South Coast Air Quality Management District

Mobile Source Committee

SYNOPSIS: 

The Mobile Source Committee met Friday, October 27, 2000. Following is a summary of that meeting.

RECOMMENDED ACTION:

Receive and file.

Cynthia Coad, Chair
Mobile Source Committee

Attendance

The meeting started at 9:05 a.m. Present: Committee Chair Cynthia Coad, Committee Vice Chair Roy Wilson, and Committee Members Jane Carney, Jon Mikels and Ron Loveridge (arrived at 9:30 a.m.). Absent: Committee Member Norma Glover. The attachment is an attendance roster.

INFORMATION ITEMS:

1. Status Report on "Procedure for Calculating Toxic Risk Reduction from Vehicle Emissions"
   
   Staff presented a brief summary of the proposed procedure. The key issue for the toxics comparisons is the use of the Unit Risk Factor for diesel particulate as a measure for whole diesel exhaust risk, and the lack of a Unit Risk Factor for whole exhaust from alternatively fueled engines. Staff also reported on the items requested by the Committee at the last meeting. These included a review of the studies on natural gas exhaust and health effects, a summary of the available information on toxic emissions from diesel and natural gas heavy duty engines, a detailed analysis of the Ecotraffic study, and a description of the staff work-plan on characterizing the exhaust of conventional and alternatively fueled, heavy-duty engines. There was also a discussion on the possible consideration of uncertainty in the calculation procedure.
   
   Several public comments were received. David Smith, representing BP-ARCO and the South Coast Clean Air Partnership, proposed an alternative procedure to compare the mass of particulate and non-methane hydrocarbon emissions as a surrogate for toxics emissions. He also proposed an alternate reduction for NOx emissions. Mr. Smith also discussed other emissions, including carbon monoxide and greenhouse gases. Lee Wallace, representing Sempra Energy and Southern California Gas Company, briefly described a compilation of health studies relating to the traditional usage of natural gas and health effects that is being completed. This summary will be forwarded to AQMD when completed. Dr. William Bunn of International Truck & Engines also supported using an alternative, mass based approach to compare emissions. He offered to work with staff to develop short-term cell culture toxicity screening tests to compare exhaust emissions. Gail Ruderman Feuer, representing the Natural Resource Defense Council, spoke briefly in support of the District’s fleet rules and the path that staff is taking to compare toxics emissions. Stephanie Williams, representing the California Trucking Association, spoke in support of using particulate mass to manage emissions from diesel engines. She also pointed out that using CNG instead of diesel fuel would reduce the payload that trucks could carry.
   
   
2. Status Report on Fleet Rule Development:
   Medium-duty Vehicle Comparisons & CO
   
   Staff noted that at the adoption of Rule 1191 in June the Board directed staff to report back on the state-of-science of control technologies for diesel-powered medium-duty vehicles, and comparison of emissions between diesel, gasoline, and alternative-fueled engines.
   
   On control technologies, staff reported on the following: 1) Medium-duty engine/vehicle certification process. The certification applies to 6,000 to 14,000 lbs gross vehicle weight rating (GVWR) engines/vehicles. There are two emission certification processes: engine certification (measured by the unit of gm/bhp-hr), and chassis certification (measured by the unit of gm/mi). Examples of affected medium-duty vehicles were also provided. 2) Control technologies. Current control technologies evolve around engine designs for both diesel engines and engines fueled with gasoline, CNG or LPG. Relative to potential diesel control technologies, there are three types of aftermarket devices that can be used to control particulate matter, and various research is being conducted for controlling NOx. In summary, staff believes that engine improvements and add-on controls are needed, and that commercial products to meet LEV-II standards most likely will not be available by 2004.
   
   On comparison of emissions, staff noted that there have been a lot of discussions about the relative amount of CO emissions that would occur from the use of alternative-fueled or gasoline engines compared to diesel engines. Staff reported that studies show that relative to NOx emissions, a fairly large amount comes from diesel emissions; relative to HC and CO emissions, emissions from all on-road diesel vehicles are about 2% of the total emissions. Projected on-road CO emissions from EMFAC7G indicate that CO levels are dropping by a few hundred tons per day on a yearly basis. It is projected that the attainment of the CO air quality standard would be achieved in the 2001-2002 timeframe. Staff also reported on emissions inventory topics. With regard to light- and medium-duty diesel vehicles, Rule 1191 affects about 0.7% of total diesel vehicles. The CO emissions for this are ~0.049 tons/day, and emissions forgone are ~0.30 tons/day. With regard to heavy-duty diesel vehicles, Rule 1191 affects about 16% of total diesel vehicles. The CO emissions for this are ~20 tons/day, and emission forgone are up to 120 tons/day. These are a small amount of the total emissions.
   
   Staff also briefly explained why medium-duty diesel engines are not included in Rule 1191. This is due to the requirement of State law. Rule 1191 basically says that a fleet operator can buy low emission or cleaner vehicles. It establishes the concept whereupon a list of rule-compliant vehicles could be used by fleet operators when purchasing vehicles. AQMD’s regulatory authority is based on Health and Safety Code Section 40919(4). The definition of low-emission vehicle is based on Health and Safety Code Section 39037.05. The definition does not include diesel technology.
   
   Staff recommended actions include: continue to monitor technological developments; evaluate new and future control technology studies; provide periodic reports as part of fleet rule implementation.
   
   
3. Pedestrian and Bike Projects Information
   
   Written report submitted, no comments.
   
   
4. Rule 2202 Activity Report
   
   Rule 2202 Summary Status Report submitted, no comments.
   
   
5. Monthly Report on Environmental Justice Initiatives
   
   Item #4 – CEQA Commenting:
   a. CEQA Document Commenting Update: Written report submitted, no comments.
   
   
6. Other Business
   
   None.
   
   
7. Public Comment
   
   None.

The meeting adjourned at 10:48 a.m.

Attachment

Attendance Roster

SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT
MOBILE SOURCE COMMITTEE

OCTOBER 27, 2000

ATTENDANCE ROSTER

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