The reference document provides regional project managers, on-site coordinators, and their contractors with sampling and analysis methods for evaluating whether ground water remediation has met pre-established cleanup standards for one or more chemical contaminants at a hazardous waste site. The verification of cleanup by evaluating a site relative to a cleanup standard or an applicable or relevant and appropriate requirement (ARAR) is mandated in Section 121 of the Superfund Amendments and Reauthorization Act (SARA). The document, the second in a series, provides sampling and data analysis methods for the purpose of verifying attainment of a cleanup standard in ground water. The first volume addresses evaluating attainment in soils and solid media. Volume 2 presents statistical methods which can be used to address the uncertainty of whether a site has met a cleanup standard.