From what I've gathered (I live near it), the spill, while not good, is not really a toxic material, some latex coating and the amount wasn't that much. Like one train car's worth. I seriously doubt it'll be an issue. I hate to say it but considering how scummy people are, 8,000 gallons of paints and such are probably dumped in that river normally as it is 1 gallon at a time by people pouring stuff out when they are done DIY projects. Watch the news tomorrow, if anything big is actually happening you'll hear about it, otherwise, continue with your trip plans.