Air pollution from diesel-powered trucks, buses and construction equipment is a major public health threat for the people of New York City, triggering thousands of asthma attacks, bronchitis, heart disease, increased cancer risks and as many as 1,800 premature deaths each year. Indeed, standing behind a city bus or diesel truck in New York City may be more dangerous than standing in front of one, as earlier NRDC advertisements on the back of New York City buses read. In 1995, diesel vehicles contributed to more than half of the particulate pollution breathed by pedestrians as they strolled along Madison Avenue, even though diesel buses and trucks were a small fraction of New York City traffic.¹

Pioneering cleaner vehicles in New York City, the New York City Council passed the nation's first alternative fuel vehicle law in 1991. Since then, the city has been a laboratory of clean fuel and clean vehicle technologies. Yet New York City has never met the federal health standard for ozone and has been listed by the U.S. Environmental Protection Agency (EPA) as a nonattainment area for particulate matter, which means that the city failed to meet another standard for clean air. And because diesel engines can last for decades, many dirty engines continue to emit large amounts of nitrogen oxides (a key component of ozone) and particulate matter in New York City's streets even today.

This paper recommends three critical measures for protecting the health of New York City's residents and visitors by cleaning up some of the city's most visible fleets, including 7,000 school buses, tour buses and sanitation trucks owned or overseen by various New York City agencies, and the 4,200 transit buses operated by Metropolitan Transportation Authority (MTA) New York City Transit:

• The New York City Council should adopt, and Mayor Michael Bloomberg should sign, Intros. 414-A, 415-A, 416-A, 417-A and 428-A as major steps toward cleaner, healthier air and getting dirty diesels off the streets of New York City.
  
  
• The Metropolitan Transportation Authority should continue its impressive progress towards implementing its 1997 and 2000 Clean-Fuel Bus commitments, and should negotiate with community leaders to develop a plan to mitigate the harmful impacts of its northern Manhattan bus depots.
  
  
• New York State should develop, fund and implement a program that provides grants and incentives for the cleanup of diesel engines in both the public and private sectors throughout the state.
  

Diesel Fumes Threaten Health of New York City Residents and Visitors

In the summer of 1995, NRDC ran a series of memorable advertisements on the backs of Metropolitan Transit Authority (MTA) New York City transit buses that read, "Standing behind this bus could be more dangerous than standing in front of it...Diesel fumes can kill. Demand clean-fuel buses." Today, new federal pollution standards are poised to make future diesel engines more than 90 percent cleaner than current models. But because these engines often last for decades, most diesel engines that were on the city's streets in 1995 are still rolling today.

As a result, New Yorkers continue to face unnecessary health threats from diesel soot and smog-forming pollution. Regulated as particulate matter (PM) and nitrogen oxides (NOx), these emissions have been linked by dozens of studies to serious health impacts, including increased asthma attacks and other emergencies, bronchitis, emphysema, heart disease and others.² In 2002, the U.S. Environmental Protection Agency (EPA) concluded that diesel particulate emissions are a likely human carcinogen and reported that evidence is emerging that diesel soot exhaust exacerbates existing allergies and asthma symptoms.³ An association of state and local air pollution regulators estimates that diesel pollution contributes to more than 125,000 cancers around the nation every year.⁴ And diesel exhaust triggers premature deaths -- indeed, a recent study estimated that roughly 1,800 New York City residents face premature death every year at our current levels of diesel pollution-and more than 20,000 premature deaths nationwide.⁵

Federal actions pave the way for New York City to make vehicles cleaner

Over the past four years, the EPA has adopted two federal rules that have triggered an unprecedented investment and innovation in cleaner diesel technologies. Both rules are premised on a comprehensive approach to cleaning up dirty diesels by combining cleaner diesel fuels, improved engine technologies and advanced pollution control technologies at the end of the tailpipe. By requiring each of the disparate components of the diesel industry to do their share, EPA's program will achieve unprecedented diesel pollution reductions and public health benefits in a cost-effective manner.

