Volume 2: Draft Gorst Planned Action Environmental Impact Statement

GORST PLANNED ACTION EIS | AFFECTED ENVIRONMENT, SIGNIFICANT IMPACTS, AND MITIGATION MEASURES• Energy emissions are generated by space heating and electrical supply to the building during its lifespan. Thespreadsheet incorporates energy intensity factors specific to Washington State.• Transportation emissions include tailpipe emissions generated by on-road vehicles used by building occupantsafter the building is constructed. For purposes of calculating GHG emissions for this screening-levelprogrammatic analysis all of the forecast commercial space was aggregated into the single land use category“Office”. Additionally, the forecast industrial space was aggregated into the single land use category “Other”.The transportation emissions do not account for vehicles passing through the Gorst study area, unless they aredirectly associated with the buildings being evaluated. These emissions account for “upstream” emissionsduring extraction and refining of the fossil fuel used over the lifespan of the building. The transportationemissions for the commercial and industrial land use categories account only for the employees working inthat space, but they do not account for the relatively small amount of vehicle travel by delivery trucks carryinggoods to or from the buildings. In addition, they do not account for vehicle travel by customers at retail orcommercial buildings. The spreadsheet was modified to assume a future fleet-wide fuel economy of 54.5 milesper gallon, consistent with EPA’s newly proposed CAFE vehicle mileage standard for 2025.“Soil Carbon” GHG Emissions from Permanent Removal of BiomassThe general term “soil carbon GHG emissions” refers to the effect of permanently removing existing vegetation forpurposes of constructing new development. This exacerbates global climate change by two mechanisms. First, theexisting biomass consisting of above-ground vegetation and below ground root mass is immediately removed anddisposed of, which immediately causes the biomass to decay and release carbon dioxide (CO2) to the atmosphere.Second, the above-ground vegetation that was permanently removed is no longer available to remove CO2 fromthe atmosphere during natural photosynthesis.The “soil carbon” GHG emission rates for each alternative were estimated using the calculation tool developed byBuild Carbon Neutral (Build Carbon Neutral 2013). That tool queries the user for the acreage of the vegetation typethat is removed, and then displays the annualized GHG emission rate.Tailpipe Emission Reductions Provided by Development Goals and PoliciesDevelopment goals and policies in the Gorst UGA are expected to reduce GHG emissions compared to traditionaldevelopment by reducing vehicle trips and fuel usage. As described above, for this assessment, the percentreductions in vehicle usage and the corresponding GHG emissions reductions for new development were derivedbased on the 2010 SMAQMD guidance document. The methodology described in the guidance documentestimates GHG reductions only as a result of reduced vehicle trip generation, but it does not attempt to estimateGHG reductions provided by other mitigation measures such as use of recycled building materials, improvedthermal insulation, reduced electricity consumption, or reduced waste generation.Within the Gorst UGA, development goals and policies from the City of Bremerton and Kitsap CountyComprehensive Plans were used to develop a development reduction factor for GHG emissions. Details on how thedevelopment strategies were used to adjust the transportation-related GHG emissions are provided in Appendix CAir Quality GHG Development Reduction Procedures & Sea Level Rise Information. The estimated percentage ofemissions reductions compared to future conditions without these development strategies (business as usual) foreach alternative was calculated to be four percent (transportation-related GHG emissions were reduced by fourpercent). Thus, per-capita and per square foot future trip generation and regional VMT values for the alternativeswere reduced by four percent compared to existing conditions.The procedures for deriving the development-related reduction factors are provided in Appendix C Air Quality GHGDevelopment Reduction Procedures & Sea Level Rise Information. The development reduction factors applied forthis analysis apply only to the land use design features inherent to the general location of the Gorst UGA; they donot attempt to account for additional project-specific design features that might be implemented for individualfuture developments in the Gorst UGA.Draft | June 2013 3-34