(CNN Business) Gone are the days of buying a last-minute pre-flight plastic bottle of water at San Francisco International Airport. If you want to hydrate, you'll either have to bring your own reusable bottle or prepare to buy an airport-approved glass or aluminum water bottle.

In an effort to make SFO more environmentally friendly, the airport is adding plastic water bottles to its list of restricted food service items starting August 20.

set a The airport, just south of San Francisco,set a goal three years ago of becoming the world's first zero-waste airport by 2021. According to the nonprofit Zero Waste Alliance, that means diverting at least 90% of waste from landfills and incinerators by recycling and composting.

"This is a big move for the airport," said Doug Yakel, SFO's public information officer. "It just further supports our green initiative."

The new practice stops airport vendors and tenants from selling or providing free bottled water in plastic. This includes all similar products sold in vending machines.

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