The evolution of local governmental ordinances requiring high intensity soil surveys for urban planning dates back to the 1960's in the Chicago Metropolitan Area. Early ordinances were designed to protect soil from erosion during construction and to reduce long-term flooding. These "first" regulations, however, were not widely adopted. In the middle 1980's, soil survey ordinances were created to plan for on-site waste treatment in residential developments. These newer requirements in subdivision ordinances have become the rule throughout the suburban area and large portions of northern and central Illinois.