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:B. SUBJECT PROPERTY AND SURROUNDING STUDY AREA INFORMATION The subject property to be developed is situated mostly atop a predominate bluff at the west en7of the town of Clements. The attached United States Department of Agriculture (USDA) and the San Joaquin County Parcel Viewer aerial photographs denote land use surrounding the subject property. A small subdivision of six lots are adjacent to the southeast of the project site. To the north are walnut orchards and the Mokelumne River, and to the west are additional walnut orchards. Clements is surrounded by hundreds of acres of agricultural production land,primarily orchards and vineyards. Historical aerial photographs of the property found in Appendix 3 illustrate the property in 1937, 1952, 1963, 1975 and 1982. In 1963, it appears the property was "terraced" for agricultural production. In the other photographs, the property appears to be fallow. . The prevailing septic system structure typically installed in the Clements area are seepage pits and sumps. This is due to the clayey, or clay/cobble shallow surface soils that are not overly conducive for effluent management from leachlines, while seepage pits and sumps installed in the deeper soils, readily manage septic effluent. In addition, the de th of groundwater is de2a2j!RR122imately 140 feet, which is favorable for the installation of these deeper septic structures. II. NITRATE LOADING STUDY FINDINGS A. SOIL PHYSICAL AND CHEMICAL CHARACTERISTICS �1. SURFACE AND SUBSURFACE SOILS The USDA Soil Maps indicate the majority of the on-site surface soils consist of a Tokay fine sandy loam (9256) soil type. This is a deep, well drained, mostly level soil on low fan terraces. It was formed in alluvium originating from granitic rock sources. The Soil Survey data indicates the surface layer is grayish brown fine sandy loam approximately 20 inches thick. TAW gra ish�brQrvn Erne sandy-loam. The substratum to 60 inches is a pale brown fine sandy loam. The Unified Soil Classification System (USCS) identifies this soil as a clayey, silty fine sand (SC-SM). A Mobile Drill Rig was used to complete a soil boring on proposed Parcel 4,near the center of the project to examine the subsurface soils. The Log of Boring (See Appendix 5) illustrates the subsurface soil characteristics. The top 60 inches of soil encountered in this exploratory boring corresponds with the USDA soil classifications. At 8.0 ft, a fine-to-medium, poorly graded sand was encountered, which extends from this 8.0 ft depth to 20 ft. This sand stratum is illustrated in Photographic Plate D in Appendix 8. Plate F illustrates the soil structure at 25 ft, which is a stiff, silty clay. This silty clay structure is first encountered at approximately 23.5 ft. The boring was terminated at the 25 ft depth; therefore, it is unknown as to the depth this stiff silty clay soil extends. However, the well log for the on-site boring that is eventually to be the well.to serve the project, illustrates a sand stratum from 21 to 50 feet. Consequently, this silty clay stratum could be relatively thin. Page -3- Chesney Consulting