-Water Quality Standards

8/12/2019 -Water Quality Standards

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Drinking Water Quality Guidelines

and Standards

Saiqa Imran

Senior Research Officer (NWQL)

National Water Quality Laboratory (NWQL) PCRWR

OUR WATER: OUR FUTURE


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Guideline: A recommended limit that should not be exceeded

WHO Guidelines for Drinking Water Quality (2006) to ensure

safety of drinking water

Standard: A mandatory limit that must not be exceeded (often reflects legal

duty or obligation)

Standards vary among countries and regions



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Why do we need

to set Guidelines

and Standards

for drinking

water?



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Rapid Increase in Pollution Load on Ground & Surface Water

Bodies of Pakistan



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Mission


To protect the healthof the people

by assuring safeand reliable

drinking water free ofall contaminants


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What is Safe Drinking Water?

Safe

adj. free from danger; secure; notinvolving risk

Websters Collegiate Dictionary, 1998



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What is Safe Drinking Water?

WHO Definition

Safe drinking water is

does not represent any significant risk to health overthe lifetime of consumption, including differentsensitivities that may occur between life stages.



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How do we know?

Drinking

Water

safeUnsafe



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Ensure safe drinking water

Identify problems

Adopt precautionary measures

Raise awareness

Determine the effectiveness of water treatment

technologies Select an appropriate water source

Influence policies to supply safe water

Through

Water Quality Testing



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Goal of Guidelines or Standards

Safe drinking water is a

basic right to all in spiteof their social and

economic conditions



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What is Guidelines? Guidelines are advisory in nature based on scientific research and

epidemiological findings and are not to be confused with legalstandards

Provide guidance to Govt. for protection of public health

A guideline value represents the conc. of constituents that does notresult in any significant risk to the health of the consumer over alifetime

Guidelines are not intended for absolute and direct application in everycountry

Guidelines (WHO) are too conservative or too liberal to be applied in aparticular country (may or may not suit to local conditions)



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How WHO Prepared the Guidelines?

1) Technical Efforts

Over 200 experts from 40 different countries

Over a period of 4 years

More than 19 review group meetings involving the participation ofnumerous institutions

2) Financial Support

Organizations and countries included;

DANIDA, NORAD, SIDA, ODA, Belgium, Canada, Denmark, Finland,

France, Germany, Italy, Japan, Netherlands, Norway, Poland, Sweden,UK, USA.



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N ti l W t Q lit L b t (NWQL) PCRWR


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How WHO GV were derived?GV= TDI x BW x P / C

GV Guidelines value, expressed in mg or g / liter of drinking water

TDI Tolerable daily intake (An estimated amount of a substance in food or drinking water in

mg or g per Kg of body weight)

BW Body weight (For adult - 60 Kg, infants - 5 kg, children - 10 kg)

P %age of the TDI (1-100%), depending on the magnitude of exposure from food and air. In

case limited information- Default value (10%) was used

C Daily drinking water consumption (For adults 2 liters, 10 kg child -1 liter and 5 kg infant -

0.75 liter)

NOAEL No-observed-adverse-effect level TDI = NOAEL

IF TDI Values = LOAEL / UF Where:

LOAEL Lower-observed-adverse-effect level TDI = LOAEL / UF Where

UF Uncertainly factor (1-10000) - UF value depends on the nature of the toxic effect, size , type

of population to be protected and the quality of the toxicological informations and is

decided on case-to-case basis

By putting TDI value

GV = NOAEL x BW x P/C GV = LOAEL / UF x BW x P/C



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National Water Q alit Laborator (NWQL) PCRWR


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Provisional Guideline Values

For substances for which the uncertainty factors were greater

than 1000

Guideline values are designated as provisional in order toemphasize the higher level of uncertainty inherent in thesevalues.

A high uncertainty factor indicates that the guideline valuemay be considerably lower than the concentration at whichhealth effects would actually occur in a real humanpopulation.

Guideline values with high uncertainty are more likely to bemodified as new information becomes available.




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Limitations of WHO Guidelines

No GV for Bottled/ Mineral water

No GV for short-term Exposure

No GV for all chemicals used for watertreatment

No GV for Materials used for water supply

No Minimum Desirable Level




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WHO GUIDELINES

Bacteriological Quality

Organ isms Gu idel ine Value

All water intended for drinking

E. Coli or thermo tolerant coliform bacteria Must not be detectable in any 100 ml sample

Treated water entering the distributionsystem

E. Coli or thermo tolerant coliform bacteria Must not be detectable in any 100 ml sample

Total coliform bacteria Must not be detectable in any 100 ml sample

Treated water in the distribution system

Coli or thermo tolerant coliform bacteria Must not be detectable in any 100 ml sample

Total coliform bacteria Must not be detectable in any 100 ml sample. In

the case of large supplies, where sufficient

samples are examined, must not be present in

95% of samples taken throughout any 12-month

period.




