Tier 4 Rules

April 23, 2017, 7am PDT
The California Air Resources Board has petitioned the U.S. EPA to adopt more stringent emissions standards for locomotives in order to improve air quality at rail yards, many of which are located adjacent to disadvantaged communities.
RailwayAge
July 20, 2016, 8am PDT
Forty so-called Tier 4 locomotives, a U.S. Environmental Protection Agency designation requiring a dramatic reduction in particulate and nitrogen oxide emissions, will be joining Metrolink's fleet covering 512 track miles in six counties.
Los Angeles Times
April 16, 2014, 7am PDT
According to a new EIA report, the cost advantages of liquefied natural gas make it an attractive alternative to diesel fuel for major U.S. freight railroad companies. Hybrid diesel-electric locomotives on order for 5 states will power HSR routes.
Progressive Railroading
March 24, 2014, 6am PDT
Thanks to the 2010 federal requirement of ultra-low sulfur diesel fuel and new Tier 4 emissions standards by the EPA, particulate emissions from non-road diesel engines, including agricultural and construction equipment, have been reduced by 99%.
Environmental Health News