Skip to main content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.


The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Contaminant Accumulation and Removal in Building Plumbing Systems



Stephen J. Treado, Mark A. Kedzierski, Daniel R. Flynn, David Wilmering, Thomas D. Montgomery, Kenneth D. Cole


This report summarizes measurements and results conducted to evaluate the accumulation and removal of water-borne contaminants in building plumbing systems. In particular, tests were conducted at the BFRL Plumbing Test Facility, which emulates a full-scale building water supply system in a controlled laboratory setting. The measurement results highlighted the difficulty in removing contaminants that have been introduced into building plumbing systems, even for relatively simple configurations such as straight pipe sections, and particularly for large water tanks such as hot water heaters. Simple flushing with cold tap water may require very long flush times to remove persistent contaminants such as diesel fuel and strychnine, and while capable of substantially reducing the number of spores in a water supply system, may benefit from supplementary decontamination procedures such as flushing with hot water, cleaning solutions or hyper-chlorination
Technical Note (NIST TN) - 1605
Report Number


contamination, decontamination, flushing, piping, plumbing, water supply
Created September 30, 2008, Updated April 17, 2009