CASE STUDY

Emergency Trunk Sewer Bypass – 3 Sewer Failures, 1 Rapid Engineered Response

SITUATION

While drilling, a contractor struck common manhole combining three fully flowing sewers; 750 mm, 550 mm, and 250 mm. The impact caused immediate sewage overflow into nearby homes and streets, creating a critical emergency that required rapid containment and full bypass support to protect the public, infrastructure, and environment.

The incident occurred within a densely regulated environmental area, requiring fully engineered, calculated, and stamped bypass designs prior to installation. Additional constraints included:

•  Deep suction manholes exceeding 40 ft
•  Restricted discharge manhole capacity
•  High-flow sewers with major peak-hour surges
•  Heavy traffic conditions, with bypass piping required to cross main streets and intersections
•  Severe winter installation and operations, with temperatures reaching -30°C
•  A long, complex, and partially unknown piping route

With multiple sewer systems compromised and no time for delay, Aquatech was mobilized as the emergency response provider to deliver a complete, engineered, and permit-ready bypass solution under extreme conditions.

APPROACH AND OUTCOMES

E N G I N E E R E D  s o l u t i o n s

Aquatech mobilized the same day, deploying materials, pumps, technicians, and installation resources to the site within hours of receiving the emergency call. Simultaneously, our engineering team began immediate design work, developing a complete bypass system and plan for submission to the City.

To maintain uninterrupted flow across all three live sewers, Aquatech engineered a large-scale, multi-point bypass system configured to divert flows from four separate upstream locations into a downstream manhole.

Bypass configuration included:
• Two 12-inch pumps + one 8-inch pump supporting the 550 mm sewer
• Five 12-inch pumps for the 750 mm trunk sewer
• Four 6-inch pumps managing the 250 mm sanitary sewer across two locations

This project demanded the broad mobilization of inventory to ensure uninterrupted bypass performance. To facilitate full isolation of the damaged sections, Aquatech deployed divers into 40 ft–deep sewer structures to install plugs ranging from 24–48 inches.

The resulting engineered design ensured controlled bypassing, safe access for repair crews, and stable management over the entire duration of the project.

M O N I T O R I N G

Given the critical nature of the bypass, Aquatech remained on-site to provide 24/7 pump watch for the entire duration of the bypass period. Continuous monitoring ensured steady flows, rapid response to any changing conditions, and precise pump performance.

Operators tracked pump performance, suction conditions, discharge flows, and system stability while coordinating equipment adjustments in real time. With dedicated day and night teams, Aquatech ensured uninterrupted, reliable operation.

The combination of engineering design, rapid deployment, specialized installation, and round-the-clock monitoring allowed repairs to be completed safely and efficiently.