CARB Demands Exhaust Update of On-Road Diesels

By Larry Stewart, Executive Editor | September 28, 2010
 2009 Volvo VHD104B dump truck

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Trucks with engines certified to EPA 2007 or later emissions standards could be compliant until 2021, and they are likely to be gradually more expensive in California over the coming years.
 Cleaire Longview DPF installed on Cat C12-powered Freightliner

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Cleaire's Longview DPF is the only on-road VDECS currently verified to reduce NOx. But its 25 percent reduction falls far short of bringing engines into parity with 2010-certified emissions.

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Electric vehicles like this 16,500-pound GVW Smith Newton bucket truck for PG&E can dramatically lower fleet emissions averages. Smith will produce vehicles up to 16,500 pounds GVW in the United States in 2010.
Eaton Hybrid Electric drive train 

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Peterbilt, Kenworth, Freightliner, and International offer the Eaton Hybrid-Electric drive train for trucks up to 40,000 pounds GVW. If the hybrid's fuel economy is at least 20 percent better than a conventional vehicle, the number of hybrids in the fleet are double counted when calculating PM and NOx indices and targets for BACT Percent Limits and Fleet Averaging.


Tenth In A Series

California contractors, mired in the initial compliance with the Air Resources Board's In-Use Off-Road Diesel Emissions Regulation, are paying scant attention to the sister rule regulating in-use on-road diesel emissions. The off-road rule's shifting requirements have demanded some strategy adjustments and the on-road rule, known as the statewide truck and bus rule or, officially, the Diesel Particulate Matter and Oxides of Nitrogen and Greenhouse Gases Control Measure for On-Road Heavy-Duty Diesel-Fueled Vehicles, appears to be no less time consuming.

"I've been up to my ears in the off-road regulation for six years, and frankly, I'm not nearly as up to speed on the on-road reg.," says Michael Shaw with Perry & Shaw, an El Cajon contractor that fields about 60 diesel machines. (Visit Construction Equipment's online emissions-management resource.) "I lost any personal interest I had in trying to keep up with the on-road regulation when I spent countless hours and resources following the off-road regulation through its workshops and public comment to completion, only to have it continue to be a moving target. I just have no faith in the process.

"I'm going to try to stay informed as to what the requirements of the on-road regulation are," he adds. "And when I decide CARB [the California Air Resources Board] thinks they know what they're doing, then I'll get serious about what we have to do to comply."

The in-use diesel truck regulation requires engine upgrades or replacements to trucks of 14,000 pounds gross vehicle weight (GVW) or heavier, so that by 2023 all of California's trucks will have emissions equivalent to 2010-model-year engines or better. The first performance deadline, requiring particulate matter (PM) filters on some engines on Jan. 1, 2011, is followed by engine or truck replacement requirements to reduce emissions of oxides of nitrogen (NOx) starting the first of January 2013. Fleets with three or fewer affected vehicles don't begin to meet performance requirements until 2015.

Potential for the on-road diesel regulation's finer points to shift, combined with the dearth of retrofit technologies available to bring existing trucks into compliance, has many contractors in the wait-and-see mode. Of course, a lack of cash to spend on trucks is discouraging investments as well.

But inaction will likely inflate compliance cost. Scant early-action incentives in the on-road measure expire by 2010. And while the cynical sit on the sidelines, the proactive are likely driving up prices for one key option — trucks with 2007-certified engines.

In general, the regulation requires truck owners to reduce fleet emissions each year for the next 12 years following one of three possible plans. The first is to install best-available control technologies (BACT) in the form of verified diesel emissions control strategies (VDECS) — which to this point are primarily diesel particulate filters (DPFs) — and replace either vehicles or engines or retrofit them to match 2010-model-year engines' emissions on a prescribed schedule. The second option is like the first in that it requires engines to be retrofit with BACTs and/or replaced, but instead of scheduling specific ranges of engine model years to be upgraded each year, it directs that certain percentages of the total fleet be upgraded each year. The third option is to meet CARB's gradually declining fleet-average emissions targets for PM and NOx. The three routes each reach the same place on or about 2023, having reduced California truck and bus fleets' emissions until the average matches the exhaust profile of a 2010-model-year, EPA-certified on-road diesel.

