IS 10500:2012 drinking water standards: parameters and limits

What is IS 10500:2012?

IS 10500:2012 is the second revision of the Indian Standard "Drinking Water: Specification", first published in 1983 and revised in May 2012. Clause 3.1 defines drinking water as water "intended for human consumption for drinking and cooking purposes from any source", treated or untreated.

The standard applies to tap water, bore wells, hand pumps, open wells and treated supplies. Packaged water is handled separately. FSSAI regulates packaged drinking water and mineral water under its food product standards, and BIS has separate product standards for them: IS 14543:2024 and IS 13428:2024.

Jal Jeevan Mission uses IS 10500 as its benchmark. The Ministry of Jal Shakti's Drinking Water Quality Monitoring and Surveillance Framework (2021) says piped water must be supplied "of prescribed quality (BIS:10500)".

What is the latest version of IS 10500?

The latest version is IS 10500:2012 with Amendments 1 to 4. The BIS programme of work for FAD 14 lists IS 10500:2012 as reaffirmed in August 2023 with four amendments, and it shows no new revision under development.

Many copies of the IS 10500 table online still show pre-amendment values. Even the Jal Jeevan Mission framework's annex comparing BIS and WHO values shows boron 1.0 and mineral oil 0.5. If your report template was built from an old copy, check it against the table above.

Where can I get the IS 10500 PDF?

The official source is BIS. The BIS standards dashboard lists IS 10500:2012 under "Drinking water" with four amendments and a download link. The Government's National Consumer Helpline also hosts a BIS copy of the 2012 text that carries the Amendment No. 2 slip.

When you file the IS 10500 PDF in your lab, file all four amendment slips with it. An assessor will expect the lab's controlled copy of the standard to be the current one.

What is the difference between acceptable and permissible limits?

The acceptable limit is the value the standard recommends you meet. The permissible limit is a higher ceiling that may be tolerated only "in the absence of an alternate source". Above the permissible limit, the source has to be rejected.

The note under Tables 1 to 4 reads: "It is recommended that the acceptable limit is to be implemented. Values in excess of those mentioned under 'acceptable' render the water not suitable, but still may be tolerated in the absence of an alternative source but up to the limits indicated under 'permissible limit in the absence of alternate source' in col 4, above which the sources will have to be rejected."

Where the permissible column says "No relaxation", the acceptable limit is the only limit. That applies to pH, nitrate, arsenic, lead, mercury, every pesticide and many more.

A simple example: a bore well with TDS of 900 mg/L is above the acceptable 500 mg/L but within the permissible 2,000 mg/L. Your report should not say it simply "complies". It should show that it exceeds the acceptable limit and is within the permissible limit, which applies only where no alternate source exists.

What are the drinking water parameters as per IS 10500?

IS 10500 sets drinking water parameters in six tables: organoleptic and physical (Table 1), general chemical (Table 2), toxic substances (Table 3), radioactive substances (Table 4), pesticide residues (Table 5) and bacteriological quality (Table 6). Clauses 4.2 and 4.3 add virological and biological requirements.

The tables below give every drinking water parameter limit in India under IS 10500, with amendments applied. "Method" is the method of test in column 5 of the standard; "Part" means a part of IS 3025 unless stated.

Table 1: organoleptic and physical parameters

Remarks in the standard: colour may be extended to 15 only if toxic substances are not suspected. Odour is tested cold and when heated, at several dilutions. Taste is tested only after safety has been established.

Table 2: general parameters concerning substances undesirable in excessive amounts

Three remarks in Table 2 change how you judge a result:

• Free residual chlorine applies only when the water is chlorinated and is tested at the consumer end. When protection against viral infection is required, the standard says it should be at least 0.5 mg/L.
• Sulphate may be extended to 400 mg/L provided magnesium does not exceed 30 mg/L.
• Iron and manganese: the remark that their total "shall not exceed 0.3 mg/l" was not changed when Amendment 1 raised iron to 1.0 mg/L. Decide how your lab applies it and record the decision.

