The purpose of this Federal Facilities Remedial Site Inspection Summary Guide is to assist Federal agencies conducting Remedial Site Inspections (SIs) to obtain sufficient information under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) to meet the requirements outlined in the National Contingency Plan (NCP). This Summary Guide identifies data items that should be included in a SI and in the SI report that is required to be provided to the US EPA. Following this guide should improve the overall quality of the information provided to EPA Regional programs and aid EPA's review of the information provided. This guide highlights elements from EPA's previous 1992 SI guidance, Guidance for Performing Site Inspections Under CERCLA. This guide also provides an update on Quality Assurance changes that have occurred since the publication of the original guidance in 1992. This Guide highlights certain data and reporting parameters for conducting a SI at Federal facilities. Data for the following four core elements of an SI are discussed: Analytical Data Quality, Site and Source Characterization, Release(s) of Hazardous Substance(s) or pollutants or contaminants to migration/exposure pathways (ground water, surface water, soil, and air), and associated targets of concern. Also included is a brief discussion on SIs involving radioactive substances (or radionuclides). Sample Completion Checklists have been included for the core data elements. These Checklists identify recommended data elements for SIs and can be utilized as effective data collection tools.