vartry water supply project a major upgrade to a 150 year ......• the stillorgan reservoir upgrade...

Vartry Water Supply Project

A major upgrade to a 150 year old scheme

Geoff O’Sullivan, Programme Manager

Ireland Water Conference 2nd April 2019

• The Vartry Supply Scheme delivers drinking water to over 200,000 people in

Wicklow and Dublin.

• The scheme provides in the region of 15% of the domestic, commercial and

industrial water needs of the Greater Dublin Water Supply Area.

• The scheme was built in the 1860s and was a huge feat of engineering with

much of the work being completed by manual labour.

• The scheme is currently on the Environmental Protection Agency’s (EPA)

Remedial Action List (RAL) which identifies supplies that are in urgent need of

improvement.

A major upgrade to a 150 year old scheme

2 Vartry Water Supply Project

• A new water treatment plant on the site of the existing plant at Vartry

• A pumping station and a 4km pipeline to secure the transfer of treated water from Vartry to Callowhill

• Upgrading the Stillorgan Reservoir

• Upgrades to the reservoir spillway and control systems to ensure public safety

Overview of the Project


1History

• Dublin population increased by 58% to 258,000 from 1800-1850

• Serious Public Health issues

• Water supply was from the Canal system and canal companies were unwilling to improve their supply

• The Vartry Scheme was recommended by a Royal Commissioner in 1860

• In 1861,The Dublin Corporation Waterworks Act was passed in face of fierce opposition from the Canal Companies. This success is credited to John Gray, Chairman of the Waterworks Committee

• In 1862 the tender of William McCormick to construct the works for £274,000 was accepted

• Works were completed in 1868

History of the Vartry Water Supply Scheme


• The scheme consisted of an impounding reservoir and filter beds near Roundwood; a 4 km long tunnel; a 28 km long 33-inch diameter pipe to two service reservoirs at Stillorgan and two 27-inch diameter pipes from Stillorgan to Dublin City

• In November 1862 the first stone was laid at Stillorgan Reservoir and supply of water to Dublin commenced in early 1868

• The scheme greatly improved sanitation in Dublin City and helped reduce outbreaks of cholera, typhus and other diseases associated with contaminated water

Construction


Stillorgan Screen Chamber

Construction


Moving Pipes at Stillorgan

Pipe laying near Kilmacanogue

History


Construction of the Stillorgan screen chamber

2Vartry to Callowhill Link

• Treated water flowed through a rock lined tunnel from the Vartry Water Treatment Plantto Callowhill.

• Groundwater was infiltrating into the tunnel; and

• The tunnel was at risk of failure and a replacement connection was required to secure the water supply to over 200,000 people in Wicklow and south Dublin.

The Need for Change

10 | Vartry Water Supply Project

Need for Change – Tunnel Infiltration


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Rain (mm) Infiltration (Ml)

• A new pumping station at the existing

Vartry Water Treatment Plant;

• 4 kilometres of pipeline from Vartry to

Callowhill;

• Two break pressure tank;

• An electrical distribution building; and

• An energy recovery building.

• Construction commenced in January

2018 and the new pipeline was

opened by Minister Eoghan Murphy in

February 2019.

Vartry Callowhill Link

12

Pipe Stringing – Callowhill Link Pipeline


Vartry Pump House


Break pressure tank & energy recovery building at Callowhill


3Water Treatment Plant Upgrade

• The Vartry Water Treatment Plant provides over 200,000 people with drinking water. It is currently on the Environmental Protection Agency’s (EPA) Remedial Action List (RAL) which identifies supplies that are in urgent need of improvement.

• There are two items that need to be addressed at Vartry

⎻ Security of supply

⎻ Drinking water quality.

• The security of supply from Vartry is at risk due to the algal (diatom) blooms which can occur from March to May each year which can reduce the amount of drinking water that the plant can output by over 50%.

Need for Change


Effect of Algae on plant output


Treatment Plant Leakage


Valve and Pipe Issues


Existing Dam Pipework - Vartry


• Replacement of Dam pipework

• New siphon

• Spillway will be upgraded and deepened

• New water treatment building (4670 m²)

• New sludge holding tanks.

• Decommissioning and landscaping of 7 No. of existing slow sand filter beds.

Proposed Upgrades - WTP

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• Construction commenced in Autumn 2018

• The construction of the new water Treatment plant schedule for completion in 2020

Vartry WTP - Project Roadmap Construction Phase


4Stillorgan Reservoir

Stillorgan Reservoirs

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• The reservoirs at Stillorgan store treated drinking water from water treatment plants at Vartry in County Wicklow and Ballymore Eustace in County Kildare.

• These reservoirs are open to the environment which is not in accordance with current best practice as it presents quality risks to the water supply.

• These risks are being managed, however, they will need to be eliminated through the covering of the stored drinking water. This will ensure a sustainable and secure supply of drinking water for the region.

Need for Change


• The Stillorgan Reservoir Upgrade

Project includes:

⎻ Draining the Gray Reservoir and constructing

a new covered reservoir and control building.

⎻ Once the new covered reservoir is

operational the Upper and Lower Reservoirs

will be drained and decommissioned. The

decommissioned areas will be reserved for

future water services facilities.

⎻ Landscaping the decommissioned reservoir

areas in accordance with a landscape

masterplan.

⎻ Pipeline modifications within the reservoir

site.

Proposed Upgrades - Stillorgan


Stillorgan Reservoir – Project Roadmap (Construction Phase)


Stillorgan Landscape


Existing

Vista

Proposed

Vista

5Summary

Project Roadmap


Link Pipeline

• Planning granted on 8th Jan 2018 subject to 9 conditions

• Procurement in parallel with planning phase

• Construction start Jan 2018 – Completed Dec ‘18

WTP

• Planning granted on 8th Jan 2018 subject to 9 conditions

• Procurement in parallel with planning phase– 2017 / 2018

• Construction Start Nov ’18 – completion date 2020

Stillorgan Reservoir

• Planning granted on 21th Dec 2017 subject to 6 conditions

• Procurement in parallel with planning phase – 2017 / 2018

• Construction Start Dec ’18 – completion date Dec 2021

Summary Status


Q&A

33

Thank you for your

time

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vartry water supply project a major upgrade to a 150 year ......• the stillorgan reservoir upgrade...

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