Specifications include, but are not limited to: 1. The Culverts shall be corrugated galvanized steel, manufactured and fabricated in accordance with AASHTO Designation M36 as required in Item 460 of the latest edition of the Texas Department of Transportation Standard Specifications for Construction of Highways, Streets and Bridges. 2. The galvanized steel pipe shall be full circle and may be fabricated with circumferential corrugations, lap joint construction with riveted or spot welded seams, or it may be fabricated with helical corrugations with continuous helical lock seam or with ultra high frequency resistance butt-welded seams. 3. Pipe shall conform to AASHTO Designation: M36 as to corrugations, dimensions, riveted seams resistance spot welded seams, end finish, size, permissible variations, workmanship and finish.