The first rule, adopted in 2001, is the "Clean Diesel Trucks and Buses Rule," which will dramatically reduced sulfur levels in the diesel fuel used by trucks, buses and cars by September 2006. Cleaner fuel will enable the use of advanced pollution controls that are unusable with our current sulfur-laden diesel fuel. Introduction of this ultra-low sulfur diesel fuel will be followed by stronger emissions standards for trucks and buses that will reduce particulate matter and nitrogen oxide emissions by more than 90 percent during their 2007-2010 phase-in periods. Once fully implemented, this rule will eliminate more than 8,300 premature deaths and more than 360,000 asthma attacks annually and will provide $17 of health and other social benefits for every dollar of investment.⁶

The second rule, adopted in 2004, is the "Clean Diesel Nonroad Diesel Rule." This rule will have even greater health and other social benefits than the trucks and buses rule, because it covers an even dirtier group of farm, construction and industrial diesel engines. This rule will also start with sharply reduced sulfur diesel fuel for nonroad diesel engines, implemented in two steps in 2007 and 2010. Each sulfur reduction will be followed by more stringent tailpipe emission standards for particulate matter and nitrogen oxides during the 2007-2014 phase-in periods. When the full inventory of older nonroad engines has been replaced, the nonroad diesel rule will prevent up to 12,000 premature deaths, one million lost work days, 15,000 heart attacks and 6,000 children's asthma-related emergency room visits annually. For every dollar invested in implementing this rule, the nation will receive $40 in health and other social benefits.⁷

These two federal rules have triggered an unprecedented flood of investment in cleaner diesel fuels and technologies. Engine companies, makers of emission control equipment and the diesel fuel industry are investing several billion dollars, collectively, in improved engine technologies, advanced catalytic and filtering technologies to slash diesel emissions and ultra-low sulfur diesel refining capacity throughout the nation.

Three Critical Measures for Cleaner Diesels-and Cleaner Air-in New York City

1. New York City should pass Intros. 414-A, 415-A, 416-A, 417-A and 428-A.

New Yorkers should not have to wait for cleaner diesels. As strong as the upcoming federal rules are, today's dirty trucks and buses will keep bumping along New York City's streets and highways until 2030 or even later. By passing Intros. 414-A, 415-A, 416-A, 417-A and 428-A now, the city will be taking steps now to accelerate the replacement of today's oldest, dirtiest diesels with cleaner new models-and to retrofit the remaining diesels with advanced emission control technologies.

Accelerating the retirement and replacement of the oldest, most polluting vehicles is the right first priority for any strategy to clean up the city's diesel pollution. Some of New York City's oldest diesels still use outdated, two-stroke engines with no electronic engine controls. Effective emission controls cannot be used on them, so retrofitting is not an option. Because vehicles generally pollute more as they age, once all of the two-stroke engines have been retired, the oldest four-stroke engines should be replaced next. There is an operating cost benefit to an engine replacement strategy: modern diesel engines have improved fuel economy, thanks to their more-efficient electronic fuel and engine controls.

According to NYC Council staff, more than 7,000 diesel school buses, tour buses, sanitation trucks and other diesel vehicles will be cleaner if Intros. 414-A, 415-A, 416-A, 417-A and 428-A pass this year. These bills will require the operators of these vehicles to use ultra-low sulfur diesel fuel (ULSD), capped at levels that are at least 97 percent lower than today's legal limits, and to use "best available retrofit technology" to clean up their tailpipe pollution.⁸ In addition, one of these bills requires the city's own fleet of cars, light trucks, and sport-utility vehicles to be as clean as possible and to cut its fuel consumption by one-fifth over the next five years -- particularly good news as gasoline prices continue to rise.

There is one unfinished piece of business to monitor in the future. Intro 414-A requires the Department of Sanitation to conduct pilot projects and feasibility studies for CNG vehicles in its street sweeper fleet. Taken together, passing this package of bills will be great news for anybody who breathes New York City air.

For the thousands of diesel engines that will continue to be used on the city's trucks, buses, construction equipment and elsewhere, there are a wide range of pollution controls that can cut particulate matter and/or nitrogen oxides significantly. With the citywide advent of ULSD, it will soon be feasible to use the most advanced emission control technologies citywide. Once ULSD is in place, the following emission controls can be used, depending on the age, duty cycle and other characteristics of the vehicle:

Active or passive diesel particulate filters (DPFs). Diesel engines that meet the equivalent of EPA's 1994 emission standards (i.e., four-stroke, electronically controlled) are likely to be compatible with diesel particulate filters (DPFs), which can reduce PM by 85 percent or more. DPFs can be paired with a lean NOx catalyst to reduce NOx by roughly 25 percent in addition to substantial PM reductions. These technologies require ultra-low sulfur diesel fuel (15 ppm) and in some cases require high operating temperatures (above 250° Celsius more than half of the time). More than 150,000 heavy-duty vehicles around the world have been equipped with DPFs.

