It’s finally OK to drink the tap water in Flint, Mich.—but only if it’s filtered, according to a June 23 announcement from the Environmental Protection Agency.

Lead levels in the city’s water are now low enough, at 15 parts per billion, that filtering will make the water safe to drink, even for children and pregnant women, according to The Hill. The State of Michigan and FEMA have offered free water filters to residents since the beginning of the year.

The path back to water safety began in early 2016 when the city switched back to Detroit’s pre-treated water, instead of continuing its nearly two-year-old plan to supply the city with water from the Flint River, which had a composition that eroded lead pipes in the city and contaminated the water.  

The state, local and federal government are still working to understand the full extent of the contamination, its political causes and its long-term public health reach.

The CDC released a report June 24 showing that nearly 100,000 people in the city were affected by the contamination. Children under 6 years old were 46 percent more likely to have elevated blood lead levels after the city switched to the Flint River as a water source, especially in children living below the poverty level or enrolled in Medicaid.

According to the CDC, even small amounts of lead in kids’ blood can lead to irreversibly lowered IQ and attention disorders. Severe lead poisoning can cause hearing loss, developmental delays and even death, according to the Mayo Clinic.