"We'd like a little more assurance," said David Webb, deputy public works director of Newport Beach.
But federal regulators will ultimately force local governments to take some action — whether or not in a regional partnership, officials say. Those deadlines could come between three and five years from now, according to Amanda Carr, Orange County chief of water quality planning.
If cities don't comply they could face fines of $10,000 per day.
The hope is to avert the type of selenium disaster that befell the Central Valley's Kesterson National Wildlife Refuge in the 1980s. Some birds there developed with eyes missing and beaks twisted.
Because of such risks, the federal government has stringent water quality standards. Generally, selenium is restricted to below 5 parts per billion in fresh surface waters.
Compare that to Newport's Big Canyon, where selenium has been measured in quantities as high as 100 parts per billion, according to city officials.
Another "hot spot" is near the former Marine Corps Air Station in Tustin, just upstream of the proposed Cienega treatment plant.
The IRWD Board of Directors was scheduled to meet Monday evening to discuss the fate of the Cienega project.