W.W. Clyde & Co. was selected as the contractor for this emergency siphon repair project. Due to the failure of a 30” trunk line, W. W. Clyde & Co. conducted a thorough system evaluation of the failed pipe as well as the remaining 42” ductile iron pipe barrel. It was found that H2S gas had caused significant damage to the sewer lines over the last 30 years causing the line to completely fail. 350 ft of significantly damaged pipe was replaced and then research was conducted to find a way to clean and assess the condition of the remaining pipe length. A company with the capability to clean and assess the condition of the pipe while under full flow was brought in and after cleaning and assessment of the pipe, it was determined only part of the remaining pipe had been damaged. Approximately half of the remaining length of 30 in and 42 in pipe was lined with CIPP liner.
All work was done while maintaining flows in either the 30 in or 42 in barrel. This was accomplished by complicated and complex moving of the flows between the two barrels while cleaning, lining and replacement was performed. All new gates were installed in the inlet box along with a lining system inside to prevent future corrosion from the H2S gas.