AWWA INF52172

With our infrastructure deteriorating at an ever accelerating pace, municipalities are faced with the financial burden of replacing pipelines. The establishment of priorities for replacement considers the critical nature of the pipeline, the risk associated with failures and the age of the pipeline. Technology is available to provide the operator with useful data that assists in the decision making process. This paper will cover methods that are available that assist the operator in assessing the condition of the pipeline, quantifying the remaining life and the likelihood of corrosion failures. Specific pipeline assessment techniques such as lose interval potential surveys, direct current voltage gradient evaluation, acoustical monitoring, stray current evaluation and soil assessment will be discussed. The applicability of these assessment techniques in the evaluation of steel, cast and ductile iron and reinforced concrete pipelines will be covered. As an alternate to immediate pipeline replacement for some pipelines, corrosion control methods that can be applied to existing steel, cast and ductile iron, and reinforced concrete pipelines will be discussed. The application of corrosion control enables the pipeline operator to extend a pipeline's operational life and to delay or eliminate the cost of pipeline replacement. Corrosion control options extend from complete cathodic protection to "hot spot" cathodic protection, pipe lining, stray current mitigation systems and corrosion monitoring systems. Case histories will be discussed describing methodologies currently being used by several municipalities in implementing corrosion control technology. Includes tables.