An earlier version of this article identified actor Leonardo DiCaprio as being among the backers of Cove. DiCaprio is not an investor in the company.

LOS ANGELES — Does the world really need another brand of bottled water?

Alex Totterman believes it does, if the packaging is completely biodegradable.

And his Culver City, Calif., start-up has the backing of some environmentally woke celebrities and business leaders, including Salesforce chief executive Marc Benioff, and former News Corp. executive James Murdoch, who has invested a tiny but undisclosed portion of the approximately $2 billion he netted when his family sold most of 21st Century Fox to the Walt Disney Co.

Cove’s new water bottle, scheduled to get a small pilot launch in December and hit store shelves more broadly in January, is the first to be made entirely from biodegradable materials, the company contends, including the bottle cap, label and adhesive.

The path toward a fully biodegradable product hasn't been easy, Totterman said, but is important given the abundance of plastic waste in every part of the environment, even in places where humans seldom tread. Cove is up against criticism that less chic options, such as tap water, are a better environmental choice than having your H2O shipped from some natural spring in another state or from halfway around the world.

"Plastic bottle beverages are the kind of single-use products that we should be moving away from most aggressively," said Alex Truelove, director of the Zero Waste Campaign for the U.S. Public Interest Research Group. "The metaphor I've used most often is, 'if your bathtub is overflowing, the first thing you do is turn off the tap.'"

But no one is turning off the tap, said Totterman, who founded Cove in 2017 to address the expanding plastic problem. Cove’s sustainable and biodegradable packaging is meant to provide a less dubious retail alternative, Totterman said, as recycling programs have failed to handle what the industry generates.

"There's been no sign of it slowing down," he said. "In fact, it looks like the industry is going to be making more and more plastic bottles."

Some of the world's biggest brands have made voluntary pledges to reduce plastic packaging and to include an average of 25% recycled content in their plastic packaging by 2025, but progress has been slow, according to a report published last year by the Ellen MacArthur Foundation and the U.N. Environment Program.

Most brands are stuck in the low single digits, according to the Foundation, which famously forecast in 2016 that plastic would outweigh fish in the oceans by 2050. At the time of the report, L'Oreal reported that 5% of its plastic packaging was recycled material. PepsiCo said it was at 3%. Nestle was at 2%. The highest was the Coca-Cola Co., at 9%.

Totterman, who previously worked at a nanotechnology startup that focused on water purification for wastewater treatment, said he hadn’t been especially interested in plastics _ he simply couldn’t avoid them.

“Microplastics were everywhere,” Totterman said, “literally raining down on us, and it’s very alarming.”

First, Totterman said, the company had to come up with a material to use for the bottle. He also needed to boost the scientific credentials of Cove's small staff and turned to a recognized bio-materials expert named Jan Ravenstijn.

"We brought on board one of the leading global PHA scientists as our chief science adviser," Totterman said. "He's been in R&D at Dow chemical and the huge traditional polymer companies for the last 20, 30 years, and is now partly retired, but he is still helping us."

The search for the perfect raw material for all the bottle’s components has “really taken three years of research and development,” he said. “It turns out there’s only a few polymers that are fully biodegradable and naturally occurring.”

In 2018, Totterman said, he found a supplier in Athens, Ga., for a type of bio-waste polymer called PHAs, or polyhydroxyalkanoates, in pellet form, which would be melted down to make plastic water bottles using Cove’s equipment at a third-party bottler in Montebello, Ca.

Many hurdles remained:Totterman didn’t see the point of producing a biodegradable bottle with an indestructible, hard plastic cap, a regular label and toxic adhesives.

"Everything had to start from scratch, Totterman said.

The estimated amount of time needed to break down the bottle varies on where it ends up: under a year in home compost, under three months in industrial compost and under five years in the ocean or an open landfill, Totterman said.

Using PHAs creates a marketing hurdle. PHAs are opaque, and when it comes to disposable water-bottle shopping, “consumers want to see what’s in the bottle,” said Adam Smith, a USC professor of environmental engineering.

Cove isn't the first company to take the opaque, trust-us-it's-good route. In 2019, New York-based All Market Inc., the parent company for Vita Coco coconut water and the energy drink Runa, introduced Ever & Ever, drinking water sold in an all-aluminum can.

Another obstacle that Totterman's company may face in winning converts is environmental exhaustion.

Americans have dutifully sorted out recyclable materials for years, only to be told that recycling in some instances has stopped working, and too many recyclable materials are winding up in landfills. Recycling plastic isn’t as simple as something like aluminum, which is easily turned into new products, PIRG’s Truelove said.

The water, Tottenham said, will be “purified alkaline water that’s sustainably sourced. We’re not using spring water. We’re not sourcing in any drought-stricken areas.” As currently planned, a 20-ounce bottle will cost $2.29. He said negotiations were ongoing with several store chains, although Whole Foods is the only one he can reveal now.

"We're hoping people are more interested in doing the right thing sustainably" and will try Cove, he said, "especially if we can make it close enough in cost to the price they are paying for water now."