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WHO GUIDELINES

Chemicals of Health Significance

Ino rgan ic Guidel ine Value (mg/l)

Antimony 0.005

Arsenic 0.01

Barium 0.7

Boron 0.3

Cadmium 0.003

Chromium 0.05

Copper 2

Cyanide 0.07

Fluoride 1.5

Lead 0.01

Manganese 0.5

Mercury 0.001

Molybdenum 0.07

Nickel 0.02

Nitrate 50

Nitrite 3

Selenium 0.01




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WHO GUIDELINES

Other Parameters (Physical)

Parameter Level

Color 15 TCU

Taste & Odor -

Temperature -

Turbidity 5 NTU

Inorganic

Aluminium 0.2 mg/l

Ammonia 1.5 mg/l

Chloride 250 mg/l

Copper 1 mg/l

Hardness -

Hydrogen Sulfide 0.05 mg/l

Iron 0.3 mg/l

Manganese 0.1 mg/l

Dissolved Oxygen -

pH -

Sodium 200 mg/l

Sulfate 250 mg/l

TDS 1000 mg/l

Zinc 3 mg/l



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WATER QUALITY STANDARDS:

WHAT ARE THEY GOOD FOR?

A basis for assessing water quality data

A "trigger" for initiating action

An "end point" for terminating action A regulatory/ educational tool




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Standards

Standards are fixed by law and adopted in countries totheir national priorities taking in account their economic,technical, social, cultural and political situation

Standards are to be established, requested and enforced

by competent national authorities by adopting a riskbenefit approach

At any time they can be changed or modified whenever

new scientific evidence becomes available




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THREE EXAMPLES

(Not adopted WHO guidelines )

SudanHigher values adopted than WHO

NO3(N) 50 mg/l instead of 10 mg/lF 7 mg/l instead of 1.5 mg/l

TDS 5000 mg/l instead of 1000 mg/l

TanzaniaHigher values adopted than WHOCadmium, Copper, Fluoride, Nitrite,Nitrate, Sulfate, Chloride and Turbidity

Industrialized countries (More concerned regarding risks affecting health)More strict than WHO guidelines as they can afford advanced treatment

systems and sophisticated laboratoriesEU's drinking water standards

Lower values adopted than WHOFe 0.2 mg/l instead of 0.3 mg/lNO2 0.5 mg/l instead of 3 mg/l




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Criteria for Formulation(Standards or regulations related to public health)

Toxicological or epidemiological findings

Economic interest

Socio-cultural characteristics

Average daily intake

Hygienic practices

Public awareness and sensitivity

Technological development

Political situation




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PSQCA DRIKING WATER STANDARDS

Character ist ics Permissible

Limi ts

Character ist ics Permissible

Limi tsAntimnoy (Sb) 0.005 (mg/l) Benzene 0.010 (mg/l)

Arsenic (As) 0.050 (mg/l) Benzo(a) pyrene 0.0070 (mg/l)

Barium (Ba) 1.0 (mg/l) Bromate 0.025 (mg/l)

Borate (B) 1.0 (mg/l) Carbon tetrachloride 0.002 (mg/l)

Cadmium (Cd) 0.003 (mg/l) Dichloromethane 0.020 (mg/l)

Chromium (Cr) 0.050 (mg/l) O-dichloromethane 1 (mg/l)

Copper (Cu) 1.0 (mg/l) P-dichloroethane 0.300 (mg/l)

Cyanide (Cn) 0.070 (mg/l) 1.2 dichloroethane 0.030 (mg/l)

Fluoride (F) 1.5 (mg/l) Cis-1.2 dichloroethylene 0.030 (mg/l)

Lead (Pb) 0.10 (mg/l) Trans1.2 dichloroethylene 0.050 (mg/l)

Manganese (Mn) 0.500 (mg/l) 1.2 dichloropropane 0.040 (mg/l)

Mercury (Hg) 0.001 (mg/l) Ethylbenzene 0.3 (mg/l)

Nickel (Ni) 0.020 (mg/l) Monochlorobenzene 0.3 (mg/l)

Nitrate (N) 10.0 (mg/l) Styrene 0.020 (mg/l)

Nitrite (NO2) 2.0 (mg/l) Tetrachloroethylene 0.040 (mg/l)

Selenium (Se) 0.010 (mg/l) Trichloroethylene 0.070 (mg/l)

Q y y ( Q )



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PSQCA DRINKING WATER STANDARDS

Character is t ics Permissib le

L imi ts

Character is t ics Permissib le

L imi ts

Toluene 0.700 (mg/l) Lindane 0.002 (mg/l)

1.1.1 trichloroethane 0.002 (mg/l) Methoxychlor 0.020 (mg/l)

1.1.2.2 tetrachloroethane 0.040 (mg/l) Pentachlorophenol 0.009 (mg/l)

