Background

@One Alliance is Anglian Water’s collaborative delivery partnership, responsible for improving efficiency, quality and performance across wastewater infrastructure investment.

In late 2010, the Wastewater Infrastructure (WWI) team undertook a detailed review of rework, cost and delay data across multiple schemes. This analysis demonstrated that traditional manhole and inspection chamber construction methods were frequently:

  • Time consuming
  • Labour intensive
  • Prone to leakage and defects
  • A recurring cause of rework and delayed handover

This prompted a strategic shift towards identifying modern alternatives that could deliver consistent quality and reduce whole life cost and carbon impact.

The challenge

The WWI team identified a clear need for:

  • Leak free chambers with the correct level of access
  • Reduced reliance on in situ wet trades
  • Faster installation and improved programme certainty
  • Lower embodied carbon compared with traditional construction
  • Solutions compatible with modern construction methods
  • A standardised suite of products usable across multiple scenarios

Any proposed solution needed to be robust, simple, repeatable and suitable for approval at asset standard level.

The solution

A Process Improvement Team (PIT) was established by @One Alliance to review available solutions and identify best in class products.

Following market assessment, the Marshalls Sealed Manhole system was selected as the preferred solution. The system addressed all identified challenges by offering:

  • A factory manufactured, fully watertight chamber
  • Elimination of in situ bases, benching and surrounds
  • Consistent quality through off site manufacture
  • Reduced waste generation and wet trade activity
  • Lower embodied carbon compared with traditional construction

The sealed manhole system was trialled across operational teams and subsequently reviewed by the Asset Standards Forum (ASF).

The outcome

The Marshalls Sealed Manhole system was fully approved by @One Alliance and the ASF, becoming a recognised solution for use across wastewater infrastructure schemes.

  • Improved construction quality and consistency
  • Reduced rework and handover delays
  • Faster installation and programme certainty
  • Lower carbon and environmental impact
  • Strong endorsement from delivery and operational teams

Nick Jarvis, Product Manager at @One Alliance, commented:

“Where a fully developed solution was available, we selected the best in class product. In this case, the Marshalls sealed manhole was fully successful, drew praise from all levels of the construction team, and is now fully approved by the Asset Standards Forum.”

The endorsement represents a significant shift towards standardised, off site manufactured access solutions across Anglian Water’s wastewater programme.