Contamination levels in Flint, Michigan’s water supply are still too high, according to Virginia Tech researchers. Professor Marc Edwards and his team released its newest water testing results Tuesday as Flint continues to recover from its ongoing water crisis.

The testing data, collected last month, shows Flint water is still testing at 23 ppb of lead at the 90th percentile. The federal action level is 15 ppb. “People have to continue using bottled water and filters until further notice,” Edwards told MLive.

Edwards said that nearly all homes in the town are considered to be at risk for elevated lead levels unless residents are certain they have no lead plumbing.