Upcoming contract opportunities

Download Notice of Intent for Utilization

1. Alternative Mechanical Subcontractor Selection Process (MC/CM)
2. Alternative Electrical Subcontractor Selection Process (EC/CM)
3. Alternative Civil Subcontractor Selection Process - Earthwork (SC/CM)
4. Alternative Civil Subcontractor Selection Process – Ground Improvements (SC/CM)

Hoffman Construction Company of Washington (GC/CM) has been selected as General Contractor/Construction Manager (GC/CM) for the King County MDCSO Wet Weather Treatment Station (WWTS) Project.

The WWTS project is a new 240 million gallons per day (MGD) capacity wet weather treatment station, which operates intermittently, and provides physical treatment steps (screening, solids removal and disinfection) during heavy storms to prevent untreated overflows into the east waterway at the mouth of the Duwamish River. The preconstruction phase of the project commenced as of April 2026 and is anticipated to continue through Q2 of 2028. Construction is expected to begin in Q2 2028 and be completed by the end of 2034. Specifically, the project includes:

1. Demolition of existing structures and foundations, shoring and excavation work, construction of a below-grade 4 million-gallon (MG) equalization basin, and soil management.
2. Influent screening, equalization and pumping, construction of a vendor supplied ballasted sedimentation treatment system and ultraviolet (UV) disinfection system, solids handling and storage, odor control systems, multiple support structures including: electrical buildings, maintenance building, control building, chemical storage, and site surface improvements.
3. Site development challenges are expected to include shallow groundwater and deep liquifiable soils with potential for seismically induced settlement (necessitating deep foundations or soil improvement).

The GC/CM intends to select all subcontractors identified utilizing an alternative procurement method in accordance with the provisions of RCW 39.10.385. The subcontractors utilizing this method include Mechanical (MC/CM), Electrical (EC/CM), Civil Earthwork (SC/CM), Civil Ground improvements, Slurry Wall (SC/CM)

The reasons for utilizing these alternative procurement processes include, but are not limited to, the following:

1. Allows the GC/CM, in partnership with King County WTD, to select subcontractor partners based primarily on qualifications and experience rather than solely basing the selection on the lowest priced responsive bid received
2. Provides opportunity to engage the subcontractors early as a collaborative project partner throughout design and construction, which will support reducing risk of errors, omissions, and/or unclear scope in the construction documents. In addition, constructability, cost savings, and better coordinated shutdown plans support key project success factors such as quality, cost and schedule certainty, which ultimately benefits KC ratepayers and comply with the project’s Consent Decree requirements and deadlines.
3. Allows response to volatility in the construction market and the challenges in the supply chain. With a subcontractor involved during design, they can analyze and recommend materials and/or equipment specific to their work for early purchase/procurement prior to construction to avoid market price increases and/or long lead times that could otherwise impact the project budget and ability to meet the Consent Decree schedule.
4. Additionally, the subcontractors will provide expertise during design and construction for phasing and sequencing construction, and commissioning upgrades.

All interested parties are hereby notified that a public hearing will be held at 10:30 am PST, August 19, 2026, at Hoffman Construction Company of Washington, 1700 - 7^th Avenue, Suite 1400, Seattle, WA 98101. Interested parties may also attend the public hearing virtually utilizing the Microsoft Teams link posted at https://www.hoffmancorp.com/trade-partners/#projects-bidding or call in (audio only) utilizing the following:

+1 971-33743200# United States, Portland

Phone Conference ID: 950 043 200#

The Request for Proposals includes (i) the evaluation criteria and applicable weight given to each criteria used for evaluation, including clear definitions of what should be considered specified general conditions work and what should be considered the fee; and (ii) protest procedures including time limits for filing a protest are available upon request. Written comments may be submitted to Kevin Ryan (206-255-7572) at Kevin-Ryan@hoffmancorp.comKevin-Ryan@hoffmancorp.com and received no later than the time of the hearing.

Protests related to the use of the alternative selection process must be submitted to King County, Valerie Tokumoto at vtokumoto@kingcounty.gov within 7 calendar days of the final determination.

