Golden Gate Bridge, Highway & Transportation District

July 13, 2007

On July 13, the information below was presented to the Board of Directors and a decision was not made as to any of the possible emission options noted. The matter will come back to the Board of Directors for further discussion and the date will be posted here once the date is determined.




In June 2006, the Board of Directors (Board) of the Golden Gate Bridge, Highway and Transportation District (District) approved construction of a new high-speed ferry that will be the largest in the Golden Gate Ferry fleet, carrying 499 passengers, subject to completion of associated environmental analyses. It will be the third high-speed vessel in the fleet. The new ferry construction project has a budget of $12 million (80% FTA, 20% District funds) and must meet all existing Environmental Protection Agency (EPA) and California Air Resources Board (CARB) emission standards.

In March 2007, the Board authorized contracting with Fast Ferry Management, Inc. (Martin J. Robbins, principal) to assist staff by providing project management and construction oversight for the new ferry including assisting in developing what requirement for emission standards should be included in the Request for Proposal for construction of the new high-speed ferry.

The question was raised by both some members of the public and by some Board members regarding whether the new high-speed ferry should be built to a standard that exceeds current CARB and federal EPA standards.

On June 23, 2007, the Board requested additional information regarding ferry emissions standards and technologies available to meet current and anticipated standards. Fast Ferry, as part of their contract, was required to conduct analysis and report options. This information is being presented to the Board on July 13, 2007 at their 10 am meeting.

Staff is seeking direction from the Board regarding what requirement for emission standards should be included in the Request for Proposal for construction of the new ferry.

Ridership Demand for a New High Speed Ferry
In July 2004, following the continuing success of high-speed ferry service since debuting in 1998, the District introduced two-vessel, high-speed service for most weekday Larkspur-San Francisco crossings. This service is provided by two high-speed ferries, with no high-speed backup vessel available in case of engine failure or annual dry-docking needs.

Using fast ferries has made it possible for the majority of commute period trips to be 30-minute crossings (down from 45-minutes). The popularity of this high-speed Larkspur ferry service has caused average weekday ridership to grow at an annual rate of 6.4% per year since April 2005. Ridership on the three weekday morning peak departures (7:10, 7:50 and 8:20 am) from Larkspur to San Francisco increased 13.4% to nearly 1,200 passenger trips between April 2005 and April 2007. At times, passengers are left behind for these three morning departures.

Propulsion Systems and Emission Reduction Technologies

Over the past few years there has been significant focus within the maritime industry and regulatory arena on reducing ferry exhaust emissions. Staff has closely monitored proposed regulations regarding emissions; the status of development of new, cleaner marine engines; and development of and experience with new technology designed to treat engine exhaust emissions (after-treatment).


Several years ago, the EPA created regulations requiring a reduction in the emission of harmful exhausts from marine engines. As a result, in January 2007, certain engine manufacturers made available engines that meet the new Tier 2 requirement. These engines are cleaner than those installed on our existing vessels. The EPA is currently considering additional regulations that would require even further reduction in marine engine exhaust emissions. It is anticipated that these regulations would require reductions in emissions that cannot presently be met with engine technology improvements and therefore, additional methods/equipment would have to be considered. This equipment is commonly referred to as after-treatment. While at present, the EPA has not adopted any further regulations mandating a higher level of emission reductions, the engine manufacturing industry has continued to work on developing further engine improvements that are expected to result in what is known as a Tier 3 engine. Such engines are not available today.

In 2006, the California State Assembly introduced draft legislation requiring that all ferry vessels meet an emission reduction criteria similar to what is required of the Water Transit Authority (WTA), Tier 2 engines plus a combined 85 percent additional reduction in particulate matter (PM) and nitrogen oxide (NOx). This standard can only be met using after-treatment technology. Due in part to a desire to see what comes of the California Air Resources Board (CARB) investigation of this same issue, the bill language was ultimately removed and replaced with language regarding an issue unrelated to the topic of marine emissions. At this time, staff is unaware of any proposed legislation proceeding through the legislative process.

CARB is involved in a rulemaking process regarding ferry emissions that could require installation of a Tier 2 or 3 engine and after-treatment technology to achieve an additional 85 percent reduction in exhaust emission (same as the WTA standard). We anticipate this requirement will be applicable to all newly constructed ferries with a capacity of more than 75 passengers. During a CARB presentation in June 2007, we were informed that this item would be scheduled for consideration by CARB's Board this September. However, the published 2007 CARB rulemaking calendar does not include this item, so it is uncertain at this time when a proposed regulation will be considered by CARB.

Main Engine Technologies

There are basically three engine manufacturers that provide engines for installation on commercial high speed ferries: Cummins, MTU/Detroit, and Caterpillar. Over the past several years, each company has developed engine technology to meet the tiered system mandated by the EPA. Currently, each manufacturer has, or is developing the Tier 2 technology. For the proposed new vessel, at a minimum, the District will install a Tier 2 engine, and we are investigating the possibility of a Tier 2 (-20) engine. A Tier 2 (-20) engine is basically an early version of the Tier 3 engine that will be required in 2012. Using our existing high speed vessels as a baseline, the new vessel, with installation of either the Tier 2 or Tier 2 (-20%) engine, will reduce emissions by 42 to 45 percent as compared to our current boats.

This year’s budget includes funds to replace the existing Tier 0 engines on the M.V. Mendocino with the new, cleaner Tier 2 engines—funded partially with grant monies specifically made available from the Carl Moyer grant program. There are plans to also replace the M.V. Del Norte engines with a Tier 2 engine in the coming years.

