Important Information for Prospective 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. Note that contractors must be pre-qualified to bid.

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

(Prequalification package release date in Mid-September 2026)

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

LMRDP Bidding Important Dates

Prequalification Package Distribution Mid-September 2026
Industry Day October 2, 2026
Prequalification Submittal Due to MSD December 1, 2026
Final Prequalification Letter Sent to Contractors March 27, 2027

Outreach Opportunities

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

Upcoming Events

  • 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.
  • Mid-September 2026: Prequalification package released for the Lower & Middle River Des Peres Tunnel—marking the formal start of the procurement process.

Previous Events

  • 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 hosted a contractor-focused informational session. Attendees met directly with MSD leadership, along with design consultant Jacobs and construction management consultant Black & Veatch, to learn more about project planning and procurement. View the presentation here.

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