At-risk wastewater pipeline identification due to flooding

Corrosion is a risk to all ferrous pipelines, and the impact of moisture from major flood events in potentially corrosive soils upon the corrosion of sensitive pipeline materials has not yet been thoroughly studied. Rapidly accelerated corrosion from flooding can cause a pipeline break and lead to environmental hazards. This research seeks to quantify the risk of wastewater pipeline components to fracturing and damage from flooding to inform decision-makers. The corrosion risk to Austin Water Utility’s aged ferrous wastewater pipelines from surrounding soil through flooding is analyzed by establishing the relationships among pipeline material, age, and the surrounding soil type. First, aged ferrous wastewater pipelines in the network were isolated. Then, the Web Soil Survey from the United States Geological Survey (USGS) for Travis County and FEMA Flood Insurance Rate Maps (FIRM) were overlaid on the selected pipelines. USGS soil data was used to locate potentially corrosive soils surrounding the pipelines. Third, FIRM flood zones were overlaid on the selected soil and pipelines in order to examine the relationship between soil type, moisture, and increased corrosion potential. Three different flood zones were evaluated. The analysis shows a total of 386 pipelines, or 27.99 miles of pipelines, were identified to be at-risk.