I just remembered another volunteer gig that I do, because we just had our monthly meeting. I serve on my county's Local Emergency Planning Committee (LEPC). We prepare the Hazardous Materials Response Plan for the county, develop evacuation plans and routes in case of an emergency, provide emergency response training, and design and manage exercises to test the emergency response plan. We work with local Homeland Security personnel, police and fire departments, hospital administrators, and others who would be involved in responding to a hazardous materials emergency. It's very interesting work!
Also, although one has to be nominated by the LEPC to join, the meetings are open to the public. So if you're in the United States and are interested, your county's LEPC's website will provide the calendar of meetings and other information you'll need to attend as a guest.