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Effects
- Home - Detection -
Advantages -
Equipment - Contact
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Introduction:
During the open forum session of
the 1998 Annual Conference of the National Association of State Fire
Marshals (NASFM), Roy Marshall, state Fire Marshall of Iowa, presented
information pertaining to a potentially serious problem that may exist in
certain fire sprinkler systems. Several of those in attendance
requested a written summary, and Marshall was also asked to provide a
document for distribution to NASFM members. The following has been
prepared in response to those requests.
At a few minutes before 4:00 AM on
April 30, 1998, staff at the Lamoni Nursing Center discovered a fire in
the north wing laundry room. The Lamoni Volunteer Fire Department
responded, set up a fire attack and called for mutual aid. Fire
Chief Roger Potts later said the fire was advanced and close to flashover.
Resident evacuation was properly performed and a combined interior and
exterior attack soon brought the fire under control. The incident might
well have resulted in tragic consequences, but because the staff was alert
and responded appropriately and fire and EMS responders knew their job and
set about it quickly and efficiently, there were no serious injuries. |
but even though the head was opened, no
water passed through it. Maintenance records were current. The dry system
had been installed in 1972. It had been inspected regularly in accordance
with NFPA standards, and yet when it was needed the system failed. Why?
When investigators pulled the head they found it plugged with hardened,
rust-colored, granular material. Eventually every head in the wing was
inspected and found to be likewise plugged. It was determined that the
branch line, which was schedule 40 steel pipe, was severely corroded and
partly plugged. Other wings of the facility had been renovated in 1995, and most of the sprinkler piping and heads in those areas had been replaced when pin hole leaks were experienced in the old system. The cause of the pinhole leaks was, at that time, unknown. Within a few days of the fire we knew the sprinkler failed because the pipes and heads were full of gunk. We didn't know what the substance was, why it was there, and whether might be present in other systems. Our search for those answers led us to Roland J. Huggins, PE, with the American Fire Sprinkler Association. Huggins has authored two articles concerning Microbiological Influenced Corrosion (MIC) that appeared in recent editions of Sprinkler Age magazine [articles featured in the July and December 1997 issues]. We initiated a test of the water supply in the failed system, and also sent samples of the pipe and material that plugged it to Bioindustrial Technologies, a testing laboratory in Georgetown, Texas. Laboratory analysis found thick, hard deposits and under-deposit pitting on the inside diameter of the branch line and in the sprinkler head itself. The most severe pitting had taken place under the largest deposits, which were concentrated on the bottom of the pipes and the head where sediment would be expected to settle. The water in the system was found to contain bacterial cells in high |
concentrations (approximately 1,000,000
cells per square inch of pipe). All of these factors, according to
the experts we consulted, were consistent with MIC. It would appear that over the years MIC had taken place in the entire sprinkler system of this nursing home. After causing pinhole leaks in other wings, those pipes were replaced. While it had not yet resulted in leaks in the wing of the fire origin, MIC caused plugged pipes and severe corrosion. The reason pinhole leaks were not observed in this wing may have simply been because the pipes were so plugged that no water passed through them. Since the Lamoni incident, we have become aware of other nursing homes in the same part of the state that have experienced unexplained pinhole leaks, possibly attributable to MIC. Might some of these systems, or others, have piping or heads so plugged as a result of MIC they wouldn't function? How big a problem is MIC, either in Iowa or other states? What's the answer? I don't know, but we first need to take steps to determine the extent of the problem. Even as I write this article, we are making plans to begin testing water for MIC in other health care facilities. In the meantime, we welcome comments and suggestions from others who may have encountered or studied this problem. EDITOR'S NOTE: Since this summary was written AFSA's Director of Technical Services Roland Huggins, PE has been working with the Iowa State Fire Marshal as part of their ongoing investigation of the MIC problem described above. Volume 17, No. 9, September 1998 |
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