After building a mini-submarine to aid in the rescue attempt of the members of the Wild Boar soccer team in Thailand, Elon Musk is now flexing his philanthropic muscles towards a long-standing issue in the United States — the Flint Water Crisis.

Musk previously noted on Twitter that he has already been helping out the citizens of Flint. Spurred on by some Flint residents and activists for the city, however, Musk opted to take a more hands-on approach. The Tesla and SpaceX CEO promptly coordinated with individuals testing the contamination levels of the city’s water system, and by Wednesday, Musk has provided an email address, [email protected], where residents can send the results of their water’s ppm (parts per million) and ppb (parts per billion) levels.

Musk’s pledge to help the people of Flint has mostly been met positively by the online community, with several of his followers even offering to lend a hand to a “barnstorming weekend” aimed at installing water filters in the homes of the city’s residents. Musk also reacted favorably to the idea of utilizing Flint’s local plumbers to help in the initiative. Despite being in China to discuss Tesla’s plans of building Gigafactory 3 in Shanghai, Musk further stated that he would call Flint Mayor Karen Weaver about plans to address the city’s water problems.

Gathering input this week, will begin taking action next week and let people know how they can help — Elon Musk (@elonmusk) July 12, 2018

Just like his efforts to help in the Thailand cave rescue operations, Musk’s pledge to help the city of Flint became a target for his staunch critics online. Key Flint activist Mari Copeny, better known as Little Miss Flint due to her letter to then-president Barack Obama about the ongoing water crisis, clarified Musk’s involvement, however, stating that the city is appreciative of the serial tech entrepreneur’s efforts to help.

Hey world. Let’s set the record straight. My team has been working with @elonmusk and his team for over a week to figure out the best solution to help #Flint with the #FlintwaterCrisis

Extremely grateful for him and all he has done so far. — Mari Copeny (@LittleMissFlint) July 12, 2018

The Flint Water Crisis started in April 2014, after the city’s drinking water source was changed from Lake Huron and the Detroit River to the much cheaper Flint River. Insufficient water treatment caused lead to be leached from lead water pipes into the residents’ drinking water. Lead pipes are viable pipes for water systems, provided that corrosion inhibitors are used to prevent lead from contaminating the water. A common corrosion inhibitor is orthophosphate, which forms low-solubility complexes with the lead in the pipes. Orthophosphates were used in Flint’s systems when the drinking water was coming from Detroit, but when the shift to the Flint River was conducted, no orthophosphate or any other anti-corrosion inhibitors were used. The absence of these inhibitors is behind the harrowing images of rust-colored water coming from Flint’s water supply.

The lead-contaminated water caused several grave problems for Flint’s residents. Between 6,000 to 12,000 children from Flint have been exposed to drinking water with high levels of lead, which could result to serious health problems. The percentage of Flint children with elevated blood-lead levels is estimated to have risen from about 2.5% in 2013 to as much as 5% in 2015 as well. An outbreak of Legionnaires’ Disease, a form of atypical pneumonia with no known vaccine, also resulted in 10 fatalities. The Legionnaires’ outbreak is linked to Flint’s contaminated water supply.

The Flint Water Crisis has resulted in several lawsuits being filed against government officials, many of which were accused of mismanaging the situation. Since the water crisis’ peak, however, the Michigan Department of Environmental Quality (MDEQ) has stated that the lead content of Flint’s water has fallen below the federal limit. As of April 2018, the MDEQ issued a statement assuring Flint’s residents that the city’s water quality “has been restored.” Regardless of this, however, many Flint residents remain skeptical that their water is now safe, especially considering that the replacement of the contaminated lead pipes is still ongoing. In this sense, Musk noted on Twitter that the planned “barnstorming” weekend in Flint would not only aim to give residents water filters for their homes; it would also attempt to fix residents’ perception of the city’s water supply.

You’re right on both counts. Most houses in Flint have safe water, but they’ve lost faith in govt test results. Some houses are still outliers. Will organize a weekend in Flint to add filters to those houses with issues & hopefully fix perception of those that are actually good. — Elon Musk (@elonmusk) July 11, 2018

While Elon Musk’s recent philanthropic ventures are attracting more attention than usual, the SpaceX and Tesla CEO’s humanitarian efforts have actually been going on for some time. It should be noted that Tesla’s big battery in South Australia was started after Musk became aware of the power crisis in the region. After Hurricane Maria ravaged Puerto Rico, Musk also promptly sent a team to help the island nation get back on its feet. As of Musk’s latest update, he noted that there are currently 11,000 projects underway in Puerto Rico.