Legislative Analyst Report - Diesel Emissions
TO: The Honorable Members of the Board of Supervisors
FROM: Elaine Forbes, Legislative Analyst
HEARING: Public Health and Environment
HEARING DATE: August 14, 2001
SUBJECT: Diesel Emissions
SUMMARY OF REQUEST
The Board of Supervisors directed the Office of the Legislative Analyst (OLA) to provide a report that summarizes the health impacts of diesel exhaust, gives an overview of the regulatory framework for and lists the sources of diesel emissions in the City and County of San Francisco (City), and gives an overview of alternative technologies. This report also presents various options by which the Board of Supervisors may effect a lowering of diesel emissions within the City and consequently improve air quality in the City.
EXECUTIVE SUMMARY
Diesel is used to fuel large commercial trucks and vans, buses, motor boats and ferries and stationary equipment, such as backup diesel generators and boilers. Historically, diesel engines have been used because they are durable and efficient, particularly for heavy-duty vehicles.
According to the California Air Resources Board (CARB), when compared to engines that use gasoline and alternative fuels, diesel engines emit large amounts of smog-forming nitrogen oxides (NOx), particulate matter with a diameter of 10 micron or less (PM10), and hydrocarbons (HC) contributing to acid rain, ground-level ozone, and reduced visibility. The CARB also links diesel exhaust to short and long-term adverse health effects in humans, which include lung cancer, aggravation of respiratory and cardiovascular disease, aggravation of existing asthma, acute respiratory symptoms, and chronic bronchitis and decreased lung function.
According to the CARB, in 2000, approximately 60% of the NOx and 18% of PM10 emitted in San Francisco County were from diesel combustion sources. Sources of these emissions include off-road equipment, recreational boats, ships, trains, trucks, motor homes, school buses, co-generation and electric utilities. The amount of pollution that a particular diesel source creates is a function of use (for example, miles traveled per day), engine type, and controls. Cleaner burning alternative fuels and alternatively fueled equipment that may significantly reduce harmful emissions as compared to conventional diesel fuel and diesel equipment are available. However, due in part to the newness of these technologies and in part to limited market demand, many of these technologies are not readily available and are expensive when compared to the cost of diesel and conventional diesel equipment.
ISSUES AND OPTIONS
The City may be able to impose additional standards on stationary sources of diesel emissions, such as backup diesel generators, provided restrictions are more stringent than and do not conflict with State and federal laws. Hence, the City may choose to regulate the operations of backup diesel generators. In contrast, the City lacks the authority to specifically regulate mobile sources of diesel emissions, such as heavy-duty trucks, because State law specifies that such regulations are solely within the State"s jurisdiction. Nevertheless, the City may still effect a reduction in diesel emissions from mobile sources by the following means:
1. Require the use of clean fuel technologies where appropriate in City fleets and equipment and, in doing so, encourage infrastructure development and set an example for the private sector.
2. Require City contractors on any project funded by the City as a term of the contract to install particulate traps when appropriate on diesel engines and/or to decrease diesel usage.
3. Create disincentives for City departments to use diesel fuel, e.g. diesel fuel surcharge and/or fines over a certain use.
4. Create incentives for alternative fuels and equipment, e.g. subsidies.
BACKGROUND
Diesel exhaust emitted from engines fueled with diesel comprises a complex mixture of gases and fine particles.1 Diesel fuel is used to fuel large commercial trucks and vans, buses, motor boats and ferries, which are collectively referred to as mobile sources. Diesel is also used to fuel stationary equipment, such as backup diesel generators and boilers, which are referred to as stationary sources. Historically, diesel engines have been used because they are durable and efficient, particularly for heavy-duty vehicles.
Health Impacts
According to the U.S. Environmental Protection Agency (EPA), diesel engines emit large amounts of smog-forming NOx, PM102, and HC contributing to acid rain, ground-level ozone, and reduced visibility.3 In August of 1998, the CARB listed diesel exhaust, specifically particulate emissions from diesel fueled engines, as a "toxic air contaminant."4 Toxic air contaminants are linked to short term and long-term adverse health effects in humans. In particular, diesel exhaust or diesel particulate matter (soot) can cause lung cancer in humans.5 Other health effects include aggravation of respiratory and cardiovascular disease, aggravation of existing asthma, acute respiratory symptoms, and chronic bronchitis and decreased lung function.6 According to the CARB, in 2000, the estimated statewide cancer burden due to toxic air contaminants was 758 cases per 1 million persons, of which 540 cases in 1 million, or about 70% were due to diesel particulate.7 According to the San Francisco Department of the Environment (SFE), the cancer risk would be much higher in neighborhoods with a large volume of diesel emissions. Additionally, children, the elderly, and persons with existing lung and/or cardiovascular problems, termed "sensitive groups", are more susceptible to the adverse impacts of diesel emissions.8 The EPA has recently proposed to list the various components of diesel exhaust as probable mobile source of air toxins due to the cancer and noncancer health effects associated with exposure.9
CURRENT LAW & PRACTICE10
Air pollutants are separated into two primary categories "criteria air pollutants" and "toxic air contaminants."11 "Criteria air pollutants" refers to pollutants that are pervasive in urban environments and for which the state and national health-based ambient air quality standards have been established.12 The term "toxic air contaminants" refers to those pollutants that are linked to short term (acute) or long-term (chronic and/or cancer causing) adverse human health effects. Toxic air contaminants differ from criteria pollutants because they occur at relatively lower concentrations and have no established ambient air quality standards. Diesel engine emissions contribute to both categories of pollutants. As discussed above, California has listed particulate matter from diesel exhaust as a toxic air contaminant.
