Reviews Are Mixed for AQMD Smog Plan

Several independent experts have concluded that the controversial new smog plan for the Los Angeles area contains some serious technical flaws--including the failure to account for high pollution levels on weekends--that could jeopardize the region’s quest for healthful air.

But other technical experts who have reviewed the same data say the South Coast Air Quality Management District has predicted future pollution levels reasonably well and has proposed as sound an anti-smog strategy as the latest science allows.

Since unveiling its draft plan in August, the AQMD has faced an intensifying wave of criticism that its projections are unreliable or perhaps biased, prompting the agency to hire five technical experts to quickly conduct a “peer review.”

One of the five reviewers, UC Berkeley engineering professor Robert Harley, concluded that the AQMD’s strategy to achieve health standards for air pollution “is not convincing.”

In a report to the AQMD, Harley said the agency failed to include smog concentrations from weekends, which for unknown reasons are often higher than on weekdays. The plan also “significantly understated” emissions from motor vehicles, Harley wrote. He called the estimates of current car and truck exhaust “unverified” and the projections “speculative.”

The harshest attacks on the plan are coming from eight former AQMD scientific advisors who resigned en masse in August, saying the agency has embarked on a course that will inadequately protect the health of the region’s 14 million residents.

Stepping up their criticism, several of the former advisors are now recommending that the smog agency scrap the entire plan and start over.

“There are fairly major errors in predictions,” said Akula Venkatram, an air quality engineer at UC Riverside. “We can’t be sure of anything [about future smog levels] given that these [vehicle emission] predictions are poor.”

On the other hand, two of the five reviewers hired by the AQMD said the agency has applied “state of the art science” and praised it for going to great lengths to refine inherent uncertainties in the data used in its computer models that predict future smog.

“I have not found any state, regional or local planning agency with such sophisticated, state-of-science models,” environmental consultant Douglas Latimer wrote in his report.

David Null of Cal State San Bernardino said tests to measure the precision of the AQMD’s simulations show them to be “reasonably close” to reality.

“Perfect or imperfect, best or not best . . . it is time to accept what the district has and to move forward,” Null wrote in his report.

Amid such conflicting reviews, the AQMD board is scheduled to vote in just over two weeks whether to adopt the plan.

Serving as the region’s blueprint to combat smog, the plan includes 61 proposed regulations to cut emissions from vehicles, businesses and consumer products in Los Angeles, Orange, Riverside and San Bernardino counties.

If adopted, the new strategy would eliminate substantially fewer tons of emissions than a plan the AQMD board adopted in 1994. About two dozen proposed measures from the 1994 plan would be dropped because the staff is more optimistic about future smog.

The dramatic change in the AQMD’s smog projections raised doubts among clean air advocates and some scientists because the complex, computer-generated smog simulations were conducted by AQMD staffers with little input from outside experts, including their own scientific advisory council.

Questions have been raised about the agency’s credibility because it has faced growing pressure to ease the regulatory burden on businesses to protect the economy. But AQMD officials defend their work, saying it contains up-to-date estimates for fumes from vehicles, dairy farms and other sources.

“Three of the reviewers, the Environmental Protection Agency, the Air Resources Board and our body of technical experts here at the agency all are in uniform agreement that we used state-of-the-science models,” said Barry Wallerstein, AQMD deputy executive officer.

Of the five reviewers hired by the AQMD, UC Berkeley’s Harley was the most critical of the data. But another, C. Shepherd Burton, an environmental consultant from San Rafael, shared the concern over the weekend smog levels. He said it adds “to the overall uncertainty” about whether the smog plan is aggressive enough.

In response, the AQMD staff Tuesday completed new tests that added weekend emission estimates. Wallerstein said they show that the region would still achieve the national standard for ozone, the main ingredient of smog, by 2010.