0.0731 square meter [m2], Autosampler=0.0614 m2) and sample composite time in days. Abbreviations: E, estimated reported laboratory value; hh:mm, hour:minute; [-], no Chemical Abstract Service Number available for given compound; –, not detected] Site num- ber Site name Site identification number Metolachlor [51218-45-2] Metribuzin1 [21087-64-9] Myclobutanil [88671-89-0] Parathion- methyl1 [298-00-0] Paraoxon- methyl1 [950-35-6] Pendimethilan1 [40487-42-1] cis-Permethrin [54774-45-7]

4 Modesto Irrigation District gage rooftop at 

Modesto

373834121000601 E0.009 – E0.028 – – – –

4 Modesto Irrigation District gage rooftop at 

Modesto

373834121000601 E0.001 – E0.002 E0.005 – E0.001 E0.001

4 Modesto Irrigation District gage rooftop at 

Modesto

373834121000601 – – – – – E0.021 –

4 Modesto Irrigation District gage rooftop at 

Modesto

373834121000601 – – – – – – –

4 Modesto Irrigation District gage rooftop at 

Modesto

373834121000601 E0.002 – – E0.009 E0.006 – E0.004

4 Modesto Irrigation District gage rooftop at 

Modesto

373834121000601 E0.002 – E0.005 E0.007 E0.006 – E0.003

4 Modesto Irrigation District gage rooftop at 

Modesto

373834121000601 E0.003 – E0.003

– – – –

5 Modesto Irrigation District gage rooftop at 

Albers Road

373841120504801 E0.009 – E0.031 E0.012 – – –

5 Modesto Irrigation District gage rooftop at 

Albers Road

373841120504801 E0.001 – E0.002 E0.006 – – –

5 Modesto Irrigation District gage rooftop at 

Albers Road

373841120504801 E0.002 – E0.003 E0.005 – E0.005 E0.004

5 Modesto Irrigation District gage rooftop at 

Albers Road

373841120504801 E0.002 – E0.003 E0.007 – E0.013 –

5 Modesto Irrigation District gage rooftop at 

Albers Road

373841120504801 E0.006 – E0.009 E0.032 E0.017 – E0.004

5 Modesto Irrigation District gage rooftop at 

Albers Road

373841120504801 E0.011 – – E0.017 E0.005 – E0.006

5 Modesto Irrigation District gage rooftop at 

Albers Road

373841120504801 E0.002 – E0.004 – – – –

16 Gridley High School precipitation gage at 

Gridley

392205121410201 – – E0.013 – – – –

16 Gridley High School precipitation gage at 

Gridley

392205121410201 – – – E0.015 E0.011 – –

16 Gridley High School precipitation gage at 

Gridley

392205121410201 – – – E0.022 E0.016 – E0.002
Appendix 5 155

Appendix 5. Calculated flux values presented in micrograms per square meter per day (μg/m2/day) for dry-deposition samples with at least one detection collected during the 

2002–04 study period at seven sites in the Central Valley, California.—Continued

[All compounds were analyzed by gas chromatography/mass spectrometry (GC/MS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. Flux calculated as the analytical result in microgram per sample (μg/sample) divided by the area of the respective sampler type (Funnel=0.0731 square meter [m2], Autosampler=0.0614 m2) and sample composite time in days. Abbreviations: E, estimated reported laboratory value; hh:mm, hour:minute; [-], no Chemical Abstract Service Number available for 

given compound; –, not detected]

Site 

number Site name

Site 

identification 

number

trans-Permethrin

[51877-74-8]

Phosmet1

[732-11-6]

Phosmet oxon1

[3735-33-9]

Prometryn

[7287-19-6]

Pronamide

[23950-58-5]

Simazine

[122-34-9]

Trifluralin1

[1582-09-8]

11 Newman rain gage at wasteway levee near 

Draper Road

371735121031201 – E0.019 – – – – E0.180

11 Newman rain gage at wasteway levee near 

Draper Road

371735121031201 E0.004 – – – – – E0.003

11 Newman rain gage at wasteway levee near 

Draper Road

371735121031201 – – – – – – E0.005

11 Newman rain gage at wasteway levee near 

Draper Road

371735121031201 E0.016 E0.007 – – – – E0.004

11 Newman rain gage at wasteway levee near 

Draper Road

371735121031201 – – – – – E0.013 –

12 Turlock rain gage near Idaho Road 372713120534901 – E0.007 – – – E0.023 E0.001

12 Turlock rain gage near Idaho Road 372713120534901 E0.008 – – – – – E0.0004

12 Turlock rain gage near Idaho Road 372713120534901 – – – E0.004 – – E0.001

12 Turlock rain gage near Idaho Road 372713120534901 E0.051 – – – – – E0.001

12 Turlock rain gage near Idaho Road 372713120534901 – E0.015 – – – E0.038 E0.001

13 Turlock Airport rain gage 372857120414001 – E0.018 – – – – E0.0005

13 Turlock Airport rain gage 372857120414001 – E0.056 – – – – E0.002

13 Turlock Airport rain gage 372857120414001 E0.175 E0.010 E0.018 – – E0.049 E0.001

13 Turlock Airport rain gage 372857120414001 – – – – – E0.011 E0.0004

10 Westley rain gage at pump building near 

lateral 6 North

373335121143001 – E0.060 – – – – –

10 Westley rain gage at pump building near 

lateral 6 North

373335121143001 – E0.003 – – – E0.0004 E0.001

10 Westley rain gage at pump building near 

lateral 6 North

373335121143001 – E0.009 – – – E0.044 E0.003

10 Westley rain gage at pump building near 

lateral 6 North

373335121143001 E0.007 E0.024 E0.020 – – – E0.002

10 Westley rain gage at pump building near 

lateral 6 North

373335121143001 – – – – – E0.078 –

10 Westley rain gage at pump building near 

lateral 6 North

373335121143001 E0.031 E0.019 E0.013 – E0.004 E0.023 E0.008
156 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 5. Calculated flux values presented in micrograms per square meter per day (μg/m2/day) for dry-deposition samples with at least one detection collected during the 2002–04 study period at seven sites in the Central Valley, California.—Continued [All compounds were analyzed by gas chromatography/mass spectrometry (GC/MS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. Flux calculated as the analytical result in microgram per sample (μg/sample) divided by the area of the respective sampler type (Funnel=0.0731 square meter [m2], Autosampler=0.0614 m2) and sample composite time in days. Abbreviations: E, estimated reported laboratory value; hh:mm, hour:minute; [-], no Chemical Abstract Service Number available for given compound; –, not detected] Site num- ber Site name Site identification number trans-Perme- thrin [51877-74-8] Phosmet1 [732-11-6] Phosmet oxon1 [3735-33-9] Prometryn [7287-19-6] Pronamide [23950-58-5] Simazine [122-34-9] Trifluralin1 [1582-09-8]

4 Modesto Irrigation District gage rooftop at 

Modesto

373834121000601 – E0.068 – – – E0.033 –

4 Modesto Irrigation District gage rooftop at 

Modesto

373834121000601 E0.003 E0.009 – – – E0.012 E0.0004

4 Modesto Irrigation District gage rooftop at 

Modesto

373834121000601 – – – – – E0.079 E0.002

4 Modesto Irrigation District gage rooftop at 

Modesto

373834121000601 – – – E0.004 – E0.077 E0.002

4 Modesto Irrigation District gage rooftop at 

Modesto

373834121000601 E0.006 E0.007 E0.015 – – E0.007 –

4 Modesto Irrigation District gage rooftop at 

Modesto

373834121000601 E0.005 E0.011 E0.017 – – E0.005 –

4 Modesto Irrigation District gage rooftop at 

Modesto

373834121000601 – – – – – E0.013 –

5 Modesto Irrigation District gage rooftop at 

Albers Road

373841120504801 – E0.188 – – – E0.067 E0.001

5 Modesto Irrigation District gage rooftop at 

Albers Road

373841120504801 – E0.010 – – – E0.059 –

5 Modesto Irrigation District gage rooftop at 

Albers Road

373841120504801 E0.013 E0.021 – – – E0.245 –

5 Modesto Irrigation District gage rooftop at 

Albers Road

373841120504801 E0.011 E0.022 – – – E0.218 E0.001

5 Modesto Irrigation District gage rooftop at 

Albers Road

373841120504801 E0.006 E0.014 E0.008 – – E0.064 –

5 Modesto Irrigation District gage rooftop at 

Albers Road

373841120504801 E0.005 – – – – – –

5 Modesto Irrigation District gage rooftop at 

Albers Road

373841120504801 – – – – – E0.032 –

16 Gridley High School precipitation gage at 

Gridley

392205121410201 – – – – – E0.025 –

16 Gridley High School precipitation gage at 

Gridley

392205121410201 – – – – – – –

16 Gridley High School precipitation gage at 

Gridley

392205121410201 E0.002 E0.009 E0.004 – – E0.002 –

1Compound is biased low (B-L) based on low and variable lab reagent spike recoveries (less than 50 percent).
Appendix 6 157

