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It’s a game of telephone: One says take the plastic bottle cap off, you hear keep it on.

“Keep it off.”

“Keep it on.”

“Does it even matter?”

The fact of the matter is that we live in a throwaway age and plastic bottles and their caps inevitably make their way to landfills and oceans.

Charles Moore, an oceanographer and founder of Algalita Marine Research Foundation, spoke at the Ted Talk Conference in Long Beach, Calif. in Feb. 2009. He says that in the grand scheme of things, less than 5 percent of plastic is recovered and zero percent is ever really recycled.

When researching the effects on marine wildlife, Moore discovered that plastic is found in both the albatross nesting in the Northwest Hawaiian Islands National Monument and the fish that we consume.

“Hundreds of thousands of the goose-sized chicks are dying with stomachs full of bottle caps…sadly, their parents mistake bottle caps for food tossing about in the ocean surface,” Moore says. “We wanted to see if the most common fish in the deep ocean, at the base of the food chain, was ingesting these poison pills. We did hundreds of necropsies, and over a third had polluted plastic fragments in their stomachs.”

For those who recycle, it starts with your driveway, with the blue curbside bins and plastic bottles that may or may not have the caps screwed on top. While the city of Phoenix may collect your recyclables among the 400,000 households they service, their next step is to take them to a separately owned transfer station. The thing is: Not every city has the same sorter or machine equipment.

Yvette Roeder, PIO for the city of Phoenix Public Works Department, says that the specific machinery at North Gateway transfer station prefers the cap to be screwed on.

“If you separate them, sometimes the caps are too small that they actually just fall through the cracks…fall through the machine,” Roeder says. “They end up going into the trash anyway.”

There are mixed signals. The city of Maricopa’s drop-off facility trains the public and its staff to remove lids on plastic bottles, executive director of Environmental Concerns Organization, Inc.,Gina D’Abella says.

Since Maricopa was incorporated into Arizona in 2003, it did not offer city-run curbside recycling until 2007. Instead residents had to rely on the Recycling Association of Maricopa, a nonprofit corporation to run their waste transfer station. D’Abella disagrees that the caps be left on, instead she suggests that they be taken off for three main reasons: liquid contamination, trapped air, and different plastic types.

In regards to liquid contamination, D’Abella says that approximately 30 percent of plastic bottles received by public recycling containers still contain liquids. That percentage is lower for residential curbside containers but still a contamination problem.

“Material Recovery Facilities, MRF, have workers sorting material from a conveyor belt that moves very fast,” D’Abella says. “Typically, the workers don’t touch contaminated material, so it ends up in a container for disposal and doesn’t get recycled.”

D’Abella added that trapped air and an attached lid cause problems when it is unloaded from the recycling trucks that pick up curbside, residential material.

“Plastic bottles with lids still attached take up a lot of space in each load, because of the trapped air inside; therefore the truck reaches load capacity faster and has to unload more frequently at the MRF,” D’Abella says. “This problem contributes significantly to the hauling costs and the carbon footprint of recycling.”

One of the most significant problems involves the differing plastic types.

PET, which stands for Polyethylene terephthalate, is a plastic resin used in synthetic fibers, beverage, food and other liquid containers. PP refers to Polypropylene, which is a thermoplastic polymer used in a variety of packing and labeling, plastic parts and reusable containers.

“If the bottle is PET, but the lid is PP, then any PP in that bale is a contaminant,” D’Abella says.

PET is the most common type of plastic used, as this is what containers like 2-liter soda bottles and peanut butter jars are made out of. PP is the 5th most common type of plastic used; it’s used most commonly for bottle caps, food containers and drinking straws.

Mark Oldfield, Communications Director for Cal Recycle based in Sacramento, Calif., seconded D’Abella’s “caps off” sentiment.

“You can’t recycle the same types of plastic together because then it causes contamination issues,” Oldfield says. “People just want the convenience of dropping everything into their curbside bin.”

Convenience seems to be the driving force of Phoenix’s recycling restrictions.

Where Phoenix says caps on, Maricopa says caps off. In the case with ASU’s restrictions, they ask students to keep the caps on.

“There is a manufacturing process in place called a float sink where all the plastic water bottles get chipped up after they’ve been collected and processed,” Alana Levine, Recycling Manager of ASU says. “They get chipped up into little pieces of plastic and those little pieces, the number two plastic, which are the caps, float up to the top and the number one plastics sink. All they have to do is skim off the number two plastics from the top and that’s how we separate the number two from the number one.”

Convenience takes precedence in regards to Arizona’s recycling policies even though it comes down to the fact that different materials cannot mix with the current machines at use.

“Because products are typically not designed with recycling or end-of-life and reuse in mind, they are often mixes of materials that make them hard to recycle and reuse,” George Basile, Ph.D., Professor at ASU School of Sustainability says.

According to Bill Campbell, Project Manager at the Walton Sustainability Solutions Initiatives, groups like his organization are working in conjunction with major manufacturers nationwide to attack the problem at the source. They’re finding ways to make plastic bottles be of the same plastic, rather than being made of differing PET and PP plastic.

“Designing with sustainability in mind can really change what our products might look like and what sorts of options we have to put them and their material into cycles,” Basile says.

And yet there is no recycling incentive in place in Arizona. California, on the other hand, is one of 11 states that belong to the “bottle bill” which gives the public a monetary incentive to recycle containers.

“The incentive provided by a redemption program would likely mean a significant increase in the amount of plastic available to recycling businesses, since more would be returned rather than thrown away,” Oldfield says. “This would in all likelihood alleviate some of the concern over bottles versus caps since more volume would probably mean more money for the recycling centers.”

The California Redemption Value, CRV, is 5 cents on containers less than 24 ounces and 10 cents on containers 24 ounces or larger. The monetary incentive begins at the checkout stand. Once the fee is initially paid it can be redeemed by returning eligible containers to any of the 2,000 recycling centers in the state of California.

“California has redemption value, recycling incentive to remain in the recyclable pile and not be thrown away,” Oldfield says. “Now that incentive doesn’t exist in some other states.”

It doesn’t exist in Arizona. With the fast pace of conveyor belts, human workers cannot possibly ensure that every plastic bottle is sorted in its proper place no matter the numerous layers of processing.

“In spite of deposit fees,much of this trash leading out to the sea will be plastic beverage bottles,” Moore says.We use 2 million of them in the United States every five minutes.”

According to Levine, in regards to ASU specifically there is a large amount of recyclable material being sent to landfills.

“In fiscal year 2014 we actually sent to the landfill 6,700 tons of material; 5.4 percent of that or about 362 tons are actually considered recyclable containers, and that includes number one plastics and number two plastics and those are very easy to recycle in the ASU system,” Levine says. “We can very easily eliminate what we are sending to the landfill just by recycling plastic bottles.”

Even still, plastic bottle caps continue to make it to sea. Moore traces the path of bottle caps with consideration of the planet’s natural current pathways.

“After a year, the ones from Japan are heading straight across the Pacific, while ours get caught in the California current and first head down to the latitude of Cabo San Lucas," Moore says. "After 10 years, a lot of the Japanese caps are in what we call the Eastern Garbage Patch, while ours litter the Philippines. After 20 years, we see emerging the debris accumulation zone of the North Pacific Gyre.”

Incentive or no incentive? Caps on or caps off?

Moore says the solution is to stop the plastic at its source. “Stop it on land before it falls in the ocean,” he says.

Reach Gretchen Burnton at or via Twitter @gretchenburnton. Reach Jessica Obert at or via Twitter @jessicaobert.


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