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Regraded Spoil Backfill Material Monitoring Program <br />To document the suitability of the regraded spoil materials as potential rooting material, <br />an overburden sampling and analysis program, will be implemented. The upper four feet <br />of regraded spoil will be sampled prior to topsoil replacement with a hydraulic soil <br />sampler, a bucket auger, or other suitable equipment to ensure that a suitable root growth <br />medium was provided. Two representative samples, each representing a two -foot depth <br />increment, will be collected from a grid system with 500 feet by 500 feet spacing. The <br />vertical sampling increments will be 0.0 to 2.0 feet and 2.0 to 4.0 feet. Trained personnel <br />will inspect the backfill surface between grid points. If a significant change in spoil <br />characteristics is observed between grid points, additional sample sites will be located. <br />Regraded backfill will also be visually inspected for compaction, possible root growth <br />problems, and the potential for slippage at the topsoil /subsoil interface. The lateral and <br />vertical sampling intensities will be closely evaluated once sufficient samples are <br />collected to determine the degree of sample variability. This sampling program will <br />ensure that the top four feet of regarded backfill is non -toxic and is chemically /physically <br />suitable for plant growth. The regraded backfill samples will be analyzed for the <br />following parameters to determine subsoil suitability: pH, acid -base potential, <br />neutralization potential, particle size (texture), saturation percent, EC, and SAR. Table <br />2.05.4(2)(d) -1 gives the criteria for evaluating topsoil suitability and the laboratory <br />analytical methods which will be used to test these materials. <br />Unsuitable Subsoil Backfill Mitigation Plan <br />If one or more parameters fall within the unsuitable range at a given grid sample point, a <br />three -part mitigation plan will be implemented. <br />1. The area around a suspect hole will be sampled on a closer spacing interval in <br />order to better define the lateral extent and variability of the unsuitable <br />material. <br />2. The regraded spoil materials will be mechanically loosened and mixed by <br />ripping, chiseling, or approved alternate forms of scarification prior to topsoil <br />Section 2.05.4(2) (d) Page 4 January 2012 <br />