Concerns over the cost and environmental impacts of desalinated water were overridden by the desire to fortify water supplies when the Orange County Water District board voted 6-2 Wednesday to approve non-binding contract terms with Poseidon, which has spent 20 years on the desalination plant proposal for Huntington Beach. The plan for the $1 billion plant and water distribution infrastructure would increase the monthly bill for the average residential customer receiving the water by an estimated $3 to $6. It would help ensure the area has water during droughts when supplies from Northern California and the Colorado River are curtailed.