Why California Does Not Need CARB's Off-Road Rule Last Monday the California Air Resources Board (CARB) very quietly admitted that it had been wrong about off-road diesel emissions. There will likely be revisions to the In-Use Off-Road Diesel rule (and perhaps some other diesel rules) at the board meeting in December, but don’t expect any apologies. It’s . . . complicated . . . when a government agency chokes one of its constituents’ most productive industries (in this case one state’s construction industry, mired in depression) with $13 billion in compliance costs and then your own data confirms the revelation that the regulation is based on wildly inaccurate assumptions. Kudos to the CARB for reevaluating its diesel emissions regulations. What comes next may well return the costs of managing most U.S. fleets to imaginable levels into the 2020s. Thank the Associated General Contractors for holding CARB’s feet to the fire. It’s a long story. Geography, meteorology, population and prosperity created uniquely horrible air-quality problems in California decades ago. Rightly motivated to protect the health of citizens, state government has done a lot of things (some good, some not so good), including declaring diesel exhaust a potential threat to human health. CARB studied diesel engines at work in California, estimated the population of machines, how much they work, how hard, and projected how much the statewide fleet should grow in the first quarter of the 21st Century. Those estimates were used to estimate how much pollution the fleet will emit and that was compared to acceptable concentrations of diesel pollutants in the air. Based on these projections, CARB created a series of regulations on the existing fleet of diesel equipment (observing the steps for fair regulation) designed to reduce their contribution to air pollution. It’s important to note that there would be little hope for relief from CARB’s In-Use Off-Road Diesel rule if not for one of the first provisions of the rule itself. It required fleet owners to report fleet information including total number of vehicles, vehicle types, horsepower and model year. Initial reporting was completed mid-2009. AGC extracted the fleet data through a Freedom of Information Act request and employed Sierra Research to analyze it. They presented the startling results last December to CARB and the public. CARB staff created a mathematical model to project emissions of California’s off-road diesel fleet. The off-road rule’s specific demands – exhaust retrofits, engine repowers, machine replacements – were devised to reduce projected emissions to levels that satisfy the state implementation plan for improving California’s air quality. The AGC analysis simply substituted 2009 fleet size and distributions of engine ages and horsepower into the model. The results suggest that the state construction industry, and the off-road diesel fleet, had changed dramatically in ways regulators didn’t anticipate. For example, CARB’s original estimate overstated the levels of nitrogen oxide(NOx) and particulate matter (PM) emissions from the state's off-road diesel engines in 2009 by close to 40%. The rule was written to force off-road diesel equipment operators to reduce NOx emissions by 5,200 tons in 2010 and 182,000 tons by 2025. AGC’s analysis of the new inventory data, however, suggests off-road diesel equipment will be 58,400 tons below the state's target levels for NOx in 2010 and 173,000 tons below the state's target by 2025. CARB also expected equipment operators to reduce PM emissions by 910 tons in 2010 and 29,530 tons by 2025. Recalculating based on the actual equipment inventory, however, the California fleet will be 2,480 tons below PM targets in 2010 and will stay below target levels into 2015. CARB, of course, conducted its own analysis of the new inventory data. The pleasant surprise is that the agency’s findings estimated emissions levels very similar to those advanced by AGC. Slide 40 in a 75-slide CARB presentation being shared at workshops in California shows that CARB initially estimated California’s construction and mining fleet (a segment that operates 80% of the state’s off-road diesels) 32% larger than 2009’s reality. CARB overestimated the size of what it calls the “industrial” fleet (17% of all off-road diesels) by 20%. The 2009 DOORS program also found the state’s off-road fleet is significantly newer than originally estimated. The 2009 data also indicated that CARB originally missed estimated hours worked per year by up to 79%, depending on machine type. Original load factors were 25% to 50% too high, and CARB staff reduced load factors by 33% for this year’s inventory update. “CARB’s new emissions inventory agrees that the emissions from regulated fleets of off-road equipment in California will be lower than the levels that CARB originally sought to achieve for at least the next five years,” says Mike Kennedy, chief counsel for AGC. “The fleet will be below the NOx targets forever, or through the last forecast that CARB makes; PM through 2015. And CARB has plenty of time to figure out how to regulate PM before then to meet their goals.” Upshot of this revelation thus far has been underwhelming. CARB staff revised the agenda of public workshops currently being held to focus on taking comment on the inventory change and suggestions for modifying California’s diesel regulations. AGC, however, is not going to be satisfied with tinkering. “AGC believes the only prudent course of action at this point is to repeal the (In-Use Off-Road Diesel) rule in its entirety and start over again,” says Kennedy. “The results are quite clear. We’re not talking about a minor mid-course correction. What’s needed is a major realignment of how the state regulates off-road diesel equipment. “The good news is that thousands of construction workers won’t have to lose their jobs on account of bad science and erroneous estimates,” says Kennedy. “The construction industry is now eager to work with the board to find ways to meet ambitious environmental goals and still protect the state’s remaining construction jobs.” And the better news is that California air-quality regulations wield unique influence over air-quality regulations appearing with increasing frequency all over the country. States whose air does not meet the Environmental Protection Agency’s (EPA) minimum standards for quality, called non-attainment areas, can adopt CARB regulations. Municipal diesel-emissions rules, often necessary in major population centers as part of state clean-air plans, are less-directly influenced by events in California. But everybody is watching what CARB does. Inevitably, CARB will lighten the regulatory load for California construction equipment owners. How much has yet to be determined, but the trend should ripple out to regulated areas in other states. One important lesson of the CARB exercise will be that when rule makers set up an off-road-diesel inventory-reporting system, cooperate. It might supply information that moderates their regulatory fervor.