HomeMy WebLinkAboutA019 - September 8, 2026, Regular Meeting of the Ames City CouncilITEM #:19
DATE:09-08-26
DEPT:W&PC
SUBJECT:WATER POLLUTION CONTROL FACILITY NUTRIENT REDUCTION
MODIFICATIONS PHASE 1 PROJECT - CHANGE ORDER #11
COUNCIL ACTION FORM
BACKGROUND:
On August 13, 2024, City Council awarded a contract to Woodruff Construction for
modifications to the Water Pollution Control Facility (WPCF) in the amount of $53,370,000.
These modifications are the first of two construction phases that will ultimately enable the
facility to achieve the goals of the Iowa Nutrient Reduction Strategy.
As is common with large construction contracts, this project has required multiple change
orders. To date, 10 change orders have been approved for a combined total adjustment in the
contract price of $159,269.16. Details regarding the scope and amounts of each change order
are outlined below in Table 1.
An 11th change order has been prepared and is ready for Council approval. The largest
single item ($56,499.68) is to remove and replace the existing 24" flow meter and
transmitter for the First-stage Trickling Filter Pumps, and to remove and replace a 12"
pneumatic pinch valve and add a new plug valve in the Raw Wastewater Pump Station.
The pricing includes all materials, installation, electrical wiring, and controls
integration.
The existing flow meter has become erratic in its readings and is essential for monitoring the
flows from the first stage trickling filter pumps to the primary clarifiers. The pinch valve controls
the equalization basin return flow back into the plant. The existing valve does not fully close,
meaning the plant cannot fully shut off flow from the equalization basins. Therefore, the valve
must be replaced. Adding the new plug valve allows the plant to have a manual option for
shutting off this flow if power is lost in the pump station. The pricing was deemed reasonable
by the consultant by comparing it to a separate contractor ’s bid for a different project with a
similar product. It should be noted that the need for these replacements were not known
at the time of the bidding.
Other smaller items included in this change order include:
Low level float switch - $1,545.13. This item includes supply of a low level float switch
with the manufacturer furnished cable, mounting hardware, and PLC programming for
use in the effluent channel in the UV building. Installation will be completed by WPCF
staff for cost savings. The switch will allow the operators to monitor the water level in the
channel that feeds the effluent return water pumps as well as aid in control of the pump
speeds and reduce the risk of damage to the pumps by drawing the water too low in the
channel.
1
ADS tee credit - $3,225.24. This changes the material of the buried perforated drain
piping tees around the perimeter of the activated sludge structure from ductile iron to
HDPE. The pricing for the ADS tees is comparable to pricing quoted by suppliers.
Additional sidewalk north of the Raw Wastewater Building - $1,090.34. This item
includes placement of approximately 30 feet of sidewalk between the blower room door
and driveway on the north side of the Raw Wastewater Building. This is to provide
sidewalk access for operators and equipment to the blower room and north stairwell to
the Raw Wastewater Building basement. The consultant has confirmed that the quoted
labor hours seem reasonable, and the cost per cubic yard of concrete matches with DOT
unit prices.
Table 1: Change Order Summary
Change Order #1
Credit for Enviromix, fire alarms, canopy; reroute gate power circuit; expansion
joint changes.
(231,878.79)
Change Order #2
Modifications to the ceiling and lighting in portions of the Administration Building.(25,280.00)
Change Order #3
Changes to Control Box A & B; changes to framing elements, reimbursement for
special inspections.
10,835.86
Change Order #4
Changes to door framing; changes to ceiling tiles; changes to electrical outlets;
additional painting requested by staff.
13,459.25
Change Order #5
Changes to valves & piping in Structure 10; changes to reinforcing and electrical
at Structure 20; add booster fan; casework changes in admin building; add (2)
well supply tanks and well control modifications; Deletion of gate valve in Control
Box A (later restored as part of Change Order #9); misc changes in Structure 20.