Appendix 6. Calculated Flux Values Presented in 

Micrograms Per Square Meter Per Day (μg/m2/day) for 

Bulk Dry-Deposition Samples With at Least One Detection 

Collected During the 2002–04 Study Period at Eight Sites in 

the Central Valley, California
158 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 6. Calculated flux values presented in micrograms per square meter per day (μg/m2/day) for bulk dry-deposition samples with at least one detection collected during the 2002–04 study period at eight sites in the Central Valley, California [All compounds were analyzed by gas chromatography/mass spectrometry (GC/MS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. Flux calculated as the analytical result in μg/sample divided by the area of the respective sampler type (Funnel=0.0731 square meter [m2], Autosam- pler=0.0614 m2) and sample composite time in days. Abbreviations: E, estimated reported laboratory value; hh:mm, hour:minute; [-], no Chemical Abstract Service Number available for given compound; –, not detected] Site num- ber Site name Site identification number Start date Start time (hh:mm) End date End time (hh:mm) Sample composite time, days Sampler type 1-Naphthol1 [90-15-3] 3,4-dichloroaniline1 [95-76-1] 11 Newman rain gage at wasteway levee near Draper Road 371735121031201 Jul 18, 2003 09:30 Aug 4, 2003 12:15 17 Funnel – – 11 Newman rain gage at wasteway levee near Draper Road 371735121031201 Nov 10, 2003 10:30 Dec 11, 2003 11:50 31 Funnel E0.007 – 11 Newman rain gage at wasteway levee near Draper Road 371735121031201 Dec 16, 2003 11:00 Jan 29, 2004 14:00 44 Funnel E0.002 E0.009 12 Turlock rain gage near Idaho Road 372713120534901 Jul 18, 2003 10:30 Aug 4, 2003 13:00 17 Funnel – – 12 Turlock rain gage near Idaho Road 372713120534901 Nov 10, 2003 11:10 Dec 11, 2003 12:40 31 Funnel E0.003 E0.003 12 Turlock rain gage near Idaho Road 372713120534901 Jan 6, 2004 12:15 Jan 29, 2004 13:00 23 Funnel E0.004 E0.015 13 Turlock Airport rain gage 372857120414001 Nov 10, 2003 11:40 Dec 11, 2003 13:20 31 Funnel E0.004 E0.008 13 Turlock Airport rain gage 372857120414001 Jan 6, 2004 11:00 Jan 29, 2004 12:10 23 Funnel E0.004 E0.011 10 Westley rain gage at pump building near lateral 6 North 373335121143001 Mar 1, 2003 11:00 Mar 27, 2003 09:20 26 Funnel – E0.004 10 Westley rain gage at pump building near lateral 6 North 373335121143001 Nov 11, 2003 10:30 Dec 11, 2003 10:50 30 Funnel E0.003 E0.005

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Feb 21, 2003 14:40 Mar 27, 2003 14:50 34 Funnel E0.003 E0.008

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Jul 22, 2003 09:30 Aug 4, 2003 15:15 13 Funnel E0.008 –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Nov 10, 2003 13:15 Dec 11, 2003 15:00 31 2Autosampler E0.003 E0.003

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Jan 6, 2004 08:40 Jan 29, 2004 09:50 23 Funnel E0.008 E0.010

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Feb 21, 2003 13:20 Mar 27, 2003 13:50 34 Funnel – E0.0055 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Jul 22, 2003 10:00 Aug 4, 2003 14:30 13 Funnel E0.011 –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Nov 10, 2003 12:10 Dec 11, 2003 14:05 31 2Autosampler E0.002 –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Nov 10, 2003 12:30 Dec 11, 2003 14:10 31 Funnel E0.004 E0.007

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Jan 6, 2004 09:35 Jan 29, 2004 10:50 23 Funnel E0.003 E0.036

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Jan 6, 2004 09:35 Jan 29, 2004 10:50 23 2Autosampler E0.003 E0.042

16 Gridley High School precipitation gage at Gridley 392205121410201 Feb 20, 2003 14:00 Mar 28, 2003 12:10 36 Funnel E0.007 E0.006

16 Gridley High School precipitation gage at Gridley 392205121410201 Jan 7, 2004 11:00 Jan 27, 2004 10:10 20 Funnel E0.004 E0.00316 Gridley High School precipitation gage at Gridley 392205121410201 Mar 2, 2004 10:40 Mar 27, 2004 14:10 25 Funnel E0.003 E0.003

16 Gridley High School precipitation gage at Gridley 392205121410201 Mar 2, 2004 10:50 Mar 27, 2004 14:10 25 2Autosampler E0.005 E0.005

15 Oroville Dam precipitation gage at spillway 393234121292701 Feb 20, 2003 15:20 Mar 28, 2003 13:20 36 Funnel E0.015 –15 Oroville Dam precipitation gage at spillway 393234121292701 Mar 2, 2004 11:40 Mar 27, 2004 15:30 25 Funnel E0.005 –
Appendix 6 159

Appendix 6. Calculated flux values presented in micrograms per square meter per day (μg/m2/day) for bulk dry-deposition samples with at least one detection collected during 

the 2002–04 study period at eight sites in the Central Valley, California—Continued

[All compounds were analyzed by gas chromatography/mass spectrometry (GC/MS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. Flux calculated as the analytical result in μg/sample divided by the area of the respective sampler type (Funnel=0.0731 square meter [m2], Autosampler=0.0614 m2) and sample composite time in days. Abbreviations: E, estimated reported laboratory value; hh:mm, hour:minute; [-], no Chemical Abstract Service Number available for given compound; –, not detected]

Site 

number Site name

Site 

identification 

number

Azinphosmethyl1

[86-50-0]

Carbaryl 

[63-25-2]

Chlorpyrifos

[2921-88-2]

Chlorpyrifos 

oxon

[5598-15-2]

Deethylatrazine, 

CIAT1

[6190-65-4]

Cyfluthrin 

[68359-37-5]

Dacthal 

(DCPA)

[1861-32-1]

Diazinon

[333-41-5]

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 E0.047 – E0.011 – – – – –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – – – – – E0.007 –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – E0.005 E0.011 – – – E0.011 E0.411

12 Turlock rain gage near Idaho Road 372713120534901 E0.044 E0.021 E0.036 – – – E0.003 –

12 Turlock rain gage near Idaho Road 372713120534901 – E0.006 E0.005 – E0.004 – E0.012 E0.011

12 Turlock rain gage near Idaho Road 372713120534901 – E0.011 E0.105 E0.048 – – E0.004 E1.21

13 Turlock Airport rain gage 372857120414001 – E0.016 E0.003 – – – E0.009 E0.008

13 Turlock Airport rain gage 372857120414001 – E0.014 E0.208 E0.067 – – E0.006 E0.690

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – – E0.007 – – – E0.006 E0.003

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – – E0.002 – – E0.043 E0.006 E0.004

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – E0.014 – – – E0.005 E0.026

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – E0.010 – – – E0.003 –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – E0.014 E0.004 – – – E0.005 E0.009

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – E0.033 E0.143 E0.061 – – E0.008 E1.73

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – E0.004 – – – E0.001 E0.005

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E0.052 – E0.219 – – – E0.006 –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – E0.005 – – – E0.007 E0.005

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – E0.011 E0.009 – – – E0.009 E0.012

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – E0.011 E0.225 E0.057 – – E0.006 E1.52

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – E0.013 E0.268 E0.068 – – E0.007 E1.81

16 Gridley High School precipitation gage at Gridley 392205121410201 – – E0.008 – – – E0.001 E0.092

16 Gridley High School precipitation gage at Gridley 392205121410201 – E0.009 E0.235 E0.075 – – E0.005 E5.26

16 Gridley High School precipitation gage at Gridley 392205121410201 – E0.012 E0.011 – – – E0.001 E0.003

16 Gridley High School precipitation gage at Gridley 392205121410201 – E0.025 E0.012 E0.014 – – E0.001 E0.009

15 Oroville Dam precipitation gage at spillway 393234121292701 – – E0.005 – – – E0.002 E0.002

15 Oroville Dam precipitation gage at spillway 393234121292701 – E0.017 – – – – E0.001 –
160 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 6. Calculated flux values presented in micrograms per square meter per day (μg/m2/day) for bulk dry-deposition samples with at least one detection collected during the 2002–04 study period at eight sites in the Central Valley, California—Continued [All compounds were analyzed by gas chromatography/mass spectrometry (GC/MS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. Flux calculated as the analytical result in μg/sample divided by the area of the respective sampler type (Funnel=0.0731 square meter [m2], Autosam- pler=0.0614 m2) and sample composite time in days. Abbreviations: E, estimated reported laboratory value; hh:mm, hour:minute; [-], no Chemical Abstract Service Number available for given compound; –, not detected] Site num- ber Site name Site identification number Diazoxon1 [962-58-3] Dichlorvos1 [62-73-7] Dimethoate1 [60-51-5] Fipronil sulfone1 [120068-36-2] Hexazinone1 [51235-04-2] Iprodione [36734-19-7] Malathion [121-75-5] Malaoxon1 [1634-78-2] 11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – E0.079 – – – – E0.103 11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – – – E0.057 E0.019 – – 11 Newman rain gage at wasteway levee near Draper Road 371735121031201 E0.050 – – E0.002 E0.071 E0.007 – – 12 Turlock rain gage near Idaho Road 372713120534901 – E0.012 E0.044 – – – – E0.031 12 Turlock rain gage near Idaho Road 372713120534901 – – – – E0.026 – – E0.012 12 Turlock rain gage near Idaho Road 372713120534901 E0.126 E0.005 – – E0.086 – – – 13 Turlock Airport rain gage 372857120414001 – – E0.013 – E0.026 E0.015 E0.009 E0.009 13 Turlock Airport rain gage 372857120414001 E0.092 – – – E0.073 E0.015 E0.006 E0.007 10 Westley rain gage at pump building near lateral 6 North 373335121143001 – – – – – E0.352 – E0.010 10 Westley rain gage at pump building near lateral 6 North 373335121143001 – – – – E0.028 E0.006 – E0.022

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – – – E0.237 E0.004 E0.007

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – – – – – E0.052

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – – E0.012 – E0.007 –4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.202 E0.004 – – E0.111 – 0.061 E0.031

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – – – E0.700 – –5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – E0.029 E0.023 – – – – E0.047

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – – – – – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – – E0.031 E0.006 – E0.013

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E0.091 – – – – E0.006 E0.004 –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E0.108 – – – – E0.007 E0.005 –

16 Gridley High School precipitation gage at Gridley 392205121410201 E0.005 – – – – E0.043 E0.008 –

16 Gridley High School precipitation gage at Gridley 392205121410201 E0.203 E0.004 – – E0.049 – E0.009 –

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – – – E0.016 – –

16 Gridley High School precipitation gage at Gridley 392205121410201 E0.006 – – – – E0.031 – E0.008

15 Oroville Dam precipitation gage at spillway 393234121292701 – – – – – E0.046 – –

15 Oroville Dam precipitation gage at spillway 393234121292701 – – – – – E0.010 – –
Appendix 6 161

Appendix 6. Calculated flux values presented in micrograms per square meter per day (μg/m2/day) for bulk dry-deposition samples with at least one detection collected during 

the 2002–04 study period at eight sites in the Central Valley, California—Continued

