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close this bookWater Manual for Refugee Situations (UNHCR, 1992, 160 p.)
View the document(introduction...)
View the documentForeword
View the documentDrinking water
View the document1. Introduction
Open this folder and view contents2. Assessment and organization
Open this folder and view contents3. The need
Open this folder and view contents4. Immediate response during emergencies
Open this folder and view contents5. Refugee water supply systems
Open this folder and view contents6. Water sources, their protection and development
Open this folder and view contents7. Pumping equipment
Open this folder and view contents8. Water treatment
Open this folder and view contents9. Water storage
Open this folder and view contents10. Water distribution systems
Open this folder and view contents11. Operation and maintenance of water supply systems
Open this folder and view contents12. Management of emergency water supply systems
View the documentAnnex A - Refugee water supply inventory forms
View the documentAnnex B - Approximate daily water requirements in refugee emergency situations
View the documentAnnex C - Guidelines on water quality
View the documentAnnex D - Recommended format for technical specifications for water well construction

Annex C - Guidelines on water quality

Source: Guidelines for Drinking Water Quality, Vol. I World Health Organization Geneva, 1984

Table 1. Microbiological and biological quality

Organism

Unit

Guideline value

Remarks

I. Microbiological quality




A. Piped water supplies




A.1 Treated water entering the distribution system

faecal coliforms

number/100 ml

0

turbidity < 1 NTU: for disinfection with chlorine, pH preferably < 8.0: free chlorine residual 0.2-0.5mg/litre following 30 minutes (minimum) contact

coliform organisms

number/100 ml

0


A.2 Untreated water entering the distribution system

faecal coliforms

number/100 ml

0


coliform organisms

number/100 ml

0

in 98% of samples examined throughout the year - in the case of large supplies when sufficient samples are examined

coliform organisms

number 100 ml

3

in an occasional sample, but not in consecutive samples

A.3 Water in the distribution system




faecal coliforms

number/100 ml

0


coliform organisms

number/100 ml

0

in 95% of samples examined throughout the year - in the case of large supplies when sufficient samples are examined

coliform organisms

number/100 ml

3

in an occasional sample, but not in consecutive samples

B. Unpiped water supplies




faecal coliforms

number/100 ml

0


coliform organisms

number/100 ml

10

should not occur repeatedly: if occurrence is frequent and if sanitary protection cannot be improved, an alternative source must be found if possible

C. Bottled drinking-water




faecal coliforms

number/100 ml

0

source should be free from faecal contamination

coliform organisms

number/100 ml

0


D. Emergency water supplies




faecal coliforms

number/100 ml

0

advise public to boil water in case

coliform organisms

number/100 ml

0

of failure to meet guideline values

Enteroviruses

-

no guideline value set


II. Biological quality




protozoa (pathogenic)

-

no guideline value set


helminths (pathogenic)

-

no guideline value set


free-living organisms (algae, others)

-

no guideline value set


Table 2. Inorganic constituents of health significance

Constituent

Unit

Guideline value

Remarks

arsenic

mg/l

0.05


asbestos

-

no guideline value set


barium

-

no guideline value set


beryllium

-

no guideline value set


cadmium

mg/l

0.005


chromium

mg/I

0.05


cyanide

mg/l

0,1


fluoride

mg/l

1.5

natural or deliberately added: local or climatic conditions may necessitate adaptation

hardness

-

no health-related guideline value set


lead

mg/l

0.05


mercury

mg/l

0.001


nickel

-

no guideline value set


nitrate

mg/l (N)

10


nitrite

-

no guideline value set


selenium

mg/l

0.01


silver

-

no guideline value set


sodium

-

no guideline value set


Table 3. Organic constituents of health significance

Constituent

Unit

Guideline value

Remarks

aldrin and dieldrin

mg/l

0.03


benzene

mg/l

10a


benzo [a]pyrene

mg/l

0.01a


carbon tetrachloride

mg/l

3a

tentative guideline value b

chlordane

mg/l

0.3


chlorobenzenes

mg/l

no health-related guideline value set

odour threshold concentration between 0.1 and 3 mg/l

chloroform

mg/l

30a

disinfection efficiency must not be compromised when controlling chloroform content

chlorophenols

mg/l

no health-related guideline value set

odour threshold concentration 0.1 mg/l

2,4-D

mg/l

100c


DDT

mg/l

1


1,2-dichloroethane

mg/l

10a


1,1 -dichloroethened

mg/l

0.3a


heptachlor and heptachlor epoxide

mg/l

0.1


hexachlorobenzene

mg/l

0.01a


gamma-HCH (lindane)

mg/l

3


methoxychlor

mg/l

30


pentachlorophenol

mg/l

10


tetrachloroethened

mg/l

10a

tentative guideline valueb

trichloroethened

mg/l

30a

tentative guideline valueb

2,4.6-trichlorophenol

mg/l

10a,c

odour threshold concentration, 0.1 mg/I

trihalomethanes


no guideline value set

see chloroform

a These guideline values were computed from a conservative hypothetical mathematical model which cannot be experimentally verified and values should therefore be interpreted differently. Uncertainties involved may amount to two orders of magnitude (i.e., from 0.1 to 10 times the number).

b When the available carcinogenicity data did not support a guideline value, but the compounds were judged to be of importance in drinking-water and guidance was considered essential, a tentative guideline value was set on the basis of the available health-related data.

c May be detectable by taste and odour at lower concentrations.

d These compounds were previously known as 1,1-dichloroethylene, tetrachloroethylene, and trichloroethylene, respectively.

Table 4. Aesthetic quality

Constituent or characteristic

Unit

Guideline value

Remarks

aluminium

mg/l

0.2


chloride

mg/I

250


chlorobenzenes and chlorophenols

-

no guideline value set

these compounds may affect taste arid odour

colour

true colour units (TCU)

15


copper

mg/l

1.0


detergents

-

no guideline value set

there should not be any foaming or taste and odour problems

hardness

mg/l (as CaCO3)

500


hydrogen sulfide

-

not detectable by consumers


iron

mg/l

0.3


manganese

mg/l

0.1


oxygen - dissolved

-

no guideline value set


pH

-

6.5-8.5


sodium

mg/l

200


solids - total dissolved

mg/l

1000


sulfate

mg/l

400


taste and odour

-

inoffensive to most consumers


temperature

-

no guideline value set


turbidity

nephelometric turbidity units (NTU)

5

preferably <1 for disinfection efficiency

zinc

mg/l

5.0


Table 5. Radioactive constituents

Constituent

Unit

Guideline value

Remarks

gross alpha activity

Bq/l

0.1

(a) If the levels are exceeded more detailed radionuclide analysis may be necessary. (b) Higher levels do not necessarily imply that the water is unsuitable for human consumption

gross beta activity

Bq/l

1