ASTM D932-85(2002)

Iron bacteria is a general classification for microorganisms that utilize ferrous iron as a source of energy and are characterized by the deposition of ferric hydroxide in their mucilaginous sheaths. The process is continuous with these growths, and over a period of time large accumulations of slimey brown deposits can occur. Iron bacteria may clog water lines, reduce heat transfer, and cause staining; objectionable odors may arise following death of the bacteria. The organic matter in the water is consequently increased, and this in turn favors the multiplication of other bacteria.

1.1 This test method covers the determination of iron bacteria by examination under the microscope. The method provides for the identification of the following genera of bacteria found in water and water-formed deposits: Siderocapsa, Gallionella (Dioymohelix), Sphaerotilus, Crenothrix, Leptothrix, and Clonothrix.

1.2 This standard does not purport to address the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.