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

(Table 34). See species ESU/DPS maps for NPDES permits and 303(d) waters colocated
within listed salmonid ESUs/DPSs in California.
Table 34. California's 2006 Section 303(d) List of Water Quality Limited Segments:
segments listed for exceeding temperature and carbofuran limits (CEPA 2007).
Pollutant Estuary Acres Affected River / Stream Miles Affected # Water Bodies
Temperature - 16,907.2 41
Carbofuran - 49 1
Estuary systems of the region are consistently exposed to anthropogenic pressures
stemming from high human density sources. For example, the largest west coast estuary
is the San Francisco Estuary. This water body provides drinking water to 23 million
people, irrigates 4.5 million acres of farmland, and drains roughly 40% of California’s
land area. As a result of high use, many environmental measures of the San Francisco
Estuary are poor. Water quality suffers from high phosphorus and nitrogen loads,
primarily from agricultural, sewage, and storm water runoff. Water clarity is also
compromised. Sediments from urban runoff and historical activities contain high levels
of contaminants. They include pesticides,polychlorinated biphenyls (PCBs), nickel,
selenium, cadmium, , mercury, copper, and silver. Specific pesticides include
pyrethroids, malathion, carbaryl, and diazinon. Other pollutants include DDT and
polynuclear aromatic hydrocarbons (PAHs).
Other wastes are also discharged into San Francisco Bay. Approximately 150 industries
discharge wastewater into the bay. Discharge of hot water from power plants and
industrial sources may elevate temperatures and negatively affect aquatic life.
Additionally, about 60 sewage treatment plants discharge treated effluent into the bay and
elevate nutrient loads. However, since 1993, many of the point sources of pollution have
been greatly reduced. Pollution from oil spills also occur due to refineries in the bay
area. As these stressors persist in the marine environment, the estuary system will likely
carry loads for future years, even with strict regulation. Gold mining has also reduced
estuary depths in much of the region, causing drastic changes to habitat.
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