Number of Sample Locations with Pesticides of Interest Detected by Basin (LASAR and SDWIS 1982-2009)

Note: There were no detections (or no samples collected) in the following Basins: Black Rock Desert, Upper Sacramento, and Northern California Coastal.

PARAMETER

Total 

Number of 

Sample 

Locations

DESCHUTES

JOHN 

DAY

KLAMATH

LOWER 

COLUMBIA

LOWER 

SNAKE

MIDDLE 

COLUMBIA

MIDDLE 

SNAKE / 

BOISE

MIDDLE 

SNAKE / 

POWDER

NORTHERN 

OREGON 

COASTAL

OREGON 

CLOSED 

BASINS

SOUTHERN 

OREGON 

COASTAL

WILLAM 

ETTE

Unknown 

sample 

location

Total number of Sampling 

Locations and Pesticide 

Detection(s)

12 1 1 8 1 253 151 21 3 68 43 634 4

Atrazine 132 2 1 1 1 12 16 1 12 86 1

Atrazine-desethyl 125 1 15 13 2 1 93

Simazine 88 31 2 55 1

Acrolein (2-Propenal) 63 61 2

Diuron 55 7 1 6 41

Dacthal 52 11 38 3

DCPA (Dacthal) 46 4 37 3 1 1

Chlorpyrifos 42 24 18 1

Metolachlor 34 6 2 26

Guthion (Azinphosmethyl) 33 25 1 7

Pentachlorophenol 31 2 3 2 1 1 3 1 18

Metribuzin 29 2 1 26

Bromacil 23 1 9 1 12

Malathion 22 7 15

2,4-D 19 11 2 6

Imidan (Phosmet) 19 13 1 5

Diazinon 17 5 12

MCPA 16 15 1

Terbacil 15 1 1 1 12

Carbaryl 13 2 3 8

4,4`-DDT 12 12

DCPA acid metabolites(a) 12 3 8 1

Dicamba 11 9 1 1

Propiconazole 11 1 10

2,4,5-T 10 9 1

delta-BHC 10 1 1 8

Dimethoate 10 2 8

Endosulfan I 10 10

Number of Sample Locations in the Basin with Pesticide Detection(s)
PARAMETER

Total 

Number of 

Sample 

Locations

DESCHUTES

JOHN 

DAY

KLAMATH

LOWER 

COLUMBIA

LOWER 

SNAKE

MIDDLE 

COLUMBIA

MIDDLE 

SNAKE / 

BOISE

MIDDLE 

SNAKE / 

POWDER

NORTHERN 

OREGON 

COASTAL

OREGON 

CLOSED 

BASINS

SOUTHERN 

OREGON 

COASTAL

WILLAM 

ETTE

Unknown 

sample 

location

Number of Sample Locations in the Basin with Pesticide Detection(s)

Endosulfan sulfate 10 3 7

Imidacloprid 10 10

Picloram 9 5 1 2 1 1

Silvex 10 10

Dieldrin 9 1 8

DIQUAT 9 1 3 5

Hexazinone 9 3 2 4

Pendimethalin 9 1 8

Prometon 9 2 2 5

4,4`-DDE 7 1 6

Heptachlor 7 2 5

Hexachlorobenzene 7 2 1 1 1 2

Oxyamyl 7 7

1,2-Dibromoethane (EDB) 6 6

Aldicarb 6 6

Malathion Oxygen Analog 6 4 2

Norflurazon 6 1 5

Dinoseb 5 1 4

Heptachlor epoxide 5 5

4,4`-DDD 4 4

Azinphos Methyl 4 3 1

Baygon 4 4

2,4,5-Trichlorophenol 3 3

alpha-BHC 3 1 2

Bentazon 3 1 2

Bentazone 3 2 1

Carbofuran 3 3

Chlorpyrifos oxon 3 3

Chlorpyriphos (Dursban) 3 2 1

Endosulfan II 3 3

Ethoprophos 3 3

ETHYLENE DIBROMIDE (EDB) 3 3

Metalaxyl 3 1 2
PARAMETER

Total 

Number of 

Sample 

Locations

DESCHUTES

JOHN 

DAY

KLAMATH

LOWER 

COLUMBIA

LOWER 

SNAKE

MIDDLE 

COLUMBIA

MIDDLE 

SNAKE / 

BOISE

MIDDLE 

SNAKE / 

POWDER

NORTHERN 

OREGON 

COASTAL

OREGON 

CLOSED 

BASINS

SOUTHERN 

OREGON 

COASTAL

WILLAM 

ETTE

Unknown 

sample 

location

Number of Sample Locations in the Basin with Pesticide Detection(s)

Napropamide 3 3

Pyraclostrobin 3 3

Triclopyr 3 1 2

Trifluralin 3 3

Aldrin 2 2

beta-BHC 2 1 1

Dalapon 2 1 1

Endrin 2 2

Ethofumesate 2 2

Fenvalerate+Esfenvalerate 2 2

gamma-BHC (Lindane) 2 1 1

Methoxychlor 2 2

Total Imidan (Phosmet) 2 2

1 2-Dibromo-3-chloropropane (DBCP) 1 1

1,1-Dichloropropene 1 1

2 4-D 1 1

ALACHLOR 1 1

Clopyralid 1 1

ENDOTHALL 1 1

Endrin Ketone 1 1

GLYPHOSATE 1 1

Imazapyr 1 1

Iprodione 1 1

Linuron 1 1

Methomyl 1 1

Myclobutanil 1 1

p,p`-Methoxychlor 1 1

Tebuconazole 1 1