After-Treatment Technology

To meet the level of emission reduction being discussed by both the EPA and CARB, it is generally accepted that after-treatment technology will be necessary which requires the installation of additional equipment on the vessel to treat the engine exhaust and reduce the amount of harmful emissions being discharged from the vessel. This after-treatment technology is commonly referred to as Selective Catalytic Recovery (SCR) and the process requires the introduction of a liquid urea to create the necessary chemical reaction. This process is explained in detail in Attachment A.

While this technology has been successfully deployed in industrial and commercial applications, and has seen limited use on large vessels, it is relatively new to the high-speed ferry industry—there are only two known installations on high-speed ferry vessels: one in Europe and the other in Vallejo, CA. The trial use of the SCR equipment on the vessel in Europe was discontinued shortly after delivery due to lack of government subsidies. The SCR equipment on the Vallejo vessel has been in operation over two years. A recent inspection by the vessel owner of the Vallejo installation has revealed disappointing results, including concerns that the equipment may be contributing to premature engine wear and failures.

The full report covering the Vallejo experience as presented to the Vallejo transit system’s General Manager is included in Attachment B. The report recommends indefinite suspension of operation of the after-treatment equipment on the Vallejo vessel. Vallejo transit officials have not yet made a decision regarding this recommendation.

The WTA presently has a contract with a Washington shipyard for construction of two small medium-speed vessels with a passenger capacity of 149, and an estimated speed of 26 knots. The specifications for these two vessels will require a Tier 2 engine with a combined 85% reduction in PM and NOx. This requirement dictates the installation of after-treatment (SCR) equipment. The shipyard and equipment manufacturers have agreed to meet this specification and will utilize the SCR technology to achieve the 85% reduction. While the SCR equipment itself will be fundamentally similar to that installed on the Vallejo vessel, the arrangement and placement of the equipment in the vessel will be different.

The SCR equipment removes primarily NOx and only a small percentage of PM. The percentage of PM estimated to be removed is less than 5%. At the present time we are not aware of any technology suitable for a marine application that captures particulate matter beyond this 5% level.

Summary of Options for New High-Speed Ferry
The following options are offered for discussion in determining the propulsion/emission requirements to be included in the procurement of the new high-speed ferry:

Option A: Comply with Current EPA Regulations and Install Tier 2 Engine

  • 42 percent reduction in emission versus current vessels
  • No significant cost increase in projected vessel capital or operating costs
  • Minimal increase in fuel consumption
  • This option is the current approved plan for the new high-speed ferry

Option B: Build to Meet Potential CARB Regulation (i.e. WTA standard): Install Tier 2 Engine and SCR After-Treatment Equipment

  • 62 percent reduction in emission versus current vessels
  • Significant cost increase in projected vessel capital costs ($1.7 million)
  • Increase in fuel consumption (11,000 additional gallons; cost $633,000 annually)
  • Increased vessel size and weight
  • Larger engine to make required speed (additional $200,000)
  • Could negotiate extended warranties and maintenance agreements but anticipate additional costs included up front to address supplier’s risk

Option C – Comply with Current EPA Regulations and Install Tier 2 (-20) Engine

  • 45 percent reduction in emission versus current vessels
  • Minimal cost increase in projected vessel capital and operating costs ($100,000)
  • Increase in fuel consumption (114,000 additional gallons; cost $314,000 annually)
  • Slight increase in vessel weight
  • Conditioned upon commitment of available engine technology

Option D – Defer Construction of New High-Speed Ferry

  • No added capacity to address passengers left behind

Option D.1 – Defer Construction of New High-Speed Ferry and Add One A.M. Trip Using Spaulding Vessel

  • Increased Operating Costs ($572,000 annually for additional crew and fuel)
  • No reduction in vessel emissions (net increase in emissions)
  • Increased capacity

Summary of annual parameters for all options

Option A
Option B
Option C
Option D

Fuel Consumed


Annual After Treatment
Operating Cost
Annualized After Treatment
Capital Cost
NOx + UHC (lb)
PM (lb)
CO (lb)
Total Emissions (tons)
Emissions Reduction (%)
Annual Total Cost per Ton of Emissions Reduction
Total Annual Emissions per Passenger (lb)


Total San Francisco Bay Area annual emissions for NOx, UHC, PM, and CO are estimated at 4,062 tons per day, or 1,483,000 tons per year. Currently, the fast ferry operations of the District account for 0.0186% of that total. The options listed above would further reduce that contribution by one-half to two-thirds.

According to the National Safety Council: One person using mass transit for an entire year, instead of driving to work, can keep an average of 9.1 pounds of hydrocarbons, 62.5 pounds of carbon monoxide, and 4.9 pounds of nitrogen oxides from being discharged into the air.

Fiscal Impact
Options “B” and “C” will require an increase in both the capital and operating budgets for the proposed new high-speed vessel.

Option “D-1” will require an increase in the Ferry Division’s Operating Budget. It is reasonable to assume that 50 to 80% of the extra capital costs could be funded by grants, but at this time there is no commitment from any granting agency to fund the increased costs. There is no outside funding source for additional operating expenses associated with any option presented. The District’s FY 07/08 Capital Budget includes $12 million for the ferry vessel replacement project funded 80% by the FTA and 20% by the District.


Attachment A: Engine Selection & Emissions Analysis Report

Attachment B: SCR Project – M/V Solano