All 12 Flint, Michigan, school buildings plus the school administration headquarters will have ultraviolet water filtration systems installed thanks to a donation by tech billionaire Elon Musk and his Musk Foundation.

The Flint school system announced the donation Thursday via Twitter, which even got a response from Musk himself. “You’re most welcome,” Musk said. “Hope to do more to help in the future.”

You’re most welcome. Hope to do more to help in the future. — Elon Musk (@elonmusk) October 5, 2018

Musk committed to the Flint water crisis in July after a random Twitter user egged him on. “I heard a bunch of people saying there’s NO WAY you could help get clean water to Flint, Michigan,” said @DylanSheaMusic.

Musk responded six minutes later with a commitment to “fund fixing the water in any house in Flint that has water contamination above FDA levels.”

“No kidding,” the CEO of SpaceX and Tesla added.

Please consider this a commitment that I will fund fixing the water in any house in Flint that has water contamination above FDA levels. No kidding. — Elon Musk (@elonmusk) July 11, 2018

Flint’s water crisis dates to 2014, when the city switched the source of its drinking water from the Detroit Water and Sewerage Department (DWSD), supplied by Lake Huron and the Detroit River, to Flint River.

Subsequent tests showed E. coli bacteria, high levels of lead and even disinfection byproducts in the Flint River water. The city switched back to the DWSD water supply more than a year later, and in 2016 President Barack Obama declared a state of emergency in Flint, which allows the Federal Emergency Management Agency to provide resources to the area.

The city is in the long process of replacing all lead pipes in Flint homes, but residents’ trust in the state and city may not come back for a long time.