2024-0011 - SRWRF Grit Chamber and East Primary Clarifier Coating and Repair Project

The City of Durango Colorado, by and through its Purchasing Administrator, invites interested, qualified bidders, capable of providing the required services, to submit bids for the Santa Rita Water Reclamation Facility (SRWRF) Grit Chamber and East Primary Clarifier Coating and Repair Project. The purpose of this project is to rehabilitate approximately 5,200 square feet of existing Primary Clarifier & Grit Chamber surfaces in an operational wastewater treatment facility. Services to be provided by the Contractor will include, but will not be limited to: existing surface preparation   including minor repairs and surfacing, disassembly and re-installation of appurtenances including baffle plates, scum skinner assembly, and Headcell grit settling tray assembly, and installation of a layered coating with a modified polymer and polyurethane/polymeric foam.  The contractor shall furnish all labor, materials, equipment, and other items necessary to complete the work in accordance with the contract documents. There will be a mandatory pre-bid conference at 10:00 a.m. (Local Time) on March 28, 2024, at the Santa Rita Water Reclamation Administrative Building, 105 S. Camino Del Rio, Durango, CO 81301, to familiarize bidders with the project.  Late arrival or failure to attend the pre-bid conference will result in disqualification. SCOPE OF WORK. 
The purpose of this project is to rehabilitate surface coatings in the East Primary Clarifier and East Grit Chamber in an operational wastewater treatment facility.  Work includes: 

1. Disassembly and removal of appurtenances that are attached to existing surfaces to be rehabilitated.  For the Primary Clarifier this includes scum baffle plates along the weir edge of the perimeter and a scum skimmer assembly (i.e. scum beach) which are typically fastened to concrete anchors.  For the Grit Chamber, this includes a Headcell grit settling tray assembly- please refer to the Field Assembly Sequence attachment for details. 
2. Surface preparation of interior tank and chamber surfaces to an SSPC-SP13/NACE 6 standard to produce a cleaned, abraded, and sound surface with no evidence of laitance, loose concrete, contaminants, or debris. The sump in the Primary Clarifier and the Effluent Trough outlet must be covered to ensure no foreign material enters piping.
3. Collect, store, and transport spent abrasive material and existing coating to landfill. 
4. Apply moisture/chemical barrier specifically developed for corrosive wastewater environments, consisting of silicone modified polyurea to interior tank walls and channel surfaces. 
5. Apply surfacer consisting of low viscosity, two-component polyurethane/polymeric blend foam to interior tank and channel surfaces.
6. Apply final/chemical corrosion barrier specifically developed for corrosive wastewater environments, consisting of silicone modified polyurea to interior tank and channel surfaces. 
7. The total thickness of the multi-layer liner system shall be a minimum of 500 mils. 
8. The contractor will be responsible for providing representative layer and/or total coating thickness measurements.