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Vantage to Pomona Heights Chapter 3 <br />230 kV Transmission Line Project FEIS Affected Environment <br /> PAGE 3-271 <br />3.13 CLIMATE AND AIR QUALITY <br />As was done in the Draft Environmental Impact Statement (DEIS) and Supplemental Draft <br />Environmental Impact Statement (SDEIS), this section describes the existing conditions (affected <br />environment) and considers issues related to climate and air quality along all Action Alternatives <br />presented in the DEIS and SDEIS, including those raised during scoping. This Final Environmental <br />Impact Statement (FEIS) section consolidates and builds on the information presented in the January <br />2013 DEIS as well as the January 2015 SDEIS and includes references to those documents throughout the <br />text where appropriate. This FEIS identifies the New Northern Route (NNR) Alternative – Overhead <br />Design Option as the Environmentally Preferred Alternative and has selected the NNR Alternative – <br />Overhead Design Option as the Agency Preferred Alternative. <br />3.13.1 Data Sources <br />Information regarding existing air quality in the Project area was obtained from various federal, state, and <br />local databases and websites. These sources include U.S. Environmental Protection Agency (USEPA) <br />AirExplorer Website, Washington State Department of Ecology (WDOE) Air Quality Website, Yakima <br />Regional Clean Air Agency (YRCAA) website, and Benton Clean Air Agency (BCAA) website. <br />3.13.2 Current Conditions and Trends, Regional Overview <br />3.13.2.1 Climate <br />The Project area is located in south-central Washington generally between the Columbia River and <br />Yakima River in south-central Washington in the Central Basin climatological region. The region’s <br />climate is semi-arid with cold winters and long, hot summers. It is situated in the rain shadow of the <br />Cascade Mountains with a low level of annual precipitation. Based on weather station data collected at <br />Priest Rapids Dam and Yakima between 1946 and 2013, the average annual temperature was 52.5 degrees <br />Fahrenheit (˚F). The average temperature in July was 74.3˚F with a range of 53.3˚F to 91.4˚F (low to high <br />monthly averages) and the average in January was 31.5˚F with a range of 21.0˚F to 40.5˚F. Winter <br />snowfall at Priest Rapids Dam and Yakima are 5.9 and 23.5 inches per year, respectively. The total <br />annual precipitation during the period for both sites was 7.57 inches (Western Regional Climate Center <br />[WRCC] 2013). The growing season averages about 150 days. During July and August, it is not unusual <br />for four to six weeks to pass without measurable rainfall. “Chinook” winds, which produce a rapid rise in <br />temperature, also occur in the region. A few damaging hailstorms are reported in the agricultural areas <br />each summer (WRCC 2013). Average annual wind speed in Yakima is 7.1 miles per hour (mph). The <br />highest average winds occur in April, with an 8.6 mph monthly average (National Oceanic and <br />Atmospheric Administration [NOAA] 2011). <br />3.13.2.2 Air Quality <br />Air quality in the region is generally good. Pollution sources are primarily from the Yakima urban area, <br />woodstoves and fireplaces, open burning, major highways (e.g., Interstate [I] 82, I-90), and fugitive dust <br />created as a result of agricultural operations and unpaved road travel. Pollutants generated by rangeland <br />fires or maneuvering activities on Joint Base Lewis-McChord Yakima Training Center (JBLM YTC) may <br />substantially affect regional air quality in the short term.