Risk Factors

  • Rubber hoses and fittings. Although cheap and easy to fit, biofilm readily forms on the surface. Rubber will also crack with age, and these cracks provide a sheltered environment that bacteria can thrive in.
  • Thermal mixing valves. TMVs are needed to reduce potentially scalding temperatures to safer levers, usually 36° to 46°C. Unfortunately, this is the range in which Legionella and Pseudomonas thrive. What's more, biofilm forms on the mesh inside the TMV, providing a protective environment for pathogens. They also have a rubber O-ring.
  • Flow straighteners. These also have meshes, and some have rubber O-rings.
  • Expansion vessels and isolation valves. These both have rubber membranes in their structure and so can suffer from the associated problems.
  • Deadlegs/dead ends. These will allow water to stagnate, making biofilm formation much easier. The still water also makes it more difficult to deliver biocides to the area.
  • Low-use outlets. Can show all the problems associated with stagnating water.
  • Galvanised Steel. Hot water and oxidising chemicals can erode the protective zinc coating to expose the steel underneath. Where this happens, tubercles can form which encourage build-up of biofilm.
  • Heat exchangers. If poorly maintained these will allow scale to form, which provides an excellent surface for biofilm to build on.
  • Hard water areas. Again, scale will encourage biofilm to form. In extreme cases the scale can also form on top of the biofilm, protecting pathogens from biocides.

ProEconomy's reputation speaks volumes and the Orca system is highly regarded by those who have installed it.