Swabbing is a mandatory stage of the water main commissioning process under IW-CDS-5020-03. It takes place at two points in the commissioning sequence. First, on completion of construction and before any disinfection, the internal surfaces must be cleansed thoroughly by scouring and swabbing to remove construction debris, sediment, and biofilm (Section 4.10.2). Second, on completion of the pressure test, foam swabs soaked in chlorine are passed through the Main a sufficient number of times to achieve clear wash water before disinfection commences (Section 4.10.4). All swab operations are carried out in the presence of the Irish Water field engineer, and full records are prepared and submitted.
What We Carry Out
- Pre-disinfection cleansing (4.10.2): foam swabs passed through the Main to scour internal surfaces before disinfection commences
- Post-test swabbing (4.10.4): chlorine-soaked foam swabs passed through the Main after pressure testing until clear wash water is achieved
- Each foam swab used only once and recovered — swabs removed in the presence of the Irish Water field engineer at their discretion
- Time, date, number and sizes of swabs introduced and removed recorded and submitted to Irish Water field engineer
- Location plans provided showing where swabs were introduced to and retrieved from the Works
- Any temporary connection to the public Waterworks fitted with double check valves to prevent backflow per IW-CDS-5020-03, 4.10.4
