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raa AV-VO rAA cva U40 Uoct RLLltrrELDER 1NU 444 SJ COUM BLDG. 19000 KLEINfELDfR Although there was no apparent overcompaction caused by construction equipment, nevertheless, it was still difficult to drill two feet using power auger equipment. As you are aware, a condition existed on the driving tee area where initial percolation tests indicated zero percolation. A test area was prepared by ripping approximately 2Y2 feet. Percolation retests in this area indicated percolation rates in the 30- to 40-nnpi range_ Rased on this 'information, we recommend that the proposed farmland disposal area be similarly ripped to loosen the near-surface silt and clay soils. Fill from adjoining farm areas could then be used to raise grade in this area. Because of the marginal percolation test results, time fact that approximately 3 feet of additional fill would be needed in this area to provide a 5-foot separation between the bottom of a norntal leach field, and the.groundwater table. We recommend that relatively-light scraper equipment or other forms of construction equipment be used for this purpose to minimize compaction. Once this process is done, we recommend that a percolation rate of 60 minutes per inch be used in design. We recommend that the farmland area be prepared and confirmation .of the design percolation .rate be obtained later in the spring and summer when the ground is drier. In our opinion, attempts to rip and prepare the farmland now when the soil is very wet will .not result in significant improvement because construction equipment would compact the soft soil. More voids would be created when the soil is drier. Prior to performing the percolation tests, the test area should be flooded for approximately one week to collapse any large void,%. The attached analytical test results indicate: that the first groundwater in this area has very low nitrate concentrations. It is our opinion that de-nitrification of any waste would be rather large considering the clayey and organic nature of the near-surface materials. Although we have not calculated the nitrate loading, we do not believe that nitrate loading will be a concern for the above reasons. Nitrate loading calculations will be provided at a later date. We trust this letter presents the requested information. if you have any questions or need additional information, please contact our office. Respectively submitted, KLEINF -'Z DER,iN I Ron Heinen, G.E. Regional M.anagerlScaior Principal RH:md cc, Scott Sullivan Cecil.Dillon i 20-1096-15120181:996 Pagc 2 oft Copyright 1998 Klcinicldcr. Inc. December 18, 1998 t