COMHAIRLE CONTAE ÁTHA CLIATH THEAS
SOUTH DUBLIN COUNTY COUNCIL

south dublin county council crest

MEETING OF SOUTH DUBLIN COUNTY COUNCIL

Monday, July 12, 2010

QUESTION NO.3

QUESTION: Councillor E. Coburn

To ask the Manager to outline the expected completion date of the Boherboy Water Supply Scheme?

REPLY:

The Boherboy Water Supply Scheme involves two separate Contracts –

  1. Contract No.2: Civil Works by Pierse Contracting and
  2. Contract No.3: Mechanical & Electrical Works by Earth Tech (ETIL), who have since been taken over and now trade as AECOM.

The commencement of the latter contract has been programmed to interface with progress milestones under the civil contract as the main mechanical and electrical equipment is housed within the main pumping station, reservoirs and chambers constructed by the civil contractor.

The Boherboy Water Supply Scheme is nearing substantial completion in physical structural terms and the following synopsis outlines the substantive work items which may have a more physical and practical impact on the Public.

Pipelaying by the civil contractor on this project involved laying over 41km of pipe of varying sizes ranging from 1600mm to 150mm diameter in open cut trenches in roads, parklands and private fields, along with pipe-jacking under the N7 at Kingswood and thrust-boring in Rathcoole and in Scholarstown. Scheme completion shall enhance water supply across the county from Newcastle in the west to Rathfarnham in the east and the more elevated areas to the south of the county including Kiltipper, Ellensborough, Oakdale, Stocking Wood and parts of Edmonstown.

At present there are short sections of pipelaying to be completed

The outstanding pipelaying enumerated above amounts to about 2.2km of the overall 41km scheme length (i.e. 5%) and comprises approximately 1.3km of pipelaying in roads, 0.4km in green spaces and 0.5km in privately owned fields.

All road closures obtained by the project contractor are discussed and sanctioned by the Roads Department, Traffic Section of South Dublin County Council. It should be noted that pipelaying along Kiltipper Road Upper is currently in progress under a 6-week road closure from 24th May to 2nd July. Pipelaying along Stocking Lane has been deferred  until after the statutory school exams and is now proposed to be carried out under a 5 week road closure from 3rd August until 6th September. The section of pipeline crossing the old N7 at Kingswood is also to be carried out under a road closure from 21st June until 9th July. This latter road closure has been considered necessary due to the scheme watermain passing directly under a Bord Gais high pressure gas main along with a myriad of other public utility services at this location. Disruption to the public arising from road closures and the works generally is regretted, but upon the scheme’s completion, South Dublin County Council will have an improved modern water network which shall enhance the Council’s delivery of water service to customers across a wide section of the County – from Newcastle to Rathfarnham as previously outlined above.

In tandem with the remaining pipelaying, the swabbing and disinfection of sections of previously laid mains will be undertaken in advance of mains becoming ‘live’. Chamber construction to house key operational valves, flowmeters and pressure reducing valves on the various sections of pipe route is progressing. In addition, outstanding connections of the scheme where newly constructed assets connect to the existing Council watermain network will be undertaken by the Council’s own Water Maintenance Section in keeping with Council practice.

The Civil Contractor’s latest programme of works is targeted for completion of the above items by early October 2010 in conjunction with other minor outstanding items.

In parallel with the above physical works in roads, parklands and areas impacting directly on the public, telemetry installation works will also be carried out at over 50 locations across the scheme with the physical installation of kiosks, ducting and cable pulling due to be completed in October 2010. This will then be followed by a commissioning phase which is dependent upon the provision of power supply by ESB/Energia and phone connection by Eircom. The commissioning phase should be completed by the year end and is reliant on the timely delivery of power supply and phone connection by each utility.

Reinstatement of grass areas, which is highly weather dependent, is currently in progress and it is anticipated that the reinstatement of all green areas will be completed in the current growing season subject to the proviso that significant inclement weather is not encountered. The very bad weather of 2009 disrupted the reinstatement work across the entire scheme and impacted on planned progress and has regrettably resulted in a large proportion of this type of work having to be deferred to this year. The project has been fortunate that progress to date has been greatly assisted by Parks Department which has assisted with reinstatement works in several of their own Parklands.

Civil works that are confined to the main reservoir sites at Saggart and Kiltalown are continuing and should be completed this autumn. This work includes completion of reservoir construction, service ducting, telemetry installation, site roads, site lighting and associated security CCTV installation and landscaping at these two reservoir locations.

The Mechanical & Electrical Contractor, AECOM, recently commenced work on site and good progress has been made to date within the Saggart Site Pumping Station. Their scope of works comprises the design, manufacture, supply, installation, testing and commissioning of pumps and their associated pipework and valves, electrical plant installation, power and instrument cabling for items such as flow meters, pressure gauges and level instruments, computer based control systems for overall scheme control, operation and supervision through the main scheme control panel and chemical monitoring systems.

Whilst it is anticipated that much of the physical construction and installation work will be substantially completed this year, it is envisaged that the scheme commissioning may continue in early 2011 with final handover of the entire scheme in March 2011. Both contracts are subject to 12 month maintenance / defect liability periods.