Eliot Sinclair was employed to conduct a ground contamination assessment for a two-lot subdivision in North Canterbury. The land use of the newly created lot would change from rural (production land) to residential. The NES(Soil) requires that potential contamination from historical or recent activities are assessed at the time of development and, if necessary, re-mediated to make the land safe for human use.
Description of problem faced/task undertaken
The PSI identified a historical shearing shed with stockyards and footrot baths on the site as potential sources of ground contamination. Soil samples were taken from the area of the historical stockyards and analysed for arsenic and organochlorine pesticides. All samples showed elevated arsenic concentrations, half of which were above NES soil contaminant standards. Organochlorine pesticides (e.g. DDT, lindane etc.) were detected but in concentrations below contaminant standards.
How the problem was solved
It was recommended that no produce, poultry or eggs should be consumed from the stockyard area. A consent notice was registered on the title identifying the historical stockyard area as ‘controlled use area’. There is no requirement under NES to remediate the proposed lot as long as no activities are proposed in the stockyard area.
As Canterbury was predominately an agricultural area in previous decades, there is a chance that arsenic, heavy metals and organochlorine pesticides are present in the soil at levels that may affect human health. Although most contamination we find is small-scale, ground contamination testing is required at the time of development, or if earthworks are proposed on land that is recorded on Environment Canterbury’s LLUR.
Eliot Sinclair will guide you throughout the process of investigation assessment and if appropriate remediation works.