[All compounds were analyzed by gas chromatography/mass spectrometry (GC/MS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. Flux calculated as the analytical result in μg/sample divided by the area of the respective sampler type (Funnel=0.0731 square meter [m2], Autosampler=0.0614 m2) and sample composite time in days. Abbreviations: E, estimated reported laboratory value; hh:mm, hour:minute; [-], no Chemical Abstract Service Number available for given compound; –, not detected]

Site 

number Site name

Site 

identification 

number

Methidathion

[950-37-8]

Metolachlor

[51218-45-2]

Metribuzin1 

[21087-64-9]

Myclobutanil 

[88671-89-0]

 Parathionmethyl1

[298-00-0]

 Paraoxonmethyl1

[950-35-6]

Pendimethilan1

[40487-42-1]

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – E0.065 – – E0.015 – –

11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – – – – – –11 Newman rain gage at wasteway levee near Draper Road 371735121031201 0.179 E0.012 – E0.005 – – E0.079

12 Turlock rain gage near Idaho Road 372713120534901 – – – – E0.014 – –12 Turlock rain gage near Idaho Road 372713120534901 – E0.005 – E0.006 E0.007 – E0.044

12 Turlock rain gage near Idaho Road 372713120534901 E0.103 E0.004 – – – – E0.063

13 Turlock Airport rain gage 372857120414001 E0.003 E0.003 – E0.007 E0.008 – E0.044

13 Turlock Airport rain gage 372857120414001 E0.092 E0.003 E0.010 – – – E0.044

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – E0.004 – E0.037 – – –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – E0.014 E0.044 – E0.010 – E0.145

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.004 E0.004 – 0.048 – – E0.010

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – E0.005 – E0.022 E0.015 E0.017 –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.008 E0.003 – E0.003 E0.007 – E0.033

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.426 E0.004 – – – – E0.084

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – E0.001 – E0.034 – – –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – – E0.062 E0.026 –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E0.005 E0.002 – – E0.010 – E0.033

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E0.006 E0.003 – E0.005 E0.024 – E0.057

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E0.157 E0.002 – E0.002 – – E0.061

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E0.187 E0.002 – E0.002 – – E0.073

16 Gridley High School precipitation gage at Gridley 392205121410201 E0.013 – – E0.012 – – –

16 Gridley High School precipitation gage at Gridley 392205121410201 E0.049 – – – E0.009 – E0.068

16 Gridley High School precipitation gage at Gridley 392205121410201 E0.007 E0.002 – – – – –

16 Gridley High School precipitation gage at Gridley 392205121410201 E0.019 E0.003 – E0.006 – – –

15 Oroville Dam precipitation gage at spillway 393234121292701 – – – – – – –

15 Oroville Dam precipitation gage at spillway 393234121292701 – – – – – – –
162 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 6. Calculated flux values presented in micrograms per square meter per day (μg/m2/day) for bulk dry-deposition samples with at least one detection collected during the 2002–04 study period at eight sites in the Central Valley, California—Continued [All compounds were analyzed by gas chromatography/mass spectrometry (GC/MS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. Flux calculated as the analytical result in μg/sample divided by the area of the respective sampler type (Funnel=0.0731 square meter [m2], Autosam- pler=0.0614 m2) and sample composite time in days. Abbreviations: E, estimated reported laboratory value; hh:mm, hour:minute; [-], no Chemical Abstract Service Number available for given compound; –, not detected] Site num- ber Site name Site identification number cis-Perme- thrin [54774-45-7] trans-Per- methrin [51877-74-8] Phosmet1 [732-11-6] Phosmet oxon1 [3735-33-9] Prometryn [7287-19-6] Pronamide [23950-58-5] Simazine [122-34-9] Trifluralin1 [1582-09-8] 11 Newman rain gage at wasteway levee near Draper Road 371735121031201 E0.061 E0.059 E0.050 – – – – E0.010 11 Newman rain gage at wasteway levee near Draper Road 371735121031201 – – – – – E0.007 – – 11 Newman rain gage at wasteway levee near Draper Road 371735121031201 E0.005 E0.005 – – E0.021 E0.009 E0.047 E0.032 12 Turlock rain gage near Idaho Road 372713120534901 E0.025 E0.012 E0.065

– – – E0.014 –

12 Turlock rain gage near Idaho Road 372713120534901 E0.005 E0.005 – – E0.079 E0.005 E0.051 E0.009

12 Turlock rain gage near Idaho Road 372713120534901 E0.030 E0.036 – – – – E0.067 E0.007

13 Turlock Airport rain gage 372857120414001 – – – – E0.025 – E0.078 E0.006

13 Turlock Airport rain gage 372857120414001 E0.044 E0.054 – – – – E0.097 E0.008

10 Westley rain gage at pump building near lateral 6 North 373335121143001 – – – – – – E0.018 –

10 Westley rain gage at pump building near lateral 6 North 373335121143001 E0.011 E0.010 – – E0.043 – E0.042 E0.007

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 – – – – – – E0.034 –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.014 E0.023 E0.024 E0.045 – – E0.011 –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.006 E0.009 – – E0.018 – E0.030 –

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.032 E0.043 – – – – E0.099 E0.009

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – – – – E0.046 –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E0.019 E0.017 E0.068 – – – E0.069 –5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – – E0.006 – E0.009 –

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 – – – – E0.029 – E0.066 E0.007

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E0.009 E0.011 – – – – E0.071 E0.004

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E0.011 E0.013 – – – – E0.085 E0.004

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – – – – E0.038 E0.003

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – – – – E0.030 E0.007

16 Gridley High School precipitation gage at Gridley 392205121410201 – – E0.010 E0.006 – – E0.024 –

16 Gridley High School precipitation gage at Gridley 392205121410201 – – – – – – E0.104 –

15 Oroville Dam precipitation gage at spillway 393234121292701 – – – – – – E0.008 –

15 Oroville Dam precipitation gage at spillway 393234121292701 – – – – – – E0.008 –

1 Compound is biased low (B-L) based on low and variable lab reagent spike recoveries (less than 50 percent).2 The autosampler for this sampling period failed to cover the dry deposition collection side at the onset of a rain event and therefore is a composite sample of dry and wet deposition, and was analyzed using 

NWQL research method LS8054.
Appendix 7 163

Appendix 7. Analytical Results Presented in Micrograms

Per Liter (μg/L) for Compounds With at Least One Detection 

Collected as Soil-Box Runoff (Aqueous Phase) Samples 

From Two Sites in the San Joaquin Valley and One Site in 

the Sacramento Valley, California, November 2002–March 

2004
164 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 7. Analytical results presented in micrograms per liter (μg/L) for compounds with at least one detection collected as soil-box runoff (aqueous phase) samples from two sites in the San Joaquin Valley and one site in the Sacramento Valley, California, November 2002–March 2004. [All compounds were analyzed by gas chromatography/mass spectrometry (GC/MS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five digit alphanumeric number in parenthesis is a code used by the USGS to uniquely identify the given compound. Abbreviations: D-U, value deleted by NWQL because compound could not be determined due to matrix interference; E, estimated reported laboratory valued; hh:mm, hour:minute; (E), estimated compound due to known poor perfor- mance by applied method (Childress and others, 1999; Sandstrom and others, 2001); –, compound not detected; <, less than laboratory reporting limit] Site num- ber Site name Site identification number Sample begin date Start time (hh:mm) Sample end date End time (hh:mm) Volume collected 1-Naphthol (E) [90-15-3] (49295) 3,4-Dichloroaniline (E) [95-76-1] (61625) Azinphos- methyl (E) [86-50-0] (82686)

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Nov 7, 2002 02:00 Nov 10, 2002 03:10 0.422 <0.09 E0.04 <0.05

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Dec 23, 2002 09:30 Jan 9, 2003 15:35 0.7 <0.09 E0.014 <0.05

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Jan 9, 2003 15:30 Jan 14, 2003 10:40 0.66 <0.09 E0.013 <0.05

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Jan 14, 2003 10:30 Mar 18, 2003 16:35 0.21 <0.09 E0.034 <0.05

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Mar 18, 2003 16:35 Dec 11, 2003 13:20 0.23 <0.09 E0.023 <0.05

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Dec 11, 2003 13:20 Dec 16, 2003 15:20 0.12 <0.09 <0.004 <0.05

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Dec 23, 2003 12:20 Dec 31, 2003 09:40 0.325 <0.09 <0.004 <0.05

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Dec 31, 2003 09:40 Feb 4, 2004 08:20 0.235 <0.09 <0.025 <0.05

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Nov 7, 2002 02:00 Nov 10, 2002 03:10 0.389 <0.09 E0.043 E0.02

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Nov 14, 2002 09:10 Dec 16, 2002 12:15 0.625 <0.09 E0.045 E0.021

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Dec 16, 2002 12:00 Dec 23, 2002 10:40 0.45 <0.09 E0.041 <0.05

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Jan 9, 2003 14:30 Jan 14, 2003 11:50 1.07 <0.09 E0.033 <0.05

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Jan 14, 2003 11:50 Feb 21, 2003 13:25 0.075 <0.09 E0.138 <0.05

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Feb 21, 2003 13:25 Apr 8, 2003 12:10 0.485 <0.09 <0.05

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 May 13, 2003 10:00 Nov 10, 2003 12:40 0.09 <0.09 E0.075 <0.05

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Nov 10, 2003 12:40 Dec 11, 2003 14:00 0.63 <0.09 E0.015 <0.05

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Dec 11, 2003 14:00 Dec 16, 2003 14:30 0.64 <0.09 E0.027 <0.05

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Feb 4, 2004 09:30 Mar 26, 2004 11:00 0.048 <0.09 E0.149 <0.05

16 Gridley High School precipitation gage at Gridley 392205121410201 Nov 4, 2003 10:15 Nov 12, 2003 10:20 1.03 E0.01 E0.01 E0.009

16 Gridley High School precipitation gage at Gridley 392205121410201 Nov 12, 2003 10:20 Dec 3, 2003 12:30 3.01 <0.09 <0.006 <0.05

