Highway ReconstructionErosion & Sediment ControlStormwater Innovation
Twin Ports Interchange Reconstruction
Duluth, Minnesota
Untangling “The Can of Worms” — Without Losing a Drop to the Environment
In partnership with Ramy Turf Products
A $435 million, five-year reconstruction of one of Minnesota’s most complex interchanges. More than 80,000 vehicles a day. Over 5,000 heavy trucks. Sensitive waterways throughout. Ero-Guard didn’t just supply erosion control materials — they helped engineer a solution MnDOT engineers recognized for its speed, practicality, and innovation.
Duluth’s Twin Ports Interchange — known locally as “The Can of Worms” — carried that nickname for good reason: a tangle of aging highways, blind merges, and left exits that created hazards for daily commuters and frustrated freight operators for decades. Its reconstruction was a generational infrastructure investment, celebrated at completion with a ribbon-cutting by Governor Tim Walz. Getting there required not just engineering precision, but an adaptive, integrated approach to environmental management that kept the site compliant and the project moving across five full construction seasons.
$435M
Total project reconstruction value
$420K
Ero-Guard environmental materials supplied
80K+
Vehicles per day through the active corridor
5 yr
Construction duration — sustained compliance throughout
The Challenge
Five Years of Active Construction. Zero Room for Environmental Failure.
The Twin Ports Interchange reconstruction presented an environmental management challenge as complex as the engineering itself. The site operated continuously across five construction seasons, with more than 80,000 daily vehicles — including over 5,000 heavy trucks — moving through or around active work zones at all times. Traffic rerouting, staged demolition, and aggressive grading schedules left soils exposed across shifting sections of the site, creating persistent erosion and sediment risk in a corridor threaded with sensitive waterways.
Duluth’s climate added another layer of difficulty. The city’s lake-effect weather patterns, steep terrain, and proximity to Lake Superior and its tributaries meant that rainfall events and seasonal transitions could rapidly escalate small erosion issues into significant regulatory and environmental problems. Maintaining compliance with MnDOT and state environmental requirements over a five-year window — without delays, fines, or corrective shutdowns — required a proactive, adaptive system capable of responding to constantly changing site conditions.
One specific challenge emerged during concrete sawing operations: the process generated high-pH slurry that could not be discharged without treatment. Standard approaches were too slow for the project’s pace. A faster, more practical solution was needed — one that MnDOT engineers would accept and that could be deployed without disrupting construction momentum.
The Solution
An Integrated System — Blankets, Mulch, Seed, and a Proprietary Innovation
Ero-Guard, in partnership with Ramy Turf Products, supplied approximately $420,000 in erosion control blankets, hydro-mulch, and custom seed blends engineered specifically for Duluth’s soils and climate. The two Nexterra companies worked in coordination to deliver a materials package that functioned as a unified system — each component supporting the others across the full arc of site stabilization, from initial slope exposure through long-term vegetation establishment.
Erosion Control Blankets — Ero-Guard
Ero-Guard erosion control blankets were installed across exposed embankments and steep slope faces throughout the five-year project. The blanket system anchored soils immediately upon installation, held through heavy rainfall events, and created the stable surface conditions necessary for seed germination — even under Duluth’s demanding northern climate.
Hydro-Mulch — Ero-Guard
Hydraulically applied mulch provided rapid, flexible coverage across disturbed areas where blanket installation was impractical given the constantly shifting site conditions. Hydro-mulch bonded to soil surfaces, reduced rainfall impact erosion, and retained moisture to support germination across the compressed staging windows typical of a large, active interchange project.
Custom Seed Blends — Ramy Turf Products
Ramy Turf Products engineered custom seed blends formulated for Duluth’s specific soil types, slope exposures, and northern climate. Species selection prioritized rapid establishment, MnDOT compliance, and long-term ecological compatibility with the corridor’s sensitive waterway context — producing thriving, enduring vegetative cover across the project area.
Innovation Spotlight
A Proprietary Solution — Recognized by MnDOT Engineers
Concrete sawing operations on the project generated high-pH slurry that posed a discharge compliance challenge. Standard treatment methods existed, but none were fast enough for the project’s pace or practical enough for deployment across an active, high-traffic interchange site.
Proprietary Innovation — pH-Neutralizing Slurry Treatment
The Ero-Guard team developed a proprietary pH-neutralizing treatment for concrete sawing slurry — enabling safe, compliant discharge without halting construction operations.
The treatment neutralized the high-alkalinity byproduct of concrete cutting on-site and in real time, eliminating the delay and logistical complexity of off-site disposal. The result: full regulatory compliance maintained, no construction stoppages, and no discharge violations across the multi-year project.
MnDOT engineers recognized the method for its speed, practicality, and effectiveness — a direct acknowledgment that innovative environmental problem-solving can remove obstacles on large-scale construction projects rather than create them.
Every element — from advanced erosion control materials to the proprietary pH treatment — contributed to a safer, more resilient, and sustainable interchange.
— Twin Ports Interchange Project Summary
The Results
Slopes Held. Waterways Protected. A Governor’s Ribbon-Cutting.
Across five construction seasons, the integrated erosion control and stormwater management system performed without failure. Slopes held firm through heavy rainfall. Runoff was controlled before reaching sensitive waterways. Vegetation established and flourished. And the project closed out on schedule — celebrated with a ribbon-cutting by Governor Tim Walz, who recognized the reconstruction as a generational investment in Minnesota’s transportation infrastructure.
Slope Stability
Slopes remained secure through five construction seasons including heavy rainfall across Duluth’s demanding northern climate. No significant erosion failures or instability events were recorded across the project corridor.
Waterway Protection
Runoff was captured and controlled before reaching sensitive waterways connected to Lake Superior. Environmental compliance with MnDOT and state requirements was maintained continuously — no corrective orders, no discharge violations, no fines.
Vegetation Establishment
Custom seed blends from Ramy Turf Products flourished across treated slopes, creating living barriers with long-term resilience. Uniform vegetative cover reduced ongoing maintenance demands across the full corridor.
Regulatory Recognition
The proprietary pH-neutralizing slurry treatment was formally recognized by MnDOT engineers for its speed, practicality, and effectiveness — setting a new benchmark for concrete sawing compliance on active highway reconstruction projects.
Schedule Performance
Proactive environmental management eliminated reactive repair cycles and compliance delays throughout the five-year build. Construction momentum was sustained across all phases, contributing to on-time project delivery.
Freight & Community Impact
The completed interchange eliminated blind merges and hazardous left exits, improved freight mobility for over 5,000 daily heavy trucks, and delivered a future-ready corridor supporting safe, reliable travel for Duluth residents and regional commerce.
Managing a Complex Infrastructure Project?
Whether you’re stabilizing slopes across a multi-year corridor, protecting sensitive waterways, or solving a stormwater compliance challenge that standard methods can’t handle — Ero-Guard has the products, the expertise, and the problem-solving to keep your project moving.
About Ero-Guard Erosion Control Products
Founded in 2004, Ero-Guard manufactures a full line of erosion control blankets and straw wattles from its Midwest facility. Products are NTPEP-evaluated and listed on 20+ state DOT approved product lists, making Ero-Guard a trusted specification choice for transportation, infrastructure, and environmental projects across the region. Pillars: Service. Quality. Integrity.
A Nexterra Environmental Company
Ero-Guard is part of the Nexterra Environmental platform — a multi-regional distributor and manufacturer of erosion control and stormwater management solutions. On this project, Ero-Guard coordinated with fellow Nexterra company Ramy Turf Products to deliver an integrated, platform-wide erosion control and vegetation solution.