Do old garden hoses belong in our blue recycling carts?

How about margarine tubs, plastic deck chairs, worn cotton clothing and bicycle tires?

Are big chunks of Styrofoam ever acceptable? And plastic bags from the supermarket? And those six-pack plastic trays from the nursery?

The answers are no, no, no, no, no, no, no and no.

About 10 percent of what appears in our curbside recycling carts doesn’t belong there, said Sara Gallegos, Napa’s recycling coordinator.

“I think people are always just hoping,” said Tim Dewey-Mattia, the public education coordinator for the city’s garbage franchise holder, Napa Recycling and Waste Services.

A tour of the city’s recycling plant near the Napa County Airport illustrates the confusion in the minds of customers. Sorters have culled all kinds of junk from the conveyor belt, which carries a fast-moving stream of discards.

Carpet padding, a child’s car safety seat, a student’s backpack, a chaise-lounge, a plastic duck decoy. Even suitcases have been inappropriately tossed.

Napans have taken to recycling with admirable gusto since single-stream curbside recycling started two years ago, said Kevin Miller, the city’s recycling manager. In the case of those Styrofoam chunks and garden hoses, too much gusto.

With single stream, which allows households to dump all recyclables into one container, recycling increased 24 percent the first year, then another 8 percent last year. That’s nearly 60,000 tons of material diverted from landfills.

The average household is producing 10.8 lbs. of waste a day, with 6.5 lbs. — 60 percent — going to single-stream recycling or yard waste recycling, Dewey-Mattia said.

Fine job, everyone, Miller said. But with a little extra effort, we could be doing even better.

Just as nearly 10 percent of what goes in blue bins shouldn’t be there, probably 10-20 percent of the garbage in gray bins should be in recycling, he said.

A plastic decal on every blue bin explains what’s appropriate for recycling and what isn’t. A fat insert in the Yellow Pages contains even more information.

Plastics are a common source of confusion. Rather than scrutinize containers for their “number,” there is a simple rule of thumb, Miller said.

If the container has a neck, recycle it. If there’s no neck, it belongs in the garbage, he said.

Shampoo bottles, orange juice jugs and milk containers all have necks. Yogurt and cottage cheese containers do not.

There are thousands of plastic formulations out there, said Greg Kelley, Napa Recycling’s general manager. The city’s recycling center is set up to sort out only plastic containers with necks, he said.

Napa Recycling does not want plastic bags, which cost $500 in labor to form into a bale that brings in maybe $35 dollars from a recycler, Kelley said.

They also tend to clog machinery at the recycling center. “They’re a maintenance nightmare,” Kelley said.

The best thing to do with plastic bags is return them to big retailers, Dewey-Mattia said. Better yet, shop with cloth bags and avoid the need for plastic, he said.

Customers often wonder how clean that mayo or peanut butter container has to be before it’s tossed into the recycling bin. “We don’t ask that people rinse all day,” Dewey-Mattia said.

The container can be dirty, but the less food the better, Gallegos said. The recycling center is forever battling rats, she said.

Colored wrapping paper, dirty paper plates, soiled paper towels — they don’t belong in the recycling bin, Kelley said.

Recycling is a social good, not a money-maker, Miller said. The city’s garbage rates would be lower if nothing were recycled and everything went to the landfill in Contra Costa County, he said.

Miller estimated that the city’s recycling program costs about $9 million a year. The sale of recyclables defrays about $3.5 million of that expense.

Once avoided costs are figured in, the recycling program costs about $1 million more than simply hauling all of Napa’s waste to a landfill, Miller said.

Why recycle if it costs more than dumping? “Because it’s a social good,” Miller said. Recycling reduces the demand for virgin materials, reducing the production of greenhouse gases and America’s dependence on oil, he said.

Recycling is mandated by state law, Miller said. Communities are required to recycle 50 percent of their waste or risk fines, he said.

Napa’s recycling rate for 2005, the most current year for which data is available, is 53 percent, he said.