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Table F-14. Groundwater pH Data for Excavation Sequencing Area DProject No. 110207, Everett, WashingtonDateBA-MW-5*UST71-MW-101* UST71-MW-103* UST71-MW-102BA6-MW101RCD-MW-101 UST70-MW-2 REC3-MW-1R PM-MW-89/21/2020 6.62 7.12 6.216.66 7.08 7.26 7.059/22/2020 6.62 7.14 6.246.68 7.12 7.24 7.079/23/2020 6.64 7.17 6.266.64 7.11 7.30 7.1010/2/2020inaccessible* inaccessible* inaccessible*6.30 7.2010/5/2020 6.33 7.2210/6/2020 6.35 7.19Avg Baseline 6.63 7.14 6.24 6.33 7.20 6.66 7.10 7.27 7.07"Trigger pH"7.137.646.746.837.707.167.607.777.5710/9/2020inaccessible* inaccessible* inaccessible*6.36 7.2610/12/2020 Dry 7.0710/19/2020inaccessible* inaccessible* inaccessible*6.33 7.0510/28/2020 6.26 6.61Notes*: Well UST71-MW-103 was located just within the CM footprint and required decommissioning to allow complete CM removal. However, the driller inadvertently also decommissioned nearby wells UST71-MW-101 and BA-MW-5 on 9/29. Consequently, adjacent non-shoreline wells UST71-MW-102 and BA6-MW-101 have been replaced as proximal wells."Trigger pH" for proximal wells is the pH that, if exceeded for 3 weeks, triggers daily monitoring of proximal well and start monitoring of downgradient wells."Trigger pH" for downgradient wells is the pH that, if exceeded for 1 week, triggers consultation with Ecology regarding response action.pH Reading in Standard UnitsProximal WellsDowngradient Wellsto Monitor if pH Increase >0.5 unit is Observed in Proximal Well(s)Baseline Readings for this Sequencing Area (3x in 1 week)Weekly (at least) Compliance Readings During CM Removal in this Sequencing AreaWeekly (at least) Compliance Readings for 3 Weeks After CM Removal is Done in this Sequencing AreaAspect Consulting12/17/2020V:\110207 KC Everett Mill\Deliverables\Interim Action Report 2020\Client Review Draft\App F pH monitoring\Appendix F pH Data TablesTable F-14Report for Second Interim ActionPage 1 of 1