A typical analysis of the chemical makeup of Christchurch water, prior to temporary chlorination.
There are 38 routine chemical tests carried out on Christchurch water with 22 of these tests establishing the presence of specific chemicals and to measure they are below acceptable limits.
| Chemical | Measure |
|---|---|
| pH | 7.8 |
| pH after aeration | 8.2 |
| Acidity to pH 8.3 (as CO3) | 1 g/m³ |
| Total alkalinity to pH 4.5 as HCO3 | 52 g/m³ |
| Turbidity (NTU) | Less than 1 |
| Nitrate Nitrogen | 1 g/m³ |
| Sulphate | 5.0 g/m³ |
| Chloride | 5.0 g/m³ |
| Calcium | 12.0 g/m³ |
| Fluoride | Less than 0.1 g/m³ |
| Magnesium | 1.5 g/m³ |
| Potassium | 1 g/m³ |
| Sodium | 6.1 g/m³ |
| Reactive silica (as SO2) | 16.0 g/m³ |
| Total hardness (as CaCO3) | 45 g/m³ |
| Conductivity at 20°C (mS/m) | 10 |
Note: Grams per cubic metre (g/m³) is equivalent to milligrams per litre (mg/l).
Deep below the surface of Whakaraupō Lyttelton Harbour are invertebrates offering important clues about the health of the harbour.
17 Dec 2025
Contractors will be working 24/7 in a ‘super week’ of construction to speed up the installation of new traffic signals and upgrades to water supply pipes on Harewood Road.
16 Dec 2025
The Addington Brook renewal project has been successfully completed, marking a major step forward for one of the most polluted waterways in Christchurch.
12 Dec 2025Request, report and pay for Council services.
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Request, report and pay for Council services.
Apply for building and resource consents.
Manage your library borrowing.
Receive your rates invoice by email.
Book an indoor or outdoor space.
Take full control of your Rec and Sport membership.
List your events on What’s On Christchurch