Option 1: equipment engines meet the most current Environmental Protection Agency (EPA) particulate matter (PM) Tier emission standards in effect for non-road diesel engines for the applicable engine power group
Option 2: equipment engines contain emission control technology verified by EPA or the California Air Resources Board (CARB) for use with "non-road engines."
Option 3: equipment engines contain emission control technology verified by EPA or CARB for use with "on-road engines," provided that such equipment is operated with Ultra Low Sulfur Diesel fuel.
Option 4: equipment engines contain emission control technology certified by manufacturers to meet or exceed emission reductions provided by either "on-road" or "non-road" emission control technology verified by EPA or CARB.
If contractors have equipment that complies with Option 1, then that equipment will not have to be retrofitted with either an oxidation catalyst or particulate filter. However, if emissions from diesel equipment comply with the most current EPA emission standards for particulate matter in effect at the time, but are superseded by newer Tier emission standards (i.e., Tier 3 emission standards replaced by Tier 4 emission standards), then the superseded diesel equipment will have to be retrofitted prior to the end of the contract with emission control technology per Options 2, 3, or 4.
Several other pertinent changes contained in MassDOT's revised diesel retrofit specification include the following:
- Rented diesel equipment greater than 50 horsepower that is used on site for 30 days or less over the life of the project will be exempt from having to comply with the revised specification. If used over 30 days, the rented equipment will have to comply with the revised specification.
- Retrofit devices that were installed under the original retrofit specification can be used to comply with the revised specification if a manufacturer certification is provided that shows the retrofit device meets the following minimum emission reductions:
For Diesel Oxidation Catalysts
- at least 20% for Particulate Matter
- at least 40 % for Carbon Monoxide
- at least 50 % for Volatile Organic Compounds
For Diesel Particulate Filters
- at least 85% for Particulate Matter
- If additional or replacement equipment is brought onto the job site after work has commenced, the contractor has 15 calendar days from the time the replacement equipment is brought on site to comply with the new specification.