THIS ORDER PERTAINS TO PROPERTY LOCATED AT THE MATTHIESSEN AND HEGELER ZINC COMPANY SITE IN LASALLE, ILLINOIS. THIS ORDER REQUIRES THE RESPONDENTS TO CONDUCT REMOVAL ACTIVITIES DESCRIBED HEREIN TO ABATE AN IMMINENT AND SUBSTANTIAL ENDANGERMENT TO THE PUBLIC HEALTH, WELFARE OR THE ENVIRONMENT THAT MAY BE PRESENTED BY THE ACTUAL OR THREATENED RELEASE OF HAZARDOUS SUBSTANCES AT OR FROM THE SITE.