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TABLE 1 PERCOLATION TEST RESULTS AND RELATED DATA EXISTING PARCEL EXISTING PERC TEST DEPTH POST SOAK PERC TEST AND PROPOSED ACREAGE PERIOD RESULTS SEPTIC SYSTEM STRUCTURE STATUS 7�- �3 00-16 9.81 Acres 42 In hes 4.5 Inches 0.0 nun/in Bdroom House: Standing Water FAIL 120 ft of Leachline in Hole (E.g.,3-40')and 3-36" Seepage Pits 300 Inch�s(25 ft) No Standing 5.6 in \ (or Sumps) Water in Hole (§ 4.0) LOCAL GROUNDWATER INFORMATION (§4.1) The 1999 Lines of Equal Depth Map and the 2003 Lines of Equal Elevation Map publishe=d\, by the San Joaquin County Flood Control illustrate the groundwater depth to be approximately 75 ft deep and the flow in a northwesterly direction. These maps are illustrated in Appendix A. The domestic well for the proposed house has not been drilled yet,but its-tentative location is illustrated on the Preliminary Plot Plan. Therefore, Sections § 4.3 4. ;14 nd4.are not applicable. (§ 4.2) The depth to groundwater may make potential adverse impact to the underlying groundwater somewhat unlikely. This will be dependent upon the underlying soil lithology ander the amount of potential contaminants that percolate from the surface soils. (§ 7.0) CONCLUSIONS (§ 6.8) The perc test results for the subject Parcel show acceptable percolation for the management of anticipated effluent flows from the proposed house at the deeper depths representative of seepage pits or sumps. The shallow soils at leachline depth will initially accept effluent water, but will quickly become saturated leading to no permeability, as evidenced by the shallow perc test results. (§ 6.7) No problems are anticipated for this septic system, other than typical lifespan concerns. An engineered septic system will not have to be installed for this Parcel unless there are continual failures. The 50%replacement area is located directly east or west of the proposed leachfield. It has generally been the policy of EHD to install seepage pits even when permeable strata exists at typical sump depth, but not at seepage pit depth. In the case of this Study,permeable strata exists at both sump and seepage pit depths, as determined in the 25 ft exploratory boring that was used for the deep perc test boring. It will be at the discretion of EHD as to the septic system structure to be installed for this project. Page-3- Chesney Consulting