Hanningfield - Sludge Treatment in Reed Bed Systems

The reed bed system at Hanningfield treats sludge using natural methods with environmental, economic, and operational advantages

Creating a sustainable and innovative Sludge Treatment Reed Bed system

Up to 225 million litres of water a day is treated at Hanningfield water treatment works. The sludge wastes from this process have previously been pumped to adjacent sludge lagoons. As these lagoons neared the end of their serviceable life, Essex & Suffolk Water started to look for an alternative and sustainable solution.

They decided to progress with a reed bed system, as this solution could offer substantial financial and environmental advantages. It was an innovative choice. Reed beds had been used for the treatment of sewage sludge since the late eighties, but had never been used for the treatment of sludge from water works.

Essex & Suffolk Water therefore hired the partnership of Orbicon and ARM Limited to create the world’s first reed bed system specifically designed to treat drinking water sludge. A test plant was set up, and following successful test results, Orbicon designed the full-scale plant with 16 reed beds.

The traditional mechanical and chemical methods of dewatering only reduce the volume of sludge. A reed bed system, on the other hand, utilizes natural processes to reduce and treat the sludge. The benefits of this method are:

  • Effective reduction of sludge residue
  • Better working environment
  • Cost effectiveness
  • No use of chemicals
  • Cleaner waste water
  • Low levels of maintenance labour and power
  • Water conservation
  • A positive impact on local nature
  • Good options for recycling, e.g. as fertilizer on agricultural land

From the water works plant, an underground pipe delivers sludge to the reed beds. The beds then naturally filter the sludge, and clear filtrate water is returned to the reservoir for re-use. On its journey back to the reservoir, the water flows into Great Prestons lagoon, where it helps sustain valuable habitat and wildlife. The Sludge Treatment Reed Bed system is a long-term solution, as solid residue is retained on the surface of each reed bed for a 15-20 year period, after which it is excavated for land application.

 

Steen M. Nielsen

Product manager
+45 40 21 22 51

A history of expertise in Sludge Treatment in Reed Bed systems

Orbicon designed the Sludge Treatment Reed Bed system, and was the consultant for the operation of the plant from 2008 to 2015.

As an expert in sludge treatment in reed bed systems, Orbicon has constructed plants in e.g. Australia, Sweden, New Zealand and the UK. We have also designed many of the reed bed systems in Denmark, where 25-30 % of sludge is treated using this method. Orbicon started developing and testing reed bed systems more than 25 years ago, and our design has proven reliable and effective throughout the years.

The EU framework directive calls for cleaner discharges from our wastewater treatment facilities. This can result in more sludge due to the improved treatment, but managing sludge can be costly. Reed beds are therefore a sustainable solution to this challenge, as they provide a natural, reliable and cost-efficient system.

Orbicon is a founding member of Global Wetland Technology, a consortium of companies in the environmental engineering sector, who specializes in wastewater treatment. As such, we are a part of a great body of knowledge and breadth of experience within constructed wetland technology.

Reed beds are a cost-effective and environmentally sustainable solution, creating a win-win situation for both investors and nature

Project
Client
Essex & Suffolk Water (part of Northumbrian Water)
Number of reed beds
16
Total reed bed area
4.2 ha (10 acres)
Location
Hanningfield (Essex, England)
Capacity
1,275 tonnes of dry solids annually
Year
2012
Team
Turnkey contractor
ARM Limited
Competencies
Role
Design and operations consultant
More than 25 years
of working with reed bed systems
Thorough knowledge
within sludge treatment
Extensive experience
in the operation and emptying of reed bed systems