Air Board Regulations Could Devastate Agriculture

The California Air Resources Board has proposed regulations for reducing diesel engine emissions that could force California growers to spend potentially hundreds of millions of dollars to update diesel-engine-powered trucks and tractors. At this point, these regulations are in draft form and California agriculture will be actively working to get the proposed regulations modified before they are put in place.


The reason that these regulations are being proposed goes back to the Federal Clean Air Act. In addition, particulate matter was identified as a toxic air contaminant in California in 1998, and
more than 70% of ambient air toxic risk from particulate matter is from diesel engine exhaust.

California data shows that the sources of diesel engine particulate emissions include: on-road engines, 27%; offroad engines, 66%; and stationary and portable engines, 7%. The state is already requiring that stationary and portable engines be registered. In the future, they must be upgraded to reduce particulate emissions.

The proposed control measures for diesel trucks and off-road mobile equipment, which includes agricultural tractors, is the real problem for California agriculture. For trucks with a gross vehicle weight of more than 33,000 pounds, the proposed regulations would essentially require that engines in older, heavy trucks be replaced twice in nine years since the engines that will be required to meet the standards in 2013 will not be available for several years.

The problem is that many heavy trucks used in California agriculture are used for only a few months of the year, during the harvest season for crops such as processing tomatoes, fruit and nut crops, and so on. These trucks may only put on 15,000 or so miles a year compared to over-the-road trucks for large truck lines that may run 150,000 miles per year or more. Thus, the heavy trucks used in California agriculture can be used for 10 to 15 years or longer.

A Looming Number

It is estimated that the proposed regulations could affect 400,000 trucks that are registered in California. The regulations do include an exemption for trucks operating less than 7,500 miles per year, or 250 hours, but these numbers are far too low for the exemption to be of use in most agricultural operations.

Interestingly enough, these proposed regulations also affect interstate trucks that come into California. If the draft regulations are put in place, the state of California will probably be sued because states cannot regulate interstate commerce, according to the U.S. Constitution.

Indications are that the off-road diesel engine emissions regulations impacting agricultural tractors will require the use of so-called Tier 4 by 2014. (Allowable diesel engine emissions levels are referred to as Tiers and the higher the number the lower the emission level.) Additionally, the regulations could possibly require early replacement of Tier 3 engines. Tier 3 engines have just been introduced by agricultural tractor manufacturers.

The regulations for both trucks and tractors allow diesel engines to be retrofitted with new pollution devices or replaced with new engines that meet the new standards. Retrofits are estimated to cost up to $35,000, but in many cases, they cannot be used because they add bulky devices to clean up the exhaust. Engine replacements are even more expensive, and, often are not feasible, particularly in older agricultural tractors.

Since these are only proposed and/or draft regulations, there is always a possibility that they might be changed to be more reasonable, and California agriculture will certainly be pushing for changes. The only thing that is certain, however, is that exhaust emission standards for older diesel engines in California will be lower in the future.