### Monitoring Urban Pesticide Runoff in California 2008 - 2009

Michael Ensminger and Kevin Kelley

CALIFORNIA ENVIRONMEN TAL PROTECTION AGENCY

California Department of Pesticide Regulation

Environmental Monitoring Branch

Surface Water Protection Program

1001 I Street, Sacramento, CA 95812

March 2011

Report 249

### i ABSTRACT

To determine the prevalent pesticid es in urba n surface waters in California, the California Department of Pesticide Regulation (CDPR) initiated a statewide urban surface water monitoring program in 2008. Water and sediment samples were collected at 25 sites in the Sacramento (SAC), San Francisco Bay ( SFB), greater Los Angeles (Orange County), and San Diego (SD) areas. Samples were co llected at stormdrain outflows and at receiving waters during rainy and during dryflow conditions. Water samples were analyzed for 63 pesticides or degradates. Se diment samples were only collected during dryflow and analyzed for pyrethroids and chlo rpyrifos. In water samples, 18 insecticides and 12 herbicides or their degradates were detected above their reporting limits. Multiple detections were common; 50% of the samples had three or more pesticides and 25% had six or more pesticides. OC and SAC had the highest detection frequencies and SD had the fewest. The most frequently detected insec ticides in water were bifenthrin, fipronil, fipronil sulfone, carbaryl, desu lfinyl fipronil, and malathi on. Chlorpyrifos and diazinon were detected, albeit infrequently, despite drastic reductions in urban use. Fipronil, fipronil sulfone, desulfinyl fi pronil, and carbaryl were more frequently detected in OC than in other areas of the study. Other pyrethr oids were infrequently detected in water samples but common contaminants of sediments. Half of the sediments contained five or more pyrethroids. The most common pyret hroids in sediment s were bifenthrin, cyfluthrin, permethrin, deltamethrin, λ -cyhalothrin, and cypermethrin. Herbicides were detected at slightly higher frequencies than insecticides; the most frequently detected herbicides were 2,4-D, triclopyr, dicamba, diuron, MCPA, and pendimethalin. Except for bifenthrin, pesticides occurre d with equal frequency in stormdrain outflows and in receiving waters. Bifenthrin was more frequen tly detected in stormdrain outflows than in receiving waters. Rain increased pesticide runo ff for all of the pesticides but fipronil (and degradates). Fipronil appeared to have a c ontinuous load dependent on use rather than

rainfall. Detection of the herbicides diuron a nd pendimethalin also correlated with use but these herbicides are routinely applied during the rainy season when pesticide detections are generally highest. Bifenthrin, fipronil, a nd diuron were detected in water samples at concentrations that potentially could be toxic to aquatic organisms.

ACKNOWLEDGEMENTS

Many people have generously given their time to help th is study succeed, especially the

staff and of the Surface Water Protection Program of the Environmental Monitoring Branch of CDPR. We especia lly thank Kean S. Goh and Sh eryl Gill for their support of this project, Carissa Ga napathy and Sue Peoples fo r sample coordination and organization between DPR and CDFG, to Jessi e Ybarra for maintaining CDPR’s West Sacramento’s facility, and to Frank Spurlock for his critical re view. In addition, we extend gratitude to Li-Ming He, currently at NOAA Fisheries, 650 Capitol Mall, Sacramento, CA for his early leadership in this project.

### ii TABLE OF CONTENTS

ABSTRACT..................................................................................................................................... i

ACKNOWLEDGEMENTS............................................................................................................. i

TABLE OF CONTENTS..............................................................................................................

.. ii

LIST OF FIGURES ....................................................................................................................... iii

LIST OF TABLES.................................................................................................................

........ iii

I. INTRODUCTION................................................................................................................ ....... 2

II. MATERIALS AND METHODS............................................................................................... 3

III. RESULTS AND DISCUSSION............................................................................................... 5

Pesticides detected in surface waters .......................................................................................... 5

Pesticides detected in sediments ................................................................................................. 7 The effect of waterbody type (storm drai n vs. creek receiving water) on pesticide

detections in urban surface waters. ............................................................................................

. 8 The effect of season (dryflow vs. rainstor m) on pesticide detections in urban surface

waters. ....................................................................................................................... .................. 8 Comparison of Pesticide Concentrations to Aquatic Toxicity Benchmarks

............................... 9 Water Quality.................................................................................................................. .......... 11 Quality Control ......................................................................................................................... 11

IV. CONCLUSIONS ................................................................................................................ .... 11

V. LITERATURE CITED ........................................................................................................... 13

VI. APPENDIX I. DATA ............................................................................................................. 28 VII. APPENDIX II. QUALITY CONTROL................................................................................ 53

### iii LIST OF FIGURES

Figure 1. Sampling sites for CDPR’s urban m onitoring project in the Sacramento, San

Francisco B ay, greater Los Angeles (O range County), and San Diego areas,

California. .................................................................................................................... ......... 20 Figure 2. Cartoon depicting a storm dr ain outflow and receiving water. ..................................... 21 Figure 3. Number of pesticides detected in water samples collected from urban creeks

and storm drain outflows in the four di fferent sampling areas of California........................ 22 Figure 4. Detection frequency of insecticid es from all sampling areas of California between April 2008 and August 2009

.................................................................................. 23 Figure 5. Detection frequency of fipronil, fi pronil sulfone, desulfinyl fipronil, and carbaryl in the four different sampling areas of California.

.................................................. 23 Figure 6

. Detection frequency of herbicides from a ll sam pling areas of California between April 2008 and August 2009 .................................................................................. 24 Figure 7. Detections of pyrethroids in sedime nts from all sampling areas of California. ............ 24 Figure 8. The influence of waterbody on frequency of pesticide detections................................ 25 Figure 9. The influence of rain on frequency of pesticide detections........................................... 26 Figure 10. PUR reported use of fipronil, di uron, pendime thalin, and synthetic auxin herbicides (2,4-D, dicamba, MCPA, and triclopyr) and their detection ratios. .................... 27

LIST OF TABLES

Table 1. Pesticides analyzed by the Californi a Departme nt of Food and Agriculture in

water or sediment.................................................................................................................. 18 Table 2. Detection frequencies (above reporting limit) of pesticides detected above US

EPA benchm ark or commonly accepted LC 50 

### values in water samples............................... 19

### 2 I. INTRODUCTION

Annual California urban pesticide us e is on the order of millions of kg of active ingredient (ai). Urban pes ticide use includes structural pest control, landscape maintenance, rights-of-way and public health pest protection app lications, as well as applications to commercial, institutional, a nd industrials areas, a nd residential home-andgarden applications. The California Depa rtment of Pesticide Regulation (CDPR) compiles pesticide use records for urban pesticide applications made by licensed applicators. Annually, professi onal applicators apply over 4 m illion kg ai of pesticides for urban (non-agriculture) pest control (CDPR 2010). Howeve r, urban pesticide use by

individual homeowners is not re ported, so that total urban use in California is greater than this reported use. Especially in dense urba nized areas, high homeow ner pesticide use is anticipated. For example, a recent survey of four large home improvement stores in

northern and southern California showed that 190 pesticide products, containing 79 different ai’s, were being sold for outdoor us e (Osienski et al. 2010). Other surveys have also shown that large numbers of pesticides are being sold in retail stores. Moran’s (2005) survey indicated that more than 320 pe sticide products containi ng 99 different ai’s were being sold in the San Francisco Bay Ar ea. Another survey in Sacramento, Stockton, and the San Francisco Bay area revealed 542 different products cont aining 112 differentai’s were available for sale (Flint 2003). Efforts have been made to estimate this nonreported urban pesticide use in California by comparing CDPR’s Pesticide Use Report (PUR) and sales database, but a recent analysis by Zhang and Spurlock (2010) demonstrated the high degree of uncertainty in those estimates. However, it has been estimated that non-agricultural pesticide uses account for approximately 20-25% of all total pesticide use in the United States; most of these uses are in ur ban areas (Aspelin and Grube 1999; Kiely et al. 2004). In 2009, excluding adjuvants, th e total reported pesticide use in California was over 68 million kg ai (CDPR 2010). Thus, these data show that large amounts of pesticides are applied in California ur ban areas, although the exact

amounts are unknown.

Due to the high volume of urban pesticide use and perhaps lack of consumer awareness, urban pesticide runoff may exceed agricultu ral runoff (Wittmer et al. 2011). Pesticide

runoff into urban creeks and rivers can occu r via stormdrains during dryflow or with stormwater runoff leading to concentrations that may be toxic to aquatic organisms (Hoffman et al. 2000; Revitt et al. 2001; Schiff and Sutula 2004; Budd et al. 2007; Sprague and Nowell 2008; Weston et al. 2009; Oki and Haver, 2009). Many urban use pesticides have been detected at concentratio ns that are sufficient to cause toxicity in laboratory bioassays (Werner, et al., 2000; Schiff et al. 2002 ; Hunt, et al., 2003; Holmes et al. 2008; Mize et al. 2008; Lao et al. 2010; Weston and Lydy 2010). In addition,

numerous urban creeks are listed on the 2006 Federal Clean Water Ac t Section 303(d) list due to the presence of organophosphorus (OP) pe sticides that often originated in urban runoff (Cal/EPA 2009). Most of th ese listings are due to the pr esence of chlorpyrifos or diazinon. Chlorpyrifos and diazinon have been ba nned from most urban (residential) uses due to unfavorable human health and ecologi cal risks. However, some urban uses of

these two OP insecticides are still allowed so that their presence in urban waterways is still possible. For instance, chlorpyrifos is allowed for sale in i ndoor ant and roach baits in child resistant packaging, as a fogger a dult mo squitocide (when applied by a public

### 3 agency), and for use in golf course turf applications at reduce d rates (US EPA 2010a). Currently in California, both chlorpyrifos and diazinon ar e used in urban areas for structural pest control, right s-of-way applications, and for landscape maintenance when applied by a licensed professional applicat or. However, the overall urban use in

California is less than 1% of the total usage prior to init iating the residential ban in 2000 (CDPR 2010).

Recent monitoring in California shows that ur ban waterways are frequently contaminated with pyrethroids, the OPs diazinon and chlor pyrifos, and fipronil (Oki and Haver, 2009; Weston et al. 2009; Weston and Lydy 2010; La o et al. 2010). Ther e is little or no published monitoring data for many other urban use pesticides in California, especially herbicides. Herbicides are often acutely to xic to algae, although the environmental impacts of herbicides on a quatic systems is not well unde rstood (Jassby et al. 2003; Miller et al. 2005; Sommer et al. 2007). In addition, there are synergistic interactions between different pesticides to aquatic invertebrates (Lydy and Belden 2006). Additional monitoring of urban waterways is therefore needed in or der to assess the potential impacts of urban pesticide use on urban surface waters. A consistent statewide monitoring program will provide useful data on the environmental fate of urban use pesticides and aid in the development and implementation of management measures. In 2008, CDPR initiated a statewide urban monito ring project to addr ess the problems of pesticides in urban waterways. Specific obj ectives of this stud y were fourfold: 1) determine what pesticides, at what concentratio ns, are present in urban runoff; 2) evaluate the magnitude of measured concentrations rela tive to water quality or aquatic toxicity benchmarks; 3) assess the effect of water body type (e.g., stormwater drain vs. creek); and 4) assess the effect of season (dryflow vs. rainstorm).

II. MATERIALS AND METHODS

Study Area . Monitoring was conducted in four larg e me tropolitan areas in northern and southern California. Twenty-five sites were sa mpled in total; four in the Sacramento area, seven in each of the San Francisco Bay, th e greater Los Angeles, and San Diego areas (Figure 1). Water and sediment samples were collected from either stormdrain outflows or from downstream receiving waters (Figur e 2); generally for each of the four main sampling areas, there were two or three stormd rain outflows for each receiving water site. Receiving waters comprised of: Pleasant Grove Creek (Sacramento [SAC] area), Grayson and Koopman/Martin Canyon Creeks (San Francisco Bay [SFB] area), and Wood Canyon and Salt Creeks (greater Los Angeles ar ea, in Orange County [OC]), Lindo Lake (inflow), and the San Diego River (San Die go [SD] area). Two stor m drain outflow sites at the San Diego River sites only contai ned water during rain events. Detailed information about the sampling sites can be found in Appendix I, Table A1

.

Field Sampling. This study was initiated in Apri l 2008 and ended at the end of the August 2009. In northern California, four dryf low and four rainstorm sampling events were completed. However, due to limited rain fall in southern California, we were only

### 4 able to sample one rain event during both the 2008 and 2009 water years 1



### . To make up for the lack of rain sampling, we complete d five dryflow sampling events. Pyrethroid monitoring was added about 10 months afte r this study was initiated, with sampling beginning in February 2009. Because of the limited rain in southern California, no pyrethroids were collected dur ing rain events. We use the term dryflow for our base

stream flow in urban surface waters as th ese waters likely never experience true baseflow, the condition where only groundwater contributes to surface water flow. Urban surface waters are augmented with water from other sources, as irrigation, washing of cars, etc. (Sprague and Nowell 2007). We will refer to dryflow conditions when surface waters receive no input from rain storms; usua lly in California from late April or early May through September or October.

Sediment samples were collect ed for pyrethroid and chlorpyrifos analysis. The collection of sediment sample timings differed somewhat from the water sample sampling. For pyrethroid analysis, sediments were colle cted twice during the study. In northern California, sediments were collected near the end of the rainy season and once in the summer. In southern California, sediments we re collected in the late spring after the termination of the rainy season. Sediments were collected both from stormdrain outflows and, when feasible to do so, receiving waters. Sediments for chlorpyrifos analysis were only collected once, in the spring of 2009.

Water samples from receiving waters were collected from stream banks close to midstream as feasible directly into 1-L gl ass amber bottles using an extendable pole and

sealed with Teflon®-lined lids. Stormdrain outflows, generally with less flow, were collected by hand directly into 1-L amber bottl es. However, dependent on flow and water depth, occasionally water samples from stormdrain outflows were collected into a

stainless steel container and aliquots were poured into 1-L glass bottles. During therainstorm event in OC, storm samples were collected as a composite sample with a HachSigma 900 Max automated sampler and split into 1-L amber bottles for transport. Sediment (up to a 2 cm depth) were collected using a stainless stee l trowel or shovel, composited in a stainless steel container, a nd individual samples were placed into clear glass Mason® jars for later chemical analys is. Sediments could not be collected at all sites. Immediately after sampling, water and se diment samples were stored on wet ice for transport. Upon arrival at the laboratory, wate r samples were refrigerated (4°C) whereas sediments samples were frozen (–20°C) until chemical analysis.

Total Suspended Solids and Total Organic Carbon. We analyzed total suspended solids (TSS) in water samples and total orga nic carbon (TOC) in both water and sediment samples. TSS was analyzed following US EPA method 160.2 (US EPA, 1971). Briefly, waters samples were filtered under vacuum through a Buchner funnel lined with a glassfiber filter, dried overnight at 103-105°C, and weighed. TOC was analyzed using a TOCV CSH/CNS analyzer (Shimadz u Corporation, Kyoto, Japan).

1 A water year is from October of one year through September of the next; e.g., water year 2009 is from October 2008 through September 2009.

### 5 Field Measurements. Water physiochemical propertie s (dissolved oxygen [DO], electrical conductivity [EC] , pH, turbidity, and temperature) were measured in situ

. Measurements were taken with a YSI 6920 V2 meter (YSI Incorporated, Yellow Springs, OH). The meter was calibrated prior to field use (Doo and Lee 2008).

To get an estimate over overall pesticide loa d, flow data measurements were collected using a Global Flow Probe Flow Meter (Globa l Water, Gold River, CA). Flow could not

be taken at all sites at all sa mpling dates, due to low or no fl ow or, in some cases, due to rapid flow in larger creeks. In specific cas es, flow was estimated using the float method (timing the movement of an object on th e surface) or by measuring volume over time (Appendix I).

Analytical Chemistry

. We analyzed for a total of 63 di fferent pesticides, or pesticide degradates, in this study. Most of the analys is were from the following pesticide groups: pyrethroids, carbamates, OP, fi pronil (FP) and FP degradates, synthetic auxin herbicides, triazines/triazinones/uracils/ureas (photos ynthesis inhibitor herbicides [PI]), and dinitroaniline herbicides (Table 1). Although some of the pesticides included in the chemical analysis are not urban use pesticid es, they were analyzed and reported by the laboratory from the same analytical method.

We report the results as: 1) nd, not detected, concentrations below the minimum detection limit; 2) tr, trace detection, where in the chem ist’s best professional judgment the analyte does exist between the reporting limit and th e minimum detection limit; 3) a numerical concentration in ng L -1 

### (pyrethroid water samples), μg L -1 

### (all other water samples), or

ng g -1 

### (dry weight; sediment samples).

QA/QC for Water and Sediment Samples . Quality control for this study followed the CDPR SOP guidelines on Chemistry Laborator y Quality Control (Segawa, 1995). Quality control consisted of blind spikes, labora tory matrix spikes, method blanks, field duplicates, and field blanks. Propazine was al so used as a surrogate spike in the PI analytical screen. Fifteen per cent of the field samples were field duplicates, field blanks, or blind spikes.

