Thirsty teens at a Brooklyn high school were so grossed out by the water dribbling out of their old drinking fountains they raised $5,000 for a new bubbler and bottle filler, hoping to quaff clean, chilled H2O.

But since the state-of-the-art HydroBoost water station was installed in June, students have not tasted a drop.

The shiny new equipment is still turned off because lab tests of water in the 95-year-old building found high levels of lead, The Post has learned.

Students at International HS at Prospect Heights, a Brooklyn school for English-learning immigrants and kids of immigrants, feel let down.

The kids typically raise money for class outings to spots like Dave & Buster’s. But last year, student leaders decided to forgo the fun and endow their alma mater with a brand-new fountain instead.

“The school is like a second home, so we wanted to do something that would benefit not just the current students, but all the students to come,” said Jessica Tapia, 18, last year’s student government secretary who graduated in June and attends York College.

“They have water fountains, but the water is not clean. It’s not drinkable,” Tapia said, adding it often looked white or murky. “We wanted to make a new one available for everybody to have fresh, clean water.”

The students ran “movie nights” on Friday, selling popcorn at 25 cents a bag, using a popcorn maker donated by a teacher. They hawked homemade food for $5 a plate.

They hit up faculty for cash.

“The students and parents of The International High School @ Prospect Heights still believe in the American Dream,” a fundraising flyer read. “Help welcome them to our country by supporting their drive to get a cold-water drinking fountain and bottle-filling station.”

The kids scraped together $3,000. Principal Nedda deCastro agreed to kick in $2,100 in city funds for the Halsey Taylor water station.

But the dream dried up. Despite the city’s efforts to get the lead out, reports say four of 261 faucets in the five-story building — including the new fountain — show lead higher than 15 parts per billion, the level requiring a shutdown.

Last week, the city Department of Education said 391 schools — about a quarter of all campuses — still have 1,165 water outlets with lead above 15 ppb.

The revelation came two days after The Post reported that the DOE was stalling on releasing the latest lead-test results. Last year, 83 percent of schools had fixtures with lead-tainted water. The city has spent $16 million on testing, and replacing taps and fountains.

At International HS, lab tests on Aug. 16 found lead levels of 15.9 ppb and 17 ppb coming out of the brand-new $5,100 water station, records show. Elsewhere in the building, lead levels are much higher — up to 248 in a basement cold-water faucet. A locker-room faucet showed 87 ppb.

“Hand-washing only. Not for drinking use,” signs over the faucets warn.

DeCastro assured staffers that the custodian flushes the pipes “nightly and every morning after a holiday.”

Math teacher Steve Watson said it doesn’t add up.

“If water from the new fountain is unsafe, how do we know that water from the old fountains can be trusted, knowing that the source of the lead is always present in the old pipes?” he asked.

A survey of the building, which houses four schools, found nine of 29 water fountains, including the new one, turned off.

Watson has written to Councilwoman Laurie Cumbo and the city Department of Environmental Protection, but so far has received no replies.

Students told The Post they still avoid the old fountains, instead paying $1 to $1.50 a day for bottled water.

“I never drink from the school fountains,” said senior Khadijah Aljahmi, 17, who baked cupcakes for the fundraiser. “I just don’t like the taste of it.”

Fellow senior Paola Arroyo, 17, who also pitched in, said water from the old fountains “tastes kind of weird.”

But when her bottle is empty, she has no choice.

“If you’ re thirsty, you don’t think about it — you just drink it,” she said.

Chancellor Richard Carranza said in a statement, “Water in New York City schools is safe for students and staff to drink, and all fixtures in DOE schools currently in use for cooking or drinking tested within the state’s standard. We remain vigilant and will begin retesting fixtures in schools this year.”

The testing will be done in 2020, a spokeswoman added.