Criteria Air Pollutants
Criteria air pollutants are regulated at the state and national levels primarily through ambient air quality standards and emissions limits for individual sources. The EPA has established National Ambient Air Quality Standards for criteria air pollutants such as ozone, carbon monoxide, NOx, sulfur dioxide, PM10, and lead.13 California has adopted more stringent ambient air quality standards than the Federal standards for most of the criteria air pollutants.14 Based on whether the national standards have been achieved, the EPA classifies air basins15 as either "attainment" or "nonattainment" for each criteria air pollutant. In 1988, the State legislature passed the California Clean Air Act, which also requires air basins to be designed as "attainment" or "nonattainment," in terms of the state standards.16 The Bay Area is currently designated nonattainment for state and national ozone standards and nonattainment for the state PM10 standards.17
The federal Clean Air Act and the California Clean Air Act require nonattainment and maintenance areas18 to develop air quality plans for how to achieve and maintain attainment. According to the CARB, the Bay Area currently has four air quality plans. Two are for the national ozone standard, one is for the state ozone standard, and one is for the national carbon monoxide standard. The Bay Area Air Quality Management District (BAAQMD) revised its Clean Air Plan in 2000, which replaced the 97-Clean Air Plan. Notably, none of the control measures in this plan specifically relates to maritime/industrial activities on Port lands.
Toxic Air Contaminants
Unlike regulations concerning criteria air pollutants, there are no regulatory standards based on volume of emission in place for toxic air contaminants.19 Rather, emissions of toxic air contaminants are evaluated on the degree of health risk that could result from exposure to these pollutants.20
At the federal level, toxic air contaminants are regulated by the 1977 amendment to the federal Clean Air Act.21 The federal Clean Air Act requires some facilities to install Maximum Achievable Control Technology (MACT).22 The MACT standards vary depending on the type of emitting source. The EPA has established MACT standards for more than 57 facilities or activities, such as perchloroethylene dry cleaning and petroleum refineries. The EPA has labeled diesel exhaust as likely carcinogen but to date has not created a MACT standard for diesel emissions.23
At the state level, toxic air contaminants are regulated by Chapter 3.5, Part 2 of Division 26 of the California Health & Safety Code.24 Assembly Bill 11807 established a process for identifying toxic air contaminants, and established the authority for the CARB to develop retrofit air toxics control measures on a statewide basis.25 The current list of toxic air contaminants includes approximately 200 compounds, and, as of August 1998, the list includes particulate emissions from diesel-fueled engines.26 Air toxics from stationary sources in California are regulated by Assembly Bill 2588, the Air Toxics "Hot Spots" Information and Assessment Act of 1987.27 Under Assembly Bill 2588, regional air districts, such as BAAQMD, are required to develop an inventory of hazardous materials released from individual facilities into the air and prioritize toxic air contaminant emissions for cancerous and non-cancerous health effects.28 High priority facilities are required to perform a health risk assessment, and if specific thresholds are violated, they are required to communicate the results to the public in the form of notices and public meetings.29 According to BAAQMD staff, depending on the risk level, emitting facilities can be required to implement varying levels of risk reduction measures. However, according to BAAQMD staff, this program has not significantly impacted diesel engines.
Regulation of Mobile Emission Sources
Criteria Pollutants. The EPA and the CARB generally regulate mobile sources of air pollutants through emissions standards, which are enforced on engine and vehicle manufacturers.30 Emissions standards and inspection programs similar to the smog check have been established for most diesel-powered vehicles, including heavy trucks.31 The current federal emissions standards took effect in 1984, and additional standards are being phased in through 2004.32 Emissions standards have improved diesel emissions overtime. According to the CARB, new heavy-duty diesel engines emit approximately one-third of the ozone precursors and one-tenth of the particulate matter compared to engines manufactured in the early 1970s.
Modifications to diesel fuel have also lowered emissions. Since 1993, all diesel fuel sold for on-road motor vehicles in California must meet specifications such as low sulfur and low aromatic content, established by the CARB.33 According to the CARB, transit agencies are required to start using low sulfur fuel by January 1, 2002, to start retrofitting a significant fraction of the older fleet prior to January 1, 2003, and to retrofit their entire fleet by January 1, 2007.
Before 1999, emissions associated with marine vessels and locomotives were largely unregulated.34 In 1999, the EPA issued rules that established emission standards for large commercial marine diesel engines in the US, but these standards take effect only for new engines manufactured in 2004, 2005, or 2007, depending on their size.35 The CARB is in the process of adopting regulations regarding Emission Standards and Test Procedures for 2003 and Later Spark-Ignition Inboard and Sterndrive Spark-Ignition Marine Engines.36
Toxic Air Contaminants. Diesel emissions from mobile sources are generally regulated through the EPA and the CARB emissions standards for motor vehicles imposed on manufacturers. Additionally, mobile source emissions are regulated through specifications for gasoline and diesel fuel sold in California imposed on fuel refineries and retailers. Both the EPA and the CARB have proposed new rules to reduce cancer risk from diesel exhaust particulate.37 The proposed federal regulations, published June 2000, will reduce the amount of sulfur in diesel fuel by 97%.38 The EPA has also proposed tighter emissions standards for heavy duty highway vehicles and engines that will take effect in 2004. The CARB estimates when these regulations are implemented, statewide cancer risk from diesel will be reduced by 75% in 2010 and by 85% in 2020. In October 2000, the CARB staff adopted a plan to reduce emissions of particulate matter from diesel engine exhaust.39 The CARB staff is current in the process of implementing regulation that would carry out the goals of the plan.
