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

Table 10. Minimum, median, and maximum concentrations of pesticides detected in samples from the 2004–05 Hood River basin, Oregon, fruit packers’ study and number of samples with pesticides detected or not detected.

[Abbreviations: µg/L, microgram per liter; –, pesticide not detected or too few detections to calculate the median]

Sample type	Receiving stream	Pesticide	Detected concentration (µg/L)			Median detected concentration at mouth of receiving stream¹	Detections	Nondetections
Sample type	Receiving stream	Pesticide	Minimum	Median	Maximum	Median detected concentration at mouth of receiving stream¹	Detections	Nondetections
Effluent	Lenz	Azinphos-methyl	0.05	0.95	37	0.12	11	5
		Phosmet	0.046	0.097	0.25	0.059	6	10
		Malathion	–	–	–	–	0	16
		Simazine	0.028	0.041	0.053	0.045	3	13
	Neal	Azinphos-methyl	–	–	–	0.059	0	1
		Phosmet	–	–	–	–	0	1
		Malathion	–	–	–	–	0	1
		Simazine	–	–	–	0.065	0	1
	Odell	Azinphos-methyl	18	–	18	no data	1	1
		Phosmet	0.65	–	0.65	no data	1	1
		Malathion	–	–	–	no data	0	2
		Simazine	–	–	–	no data	0	2
	Unnamed	Azinphos-methyl	4.7	–	12	no data	2	1
		Phosmet	0.85	–	17	no data	2	1
		Malathion	–	–	–	no data	0	3
		Simazine	–	–	–	no data	0	3
Surface Water	Hood	Azinphos-methyl	0.03	–	–	–	1	1
		Phosmet	–	–	–	–	0	2
		Malathion	–	–	–	–	0	2
		Simazine	–	–	–	–	0	2
	Lenz	Azinphos-methyl	0.14	1.3	4.8	0.12	9	1
		Phosmet	0.063	0.14	1.8	0.059	4	6
		Malathion	0.041	–	0.041	–	1	9
		Simazine	0.029	0.062	0.17	0.045	6	4
	Neal	Azinphos-methyl	0.063	–	0.063	0.059	1	4
		Phosmet	0.025	–	0.025	–	2	3
		Malathion	0.015	–	0.015	–	2	3
		Simazine	0.028	0.04	0.42	0.065	3	2
	Odell	Azinphos-methyl	0.033	0.045	0.26	no data	5	5
		Phosmet	0.025	0.043	0.043	no data	3	7
		Malathion	–	–	–	no data	0	10
		Simazine	0.024	0.027	2.4	no data	5	5
	Unnamed	Azinphos-methyl	–	–	–	no data	0	1
		Phosmet	–	–	–	no data	0	1
		Malathion	–	–	–	no data	1	0
		Simazine	0.068	–	0.068	no data	1	0

¹Ambient concentrations are from June and September 2004 and September and October 2005, the months when the fruit packing effluent samples were collected.

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