How to choose sewer bypass pumping for a planned outage in Canada

Assign responsibility before choosing a rental or managed service

Choose sewer bypass pumping by assigning responsibility for design, shutdown readiness, overnight operation and changeback—not by relying on a package labelled “rental” or “monitored”. Make a responsibility schedule a tender deliverable, including duties retained by the owner or delegated to subcontractors.

Toronto’s September 2019 specification is an older contract example rather than a Canada-wide requirement, and it covers sewer bypass pumping during rehabilitation or when sewer pipes of 450 mm or less are put out of service, with some clauses specifically addressing liner installation, so it does not necessarily apply directly to a pumping-station outage. It assigns bypass design, regulatory approvals, commissioning, operation, maintenance, monitoring, decommissioning and removal to the contractor, alongside spill prevention and cleanup. [1] It retains separate City review and acceptance, licensed-operator duties and Engineer approval for system changes; contractor responsibility does not put every approval in the contractor’s hands. [1]

Use that distinction to structure the schedule:

• Design and approvals: who prepares the diversion design, obtains engineering sign-off, submits applications and secures acceptance?
• Installation and commissioning: who installs the system, demonstrates readiness and supplies acceptance records?
• Operation and incidents: who operates, maintains and monitors the bypass, responds to emergencies and handles reporting?
• Changeback and removal: who authorises and carries out flow reinstatement, witnesses it and accepts demobilisation?

Stormtec illustrates why the scope needs spelling out: it advertises equipment packages without an operator as well as managed, engineered sewer-bypass solutions, with on-site 24-hour monitoring available. Neither description commits Stormtec to anything on a particular project. [4] Stormtec’s About page identifies it as a water management solutions provider in Western Canada. [5] Confirm availability for the specific project before requesting a proposal.

Require bidders to identify exclusions, retained owner duties and subcontracted responsibilities against the same schedule. A “managed service” label still needs a defined scope and contractual accountability.

Issue an outage brief suppliers can price against

Give every bidder the same outage brief and timing assumptions. Calgary’s October 2020 sewer bypass guidelines provide an older, separate jurisdiction-specific example for temporary diversions of City-owned sanitary or storm sewers with a Final Acceptance Certificate. Treat them as guidance that is separate from Toronto’s contract. [3]

Build the brief around these items:

• Project and shutdown: identify the station, location, owner, reason for shutdown, proposed outage window, milestones, timing constraints and consequences if the bypass cannot proceed. [3]
• People and interfaces: name the contractor, consultants, subcontractors, project contacts, on-site 24-hour emergency contact and Incident Manager; describe how the bypass fits into construction. [3]
• Site access: show proposed equipment locations, access routes and relevant restrictions for bidders to address. [3]

Ask bidders to identify the design-flow information they need, who will supply it and how it will be validated before and during operation. Calgary calls for minimum, maximum and typical flows, with supporting sources; measured flows require the measurement period, devices, calculations and external data. [3]

Request an integrated schedule covering submissions, approvals, setup, testing, outage start, high-risk work, bypass completion and dismantlement. Calgary requires an integrated schedule and places City approval and receipt of the permit before equipment mobilisation. [3]

Supply project flows, dates, access restrictions and owner interfaces. Mark missing information for clarification rather than allowing bidders to price different, unstated assumptions.

Compare the pump and pipework design

Calgary’s guideline also lists the technical content it expects in a bypass plan. Outside Calgary, the same items give you a common format for comparing how bidders propose to move the flow. [3]

• Pump type and sizing: pumps must be automatic self-priming or prime-assisted, electric or diesel. The plan names the manufacturer, type (centrifugal, submersible), model and power source, with a pump curve showing the duty point and calculations for static lift, friction loss, total dynamic head (TDH) and net positive suction head (NPSH). Submersible pumps are recommended where suction lift exceeds 4 m (13 ft). [3]
• Cavitation margin: the calculated NPSH margin (NPSHa minus NPSHr) must be at least 0.9 m (3 ft), with NPSHr taken from the pump manufacturer. [3]
• Multiple pumps: pumps run in parallel for larger flows and in series for higher head, each with its own stop/start control. Identical pumps in similar condition are usually simplest. [3]
• Redundancy: the plan must show 100% redundancy, including redundant power supplies and secondary pumping that matches or exceeds primary capacity, and state how many of each component stay on site. [3] Toronto’s standby rule, covered under overnight coverage below, sets a similar capacity test. [1]
• Pipework and site: pipe and fitting sizes and capacities, materials, the locations of temporary pipe supports, thrust blocks and restraints, protection for suction and discharge manholes, and noise control for pumps and generators, which matters most for overnight work in residential areas. [3]

Ask bidders to submit these items in the same format so differences in pump selection, redundancy and pipe routing are visible before award.