Statistics. Statistical analyses was conducted using the non-parametric Mann-Whitley mean comparison test, significance at the 0.05 level, with Minitab ® 

### Statistical Software (Release 15). Regression analysis wa s also determined using Minitab ® 

### , significance also

at the 0.05 level.

III. RESULTS AN D DISCUSSION

Pesticides detected in surface waters

Of the 63 pesticides or analytes in the ch emical analysis, we detected 30 different pesticides (including degradat es) above their analytical reporting limit (18 insecticides and 12 herbicides). Many pesticides in the analyses were not urba n use pesticides and

### 6 detections were not expected; nonetheless, 77 % of the sampling sites contained at least one pesticide. Of the detected pesticid es, OC and SAC had the highest detection frequency (24 and 20%, respectively), then SFB (14%) with SD having the fewest (4.5%). Frequently, more than one pesticid e was detected in a water sample, which significantly differed among the four different study regions. OC had significantly higher median number of pesticides per water sample (6) than did SAC (4), which was significantly higher than SFB (2), which was significantly higher than SD (0; p =0.000- 0.135, Figure 3). OC residents tend to have slight ly more pest problems than residents in northern California which may warrant more pesticide applications (Flint 2003). Our data would suggest higher use than the other ar eas of the study. SD may also have higher levels of pesticides in surface water; for example, the San Diego Storm Water Department (2010) has recently reported high levels of pyrethroids in this area. And, although we report fewer pesticides found at one time in urban streams than in a 10 year review by Gilliom et al. (2006), different anal yses, sampling regimes, or differences in pesticide use (e.g., much reduced urban use of diazinon or chlorpyrifos) may account for

the differences.

The most frequently detected insecticides in surface waters were, in decreasing order, bifenthrin, fipronil (FP), FP su lfone, carbaryl, desulfinyl FP, malathion, and permethrin (Figure 4). Bifenthrin was the most freque ntly detected insect icide and second most detected pesticide in the study, with a 56% detection fr equency. The high detection frequency was attributed to the high number of detections in SAC and SFB during rain runoff. For example, in northern California, bifenthrin dryflow de tection frequency was

27% but increased to 97% duri ng rainstorm events. We had si milar dryflow detections of

bifenthrin in southern Calif ornia (29%) but because bifent hrin was added later in the study, there is no rainstorm sampling of bifenthr in in this part of the state. Because rainfall greatly enhances bifenthrin detections, additional sampling during rainstorm

events in southern California is needed to determine the full contamination of bifenthrin

in the urban runoff.

Other pyrethroids were detected in waters samples, albeit infrequently. The detection frequency of other pyrethroids in water sample s: permethrin (both cis and trans isomers) 9.7%; cypermethrin 4.2%; esfenvalera te/fenvalerate, cyfluthrin, and λ -cyhalothrin, 1.4%. All pyrethroids were detected abov e their analytical reporting limit.

Fipronil and degradates were fr equently detected. This group had a higher percentage of

trace detections than detectio ns above their analytical repo rting limit. Fipronil had a 30% detection frequency; if trace detections are included, detection frequency increased to

73%. This was also observed for the five de gradates (percentage of detections above reporting limit, detections incl uding trace detections):

• FP sulfone (27%; 77%);

• Desulfinyl FP (17%; 79%);

• FP amide (4.5%; 64%);

• Desulfinyl FP amide (3%; 42%);

• FP sulfide (0.6%; 54%).

### 7 Fipronil, FP sulfone, and desulfinyl FP had higher detection frequencies in OC than in other areas of California (Figure 5).

Carbaryl was the fourth most frequently de tected insecticide in surface waters (18% detection frequency, with trace detections, 28%). Carbaryl was also more frequently

detected in OC than in other areas of th e state (Figure 5). Three OPs were detected. Malathion was most frequently detected of these, with a 14% dete ction frequency (with trace detections, 25%). Diazinon an d chlorpyrifos were also infrequently detected, with a 6.5% and 4.5% detection frequency, respec tively. The reduced urban detections of diazinon and chlorpyrifos over past sampling (G illiom 2006) are likely due to the drastic

reduction of these insecticides in urba n areas (US EPA 2010a, 2010b). The only other

insecticide detected in the study was oxamyl (a carbamate), detected once in a water sample from southern California.

The most frequently detected herbicides were 2,4-D, triclopyr, dicamba, diuron, MCPA, and pendimethalin (Figure 6). 2,4-D was the mostfrequently detected pesticide in this study and as a group, the synthetic auxin herb icides (2,4-D, triclopyr, dicamba, and MCPA) were frequently detected in all areas but SDR. MCPA was also rarely detected in OC. For urban use, these four herbicides have similar uses and application timings. Frequency of detection ranged from 23% (M CPA) to 65% (2,4-D); detection frequency

increased from 30% - 72% if trace detections are considered. Diuron was also frequently detected (30% detection frequenc y; with trace detections, 57%).

The dinitroaniline herbicides pendimethalin, oryzalin, and prodiamine were also detected, albeit less frequently than the synthetic a uxins and diuron. Their detection frequency ranged from 8% - 20% and if trace detecti ons are considered, detection frequency increased to 21% - 37% (Figure 6). Of thes e, pendimethalin had much higher detection frequency in SAC (54% detection frequenc y) than in other areas (SFB was second highest, with 19% detection frequency). Prodiamine was on ly detected in northern California. Simazine, prometuron, and oxyfluor fen were detected less than 5% of the

time.

Pesticides detected in sediments

We did not detect chlorpyrifos in any sedi ment samples, but pyret hroids were abundant.

All of the sediments contained at least one pyrethroid, over half contained at least five pyrethroids (median), and up to eight different pyrethroids were detected in one sediment sample (Figure 7, A). Bifenthrin was the mo st frequently detected pyrethroid; it was detected in all but two sediment samples. Sediment also commonly contained cyfluthrin, permethrin (both cis and tr ans isomers), deltamethrin λ -cyhalothrin, and cypermethrin; in

addition esfenvalerate/fenvale rate and resmethrin were detected (Figure 7, B).

Appendix I contains the complete analytical re sults (for both water and sediment) for the study ( Tables A2-A10 ).

### 8 The effect of waterbody type (storm drai n vs. creek receiving water) on pesticide

detections in urban surface waters.

There were little differences between detec tion frequencies between storm drain outflows and receiving waters, with most pesticides having less than 10% di fference between these two different water bodies (Figure 8). Bifenthr in was the main exception. Bifenthrin had a 64% detection frequency in stormdrain outf lows but only a 36% detection frequency in receiving waters. Except for bifenthrin and pendimethalin, there were less than 10% differences between detections in receiving waters and stormdrain outflows. For most pesticides, sampling at stormdrain outflow s gives a good representation of urban runoff and is often easier and safer to sample than from larger receiving waters. Other pyrethroids may behave like bife nthrin, but we did not have sufficient detections in water

to make this determination.

In addition, there were no si gnificant differences in the me dian number of pesticides detected per sample between stormdrain out flows and receiving waters (median 3.0 and 2.5, respectively; p =0.584).

The effect of season (dryflow vs. rainstorm) on pesticide detections in urban surface

waters.

Generally, we detected more pesticides during rainstorms than during dryflow sampling. Fipronil (and degradates) were a main contra diction; these were detected frequently during both dryflow and rainstorm events (Figur e 9). This was biased by detections from OC, where dryflow sampling had high detecti ons of fipronil (71% detection frequency) and its degradates (up to 77% detection frequency). Although fi rst flush detections (first rainstorm of the water year) gave the highest detection frequencies in northern California and in San Diego, this was not true in Orange County. Detectio ns of fipronil (and degradates) during the first fl ush in Orange County had sim ilar detection frequencies as several of the dryflow sampling events. However, regardless of rain or dryflow sampling,

detections from northern Californi a correlated well with PUR use (r 2 

### =75%; p =0.006) but

detections from southern California did not (r 2 

### =28%; p =0.08). The poor correlation in southern California was likely due to few detections with low to moderate use in San Diego and to high detections in Orange C ounty with moderate use. Although fipronil runoff can be influenced by rainfall, it also behaves as other urban use pesticides that show a continuous load independent of rain events (Wittmer et al. 2011). The use of pesticides that have a continuous load into urban surface waters may be a concern. To prevent runoff, overall use would need to decr ease, not just use dur ing the rainy season. As fipronil use increases, runoff into urban su rface waters will likely increase, regardless

of season.

All other detected pesticides had detec tion frequencies between 18-69% higher during rainstorm sampling than during dryflow sa mpling. Bifenthrin was most frequently detected pesticide during rainstorms. Alt hough bifenthrin has higher reported use during dry weather than during the rainy season (CDPR 2010) 2 

### , detections were higher during

2 Although we cannot account for homeowner use, this use likely follows application timings made by professional applicators.

### 9 rainstorm sampling. Bifenthrin had a 97% detection frequency during rain sampling compared to a 28% detection frequency duri ng dryflow. Rain runoff may be initially driving bifenthrin into th e water via sediment and or ganic carbon and keeping it suspended. Bifenthrin is known to be tigh tly bound to sediment and organic carbon. During rainstorm sampling events, the median c oncentrations of TSS, TOC, and turbidity were significantly higher than these pa rameters taken during dryflow sampling ( p =0.0000-0.0035). Herbicides were more frequently detected during rain sampling than during dryflow sampling. We had detection frequencies be tween 26-46% higher during rain sampling (Figure 9). In California, many herbicides ar e applied during the rai ny season for residual

weed control and would be less effective applied at other time s of the year. Applications during the rainy season increase runoff into surface waters. Two of the herbicides we frequently detected, diuron and pendimetha lin, had their highest use and detections during the rainy season (Figure 10). As use d ecreased in the spring through summer, the

number of detections also decreased. Both diuron and pendimethalin had a good correlation between use and detections (r 2 

### =85%, p =0.001 and r 2 

### =94%, p =0.01, respectively). Synthetic auxin herbicides al so had higher detections frequencies when sampled during rainstorm events than during dr yflow. Synthetic auxins are used late in the rainy season (March – May) to control fl ushes of germinated weeds but they also have use in the summer months. Although our detections frequencies are higher during rain runoff, we also detected synthetic a uxins in dryflow sampling. We did not have a good correlation between reported use and de tections, possibly due to unreported homeowner use or to the persiste nce of some of these herbicid es when applied in the late summer (Figure 10; August, September) and then are detected in some of the first rainfalls of the season (October, November).

Differences between the number of pesticid es per sample during dryflow and rainstorm sampling give additional evidence that pesticid es tend to runoff into urban surface waters when it rains. The median number of pesticid es detected per sample during a rainstorm event was significantly greater than sample s collected during dryflow (median 7.0 and 1.0, respectively; p =0.000).

Comparison of Pesticide Concentrations to Aquatic Toxicity Benchmarks

Established aquatic toxicity benchmarks can be used to interpret monitoring data and prioritize sites and pesticides for further i nvestigation (US EPA 2010c). For this analysis,

we used acute benchmarks available from US EPA OPP. But for pyrethroids we used

established H. azteca LC 50 

### s (where available) due to the sensitivity of this organism to pyrethroids (Anderson et al . 2006, Weston and Jackson 2009). In water samples, we detected eleven pesticides above their benchmarks or LC 50 

### s (Table 2). In all, 76% of the sampling sites had at least one pesticide above its benchmark/LC 50 

### . This value comparable to the 83% value for urban stream s as stated by Gilliom et al. (2006) during a 10 year review (1992-2001) of USGS data. Any differences are likely due to changes in urban insecticide use that has occurred (decr eased chlorpyrifos and diazinon use offset with increased pyrethroid use), as well as different sampling sites and monitoring regimes. Of OPs, we only detected chlor pyrifos twice above its benchmark value and malathion once, all in northern California. Py rethroids (mostly bifenthrin), fipronil, and

### 10 diuron were the only other pesticides detected at concentrations above their toxicity benchmarks. None of the other pesticides were detected above their benchmarks.

Pyrethroids were frequently detected above their LC 50 

### s and this group of pesticides had the highest percentage of dete ctions with the potential to be toxic to sensitive aquatic organisms. Pyrethroids are hi ghly hydrophobic and associate with the dissolved organic carbon and suspended sediment in water samp les which may limit th eir bioavailability. Taking these factors into consideration with the equation by Spurlock et al. (2005) and using the K

oc 

### value of 240000 (NPIC 2011), the bioava ilability of bifenthrin ranged

between 14% - 58% of the total concentrations. With these va lues, we would expect that approximately 20% of the bifenthrin detections would be toxic to H. azteca . However,

K
oc 

### values are highly variable. For bifenthr in, Laskowski (2002) lists a range of K

oc 

### values from 116000 – 888000 ml g -1 

### . Based on this range of uncertainty in K

oc 

### , the

estimated fraction of bifenthrin detections wi th bioavailable concentrations sufficiently high to cause toxicity to H. azteca ranged between 3% and 30%. We cannot know precisely what the overall toxic potential for bifenthrin was in the urban waterways where we sampled. However, it is likely that some of the bifenthrin woul d have been available for uptake and toxicity to sensitive aquatic species in these waterways.

Although infrequently detecte d, cyfluthrin, cypermethrin, λ -cyhalothrin, and

esfenvalerate were all detected a bove their respective benchmarks/LC 50 

### s. Half of all the permethrin detections were also above its benchmark (Table 2, estimated bioavailability)

Fipronil had the second highest number of detections above its US EPA toxicity benchmark, with 20 detections ( 13% of all fipronil detections). Most of these detections above the benchmark (80%) were from OC, mostly during dryflow sampling. The fipronil degradates FP sulfone (MB46136) and FP sulfide (MB45950) are more toxic than fipronil itself (FAN 2010) even though fi pronil has a lower benchmark. Using EPA benchmark values, Mize (et al. 2008) estimated LC 50 

### values for the sulfone and sulfide degradates to be 0.06 and 0.22 μg L -1 

### , respectively, for sensitive species. Using these

LC 50 

### s, FP sulfone was detected 36 times (23% of FP sulfone total detections, mostly in OC) over its LC 50 

### . Likely FP sulfone has the potential to contribute to toxicity in these waters. No other fipronil degr adates were detected above benchmarks (we could not find any toxicity values for desulfi nyl FP or desulfinyl FP amide). Th is data also indicates that most of the potential toxicity of fipronil was in OC.

Diuron was the only herbicide that was dete cted above its US EPA benchmark for nonvascular plants. Eight water samples (5% of total) contained conc entrations above its benchmark; all were detected in northern California, mostly during rainstorm sampling. In past work, the potential importance of diuron toxicity to the overall food chain has been overshadowed by pesticides that cause t oxicity to aquatic inve rtebrates (Munn et al. 2006, Sprague and Nowell 2008). The ecologica l importance of diuron toxicity to phytoplankton is not well understood (Jassby et al. 2003, Miller et al. 2005, Sommer et al. 2007).

### 11 In pesticide risk assessment, toxicity is usually based on exposure to one stressor or contaminate. However, it is more common for aquatic organisms to be exposed to multiple stressor or contaminants, often in complex mixtures of herbicides and insecticides. For example, our results show th at 50% of the water from one site contained 3 or more pesticides, 25% of the sites contai ned six or more pesticides, and 15% of the sites contained eight or more pesticides. Other work ha s shown similar results (Gilliom 2006). The accumulated number of pesticides found at one time likely has a negative effect on overall stream health. Generally, pest icides within the same pesticide class (with a common mode of action) are likely to have an additive effect wher eas pesticides from different chemistry classes are likely to have more varied e ffects, such as synergism or antagonism (Lydy and Belden 2006). However, little is known about interactions among multiple pesticides on the toxicity to aquati c organisms as all chemical combinations (pairs, triplets, etc.) are impossible to investigate (Lydy and Belden 2006). These combinations, in addition to other chemical contaminants (e.g., metals and salts) and physical stressors (as dissolved oxygen c oncentrations, temperature, and habitat degradation) likely interact to degrade natu ral habitats. Our work suggests that multiple pesticide stressors are common occurrences in urban surface waters and that toxicity tests should investigate these interactions.

Water Quality

Water temperature, pH, EC, turbidity, DO, T SS, and TOC were measured in this study. DO, pH, and EC have specific water quality objectives and generally were within water quality objectives. DO exceeded water quality objectives 20% of the time but pH and EC only exceeded the objectives 2% and 9% of th e time, respectively. Median concentrations of turbidity (3.1 NTU), TSS, and TOC were low (6.6 and 7.8 ppm, respectively). There were little differences in water quality betw een stormdrain outflows and receiving waters but there were some water quality differences between northern and southern California, and between dryflow and rain runoff. All of the water quality parameters can be found in the Appendix I, Tables A11 - A15

.

Quality Control

Quality control was acceptable for the study. Ninety-eight percent of all matrix and propazine spikes were recovered within accepta ble levels and there were no detections in

the lab blanks. Appendix II has more detailed informa tion about quality control.

