HomeMy WebLinkAboutDSD-2025-278 - Carson Drive Sanitary Pumping Station Purchase Order Increase
Development Services Department www.kitchener.ca
REPORT TO: Finance and Corporate Services Committee
DATE OF MEETING: June 16, 2025
SUBMITTED BY: Chris Spere, Director Engineering Services, 519-783-8897
PREPARED BY: Steve Allen, Manager Engineering Design and Approvals, 519-783-
8306
WARD(S) INVOLVED: Ward 1
DATE OF REPORT: June 5, 2025
REPORT NO.: DSD-2025-278
SUBJECT: Carson Drive Sanitary Pumping Station Purchase Order Increase
RECOMMENDATION:
That the Purchase Order issued to Sona Constructor be increased by $75,000.00 to
account for additional construction costs related to the rehabilitation of the Carson
Drive Sanitary Pumping Station.
REPORT HIGHLIGHTS:
The purpose of this report is to seek Council authorization to increase the purchase
order issued to Sona Constructor to cover additional costs related to the rehabilitation
of the Carson Drive Sanitary Pumping Station (Carson SPS)
The key finding of this report is that additional work was required to complete the
intended scope of the project.
The financial implications have no impact to capital budgets. Costs of the additional
work are included in the approved capital forecast for the project.
Community engagement included letter notification to surrounding residents and the
placement of project information signs at the project site.
This report supports the delivery of core services.
BACKGROUND:
The Carson Drive Sanitary Pumping Station (Carson SPS) is located at 230 Carson Drive.
The station was built in 1977 and services an area of approximately 363 ha or about 6500
residents. The station is an essential component of the sanitary servicing for the area and
its purpose is to pump domestic sewage from a low point in the area to a higher elevation
identified in 2021 through the Sewage Pumping Station Assessment Study that reviewed a
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total of 22 stations throughout the city for condition and compliance with standards and best
practices.
A number of critical upgrades were identified for the Carson SPS in the study as well as
through input from Operations staff. These include the installation of an underground grinder
chamber and associated by-pass manhole, a metering chamber, and a swab launch/by-
pass maintenance hole. These features are standard for new sewage pumping stations but
not at the time Carson SPS was originally constructed.
A tender for the construction of these works was awarded by Council in late summer 2022
and construction commenced in late-fall of 2022.
REPORT:
Early in the work the contractor encountered difficulty with the deep excavations specifically
related to ground water seepage into the excavation which prevented the establishment of
a stable and safe trench to install the deepest chamber. Work was suspended to complete
a hydro-geotechnical investigation and provide recommendations to address the ground
water challenges. Once completed, a well-point system was installed to assist in lowering
the water table and construction was able to advance. As an additional measure, the shoring
system required changes to provide more protection from groundwater seepage.
Geotechnical investigations completed prior to the tendering period for a previous adjacent
project were provided to the bidders to help them assess the level of effort related to
managing the groundwater during excavations. This pre-construction investigation showed
high water levels, however the amount of effort required to effectively address the ground
water was greater than what the successful Investigations
by the dewatering contractor during construction noted highly variable geology which
differed from the precious information and complicated the dewatering effort. As the
information provided at the time of bidding did not quantify the effort required, the contractor
had a reasonable basis for payment for the additional costs incurred. The increase required
is the amount needed beyond the staff-delegated approval limits.
STRATEGIC PLAN ALIGNMENT:
This report supports the delivery of core services.
FINANCIAL IMPLICATIONS:
Capital Budget The recommendation has no impact on the existing Capital Budget. There
is sufficient funding in the capital account to accommodate the additional expense.
Operating Budget The recommendation has no impact on the Operating Budget.
COMMUNITY ENGAGEMENT:
INFORM
the council / committee meeting.
PREVIOUS REPORTS/AUTHORITIES:
There are no previous reports/authorities related to this matter.
APPROVED BY: Justin Readman, General Manager of Development Services