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[3] SOIL PROFILE The soil profile from 0 ft to 4 ft consists of a dark brown/black silt� clilt, which was wet from recent rains. Soil at the typical leachline depth of 42 inches consists of this stratum. The Unified Soil Classification System classifies (USCS) this soil as CL-ML: silty, lean clay, with cemented silts hardpan. At 4 ft,the soil texture changes to a yellowish brown fine sandy silt(SM-ML). Fine sand content increases with depth; however, so does the density. Although a 25 ft boring was not complete�n the subject property, from previous seepage pit installations the proximity of the new house, sand strata exists from approximately J8 to 21 ft in this locale. Well Driller's Logs close to the subject property were on file at the Environmental Health Department, documenting the underlying soil strata. The logs do not reference the known sand stratum because if it was encountered, it was probably too thin for the drillers to recognize it. The well logs illustrate that the underlying strata consist predominately of clays. [4] PERCOLATION TESTING Percolation testing was conducted on both Parcel 1 and Parcel 2. Since Parcel 1 was not designated as the "Designated Remainder" on the Tentative Map, a perc test was done on this Parcel in accordance with Environmental Health Department regulations. A Log of Boring for the percolation test holes accompanies the FIELD PERCOLATION TESTING REPORT and illustrates the subsurface soil characteristics, as referenced above to the test depth of 12.5 ft. The boring was drilled, scarified and pre-saturated the day before testing on October 22, 2001. Readings were taken over a four-hour test period since the soil possesses a silty structure. Due to indigenous surface and subsurface clay and silt soil properties, and the fact that the Van Vuren's have their own backhoe, it was decided to proceed with soil profiling and percolation testing by using this backhoe. The backhoe test pit provides greater evaluation of the soil characteristics than with an augered borinlK percolation testing, the trench pump-in test (Se Metcalf& Eddy - Wastewater Engineering - Treatment, Disposal, Reuse, P. 1050) was done in lieu of the traditional six-to-eight inch diameter augered boring. Percolation testing was performed in accordance with San Joaquin County Department of Environmental Health regulations. The attached Site Plan denotes the location of the percolation trench pump-in tests and the FIELD PERCOLATION TESTING REPORT illustrates the perc test results. The subsurface soil strata indicate that seepage pits will have to be installed at the end of each leachline. Additionally, the information obtained from the Environmental Health Department regarding the number of permits for repairs/additions also indicates the need for the installation of seepage pits. I I 2 Vaffey Ag research