IV. CONCLUSIONS

The main conclusions from th e study are listed below.

1. Urban water bodies contain numerous pesticid es at any given time. We detected 30 different pesticides and degradates. The main insecticides detected in water samples were bifenthrin, fipron il, fipronil sulfone, car baryl, desulfinyl fipronil, and malathion. The main herbicides detected were 2,4- D, triclopyr, dicamba, diuron, MCPA, and pendimethalin.

### 12 2. Urban surface waters often contain more th an one pesticide. Fifty percent of the sampled waters had three or more pesticides and 25% of the sampled waters had six or more pesticides.

3. Fipronil, fipronil sulfone, desulfinyl fiproni l, and carbaryl occur at higher frequencies in Orange County (greater Los Angeles ar ea) than in other areas of California.

4. San Diego area had fewer pesticide detec tions than did other areas of the study.

5. Diazinon and chlorpyrifos are still detected in urban waters, albeit infrequently.

6. Pyrethroids are found in urban surface waters. Bifenthrin is the main pyrethroid (56% detection frequency) followed by permethr in (10% detection frequency). In urban surface waters, only about one-third of the pyr ethroid concentration is bioavailable to aquatic organisms.

7. Sediments contain numerous pyrethroids and pyrethroids are more likely to occur in

sediments than in water. Bifenthrin was most frequently detected (95% detection frequency), but cyfluthrin, cypermethrin, deltamethrin λ -cyhalothrin, and permethrin were common contaminants of urban sediments (32%-78% detection frequency).

8. Rainstorms drive most pesticides into urban surface waters. Bifenthrin, diuron, MCPA, 2,4-D, malathion, dicamba, triclopyr , pendimethalin, and carbaryl are more frequently found during rain runo ff than during dryflow sampling.

9. Fipronil (and degradates) can be found fr equently in urban surface waters during dryflow. Although rain may increase runoff, it is not needed to tr ansport fipronil into

urban surface waters.

10. Pesticides are detected in storm drain outfl ows and receiving wate rs with about equal frequency, except for bifenthrin (and perhaps other pyrethroids). Bifenthrin is more commonly found in stormdrain outflow s than in receiving waters.

11. Bifenthrin, fipronil, and diuron are detected in water at concentrations that potentially could be toxic to aquatic life. Other pyre throids are infrequently detected but at concentrations that potentia lly could be toxic to aquatic organisms. Fipronil sulfone may also have toxicological concerns.

From this work, we can make r ecommendation for future research:

1. Southern California, and especially the Or ange County area, had high detections of insecticides. Other high urban use insect icides (i.e., imidacloprid) should be

monitored to determine the extent of total insecticide runoff. We also had little storm

runoff data for bifenthrin in Southern Calif ornia; additional monito ring of bifenthrin during rainstorm events is warranted. Bioavail able concentrations of bifenthrin need to be estimated in monitoring studies.

2. Determine if other high urban use pesticides , like the fungicide chlorothalonil, are

common contaminants of urban surface waters.

3. More work in the San Diego area is warra nted to determ ine if the low level of detections are typical to this area. Future studies in the San Diego area should look at additional neighborhoods and cree k sites to determine the ex tent of pesticide runoff.

4. Additional monitoring of fipr onil during dryflow is warranted to determine if runoff

is related to use rather than rainfall. Sa mpling should occur monthly, at the end of the month, to correspond with PUR monthly use summaries.

5. Determine if diuron and pendimethalin de tections during rainy season occur only during rain runoff or if they are common in the rainy season when it is not raining.

### 13 6. Conduct toxicity testing w ith two-way and three-way mixtures of pesticides commonly found in urban waters. Test s should include algae and aquatic

invertebrates common to California.

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### 18 Table 1. Pesticides analyzed by the Californi a Department of Food and Agriculture in water or sediment, with their method dete ction and reporting limits, and holding times

. 

### Specific methods can be found at http://www.cdpr.ca.gov/docs/emon/pubs/em_methd_main.htm.

Analyte Group (method) Method

Detection Lim it (μg L -1 

### ) Reporting Limit (μg

L -1 

### ) Holding

time (days)

Carbamate Insecticides (H PLC; method EMON-SM 11.3)

Analytes: aldicarb, aldica rb sufoxide, aldicarb sulfone, methomyl, carbofuran, 3-OH carbofuran, carbaryl, oxamyl, methiocarb 0.01 – 0.02 0.05 28 (acidified)

Fipronil Insecticides (GC/MSD in SIM mode; method EMON-SM 05-013)

Analytes: fipronil (FP), desulfinyl FP, desulfinyl FP amide, FP sulfide, FP sulfone,

FP amide 0.003 – 0.005 0.05 14

Organophosphorus Insecticides in Water (method EMON-SM 46-0)

Analytes by GC/FPD: azinphos methyl, dichlorvos, dimethoate, disulfoton, ethoprop, fenamiphos, fonofos, malathion, methidathion, methyl parathion, phorate, profenofos, tribufos (plant growth regulator - defoliant) 0.008 – 0.0142 0.03 –

0.05 7

Analytes by GC/MS: chlorpyrifos, diazinon 0.0008 – 0.0012 0.01 7

Pyrethroid Insecticides (GC-ECD; wa ter method, EMON-SM 05-003; sediment method EMON-SM 52.9)

Water 0.001 – 0.008 0.005 –

0.015 4 Analytes: bifenthrin, cyfluthrin, cypermethrin, deltamethrin/tralomethrin, esfenvalerate/fenvalerate, fenpropathrin, λ -cyhalothrin, permethrin (cis, trans), resmethrin Sediment (μg kg -1 

### ) 0.107 – 0.183 1.0 183

Triazine/Triazinone/Uracil/Urea Herbic ides (LC/MC/MC; method EMON-SM 62.9)

Analytes: atrazine, ACET (deisopropyl atrazine), bromacil, DACT (diamino chlorotriazine), DEA (deethyl atrazine), diuron, hexazinone, metribuzin, prometon, prometryn, simazine and norflurazon (a phytoene desaturase inhibitor) 0.01 – 0.04 0.05 14

### 19 Table 1 continued.

Synthetic Auxin Herbicides (G C/MS; method EMON-SM 05-012)

Analytes: 2,4-D, dicam ba, MCPA, triclopyr 0.064 0.1 12

Dinitroaniline Herbicides (GC/TQMS or LCQ; method EMON-SM 05-006)

Analytes: benfluralin, et halfluralin, oryzalin, pendimethalin, prodiamine, trifluralin, oxyfluorfen (diphenyl ether herbicide) 0.0048 – 0.015 0.05 14

Table 2. Detection frequencies (above reporting limits) of pesticides detected above US EPA benchmark or commonly accepted LC 50 

### values in water samples (N = 155; pyrethroids, N = 72).

Detection Frequency (DF)

Pesticide Benchmark (μg L -1 

### ) A 

### DF for the Study DF greater than

benchmark or LC 50


### Diuron 2.4 30% 5%

Fipronil (FP) 0.11 30% 13%

FP sulfone 0.36 27% 0.6%

Chlorpyrifos 0.05 4.5% 1.3%

Malathion 0.3 14% 0.6%

Benchmark or

LC 50 

### (ng L -1 

### ) --Pyrethroid DF above

estimated bioavailable

concentration E



### --

Bifenthrin B 

### 7.7 56% 20%

Permethrin A,C 

### 10 11.1% 5.6%

Cyfluthrin B 

### 2.3 1.4% 1.4%

λ -Cyhalothrin A 

### 3.5 1.4% 1.4%

Cypermethrin B 

### 2.3 4.2% 4.2%

Esfenvalerate A, D 

### 25 1.4% 1.4%

A Lowest acute fish or invertebrate benchmark (US EPA 2010c)

B Hyalella azteca LC 50 (Weston and Jackson 2009)

C Both cis and trans isomers

D Analysis does not differentiate between esfenvalerate and fenvalerate

E Using equation from Spurlock et al. (2005) and K

oc values from PPDB (2011) and NPIC (2011).

### 20 Figure 1. Sampling sites for CDPR’s urban m onitoring project in the Sacramento, San Francisco Bay, greater Los Angeles (Orange County), and San Diego areas, California.

### 21 Figure 2. Cartoon depicting a storm drain outflow and receiving water ( from http://www.stormwater.co.trumbull.oh.us/). storm drain outflow

storm drain receiving water

### 22 Figure 3. Number of pesticides detected in water samples collected from urban creeks

and storm drain outflows in th e four different sampling area s of California (Sacramento [SAC], San Francisco Bay [SFB], greater Lo s Angeles [OC], and San Diego [SD] areas of California, USA) and in samples combined from all four sampling areas. All detections were above the analytical reporting limit; * 

### indicates the median number of pesticides detected per water sample. 0% 5% 10% 15% 20% 25%

0 1 2 3 4 5 6 7 8 9 10 11 12 13Percentage of samples SAC



## *

0% 5% 10% 15% 20% 25%

0 1 2 3 4 5 6 7 8 9 10 11 12 13 OC 

## *

0% 5% 10% 15% 20% 25% 30% 35%

0 1 2 3 4 5 6 7 8 9 10 11 12 13

Number of Pesticides Detected in Water SamplesPercentage of samples SFB



## *

0% 5% 10% 15% 20% 25%

0 1 2 3 4 5 6 7 8 9 10 11 12 13
Number of Pesticides Detected in Water SamplesPercentage of Samples All Areas



## * 0% 10% 20% 30% 40% 50% 60% 70%

0 1 2 3 4 5 6 7 8 9 10 11 12 13

Number of Pesticides Detected in Water Samples 

## * SD

### 23 0% 10% 20% 30% 40% 50% 60% 70%

Bif FP FP

So Carb Ds

FP Mala Per Diaz Chlr FP

Am Cyp DsFP

Am FP

SiDetection Frequency Detection > RL Trace Detection (MDL-RL)



### Figure 4. Detection frequency of insecticid es from all sampling areas of California between April 2008 and August 2009. Bif, bife nthrin; FP, fipronil; FP So, FP sulfone; Carb, carbaryl; Ds FP, desulfinyl FP; Mal, mala thion; Per, cis and tr ans-permethrin; Diaz, diazinon; Chlr, chlorpyrifos ; FP Am, FP amide; Cyp, cypermethrin; Ds FP Am, DSFP amide; FP Si, FP sulfide. There was also one detection each of cyfluthrin, λ -cyhalothrin, esfenvalerate/fenvalerate, and oxamyl. RL , reporting limit; MDL, minimum detection

limit.

Figure 5. Detection frequency of fipronil, fi pronil sulfone, desulfinyl fipronil, and carbaryl in the four different sampling ar eas of California (Sacramento [SAC], San Francisco Bay [SFB], greater Los Angeles [OC] , and San Diego [SD] areas of California, USA). All detections were above the analytical reporting limit. 0% 20% 40% 60% 80%Detection Frequency

Fi p ronil

0% 20% 40% 60% 80%

Fipronil

Sulfone

0% 20% 40% 60% 80%

SAC SFB OC SDRDetection Frequency Desulfinyl Fipronil

0% 10% 20% 30% 40%

SAC SFB OC SDR Carbaryl

### 24 0% 10% 20% 30% 40% 50% 60% 70%

2,4-D Tric Dica Diur MCPA Pend Oryz Prod Simz Prom OxyfDetection Frequency Detection > RL Trace Detection (MDL-RL)



### Figure 6

. Detection frequency of herbicides from a ll sam pling areas of California between April 2008 and August 2009. Tric, tric lopyr; Dica, dicamba; Diur, diuron; Pend, pendimethalin; Oryz, oryzalin; Prod, prodiamin e; Simz, simazine; Prom, prometon; Oxyf, oxyfluorfen. There was also one detection of ACET (deisopropyl atrazine), one trace detection of bromacil, and one trace detection of trifluralin. RL, reporting limit; MDL,

minimum detection limit.

Figure 7. Detections of pyrethroids in sedime nts from all sampling areas of California. A, percentage of pyrethroid detections per sample ( * 

### indicates the median number of pyrethroids detected). B, de tection frequency of pyrethroids in sediment samples (Bif, bifenthrin; Cyf, cyfluthrin; Cyp, cype rmethrin; Del, deltamethrin; Esf, fenvalerate/esfenvalerate; λ -Cyh, λ -cyhalothrin; cPer, tPer, ci s- and trans- permethrin; Res, resmethrin). 0% 5% 10% 15% 20% 25% 30%

0123456789

Number of Pyrethroids Detected in one Sediment SamplePercentage of Samples 

### * A

0% 20% 40% 60% 80% 100%

Bif Cyf Cyp Del Esf λ -Cyh cPer tPer Res

Pyrethroids Detected in Sediment SamplesDetection Frequency B

### 25 -10%

0% 10% 20% 30%

Bif Pend FP 2,4-D MCPA FP So Mala Dica DsFP Carb

PesticideDetection Frequency (DF) Difference(DF stormdrain outflow samples -DF receiving water samples)i

positive value = higher DF in stormdrain outflows (by the indicated value)

negative value = higher DF in receiving waters (by the indicated value)

Diur Tric



### Figure 8. The influence of waterbody on frequency of pesticide detections. Detection Frequency (DF) differences were determined by subtracting the detection frequency of

storm drain outflow samples from the de tection frequency of receiving water (DF receiving water – DF stormdrain outflow). T hus, a positive value on the y-axis (Detection Frequency Difference) indicate s higher detection frequency in stormdrain outflows and a negative value indicates a higher detection freq uency in receiving waters. Bif, bifenthrin; Pend, pendimethalin; FP, fipronil; FPSo, FP su lfone; Mala, malathion; Dica, dicamba; DsFP, desulfinyl FP; Carb, carbaryl; Diur, di uron; Tric, triclopyr. Only pesticides or degradates detected with a greater than 10% detection frequency dur ing the entire study are included in the figure.

### 26 -20% -10%

0% 10% 20% 30% 40% 50% 60% 70% 80%

Bif Diur MCPA 2,4-D Mala Dica Tric Pend Carb FP FPSo DsFP

PesticideDetection Frequency (DF) Difference(DF rain samples - DF dryflow samples)i

positive value = higher DF during rainstorm events (by the indicated value)

negative value = higher DF during dryflow events (by the indicated value)



### Figure 9. The influence of rain on frequency of pesticide detections. Detection Frequency (DF) differences were determined by subtra cting the detection fr equency of dryflow samples from the detection frequency of rain storm samples (DF rainstorm – DF dryflow). Thus, a positive value on the y-axis (Detec tion Frequency Difference) indicates higher detection frequency during rainstorm sampling (by the indicated value) and a negative value indicates a higher detection frequency during dryflow sampling). Bif, bifenthrin; Diur, diuron; Mala, malathion; Dica, dicamba ; Tric, triclopyr; Pend, pendimethalin; Carb; carbaryl; FP, fipronil; FPSo, FP sulfone; DsFP, desulfinyl FP. Only pesticides or degradates detected with a greater than 10% detection frequency dur ing the entire study are included in the figure.

