RFQ Contractor - Harwood's Mill Dam Improvements Project

The purpose of this Invitation for Qualified Contractors (IFQC) is to solicit pre-qualification applications for the selection of qualified Contractors to be invited to bid for the provision of all materials, labor, tools, and equipment for construction of the Harwood's Mill Dam Improvements Project located in Yorktown, York County, Virginia. The purpose of this Project is to bring the earthen dam and spillway features into full compliance with the VDCR Dam Safety Act, and to improve the overall condition of the structure and its appurtenances. The project will replace the existing concrete spillway chute, training walls, and outlet works with new concrete structures. All new spillway structures will be supported on steel pipe piles. In addition, construction of a new concrete crest wall along the embankment sections will increase the maximum storage and provide capacity to safely pass the 100% PMF storm event. The project consists of the demolition of the existing spillway chute, outlet works, and settling basins and other structures associated with a decommissioned water treatment plant formerly located at the project site. The project also includes the construction of a new spillway chute slab, training walls, intake structure and outlet flume, access bridge, concrete crest wall, and the rehabilitation of the existing spillway weir. All new concrete structures except the concrete crest wall along the crest of the embankment section will be supported on steel pipe piles. Some major features of work include erosion and sediment controls, cofferdam design and installation for diversion and control of reservoir discharges during construction, groundwater dewatering prior to deep excavations, and design and installation of a temporary reservoir drawdown system for use during construction. The reservoir will be nominally lowered during construction but must remain at an elevation for uninterrupted raw water supply to the adjacent Harwood's Mill Treatment Plant throughout construction. The principal spillway and outlet works demolition and re-construction will be subdivided into two mandated phases of work to ensure that a means to pass reservoir inflows remains available during construction. Refer to Section B of this IFQC for more information on the project scope of work. The Owner intends to award a single contract for all work required on the project. Harwood's Mill reservoir stores water for the Harwood's Mill Water Treatment Plant, which must remain fully operational during the entire project. Conditions contained in all permits, including the Virginia Department of Conservation and Recreation (DCR) Dam Alterations Permit, Virginia Department of Environmental Quality (DEQ), Virginia Marine Resources Commission (VMRC), the US Army Corps of Engineers, and York County erosion and sedimentation control plan approvals must be strictly followed to ensure source water quality and protection of all downstream property owners. Questions regarding this IFQC must be submitted in writing through the OpenGov Procurement Question/Answer Tab via the City's e-Procurement portal, on or before Tuesday, January 24, 2023 by 1:00 pm. Construction of the Harwood's Mill Dam Improvement Project is anticipated to span approximately 28 to 30 months. The work will be completed in accordance with the construction sequencing described in the bid documents which will provide for temporary diversion of water. The reservoir and adjacent Harwood's Mill Water Treatment Plant will remain in service throughout construction. The reservoir will be only nominally lowered and remain subject to fluctuation during construction due to variability in natural inflows. The normal raw water intake into the WTP will be sufficient to manage normal sunny day base flow into the water without spillway discharge; however, heavy precipitation events will likely result in increased reservoir elevations. The spillway and outlet works demolition and reconstruction will be conducted using a mandated two phase approach such that either the existing principal spillway (Phase 1) or the new low-level outlet works (Phase 2) will be available to pass significant inflow that cannot be managed by the raw water pump station intake. The existing emergency spillway will also be available to supplement the primary spillway or low-level outlet works during both phases of construction. The Contractor must also provide a temporary reservoir drawdown system to return the reservoir level to the lowered construction pool after significant precipitation events that cause the reservoir level to rise. Control of surface water and mitigation of flood risk is, therefore, of paramount importance. In concert with the diversion of water sequencing, a phased approach is necessary for other major elements of the work including, but not limited to, installation and relocation of cofferdams, demolition and removal of existing structures, embankment excavation, foundation dewatering, reinforced concrete placement, and embankment backfill placement. Work to be performed for the Harwood's Mill Dam Improvement Project will include, but is not limited to the following construction activities: a. Design, installation, maintenance and removal of temporary works, including but not limited to control and diversion of water systems, cofferdams, groundwater dewatering systems, temporary reservoir drawdown system, temporary excavation support and all other temporary works necessary for construction and water diversion. b. Demolition and removal of the spillway chute. c. Demolition and removal of the concrete steps and sidewalk and foot bridge, and abandoned WTP structures such as the screen chamber, distribution chamber, chemical feed facility, settling basins, and storm water pipes. d. Installation of a steel pipe pile foundation system to support all major concrete structures with the exception of the embankment crest wall, which will be on a shallow foundation. e. Installation of permanent steel sheet pile cutoff walls with interlock sealant. f. Construction of a new concrete spillway chute (slab) with sub-slab filter drain system, north spillway training wall, south spillway training wall, a thrust block at the toe of the existing spillway weir, intake structure with new stop-logs and gates, and outlet flume. g. Construction of an access bridge across the outlet channel. h. Construction of concrete stairs and concrete sidewalk. i. Construction of a reinforced concrete crest wall. j. Temporary soil stockpiling, permanent spoiling of excess earthen and demolition materials, and debris disposal. k. Temporary traffic control on U.S. Route 17, as needed. l. Backfill of existing sedimentation basins and re-grading / earthwork on site area north of spillway. m. Piezometer installation. n. South embankment toe drain and emergency spillway underdrain cleanout. o. Temporary erosion and sediment control measures, and maintenance throughout construction. p. Construction and maintenance of temporary access. q. Grading, landscaping, erosion and sediment control, installation and maintenance of turbidity booms/curtains, and site restoration. Applicants invited to submit a bid as part of Step Two will be required to provide a bid bond equal to 5% of the total bid amount as part of the bid. The successful Bidder shall provide performance and labor and material payment bonds for 100% of the bid amount using the City's Forms, as well as verification of insurance to meet City standards and requirements. The City anticipates that Step One (prequalification) will be completed on or about March 3, 2023 and the Invitation for Bids will be issued on or about March 6, 2023. These anticipated dates are subject to change. Pre-qualified Applicants will be provided at least sixty (60) days to submit a bid as part of Step Two (Invitation for Bids). The City reserves the right to contact Applicants during the review and evaluation process for clarification or additional information. Additional information must be submitted to the City no later than five (5) calendar days after receipt of the City's request for additional information. Question Submission Deadline January 24, 2023, 1:00pm - Questions regarding this IFQC must be submitted in writing through the OpenGov Procurement Question/Answer Tab via the City's e-Procurement portal,

Division 02 -	Existing Conditions, Subsurface Investigation.
Division 31 -	Earthwork, Site Clearing, Grading, Excavation and Fill, Subgrade Preparation, Excavation, Shoring, Tunneling and Mining, Tunnel Excavation.
Division 35 -	Waterway and Marine Construction, Dam Construction and Equipment.