Laterals: Approximately 240,000 feet of 4-inch corrugated perforated single-wall plastic drain tile. Target bottom of pipe depth: 3 feet (±.25 feet) depth. Laterals should be spaced on 50’ intervals following the land contours. o Tile in 2 areas of the farm may be installed at 25’ and 12.5’ intervals for research purposes. Acreages TBD Tile depth and grade to follow industry best practices. Laterals are shown in blue on the preliminary design. Design to meet a minimum of ½ inch/day drainage coefficient (DC) Laterals be designed on the contour, where possible and as appropriate (aerial image/map provided under Attachments Tab shows an example of a potential layout) Mains, Sub mains & outlets: Approximately 3,800 feet 5-inches (shown in red on preliminary design) and 13,200’ 6- inch (shown in yellow on preliminary design) corrugated perforated single-wall plastic drain tile. Final sizing of sub-mains to be done by the successful bidder. Main outlets: 20’ lengths of aluminized corrugated metal pipe with animal guards for each outlet. Method of installation: ISU prefers tile laterals and sub mains to be plowed in. Mains can be trenched or dug in. (Describe this in your attachment to be provided under the Response Attachments tab) Method of installation shall include automatic machine control; preference given to GPScontrolled installation The method of installation shall be capable of installing accurately at the maximum depths indicated. Mechanical closure of tile trench to allow natural settling and reduce surface roughness is considered incidental and should be included in the per-foot bid amount. GPS installation data needs to be provided to ISU at completion and before final payment will be made