### 27 Figure 10. PUR reported use of diuron, pendime thalin, and synthetic auxin herbicides (2,4-D, dicamba, MCPA, and triclopyr) and thei r detection ratios. The detection ratio is the number of detections (greater than the reporting lim it) per number of sampling events for that particular month. A detection frequency of 1.0 indicates that one pesticide was detected at one site. PUR use data was an average of 2008 – 2009 for the counties sampled, except: point a (pendimethalin), sampled only in southern California, x indicates actual use for the collected samples and this data was used in the correlation. 0 400 800 1200 1600 2000

J FMAMJ J ASOND

MonthPendimethalin Use (lb ai)i

0 0.1 0.2 0.3 0.4 0.5 0.6Detection Ratio

a 0 3000 6000 9000 12000

J FMAM J J ASOND MonthDiuron Use (lb. ai)

0 0.2 0.4 0.6 0.8Detection Ratio

0 500 1000 1500 2000 2500 3000 3500 4000 4500

J FMAMJ JASOND

MonthSynthetic Auxin Use (lb ai)i

0 0.5 1 1.5 2 2.5 3 3.5Detection Ratio

3 4 5 Use Detection Ratio28VI. APPENDIX I. DATAAppendix I contains data for the urban study, April 2008 – August 2009. Abbreviations commonly used in the Appendix tables:Abbreviation DefinitionFP fipronilmv missing value, not data available or site not samplednd not detectedppm parts per million (mg L-1)RW receiving waterStDr storm drain outflowtrtrace detection (below the reporting limit but above theminimum detection limit).29Table A1. Characteristics ofthe sampling sites in Study 249.Datum: WGS84 (Decimaldegrees)Watershed Site Location Site ID Site TypeUrban LandUseApproximateArea(Acres)ApproximateResidenceNumberLongitude LatitudeCity CountyGraysonCreekShadowood ParkbetweenChilpancingoParkway and 2ndAvenue SouthGRY010StormDrainMixedresidentialandcommercial320 600 37.97967 -122.06878Martinez/PleasantHillContraCostaGraysonCreekBlackwood Ave. and2nd Ave SouthGRY020StormDrainMixedresidentialandcommercial670 1200 37.98097 -122.06929Martinez/PleasantHillContraCostaGraysonCreekGrayson Creek atCenter AvenueGRY030ReceivingWaterMixedresidentialandcommercial37.983549 -122.0685Martinez/PleasantHillContraCostaMartinCanyon/KoopmanCanyonCreekDonohue Drive atFire StationMCC010StormDrainMostlyresidential500 1300 37.70922 -121.93335 DublinAlamedaMartinCanyon/KoopmanCanyonCreekEnd of MillbrookAvenueMCC020StormDrainMostlyresidential225 650 37.71668 -121.93524 DublinAlamedaMartinCanyon/KoopmanCanyonCreekDublin Blvd bySafeway and I-680MCC030StormDrainMixedresidentialandcommercial290 450 37.70686 -121.92711 DublinAlamedaMartinCanyon/KoopmanCanyonCreekDublin Blvd bySafeway and I-680MCC040ReceivingWaterMixedresidentialandcommercial37.706412 -121.92669 DublinAlamedaPleasantGroveCreekDr. Paul J. DuganPark on DiamondWoods CirclePGC010StormDrainMostlyresidential50 250 38.80477 -121.32733 Roseville Placer30Table A1 continued.Watershed Site Location Site ID Site TypeUrban LandUseApproximateArea(Acres)ApproximateResidenceNumberDatum: WGS84 (Decimaldegrees)City CountyPleasantGroveCreekOpal and ParksideWay, righthand sideof streamPGC020StormDrainMostlyresidential150 450 38.80232 -121.33855 Roseville PlacerPleasantGroveCreekAt Crocker RanchRoadPGC030StormDrainMostlyresidential85 300 38.79908 -121.34698 Roseville PlacerPleasantGroveCreekAt Veteran'sMemorial ParkPGC040ReceivingWaterMostlyresidential38.79857 -121.34802 Roseville PlacerSalt CreekSouth neighborhood(contributing)SC 1StormDrainMostlyresidential96 460 33.50908 -117.6907LagunaNigelOrangeSalt CreekNorth neighborhood(contributing)SC 3StormDrainMostlyresidential120 245 33.51197 -117.6971LagunaNigelOrangeSalt CreekBelow Niguel RoadbridgeSC 5ReceivingWaterMostlyresidential33.50547 -117.709LagunaNigelOrangeWoodCanyonAbove constructedwetlandWC 1StormDrainMostlyresidentialNA1NA 33.58247 -117.7453AlisoViejoOrangeWoodCanyonBelow constructedwetlandWC 2StormDrainMostlyresidential194 283 33.58155 -117.7457AlisoViejoOrangeWoodCanyonSouth neighborhood(contributing)WC 3StormDrainMostlyresidential66 307 33.58158 -117.7457AlisoViejoOrangeWoodCanyonReceiving waterbelow storm drainsAV01ReceivingWaterMostlyresidential33.58131 -117.74585AlisoViejoOrangeSan DiegoRiverAt Fashion ValleyRoadSDR101ReceivingWaterMixedresidentialandcommercial32.76436 -117.1701SanDiegoSanDiegoSan DiegoRiverAbove Fashion ValleyRoadSDR102StormDrainMixedresidentialandcommercialNA NA 32.76528 -117.16914SanDiegoSanDiegoSan DiegoRiverAt Camino de laReinaSDR103StormDrainCommercial NA NA 32.76568 -117.16511SanDiegoSanDiegoSan DiegoRiverCamino de la Reina& Camino Del ArroyoSDR104StormDrainMixedresidentialandcommercialNA NA 32.76679 -117.15823SanDiegoSanDiego31Table A1 continued.Watershed Site Location Site ID Site TypeUrban LandUseApproximateArea(Acres)ApproximateResidenceNumberDatum: WGS84 (Decimaldegrees)City CountyLindoLakeAt Lindo Lake SDR151StormDrainMostlyresidentialNA NA 32.85731 -116.9128 LakesideSanDiegoLindoLakeAt Lindo Lake SDR156StormDrainMostlyresidentialNA NA 32.85724 -116.91274 LakesideSanDiegoLindoLakeAt Lindo Lake SDR158ReceivingWaterMostlyresidential32.85715 -116.91314 LakesideSanDiego1Data not availableTable A2. Detections of insecticides in water samples fromSacramento area sampling sites. Concentrations are in μg L-1unless specified.

Sample Date Site ID Waterbody Sampling Event Carbaryl Desulfinyl fipronil Desulfinyl FP amide Fipronil Fipronil amide Fipronil sulfide Fipronil sulfone Chlorpyrifos Malathion Bifenthrin (ng L

-1 ) Cyfluthrin (ng L

-1 ) Cypermethrin (ng L

-1 ) Permethrin cis (ng L

-1 ) Permethrin trans (ng L

-1 )4/21/2008 PGC010 StDr Dryflow nd tr ndtr nd nd tr nd nd mv mv mv mv mv4/21/2008 PGC020 StDr Dryflow 0.065 tr ndtr nd nd tr nd tr mv mv mv mv mv4/21/2008 PGC030 StDr Dryflow nd 0.054 tr0.064 tr tr 0.118 nd nd mv mv mv mv mv4/21/2008 PGC040 RW Dryflow nd tr tr trtr tr 0.078 nd nd mv mv mv mv mv6/23/2008 PGC010 StDr Dryflow nd tr trtr tr tr tr nd nd mv mv mv mv mv6/23/2008 PGC020 StDr Dryflow tr tr tr0.164 tr tr tr nd nd mv mv mv mv mv6/23/2008 PGC030 StDr Dryflow nd tr ndtr nd nd tr nd nd mv mv mv mv mv6/23/2008 PGC040 RW Dryflow nd tr ndtr nd nd tr nd nd mv mv mv mv mv8/4/2008 PGC010 StDr Dryflow nd tr tr trtr tr 0.064 nd nd mv mv mv mv mv8/4/2008 PGC020 StDr Dryflow nd tr tr trtr tr tr nd nd mv mv mv mv mv8/4/2008 PGC030 StDr Dryflow nd tr tr 0.066 tr tr tr nd nd mv mv mv mv mv8/4/2008 PGC040 RW Dryflow nd tr tr 0.061 tr tr tr nd nd mv mv mv mv mv11/1/2008 PGC010 StDr Rain tr tr tr 0.107 tr tr 0.059 nd tr mv mv mv mv mv11/1/2008 PGC020 StDr Rain 0.129 tr tr 0.146 tr tr 0.064 nd 0.357 mv mv mv mv mv11/1/2008 PGC030 StDr Rain nd tr tr 0.064 tr tr tr nd tr mv mv mv mv mv11/1/2008 PGC040 RW Rain tr tr nd trtr tr tr nd tr mv mv mv mv mv2/13/2009 PGC010 StDr Rain nd tr tr 0.057 tr tr tr nd tr 203 nd 18.9 nd nd32Table A2 continued.

Sample Date Site ID Waterbody Sampling Event Carbaryl Desulfinyl fipronil Desulfinyl FP amide Fipronil Fipronil amide Fipronil sulfide Fipronil sulfone Chlorpyrifos Malathion Bifenthrin (ng L

-1 ) Cyfluthrin (ng L

-1 ) Cypermethrin (ng L

-1 ) Permethrin cis (ng L

-1 ) Permethrin trans (ng L

-1 )2/13/2009 PGC020 StDr Rain nd tr tr 0.118 tr tr 0.058 nd 0.040 48.5 nd nd nd nd2/13/2009 PGC030 StDr Rain nd tr tr 0.067 tr nd tr nd nd 43.6 nd nd nd nd2/13/2009 PGC040 RW Rain nd tr nd tr nd nd tr nd nd 17 nd nd nd nd4/7/2009 PGC010 StDr Rain nd tr nd tr nd nd tr nd 0.048 98.5 nd nd nd nd4/7/2009 PGC020 StDr Rain nd tr nd tr nd nd tr nd 0.121 19.2 nd nd nd nd4/7/2009 PGC030 StDr Rain nd tr nd tr tr nd tr nd nd 46.7 nd nd nd nd4/7/2009 PGC040 RW Rain nd tr nd tr tr nd tr nd nd 7.74 nd nd nd nd4/13/2009 PGC010 StDr Dryflow mv mv mvmv mv mv mv mv mv 25.7 nd nd nd nd4/13/2009 PGC020 StDr Dryflow mv mv mvmv mv mv mv mv mv 8.58 nd nd nd nd4/13/2009 PGC030 StDr Dryflow mv mv mvmv mv mv mv mv mv20.8 18.9 nd 28.5 25.44/13/2009 PGC040 RW Dryflow mv mv mvmv mv mv mv mv mv nd nd nd nd nd5/1/2009 PGC010 StDr Rain tr tr nd tr nd nd tr nd 0.068 20.3 nd 15.1 nd nd5/1/2009 PGC020 StDr Rain nd tr nd tr nd nd tr nd 0.064 14.5 nd nd nd nd5/1/2009 PGC030 StDr Rain nd tr nd tr tr nd tr 0.012 0.192 20.1 nd nd nd nd5/1/2009 PGC040 RW Rain tr tr nd tr nd nd tr nd 0.040 8.87 nd nd nd nd8/27/2009 GRY010 StDr Dryflow nd nd nd nd tr tr tr nd nd nd nd nd nd nd8/27/2009 GRY020 StDr Dryflow nd nd nd nd nd tr nd nd nd nd nd nd nd nd8/27/2009 GRY030 RW Dryflow nd tr nd nd nd nd nd nd nd nd nd nd nd nd8/27/2009 MCC010 StDr Dryflow nd nd nd nd tr nd nd nd nd nd nd nd nd nd8/27/2009 MCC020 StDr Dryflow nd nd nd nd nd nd tr nd nd nd nd nd nd nd8/27/2009 MCC030 StDr Dryflow nd nd nd nd tr nd nd nd nd nd nd nd nd nd8/27/2009 MCC040 RW Dryflow nd nd nd nd tr nd nd nd nd nd nd nd nd nd33Table A3. Detections of insecticides in water samples from San Francisco Bay area sampling sites.Concentrations are in μg L-1unlessspecified.

Sample Date Site ID Waterbody Sampling Event Carbaryl Desulfinyl fipronil Desulfinyl FP amide Fipronil Fipronil amide Fipronil sulfide Fipronil sulfone Chlorpyrifos Diazinon Malathion Bifenthrin (ng L

-1 ) Cypermethrin (ng L

-1 ) Permethrin cis (ng L

-1 ) Permethrin trans (ng L

-1 )4/22/2008 GRY010 StDr Dryflow nd nd nd trtr tr tr nd nd nd mv mv mv mv4/22/2008 GRY020 StDr Dryflow nd ndnd nd nd nd nd nd nd nd mv mv mv mv4/22/2008 GRY030 RW Dryflow nd tr nd nd nd nd nd nd nd nd mv mv mv mv4/22/2008 MCC010 StDr Dryflow nd ndnd nd tr nd nd nd nd nd mv mv mv mv4/22/2008 MCC020 StDr Dryflow nd ndnd nd nd nd tr nd nd nd mv mv mv mv4/22/2008 MCC030 StDr Dryflow nd ndnd nd nd nd nd nd nd nd mv mv mv mv4/22/2008 MCC040 RW Dryflow nd ndnd nd nd nd nd nd nd nd mv mv mv mv6/24/2008 GRY010 StDr Dryflow tr ndnd tr nd tr nd nd nd nd mv mv mv mv6/24/2008 GRY020 StDr Dryflow nd ndnd nd nd nd nd nd nd nd mv mv mv mv6/24/2008 GRY030 RW Dryflow nd nd nd tr nd nd nd nd nd nd mv mv mv mv6/24/2008 MCC010 StDr Dryflow nd ndnd nd tr nd nd nd nd nd mv mv mv mv6/24/2008 MCC020 StDr Dryflow nd trnd nd nd nd nd nd nd nd mv mv mv mv6/24/2008 MCC030 StDr Dryflow nd ndnd nd nd nd nd nd nd nd mv mv mv mv6/24/2008 MCC040 RW Dryflow nd nd ndnd tr nd nd nd nd nd mv mv mv mv8/6/2008 GRY010 StDr Dryflow nd tr nd trtr tr tr nd nd nd mv mv mv mv8/6/2008 GRY020 StDr Dryflow nd tr nd trtr tr tr nd nd nd mv mv mv mv8/6/2008 GRY030 RW Dryflow nd tr nd trtr tr tr nd nd nd mv mv mv mv8/5/2008 MCC010 StDr Dryflow nd tr trtr tr tr tr nd nd nd mv mv mv mv8/5/2008 MCC020 StDr Dryflow nd tr trtr tr tr tr nd nd nd mv mv mv mv8/5/2008 MCC030 StDr Dryflow nd tr trtr tr tr tr nd nd nd mv mv mv mv8/5/2008 MCC040 RW Dryflow nd tr nd trtr tr tr nd nd nd mv mv mv mv11/1/2008 GRY010 StDr Rain nd tr nd 0.061 tr tr tr nd nd nd mv mv mv mv11/1/2008 GRY020 StDr Rain 0.294 0.059 nd0.458 tr tr 0.085 nd nd nd mv mv mv mv11/1/2008 GRY030 RW Rain 0.28 tr nd tr tr tr tr nd nd nd mv mv mv mv11/1/2008 MCC010 StDr Rain nd tr nd 0.05 tr tr tr nd nd 0.075 mv mv mv mv11/1/2008 MCC020 StDr Rain nd tr nd trtr tr tr nd nd tr mv mv mv mv11/1/2008 MCC030 StDr Rain tr tr nd 0.078 tr tr tr nd nd tr mv mv mv mv11/1/2008 MCC040 RW Rain nd tr nd trtr tr tr nd nd nd mv mv mv mv2/15/2009 GRY010 StDr Rain nd tr nd tr tr tr tr 0.0104 nd nd 16.2 nd nd nd2/15/2009 GRY020 StDr Rain nd tr nd tr tr tr tr nd 0.0547 nd 32.6 nd nd 15.52/15/2009 GRY030 RW Rain nd tr nd tr tr nd tr 0.0228 0.0388 nd 23.4 nd nd nd2/15/2009 MCC010 StDr Rain nd tr ndtr tr nd tr 0.014 0.0414 nd 19.7 nd nd nd34Table A3 continued.

Sample Date Site ID Waterbody Sampling Event Carbaryl Desulfinyl fipronil Desulfinyl FP amide Fipronil Fipronil amide Fipronil sulfide Fipronil sulfone Chlorpyrifos Diazinon Malathion Bifenthrin (ng L

-1 ) Cypermethrin (ng L

-1 ) Permethrin cis (ng L

-1 ) Permethrin trans (ng L

-1 )2/15/2009 MCC020 StDr Rain nd tr trtr tr nd tr 0.0229 0.0432 nd 13.7 nd nd nd2/15/2009 MCC030 StDr Rain nd tr ndtr nd nd tr 0.0539 0.0458 nd 27.2 nd 16.1 23.92/15/2009 MCC040 RW Rain nd tr ndtr nd nd tr 0.0507 nd nd 27.2 nd 16.1 23.94/7/2009 GRY010 StDr Rain nd tr nd tr tr nd tr nd nd 0.079 8.02 nd nd nd4/7/2009 GRY020 StDr Rain nd tr nd tr tr nd tr nd nd 0.06 6.6 nd nd nd4/7/2009 GRY030 RW Rain 0.094 tr nd tr tr nd tr nd nd 0.055 20 nd nd nd4/14/2009 GRY010 StDr Dryflow mv mv mvmv mv mv mv mv mv mv nd nd nd nd4/14/2009 GRY020 StDr Dryflow mv mv mvmv mv mv mv mv mv mv nd nd nd nd4/14/2009 GRY030 RW Dryflow mv mv mvmv mv mv mv mv mv mv nd nd nd nd4/14/2009 MCC010 StDr Dryflow mv mv mvmv mv mv mv mv mv mv nd nd nd nd4/14/2009 MCC020 StDr Dryflow mv mv mvmv mv mv mv mv mv mv nd nd nd nd4/14/2009 MCC030 StDr Dryflow mv mv mvmv mv mv mv mv mv mv nd nd nd nd4/14/2009 MCC040 RW Dryflow mv mv mvmv mv mv mv mv mv mv nd nd nd nd5/1/2009 GRY010 StDr Rain tr tr nd 0.067 tr tr tr nd nd nd nd nd nd nd5/1/2009 GRY020 StDr Rain 0.069 tr nd tr tr tr tr nd nd nd 9.2 nd nd nd5/1/2009 GRY030 RW Rain 0.187 tr nd tr nd nd tr nd nd tr 8.4 nd nd nd5/1/2009 MCC010 StDr Rain tr tr nd tr nd nd tr nd nd tr 5.89 nd nd nd5/1/2009 MCC020 StDr Rain tr tr nd tr nd nd tr nd nd nd 13.9 nd nd nd5/1/2009 MCC030 StDr Rain 0.119 tr nd tr nd nd tr nd nd nd 5.47 nd nd nd5/1/2009 MCC040 RW Rain 0.369 tr nd tr nd nd tr nd nd tr 5.25 nd nd nd8/27/2009 GRY010 StDr Dryflow nd nd nd nd tr tr tr nd nd nd nd nd nd nd8/27/2009 GRY020 StDr Dryflow nd nd nd nd nd tr nd nd nd nd nd nd nd nd8/27/2009 GRY030 RW Dryflow nd tr nd nd nd nd nd nd nd nd nd nd nd nd8/27/2009 MCC010 StDr Dryflow nd nd nd nd tr nd nd nd nd nd nd nd nd nd8/27/2009 MCC020 StDr Dryflow nd nd nd nd nd nd tr nd nd nd nd nd nd nd8/27/2009 MCC030 StDr Dryflow nd nd nd nd tr nd nd nd nd nd nd nd nd nd8/27/2009 MCC040 RW Dryflow nd nd nd nd tr nd nd nd 0.0105 nd nd nd nd nd35Table A4. Detections of insecticides in water samples from Orange County area sampling sites. Concentrations are in μg L-1unless specified.

