This was and is the largest inland oil spill in US History, over 700,000 gallons of Diesel Fuel (Off-shore and at sea tanker have spilled more, but those are NOT in internal waters).
I was in the National Guard at that time. The oil storage tank was just upstream from the water intake for the water of the South Pittsburgh Water Company. While the water for the City of Pittsburgh itself was NOT affected (Most of Pittsburgh gets its water from the Allegheny River), the Suburbs to the South of the City had their water cut off. I was called into service to haul water buffaloes to various places in the South Hills so that people would have water. It was declared a national emergency and I stayed at the Local Air Force base, where the Water Buffaloes were kept (The US Air Force Flew in addi tonal Buffaloes, we needed them). I also refueled with Air Force Diesel when I needed additional fuel. This was all due to the fact it was a NATIONAL EMERGENCY.
My point is, while the Spill was a "local" spill, the Federal Government provided all the help it could (i.e. personnel, fuel, equipment). That happens in almost ANY emergency, for only the Federal Government has the resources to bring to bare (Even as the locals are doing most of the work). Did Pennsylvania have the water Buffaloes to provide water to everyone? No, but the Federal Government could gather such buffaloes from its own reserves AND other states and get them to where they were needed. The State could NOT. The federal Government, the State Government and the local government all worked together to get the job done (It was funny, watching the local health inspector climbing the water buffaloes kept in an Air Force Hanger, testing the water in the Buffaloes to make sure the water was "safe". It not enough chlorine was in the test sample, he had hid handle bottle of Clorox to add to the water, thus a local official making sure the water was safe, in a federal hanger, testing water to be hauled out by the State National Guard, in water buffaloes provided by the Federal and state governments).
No disaster can be handle by local officials, they do NOT have the resources to address such problems. Most states do NOT have the resources, again most are to small in population to have the revenue to provide the needed aid. Only the Federal Government has the resources and is far enough away from the problem to correctly asses it and provide the needed resources. Local Government can provide the volunteers and direct where the aid is needed the most, but the aid has to come from someone NOT affected by the Disaster. Thus the Federal Government is the only agency that can provide the needed level of resources and supervision of how and who gets the resources to provide the fastest and most efficient care of victims of disasters.
For more on the Spill:
http://query.nytimes.com/gst/fullpage.html?res=940DEEDA123EF936A35752C0A96E948260http://www.pittsburghcitypaper.ws/gyrobase/Content?oid=oid%3A28974