Regulation of Stationary Emissions Sources
Criteria Pollutants. BAAQMD is the primary regional agency that regulates air pollutant emissions from stationary sources for the Bay Area. BAAQMD regulates stationary sources through its permit authority and through planning and review activities. BAAQMD"s permit authority is used to regulate diesel generators, as well as concrete and asphalt plants.40 In order to qualify for a BAAQMD permit, some new diesel equipment must be equipped with Best Available Control Technology (BACT) to control emissions.41 While BAAQMD requires facilities operating an internal combustion engine to obtain a permit, BAAQMD"s rules exempt emergency backup generators from this permitting requirement.42 To better monitor the numbers and operation of emergency backup diesel generators, BAAQMD has proposed new regulations that will require all backup generators, except for very small generators and the CARB-certified portable generators, to obtain permits.43 However, the proposed regulations will not change emissions standards for existing backup generators. Given the increased reliance on backup generators spurred by California"s energy situation, BAAQMD and the CARB may tighten the emissions standards for diesel backup generators in the future.
Other Permits. The San Francisco Department of Public Health (DPH) requires a business to register with the department if it stores 55 gallons or more of hazardous materials, including fuel, such as gasoline or diesel.44 Because DPH is not required to track the use of the fuel stored, DPH does not have any information regarding the existence of a backup diesel generator at a facility. The City may wish to enhance DPH"s permit process for tracking and enforcement purposes.
DIESEL EMISSIONS IN CALIFORNIA
The CARB maintains a California Emission Forecasting System (CEFS) that provides data on criteria air pollutants by category. Data include information about reactive organic gases (ROG), NOx and PM10. According to the CARB, diesel-fueled vehicles and engines cause an annual emission of approximately 28,000 tons of PM10.45 The CARB estimates that on-road mobile sources such as trucks, buses, and cars contribute about 27 percent of total PM10 emissions, other off-road mobile sources such as mobile equipment, trains, ships and boats, and stationary sources accounts for 66 percent, and the remaining 7 percent caused by stationary and portable engines.46
Stationary Sources. As noted above, the CARB estimates that stationary sources account for approximately 7 percent of diesel particulate emissions statewide. However, due to energy shortages, use of backup diesel generators may account for a greater share of total air pollution. Under normal circumstances, diesel generators would operate 8-16 hours per year for reliability testing, according to a BAAQMD representative. However, if businesses participating in the voluntary curtailment program are asked to reduce their electrical usage or if blackouts due to electricity shortages occur, the need to operate these generators increases, resulting in an increase emission in NOx, ROG and PM10.47 Because backup diesel generators qualify for the permit exemption, BAAQMD does not currently have an inventory of all sources, and consequently cannot accurately analyze the air quality impacts of increased use.
DIESEL EMISSIONS IN SAN FRANCISCO
According to the CARB"s California Emission Forecasting System, as of May 30, 2001, diesel emissions accounted for 60% of NOx, 18% of PM10, and 7% of ROG in the County of San Francisco.
Table 1: San Francisco County Pollution Emissions, annual average in 2000 (tons/day) | ||||
ROG | NOx | PM10 | ||
Total* | 47.59 | 58.74 | 10.61 | |
Diesel Combustion Sources | 3.16 | 35.22 | 1.9 | |
% from Diesel Sources | 7% | 60% | 18% | |
Source: CARB, May 30, 2001 and June 6, 2001 | ||||
*All emissions are represented in Tons per Day | ||||
According to CARB data, San Francisco differs from the state overall in that other mobile sources such as off road equipment, recreational boats, ships, and trains are estimated to produce slightly more ROG and PM10 as a percent of the total, than do on-road motor vehicles (Please see Attachment 1: San Francisco and Statewide Diesel Emissions as a percent of the total by source). Industrial cargo shipping and rail activities likely explain this slight difference. As discussed above in the Current Law & Practice section, before 1999, marine vessels were largely unregulated. According to SFE, diesel ferries are often more polluting than buses. Notably, however, on-road diesel vehicles are still a significant source of pollution in San Francisco County.
