Plant and process improvements at an EFW facility

- Eco Park Surrey case study -

Developing a holistic strategy to provide plant and process improvements

The issue

The innovative facilities of Eco Park Surrey were built between 2015-2017. They were constructed to process household waste to generate power for the national grid, enable recycling and reuse as well as to provide fertilizer for farming; thereby supporting a sustainable planet agenda. As each facility at the Eco Park was completed it underwent a period of commissioning to ensure it operated in the way it was designed and as efficiently as possible.

The Eco Park team approached Aqua Enviro to provide technical and commissioning support. Aqua Enviro, a SUEZ company, reviewed a wide range of issues that required attention – grit accumulation in the anaerobic digesters, plastic contamination of the biofertiliser, power generation downtime due to H2S presence in the biogas, struvite and suboptimal digester performance.
The solution

Aqua Enviro brought together a team of technical experts to develop a holistic strategy to address the various issues. As an initial step the team began daily on site sampling and analysis to develop performance benchmarks against which the benefits of our interventions could be assessed.

Examples of the subsequent remediation activities include:

  • Performance enhancement using FMEA (failure mode effect analysis) studies
  • A full review of the plant design
  • Recommendations to procure and incorporate additional systems, with additional commission support
  • The plant capacity was enhanced by implementing a system upgrade to a MBR (membrane bio reactor)
  • Addressing the struvite scaling issues in order to enhance operational life of the plant as well as its reliability while at the same time reducing maintenance downtime.

The role grew through the project from one of ‘hands off’ advisory role to become fully integrated into the dayto- day management and operation of the plant and its process.

Key deliverables

✓ Enhanced plant throughput 

✓ Reduced operational costs

✓ Maximised power generation

✓ Reduced waste disposal and emissions

✓ Enhanced digestate cake quality

✓ Reduced struvite scaling

 ✓ Optimised plastics removal

✓ Reduced maintenance downtime

The results
  • Enhanced plant capacity by 50%
  • Reduced environmental emissions and costs by removing the need to tanker up to 100m3/d of waste for off-site processing
  • Takeover test requirements of 40,000 tonnes of waste processed per annum were met
  • Client saved c.a. £1.1 million from reduced waste tankering over 9 months
  • Reduced maintenance downtime by 30%
  • Process steps for removing plastics were optimised, enhancing the quality of the final biofertiliser product
  • Short and long term strategy to mitigate H2S presence thereby overcoming power generation issues.


1.1 million

in savings over nine months

Differentiating factors

Aqua Enviro has a the breadth of sector expertise and capabilities which enables them to rapidly adapt the support to each client’s situation as it evolves.

The consultancy has a highly collaborative approach working with the client’s teams, data provision and facilities. They provide strategic, technical and operational guidance to ensure their client achieves their goals be they sustainability, financial & operating efficiencies and/or regulatory and contractual compliance.

The future

The Aqua Enviro consultancy team has a long standing relationship with Eco Park Surrey continuing to provide remote data and performance monitoring to ensure the continued delivery of all technical and commercial objectives.

Great approach to problem solving with a desire to work in partnership with the client.

Justin Hampton-Plant Manager, Eco Park Surrey