As per IS 10500 : 2012, what is the acceptable limit and the permissible limit (in the absence of an alternate source) for Total Dissolved Solids (TDS)?
- A250 mg/L and 1000 mg/L
- B500 mg/L and 1000 mg/L
- C500 mg/L and 2000 mg/LCorrect
- D300 mg/L and 600 mg/L
Solution
Concept
IS 10500 limits for TDS
Formula
NONE
Step-by-step solution
1. Refer to IS 10500:2012 Table 1 for physical parameters of drinking water. 2. The acceptable limit for Total Dissolved Solids (TDS) is specified as 500 mg/L. 3. The permissible limit in the absence of an alternate source is 2000 mg/L. 4. Hence, the correct limits are 500 mg/L and 2000 mg/L. Answer: C
Explanation
As per IS 10500:2012 (Drinking Water Specification, Table 1), the acceptable limit for Total Dissolved Solids (TDS) is 500 mg/L. In the absence of an alternate drinking water source, the maximum permissible limit is 2000 mg/L. High TDS affects palatability and may cause gastrointestinal irritation.
Why the other options are wrong
A) 250 mg/L is the acceptable limit for chlorides, not TDS. B) 1000 mg/L is the permissible limit for chlorides, not TDS. D) 300 mg/L and 600 mg/L were earlier standard thresholds for hardness.
Shortcut
IS 10500 TDS: Acceptable = 500 mg/L, Permissible = 2000 mg/L.
Common mistake
Confusing the permissible limit of 2000 mg/L with hardness/alkalinity limit of 600 mg/L.
Correct answer: C) 500 mg/L and 2000 mg/L