Volume 2: Draft Gorst Planned Action Environmental Impact Statement

GORST PLANNED ACTION EIS | AFFECTED ENVIRONMENT, SIGNIFICANT IMPACTS, AND MITIGATION MEASURESConstruction Emissions, Commercial Sources, and Air ToxicsUnder Alternative 3, the Gorst UGA is expected to experience greater population growth and less employmentgrowth than under Alternative 1. Development under this alternative would result in a greater increase in localizedair pollutant emissions from construction activities and regional tailpipe emissions from vehicle travel. However,this alternative would result in a smaller increase in commercial activities compared to Alternative 1. Regardless,air quality impacts from construction activities, commercial operations, and mobile source air toxics would besimilar to those described under Impacts Common to All Alternatives.Emissions from Vehicle TravelAs shown in Table 3.3-5 Gorst UGA Contribution to Forecast 2035 Puget Sound Regional VMT, the forecasted VMTfor Alternative 3 is higher than the forecasted values for Alternative 1. However, the net increases in VMT forecastas a result of this alternative are inconsequentially small compared to the Kitsap County VMT forecast for 2035 andits implied impact on regional emissions and photochemical smog. Therefore, regional air quality impacts causedby population growth and transportation emissions in the Gorst UGA (associated with Alternative 3) would not besignificant.GHG EmissionsThe annual GHG emissions for Alternative 3 are calculated based on the future land use listed in Table 3.3-2Assumed Land Use and Population Growth for GHG Emission Calculations - Gorst UGA and the developmentreduction described previously. Table 3.3-6 Comparison of Annual GHG Emissions - Gorst UGA lists the life-cycleGHG emissions increases caused by future development in the Gorst UGA under each alternative. The future GHGemission increases within the Gorst UGA for Alternative 3 would be higher than the GHG emission increasesresulting from Alternative 1, but less than the GHG emission increases resulting from Alternative 2.Alternative 3 would provide more residential growth in the Gorst UGA than Alternative 1. Therefore, it wouldincrease localized GHG emissions within the Gorst UGA compared to Alternative 1. The increase of future GHGemissions in the Gorst UGA for Alternative 3 (above what future GHG emissions are estimated for the No ActionAlternative 1) is only 5,448 metric tons CO2-equivalent per year which is less than the 10,000 metric tons CO2-equivalent per year reporting threshold for stationary sources. Therefore, this evaluation demonstrates that GHGimpacts caused by increased development in the Gorst UGA (associated with Alternative 3) would not besignificant.Additionally, in comparison to state-wide annual GHG emissions (101,000,000 metric tons CO2-equivalent in2008), the relatively small increase in GHG emissions within the Gorst UGA associated with Alternative 3 is notconsidered to be significant.“Soil Carbon” GHG Emissions From Biomass RemovalGHG emissions associated with soil disturbance and biomass removal was calculated based on the total acreage ofdisturbed land that is anticipated. As noted above, impacts associated with land disturbance would be greatest forAlternatives 2 and 3 (117 acres of permanent land disturbance, causing an annualized GHG emission rate of 237metric tons CO2-equivalent per year). This relatively small contribution to GHG emissions by biomass removal ismuch lower than the contribution from future operational activity. For Alternative 3 the annualized GHG emissionrate caused by biomass removal is 237 metric tons per year, while Table 3.3-6 Comparison of Annual GHGEmissions - Gorst UGA shows the increased operational GHG emission rate is 12,922 metric tons per year.Therefore, the GHG emissions caused by biomass removal are not considered significant.Indirect/Cumulative ImpactsDevelopment facilitated by the alternatives would result in indirect effects. For example, additional people andvehicles in the Gorst study area could lead to a greater concentration of pollutants that could adversely affect airquality.Draft | June 2013 3-40