Ongoing disagreements between Poseidon Water and state regulators over a proposed desalination plant in Huntington Beach have resulted in a March 17 permit hearing being postponed at the company’s request.

Poseidon is seeking the final permit needed, from the state Coastal Commission, before it can finalize contract terms with the Orange County Water District and begin construction on a controversial, $1.4 billion plant that would produce enough drought-proof water for 400,000 people. The hearing slated for next month is now expected in May.

Environmentalists have rallied steadfastly against the plant, arguing that the more costly water is not needed in the north and central parts of the county it would serve, that it would kill marine life unnecessarily, that proposed mitigation for the environmental damage is inadequate, and that the site is vulnerable to sea-level rise.