As per IS 10500:2012, the value of Nitrate in drinking water should be in the range of :
- Aup to 45 mg/LCorrect
- Bup to 60 mg/L
- Cup to 30 mg/L
- Dup to 15 mg/L
Solution
Concept
Nitrate limit in drinking water
Step-by-step solution
1. IS 10500:2012 gives an acceptable limit of 45 mg/L for nitrate (as NO₃), with no relaxation in the absence of an alternate source.
Explanation
High nitrate causes methaemoglobinaemia (blue baby syndrome) in infants, hence the limit of 45 mg/L.
Why the other options are wrong
60, 30 and 15 mg/L are not the specified limit in IS 10500:2012.
Shortcut
Nitrate 45 mg/L; fluoride 1.0 mg/L; chloride 250 mg/L; sulphate 200 mg/L.
Common mistake
Choosing the WHO value of 50 mg/L (not offered).
Correct answer: A) up to 45 mg/L