Environmental concerns prompt tighter Transmission Gully controls

Monday 10th June 2019

Greater Wellington Regional Council has imposed a stricter environmental regime on the construction of the 27-kilometre Transmission Gully highway north of Wellington due to ongoing concerns about erosion and sediment control failures.

The local body authority last year adopted a new approach to earthworks management in the Porirua harbour catchment to mitigate the environmental impact in preparation for a busy summer of work.

That included a ‘pause works’ mechanism Greater Wellington can trigger in response to environmental incidents, requiring a temporary halt in the affected area until the CPB Contractors-HEB Construction joint venture building the highway can show the problem has been fixed correctly, adverse environmental impacts have been addressed or mitigated, and measures introduced to prevent a repeat, a council spokesman said.

Last month, Greater Wellington’s environment committee was told the joint venture was fined in February over non-compliant discharges from the Porirua Link Roads project, following previous warnings for similar incidents.

"Due to GWRC’s ongoing concerns regarding the number and nature of erosion and sediment control failures, incidents and/or non-compliances with consent conditions on the projects since commencement of construction, as part of the three-monthly earthworks open area review and decision process, GWRC requested in March 2019 that CPB HEB JV automatically pause works in the catchment of any erosion or sediment control device/measure that has failed or is associated with an incident or discharge.”

A key environmental matter for the council is protecting Porirua harbour from sediment discharges. While it imposed conditions on consents to limit and mitigate those discharges, the council discovered the limitations in its monitoring systems meant it was hard to work out whether the conditions were being met.

Over the course of the project, the joint venture has been issued 11 infringement notices, two abatement notices that were cancelled once council was satisfied the joint venture met its requirements, 20 formal warnings over 40 separate incidents, and 12 formal advisory letters relating to 30 separate incidents. Two infringement notices that were linked to the cancelled abatement notices were withdrawn.

As at May 22, decisions on whether to pursue enforcement for another 11 incidents were pending, the council spokesman said in an email.

Since Greater Wellington introduced the new requirement, there have been seven failures that prompted a pause in work.

"The requirement does not require work to pause across the entire project, only in areas where there has been a failure or incident," the council spokesman said.

A CPB-HEB spokeswoman said Transmission Gully operates its environmental compliance with an equal approach to safety.

“This means that if an incident on site causes an erosion and sediment control device to fail, works are stopped within the catchment area the control device is protecting,” she said in an emailed statement.

“Once the problem has been identified and fixed, the approving manager at GWRC provides the approval for works to restart.”

In its 2018 annual report, Cimic Group, the ASX-listed parent of the senior JV partner CPB Contractors, noted 13 legal breaches for environmental incidents on Transmission Gully for which it was fined $750 each time, or a $2,250 total fine.

Cimic has a hand in all of the Transmission Gully work. Its project finance subsidiary Pacific Partnerships holds a 15 percent stake of Transmission Gully’s lead contractor Wellington Gateway Partners, and its Ventia 50/50 joint venture has the 25-year operation and maintenance sub-contract once the road is built.

(BusinessDesk)

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