16 Gridley High School precipitation gage at Gridley 392205121410201 Dec 3, 2003 12:30 Dec 12, 2003 11:00 4.2 <0.09 E0.008 <0.05

16 Gridley High School precipitation gage at Gridley 392205121410201 Dec 12, 2003 11:00 Dec 18, 2003 10:10 2 D-U E0.009 <0.05

16 Gridley High School precipitation gage at Gridley 392205121410201 Dec 18, 2003 10:00 Dec 23, 2003 08:00 1.22 D-U <0.004 <0.05

16 Gridley High School precipitation gage at Gridley 392205121410201 Dec 23, 2003 08:00 Dec 30, 2003 09:45 3 <0.09 <0.005 <0.05

16 Gridley High School precipitation gage at Gridley 392205121410201 Dec 30, 2003 09:45 Jan 27, 2004 10:20 0.17 <0.09 <0.004 <0.05

16 Gridley High School precipitation gage at Gridley 392205121410201 Jan 27, 2004 10:20 Feb 6, 2004 10:30 0.18 E0.02 <0.004 <0.05

16 Gridley High School precipitation gage at Gridley 392205121410201 Feb 6, 2004 10:30 Feb 17, 2004 14:20 0.11 <0.09 <0.004 <0.05

16 Gridley High School precipitation gage at Gridley 392205121410201 Feb 17, 2004 14:20 Feb 20, 2004 10:30 1.28 <0.09 <0.004 <0.05

16 Gridley High School precipitation gage at Gridley 392205121410201 Feb 20, 2004 10:30 Mar 2, 2004 11:00 4.18 <0.09 <0.004 <0.05

16 Gridley High School precipitation gage at Gridley 392205121410201 Mar 2, 2004 11:00 Mar 27, 2004 14:10 0.24 E0.01 E0.012 <0.05
Appendix 7 165

Appendix 7. Analytical results presented in micrograms per liter (μg/L) for compounds with at least one detection collected as soil-box runoff (aqueous phase) samples from two sites in the San Joaquin Valley and one site in the Sacramento Valley, California, November 2002–March 2004.—Continued[All compounds were analyzed by gas chromatography/mass spectrometry (GC/MS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five digit alphanumeric number in parenthesis is a code used by the USGS to uniquely identify the given compound. Abbreviations: D-U, value deleted by NWQL because compound could not be determined due to matrix interference; E, estimated reported laboratory valued; hh:mm, hour:minute; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); –, compound not detected; <, less than laboratory reporting limit]

Site 

number Site name

Site 

identification 

number

Carbaryl 

(E)

[63-25-2]

(82680)

Chlorpyrifos

[2921-88-2]

(38933)

Dacthal, 

DCPA

[1861-32-1]

(826820)

Diazinon

[333-41-5]

(39572)

Diazoxon 

(E)

[962-58-3]

(61638)

Dimethoate

[60-51-5]

(82662)

Hexazinone

[51235-04-2]

(04025)

Iprodione 

(E)

[36734-19-7]

(61593)

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.012 0.009 0.018 0.026 <0.04 <0.006 D-U <1.424 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.007 0.016 0.009 0.154 E0.04 <0.006 D-U <1.42

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 <0.041 0.039 0.009 0.304 E0.04 <0.006 D-U <1.424 Modesto Irrigation District gage rooftop at Modesto 373834121000601 <0.041 0.061 0.013 0.1 <0.04 <0.006 D-U E0.0854 Modesto Irrigation District gage rooftop at Modesto 373834121000601 <0.041 <0.005 0.016 0.02 <0.01 <0.006 D-U <1.42

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 <0.041 0.053 0.031 0.101 <0.01 <0.006 <0.013 <1.42

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 <0.041 0.015 0.009 0.124 E0.03 <0.006 <0.025 <1.424 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.018 0.083 0.015 0.874 E0.09 <0.006 0.023 <1.42

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 <0.041 0.011 0.009 0.012 <0.04 <0.006 D-U <1.42

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 <0.041 0.024 0.015 0.026 <0.04 E0.027 D-U <1.42

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 <0.041 0.028 0.01 0.043 <0.04 <0.006 D-U <1.425 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E0.004 0.544 0.005 1.62 E0.09 <0.006 D-U <1.42

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 <0.041 0.06 0.021 0.37 E0.08 <0.006 D-U E3.52

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 <0.041 0.017 0.013 0.042 <0.12 D-U D-U D-U

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 <0.041 <0.005 <0.003 <0.005 <0.01 <0.006 <0.013 <1.425 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 <0.041 0.009 0.01 0.011 <0.01 <0.006 <0.013 <1.425 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 <0.041 0.015 0.011 0.096 E0.02 <0.006 <0.013 <1.42

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 <0.041 <0.005 0.047 <0.005 <0.01 <0.006 <0.013 E0.356

16 Gridley High School precipitation gage at Gridley 392205121410201 E0.023 0.005 0.008 0.012 <0.01 <0.006 E0.007 <1.42

16 Gridley High School precipitation gage at Gridley 392205121410201 E0.011 E0.003 E0.003 0.005 <0.01 <0.006 <0.013 <1.42

16 Gridley High School precipitation gage at Gridley 392205121410201 E0.024 0.005 0.006 0.01 <0.01 <0.006 <0.013 <1.42

16 Gridley High School precipitation gage at Gridley 392205121410201 <0.055 E0.004 0.004 0.013 <0.01 <0.006 <0.013 <1.42

16 Gridley High School precipitation gage at Gridley 392205121410201 E0.034 0.009 0.005 0.031 <0.01 <0.006 <0.013 <1.42

16 Gridley High School precipitation gage at Gridley 392205121410201 E0.012 0.018 E0.003 0.022 E0.01 <0.006 <0.013 <1.42

16 Gridley High School precipitation gage at Gridley 392205121410201 <0.041 0.025 0.007 0.078 <0.01 <0.006 <0.013 <1.42

16 Gridley High School precipitation gage at Gridley 392205121410201 <0.041 0.057 0.01 1.75 E0.09 <0.006 <0.013 <1.4216 Gridley High School precipitation gage at Gridley 392205121410201 E0.043 0.042 0.014 0.796 E0.09 <0.006 <0.013 <1.42

16 Gridley High School precipitation gage at Gridley 392205121410201 <0.041 0.014 0.004 0.131 E0.01 <0.006 <0.013 <1.4216 Gridley High School precipitation gage at Gridley 392205121410201 <0.041 0.007 0.004 0.07 <0.01 <0.006 <0.013 E0.016

16 Gridley High School precipitation gage at Gridley 392205121410201 E0.045 0.028 0.01 0.046 <0.01 <0.006 <0.013 E0.046
166 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 7. Analytical results presented in micrograms per liter (μg/L) for compounds with at least one detection collected as soil-box runoff (aqueous phase) samples from two sites in the San Joaquin Valley and one site in the Sacramento Valley, California, November 2002–March 2004.—Continued [All compounds were analyzed by gas chromatography/mass spectrometry (GC/MS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five digit alphanumeric number in parenthesis is a code used by the USGS to uniquely identify the given compound. Abbreviations: D-U, value deleted by NWQL because compound could not be determined due to matrix interference; E, estimated reported laboratory valued; hh:mm, hour:minute; (E), estimated compound due to known poor perfor- mance by applied method (Childress and others, 1999; Sandstrom and others, 2001); –, compound not detected; <, less than laboratory reporting limit] Site num- ber Site name Site identification number Malathion [121-75-5] (39532) Malaoxon (E) [1634-78-2] (61652) Methidathion [950-37-8] (61598) Metolachlor [51218-45-2] (39415) Metribuzin [21087-64-9] (82630) Myclobutanil (E) [88671-89-0] (61599) Parathion- methyl [298-00-0] (82667)

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.02 <0.12 <0.006 0.309 0.028 E0.064 0.02

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 <0.027 <0.008 0.009 0.193 0.09 E0.047 <0.006

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 <0.027 <0.008 0.022 0.143 0.112 E0.049 <0.006

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 <0.027 <0.008 <0.006 0.046 0.025 E0.104 <0.006

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 <0.027 <0.008 <0.006 0.02 <0.006 E0.052 <0.006

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 <0.027 <0.008 <0.006 0.05 <0.006 <0.008 <0.0154 Modesto Irrigation District gage rooftop at Modesto 373834121000601 <0.027 <0.008 0.013 E0.01 <0.015 E0.026 <0.015

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 <0.027 <0.008 0.045 E0.009 <0.015 E0.021 <0.015

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 <0.027 <0.008 <0.006 0.132 0.034 E0.067 0.042

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 <0.027 <0.008 <0.006 0.309 0.116 E0.075 <0.006

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 <0.027 <0.008 0.016 0.154 0.043 E0.053 <0.006

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 <0.027 <0.008 0.054 0.066 0.069 E0.039 <0.006

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 <0.027 <0.008 0.064 0.089 0.069 E1.02 <0.006

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E0.015 <0.125 <0.006 0.029 <0.125 E D-U <0.006

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 <0.027 <0.008 <0.006 0.046 <0.006 E0.117 0.085

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 <0.027 <0.008 0.01 E0.012 <0.006 E0.028 E0.0145 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 <0.027 <0.008 0.044 0.023 0.021 E0.034 <0.015

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 0.089 <0.008 0.115 <0.013 <0.006 E0.151 <0.015

16 Gridley High School precipitation gage at Gridley 392205121410201 <0.027 E0.012 <0.006 <0.013 <0.006 <0.008 0.04116 Gridley High School precipitation gage at Gridley 392205121410201 <0.027 <0.008 <0.006 <0.013 <0.006 <0.008 0.01716 Gridley High School precipitation gage at Gridley 392205121410201 <0.027 <0.008 <0.006 <0.013 <0.006 <0.008 E0.01316 Gridley High School precipitation gage at Gridley 392205121410201 <0.027 <0.008 <0.006 <0.013 <0.006 <0.008 E0.01116 Gridley High School precipitation gage at Gridley 392205121410201 <0.027 <0.008 <0.006 <0.013 <0.006 <0.008 E0.01116 Gridley High School precipitation gage at Gridley 392205121410201 <0.027 <0.008 <0.006 <0.013 <0.006 <0.008 E0.008