Table 2: San Francisco County Diesel Emissions as a percent of the total by source, | |||||||||||
annual average in 1995 and 2000 (tons/day) | |||||||||||
1995 ROG | 2000 ROG | 1995 NOx | 2000 NOx | 1995 PM10 | 2000 PM10 | ||||||
Fuel combustion (co-generation, electric utilities, etc) | 0% | 1% | 0% | 1% | 1% | 3% | |||||
On-road motor vehicle (trucks, motor homes, school buses) | 26% | 23% | 42% | 42% | 29% | 23% | |||||
Other mobile sources (off road equipment, recreational boats, ships, and trains) | 74% | 76% | 58% | 57% | 70% | 74% | |||||
Total | 3.37 | 3.17 | 36.38 | 35.23 | 2.04 | 1.90 | |||||
Source: CARB, June 6, 2001 | |||||||||||
*All emissions are represented in Tons per Day | |||||||||||
Locations of Diesel Emissions in San Francisco. According to the CARB, diesel exhaust is emitted throughout San Francisco, but is concentrated around areas zoned for industrial uses, such as cargo shipping, the Potrero and Hunters Point power plants, and other areas with businesses that use diesel trucks and equipment. Additionally, diesel exhaust is concentrated along major thoroughfares such as Highway 101 and Interstate 280 that experience a high volume of truck travel. According to Administrative Services, many businesses that use diesel equipment were displaced from Mission Bay and have relocated in the Bayview neighborhood. Additionally, concrete companies and delivery trucks use diesel vehicles and the Port tenants employ diesel to haul cargo. According to the CARB, the most polluting trucks may be used for hauling of cargo in port areas because older trucks are more suitable for short trips. According to the Department of Health, urban canyons are also potentially high exposure areas. These factors suggest that the Bayview/Hunters Point, Potrero Hill, and Dog Patch neighborhoods may experience higher diesel emissions than does the City overall. However, no studies of the actual diesel exhaust particulate matter concentrations in San Francisco have been conducted and the results of the aforementioned factors remain speculative.
City and County of San Francisco Diesel Use. In the City, 22 agencies and departments use diesel vehicles and equipment.48 According to Central Shops, these departments combined own or lease approximately 1183 on-road diesel vehicles and other mobile equipment, 110 pieces of stationary equipment49 and 108 diesel sources which are classified special, representing a total diesel inventory of 140150 items.
Table 3: City Diesel Fleets and Equipment | |||
Number | Percent of Total | ||
Mobile sources (ambulances, boats, buses, bookmobile, forklifts, mowers, packers, pickups, rescue vehicle, school buses, sewer cleaning equipment, sweepers, tractors, trailers, trucks, and vans) | 1183 | 84% | |
Stationary sources (compressor, fire abrial, generators, high pressure equipment) | 110 | 12% | |
Other | 108 | 12% | |
Source: Central Shops, May 2001. | |||
*Total excludes 8 Historic Fire Engines and equipment not serviced by Central Shops | |||
Eight departments use 95% of the diesel sources, they are MUNI (39%), the School District (14%), the Department of Public Works (13%), the Public Utilities Commission (11%), the Fire Department (10%), Recreation and Parks (5%), the Police Department (2%), and the Airport Commission (2%). (Please see Chart 1: City and County of San Francisco for more information).51 The School District does not have its own the school bus fleet, but rather it contracts with Laidlaw Transit who provides the bus service.
The amount of pollution that a particular diesel source emits is a function of use (fuel consumption serves as a proxy for use), engine type, and controls. According to Central Shops, the City consumed approximately 6 million gallons annually (this figure does not include fuel used by Hetch Hetcy outside of San Francisco). Of diesel fuel consumed, 77% of the consumption was by MUNI.
Table 4: City Diesel Fuel Usage, May 2000 - April 2001 | |||
Number | Percent of Total | ||
The PUC, the Port and the Airport* | 654,640 | 11% | |
MUNI* | 4,800,000 | 77% | |
Fire Department | 235,682 | 4% | |
School District** | 200,000 | 3% | |
Other Departments that Purchase Diesel Through Central Shops | 309,678 | 5% | |
Total | 6,200,000 | ||
Source: Central Shops, May 2001. | |||
*based on estimate provided by Administrative Services | |||
**based on estimate provided by School District staff. | |||
ALTERNATIVES TO DIESEL
Several alternative fuels to diesel exist, including compressed natural gas (CNG), liquefied natural gas (LNG), and electric power. Also available are low sulfur content diesel fuel and biodiesel fuel, which burn cleaner. Diesel particulate traps can be installed in diesel vehicles and equipment to significantly reduce PM10 emission. However, due in part to the newness of these technologies and in part to limited market demand, many of these technologies are not readily available, are expensive, and some have not been proven to reliably reduce pollution. According to SFE, the market is in a transitional period. At this time cleaner technologies cannot compete with the cost and availability of diesel.52 However, as regulations tighten on emissions and market demand increases for cleaner alternatives to diesel, the availability of viable alternative fuel options likely will continue to increase and the cost of such technologies likely will continue to decrease, according to SFE.
Compressed Natural Gas (CNG), Liquified Natural Gas (LNG). According to SFE no diesel engine on the market can match the emissions reductions of the cleaner-burning alternative fuels. Compressed natural gas and stored electric power currently lead alternative fuel technologies for transit and school buses, whereas liquefied natural gas has been used for most other heavy-duty applications. Liquified natural gas is a condensed fuel, which makes the fuel lighter per unit volume and gives the vehicles advantages in terms of power and distance when compared to CNG. However, the infrastructure (fueling stations and fuel availability) for LNG and CNG is problematic. LNG currently must be trucked in and entities using the technology typically need holding tanks. CNG fueling stations are more available but require careful route planning, particularly for long trips.
Electric Power. Zero emission electric vehicles are the cleanest vehicles available, according to SFE. The only emissions from an electric vehicle are those from the power plant with natural gas utility boiler that creates the electric power and this is typically less than 5% of the total emissions from an internal combustion engine. Although California is in the middle of an electricity crisis, this should not dissuade one from using electric vehicles. Electric vehicles usually charge at night when demand for electric energy low and thus, in most cases, electric cars are not a burden to the power grid. The limitations of electric vehicles are the lack of range, the lack of charging infrastructure, and the long time it takes to recharge.
