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Gerin GENESIS ENGINEERING&REDEVELOPMENT Ms. Terrell April 4, 2013 Page 2 All sampling and analysis conducted under this Work Plan will be consistent with Attachment 1 (Sampling and Analysis Plan)of this Work Plan and Appendix A(Sampling and Analysis Plan)of GE&R's Treatability Study Work Plan dated May 10, 2012. Lateral Extent of Injected Amendment The lateral extent of the injected amendment will be evaluated by drilling a series of borings between selected injection points and the associated monitoring well in the Treatment or Transition Zone. The presence of amendment in a boring will be evaluated through visual observation of soil cores. Over time,the amendment is expected to tum black, and its color should be visually distinct from the natural geologic materials. The evaluation of lateral extent will be conducted through a sequential process where the data from one step will be used to guide the next step. The proposed boring plan is shown on Figure 3, and all borings will be advanced to a depth of 45 feet below the ground surface ("bgs"). The steps in this process are: 1. Advancing a boring at a distance half way between the injection point and the associated monitoring well. If amendment is visually observed in the core, then the process will move to step 2a. If amendment is not visually observed in the core, then the process will move to step 2b. 2a. Advance a boring at a distance half way between the first injection point and the associated monitoring well. If amendment is detected in the core,then the lateral extent will have been defined from that injection point and no additional borings will be advanced along this line. 2b. Advance a boring at a distance half way between the first boring and the injection point. If amendment is detected, in the core,then the lateral extent will have been defined from that injection point. This process will be employed around Monitoring Wells MW-103, MW-104, and CRW-4 until the lateral extent of amendment has been defined for at least one injection point around each of the wells. Effectiveness of Amendment in Reducing Nitrate The wells sampled as a part of the MRP are the primary points of monitoring for the effectiveness of the amendment in reducing nitrate to Nz. In order to obtain data on the effectiveness of the amendment at locations between a monitoring well and injection point, reconnaissance groundwater samples will also be collected from the borings drilled to evaluate the lateral extent of the amendment.