ARCHIVED REPORTS_MAY & JULY 2014-TPR

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1-4 1.7 Area Climate The climate of the region is typical of the California Central Valley. Winters are generally cold and wet with fog, while summers are hot and dry. Climatological data used in the site design was gathered from representative weather stations near the site. Representative climatologic stations were selected based on their proximity to the site and a reliable period of records for the station. 1.7.1 Temperature Summer high temperatures often exceed 100 degrees Fahrenheit (0 F), averaging from the low 90's in the northern part of the valley to the high 90's in the south. The daily summer temperature variation can be as high as 30 0 F. Winters for the most part are mild and humid. Average high temperatures during the winter are in the 50's, while the average daily low temperature is approximately 45 0 F. 1.7.2 Precipitation Precipitation at the project site is typical of the Central Valley region. Rainfall is seasonal, with approximately 90 percent of the rainfall occurring between November and April. Snowfall is unusual at the site. Figure 4 presents an isohyetal precipitation map for San Joaquin County showing lines of equal precipitation on a countywide basis (San Joaquin County Department of Public Works, 1991). The isohyetal precipitation map divides the whole of San Joaquin County into three rainfall intensity zones. The project site is located in Zone 2 of the three rainfall zones, as shown on Figure 4. Mean annual precipitation for Zone 2 on the San Joaquin County isohyetal precipitation map is approximately 13.5 inches. Specific precipitation intensities are based on precipitation data from the Stockton weather station number 800-8560, located approximately 8 miles northwest of the site at latitude 38 0 00', longitude 121 0 316', and an elevation of 12 feet National Geodetic Vertical Datum (NGVD) (California Department of Water Resources, 1981). This precipitation was selected due to its long and reliable period of record and its proximity to the project site. The precipitation depth-duration-frequency data for the site from the Stockton W8AP Station Number 800-8560 are: • 100-year, 24-hour storm intenSity of 3.58 inches* • 1,000-year, 24-hour storm intensity of 4.92 inches* • 100-year annual precipitation of 25.42 inches • Annual mean precipitation of 14.27 inches *Source: Non-Water Corrective Action Plan for Forward landfill, Geologic Associates, November 2011. Forward Resource Recovery Facility SWT Engineering Transfer/Processing Report -May~ 2014 z:\projects\aliied waste\forward\resource recovery facility\5 yr permit rvw 2013-14\tpr 2014\text\secl.doc