Exhausted by Diesel
How America's Dependence on Diesel Engines Threatens Our Health
MINIMAL REGULATION OF DIESEL EXHAUST
'Hands-Off' Federal Treatment
While U.S. EPA has regulated the content of diesel fuel and has attempted to require diesel manufacturers to lower emissions from those engines, it has taken a "hands-off" policy toward forcing engine manufacturers to produce engines that run on cleaner fuels. Instead, each of U.S. EPA's federal rule makings has required the industry to push technology further to clean up diesel engines -- while not mandating standards that would require a transition to alternative fuels.
An expeditious transition to alternative fuels is exactly what is needed to achieve national air quality goals. New heavy-duty engine standards, which were adopted by U.S. EPA in 1997 for implementation in 2004, reflect U.S. EPA's willingness to prolong the use of diesel engines. These standards are nearly 40 percent more stringent than the levels being achieved by diesel engines today for NOx, but fail to require reduction of particulates. Diesel engines may have difficulty in meeting the 2004 standards but heavy-duty natural gas engines available today are already being certified at levels better than 2004 standards. U.S. EPA can and must do more to move heavy-duty transportation away from the current dependency on diesel. Their failure to address particulate emissions from diesel engines is especially troubling given the ample evidence that particulates are a major health threat.
Similarly, U.S. EPA must push other major sources of diesel exhaust such as construction and farm equipment to use alternative fuels. Currently proposed standards only moderately reduce emissions from these sources and certainly do not promise increased use of alternative-fuel technologies.
Federal Clean Fuel Fleet Program Unlikely to Realize Full Potential
U.S. EPA's Clean Fuel Fleet program was implemented as part of the 1990 Clean Air Act Amendments.102 The program applies to 22 metropolitan areas in non-attainment of the federal ozone or carbon monoxide air quality standards. The program requires the affected regions to mandate the purchase of clean-fuel fleet vehicles by public and private fleet owners operating more than ten vehicles which are centrally-fueled or have that fueling potential. Beginning with the model year 1999, 30 percent of all new purchases by fleets subject to this program are required to be clean-fuel vehicles. For the model year 2000, this clean fuel vehicle purchasing requirement increases to 50 percent, and to 70 percent for model year 2001.
Since 1993, though, the U.S. EPA has been backpedaling on this program, each year further weakening its provisions. First, in 1994, the U.S. EPA weakened the heavy-duty vehicle emission standard in order to accommodate diesel technology. The 1990 Clean Air Act Amendments established a Heavy-Duty Clean Fuel Vehicle Low-Emission Vehicle (combined nonmethane hydrocarbon (NMHC) plus NO) standard of 3.15 grams per brake horsepower-hour (g/Bhp-hr) to be implemented in the 1998 model year. In 1994, the U.S. EPA weakened this standard to 3.8 g/Bhp-hr because it determined that the "emission standard of 3.15 g/Bhp-hr is infeasible for clean diesel-fueled engines..." This weakening of the standard to further continued diesel use runs counter to the basic premise of the entire clean fuel program -- to push the market toward clean fuel technologies. Indeed, several heavy-duty natural gas engines are currently certified below the more stringent standard.
Second, the U.S. EPA has allowed regions covered by the Clean Fuel Fleet program to "opt out" if they can demonstrate equivalent emission reductions through another program. Sixteen of twenty two regions have done just that. Again, this "opt out" allowance defeats the purpose of the program, which goes well beyond achieving equivalent emission reductions in the twenty two non-attainment regions. The Clean Fuel Fleet program provides an essential opportunity to push cleaner vehicle technology for the entire country. If implemented effectively, the program could take a major step toward commercializing and demonstrating on a large scale the viability of clean fuel technologies. The slight "nudge" generated by implementing this program in the six regions which remain in the program simply doesn't sufficiently advance cleaner vehicle technologies. And third, in another blow to the program, the U.S. EPA has delayed even the weakened standard so that it will first apply to the 1999 model year.
Table 2: Dirty Cities -- Some Opt Out of Clean Fuel Fleet Program
NON ATTAINMENT AREAS STILL IN THE
CLEAN FUEL FLEET PROGRAM
|NON ATTAINMENT AREAS WHICH HAVE OPTED OUT OF THE CLEAN FUEL FLEET PROGRAM|
California Also Unwilling to Push
Unfortunately, the California Air Resources Board (CARB), which has a reputation for pushing cleaner technologies, has been unwilling to go further than the U.S. EPA in moving the heavy-duty diesel truck and equipment industry to cleaner alternatives. This is especially surprising in light of the fact that California needs every ounce of emission reductions which can be identified to achieve health-based air quality standards.