Sample Date Site ID Waterbody Sampling Event Carbaryl Oxamyl Desulfinyl fipronil Desulfinyl FP amide Fipronil Fipronil amide Fipronil sulfide Fipronil sulfone Diazinon Malathion Bifenthrin (ng L

-1 ) Fenvalerate/ esfenvalerate ( n g L -1 ) Lambdacyhalothrin ( n g L -1 ) Permethrin cis (ng L

-1 ) Permethrin trans (ng L

-1 )4/8/2008 AV01 RW Dryflow 0.159 nd 0.060 tr 0.232 tr tr 0.107 nd nd mv mv mv mv mv4/8/2008 SC1 StDr Dryflow 0.078 nd tr tr trtr tr 0.051 nd nd mv mv mv mv mv4/8/2008 SC3 StDr Dryflow tr 0.112 tr trtr tr tr 0.068 nd nd mv mv mv mv mv4/8/2008 SC5 RW Dryflow nd nd tr tr 0.052tr tr 0.060 nd nd mv mv mv mv mv4/8/2008 WC1 StDr Dryflow nd nd tr tr trtr tr tr nd nd mv mv mv mv mv4/8/2008 WC2 StDr Dryflow 0.197 nd tr tr 0.140 tr tr 0.092 nd nd mv mv mv mv mv4/8/2008 WC3 StDr Dryflow nd nd 0.118 0.072 0.359 0.145 tr 0.187 nd nd mv mv mv mv mv5/13/2008 AV01 RW Dryflow 0.091 nd 0.053 tr 0.099 tr tr 0.064 nd nd mv mv mv mv mv5/13/2008 SC1 StDr Dryflow nd nd tr tr trtr tr tr nd tr mv mv mv mv mv5/13/2008 SC3 StDr Dryflow nd nd 0.126 tr 0.391 tr tr 0.110 nd tr mv mv mv mv mv5/13/2008 SC5 RW Dryflow tr nd tr tr trtr tr tr nd nd mv mv mv mv mv5/13/2008 WC1 StDr Dryflow 0.682 nd tr trtr tr tr 0.053 nd nd mv mv mv mv mv5/13/2008 WC2 StDr Dryflow 0.086 nd 0.056 tr0.106 tr tr 0.066 nd nd mv mv mv mv mv5/13/2008 WC3 StDr Dryflow 0.130 nd 0.056 0.062 0.094 0.101 tr 0.104nd 0.057 mv mv mv mv mv6/13/2008 SC1 StDr Dryflow 0.108 nd tr tr 0.076 0.051 tr 0.070 nd tr mv mv mv mv mv6/13/2008 SC3 StDr Dryflow nd nd 0.167 tr0.175 nd tr 0.140 nd nd mv mv mv mv mv6/13/2008 SC5 RW Dryflow nd nd tr tr 0.062tr tr 0.056 nd 0.232 mv mv mv mv mv6/14/2008 AV01 RW Dryflow 0.111 nd 0.061 tr 0.063 tr tr 0.082 nd nd mv mv mv mv mv6/14/2008 WC1 StDr Dryflow nd nd 0.111 tr 0.179 tr tr 0.080 nd tr mv mv mv mv mv6/14/2008 WC2 StDr Dryflow 0.161 nd tr tr0.059 tr tr 0.060 nd nd mv mv mv mv mv6/14/2008 WC3 StDr Dryflow nd nd 0.093 0.078 0.064 0.113 tr 0.171 nd nd mv mv mv mv mv11/26/2008 AV01 RW Rain 0.109 nd 0.085 0.058 0.1640.088 tr 0.141 nd tr mv mv mv mv mv11/26/2008 SC1 StDr Rain 0.088 nd tr tr 0.103 tr tr 0.076 nd 0.109 mv mv mv mv mv11/26/2008 SC3 StDr Rain 0.057 nd 0.050 tr 0.148 tr tr 0.061 nd 0.168 mv mv mv mv mv11/26/2008 SC5 RW Rain 0.129 nd 0.059 tr 0.120tr tr 0.077 0.064 0.119 mv mv mv mv mv11/26/2008 WC2 StDr Rain tr nd tr tr 0.076 tr tr 0.091 nd tr mv mv mv mv mv11/26/2008 WC3 StDr Rain 0.180 nd 0.093 tr 0.196 0.064 tr 0.160 nd nd mv mv mv mv mv5/5/2009 AV01 RW Dryflow nd nd 0.053 tr 0.072 tr tr tr nd nd nd nd nd nd nd5/5/2009 SC1 StDr Dryflow nd nd 0.069 tr 0.085 tr tr 0.064 nd nd nd nd nd nd nd5/5/2009 SC3 StDr Dryflow nd nd 0.129 tr 0.099 tr tr 0.077 nd nd 26.4 27.8 17.9 25.9 37.75/5/2009 SC5 RW Dryflow tr nd tr trtr tr tr tr nd tr nd nd nd nd nd5/5/2009 WC1 StDr Dryflow nd nd tr tr tr tr tr tr nd nd 12.3 nd nd nd nd5/5/2009 WC2 StDr Dryflow nd nd 0.051 tr tr tr tr tr nd nd nd nd nd nd nd36Table A4 continued.

Sample Date Site ID Waterbody Sampling Event Carbaryl Oxamyl Desulfinyl fipronil Desulfinyl FP amide Fipronil Fipronil amide Fipronil sulfide Fipronil sulfone Diazinon Malathion Bifenthrin (ng L

-1 ) Fenvalerate/ esfenvalerate (ng L

-1 ) Lambda-cyhalothrin (ng L

-1 ) Permethrin cis (ng L

-1 ) Permethrin trans (ng L

-1 )5/5/2009 WC3 StDr Dryflow nd nd 0.061 tr0.464 tr tr 0.069 0.015 nd 5.18 nd nd nd nd8/1/2009 SC1 StDr Dryflow nd nd tr tr tr tr tr tr nd nd nd nd nd nd nd8/1/2009 SC3 StDr Dryflow nd nd 0.144 0.063 0.518 tr tr 0.244 0.029 tr 23.7 nd nd 21.7 25.98/1/2009 SC5 RW Dryflow nd nd 0.064 tr 0.132 tr tr 0.072 nd nd nd nd nd nd nd8/1/2009 WC2 StDr Dryflow tr nd 0.061tr 0.126 tr tr 0.07 nd nd nd nd nd nd nd8/1/2009 WC3 StDr Dryflow nd nd 0.102 tr2.11 0.094 0.057 0.546 nd nd 11.7 nd nd 15.5 nd37Table A5. Detections of insecticides in water samples fromSan Diego area sampling sites.Concentrations are in μg L-1.SampleDate Site ID WaterbodySamplingEvent CarbarylDesulfinylfipronilDesulfinylfipronilamideFipronilFipronilamideFipronilsulfideFipronilsulfone Diazinon Malathion4/7/2008 SDR101 RW Dryflow nd nd nd nd nd nd nd nd nd4/7/2008 SDR102 StDr Dryflow 0.05 nd nd nd nd nd nd nd nd4/7/2008 SDR151 StDr Dryflow nd nd nd nd nd nd nd nd nd4/7/2008 SDR156 StDr Dryflow nd nd nd nd nd nd nd nd nd4/7/2008 SDR158 RW Dryflow nd nd nd nd nd nd nd nd nd5/12/2008 SDR101 RW Dryflow nd tr nd nd nd nd tr nd nd5/12/2008 SDR102 StDr Dryflow nd nd nd nd nd nd nd nd nd5/12/2008 SDR151 StDr Dryflow nd nd nd nd nd nd nd nd nd5/12/2008 SDR156 StDr Dryflow nd nd nd nd nd nd nd nd nd5/12/2008 SDR158 RW Dryflow nd nd nd nd nd nd nd nd nd5/12/2008 SDR159C StDr Dryflow nd nd nd nd nd nd nd nd nd6/12/2008 SDR151 StDr Dryflow nd nd nd nd nd nd nd nd nd6/12/2008 SDR156 StDr Dryflow nd tr nd nd nd nd nd nd nd6/12/2008 SDR158 RW Dryflow nd nd nd nd nd nd nd nd nd6/13/2008 SDR101 RW Dryflow nd tr nd nd nd nd tr nd nd6/13/2008 SDR102 StDr Dryflow nd nd nd nd nd nd nd nd nd11/26/2008 SDR101 RW Rain tr tr tr tr tr nd tr nd 0.05811/26/2008 SDR102 StDr Rain nd tr nd tr tr nd tr nd nd11/26/2008 SDR103 StDr Rain nd tr nd nd nd nd nd nd nd11/26/2008 SDR104 StDr Rain nd tr tr tr tr nd tr nd nd11/26/2008 SDR151 StDr Rain 0.066tr tr 0.053 tr tr 0.071 nd 0.15711/26/2008 SDR156 StDr Rain 0.055 tr tr tr tr tr tr nd 0.24811/26/2008 SDR158 RW Rain 0.066 tr tr 0.058 tr tr 0.079 nd 0.1545/6/2009 SDR101 RW Dryflow nd tr nd nd nd nd tr 0.0146 nd5/6/2009 SDR102 StDr Dryflow nd nd nd nd nd nd nd nd nd5/6/2009 SDR156 StDr Dryflow nd tr nd nd tr nd tr nd nd5/6/2009 SDR158 RW Dryflow nd tr nd nd nd nd tr nd nd8/1/2009 SDR101 RW Dryflow nd tr nd nd nd nd nd nd nd8/1/2009 SDR102 StDr Dryflow nd nd nd nd nd nd nd nd nd8/1/2009 SDR156 StDr Dryflow nd tr nd tr nd nd tr nd nd8/1/2009 SDR158 RW Dryflow nd tr nd nd nd nd nd nd nd38Table A6. Detections of herbicides inwater samples from Sacramento area sampling sites. Concentrations are in μg L-1.

Sample Date Site ID Waterbody Sampling Event 2,4-D Dicamba Diuron MCPA Oryzalin Oxyfluorfen Pendimethalin Prodiamine Prometon Triclopyr4/21/2008 PGC010 StDr Dryflow1.29 0.25 nd tr nd nd 0.232 0.053 nd nd4/21/2008 PGC020 StDr Dryflow2.51 0.73 tr 0.101 nd nd 0.067 nd nd nd4/21/2008 PGC030 StDr Dryflow2.4 tr nd nd nd nd 0.396 tr nd 0.3244/21/2008 PGC040 RW Dryflow0.48 0.071 nd tr nd nd tr nd tr 0.15/27/2008 PGC010 StDr Dryflow11.475 0.296 nd 0.059 nd nd 0.051 tr 0.234 nd5/27/2008 PGC020 StDr Dryflow8.22 3.07 tr 13.59 nd nd 0.07 tr nd 1.4845/27/2008 PGC030 StDr Dryflow1.494 tr nd nd nd nd 0.05 tr nd 0.2865/27/2008 PGC040 RW Dryflow0.747 0.069 nd nd nd nd nd nd tr 0.2756/23/2008 PGC010 StDr Dryflow0.3 tr nd nd nd nd tr tr tr nd6/23/2008 PGC020 StDr Dryflow3.622 0.114 nd nd nd nd nd tr nd nd6/23/2008 PGC030 StDr Dryflow0.079 nd nd nd nd nd 0.349 nd nd nd6/23/2008 PGC040 RW Dryflow1.228 nd nd nd nd nd nd nd nd tr11/1/2008 PGC010 StDr Rain0.209 0.186 tr 0.061 nd nd tr tr 1.6 tr11/1/2008 PGC020 StDr Rain0.697 0.069 tr tr tr nd nd tr tr 0.06111/1/2008 PGC030 StDr Rain0.221 0.058 nd tr nd nd nd 0.085 nd 0.24211/1/2008 PGC040 RW Rain0.214 tr tr 0.086 nd nd nd nd nd 0.2332/13/2009 PGC010 StDr Rain3.51 tr 0.214 tr tr nd 0.051 0.06 nd tr2/13/2009 PGC020 StDr Rain2.01 0.401 tr 1.05 1.04 nd 0.094 0.096 nd 0.4152/13/2009 PGC030 StDr Rain0.147 0.096 tr 0.175 0.151 nd tr 0.062 nd nd2/13/2009 PGC040 RW Raintr nd 0.429 nd 0.194 nd tr tr nd nd4/7/2009 PGC010 StDr Rain10.4 0.947 tr 3.3 tr nd 0.163 nd nd 0.8384/7/2009 PGC020 StDr Rain1.27 0.135 17.6 0.268 tr nd 0.161 tr nd 0.1064/7/2009 PGC030 StDr Rain3.46 0.189 0.134 nd tr nd 0.096 tr nd tr4/7/2009 PGC040 RW Rain1.02 0.085 6.76 0.141 tr nd tr nd nd tr5/1/2009 PGC010 StDr Rain0.429 0.079 nd 0.082 nd nd 0.067 nd 0.268 nd5/1/2009 PGC020 StDr Rain0.37 0.167 0.921 0.103 tr nd 0.064 nd nd 0.0845/1/2009 PGC030 StDr Rain0.196 0.355 tr 0.44 tr nd 0.084 nd nd 0.13739Table A6 continued.

Sample Date Site ID Waterbody Sampling Event 2,4-D Dicamba Diuron MCPA Oryzalin Oxyfluorfen Pendimethalin Prodiamine Prometon Triclopyr5/1/2009 PGC040 RW Rain 0.479 0.114 0.135 0.266 tr tr nd nd nd 0.0858/28/2009 PGC010 StDr Dryflow 0.164 0.118 nd nd mv mv mv mv nd nd8/28/2009 PGC020 StDr Dryflow 0.1270.075 tr nd mv mv mv mv nd 0.1368/28/2009 PGC030 StDr Dryflow 0.162 0.07 nd nd mv mv mv mv nd nd8/28/2009 PGC040 RW Dryflow nd0.543 nd nd mv mv mv mv nd ndTable A7. Detections of herbicides in water samples fromSan Francisco Bay area sampling sites. Concentrations are in μg L-1.

Sample Date Site ID Waterbody Sampling Event 2,4-D ACET Dicamba Diuron MCPA Oryzalin Oxyfluorfen Pendimethalin Prodiamine Prometon Triclopyr4/22/2008 GRY010 StDr Dryflow nd nd nd tr nd nd nd tr nd nd tr4/22/2008 GRY020 StDr Dryflow nd nd nd 0.11 nd nd nd nd nd nd 0.1264/22/2008 GRY030 RW Dryflow 0.163 nd nd nd nd nd nd nd nd nd 0.354/22/2008 MCC010 StDr Dryflow0.905 nd tr 0.088 nd nd nd nd nd nd 0.064/22/2008 MCC020 StDr Dryflow 0.101 nd nd 0.477 nd nd nd nd nd nd nd4/22/2008 MCC030 StDr Dryflow nd nd nd tr nd nd nd nd nd nd nd4/22/2008 MCC040 RW Dryflow10.1 nd 0.544 1.7 nd nd nd nd nd nd nd5/28/2008 GRY010 StDr Dryflow 0.069 nd nd tr nd nd nd nd nd nd 0.1195/28/2008 GRY020 StDr Dryflow 0.069 nd nd tr nd nd nd nd nd nd 0.1195/28/2008 GRY030 RW Dryflow 0.073 nd tr nd tr nd nd nd nd nd 1.0755/28/2008 MCC010 StDr Dryflow 0.052 nd nd nd nd nd nd nd nd nd nd5/28/2008 MCC020 StDr Dryflow0.047 nd nd 0.072 nd nd nd nd nd nd tr5/28/2008 MCC030 StDr Dryflow tr nd nd tr 0.063 nd nd nd nd nd tr5/28/2008 MCC040 RW Dryflow nd nd nd 3 0.071 nd nd nd nd nd tr6/24/2008 GRY010 StDr Dryflow nd nd nd nd nd nd nd nd nd nd tr6/24/2008 GRY020 StDr Dryflow nd nd nd nd nd nd nd nd nd nd 0.1246/24/2008 GRY030 RW Dryflow 0.284 nd nd tr nd nd nd nd nd nd 0.3256/24/2008 MCC010 StDr Dryflow nd nd nd nd nd nd nd nd nd nd nd6/24/2008 MCC020 StDr Dryflow0.142 nd tr 0.148 nd nd nd nd nd nd nd40Table A7 continued.

