SU0007436 SSNL - Laserfiche WebLink

Home Browse Search

Fhe the above land use could create environmental concerns that may be discovered in s may be presumably from agricultural inputs, and will be discussed in Conclusions eport. s only one septic system currently on the property, located at the house in the southwest corner of the property. There may have also been a septic system at the defunct milk barn. Septic system design criteria for slopes do not have to be considered. (§ 3.4) The subject property is on the border of the areas designated as "Hard Pan"and"Sand/ Sandy Areas"by EHD's map denoting the various soil types and septic system requirements throughout the County. North of the Lone Tree Creek,the soil is designated hardpan. South of Lone Tree Creek, the soil is designated sand/sandy. Due to this proximity to "hard pan" areas, and the depth to the water table at approximately 55 ft below grade as discussed below, deeper septic system management structures such as sumps and seepage pits are installed in this locale. (§ 3.2,3.3,3.4, 3.5, and 3.6) A review of Application Permits on microfiche file at EHD reveals there have been six Applications for Repairs/Additions/Replacements to septic systems within the one-half mile radius study area on Lone Tree Road exclusively. (§ 5.4) This can be considered a medium number of Repairs/Additions/Replacements, and can be attributed to the medium-to-low density housing within the study area. (§ 5.1 and 6.0) SOIL PROFILE AND PERCOLATION TESTING (§5.4) The USDA Soil Map shows the on-site soil to consist of three distinct soil type classifications, as illustrated on the USDA Soil Map in Appendix 2: Jacktone clay(#180) which is found in the northwest quarter of the property,Madera sandy loam(#193) which extends as a "finger"through the middle of the property, and Manteca fine sandy loam(#196)which is near the southern one-quarter of the property. The Jacktone soils are silty clays,while the Madera and Manteca series soils are silty sands/sandy silts. Percolation tests for all four proposed Parcels were conducted in the Manteca fine sandy loam soil. Typically, this soil type down to five feet is well-drained with moderate-to-rapid permeability. This was observed in all of the shallow test results. In addition to the shallow perc test results, the deeper tests also exhibited excellent permeability. Sufficient soil "fines"exist within the encountered soil to impede very rapid percolation, which would occur with a sandy soil. Therefore, treatment of septic effluent can take place within this soil environment before reaching the water table. (§ 5.2,5.3, and 5.4) A Log of Boring using the Unified Soil Classification System (USCS), as observed from the deep perc test borings completed on each of the four proposed Parcels is found on the EHD PERCOLATION TEST DATA SHEET. Generally, the underlying soils show a sandy silt. No cemented silts hardpan/plowpan was encountered in any of the test borings. it Page -3- Chesney Consulting