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N.New Hope Road (27300)-Septic Feasibilty and Design Project No.E09041.000 <br />Page 2 14 July 2009 <br />Subsurface Exploration <br />Two pits were excavated in the proposed disposal area on 24 April 2009 and logged by a <br />representative of Youngdahl Consulting Group,Inc.Excavation was performed using a skid- <br />steer front loader with a 3-foot wide bucket.The exposed soils were observed and classified for <br />color:and material type based on the Unified Soil Classification System.Following completion of <br />the percolation test,the excavated pits were backfilled with native soil to the existing ground <br />surface. <br />Subsurface Conditions <br />The test pits completed for this investigation encountered relatively similar soil conditions within <br />the maximum 4.5 foot depth of exploration.Soils encountered during the exploration included <br />interbedded SILTS and SANDS,which are indicative of stream deposits.The silts displayed <br />slight to moderate cementation and the sands displayed low to moderate cementation. <br />Groundwater was not encountered during our exploration. <br />Groundwater Depths <br />Based upon a telephone call with San Joaquin Environmental Health Department personnel,the <br />estimated depth to groundwater is approximately 10 feet in the vicinity of the subject property. <br />No known data exists for the well located in the southwest portion of the property. <br />Percolation Testing <br />Percolation testing for the proposed septic disposal area was performed on the 27 April 2009. <br />Testing was performed in general accordance with adherence to the San Joaquin County, <br />Environmental Health Department procedures.The percolation test results are presented below. <br />Testing Procedures <br />On 24 April 2009,a staff geologist,working under the direction of a Certified Hydrogeologist, <br />excavated one percolation test hole to a depth of approximately 42 inches below adjacent soil <br />grades.The test hole was lined with pea gravel and filled with water on 26 April 2009 for the <br />presoak requirement,per the San Joaquin County Environmental Health Department <br />specifications.On 27 April 2009,the following day,percolation testing commenced.Water was <br />placed in the hole to a minimum depth of 6 inches over the gravel and the water level recorded <br />to begin the test.After Y2-hour elapsed,the water level was recorded as the finish level for that <br />time period,then the hole was refilled to the initial level and the level recorded.The fill/refill <br />procedure was performed for 3 hours.Beginning with the 4th hour of testing,the record interval <br />was every 10 minutes,using the fill/refill method described above. <br />Test Results <br />FOllowing completion of the 4 hour percolation test procedure,the final test result was a water <br />fall rate of 2 minutes per inch. <br />Septic System Design Recommendations <br />We understand that the project will be a four bedroom single-family residence with associated <br />kitchen,laundry facility,and two bathrooms. <br />Septic Tank Volume <br />Environmental officials for San Joaquin County have stated that the septic tank volume on this <br />project must be a minimum of 1,600-gallon capacity and sufficient to retain waste for a minimum <br />of 24 hours.In case of future additions to the residence,we recommend using a minimum <br />2,OOO-galion septic tank capacity.An effluent filter should be installed in the outlet of the septic <br />tank.