Particulate Traps. Exhaust emission control devices on diesel engines, which are similar to catalytic converter on cars, have improved significantly in terms of their ability to trap and burn up particulate matter and consequently need not be replaced regularly like the older particulate traps. The newer particulate traps are relatively inexpensive, ranging between $1,000 and $5,000 dollars, but require Ultra Low Sulfur fuel (less the 15 parts per million) in order to be effective. In California, British Petroleum, based in Los Angeles, manufactures this fuel which is $.05 more per gallon than diesel, excluding transportation costs. Additionally, newer particulate traps are most applicable to 4-stroke diesel engines, which were generally manufactured after the late 1980s. With the EPA mandated reduction of sulfur content in highway diesel fuel by 2006, the use of particulate traps may become as prevalent as the use of catalytic converters in gasoline-fueled vehicles.
Biodiesel. According to the Department of Energy, biodiesel (mono alkyl esters) is a cleaner-burning diesel fuel made from natural, renewable sources such as vegetable oils (soybean, peanuts, cottonseed and sunflower oil). The use of biodiesel in a conventional diesel engine results in substantial reductions of unburned hydrocarbons, carbon monoxide, and particulate matter, and a slight increase in NOX as shown in the following table of biodiesel reduction.
Table 5: Biodiesel Reduction | ||
100% Biodiesel (B100) | Blend - 20% Biodiesel, 80% Diesel (B20) | |
HC | -93% | -30% |
CO | -50% | -20% |
PM10 | -30% | -22% |
NOx | 13% | 2% |
Source: US EPA | ||
Just like petroleum based diesel, biodiesel operates in combustion-ignition engines. Biodiesel requires few if any engine modifications and performs as well as diesel. The Department of Energy issued interim final rules to allow fleets required by the Energy Policy of 1992, as amended by the Energy Conservation and Reauthorization Act for 1998 to purchase alternative fuels to receive credit for using biodiesel.53
According to the Department of Energy, biodiesel is relatively unknown and faces several barriers to gaining widespread commercial use. According to SFE, biodiesel must overcome a number of regulatory obstacles, and its price must become more competitive before it will make any significant market penetration. Biodiesel currently costs over $2 per gallon, compared to diesel, which costs between $1.20 and $1.60 per gallon.54
CITY AND COUNTY OF SAN FRANCISCO"S EFFORTS TO DATE
Clean Air Ordinance. On October 15, 1999, the Board of Supervisors enacted the Healthy Air and Smog Prevention Ordinance, which established the Clean Air Program to develop infrastructure for alternative fuel vehicles and establish criteria for the City"s procurement of zero-emission and ultra-low emission vehicles. SFE currently administers the Clean Air Program. The program promotes non-petroleum and compressed natural gas alternatives to diesel. The ordinance also prohibits city agencies and departments from purchasing or leasing additional diesel equipment unless exempted, requires any medium and heavy duty vehicles purchased or leased to be certified as vehicle with the lowest emission possible unless exempted, and encourages replacement of highly polluting vehicles and equipment that are over 12 years old. The Director of Administrative Services are authorized to grant exemptions for emergency vehicles and in instances when departments demonstrate that costs and/or availability of alternatives would be prohibitive. SFE also works with private industry to assist them to transition from diesel to clean alternatives. The largest project is with NorCal, which is in the process of replacing its diesel garbage transfer truck fleet to a liquified natural gas fleet. These trucks travel as much as 600 miles per day. The City has obtained grant funding to cover the incremental cost between the diesel and liquified gas trucks.
Compressed Natural Gas (CNG) Projects. Olympian Station at 3rd and 23rd Streets -
SFE"s Clean Air Program staff has cooperated in the development of a CNG fueling facility in conjunction with Olympian Oil and Pickens Fuel Corp. Olympian Oil and Pickens Fuel have leveraged grant funding provided through the City"s Clean Air Program to develop a CNG fueling station at the existing gasoline/diesel fueling station owned/operated by Olympian Oil. The CNG facilities are scheduled to operate by Winter 2001.
Central Shops/Recreation and Parks Department - To expand the CNG fueling infrastructure in the City, Clean Air Program staff is working with Central Shops and the Recreation and Parks Department to expand the existing fueling facility at the Golden Gate Park maintenance yard to include CNG. Clean Air Program staff is preparing a draft request for proposals for review by Central Shops and the Recreation and Parks Department.
Biodiesel Demonstration Projects. SF Intl. Airport (SFO) - The San Francisco International Airport recently completed a four-week demonstration project using biodiesel. The project sought to determine the operational impacts of biodiesel fuel with respect to vehicle performance (acceleration, mileage) as well as maintenance issues. The project included using biodiesel on four buses (two Rental Car Shuttles and two Long-Term Parking Buses). A 20% blend of biodiesel (B20) with regular diesel was used during the initial two weeks, followed by a 100% biodiesel blend (B100) for the last two weeks. Emissions and opacity testing were not included as evaluation criteria. According to Airport staff, biodiesel at 20% and 100% performed well without the visible emissions and odor associate with diesel. Pure biodiesel performed better than the 20% blend. Price remains an obstacle in permanently using biodiesel, according to Airport staff. Currently, the 100% blend is $.50 more per gallon and the 20% blend is $.08 higher.
