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New Hope Soil Suitability *WO April 3,2008 File No. 2836-001.01 Page 4 wil_need elevated slightly to provide for minimum clearance..between- the sands y (probable groundwater location) and the points of discharge. In as much as the each property will be large, it should be possible to find areas of each site where stratification is most favorable to separation between the point of discharge and the depths of predominately sandy soils (likely the free groundwater level). /6.0 PERCOLATION TEST INFORMATION The locations of each percolation test site are shown on the attached Plate 2. As can be seen, there is one test hole on each proposed property; each hole is approximately 200 feet westerly of the easterly boundary of each property. Each percolation test hole was six inches in diameter and 36 inches deep. All holes were "scratched" with a wire brush to remove smeared surfaces. The bottom two inches of each test hole was covered with 3/8a'-inch pea gravel. The holes were drilled by hand auger on March 25, 2008, and were pre-saturated at the time of drilling. Testing was performed on March 26 and again on March 27, as requested by the County. All holes were uniform and without significant sloughing and raveling following the pre-saturation and the two test intervals. The tests were performed by the placement of six inches of water over the pea gravel, with the holes refilled as necessary during the testing. All tests were conducted for four hours with readings on one-half hour intervals. The final readings at each test site were ` observed by Lisd'Maden f San Joaquin County. Copies of the actual field tests are attached as Plates—ffgo-gh 6,Pere Test Rate Form 1c. As discussed briefly above, it may be necessary to elevate leach fields slightly on the properties created by the proposed subdivision. Other than this, we would expect that conventional waste disposal systems to be appropriate. Although no percolation was) easured for percolation test 5 (on Lot 5), because of the sizes of all of the proposed properties, we would expect with proper siting that appropriate permeability rates ar obtainable. The size of the proposed properties (and their cost) likely will give rise to relatively large dwellings whose owners are able to design and configure safe and effective waste disposal systems. 7.0 CONCLUSIONS The average ground surface elevation at the site is on the order of 0 feet, USGS datum. In addition, the Mokeli mne River will form the westerly boundary of each proposed property. All the prop are a the 100 year flood level. Measured free groundwater levels w 7.50 and 5.75 fee below ground surface at the time of our late March 2008 testing, a would exp t significantly higher free groundwater levels during extended high stage con i ions on the Mokelumne and/or during heavy irrigation. r In spite of these conditions, the apparent long term success of completely in ground systems at both existing residential sites and the sizes of the proposed properties, should 1W