ARCHIVED REPORTS_XR0004515 - Laserfiche WebLink

Home Browse Search

Mr Ran Rowe February 9,2000 and were not detected at more than 30 ft bgs The honzontal extent of MTBE is defined to the north by well MW-3 CPT bongs CPT-1,CPT-2,and CPT-11 show that MTBE concentrations in ground water decrease with depth along the southeastern edge of the site, in the vicinity of the source area Concentrations attenuate to 141 pglL at 55 5 ft bgs in CPT-11 INVESTIGATION PROCEDURES AND RESULTS Cambria's scope of work for the investigation included the onsite installation of two four-mch monitoring wells,and one nested well with two two-inch casings One nested well,with two two-mch casings,was installed offsite The monitoring well locations and the CPT boring locations are shown in Figure 1 Analytical results for soil samples are presented in Table 1 Monitoring wells MW-4A and MW-413, were constructed of two 4-mch casings in separate 1 I-Inch borings MW-4A was completed at 75 fbg and is screened from 70 to 75 fbg MW-4B was completed at a depth of 49 fbg,and screened from 44 to 49 fbg MW-5(A,B) was completed at a depth of 75 fbg,MW-5A was screened from 70 to 75 fbg,and MW-513 was screened from 44 to 49 fbg MW-6 (A,B)was completed at a depth of 73 fbg,MW-6A was screened from 68 to 73 fbg,and MW-613 was screened from 49 to 54 fbg MW-5(A,B),and MW-6(A,B)were each constructed with two two- inch casings in one 12-inch boring The results of Cambria's October 25 through October 29, 1999 well installations are summarized below The monitonng well locations are shown in Figure 1 Analytical results for soil and groundwater samples are presented in Tables 1 Cambia's Standard Field Procedures for Monitoring Wells are in Attachment D Soil Boring and Well Installation Permits The Property at 341 East Mann Street is covered by SJCPHS Drilling Permits Nos 016251 and 016252,presented in Cambia's April 16, 1998, Monitoring Well and CPT Investigatmn Report SJCPHS Drilling Permit No 020-867 (Attachment A)covers monitoring well MW-6(A,B) Dnlhng Date• MW-4A and MW-413 well casing and sand pack were installed and temporarily sealed on October 25, 1999,and the grouting was completed on October 27, 1999 MW-5(A, B) well casing and sand pack were YY iM,Laucu aid temporarily sealed on October 26, 1999, and the grouting was completed on October 27, 1999 MW-6(A,B)well casing and sand pack were installed and temporarily sealed on October 28, 1999, and grouting was completed on October 29, 1999 3