Extreme Sewer Makeover: Large-Diameter Interceptor Edition

The Big Dry Creek Interceptor (BDCI) serves approximately 90,000 residents with collection through five separate sanitary sewer districts in south suburban Denver. Through internal pipe investigations spanning nearly two decades, the Southgate Sanitation District (District), located in Centennial, Colorado, identified sanitary sewer manholes and main line segments on the BDCI requiring rehabilitation due to aging and deterioration. A multi-year, five phase rehabilitation program was initiated to rehabilitate all remaining unlined RCP segments in the District-controlled portion of the BDCI. The results of the evaluation, analysis, criticality, project grouping, and engineer’s opinions of probable construction costs (EOPCCs) were utilized to phase the BDCI Sanitary Sewer Rehabilitation Project (Project). Due to the criticality of the BDCI, several unique design and construction solutions were required to provide crucial rehabilitation of vintage infrastructure to serve communities and protect natural resources.