16 Gridley High School precipitation gage at Gridley 392205121410201 <0.027 <0.008 <0.006 <0.013 <0.006 <0.008 <0.015

16 Gridley High School precipitation gage at Gridley 392205121410201 <0.027 <0.008 0.043 <0.013 <0.006 <0.008 <0.015

16 Gridley High School precipitation gage at Gridley 392205121410201 <0.027 <0.008 0.038 <0.013 <0.006 <0.008 <0.015

16 Gridley High School precipitation gage at Gridley 392205121410201 <0.027 <0.008 <0.006 E0.002 <0.006 E0.003 <0.015

16 Gridley High School precipitation gage at Gridley 392205121410201 <0.027 <0.008 <0.006 <0.013 <0.006 E0.008 <0.015

16 Gridley High School precipitation gage at Gridley 392205121410201 E0.022 <0.008 0.019 0.015 <0.006 E0.022 <0.015
Appendix 7 167

Appendix 7. Analytical results presented in micrograms per liter (μg/L) for compounds with at least one detection collected as soil-box runoff (aqueous phase) samples from two sites in the San Joaquin Valley and one site in the Sacramento Valley, California, November 2002–March 2004.—Continued[All compounds were analyzed by gas chromatography/mass spectrometry (GC/MS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five digit alphanumeric number in parenthesis is a code used by the USGS to uniquely identify the given compound. Abbreviations: D-U, value deleted by NWQL because compound could not be determined due to matrix interference; E, estimated reported laboratory valued; hh:mm, hour:minute; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); –, compound not detected; <, less than laboratory reporting limit]

Site 

number Site name

Site 

identification 

number

Paraoxonmethyl 

(E)

[950-35-6]

(61664)

 Pendimethalin

[40487-42-1]

(82683)

Prometon 

(E)

[1610-18-0]

(04037)

Prometryn

[7287-19-6]

(04036)

Pronamide

[23950-58-5]

(82676)

Simazine

[122-34-9]

(04035)

Trifluralin

[1582-09-8]

(82661)

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 <0.03 0.094 <0.01 <0.005 <0.004 0.765 0.021

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 <0.03 0.029 <0.01 0.009 0.006 0.297 E0.009

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 <0.03 0.03 <0.01 0.009 <0.004 0.246 E0.008

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 <0.03 0.07 <0.01 <0.005 <0.004 0.25 <0.009

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 <0.03 <0.035 <0.01 0.03 <0.025 0.083 <0.009

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 <0.03 <0.095 <0.01 <0.065 <0.004 <0.005 <0.009

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 <0.03 0.039 <0.01 <0.005 <0.004 0.027 <0.009

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 <0.03 E0.095 <0.01 0.007 <0.004 0.077 <0.015

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 <0.03 0.071 <0.01 <0.005 <0.004 0.388 0.015

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 <0.03 0.065 E0.01 0.088 0.017 0.934 <0.009

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 <0.03 0.06 <0.01 0.023 <0.004 0.324 <0.009

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 <0.03 0.033 <0.01 <0.006 0.004 0.146 E0.0055 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 <0.03 <0.022 <0.01 <0.005 <0.004 1.01 <0.009

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 D-U 0.039 D-U D-U <0.004 E0.082 <0.0095 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 <0.03 <0.022 <0.01 <0.005 <0.004 0.556 <0.009

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 <0.03 0.024 <0.01 0.017 <0.009 0.056 <0.0095 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 <0.03 0.032 <0.01 0.017 <0.004 0.076 <0.009

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 <0.03 <0.022 <0.01 <0.005 <0.004 0.534 <0.009

16 Gridley High School precipitation gage at Gridley 392205121410201 E0.02 E0.014 E0.01 <0.005 <0.004 0.025 <0.009

16 Gridley High School precipitation gage at Gridley 392205121410201 <0.03 E0.009 <0.01 E0.003 <0.004 0.017 <0.009

16 Gridley High School precipitation gage at Gridley 392205121410201 <0.03 E0.013 D-U 0.007 <0.004 0.019 <0.009

16 Gridley High School precipitation gage at Gridley 392205121410201 <0.03 0.023 E0.01 0.007 <0.004 0.026 <0.009

16 Gridley High School precipitation gage at Gridley 392205121410201 <0.03 0.022 E0.01 <0.005 <0.004 0.024 <0.009

16 Gridley High School precipitation gage at Gridley 392205121410201 <0.03 E0.015 <0.01 <0.005 <0.004 0.028 <0.009

16 Gridley High School precipitation gage at Gridley 392205121410201 <0.03 <0.022 <0.01 <0.005 <0.004 <0.005 <0.009

16 Gridley High School precipitation gage at Gridley 392205121410201 <0.03 <0.022 <0.01 <0.005 <0.004 0.039 <0.009

16 Gridley High School precipitation gage at Gridley 392205121410201 <0.03 <0.022 <0.01 <0.005 <0.004 0.06 <0.009

16 Gridley High School precipitation gage at Gridley 392205121410201 <0.03 E0.022 <0.01 <0.005 <0.004 0.014 <0.009

16 Gridley High School precipitation gage at Gridley 392205121410201 <0.03 <0.022 <0.03 <0.005 <0.004 0.021 <0.009

16 Gridley High School precipitation gage at Gridley 392205121410201 <0.03 0.029 E0.01 <0.005 <0.004 0.141 <0.009
168 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides References Cited Childress, C.J.O., Foreman, W.T., Connor, B.F., and Maloney, T.J., 1999, New reporting procedures based on long-term method detection levels and some consid- erations for interpretations of water-quality data provided by the U.S. Geological Survey National Water Quality Laboratory: U.S. Geological Survey Open-File Report 99–193, 19 p. Sandstrom, M.W., Stroppel, M.E., Foreman, W.T., and Schroeder, M.P., 2001, Methods of analysis by the U.S. Geological Survey National Water Quality Labora- tory–Determination of moderate-use pesticides and selected degradates in water by C-18 solid-phase extraction and capillary-column gas chromatography/mass spec- trometry with selected-ion monitoring (methods 2002/2011): U.S. Geological Survey Water-Resources Investigations Report 01–4098, 70 p.
Appendix 8. 169

Appendix 8. Analytical Results Presented in Micrograms

Per Liter (μg/L) for Compounds With at Least One Detection 

From the Soil Box as Soil-Box Runoff (Suspended Sediment) 

Samples Collected at Two Sites in the San Joaquin 

Valley and One Site in the Sacramento Valley, California, 

November 2002–March 2004
170 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 8. Analytical results presented in micrograms per liter (μg/L) for compounds with at least one detection from the soil box as soil-box runoff (suspended sediment) samples collected at two sites in the San Joaquin Valley and one site in the Sacramento Valley, California, November 2002–March 2004. [All compounds were analyzed by gas chromatography/mass spectrometry (GC/MS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five digit alphanumeric number in parenthesis is a code used by the USGS to uniquely identify the given compound. Abbreviations: D-U, value deleted by NWQL because compound could not be determined due to matrix interference; E, estimated reported laboratory valued; GFF, glass fiber filters; hh:mm, hour:minute; g, gram; L, liter; NA, not appli- cable; [-], no Chemical Abstract Service Number available for given compound; <, less than laboratory reporting limit; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); –, compound not detected] Site num- ber Site name Site identification number Sample begin date Start time (hh:mm) Sample end date End time (hh:mm) Number of GFF per sample Volume filtered (L) Estimated suspended sediment mass (g) 1-Naphthol1 (E) [90-15-3] (S0282)

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Dec 23, 2002 09:30 Jan 9, 2003 15:35 1 0.7 0.23 <0.79

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Jan 9, 2003 15:30 Jan 14, 2003 1040 1 0.66 0.22 E0.73

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Jan 14, 2003 10:30 Mar 18, 2003 16:35 1 0.21 0.31 <0.79

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Mar 18, 2003 16:35 Dec 11, 2003 13:20 1 0.23 0.25 <0.794 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Dec 11, 2003 13:20 Dec 16, 2003 15:20 1 0.12 0.68 <0.79

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Dec 23, 2003 12:20 Dec 31, 2003 09:40 1 0.31 0.26 <0.79

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Dec 31, 2003 09:40 Feb 4, 2004 08:20 1 0.235 0.19 <0.795 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Nov 7, 2002 02:00 Nov 10, 2002 03:10 1 0.389 3.88 <0.79

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Jan 9, 2003 14:30 Jan 14, 2003 11:50 1 1.7 0.48 <0.79

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Feb 21, 2003 13:25 Apr 8, 2003 12:10 1 0.475 0.63 <0.79

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 May 13, 2003 10:00 Nov 10, 2003 12:40 1 0.9 0.17 <0.79

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Nov 10, 2003 12:40 Dec 11, 2003 14:00 1 0.61 0.35 <0.79

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Dec 11, 2003 14:00 Dec 16, 2003 14:30 2 0.64 0.32 <0.79

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Feb 4, 2004 09:30 Mar 26, 2004 11:00 1 0.48 0.20 <0.79

16 Gridley High School precipitation gage at Gridley 392205121410201 Nov 4, 2003 10:15 Nov 12, 2003 10:20 5 0.989 4.44 <0.79

16 Gridley High School precipitation gage at Gridley 392205121410201 Nov 12, 2003 10:20 Dec 3, 2003 12:30 6 2.8 2.36 <0.79

16 Gridley High School precipitation gage at Gridley 392205121410201 Dec 3, 2003 12:30 Dec 12, 2003 11:00 9 3.745 4.73 <0.79

16 Gridley High School precipitation gage at Gridley 392205121410201 Dec 12, 2003 11:00 Dec 18, 2003 10:10 5 2 3.56 <0.79

