Our School is Toxic (what a surprise)

So my group and I decided to look at the lead levels of around our school and we saw that it was 11 which if inside a human would be really high. I want to say I’m surprised that the lead levels were high like that but to be completely honest, I can’t be. What I am wondering is how can we reduce the lead not only in our school but also in the area where our school is at?