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i September 30, 2015 Monitoring Well Abandonment and Installation Workplan Filter pack material will be placed in the well boring to a depth of 1-foot above the top of the well screen.The filter pack depth will be checked,and the volume of fl ter pack material considered for verifying that no bridging of filter-pack materials occur ed. Each well will be gently surged during filter-pack installation(i.e.,surging will occur aft r the filter-pack is poured into the annulus between the casing and borehole wall,but pri r to the installation of the transition and sanitary seals). 4.3. Transition and Sanitary Seals The remaining annular space will be filled with a transition seal (mini um thickness of 2 feet) set on top of the filter pack,followed by a neat-cement based san tary seal to land surface (minimum thickness of 10 feet).Bentonite will be used for the transition seal. For depths greater than 30 feet,and where water is present in the borehole,the material will be installed by use of a tremie pipe or equivalent.Where bentonite exists in the borehole in dry form,potable water will be added and sufficient time allowed for the I entonite to properly hydrate before placement of the sanitary seal. The sanitary seal will be placed within the annular space between the top of the transition seal to land surface.Sealing material shall be neat cement.Drilling fluff I or cuttings from the borehole will not be used as the sealing material.All water used for se 11ing mixtures shall be potable. 4.4. Surface Seals Surface features will serve to prevent physical damage;prevent the ei trance of surface water,pollutants,and contaminants; and prevent unauthorized acces .The top of each monitoring well will be protected by a locking cover or equivalent lev 1 of protection to prevent unauthorized access.The top of the well casing will be sealed ith a removable plug that provides a means to secure and lock the well.The sealed well-casing will be set in a locking monument style well cover(above ground completion) that extends at least 2 feet above land surface,surrounded by four protective bollards.If warrani ed by final post- construction site conditions,the monitoring well may be modified to a set below grade in a traffic-rated vault box with lid(below ground completion). S. Well Development HydroFocus personnel will develop the wells using surging,bailing,and pumping techniques.Well development will be performed with care so as to prevent damage to the well and any strata surrounding the well that serve to restrict thement of poor quality mo e water.A pump will be utilized to further develop the wells no less tha�24 hours after sanitary seal placement,per S]CEHD Well Standards.Well development will continue until the flowing water is visually clear(1.5 hour per well minimum development time) and pH, conductivity and temperature of purge water stabilize within plus or minus 10%;the volume of purge water shall be recorded on a standard well development form (see Appendix C for an example well development form). HydroFocus, Inc. 8