Efforts to Improve Regional Air Quality (Goal 1)

February 25, 2011

Last week's post demonstrated the extent to which SEPTA reduces regional greenhouse gas emissions by taking cars off the road, reducing congestion, and supporting energy efficient, transit-oriented development. These functions make SEPTA one of the region's most valuable assets in mitigating and adapting to global climate change.

But climate change is just one area in which SEPTA is working to improve the region's environmental performance. This week, we'll describe SEPTA's efforts to improve regional air quality by reducing criteria air pollutant emissions from its combustion engine vehicles.

A Regional Problem

Improving air quality is a critical priority for the Greater Philadelphia region. In 2007, Philadelphia was rated the second worst city in the United States for asthma suffers by the Asthma and Allergy Foundation of America. Today, the region remains designated as a "non-attainment" area based on National Ambient Air Quality Standards (NAAQS) for ozone and direct fine particulate matter. Portions also remain designated as "maintenance areas" (previously designated as non-attainment) for carbon monoxide (CO).

Diesel fuel consumption is a major contributor to these deleterious conditions. For years, regulatory bodies such as the U.S. Environmental Protection Agency (EPA) have responded by issuing increasingly stringent emissions standards. These standards have driven diesel engine manufacturers to develop cleaner-burning diesel-powered vehicles.

SEPTA's Answer

Since 2000, SEPTA has overhauled virtually its entire bus fleet with these cleaner-burning diesel vehicles. Purchasing (and retiring) more than 100 buses per year, each successive bus procurement cycle has reduced the average age of SEPTA's fleet from 9.6 to 6.5-years-old and in so doing has improved its air quality performance as measured by two key indicators: particulate matter (PM) and nitrogen oxides (NOx).

Above and beyond the procurement of cleaner vehicles, SEPTA has also implemented measures to clean its fuel. Notably, a policy to purchase Grade No. 2 ultra-low-sulfur diesel (ULSD) fuel for all buses has contributed incremental reductions in particulate matter by mitigating the poisonous impact that sulfur has on diesel engine converters. The outcomes of these vehicle and fuel-related bus procurement initiatives are impressive: since 1999, SEPTA has reduced PM and NOx emissions from its bus fleet by 80 percent and 60 percent respectively.

While the lion's share of SEPTA's local criteria air pollutants are generated by its bus fleet, incremental reductions have also been realized by upgrading facilities and utility fleets. Across the region, SEPTA has begun to upgrade aging, inefficient boiler systems with new versions that have lower NOx emission profiles. Low-NOx boilers reduce emissions by 70 to 85 percent compared to older, conventional boiler equipment.

SEPTA is also committed to upgrading its diesel-powered utility fleet, and is actively seeking out financial resources to accelerate performance improvements in this area. Recently, SEPTA submitted a grant application under the EPA's "Clean Diesel" program to repower a diesel maintenance locomotive with a state-of-the-art "GenSet" technology. Installation of the GenSet would result in significant emissions reductions by replacing an aging, inefficient engine technology with one meeting the latest EPA emissions standards for locomotives. The application was endorsed by the City of Philadelphia's Air Management Services and Mayor's Office of Sustainability. Awards are expected to be announced in the Spring of 2011.

A Plan to Enhance Performance

Existing initiatives, as reflected in its bus procurements, ULSD policy, low-NOx boiler upgrades, and Clean Diesel grant application, exemplify SEPTA's approach to reducing criteria air pollutants and improving regional air quality. SEP-TAINABLE commits to continuous improvement on these fronts.

Procurements. With each passing vehicle procurement cycle, SEPTA has continued to improve its air quality performance, as demonstrated by dramatic reductions in NOx emissions and particulate matter. SEPTA continues to prioritize emissions reductions in future vehicle procurements while evaluating new opportunities to fund retrofit projects, such as EPA's Clean Diesel program. For calendar years 2012 through 2015, SEPTA plans the addition of 285 new, state-of-the-art clean diesel and hybrid buses which will further complement SEPTA's fleet and continue the overall reduction in emissions and air-borne contaminants.

Facility Retrofits. Wherever possible, SEPTA should plan to replace old conventional boilers with low-NOx boilers that also meet new CO and PM emissions standards. Alternatively, SEPTA can evaluate opportunities to retrofit older boilers to burn fuel more efficiently using a higher-grade of heating oil.

What's Next

Over the past two weeks, we've laid out SEPTA's agenda to mitigate and adapt to global climate change and improve regional air quality performance. Next week, we'll shift to a focus on SEPTA's agenda for water conservation, and its initiatives to both reduce consumption and mitigate stormwater runoff.

Next Week: SEPTA's Water Footprint