Volume 2: Draft Gorst Planned Action Environmental Impact Statement

GORST PLANNED ACTION EIS | AFFECTED ENVIRONMENT, SIGNIFICANT IMPACTS, AND MITIGATION MEASURES3.3 Air QualityThis section describes the current air quality conditions in the region, existing regulations and policies that governallowable air pollutant emissions, and existing regulations and policies that have been developed to reduce GHGemissions. Impacts of the alternatives (Alternative 1 - No Action, Alternative 2 – Regional Commercial Center, andAlternative 3 – Complete Community) and the Gorst Watershed Framework Plan are analyzed at a programmaticlevel. This section also provides a screening-level forecast of GHG emission rates that would be generated by thealternatives and within the Gorst Watershed area.Current air quality regulations would prevent new developments and commercial facilities within the Gorst studyarea from generating unacceptable air pollutant emissions that would affect nearby areas during construction oroperation. Because all of the alternatives would increase population, commercial space, and industrial space in theGorst study area above existing conditions, the air pollutant emissions generated within the Gorst study area areexpected to increase. Similarly, regional vehicle miles traveled (VMT) by vehicles used by Gorst residents and thosewho work in Gorst would also increase in the Gorst study area, along with the tailpipe emissions generated bythose vehicles. However, the VMT generated by the new homes and businesses in the Gorst study area would be asmall fraction of the overall VMT generated within Kitsap County, so it is unlikely that any of the alternatives wouldsignificantly affect regional air quality.Affected EnvironmentExisting Air Pollution SourcesTypical air pollution sources in the Gorst study area include vehicular traffic, commercial and retail businesses, lightindustry, and residential wood-burning devices. While many types of pollutant sources are present, the singlelargest contributor to most criteria pollutant emissions is expected to be derived from on-road vehicles, whichcontribute the majority of the carbon monoxide (CO), volatile organic compounds (VOCs), and nitrogen dioxide(NO2). Secondary sources of emissions are derived from commercial and industrial land uses. Additionally, spaceheating (e.g., gas and diesel heating equipment) and wood-burning appliance emissions contribute to backgroundair quality.Key Criteria Air PollutantsThe following paragraphs describe the sources and environmental effect of key criteria pollutants (CO, ozone, andparticulate matter) considered in this analysis.CO is a product of incomplete combustion generated by mobile sources, residential wood combustion, andindustrial fuel-burning sources. CO is a concern related to on road mobile sources because it is the pollutantemitted in the greatest quantity for which short-term health standards exist. CO is a pollutant whose impact isusually localized, and CO concentrations typically diminish within a short distance of roads. The highest ambientconcentrations of CO usually occur near congested roadways and intersections during wintertime periods of airstagnation.Ozone is a highly reactive form of oxygen created by an atmospheric chemical reaction of nitrogen oxides andVOCs, both of which are emitted directly from industrial and mobile sources. Ozone problems tend to be regionalin nature because the atmospheric chemical reactions that produce ozone occur over a period of time, andbecause, during the delay between emission and ozone formation, ozone precursors can be transported far fromtheir sources. Transportation sources like automobiles and trucks are some of the sources that produce ozoneprecursors.Particulate matter is generated by industrial emissions, residential wood combustion, motor vehicle tailpipes, andfugitive dust from roadways and unpaved surfaces. When first regulated, particle pollution was based on “totalsuspended particulate,” which included all size fractions. As sampling technology has improved and theimportance of particle size and chemical composition has become clearer, ambient standards have been revised toDraft | June 2013 3-26