Carbaryl, Carbofuran, and Methomyl - National Marine Fisheries ...

fish from urban steams compared to fewer than 800 unique 5-compound mixtures
detected in fish from agricultural and mixed land use steams. The relative contributions
of most organochlorine compounds to mixtures in fish were about the same for urban and
agricultural streams.
More than half of all agricultural streams sampled and more than three-quarters of all
urban streams had concentrations of pesticides in water that exceeded one or more
benchmarks for aquatic life. Aquatic life criteria are EPA water-quality guidelines for
protection of aquatic life. Exceedance of an aquatic life benchmark level indicates a
strong probability that aquatic species are being adversely affected. However, aquatic
species may also be affected at levels below criteria. Finally, organochlorine pesticides
that were discontinued 15 to 30 years ago still exceeded benchmarks for aquatic life and
fish-eating wildlife in bed sediment or fish-tissue samples from many streams.
National Pollutant Discharge Elimination System
Pollution originating from a discrete location such as a pipe discharge or wastewater
treatment outfall is known as a point source. Point sources of pollution require a National
Pollutant Discharge Elimination System (NPDES) permit. These permits are issued for
aquaculture, concentrated animal feeding operations, industrial wastewater treatment
plants, biosolids (sewer/sludge), pre-treatment and stormwater overflows. The EPA
administers the NPDES permit program and states certify that NPDES permit holders
comply with state water quality standards. Nonpoint source discharges do not originate
from discrete points; thus, nonpoint sources are difficult to identify, quantify, and are not
regulated. Examples of nonpoint source pollution include, but are not limited to, urban
runoff from impervious surfaces, areas of fertilizer and pesticide application, and manure.
According to EPA’s database of NPDES permits, about 243 NPDES permits are colocated
with listed Pacific salmonids in California. Collectively, the total number of
EPA-recorded NPDES permits in Idaho, Oregon, and Washington, that are co-located
with listed Pacific salmonids is 1,978. See ESU Figures in the Status of Listed Resources
section for NPDES permits co-located within listed salmonid ESUs within the states of
200