The First Ever UV Curing of Sewage Pipes
in Minnesota

Challenge

Medicine Lake’s sewer main was 50 years old, originally installed in 1967. It had reached its life expectancy and needed to be rehabilitated. Recent televising of the City’s pipes indicated the presence of two partially collapsed lines, plus numerous other deficiencies, including high levels of infiltration.  The pipes urgently needed rehabilitation before a catastrophic collapse occurred. The primary issue with utilizing the traditional methods of steam and hot water cured CIPP lining process were the difficult terrain and access to the pipes located in the back yard between the homes and lake.

Solution

For the first time ever in Minnesota, UV Curing was used to repair the City’s sewer pipes. A sock liner was installed in the existing pipe, inflated with compressed air, and cured with UV light to harden the lining in the pipe. Via man holes and robotics, the pipes were repaired without any digging, ultimately creating a faster process for the installation, fewer downtime in service for local residents, and a new pipe with a 50 year design life. One of the key advantages of UV curing is the relatively small footprint needed for the lightweight equipment utilized, critical in tight quarters and sensitive areas near lakes and in backyards.

Features

  • 9,500 lf of 8” sewer pipe lined and cured with UV
  • 50+ year life expectancy
  • Rate of curing was 5 ft of piping per minute
  • Health concerns minimized due to encapsulation of Styrene odors
  • Minimal footprints on local environment and resident’s yards.

Project
Medicine Lake Sanitary Sewer Rehabilitation

Location
Medicine Lake, Minnesota

Services
Civil Engineering
Transportation Planning
Trenchless Technology