This paper contrasts the costs of managing wet weather induced inflow and infiltration (I/I) with the policy requirements of the Federal and State water quality agencies. The presentation describes the framework in which the study was conducted, illustrates the techniques used for coordinating the study with regularatory agencies during the conduct of the study, and presents the costs of alternative levels of improvements. The 2-1/2 year study culminated in the preparation of an EPA Step1 201 Facilities Plan and a State of California required Environmental Impact Report (EIR).1