Clearing Blocked Force Mains



11:00-11:25 a.m.

Clearing Blocked Force Mains

Speaker:  Kent Ford, Vice President, CleanServe


The city of Houston experienced an unusual occurrence. Several force mains began depositing material, which seemed to be a combination of sand and other minerals, on their walls immediately downstream of the lift stations. Flow was severely restricted, pumps were running constantly, but moving very little wastewater through the pipe, using excess power and potentially damaging the pumps. To remedy the situation, CleanServe first focused on a 1,500-foot length, 12” diameter line with buildup that reduced it to about 1” diameter. T Construction provided by-pass and access to the line, and using a combination of nozzles and other cutting tools, CleanServe crews were able to restore the line to 95% of its original capacity in 4 days. Building on the knowledge gained, CSI developed a plan to clean a considerably longer (5,600 feet) 16” line with no access points. After T Construction added access points and provided bypass pumping, CleanServe restored the line to capacity in 15 days.