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CONBTROCTION OF WETPOND TREATMENT CELL: <br />Over-excavate the wetponi treatment cell by a minimum of 6 <br />inches as compared to final grade. Immediately after it has <br />been graded, roughen the bottom arid sides of the treatment <br />cell by raking and place topsoil (a minimum of 6 inchesl to <br />bring the bottom elevation to final design grade. <br />Sod the treatment cell immediately afCer the topsoil has <br />been placed. Lay sod to a minimum of 1.0 feet of vertical <br />depth above the bottom of the treatment cell. Lay the sod <br />pieces with their long axis perpendicular to the direction <br />of flow in the cell and stagger the pieces to avoid a <br />continuous lonqitudinal seam in the bottom of the cell. <br />To plant the required wetland vegetation, punch holee in the <br />sod with a bar or stake approximately equivalent to the <br />diameter of the plants' root wads. Insert the plants in the <br />holes and tamp the sod and earth down around the plants. <br />Locate the plants in the bottom of the treatment cell only <br />and in a staggered pattern - not in a straight line. <br />NOTE: Topsoil shall, at a minimum, meet the standard for <br />Topsoil Type A, as specified in secY.ion 9-14.1(1) of the <br />1991 Standard Specifications for Road, Bridge, and Municipal <br />Construction (WSDOT, APWA) with the following modification - <br />100$ of the topsoil shall pass through a 1/2" sieve. <br />Topaoil TVDe A- excerpts from WSDOT, APWA std 9-14.1(1) <br />with City modification. <br />Topsoil shall be free from materials toxic to plant growth, <br />noxious weeds, rhizomes, roots, subsoil, stones, and other <br />debris. 100$ of the topsoil shall pass through a 1/2 inch <br />sieve. <br />Topsoil Type A shall consist of a sandy clay loam, sandy <br />loam, loam, clay loam, silty clay loam, or silt loam soil. <br />The mix may not be more than 50� sand nor 20� clay. Total <br />organic matter shall be 1$ to 10�. A maximum of 20� of the <br />mix volume may be retained on a 1/4" sieve. <br />Burface PonG Fencina Reauirementa: <br />All ponds with a maximum depth greater than three feet are <br />r.equired to be fenced with a six foot high perimeter fence <br />unless one of the following conditions is met: <br />1) a 10 foot wide safety bench for every three feet of <br />design water depth and the side slopes of the pond are no <br />qreater than �:1 (H:V); or <br />