Editors' Summary: One of the most significant issues in nonresidential real estate transactions today is determining what level of due diligence by a prospective property owner is sufficient to qualify for the "innocent landowner" defense under CERCLA §101(35). One reason for this is that a large percentage of commercial property, and virtually all industrial property, is impacted by environmental contamination, and few properties can be properly valued without assessing such contamination. Another reason is the strict liability scheme under CERCLA and the extraordinary breadth of the Superfund liability net. A committee of the ASTM (formerly named the American Society for Testing and Materials), an industry coalition representing lenders, realtors, environmental consultants, and the legal community, is considering a proposed guide for lay persons to follow in conducting Phase I environmental site assessments or audits. The author examines this proposal and analyzes its flaws. He concludes that it is inadequate and proposes a workable alternative.