It is no secret that the quality of drinking water supply in India is not very safe to drink and is either treated with harsh chemicals like chlorine or fluorine or has TDS (Total Dissolved Solids) levels. Did you know that about two-thirds of the country consume untreated and unsafe water? Further diseases related to drinking water contamination is a major problem in a country like ours where river water and ground water are often polluted due to poor sanitation , agricultural/industrial run off. etc,. With this background, the standards established by water quality monitoring boards like the Bureau of Indian Standards (BIS) are essential to be followed. These guidelines define and monitor drinking water quality, and are crucial in preventing waterborne diseases, and safeguarding public health.
Regulatory Bodies Governing Water Quality in India
Bureau of Indian Standards (BIS)
In India the Bureau of Indian Standards (BIS) is responsible for establishing drinking water quality standards. Its responsibilities include:
- Developing Standards
- Certification and Ensuring Compliance
- Creating public Awareness
Central Pollution Control Board (CPCB)
The Central Pollution Control Board (CPCB) is another body that monitors and enforces water quality norms in India. Its primary functions include:
BIS Standards for Drinking Water (IS 10500:2012)
The BIS has established IS 10500:2012 as the benchmark for assessing drinking water quality in India.
Overview of IS 10500:2012
First introduced in 1983 and revised periodically, the latest version of this standard was released in 2012. The IS 10500:2012 defines the permissible and acceptable limits for physical, chemical, and microbiological parameters to ensure the safety and quality of drinking water. The distinction between acceptable and permissible limits is for those areas where alternate water sources are unavailable.
Key Parameters
- Physical Parameters
- Color: Acceptable limit is 5 Hazen units (used for measuring water discoloration), permissible up to 15 in the absence of toxic substances.
- Odor and Taste: Must be agreeable.
- Turbidity: Limited to 1 NTU(Nephelometric Turbidity unit used to measure turbidity), with a permissible relaxation up to 5 NTU.
- pH Value: Ranges between 6.5 to 8.5.
- Chemical Parameters
- Total Dissolved Solids (TDS): Acceptable limit is 500 mg/l, permissible up to 2000 mg/l.
- Hardness of Water: While 200 mg/l is acceptable, 600 mg/l is a permissible limit.
- Heavy Metals: Strict limits include lead (0.01 mg/l), arsenic (0.01 mg/l), and mercury (0.001 mg/l), with no permissible relaxation as these are toxic to humans.
- Microbiological Parameters
- Drinking water must be free from E. coli and coliform bacteria in a 100 ml sample. The detection of such contaminants renders the water unfit for consumption.
Acceptable and Permissible Limits
The BIS standard divides water quality benchmarks into two categories:
- Acceptable Limit: Ideal for safe consumption.
- Permissible Limit: Tolerated only in the absence of an alternate source.
|
Parameter |
Acceptable Limit |
Permissible Limit |
|
pH Value |
6.5 – 8.5 |
No relaxation |
|
Turbidity (NTU) |
1 |
5 |
|
Total Hardness (mg/l) |
200 |
600 |
|
Iron (mg/l) |
0.3 |
No relaxation |
|
E. coli (per 100 ml) |
Not detectable |
Not detectable |
Resources: BIS Standards can be downloaded from the official website of Bureau of Indian Standards (BIS) - https://www.bis.gov.in/ or from CPCB website - https://cpcb.nic.in/water-quality-criteria/ / https://cpcb.nic.in/wqm/BIS_Drinking_Water_Specification.pdf
Implementation and Compliance
-
Role of Water Supply Agencies
Municipal and private water suppliers, responsible for treating water, are accountable for implementing drinking water standards in India. -
Monitoring and Testing
Regular testing of water quality is essential to identify contaminants and ensure compliance. -
Public Awareness
Informed consumers can demand safe water, report quality issues, and take steps to ensure the water they consume meets BIS specifications.
While BIS standards provide the guidelines, it is also important that the local authorities and informed consumers make sure the specifications are complied with, ensuring the water we drink is safe and free of contaminants. From an individual consumer perspective, one can take additional safety precautions by installing water purification systems like RO (Reverse Osmosis), UV, and UF.
FAQ Section
- What are the BIS standards for drinking water?
The BIS standards, specified in IS 10500:2012, define acceptable and permissible limits for physical, chemical, and microbiological parameters to ensure water is safe for consumption.
- Where can I find the BIS standards for drinking water in PDF format?
You can download the BIS standards from the official BIS website or purchase them from authorized outlets. Summaries and interpretations are also available on educational and government websites.
- Why is it important to adhere to drinking water quality standards?
Adhering to these standards protects public health by preventing waterborne diseases and minimizing exposure to harmful contaminants.
- How often should water quality be tested?
Water quality should ideally be tested regularly, at least once every six months, especially in areas where contamination risks are high or water sources are untreated.
- What should I do if my water supply does not meet BIS standards?
If your water supply fails to meet BIS standards, consider reporting the issue to local authorities or water supply agencies. Additionally, you can use home water treatment solutions like RO purifiers or UV filters to ensure safe drinking water.
