ARCHIVED REPORTS XR0000789 - Laserfiche WebLink

Home Browse Search

ecorporatio'n May 15, 2000 A Member of The IT Group Mr Ed Ralston • Page 2 One Geoprobe® (GP-1) was advanced to a depth of approximately 40 feet below ground surface (bgs) on July 24, 1998 Two groundwater monitoring wells (MW-I and MW-2) were installed on August 21, 1998 During installation of Well MW-4, the drill ng auger broke a mismarked City of Lathrop water main Approximately 600,000 to one million gallons of water were discharged from the broken water main On September 14, 1998 IT returned to the site to install wells MW-3 and MW-4 { Based. on recent gr {O Based monitoring data from the site, depth to water is encountered between Viand 15 feet below ground surface (bgs) Historical depths to groundwater obtained from the DWR report a historical shallow depth of 6 feet bgs and a maximum depth to groundwater of 33-112 feet bgs PROPOSED SCOPE OF WORK S The scope of work proposed for this investigation will include the installation of dg--Ie' groundwater monitoring wells to delineate the lateral extent of hydrocarbons in the soil and groundwater As required by the Occupational Health and Safety Administration (OSHA) Standard "Hazardous Waste Operations and Emergency Response" guidelines (29 CFR 1910 120), and by California Occupational Health and Safety Administration (Cal-OSHA) "Hazardous Waste Operations and Emergency Response" guidelines (CCR Title 8, Section 5192), IT will prepare a Site-Specific Health and Safety Plan prior to the commencement of fieldwork The Site-Specific Health and Safety Plan will be reviewed by the field staff and contractors before beginning field operations at the site A draft Site-Specific Health and Safety Pian has been included in Attachment A i The specific scope of work is discussed below , • Monitoring Well Installation. Five groundwater monitoring wells (MW-5 through MW-9) will be installed Tentative locations are shown on Figure 2 The wells will be S� installed with a well screen interval 15 feet below and 5 feet above the current water Y level All work will be done in accordance with the permits obtained from the SJCPHS/EHD and the City of Lathrop • Soil Selection and Analysis. Soil samples will be collected every five vertical feet in the monitoring well borings Selected soil samples will be submitted to a California State-certified laboratory and analyzed for the presence of total petroleum hydrocarbons quantified as gasoline (TPH-g), benzene, toluene, ethylbenzene, and total xylenes (BTEX), and methyl tertiary-butyl ether (MtBE) by EPA Methods 8015 Modified and 8020 The highest MtBE detection from each boring will be confirmed by EPA Method 8260 In addition the sample will be analyzed for 1,2-dichloroethane (1,2- DCA), ethylene &bromide (EDB) and total lead Sampling and analytical methods are Spresented in Attachment B 11SACRFp11COMMON`rancfpl\Projects\Projects1911\00n1C10102\WorkP1an doc