Tunnelling works complete on NI Water’s £7.8m wastewater upgrade at Meadow Lane
10 June 2024 12:13
Meadow Lane Project team 1 (L-R, back row) Conor Ward BSG, John Griffin, Tzvetelina Bogoina (both NI Water), Michael Watson BSG and Fergus Kerr McAdam.
Breakthrough!! NI Water’s contractor, BSG has completed the tunnelling element of work associated with laying 620m of new large diameter sewer under Meadow Lane.
The 25-tonne Tunnel Boring Machine (TBM) broke through to the new stormwater storage tank last week to complete this significant element of work.
The new 1500mm diameter pipe, which is laid 8m below ground level, forms an important part of this major NI Water investment to increase the capacity in the network. Tunnelling methods were employed by NI Water and BSG to help reduce disruption on Meadow Lane and complete the installation of the new pipe in the quickest possible timescale - traditional open-cut methods would have taken around a year to complete!
Instead, open-cut methods – which require traffic management - are only being employed to tie into the existing network. BSG is due to commence the second connection on Meadow Lane this week.
On site to see the TBM breaking through was NI Water’s Director of Infrastructure Delivery, Tzvetelina Bogoina, who commented:
“I was delighted to see the completion of the tunnelling works in relation to the extensive Meadow Lane wastewater upgrade. This has been a challenging element of the project and only made possible by the support of local businesses and council who accommodated tunnelling pits within their land ownership.
“NI Water is grateful to these landowners as well as local businesses and the wider public for their ongoing patience as we deliver this important project to protect the environment and support growth in the area. I’d like to pay tribute to the project team from McAdam and BSG, as well as their subcontractors from B&W Tunnelling, for their unfaltering efforts to complete this major element of work.”
Reinstatement of the tunnelling pits at Meadow Lane East Car Park, Tim Hortons and at Annagh Fields will be carried out once all the connections have been completed.
In addition to the pipelaying aspect, work is continuing apace on the new 20m diameter stormwater storage tank, which at 9m deep is capable of holding 1,500,000 litres of rain/storm water. That’s the equivalent to the same volume as 18,750 household baths! This tank forms a key part of the new wastewater pumping station and will help reduce the risk of out-of-sewer flooding in the area.
The new infrastructure being installed and constructed will support local development and economic growth and provide environmental protection in this part of Portadown. The project is due to be fully completed by mid 2025.
“Up, up and away!” The Tunnel Boring Machine is craned off site.
Ends
For further information, please email press.office@niwater.com
Notes to Editor:
Key facts:
TBM
- TBM outside diameter - 1.8m
- TBM length - 6m
- TBM weight - 25 tonne
Tunnelling
- Tunnelling length – 380m
- Tunnel depth - 8m below ground level (26 feet below ground level)
- 150 x 2.5m long pipes installed under Meadow lane
- Weight of entire tunnelling pipe installed is 750 tonnes
- 1000m3 (or 2000 tonnes) of material excavated and removed using the TBM
Benefits of tunnelling
- Health and Safety - Removed the need for 380m of deep excavations, working near live services and associated operation of large plant along Meadow Lane. Consequently removed significant risk to both the workforce and general public.
- Environmental – significant carbon reduction: The tunnelling removed the requirement to excavate and dispose of 8000m3 of spoil material and approximately 7200m3 of replacement fill material. This negated the need for almost 1800 lorry movements in the area!
- Reduced disruption - Allowed 380m of 1500mm internal diameter pipework to be installed in the area with minimal disruption to the general public.
- Programme - Reduced programme timescales by almost one year. If installed by traditional open-cut methods it would take approximately 18 months and cause significant disruption.
General facts
- The new infrastructure being installed and constructed will provide increased capacity in the network as well as first-time stormwater storage to support local development and economic growth and provide environmental protection in the area.
- The project will facilitate the closure of five storm overflows on the network which will improve the water quality in the River Bann.
- 620m of new large diameter sewer – to provide increased capacity in the network - is being laid by both tunnelling and open-cut methods.
- The majority of the new sewer is 1500mm in diameter – almost 5 feet in old money!
- The underground stormwater tank being constructed at the new Meadow Lane Wastewater Pumping Station is 20m wide and 9m deep and is capable of holding 1,500,000 litres of stormwater (rain/surface water) – that’s the same volume as 18,750 household baths!
- The new stormwater tank will provide better protection to the environment and reduce the risk of out-of-sewer flooding in the area.
- 140 concrete secant piles – measuring 750mm in diameter, 18m in length and weighing 19 tonnes each - were installed in the construction of the new underground stormwater storage tank. If laid out end to end, the piles would almost stretch from Portadown to Craigavon.
- At the end of May 2024 almost 40,000-man hours had been employed by BSG in the construction of the new pumping station and installation of pipelines.