1. Water Quality
Criteria

2. International standards for drinking water are given below.
1-Fluoride
• Water is tested for Fluoride
ion concentration.
• Its deficiency is harmful and
causes diseases.
• Fluoride ion is added to water
to bring its concentration
upto 1ppm.

3. • Makes enamel on the surface of teeth.
• However, above 2ppm concentration
causes brown molting of teeth
• Above 10ppm causes harmful effects
to bones and teeth

4. 2-Lead
• Water gets contaminated with
lead.
• Upper limited of lead in water is
50ppm.
• Excessive amount can damage
liver and reproductive system.

5. 3-Sulphates
• Range of sulphates in drinking
water is 500ppm.
• Above this range it has harmful
effects.
• Moderate concentration is
harmless

6. 4-Cholride
• The limit of chloride ion is 250
mg/L.
• Above this limit it
corrosiveness of water.
• In combination with Sodium,
gives a salty taste to water.

7. 5-Iodide
• The limit of iodide is 4.0 mg/L.
• It is essential and beneficial
element in metabolism.
• Its deficiency can cause goiter.

8. 6-Nitrate
• The limit of Nitrate is 10mg/L.
• Above this, it can cause fatal
blood disorder in infants.

9. 7-Aluminium
• Its limit is 50-200ug/L.
• It has no necessary role in
human or animal diet.
• Non-toxic in natural water.
• Toxic in when pH of water gets
lower.

10. 8-Barium
• Its normal range in 2000ug/L.
• Concentration above 2000ug/L can cause
death.
• Smaller concentration can cause damage
to heart, blood vessels and nerves.

11. 9-Boron
• Its limit is 2.4mg/L.
• Its essential for plant
growth.
• May be toxic when
concentration is higher

12. 10-Cadmium
• Its range is 5ug/L
• Toxic when its range is
more than 5ug/L
• Can cause damage to the
liver, kidney.