In New Jersey, they can’t even pump their own gas.But at two sporting venues in South Philly, they’re about to start letting you pour your own beer.“Beer fountains” — they’re officially called Draftserv machines, but the similarity to soda fountains seems apt — were quietly installed at the Wells Fargo Center last month. They are set to debut at Lincoln Financial Field this weekend.To work them, customers buy a prepaid card and pour away. And yes, there’s a cashier checking IDs and making sure the obscenely inebriated can’t use them.RELATED:Gourmet grub comes to the LincDomestic beer — that’s Bud Light -- costs 41 cents per ounce. Premium brew — that’s Goose Island and Stella Artois — costs 64 cents an ounce.Customers can pay for as much beer as they want, but the machine limits servings to 32 ounces. Max that out, and you’ll have to wait 8 minutes.But you can buy half a beer, if you want, said Justin Musciano, the concessions manager at the Wells Fargo Center for Aramark.The cards are sold in $20 increments and are good throughout the season. So, for those that can’t drink 50 ounces of beer (about three pints), there’s always next time. The machine has a countdown clock that tells customer how many ounces they have left on their tab.RELATED:$45,000 to rent out Broad Street LineMusciano says the system, which is in about half a dozen other stadiums across the country, is about convenience."If you are a guy and you want another beer, you’ve already paid for it. You're back in your seat before you know it,” Musciano said.The system promises to reduce spillage and waste. That’s a big profit boost for concessionaires. How might it do that, you ask. When a bartender spills beer while pouring, the business pays. butyou pour your own beer, you end up paying for what you spill.