SAN FRANCISCO (KCBS) — In a country that’s still minting pennies, there’s a renewed push to swap out the dollar bill for a dollar coin.

The switch could save taxpayers at least $4 billion dollars over 30 years, according to a former Treasury official.

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It’s not just a matter of making it easier to feed the parking meter, or getting a snack when the vending machine won’t take your dollar.

“It’s because the coins last longer. So, a coin takes about 18 cents to make, and lasts 30 years or more. The dollar bill takes five cents to make, and it can last as short as 18 months, and as long as maybe five years. So, it’s just re-printing the same billions of notes every year,” Aaron Klein, former Deputy Assistant Treasury Secretary said.

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Klein says environmental concerns make the coins a better choice as well.

“The ink that’s printed on them is toxic, so it can’t be recycled,” Klein said.

We have had specially-minted dollar coins before but never something meant for widespread use. Klein says while a majority of Americans like the idea of a dollar coin, but it’s harder to get government agencies like the Mint and the Treasury on board.

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The coins are also harder to counterfeit than paper bills.