May 22, 2018
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Green Light: Diesel Particulate Filters

Tailpipe Display

The tailpipe on the left has operated without a filter and the one on the right has.

In honor of sustainable projects and greening our community, I’ve decided to dedicate the first blog post of every month to highlighting a renewable, environmentally-positive project at MTD. Each of our properties boasts a long history of green initiatives, as well as dozens currently in progress. These posts will be categorized in the blog as “Green Lights.” This month, I’m going to introduce you to our diesel particulate filters.

A result of burning diesel or gasoline for energy is an output that contains harmful pollutants to our bodies and planet. Dr. Xinlei Wang, Professor of Bioenvironmental Engineering in the Department of Agricultural and Biological Engineering at the University of Illinois, approached MTD with an idea. Let’s create a filter to attach to the tailpipe of a bus to capture damaging matter before it can enter the air.

Dr. Xinlei Wang speaks with a member of the press.


Our Director of Maintenance eagerly agreed (he’s a total greenie) and research began in 2007. Initial research was funded by the EPA to study the feasibility of Dr. Wang’s idea against the cost of producing, installing, and maintaining the filters. Four diesel particulate filters were designed, created, and placed on four, in-service buses. Two of them were 40-foot and two were 60-foot articulated buses.

Dr. Wang and his students monitored the filters for three years. To give you some perspective, in one year a single bus travels an average of 45-50,000 miles. In a single day, a MTD bus will operate 18-22 hours a day. Needless to say, after three years a lot of valuable data had been collected.

Note the tailpipe attached on top, the cylinders below contain the filter.

Dr. Wang and his team found that their filters captured 90 percent of the subparticulates and 75-85 percent of the hydrocarbons and carbon monoxide emitted from the burning of diesel fuel in the engine. Over the course of one year, a single filter captured six tons of pollution. The four filters combined captured 24 tons.

This was success you could take to the bank. The American Lung Association donated funds for the placement of three more filters in the spring of 2009. Shortly after, funds were awarded from the EPA through ARRA grants to purchase 43 more filters in February 2010. You can watch the entire press conference that announced these funds on YouTube. Make sure to watch parts one and two! The Director of the Illinois EPA, Doug Scott, came to our facilities in Urbana on October 13, 2010 to congratulate MTD and the University of Illinois on the success of the DPF project. Photos of the event were posted on our Flickr page.

Currently, 80 percent of our fleet has been retrofitted with the filters. Each new hybrid bus that we purchase is delivered to the District with a filter already installed. As we continue to retire buses from the 1990s, and purchase hybrid buses as their replacements, MTD will eventually operate a 100 percent clean burning fleet. Cleaner air is a part of our present and future for the Champaign, Urbana, Savoy, and University of Illinois community.

Internal publication about the monitoring device installed on all buses with DPFs.

To read more about this project and its impact on our operators, read an article published on Mass Transit Magazine’s recent “Green Forum.” For those who may be interested, the manufacturer of our diesel particulate filters is Engine Control Systems.

If you’re too jazzed to wait until next month’s Green Light, visit the “Go Green” section on our website!

About Amy Snyder

Amy Snyder is the Customer Service Manager at the Champaign-Urbana Mass Transit District. She writes and manages content for this blog, The Inside Lane, as well as the social media pages for CUMTD.
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4 Responses to Green Light: Diesel Particulate Filters

  1. Jtron says:

    I have done some testing myself and have come to see that DPF filters are making vehicles burn more fossil fuels. By deleting a DPF and running a programer to bypass the re-gen cycle we have seen gains of 5-7 mpg. so in conclusion a DPF is actually causing more problems than it is solving.

  2. Willard Broom says:

    This project also had a “champion” on the MTD’s Board of Trustees–John Chato. He was a strong advocate for the effort and other sustainability initiatives. John’s involvement gave support and encouragement to Dr. Wang and to the MTD staff.

  3. asnyder says:

    Jtron, I forwarded your comment to our Maintenance Director. He said that We have not seen any decrease in miles per gallon with engines operating with DPFs. Please feel free to share your sources of information.

    Willard, thank you for reminding us about John Chato. He was instrumental in making this project a reality.

  4. Pingback: MTD Participates in Adopt Urbana Program | The Inside Lane

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Champaign-Urbana Mass Transit District
1101 East University Avenue
Urbana, IL 61802-2009
(217) 384-8188
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