SHA’s operations and maintenance fleet includes approximately 906 light duty pieces and 1359 pieces of diesel powered equipment. A total of 750 of the light duty pieces are gasoline-powered.
Maintaining our fleet vehicles at peak operating conditions is one of the ways that we lessen our environmental impact. The agency also explores innovations and examines best practices to further protect the environment.
Some techniques are fairly simple and easy to implement. This includes SHA’s engine idling policy. It helps the agency reduce emissions by switching off engines after five minutes of idling.
Other methods involve a little more work. SHA received a $250,000 grant from the Environmental Protection Agency (EPA) to aid in retrofitting many of our diesel trucks with diesel oxidation catalysts. When we completed the installation of these devices, we almost immediately saw a 50% reduction in diesel emissions. Replacement vehicles come with the new filters, so as SHA replaces aging vehicles, we expect to see even further reductions in diesel emissions. This effort has enabled SHA to comply with the EPA’s Clean Air Act standards for ozone and particulate matter levels in the Chesapeake Bay area.” In order to become compliant with more stringent 2010 EPA regulations, SHA started purchasing dump trucks and other heavy-duty on road vehicles which are now equipped with Selective Catalytic Reduction systems (SCR). When EPA 2010 standards went into effect, no heavy-duty diesel engine can emit levels of nitrogen oxide (NOx) higher than .2 g/bhp-hr (grams per brake horsepower-hour), a standard more stringent than any in place in Europe. SCR is the only technology to date that has been proven to be able to meet this standard. In addition, SCR systems will reduce NOx emissions by up to 90%, Hydrocarbons (HC) and carbon monoxide (CO) emissions by 50-90% and Particulate matter (PM) emissions by 30-50%. As of the summer of 2014, a total of 164 heavy-duty vehicles were purchased by SHA with these systems. This number will increase as SHA replaces older vehicles.