Agricultural officials announced Tuesday they have banned the use of a pesticide on a large portion of Orange County farmland because a toxic chemical is seeping into Newport Bay and contaminating shellfish.
State officials also said they are considering a broader ban in other areas of California where the pesticide is endangering marine life.
The restriction on endosulfan in Orange County replaces a temporary emergency ban imposed in April by the county agricultural commissioner's office.
"We have now restricted the material to the point where it can no longer be used in the area that drains into Newport Bay," said Frank Parsons, deputy agricultural commissioner.
Orange County growers with fields that drain into Newport Bay or its tributaries can no longer use the pesticide, which is spread mostly on strawberries and peppers to kill aphids. Fields affected by the ban are in Irvine, Tustin and El Toro, the heart of Orange County's remaining farmland.
Health officials note that endosulfan is a persistent and long-lasting chemical that can kill marine life. Shellfish such as mussels tend to accumulate large amounts of chemicals in their tissues even if the chemical is diluted in waterways.
The recommendation for a total ban came Tuesday from the state Department of Food and Agriculture, and the order was imposed by County Agricultural Commissioner James Harnett.
Officials said endosulfan has caused serious pollution problems in other areas of California as well.
Since 1965, 32 fish kills linked to the chemical have occurred in Colusa, Glenn, Imperial, Merced, Riverside, San Joaquin, San Mateo and Yolo counties, according to an April report by the Department of Food and Agriculture. A fish kill from the chemical has occurred somewhere in California every year for the past decade, the report says.
State officials are now studying whether to restrict use of the chemical in the Monterey area, which along with Newport Bay has some of the highest concentrations of the chemical found in shellfish, apparently from farm drainage.
"It's not as clear-cut in that area where the endosulfan is coming from. It's a larger watershed than Newport Bay," said Veda Federighi, a spokeswoman for the agricultural department's pesticide division in Sacramento. "We just want to pin it down better where it's coming from before we impose a ban."
The state agency also is considering a ban in the Imperial Valley, another farm-rich area.
State Sen. Marian Bergeson (R-Newport Beach) said Tuesday she is encouraged by the action but is urging the agricultural department to consider a statewide ban.
"Monterey and other areas are looking at problems with endosulfan, too. If the same thing is happening statewide that has happened in Newport Bay, it should be banned in other areas, too," said Bergeson, who authored a 1988 resolution that required a state review of Newport Bay's pollution. The review prompted Newport Beach officials to recommend the endosulfan ban.
The decision to restrict the chemical around Newport Bay is not unusual in California. Other pesticides have been banned from use in specific geographic areas because of special circumstances, such as drainage into a bay or river, said Doug Okumura, the state's branch chief of pesticide enforcement.
Before the interim ban, endosulfan was spread by about 20 Orange County growers on several hundred acres of crops in the Newport Bay drainage area, Parsons said.
"From what I understand from growers, it's not very widely used here and there are other alternatives for them to use," said Nancy Jimenez, executive director of the Orange County Farm Bureau, which represents growers still using endosulfan. "I don't really anticipate any widespread problems with the ban."
Tuesday's recommendation by Rex Magee, state associate agricultural director, came after an environmental monitoring team from the department surveyed farms in the area and discovered runoff flowing into the bay.
The team found runoff spilling from one field at a rate of 10 liters per second, according to a memo by the department's chief of environmental monitoring. The memo said the restriction will help decrease the runoff into the bay, but it will not eliminate it because development in the area is churning up endosulfan residue in the sediment, which is draining into the bay.
The bay's endosulfan problem was first detected by water-quality officials several years ago, when high concentrations of the pesticide were found in mussels. But it didn't prompt action until this year, after a resident who serves on Newport Beach's harbor quality committee complained to the Newport Beach City Council.
Regional water quality officials have proposed a plan for cleaning up the beleaguered bay. Endosulfan is only one of many contaminants, including industrial chemicals, pesticides, fertilizer and sewage, that are polluting the waterway.
Parsons said the restriction might not be permanent, but he doesn't anticipate it ever being lifted.
"It's a very remote possibility that endosulfan would ever be used again in this area," he said.
Under the temporary ban, the county agricultural office could have granted special permits to growers to use endosulfan if they proved their crops were in danger without it. No growers requested them. The new order, however, stops all use in the Newport Bay watershed under any circumstances.
The area where the pesticide is banned is bound by the Costa Mesa Freeway, Santiago Canyon Road, El Toro Road and the Pacific Ocean.
Mussels are not harvested in Newport Bay, so the pollution probably does not pose a threat to consumers. But state and federal water law requires that waterways be kept safe for all forms of marine and wildlife.
Times correspondent Laura Michaelis contributed to this report.