Wednesday afternoon, on the heels of his belated effort to rescue a youth soccer team from a Thai cave with a tiny submarine, Elon Musk promised to fix another seemingly intractable problem. “Please consider this a commitment that I will fund fixing the water in any house in Flint that has water contamination above FDA levels,” Musk wrote in a tweet. “No kidding.”

You can nitpick pieces of this—the EPA, not the FDA, determines how many parts per billion of lead is safe in drinking water—or dismiss it as just another manifestation of Musk’s itinerant savior complex. But know that Flint, at least, welcomes Musk’s help. Just maybe not the version that’s on offer.

Which, in fairness, continues to evolve. Musk went on to invite residents to tweet their water quality test results to him—no takers yet, it seems—and said he would send someone over to install a water filter. When a reporter suggested that many Flint houses have safe water already, Musk pivoted to organizing “a weekend in Flint to add filters” to the remaining houses that lack them.

'There are many people in Flint, I think it’s safe to say, who are never going to trust tap water again.' Benjamin Pauli, Kettering University

Flint does need help, but filters are one thing it already has plenty of; the city distributes those and water testing kits, for free, at City Hall, and will continue to until Flint’s remaining 14,000 damaged lead and galvanized water service pipes have been fully replaced. And even then, slapping a filter on a kitchen faucet doesn’t address the deep-seated problems still felt by the Flint community four years after its crisis began.

“We had a lot of things damaged as a result of the corrosive water,” says Flint Mayor Karen Weaver, who offered in a tweet Wednesday to talk through her city’s “specific needs” with Musk. “This is about reestablishing trust, and rebuilding trust. While filters have been helpful, we still need access to bottled water. People need to see all new pipes going in. That’s how you’re going to reestablish trust. And we know that’s what the residents deserve.”

Musk took her up on it, suggesting he'd call on Friday. Weaver says her office and Musk’s are still sorting out schedules, but preliminary conversations have been promising.

Filtering Down

It’s worth spending more time talking about those filters, not because they demonstrate Musk’s lack of familiarity with Flint’s current situation, but because they underscore the city’s deeper challenges.

First, it's important to note that Flint's drinking water has met federal standards for contaminants for at least a year. "From every objective measure that is out there, Flint's water is like any other US city with old lead pipes," says Siddhartha Roy, who works on the Virginia Tech research team that helped shed light on the Flint water crisis and has tracked it ever since. Water from old lead pipes still isn't ideal, obviously, and makes filters a necessity. But even then, Flint residents remain understandably wary.

“There are many people in Flint, I think it’s safe to say, who are never going to trust tap water again under any circumstances,” says Benjamin Pauli, a social scientist at Flint’s Kettering University, who has been involved in clean water activism efforts. “It’s true that the filters solve a lead problem at point of use, but there are lots of other issues with the filters.”

Not all residents know how to install and maintain them, for one. A March survey of 2,000 residents by Flint News showed that 15 percent of respondents didn’t have a filter, while over a third weren’t confident in their ability to change the filter at the appropriate time.

And then there's what Roy calls the "big trust gap" that makes Flint activists and residents suspicious of even working filters. That's because they effectively get lead out of the water at a specific tap, but don’t clear away bacteria. For a city that suffered a deadly spike in Legionnaires’ disease in 2014 and 20151, which has been linked to corrosive water from the Flint River, that causes understandable unease. But Roy notes that the current bacteria found in Flint's filters has not been shown to be harmful.