You don't have to declare which compliance option you intend to use, or stick with any one compliance option from year to year. Once the requirement of any one compliance option is met for PM, and any one option is met for NOx, the fleet is in compliance. A fleet calculator spreadsheet is available on the CARB website at to help evaluate different choices. The calculator determines when any of the three options are satisfied for either pollutant; and it accounts for vehicles that qualify for credits, delays and other provisions. It does not, however, help much with comparing compliance costs.

"We developed a compliance planning tool in-house that takes all three compliance options [considering the data you input] and compares and contrasts them," says Charlie Cox, with emissions-retrofit dealer, IRONMAN Parts, in Corona, Calif. "So you can see which one is going to make you spend the most money and when it's going to make you spend it. One [option] may look good for the first three years and then slaps you with a big purchase demand on the fourth year.

"The more fleets that I run through this thing, the more obvious it is that the purchase preferences and fleet makeup of each fleet have everything to do with which option makes the most sense," he says. "The BACT Schedule option has its pros and cons. It's simple — harsh, but simple. You don't even have to report under that option, so life is easier. Some people want that.

"But I also have clients who say things like, 'I like my '98s — they get great fuel economy — but my '02s aren't nearly as nice. I'd rather keep my '98s.' Well, he'd better not choose the BACT Schedule option; it's going to tell him exactly when those need to be gone."

Cox is impressed at the significance of factors other than cost driving many strategies.

"If they normally turn over a lot of trucks every year — a high percentage of the fleet — then they're likely a good candidate for the BACT Schedule," Cox says. "Whereas if they turn over a very low percentage of their fleet, then the fleet averaging option is more likely a good choice.

"Other fleet managers look at the BACT percentage option and realize the expenses there tend to be more uniform than the BACT schedule (which costs like a rollercoaster — extremely low expenses to extremely high expenses from one year to the next)," he says. "Fleet average tends to be less of a rollercoaster, but there are still years with high costs and low. The BACT percentage option allows you to blend retrofits and replacements so that you have a nice, stable expenditure each year.

"If you want to keep trucks as long as humanly possible, then fleet averaging is probably more for you," Cox says. "If you want to be somewhere halfway in between, BACT percentage limits will also let you pick and choose which ones go where and when. All you have to do is meet the percentages."

How far some truck owners might go to simplify compliance has surprised Cox.

"I sat down with a P&D-fleet guy the other day who completely surprised me with his reaction to the numbers we came up with," Cox says. "He said, 'Well why don't I just go buy a boatload of '07s [trucks with engines certified to 2007-model-year emissions standards]?' He was talking about buying 225 2007s in the next year and a half.

"To me, that seemed like a crazy purchase, considering the cost. But he said, 'No I'll get a great deal on them now.'"

A fleet judiciously replaced with 2007-certified trucks could be compliant until 2021 via the BACT Schedule. But already pricey 2007-to-2009 trucks are likely to hold value, if not appreciate, in California as demand for them increases between now and 2014.

Ultimate compliance — 2010 emissions standards — is impossible at the moment, so there is no silver bullet for sale right now that guarantees a truck's indefinite place in a fleet. Trucks with 2010-certified engines will be available on Jan. 1, but buying brand-new replacements will likely be the expensive play. Volvo Trucks will add a $9,600 surcharge to vehicles that meet EPA 2010 emissions standards, and Daimler Trucks (Freightliner) will levy emissions-control surcharges from $6,700 to $9,000 per vehicle, depending on engine choice. Navistar's price increases will reach $1,600 per vehicle, which is added to an average $1,000-per-unit price hike early in 2009.

Retrofitting some trucks with VDECS will be less expensive, but these trucks will need to be replaced or fit with additional, as-yet-unverified technologies to bring them to emissions parity with 2010 engines. And today's VDECS applications are limited. Costs range from $10,000 to $30,000, but average between $15,000 and $20,000 per engine.

The best candidates for retrofitting are 1998- to 2002-model diesels because they already have some pollution-control technologies that will limit the need for regeneration and maintenance. The ideal retrofit device is a passive one, that regenerates (burns accumulated soot off the filter element) while the truck is working. The engine must run at a specified minimum temperature for at least 25 percent of its duty cycle for passive filters to be reliable. The alternatives are active VDECS, which regenerate using electric energy or diesel fuel and require that the truck be taken out of production during the process.

