Title:
Title
Change Order: E. A. Fairbairn Water Treatment Plant (FWTP) Filters #9-16 Rehabilitation Project
End
FileID
File ID: 2019-00590
Location
Location: District 6
Recommendation:
Recommendation
Adopt a Resolution: 1) authorizing the City Manager or the City Manager’s designee to execute Change Order No. 6 to City Agreement No. 2018-0672 with Utility Service Co. Inc., for an amount not-to-exceed $499,536, bringing the agreement’s total not-to-exceed amount to $4,502,396; 2) resetting the City Manager’s authority to issue Change Orders for the Agreement; and 3) approving budget related transfers.
Contact: Megan Thomas, Project Manager, (916) 808-1729; Michelle Carrey, Supervising Engineer, (916) 808-1438; Dan Sherry, Engineering & Water Resources Division Manager, (916) 808-1419, Department of Utilities
Body
Presenter: None
Attachments:
1-Description/Analysis
2-Change Order
3-Resolution
Description/Analysis
Issue Detail: Staff recommends Council approve Change Order No. 6 with Utility Service Co. Inc. (USCI) for the City Agreement No. 2018-0672, to complete additional concrete coating repairs on the walls and floors of the filters due to the unforeseen soft condition of the concrete.
Policy Considerations: This Change Order exceeds the City Manager’s approval authority and requires Council approval.
Economic Impacts: This Change Order is expected to create 2.00 total jobs (1.15 direct jobs and 0.85 jobs through indirect and induced activities) and create $308,430.70 in total economic output ($194,406.23 of direct output and another $114,024.47 of output through indirect and induced activities).
The indicated economic impacts are estimates calculated using a calculation tool developed by the Center for Strategic Economic Research (CSER). CSER utilized the IMPLAN input-output model (2009 coefficients) to quantify the economic impacts of a hypothetical $1 million of spending in various construction categories within the City of Sacramento in an average one-year period. Actual impacts could differ significantly from the estimates and neither the City of Sacramento nor CSER shall be held responsible for consequences resulting from such differences.
Environmental Considerations: The subject project was reviewed and determined to be categorically exempt from the California Environmental Quality Act (CEQA). The project includes maintenance and minor alteration of existing public utility facilities (CEQA Guidelines Section 15301) and replacing existing filter media and coating existing structures within the treatment process involving no expansion of capacity (CEQA Guidelines Section 15302 (c)).
Sustainability: The proposed project is consistent with the 2035 General Plan as it maintains existing water treatment capacity by replacing filter media that has reached the end of its useful life and will improve the life of the treatment plant facilities by providing a protective coating on the filter basins.
Commission/Committee Action: Not applicable.
Rationale for Recommendation: During the surface preparation of the concrete filter walls and floors, it was realized that the concrete was soft in more surfaces than anticipated for a 14-year-old asset. The softness extended more than an inch beyond the existing concrete surface, which would eventually impact the rebar and structural aspects of the filter walls. A new coating is required to provide a barrier to protect the rebar.
In order for the coating application to meet City specifications and coating application requirements, the voids need to be filled with a cement-based material which will provides the needed smooth surface for the coating application. This work will result in an extended life of the filter structures.
Financial Considerations: The FWTP Filters No. 9-16 Rehabilitation Project has an original contract not-to-exceed amount of $3,808,312. The net change by previous change orders in the amount of $194,549, increased the contract not-to-exceed amount to $4,002,861. Proposed Change Order No. 6 in the amount of $499,536 will increase the contract not-to-exceed amount to $4,502,397. Staff recommends transferring $250,000 from the Base CIP Contingency-Water Project (Z14000700) to the FWTP Rehab project (Z14130200). Sufficient funding for the project will be available after the transfer is made.
There are no General Funds allocated or planned for this project.
Local Business Enterprise (LBE): USCI is not an LBE, but has partnered with an LBE, Mason Painting, Inc., for this project to exceed the minimum LBE participation requirement. Mason Painting, Inc. has been providing coating services for the project.
Background: The FWTP is one of two City treatment plants that provide drinking water for the City of Sacramento. As part of the treatment process, the plant uses filters to finish cleaning the water, so it will meet drinking water standards and can be distributed into the City’s drinking water system. Generally, filter media life ranges between 12 and 15 years at which time it starts losing the ability to efficiently finish cleaning the water and plant production capacity is affected. Actual life of filter media is dependent on use, backwash cycles, and quality of the source water being treated.
