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. 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. In place of plastic bottles, the vendors will be able to sell or provide reusable recyclable aluminum, glass and certified compostable water bottles, according to the airport. Travelers can bring empty disposable plastic water bottles to refill. However, airport security still bans passengers from bringing filled bottles of water from outside. SFO defines a bottle of water as drinking water in a sealed box, bag, can, bottle or other container intended primarily for single-service use and having a capacity of 1 liter or less. This includes purified water, mineral water, carbonated or sparkling water, and electrolyte-enhanced water. The ban does not apply to any flavored drinks like soda, iced tea or coffee and juice. Yakel said SFO has over 100 refillable water hydration stations for travelers bringing their own reusable water bottles, and it will add more. In September, California Gov. Jerry Brown signed a law that stops dine-in restaurants from automatically providing plastic straws to customers, making it the first state to partially ban them. Violating the law costs restaurants a $25 a day fine. In March, SFO also transitioned away from single-use plastic food service ware and utensils. Yakel said he knows that other airports are looking to make the same move to eliminate bottled water, but as far as he knows, his is the first to have this initiative. The ban is only one of the things that makes SFO unique. The airport is also one of the few with a free yoga room for travelers to use at their leisure.