Sample Date Site ID Waterbody Sampling Event 2,4-D ACET Dicamba Diuron MCPA Oryzalin Oxyfluorfen Pendimethalin Prodiamine Prometon Triclopyr6/24/2008 MCC030 StDr Dryflow tr nd nd 0.233 nd nd nd nd nd nd nd6/24/2008 MCC040 RW Dryflow tr nd nd 2.68 tr nd nd nd nd nd nd11/1/2008 GRY010 StDr Rain 0.093 nd nd 0.391 nd nd nd 0.115 tr nd 0.25511/1/2008 GRY020 StDr Rain 0.209nd 0.096 0.414 0.207 nd nd 0.05 tr nd 0.22811/1/2008 GRY030 RW Rain 0.408 nd0.064 0.169 0.127 0.116 nd 0.057 tr nd 6.74611/1/2008 MCC010 StDr Rain 0.186nd tr 0.054 0.157 0.077 nd nd nd nd 0.11511/1/2008 MCC020 StDr Rain 0.613nd tr 3.9 0.088 nd nd nd tr 0.133 tr11/1/2008 MCC030 StDr Rain 0.103nd nd 0.306 0.098 tr nd tr nd 1.6 0.17311/1/2008 MCC040 RW Rain 0.173 ndtr 6.82 0.151 nd 0.07 tr nd nd 0.122/15/2009 GRY010 StDr Rain tr nd nd tr nd tr nd tr 0.09 nd nd2/15/2009 GRY020 StDr Rain tr nd nd 0.445 nd tr nd 1.02 0.061 nd nd2/15/2009 GRY030 RW Rain 0.118 ndtr 0.26 tr 0.096 nd 0.073 0.142 nd 0.3472/15/2009 MCC010 StDr Rain 1.107nd tr tr 0.167 0.129 nd nd nd nd 0.22/15/2009 MCC020 StDr Rain 0.461nd 0.111 0.209 0.052 tr nd nd nd nd 0.0762/15/2009 MCC030 StDr Rain 0.121nd tr tr 0.082 0.11 nd 0.604 nd nd 0.1372/15/2009 MCC040 RW Rain 0.28nd tr 0.709 0.077 nd nd 0.651 nd nd 0.114/7/2009 GRY010 StDr Rain 0.102 nd 0.054 nd nd 0.06 nd nd tr nd 0.3224/7/2009 GRY020 StDr Rain 0.251nd 0.065 0.162 nd nd 0.052 nd 0.052 nd 0.0734/7/2009 GRY030 RW Rain 0.423 nd 0.102 0.104 0.143 0.41 nd 0.675 0.056 tr 0.2545/1/2009 GRY010 StDr Rain 0.094 0.086 tr nd nd nd nd nd nd nd 0.0995/1/2009 GRY020 StDr Rain 0.439 nd 0.101 tr 0.275 nd nd tr nd nd 0.1535/1/2009 GRY030 RW Rain 0.131 nd tr tr nd nd nd tr tr nd 0.1795/1/2009 MCC010 StDr Rain 0.339 nd0.063 tr 0.079 tr nd nd nd tr 0.2055/1/2009 MCC020 StDr Rain 0.524nd 0.05 27.6 0.212 nd nd nd nd nd 0.2545/1/2009 MCC030 StDr Rain 0.141nd tr 0.377 nd nd nd tr nd nd 0.085/1/2009 MCC040 RW Rain 0.275 nd0.055 10.9 0.122 tr nd tr nd nd 0.2078/27/2009 GRY010 StDr Dryflow ndnd nd nd nd mv mv mv mv nd 0.0548/27/2009 GRY020 StDr Dryflow trnd nd nd nd mv mv mv mv nd 0.1728/27/2009 GRY030 RW Dryflow ndnd nd nd nd mv mv mv mv nd 0.0968/27/2009 MCC010 StDr Dryflow ndnd nd nd nd mv mv mv mv nd 0.0538/27/2009 MCC020 StDr Dryflow 0.075 nd nd nd nd mv mv mv mv nd nd8/27/2009 MCC030 StDr Dryflownd nd nd nd nd mv mv mv mv nd nd8/27/2009 MCC040 RW Dryflow ndnd nd 1.49 nd mv mv mv mv nd nd41Table A8. Detections of herbicides inwater samples fromOrange County sampling sites. Concentrations are in μg L-1.

Sample Date Site ID Waterbody Sampling Event 2,4-D Dicamba Diuron MCPA Oxyfluorfen Pendimethalin Prodiamine Prometon Simazine Triclopyr4/8/2008 AV01 RW Dryflow 0.39nd 0.054 nd nd tr nd nd 0.058 0.114/8/2008 SC1 StDr Dryflow 0.052 nd tr nd nd nd nd nd 0.057 0.114/8/2008 SC3 StDr Dryflow 0.144 0.06 0.099 nd tr 0.138 nd nd 0.095 0.1434/8/2008 SC5 RW Dryflow 0.151 nd tr nd nd nd tr nd 0.06 0.3874/8/2008 WC1 StDr Dryflow 0.096 nd tr nd nd tr nd nd tr nd4/8/2008 WC2 StDr Dryflow 0.573nd 0.051 nd nd tr nd nd tr 0.1494/8/2008 WC3 StDr Dryflow 0.136nd tr nd nd 0.077 nd nd tr 0.1155/13/2008 AV01 RW Dryflow nd 0.056 tr nd nd tr nd nd tr 0.1385/13/2008 SC1 StDr Dryflow nd tr tr nd nd nd nd nd tr 0.4625/13/2008 SC3 StDr Dryflow nd tr 0.05 nd nd tr nd nd tr 0.5095/13/2008 SC5 RW Dryflow nd 0.117 nd nd nd nd nd tr tr 0.235/13/2008 WC1 StDr Dryflow nd nd tr nd nd tr nd nd tr tr5/13/2008 WC2 StDr Dryflow nd nd tr nd nd nd nd nd tr 0.0735/13/2008 WC3 StDr Dryflow nd nd tr nd nd nd nd nd tr 0.0616/13/2008 SC1 StDr Dryflow 0.256 nd tr nd nd nd nd nd tr 0.6266/13/2008 SC3 StDr Dryflow 0.058 nd nd nd nd nd nd nd nd nd6/13/2008 SC5 RW Dryflow 0.1 0.062 nd nd nd nd nd nd tr 0.1526/14/2008 AV01 RW Dryflow 0.152 nd tr nd nd nd nd nd tr 0.2656/14/2008 WC1 StDr Dryflow 0.7110.169 tr 0.482 nd nd nd nd tr 0.216/14/2008 WC2 StDr Dryflow 0.276 tr tr nd nd nd nd nd tr 0.2086/14/2008 WC3 StDr Dryflow 0.409 0.17 tr nd nd nd nd nd tr 0.29711/26/2008 AV01 RW Rain 0.1657 0.054 0.22 nd nd nd nd nd nd 0.1311/26/2008 SC1 StDr Rain 0.547 tr 0.271 nd nd nd tr nd nd 0.15211/26/2008 SC3 StDr Rain 0.111 nd 0.132 nd nd 0.215 nd nd nd 0.29911/26/2008 SC5 RW Rain 0.204 nd 0.228 tr nd nd nd nd nd 0.10311/26/2008 WC2 StDr Rain 1.571 0.369 tr tr nd nd nd nd nd 0.12711/26/2008 WC3 StDr Rain 0.191 tr 0.273 nd nd tr nd nd nd 0.0885/5/2009 AV01 RW Dryflow 0.182 nd nd nd nd tr nd nd nd 0.1255/5/2009 SC1 StDr Dryflow 0.57 0.314 nd nd nd nd tr nd nd 0.0565/5/2009 SC3 StDr Dryflow 0.969 nd nd nd nd nd nd nd nd 0.0865/5/2009 SC5 RW Dryflow 0.406 tr nd nd nd nd tr nd nd 0.0735/5/2009 WC1 StDr Dryflow tr nd tr nd nd nd nd nd nd tr5/5/2009 WC2 StDr Dryflow 0.351 nd tr nd nd tr nd nd nd 0.28742Table A8 continued.

Sample Date Site ID Waterbody Sampling Event 2,4-D Dicamba Diuron MCPA Oxyfluorfen Pendimethalin Prodiamine Prometon Simazine Triclopyr5/5/2009 WC3 StDr Dryflow 0.196 nd nd nd nd 0.292 nd nd nd 0.2158/1/2009 AV01 RW Dryflow 0.324 0.088 tr nd mv mv mv nd nd 0.0748/1/2009 SC1 StDr Dryflow 0.065 trnd 0.238 mv mv mv nd nd tr8/1/2009 SC3 StDr Dryflow 1.454 0.517 nd 0.424 mv mv mv nd nd 0.0868/1/2009 SC5 RW Dryflow tr tr nd tr mv mv mv nd nd 0.1648/1/2009 WC2 StDr Dryflow 0.745 0.150 0.063 nd mv mv mv nd nd tr8/1/2009 WC3 StDr Dryflow 0.330 0.193 tr nd mv mv mv nd nd 1.329Table A9. Detections of herbicides inwater samples fromSan Diego Sampling sites. Concentrations are in μg L-1.

Sample Date Site ID Waterbody Sampling Event 2,4-D Bromacil Dicamba Diuron MCPA Oryzalin Prodiamine Prometon Simazine Triclopyr Trifluralin4/7/2008 SDR101 RW Dryflow0.052 nd nd nd nd nd nd tr 0.13 0.051 nd4/7/2008 SDR102 StDr Dryflownd nd nd nd nd nd nd nd nd nd nd4/7/2008 SDR151 StDr Dryflownd nd nd nd nd nd nd nd nd nd nd4/7/2008 SDR156 StDr Dryflownd nd nd nd nd nd nd nd nd nd tr4/7/2008 SDR158 RW Dryflownd nd nd nd nd nd nd nd nd nd nd5/12/2008 SDR101 RW Dryflownd nd nd nd nd nd nd nd tr nd nd5/12/2008 SDR102 StDr Dryflownd nd nd nd nd nd nd nd nd nd nd5/12/2008 SDR151 StDr Dryflownd nd nd nd nd nd nd nd tr nd nd5/12/2008 SDR156 StDr Dryflownd nd nd nd nd nd nd nd nd nd nd5/12/2008 SDR158 RW Dryflownd nd nd nd nd nd nd nd nd nd nd5/12/2008 SDR159C StDr Dryflownd nd nd nd nd nd nd nd nd nd nd6/12/2008 SDR151 StDr Dryflownd nd nd nd nd nd nd nd nd nd nd6/12/2008 SDR156 StDr Dryflownd nd nd nd nd nd nd nd nd nd nd6/12/2008 SDR158 RW Dryflownd nd nd nd nd nd nd nd nd nd nd43Table A9 continued.

Sample Date Site ID Waterbody Sampling Event 2,4-D Bromacil Dicamba Diuron MCPA Oryzalin Prodiamine Prometon Simazine Triclopyr Trifluralin6/13/2008 SDR101 RW Dryflowtr nd nd nd nd nd nd nd 0.057 nd nd6/13/2008 SDR102 StDr Dryflownd nd nd nd nd nd nd nd nd nd nd11/26/2008 SDR101 RW Rain0.085 tr nd tr nd 0.383 nd 1.34 nd 0.114 nd11/26/2008 SDR102 StDr Rainnd nd nd 2.03 nd nd nd nd nd nd nd11/26/2008 SDR103 StDr Rainnd nd nd nd nd nd nd nd nd nd nd11/26/2008 SDR104 StDr Raintr nd nd 0.059 nd 0.208 nd nd nd nd nd11/26/2008 SDR151 StDr Rain0.261 nd 0.053 0.234 0.11 nd nd nd nd 0.059 nd11/26/2008 SDR156 StDr Rain0.132 nd nd nd nd nd nd tr nd nd nd11/26/2008 SDR158 RW Rain0.339 nd 0.07 0.238 nd tr nd nd nd nd nd5/6/2009 SDR101 RW Dryflownd nd nd nd nd nd nd nd nd nd nd5/6/2009 SDR102 StDr Dryflownd nd nd nd nd nd nd nd nd nd nd5/6/2009 SDR156 StDr Dryflownd nd nd nd nd nd nd nd nd nd nd5/6/2009 SDR158 RW Dryflownd nd nd nd nd nd nd nd nd nd nd8/1/2009 SDR101 RW Dryflow ndnd nd nd nd mv mv nd nd nd mv8/1/2009 SDR102 StDr Dryflow ndnd nd nd nd mv mv nd nd nd mv8/1/2009 SDR156 StDr Dryflow ndnd nd nd nd mv mv nd nd nd mv8/1/2009 SDR158 RW Dryflow ndnd nd nd nd mv mv nd nd nd mv44Table A10. Detections of pyrethroids in sediments (units, μg kg-1dry wt.). All sediments werecollected during dryflow.

Site ID Area Waterbody Sample Date Bifenthrin Cyfluthrin Cypermethrin Deltamethrin Fenvalerate/ esfenvalerate Lambdacyhalothrin Permethrin cis Permethrin trans Resmethrin FenopropathrinPGC010 SAC StDr 8/4/2008 438.4 75.2 45.3 13.2 nd 8.1 89.2 38.4 nd ndPGC020 SAC StDr 8/4/2008 196.2 13.2 6.7 2.8 nd 2.6 16.7 10.7 nd ndPGC020 SAC StDr 8/4/2008 101.128.6 10.2 nd nd 6.9 66.9 45.2 nd ndPGC020 SAC StDr 8/4/2008 605.614.7 19.7 nd nd nd 22.6 12.2 nd ndPGC030 SAC StDr 8/4/2008 63.5 9.8 4.6 2.1 nd 2.0 45.0 24.0 nd ndPGC010 SAC StDr 4/13/2009 679.8148.6 53.6 20.3 nd 14.8 113.1 52.8 nd ndPGC010 SAC StDr 4/13/2009 41.5 5.5 nd 2.0 nd nd 3.4 nd nd ndPGC020 SAC StDr 4/13/2009 61.4 4.4 nd nd nd nd 7.4 2.9 nd ndPGC020 SAC StDr 4/13/2009 323.5 83.7 22.7 7.5 4.9 4.1 40.7 35.6 nd ndPGC020 SAC StDr 4/13/2009 267.9 49.6 22.6 14.0 nd 5.8 58.2 35.5 24.0 ndPGC030 SAC StDr 4/13/2009 24.0 2.9 nd nd nd nd 5.2 3.1 nd ndMCC010 SFB StDr 8/5/2008 37.523.4 nd 7.2 nd nd 5.0 4.1 nd ndMCC020 SFB StDr 8/5/2008 0.1 18.9 nd nd nd nd nd nd nd ndMCC030 SFB StDr 8/5/2008 25.519.6 nd 5.2 nd nd 3.8 nd nd ndGRY010 SFB StDr 8/6/2008 7.8 nd nd nd nd nd nd nd nd ndGRY020 SFB StDr 8/6/2008 13.12.9 nd 1.8 nd nd 4.6 1.8 nd ndGRY030 SFB RW 8/6/2008 8.9 1.9 nd nd nd nd 2.2 nd nd ndGRY030 SFB RW 8/6/2008 9.3 nd nd nd nd nd 2.8 nd nd ndGRY020 SFB StDr 4/14/2009 17.9 2.1 nd nd nd nd 3.3 2.2 nd ndGRY030 SFB RW 4/14/2009 26.8 7.1 nd 2.3 nd nd 7.0 5.2 nd ndGRY030 SFB RW 4/14/2009 23.0 5.8 nd nd nd nd 5.7 5.2 nd ndMCC010 SFB StDr 4/14/2009 11.94.3 nd nd nd 1.5 4.3 4.1 nd ndSC1 OC StDr 6/13/2008 45.014.1 nd 2.2 nd nd 23.5 21.5 nd ndSC3 OC StDr 6/13/2008 39.7 38.2 nd 26.8 nd 4.6 45.3 46.5 nd ndSC5 OC RW 6/13/2008 25.2 7.0 nd 4.7 nd 1.9 11.5 8.6 nd ndAV01 OC RW 6/14/2008 236.5 44.6nd 12.3 9.4 21.6 45.7 27.5 nd ndWC1 OC StDr 6/14/2008 323.7 89.318.2 15.7 4.0 31.9 149.0 206.7 nd ndWC2 OC StDr 6/14/2008 141.0 39.0 nd 6.9 6.6 31.0 62.6 67.0 nd ndWC3 OC StDr 6/14/2008 207.6 67.222.0 50.7 20.3 30.1 171.0 207.6 nd ndSC1 OC StDr 5/5/2009 14.2 3.7 nd 5.8 nd nd 16.4 19.5 nd ndSC3 OC StDr 5/5/2009 nd nd nd 2.7 nd 7.5 6.8 15.6 nd ndSC5 OC RW 5/5/2009 nd nd nd nd nd 3.1 2.2 2.7 8.3 ndSDR151 SD StDr 6/12/2008 3.3 nd 1.9 nd nd nd nd nd nd nd45Table A10 continued.

