Despite a state report to the contrary, Sebastopol officials said the Laguna de Santa Rosa wetlands is plagued by excessive amounts of two nutrients and pointed to an infestation of the water weed Ludwigia as proof.

Mayor Larry Robinson, in a letter today to the State Water Resources Control Board, said nitrogen and phosphorus from residential and agricultural runoff are contributing to a serious public health problem that threatens the laguna's future.

Robinson criticized an agency report that said the nutrients are no longer at dangerous levels and recommends they be removed from a federal list of substances polluting the laguna.

Such a "delisting," officials said, could jeopardize hundreds of thousands of dollars for laguna protection and restoration.

"Why they are trying to take this action is beyond me," Robinson said. "There's a serious load of nitrogen and phosphorus in there."

Craig J. Wilson, the agency's chief of water quality assessment, declined to comment.

He referred calls to water board spokesman Chris Davis, who said numerous tests showed nitrogen and phosphorus levels did not exceed public health protection levels.

The federal Environmental Protection Agency put the nutrients on the list of laguna pollutants in 2002, but "our analysis couldn't support their findings," Davis said.

The real culprit is dissolved oxygen, a pollutant that is linked to the presence of nitrogen and phosphorus, Davis said.

He said removing dissolved oxygen will reduce levels of nitrogen and phosphorus.

"That will be part of the solution," he said.

But some expressed doubt about the approach.

Robinson said de-listing the nutrients would take away impetus to mount a costly campaign to restore the laguna, an effort that could include dredging.

"De-listing would remove funding sources to clean it up," Robinson said. "It will also make it harder to enact regulation of runoff."

Brenda Adelman, a spokeswoman for the Russian River Watershed Protection Committee, said it could lead to increased wastewater discharge from Santa Rosa.

Adelman said the action appears to be influenced by two Santa Rosa consultants who have been lobbying the state to remove nitrogen and phosphorus, she said.

Adelman said if the two substances are removed from the list, Santa Rosa would be able to discharge more wastewater from its regional treatment plant into the laguna.

"I'm concerned it's a political thing," she said.

Robinson also complained about the lack of public input before the decision, which is expected from the EPA by April.

And he criticized the state agency for eliminating regional board meetings in Santa Rosa. A Dec. 6 hearing on the de-listing is in Sacramento.

"We want them to hold a public hearing in Sonoma County so people who have done a lot of research can present their findings and opinions," Robinson said.

You can reach Staff Writer Paul Payne at 521-5250 or ppayne@pressdemocrat.com.