Cargill is in a fight with California environmentalists over the future of a salt production site the company is no longer using.

The 1,400 acres of former wetlands along San Francisco Bay were diked off from the tides to create salt evaporation ponds. Cargill hasn't used the ponds since a consolidation in 2005.

Now, the food giant is partnering with an Arizona luxury home builder to pave over the ponds and build a 12,000-unit housing development.

A group called Save the Bay has mobilized against the project, calling it a "reckless" plan that will permanantly destory the largest stretch of restorable bay shoreline in the region.

The development partnership representing Cargill says the homes address a growing need for housing in the area, and that it would include green space and wetland restoration.

Another wild card: the threat of rising sea levels. No local, state or federal agency has authority to block coastal development based on that threat, however, according to the San Jose Mercury News.