Army Engineers Sweep Park for Old Ordnance

The U.S. Army Corps of Engineers has begun scouring a section of O’Neill Regional Park in southern Orange County for half-century-old bombs, finding four expended bombs and an inert practice rocket, authorities said Wednesday.

Technicians are focusing their search on a 22-foot-wide corridor planned as a bike trail where 11 small bombs were discovered last fall by workers laying asphalt.

The sweep for unexploded ordnance at the former U.S. Navy Trabuco Bombing Range had been scheduled for 2023, but the search was moved up with the discovery of the small bombs under a foot of soil. Work at the site began Tuesday.

Corps of Engineers officials said the 3,200-foot bikeway is scheduled to be cleared for use by June 4. About 30% of the path was swept for ordnance in the first two days, officials said Wednesday.

The bombing range was used mainly by pilots from the former El Toro Marine Corps Air Station from 1944 to 1956.

In addition to finding unexploded bombs, pieces of another and a rocket, technicians digging down 18 inches uncovered nails, wires and doorknobs.

Corps officials said they weren’t sure what to expect when they began their search.

“I’m not sure if only finding one [bomb] the first day was a surprise,” said B.J. Allen, an Army safety specialist. “I don’t think we’d have been shocked to find a cluster of 100. Remember, this was a practice bombing range. So you had a lot of military people doing exactly that: practicing how to drop bombs.”

The crews began surveying and digging for ordnance within 2 feet of the surface on the southern edge of the bike trail, working their way to the northern end, where the 11 bombs were uncovered last year. Any unexploded munitions will be removed, taken to a remote location in the park and destroyed.

Before digging began, fliers were sent to homes in the Rancho Santa Margarita neighborhood explaining the project. Bikers and joggers were advised to avoid the area during the cleanup, but some ignored the “Explosives, Keep Out” sign on Arroyo Vista Road.

“I’ve lived here 16 years, and I’ve never seen a bomb yet in this park,” Wayne Justl, 42, said. “I guess it’s just ‘Out of sight, out of mind.’ If I started looking, I’d imagine I’d find more snakes and rodents than bombs.”

The Defense Department has estimated that 1,030 former military sites are now in private or public ownership, and at least 620 of them are believed to contain unexploded ordnance. The Corps of Engineers, which focuses on cleaning up the most dangerous sites, gave the former Trabuco Bombing Range the second-highest of five priority levels, or scores. The September discoveries and pressure from Rep. Gary Miller (R-Diamond Bar) advanced the cleanup, at least for the bike path.

After the bike path sweep is completed, officials will reevaluate the site and develop a new score within 60 days.

“It’s hard to say what the magic number would be to change that score,” said project manager Larry Sievers. “But if we found something like 50, that would make a reevaluation likely.”

In 2001, a sweep of the entire park was estimated to cost $2.7 million. The technicians said combing along the bike path will cost about $270,000.