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Appendix 6: Maximum Acceptable Values for Determinands in the Drinking-water Standards for New Zealand 2005

Maximum Acceptable Values for Determinands in the Drinking-water Standards for New Zealand 200524

Table 2.1: Maximum acceptable values (MAV) for microbial determinands

Micro-organism MAV1
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

Notes

1 These are maximum acceptable values (MAVs) for regulatory purposes. They do not represent a dose/response relationship that can be used as the basis for determining acceptable concentrations of pathogens in drinking-water.

2 Indicator organism.

Table 2.2: Maximum acceptable values (MAVs) in mg/L for inorganic determinands of health significance

Name MAV Remarks
antimony 0.02  
arsenic 0.01 For excess lifetime skin cancer risk of 6 x 10-4. PMAV used because of analytical difficulties
barium 0.7  
beryllium1 0.004 PMAV
boron2 1.4  
bromate 0.01 For excess lifetime cancer risk of 7 x 10-5. PMAV
cadmium 0.004  
chlorate 0.8 PMAV. Disinfection must never be compromised. DBP (chlorine dioxide)
chlorine 5 Free available chlorine expressed in mg/L as Cl2. ATO. Disinfection must never be compromised
chlorite 0.8 Expressed in mg/L as ClO2. PMAV. Disinfection must never be compromised. DBP (chlorine dioxide)
chromium 0.05 PMAV. Total. Limited information on health effects
copper 2 ATO
cyanide 0.08 Total cyanides
cyanogen chloride 0.08 Expressed in mg/L as CN. Total. DBP (chloramination)
fluoride3 1.5  
lead 0.01  
lithium1 1 PMAV
manganese 0.4 ATO
mercury 0.002 Total
molybdenum 0.07  
monochloramine 3 DBP (chlorination)
nickel 0.02 PMAV
nitrate, short term4 50 Expressed in mg/L as NO3. The sum of the ratio of the concentrations of nitrate and nitrite to each of their respective MAVs should not exceed one
nitrite, long term 0.2 Expressed in mg/L as NO2. PMAV (long term)
nitrite, short term1,4 3 Expressed in mg/L as NO2. The sum of the ratio of the concentrations of nitrate and nitrite to each of their respective MAVs should not exceed one
selenium 0.01  
silver 0.1 PMAV
uranium 0.02 PMAV

Notes: Where WHO Guideline values are based on 60 kg bodyweight, the DWSNZ uses 70 kg bodyweight. See the datasheets for calculations (WHO 2004).

1 MAV retained despite no WHO guideline value.

2 WHO guideline PMAV is 0.5 mg/L.

3 For oral health reasons the Ministry of Health recommends that the fluoride content for drinking-water in New Zealand be in the range of 0.7–1.0 mg/L. This is not an MAV.

4 Now short term only. The short-term exposure MAVs for nitrate and nitrite have been established to protect against methaemoglobinaemia in bottle-fed infants.

Table 2.3: Maximum acceptable values (MAVs) in mg/L for organic determinands of health significance (including cyanotoxins and pesticides)

