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HomeMy WebLinkAboutClosing the Stationary Diesel Engine Loophole , ,.. CHAPTER 4, Closing the Stationary Diesel Engine Loophole Under national air quality policy, there is a narrow legal thread that divides those engines classified as "nonroad" mobile pollution sources and those categorized as "stationary " pollution sources~ In short, the legal distinction hinges on the residence time of the engine. An engine that is moved from site to site more than one time a year is deemed mobile and therefore regulated under the federal program for nonroad engines.1 This means that a diesel generator on wheels that is relocated more than once a year is classified as a nonroad mobile engine4 But if a similar diesel generator remains in place at an industrial site for more than 12 consecutive months it is categorized as a stationary engine. These two generators are categorized differently for legal purposes even though the engines themselves are largely the same, as are the airborne contaminants discharged, the fuel used, and the available technology solutions to control their exhaust. The consequences of these legal delineations are momentous. The federal government is directed by the Clean Air Act to control air pollutants from mobile nonroad engines. Because the federal government has primary jurisdiction to establish emission standards for the pollution sources deemed mobile, disparate state emission standards for nonroad engines are generally preempted. In contrast, both EPA and the states have broad concurrent authority to control pollution discharged from stationary diesel generators or other stationary engines. But EPA's pollution control program for stationary sources tends to focus on large, centralized pollution sources such as refineriest smelterst pulp and paper mills and power plants. EPA therefore devotes few resources to smaller, more-dispersed engines that collectively have serious air pollution impacts. In practice, EPA has never established air quality standards for stationary diesel- powered engines. Z While federal emission standards for nonroad diesel engines lag behind their onroad counterparts, the same stationary diesel engines have been overlooked altogether. EPA recently explained the legalistic distinction between "nonroad7t and "stationary" engines: Stationary engines are used in many applications where they can be installed in a fixed location, such as power generators or irrigation pumps. Nonroad (mobile) applications include these same types of equipment if they are made to be portable (or transportable). For example, a generator mounted on a pallet or a trailer would generally not be considered stationary. 3 There is increasing urgency to address this divide that allows stationary diesel generators and other stationary diesel engines to elude any meaningful emission standards. Stationary diesel engines have long been used in a variety of applications including agricultural use, and oil and gas extraction. Oil and gas activities have recently exploded in places like the Rocky Mountain West., contributing to rising air pollution levels. Likewise., the increasing reliat)ce on distributed generation sQurces (see box on next page) to meet new electricity demand is expanding the use of high-polluting diesel generators. Diesel 36 t \ ~ generators also are a predominant source of back-up power. The California Energy Commission estimates that diesel alone provides more than 90 percent of large backup electric generating power in California. 4 Curbing the Harmful Pollution from Sm~ll-Scale Electric Generators Economic forces, and deregulation ,in, the, energy ..market ,have led to " growth in~maller, , more dispersed- sources of electrical power, commonly referred. ' to as "distribtited" generation. Distributed generation often' serves niche market needs and includes small.wind'generators, fuel ,cells"small ,turbines, gas-frred , . . - combined cycle power generators, and diesel-powered 'internal combustion engines., Unlikeconventlonal power stations, Which are large and centralized, - .. - distributed generation sources tend to be 'smaller and, are, scattered across- metropolitan areas. Distributed 'generation ,',' sources may, serve important local needs" in providing '~reliable,affordable,andsecureenergysource. But, the ,'very attributes that give tl1emanimble~niche -role in the energy market also 'have allowed themlo eludemeaningful-air-qualitystandards.Few, states or localities regulate air pollution JromtheSe s01.lrces.Even though these sources_are smaller in ,scale, diesel electric generators arid other distributed generation sourcescan-b()thindivid~aIIy ',andcQllectively' have serious air pollution :-andpublic_health impacts'- Di~l generatotsare the most. harmfuIcategoryof distributed _generation, producing levels "of particulatesand.smog-forming"contaminants manytiniesgreaterthall other. distributed generation sources. 