17 Jul 2015

Nelson City Council and Port Nelson welcome Government support for Calwell Slipway Remediation Project.

With funding support confirmed from the Government today, Nelson City Council and Port Nelson are set to enter an important phase to remediate an area of contaminated seabed at the port.

calwell slipway

The Calwell Slipway has been in operation since 1970 and is the third largest slipway in New Zealand, making it a significant commercial asset to the Nelson region. Historic ship repair work has contaminated the marine sediment in the Calwell Slipway Basin.

The Ministry for the Environment has today announced funding of $200,000 for the remediation planning and detailed design phase, while Port Nelson will contribute the other $200,000.

Councillor Brian McGurk, Planning and Regulatory Chair, says this is a critical project to help clean up Nelson’s environment.

“We’re pleased the Port is being proactive in addressing any risks posed by the contamination.

“This is a great opportunity to clean up a historically contaminated site, and deliver a beneficial environmental outcome for the Nelson region.”

Earlier phases of the project have investigated the extent of the contamination and established remediation targets. Investigations have also been completed on a number of potential remediation options for the site.

A study was then commissioned to optimize the options, and as a result a preferred remediation option has been established.

Port Nelson Chief Executive Martin Byrne says the funding support will help achieve an important goal to clean up an area of the port that was found to be contaminated after routine sediment monitoring was undertaken in 2009, prior to maintenance dredging of the slipway basin.

Since then, dredging of the slipway basin has been put on hold. It was last dredged in 1984, and now needs to be dredged again to restore navigability.

“We are now in a position to move forward and the key objectives for the upcoming phase of the project are to plan the remediation itself, right down to detailed designs, to start to engage the community and begin consenting for the remediation phase.”

The main contaminants are Tributyltin and Copper. Tributyltin was used as a surface coating to reduce the growth of weed and other organisms on ship hulls and was discontinued during the 1990's, although residual levels may still be present on some older vessels.

Calwell Slipway is now managed so that all contaminated material from ship maintenance is collected, avoiding further contamination.