16 Gridley High School precipitation gage at Gridley 392205121410201 Dec 18, 2003 10:00 Dec 23, 2003 08:00 2 1.22 0.72 <0.7916 Gridley High School precipitation gage at Gridley 392205121410201 Dec 23, 2003 08:00 Dec 30, 2003 09:45 5 3 1.65 <0.7916 Gridley High School precipitation gage at Gridley 392205121410201 Dec 30, 2003 09:45 Jan 27, 2004 10:20 1 0.17 0.37 <0.79

16 Gridley High School precipitation gage at Gridley 392205121410201 Jan 27, 2004 10:20 Feb 6, 2004 10:30 1 0.18 –0.66 <0.79

16 Gridley High School precipitation gage at Gridley 392205121410201 Feb 6, 2004 10:30 Feb 17, 2004 14:20 1 0.11 0.200 <0.7916 Gridley High School precipitation gage at Gridley 392205121410201 Feb 17, 2004 14:20 Feb 20, 2004 10:30 4 1.16 1.63 <0.7916 Gridley High School precipitation gage at Gridley 392205121410201 Feb 20, 2004 10:30 Mar 2, 2004 11:00 38 4.18 21.82 <0.79

16 Gridley High School precipitation gage at Gridley 392205121410201 Mar 2, 2004 11:00 Mar 27, 2004 14:10 1 0.24 0.76 <0.79

Samples ruined during laboratory prep

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Nov 7, 2002 02:00 Nov 10, 2002 03:10 NA NA NA NA

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Nov 14, 2002 09:10 Dec 16, 2002 12:15 NA NA NA NA

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Dec 16, 2002 12:00 Dec 23, 2002 10:40 NA NA NA NA

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Jan 14, 2003 11:50 Feb 21, 2003 13:25 NA NA NA NA
Appendix 8. 171

Appendix 8. Analytical results presented in micrograms per liter (μg/L) for compounds with at least one detection from the soil box as soil-box runoff (suspended sediment) samples collected at two sites in the San Joaquin Valley and one site in the Sacramento Valley, California, November 2002–March 2004.—Continued[All compounds were analyzed by gas chromatography/mass spectrometry (GC/MS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five digit alphanumeric number in parenthesis is a code used by the USGS to uniquely identify the given compound. Abbreviations: D-U, value deleted by NWQL because compound could not be determined due to matrix interference; E, estimated reported laboratory valued; GFF, glass fiber filters; hh:mm, hour:minute; g, gram; L, liter; [-], no Chemical Abstract Service Number available for given compound; <, less than laboratory reporting limit; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); –, compound not detected]

Site 

number Site name

Site 

identification 

number

3,4-dichloroaniline1

(E)

[95-76-1]

(S0287)

Carbaryl1

(E)

[63-25-2]

(S0295)

Chlorpyrifos1

[2921-88-2]

(S0296)

Dacthal 

(DCPA) 

[1861-32-1]

(S0300)

Diazinon

[333-41-5]

(S0302)

Fipronil

[120068-37-3]

(S0314)

Iprodione1

(E)

[36734-19-7]

(S0322)

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.69 <0.16 <0.08 <0.08 0.53 <0.08 <0.794 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.40 <0.16 0.75 E0.37 0.81 <0.08 <0.79

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E0.36 <0.16 <0.08 <0.08 0.18 <0.08 <0.794 Modesto Irrigation District gage rooftop at Modesto 373834121000601 <5.9 <0.16 <0.08 <0.08 <0.08 E0.13 <0.79

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 <5.9 <0.16 <0.08 <0.08 <0.08 <0.08 <0.794 Modesto Irrigation District gage rooftop at Modesto 373834121000601 <5.9 <0.16 <0.08 <0.08 <0.08 <0.08 <0.79

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 <5.9 <0.16 <0.08 <0.08 0.16 <0.08 <0.795 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E0.31 <0.16 <0.08 0.69 <0.08 <0.08 <0.79

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E0.78 <0.16 0.86 E0.21 0.37 <0.08 <0.79

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E0.87 <0.16 <0.08 <0.08 0.58 <0.08 E0.115 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 <5.9 <0.16 <0.08 <0.08 <0.08 <0.08 <0.79

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E0.14 <0.16 <0.08 <0.08 <0.08 <0.08 <0.79

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 <5.9 <0.16 <0.08 <0.08 0.64 <0.08 <0.795 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 <5.9 <0.16 <0.08 <0.08 <0.08 <0.08 <0.79

16 Gridley High School precipitation gage at Gridley 392205121410201 <5.9 E0.14 0.57 E0.49 <0.08 <0.08 <0.79

16 Gridley High School precipitation gage at Gridley 392205121410201 <5.9 <0.16 E0.15 E0.10 <0.08 E0.30 <0.79

16 Gridley High School precipitation gage at Gridley 392205121410201 <5.9 E0.35 E0.21 E0.15 <0.08 <0.08 <0.79

16 Gridley High School precipitation gage at Gridley 392205121410201 E0.14 E0.65 E0.31 E0.18 <0.08 <0.08 <0.79

16 Gridley High School precipitation gage at Gridley 392205121410201 <5.9 E0.40 E0.49 E0.26 <0.08 <0.08 <0.7916 Gridley High School precipitation gage at Gridley 392205121410201 <5.9 <0.16 E0.50 E0.10 <0.08 <0.08 <0.7916 Gridley High School precipitation gage at Gridley 392205121410201 <5.9 <0.16 <0.08 <0.08 <0.08 <0.08 <0.79

16 Gridley High School precipitation gage at Gridley 392205121410201 <5.9 <0.16 <0.08 <0.08 0.52 <0.08 <0.7916 Gridley High School precipitation gage at Gridley 392205121410201 <5.9 <0.16 <0.08 <0.08 0.31 <0.08 <0.79

16 Gridley High School precipitation gage at Gridley 392205121410201 E0.22 E0.37 0.72 E0.26 0.13 <0.08 <0.79

16 Gridley High School precipitation gage at Gridley 392205121410201 <5.9 E0.16 0.14 E0.25 0.29 <0.08 E0.16

16 Gridley High School precipitation gage at Gridley 392205121410201 E0.17 <0.16 <0.14 <0.08 <0.08 <0.08 <0.79
172 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 8. Analytical results presented in micrograms per liter (μg/L) for compounds with at least one detection from the soil box as soil-box runoff (suspended sediment) samples collected at two sites in the San Joaquin Valley and one site in the Sacramento Valley, California, November 2002–March 2004.—Continued [All compounds were analyzed by gas chromatography/mass spectrometry (GC/MS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five digit alphanumeric number in parenthesis is a code used by the USGS to uniquely identify the given compound. Abbreviations: D-U, value deleted by NWQL because compound could not be determined due to matrix interference; E, estimated reported laboratory valued; GFF, glass fiber filters; hh:mm, hour:minute; g, gram; L, liter; [-], no Chemi- cal Abstract Service Number available for given compound; <, less than laboratory reporting limit; (E), estimated compound due to known poor performance by applied method (Childress and others, 1999; Sandstrom and others, 2001); –, compound not detected] Site num- ber Site name Site identification number Malaoxon1 (E) [1634-78-2] (S0324) Myclobutanil (E) [88671-89-0] (S0330) Parathion- methyl [298-00-0] (S0332) Pendimethalin [40487-42-1] (S0333) Simazine [122-34-9] (S0343) Trifluralin [1582-09-8] (S0348)

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 D-U E0.69 <0.16 <0.11 E0.93 <0.08

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 D-U <0.08 <0.16 <0.11 E0.84 <0.08

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 D-U <0.08 <0.16 <0.11 0.26 <0.08

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 D-U <0.08 <0.16 <0.11 <0.16 <0.08

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 D-U <0.08 <0.16 <0.11 <0.16 <0.08

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 D-U <0.08 <0.16 <0.11 <0.16 <0.08

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 D-U <0.08 <0.16 <0.11 <0.16 <0.08

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 D-U E0.89 <0.16 0.96 0.13 0.81

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 D-U <0.08 <0.16 0.17 E0.68 E0.1

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 D-U E0.12 <0.16 0.15 0.11 <0.08

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 D-U <0.08 <0.16 <0.11 0.68 <0.08

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 D-U <0.08 <0.16 <0.11 E0.75 <0.08

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 <0.40 E0.5 <0.16 <0.9 0.11 <0.08

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 D-U <0.08 <0.16 <0.11 <0.16 <0.08

16 Gridley High School precipitation gage at Gridley 392205121410201 <0.40 <0.08 E0.27 0.13 E0.96 <0.0816 Gridley High School precipitation gage at Gridley 392205121410201 <0.40 <0.08 E0.26 <0.11 E0.21 <0.0816 Gridley High School precipitation gage at Gridley 392205121410201 <0.40 <0.08 E0.80 0.7 E0.47 <0.0816 Gridley High School precipitation gage at Gridley 392205121410201 <0.40 <0.08 0.92 E0.46 E0.73 <0.0816 Gridley High School precipitation gage at Gridley 392205121410201 E0.23 <0.08 <0.16 E0.37 E0.59 <0.08

16 Gridley High School precipitation gage at Gridley 392205121410201 <0.40 <0.08 E0.20 E0.24 E0.26 <0.0816 Gridley High School precipitation gage at Gridley 392205121410201 D-U <0.08 <0.16 <0.11 <0.16 <0.08

16 Gridley High School precipitation gage at Gridley 392205121410201 D-U <0.08 <0.16 <0.11 <0.16 <0.08

16 Gridley High School precipitation gage at Gridley 392205121410201 D-U <0.08 <0.16 <0.11 <0.16 <0.08

16 Gridley High School precipitation gage at Gridley 392205121410201 <0.40 <0.08 <0.16 <0.11 E0.72 <0.0816 Gridley High School precipitation gage at Gridley 392205121410201 <0.40 E0.86 E0.86 0.16 0.22 E0.1816 Gridley High School precipitation gage at Gridley 392205121410201 D-U <0.08 <0.16 <0.11 0.24 <0.08

1Compound is biased low (B-L) because of low laboratory matrix and reagent spike recoveries, see table 10. Compounds with non-detections are not presented in the appendix but concentrations may be 

present in low concentrations in the environment.
Appendix 8. 173

References Cited

Childress, C.J.O., Foreman, W.T., Connor, B.F., and Maloney, T.J., 1999, New reporting procedures based on long-term method detection levels and some considerations for interpretations of water-quality data provided by the U.S. Geological Survey National Water Quality Laboratory: U.S. Geological Survey Open-File Report 

99–193, 19 p.

