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Customer/Main Contractor:
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John Leen Plumbing/L T Mcguinness
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Consultant:
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Michael Stretton Ltd.
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Date:
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November 2019
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Type:
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Mobile Plant Fleet, Underground Services, Traffic Management, Connections, Patchliners
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Customer Type:
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Commercial
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Scope:
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Installation of a 50 dia. domestic connection from the main to the boundary
Installation of 150 dia. uPVC wastewater connection and a 225 dia. uPVC stormwater connection from the main to the boundary
Disconnection of existing wastewater, stormwater and water connections from the main
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This project included challenging commercial CBD connection work inside a busy construction site and outside the site in the pedestrianied section of Cuba St in Wellington’s CBD. There was time pressure on the work to meet the developers handover dates.
Inside the site we had to work closely with the main contractor to coordinate with the main contractor so that our work could proceed around their temporary works activities associated with the façade. Outside the site we installed pedestrian traffic management to create a safe working area – we worked with Wellington City Council RCA to ensure that our traffic management plan was in accordance with their constraints and that reinstatement of pavers in the area was to the required standard.
There were some significant design changes asscoaited with the position of the public network that we worked through with the main contractor to deliver a cost effective, high quality product.
The domestic water connection was a 50mm ID PE from a 200mm ID DI main. A water meter was insatalled as part of the domestic connection. We worked with the WWL Operations Engineer to propose and execute a large diameter live tap of the main that eliminated the need for a challenging shutdown of the main. If we had to shutdown the main then the impact on businesses in Cuba St, many of whom start early in the morning and remain open until the early hours of the following morning, would have been significant. A live tap also minimised other risks associated with working at night and risks of contamination to the network. By completing the work in this manner we were able to offer a saving to the developer associated with not working at night.
We applied for wastewater and stormwater connections and liaised with the WWL maintenance contractor to facilitate those connections within our site and in accordance with the programme. The connections in this location were into existing manholes and our team rebenched the connections to a high standard. We then used a CIPP point repair system to complete trenchless disconnections of the existing wastewater and stormwater connections.
As built information for the private network was supplied to the developer for their use in closing building consents. As Built information for the connections – including a water meter as built – was provided to WWL and the developer so that it can be included on the GIS network.
This project included some significant challenges but it was delivered within the customers programme and they were satisfied with the result. This type of work is at the core of our business and this project demonstrates some of our key capabilities. We can deliver value for money by self delivering all aspects of the construction, providing efficiency by delivering all three waters in the same mobilisation and traffic management set up and using trenchless solutions for disconnections.
We have the capability to undertake large diameter live taps and will continue to seek approval from WWL on a case by case basis this method will mitigate risks associated with service interruption, out of hours working and contamination of the network; there is also opportunity to provide cost savings to the customer by completing connections in this manner.
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Large diameter domestic connection installed by live tapping.
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Installation of wastewater and stormwater connections around heavily congested services
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