The debate over ocean water desalination is fierce here in San Diego, where Poseidon Resources is trying to build a desalination plant on the Carlsbad coast. But local environmental groups are crying foul.

The desalination plant would remove the salt from ocean water that's already being sucked in by the Encina Power Plant. One-hundred million gallons per day will be used to make drinking water.

Poseidon says they can provide 50 million gallons of fresh water to North County homes daily, but environmentalists say not so fast.