PUYALLUP, Wash. — Everyone likes to feel good about recycling – making sure bottles, cans and cardboard boxes make it into the blue bin. But have you ever thought about what happens once it leaves your house, and how much is actually able to be reused?

Contamination of single-stream recycling is a major issue – that’s non-recyclable items that have to be sorted out. Some industry studies estimate one in four items going into single-stream bins are not recyclable.

Turns out there’s a term for recycling optimism – “wishcycling.” But erring on the side of recyclable can cause problems for the system.

An exclusive KING 5 News survey suggests most Washingtonians try to be good recyclers. About 83% of adults polled say they recycle most or almost all items they are required to recycle. Just 4% say they recycle almost none of those items.

Sandy Calica of Puyallup considers herself a pretty solid recycler. But she finds herself with a few questionable items every week.

“Not knowing what is recyclable and what is not,” she said. “…not knowing now what to throw in there and not throw in there. Makes it hard.”

She kept a record of her questions between collection dates – like bleach containers or mixed-material cartons. Then right before her pickup day, KING 5 brought Sheryl Rhinehart of Pierce County Planning and Public Works to dig through and find the issues.

“I think people have a lot of questions about what belongs in recycling, and I can help clear it up for her,” said Rhinehart.

Right off the bat, she wanted to make one thing abundantly clear – each county's system is different, and depending on where your recycling goes, some items may or may not be accepted. But for Pierce County specifically she found some really common issues at Sandy’s house.

First – oddly shaped plastic containers. She pulled out a suspect plastic food bowl that might be recyclable but might get pulled out.

“Not everything made of plastic belongs in the recycling cart,” she said. “We want you to look at the shape of the object. So what we accept in the county is a bottle, a jug, a tub or a bucket.”

RELATED: New recycling rules in Olympia eliminate glass and more from bins

The second issue came from the same piece, which was unwashed and speckled with food debris. Rhinehart said if anything it needs a good rinse, and might be recyclable in the end.

The third frequent culprit – a chicken stock carton: cardboard with an inner lining.

“This is an a-septic container with paper and a layer of foil,” said Rhinehart. “In Pierce County these are not accepted in the recycling.”

But the fourth issue is one they didn’t find in Calica’s bin – crinkly plastic.

“Don’t put plastic bags in your recycling cart, don’t put recyclables in plastic bags, don’t put bags of bags in, don’t put wrap from around a case of water in – keep any plastic bag or wrap out,” said Rhinehart.

Calica said this will make her more cautious before she recycles an iffy item.

“Because now I know more of what not to put in recycling, and I’ll be more cautious about putting something in recycling out of convenience,” she said.

That’s the type of effort that helps recyclers address contamination – making sure the process can operate with a lower cost and higher efficiency.

“If there is even a single pint-sized coffee half and half container in a bale of mixed paper, that could cause the entire bale of paper to be rejected,” said Rhinehart. “So you’ve spent time and energy and money putting together this bale of material, then the recyclers say no, we can’t take that. So there is an impact of that contamination down the road.”

Again – recycling guidelines are county specific and posted online. Here’s regulations in King County, Pierce County and Snohomish County.

RELATED: King County will no longer accept plastic bags, wraps in recycling