Sanitary Sewer Installation

A pipe laser establishes the working line and slope from a confirmed downstream invert, while survey checks verify maintenance-hole inverts and intermediate pipe elevations. Harrowgate also inspects bedding and bell relief so the pipe does not settle after the laser check. Instrument setup is rechecked after movement, impact, or a long interruption.

Common causes are disturbed bedding, soft trench bottom, incorrect laser setup, pipe movement during embedment, inadequate haunch compaction, groundwater loss of fines, or differential settlement at a structure. Harrowgate controls the base, confirms grade progressively, balances sidefill, and reviews CCTV so a sag is corrected before final surface restoration.

The municipality and specification determine the required combination of CCTV, visual inspection, infiltration or exfiltration testing, low-pressure testing, deflection measurement, maintenance-hole testing, and cleaning. Harrowgate prepares isolated reaches, supplies access, corrects defects, and repeats failed tests. Acceptance records are tied to the exact reach between identified structures.

Only through the approved municipal or private connection detail and permit. The main material, diameter, condition, flow, connection fitting, lateral angle, elevation, and sealing method must be confirmed. Harrowgate exposes and measures the main, protects downstream flow, makes the approved connection, and records it before backfill.

Bypass is required when work would interrupt active wastewater flow or expose a connection that cannot safely remain live. The plan considers peak flow, solids, redundancy, power, alarms, hose routing, discharge point, containment, and emergency response. Harrowgate coordinates the approved setup with the owner before isolating the existing sewer.

Pipe and concrete structures can settle or move differently. A gasketed flexible connector maintains a watertight interface while accommodating limited differential movement, reducing the chance of a cracked pipe or open annulus. Harrowgate installs the specified connector square to the wall and controls bedding and compaction at the structure transition.

Provide plan and profile, pipe material and stiffness, maintenance-hole schedule, bedding details, connection information, municipal specifications, groundwater data, bypass flows, testing and CCTV criteria, environmental approvals, excess-soil requirements, traffic staging, and restoration sections. Reliable existing inverts and building outlet elevations are essential for assessing constructability.