USGS Scientific Investigations Report 2011-5082 - Occurrence and Distribution of Pesticides in Surface Waters of the Hood River Basin, Oregon, 1999

Table 9. Occurrence of multiple pesticides in a single sample from Hood River basin, Oregon, 1999–2009.

[Numbers in parentheses (n) indicate the number of samples in which that combination was detected. Where not listed, n=1. Sample size includes all (unscreened) samples. Abbreviations: AT, atrazine; AZ, azinphos-methyl; C, chlorpyrifos; CB, carbaryl; DR, diuron; EN, endrin; FL, fluometuron; HX, hexazinone; IM, imidacloprid; MA, malathion; MM, methomyl; N, norflurazon; PH, phosmet; PX, propoxur; PZ, propiconazole; PY, pyraclostrobin; S, simazine; – no mixtures detected]

Site	Year	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Annual Total
Evans	2003	C,S	–	–	–	–	–	–	–	1
Hood, mouth	2000	C,S	–	–	–	–	–	–	–	1
	2009	–	–	CB,SDR,S	–	–	–	–	–	2
Hood, West Fork, mouth	2009	–	–	DR,S	–	–	–	–	–	1
Indian	1999	C,S (n=2)	–	–	–	–	–	–	–	2
Lenz	2001	C,S (n=2)	–	–	–	–	–	–	–	2
	2002	C,S	C,S	AT,S	AZ,PH,SAZ,S	AZ,S	–	–	–	6
	2003	C,SAT,C,S	–	–	AZ,S (n=7)	–	AZ,S (n=2)	AZ,S (n=2)	AZ,PH, S (n=2)	15
	2004	AZ,S	–	AZ,S	AZ,MA,S	–	–	AZ,PH	–	4
	2005	–	–	–	–	–	–	AZ,PH,S (n=2)AZ, S (n=2)	AZ,PH	5
	2006	–	–	–	AZ,S	–	–	–	–	1
	2008	–	PH,S	–	–	–	–	–	–	1
	2009	DR,N,S	DR,PYDR,S (n=2)PX, DR,MM,PY	CB,DRCB,DR,HX,PY	DR,S	–	–	AZ,DR,S	CB,DR,IM	10
Neal, middle	2005	–	–	–	–	–	–	AZ,PHAZ,PH,S	–	2
	2007	–	–	PH,S	–	–	–	–	–	1
	2009	–	HX,PYPX,HX,MM	DR,HXDR,HX,PZ,S	DR,HX	–	–	–	DR,PZ	6
Neal, mouth	1999	C,S, (n=2)	–	–	–	–	–	–	AZ,S	3
	2000	C,S, (n=5)	C,S (n=4)	CB,DR,S	AZ,CB,DR,MA, SAZ,CB,DR,SAZ, DR,MA,SCB,DZ, DR,SDR,S (n=2)	CB,DR,MA,S	–	–	–	17
	2001	–	–	–	AZ,MA,SPH,S	–	–	–	–	2
	2002	–	–	–	AZ,S (n=3)	AZ,SMA,S	–	–	–	5
	2003	C,DZ,S	–	–	AZ,S (n=6)	–	AZ,S	–	–	8
	2004	–	–	–	AZ,MA,S	–	–	–	–	1
	2005	C,S	–	–	AZ,S (n=2)	–	–	–	–	3
	2007	–	–	AZ,S (n=2)	–	–	–	–	–	2
	2009	DR,HXDR,S	DR,HXDR,HX,PY	CB,DR,HXCB,DR, HX,PZDR,HX	CB,DRCB,DR,SDR,S	–	–	–	DR,PZ,S	11
Neal, upper, below diversion	2009	–	FL,HXPX,HX,MM	DR,HX	–	—	–	–	–	3
Rogers	2009	–	PX,EN,MM	–	–	–	–	–	–	1
Total mixture samples		22	17	17	36	4	3	10	7	116

Occurrence and Distribution of Pesticides in Surface Waters of the Hood River Basin, Oregon, 1999–2009