There are just three VDECS allowed on pre-1993 on-road diesels, and none are passive. Of the 14 VDECS capable of working with 1993 or later diesels, half are passive models. Two of those passive VDECS are not verified to work with original-equipment oxidation catalysts, which disqualifies them from use with many engines built in the late 1990s through 2007. Ten of the 14 on-road VDECS are not verified for use with engines that use exhaust-gas recirculation (EGR), which precludes them from being applied to most domestic diesels built since October 2002 (only one passive VDECS will work with EGR).

Lots of owners of pre-1994 trucks should be considering 2007-or-later models as replacements between now and 2011. It's also possible to repower older trucks or build glider kits with engines certified to 2007 emissions standards.

Replacing with 2007-certified engines can only be part of a much broader strategy if cost is to be contained, though.

"It takes a real keen understanding of the rules to try to model what's going to be the cheapest legal path to compliance," says Sean Edgar, of the consultancy Clean Fleets Coalition in Sacramento, "Because in the short term people want to minimize their outlay of capital, but in the long term CARB has a plan that by 2023 everybody's going to be using near-zero-emissions engines."

Edgar advises diesel-equipment owners in California on environmental regulatory compliance. His client list includes hundreds of dump-truck and solid-waste companies. He says the first step to lowest-cost compliance for most truck owners is to carefully inventory their engines.

"CARB's rules are all about the engine, not necessarily the year of the truck," he says. "And the year of the engine is not necessarily the same as the year of the truck. You have to absolutely have clear information about what engine model year is in your existing trucks.

"And the in-use on-road diesel rule is about diesel engines in vehicles that are greater than 14,000 pounds GVW," he adds. "That includes a lot of the smaller Class 4 and 5 equipment that is very common in construction use.

"You also have to understand the current use of the vehicle because there are some mileage-weighted thresholds," Edgar says. "Lower-use vehicles may not have to comply as quickly."

Edgar's greatest challenge to California truck owners, though, may be to thoroughly understand their owning-and-operating costs.

"People understandably do not like the idea of taking on truck or equipment payments right now, economic conditions being what they are," he says. "But I understand from working with a lot of equipment owners that they're spending significant money keeping older trucks on the road."

Neglecting to recoup all of the costs arising from owning and operating equipment — depreciation or cost of capital, for example — because of accounting practices or ownership biases gives a decision maker a false sense of a truck's economy. Failing to accurately measure fuel use or mileage can also make trucks appear much less expensive to operate than a newer replacement.

Underestimating truck costs makes it more difficult to decide which emissions-cleanup option — retrofit, repower, replacement — will be most cost effective in the long term. Worse yet, inaccurate or incomplete accounting can lead managers to retain trucks that might be effectively replaced by subcontractors, dramatically reducing the owner's exposure to regulatory liability.

Properly accounting for all equipment costs is an exercise in which all construction-equipment owners in air-quality non-attainment areas should seriously engage. Because even if your state does not adopt the CARB diesel-emissions regulations to clean up their air, chances are very good that municipal and other local agencies responsible for air quality will soon impose regulations that will force diesel owners to invest in cleaner diesels.

Visit for emissions management resources.



Scheduling BACT Retrofits

The BACT Schedule compliance option lists the compliance date, engine model years affected, and required actions. Fleets that comply with this schedule do not have any reporting requirements. In any given year, engines about seven years old or newer will always meet the requirements of this schedule. A fleet can meet the replacement requirement by replacing a vehicle with one that has a 2010-model-year engine or with one that has a later compliance date on the schedule. For example, a fleet owner with a 1994 engine could meet the Jan. 1, 2013, compliance requirements by replacing the existing truck with one that has a 2007-model-year engine originally equipped with a PM filter. According to the schedule, no further action would be required for that truck until 2021. By 2021, the truck would need to be replaced with one powered by a 2010-model-year engine or newer. In this way, a fleet could comply by purchasing used vehicles and would not need to purchase 2010-model-year engines until 2021.

