2021-07-21_PERMIT FILE - C1981019 ‎(5)‎

• Permit No: C1981019
• IBM Index Class Name: Permit File
• Doc Date: 7/21/2021
• Doc Name: Point of Compliance Well Investigation Report
• Section_Exhibit Name: Exhibit 07 Item19 Point of Compliance Well Investigation Report
• Media Type: D
• Archive: No

Point of Compliance Well Investigation

AECOM
i

Table of Contents
1. Introduction ..................................................................................................................... 1
1.1 Background .......................................................................................................... 1
1.2 Previous Studies .................................................................................................. 2
1.3 2019-2021 Groundwater Investigation Approach and Objectives ......................... 2
2. Field Data Collection ....................................................................................................... 4
2.1 Temporary Well Installation and Development ..................................................... 4
2.2 Baseline Sampling ............................................................................................... 4
2.3 Analytical Program ............................................................................................... 5
2.4 Temporary Well Abandonment ............................................................................. 5
3. Data Analysis ................................................................................................................... 6
3.1 Establishing Site Background Values ................................................................... 6
3.2 Temporary Well Concentration Results ................................................................ 7
3.3 Point of Compliance Well Recommendations ....................................................... 9
3.4 Proposed Compliance Standards ....................................................................... 10
4. Conclusions ................................................................................................................... 12
5. References .................................................................................................................... 14

Tables
Table 1 Temporary Monitoring Well Construction Details
Table 2 Comparison of the Regulation No. 41 Basic Standards for Ground Water to Site
Background Concentrations
Table 3 Dissolved Arsenic Concentration Statistics in Temporary Site Monitoring Wells
Table 4 Chloride Concentration Statistics in Temporary Site Monitoring Wells
Table 5 Field pH Statistics in Temporary Site Monitoring Wells
Table 6 Dissolved Iron Concentration Statistics in Temporary Site Monitoring Wells
Table 7 Dissolved Manganese Concentration Statistics in Temporary Site Monitoring
Wells
Table 8 Dissolved Mercury Concentration Statistics in Temporary Site Monitoring Wells
Table 9 Nitrate (as N) Concentration Statistics in Temporary Site Monitoring Wells
Table 10 Nitrate + Nitrite (as N) Concentration Statistics in Temporary Site Monitoring
Wells
Table 11 Nitrite (as N) Concentration Statistics in Temporary Site Monitoring Wells
Table 12 Dissolved Selenium Concentration Statistics in Temporary Site Monitoring Wells
Table 13 Sulfate Concentration Statistics in Temporary Site Monitoring Wells
Table 14 Total Dissolved Solids Concentration Statistics in Temporary Site Monitoring
Wells
Table 15 Dissolved Zinc Concentration Statistics in Temporary Site Monitoring Wells
Table 16 Proposed Groundwater Compliance Standards