EC2 Residences,
One Crown Place

One Crown Place – 19 Sun Street, London 

Grey Water Recycling System Investigation & Rectification Case Study 

Project Overview 

One Crown Place is a major mixed-use development located at 19 Sun Street on the edge of the City of London, combining premium commercial office space with high-end residential accommodation and retail facilities. 

Designed with a strong sustainability focus, the development incorporates grey water recycling infrastructure intended to reduce potable water demand through non-potable water reuse across the building. 

Indratec was appointed to investigate ongoing operational issues affecting the grey water treatment system and develop engineering solutions to restore reliable long-term performance. 

Grey Water Recycling Scope 

Detailed system investigations identified significant plumbing crossover issues within the building’s water network, resulting in incorrect flows entering the grey water treatment system. 

These cross-connections were causing excessive organic loading within the treatment plant, leading to unstable biological conditions and reduced treatment performance. 

Current Scope Includes 

• System investigation and fault diagnosis 
• Identification of plumbing crossover issues 
• Assessment of hydraulic and organic loading conditions 
• Development of rectification strategies 
• Engineering modifications to improve treatment stability 

Engineering Solution 

Indratec is currently working alongside the project team to engineer practical solutions around the existing building infrastructure and incorrect plumbing configuration. 

The crossover issues within the water pipework network have resulted in unintended flows entering the grey water system, creating elevated organic loading conditions beyond the original treatment design parameters. 

Current engineering works are focused on: 

• Isolating and identifying cross-connections 
• Reducing unintended organic loading 
• Modifying system operation and flow management 
• Improving treatment stability and resilience 
• Developing phased rectification solutions within a live building environment 

Due to the complexity of the existing infrastructure, the project requires a carefully coordinated approach balancing operational continuity with long-term system correction. 

Project Engineering Challenges 

Key engineering considerations include: 

• Incorrect plumbing configuration within existing infrastructure 
• Organic overload conditions within treatment processes 
• Investigation works within an occupied building 
• Limited access to concealed services 
• Maintaining operational continuity during rectification works 
• Developing practical engineering solutions around existing constraints 

Technical Summary 

Project One Crown Place – 19 Sun Street 

Location – City of London 

Building Use – Mixed-Use Commercial & Residential 

System Type – Grey Water Recycling 

Project Scope – Investigation & Rectification Works 

Key Issue – Plumbing Crossovers & Organic Overload 

Current Works – Engineering Modifications & Flow Rectification 

Engineering – Focus Treatment Stability & System Recovery  

Outcome 

Indratec is currently progressing investigation and rectification works aimed at restoring stable and reliable operation of the building’s grey water recycling infrastructure. 

Through detailed system analysis and targeted engineering modifications, the project is focused on overcoming complex plumbing crossover issues and improving long-term treatment performance within a challenging live building environment.