Table 1. Summary of detected pesticides from stations in the STORET database, 1973-93

[--, no data available; mg/L, micrograms per liter; concentrations in red exceed aquatic life or human health criteria]
Pesticide Number
of
detections/
samples		 Percentage
of
detections		 Maximum
concentration
(mg/L)		 Aquatic
criteria
(mg/L)		 Lifetime
HAL1
 (mg/L)		 MCL1
 (mg/L)		 Minimum
reporting
level
(mg/L)

Herbicides

Simetone 15/15
100
0.10
--
--
--
0.10
2,4-D 39/115
34
12
--
70
70
0.050
2,4-DP 12/57
21
0.12
--
--
--
0.010
2,4,5-T 5/94
5
4.5
--
70
--
0.010
2,4,5-TP (Silvex) 3/111
3
0.01
--
50
50
0.025

Insecticides

DDE 1/46
2.2
0.01
--
--
--
0.010
Pentachlorophenol 2/157
1.3
4
213
--
1
4
Chlordane 3/349
0.9
2
20.004
--
2
0.10
Parathion 6/846
0.7
0.10
20.013
--
--
0.10
Phosdrin 5/817
0.6
0.1
--
--
--
0.10
Trithion 5/821
0.6
0.1
--
--
--
0.10
Ethion 5/846
0.6
0.1
--
--
--
0.10
Guthion 4/843
0.5
0.1
20.01
--
--
0.10
Malathion 4/845
0.5
0.1
20.1
200
--
0.10
Diazinon 4/846
0.5
0.1
30.009
0.6
--
0.10
Dieldrin 4/1008
0.4
0.05
20.0019
--
--
0.010
Alpha endosulfan 1/255
0.4
0.05
20.056
--
--
0.05
Methoxychlor 2/561
0.4
0.1
20.03
40
40
0.05
o,p-DDT 3/900
0.3
0.11
20.001
--
--
0.05
p,p-DDT 3/926
0.3
0.22
20.001
--
--
0.05
Mirex 1/345
0.3
0.1
20.001
--
--
0.05
Lindane 3/1096
0.3
0.42
20.08
0.2
0.2
0.01
o,p-DDD 2/901
0.2
0.12
--
--
--
0.05
Toxaphene 2/1005
0.2
2
20.0002
--
3
0.05
p,p-DDD 1/926
0.1
0.05
--
--
--
0.05
p,p-DDE 1/928
0.1
1.7
--
--
--
0.05
Heptachlor epoxide 1/995
0.1
0.01
20.0038
--
--
0.01
Aldrin 1/1009
0.1
0.01
--
--
--
0.1/0.01
1HAL, health advisory level; MCL, maximum contaminant level (U.S. Environmental Protection Agency, 1996).
2Freshwater chronic water-quality criteria (U.S. Environmental Protection Agency, 1997).
3Freshwater chronic water-quality criteria recommendations from National Academy of Sciences and National Academy of Engineers (1973), modified from Nowell and Resek (1994).

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