SR0082226 SSNL - Laserfiche WebLink

Home Browse Search

4 KL E/NFEL DER Bright People.R,9ht5111tp s. 2 FIELD INVESTIGATION AND LABORATORY TESTING 2.1 FIELD INVESTIGATION On April 9, 2020, percolation test holes P-1 and P-2 were drilled adjacent the existing leach field area to depths of about 6 and 23 feet below site grade, respectively. The approximate percolation test hole locations are presented on Figure 2. Following drilling, the sides of the test holes were scored, and significant loose material was removed from the bottom of the holes. The percolation test holes were then prepared by first placing about 2 inches of fine gravel at the bottom of the holes and installing a 4-inch diameter, perforated PVC pipe. Before 10:00 AM on April 9, 2020, about 6 inches of water was placed in the holes for pre-soaking. On April 10, 2020,the percolation test for test hole P-1 was started at about 11:03 AM and at about 2:00 PM for percolation test hole P-2 in accordance with San Joaquin Environmental Health Department (SJCEHD) accepted guidelines, using clear potable water. The holes did not exhibit sloughing or caving and were empty of water prior to testing. From a fixed reference point (a marked location on the side of PVC pipe), the drop in water level was measured in approximate 30-minute intervals for 4 hours (SJCEHD Procedure #2) in percolation test hole P-1, refilling as necessary to maintain the prescribed amount of water over the gravel. Percolation test hole P-2 drained more rapidly and was measured in approximately 10-minute intervals for 1 hour (SJCEHD Procedure #3). Under the observation of a representative from the SJCEHD, the last 30- and 10-minute readings of the tests were observed and the percolation rates, in minutes per inch, were calculated. Copies of our field percolation test results are attached on Figure 5. The percolation test holes were located in the field by visual sighting and/or pacing from existing site features; therefore, the locations shown on Figure 2 should be considered approximate. 2.2 LABORATORY TESTING A laboratory test on a water sample recovered from the on-site well neared the proposed septic system modification area were performed by Fruit Growers Laboratory (FGL). The following laboratory tests were assigned. Nitrate (N) The water sample obtained from the well was delivered to a laboratory on ice the same day using chain-of-custody procedures. Laboratory test results are presented in Appendix B. 20210068.001A/ST020R110989 Page 3 of 14 April 30, 2020 ©2020 Kleinfelder www.kleinfelder.com