Arsenic
Drinking Water Quality Testing - Arsenic
Arsenic is a chemical which can occur naturally in water in areas with geothermal activity or it can be present due to land use and environmental factors.
This page shows the Selwyn District Council’s testing results for arsenic for water sources used for drinking water measured in g/m3. Taumata Arowai, the drinking water regulator, is responsible for setting the New Zealand Drinking Water Standards, which specify the maximum amount of different chemicals, including arsenic, that are safe to have in our drinking water. This is known as the Maximum Acceptable Value (MAV). In most cases the limits are based on the level of risk from a lifetime of drinking the water.
Select a scheme boundary to find the most recent arsenic result for each source. Data is updated monthly.
When you click on the map the colours shown represent the arsenic level compared to the Maximum Acceptable Value (MAV) of 0.01 g/m3. The colours show arsenic levels of:
| value less than 0.005g/m3 |
values between 0.005g/m3 & 0.01g/m3 |
value more than 0.01g/m3 |
Explore arsenic readings over time
The Water Scheme filter applies to the table and graph below.
Explore arsenic readings over time
The Water Scheme filter applies to the table and graph below.
Arsenic testing and frequency
The drinking water regulator sets a frequency of testing source depending on the population which ranges from annual to every three years. Selwyn District Council has chosen to test all drinking water supplies annually.
All samples are analysed in an IANZ Accredited Laboratory. The detection threshold for arsenic is 0.0011 g/m3. New Zealand’s water legislation sets required units as “mg/L”, which is a different way of expressing g/m3.