Flow-through filters (FTFs). FTFs can reduce PM by roughly 50 percent on certain trucks and buses with moderate PM emissions. These controls work best on engines built after 1990 with electronic controls and engine out emissions no higher than 0.2 gram per brake horsepower-hour (g/bhp-hr). These controls work best with fuels that have a maximum of 500 ppm sulfur. They have only recently come into commercial use, but they are a promising new control choice for older vehicles that are not compatible with DPFs.

Diesel oxidation catalysts (DOCs). Most diesel vehicles, no matter how old, can be outfitted with a DOC, which can reduce PM by 20 to 50 percent. Higher efficiency DOCs that reduce PM by more than 30 percent cost more because they use more expensive proprietary precious metal catalysts. These controls can tolerate sulfur levels up to 500 parts per million (ppm). More than 1.5 million DOCs have been installed on trucks, buses and other heavy diesel engines since the mid-1990s.

NOx reduction strategies. Most advanced NOx reduction strategies are still in a research and development phase and are relatively expensive compared to PM controls. Exhaust gas recirculation (EGR) can reduce NOx by as much as 40 percent, but retrofits with this technology have proven to be difficult on many vehicles as they can raise PM emissions and interfere with other exhaust controls. Selective catalytic reduction (SCR), now emerging for commercial use on motor vehicles, can achieve up to 90 percent NOx reductions. SCR requires the use of urea or another reductant, which means that users of SCR must install or have access to area supplies and infrastructure. Lean NOx catalysts, commercially available as retrofits, yield relatively low NOx reductions of roughly 20 percent.

In some cases, the useful life of a vehicle exceeds the useful life of the engine, and fleet owners repower an existing vehicle with a newer engine. Fleets in the construction, farm and industrial sectors most often use this strategy, especially on equipment that is very expensive or technically specialized. However, it is extremely difficult and expensive to repower a mechanically controlled vehicle with a modern (electronically controlled) engine. Engine costs can be as low as $25,000 or less, but installation cost can be double that or higher. While repowers have been and will be used by many fleets, NRDC has not found that they are generally cost-effective, compared with retirements, replacements and retrofits.

Other diesel cleanup strategies can be simple to implement, although difficult to monitor and enforce. For example, improving maintenance practices and reducing idling times makes sense everywhere. Effective maintenance programs help ensure the effectiveness and durability of any retrofit strategy, and typically improve fuel economy and overall engine performance. Idling reductions can and should be implemented wherever possible to reduce pollution and conserve fuel.

2. The MTA should continue its impressive progress toward its 1997 and 2000 clean-fuel bus commitments and work with community leaders to develop a mitigation plan for its northern Manhattan bus depots.

In 1997 and 2000, Governor George E. Pataki and the Metropolitan Transportation Authority (MTA) announced a series of commitments to cleaner transit buses in New York City, largely in response to NRDC's Dump Dirty Diesels Campaign. In 1997, they promised New Yorkers that three MTA New York City Transit (NYCT) bus depots would be converted to compressed natural gas (CNG) fueling and that 500 CNG buses would be purchased.

Then, in 2000, they committed NYCT to a fleetwide clean-fuel bus program. NRDC applauded these commitments, each of which followed months of discussions with the MTA and NYCT staff. When announced, the 2000 Clean-Fuel Bus Program was the nation's strongest commitment to cleaner diesel buses. The program consisted of several key elements:

• Fleetwide use of ULSD by the end of 2000
  
  
• Early retirement of all two-stroke, pre-1991 diesel bus engines by the end of 2003
  
  
• Purchase of the cleanest available replacement buses, including more than 650 natural gas buses and almost 400 hybrid-electric buses (that operate on a combination of diesel fuel and electric power)⁹
  
  
• Retrofitting of all remaining 2,000+ diesel buses with diesel particulate filter technology
  
  
• Completing the three-depot CNG plan announced in 1997, with the conversion of the Manhattanville depot in West Harlem to CNG
  

To underscore their commitment to resolving the decades-long concerns about diesel bus pollution in Harlem and other uptown communities, Governor Pataki and the MTA announced this plan at the Manhattanville bus depot, slated to be the only Manhattan CNG bus depot in the fleet.

