2022-12-16_PERMIT FILE - M2021067

• Permit No: M2021067
• IBM Index Class Name: Permit File
• Doc Date: 12/16/2022
• Doc Name: Adequacy Review Response
• From: Asphalt Specialties Co.
• To: DRMS
• Email Name: ECS
• Email Name: MAC
• Media Type: D
• Archive: No

Stiles Mining Resource
Groundwater Monitoring and Mitigation Plan
December 2022
Page i
TABLE OF CONTENTS
Section Page
1.0 INTRODUCTION..................................................................................................................1
2.0 BACKGROUND AND HISTORIC DATA..........................................................................1
3.0 GROUNDWATER QUALITY MONITORING.................................................................1
3.1 MONITORING WELL NETWORK.............................................................................1
3.2 GROUNDWATER SAMPLING EVENT FREQUENCY AND SCHEDULE............2
3.3 GROUNDWATER SAMPLE COLLECTION PROCEDURES ..................................3
3.4 LABORATORY ANALYSIS OF GROUNDWATER SAMPLES..............................3
3.5 SITE-SPECIFIC GROUNDWATER QUALITY BENCHMARKS.............................4
3.6 GROUNDWATER QUALITY DATA EVALUATION AND REPORTING.............5
3.6.1 No Exceedances in Points of Compliance Wells...............................................5
3.6.2 Exceedances in Points of Compliance Wells.....................................................5
3.7 MITIGATION MEASURES FOR GROUNDWATER QUALITY IMPACTS...........5
3.7.1 Confirmation Sampling......................................................................................5
3.7.2 Evaluation of Existing Data Set.........................................................................6
3.7.3 POC Well Exceedance Groundwater Quality Monitoring.................................6
3.7.4 Potential Corrective Action Measures...............................................................6
4.0 GROUNDWATER QUANTITY MONITORING..............................................................7
4.1 MONITORING WELL NETWORK.............................................................................7
4.2 GROUNDWATER MEASUREMENT FREQUENCY AND SCHEDULE................7
4.3 GROUNDWATER LEVEL DATA EVALUATION AND REPORTING..................8
4.4 MITIGATION MEASURES FOR GROUNDWATER LEVEL IMPACTS................8
4.4.1 Collect Groundwater Levels in Nearby Well(s)................................................8
4.4.2 Evaluation of Existing Data Set.........................................................................8
4.4.3 Potential Corrective Action Measures...............................................................9
LIST OF FIGURES
FIGURE I SITE LOCATION MAP
FIGURE 2 GROUNDWATER MONITORING WELL LOCATION MAP
LIST OF TABLES
TABLE 1 GROUNDWATER QUALITY SAMPLING PARAMETERS AND
DEFAULT BENCHMARKS
LIST OF APPENDICES
APPENDIX A MONITORING WELL CONSTRUCTION LOGS