A sewage spill that forced the closure of a section of Laguna Beach is expected to keep swimmers out of the water through the Fourth of July holiday weekend, officials said Friday. The Orange County Health Care Agency closed ocean waters extending one-quarter mile north and one-quarter mile south of Anita Street at Thalia Beach after approximately 2,000 gallons of sewage spilled into the ocean Thursday because of a malfunctioning force main sewer line pump.