In 1983, the California Legislature enacted A.B. 1807, the Toxic Air Contaminants Hot Spots Law.103 Under this law, the CARB must determine which substances are "air pollutant[s] which may cause or contribute to an increase in mortality or an increase in serious illness, or which may pose a present or potential hazard to human health".104 There are a series of exposure and health effects-related criteria which must be satisfied before a substance can be declared a Toxic Air Contaminant (TAC). The process involves a careful review of the available science, public review and comment, and review by an independent panel of scientists. Once a substance is identified as a TAC, the CARB must evaluate the degree of risk and determine whether reductions in exposure are necessary. If such a determination is made, then exposure must be reduced to the lowest level achievable through the best available control technology.
Diesel exhaust entered the TAC designation process in 1989, and has undergone three draft review reports, three public comment periods, and five public workshops or scientific conferences.105 Due to vigorous opposition from the trucking industry and the engine manufacturers, the process has been extensively delayed. At long last, diesel exhaust is nearing the end of the arduous process. The State of California's Scientific Review Panel unanimously endorsed the listing of diesel exhaust as a TAC on April 22, 1998. The Scientific Review Panel's unanimous decision could have national implications as the U.S. EPA pushes ahead with its own draft report. The listing will be finalized by the CARB early this summer. Listing as a TAC will only begin the long process of actually controlling diesel emissions under California law.
Focus #4: Proposition 65 - The People's Own Protection
On November 4, 1986, by a two to one margin, California voters approved the "Safe Drinking Water and Toxic Enforcement Act of 1986," more commonly known as Proposition 65. Proposition 65 is founded on two essential principles of good public health. First, the public has a right to know if they are being exposed to dangerous chemicals so they can take action to protect themselves. Second, once a chemical is identified as particularly dangerous, the burden to prove that a particular exposure is insignificant is shifted to the polluter.
The provisions of Proposition 65 are remarkably simple. The law prohibits the discharge of any chemical that is a carcinogen or reproductive toxicant into sources of drinking water except in amounts that the discharger can prove are insignificant.106 Furthermore, Proposition 65 prohibits exposing any person to carcinogens or reproductive toxicants without prior warning unless the polluter can show that the exposure poses no significant risk103
In order to be subject to Proposition 65, chemicals must first be listed by the Governor as "known to cause cancer" or reproductive harm. In recent years, the Governor has come under intense criticism from public health advocates for unjustifiably delaying listing of numerous reproductive toxicant and carcinogenic chemicals under Proposition 65.108
Under California regulations, a chemical poses a "significant risk" of cancer if it poses a risk of more than one additional cancer case out of 100,000 people exposed over their lifetime.109 To determine a "no significant risk level" for reproductive toxicants it is necessary to first identify the highest dose that does not appear to cause adverse reproductive effects in animal studies, and then divide that dose by a safety factor of one thousand.110 The Governor of California listed diesel exhaust as known to cause cancer in 1990.111 According to NRDC's monitoring, numerous Californians are being exposed to diesel exhaust by individual, identifiable companies at levels that are 10-100 fold higher than the level that would require warnings under Proposition 65. Yet, contrary to the law, these people are not being warned and do not know that they are being subjected to excessive cancer risks. NRDC, the Coalition, and the Environmental Law Foundation intend to target four of the worst diesel offenders in California -- and nationwide -- by filing the first in a series of lawsuits under Proposition 65 concurrently with release of this report.
103. For example, see Joel Thomas Boer and Dr. James L. Sadd, "In Whose Back Yard?" The Demographics of Populations Proximate to Hazardous Waste Facilities in Los Angeles County," 5 Environmental Law News 1, 14 (Spring 1996), finding that people of color are twice as likely as "Anglos" to live in a census tract within one mile of a large capacity hazardous wasted transfer, storage or disposal facility in Los Angeles County.
107. For more specific information, see the U.S. Department of Energy's Heavy Vehicle and Engine Resource Guide, available from the U.S. Department of Energy at 800.423.1DOE or their Website at www.afdc.doe.gov.
108. Memo from Caterpillar Inc. to Mr. Robert Shepherd, Power Systems Associates, dated March 3, 1997, states that a 1000 hour duel fuel durability test found that fuel consumption was 86.9% natural gas and 13.1% diesel.
109. "Grocery Chain Puts LNG Tractors on California Road", Alternative Fuels in Trucking, August 1997, Volume 6, Issue 1, Page 3; Raley's LNG Truck Fleet Start-Up Experience, National Renewable Energy Laboratory, DOE [hereinafter referred to as "NREL report on Raley's"].
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