The filter media within FWTP Filters #9-16 was originally installed in 2004 with the construction of the FWTP Expansion Project. At that time, filter media smaller than designed was installed by the contractor resulting in a settlement to the City to account for the anticipated shorter life expectancy of the material. Over the past couple of years, the filter media efficiency of Filters #9-16 has begun to impact the water treatment plant’s ability to treat water at the designed capacity. This project will replace the existing filter media in the 8 filter basins to maintain the design capacity of the treatment plant.
Upon initial inspection of the filter basins, the structural concrete showed initial signs of corrosion where the aggregate of the concrete had become exposed. To prolong the life of the concrete, coating of the basins was recommended. Since coating of filter basins could only occur when filter media is removed, coating the basins was included as part of the project base bid scope.
Steel bulkheads installed as part of the original construction of the FWTP in 1964 had lost their original protective coating and required a replacement coating to protect the steel from corroding further. Additive Item #1, which incorporated surface preparation and coating of the steel bulkheads, was included as part of the bid scope.
After the bid results came in on November 1, 2017, a bid protest was filed which delayed the award of the contract. On May 15, 2018, Utility Service Co. Inc. was awarded the contract by Council.
Due the delay caused by the bid protest, Change Order No. 1 was approved and provided an additional 85 construction days. The extra time addressed additional contract restrictions required to ensure the treatment plant could address water production needs during the summer months. There were no additional costs associated with this change order.
Change Order No. 2 approved an additional 28 construction days to address delays caused by suppliers not being able to meet the contract specifications that required the contractor to solicit other suppliers that could meet the specifications. There were no additional costs associated with this change order.
Since the existing filters were in use, there was limited information City staff could obtain regarding the condition of the filters during the design phase of the project. Once the Contractor started working on the first set of filters and the old filter media was removed, the City and Contractor were able to evaluate the condition of the concrete. When the coating preparation of the concrete commenced, the condition of the filter basins became more apparent and actual line item quantities could be determined based on what was found. Filter nozzles were in better condition than originally anticipated as was any apparent cracking of the concrete, while the expansion joints existing within the filters were more prevalent requiring additional joint sealant than originally anticipated. The City was able to negotiate better pricing on line items that increased by more than 20% and saved funds where line items could be reduced due to the condition of the filters. The total cost of the change order was $98,691.25 with an additional 40 calendar days of construction time due to some of the extended line items.
Change Order No. 4 was a corrective change order that addressed an error from the original base bid of one of the line items where all of the quantities were not included in the base bid price calculation. This change order increased the total contract by $14,640.00 to address this error.
In November 2018 when the treatment plant was taken off-line, the Contractor was able to commence work on the bulkheads throughout the plant. Since the grit basin was the most time restrictive location, work commenced on 3 of the bulkheads located there. Unfortunately, during the surface preparation of the steel surfaces, it was quickly realized that the structural steel was impacted more than originally anticipated and a series of weak points were found. The smaller bulkheads had sufficient steel remaining to complete a temporary repair until staff could schedule a more permanent repair for the next treatment plant shutdown period. However, due to the minimal structural steel remaining on the larger of the bulkhead, there was no temporary repair feasible that could have been implemented, and an emergency directive was given to the contractor to build a new replacement bulkhead for this location. Within 3 weeks, the contractor was able to build, coat, and install the new bulkhead which allowed the treatment plant to return to service without an extended interruption. Without this effort, the treatment plant wouldn’t have been able to return to service. Final costs of the time and materials were put together and submitted in spring for a total of $81,217.42 which included the temporary repairs on the smaller bulkheads and the replacement of the larger bulkhead. Change Order No. 5 increased the project schedule by 8 calendar days to account for the extra effort.
Since each filter could have different conditions within, it wasn’t until the second round of filters were cleared of media that staff had a better understanding of what change orders would be needed to complete the project. Since more than the initial filters had the same concrete condition that required parge coating (a cement based coating) on the walls, Change Order No. 6 is needed to increase the parge coating quantities to complete the remaining filters and address the separate parge needed to properly coat the floors.