The 1974 Safe Drinking Water Act (SDWA), with amendments, established a joint Federal-State system for protecting the nation's underground sources of drinking water (USDW). It specifically instructed the United States Environmental Protection Agency (USEPA) to establish a program that would protect the nation's potentially usable fresh water aquifers from contamination by underground injection well operations. EPA has required all States to have an Underground Injection Control (UIC) program. An essential Part of the UIC program is the field inspection of underground injection operations to monitor compliance with the provisions of the SDWA, the UIC regulations, and with conditions set forth in UIC permits. This UIC Inspection Guide was developed specifically for inspection personnel. Every effort was made to include information useful to the inspector in carrying out his duties in the field. A conscious effort was also made to exclude material that does not enhance his ability to perform as required. This Guide is intended to help the inspector complete inspections efficiently and prepare comprehensive, well organized reports.