ARCHIVED REPORTS XR0011757 - Laserfiche WebLink

Home Browse Search

____ i I ,Report: Groundwater-quality Monitoring—June 23-28,2005, 7500 West Eleventh Street, Tracy, CA- Page t wr =s� Table of Contents PROFESSIONAL CERTIFICATION AND LIMITATIONS........................•...•.- _,. ,r 1.0 INTRODUCTION ......................................... ...................... ; r 1.1 Site Location......................................................................................................................... 1 :. 1.2 Site Codes.......................................................................... 1.3 Background..........................................................................................................................2 1.3.1 Site Characterization Studies ...................................................... . . 2 1.3.2 Groundwater-quality Monitoring ........................................ 3 1.3.3 Monitoring of LNAPL ................................................................................ • 1.3.4 Testing of Water in Potable Water-supply Wells........................................................................4 1.3.5 Evaluation of Natural Attenuation 4 1.4 Geology and Hydrogeology..............................."-"-.......................................................... r.::•, ...........................................6 1.5 Distribution of Hydrocarbons in the Subsurface....................... ................... 1.5.1 Primary Plume................... ............................................... J 1.5.2 Secondary Plume........................................................................................................... 1.5.3 Dispersed Petroleum Hydrocarbons in Shallow Soils...................................................8 `=> 2.0 3i_1NE 2005 GROUNDWATER-QUALITY MONITORING ROUND .................................. 2.1 Groundwater Elevations and Flow Direction............................. ........................................- 9 2.1.1 Groundwater Mound................................................................................................... I I 2.2 Purging of Groundwater-quality Monitoring Wells............................................ 2.2.1 Disposal of Purge Water .......................................................................... 12 , 2.3 Recovery of Groundwater Samples from Monitoring Wells.............................................. 1 :- 13 - `�. 2.4 Analyses of Groundwater Samples .................................................................................... 2.5 Groundwater Quality in the Near-Surface Unconfined Aquifer.........................................13 2.5.1 Analytes of Concern in Groundwater Along Principal Plume Axis ...........................14 2.5.2 Analytes of Concern in Groundwater around Fringes of Principal Plume.............. ....15 2.5.3 Analytes of Concern in Secondary Groundwater Plume ........................................ ,. . ... 16 c=_1 3.0 MONITORING OF FLOATING PRODUCT 4.0 MONITORING OF POTABLE WATER SUPPLIES .......................... ...... 17"> 4.1 Recovery and Analysis of Samples from Potable Water Supply Wells............................. f18 4.2 Results of Potable Water Sampling "•"• 18 4.3 Notification to Well Owners ............................................................................... r f 5.0 CONCLUSIONS ...............20 6.0 RECOMMENDATIONS................................................ .21 8.0 REFERENCES v TABLES Table 1: Depths to Groundwater 4: Table 2: Results of Analyses of Samples of Groundwater Table 3: Thickness of Floating Product in Monitoring Well MW-7 '! �•� Table 4: Results of Analyses of Samples from Potable Water Wells '�� sic