On December 17, 2010, the California Air Resources Board (CARB) amended an earlier regulation to reduce diesel engine emissions in off-road vehicles. The original rule, adopted in July 2007, targeted both particulate matter (PM) and oxides of nitrogen (NOx). It called for equipment owners to disclose and label their diesel-powered equipment in preparation to meet new emission targets, the first of which was to kick in on March 2010. Nearly three years later, on February 11, less than a month before the first compliance dates were to be met, CARB issued a delay.
“The rule, which didn’t go into effect until 2008, was an effort by CARB to clean up existing products being operated within the state,” says engine consultant John Fischer. “In particular, diesel engines last a long time and current (older) ones would generate more pollutants than newer (Interim Tier 4 and finally ‘full’ Tier 4) ones. The original rule promoted the retrofitting of emissions reduction devices as well as turning over of the fleet, what CARB refers to a ‘fleet modernization.’
“Fitting with a Diesel Particulate Filter (DPF) can be done on older engines to reduce particulates. NOx reduction, however, is not easily retrofitted, but can be accomplished by trading up to a new machine with an engine that generates lower levels of NOx.”
The actual compliance date depended on the size of the diesel-powered fleet. The March 2010 date applied to CARB’s definition of large fleets, those with a total fleet horsepower in excess of 5,000. Contractors and rental companies with a total fleet horsepower of 2,501 to 5,000 had until the beginning of 2013 and smaller operators had until 2015 to meet new emission standards. Similar rules applied to diesel-powered on-road vehicles and portable power equipment.
Caught off guard
Large and medium fleets were required to meet both new PM and NOx targets whereas smaller operators were required to meet PM targets only. CARB gave this rationale for the less stringent, small-fleet requirements, including the later compliance date: Small fleet operators would likely find understanding and financing the new regulations more difficult than their bigger counterparts, and their large number (contractors with only a few pieces of equipment) would create enforcement challenges early on.
Again, rental companies with large diesel off-road fleets originally had until March 2010 to meet compliance PM and NOx target rates. As Fischer pointed out, they could do that in any of several different ways by applying exhaust retrofits; repowering equipment with new engines or rebuilding the old engines; and accelerating fleet turnover.
“The rule caught us completely off guard,” relates Tyler Hardy, general manager of product support for Livermore, California-based Cresco Equipment Rentals. “Up to that point, meeting emissions standards had been the responsibility of OEM’s, The new rule changed that, and gave all of us in the rental business something new to think about.”
Indeed, with 19 store locations and an off-road diesel fleet average well over 100,000-hp, Cresco had its share of homework to do, starting with meeting the reporting, labeling, and disclosure rule requirements. “We had to get data on and track every piece of diesel equipment in our fleet,” recalls Hardy. “We hired an individual to do just that, a job that took up probably 60 percent of his time.”
In addition to recording engine serial numbers and emission families on spread sheets, for most of its diesel-powered off-road equipment the company had to document equipment and submit relevant information to CARB’s Web Site In return, equipment was issued an EIN number and decal to be placed on the left side of the equipment. Diesel-powered portable equipment and on-road equipment also had to be recorded and tracked.