CLIENT: Donegal County Council

  • Led consortium for €55million contract
  • €22.5million Design and Build contract completed
  • Operation and Maintenance contract for 20 years from 2013 
  • Waste water treatment plant 
  • Sludge centre 
  • Population equivalent: 80,000

The Brief

Donegal Co. Council sought tenders for a DBOM Contract to provide the necessary treatment facilities at Letterkenny to treat an ultimate population equivalent of 80,000 (40,000 loading for biological treatment). The initial Letterkenny WWTW at Maghernan was treating a population equivalent of 25,000. The plant was severely overloaded and a new plant was required to treat an ultimate population equivalent of 80,000. Response Engineering as lead bidder in a joint venture with Severn Trent Services International and Ward & Burke, was the successful bidder.

The Operations and Maintenance Contract will run for 20 years from 2013.

The Solution

As service provider we designed, constructed and commissioned a new WWTW comprising Inlet Works, Primary Settlement, Activated Sludge Reactors, Final Clarifiers and UV Disinfection unit. We also provided a new influent main pumping station and a final effluent pumping station with rising main and outfall to the estuarine reach of Lough Swilly. A facility for treatment of solid waste leachate was included. We also provided a Sludge Treatment Centre comprising Reception Facilities for imported sludges, Gravity Belt Thickeners for biological and waterworks sludges, Holding Tanks, Digestors, Dewatering Centrifuges, Thermal Drier and ultimately sustainable disposal outlets for treated biosolids.

Our contract includes for the operation and maintenance of all facilities for a period of 20 Years in accordance with a Performance Management System based on the WSNTG model.

Chairman's Review

Speaking on behalf of Response Group, Chairman Noel Hanley said “We are immensely proud of the finished development and the performance of Response in delivering this prestigious project on time and within budget. The scheme is designed to the highest standards and built accordingly. Response demonstrated once again its expertise in the Design, Build and Operate field in completing this complex project. We look forward to working with our partners Severn Trent Services during the Operational phase.  Many thanks to the Response team and other stakeholders, particularly Donegal CC, Severn Trent Services, Ward & Burke and Nicholas O' Dwyer for the integrated and professional team approach, which was a hallmark of the scheme throughout”

Additional Information

PROCESS SUMMARY:

  • Wastewater Pumping
  • Screening/Grit Removal
  • Stormwater
  • Primary Settlement
  • Carousel Aeration
  • Final Clarifiers
  • UV Disinfection
  • Sludge Reception Centre
  • Sludge Holding
  • Belt Thickening
  • Centrifuge Dewatering
  • Sludge Digestion
  • Thermal Drying
  • Biosolids Disposal
  • Odour Control
  • ICA/SCADA

STANDARDS: 

WASTEWATER

  • BOD : 25mg/l
  • COD : 125 mg/l
  • SS : 35 mg/l
  • NH3 : 5mg/l

SLUDGE

  • Faecal Coliform (MPN/gDS) : <1000
  • Salmonella (MPN/4g/DS)      : < 3

© Response Group 2013

Main Office: Response Group, Railway Road, Charleville, County Cork, Ireland