SITE INFORMATION AND CORRESPONDENCE

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Table 1 Monitoring Plan (proposed November 2009) Applied Aerospace Structures Corporation, Stockton, California Shallow Monitorn Pump ring Wells Proposed Well ID Intake Location Concentration trends Well Function and Comments Sampling MW -15 Depth NE of source Six ears w/ onlytrace detections. y No sampling since August 2002 Schedule MW -3 (feet) upgradient of extraction Then downward and ND for I.5 years. Downgradient SE sentry well S Shallow Monitorn Wells ring Wells MW -2 58.0 Upgradient No VOCs detected Upgradient background well; no sampling since April 1998 NS MW -15 Transgradient NE of source Six ears w/ onlytrace detections. y No sampling since August 2002 NS MW -3 60.5 area; upgradient of extraction Then downward and ND for I.5 years. Downgradient SE sentry well S MW -16 91.5 wells GW -2R and GW -4. ND for 8 years except for TCE Monitors Intermediate depth zone offsite to east, has A MW -14 76.0 Downgradient, NE corner of Long-term decreasing trend prior to Downgradient control point located at DIE property corner S MW -4 54.0 property 2000, one detection since 2003 ND due to operation of nearby Monitors former offsite contaminant migration pathway S MW -511 56.7 South of Bldg #2 extraction well GW -7 towards the southeast Downgradient slightly SE of DCE and TCE: may be rising slightly Shallow groundwater zone outside former Source Area (co - g S M W-6 55.7 after former downward trend. located with MW -7 and MW -10) source former source area MW -9 52.5 North Flank of source area DCE. strong downward trend, < 1 Monitors transgradient north of former source area S pgfL DCE: early fluctuations, long-term MW -I1 55.0 Offsite north of MW -12 downward trend Monitors offsite farthest to east-northeast S TCE, PCE'. reached ND in 2002 TCE: early fluctuations, downward Offsite due east of MW -4 trend, ND since 2004. Offsite migration monitoring well, east of MW -4 S MW -12 5T0 and GW -6, across Airport DCE: long-term downward trend, Blvd. approaching ND south of MW -12, east for 8 years except one DCE Downgradient SE sentry well A MW -13 1 64.0 JOffsite of Bldg # 1 IND detection (0.94 pg/L) in 2003 Offsite Southeast Monit ring Wells OB -1 NA 200 feet east-southeast of DCE: downward trend 5 years. Offsite downgradient of MW -5R and GW -7 S MW -15 59.0 MW -5R TCE: stable Source Area plume core NS 300 feet east of SE corner, in stable 2 years Downgradient SE sentry well S MW -16 91.5 Carpenter Road ND for 8 years except for TCE Monitors Intermediate depth zone offsite to east, has A MW -14 76.0 300 feet southeast of SE 2 ears Downgradient SE sentry well S MW -17 105.0 corner, in cul-de-sac stable y Intermediate Depth Monitoring Wells OB -1 NA Co -located with MW -6 and ND three years DCE: prior to 2006, downward trend Intermediate depth just beyond downgradient edge of S MW -10 85.0 IvIW_7 and less than 1.5 pg/L Source Area plume core NS 100 ft. E of GW -5 nearNA TCE, PCE: ND since May 2000. Piezometer, water level observations do—gradient NS OB -3 NA Co -located with MW -12 ND for 8 years except for TCE Monitors Intermediate depth zone offsite to east, has A MW -14 76.0 offsite detections < WQO in 2006 become a sentry well Dee Monitorin Well OB -1 NA Co -located with MW -6 and NA Monitors deep g.w, zone downgradient of Source Area A MW -7 103.3 MW -10 All ND for 9 years plume. Function is now redundant. NS Observation Wells OB -1 NA 25 ft NE of GW -1 NA Piezometer, water level observations in Source Area NS OB -2 NA 50 ft. N of GW -1 NA Piezometer, water level observations in Source Area NS 100 ft. E of GW -5 nearNA Piezometer, water level observations do—gradient NS OB -3 NA extraction well (GW -5) entrance gate MW -I and MW -8 abandoned due to building construction. No. Wells ND = Not detected NA = Not applicable NS = No sapling, semiannual water level monitoring. 5 m TCE = trichloroethene A = Annual, sample in August only 3 DCE = 1,1-dichloroethene S = Semiannual, sample in February and August 10 TCA = 1,1,1 -trichloroethene Q = Quarterly, continue quarterly sampling 0 Page 1 of 1 MW trends table Nov2009.XLS 11/24/2009