The Santa Clara Valley Transit Authority (VTA) has successfully tested a new diesel emission control technology on its buses, potentially bringing the elimination of older diesel bus emissions in California a step closer, reports the Oil and Gas Journal.

The Santa Clara VTA has installed the Extengine Advanced Diesel Emission Control (ADEC) system on a ten-year-old bus as part of a demonstration project funded by the California Transit Association.

Managed by the California Air Resources Board (CARB), the experiment revealed a more than 90 per cent reduction in Nitrogen Oxide (NOx) emissions, and a 95 per cent reduction in Particulate Matter emissions (PM) from the vehicle.

The ADEC system's results are far more impressive than any recorded in tests of other systems, suggesting that the most effective way to reduce emissions from older vehicles has been found.

Extengine Transport Systems president Phil Roberts said 'each older diesel bus can spew hundreds of pounds of NOx, soot and other pollutants into the air each year, but the test results show that number can be reduced to a mere fraction by installing the ADEC system.

'Plus, the retrofit system's cost is substantially lower than buying a new diesel or CNG bus. There just aren't many transit bus operators that can afford to replace their diesel-powered fleets in these days of big budget deficits'.