RIALTO - The City Council voted in closed session on Tuesday night to settle its lawsuits against San Bernardino County regarding perchlorate contaminating groundwater.

Under the terms of the agreement, which the council unanimously approved, the county would pay Rialto $4 million and clean up the western portion of the contamination.

That cleanup could costs tens of millions of dollars.

"They are really the only responsible party that has stepped forward," Councilman Ed Scott said.

The county's contamination is flowing from the county-owned Mid-Valley Sanitary Landfill in Rialto's north end.

The county Board of Supervisors still has to approve the deal.

Perchlorate, used to produce explosives, is flowing through local drinking water, but officials say it is not being served to residents.

The city filed a federal lawsuit against dozens of parties, including the county, that it suspects of contaminating the water.

The city has also filed a separate lawsuit against the county in state court.

Also during the closed session, the council voted to have one of its outside attorneys, Susan Trager, manage its perchlorate-related legal battle.

Former City Attorney Bob Owen had served in that role until the council fired him in January.