MICKit(tm)FPS can be used to test for microbes important in MIC
of fire protection system piping.
For and Treating MIC
For MIC to Help Prevent Long-Term Effects
Daniel H. Pope, Ph.D.
Note: This is not intended to be an endorsement of any particular product
or manufacturer. However, the number of questions we received regarding
the article "Microbiologically Influenced Corrosion," which appeared
in the July 1997 issue of Sprinkler Age, prompted us to provide additional
information on testing for MIC.
is microbiologically influenced corrosion. Simply put, MIC is corrosion
influenced by the activities of bacteria. MIC results in the formation
of deposits (nodules) and subsequent severe under-deposit pitting.
This can lead to blockage of pipes and rapid failure of the fire protection
system (FPS) piping. It has recently been recognized that MIC in FPS
is a problem throughout North America. Many different types of materials
(e.g., steel and copper) and systems (e.g., wet and dry) are affected.
for MIC in Your FPS
MICkit FPS was developed by Bioindustrial Technologies, Inc.
(BTI) to test for microbes important in MIC of fire protection system
piping. Like BTI's other test kits, it is designed to be used by field
personnel on-site. Rapid processing of the samples into the MICkit
FPS is critical in obtaining accurate information about MIC-type bacteria.
The MICkit FPS is used to enumerate viable bacteria of the following
bacteria: BTI-AERO media grows general aerobic bacteria (bacteria that
require oxygen to live). Aerobes are very important in forming biofilms
and nodules, with resulting biofouling (slime formation) and microbiologically
influenced corrosion (MIC) in aerobic systems.
bacteria: BTI-APB media grows acid-producing bacteria (APB), which
are microorganisms capable of producing organic acids. Organic acids
are an important factor in biofouling and microbiologically influenced
bacteria: BTI-SRB media grows more types of sulfate-reducing bacteria
(SRB) more rapidly than API RP-38. SRBs are strictly anaerobic bacteria
which are an important factor in biofouling and microbiologically influenced
bacteria: BTI-IRB media grows iron-related bacteria (IRB) which are
capable of precipitating iron through a variety of metabolic processes.
These bacteria are responsible for forming nodules and deposits on
surfaces (i.e., pipes).
nutrient bacteria: BTI-LNB media grows bacteria from samples containing
low levels of organic foodstuffs (e.g., potable water, well water,
demineralized water, condensates, etc.). These low nutrient bacteria
(LNB) are aerobic bacteria that are very important in the processes
of biofouling and MIC in systems using such water (i.e., FPS).
is also important to determine the basic chemistry of the water being
used in the system. Residual chlorine, hardness, and pH are important
chemical parameters that should be measured. BTI also provides a kit
for such tests.
Your FPS for MIC
to the July 1997 article about MIC indicated the problem can be found
in a variety of U.S. regions and in different types of fire sprinkler
system piping. Therefore, monitoring your piping for MIC can be important
to your system's integrity no matter where you are located.
for MIC in your fire protection system piping should include analysis
of source water and water from several points in the system. If possible,
examine the inside of one or more sections of pipe for the presence
of nodules and bacteria. Monitoring should be done routinely since
conditions can change over time.
If You Have MIC?
interior of the FPS must first be cleaned to remove existing deposits
and other debris. Treatment with a biocide without prior cleaning will
not stop existing MIC sites from continuing to corrode.
cleaning the FPS, all water entering the system must be treated to
kill microbes entering the FPS. Tests of the success of cleaning and
treatment should be done routinely.
NOTE: For more Information, contact Bioindustrial
Technologies, Inc. (BTI); at phone 800-798-4650 or Fax: 512-863-8097;
Address: 40105 Industrial Park Circle, Georgetown, TX 78626; E-mail: firstname.lastname@example.org or
basic information guide available at: http://www.io.com/~bti/