Gravity Sewer Amplification

About the project

Pensar was engaged to repair damage to existing gravity sewer pipework which was causing repeated blockages. With the site located within a car park, access was tight with high stakeholder impact.


West Gosford, New South Wales

Client & Duration

Central Coast Council
September 2020 - October 2020

Project Scope

  • Excavation and installation of a new gravity sewer with DN225 pipework
  • Installation of three new 1050mm sewer manholes
  • Installation of a DN400mm 60m micro tunnel, install carrier pipework and grout fill
  • Completed two new live sewer manhole connections
  • Dewater excavations of ground water
  • Restored the car parking area and line marking


  • Completing the micro tunnel under multiple services including 11kva power cable to a local substation
  • Dewatering of all open excavations and meeting discharge requirements
  • Site constraints due to the works being completed in an operating car park and business precinct
  • Delivery of the project in a short timeframe to meet all stakeholders’ requirements
  • Multiple sewer bypasses were implemented to complete critical live sewer connections


  • Zero incidents during the delivery of works
  • Successful delivery of a 60m micro tunnel and installation of new gravity sewer pipework and manholes
  • Zero complaints from local businesses or community members due to efficient communication and site management
  • Multiple sewer bypasses were implemented to complete critical live sewer connections
  • Worked closely with the Central Coast Council to meet project timeframes and deliverables
  • Zero sewage spills or environmental incidents

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