Promulgation of Reid Vapor Pressure Standard; Michigan

In this action, the Environmental Protection Agency (EPA) is approving a revision to the Michigan State Implementation Plan (SIP) establishing a summertime gasoline Reid vapor pressure (RVP) limit of 7.8 pounds per square inch (psi) for gasoline sold in Wayne, Oakland, Macomb, Washtenaw, Livingston, St. Clair, and Monroe counties in Michigan (Detroit--Ann Arbor consolidated metropolitan statistical area (CMSA)). The marketing of less volatile gasoline reduces excessive evaporation of fuel during the summer months. Evaporated gasoline combines with other pollutants on hot summer days to form ground-level ozone, commonly referred to as smog. Ozone pollution is of particular concern because of its harmful effects on lung tissue and breathing passages. On August 30, 1996, the EPA published a Notice of Proposed Rulemaking (NPRM) proposing to approve the SIP revision. During the comment period EPA received comments from one commentator, which were adverse. This document summarizes the comments received, EPA's responses and finalizes the approval of Michigan's SIP revision to establish a RVP limit of 7.8 psi for gasoline sold in the Detroit--Ann Arbor CMSA.