Please see post #7.
BNSF needs to hire an environmental consultant...
As with trucks, an effective operational strategy to reduce locomotive emissions is to reduce idling. Locomotives may idle for as long as eight hours while cars are switched or while the train waits on a siding for other trains to pass. Idling may also be needed to keep the engine warm in cold weather and to keep accessories from freezing. However, locomotives are often kept idling even when there are no operational reasons to do so. EPA estimates that idling accounts for 60 percent of switch yard locomotive operating time and 12.5 percent of line-haul locomotive operating time.55
In order to reduce idling time, fuel consumption, and pollutant emissions, an APU can be used to provide power when a locomotive is idling. The CSX Corporation has developed an APU that automatically shuts down the main locomotive engine while maintaining all vital main engine systems, such as climate control and heating engine fluids in cold weather. The device is powered by a small diesel engine, and parallels all circulation systems on the locomotive. CSX and International Road and Rail, based in Canada, have formed a joint venture company called EcoTrans Technologies to manufacture and sell the system. EcoTrans estimates that the APU can eliminate 90 percent of switcher idling time. We estimate that retrofitting 50 percent of the switcher locomotives in the Baltimore and Houston regions with APUs, and reducing idling to the extent possible with these devices, would reduce annual NOx emissions by 231 tons and 277 tons respectively. These reductions represent 10 percent and 6 percent of the total annual freight railroad emissions in these regions, respectively.
Locomotives can also be installed with automatic shut-down devices. These devices monitor the locomotive temperature and restart it as necessary to maintain minimum temperatures. Newer locomotives are also equipped with a low idle setting that reduces fuel use and emissions during extended idle periods. Replacing older switch yard locomotives with these newer units can help to reduce the emissions associated with idling.56
http://www.fhwa.dot.gov/ENVIRONMENT/freightaq/chapter4.htmThe past is our future... with a few modifications. :)