Across the Islands, residents are improperly dumping tons of trash in public school bins, creating extra disposal costs for the state Department of Education and added work for utility crews and custodians.

And some of the trash is pretty disgusting stuff.

"We even had a dead cow in Wahiawa Intermediate," said Dolly Gines, whose eight-person utility crew removes the unwanted trash. "They threw the head and dead carcass in the yard."

The problem has become more pronounced on O'ahu in the past three years, but officials say every island has experienced it, and the costs are mounting.

Neighbors dump all kinds of trash at Ben Parker Elementary School almost every weekend, DOE officials said. On a recent Monday this month, there was a computer on the ground, and in the trash bin there were a mattress, numerous trash bags and a couch.

People have left engine blocks, tires, fans, party leftovers and even abandoned cars at Ben Parker, said Cory DeJesus, Castle Complex assistant facility manager.

"When people catch fish in big masses, they will bag the fish guts and throw it into our Dumpsters," DeJesus said. "Cats rip open the bag and the smell reeks."

Disposing of the trash at O'ahu landfills is costing DOE an average of $600 a month for tipping fees, said Ray Minami, administrative director for DOE Business Services. Items with hazardous material or that need special handling, such as refrigerators, computer monitors and batteries, are more expensive to dispose of.

Other costs have included a one-time $4,000 fee to get rid of tires from Kalani High School and $5,000 to remove a dead tree and mulch from Waipahu High School.

Minami said he is not aware of the full cost to the DOE. But he said the problem is statewide, although it doesn't appear to be as bad on the Neighbor Islands as at O'ahu schools.

He said students and the schools suffer the most.

"If we can't remove it immediately, it does pose a health and sanitation problem," he said. "Another impact is it does cost us money. It takes away funds that we could be using for more beneficial expenses rather than tipping fees for trash."

Schools have tried several methods to stop the practice, such as locks, enclosures and fencing, but nothing seems to work, he said.

At Ben Parker Elementary, custodians are pulled off regular duties to clean up the mess and sort the items, because contractors for trash pickup won't take anything but school rubbish, said principal Wade Araki. The process is becoming a regular Monday-morning routine.

Once the schools sort the items, Gines' crew delivers them to recycling centers or the landfill, where the schools pay a disposal fee.

Robert Louis Stevenson Middle School seems to be continually calling for removal, and part of the problem there is the school trash bin is hidden from public view, allowing people to dump their garbage in secret, she said.

In another case, crews at 'Ahuimanu Elementary School removed a playground made with old tires and stored them for pickup. But neighbors then decided to add their old tires to the pile.

At Ma'ema'e Elementary, her crew even removed an old car, Gines said.

People have left couches at Pu'ohala Elementary School, a fiberglass hot tub at King Intermediate School and mattresses at Castle High School, DeJesus said.

What baffles DOE officials is that residents only need to call the city bulky-item pickup service and it will come to residents' homes, DeJesus said. Bulky-item pickup doesn't pick up from schools. The city also will pick up unwanted vehicles, but not from the schools, she said. Most other items can be taken to city convenience centers around the island.

Ben Parker tried to solve the problem with a locking trash bin, but that didn't stop people, Araki said.

"It caused even more trouble for us because now people are just throwing the bags on the top of the Dumpster," Araki said. "So we have an empty Dumpster, but we have everybody's trash."

Gines, the crew supervisor, said she collects invoices and knows the extra work is costing thousands of dollars. Most of the invoices are small, but the numbers add up. A trip to the construction waste dump is $116 a load, no matter how small it is, and to dump at the Waimanalo Gulch costs from $56 to $114, she said.

"If I could add up the invoices, I'm sure it would be very huge figure," she said, citing the $4,000 for the tire removal at Kalani High and the $5,000 for the tree and mulch removal at Waipahu High. "That money could go for equipment, building maintenance, minor repairs to keep the facility up and running. It's money the schools need."

The problem has been escalating islandwide for three years since her crew began responding to requests to remove waste that the regular trash pickup wouldn't take, she said. The amount of time the crew spends on disposal has risen since 2002.

"It seems like for my crew, at least, 80 percent of our time is spent on disposal," Gines said, adding that the crew's primary responsibility is supposed to be moving equipment and furniture for all O'ahu schools.

Reach Eloise Aguiar at eaguiar@honoluluadvertiser.com.