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Changes to diesel rules give options to truck owners

Issue Date: February 16, 2011
By Dave Kranz

Recent changes to state air-quality regulations governing diesel trucks have given farmers and ranchers more time to qualify trucks for the agricultural provisions of the rules, and more options for complying if their trucks don't meet the mileage limits for agricultural trucks.

"If you've reported before, you'll be a step ahead. But if you did not report before, you can still do it," said Cynthia Cory, director of environmental affairs for the California Farm Bureau Federation, during a seminar on the truck rules at last week's World Ag Expo in Tulare.

The California Air Resources Board originally adopted its truck and bus rules in 2008, requiring owners of diesel trucks qualifying for the agricultural provisions to report their trucks by March 31, 2010. But last December, the ARB adopted a number of changes to the regulations—including an extension of the application date for agricultural trucks until March 31, 2011.

"If you did not sign up before, you can still sign up," Cory said. "As long as you owned those trucks by 2009, and you didn't sign up by last year, you can still sign up agricultural trucks."

Qualified agricultural trucks have additional time to meet requirements to replace diesel engines with newer, cleaner-running models—if they stay under annual mileage limits. The rule delays the compliance date until Jan. 1, 2017, for agricultural trucks:

  • With engine dates of 2006 or newer, driving 25,000 miles a year or less;
  • With engine dates of 1996 through 2005, driving 20,000 miles a year or less;
  • With engine dates earlier than 1996, driving 15,000 miles a year or less.

The extension continues until Jan.1, 2023, for agricultural trucks driven less than 10,000 miles a year. Compliance is also delayed until 2023 for what the ARB calls "specialty agricultural vehicles," including cotton module movers, water trucks, livestock feed trucks, trucks that exclusively supply agricultural aircraft, and lettuce harvest trucks with self-loading beds. These specialty vehicles do not have mileage limitations but they must be used for these specific purposes.

Trucks qualified for the agricultural provisions must also display an "AG" marking on both doors.

"The idea is for everyone, by 2023, to be driving 2010 engines in California," Cory said.

That goes for non-agricultural trucks as well, she said, adding that the rule changes adopted last December provide additional flexibility for owners of trucks that cannot meet the agricultural provisions to comply. The ARB said the amendments would "reduce overall compliance costs by about 60 percent as California recovers from the recession."

According to the ARB, the amendments exempt about 150,000 lighter trucks from having to retrofit with particulate filters and delay the initial compliance date for retrofitting heavier trucks, allowing them to operate another eight years before being required to meet 2010 emissions standards.

Farm Bureau's Cory said the changes to the overall truck rule could be useful for farmers, ranchers and agricultural business owners whose trucks might not meet the mileage limits for agricultural trucks.

"Before, most (owners of agricultural trucks) couldn't even use it," she said, "but now I'm hoping with that new flexibility, if the ag rule doesn't work for them that maybe the other part of the truck rule will."

Full information about the diesel truck rules may be found on the ARB website at

Meanwhile, the board has begun contacting owners of agricultural trucks who registered their vehicles with the ARB last year. Letters from the ARB to those truck owners were due to begin arriving as early as last week, Cory said. These letters will confirm that ARB received the information previously sent and ask for clarification if there were any uncertainties, she said.

By March 31, the ARB said, agricultural fleets "must report information about qualifying vehicles including odometer readings from Jan. 1, 2011." Paper reporting forms may be downloaded from the ARB website and an online reporting system has been established at

"With ag, you have to report because (agricultural trucks) have low-mileage provisions and they have to verify that you're staying under the mileage," Cory said. "Every year on Jan. 1, after you get up after your New Year's celebration, ARB would like you to go out that morning and read your odometer on your trucks, because it's supposed to be a Jan. 1 odometer reading for the ag mileage."

In future years, the March 31 reporting date will move up to Jan. 31.

The ARB has also created new compliance rules for logging trucks, requiring owners to begin reporting by January 2012 and to phase in use of 2010 engines beginning in 2014. Logging trucks must also display the "AG" label on both doors.

In addition, the board established provisions for diesel trucks operated exclusively in regions of the state that have attained air standards for nitrogen oxide. In these so-called NOx exempt areas, located in northern and coastal counties, implementation of the regulations has been delayed until 2014 and all engines must have particulate filters by 2016.

"And you have to put an NE sticker on the truck or you have to have a GPS unit, so they can prove you're not going out of that NOx exempt area," Cory said.

Earlier this month, the ARB began conducting training workshops to help owners of agricultural trucks comply with the diesel truck rules. The workshops continue through early March at sites around California. A full list of locations, dates and times may be found at

(Dave Kranz is editor of Ag Alert. He may be contacted at

Permission for use is granted, however, credit must be made to the California Farm Bureau Federation when reprinting this item.

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