An old industrial lot northeast of the Tamien Caltrain station, slated to house a two-story elementary charter school, contains toxic levels of herbicides, oils and arsenic, according to an environmental report from the city of San Jose. The Santa Clara County Board of Education at its Wednesday meeting plans to discuss a zoning exemption for the new Rocketship charter school. The county board will also discuss in closed session the potential special election over Trustee Darcie Green’s seat.