Important Dates for Prospective Tunneling Contractors

MSD Project Clear is advancing two major Combined Sewer Overflow (CSO) tunnel projects and seeks to actively engage the tunneling community ahead of procurement.

Projects Description Bidding
Lower & Middle River Des Peres CSO Storage Tunnel 9-mile, 30-foot finished diameter Summer 2027

(Prequalification package release date in October/November 2026)

Upper River Des Peres and River Des Peres Tributaries Storage Tunnel 6-mile, 18-foot finished diameter Summer 2029

MSD is hosting and participating in several outreach opportunities in 2026 to connect with qualified contractors, share early project details, and support team formation:

  • June 2026:Project Clear Update: St. Louis MSD Shares Plans of Final Two Major Tunnel Projects” featured in the June issue of Tunnel Business Magazine, highlighting project scope, schedule, and delivery approach.
  • June 16, 2026: Coinciding with the North American Tunneling conference in Anaheim, CA, MSD will be hosting a contractor-focused informational session at the Anaheim Marriott from 4:00–5:00 PM in the Grand Ballroom C & D. Meet directly with MSD leadership, along with design consultant Jacobs and construction management consultant Black & Veatch, to learn more about project planning and procurement. RSVP by June 9 here.
  • October 2, 2026: Industry Day (St. Louis, MO). MSD’s signature outreach event will provide detailed insight into the Lower & Middle River Des Peres Tunnel, including design considerations, contracting approach, and project expectations. The event includes a networking breakfast, technical presentations, and optional self-guided review of the project alignment. More information is coming soon.
  • October/November 2026: Prequalification package released for the Lower & Middle River Des Peres Tunnel—marking the formal start of the procurement process.

Contractors are strongly encouraged to engage early to better understand project requirements, connect with potential partners, and position their teams for upcoming opportunities.

For questions, please contact project leaders at LMRDPTunnel@stlmsd.com or using the following contact information.

Contact Us

Information Construction Dept Design Dept
Name Mr. Allen Muehlher Ms. Patricia Pride
Email AFMUEH@stlmsd.com PAPRID@stlmsd.com
Phone 314-768-6239 314-768-6275