Sewer bypass pumping is a critical solution during maintenance, repair, or replacement of sewer lines and pump stations. By temporarily diverting flow, it ensures uninterrupted service to the community while allowing safe access for crews to complete works.
Critical Operation
Sewer bypass failures can result in environmental contamination, regulatory fines, and public health emergencies. Redundancy and monitoring are essential.
Why Sewer Bypass Is Needed
Pipeline Maintenance
When sections of sewer are isolated for cleaning, lining, or repair
Pump Station Upgrades
During refurbishment or replacement of pumps, valves, or controls
Emergency Response
Handling overflows caused by blockages, storm events, or equipment failure
Regulatory Compliance
Preventing untreated sewage discharges into waterways
Key Challenges
Continuous Flow
Systems often run 24/7 with no tolerance for downtime
Variable Inflows
Peak demand during wet weather or high usage periods
Solids Handling
Raw sewage contains rags, grease, and debris that can clog pumps
Site Constraints
Urban worksites often have limited space and noise restrictions
Environmental Risk
Spills or leaks can cause major fines and reputational damage
Pump Selection for Bypass Applications
Diesel Auto-Prime Pumps
Capable of handling fluctuating flows, solids, and air entrainment. Reliable for long-duration runs.
Dry-Prime Trash Pumps
Specifically designed for raw sewage and solids-laden fluids with large solids passage.
Submersible Pumps
Used in confined spaces or wet wells, often as assist or standby units.
Redundancy Required
Always size with standby units (N+1) to ensure uninterrupted operation.
Step-by-Step Setup
Site Assessment
- Survey sewer flows and peak demand
- Identify suction and discharge points
- Review environmental and traffic management requirements
Equipment Selection
- Choose pumps with solids-handling impellers
- Size pumps for peak flow, not average flow
- Include at least one standby pump for redundancy
Pipework & Connections
- Use temporary HDPE pipework or lay-flat hoses for discharge
- Ensure secure connections with quick-release fittings
- Bypass around the isolated section safely and efficiently
Setup & Commissioning
- Position pumps above flood level and on stable ground
- Prime pumps and test suction/discharge connections
- Run a full-flow test before isolating sewer line
Operation & Monitoring
- Use flow meters and telemetry for remote monitoring
- Keep trained staff onsite for routine checks
- Monitor suction strainers for rags and blockages
Best Practices
Always build in redundancy (N+1 pumping capacity)
Design suction lines to handle solids – use larger diameters and minimise bends
Use sound-attenuated enclosures in residential areas to meet noise limits
Provide spill containment and bunding for diesel-driven units
Establish an emergency response plan in case of overflow
Environmental & Compliance Considerations
Permits Required
Obtain permits from local water authorities before bypass works
Spill Prevention
Use secondary containment systems to prevent contamination
Waste Disposal
Dispose of screenings and solids according to regulations
Documentation
Record flow rates, pump performance, and compliance checks
Summary
Key Takeaways
- Careful planning – assess flows, site constraints, and regulatory requirements
- Reliable pump selection – choose solids-handling pumps sized for peak flow with N+1 redundancy
- Strict environmental safeguards – spill containment, permits, and proper waste disposal
- Continuous monitoring – telemetry, trained staff, and emergency response plans