| The purpose of this study was to develop a prediction map that could identify high risk areas that are prone to microbiologically influenced corrosion (MIC) to underground pipelines. Information from the USDA Soil Survey Geographic database, an Access database, was used to create a query table that identified five soil types in Cayuga County, New York that had characteristics for the growth of anaerobic microorganisms causing corrosion on the exterior of underground metal pipelines. Geographic Information Systems was used to create a prediction map that could identify high risk areas of microbiologically influenced corrosion. A 13 km (8 mi) pipeline in Cayuga County intersected 12 locations that were potentially at increased risk for MIC. An attempt was made to validate the utility of the prediction map by examining the landscape, vegetation, bacterial titers, and bacterial identification. Soil samples were taken from each of the five high risk soil types in a 200 km2 (77 mi2) area around the pipeline and cultured for anaerobic bacteria. Statistical analyses indicated that two of the five soil types had significantly more anaerobic bacteria than other soils. Gas chromatographic analyses of cellular fatty acids in cultured bacteria were consistent with the presence of three anaerobic bacterial genera (Eubacteria, Clostridium, and Peptostreptococcis) involved with MIC. By identifying areas at risk, regulators can focus their inspection on pipeline segments at risk to this rapid corrosion process, so that mitigating steps can be taken to prevent potential leaks which may cause loss of life and harm the environment. |
