Technical Notes

PWTAG Technical notes are updates or new material for the standards and guidance given in the PWTAG book, Swimming Pool Water and the PWTAG Code of Practice and should be read in association with these publications.

PWTAG keeps pool operators up to date by providing guidance through these technical notes on the issues of the day.

Combining PWTAG’s specialist expertise and published scientific data, we aim to optimise swimming pool technical operation.

PWTAG Technical Notes Downloads

Click or tap one of the following links to download a PDF for each topic.

• Faecal contamination (Technical Note 2 – supplemented July 2020)
• Sulphate attack (Technical Note 3)
• Dealing with sodium hypochlorite spillage (Technical Note 5)
• Carbon dioxide for pH control (Technical Note 6)
• Interactive water features (Technical Note 13)
• Atmospheric determination of chloramines (Technical Note 16)
• Blood or vomit in the pool (Technical Note 17)
• Preventing and dealing with algae in pools (Technical Note 18)
• Superchlorination of swimming pool water (Technical Note 23)
• Polyaluminium chloride (PAC) dosing (Technical Note 24)
• How PWTAG deals with the new (Technical Note 26)
• Microbiological sampling (Technical Note 27)
• Notes on the hygiene of pool play equipment (Technical Note 29)
• Cryptosporidium – what pool operators need to know (Technical Note 30)
• Ultraviolet disinfection – specification, maintenance and validation (Technical Note 31)
• Balance tank design for deck-level pools (Technical Note 32)
• Gassing accidents (Technical Note 33)
• Cloudy water (Technical Note 34)
• Bunds for pool chemicals (Technical Note 35)
• Understanding breakpoint chlorination (Technical Note 36)
• Phosphate in pool water (Technical Note 37)
• Dechlorinating backwash water prior to discharge (Technical Note 38)
• Residual control
• Choosing an acid pH correctant (Technical Note 40)
• UV installations in swimming pool plant rooms (Technical Note 41)
• Glass filter media (Technical Note 42)
• Swimming pool covers safety and operation (Technical Note 48)
• Swimming pool circulation pumps and variable speed drives (Technical Note 49)
• Swimming pool filter specification (Technical Note 50)
• Lowering pH: No Problem (Technical Note 52)
• Microbiological Testing (Technical Note 53)
• Understanding and determining the importance of the active free chlorine content of the free chlorine test (Technical Note 60)
• Combined Chlorine – Understanding it and getting rid of it (Technical Note 61)

PWTAG Technical Notes Archive

Coronavirus – Pools post lockdown

Since 19 July 2021 swimming pools and spas in England are, in theory, able to operate as they want. Like theatres, pubs and clubs, they are free to return to normal practice. The situation varies in Wales, Scotland and Northern Ireland where operators should consult the UK government website.

Accordingly, PWTAG has moved the many technical notes relating to Covid-19 – about closing and reopening pools etc – to the archive section below. There is material in them that may well continue to be useful, as the pandemic is still with us. Let’s hope we don’t have to move them back into the active section.

To operators concerned about the safety and effectiveness of ‘normal practice’ this report makes reassuring reading.