Pipeline Chlorination & Disinfection

We ensure the removal of potential harmful contaminants with highest regard to the safety of the end consumer.

The chlorination and disinfection of water mains and pipelines is a critical phase of the pipeline commissioning process to ensure that the water main can be safely put into operation without any risk to the end user.

Our specialist engineers carry out the chlorination process to the highest standards and strictly in accordance with the Irish water Code of Practice. We have a strong reputation in this area and have delivered this service at multiple domestic and commercial sites across Ireland working extensively with Irish Water, Local Authorities, Industrial/Health Sector, Consultant Engineers and Civil Contractors.

Typically the chlorination and disinfection of a water main is carried out over a three day period as follows:

Day 1 Chlorination  – Pipeline is swabbed, flushed and dosed with chlorine to the required concentration as outlined in the Irish Water Code of Practice. Chlorine residual sampling is also carried out by Blueline Testing on site. Pipeline is left for a period of 24 hours contact time.

Day 2 Dechlorination – Further chlorine residual sampling is carried out by Blueline Testing to ensure the chlorine residual is at an acceptable standard as outlined in the Irish Water Code of Practice. The pipeline is then dechlorinated in an environmentally safe manner, flushed with potable water and left to stand for a further 24 hours.

Day 3 Microbiological Sampling – Further chlorine residual sampling is carried out by Blueline Testing along with water samples taken for detailed microbiological analysis off site in the laboratory.

After completion of the three days a detailed chlorination report is issued by Blueline Testing to the client.

A good water supply is required on site to successfully complete the chlorination process. In most cases this water supply is readily available on site. If necessary Blueline Testing also have the capability to provide a clean water tanker service in instances where there is not an adequate supply of water on site or where the site water is of a poor quality.

The Chlorination Process


Swabbing and flushing of a pipeline ensures that all internal surfaces are cleansed and that any debris which may have entered the pipe during the construction process is properly removed.


The pipework is sterilised with a high-level chlorine solution and allows it to remain in contact with the internal pipework surfaces for a period of 16 to 24 hours.


Chlorine levels are checked at the end of the contact period and if found to meet the minimum requirements the pipework is flushed with potable water.


The highly chlorinated water which is flushed out during the flushing operation is then de-chlorinated . Flushing continues until the chlorine concentration at the end of the line is similar to the mains supply.


Water quality samples are then collected and transported to our state of the art laboratory where they are tested for the presence of the bacteria and other pathogens, as well as disinfection residuals as set out by Irish Water.


A formal Chlorination Report, including the bacteria analysis is issued on completion of the laboratory results. This will need to be issued to Irish Water. If the results are clear, mains connection can progress.

Request a Quote

To request a quote or make a booking for this service please give us a call or send us an email.