ARCHIVED REPORTS - Laserfiche WebLink

Home Browse Search

2012 Annual Groundwater Monitoring and Evaluation Report Full-Scale In Situ Hexavalent Chromium Reduction Treatment Implementation Former Marley Cooling Tower Site, Stockton,California February 2013 TABLE OF CONTENTS 1.0 INTRODUCTION.............................................................................................................. 1-1 2.0 BACKGROUND ................................................................................................................2-1 3.0 GROUNDWATER MONITORING AND SAMPLING...................................................3-1 3.1 MONITORING AND SAMPLING PLAN..................................................................3-1 3.1.1 Analytical Methods and Field Parameters..............................................................3-1 3.1.2 Background and Compliance Wells........................................................................3-2 3.1.3 Northern Injection Area Wells................................................................................3-3 3.1.4 Southern Injection Area Wells................................................................................3-3 3.2 GROUNDWATER ELEVATION, ESTIMATED GRADIENT, AND LINEAR VELOCITY ..................................................................................................................3-3 3.2.1 Shallow Zone..........................................................................................................3-4 3.2.2 100-Foot Sand Zone................................................................................................3-4 3.2.3 Intermediate Zone...................................................................................................3-5 4.0 LABORATORY AND FIELD SAMPLE RESULTS AND DISCUSSION......................4-1 4.1 DATA VALIDATION AND QUALITY ASSISTANCE/QUALITY CONTROL.....4-1 4.2 ANALYTICAL RESULTS ..........................................................................................4-1 4.2.1 Hexavalent and Total Chromium............................................................................4-2 4.2.2 Iron..........................................................................................................................4-6 4.2.3 Manganese ..............................................................................................................4-6 4.2.4 Arsenic....................................................................................................................4-7 4.2.5 Sulfate.....................................................................................................................4-8 4.2.6 General Chemistry..................................................................................................4-9 4.3 FIELD PARAMETERS..............................................................................................4-10 5.0 GROUNDWATER TREATMENT ACTIVITIES.............................................................5-1 6.0 PERFORMANCE EVALUATION....................................................................................6-1 6.1 EXTENT OF TREATMENT ZONE IN GROUNDWATER ......................................6-1 6.1.1 Phase I and Phase II of the Pilot Study...................................................................6-1 6.1.2 Full-Scale In Situ Groundwater Remediation.........................................................6-1 6.2 GROUNDWATER GEOCHEMISTRY.......................................................................6-2 6.3 ANALYSIS OF IN SITU REMEDIATION EFFECTIVENESS .................................6-3 6.4 DECISION LOGIC FOR PERFORMANCE MONITORING DATA EVALUATION ............................................................................................................6-4 6.5 GROUNDWATER EXTRACTION AND TREATMENT..........................................6-4 7.0 SUMMARY AND CONCLUSIONS .................................................................................7-1 (D MWH. i