The results are mostly impressive. An independent analysis shows that fleetwide emissions reduced by more than 85 percent since 2000.¹⁰ Other highlights of MTA and NYCT's progress towards cleaner buses include the following:

• The fleet has used ULSD exclusively since September 2000
  
  
• The two-stroke engines are largely gone, replaced by either new buses or buses that have been repowered with new engines
  
  
• Hybrids and CNG buses are an increasing sight on New York City streets (there are 346 CNG buses and 126 hybrids on the streets now, with more of each on back-order)
  
  
• More than 2,300 of the pre-existing diesel buses have been equipped with DPFs that have been shown to reduce particulate matter emissions by more than 90 percent
  

The commitment of the MTA and NYCT to its clean-fuel bus program and its implementation progress is undeniable and NRDC continues to support strongly the clean-fuel bus program.

Yet, recent news about the MTA's plans in northern Manhattan is concerning. In March 2005, the MTA announced a shift of the funds that were allocated to the CNG bus purchases to the purchase of more hybrid buses.¹¹ As a result, funds to buy 120 CNG buses and 55 new articulated buses will be used to buy 100 hybrid buses, with a contract option that could yield 400 more. The strong emissions record of the hybrid buses is impressive. But the MTA touts the fuel-saving benefits of the hybrids as the reason to prefer them to CNG ignoring the staggering incremental cost of the hybrids, which can be as high as $200,000 per bus.

Both CNG and hybrid buses provide benefits for New York City and each can play a role in improving air quality. CNG buses provide virtually no particulate emissions; use a non-petroleum fuel; and offer a record of service around the world that is longer than a decade. Hybrid buses offer comparable particulate emissions to CNG; 30-40 percent fuel savings, according to NYCT; and a new technology platform for fuel-efficient vehicles in other heavy-duty vehicle sectors. But they are just beginning to gain real-world experience, so it remains whether they can be cost-effective in the urban bus sector.

Beyond the emissions debate, the MTA's apparent decision to abandon its future CNG purchases for the NYCT fleet has broken its prior commitment to the communities of northern Manhattan. These communities have shouldered the disproportionate burden of being home to all but one of NYCT's Manhattan bus depots for decades. They are also home to some of the highest asthma rates in the nation. Consequently, community leaders in West Harlem were looking forward to having the harmful impacts of these depots mitigated by converting the Manhattanville depot to CNG. Rather than unilaterally abandoning their West Harlem CNG commitment, Governor Pataki, the MTA and NYCT should instead invite uptown community leaders back to the negotiating table and develop, with those leaders, a comprehensive plan for mitigating the negative environmental impacts of the NYCT bus depots throughout northern Manhattan.

3. New York State should adopt financial incentives to fund cleaner diesels throughout the state

New York should follow the lead of other state, regional and municipal programs that are successfully retiring, replacing and retrofitting thousands of old polluting diesel vehicles. Typically, these programs provide cost-effective grants or incentives to diesel users in both the public and private sector, prioritizing their investments on a range of issues including cost-effectiveness and cost-sharing provisions that require fleet operators to provide some level of matching funds to the government's contribution, which helps ensure that the fleet operators are fully committed to the program's success. These programs include California's Carl Moyer Program and the Texas Emission Reduction Plan (TERP), as well as municipal programs like the Sacramento Emergency Clean Air Transportation (SECAT) Program, as well as many metropolitan area programs administered through the U.S. Department of Energy's Clean Cities Program, local air quality management districts or regional government authorities. The EPA has compiled a list of such programs.¹²

California's Carl Moyer Memorial Air Quality Standards Attainment Program provides incentives for reducing particulate matter and nitrogen oxides from heavy-duty diesel engines in both the highway and nonroad sector. The program funds the incremental cost of cleaner engines and equipment. All diesel engines are eligible, including airport equipment, locomotives and marine diesel engines. During its first three years, the Moyer Program cut NOx emissions by roughly 11 tons/day at an average cost of approximately $4,000/ton-well below its cap of $13,600 per ton reduced. Roughly, $100 million has been granted to date, as incentives to cleaner diesels in both the public and private sector. The grants have gone to private companies, public agencies and individuals-the program is open to anybody who can demonstrate the opportunity for cost-effective emissions reductions. The program is expected to expand considerably in the future, thanks to Governor Schwarzenegger's proposal to increase its funding to up to $140 million/year.