Chlorure de vinyl 0.005 (mg/l) Simazine 0.002 (mg/l)

Xylenes 0.5 (mg/l) Aldrine 0.000030 (mg/l)

Alachlor 0.020 (mg/l) Dieldrine 0.000030 (mg/l)

Aldicarb 0.010 (mg/l) 2,4,5 TP 0.009 (mg/l)

Atrazine 0.002 (mg/l) Di(2-ethylhexy) adipate 0.0080 (mg/l)

Carbofuran 0.007 (mg/l) Di(2-ethylhexy)

phtalate

0.080 (mg/l)

Chlordane 0.00020 (mg/l) Total trichlorobenzenes 0.020 (mg/l)

1,2-dibromo-3-chloropropane 0.001 (mg/l) Hexachlorobenzene 0.001 (mg/l)

2,4-D 0.030 (mg/l) Diquat 0.010 (mg/l)

Ethylene dibromide 0.00003 (mg/l) Pentachlorophenol 0.009 (mg/l)

Heptachlor 0.00003 (mg/l)

Heptachlor epoxide 0.00003 (mg/l)

y y ( )



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PSQCA DRIKING WATER STANDARDS

Microbiological Limits

Ozonation Other Process

Escherichia coli 0/250 ml 0/250 ml

Total Coliforms 0/250 ml 0/250 ml

Enterococci (Streptoco---) 0/250 ml 0/250 ml

Sporulated SRA 0/100 ml 0/50 ml

Pseudomonas aeruginosa 0/250 ml 0/250 ml

Parasites and Pethogenic micro-organisms Shall be free Shall be free

y y ( )



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PSQCA Standards for Bottled water

Bottled water:Water other than natural mineral water which is filled into hermetically

sealed containers/bottles of various compositions forms, and

capacities that may be safe and suitable for direct consumption.



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PSQCA Standards for Bottled Water

Characteristics Units Maximum Permissible Limit

(ppm)

PSQCA

Alkalinity (m.mol/l)NGVS

Bicarbonate (mg/l)NGVS

Calcium (mg/l)100

Carbonate (mg/l) NGVS

Chloride (mg/l)250

Co lour (TCU)5

Conductivity (S/cm)NGVS

Fluoride (mg/l)0.7

Hardness (mg/l) NGVS

Iron (mg/l)0.3

Magnesium (mg/l)50

Odor -Unobjectionable

Nitrate-N (mg/l)10



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Cont.Characteristics Units Maximum Permissible Limit (ppm)

PSQCA

pH -6.5-8.5

Potassium (mg/l)10

Sodium (mg/l)50

Sulfate (mg/l)250

Taste -Unobjectionable

TDS (mg/l)500

Turbidity (NTU)0.5

Phosphate (mg/l)NGVS

Arsenic mg/l 0.010

Lead mg/l 0.010

Total Coliform MPN/100Liter 0

E-Coli MPN/100Liter 0



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General public, in Pakistan, use subjective quality criteria like brackish,foul smelling, bad tasting, turbid or colored water to determine that it is

not suitable for drinking.

The agencies responsible for monitoring of water quality perform periodic

checks of the basic water parameters against certain recommendedstandards.

Research-based standards and guidelines for quality drinking water must

be available to monitoring agencies.

Need for National Standards for Drinking Water Quality



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In 2002, the Pakistan Standards Institute compiled the preliminary standards for quality drinking

water.

In 2004, Pakistan Council of Research in Water Resources prepared a report related to water

quality in Pakistan with recommendations for establishing water quality standards.

Johri (2005) from WHO office proposed a framework of action for improving the quality of

drinking water in Pakistan

In March 2005,Health Services Academy, the Ministry of Health, in collaboration with World

Health Organization (WHO) sponsored, organized and conducted a 4-day workshop in Islamabad

to update the existing water quality standards in accordance with the quality guidelines of WHO.

The workshop was designed to seek input of experts from all important federal, provincial andprivate agencies

Through a combination of lectures, discussions, intense work Sessions, and utilization of reading

literature provided by WHO and Ministry of Health, quality standards for drinking water in

Pakistan were finalized.

Establishment of National Standards for Drinking Water Quality



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National Standards for Drinking Water Quality

Characteristics Units Maximum Permissible Limit (ppm)

NSDWQ

Alkalinity (m.mol/l) NGVS

Bicarbonate (mg/l) NGVS

Calcium (mg/l) NGVS

Carbonate (mg/l) NGVS

Chloride (mg/l) 250

Co lour (TCU)


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NSDWQ

pH -6.5-8.5

Potassium (mg/l)NGVS

Sodium (mg/l)NGVS

Sulfate (mg/l)NGVS

Taste -Unobjectionable

TDS (mg/l)


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NSDWQ

Aluminium (Al) mg/1-


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ANY QUESTION ?



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THANK YOU

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