Reasons for contaminated systems
There are many reasons why a water system can become contaminated with pathogens such as Legionella or Pseudomonas. It is likely that the pathogens are already in any water system, but at low concentrations where they will not have any effect on health. Problems arise when the pathogens are able to reach high concentrations and where there is also an exposure route.
The reasons that contamination occurs in the pipework can include water temperatures, over-sized pipework (or other installation mistakes), long travel distances, long stagnation phases, short circuits in the cold water/warm water system, dead legs, not enough thermal disinfection, retrograde contamination or simply a growing bio-film colony in the hot and cold water systems. The age of the system is one of the less important factors, though the older the system the higher the chance for dead legs and areas of stagnation. In addition the piping materials have an influence on the speed and extent of bacterial colonisation i.e. iron is a source of nutrients for bacteria and is a good growing medium for biofilm, copper is mildly phytotoxic and plastic makes a good base for biofilm.
Microbial Contamination In Cold Water Systems
The microbiological problems in a cold water installation can be caused by mistakes in the installation process and through germ entry into the cold water supply.
The risk of legionella in cold water systems is in many cases underestimated. A lack of insulation coupled with low flow rates in pipe systems that are over-sized can lead to the cold water warming up, which can further the growth of legionella. Typically legionella can be found in cold water systems if it is not guranteed that water temperatures are maintained at below 25°C. A common source of heat in cold water pipes is heat loss from adjacent warm water pipes. This problem is exacerbated when the hot water pipe temperatures are heavily increased to provide thermal protection against Legionella in the hot water system or where a desinfection treatment with temperatures above > 70°C has been implemented.
If you have a situation where there are increased temperatures in a cold water system this system should also be checked for Legionella.
A statistical check of about 20,000 tests in Germany (BMBF-Verbundprojekt, biofilm in drinking water installations, see also above) concluded thatLegionella was found in 12 % of all the hot water testsconducted and that almost 3% also included Pseudomonas, both bacteria were also found in cold water systems more than was expected, (Knowlege resulted from the BMBF-Verbundprojekt „Biofilme in drinking water-nstallation“, Prof. Dr. Hans-Curt Flemming, IWW Mühlheim, Moritzstraße 26, 45476 Mühlheim).
An issue that has not received a lot of attention yet (except in hospitals) is the occurrence of Pseudomonas, which is one of the most important opportunistic pathogens, and which has a hugh growing potential in technical water systems. Pseudomonas exhibits optimal growth at 37°C, but grows at a broad temperature range of 4°C to 42°C.
How the Aquadron Addresses Legionella
The Aquadron can be used on drinking water and treats all of the water that passes through the system, it does this by proportionally dosing all of the water with Anolyte, 24 hours a day, seven days a week. The Anolyte passes through the whole system, removing biofilm and killing bacteria, it even works in the shower heads and taps, at a point that is beyond the thermal mixing valves and that is not protected by thermal treatment. This ensures that bacterial colonies can not form in the pipework system.
When it is used on the hot water system it is possible to operate without the thermal barrier, this means that water temperatures can be reduced, which reduces the leaching of heat into the cold water pipework.
for more details on the Aquadron Legionella System. Click here
for project examples in hospitals and care homes.