---
kind: "section"
citation: "21 C.F.R. § 112.151"
title: "21"
number: "112.151"
heading: "What methods must I use to test the quality of water to satisfy the requirements of subpart E of this part?"
url: "https://uscodex.org/cfr/21/112.151"
---

# §112.151. What methods must I use to test the quality of water to satisfy the requirements of subpart E of this part?


You must test the quality of water using:

- (a) The method of analysis published by the U.S. Environmental Protection Agency (EPA), “Method 1603: Escherichia coli (E. coli) in Water by Membrane Filtration Using Modified membrane-Thermotolerant Escherichia coli Agar (Modified mTEC), EPA-821-R-09-007),” December, 2009. The Director of the Federal Register approves this incorporation by reference in accordance with 5 U.S.C. [552(a)](/usc/5/552.md?p=a) and [1](/usc/5/1.md) CFR [part 51](/cfr/21/part51.md). You may obtain a copy from EPA, Office of Water (4303T), 1200 Pennsylvania Avenue NW., Washington, DC 20460. You may inspect a copy at FDA's Main Library, 10903 New Hampshire Ave., Bldg. 2, Third Floor, Silver Spring, MD 20993, 301-796-2039, or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html; or
- (b)
  - (1) A scientifically valid method that is at least equivalent to the method of analysis in [§ 112.151(a)](#a) in accuracy, precision, and sensitivity; or
  - (2) For any other indicator of fecal contamination, index organism, or other analyte you may test for pursuant to [§ 112.43(d)](/cfr/21/112.43.md?p=d), a scientifically valid method.

## Notes

### Amendments

[80 FR 74547, Nov. 27, 2015, as amended at 89 FR 37518, May 6, 2024]

### Authority

Authority: 21 U.S.C. 321, 331, 342, 350h, 371; 42 U.S.C. 243, 264, 271.

### Source

Source: 80 FR 74547, Nov. 27, 2015, unless otherwise noted.

### Amendments

[80 FR 74547, Nov. 27, 2015, as amended at 89 FR 37518, May 6, 2024]