The Structures – The Problems


Xypex products play a major role in the prevention and treatment of problems common to both segments in Wastewater Infrastructure: the Sanitary Sewer Collection System and the Wastewater Treatment Plant. While both segments encounter the problems of microbial induced corrosion and water infiltration to varying degrees, they are deemed primary to both.

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Sewage Collection Structures

  • Manholes
  • Storm Drains
  • Sewer Pipes
  • Pump/Lift Stations
  • Combined Sewer Overflow & Interceptors


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 Wastewater Treatment Structures

  • Headworks
  • Grit Chamber
  • Primary, Secondary Treatment, Tertiary Treatment
  • Disinfection Structures
  • Digesters



Microbial Induced Corrosion

Slow flow and long retention times in a sanitary sewer are the precursor to microbial induced corrosion in sewer and wastewater treatment structures.

During transit time, dissolved hydrogen sulfide (H2S) is produced in the waste flow liquid by sulfate-reducing bacteria under anaerobic conditions. Hydrogen sulfide gas is released into the sewer atmosphere by turbulence and dissolves in the moisture and slime on the sewer crown. Bacteria turn the sulfur compounds into sulfuric acid which attacks the concrete by means of acidic corrosion and longer term through expansive sulfate attack. This causes the concrete to slowly corrode and self-destruct.



Infiltration & Exfiltration

A common source of water infiltration into manholes and sewer line is cracks or displaced joint lines caused by frost heaving, ground traffic or settlement. Water infiltration can increase total flow by as much as 25% - 30% which significantly raises chemical treatment costs while at the same time potentially creating capacity problems for wastewater plants.

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