1122 75TH ST SW 2018-01-02 MF Import

CONBTROCTION OF VEGETATED BWALEB: Prepare the swale fcr sod immediately after it has been graded. Roughen the bottom and sides of the swale by raking, place 4" (minimum) of topsoil, an3 fertilize with an appropriate fertilizer at the rate of 7 lbs per 100o square feet before laying the sod. In general, use a 10-20-20 (N- P-K1 fertilizer. However, use a non-phosphorus containinq -' •---- ON TE: Topsoil shall meet the standard for Topsoil Type A, as specified in section 9-14.1(1) of the 1991 Standard Specifications for Road, Bridge, and Municipal Construction (WSDOT, APWA) with the followinq modification - 100$ of the topsoil shall pass throuqh a 1/2" sieve. Sod the swale immediately after the sides and bottom of the swale have been prepared. Lay sod to a minimum of 1.0 feet of vertical depth above the bottom of the swale. Anchor the sod in place in the bottom of the swale and to 3..0 feet of vertical depth above the bottom of the swale with stakes, metal staples or other means. ON TE: Lay the sod pieces with their long axie perpendicular to the direction of flow in the swale, and staqger the pieces to avoid a continuous lonqitudinal seam in the bottom of the swale. Hand-seed or hydroseed the swale with the specified seed mix in addition to sodding. If the swale is cor�pleted between April 1 and September 1, hand-seed the swa.le immediately. If the swale is completed between September 1 and April 1, hand-seed after April 1, but before April 30, of the spring following completion. Disperse 5 lbs of seed per 1000 square feet evenly over the saci and all bare areas of the swale. To plant wetland veqetation required for biofiltration swales, punch holes in the sod with a bar or stake approximately equivalent to the diameter of the plants� root wads. Insert the plants in the holes and tamp the sod and earth down around the plants. Locate the plants in the otto of the swale only and in a staggered pattern - not in a straight line. HOTE: Wetland vegetation planted after March 15 will require irrigation through the first summer to ensure plant viability. Wetland Dlants ideallv should be ulanted batween Oatohsc and March.