Name MAV Remarks
acrylamide 0.0005 For excess lifetime cancer risk of 10-5
alachlor 0.02 Pesticide. For excess lifetime cancer risk of 10-5
aldicarb 0.01 Pesticide
aldrin + dieldrin 0.00004 Pesticide. The sum of, not each
anatoxin-a 0.006 Cyanotoxin. PMAV
anatoxin-a(s) 0.001 Cyanotoxin. PMAV
atrazine 0.002 Pesticide. Cumulative for atrazine and congeners DEA, DIA, and DACT
azinphos methyl 0.004 Pesticide. PMAV
bentazone 0.4 Pesticide. PMAV
benzene 0.01 For excess lifetime cancer risk of 10-5
benzopyrene 0.0007 For excess lifetime cancer risk of 10-5
bromacil 0.4 Pesticide. PMAV
bromodichloromethane 0.06 For excess lifetime cancer risk of 10-5. THM
bromoform 0.1 THM
carbofuran 0.008 Pesticide
carbon tetrachloride 0.005  
chlordane 0.0002 Pesticide
chloroform 0.2 THM
chlorotoluron 0.04 Pesticide
chlorpyriphos 0.04 Pesticide
cyanazine 0.0007 Pesticide
cylindrospermopsin 0.001 Cyanotoxin. PMAV
2,4-D 0.04 Pesticide
2,4-DB 0.1 Pesticide
DDT + isomers 0.001 Pesticide. Sum of all isomers
di(2-ethylhexyl)adipate 0.1 PMAV
di(2-ethylhexyl)phthalate 0.009  
diazinon 0.01 Pesticide. PMAV
1,2-dibromo-3-chloropropane 0.001 Pesticide. For excess lifetime cancer risk of 10-5
dibromoacetonitrile 0.08 DBP (chlorination)
dibromochloromethane 0.15 THM
1,2-dibromoethane 0.0004 PMAV. For excess lifetime cancer risk of 10-5
dichloroacetic acid 0.05 PMAV. DBP (chlorination)
dichloroacetonitrile 0.02 PMAV. DBP (chlorination)
1,2-dichlorobenzene 1.5 ATO
1,4-dichlorobenzene 0.4 ATO
1,2-dichloroethane 0.03 For excess lifetime cancer risk of 10-5
1,1-dichloroethene 0.03  
1,2-dichloroethene 0.06 Total of cis and trans isomers
dichloromethane 0.02  
1,2-dichloropropane 0.05 Pesticide. PMAV.
1,3-dichloropropene 0.02 Pesticide. Total of cis and trans isomers. For excess lifetime cancer risk of 10-5
dichlorprop 0.1 Pesticide
dimethoate 0.008 Pesticide
diquat 0.01 Pesticide. PMAV
diuron 0.02 Pesticide. PMAV
EDTA (editic acid) 0.7  
endosulfan 0.02 PMAV
endrin 0.001 Pesticide
epichlorohydrin 0.0005 PMAV
ethylbenzene 0.3 ATO
fenoprop 0.01 Pesticide
fluoranthene 0.004 PMAV
formaldehyde 1 DBP
heptachlor and its epoxide 0.00004 Pesticide. PMAV. Mainly occurs as the epoxide
hexachlorobenzene 0.0001 Pesticide. PMAV
hexachlorobutadiene 0.0007  
hexazinone 0.4 Pesticide. PMAV
homoanatoxin-a 0.002 Cyanotoxin. PMAV
isoproturon 0.01 Pesticide
lindane 0.002 Pesticide
malathion 1 Pesticide. PMAV
MCPA 0.002 Pesticide
MCPB1 0.03 Pesticide. PMAV
mecoprop 0.01 Pesticide
metalaxyl 0.1 Pesticide. PMAV
methoxychlor 0.02 Pesticide
methyl parathion 0.01 Pesticide. PMAV
metolachlor 0.01 Pesticide
metribuzin 0.07 Pesticide. PMAV
microcystins 0.001 Cyanotoxin. PMAV (Expressed as MC-LR toxicity equivalents)
molinate 0.007 Pesticide
monochloroacetic acid 0.02 DBP (chlorination)
monochlorobenzene 0.3 PMAV. ATO
nitrilotriacetic acid (NTA) 0.2  
nodularin 0.001 Cyanotoxin. PMAV
oryzalin 0.4 Pesticide. PMAV
oxadiazon 0.2 Pesticide. PMAV
pendimethalin 0.02 Pesticide
pentachlorophenol 0.009 Pesticide. PMAV
permethrin 0.02 Pesticide. PMAV
phenylphenol 1.4 Pesticide. PMAV
picloram 0.2 Pesticide. PMAV
pirimiphos methyl 0.1 Pesticide. PMAV
primisulfuron methyl 0.9 Pesticide. PMAV
procymidone 0.7 Pesticide. PMAV
propanil 0.02 Pesticide. PMAV. Some degradation products may be toxic
propazine 0.07 Pesticide. PMAV
pyridate 0.1 Pesticide. PMAV
pyriproxifen 0.4 Pesticide
saxitoxins 0.003 Cyanotoxin. Expressed as STX equivalent. PMAV
simazine 0.002 Pesticide
styrene 0.03 ATO
2,4,5-t 0.01 Pesticide
terbacil1 0.04 PMAV
terbuthylazine 0.008 Pesticide
tetrachloroethene 0.05  
thiabendazole 0.4 Pesticide. PMAV
toluene 0.8 ATO
tributyltin oxide 0.002 PMAV
trichloroacetaldehyde 0.01 PMAV
trichloroacetic acid 0.2 DBP (chlorination)
trichlorobenzenes 0.03 PMAV. Total concentration of all isomers. ATO
1,1,1-trichloroethane 2 PMAV
trichloroethene 0.08 PMAV
2,4,6-trichlorophenol 0.2 For excess lifetime cancer risk of 10-5. ATO
triclopyr 0.1 Pesticide. PMAV
trifluralin 0.03 Pesticide. Technical grade may contain carcinogens
trihalomethanes (THMs)   The sum of the ratio of the concentration of each THM to its respective MAV should not exceed oneThe individual members of this group are indicated in the table as THM
vinyl chloride 0.0003 For excess lifetime cancer risk of 10-5
xylenes (total)1 0.6 ATO
1080 0.0035 Pesticide. PMAV

Notes:

  • DBP indicates a disinfection by-product. Any difficulty in meeting a MAV must never be a reason to compromise adequate disinfection. Trihalomethanes are DBPs. Some DBPs may also have other sources.

  • Where WHO Guideline values are based on 60 kg bodyweight, the DWSNZ uses 70 kg bodyweight. See datasheets for calculations (WHO 2004).

1 Institute of Environmental Science and Research report Gallagher LM and Fowles JF 22.03.05.

Table 2.4: Maximum acceptable values (MAVs) in Bq/L for radiological determinands

Radioactive constituents MAV Unit
total alpha activity 0.10 Bq/L excluding radon
total beta activity 0.50 Bq/L excluding potassium-40
Radon 100 Bq/L

Abbreviations used in Appendix 6 tables

PMAV
Provisional MAV (because it is provisional in the WHO Guidelines (WHO 2004) or WHO has no guideline value but the DWSNZ has retained a MAV or developed its own).

ATO
Concentrations of the substance at or below the health-based guideline value that may affect the water’s appearance, taste or odour.

DBP
Disinfection by-product. Any difficulty meeting a DBP MAV must never be a reason to compromise adequate disinfection. Trihalomethanes and haloacids are DBPs. Some DBPs may also have other sources.

THM
Trihalomethane, of which there are four: bromoform, bromodichloromethane, chloroform and dibromochloromethane.

 


24 The information in Appendix 6 is directly quoted from pages 8–13 of the Drinking-water Standards for New Zealand 2005.