Many institutions maintain fleets of trucks, buses, ambulances, and other vehicles on site. Do this carefully to keep gasoline, oil, and soap suds out of storm drains and waterways. Vehicle maintenance should be done indoors, using drop cloths and drip pans. If there is a spill, clean it up promptly using absorbent sand and kitty litter.
The Massachusetts Office of Energy and Environmental Affairs has published guidelines on fleet maintenance for municipal governments. It's good advice for businesses, churches, hospitals, and other institutions, too!