It’s irritating – and expensive – to have to dump a perfectly good, sealed container of bottled water before entering an airport security checkpoint only to pay an inflated price for a fresh bottle on the other side.

To avoid that scenario, many travelers take along an empty, wide-mouthed bottle and fill it up at a water fountain or in a bathroom sink on the post-security side.

I’m happy to report that an increasing number of airports are installing water bottle refill stations to make this task easier – and greener.

San Francisco International Airport (SFO) has at least four hydration stations throughout the terminals, and there are water-bottle refill stations in Chicago at O’Hare and Midway airports and at Hartsfield-Jackson Atlanta International Airport.

This week, Oregon’s Portland International Airport sent out a tweet alerting travelers to some new water-bottle refill stations there. Given how expensive real-estate is for retail outlets at airports, its interesting to note that these are inside shops.

Do you know of other airports that have these helpful gadgets? Send a note – and perhaps a photo – along and we’ll make a list.