Central Shops and DPW - Central Shops in conjunction with DPW will be conducting an eight-week demonstration. The project will involve using biodiesel blends with diesel-powered street cleaners, comparing performance and maintenance with similar vehicles powered by regular diesel and compressed natural gas (CNG). The first two weeks will test a 20% soybean based biodiesel blend, the second two weeks will test a 100% soybean based biodiesel blend, the third two week period will test a 20% recycled vegetable oil based biodiesel blend and finally the last two week period will test a 100% recycled vegetable oil based biodiesel blend.
ISSUE ANALYSIS
City and County of San Francisco"s Regulatory Authority
Mobile Sources. The City lacks the authority to specifically regulate mobile sources of diesel emissions because State law specifies that such regulations are solely in the jurisdiction of the State.55 However, the City may be able to effect a reduction in diesel emissions and achieve cleaner air by the following means:
1. Require the use of clean fuel technologies where appropriate in City fleets and equipment and, in doing so, encourage infrastructure development and set an example for the private sector.
2. Require City contractors on any project funded by the City as a term of the contract to, when appropriate, install particulate traps on diesel engines and/or to decrease diesel usage.
3. Create disincentives for City departments to use diesel fuel, e.g. diesel fuel surcharge and/or fines over a certain use.
4. Create incentives for alternative fuels and equipment, e.g. subsidies.
Additionally, the City has an obligation through the California Environmental Quality Act to mitigate significant negative environmental impacts for any discretionary activities taken by the City. With the listing of diesel exhaust as a toxic air contaminant, the City may condition any discretionary approval of a project on the use of alternative fuels or to retrofit vehicle to reduce emissions. According to Port staff, the Port of San Francisco has begun to condition leases on the applicant"s commitment to reduce diesel emissions and may begin an incentive program for Port tenants who use clean fuels. Port staff indicates that they are in the process of negotiating the first lease that will condition cleaner technologies.
Stationary Sources. BAAQMD, in conjunction with the CARB, permits stationary sources and sets emissions standards. California counties and municipalities may be able to impose additional standards so long as they are not less stringent and do not conflict with state law.56 Using this authority, the City may choose to regulate backup diesel generators. To do so, the City may wish to enhance DPH"s permit process for tracking and enforcement purposes.
Other Issues and Options
City Fleets. The City may wish to reexamine its existing diesel equipment and fleets. As an interim solution, incentive programs, such as funding for particulate traps, and matching funds for clean fuel replacement of older diesel vehicles would allow City Departments to improve their fleets. Additionally, disincentive programs, such as a surcharge on City Department for diesel fuel could be transferred into a clean vehicle purchase fund.57 This type of disincentive is economically prudent because increasing the cost of diesel begins to charge the user directly for the pollution diesel engines create.
Interim versus Permanent Solutions. Replacing high mileage diesel vehicles and older on and off-road sources provides the largest reduction in air pollution, according to the CARB. However, appropriate and cost efficient natural gas technologies may not be immediately available. Infrastructure, such as fueling stations, may need further development in order to make a move from diesel to alternative fuels practical and cost effective. In the interim, the City may wish to encourage itself and the private sector to use new particulate traps and Ultralow Sulfur fuel, or, for older and/or incompatible engines, older particulate traps which do not require Ultralow Sulfur fuel, and require City contractors and departments to use these technologies.
Sensitive Groups. Diesel vehicles that have high levels of use and/or contact with persons considered "sensitive groups" (children, the elderly, and persons with existing lung and/or cardiovascular problems), in particular, may be suited for an interim solution. For example, the SFUSD contracts with Laidlaw to operate 203 school buses for the transportation of students at the K-12. These buses rely on diesel fuel without any type of particulate trap or modified diesel. Emissions from these school buses, as discussed above, are linked with adverse health effects, including respiratory disease. The Natural Resources Defense Council (NRDC), a nonprofit environmental organization, did a study in February 2001 which showed that a child riding on a diesel school bus may be exposed to a cancer risk that is 23 to 46 times greater than the risk considered "significant" by the EPA.58 According to the NRDC, 2,600 clean alternative fuel buses, such as those that run on natural gas and propane, are in the US today and are used by universities, etc. BAAQMD has set aside funds earmarked to help public school fleet operators cover the incremental costs of purchasing cleaner alternatives. However, the school bus fleet used by SFUSD would not currently qualify for these funds because Laidlaw privately owns the fleet. Nevertheless, Laidlaw is eligible for BAAQMD"s school bus retrofit program, which covers the cost of installing particulate traps on existing diesel buses. To participate in this program, Laidlaw must commit to purchasing Ultra Low Sulfur Diesel which is currently more costly than "regular" diesel.
CONCLUSION
The City has promoted the use of environmentally sound energy sources as clean alternatives to diesel. The City has established the Clean Air Program, funded several alternative fuel vehicle projects, and has assisted private industry in transitioning to alternative fuels. To have a larger impact on air quality in San Francisco, the City may wish to impose additional standards on stationary sources of diesel emissions, such as backup diesel generators, and may wish to require lower diesel usage and/or control technologies as part of contractual agreements. Combined, these efforts could significantly lower diesel emissions. The City may also wish to reexamine its existing diesel equipment and fleets and move to cleaner alternatives. This would set an example to the private sector and would further develop the infrastructure necessary to make alternatives more affordable and practical.
