The maximum permissible concentration of total hardness in drinking water is 500 milligrams per liter (mg/L). Hardness is caused by the presence of dissolved minerals, such as calcium and magnesium. These minerals can cause scale buildup in pipes and appliances, and can also affect the taste of water. However, they are not considered to be harmful to human health.
The World Health Organization (WHO) recommends that the total hardness of drinking water should not exceed 500 mg/L. This limit is based on the assumption that people will drink about 2 liters of water per day. At this level of consumption, the amount of minerals ingested from drinking water is not considered to be harmful.
Some people may prefer to drink water with a lower level of hardness. This is because hard water can cause scale buildup in pipes and appliances, and can also affect the taste of water. If you are concerned about the hardness of your water, you can have it tested by a professional. You can also install a water softener to reduce the hardness of your water.
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a brief explanation of each option:- Option A: 50 milligrams per liter (mg/L) is a very low level of hardness. This level of hardness is unlikely to cause any problems.
- Option B: 100 mg/L is a moderate level of hardness. This level of hardness may cause some scale buildup in pipes and appliances, but it is not considered to be harmful to human health.
- Option C: 200 mg/L is a high level of hardness. This level of hardness can cause scale buildup in pipes and appliances, and can also affect the taste of water. Some people may prefer to drink water with a lower level of hardness.
- Option D: 500 mg/L is the maximum permissible concentration of total hardness in drinking water. This limit is based on the assumption that people will drink about 2 liters of water per day. At this level of consumption, the amount of minerals ingested from drinking water is not considered to be harmful.