Drinking water
Drinking water standards in New Zealand [2005] {GV= Guideline value}
| Determinand | GV | Units | Comments |
| aluminium | 0.10 | mg/L | Above this, complaints may arise due to depositions or discoloration. |
| ammonia | 1.50.3 | mg/L | Odour threshold in alkaline conditions.For control of chloramine formation in chlorinated water. |
| calcium | See hardness. | ||
| chloride | 250 | mg/L | Taste, corrosion. |
| chlorine | 0.6–1.0 | mg/L | Taste and odour threshold (MAV 5 mg/L) |
| 2-chlorophenol | 0.00010.01 | mg/L | Taste threshold.Odour threshold. |
| colour | 10 | TCU | Appearance. |
| copper | 1 | mg/L | Staining of laundry and sanitary ware (PMAV 2 mg/L) |
| 1,2-dichlorobenzene | 0.0010.002 | mg/L | Taste threshold.Odour threshold (MAV 1.0 mg/L) |
| 1,4-dichlorobenzene | 0.00030.006 | mg/L | Odour threshold.Taste threshold (MAV 0.4 mg/L) |
| 2,4-dichlorophenol | 0.00030.04 | mg/L | Taste threshold.Odour threshold. |
| ethylbenzene | 0.0020.08 | mg/L | Odour threshold.Taste threshold (MAV 0.3 mg/L) |
|
hardness (total) (Ca + Mg) as CaCO3 |
200 100–300 |
mg/L | High hardness causes scale deposition, scum formation. Low hardness (<100) may be more corrosive.Taste threshold. |
| hydrogen sulphide | 0.05 | mg/L | Taste and odour threshold. |
| iron | 0.2 | mg/L | Staining of laundry and sanitary ware. |
| magnesium | See hardness. | ||
| manganese | 0.040.10 | mg/L | Staining of laundry.Taste threshold (MAV 0.4 mg/L) |
| monochlorobenzene | 0.01 | mg/L | Taste and odour threshold (MAV 0.3 mg/L) |
| odour (threshold odour number) | 3 | Odour should be acceptable. | |
| pH | 7.0–8.5 | Should be between 7.0 and 8.0. Most waters with a low pH have a high plumbosolvency. Waters with a high pH: have a soapy taste and feel. Preferably pH <8 for effective disinfection with chlorine. | |
| sodium | 200 | mg/L | Taste threshold. |
| styrene | 0.004 | mg/L | Odour threshold (MAV 0.03 mg/L) |
| sulphate | 250 | mg/L | Taste threshold. |
| taste | Should be acceptable to most consumers. | ||
| temperature | Should be acceptable to most consumers, preferably cool. | ||
| toluene | 0.030.04 | mg/L | Odour.Taste threshold (MAV 0.8 mg/L) |
| total dissolved solids | 1000 | mg/L | Taste may become unacceptable from 600–1200 mg/L. |
| trichlorobenzenes (total) | see below | (MAV 0.03 mg/L) | |
| 1,2,3-trichlorobenzene | 0.01 | mg/L | Odour threshold. |
| 1,2,4-trichlorobenzene | 0.005 | mg/L | Odour threshold. |
| 1,3,5-trichlorobenzene | 0.05 | mg/L | Odour threshold. |
| 2,4,6-trichlorophenol | 0.0020.3 | mg/L | Taste threshold.Odour threshold (MAV 0.2 mg/L) |
| turbidity | 2.5 | NTU | Appearance. For effective terminal disinfection, median turbidity <1 NTU, single sample <5 NTU. |
| xylene | 0.02 | mg/L | Odour threshold (MAV 0.6 mg/L) |
| zinc | 1.5 | mg/L | Taste threshold. May affect appearance from 3 mg/L. |
Maximum acceptable values (MAV) for microbial determinands
| Micro-organism | MAV 1 |
| Escherichia coli (E. coli) 2 | Less than 1 in 100 mL of sample |
| viruses | No value has been set due to lack of reliable evidence |
| total pathogenic protozoa | Less than 1 (oo)cyst per 100 L of sample |