Attachment 1: San Francisco and Statewide Diesel Emissions as a percent of the total by source, | |||||||
Annual average (tons/day) | |||||||
2000 ROG, SF | 2000 ROG | 2000 ROG, CA | 2000 NOx, SF | 2000 NOx, CA | 2000 PM10, SF | 2000 PM10, CA | |
On-road motor vehicle (trucks, motor homes, school buses) | 23% | 31% | 43% | 41% | 23% | 27% | |
Other mobile sources (off road equipment, recreational boats, ships and commercial, and trains) | 77% | 69% | 57% | 59% | 77% | 73% | |
Total | 3.15 | 119.50 | 34.83 | 1385.70 | 1.84 | 66.70 | |
Source: Air Resources Board, August 8, 2001 | |||||||
*All emissions are represented in Tons per Day | |||||||
City and County of San Francisco: Diesel Fuel Use, September 1999 - August 2000 | ||
Department | Total | % of the total* |
Muni | 5,486,653.00 | 87.72% |
Department of Public Works | 246,041.00 | 3.93% |
Fire Department | 193,821.00 | 3.10% |
Airport | 99,413.00 | 1.59% |
The PUC | 95,372.00 | 1.52% |
Park and Recreation | 58,019.00 | 0.93% |
The Port | 23,572.00 | 0.38% |
Public Health | 19,062.00 | 0.30% |
Dept of Youth Guidance | 16,543.00 | 0.26% |
Hall of Justice | 12,377.00 | 0.20% |
Sheriff | 8,800.00 | 0.14% |
City College of SF, Building Grounds | 6,486.00 | 0.10% |
Central Shops | 2,442.00 | 0.04% |
total | 6,254,868.00 | |
Source: Central Shops, July 13, 2001 | ||
* Percentages do not add up to 100% due to rounding | ||
1 Report to the Air Resources Board on the Proposed Identification of Diesel Exhaust as a Toxic Air Contaminant: Part A, Exposure Assessment, As Approved by the Scientific Review Panel on April 22, 1998 (Exposure Assessment Report) at p. A-5. Available online at: http://www.arb.ca.gov/toxics/dieseltac/part_a.pdf.
2 According the CARB, one of the main characteristics of diesel exhaust is the release of particles at a markedly greater rate than from gasoline-fueled vehicles, on an equivalent fuel energy basis. Almost all of diesel particle masses are fine particle matter (PM10). Because of their small size, these particles can be inhaled and a portion may become trapped within the small airways and lung. Exposure Assessment Report at A-1.
3 See e.g., 62 Fed. Reg. 54694 (October 21, 1997).
4 17 CCR § 93000.
5 The Scientific Review Panel reported that over 30 human epidemiological studies have investigated the potential cancer causing effect of diesel exhaust. These studies, on average, found that long-term occupation exposures to diesel exhaust were associated with a 40 percent increase in the relative risk of lung cancer. A summary of the Scientific Review Panel report is available online at http://www.arb.ca.gov/toxics/dieseltac/de-fnds.pdf.
6 For a detailed discussion of the health effects associated with diesel emissions, see Report to the Air Resources Board on the Proposed Identification of Diesel Exhaust as a Toxic Air Contaminant: Part B, Health Risk Assessment for Diesel Exhaust" prepared by the California Environmental Protection Agency, Office of Environmental Health Hazard Assessment, Air Toxicology and Epidemiology Section (May, 1998). Available online at: ftp://ftp.arb.ca.gov/carbis/regact/diesltac/partb.pdf.
7 "Risk Reduction Plan to Reduce Particulate Matter Emissions from Diesel-Fueled Engines and Vehicles, California Environmental Protection Agency - Air Resources Board - Stationary Source Division, Mobile Source Division, October, 2000 (Diesel Risk Reduction Plan) at p. 16, Table 7. Available online at: http://www.arb.ca.gov/diesel/documents/rrpFinal.pdf.
8 See http://www.arb.ca.gov/html/gloss.htm#S.
9 66 Fed. Reg. 17230 (March 29, 2001).
10 For a summary of current regulations regarding diesel and diesel engines, see Diesel Risk Reduction Plan; Appendix V. Available online at: http://www.arb.ca.gov/diesel/documents/rrpapp5.PDF.
11 See http://www.epa.gov/oar/oaqps/peg_caa/pegcaa03.html#htmo#topic3a. EPA"s use of the terms "Hazardous Air Pollutants" and "Air Toxics" are equivalent to CARB"s use of the term "Toxic Air Contaminants."
12 Ibid.
13 42 U.S.C. § § 7408, 7409; 40 CFR Part 50.
14 17 CCR § 70200; see Attachment 1: State and National Criteria Air Pollutant Standards; available on line at: http://arbis.arb.ca.gov/aqs/aaqs2.pdf
15 San Francisco is in an air basin that includes Alameda, Contra Costa, Marin, San Francisco, San Mateo, Santa Clara, Napa and portions of Solano and Sonoma. In 1975, the State of California established Bay Area Air Pollution Control District with regulatory authority over this air basin. (Stats. 1975, ch.957, p. 2157, §12.) The district was subsequently renamed the Bay Area Air Quality Management District (BAAQMD). (H&SC § 40200).
