No hard data on extent of contaminated land in Hawke's Bay

Even old rose gardens treated with copper-based sprays could be classed as contaminated under hazardous activities and industries criteria. Photo/File

Hawke's Bay may have up to 4000 contaminated land sites, but a lack of resources to identify and investigate potential hazardous areas means the exact number and locations are unknown.

A report into the state of the country's biodiversity, soils and ecosystems released last week showed an overall environmental decline, but a lack of consistent data meant not all human activities, such as the extent of land contamination, could be captured.

The report, Our Land 2018, was the latest from the Ministry for the Environment and Stats NZ as part of an environmental reporting series started in 2015.

It showed urban growth had led to the loss of some of the country's most versatile land, and that erosion and farming intensification had had a significant effect on the quantity and quality of soil.

Although there was no integrated national database of sites contaminated by hazardous substance use, storage or disposal, regional councils, and sometimes district councils, recorded contaminated sites on a Hazardous Activities and Industries List (HAIL).

A local authority survey conducted in 2012/2014 reported 19,568 sites nationwide were identified as contaminated.

"Many regional councils estimated that up to three times as many HAIL sites could be identified in their regions," the report said.

Contamination sources ranged from pesticides such as agrichemicals and those used for animal treatment, to timber treatment chemicals and metals from mining.

Hawke's Bay Regional Council compliance manager Wayne Wright said HAIL lists varied between councils depending on the region and the resources available.

"In Hawke's Bay the list was put together with sites that were known to be contaminated, but has also been added to with sites that may have been an old scrap metal business or lawnmower repairer, but they haven't been proven to have an issue."

Among the sites listed as potentially contaminated across the region were service stations, landfills, chemical manufacturers, wood treatment plants, railway yards and drycleaning businesses.

What the list did not include was any orchards or all potentially contaminated farms, Wright said.

"It's likely there could be farms that were contaminated from things like sheep dips but they are not on the list, and we don't put in orchards."

He said that under the HAIL criteria even an old rose garden that had had copper-based sprays used on it could be classed as a contaminated site.

While some councils may have funded more resources to investigate potential land contamination, in Hawke's Bay there was one person whose role was to look after hazardous sites, as well as other duties, Wright said.

"This council has an outcomes focus and we are dealing with ones we know about such as the old Roys Hill landfill, which has controls and is monitored as part of the Hastings District Council's resource consent to check there are no discharges happening into water."

The report came as consultation on the regional council's long-term plan proposals was close to finishing.

The plan included upscaling and accelerating work in land and water management, with stronger regulation and more incentives for change.

Council chairman Rex Graham said the national report made for disturbing reading, but he was heartened that the region was looking to make changes to improve land and waterways.

"The report notes greater investment in science and monitoring of land and biodiversity is required. The Hawke's Bay Regional Council fully agrees and is pleased to be able to play its part in this effort within the proposed long-term plan.

"This new national report comes as no surprise to us and as a community we need to dig further into our pockets and support the regional council's work."