Rock shall consist of large rip-rap or boulders from an approved source, ranging in size from 200 to 500mm. The wood and concrete debris shall be from an on-site source and shall be approved for use by the Engineer prior to incorporating into the snake hibernacula. The drain outlet shall consist of non-perforated and perforated Schedule 40 PVC pipe, which shall be fitted with a backflow prevention valve.
15.2 Root Balls
This work shall consist of the supply and placement of salvaged tree root balls in the benched areas along the south side of the drain between Stations 0+020 to 0+070, 0+080 to 0+130, and 0+140 to 0+180. The root balls shall be salvaged from the clearing process at the beginning of construction. In order to prevent the root balls from being washed away, the stumps shall be anchored with cable and screw anchors.
15.3 Armour Rock Vanes
OPSS Forms 314, 501, 511, 1004, 1010 and 1860 shall apply and govern except as amended or extended herein. The work shall consist of construction of rock vanes at Stations 0+020, 0+072, 0+132, 0+181, 0+397, 0+469, and 0+570, as detailed in the Drawings, and shall include excavation, installation of geotextile, and placement of armour rock, gabion rock, rip-rap and round stone.
16.0 Topsoil
This work shall consist of supply, placement and grading a minimum thickness of 100mm (4”) of clean topsoil at the locations indicated in the Drawings. The topsoil supplied shall be free from roots, vegetation and other debris and shall be from a source approved by the Owner/Engineer.
17.0 Seed and Mulch
This work shall consist of all material, labour and equipment required to supply and place hydraulic seed, mulch and fertilizer on the areas indicated in the Contract Drawings and areas that have been disturbed during construction.
The seed mixture supplied shall have the following composition:
10% Red Clover (Medium Type)15% Quebec Perennial Ryegrass
25% Tall Fescue
25% Creeping Red Fescue
15% Richmond Timothy
10% Kentucky Bluegrass
The mix shall be applied at the rate of 100 kg/hectare and the fertilizer (8-32-16) shall be applied at a rate of 200 kg/hectare.
The Contractor shall be responsible to water the planted areas as required to ensure that the seed germinates and the grass grows. Areas of the site with less than 75%