Long-Term Solution To An Age-Old Problem: Maintaining Aging Maintenance Holes In Laredo, Texas

摘要

Founded in 1755 and home to the nation's third largest port, after Los Angeles and New York, Laredo is one of Texas' fastest growing cities. It is also home to some exceptionally old infrastructure. While implementing modern materials and technologies since the 1980's, the City still maintains miles of collection system that is over a hundred years old. Additionally, hot temperatures contribute to some of the highest levels of hydrogen sulfide (H_2 S) in the nation. H_2 S is a threat to concrete structures and to maintenance workers who enter them. To combat the resulting microbiologically induced corrosion (MIC) caused by H_2 S, Laredo previously applied cementitious AND epoxy liners, requiring two trips to protect maintenance holes (MH). In 2015 the City instituted new technologies which improves worker safety and efficiencies, while reducing costs in their internal rehabilitation program. This paper will outline the ongoing, proactive MH rehabilitation program Laredo has cost-effectively and successfully implemented.