Would a $30 container fee for the Ports of Los Angeles and Long Beach have much impact on shipping? A study released today by the Coalition for Clean Air suggests it wouldn't. The study, funded by the coalition and the Natural Resources Defense Council, found that ship diversions resulting from a container fee would be less than 1.5 percent. The coalition is pushing legislation by State Sen. Alan Lowenthal that would impose the $30-per-container fee as a way of financing infrastructure and environmental clean-up projects. Lowenthal has been trying to link the legislation with a November bond measure that would finance work on the badly congested Long Beach (710 Freeway). Opponents of the bill, which include the California Association of Port Authorities and the California Chamber of Commerce, say the fee would have a devastating impact on the California economy.