Quaker Valley High School students are sorting items left on their lunch trays and learning an environmentally friendly way to dispose of what used to be considered waste in the cafeteria's new "Recycling Centre."

They're placing recyclable paper, glass and plastic into one bin; depositing leftover food, orange rinds, banana peels and even the brown bags into a compost container; and dumping whatever is left into the garbage.

As of last week, Quaker Valley students became the first in Pennsylvania to totally compost their lunchtime food waste. The composting program was approved by the school board in February, and was up and running April 14 at the high school.

"We're putting our toes in the water," said Joseph Marrone, director of administrative services.

The program is being called, with appropriate apologies to Dr. Seuss, "How to Green Your Eggs and Ham."

The Citizens Climate Corps, a grass-roots environmental organization in the Quaker Valley area, alerted the school district to the benefits of composting, and hooked them up with AgRecycle, the company that will turn Quaker Valley's food waste into compost.

"This is the first project for our group. We're excited that Quaker Valley picked it up," said Sharon Pillar.

She and group member Andrew Conry-Murray stopped by the high school on April 14 to see the program in action.

"A school district is a smart place to begin a composting program as it demonstrates how to be responsible citizens and good stewards of our natural and economic resources," Mr. Conry-Murray said. "Schools also produce considerable amounts of food waste, so composting will divert significant amounts of waste from our overburdened landfills."

Dr. Marrone said the district expects to cut its trash costs by 15 percent. Although it will pay fees to AgRecycle for taking away the food waste, those fees are considerably lower than the fees charged by Waste Management, he said.

"We are sending out 12 45-gallon bags a day, the majority of which is food waste" from the high school, he said.

Students in the environmental science class, which had just finished a unit on waste management, were on hand to direct their classmates where to put each item in the three-section container.

"I think it's going to take a while for people to get used to it, but I think it's a really good thing and they should put more effort into getting people to understand it," said senior Leandra Boreman of Bell Acres.

The students are producing videos that will explain the program, and motivate students to participate in it.

Students in the environmental science class also heard about the science of composting last month from Carla Castagnero, president of AgRecycle.

AgRecycle, headquartered in Cheswick, was founded in 1991 and is one of the oldest composting companies in the United States, said Ms. Castagnero.

"We almost went out of business three times in the '90s," she said. "It was hard to get people to understand that there are alternatives to throwing things away."

She stressed that AgRecycle is a "second-tier company" accepting leftovers that can't be used for anything else, such as to donate to food banks.

"Feed first. If this stuff can be used to feed people, do it," she said.

Compost can be made from food, vegetable wastes such as peels, yard waste, paper and newsprint, clean wood waste and corrugated cardboard, even if it is waxed, she said. The wax coating on cardboard is usually paraffin, which melts in a compost pile, she added.

"There is a lot of science involved in composting," Ms. Castagnero said. "A good composting operation has no odor and no food that you can see."

Since most food is mostly water and nitrogen, carbon-based items such as yard debris or corrugated cardboard have to be added for a 30-to-1 ratio of carbon to nitrogen, she said. Semi-finished compost is used as filler.

"The only thing we add to compost is water and sunshine," she added.

Composting is an aerobic process, as opposed to anaerobic, which produces methane gas. "We are actually helping our carbon footprint, not causing it," she said.

Composting is a different type of recycling, Ms. Castagnero said. Plastic is recycled into plastic, glass into glass and paper into paper. But food waste is recycled into "a product that doesn't look like anything that went into it."

Their composting piles in Washington and Butler counties are known as "wind rows," and are 16 feet wide, 175 feet long and 8 feet high.

AgRecycle has several well-known clients in Western Pennsylvania, including the Pittsburgh Pirates and the Pittsburgh Zoo. The Pirates, she said, "recycle more than any other sports organization east of the Mississippi River."

The zoo has been recycling its yard debris, manure from herbivores and bedding for the past 15 years. "We loved it when they brought the koala in," she said, because the marsupial only ate a small fraction of the many varieties of eucalyptus leaves that were brought in for it. "We had tractor-trailers of eucalyptus coming in. We were sort of sorry to see him go."

A tractor-trailer full of vegetative food waste will eventually yield two shovels of compost, Ms. Castagnero said. Their finished compost is purchased mostly by landscapers.

Finished compost is considered a "low-level fertilizer," she said.

"Compost is a soil amendment, and it does not have enough structure for you to plant in it alone. It has to be combined with soil."

Quaker Valley will receive the compost made from its waste for the butterfly gardens at Osborne and Edgeworth elementary schools, the middle school greenhouse and the high school herb garden, Dr. Marrone said.

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