5 Such diesel generators ",may ,be located,near','homes,:businesses" schoolstand other population centers. Environmental. DefenserecentIy . conducted all extensive risk 'ass~ssment offia(::kupdiesel, gen'eratorsin theS~ ,Diego, San Joaquin, Sacramento, ,,'and Los: Angeles areas ,",~d.".foundthat.', over 150,000 school children attend schools in high-risk zones. 6 Closing the Diesel Divide EPA is on the right track in developing new emission standards and fuel content requirements to curb the airborne contaminants from high-polluting diesel nonroad engines. But EPA needs to ensure the same clean air program is applied to the stationary diesel engines that have altogether eluded comprehensive air pollution abatement requirements. In California alone, one of the few states with a reliable inventory, there are more than 16,000 stationary diesel engines including both emergency backup generators and prime engines.1 Unlike backup generators, which typically operate on a limited basis, primary engines run on a regular basis to supplement or substitute energy from the power grid. These stationary diesel engines have a pollution potency many times that of other engines. A typical diesel generator discharges more than 10 times the particulate-related pollution of a gas-powered internal combustion engine.8 So 16.000 diesel generators release as much harmful particulate pollution as more 37 ( ..It than 160,000 other conventionally-powered generators" Because diesel particulates are one of the most dangerous airborne contaminants, closing the regulatory loophole for stationary diesel engines is a public health imperative. The process to clean up diesel generators can begin now. Several states have begun tackling the pressing air pollution problem associated with diesel generators. In 2001, Texas established the nation's first statewide emission standards for new small-scale generators. 9 In east Texas, which contains the most polluted areas of the state, the emission standards for distributed generating facilities are essentially based on micro-turbine technology..lO The standards in west Texas assume that high usage small-scale generators are powered by natural gas.11 As part of its statewide Diesel Risk Reduction Program, the California Air Resources Board is developing emission standards for stationary diesel engines more far-reaching than those adopted in Texas. The proposed California standards would establish particulate and NOx emission limits on new and existing diesel generators used in both prime and emergency backup applications.12 Importantly, the draft California rules would go beyond the Texas program by establishing standards for stationary diesel engines currently operating. The policy transition to cleaner stationary diesel engines should be smooth. Air pollution control technologies can be transferred from nonroad mobile engines to stationary engines. Stationary engines should be even easier and less costly to control than nonroad equipment which is mobile and operated under a variety of conditions. There are also important policy parallels. Indeed, an effective pollution abatement program for new stationary diesel engines must have some of the same core attributes asa well-designed program for new nonroad mobile engines~ These include rigorous particulate and NOx emission standards, complementary low sulfur fuel standards, procedures to certify that new engines in fact meet the emission standards, and effective in-use testing to ensure that durable pollution cuts are achieved in practice. 13 There are also material differences. Due to their different regulatory classifications, stationary source pollution control programs may establish emission standards for existing engines and equipment. Given the enormous public health gains to be made, states and the federal government should follow California's lead and put in place rigorous emission standards for existing stationary diesel engines. This will ensure the important work to close the stationary engine diesel loophole is comprehensive and, most importantly, will help secure cleaner) healthier air in the near-term. 38 l .\,. 1 EPA's definit.ion of "nonroad engine" is codified at 40 CFR 89.2 and was adopted on June 17,1994 after an extensive rulemaking process. 59 Fed. Reg. 31,306 (June 17. 1994). EPA's definition interprets several provisions ~f the federal Clean Air Act including the definition of "stationary source" in section 302fz), the definition of non road eng ine" in section 216( 1 al. the definition of .. nonroad veh ide" j n section 216{ 11 J. and the definition of "stationary source" in section 111 (aH31 of the Act. Z Under a court-ordered schedule EPA for the first time recently proposed emission standards for reciprocating internal combustion engines including diesel-powered engines. But these standards only apply to large stationary engines co-located with other large pollution soun;es, thereby excluding vast numbers of engines. In addition. EPA's proposed standards do not limit particulate matter or smog-forming nitrogen oxides, two key harmful contaminants. 