Consent 1.B.
Regular City Council Meeting
- Meeting Date:
- 01/09/2017
- TITLE
- W.O. 15-10 -- Water Treatment Plant Chemical Building/Disinfection Improvements, Change Order 8
- PRESENTED BY:
- David Mumford
- Department:
- Public Works
Presentation:
PROBLEM/ISSUE STATEMENT
This project is renovating and remodeling the existing Chemical Building at the Water Treatment Plant (WTP), updating and enhancing the plant's chemical treatment system (chemical feeder lines, pumps, etc.), constructing a new UV disinfection facility, installing new flow meters in the Control Structure, installing redundant large-diameter effluent and backwash supply lines, and all associated electrical and site work.
The existing Chemical Building is 60-plus years old. As such, many things have been encountered that were not included in previous record drawings (therefore not included in this project's contract drawings) or were completely unknown to current Plant Staff. These unknowns have caused some of the project's designs to be revised and/or added to post-bid, resulting in change order items. As discrepancies have been discovered, old record drawings have been updated to ensure that future work will be done utilizing more accurate drawings.
Similarly, all of the new piping is to be installed across areas of the plant that already contain multiple underground facilities (water lines, flumes, electrical duct banks, sewer lines, etc.). Many of these underground facilities have been discovered in locations contradictory to where previous record drawings indicate. Much of the new piping is very large diameter (between 42" and 60") and is to be installed very deep (over 20 feet below surface). In addition to the unknown and/or mis-located underground facilities, problems were discovered with existing infrastructure (i.e. valves that would not close or operate correctly, slide gates that would not stop flow as intended, leaks in primary water lines, etc.). Now that these things have been identified, some of them can be fixed now and some will be fixed in the future. Regardless, these issues resulted in multiple changes that caused the contractor to incur additional costs and need additional time to complete contract work--addressed with change orders.
City Ordinance allows the City Administrator to approve change orders totaling the lesser of 10% of the original contract amount, up to $500,000 or the budgeted contingency. The project has now encountered changes such that the total will exceed $500,000, so Council is requested to approve Change Order 8 to allow work to continue and the project be completed as required. In addition, Staff is requesting that the City Administrator be allowed to approve an additional $100,000 in change orders (beyond the current cumulative total, including Change Order 8) for this project. Due to the process that must be followed to have items presented to Council, it takes at least three weeks (but can take longer) to get change order approval through City Council. As these issues are encountered, the contractor needs immediate approval to proceed with the modifications to the work or a Stop Work Order would need to be issued until Council approval could be obtained. This would result in higher costs for the modifications and extensive down-time on the project. The percent of change orders approved by the City Administrator will still be less than 10% of the original project cost, but due to the high cost of this project, change orders over $500,000 are above City Administrator's current approval.
Change order 8 consists of: Modifications to piping between Clearwells #1 and #2 due to conflicts with two water lines; the water lines were known to be in the area but depth and exact location were unknown. The installation of the new 24" backwash supply line (BWS) conflicts with a sanitary sewer line that was found in a location contradictory to previous record drawings. The sewer line can be cut and reinstalled to avoid the BWS line, but bypass pumping will be required in addition to repairing and relocating the sewer line. The costs of this are less than trying to relocate the BWS line. Finally, CO #8 includes a CREDIT for eliminating the installation of new sun shades on the exterior of the Chemical Building that were deemed unnecessary.
The existing Chemical Building is 60-plus years old. As such, many things have been encountered that were not included in previous record drawings (therefore not included in this project's contract drawings) or were completely unknown to current Plant Staff. These unknowns have caused some of the project's designs to be revised and/or added to post-bid, resulting in change order items. As discrepancies have been discovered, old record drawings have been updated to ensure that future work will be done utilizing more accurate drawings.
