Environmental effects of sodium hydroxide?

I'm doing a project on oven cleaner and its main active ingredient sodium hydroxide. I'm asked to talk about the environmental effects sodium hydroxide has on the environment and so far I only have that it is hazardous to water and can kill fish. Does anyone know of other effects that sodium hydroxide has on the environment? Also, on a semi-related note, does anyone know what happens to hazardous waste after it goes to a hazardous waste site? Any answers would be appreciated.