MALIBU, Calif. (AP) — The mystery: Just whose waste is befouling the most celebrity-saturated stretch of California coast?
   The suspects: Malibu residents whose septic tanks might let what gets flushed down the toilet flow down the hills and into the Pacific.
   The strategy: DNA testing and a pledge, if need be, to get court warrants to inspect leaky tanks buried beneath the backyards of Hollywood stars.
   “Going to get messy’
   ‘‘This is going to get messy,’’ predicts Mark Pestrella, the Los Angeles County public works official tasked with the project.
   Loyalty to septic system

Complaints filed against state firms    

PORTLAND (AP) — The U.S. Equal Employment Opportunity Commission has filed three discrimination complaints against Oregon employers in the past two weeks, making it the agency’s busiest year in Oregon since 1998.
   The lawsuits against Conway Inc., Video Only Inc., and Gresham Nissan Subaru Inc. bring to four the number of lawsuits filed so far this year — three shy of the 1998 total.
   The number of lawsuits could be on the upswing because the agency consolidated offices this year, shifting responsibility over Oregon from its Seattle office to San Francisco.
   ‘‘The San Francisco district office is a very aggressive office,’’ said Joan Ehrlich, the district director in San Francisco. ‘‘I believe in ending discrimination. If we have to, we’ll file a lawsuit.’’
runs deep in a city that was incorporated to stop construction of a sewer line. Residents who fiercely deny that their tanks are the source of ocean bacteria also fiercely guard their privacy and their right to flush the estimated 2,400 septic tanks in a city strung along 25 miles of coast.
   After decades of wrangling, county officials are promising to get tough — threats of hefty fines by clean water regulators were an important push.
   Sea water to be tested
   Over the next few months, investigators will begin testing sea water. If DNA tests show waste is human and not from, say, raccoons or coyote, they’ll follow the trail up creeks that traverse neighborhoods in Malibu, where clean water advocates such as Pierce Brosnan and Ted Danson live.
   Where the tests show a concentration of human waste, inspectors will sleuth out the source. Though they won’t request DNA samples from residents to match waste with its human source, they say they may ask a judge for authority to inspect tanks of property owners who bar them from taking samples.
   Privacy is a concern
   ‘‘It is a big deal that the county is now saying ‘We’re willing to go on to properties to see what the source of fecal contamination is,’’’ said Mark Gold, executive director of the local environmental group Heal the Bay.
   Malibu leaders have argued that pollution comes from a wastewater treatment plant, storm runoff and bird droppings. The lack of a sewer system limits development and preserves rustic details amid million-dollar homes.