Pesticides and pesticide degradation products in stormwater runoff: Sacramento River Basin, California

Water Resources Bulletin



Pesticides in stormwater runoff, within the Sacramento River Basin, California, were assessed during a storm that occurred in January 1994. Two organophosphate insecticides (diazinon and methidathion), two carbamate pesticides (molinate and carbofuran), and one triazine herbicide (simazine) were detected. Organophosphate pesticide concentrations increased with the rising stage of the hydrographs; peak concentrations were measured near peak discharge. Diazinon oxon, a toxic degradation product of diazinon, made up approximately 1 to 3 percent of the diazinon load. The Feather River was the principal source of organophosphate pesticides to the Sacramento River during this storm. The concentrations of molinate and carbofuran, pesticides applied to rice fields during May and June, were relatively constant during and after the storm. Their presence in surface water was attributed to the flooding and subsequent drainage, as a management practice to degrade rice stubble prior to the next planting. A photodegradation product of molinate, 4-keto molinate, was in all samples where molinate was detected and made up approximately 50 percent of the total molinate load. Simazine, a herbicide used in orchards and to control weeds along the roadways, was detected in the storm runoff, but it was not possible to differentiate the two sources of that pesticide to the Sacramento River.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Pesticides and pesticide degradation products in stormwater runoff: Sacramento River Basin, California
Series title Water Resources Bulletin
DOI 10.1111/j.1752-1688.1996.tb04065.x
Volume 32
Issue 5
Year Published 1996
Language English
Publisher American Water Resources Association
Publisher location Herndon, VA, United States
Contributing office(s) California Water Science Center
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Water Resources Bulletin
First page 953
Last page 964
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