Make shutdown readiness a documented hold point

Make readiness an explicit tender hold point: the shutdown proceeds after the named owner representative accepts the required evidence. Use the municipal examples below to build that gate, not as interchangeable rules for Canadian projects.

Toronto: acceptance and witnessed testing

Under Toronto’s example specification, construction starts only after City review and acceptance. The Contract Administrator then issues an acceptance letter identifying the City contact and whether a pre-construction meeting is needed. The bypass plan and site-specific spill response plan must remain at the site office or trailer during operations. [1]

The specification requires clean-water leakage testing before operation, with 48 hours’ notice to the City and Contract Administrator. A licensed wastewater collection operator performs the test, witnessed by a Toronto Water licensed operator. Documented hydrostatic testing and a trial run also form part of readiness evidence. [1]

Keep the trigger in context: these provisions concern liner work. Bypass pumping must be installed and operating before the final pre-installation inspection, with capacity and configuration approved before liner installation—not automatically before a sewage-station shutdown. [1]

Calgary: submission, accountability and permit

Calgary’s guideline calls for submission at least six weeks before starting bypass-related work. Following City approval, the Bypass Pumping Permit must be received and a copy delivered to site before equipment mobilises. [3]

Design accountability includes review and signature/stamp by a competent Professional Engineer registered in Alberta and/or formalised accountability through the witnessed Appendix E Accountability Agreement, together with required checklists. The plan must explain how flows will be validated before and during operation. [3]

Build the project’s readiness register

Attach a readiness register to the tender. Require it to record:

• Each required plan, approval, permit, test and checklist.
• The responsible party and required witness or reviewer.
• Acceptance evidence, including signed records and test results.
• Outstanding defects, their resolution and acceptance status.
• The owner-authorised release decision, its date and conditions.

Name the station shutdown’s release authority and acceptance criteria in the tender. Do not assume municipal plan acceptance alone authorises the outage.

Specify overnight coverage, connected standby and response

Toronto’s example contract requires constant monitoring, including overnight, by contractor employees capable of operating the equipment and switching to standby—not remote alarms alone. [1] On liner-installation dates, primary and standby pumps and power supplies must be on site; standby capacity must equal or exceed primary capacity, with standby equipment connected for immediate emergency use. [1]

Turn those distinctions into explicit tender commitments. Ask each bidder to state:

• Staffing: staffed hours, monitor numbers and competence, shift handovers and absence cover.
• Alarm response: who receives and acknowledges alarms, escalation contacts, dispatch arrangements and site-attendance commitments.
• Standby readiness: what remains connected, who checks readiness, and who handles power continuity and refuelling.

Separate alarm receipt, acknowledgement, dispatch, arrival and restoration rather than accepting an undefined “response time”. Winnipeg’s records of incidents illustrate the distinction: one recorded a power alarm at 6:20 p.m., standby-crew dispatch at 6:55 p.m., generator connection at 7:01 p.m. and normal operation after utility power returned at 3:05 a.m. [2] Another recorded power-failure alarm at 10:40 p.m. and temporary-pump crew arrival at 11:55 p.m.; utility power returned before setup was completed. Those times describe Winnipeg’s own incidents and should not be read as supplier service levels. [2]

Require a site-specific spill-response plan naming the people responsible for notifications, escalation and documentation. Toronto specifies City and MECP Spill Action Centre notification provisions and a responsible liaison/documentation person; Calgary requires an emergency spill-response plan kept on site and a 24-hour emergency contact. [1][3]

Calgary’s cited guideline does not establish exact overnight staffing in its available operational provisions. [3] Confirm the applicable owner requirement and write staffing and response commitments into the contract rather than importing Toronto’s rule automatically.

