Anything from the train derailment is long gone. You should be more concerned about local air pollution sources like power plants, asphalt batching, and diesel exhaust. Not to mention the multiple quarries in Rhode Island that don't do adequate dust suppression and blanket the neighborhood with silica dust (carcinogen)

however if your heart is set on it, you could run method 8260C on liquid water. However, there's nothing specific about snow that would change the results vs all the rain we've had since the derailment.