Testing in May 2023 revealed chemical contamination at Tāhunanui's Back Beach. Photo: Nelson Regional Development Agency / Supplied
- Work to remove contaminated sawdust and sand will start at Tāhunanui's Back Beach in Nelson in September
- The sawdust from a local timber mill was used as fill for the raised carpark in the 1960s and was exposed by erosion in 2022
- Testing found concentrations of arsenic, chromium, copper and boron last year
- It's expected to take at least six weeks to remove the contaminated material and traffic conditions will be impacted
- People are being told to steer clear of the cordoned off work area, but the risk of contaminants affecting nearby areas is considered low
Work to remove sawdust and sand that is contaminated with arsenic and other chemicals will start on a popular Nelson beach next month.
The material became exposed by erosion at Tāhunanui's Back Beach in 2022 but it was not until May 2023 that testing revealed chemical contamination.
At least 6500 cubic metres of sawdust, and even more sand, is expected to be removed from a raised carpark and taken to the York Valley Landfill's hazardous waste facility over at least six weeks.
The site will then restored with low level dunes and a new gravel carpark, but an alternative carpark will be available in September.
Nelson City Council community services group manager Andrew White said every care to remove the contaminated material efficiently and safely was being taken.
"Tāhunanui Beach is a well-loved location for many in Nelson. Ensuring the work is completed safely and before the busy summer season starts is a priority," White said.
"The risk of contaminants affecting recreational areas is considered low, as these risks are generally associated with long-term exposure, however, we ask people to keep a close eye on their children and pets, stay clear of the work area and be aware of trucks moving through the reserve on weekdays."
The areas that will be affected by the removal of contaminated sawdust from Tāhunanui’s Back Beach, which is set to begin in September. Photo: Supplied / Nelson City Council
Work to assess the coast showed that removing the material and restoring the area was unlikely to have a material impact on erosion of the shoreline.
White said they had chosen plant species to help support the dunes and native species, and pre-clearance checks for nesting birds and native lizards would be made before work started.
Nelson Mayor Nick Smith said the work would be disruptive around the reserve, but they wanted to get the popular beach back in pristine condition for Christmas.
He was hopeful the government would help fund the estimated $5.2 million to remediate the site after providing funding to investigate and design the work.
A funding application has been lodged with the Ministry for the Environment and the government previously indicated it would assist with the cost, he said.
"We have decided to get on with this remediation work, so we get it done before the busy summer season, minimise the cost of maintaining the short-term protection measures and reduce the risk of a major storm spreading the material," Smith said.
The areas that will be affected by the removal of contaminated sawdust from Tāhunanui’s Back Beach, which is set to begin in September. Photo: Supplied / Nelson City Council
Road access to Back Beach will be closed from the end of the Skate Nelson carpark during the removal with contaminated material being covered and transported on trucks via Bisley Walk.
Traffic management and parking restrictions will be in place but businesses in the reserve will remain open.
Tāhunanui Liaison Councillor Campbell Rollo said the council committed to finding a solution when the contamination was confirmed and has been in regular contact with stakeholders
About 20 additional car parks will be created during the clean up.