After lead was found in the water fountain at South Oak Cliff High School this August, Dallas ISD is testing the fountains and sinks on all of its 228 campuses beginning Oct. 1.

The news comes weeks after Fort Worth ISD removed around 500 drinking fountains because lead was discovered in dozens of older models installed at elementary schools. According to the Dallas Morning News, the same manufacturer provided water fountains in Dallas schools.

District spokeswoman Robyn Harris told NBC 5 that the testing was “out of an abundance of caution.” DISD will randomly tests sinks and drinking fountains made before 2008.

The district-owned Cotton Building at 3701 S. Lamar St., which does not house students but DISD employees, has been providing bottled water for workers after trace amounts of lead and arsenic were found in water sources at the historic building.

Lead is a naturally occurring toxin that can be found in water, soil and air, and is particularly damaging to young brain’s because children absorb the chemical more quickly.