County Posts Its 2nd Best Clean-Air Year

Ventura County this year had its second best clean-air year since records began in 1973, air pollution control officials announced Wednesday.

The smog year, which runs from May through October, produced a level of ozone pollution high enough to violate federal health standards on only 13 days. Ozone is formed when emissions from cars and industry mix in sunlight.

That is an increase of three days over 1992, the most pollution-free year on record. But the trend is definitely downward, said William Mount, deputy air pollution control officer for the county.

As usual, Simi Valley had the most health standard violations with eight, while the Fillmore/Piru area had none. Ventura County is ranked 13th worst in the nation for highest concentrations of ozone pollution, down from fourth worst last decade.

“We expect over the long term that the air quality will continue to improve with the continued reductions in emissions,” Mount said.

In addition to lowered emissions mandated by air pollution regulations, Mount said the weather also cooperated this year with few days conducive to forming ozone.

District meteorologist Kent Field said it would be difficult to know exactly how much each factor contributes to the smog until the county has another year of typical smog-producing patters.

Those patterns include a high pressure zone that traps air close to the ground, a lack of wind to leave the air stagnant and warm temperatures.

Mount said the trend toward fewer days with polluted air means there is a “great likelihood” the county will reach the federal standard by 2005. That requires no more than one violation per year over three years.

Days violating federal health standards for ozone pollution during the 1993 smog year, which runs May through October:

Ventura 2 Oxnard 1 Thousand Oaks 5 Ojai 1 Simi Valley 8 Fillmore/Piru 0

Source: Ventura County Air Pollution Control District.