1. What are the proposed rule changes?
The EPA has not yet announced what, exactly, the changes will entail - although they will definitely tighten regulations compared to what they were in 2001. NOx emissions have been dropping steadily, with the EPA reporting that they were down 40% between 2007 and 2017. The new changes will likely reflect this.
The changes may or may not have a significant impact on existing diesel buses, due to how diesel has become much cleaner over the past two decades.
2. Will the rule changes mandate new hardware?
Again, this is unknown, but it seems likely. The EPA has indicated that it is interested in adding requirements for onboard diagnostics and other mechanisms which would allow fleet operators to quickly demonstrate compliance with the new rules.
3. Has the EPA signaled any other changes?
The agency has indicated that they are hoping to reduce the regulatory burdens for certifying and maintaining NOx-compliance engines. How they plan to do this is unknown, but any reduction in red tape will be good news for school bus fleet managers.
4. What are the dangers of NOx emissions?
NOx refers to two closely related chemicals: nitrous oxide and nitrous dioxide. Nitrous dioxide, which is formed when nitrous oxide binds with free oxygen in the atmosphere, is poisonous to people and many animals in high concentrations. NOx gases, in general, also contribute to smog and the creation of acid rain.
NOx is considered among the most harmful of engine emissions, and governments around the world are continually looking for new ways to reduce this form of pollution.
Stay Tuned for More Updates
At present, not too much is known about the EPA's planned changes, but we will be following the issue and adding information as it becomes available.
In the meantime, are there any particular changes you're hoping to see? Let's talk about it in the comments.