DEPARTMENT: Transportation
FILE TYPE: Consent Action
TITLE
title
Authorization To Execute Contract Amendment With Alliant Engineering, Inc., For Professional Engineering Services For County Road Retaining Wall Assessments And Final Design of County State Aid Highway 38 (McAndrews Road) Retaining Walls, County Project 97-218
end
PURPOSE/ACTION REQUESTED
Authorize the execution of the first contract amendment with Alliant Engineering, Inc., for engineering design services for County State Aid Highway (CSAH) 38 (McAndrews) in the City of Apple Valley, County Project (CP) 97-218.
SUMMARY
To provide a safe and efficient transportation system, Dakota County is proceeding with CP 97-218, which involves the analysis, repair, or replacement of retaining walls along county roadways. Some retaining walls are showing signs of deterioration. This project will evaluate 24 retaining walls to identify and prioritize repair/replacement before wall failure compromises the integrity of the bike/pedestrian trails and roadways.
The County has identified four priority retaining walls along CSAH 38 for final design (Attachment: Location Map). These walls, constructed in 1992, are deteriorating and require either full replacement or a solution with a similar service life.
In addition to CSAH 38, Dakota County is requesting the Consultant to evaluate an additional 20 retaining walls. The evaluation will provide recommendations for corrective action, preliminary cost estimates, and a priority list for repairs. This will help Dakota County plan funding in future Capital Improvement Programs (CIP).
By Resolution No. 23-427 (September 2023), Dakota County authorized a contract with Alliant for the county-wide evaluation and replacement of retaining walls on CSAH 38. Since then, the project scope has evolved due to the complications associated with avoiding significant permanent easement requirements and subsequent damages to the private property, requiring numerous wall offsets, material evaluations, and an extended project duration.
Staff explored several alternative solutions that better respect the existing physical constraints. After evaluating various options, a Cast-In-Place wall method is chosen, which eliminates the need of a permanent easement since all the construction activities will take place within the County’s right of way.
Need for Amendment
The need for an amendment arises due to several out-of-scope tasks that have been identified (after choosing Cast-In-Place wall method), as essential for the successful completion of the project. These tasks include:
1. Realigning the Trail: The original contract did not include the realignment of the trail to provide a 10-foot trail and a 2-foot buffer to the wall. This became necessary due to the placement of the cast-in-place retaining wall.
2. Specialty Design for Footing: The design of a specialty cast-in-place wall footing to fit within the limits of the existing retaining wall was not part of the original scope.
3. Drainage Design: The creation of a drainage design for the low point behind the wall and adjustments to roadway catch basins were additional tasks that were not initially included.
4. Use of Soil Solidification: Investigating and potentially implementing soil solidification options instead of sheet piling was not part of the original contract.
5. Widening the Boulevard: The decision to widen the boulevard to allow for a future trail was an additional requirement that was not included in the initial scope.
6. Adjustments for Sightline Issues: Addressing sightline issues at the intersection of Diamond Path and CSAH 38, which required adjusting the alignment and removing a portion of the existing small block wall, was not part of the original agreement.
These additional tasks have extended the duration and complexity of the project, necessitating an amendment to the contract to ensure all necessary work is completed effectively. The negotiated additional cost of the contract is $148,562, which exceeds the approved contract amount of $254,761 (Attachment: Additional Tasks Estimate). The current Engineer’s Estimate for the retaining wall replacement at the 4 locations along CSAH 38 is $9.8 million. The amended consultant contract value represents 4.12 percent of the anticipated construction costs and is in line with what is expected for this type of transportation project.
RECOMMENDATION
recommendation
Staff recommends authorizing the first contract amendment for additional design services with Alliant Engineering, Inc., for an amended contract value not to exceed of $403,323.00.
end
EXPLANATION OF FISCAL/FTE IMPACTS
The adopted budget for the 2025 Transportation Capital Improvement Program for CP 97-218 includes $1,300,000 carried over from previous years, ensuring there are sufficient funds for the recommended contract amendment.
☒ None ☐ Current budget ☐ Other
☐ Amendment Requested ☐ New FTE(s) requested
RESOLUTION
body
WHEREAS, to provide a safe and efficient transportation system, Dakota County is proceeding with County Project (CP) 97-218; and
WHEREAS, CP 97-218 is the analysis, repair, or replacement of retaining walls showing signs of deterioration along County roadways in various locations throughout Dakota County; and
WHEREAS, by Resolution No. 23-427, the County Board executed contract DCA-20887 with Alliant Engineering, Inc., for CP 97-218 with the amount not to exceed $254,761.00; and
WHEREAS, through project development, staff identified design elements that are necessary to realign the trail, correct sightline deficiencies, and maintain design standards that were not accounted for in the original scope; and
WHEREAS, a first contract amendment in the amount of $148,562.00 is needed for Alliant Engineering, Inc., to complete the additional design elements; and
WHEREAS, staff negotiated the cost of the out-of-scope items with Alliant Engineering, Inc., and concurs with the fee for the required work; and
WHEREAS, staff recommends amending Alliant Engineering, Inc.’s contract in an amount not to exceed $403,323.00; and
WHEREAS, sufficient funds exist within the budget for CP 97-218 to proceed with the requested consultant contract amendment.
NOW, THEREFORE, BE IT RESOLVED, That the Dakota County Board of Commissioners hereby authorizes the Physical Development Director to execute the contract amendment with Alliant Engineering, Inc., in the amount not to exceed $403,323.00 for design services for County Project 97-218, subject to approval by the County Attorney’s Office as to form.
end
PREVIOUS BOARD ACTION
23-427; 9/26/23
ATTACHMENTS
Attachment: Location Map of 4 Walls
Attachment: Additional Tasks Estimate
BOARD GOALS
☐ Thriving People ☐ A Healthy Environment with Quality Natural Resources
☒ A Successful Place for Business and Jobs ☐ Excellence in Public Service
CONTACT
Department Head: Erin Laberee
Author: Imran Ahmed