Soil tainted with hazardous materials has been discovered at school construction sites in San Jose and Oakland.
Toxics experts found farm pesticides at one school under construction in San Jose.
In Oakland, experts plan to remove coal tar contaminants from the ground at Dewey Continuation High School where school officials are considering an expansion project.
The soil tests come as part of a state law that took effect two years ago requiring experts to test the soil before building new schools. That law put the California Department of Toxic Substances Control in charge of testing and detecting potential school hazards.
The reopening of San Francisco´s Parkside Elementary School is being delayed experts check for lead contamination.