Clean-Diesel Beats Cng In Key Public Transit Battles

Diesel Fuel News, Dec 25, 2000 by Jack Peckham

Clean-diesel advocates are starting to turn the tide in the relentless war by compressed natural gas (CNG) advocates and their "green" allies to ban diesels and force taxpayers to spend huge sums on a relative handful of CNG buses, with questionable clean-air benefits.

Latest examples:

* California's San Francisco Municipal Transportation Authority last week voted 6-1 to pursue the "clean-diesel path" for transit buses, while Santa Clara Valley Transportation Authority (VTA) likewise voted 7-5 for clean-diesel rather than the CNG path. Both votes came despite intense lobbying by the usual coalition of gas company interests, American Lung Association, Natural Resources Defense Council and others. At the Santa Clara hearings, the "greens" outnumbered clean-diesel defenders by 4 to 1, but clean-diesel's superior cost-effectiveness arguments won out.

The "greens" claimed that up to 150,000 people with lung illnesses could be harmed by diesels, but the VTA staff pointed out that far more clean-diesel buses can be bought with the money that otherwise would be diverted for much more costly CNG technology.

Standing up for clean-diesel technology in the debate were Diesel Technology Forum, Cummins, BP (Arco), Western States Petroleum Association and the Teamsters union, which represents bus drivers.

In California, all new transit buses must be equipped with particulate matter (PM) filters and use ultra-low-sulfur diesel (ULSD with 15 ppm sulfur cap). According to published studies, ULSD/trap-equipped green-diesel buses are as clean or cleaner than CNG on PM and "toxics," although green-diesel will have slightly higher NOx emissions until late 2002.

* Orange County Transit Authority (Santa Ana, Cal.) just took delivery of its first diesel-electric hybrid transit bus, equipped by Cummins, GM-Allison and New Flyer. The new bus, equipped with a catalyzed particulate matter (PM) filter, will also reduce nitrogen oxides (NOx) by about 50%, the technology partners said. Separately, Utah Transit Authority announced it aims to deploy three diesel-electric hybrid buses next year, followed a failed experiment with CNG buses.

* Washington, DC's Metro Area Transit Authority (WMATA) management announced it will ask for formal board approval to convert its entire fleet of 1,400 diesel buses to ultra-low-sulfur diesel (ULSD) starting next July, the agency's coming fiscal year. If approved, the move would immediately cut sulfate PM emissions, and later, when combined with PM filter retrofits, diesel buses will be as clean or cleaner than CNG buses on PM and "toxics."

WMATA's board recently voted to buy 100 CNG buses following an anti-diesel lobbying campaign that included pressuring DC's Mayor, regional government officials and WMATA board members. The campaign featured a "Diesel Exhaust Kills, Buy CNG" skull-and-crossbones propaganda leaflet campaign (see Diesel Fuel News 9/25/2000, p4).

Despite a staff report showing that WMATA could retrofit 1,000 diesel buses to eliminate the PM and toxics problems for half the cost of buying 100 CNG buses, WMATA board members were partly cowed by the "diesel kills" campaign, along with unproven allegations by DC Health Department that diesel exhaust may account for some of the elevated asthma levels in poor neighborhoods in Washington, DC. However, just this month, the Washington Post reported that mice urine, a household contaminant commonly found in poor neighborhoods, "may be a major contributor to asthma among poor children," according to a new study by prestigious Johns Hopkins University scientists.

Meantime, WMATA could face hundreds of millions of dollars of new costs to repair its Metro subway tunnels because of faulty water-leak-prevention design. "If the participating [regional] governments [that fund Metro] don't allocate sufficient money in prosperous times, what on earth will the region do when times get tough?" the Washington Post pointed out in a recent editorial.

Taxpayers and transit riders could similarly ask what will happen to bus service if WMATA diverts hundreds of millions of dollars to buy a relative handful of expensive CNG systems, when it may need those funds far more urgently to fix subway tunnel water leaks for its zero-emissions electric trains. Washington also could buy far more clean-diesel buses and retrofit existing buses with the dollars diverted for costly CNG.