IndustryFood Production

CategoryWastewater Treatment Plant Upgrade

CompletedSafely, on time and budget

errigal bay seafood

Project Description


Errigal Bay Seafood, Carrick, Co. Donegal.

In preparation for expansion Errigal Bay focused on sustainability, environmental impacts, and optimising performance. Nutrient removal capabilities were also important to minimise waste on their existing Wastewater Treatment Plant (WWTP).

In conjunction with Udaras Na Gaeltacht Errigal commissioned WEW Engineering to carry out a survey and assessment of the WWTP and prepare a report identifying the upgrade options available to ensure increasingly strict nutrient discharge limits assigned by Errigal and their personal goals.

The required capacity and quality needs were identified as follows:



The existing WWTP was configured as a standard Activated Sludge (AS) Plant which while capable of providing high-quality effluent was restricted in capacity in terms of nutrient removal. In order to meet the tighter discharge limits the existing Plant needed to incorporate the following unit operations:

  • Inlet Screening
  • pH Correction
  • Balancing and Equalisation
  • Single Stage Aeration System
  • Secondary Clarification
  • Chemical Phosphorous Reduction
  • RAS/EAS sludge Pumping
  • Sludge Thickening and Dewatering


WEW were engaged initially to provide a report on upgrade options. However, on request of Errigal undertook the roll of full Engineering Procurement and Construction Management (EPCM) Service Providers for the Project. This involved developing the detailed design and engineering requirements, asset and condition surveys including process assessment, tankage, pumping, mechanical and electrical plant and equipment consideration.

water treatment

Project Scope

  • Site appraisals, assessment of existing assets
  • Process selection study and report
  • Preparation of process and instrumentation Diagrams (P&ID’s)
  • Full process, mechanical and ICA design
  • Preparation of detailed drawings and tender documents
  • Full Procurement Services (incl. Tender evaluation)
  • Duties of PSDP & PSCS
  • Full construction management and site supervision
  • Technical support up to commissioning and handover


The upgrade of the existing plant incorporating the following:


  • New Anoxic Tank and Splitter Chamber
  • New Fine Bubble Diffused Aeration (FBDA) system (inc Air Blowers)
  • New Final Clarifier
  • MLSS and RAS/EAS Recycle Pumping
  • New Flocculation/Mixing tanks
  • New Tertiary MicroScreen System
  • New Electrics including MCC and VSD Drives
  • New PLC/HMI Plant Control System

Projects Outcomes

WEW Engineering acted as EPCM Consultant, in conjunction with O’ Donnell Brothers Ltd for Civil works, McDevitt Engineering Ltd for Mechanical works, CSL Ltd for Electrical works and ICA. The Plant upgrade was completed and commissioned on schedule with successful biological nutrient removal being achieved. The limits were met despite the seasonal load and temperature variations. This enabled the Client to pursue sustainability and reduction of their environmental impact, while continuing to grow the business and expand the product range.


waste water treatment plant

Innovative Water, Energy & Wastewater Solutions

Contact Us