Request for Committee Action
A briefing memo explaining the purpose, background, and impact of the requested action.
Contract amendment with Engineering and Construction Innovations, Inc. for 10th Ave Water Main River Crossing Project (RCA-2020-00423)
ORIGINATING DEPARTMENT
To Committee(s)
| # | Committee Name | Meeting Date |
|---|---|---|
| 1 | Policy & Government Oversight Committee | May 6, 2020 |
Action Item(s)
| # | File Type | Subcategory | Item Description |
|---|---|---|---|
| 1 | Action | Contract/Agreement | Authorizing an increase to Contract No. COM000435 with Engineering and Construction Innovations, Inc., in the amount of $489,058.70 for a total amount not to exceed $16,088,783.70, for project changes for the 10th Ave Water Main River Crossing Project due to unforeseen conditions. |
Previous Actions
2019-00287 - Bid for 10th Ave Water Main River Crossing Project
Ward / Neighborhood / Address
| # | Ward | Neighborhood | Address |
|---|---|---|---|
| 1. | Ward 2 | Cedar Riverside | |
| 2. | Ward 3 | Marcy Holmes | |
| 3. | Ward 6 | Cedar Riverside |
Background Analysis
Public Works is replacing the 54” water main that was suspended to the 10th Avenue Bridge with a new water main that will be tunneled under the Mississippi River near the 10th Avenue Bridge. The work generally includes construction of two deep shafts on either side of the river, tunneling a casing pipe under the river, installation of a new water main inside the casing pipe, and replacement of direct-buried water main on either side of the river to connect the new water main to the existing water main.
During the work, a number of changes were deemed necessary due to unforeseen conditions. A summary of the changes includes:
- Removal of 54” diameter standpipes for the contractor to do its work: Originally the bridge contractor was going to do this work, but schedule changes dictated the work be done earlier. $91,000.00
- Replace existing pipe in existing tunnel instead of cleaning and lining as called for in the plans:: this was a no-cost betterment to the project and is added for contract documentation purposes.
- Deletion of new service Line to US Army Corp of Engineers Facility: This work was removed from the project to be done separately, as the routing was undesirable. -$35,171.01 (credit)
- Existing tunnel differing conditions: The contractor needed to do demolition in a portion of an existing tunnel, and currently available plans did not show some aspects of the tunnel. Once the work began, it was determined that additional demolition beyond what was shown in the contract documents was necessary, and additional shoring, reconfiguration of some of the pipe fittings and safety measures were needed. $185,244.06
- Replacement of additional pipe: Once demolition on the project began, it was discovered that a section of pipe that was to remain was in poor condition, with deteriorated lining, and needed to be replaced. $159,578.31
- Void bulkhead and probing, shaft grouting: Voids were discovered near the existing water main tunnel face which needed to be filled. Also, the existing shaft connected to the existing tunnel was leaking excessive and unforeseen amounts of groundwater into the tunnel. The contractor was directed to stem the flow of groundwater using injected grout around the shaft. $34,608.66
- New hydrant: Upon developing a plan for disinfection and future maintenance of the main, it was determined a new hydrant to be connected to the main that is being constructed was necessary. $23,895.48
- Vault roof modification: Reconstruction of an existing concrete vault roof to accommodate new piping, in a manner that was not foreseen in the original work planning. $29,903.20
The cost of these improvements is $489,058.70. Funding is available in the project budget for costs associated with this amendment.