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Project No.: D-6289-08 St. Barbara Catholic School Percolation -Infiltration Tests • The borehole diameter was 8 inches. • The bottom elevation of test holes is at or 12 inches below the proposed invert of infiltration basin. CITY OF SANTA ANA Planning and Building Agency may, lS. Approved FOR PERMIT ISSUANCE • Groundwater observed was at 14 feet below the existing ground level. • Infiltration basins are supposed to be at least 10 feet above the groundwater level. • Rotate the auger until all the cuttings are removed. • Sides of the hole were not smeared after drilling and there was no caving. • The bottom of the test hole was covered with 2 inches of gravel prior to testing. • Holes were filled with clear water to appropriate depths from the ground surface (Minimum required is 5 x radius of the hole (5 x 4" = 20 inches) from the bottom. • On these two locations, two consecutive measurements showed that more than 6 inches of water seeped away in 25 minutes test (Pre -Percolation Data Sheets). No pre-soaking overnight was required. Thus, the tests were run for at least an additional hour (60 Minutes) with measurements taken every 10 minutes (Percolation Test Results). The drop that occurs during the final reading is used to calculate the percolation and then infiltration rate. Both Pre -Percolation data Sheets and Field Percolation Test Results are presented on Plates 1 through 4 in Appendix C, Infiltration calculations are presented on Plates 5 and 6 respectively for PC-1 and PC-2 in Appendix D. Infiltration results using another method, Reduction Factor Method, Rf are presented on Plates 7 and 8 for PC-1 and PC-2 respectively in Appendix E. • A sounder was used to determine the water level. • Measurements were taken with a precision of 0.25 inches or better. 3