Table 3: parameters concerning toxic substances

Every toxic substance has "No relaxation", so the acceptable limit is the only limit.

Pesticides are item (vii) of Table 3, with limits in Table 5.

Table 4: radioactive substances

Table 5: pesticide residues

Pesticide limits are in micrograms per litre (µg/L), not mg/L. The standard says pesticide analysis "shall be conducted by a recognized laboratory using internationally established test method". Where two methods are given, the USEPA method is the reference.

Table 6: bacteriological quality

The footnotes matter. E. coli is the more precise indicator of faecal pollution, and thermotolerant coliforms are an acceptable alternative. The standard also says total coliforms are "not acceptable indicators of the sanitary quality of rural water supplies, particularly in tropical areas". That is why the total coliform requirement sits under treated water only. If either E. coli or total coliforms are detected, immediate investigative action is required, starting with repeat sampling.

Virological and biological requirements

• MS2 phage: absent in 1 litre, tested by USEPA method 1601 or 1602 (1602 is the referee method, as amended by Amendment 3).
• Cryptosporidium: absent in 10 litres, by USEPA 1622, USEPA 1623 or ISO 15553:2006.
• Giardia: absent in 10 litres, by USEPA 1623 or ISO 15553:2006.

Which test methods does IS 10500 use?

IS 10500 points mainly to the IS 3025 series, "Methods of sampling and test (physical and chemical) for water and wastewater". Some parameters use annexes of IS 13428, IS 14194 for radioactivity, IS 15185 for E. coli and coliforms (Amendment 2), and USEPA, APHA and ASTM methods for pesticides and trace organics.

Amendment 3 added a note to Tables 2 and 3: "Approved and validated international test methods from ISO/APHA/ASTM/AOAC/EPA/EN may also be followed." In a dispute, the method in column 5 is the referee method. Many labs therefore use APHA Standard Methods, for example APHA 4500-Cl B for chloride, alongside the IS 3025 parts.

Sampling follows clause 5 as rewritten by Amendment 3: IS 1622 and IS 3025 (Part 1), and IS 15185 for bacteriological samples. Both sampling standards have since changed: the BIS portal shows IS 3025 (Part 1):1987 superseded by IS 17614 (Part 1):2021, and IS 1622 revised as IS 1622:2026.

Which drinking water parameters are tested most often?

Most routine tests cover a short list, not all of the tables above. The Jal Jeevan Mission framework sets 16 basic parameters: pH, TDS, turbidity, chloride, total alkalinity, total hardness, sulphate, iron, total arsenic, fluoride, nitrate, total coliforms, E. coli or thermotolerant coliforms, free residual chlorine, colour and odour. It marks iron, arsenic and fluoride as region-specific.

A full IS 10500 test adds the metals, organics, pesticides and radioactivity. These need instruments such as AAS or ICP, GC or GC-MS, and alpha/beta counters. For a list of equipment by parameter group, see how to start a water testing lab.

What mistakes do labs make when reporting against IS 10500?

The most common mistakes are old limits, wrong units and judging a parameter that does not apply to the sample. Each one can turn a correct result into a wrong report.

1. Pre-amendment limits. Iron at 0.3, boron permissible at 1.0, arsenic permissible at 0.05 and mineral oil at 0.5 are all out of date.
2. "Complies" for a result above the acceptable limit. A chloride of 595 mg/L is within the permissible 1000 mg/L, but the report must show that it exceeds the acceptable 250 mg/L.
3. Wrong units. Nitrate is "as NO3" (45 mg/L), not as nitrogen. Ammonia is "as total ammonia-N". Pesticides are in µg/L.
4. Free residual chlorine judged on unchlorinated water. The limit applies only when the water is chlorinated.
5. Total coliforms judged on an untreated bore well. Table 6 places total coliforms under treated water entering or in the distribution system.
6. Packaged water reported against IS 10500. Packaged drinking water and mineral water have their own FSSAI standards and BIS product standards (IS 14543:2024 and IS 13428:2024).