This approach refers to installing advanced exhaust controls (retrofitting vehicles and equipment), or replacing (repowering) engines.
Of the three approaches, retrofitting is the most cost-effective strategy on a cost per ton of pollutant-reduced basis. Typically, diesel retrofits involve adding a device to remove emissions from the engine exhaust. Retrofits can be very effective, eliminating up to 90% of pollutants, depending on the device. Some examples of devices are diesel oxidation catalysts, diesel particulate filters and closed crankcase ventilation systems.
DEQ offers technical assistance on these approaches and can refer fleet managers to vendors and other resources for more information. Grant money may be available to help with costs.