16 Stats. 1988, ch.1568.
17 See http://www.baaqmd.gov/planning/resmod/baas.htm.
18 Maintenance areas are classified attainment but have once been designated as nonattainment.
19 For a current list of Toxic Air Contaminants, see http://www.arb.ca.gov/toxics/taclist.htm.
20 According to the EPA, a risk level of 1 in a million implies a likelihood that one person out of one million equally exposed people would contract cancer if exposed continuously (e.g., 8 hours per day over 40 years for workers; continuous exposure over 70 years for residents), to the pollutant in question. See www.epa.gov/ttn/atw/nata/gloss1.html.
21 See 42 U.S.C. § 7412; see also, 40 CFR Parts 61, 63.
22 See 40 CFR Part 63.
23 See Federal Register, Vol 65, No 107, Part 35446.
24 H&SC §§ 39650 et seq.
25 Stats. 1983, ch. 1047, § 1; H&SC §§ 39662, 39666.
26 See 17 CCR §§ 93000, 93001.
27 Stats. 1987, ch. 1252, § 1; H&SC §§ 44300 et seq.
28 See H&SC §§ 44340, 44344.4.
29 H&SC §§ 44360 et seq.
30 See 13 CCR §§ 1950-1975, 2230-2231, 2400-2427. California began to regulate on-road heavy-duty diesel truck emissions in 1969, and EPA put similar regulations into place in 1974.
31 13 CCR §§ 2180-2188, 2190-2194.
32 By 2004 the emission standard for new heavy-duty diesel vehicles will be an aggregate of 2.4 grams of NOx and ROG combined, per brake horsepower-hour or an aggregate of 2.5 grams of NOx and ROG, combined, per hoursepower-hour with a .5 gram per horsepower-hour ROG cap. See 40 CFR Part 86. The current set of emissions standards for reducing PM10 from on-road, diesel-powered vehicles took effect beginning in 1982 and increasingly stringent standards were phased in through the 1996 model year. Ibid.
33 13 CCR §§ 2281, 2282.
34 In general, a state may not adopt or enforce any standard related to the control of emissions from new nonroad engines or nonroad vehicles. 42 U.S.C. § 7543(e). However, except for new engines used in locomotives and new engines used in farm and construction equipment rated under 130 kW, California may seek a waiver of federal preemption for nonroad engines and nonroad vehicles. 42 U.S.C. § 7543(e)(2)(A). CARB has been granted the authority to regulate emissions from all nonroad engines, except for new engines used in locomotives and new engines used in farm and construction equipment rated under 130 kW. See e.g., 62 Fed. Reg. 50152 (September 24, 1997).
35 64 Fed. Reg. 73300 (December 29, 1999) codified in 40 CFR Parts 89, 92, and 94.
36 See http://www.arb.ca.gov/regact/regup01.htm#marine.
37 65 Fed. Reg. 35420 (June 2, 2000); see http://www.arb.ca.gov/cbg/meeting/2001/40501ARB.PDF.
38 65 Fed. Reg. 35420 (June 2, 2000). Reducing the sulfur content in diesel fuel will allow for wide use of particulate traps, which require the use of low sulfur content diesel fuel. The particulate traps should reduce particulate matter emissions.
39 Ibid.
40 BAAQMD Regulation 2. Available online at: http://www.baaqmd.gov/regs/rulereg.htm.
41 BAAQMD Regulation 2, Rule 2. Available online at: http://www.baaqmd.gov/regs/rg0202.pdf.
42 Regulation 2-1-114.
43 Proposed Amendments to Regulation 2, Rule 1: General Requirements and Regulation 9, Rule 8: Nitrogen Oxides and Carbon Monoxides from Stationary Internal Combustion Engines available online at: http://www.baaqmd.gov/ruledev/reg-pmt/r0201ph1.htm.
44 SFHC § 1110.
45 Diesel Reduction Plan at 1.
46 Ibid.
47 In return of a lower electricity rate, businesses participating in the voluntary curtailment program must reduce their electricity consumption when requested by the utilities.
48 For the purposes of this Report, vehicles used by the San Francisco Unified School District (SFUSD) are included in the City"s inventory of vehicles because the number of vehicles that are used. However, SFUSD is a quasi-state agency and is not subject to the City"s jurisdiction.
49 Equipment that Central Shops does not service is not included in this inventory. According to Central Shops staff, irregularly used back-up generators are likely undercounted.
50 Excludes 8 historic diesel fire engines.
51 City contracts involving very small number of vehicles are not included in this analysis.
52 Diesel fuel is much less expensive because it is a less refined fuel source as compared to alternative fuels.
53 64 Fed. Reg. 27169 (May 19, 1999), codified at 40 CFR Part 490.
54 Approximate price as of August 8, 2001. Market price varies depending on the size of the delivery.
55 H&SC §§ 39003, 39500; Western Oil and Gas Association v. Orange County Air Pollution Control District (1975) 14 Cal.3d 411.
56 H&SC§§ 39002, 39037, 41508; People v. City of Mendocino, (1984) 36 Cal.3d 476.
57 Currently, Central Shops charges approximately $.30 less than the top of the private market for diesel. Consequently, the appropriate surcharge may be between .05 and .30 cents per gallon.
58 "No Breathing in the Aisle - Diesel Exhaust in School Buses," Natural Resources Defense Council and the Coalition for Clean Air, January, 2001 at p.11. Available online at: http://www.nrdc.org/air/transportation/schoolbus/schoolbus.pdf.