Nereda design capacity

  • 4896 m3/d
    Dry Weather Flow
  • 626 m3/h
    Peak Flow
  • 22000 PE
    PE (PE = 60 gBOD/d)

Project facts

  • Client
    Irish Water
  • Licensee
  • Location
    Clonakilty, Ireland
  • Period
  • Wastewater
  • Project type
  • Process configuration
    Pre-treatment + Nereda 

About the Clonakilty Nereda WWTW

Clonakilty, sometimes referred to as Clon, is a town located at the head of the tidal Clonakilty Bay. Clonakilty wastewater treatment plant (WWTP) is sited in County Cork, the second most populous county in Ireland. The municipal plant serves a population equivalent of 22,000.

The challenge

As part of utility provider Irish Water’s €7 million infrastructure investment, Clonakilty was one of 13 sites upgraded in County Cork. The scheme arose from the need to protect Clonakilty Harbour, which is classified as a National Heritage Area, Special Area of Conservation and a Special Protection Area. The old plant also experienced some odour issues which needed to be addressed, due to its capacity being overloaded. In addition to matters of conservation, the capacity of the plant needed to be increased, to enable reliable treatment of a greater volume of effluent, to allow the discharged water quality to be enhanced. This would be beneficial both to locals and visitors to the area.

Ireland Clonakilty | Royal HaskoningDHV

Image: Overview of the Clonakilty WWTP

The solution

The main contractor, EPS Group, was awarded a 20-year design, build and operate (DBO) contract at Clonakilty WWTP. EPS selected Nereda technology for Clonakilty, its first use in Ireland. Clonakilty’s average capacity is now 4896 m³/day, with peak flow capability of 626 m³/hour. The upgraded process combines screening, grit and FOG removal. The award-winning Nereda technology uses aerobic granular biomass and requires much less energy and process stages to produce clean water, while it only needs a third of the footprint of other conventional water treatments.

The outcome

Clonakilty WWTP became operational in 2015. It was the first of a number of WWTPs in Ireland – including the large wastewater treatment plant of Dublin, Ringsend – to use Nereda technology. The new plant helps utilities provider Irish Water meet its requirements under European Union Urban Wastewater Treatment Directive, which endeavours to improve health, water quality and the integrity of the environment, including the environmentally sensitive estuary and a tourist attraction. A key factor at Clonakilty is that the construction of the upgrade is largely underground, to minimise the visual impact of the project on its surroundings. As a result of the implementation of Nereda technology, Cork County Council won the ‘Local Authority Engineering Initiative Award’ at the Engineers Ireland Excellence Awards 2015, for its innovation and creativity.

We are delighted to provide Nereda as the next generation wastewater treatment technology to our clients. Nereda is a cutting-edge development which offers very low cost of ownership to end-users of wastewater treatment plants.

Jim Palmer

Technical director EPS Group


  • Low noise and odour

  • Green and sustainable 

  • Considerable energy savings

  • Greater treatment capacity

  • Minimal chemical use

  • Ensure treated effluent complies with EPA standards

  • Allow for future growth in population and economic development

  • Increase wastewater treatment capacity

  • Resolve odour and noise issues