Firefighters on Wednesday battled acrid smoke from a three-acre compost fire for a second day as officials warned schools to curtail students' physical activity and fielded complaints about the fire's noxious odor from residents as far as 20 miles away.
Fire officials also unveiled maps showing how far smoke from the smoldering pile at PictSweet Mushroom Farm is blowing. Early mornings it settles over Oxnard, and in the afternoons and early evenings onshore winds blow it toward east Ventura, Santa Paula and Camarillo. In late evenings, it settles in a one-mile radius around the mushroom farm.
Firefighters said they still didn't know when the fire would be extinguished, or exactly how.
Robert Levin, the county's health officer, acknowledged the public nuisance, and said officials want to keep it from becoming a public health threat. To what extent the fire might threaten public health is unknown, pending the results of air quality tests, he said.
Healthy people will probably not be affected, he said, but residents with respiratory and heart problems should take precautions.
Many schools didn't take any chances. Richard Duarte, superintendent of the Oxnard Elementary School District, advised principals to plan as they would for a heavy smog day, restricting strenuous outdoor activities.
For some schools, that wasn't enough. At Oxnard's Emilie Ritchen Elementary School, staff members said many students complained of nausea and burning eyes, despite spending most of the day indoors.
"We have a lot of kids who have allergies and asthma who were really affected," said fifth- and sixth-grade teacher Anneliese Ullrich, who used her class's physical education time on Wednesday for a history lesson.
In Ventura, Bob Tripp, who manages Ventura Marina Mobile Home Park, one mile west of the fire, was flooded with calls Wednesday from residents complaining about the smell.
Tripp, who has asthma, said the smoke left him short of breath when he tried to play golf at Oxnard's River Ridge Golf Course.
At the site of the blaze, firefighters in oxygen masks used heavy equipment to drag what fuel they could away from the massive heap of straw and horse manure, which is piled 15 feet high. The material, which came from Santa Anita and two other racetracks, is used as fertilizer for PictSweet's mushrooms.
County workers drew water samples from a nearby barranca, which leads to settling ponds next to the Santa Clara River. Meanwhile, fire officials experimented with ways to extinguish the blaze without risking either public health or the Santa Clara River's fragile environment.
Water poured on the burning manure could drain off and pollute the river, but accelerating the fire could intensify air pollution, officials said. Using fire-retardant foam could leech pollutants into ground water, and an attempt to pump compressed air into the mound through pipes has brought mixed results, authorities said.
Until they decide the safest way to put it out, fire officials don't know how long the blaze will burn, county Fire Chief Bob Roper said.
Finding out exactly what is in the air and how badly it might affect public health could also take time, said Dick Baldwin, the county's air pollution control officer. Samples must be sent to state labs, where they will be tested for a variety of toxins and the total amount of airborne particulates.
Workers taking samples near the blaze early Wednesday found that particulates were at least three times acceptable levels, but Baldwin said that could be misleading because state standards are measured over a 24-hour period.
"What we got was a very high one-hour reading," he said. "What it suggests is that for a very short time, particulate readings were very high. We don't know what it means."
In the meantime, Levin said, county workers are trying to get the word out to nursing homes, hospitals and housebound residents for people with respiratory or heart ailments to take precautions, such as staying indoors and restricting activity when possible.
Sandi Wells, spokeswoman for the Ventura County Fire Department, said spontaneous combustion may have caused the blaze, and that officials don't suspect arson.