​ ​ ​ ​ ​
Contact

Search

Arsenic

Arsenic Values for the Wairau Plain

The presence of high levels of arsenic in Marlborough groundwater has only been discovered as recently as 2001. A knowledge of its occurrence in the groundwater we drink is very important as the long-term consumption of groundwater with concentrations above 0.01 g/m or parts per million, is toxic to human health.

All of the research to date points to a natural source, with the exception of isolated sites linked with historic land uses such as landfills or sheep-dips. The treatment technology exists to remove arsenics or reduce arsenic levels in groundwater to safe concentrations.

The above figure shows the distribution of measured arsenic concentrations for deeper aquifer systems only, and omits results for the Rārangi Shallow Aquifer, where most of the intensive research by the Marlborough District Council has occurred. The higher values in the Taylor River and Pass area represent landfill monitoring.

While we only have a small number of measurements to date, levels of iron and manganese have been used as an indicator of the existence of arsenic due to its similar chemical behaviour in local groundwater. The advantage of this approach is that there are many more measurements of these parameters than exist for arsenic.

Share this

Share this page

Sharing...