Water treatment in “the house for elderly”

We have been asked to analyze a plumbing system in a residence for the elderly that had previously been equipped with a traditional bacteriological treatment system but unfortunately the legionella problem appeared every few months with an unacceptable frequency forcing the operator to frequent thermal shocks.

Photo of the entrance to the complex

The situation was not of satisfaction of the Management because, although within the limits of the law, the thermal shock and the chemical products used, constituted a heavy recurring cost; in addition, the thermal shock is known to be detrimental to the health of metal pipes.

The complex consists of two main bodies: a first body built for some decades and a second added recently; in the latter recent construction the problems are relatively negligible, in the older part they were much more worrying and it is the case that often occurs in the presence of old pipes, pipe trunks plugged in output and abandoned for subsequent modifications but still connected to the main line, etc.

We know that the thermal shock is effective in the immediate but essentially ephemeral because it eliminates the bacteria that are in the water but not those that live and feed in the biofilm and the biofilm as well as in the layer of limestone that settles on the inner surface of the tubes and then, after a few weeks, they reappear and start to proliferate. In no way is it possible to treat old and abandoned pipes as the water does not flow inside and this is the reason why the guidelines state region, recommend, in case of changes, not leave dead logs because they will be the source of unsolvable future problems.

The technology that we propose, represented by the AQUARING devices, instead exercises a more long-term action as we propose two different models with two different objectives: eliminate the incoming bacteria and prevent the formation of limestone and bio film, with the second model kill / contain the bacteria that circulate with the recirculation water and at the same time operate to dismantle the layers of limestone and bio pre-existing films.

This action is extremely important and lasts over time, as it is not known, even more than a year, and without this it becomes unrealistic to think of eliminating the legionella bacteria unless you resort to traditional systems such as sandblasting or pipe cleaning with acid and contemporary treatment to prevent the entry of new bacteria.

Having seen the system, we installed two AQUARING devices:

  • A AQUARING L 63 model on the cold water pipe before the heat exchanger
  • A AQUARING SP 63 model on the hot water recirculation pipe immediately after the mixing valve and before this divides into the two different distribution lines on the two different wings of the assembly.

Installation detail

The controls carried out later showed an immediate effect on limescale formation while the behavior towards the bacteria was different: the new immediate efficacy, the old positive result on some points, contrasting on others. The result, however, was what was expected and that we find in the various sites we meet and just for the reasons mentioned above.

Photo of mounted models

It was interesting to see that one of the faucets in this part of the plant had started to come out with dark, dirty water, which visibly stained the white surface of the bathtub with concern of the maintenance worker who had never seen it before, but to we are an obvious sign that the cleaning action was taking place; however, not wanting the process to go too long and to be certain of a quick and effective action, we decided to install a third appliance in the recirculation of hot water.

Third model

The whole series of subsequent analyzes have therefore confirmed the classic trend: reduction of bacteria before and after new growth, then progressive decrease until it is within the limits of the law.