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A. Groundwater Wells <br /> During the spring/summer of 2020,three(3) groundwater monitoring wells will be installed to a depth of <br /> approximately 50-60ft,where the previous Yule Creek channel flowed as depicted in Figure 1. <br /> • MW I is located approximately 225ft above the point of release and is intended to serve as an <br /> upgradient background monitoring well, <br /> • MW 2 is located at approximately 250ft downgradient from the spill area, and <br /> • MW 3 is located approximately 750ft downgradient from the spill area, <br /> Figure l depicts the approximate locations of the wells;however,actual locations of the wells may change <br /> depending on site layout and subsurface soil conditions. <br /> The monitoring wells will be constructed with 2" schedule 40 PVC with approximately 40-50ft of solid <br /> PVC riser and the bottom 5-1 Oft consisting of 10-slot perforated screen. Once the PVC is installed, pea- <br /> gravel will be utilized to backfill around the screened interval to allow for groundwater to flow. Backfill <br /> above the screened interval around the solid PVC riser may consist of road-base fill, native soil from the <br /> surrounding area,and blasting material stockpiled at the quarry as long as it does not contain rocks larger <br /> than 2 ". Refer to Figure 2 for a diagram of the groundwater monitoring well installation. <br /> Once backfilled, the 2"PVC riser will extend above ground approximately 2-3ft and will be capped with <br /> a J-Plug or threaded plug to prevent precipitation and any foreign material from entering the well and <br /> locked for security. As outlined in the top view of Figure 2,marble blocks will be placed around the well <br /> to ensure integrity of the well and prevent damage from surface activities. <br /> Development of the groundwater monitoring wells will be completed by utilized a submersible pump <br /> designed to remove sediment or a steel submersible bailer.A minimum of 3 casing volumes will be purged <br /> from each well. <br /> B. Sump Well <br /> A 4" PVC groundwater monitoring well was installed on November 15, 2019 within the sump area after <br /> it had been reinforced with marble blocks on the downgradient side and backfilled 10-12ft. Marble blocks <br /> were also placed around a small area of the backfilled sump area that had been left open to allow for <br /> groundwater monitoring and to provide protection to the well from settling/shifting soils or large snow <br /> accumulation and movement. <br /> The well was installed to a depth of 15 feet below the current ground surface of the sump basin,with 1 Oft <br /> of solid 4" PVC riser and 5ft of 4" slotted PVC extending below the water table. Pea-gravel was placed <br /> around the slotted PVC to provide stabilization and allow for groundwater flow. <br /> Development of the sump groundwater monitoring well consisted of purging water utilizing a stainless- <br /> steel bailer until the water indicated that sediment had been removed. A 4-inch J-Plug was placed in the <br /> top of the PVC riser, to prevent precipitation and foreign material from entering the well. <br /> 2 <br />