Sandstrom, M.W., Stroppel, M.E., Foreman, W.T., and Schroeder, M.P., 2001, Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory–Determination of moderate-use pesticides and selected degradates in water by C-18 solid-phase extraction and capillary-column gas chromatography/mass spectrometry with selected-ion monitoring (methods 2002/2011): U.S. Geological Survey Water-Resources Investigations Report 01–4098, 70 p.
174 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides

Appendix 9. Analytical Results Presented in Micrograms

Per Kilogram (μg/Kg) for Compounds With at Least One 

Detection From the Soil Box as Surficial-Soil Samples 

Collected at Two Sites in the San Joaquin Valley and One 

Site in the Sacramento Valley, California, November 2002–

March 2004
Appendix 9 175

Appendix 9. Analytical results presented in micrograms per kilogram (μg/Kg) for compounds with at least one detection from the soil box as surficial-soil samples collected at two sites in the San Joaquin Valley and one site in the Sacramento Valley, California, November 2002–March 2004. [The background concentrations and control samples are considered quality assurance samples but are presented with the environmental samples for comparative purposes. All compounds were analyzed by gas chromatography/mass spectrometry (GC/MS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five digit alphanumeric number in parenthesis is a code used by the USGS to uniquely identify the given compound. Mix 1 collected near site 10 (Westly Raingage). Mix 2 collected near site 11 (Newman Raingage). Mix 3 collected near site 5 (Modesto Irrigation District at Albers Road). Mix 4 collected near site 16 (Gridley High School). Sample weight was wet weight in grams. Total area of soil box is 0.374 square meters. Abbreviations: CSUS, California State University, Sacramento; E, estimated reported laboratory value; NA, not applicable; [-], no Chemical Abstract Service Number available for given compound; <, less than laboratory reporting value]

Site 

number Site name

Site 

identification 

number

Start 

date

Start 

time

(hh:mm)

End 

date

End 

time

(hh:mm)

1-Napthol1

(E) 

[90-15-3]

(S0282)

2,6-Diethylaniline1

(E)

[579-66-8]

(S0283)

2-Chloro-2,6-diethylacetanilide1

[6967-29-9]

(S0285)

Environmental surficial-soil samples

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Aug 14, 2002 10:00 Oct 4, 2002 11:15 <10 <30 <14 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Oct 4, 2002 11:15 Jul 22, 2003 09:50 <10 <30 <1

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 Jul 22, 2003 10:15 Jul 8, 2004 10:00 <10 <30 <15 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Aug 14, 2002 11:00 Oct 4, 2002 12:00 <10 <30 <1

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Oct 4, 2002 12:00 Jul 22, 2003 10:15 <10 <30 <1

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 Jul 22, 2003 11:00 July 8, 2004 10:30 <10 <30 <1

16 Gridley High School precipitation gage at Gridley 392205121410201 Feb 7, 2003 11:30 Jul 21, 2003 09:30 <10 <30 <1

16 Gridley High School precipitation gage at Gridley 392205121410201 Jul 21, 2003 09:30 Jun 3, 2004 10:15 <10 <30 <1

Quality-assurance surficial-soil control samples

14 Soil Control Box at CSUS Placer Hall at Sacramento2 383343121252501 Aug 15, 2002 10:00 Oct 9, 2002 12:00 <10 <30 <1

14 Soil Control Box at CSUS Placer Hall at Sacramento2 383343121252501 Oct 9, 2002 12:00 Jul 31, 2003 09:50 <10 <30 <1

14 Soil Control Box at CSUS Placer Hall at Sacramento2 383343121252501 Jul 31, 2003 09:50 Jul 26, 2004 08:00 <10 <30 <1

Quality-assurance background concentration surficial-soil samples

NA Mix 1 373335121143001 Aug 1, 2002 12:00 NA NA <10 <30 <1

NA Mix 2 371735121031201 Aug 1, 2002 12:15 NA NA <10 <30 <1

NA Mix 3 373841120504801 Aug 1, 2002 12:30 NA NA <10 <30 <1

NA Mix 4 392205121410201 Feb 7, 2003 11:30 NA NA <10 <30 <1
176 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 9. Analytical results presented in micrograms per kilogram (μg/Kg) for compounds with at least one detection from the soil box as surficial-soil samples collected at two sites in the San Joaquin Valley and one site in the Sacramento Valley, California, November 2002–March 2004.—Continued [The background concentrations and control samples are considered quality assurance samples but are presented with the environmental samples for comparative purposes. All compounds were analyzed by gas chromatography/mass spectrometry (GC/MS) at the U.S. Geological Survey (USGS) National 

Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name 

in brackets. The five digit alphanumeric number in parenthesis is a code used by the USGS to uniquely identify the given compound. Mix 1 collected near site 10 (Westly Raingage). Mix 2 collected near site 11 (Newman Raingage). Mix 3 collected near site 5 (Modesto Irrigation District at Albers Road). Mix 4 collected near site 16 (Gridley High School). Sample weight was wet weight in grams. Total area of soil box is 0.374 square meters. Abbreviations: CSUS, California State University, Sacramento; E, estimated reported laboratory value; NA, not applicable; [-], no Chemical Abstract Service Number available for given compound; <, less than laboratory reporting value]

Site 

number Site name

Site 

identification 

number

3,4-Dichloroaniline 

(E)

[95-76-1]

(S0287)

4-Chloro2-methlyphenol1

(E)

[1570-64-5]

(S0288)

Carbaryl3

(E)

[63-25-2]

(S0295)

Chlorpyrifos

[2921-88-2]

(S0296)

Chlorpyrifos 

oxon1

(E)

[5598-15-2]

(S0297)

Dacthal 

(DCPA) 

[1861-32-1]

(S0300)

Diazoxon1

(E)

[962-58-3]

(S0303)

Environmental surficial-soil samples—Continued

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E2 <10 E0.6 E0.8 <30 1 <5

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 <75 <10 E0.8 2 E3 1 <5

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 <75 <10 <4 2 <30 1 <5

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E3 <10 E0.3 1 <30 E0.9 <55 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 <75 <10 E0.9 10 E5 E1 <55 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E2 <10 E1 7 <30 E0.9 <5

16 Gridley High School precipitation gage at Gridley 392205121410201 E1 <10 E2 1 <30 E0.8 <5

16 Gridley High School precipitation gage at Gridley 392205121410201 E1 <10 <2 E0.9 <30 E0.8 <5

Quality-assurance surficial-soil control samples—Continued

14 Soil Control Box at CSUS Placer Hall at Sacramento2 383343121252501 E4 <10 E2 <1 <30 E0.6 <5

14 Soil Control Box at CSUS Placer Hall at Sacramento2 383343121252501 <75 <10 E1 <1 <30 E0.7 <514 Soil Control Box at CSUS Placer Hall at Sacramento2 383343121252501 <75 <10 E2 E0.6 <30 E0.7 <5

Quality-assurance background concentration surficial-soil samples—Continued

NA Mix 1 373335121143001 E5 <10 E1 <1 <30 E0.6 <5

NA Mix 2 371735121031201 E6 <10 E2 E0.7 <30 E0.6 <5

NA Mix 3 373841120504801 E4 <10 E2 E0.9 <30 E0.8 <5

NA Mix 4 392205121410201 E0.9 <10 E2 <1 <30 <1 <5
Appendix 9 177

Appendix 9. Analytical results presented in micrograms per kilogram (μg/Kg) for compounds with at least one detection from the soil box as surficial-soil samples collected at two sites in the San Joaquin Valley and one site in the Sacramento Valley, California, November 2002–March 2004.—Continued [The background concentrations and control samples are considered quality assurance samples but are presented with the environmental samples for comparative purposes. All compounds were analyzed by gas chromatography/mass spectrometry (GC/MS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five digit alphanumeric number in parenthesis is a code used by the USGS to uniquely identify the given compound. Mix 1 collected near site 10 (Westly Raingage). Mix 2 collected near site 11 (Newman Raingage). Mix 3 collected near site 5 (Modesto Irrigation District at Albers Road). Mix 4 collected near site 16 (Gridley High School). Sample weight was wet weight in grams. Total area of soil box is 0.374 square meters. Abbreviations: CSUS, California State University, Sacramento; E, estimated reported laboratory value; NA, not applicable; [-], no Chemical Abstract Service Number available for given compound; <, less than laboratory reporting value]

Site 

number Site name

Site 

identification 

number

Dichlorvos1

(E)

[62-73-7]

(S0304)

Dicrotophos1

(E)

[141-66-2]

(S0305)

Dieldrin

[60-57-1]

(S0306)

Dimethoate

[60-51-5]

(S0307)

Fenamiphos1

(E)

[22224-92-6]

(S0310)

 Fipronil 

sulfone

[120068-36-2]

(S0316)

Desulfinylfipronil

[-]

(S0317)

Environmental surficial-soil samples—Continued

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 <30 <3 3 9 <30 1 E0.8

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 <30 <3 2 <2 <30 1 E0.6

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 <30 <3 2 <2 <30 1 E0.7

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 <30 <3 3 E6 <30 2 E0.9

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 <30 <3 2 <3 <30 1 E0.6

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 <30 <3 3 <4 <30 1 E0.7

16 Gridley High School precipitation gage at Gridley 392205121410201 <30 <3 E0.6 <2 <30 <1 <1

16 Gridley High School precipitation gage at Gridley 392205121410201 <30 <3 E0.5 <2 <30 <1 <1

Quality-assurance surficial-soil control samples—Continued

14 Soil Control Box at CSUS Placer Hall at Sacramento2 383343121252501 <30 <3 3 10 <30 1 E0.6

14 Soil Control Box at CSUS Placer Hall at Sacramento2 383343121252501 <30 <3 2 <2 <30 1 E0.6

14 Soil Control Box at CSUS Placer Hall at Sacramento2 383343121252501 <30 <3 3 <2 <30 1 E0.6

Quality-assurance background concentration surficial-soil samples—Continued

NA Mix 1 373335121143001 <30 <3 3 E18 <30 1 E0.6

NA Mix 2 371735121031201 <30 <3 4 26 <30 1 E0.6

NA Mix 3 373841120504801 <30 <3 3 E23 <30 2 E0.8

NA Mix 4 392205121410201 <30 <3 E0.4 <2 <30 <1 <1
178 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 9. Analytical results presented in micrograms per kilogram (μg/Kg) for compounds with at least one detection from the soil box as surficial-soil samples collected at two sites in the San Joaquin Valley and one site in the Sacramento Valley, California, November 2002–March 2004.—Continued [The background concentrations and control samples are considered quality assurance samples but are presented with the environmental samples for comparative purposes. All compounds were analyzed by gas chromatography/mass spectrometry (GC/MS) at the U.S. Geological Survey (USGS) National 

Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name 

in brackets. The five digit alphanumeric number in parenthesis is a code used by the USGS to uniquely identify the given compound. Mix 1 collected near site 10 (Westly Raingage). Mix 2 collected near site 11 (Newman Raingage). Mix 3 collected near site 5 (Modesto Irrigation District at Albers Road). Mix 4 collected near site 16 (Gridley High School). Sample weight was wet weight in grams. Total area of soil box is 0.374 square meters. Abbreviations: CSUS, California State University, Sacramento; E, estimated reported laboratory value; NA, not applicable; [-], no Chemical Abstract Service Number available for given compound; <, less than laboratory reporting value]

Site 

number Site name

Site 

identification 

number

Iprodione1

(E)

[36734-19-7]

(S0322)

Malathion

[121-75-5]

(S0325)

Metolachlor

[51218-45-2]

(S0328)

Metribuzin

[21087-64-9]

(S0329)

Myclobutanil 

(E)

[88671-89-0]

(S0330)

Parathionmethyl

[298-00-0]

(S0332)

Paraoxonmethyl 

(E)

[950-35-6]

(S0331)

Environmental surficial-soil samples—Continued

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E6 10 55 E12 E10 <2 <5

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E9 <2 9 E2 E9 <2 <5

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E15 <2 5 <4 E10 <4 <55 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E6 12 66 E12 E17 <2 <5

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E28 <2 12 E5 E14 <3 E4

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E22 <2 7 E1 E17 <4 <5

16 Gridley High School precipitation gage at Gridley 392205121410201 E1 <2 <1 <4 <1 E6 E4

16 Gridley High School precipitation gage at Gridley 392205121410201 E0.9 <2 <1 <4 <1 <2 <5

Quality-assurance surficial-soil control samples—Continued

14 Soil Control Box at CSUS Placer Hall at Sacramento2 383343121252501 E6 6 76 E16 E16 <2 <5

14 Soil Control Box at CSUS Placer Hall at Sacramento2 383343121252501 E7 <2 37 E15 E13 <2 <514 Soil Control Box at CSUS Placer Hall at Sacramento2 383343121252501 E5 <2 31 E6 E13 <2 <5

Quality-assurance background concentration surficial-soil samples—Continued

NA Mix 1 373335121143001 E5 18 58 E15 E18 <2 <5

NA Mix 2 371735121031201 E9 25 128 E23 E14 <2 <5

NA Mix 3 373841120504801 E8 27 108 E25 E12 <2 <5

NA Mix 4 392205121410201 <10 <2 <1 <4 <1 <2 <5
Appendix 9 179

Appendix 9. Analytical results presented in micrograms per kilogram (μg/Kg) for compounds with at least one detection from the soil box as surficial-soil samples collected at two sites in the San Joaquin Valley and one site in the Sacramento Valley, California, November 2002–March 2004.—Continued [The background concentrations and control samples are considered quality assurance samples but are presented with the environmental samples for comparative purposes. All compounds were analyzed by gas chromatography/mass spectrometry (GC/MS) at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name in brackets. The five digit alphanumeric number in parenthesis is a code used by the USGS to uniquely identify the given compound. Mix 1 collected near site 10 (Westly Raingage). Mix 2 collected near site 11 (Newman Raingage). Mix 3 collected near site 5 (Modesto Irrigation District at Albers Road). Mix 4 collected near site 16 (Gridley High School). Sample weight was wet weight in grams. Total area of soil box is 0.374 square meters. Abbreviations: CSUS, California State University, Sacramento; E, estimated reported laboratory value; NA, not applicable; [-], no Chemical Abstract Service Number available for given compound; <, less than laboratory reporting value]

Site 

number Site name

Site 

identification 

number

Pendimethalin

[40487-42-1]

(S0333)

cis-Permethrin3 

[54774-45-7]

(S0340)

trans-Permethrin3

[51877-74-8]

(S0341)

Phorate1

(E)

[298-02-2]

(S0334)

Phorate oxon1

[2600-69-3]

(S0335)

Phosmet1

[732-11-6]

(S0336)

Environmental surficial-soil samples—Continued

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E40 <5 <5 <5 <7 <304 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E30 <5 <5 <5 <7 <304 Modesto Irrigation District gage rooftop at Modesto 373834121000601 E26 <5 <5 <5 <7 <305 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E62 <5 <5 <5 <7 <305 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E31 <5 <5 <5 <7 <305 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 E26 <5 <5 <5 <7 <30

16 Gridley High School precipitation gage at Gridley 392205121410201 <1 <5 <5 <5 <7 <3016 Gridley High School precipitation gage at Gridley 392205121410201 <1 <5 <5 <5 <7 <30

Quality-assurance surficial-soil control samples—Continued

14 Soil Control Box at CSUS Placer Hall at Sacramento2 383343121252501 E54 <5 <5 <5 <7 <30

14 Soil Control Box at CSUS Placer Hall at Sacramento2 383343121252501 E39 <5 <5 <5 <7 <3014 Soil Control Box at CSUS Placer Hall at Sacramento2 383343121252501 E40 <5 <5 <5 <7 <30

Quality-assurance background concentration surficial-soil samples—Continued

NA Mix 1 373335121143001 58 E11 6 <5 <7 <30

NA Mix 2 371735121031201 48 <5 <5 <5 <7 <30

NA Mix 3 373841120504801 47 <5 <5 <5 <7 <30

NA Mix 4 392205121410201 <1 <5 <5 <5 <7 <30
180 Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides Appendix 9. Analytical results presented in micrograms per kilogram (μg/Kg) for compounds with at least one detection from the soil box as surficial-soil samples collected at two sites in the San Joaquin Valley and one site in the Sacramento Valley, California, November 2002–March 2004.—Continued [The background concentrations and control samples are considered quality assurance samples but are presented with the environmental samples for comparative purposes. All compounds were analyzed by gas chromatography/mass spectrometry (GC/MS) at the U.S. Geological Survey (USGS) National 

Water Quality Laboratory (NWQL). The Chemical Abstract Service Number is given below each compound name 

in brackets. The five digit alphanumeric number in parenthesis is a code used by the USGS to uniquely identify the given compound. Mix 1 collected near site 10 (Westly Raingage). Mix 2 collected near site 11 (Newman Raingage). Mix 3 collected near site 5 (Modesto Irrigation District at Albers Road). Mix 4 collected near site 16 (Gridley High School). Sample weight was wet weight in grams. Total area of soil box is 0.374 square meters. Abbreviations: CSUS, California State University, Sacramento; E, estimated reported laboratory value; NA, not applicable; [-], no Chemical Abstract Service Number available for given compound; <, less than laboratory reporting value]

Site 

number Site name

Site 

identification 

number

Prometon 

(E)

[1610-18-0]

(S0338)

Simazine

[122-34-9]

(S0343)

Terbufos1

[13071-79-9]

(S0345)

Trifluralin

[1582-09-8]

(S0348)

Sample 

wet weight, 

grams

(S0433)

Environmental surficial-soil samples—Continued

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 <3 53 <1 17 32.2

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 <2 9 <1 11 43.3

4 Modesto Irrigation District gage rooftop at Modesto 373834121000601 <2 4 <1 8 37.8

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 <2 72 <1 17 32.6

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 <2 20 <1 8 41.9

5 Modesto Irrigation District gage rooftop at Albers Road 373841120504801 <2 12 <1 7 41.9

16 Gridley High School precipitation gage at Gridley 392205121410201 E2 11 <1 E0.6 33.7

16 Gridley High School precipitation gage at Gridley 392205121410201 <2 2 <1 E0.3 33.1

Quality-assurance surficial-soil control samples—Continued

14 Soil Control Box at CSUS Placer Hall at Sacramento2 383343121252501 <2 81 <1 21 42.2

14 Soil Control Box at CSUS Placer Hall at Sacramento2 383343121252501 E2 54 <1 10 44.614 Soil Control Box at CSUS Placer Hall at Sacramento2 383343121252501 <2 46 <1 11 45.7

Quality-assurance background concentration surficial-soil samples—Continued

NA Mix 1 373335121143001 E1 99 <1 17 40.9

NA Mix 2 371735121031201 E1 70 <1 31 42.2

NA Mix 3 373841120504801 E2 128 <1 25 34.6

NA Mix 4 392205121410201 E2 10 <1 E0.1 28.3

1Compound is biased low (B-L) because of low laboratory matrix and reagent spike recoveries, see table 11. Compounds with non-detections are presented in the appendix because concentrations may be 

present in low concentrations in the environment.

2Site 14 in the Sacramento Valley was considered a control and the results are presented with appendix 8, but discussed in the soil box field quality control section of this report.3Compound is biased high (B-H) because laboratory matrix and reagent spike recoveries were greater than 150 percent, see table 11. 
Prepared by the Sacramento Publishing Service Center.

For more information concerning this report, contact:

Director

U.S. Geological Survey

California Water Science Center

6000 J Street, Placer Hall

Sacramento, CA 95819

GS-W-CAWSC_WWW@usgs.gov

or visit our Web site at:

http://ca.water.usgs.gov
Zamora and others—Methods, Quality Assurance, and Data for Assessing Atmospheric Deposition of Pesticides in the Central Valley of California—SIR 2013–5023