SALTON CITY - A 200-foot ditch is ground-zero for testing a chemical treatment designed to keep fertilizer runoff out of the troubled Salton Sea, preventing the massive fish kills and rotten egg odor often plaguing the desert region.

"When that happens, we can get dozens of complaints a day," said Tom Kirk, executive director of the Salton Sea Authority.

The fish kills and stench harm the 400 bird species, including endangered brown pelicans, that use the Salton Sea for feeding and nesting, and the foul odor makes it less desirable to visitors.

Fertilizer entering the sea is the main offender. Once fertilizer runoff makes it into the large lake, one of its main ingredients, phosphorous, encourages algae to grow.

When algae blooms die, they suck up oxygen, which leads to fish kills and a pungent odor in the blistering summer and early fall months. As many as 15 million fish have died in a summer.

At the test ditch, which sits on a fish farm run by Kent SeaTech, Professor Chris Amrhein from the University of California, Riverside, helped turn on the nozzle Thursday that pumped water from the Whitewater River into the ditch.

The environmentally friendly chemical Alum is dribbled into the ditch, causing the phosphorous to drop to the bottom where it is then scooped up.

"We want to make this as low-tech as possible. We don't want expensive gadgets at the sea," Kirk said.

If it works, the treatment could be applied to the hundreds of agricultural drains that feed the sea, Amrhein said.

SIMI VALLEY - Perchlorate has been detected in groundwater silt where a housing development is planned downhill from the old Rocketdyne Santa Susana Field Laboratory.

Environmentalists said Thursday they fear contamination from the research facility is seeping offsite.

Water regulators and the Boeing Co. cautioned that tests for perchlorate sometimes are in error and that further testing is needed to make sure the rocket fuel byproduct is in the groundwater. Perchlorate has been linked to thyroid dysfunction in humans.

The current limit on perchlorate in drinking water is 4 parts per billion. Consultants for the Runkle Canyon development found perchlorate at 50 ppb and 60 ppb in two different samples pulled from 37 feet and 56 feet below ground.

The tests were made at the midpoint between the Rocketdyne site in the Simi Hills and the Simi Valley floor, said Dan Hirsch of the watchdog Committee to Bridge the Gap organization.

"It's very strong evidence connecting the dots between the contamination at field lab and Simi Valley," Hirsch said.

GreenPark development wants to build 550 homes on the Runkle Canyon property northwest of the field lab. An environmental impact report will be released soon.

"We've done a lot of testing around the facility," Boeing spokesman Dan Beck said. "It cannot be definitively said Rocketdyne is responsible for offsite perchlorate."

"We're going to be looking at the findings," said Dennis Dickerson, executive director of the Los Angeles Regional Water Quality Control Board. "Our first step is really to look at the original testing documents."

LOS ANGELES - A judge ruled Deputy District Attorney Steve Ipsen intentionally argued different theories of the same murder in two death penalty trials to get convictions against each defendant.

Superior Court Judge Thomas L. Willhite sent his written findings this week to the California Supreme Court to determine whether Ipsen engaged in misconduct in the two 1990 cases and what should happen to the death row inmates as a result.

"Ipsen's argument of inconsistent factual theories was an intentional strategic decision designed to fit the evidence Ipsen presented and to maximize the portrayal of each defendant's culpability," Willhite wrote.

The California Supreme Court ordered a hearing after inmates Tauno Waidla and Peter Sakarias petitioned the high court alleging prosecutorial misconduct.

Waidla and Sakarias were convicted of robbing and murdering fellow Estonian immigrant Viivi Piirisild.

Ipsen argued in Waidla's trial that Waidla struck the fatal blow. He then argued in Sakarias' trial that Sakarias struck the fatal blow, according to the judge's report.

The state Supreme Court can order a retrial or reduce the sentences to life without the possibility of parole, attorneys said Thursday.

Ipsen claimed he inadvertently made the conflicting arguments.

"I didn't intend to mislead the jury," Ipsen testified during an October hearing before Willhite.

But attorneys for the inmates said Ipsen purposely manipulated the evidence and violated their clients' due process rights.

"There were just too many things to believe that it was a coincidence," Sakarias attorney Cliff Gardner said. "I think that the state should not be intentionally arguing inconsistent theories just to put two people away."