The basic setup plugs or blocks the pipe upstream of the work zone, captures the flow at a manhole or wet well, and pumps it through a temporary hose or pipeline to a downstream reconnection point past the work area. Sizing the system correctly requires knowing peak flow, pipe diameter, depth, and how long the bypass needs to run. Undersizing it risks the sanitary sewer overflow the bypass exists to prevent.
Bypass pumping is required infrastructure on almost any sewer rehabilitation or repair project. CIPP, sliplining, pipe bursting, manhole work, and point repairs all typically need flow diverted out of the way before work can start. That makes it a near-universal, if often underpriced, line item on sewer bids. Because a bypass failure during construction is itself a reportable overflow event, agencies increasingly specify redundancy requirements (backup pumps, monitoring, and response plans) as part of the bypass plan a contractor has to submit before work begins. Bypass pumping requirements (flow rates, pipe sizes, duration) are driven by the same scope data that determines the rest of a sewer rehab bid. Nonlinear extracts that data from a project's specs and drawings.
