Question

Given below are two statements

Statement I:  Volatile Organic Chemical (VOCs) are contaminated more commonly found in groundwater than in surface water

Statement II: VOCs are one of the criterion parameters to determine drinking water quality

In light of the above statement, choose the correct answer from the option given below

1. Both statement I and statement II are true
2. Both statement I and statement II are false
3. Statement I is correct but statement II is false
4. Statement I is incorrect but statement II is true

Answer 1

Correct Answer - Option 3 : Statement I is correct but statement II is false

Statement I:  Volatile Organic Chemical (VOCs) are contaminated more commonly found in groundwater than in surface water.Explanation:

• Volatile organic compounds (VOC) are organic chemicals that have a high vapour pressure at room temperature.
• High vapour pressure correlates with a low boiling point, which relates to the number of the sample's molecules in the surrounding air, a trait known as volatility.
• VOCs (volatile organic compounds) are EPA-regulated contaminants present in the air you breathe and in water.
• VOCs originate from a host of common household products, from bug sprays to paint thinners.
• Through spillage and runoff, they can end up in your water supply.
• Most VOCs enter the water supply directly as a result of human activity.
• Improper disposal of volatile organic compounds causes them to leach into the ground.
• Although VOCs tend to escape from surface water through volatilization (evaporation) into the air, once dissolved in groundwater they are more persistent.
• Once they’ve infiltrated the groundwater, they can migrate from aquifers to lakes and reservoirs.

Thus, Statement I is true.

Statement II: VOCs are one of the criterion parameters to determine drinking water quality.

Explanation:

• The Bureau of Indian Standards (BIS) has prepared a draft standard for criteria parameters of the supply system of piped drinking water.
• The water treatment process should be planned in such a manner that after treatment the drinking water should conform to the Indian Standard (IS) 10500 developed by the BIS. 
• VOC's are not one of the criteria parameters to determine the quality of drinking water as per BIS, EPA or WHO standards.

​Thus, Statement II is false.

Hence, Statement I is correct but statement II is false.

The criteria parameters according to IS:10500  for determining the quality of drinking water are:

Parameters	Requirement (Acceptable Limit)	Permissible Limit in the Absence of Alternate Source
Alkalinity	200	600
pH	7 - 8.5	<6.5 & > 9.2
Hardness (mg/L)	200	600
Chloride content (mg/L)	250	1000
Free ammonia (mg/L)	0.15	0.15
Organic ammonia (mg/L)	0.3	0.3
Nitrite (mg/L)	0	0
Nitrate (mg/L)	45	45
Fluoride content (mg/L)	1	1.5
Iron as Fe (mg/L)	0.1	1.0
Sulphate (mg/L)	200	400
Calcium (mg/L)	75	200