PEI's Recommended Practices for Installation and Testing of Vapor-Recovery Systems at Vehicle-Fueling Sites (PEI/RP300-09) provides concise instructions for installation and testing of Stage I and Stage II equipment. In addition to being completely revised and reorganized, the fourth-edition includes a chapter on decommissioning Stage II vapor-recovery piping. The recommended practices also reference the most recent revisions by the California Air Resources Board (CARB) to its vapor recovery testing procedures. The 2009 edition of PEI/RP300 contains 28 illustrations and various photographs on all phases of proper vapor-recovery equipment installation and testing and a section related to definitions. Chapters covering Stage I and Stage II vapor-recovery systems, Stage II vapor-recovery system components, underground piping and fittings, testing (pressure decay, dynamic backpressure, and air-to-liquid volume ratio), electrical installation, testing and inspection, and documentation and training are included. There are appendices with pressure decay test tables and sample forms for recording pressure decay data, dynamic backpressure test data, and A/L test data when using an air volume meter. A decommissioning checklist and bibliography are also included.