The requirement that a site be cleaned up before it is redeveloped is a result of the Love Canal disaster in Niagara Falls, New York. Hooker Chemical had used an abandoned canal site as a toxic waste dump for many years. When they sold the site to the City of Niagara Falls, it was disclosed that Hooker Chemical had used the location for disposal of toxic waste. Hooker Chemical stipulated in the sale contract the city would assume all future responsibility. The city built a school on part of the site and sold the rest for residential development.Click here to read article.