Agree who authorises changeback and accepts removal

Make changeback a separate acceptance step, not simply the end of the permanent works. Name who will authorise the return to normal service, execute it, witness required changes and accept demobilisation. Confirm these authorities with the owner rather than assigning them by assumption.

Toronto’s example distributes those duties:

• Execution and attendance: the contractor stops bypass pumping when no longer required and returns flow to the new or existing sewer; a licensed wastewater collection operator must attend shutdown and flow reinstatement. [1]
• Approval and witnessing: system changes require Engineer approval and witnessing by a Toronto Water licensed operator. [1]
• Removal gate on liner-installation dates: bypass pumps and related equipment cannot be disconnected or removed until service connections are reinstated and post-installation video is recorded. [1]

Toronto also makes flushing with potable water, disposal of residual sewage to the specified sewer, restoration to pre-bypass condition and documented cleanup part of contractual closeout. [1]

Specify handover records. Toronto requires daily flow-control forms emailed to the Contract Administrator and pump-operation, maintenance and fuel-monitoring records when requested; a non-mandatory commentary appendix also describes a change log maintained by Toronto Water’s witnessing operator. [1] Identify who submits each record and who checks it before closing the work.

Calgary requires completion and dismantlement scheduling, but its cited guideline does not identify a changeback authoriser or establish final removal-acceptance details in the available provisions. [3] Put those names, approval steps and release conditions into the project documents before the outage.

Request a complete price and explicit extension terms

Price the assigned responsibilities, not just the pumps. Ask bidders to complete the same pricing schedule:

• Design and approvals: design, engineering sign-off, submissions and approval coordination.
• Getting ready: mobilisation, installation, testing and required witness attendance.
• Outage coverage: duty and connected standby equipment, staffing, overnight monitoring, power or fuel, and emergency attendance.
• Closing out: changeback, removal, cleanup and restoration.

Toronto’s example includes all labour, equipment and material in the contract price and uses lump-sum milestone payments. That shows a contract-pricing model; it gives no market rates for rental, design or monitoring. [1]

Require assumptions, exclusions and charging units against each item. Ask whether overnight coverage is included and which services the owner must supply. Have bidders price these boundaries rather than leave them under “by others”.

What to confirm with each provider

Stormtec says it provides detailed pre-construction estimates, but its cited page does not state prices, minimum terms, cancellation terms, warranty or insurance details. [4] Request a written quotation and contract covering:

• Price and duration: charging units, minimum charges, outage-extension rates, standby or delay charges and remobilisation costs.
• Cancellation: deadlines, charges and refund treatment.
• Contract protections: warranty and insurance details, plus who can authorise additional expenditure.

As a vendor example, Stormtec says it includes redundant backup systems in every sewer-bypass project it manages; compare that claim with the redundancy shown in its project-specific design. [4]

For extension and delay charges, ask when each charge starts and stops, and negotiate these terms explicitly.

Close responsibility and evidence gaps before award

Return incomplete bids for written clarification rather than treating silence as inclusion. For equipment rental, assign the services outside the hire package. For a managed proposal, record precisely which responsibilities the supplier accepts.

Before award, check the contract attachments together:

• Responsibility schedule: each required task has an accountable party, including owner and subcontractor duties.
• Readiness register: evidence, witnesses, acceptance criteria and outage-release authority are recorded.
• Coverage commitments: overnight personnel, standby readiness, emergency contacts and response commitments are explicit.
• Changeback acceptance: authorisation, execution, witnessing and removal conditions are assigned.
• Pricing schedule: inclusions, exclusions, extension charges and cancellation terms are agreed.

Use Toronto’s specification and Calgary’s guidelines as separate examples while confirming the owner’s requirements and local approvals for the actual project. [1][3] Attach the agreed schedules to the contract so the award rests on defined responsibilities and evidence, not a service label.

References

1. Engineering & Construction Services Division Standard Specifications for (toronto.ca)
2. Reports on untreated sewage | City of Winnipeg (winnipeg.ca, 2024)
3. SEWER BYPASS GUIDELINES OCTOBER 2020 (calgary.ca)
4. Pumping Water | Stormtec Bypass | Sewer Bypass | Sanitary Bypass (stormtec.ca)
5. COR and EOCP Certified Water Management Partners | Stormtec (stormtec.ca)