Deadline to meet pollution standards

Growers in the eight-county San Joaquin Valley Air Pollution Control District, which includes Merced County, have until January 2010 to replace older, high-polluting, Tier 0 diesel engines greater than 50 horsepower with EPA-certified Tier 3 or Tier 4 engines.

The rule is the latest installment in complying with District Rule 4702, which regulates air pollution emissions from ag engines not used in tractors or ag implements, such as irrigation pump engines. Growers statewide will need to meet a similar requirement by January 2011 under parallel rules by the State Air Board.

In addition, San Joaquin Valley growers after January face more onerous permitting requirements if they plan to install or modify ag engines, depending on whether they qualify as a "significant polluter." The cutoff for "significant polluter" will be lowered from 12.5 tons per year because of the severe nonattainment for ozone status of the San Joaquin Valley.