BACT Schedule
Compliance Date January 1 Existing Engine Model Years Required Actions
PM Filter — Highest level verified diesel emissions control technology to reduce PM.
* By 2014 all engines must have a PM filter regardless of engine model year.
Source: California Air Resources Board
2011 Pre–1994 Install PM Filter
2012 2003 – 2004 Install PM Filter
2013 2005 – 2006 Install PM Filter
1994 – 1999 Replace Vehicle
2014* 2000 – 2002 Replace Vehicle
2015 Pre – 1994 Replace Vehicle
2016 2003 – 2004 Replace Vehicle
2017 2005 – 2006 Replace Vehicle
2018, 2019, 2020 All pre–2007 No new requirements
2021 2007 or equivalent Replace Vehicle
2022 2008 Replace Vehicle
2023 2009 Replace Vehicle

BACT Percentage Choices

Complying via BACT Percentage Limits offers truck-fleet owners flexibility to select which vehicles to upgrade first, but requires users to report fleet information annually. The table's middle column lists minimum percentages of fleet engines that need Level 3-verified particulate-matter (PM) filters. The right column holds the percentage of fleet engines matching 2010-model-year emissions standards needed to satisfy NOx BACT requirements. A fleet of four trucks, for example, could meet the 25-percent PM filter requirement in 2011 by installing a PM filter on any truck. If by then the fleet already has a 2007-model-year or newer engine originally equipped with a PM filter, that truck would meet the PM-filter requirement. In 2012, two trucks would need PM filters. By 2013, the fleet would need to replace a vehicle (25 percent of the fleet) with one having a 2010 engine, or add a retrofit to bring one truck up to 2010 standards (Note: There currently are no retrofit technologies that match 2010-model-year NOx reductions). A 2010 or later model truck would have a DPF, satisfying the 75-percent PM-filter requirement. By 2014, the fourth vehicle would need to be replaced with one having a 2010 or later engine. The fleet would be set until 2017, when one of the trucks with only an aftermarket PM filter would need to be replaced. By 2020, the fourth vehicle would need replacing.

BACT Percentage Limits
Compliance Date January 1 Percent Meeting BACT PM Filter 2010 Engine*
Source: California Air Resources Board
2011 25% N/A
2012 50% N/A
2013 75% 25%
2014 100% 50%
2015 100% 50%
2016 100% 60%
2017, 2018, 2019 100% 80%
2020, 2021, 2022 100% 90%
2023 100% 100%

The Fleet-Average Option

Fleet averaging allows a truck owner to gradually retrofit and replace engines to meet fleet-average emissions targets for PM and NOx. Targets decline so that by 2014 all engines should have PM filters, and by 2023 all trucks should have emissions equivalent to 2010-model-year engines. The NOx and PM emissions factors and targets for each engine are based on the engine model year and vehicle weight class. Applying a VDECS reduces the emissions factor by the percent reduction for which the retrofit device is verified. Fleets may comply with some engines emitting above the target if they also have enough engines below the targets that the fleet average meets the goal. Owners complying via fleet average must report fleet information annually. Hybrid vehicles earn a credit up until 2017 that double counts their very low emissions levels when calculating the PM and NOx indices and target rates. Alternate-fuel or heavy-duty pilot ignition engines are allowed to apply the NOx emission factor for the engine model year to which the engines are certified in calculating the NOx index and zero for the PM index.

Engine Emissions Factors (grams/mile)
Greater Than 33,000 lbs Less Than 33,001 lbs
Model Year* PM NOx PM NOx
* Engine model year emissions standard met
Source: California Air Resources Board
1900 3.36 22.0 1.65 14.2
1991 1.25 22.0 0.84 14.2
1994 0.81 22.0 0.43 14.2
2004 0.81 12.0 0.43 6.7
2007 0.11 7.0 0.06 4.0
2010 0.11 1.6 0.06 0.8

Fleet Emissions Targets (grams/mile)
Greater Than 33,000 lbs Less Than 33,001 lbs
Model Year* PM NOx PM NOx
Source: California Air Resources Board
2011 0.710 0.38
2012 0.530 0.29
2013 0.320 14.4 0.17 8.5
2014 0.110 9.8 0.06 5.8
2015 0.110 9.8 0.06 5.8
2016 0.110 7.8 0.06 4.6
2017 0.110 6.0 0.06 4.0
2018 0.110 6.0 0.06 4.0
2019 0.110 6.0 0.06 4.0
2020 0.110 4.4 0.06 3.2
2021 0.110 4.4 0.06 3.2
2022 0.110 3.0 0.06 1.6
2023 0.110 1.6 0.06 0.8

The Running Green Series

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A Mercenary Guide to Reducing Diesel Emissions 

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