City Council Meeting Date: September 1, 2020
To: Mayor and City Council
City Administrator
From: Sean M. Simonson, Engineering Division Manager
David E. Bennett, Public Works Director/City Engineer
Cole Johnson, Water Quality Technician
Subject:
TITLE
Consider Approving Plans and Specifications and Order Advertisement for Bids for the Golf Course, Parmeadow Ponds 1 & 3 Dredging Project - (STRM2020-K25)
BODY
Action Requested:
The City Council considers approval of the attached Resolution approving the plans and specifications and authorizing the advertisement for bids for the Golf Course, Parmeadow Ponds 1 & 3 Dredging Project - (STRM2020-K25)
Summary Report:
In 2017, the City of Northfield performed a Stormwater Pond Assessment on 56 ponds within the City of Northfield. Out of this pond assessment project, eight ponds were isolated for further assessment due to the total sediment accumulation discovered during the pond assessment. These eight ponds were then ranked one to eight based on their percent full of sediment. The Golf Course Pond, and Parmeadow Pond #3 were ranked #1 and #2 respectively based on the criteria above, and Parmeadow Pond #1 was ranked #7 (Attachment 2).
Staff has developed a cleaning program for these eight ponds through the Capital Improvement Program (CIP), and these three ponds are scheduled for cleaning in the adopted 2020-2024 CIP.
This pond dredging projects include dewatering, excavating, and disposing of the accumulated sediment in the ponds. All of the ponds had the sediment tested for hazardous substances or petroleum products, specifically carcinogenic and noncarcinogenic Polycyclic Aromatic Hydrocarbons (cPAH/PAH), copper, or arsenic which may have been disposed or released into the ponds. The Minnesota Pollution Control Agency (MPCA) requires sediment testing for the aforementioned contaminants so their guidance and practices were followed when completing the testing. The testing indicated that Parmeadow Pond #1 and Parmeadow Pond #3 were categorized as Level 1 sediment, which allows the excavated sediment to be reused on properties with a residential or recreational use. The Golf Course Pond sediment was categorized as a Level 3 sediment, which requires the sediment to be disposed of at a Municipal Solid Waste landfill.
In addition to the sediment removal, miscellaneous slope re-grading and seeding, storm pipe repair, and rock weir replacement is proposed with the dredging project.
Due to these ponds being located in-line with Spring Creek, additional permitting was required to complete the pond dredging project. The City of Northfield applied for a Work in Waters permit with the MnDNR, which is expected to be issued on September 10, 2020. Staff has already received comments back from the DNR regarding the stipulations of the permit. As part of this permit review, a review was also performed by the non-game wildlife division of the MnDNR. This review identified Blanding’s and Wood Turtles, which are listed as endangered and threatened respectively, within 1-mile of the project. Due to this finding, additional stipulations are required regarding dewatering of the ponds. The dewatering of the ponds must occur prior to October 1, 2020, to meet the requirements of the permit. With the current schedule for the project (Attachment 3), the bids are scheduled to be opened on October 1, 2020, and the contract is scheduled to be awarded at the October 6, 2020 City Council meeting.
Due to the dewatering restrictions of the permit, Staff has removed the initial pond dewatering out of the contract, and has solicited quotes to have this work completed prior to the contract award in order to complete the project with the proposed schedule. Once the dredging project contract is awarded, the dewatering will transfer to the successful Contractor.
Alternative Options:
The City Council could delay this project; however, staff would not recommend that option.
Financial Impacts:
Below are the estimated total project costs, and the estimated total project funding.
|
TOTAL PROJECT COST |
|
|
ENGINEER'S ESTIMATE |
|
Storm Sewer |
$590,726 |
|
Subtotal |
$590,726 |
|
Contingency (10%) |
$59,073 |
|
Construction Total |
$649,799 |
|
Overhead (20%) |
$129,960 |
|
TOTAL PROJECT COST |
$779,758 |
|
PROJECT FUNDING |
|
FUNDING SOURCE |
PROJECT FUNDING |
|
Storm Fund |
$779,758 |
|
TOTAL FUNDING |
$779,758 |
Tentative Timelines:
The bids will be received on October 1, 2020 and awarded October 6, 2020. Construction is scheduled to be completed during the fall/winter of 2020/2021, with final completion in the spring of 2021.