Facts & Figures

 ClientUnited Utilities
 LocationBlackburn, UK
 Operation Start2021
 Project TypeGreenfield
 Process ConfigurationPre-treatment + Nereda + Cloth filtration + UV
 Nereda Design Capacity:
  • Dry Weather Flow66 MLD
  • Peak Flow12,053 m3/h
  • PE321,500 PE (PE = 60 gBOD/d)
 In the Media:Utilityweek - United Utilities to install Europe’s largest Nereda plant
 Utilityweek - United Utilities to roll out Nereda treatment technology
 Lima team wins £165M water projects
 Europe’s largest purpose-built Nereda® process plant at Blackburn WwTW
 UK Water Projects - Blackburn and Darwen WwTWs (2019)

About Nereda® at Blackburn wastewater treatment works

Blackburn is a town in Lancashire, England, to the North of the West Pennine Moors on the southern edge of the Ribble Valley. It is 34 km north west of the city of Manchester.


As part of £100 million infrastructure upgrade, United Utilities identified a need to provide improved effluent quality to protect the bathing waters and shellfish waters at Blackburn, and replace the life-expired existing wastewater asset. In addition to the flows coming from 450,000 p.e. the works also needs to be able to treat effluent from a nearby brewery and sludge return liquors from the on-site digestion plant.


On behalf of United Utilities, construction partner LiMA selected Nereda technology to meet the stringent effluent quality requirements at this works. With its high-quality effluent standards and small footprint, the Nereda process provides United Utilities with an innovative, reliable, efficient and sustainable solution. The new plant will work on gravity from the existing pre-treatment plant at Nabs Head, where it flows via an aqueduct to the main Blackburn works. At the works six 12,000 m³ Nereda reactor tanks will be installed, along with two sludge buffers for waste sludge thickening and a water level correction buffer. The Nereda reactors will have the capacity to treat 430,000 p.e. with a peak flow of 12,090 m³ wastewater per hour.


The project is due to be fully operational by March 2021 to meet statutory requirements and when complete will be Europe’s largest purpose built Nereda installation to date, with a total Nereda volume of 72,000m³. The first phase of the Nereda installation will be complete by 2020. When commissioned, the new Blackburn installation will treat wastewater from Darwen, allowing the existing works to be decommissioned. The project will deliver improvements to the local watercourses that are tributaries of the River Darwen, which feeds into the River Ribble and UV disinfection will protect downstream bathing and shellfish waters.

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The local benefits of the project

Nereda logo small Improved wastewater treatment
Nereda logo small Sustainable solution
Nereda logo small Environmentally compliant
Nereda logo small  Enhanced capacity
Nereda logo small  Streamlined efficiency