Attachment D Description of Base Bid and Alternates~2.docx

This document is an Attachment D from the Oregon Department of Transportation (ODOT) describing the base bid and alternate options for the Brush Creek Repairs project, a stream restoration initiative. The project scope includes temporary traffic control, installation of temporary water management systems, removal of existing streambed material, channel bed grading between an existing concrete weir structure, and installation of a bentonite layer to seal the stream channel from subsurface leakage. The contract will be awarded to the lowest responsive bidder based on combined totals from either the Base Bid paired with Add Alternate 1 or the Base Bid paired with Add Alternate 2, with bid submissions due April 7, 2025. All work must comply with contract specifications and plans detailed in Attachments A and B.

Two additive alternates have been developed to determine the most cost-effective channel sealing approach. Add Alternate 1 involves constructing a 4-inch shotcrete liner over the bentonite layer, while Add Alternate 2 involves installing a 30-mil geomembrane liner over the bentonite layer. ODOT has confirmed funding availability for either alternate option. The procurement is open to qualified contractors with demonstrated capabilities in stream restoration and environmental engineering. Specific pricing information and budget details are contained in Attachment C (Bid Pricing Form), with comprehensive technical specifications and project plans provided in Attachments A and B.