New York — Two teachers on their lunch break scanned a refrigerated shelf inside a Manhattan coffee shop lined with drink bottles: Naked Juice, Perrier, Smartwater, New York City tap water.

“Tap water?” said Alison Szeli, 26, picking up the clear plastic bottle with orange letters: “Tap’d NY. Purified New York City tap water.” She studied the description: “No glaciers were harmed in making this water.” She compared prices: Smartwater cost $1.85. Tap’d NY was 35 cents less. Szeli and her co-worker went for tap, carrying the bottles to the cash register. “It’s cheaper,” Szeli said. “Water is all the same anyway. I just prefer to buy my own water in bottles.” A few feet away, a scruffy-haired 29-year-old in jeans and a striped shirt delivered a shipment of Tap’d NY out of a rented Scion. Craig Zucker, founder of Tap’d NY, stopped unloading long enough to notice the two customers buying his brand. He smiled.

In the five months since he started the company, he has proved his hunch: People are willing to pay for New York City tap water, and not just in monthly utility bills.

“It doesn’t require energy or pumping,” Zucker said, “and it’s so pure and clean.”

To bottle the stuff, Zucker and his business partner, Jon Flax, 26, who was recruited from Craigslist, pump the water together from a main in a Brooklyn warehouse they rent. Their water bill costs about $2 for every 748 gallons. They fill up a 5,300-gallon leased tanker truck, hiring a driver to transport the water 12 miles across the river to New Jersey to be bottled.

P.T. Barnum was correct.