Site ID Area Waterbody Sample Date Bifenthrin Cyfluthrin Cypermethrin Deltamethrin Fenvalerate/ esfenvalerate Lambdacyhalothrin Permethrin cis Permethrin trans Resmethrin FenopropathrinSDR158 SD RW 6/12/2008 1.3 nd nd nd nd nd nd nd nd ndSDR101 SD RW 6/13/2008 0.1 nd nd nd nd nd nd nd nd ndSDR102 SD StDr 6/13/2008 0.1 2.0 nd nd nd nd 1.7 1.6 nd ndSDR101 SD RW 5/6/2009 3.8 nd nd nd nd nd nd nd nd ndSDR101 SD RW 5/6/2009 4.6 nd nd nd nd nd nd nd nd ndSDR102 SD StDr 5/6/2009 3.23.1 nd nd nd nd 6.5 8.4 5.0 ndSDR156 SD StDr 5/6/2009 8.34.2 7.9 nd nd nd 3.2 2.9 nd ndSDR158 SD RW 5/6/2009 10.7 6.0 4.0 1.8 nd nd 2.1 nd nd nd

### 46 Table A11. Summary of the water qualit y parameters for the entire study.

pH EC (mS

cm -1 

### ) DO (mg L 1 

### ) Temperature (°C) Turbidity (NTU) TSS (mg

L -1 

### ) TOC (mg

L -1 

### )

Median 7.6 1.0 8.4 16.9 3.1 7.2 7.8

Range 6.1 –

8.6 0.06 –

4.47 1.5 –

18.3 6.9 – 25.9 0 – 236.6 0 – 844.3 1.2 –

106.4

Criteria

for

water quality 1 

### 6.5 –

8.5 > 3.0 (severe) < 5.0 15.6 – 23.9 (seasonal),

or not
2.8°C

above

natural

levels > 1 NTU or

20% based

on natural

levels 2 

### Shall not

cause a nuisance

or adversely

affect

beneficial

uses. --

Percent

outside

criteria 2% 9% 20% -- Background

natural

levels

unknown unknown

1 Criteria from Central Valley Regional Water Quality Board, Water Quality Control Plan for the Sacramento and San Joaquin River Basins, http://www.waterboards.c a.gov /cen tralvalley/water_issues/basin_plans/ ; The San Diego Regional Water Quality Board, San Diego Region Basin Plan, http://www.waterboards.ca.gov /sand iego/water_issues/programs/basin_plan/ ; San Francisco Bay Area Regional Water Quality Control Board, basin plan, http://www.swrcb.ca.gov/rwqcb2/basin_planning.shtml

2 Determined based on medians of sampling sites. If NTUs medians were between 1 – 5, and increase of 1

NTU over the median was an exceedance. If the median s were between 5 – 50 NTUs, an increase of 20% or more was an exceedance. Most exceedances (70%) we re during rainstorm sampling and in stormdrain outflows (67%).



### Water Quality Parameters by Category There generally were little differences in water quality parameters between stormdrain outfalls and receiving waters. However, storm drain outflows ha d significantly higher DO and lower conductivity (EC) than receiving waters ( p =0.0031-0.0163; Table A11). Rainfall was the bi ggest factor influe ncing differences between these water quality parameters. With dryf low conditions EC and temperature values were significantly higher than those obs erved with rainstorm events ( p =0.000), whereas during rain events, DO, turbidity, TSS, and TOC were signifi cantly higher than during dryflow ( p =0.000-0.0035; Table A12). Between areas of the state, northern California had signifi cantly higher DO ( p =0.000) whereas southern California had significantly higher conductivity and temperature ( p =0.000; Table A13). These may be

rainfall effects.

### 47 Table A12.Water quality median co ncentrations between stormdrain outflows and receiving waters.

pH EC (mS

cm -1 

### ) DO (mg L 1 

### ) Temperature (°C) Turbidity (NTU) TSS (mg

L -1 

### ) TOC (mg L -1 

### )

Stormdrain

outflows 7.63 0.82 8.4 17.2 2.6 7.1 7.3

Receiving

waters 7.67 1.43 6.9 18.0 3.9 6.1 8.8

Significant p values n.s. 0.0031 0.0163 n.s. n.s. n.s. n.s.

Table A13. Water quality median concentratio ns between dryflow and rainstorm sampling.

pH EC (mS

cm -1 

### ) DO (mg L 1 

### ) Temperature (°C) Turbidity (NTU) TSS (mg

L -1 

### ) TOC (mg

L -1 

### )

Dryflow 7.69 1.46 7.3 18.6 1.1 4.4 6.9

Rainstorm 7.62 0.29 9.0 15.8 17.4 31.1 9.5 Significant p values. n.s. 0.000 0.000 0.000 0.000 0.000 0.0035

Table A14. Water quality median concentrations between northern and southern California.