(40,743.03)
Change Order #6
Integrate doors into fire alarm in Admin; change paving to PCC for (8) parking
stalls; credit for brass tags vs stainless; credit for rehab slide gate valves in
Structure 10 versus replacement; Structure 200 berm elevation changes; corner
guards in Structure 200; changes to the 4" DCW line near the RWPs.
$71,844.57
Change Order #7
Add asbestos and lead abatement for demolition of old admin building; add
remote control for trolley hoist; misc electrical changes; add door holder/closer;
extend water line in grit building; additional fencing; removal of unknown
foundation under old admin building; add additional wireless access points.
$44,527.37
Change Order #8
Relocate overhead door; door hardware change; credit from water line
relocation; door opener to Room 20012; add corner guards in admin building;
substitute PLC type.
$3,843.61
Change Order #9
Credit for eliminating crimp connectors; install water supply, drain, and install
owner-supplied sink in shop; credit for eliminating hangers on energy recovery
unit duct; remove and replace gate door in Control Box A.
$81,739.80
2
Change order #10
Supply and install (6) new VFDs for the Raw Wastewater Pumps, add (4) load
transfer plates, credit for expansion joint material change, no-cost correction to
Change Order #9.
$230,920.52
Change Order #11 - this action
Remove and replace flow meter FM-8; remove and replace pinch valve
PHV-03; install new plug valve ahead of PHV-03; supply owner-installed
float switch for Disinfection Building ERW; credit for substituting HDPE
tees in lieu of ductile iron tees around Structure 80; provide and install 30
lf of sidewalk adjacent to Structure 10.
$55,909.91
Total Approved Change Orders (Including this action)
Percent of Original Contract
$215,179.07
0.40%
Table 2 below summarizes the overall project budget, including the $500,000 grant that was
received earlier this year.
Table 2: Total Project Funding & Expenses
Funding Expenses
Prior Years
FY 2023 1,000,472
FY 2024 1,438,643
FY 2025 18,573,090
FY 2026 (Preliminary)26,608,806
FY 2027 (Includes pending carryovers)15,018,184
WTFAP Grant - Iowa Finance Authority 500,000
Engineering 6,038,000
Construction
Original Contract 53,370,000
Change Order #1 (231,878)
Change Order #2 (25,280)
Change Order #3 10,836
Change Order #4 13,459
Change Order #5 (40,743)
Change Order #6 71,845
Change Order #7 44,527
Change Order #8 3,844
Change Order #9 81,380
Change Order #10 230,921
Change Order #11 - This Action 55,910
Owner Allowance (furnishings, etc.) 400,000
All Other Expenses 122,675
TOTAL 63,139,195 60,145,496
Remaining Available Contingency 2,993,699
3
The Clean Water State Revolving Fund (CWSRF) loan was approved in a not-to-exceed
amount of $65,185,000 to provide a cushion for unanticipated project changes and prevent
unnecessary issuance costs associated with increasing the not-to-exceed amount as a
separate action, should it be necessary.
It should be noted that the SRF program is a reimbursement program, meaning that the City
first spends the money, then the program reimburses for eligible expenses. This method
ensures the City will only borrow for expenses the City Council has authorized and are
necessary to complete the project, thus minimizing interest expense associated with the
improvements.
ALTERNATIVES:
1. Approve Change Order #11 to the contract with Woodruff Construction for the Water
Pollution Control Facility Nutrient Reduction Modifications Phase 1 Project in the amount
of $55,909.91.
2. Do not approve the change order. This would reject the recommended changes to the
contract documents.
CITY MANAGER'S RECOMMENDED ACTION:
The proposed changes are to maintain and improve the reliability and function of the
Water Pollution Control Plant Modifications. The consultant, contractor, and City staff
have worked closely together to come up with reasonable, cost-effective
recommendations. Therefore, it is the recommendation of the City Manager that the City
Council adopt Alternative No. 1 as described above.
ATTACHMENT(S):
CO11Encl.to Owner_signed.pdf
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42