67 Fed. Reg. 77,829 (December 19.2002). 3 U,S. Environmental Protection Agency, .'Emission Regulations for Stationary and Mobile Engines:. EPA 420-F-034 {Sept. 20021 1-2. 4 California Energy Commission. BUGS 1: Database of Public Back-up Generators [BUGS} in California. {Aug. 15. 2001 J. 5 Jim Lents and Juliann Emmons Allison. "Can We Have OUf Cake and Eat it Too? Creating Distributed Geheration Technology to Improve Air Quality" {Energy Foundation, Dec. 1. 2000113-18- 6 Nancy Ryan. Kate Lan~en, and Peter Black, "Smaller, Closer, Dirtier: Diesel Backup Generators in California" (New York: Environmental Defense, 20021. Available online at http :/Iwww. environmentaldefense.org/documents/2272_BUGsreport. pdf 7 California Air Resources Board, "Risk Reduction Plan to Reduce Particulate Matter Emissions from Diesel-Fue\ed Engines and Vehicles:' Oct. 2000, app. 2. p. 17. Available on-line at http://www.arb.ca.gov/dieseVdocuments/rrpapp2.PDF. 8 Lents & Emmons Allison, note 5, supra, 13-18. 9 Texas Natl,Jral Resources Conservation Commission (since renamed), "Air Quality Standard Permit for Electric Generating Units" {adopted May 23, 20D1}. establishes emission standards for units 10 MW or less. Texas explained the need for the standards: "The Public Utility Commission (PUe) of Texas anticipates that small electric generating units {EGUs) may become an attractive option for electric customers as an alternative to central station generating units as a primary source of electricity due to electric restructuring and electric reliability concerns." Ibid. at p. 3. 10 "The initial East Texas standards. . . recogniz[e] the unique ozone problems in East Texas and should allow for authorization of fuel cells, micro turbines, clean turbines using catalytic combustors or flue gas cleanup, and the very cleanest reciprocating engines using catalytic converters." Texas Air Quality Standard Permit for Electric Generating Units at p. 5_ 11 "The West Texas standards, . . should allow for clean reciprocating engines to register under the standard permit, as well as clean diesel engines operating as peaking units'. defined as units that operate less than 300 hours a year. Texas Air Quality Standard Permit for Electric Generating Units at p, 5 & 18. 12 California Air ResQurces Board, "Proposed Airborne Toxic Control Measure To Reduce Diesel Particulate Matter Emissions from In-Use Stationary Diesel-Fueled CI Engines Greater than 50 Horsepower and To Reduce Diesel Particulate Matter Emissions from New Stationary Diesel-Fueled CI Engines" {November 2002 discussion draftsL 13 Lents & Emmons Allison, note 5. supra. 23-29. 39 " -~ " <.:0. TABLE 2 Toxic Air Contaminants and Hazardous Air Pollutants in Diesel Exhaust Acetaldehyde* Chlorine MethyL ethyl ketone Acrolein Chlorobenzene Naphthatene* \ ALuminum Chromium compounds* Nickel* Ammonia Cobalt compounds* 4-nitrobiphenyl* Aniline* Copper Phenol Antimony compounds* C reso l Phosphorus Arsenic* Cyanide compounds POM (including PAHsl Barium Dibenzofuran Pr~pionaldehyde Benzene* Oibutylphthalate Selenium compounds* Beryllium compounds* Ethyl benzene Silver Biphenyl Formaldehyde* Styrene* Bis [2-ethylhexyl]phthalate* H exa ne Sulfuric acid Bromine Lead compounds* Toluene* 1,3-butadiene* Manganese co~pounds Xylene isomers and mixtures Cadmium* Mercury compounds* Zinc Chlorinated dioxins* Methanol *This compound or class of compounds is known by the State of California to cause cancer or reproductive toxicity. See California EPA, Office of Environmental Health Hazard Assessment, "Chemicals Known to the State to Cause Cancer or Reproductive Toxicity:' May 31,2002. Note: Toxic air contaminants on this list either have been identified in diesel exhaust or are presumed to be in the exhaust, based on observed chemical reactions or presence in the fuel or oiL See California Air Resources Board, "Toxic Air Contaminant Identification List Summaries. Diesel Exhaust," September 1997. available online at http://www.arb.ca'9ov/toxics!tac!factphts/diesex.pdt. Health Effects Specific to Diesel Exhaust The major pollutants that make up diesel exhaust each pose threats to public health and the environment~ In addition, a growing body of research on the hazards of diesel exhaust shows that this particular combination of pollutants causes significant cancer risk and both acute and chronic health problems.. Cancer risk Numerous governmental agencies and scientific bodies have concluded that diesel exhaust is a probable human carcinogen (Table 3)" The first major study to investigate the contribution of diesel exhaust to people's exposures to toxic air pollutants was the Multiple Air Toxies Exposure Study (MATES-II), conducted by California's South Coast Air Quality Management District in 1998 and 1999 and one of the most comprehensive urban air toxies studies ever undertaken. The results were alarming: 70 percent of the cancer risk from air pollution for those living in the Los Angeles air basin (one of the most polluted in the country) was due to diesel particulate emissions~ 5 19