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Drinking water quality

standards and Lists Appendix 9

I and II Substances

A9.1 Drinking water quality guidelines and standards

Parameter World Health European Union United States Environmental Protection
Organization parametric value Agency primary
guideline value and secondary standards

NPDWR
Microbiological parameters MCLG MCL or TT
E. coli or thermotolerant coliform 0 in 100 mL 0 in 100 mL sample – –
bacteria sample
Total coliforms* (including faecal – 0 in 100 mL sample 0 No more than 5% of
coliform and E. coli) samples total coliform-
Enterococci – 0 in 100 mL sample – positive in a month
Cryptosporidium – – 0 TT
Giardia lamblia – – 0 TT
Heterotrophic plate count – – n/a TT
Legionella – – 0 TT
Viruses (enteric) – – 0 TT
Turbidity† 5 NTU n/a n/a TT
Disinfection byproducts
Bromate 0.025 mg L −1 0.01 mg L −1 0mgL −1 0.010 mg L −1
Chlorite 0.2 – 0.8 1.0
Haloacetic acids <0.1 – n/a 0.060
Total trihalomethanes ‡ 0.1 n/a 0.080
Disinfectants MRDLG MRDL
Chloramines (as Cl ) 3mgL −1 – 4mgL −1 4.0 mg L −1
2
Chlorine (as Cl ) 5 – 4 4.0
2
Chlorine dioxide (as ClO ) n/a – 0.8 0.8
2
Radionuclides MCLG MCL or TT
Alpha particles 0.1 Bq L −1 – 0 15 pCi L −1
Beta particles 1 Bq L −1 – 0 4 millirems a −1
Radium-226, -228 (combined) – – 0 5 pCi L −1
Uranium 2 (P) mgL −1 – 0 30 mgL −1
Tritium – 100 Bq L −1 – –
Total indicative dose – 0.10 mSv a −1 – –
Pesticides MCLG MCL or TT
−1
Alachlor 20 mgL −1 0.1 mgL for an individual 0 mgL −1 2 mgL −1
Aldicarb 10 pesticide (except where – –
−1
Aldrin/dieldrin 0.03 indicated); 0.5 mgL for – –
Atrazine 2 the sum of all individual – –
pesticides 3 3