Mains Injection & Pipework Chlorination


What’s the Issue?

I would like to organise a chlorination of my water system but I am not sure how I go about this?

I have received an adverse result on some recent water sampling and would like to know what the next steps are and if I need to chlorinate my water system?


What is your obligation?

Prior to a connection of new pipework to the mains supply, a mains injection or chlorination of pipework should be undertaken or the Water Utilities have the right to refuse connection. Requirements for chlorination and testing can vary however, depending on your utility company.

If there has been a possible indication of contamination to the water supply it may have been recommended that a mains injection or chlorination of pipework is undertaken to eradicate these issues.



Failure to meeting the correct standards of BS 8558 (and Guide PD855468) can result in the water board refusing a connection, causing you further delays and unnecessary costs. If routine inspection shows it to be necessary or an outbreak occurs and the water system has not been subject to cleaning & disinfection in line with the current guidelines then this could lead to a potential break out of contamination within the buildings water system and if a person was to contract Legionnaires disease as a result of this, the landlord/employer or person who controls the premises may be liable to prosecution and would have to demonstrate to a court that they have fulfilled their legal duty.


How we can help?

Atom Water Treatment have a fully qualified and experienced team ready to support and assist with your current obligations and responsibilities to ensure you meet your requirements. We carry out all of our disinfections to the latest standards of BS 8558 (and Guide PD855468). Our team of experts create a detailed method statement prior to the works, followed by full certification, photographic reports and service sheets upon completion. We work together with an independent UKAS accredited laboratory to able to provide water sampling analysis and full written reports along with any necessary recommendations required.

Contact us for a free no obligation quote including any further advice and guidance you may require.

Book a Consultation

or call the office

0203 597 5035

A mains injection or pipework chlorination is often required to any new installation, if contamination has been identified within the water system or where major extensions or alterations have been carried out on the water system. It also may be necessary in cases where an adverse sample result has been identified or if the water system has not been in regular use and therefore, the pipework has not been subject to regular flushing.

The process usually entails the injection of chlorine via an injection point to achieve the correct levels of 50ppm. The water is then drawn through to all the outlets and retested to ensure the correct chlorine levels have been achieved. The pipework should then be left for at least one hour before retesting of the levels and flushing with fresh clean water.

These works should be undertaken in accordance with the current guidelines of BS 8558 (and Guide PD855468) alongside any additional requirements of specific water authorities. The final flushing is then normally subject to sampling for chemical and microbiological testing and submitted to an independent UKAS accredited laboratory for analysis.

If these standards are not met, the local water board have the right to refuse the final connection of the water system to the mains water supply. This is to prevent any possible contamination from the water system feeding back and contaminating the mains water supply.