Date: Fri, 30 Jan 2009 16:25:33 -0500
They (the Weston folks) may be right. I did a little Google research, starting from the Metrolinx FAQ ( http://www.metrolinx.com/gsse/FAQs/default.aspx) and then looking for definitions of the "2010 Tier 3 Environmental Protection Agency emission control requirements" mentioned there. From what I can tell, Tier 3 may be inadequate and Tier 4, a much more stringent standard, already exists. I don't know if locomotive engines are already being built to Tier 4 standards though.
Metrolinx does say they are planning to electrify this train route at a later date, but I question whether saying that simply excuses them from going for the higher Tier 4 standard now.
Diesel exhaust is considered a "probable carcinogen", it contributes considerable amounts of ozone, fine particulate matter (PM) and nitrogen oxide compounds (NOx) to the air.
Currently, GO trains are powered by older diesel-electric F59PH locomotives (1988, the "electric" part is not for locomotion but for lights, heat, etc) that do not meet Tier 3 standards.
Remanufactured locomotives EPA estimates 50-60% PM reduction, 15-20% NOx reduction (Tier 0 only); Effective as soon as certified remanufacture systems are available (as early as 2008), required no later than 2010 (2013 for Tier 2 locomotives)
New locomotives Tier 3 EPA estimates 50% PM reduction; [no NOx reduction?] Effective in 2011 for switcher locomotives, 2012 for line-haul and passenger locomotives Tier 4 EPA estimates 90% PM, 80% NOx reduction; Effective in 2015.