SITE INFORMATION AND CORRESPONDENCE_FILE 1

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entirely paved. The Ag Chem area is used for manufacturing and storing of agricultural fertilizers. Previous operations also included pesticide formulation. The area has a Mediterranean -type climate, characterized by hot, dry cloudless summers, and mild, humid winters with very low rainfall. The mean temperature is 62.9°F. Precipitation in the area averages 14.3 inches annually, prevailing wind flow is northerly in summer and southerly in winter. The area topography is relatively flat and the ground surface drains to the southwest. No surface water bodies exist within a half mile radius of the facility. The nearest residential development area is 2,000 feet to the northwest. Interstate 5 is one mile to the west. Groundwater in the Lathrop area was, to a depth of 20 feet below ground surface (bgs) in 1991 and flows to the north/ northwest. Groundwater beneath the Simplot facility, however, is at 10 to 15 feet bgs and flows to the southwest according to the Regional Water Quality Control Board (RWQCB). Shallow groundwater has been found to contain detectable amounts of pesticides since 1982. Groundwater remediation is being conducted under the direction of the RWQCB and consists of eight extraction wells, on-site treatment, and re-injection into deeper groundwater aquifers using two injection wells. The groundwater treatment plant was constructed immediately west of the Ag Chem area. Monitoring wells in various aquifer zones are located in 21 stations around the facility. The area is described as being once a natural grassland community, however, the area has been disturbed by agricultural and development. Most of the Simplot facility is cleared of trees and grass and is in industrial use. A review has been completed of the California Department of Fish and Game Natural Diversity Data Base. The review did not identify any known threatened or endangered species in the immediate vicinity of the Simplot facility. Plant species of interest are the Delta button celery, Wright's trichocornis, and slough thistle. These plants species were identified about two miles from the facility. Animal species of interest are the tricolored blackbird, tiger salamander, and the Swainson's hawk. The closest sighting was for the tricolored blackbird and was seen one mile southeast of the facility. These identified plant and animal species require a riparian habitat or stands of trees which is absent at or around the Simplot facility. Migration onto the Simplot facility would not be expected. Activities will require the use of a temporary storage area in the Ag Chem area for washwater and utilities, such as water and electricity.