Even with the windows up, the sour stench of rotting food invades Michael Gross’ car. He drives slowly, slaloming towering piles of trash and mountains of food and household waste. We’re inside Zanker Recycling’s anaerobic digester in north San Jose, a aircraft hangar-sized building that takes all the food scraps from San Jose’s restaurants and grocery stores, removes overlooked recyclables and trash, and composts what remains.

Gross, Zanker's director of sustainability, stops his car by a pile of trash that has been separated from the compostables and will be buried at the nearby Newby Island landfill.

“If you start looking at what’s really in this,” he says, “it’s plastics.”

A dozen laminated Tesla press passes peek out from the damp, hellish mound. There’s a nest of styrofoam clamshells. Soggy plastic bags dominate: sandwich bags, black trash-can liners and a rainbow of slime-streaked takeout sacks. About 40 percent of the material that enters this anaerobic digester can’t be composted.

Gross drives past large chambers filled with varying stages of compost decay to our destination, where finished product is mixed with yard trimmings. Even these piles, which have been screened several times over, are laced with shreds of plastic.

“It’s just plastic bags, plastic bags, plastic bags,” Gross says. “And they’re not going to break down, they’re not going to go anywhere.”

These bags are a pestilence to all of Zanker’s four recycling sites. They get trapped in litter fencing. They clog and jam sorting machines. They tear into smaller and smaller pieces, drifting like confetti into piles of mulch, fertilizer and wood chips the recycling facility sells. They never go away completely, and removing them costs Zanker upwards of $655,000 annually. The city of San Jose pegged the figure even higher, estimating plastic bags cost recycling plants $1 million a year in jammed and broken machinery.

San Francisco passed the nation’s first plastic bag ban in 2007, San Jose followed in 2012 and more than 150 California jurisdictions now have a bag ban.

Nevertheless, Bay Area residents continue to use 3.8 billion plastic bags each year, of which more than a million end up in the San Francisco Bay. Ocean currents then carry them to the Great Pacific Garbage Patch, an area one-and-a-half times the size of Texas choked with floating trash, most of it plastic.

To the relief of Gross, other recyclers and environmentalists, one of two propositions on the November ballot could make plastic bags in California a thing of the past. The other appears to have less noble intentions.

Proposition 67 calls for a referendum on a statewide bag ban passed in 2014, while Prop. 65 would redirect revenue from reusable bag sales to environmental purposes. Both were put on the ballot by the American Progressive Bag Alliance (APBA), a group whose name conjures images of canvas-tote-wielding environmentalists but in actuality is a plastic manufacturers association that has spent more than $6.1 million—raised from five bag companies, only one of which is in California—to put both propositions on the ballot.

Known as the Plastic Bag Ban Veto Referendum, Prop. 67 calls for a referendum on Senate Bill 270, a law that created a statewide ban on the kind of single-use plastic bags once prevalent in pharmacies, grocery stores and corner markets. The bill also set a minimum 10-cent fee for recycled paper or reusable plastic bags, and allocates $2 million for jobs making and recycling reusable plastic bags.

South Bay state legislators Jim Beall, Bob Wieckowski and Nora Campos all voted in favor of SB 270 in 2014, but the legislation was put on hold after the Alliance gathered enough signatures to request a referendum. The bag ban would become state law with a majority of “yes” votes in November, while a majority “no” vote would leave California cities and counties to regulate the matter.

“The end goal of [Prop. 67] is to move consumers to reusable bags,” says Dave Heylen, vice president of communications for the California Grocers Association.

While paper bags actually have a larger carbon footprint, plastic bags’ harm to the environment, especially waterways, is well documented. And while recycling is the solution to many consumption problems, plastic bags often aren’t accepted by curbside waste programs because they can’t be processed with other plastics. For this reason, Heylen explains, the California Grocers Association lobbied to pass SB 270 because they believe it will protect the environment and provide consistency for business owners and customers.

The Yes on 67 campaign has raised more than $3.5 million. Its single largest contribution was $150,000 from grocery giant Albertsons Safeway. Other top donors include the California Grocers Association, environmental nonprofit Save the Bay and Tom Steyer, an environmental advocate, major donor to Democratic causes and possible California gubernatorial candidate. Gov. Jerry Brown, the state Democratic Party, the Green Party and numerous elected officials, environmental groups and newspapers have endorsed Prop. 67. As of 2014, the last time polling was done, nearly 60 percent of voters supported the ban.

Heylen contends that these strong numbers spurred the APBA to put Prop. 65 on the ballot in an attempt to confuse voters and help out-of-state plastics companies “manipulate the system so they can get what they want.”

Jon Berrier, a spokesman for the APBA, disputes this characterization, arguing that Prop. 65 will prevent grocers from padding their wallets with millions in bag fees. SB 270 allows stores to keep proceeds from bag sales, as long as this money covers the cost of bags and customer outreach to comply with the legislation. But SB 270 doesn’t include oversight mechanisms to ensure store owners use the money as intended, and an APBA-commissioned report estimates that revenue from bag fees—at $0.10 per paper bag and $1 per reusable bag—could be between $189 and $442 million annually, depending on how much shoppers reuse bags.

“[SB 270] was a big special-interest giveaway to the members of the California Grocers Association, to the tune of hundreds of millions of dollars per year that they’ll be able to collect and receive profits on as the result of these bag fees,” Berrier claims.

Along with the APBA, the No on 67, Yes on 65 campaign is supported by the California Republican Party, Libertarian Party of California, Howard Jarvis Taxpayers Association, and a few manufacturing and labor organizations.

Heylen denies that Prop. 67 is about profit, as bags usually cost stores $0.08 to $0.15 each. Only retailers large enough to buy in bulk would see profits off 10-cent bag fees, he adds.

Supporters of Prop. 67 say the APBA put forward Prop. 65 to turn grocers against the bag ban. If both propositions pass, Prop. 65 would divert bag fee revenues into a trust fund administered by the state’s Wildlife Conservation Board. The money would be granted to various environmental projects, including drought mitigation, habitat restoration, recycling, clean drinking water, parks, beach cleanup and litter removal.

The California Grocers Association has not taken an official position on Prop. 65, but Heylen characterized it as meddling by out-of-state companies. There’s a lot at stake for the plastics industry: California represents between 10 and 14 percent of the country’s 100 billion-bag plastics market. Hilex Poly Co. LLC, a plastic bag manufacturer, has given 44 percent of the $6.1 million raised by the campaign to defeat the bag ban and support Prop. 65.

If both propositions pass and the bag ban receives more votes, grocers will get to keep bag fee revenues, as outlined in SB 270. But if both pass and Prop. 65 has a wider margin of victory, the ban likely would go into effect with bag fees diverted to the wildlife conservation fund.

California’s Legislative Analyst Office noted that if both props pass but 65 receives more votes, courts could interpret a vaguely worded clause as overruling the state’s bag ban. Berrier denies this would happen, saying it would simply nullify the part of Prop. 67 that allows grocers to keep bag fees.

Even if Prop. 65 doesn’t conceal dark intentions, it and the referendum on SB 270 still upset people like Gross, Zanker's sustainability director.

“We already had 150 communities in the state of California that had plastic bag bans,” Gross says. “It’s really the will of the citizens here.”