pH EC (mS

cm -1 

### ) DO (mg L 1 

### ) Temperature (°C) Turbidity (NTU) TSS (mg

L -1 

### ) TOC (mg L -1 

### )

Northern

California 7.7 0.37 8.7 16.7 2.9 7.1 6.9

Southern

California 7.56 1.73 7.1 18.6 2.7 6.1 9.1

Significant p values n.s. 0.000 0.000 0.000 n.s. n.s. n.s.48Table A15. Water quality parameters at theindividual sampling sites of the urban study.Region AreaSampleDate Site IDWaterBodySampleEventFlow(cfs)1pHEC (mScm-1)DO (mgL-1)Temp(°C)Turb(NTU)TSS(ppm)TOC(ppm)NoCal SAC 21-Apr-08 PGC010 StDr Dryflow nf 7.29 0.167 5.88 13.34 3.8 4.41 10.32NoCal SAC 21-Apr-08 PGC020 StDr Dryflow 0.23 7.04 0.217 5.43 11.03 3.4 30.87 7.724NoCal SAC 21-Apr-08 PGC030 StDr Dryflow fl 7.66 0.143 9.28 15.17 2.5 4.37 9.432NoCal SAC 21-Apr-08 PGC040 RW Dryflow fl 7.75 0.487 7.75 13.58 mv 1.95 6.875NoCal SAC 27-May-08 PGC010 StDr Dryflow nf 7.35 0.183 8.33 17.66 13.2 5.73 11.29NoCal SAC 27-May-08 PGC020 StDr Dryflow nf 7.06 0.193 4.45 16.15 4.9 4.95 10.81NoCal SAC 27-May-08 PGC030 StDr Dryflow 0.015 7.75 0.198 8.43 19.01 4.2 6.44 13.42NoCal SAC 27-May-08 PGC040 RW Dryflow nf 7.74 0.508 5.817.45 0.9 2.50 11.31NoCal SAC 23-Jun-08 PGC010 StDr Dryflow nf 7.11 0.215 4.3 21.89 2.5 4.21 11.65NoCal SAC 23-Jun-08 PGC020 StDr Dryflow 0.05 6.82 0.176 3.2 20.78 0.1 2.93 10.47NoCal SAC 23-Jun-08 PGC030 StDr Dryflow 0.035 7.5 0.144 7.52 23.65 1.3 2.63 8.931NoCal SAC 23-Jun-08 PGC040 RW Dryflow nf 7.57 0.369 4.24 22.78 1 3.23 8.983NoCal SAC 04-Aug-08 PGC010 StDr Dryflow nf 7.24 0.182 4.96 22.4 0 11.83 12.29NoCal SAC 04-Aug-08 PGC020 StDr Dryflow 0.13 6.77 0.316 4.87 19.81 mv 2.26 9.34NoCal SAC 04-Aug-08 PGC030 StDr Dryflow 0.0142 7.64 0.181 7.37 24.47 88.3 6.59 10.97NoCal SAC 04-Aug-08 PGC040 RW Dryflow nf 7.22 0.338 3.53 21.24 2.4 5.84 8.788NoCal SAC 01-Nov-08 PGC010 StDr Rainfl 7.22 0.198 9.06 16.64 6.7 8.47 10.73NoCal SAC 01-Nov-08 PGC020 StDr Rain2.22 7.59 0.15 8.13 16.68 4.5 7.53 7.919NoCal SAC 01-Nov-08 PGC030 StDr Rain 1.28 7.7 0.135 9.47 17.31 9 7.14 7.967NoCal SAC 01-Nov-08 PGC040 RW Rainfl 7.52 0.313 6.47 15.88 18 66.36 12.1NoCal SAC 13-Feb-09 PGC010 StDr Rain2.49 7.62 0.113 11.26 6.94 12.2 13.88 13.95NoCal SAC 13-Feb-09 PGC020 StDr Rain 4.99 7.57 0.204 11.02 7.47 24 mv 15.67NoCal SAC 13-Feb-09 PGC030 StDr Rain 4.66 7.73 0.277 11.93 8.5 27 15.48 15.8NoCal SAC 13-Feb-09 PGC040 RW Rain135.98 7.68 0.174 10.57 7.8 45.4 81.14 mvNoCal SAC 07-Apr-09 PGC010 StDr Rainfl 7.4 0.129 8.5 13.47 6.5 4.88 6.759NoCal SAC 07-Apr-09 PGC020 StDr Rainfl 7.35 0.96 9.3 13.57 8.7 9.87 6.06NoCal SAC 07-Apr-09 PGC030 StDr Rainfl 7.67 0.105 9.91 14.23 mv 2.00 6.109NoCal SAC 07-Apr-09 PGC040 RW Rainfl 7.76 0.385 8.02 14 16.5 20.00 6.339NoCal SAC 13-Apr-09 PGC010 StDr Dryflow nf 6.99 0.184 1.5 14.23 2.2 1.12 8.749NoCal SAC 13-Apr-09 PGC020 StDr Dryflow nf 6.78 0.352 2.1 13.8 2 1.75 9.4495NoCal SAC 13-Apr-09 PGC030 StDr Dryflow fl 7.48 0.173 7.4 16.66 87.4 13.75 18.61NoCal SAC 13-Apr-09 PGC040 RW Dryflow fl 7.1 0.22 2.43 14.85 3.1 5.50 6.112NoCal SAC 01-May-09 PGC010 StDr Rain1.4 7.67 0.076 8.79 18.04 3.9 6.14 3.119NoCal SAC 01-May-09 PGC020 StDr Rain1.25 7.47 0.078 8.62 17.68 8.6 11.96 4.266NoCal SAC 01-May-09 PGC030 StDr Rainfl 7.38 0.063 9.57 16.8 5.8 14.46 4.122NoCal SAC 01-May-09 PGC040 RW Rain fl 7.89 0.267 8.72 16.56 7.2 12.24 6.084NoCal SAC 28-Aug-09 ANT001 StDr Dryflow 0.02 7.99 0.493 7.24 24.46 2.8 2.62 20.4549Table A15 continued.Region AreaSampleDate Site IDWaterBodySampleEventFlow(cfs)1pHEC (mScm-1)DO (mgL-1)Temp(°C)Turb(NTU)TSS(ppm)TOC(ppm)NoCal SAC 28-Aug-09 FOL001 StDr Dryflow 0.02 6.61 0.201 6.69 21.46 0.3 0.71 5.698NoCal SAC 28-Aug-09 FOL002 StDr Dryflow fl 8.03 0.28 8.19 20.55 0 28.48 1.77NoCal SAC 28-Aug-09 NAT001 StDr Dryflow fl mv mv mv mv mv 2.12 5.38NoCal SAC 28-Aug-09 PGC010 StDr Dryflow nf 6.96 0.206 2.11 23.37 2.4 6.07 9.713NoCal SAC 28-Aug-09 PGC020 StDr Dryflow 0.01 6.74 0.153 1.17 21.1 0 5.20 10.14NoCal SAC 28-Aug-09 PGC030 StDr Dryflow fl 7.59 0.193 6.95 25.28 0.1 2.81 7.49NoCal SAC 28-Aug-09 PGC040 RW Dryflow nf 7.18 0.348 3.65 20.88 4 7.91 9.87NoCal SFB 22-Apr-08 GRY010 StDr Dryflow 0.44 8.04 2.22 9.58 13.11 8.7 3.24 4.85NoCal SFB 22-Apr-08 GRY020 StDr Dryflow 0.33 8.12 1.883 10.59 14.02 0.6 0.57 4.24NoCal SFB 22-Apr-08 GRY030 RW Dryflow 5.53 8.36 1.581 14.7717.12 1.1 2.80 4.295NoCal SFB 22-Apr-08 MCC010 StDr Dryflow 0.41 8.25 1.822 12.615.86 1.1 9.90 3.288NoCal SFB 22-Apr-08 MCC020 StDr Dryflow fl 8.17 1.84 10.4 11 0.3 7.18 106.4NoCal SFB 22-Apr-08 MCC030 StDr Dryflow 0.33 8.24 1.087 9.7515.68 0.2 0.00 1.358NoCal SFB 22-Apr-08 MCC040 RW Dryflow fl 7.82 1.641 8.53 12.88 0.1 0.00 3.292NoCal SFB 28-May-08 GRY010 StDr Dryflow 0.05 7.97 1.861 8.62 15.72 0.9 6.02 4.795NoCal SFB 28-May-08 GRY020 StDr Dryflow 0.024 8.1 1.577 10.34 16.95 0.7 2.79 3.982NoCal SFB 28-May-08 GRY030 RW Dryflow 2.02 8.3 1.497 12.820.51 1.7 5.51 4.348NoCal SFB 28-May-08 MCC010 StDr Dryflow 0.28 8.15 1.853 9.7716.87 0.5 12.08 3.307NoCal SFB 28-May-08 MCC020 StDr Dryflow 0.29 8.21 1.484 9.57 14.25 0 0.74 6.571NoCal SFB 28-May-08 MCC030 StDr Dryflow 0.27 8.16 1.077 8.89 17.61 0 4.98 2.466NoCal SFB 28-May-08 MCC040 RW Dryflow 0.73 7.95 1.598 9.3 15.84 0 1.32 3.218NoCal SFB 24-Jun-08 GRY010 StDr Dryflow fl 8.18 1.296 7.5 18.77 2.4 19.52 4.843NoCal SFB 24-Jun-08 GRY020 StDr Dryflow 0.01 8.18 2.01 12.14 18.78 0 3.06 3.745NoCal SFB 24-Jun-08 GRY030 RW Dryflow 0.90 8.58 1.092 18.29 25.91 8.9 15.08 5.381NoCal SFB 24-Jun-08 MCC010 StDr Dryflow 0.04 8.13 1.975 9.92 17.95 0 2.30 3.189NoCal SFB 24-Jun-08 MCC020 StDr Dryflow fl 8.26 1.591 9.23 15.92 0 0.67 5.83NoCal SFB 24-Jun-08 MCC030 StDr Dryflow 1.23 7.85 1.147 5.83 19.08 0 mv 7.921NoCal SFB 24-Jun-08 MCC040 RW Dryflow 2.18 7.72 1.648 4.69 18.22 0 mv 15.79NoCal SFB 05-Aug-08 MCC010 StDr Dryflow 0.14 8.05 0.193 8.42 18.12 0 0.94 3.024NoCal SFB 05-Aug-08 MCC020 StDr Dryflow fl 8.34 1.564 8.27 16.93 2.2 12.90 6.985NoCal SFB 05-Aug-08 MCC030 StDr Dryflow 0.1 8.17 0.82 7.68 19.93 0 16.79 9.464NoCal SFB 05-Aug-08 MCC040 RW Dryflow fl 7.66 1.644 3.71 19.63 9.7 2.28 5.015NoCal SFB 06-Aug-08 GRY010 StDr Dryflow 0.0188 7.78 0.928 7.93 17.26 2.6 7.65 4.565NoCal SFB 06-Aug-08 GRY020 StDr Dryflow 0.059 8.11 1.75 9.64 19.71 0.3 6.66 3.77NoCal SFB 06-Aug-08 GRY030 RW Dryflow 5.15 8.17 0.699 7.45 20.38 3.9 8.79 3.826NoCal SFB 01-Nov-08 GRY010 StDr Rain7.00 7.17 0.306 8.8616.99 177.2 844.31 12.48NoCal SFB 01-Nov-08 GRY020 StDr Rain 0.42 7.42 0.383 9.21 17.4 97 470.73 15.0150Table A15 continued.Region AreaSampleDate Site IDWaterBodySampleEventFlow(cfs)1pHEC (mScm-1)DO (mgL-1)Temp(°C)Turb(NTU)TSS(ppm)TOC(ppm)NoCal SFB 01-Nov-08 GRY030 RW Rainfl 7.76 0.282 5.94 17.18 201.6 647.93 13.5NoCal SFB 01-Nov-08 MCC010 StDr Rain3.60 7.84 0.328 9.03 18.08 16.8 67.63 11.245NoCal SFB 01-Nov-08 MCC020 StDr Rain4.00 7.74 0.737 8.46 12.73 165.3 31.09 10.76NoCal SFB 01-Nov-08 MCC030 StDr Rain39.00 7.37 0.076 9.37 17.37 24.5 59.50 5.546NoCal SFB 01-Nov-08 MCC040 RW Rain81.00 7.59 0.186 8.6618.61 56.7 282.61 9.503NoCal SFB 15-Feb-09 GRY010 StDr Rain18.60 7.73 0.41 11.06 9.46 79.2 187.93 8.006NoCal SFB 15-Feb-09 GRY020 StDr Rain5.73 7.67 0.279 11.2 9.38 55.8 150.87 3.714NoCal SFB 15-Feb-09 GRY030 RW Rainfl 7.68 0.193 10.54 9.96 52 111.13 4.58NoCal SFB 15-Feb-09 MCC010 StDr Rain6.46 8.04 0.434 11.36 11.41 4.1 7.00 4.817NoCal SFB 15-Feb-09 MCC020 StDr Rain2.80 8.1 0.539 10.84 10.57 2.9 7.50 5.004NoCal SFB 15-Feb-09 MCC030 StDr Rain7.32 7.52 0.141 10.31 12.21 21.1 19.70 4.819NoCal SFB 15-Feb-09 MCC040 RW Rain91.80 7.8 0.286 10.79 11.72 21.8 40.69 3.983NoCal SFB 07-Apr-09 GRY010 StDr Rain3.28 7.35 0.651 9.43 12.13 34.8 103.95 9.59NoCal SFB 07-Apr-09 GRY020 StDr Rain0.64 7.86 1.151 9.41 14.14 16.5 29.10 8.704NoCal SFB 07-Apr-09 GRY030 RW Rain52.50 7.55 0.399 8.4113.39 101.9 115.50 9.607NoCal SFB 14-Apr-09 GRY010 StDr Dryflow 0.07 8.04 2.277 9.15 12.11 0.7 3.12 5.717NoCal SFB 14-Apr-09 GRY020 StDr Dryflow 0.07 8.06 1.44 10.38 14.33 2.6 26.52 4.556NoCal SFB 14-Apr-09 GRY030 RW Dryflow 1.29 8.18 1.779 9.66 16.85 0 3.84 4.412NoCal SFB 14-Apr-09 MCC010 StDr Dryflow 0.30 8.32 1.952 12.03 12.73 0 25.25 2.511NoCal SFB 14-Apr-09 MCC020 StDr Dryflow 0.00 8.28 1.298 10.21 11.85 0 1.61 6.922NoCal SFB 14-Apr-09 MCC0201StDr Dryflow 0.16 mvmv mv mv mv 12176.422592NoCal SFB 14-Apr-09 MCC030 StDr Dryflow 0.16 7.98 1.1 9.53 15.65 0 0.81 1.155NoCal SFB 14-Apr-09 MCC040 RW Dryflow 0.164 7.88 1.685 9.78 13.25 0 0.10 2.684NoCal SFB 01-May-09 GRY010 StDr Rain9.00 7.62 1.09 8.39 15.75 31.8 43.59 12.27NoCal SFB 01-May-09 GRY020 StDr Rain1.66 7.6 0.364 9.3 16.64 13.1 11.90 9.507NoCal SFB 01-May-09 GRY030 RW RainFl 7.61 0.451 6.92 16.39 32.2 61.29 16.37NoCal SFB 01-May-09 MCC010 StDr Rain3.59 7.8 0.539 9 15.83 122.3 3.82 12.4NoCal SFB 01-May-09 MCC020 StDr Rain1.24 7.88 0.178 8.98 15.79 10.3 8.59 9.889NoCal SFB 01-May-09 MCC030 StDr Rain0.837 7.42 0.15 9.06 16.47 7.5 9.26 9.56NoCal SFB 01-May-09 MCC040 RW RainFl 7.68 0.212 9.41 15.89 6.6 11.31 9.067NoCal SFB 27-Aug-09 MCC010 StDr Dryflow 0.08 8.21 2.07 9.65 18.01 0 1.31 6.161NoCal SFB 27-Aug-09 MCC020 StDr Dryflow fl 8.32 1.104 8.07 17.7 0 1.31 11.24NoCal SFB 27-Aug-09 MCC030 StDr Dryflow 0.03 8.14 0.889 8.45 20 2.7 7.94 2.028NoCal SFB 27-Aug-09 MCC040 RW Dryflow nf 7.52 1.668 2.2818.74 0.7 4.70 95.11NoCal SFB 27-Aug-09 GRY010 StDr Dryflow fl 7.34 0.8 1.33 16.77 3.9 12.94 6.757NoCal SFB 27-Aug-09 GRY020 StDr Dryflow fl 8.22 1.825 8.58 18.5 0 0.40 5.01NoCal SFB 27-Aug-09 GRY030 RW Dryflow 0.96 8.26 1.025 12.26 24.44 7.5 7.58 6.0212Values for TOC and TSS are high because this sample was mostly sediment, unlike the preceding sample from the same site.51Table A15 continued.Region AreaSampleDate Site IDWaterBodySampleEventFlow(cfs)1pHEC (mScm-1)DO (mgL-1)Temp(°C)Turb(NTU)TSS(ppm)TOC(ppm)SoCal OC 08-Apr-08 SC1 StDr Dryflow 0.02 7.53 4.289 7.7214.46 3.2 5.19 8.963SoCal OC 08-Apr-08 SC3 StDr Dryflow 0.05 8.2 1.527 9.5816.43 6.8 17.18 15.55SoCal OC 08-Apr-08 SC5 RW Dryflow0.52 7.7 3.193 10.38 14.92 1.4 6.55 10.42SoCal OC 08-Apr-08 WC1 StDr Dryflow 0.06 8.3 1.059 10 16.16 1.4 0.00 2.327SoCal OC 08-Apr-08 WC2 StDr Dryflow 0.09 7.59 1.238 5.57 15.39 0 20.80 5.01SoCal OC 08-Apr-08 WC3 StDr Dryflow 0.01 8.17 2.703 8.6816.13 0.7 2.06 9.575SoCal OC 08-Apr-08 AV01 RW Dryflow0.12 7.94 1.28 9.09 16.54 4.3 7.60 5.414SoCal OC 13-May-08 SC1 StDr Dryflow nf 7.57 3.095 7.0715.75 4.3 16.07 10.74SoCal OC 13-May-08 SC3 StDr Dryflow fl 8.53 1.793 7.6 17.6 mv 4.45 9.297SoCal OC 13-May-08 SC5 RW Dryflow 1.46 7.82 4.287 9.53 16.07 0 8.25 9.302SoCal OC 13-May-08 WC1 StDr Dryflow 0.12 8.28 1.039 8.66 17.65 0 0.51 3.588SoCal OC 13-May-08 WC2 StDr Dryflow 0.32 7.58 1.244 4.91 17.86 0 0.40 5.412SoCal OC 13-May-08 WC3 StDr Dryflow fl 8.11 3.741 7.88 17.86 0.4 22.75 11.72SoCal OC 13-May-08 AV01 RW Dryflow3.20 7.68 1.638 5.76 17.86 2.4 9.62 7.806SoCal OC 13-Jun-08 SC1 StDr Dryflow fl 7.4 4.107 5.81 19.29 0.4 8.01 MvSoCal OC 13-Jun-08 SC3 StDr Dryflow fl 8.14 2.315 8.18 22.42 3.1 12.75 33.33SoCal OC 13-Jun-08 SC5 RW Dryflow 0.42 7.9 3.844 mv 19.85 0 3.77 10.85SoCal OC 14-Jun-08 WC1 StDr Dryflow 0.10 8.13 0.907 mv 19.4 0 1.26 5.134SoCal OC 14-Jun-08 WC2 StDr Dryflow 0.17 7.33 1.253 mv 17.27 0 1.05 6.443SoCal OC 14-Jun-08 WC3 StDr Dryflow 0.05 8.01 1.529 8.5519.04 0.4 17.89 10.08SoCal OC 14-Jun-08 AV01 RW Dryflow 0.24 7.49 1.378 5.117.51 3.5 4.76 7.509SoCal OC 26-Nov-08 SC1 StDr Rainfl 6.08 0.646 7.87 15.46 mv mv mvSoCal OC 26-Nov-08 SC3 StDr Rainfl 6.63 0.305 8.31 15.82 mv 295.83 12.69SoCal OC 26-Nov-08 SC5 RW Rainfl 6.47 0.594 8.84 14.72 mv 211.25 9.343SoCal OC 26-Nov-08 WC2 StDr Rainfl 7.43 1.072 9.34 15.58 mv 24.29 6.213SoCal OC 26-Nov-08 WC3 StDr Rainfl 7.63 0.569 8.18 14.43 mv 116.02 7.416SoCal OC 26-Nov-08 AV01 RW Rainfl 7.41 1.379 7.44 15.23 mv 79.80 10.56SoCal OC 05-May-09 SC1 StDr Dryflow fl 6.98 4.472 6.45 20.55 mv 31.68 14.16SoCal OC 05-May-09 SC3 StDr Dryflow fl 7.6 1.658 7.61 21.14 mv 230.75 17.88SoCal OC 05-May-09 SC5 RW Dryflowfl 7.26 3.341 7.43 18.24 mv 2.53 10.68SoCal OC 05-May-09 WC1 StDr Dryflow nf 6.67 1.836 5.1520.3 mv 434.44 5.696SoCal OC 05-May-09 WC2 StDr Dryflow fl 6.98 1.197 4.39 18.98 mv 0.00 4.392SoCal OC 05-May-09 WC3 StDr Dryflowfl 7.03 2.968 5.53 18.25 mv 4.95 12.315SoCal OC 05-May-09 AV01 RW Dryflowfl 6.82 1.362 5.24 18.94 mv 0.75 4.953SoCal OC 01-Aug-09 AV01 RW Dryflow fl 7.63 0.99 6.61 22.87 5 0.74 7.184SoCal OC 01-Aug-09 WC2 StDr Dryflow mv mv mv mv mv mv 0.00 7.194SoCal OC 01-Aug-09 WC3 StDr Dryflow mv mv mv mv mv mv 12.12 17.7352Table A15 continued.Region AreaSampleDate Site IDWaterBodySampleEventFlow(cfs)1pHEC (mScm-1)DO (mgL-1)Temp(°C)Turb(NTU)TSS(ppm)TOC(ppm)SoCal OC 01-Aug-09 SC1 StDr Dryflow nf mv mv mv mv mv 15.23 13.15SoCal OC 01-Aug-09 SC3 StDr Dryflow mv mv mv mv mv mv 2.83 26.27SoCal OC 01-Aug-09 SC5 RW Dryflow fl 7.33 2.494 3.67 21.19 3.3 0.47 14.13SoCal SD 07-Apr-08 SDR101 RW Dryflow 2.2 7.7 2.565 6.7919.1 2.6 0.00 70.21SoCal SD 07-Apr-08 SDR102 StDr Dryflow 0.06 7.44 3.176 7.1720.59 11.5 26.91 3.611SoCal SD 07-Apr-08 SDR151 StDr Dryflow 0.28 7.36 2.59 4.62 21.17 0 0.00 1.545SoCal SD 07-Apr-08 SDR156 StDr Dryflow 0.01 8.13 0.993 9.04 17.08 0 0.00 1.553SoCal SD 07-Apr-08 SDR158 RW Dryflow nf 7.35 2.566 4.5120.15 14.5 4.20 77.69SoCal SD 12-May-08 SDR101 RW Dryflow 17.21 7.81 3.025 5.4620.45 0.2 1.26 7.956SoCal SD 12-May-08 SDR102 StDr Dryflow fl 7.41 3.462 6.85 20.73 12.2 4.13 3.457SoCal SD 12-May-08 SDR151 StDr Dryflow 0.5806 7.31 2.587 3.62 21.45 0 0.00 1.392SoCal SD 12-May-08 SDR156 StDr Dryflow fl 8.04 0.974 7.7 17.98 0 2.30 3.383SoCal SD 12-May-08 SDR158 RW Dryflow fl 7.41 2.559 4.59 20.73 8.1 7.25 1.565SoCal SD 12-May-08 SDR159C StDr Dryflow 0.43 7.36 2.595 4.6 21.36 0 0.00 1.493SoCal SD 12-Jun-08 SDR151 StDr Dryflow 0.0668 7.22 2.578 3.62 21.61 0 0.00 1.284SoCal SD 12-Jun-08 SDR156 StDr Dryflow fl 7.78 0.678 mv 19.55 7.6 0.00 2.463SoCal SD 12-Jun-08 SDR158 RW Dryflow nf 7.21 2.547 5.0521.39 4.8 6.41 1.689SoCal SD 13-Jun-08 SDR101 RW Dryflow 1.07 7.55 3.015 2.32 22.64 0 1.33 9.852SoCal SD 13-Jun-08 SDR102 StDr Dryflow fl 7.38 3.237 6.2 20.97 9.9 21.10 4.142SoCal SD 26-Nov-08 SDR101 RW Rain67.50 7.71 1.489 7.1 16.88 37.7 98.20 10.8SoCal SD 26-Nov-08 SDR102 StDr Rain1.80 7.4 1.132 8.07 17.99 7.4 10.53 6.131SoCal SD 26-Nov-08 SDR103 StDr Rain0.03 8.15 0.195 8.75 17.22 0 4.25 16.25SoCal SD 26-Nov-08 SDR104 StDr Rain2.00 7.62 0.148 4.37 16.59 13.5 43.38 10.18SoCal SD 26-Nov-08 SDR151 StDr Rainnf 7.92 0.264 8.79 16.62 218 218.83 14.5SoCal SD 26-Nov-08 SDR156 StDr Rainfl 7.48 0.14 8.26 17.1 13.6 41.31 20.66SoCal SD 26-Nov-08 SDR158 RW Rainfl 7.4 0.29 8.37 16.32 236.6 213.67 14.19SoCal SD 06-May-09 SDR101 RW Dryflow 3.22 7.6 2.947 3.68 21.88 0 6.12 8.313SoCal SD 06-May-09 SDR102 StDr Dryflow 1.77 7.31 3.462 7.1621.12 10.4 9.28 3.735SoCal SD 06-May-09 SDR156 StDr Dryflow 0.01 8.13 0.977 8.82 18.24 0 43.51 1.745SoCal SD 06-May-09 SDR158 RW Dryflow nf 7.39 1.898 2.921.38 14.4 31.50 9.094SoCal SD 01-Aug-09 SDR101 RW Dryflow 1.13 7.57 4.074 0.94 23.31 2 4.55 20.58SoCal SD 01-Aug-09 SDR102 StDr Dryflow 0.13 7.48 3.588 6.75 22.37 12 4.61 9.694SoCal SD 01-Aug-09 SDR156 StDr Dryflow nf 8.17 0.815 7.0122.36 94.2 1456.69 5.689SoCal SD 01-Aug-09 SDR158 RW Dryflow nf 7.32 2.637 0.8823.22 8.2 3.91 10.521fl, the water in the waterbody was flowing but flow could notbe taken; nf, the water in the waterbody was not flowing.

### 53 VII. APPENDIX II. QUALITY CONTROL

1. Holding ti mes. Holding times are the length of time from wh en the sample is collected to when it is extracted prior to analysis, and vary for the different analyte screens (Table 1). All analyses met there holding times, except for two synthetic auxin analyses. The holding times for two of these batches failed by one and two days. Due to a lab error, another ba tch was not extracted until 50 days after sampling. Conducting a lab duplicate analysis conf irmed that exceeding the holding tim e did not affect the degradation of these samples.

2. Lab Blanks. There were no detections in any of the lab blanks.

3. Matrix and propazine surrogate spikes. With analytical batch, control water or sediment is spiked with

known concentrations of the pesticides in that particular analytical screen. For the study there were 698 matrix spikes; 98% of these were recovered with in acceptable limits. All 194 propazine surrogates (a triazine surrogate) were recovered with laboratory acceptable limits, as we re all of the sediment matrix spikes.
4. Blind spikes, Field Blan ks, and Field Duplicates. About 15% of the samples were blind spikes, field blanks, or field duplicates. Twenty-seven analytes in 15 blind spikes were all r ecovered within acceptable limits. However, in one analysis, fipronil was detected as a trace detection for fipronil, without fipronil added to the sample.

There were no detections in any of the 37 field blanks . Of 90 field duplicate analys es (water samples), 96% had good reproducibility (less than 25% difference) between the original field sample and the field duplicate. Sediment samples had more variation, with only 80% of the samples having good reproducibility. The sediment matrix may be interf ering with the analysis and causi ng some variation in the data.