Texas runs the Texas Emissions Reduction Program (TERP). This incentive program, begun in 2001, reduces diesel pollution by funding the incremental costs linked with cleaner engines, engine repowers or retrofits, cleaner fuel use or infrastructure, and the demonstration of new technologies. This program is funded through various fees and surcharges on motor vehicle sales, leases, inspections and registrations. As of summer 2004, more than $40 million had been invested in more 100 projects, reducing NOx by 4.56 tons/day at an average cost of roughly $5,500 per ton reduced-well below its program cap of $7,000 per ton. By the end of FY 2004, Texas expected to fund 200 more projects, investing another $80 million. These projects were projected to cut NOx emissions by an additional 9.55 tons/day, at an average cost-effectiveness of $6,000/ton.

New York State was an early proponent of using matching funds to help transit operators and municipalities reduce their diesel pollution. The Clean Water/Clean Air Bond Act of 1996 provided $55 million to buy clean-fuel buses that could be used in the transit or school bus sectors. Today, the opportunities for investing in cleaner trucks, buses and nonroad equipment in New York State are far greater-and other states are taking advantage of them in ways that New York is not. NRDC strongly urges the State Legislature and/or Governor Pataki to develop and implement a statewide incentive program to take advantage of these opportunities.

Conclusion

Diesel pollution is a fixable problem. By using ultra-low sulfur diesel fuels, best available retrofits and accelerating the retirement of the oldest, dirtiest diesels and their replacement with the cleanest available fuels and technologies, the plume of black smoke that follows many New York trucks, buses, tractors and bulldozers can be a thing of the past. While federal rules will gradually bring cleaner diesels to New York, NRDC strongly urges City, State and MTA decision-makers to implement our three-step plan to clean up the city's diesel pollution problem as quickly as possible.

Notes

1. 52.8% of the PM measured on Madison Avenue in the mid-1990s was are attributable to diesels. NYS DEC, New York State Implementation Plan: Inhalable Particulate (PM10), September 1995, p.11.

2. For a comprehensive discussion of the health impacts of diesel exhaust, please see Chapter 1 of NRDC, Harboring Pollution: Strategies to Clean Up U.S. Ports, August 2004, available at www.nrdc.org/air/pollution/ports/contents.asp

3. 67 Federal Register 56290 (September 3, 2002)

4. State and Territorial Air Pollution Program Administrators (STAPPA) and the Association of Local Air Pollution Control Officials (ALAPCO), Cancer Risk from Diesel Particulate: National and Metropolitan Area Estimates for the United States, March 15, 2000. Available at www.4cleanair.org/FINALNonroadHDDReport.pdf.

5. Clean Air Task Force, "Diesel and Health in America: The Lingering Threat," February 2005.

6. www.epa.gov/otaq/diesel.htm

7. www.epa.gov/nonroad-diesel/2004fr.htm

8. Currently, sulfur levels in the highway diesel fuel that is used by trucks and buses is capped at 500 ppm. Sulfur levels in so-called nonroad diesel fuel that is used in construction equipment is not regulated at all, and averages approximately 3,400 ppm.

9. This was a modification and expansion of the 1997 commitment to CNG bus purchases, which had not yet been purchased at that time.

10. Information provided to NRDC by Michael J. Bradley & Associates, November 2004. Additional details provided in "Diesel Pollution Control Options Used at New York City Transit: Lessons for Asia," presented by Dana Lowell, MTA New York City Transit at the Better Air Quality for Asia Conference, December 2003.

11. New York Times, "City To Buy Diesel-Electric Buses, Not Natural Gas Ones," March 28, 2005, B3.

12. US EPA, Voluntary Diesel Retrofit Program, Funding Sources, www.epa.gov/otaq/retrofit/retrofunding.htm

last revised 4.19.05