Stage 2 - Kilsellagh Water Treatment Plant Design Objectives

• To Provide for the Construction of a new Water Treatment Works in Accordance with the EU (Drinking Water) Regulations, 2000 S.I. No. 439 of 2000, replacing existing facility which was provided in 1970 comprising microstraining and chlorine and fluorine dosing
• To ensure compliance with the maximum admissible concentrations (MAC) for colour, manganese and iron and to eliminate the threat from concentrations of trihalomethanes (THMs)

Kilsellagh Water Treatment Plant

• Safe yield 1976 Preliminary Report, 5,800 m3 /day
• Proposed Design 4,540 m3 /day working in tandem with the new treatment works at Foxes Den and Carns Hill
• Present Demand 7,200 m3 /day or 124% of Safe Yield
•  6,380 m3 /day to Sligo Urban
• 820 m3 /day to Rosses Pt, Ballincar
• Planning Permission 400 m3 /hr with a min. capacity of 4,540 m3 /day granted 4th Oct ’02
• The Plant will have the capacity to deliver 8,000 m3 over a 20 hr period with the provision of a 2,200 m3 storage reservoir
• This reservoir is supplemented by the existing storage reservoirs at Faranacardy (5,860 m3), Cregg (545 m3) and Rosses Pt (1,300 m3)

Project Update

• Review of PR (August 1999)
• Review of Water Quality and demand projections
• Review of Statutory Approvals and CPO
• Site Investigations
• Risk Assessment
• Preparation of Contract Documents (Performance Specification)
• WSPP Report for all stages
• Project Supervisor Design Stage
• Pre-Qualification
• Tender Process and Assessment
• Review of Contractor’s Submission
• Contract Supervision & Reporting
• Payment Certification & Final Account

Project Goals

• Treatment Works (400m3/hr) by DBO Contract
• Complete access road from Kilsellagh Dam Site
• Connection to new pipelines, upstream and downstream
• Provide Service Reservoir (2,200m3)
• Provide for Booster Pumping Station for GWSS
• 20 Year Operate & Maintain Period

DBO Contract Issues

• Water Demand Projections
• Robust Raw Water Characterisation
• Performance Standards
• Risk Assessment / Allocation
• Detailed Site Investigations
• Statutory Approvals
• Environmental Issues
• Safety

DBO Procurement Issues

• Prequalification Procedure
• Vitally Important
• Robust Technical and Financial Assessment of Candidates required

Tender Assessment

• Generally 3 months minimum
• ROBUST !! – could be challenged
• Whole Life Costs

Water Services Pricing Policy

Charging Structure

• Circulars Consolidated L16/02
• Industry / Commercial

Capital Cost

•  Water Treatment Plant
• Reservoirs & Booster Stations
• Pipelines

O&M Cost

• Water Treatment Plant
• Pumping Stations
• Capital Replacement Fund
• Model Agreements
• Impact on Local Authority Financing

Water Demand Projections

• Gravity Source
• Safe Yield 5,800m3/d
• Current Output 7,200m3/d
• Nominal Rated Output 4,540 m3/d
• Maximum Design Output 400m3/h
• (8,000m3/d winter)

Raw Water Characterisation & Treated Water Standards

• Water Sampling Programme 1990 / 1991
• A2 Quality Source
• S.I No. 439 of 2000
• Initiate New Raw Water Sampling Programme Sept ‘04
• Colour, Iron and Manganese Issues
• Cryptosporidium
• Organophosphates
• THM formation
• Plumbosolvency Control

 
Possible Treatment Technologies

• Jar Tests 1990/1991
• Pilot Plant Testing 1996/1997
• Membrane Filtration
• Ozone
• Catalytic Media Filtration
• Activated Carbon
• MIEX (Magnetic Ion Exchange)
• DAF

  
Risk Allocation

Contractor

• Design 
• Construction
• Time & Cost Overruns 
• Ground Conditions 
• Inadequate Designs   

Employer 

• Planning 
• Site Acquisition 
•  Deterioration in Raw Water
• Change in Water Quality 
   

Site Investigations

• Steep site, drop of 16m
• Site Investigations complete 1998
• Comprehensive set of results
• Review existing results
    

Statutory Approvals & Environmental Issues

• Planning Permission
  • 4th October 2002 for Treatment Works
  • 8th February 2003 for Access Road
• Discharge Licence - 21st December 2001
• Compulsory Purchase Order - Confirmed March 2003
• Protection of Raw Water Reservoir
• Tree Protection
• Fish Life