REDUCING DIESEL PARTICULATE EMISSIONS AT WASTEWATER UTILITIES

Wastewater utilities use diesel engines for a number of important applications including emergencystandby power for wastewater pumping and treatment and sewer maintenance. Use of these engines is critical to utilities' mission of protecting public health and the environment. It has, however, been recognized that particulates emitted from diesel engines can cause significant health impacts.This paper will explore how wastewater agencies in California are embarking on a process of curbing diesel emissions to protect the public without compromising the reliability they need. It will also discuss national implications of California's progress on diesel emissions control.In 2000, the California Air Resources Board (CARB) adopted a Diesel Risk Reduction Plan. This plancalled for development of regulations to reduce emissions from all categories of diesel engines including stationary engines, portable engines, heavy-duty diesel vehicles, and off-road vehicles. Wastewater utilities operate engines in all of these categories and have therefore had a large stake in the process as these regulations are developed. Many of the regulations call for retrofit or replacement of engines, and utilities must be strategic about which engines they retrofit or replace when in order to maintain compliance while considering asset management approaches.Regulations adopted in California often spread quickly to other states. Therefore, wastewater utilities around the country can learn from the approaches used by California agencies, both for negotiating the regulations and for complying with them.