Sections 51 explained: this guide covers what it means, who it applies to, the step-by-step process, documents required, fees, due dates and penalties in India — so you can stay compliant with confidence and avoid costly mistakes.
Sections 51 to 54 set up the testing chain behind effluent sampling. The Central Government and each State Government can establish or specify a Central Water Laboratory and a State Water Laboratory. Government analysts are appointed for those laboratories, and Board analysts for the Boards' own laboratories. A document purporting to be a report signed by either kind of analyst may be used as evidence.
This article is current as amended up to the Water (Prevention and Control of Pollution) Amendment Act, 2024 (these sections were not changed by it). Later amendments and notifications should be checked. If an analyst's report is the basis of a notice to you, our legal consultation team can advise on how to meet it.
The Central Government may establish or specify a Central Water Laboratory (section 51), and a State Government a State Water Laboratory (section 52), and may make rules on their functions, sample submission, report form and fees. Government analysts are appointed for those laboratories, and Board analysts for the Boards' own laboratories (section 53). A document purporting to be a report signed by a Government or Board analyst may be used as evidence of the facts stated (section 54). Under section 22(4), the report of the section 51 or 52 laboratory prevails over the Board's laboratory if they differ.
Section 51: the Central Water Laboratory
Section 51(1). The Central Government may, by notification in the Official Gazette:
- (a) establish a Central Water Laboratory; or
- (b) specify any laboratory or institute as a Central Water Laboratory, to carry out the functions entrusted to it under the Act.
Section 51(2). After consultation with the Central Board, the Central Government may make rules prescribing:
- (a) the functions of the Central Water Laboratory;
- (b) the procedure for submitting samples of water, sewage or trade effluent for analysis or tests, the form of the report and the fees payable for it;
- (c) other matters necessary or expedient for the laboratory to carry out its functions.
Section 52: the State Water Laboratory
Section 52 is the mirror for a State. The State Government may by notification establish a State Water Laboratory or specify any laboratory or institute as one, and, after consultation with the State Board, may make rules prescribing the same three matters: functions, procedure for submission with the form of report and fees, and other incidental matters.
| Point | Section 51 | Section 52 |
|---|---|---|
| Laboratory | Central Water Laboratory | State Water Laboratory |
| Established or specified by | Central Government, by notification | State Government, by notification |
| Rules after consulting | Central Board | State Board |
| Used in sampling for | Union territories (section 21(3)(e)(i)) | Any other area (section 21(3)(e)(ii)) |
A laboratory "specified" under these sections can be an existing laboratory or institute. It need not be a new Government building. The notification is what gives it status; check it when you rely on a report.
Section 53: analysts
| Sub-section | Who appoints | Appointed as | For analysis of samples sent to |
|---|---|---|---|
| (1) | Central Government, by notification | Government analysts, with the prescribed qualifications | A laboratory established or specified under section 51(1) |
| (2) | State Government, by notification | Government analysts, with the prescribed qualifications | A laboratory established or specified under section 52(1) |
| (3) | Central Board or State Board, by notification, with the approval of the Central or State Government | Board analysts, with the prescribed qualifications | A laboratory established or recognised by the Board under section 16 or section 17 |
Section 53(3) is "without prejudice to" section 12(3) (the Board's power to appoint officers and employees). The qualifications are prescribed; the Act sets none.
Section 54: reports of analysts
"Any document purporting to be a report signed by a Government analyst or, as the case may be, a Board analyst may be used as evidence of the facts stated therein in any proceeding under this Act."
Two points:
- "Purporting to be". The document must appear to be a report signed by the right kind of analyst.
- "May be used as evidence of the facts stated". The section lets the report be used. It does not say the report is conclusive. The sampling safeguards in section 21 still apply: the result of an analysis of sewage or trade effluent "shall not be admissible in evidence in any legal proceeding unless" section 21(3), (4) and (5) are complied with.
How the laboratories fit into sampling
Section 21 describes the sample being divided into two parts. One part goes to the Board's laboratory under section 16 or 17 and is analysed by a Board analyst (section 22(1)). If the occupier asks, the second part goes to the Central Water Laboratory or State Water Laboratory, where a Government analyst analyses it (section 22(3)). If the results differ, "the report of the latter shall prevail" (section 22(4)). See sections 21 to 23.
So the laboratory and analyst sections are not only background. They are how a Board's own result can be tested against an independent Government laboratory, at the occupier's cost.
The Environment (Protection) Act has comparable provisions for environmental laboratories and Government Analysts; see sections 12 to 14 of that Act. The Air Act has its own; see sections 26 to 30 of the Air Act.
A checklist when you receive an analyst's report
| Question | Why it matters |
|---|---|
| Was the sample taken with the notice, division, sealing and signatures required by section 21? | Section 21(2): the result is otherwise inadmissible |
| Was it analysed at a laboratory established, recognised or specified under section 16, 17, 51 or 52? | Sections 22, 51 and 52 |
| Is the signatory a Board analyst or Government analyst appointed by notification? | Sections 53 and 54 |
| Did you ask for the second part to go to the section 51 or 52 laboratory? | Section 22(4) lets that report prevail |
| Do the two reports differ? | If so, the section 51 or 52 report prevails |
| Who bears the cost of the second analysis? | The occupier, under section 22(5) |
An example
Hooghly Jute Mills Limited receives a Board analyst's report showing an exceedance. At sampling the plant manager had asked for the second part of the sample to go to the State Water Laboratory. The Government analyst there reports a value within the standard. The company produces both reports at the hearing. Under section 22(4), the State Water Laboratory's report prevails, and the Board has to consider whether the exceedance can be shown at all. The company pays the cost of the second analysis, as section 22(5) requires.
Need help with analyst reports?
When a case rests on a laboratory report, the first job is to test the chain behind it. Our legal consultation team can review the sampling record, the laboratories and analysts involved, and advise on the reply.
Key takeaways
- The Central and State Governments may establish or specify Central and State Water Laboratories and make rules on their functions, procedure, reports and fees.
- Government analysts serve those laboratories; Board analysts serve the Boards' own laboratories.
- A document purporting to be an analyst's signed report may be used as evidence of the facts stated.
- A section 51 or 52 laboratory's report prevails over a Board laboratory's report if they differ.
- The Act sets no fee or qualification; these are prescribed.
Read next
- Sections 21 to 23: taking samples, reports and entry
- Sections 12 to 14 of the EP Act: laboratories and Government Analysts
- Sections 26 to 30 of the Air Act: samples, laboratories and analysts
- Section 16: functions of the Central Pollution Control Board
Disclaimer: Based on the Environment (Protection) Act, 1986, the Air (Prevention and Control of Pollution) Act, 1981 and the Public Liability Insurance Act, 1991 as amended by the Jan Vishwas (Amendment of Provisions) Act, 2023 (in force for these Acts from 1 April 2024), the Water (Prevention and Control of Pollution) Act, 1974 as amended by its Amendment Act of 2024 (which applies only in the States and Union territories it names and in States that adopt it), and the National Green Tribunal Act, 2010 as amended by the Tribunals Reforms Act, 2021, as consulted on 3 October 2026. Later amendments, rules and notifications should be checked. This article is general information, not legal advice; check the official text before acting.