No invitations to bid at this time.

Heavy Civil General Contractor/Construction Manager (GC/CM) Services for Mouth of Duwamish Combined Sewer Overflow (MDCSO) Chelan Wet Weather Storage

KING COUNTY’S E-PROCUREMENT SUPPLIER PORTAL

The official advertisement (RFP KC001590) for this project will be published through King County’s E-Procurement system. To receive future notifications, please be sure your firm is registered in King County’s E-Procurement Supplier Portal. For registration information, please visit: https://kingcounty.gov/en/dept/executive-services/about-king-county/business-operations/finance-business-operations/procurement-payables/supplier-portal

Questions about the RFP? Contact Leeann Snyder, Contract Specialist, lsnyder@kingcounty.gov, 206-263-3517.

The Mouth of Duwamish Combined Sewer Overflow (MDCSO) Program involves the construction of new facilities to manage combined sewer overflow events, improve water quality, and meet regulatory requirements. This Heavy Civil GC/CM project includes preconstruction and construction for the MDCSO Chelan Wet Weather Storage. The Chelan Wet Weather Storage Project will serve combined sewer basins west of the Duwamish River. These basins receive both sanitary wastewater and stormwater. During rainfall events, flow in the combined sewer may exceed the sewer capacity, resulting in overflows to nearby waterbodies. The project includes construction of several new facilities including a 7-million gallon below grade combined sewer overflow (CSO) storage tank, a diversion structure, demolition and replacement of the Chelan regulator station, and installation of approximately 2,600 lineal feet of open-cut and trenchless (e.g., microtunneling and/or pipe ramming) influent 60-inch pipe.

Reference Material Files:

• Proposed Facilities Fact Sheet
• Chelan Wet Weather Storage Fact Sheet
• The Consent Decree in the case entitled United States of America and the State of Washington v. King County (USDC Civil Action No. 2:13-cv-677JCC lodged in the United States District Court, Western District of Washington on April 16, 2013)
• Amended agreement to 2013 Consent Decree
• First material modification to the Consent Decree

Prospective proposers can view more details at: https://kingcounty.gov/procurement/solicitations

Complete Solicitation Documents, including project details, specifications, and contact information are available on the Procurement and Payables web page at: https://kingcounty.gov/procurement/supplierportal

Progressive Design Build Services for South Interceptor Rehabilitation Project (KC001390)

As part of RFP Addendum 1, Progressive Design Build Services for South Interceptor Rehabilitation Project (KC001390), the following are being provided to the general public and as reference documents to the shortlisted firms. The listed reference documents are for general information only and shall not be relied upon for design development.

Reference Materials:

Flow Monitoring

• SINT001_20190901_20241125.csv
• SINTR18-03_DVQFINAL_20230518_20250303.csv
• SINTR18A-04_DVQFINAL_20230518_20250301.csv
• South-Interceptor-Portable-Flow-Monitoring-Locations.png

Video

• Q2_JunctionStructure_ESI1.RO1-01_20240925
• Q2_JunctionStructure_ESI1.RO1-01_20240925.jpg
• SOUTH INTERCEPTOR 8_2021-AMH 'RE_SINT.R18-01'-AMH 'RE_SINT.RO1-68'
• SOUTH INTERCEPTOR 8_2021-AMH 'RE_SINT.R18-02'-AMH 'RE_SINT.R18-01'
• SOUTH INTERCEPTOR 8_2021-AMH 'RE_SINT.R18-03'-AMH 'RE_SINT.R18-02'
• SOUTH INTERCEPTOR 8_2021-AMH 'RE_SINT.RO1-67'-AMH 'RE_ESI1.RO1-01'
• SOUTH INTERCEPTOR 8_2021-AMH 'RE_SINT.RO1-68'-AMH 'RE_SINT.RO1-67'

Complete Solicitation Documents, including project details, specifications, and contact information are available on the Procurement and Payables web page at: https://kingcounty.gov/procurement/supplierportal

Contact: Melissa Jordan, Contract Specialist, at mejordan@kingcounty.gov.