Where Council Water Supplies are not available private bores may be used, with consent from Environment Canterbury, to supply a potable water source. The table below shows what determinands are required to be tested for and the parameters they must meet to be considered acceptable for potable use.
Determinand | Unit | MAV | AVs |
|---|---|---|---|
Alkalinity | mg/l | ||
Ammonia N | mg/l | 1.5 | |
Arsenic | mg/l | 0.01 | |
Bicarbonate | mg/l | ||
Boron | mg/l | 2.4 | |
Calcium (Dissolved) | mg/l | 200 | |
Calcium (Total) | mg/l | 200 | |
Carbon Dioxide (Free) | mg/l | ||
Carbonate | mg/l | ||
Chloride | mg/l | 250 | |
Conductivity | mS/m or μS/cm | ||
Copper | mg/l | 2 | 1 |
E.coli | MPN | < 1 | |
Fluoride | mg/l | 1.5 | |
Hardness (Total) | mg/l | 200 | |
Iron | mg/l | 0.3 | |
Lead | mg/l | 0.01 | |
Magnesium | mg/l | 200 | |
Manganese | mg/l | 0.4 | 0.04 (staining); 0.1 (taste) |
Mercury | mg/l | 0.007 | |
Nitrate N | mg/l | 11.3 | |
Non-purgeable Organic Carbon | mg/l | ||
pH | pH | 7 - 8.5 | |
Phosphorus | mg/l | ||
Potassium | mg/l | ||
Silica | mg/l | ||
Sodium | mg/l | 200 | |
Sulphate | mg/l | 250 | |
Total Coliforms | MPN | < 1 | |
Total Dissolved Solids | mg/l | 600 | |
Turbidity | mg/l | 5 | |
Zinc | mg/l | 1.5 |
Managing a Private Bore Supply
This booklet has been put together for local private water supply well owners, and contains information on how to ensure water supplied to a home or workplace is safe to drink.