This talk will present a regulatory perspective on site closure and the attainment of cleanup standards. Two major questions arise in evaluating the attainment of a cleanup standard: (1) Is the site really contaminated because a few samples are above the cleanup standard, and (2) Is the site really 'clean' because the sampling shows that the majority of samples are below the cleanup standard. Statistical methods allow for decision making under uncertainty and permit valid extrapolation of information that can be used with confidence to determine whether the site meets the cleanup standard. A case study is presented that illustrates some of these methods.