Manholes are an intregral part of conveying wastewater, giving workers access to the buried pipeline for routine maintenance at different points along the way to the treatment plant.
Manholes have traditionally been built with concrete, but corrosion has always been a problem.
Over time, acid and bacteria produced by the wastewater can eat away at concrete, which then requires expensive rehabilitation or replacement. For example, the City of Las Vegas has budgeted $680 million dollars to fix damaged manholes and pipes over the next five years.
Locally, VVWRA has a new tool to fight manhole corrosion. Geneva Polymer Products of Las Vegas recently replaced two damaged concrete manholes in Victorville (near I-15 and E St.) using their patented Armorock system. Armorock comes as precast pieces made from a polyester resin, acid resistant sand and aggregate.
The result is a manhole that stands up to corrosion and is stronger than concrete. Mike Bussio of Geneva Polymer said, “Our product comes with a 50 year warranty, but the life cycle of Armorock is actually 100 years.” Bussio says the technology behind the Armorock product has been around for 50 years, but until recently it has been too expensive to compete with concrete.
With the price dropping, Las Vegas and many Southern California agencies have begun turning to polymer manholes. VVWRA’s Latif Laari said, “We are pleased with the Armorock manholes so far and look forward to possibly using them on future projects.”
VVWRA has also installed about 100 GMI composite manhole covers that are 75% lighter than traditional metal covers. The lighter covers are safer for maintenance crews to work with and because they are a composite material, they have no value to scrap metal thieves.