Potable water pipe disinfection and building installations: responsibilities
Potable water pipe disinfection is the responsibility of different authorities. While the waterworks and municipal authorities are responsible for ensuring high water quality right up to the transfer point to the building’s mains connection, from this point on the operator of the building installation is responsible for maintaining the water quality in the drinking water pipes through proper potable water line cleaning.
Basically, the municipal authorities take care of everything in front of the water meter (and are therefore responsible for sanitizing potable water lines), while the building’s owner is responsible for everything behind it (and as far as every tap).
Besides the drinking water pipes, relevant building installations may include water meters, filters, dosing systems, softeners and heating systems (boilers and hot water pipes). And the potential problems that need to be avoided and corrected are just as diverse as the installations themselves.
For example: corrosion in drinking water pipes, microbial growth and biofilm formation in filters, and/or pipes containing stagnant water, legionella growth in hot water installations, etc.
Corrosion in drinking water pipes & corrosion inhibitor for water
Depending on its chemical composition (hardness, CO2 content, mineralisation, etc.), water is either corrosive or depository. The softer and hotter the water, the sooner it will begin to corrode metal water pipes. The same is true for galvanised water pipes. Drinking water pipes made from cast iron, copper or even lead (now banned) are also not immune to corrosion. The problem is that fragments of metal may become detached from the pipes and pollute the water. Although “red water” contaminated with iron/rust is not poisonous, other metals can represent a health risk.
Drinking water pipes that are seriously damaged by corrosion must always be replaced. Larger pipes can be repaired using plastic inlays.
Alternatively, drinking water pipes can be cleaned using a corrosion inhibitor for water, for example phosphate, phosphonate or polyphosphate solutions. These mineral solutions (such as Corfit Pipe Shield) form a thin protective layer inside corroded drinking water pipes and prevent further corrosion.
Silicate products can also be added to the water to ensure permanent treatment of the pipes. (Corfit Pipe Care A / Corfit Pipe Care B / Corfit Pipe Care Si)
Potable water pipe disinfection : stagnant water
Drinking water is rarely sterile but it requires potable water pipe disinfection in a certain point. In order to be classified as drinking water it may not contain more than a specified number of microbes. If the water remains in a section of the pipeline for a long time (so-called stagnation zones or dead strands), bacteria and algae can multiply. It is even possible for these stagnation zones to cause backward contamination in the regular drinking water pipes.
As a quick remedy and form of prevention, it is advisable to regularly flush critical pipe sections — especially if a drinking water pipe has not been used for two weeks or longer. It is important to ensure that water-carrying extinguishing pipes are also flushed. For prolonged periods of non-use, these pipes can be drained.
On the other hand, if significant microbial contamination with biofilm formation has already taken hold due to negligence, the potable water pipe disinfection of drinking water pipes must be performed with Sanosil S015 or Super 25 water pipe cleaning chemical (disinfectants), which contain hydrogen peroxide (shock disinfection of the drinking water pipe with subsequent flushing).
Combatting legionellae: disinfecting potable water piping and hot water installations
Legionellae are a serious problem in hot water systems — they multiply explosively at temperatures between 30 and 40 degrees Celsius. If water droplets containing legionellae are then inhaled when showering, they can cause severe, sometimes fatal pneumonia.
Although the problem can be eliminated in many cases by means of a legionella protection circuit (in which the water in the boiler is sporadically heated to +60 degrees Celsius), this is not always possible for technical or design-related reasons. In such cases, only the sporadic or continuous treatment of the water pipes and hot water installations with a drinking water line disinfection product is effective (same procedure as with stagnant water: shock disinfection of potable water lines and all pipes, leave to take effect, then flush).
Disinfecting water softeners, filters, water meters and other water installations
In addition to drinking water pipes, a large number of other installations also require regular cleaning and maintenance. For example, filters must be changed, softeners rinsed and salt tanks cleaned on a regular basis. However, frequent disinfection of these system components with a water pipe cleaning chemical may or may not be necessary.
Flushing with drinking water pipework disinfection solution (or filling and leaving for a while) is one option; alternatively, after potable water pipe cleaning, all disassembled and cleaned parts can be directly sprayed with undiluted disinfectant for potable water pipe disinfection (Sanosil S003).