Laserfiche WebLink
<br />9. In no case shall the width of the filter materJ.al in a <br />single bed exceed ten (10) feet. <br /> <br />10. A rubber tired tractor may be used for plowing or disking, <br />but in no case shall a rubber tired tractor be used after the <br />surface preparation is completed. A crawler or track-type tractor <br />shall be used for mound construction where the soil percolation <br />rate is slower than 15 minutes per inch. <br /> <br />11. The discharge pipe from the pump to the mound area shall <br />be installed prior to soil surface preparation. The trenah shall <br />be carefully backfilled and compacted to prevent seepage of <br />effluent. <br /> <br />12. Soil Surface Preparation. <br /> <br />a. All vegetation in excess of four inches in length and <br />dead organic debris must be removed from the surface of <br />the total area selected for the mound, including the area <br />under the banks. <br /> <br />b. The total area selected for the mound, including the <br />dikes, shall be plowed to a depth of at least eight (8) <br />inches. Furrows shall run perpendicular to the direction <br />of slopes. All furrows shall be thrown uphill and there <br />shall be no dead furrow under the mound. The soil shall <br />be plowed only when the moisture content of a fragment <br />eight (8) inches below the surface is below the plastic <br />limit. <br /> <br />c. In soils having percolation rates faster than fifteen <br />(15) minutes per inch (sandy loams) in the top eight (8) <br />inch depth, disking may be used for surface preparation <br />as a substitute for plowing. <br /> <br />d. Mound construction shall proceed immediately after <br />surface preparation is completed. <br /> <br />e. The original soil must not be excavated or moved more <br />than one foot from its original location during soil <br />surface preparation. <br /> <br />13. A minimum of twelve (12) inches of soil defined as sand <br />shall be placed where the filter material is to be located. A <br />crawler tractor with a blade shall be.used to move the sand into <br />place. At least six (6) inches of sand shall be kept under the <br />tracks to minimize compaction of the plowed layer. The sand layer <br />upon which the filter material is .placed shall be level. <br /> <br />14. A depth of at least nine (9) inches of filter material <br />shall be placed over the bed area below the distribution pipe. <br /> <br />10 <br />