Similarly, all of the new piping is to be installed across areas of the plant that already contain multiple underground facilities (water lines, flumes, electrical duct banks, sewer lines, etc.). Many of these underground facilities have been discovered in locations contradictory to where previous record drawings indicate. Much of the new piping is very large diameter (between 42" and 60") and is to be installed very deep (over 20 feet below surface). In addition to the unknown and/or mis-located underground facilities, problems were discovered with existing infrastructure (i.e. valves that would not close or operate correctly, slide gates that would not stop flow as intended, leaks in primary water lines, etc.). Now that these things have been identified, some of them can be fixed now and some will be fixed in the future. Regardless, these issues resulted in multiple changes that caused the contractor to incur additional costs and need additional time to complete contract work--addressed with change orders.
City Ordinance allows the City Administrator to approve change orders totaling the lesser of 10% of the original contract amount, up to $500,000 or the budgeted contingency. The project has now encountered changes such that the total will exceed $500,000, so Council is requested to approve Change Order 8 to allow work to continue and the project be completed as required. In addition, Staff is requesting that the City Administrator be allowed to approve an additional $100,000 in change orders (beyond the current cumulative total, including Change Order 8) for this project. Due to the process that must be followed to have items presented to Council, it takes at least three weeks (but can take longer) to get change order approval through City Council. As these issues are encountered, the contractor needs immediate approval to proceed with the modifications to the work or a Stop Work Order would need to be issued until Council approval could be obtained. This would result in higher costs for the modifications and extensive down-time on the project. The percent of change orders approved by the City Administrator will still be less than 10% of the original project cost, but due to the high cost of this project, change orders over $500,000 are above City Administrator's current approval.
Change order 8 consists of: Modifications to piping between Clearwells #1 and #2 due to conflicts with two water lines; the water lines were known to be in the area but depth and exact location were unknown. The installation of the new 24" backwash supply line (BWS) conflicts with a sanitary sewer line that was found in a location contradictory to previous record drawings. The sewer line can be cut and reinstalled to avoid the BWS line, but bypass pumping will be required in addition to repairing and relocating the sewer line. The costs of this are less than trying to relocate the BWS line. Finally, CO #8 includes a CREDIT for eliminating the installation of new sun shades on the exterior of the Chemical Building that were deemed unnecessary.
ALTERNATIVES ANALYZED
City Council may:
- Approve Change Order 8 in the amount of $ 60,668.46 and increase City Administrator signing authority an additional $100,000 beyond the cumulative total of change orders; OR
- Approve Change Order 8 in the amount of $ 60,668.46, but do not increase City Administrator signing authority an additional $100,000. This option will require all additional change orders to be presented to Council which would result in higher costs and unanticipated down time; OR
- Disapprove Change Order 8, but increase City Administrator signing authority an additional $100,000. This option would essentially not allow work to be completed and the project to proceed as required for the WTP to best maintain its water-producing operations; OR
- Disapprove Change Order 8 and do not increase City Administrator signing authority an additional $100,000. This option would essentially not allow work to be completed and the project to proceed as required for the WTP to best maintain its water-producing operations, and require all additional change orders to be presented to Council which would result in higher costs and unanticipated down time .
FINANCIAL IMPACT
This project is being funded by Water funds. Change Order #8 (CO 8) represents an addition to the project's costs. The approved project budget includes a contingency to pay for unforeseen circumstances characteristic with those depicted in CO 8. There are adequate funds available to cover the additional costs. The table below summarizes the financial impact to the project.
| ORIGINAL CONSTRUCTION CONTRACT: | 300 DAYS | $6,904,700.00 | |
| ADDITIONAL DAYS | ADDITIONAL COSTS | % OF CONTRACT | |
| Change Orders 1-7 | 53 | $495,932.23 | 7.18% |
| Change Order 8 | 3 | $ 60,668.46 | 0.88% |
| TOTALS: | 56 | $556,600.69 | 8.06% |
RECOMMENDATION
Staff recommends Council approve Change Order 8 in the amount of $ 60,668.46, and increase Change Order signing authority for the City Administrator an additional $100,000 beyond the cumulative total of change orders, for W.O. 15-10 -- Water Treatment Plant Chemical Building / Disinfection Improvements.