This chapter considers the set of laws introduced to address the patchy nature of pre-existing regimes. Although its focus is relatively narrow—that is, on the regulation of the clean-up of historically contaminated land—it is always important to bear in mind that the basic building blocks of statutory liability for cleaning up pollution can often be found in subject-specific legislation. The focus on the clean-up of contamination caused by historical sources presents a number of significant challenges, such as when should clean-up be required, to what level, and for what purposes. The most significant of all of these issues, however, is the identification of the party, or parties, responsible for paying the consequences of historic pollution.