PWTAG funded research at Cranfield University from 1994 to 2002. This produced some very instructive results, particularly on disinfection byproducts. Like all its research, this feeds into PWTAG's guidance and publications.

Research on the accuracy of pool test kits and the effects of water hardness on grout erosion have also both been useful in formulating guidance.

Swansea University
In 2005, PWTAG's research focus switched to Swansea University and largely to filtration. This was in response to epidemiological evidence that the protozoa Cryptosporidium presented in practice a bigger gastrointestinal threat to pools than bacteria and viruses. Unlike the latter, the infective particles - oocysts – of Cryptosporidium are not readily killed by chlorine at the concentrations used in pools. Their relatively large size, though, means they can be filtered out if filtration is good. So research focused on maximising the effectiveness of filtration. The work has emphasised the importance of medium-rate filtration and good coagulation. The results of this research and the strategies for minimising the risk of cryptosporidiosis from pools are reflected in the new edition of Swimming Pool Water.

Work on glass filter media has endorsed PWTAG’s scepticism about many of the claims made for it; this is reflected in the filtration chapter of the new edition of Swimming Pool Water.

That work continues, as do investigations into other aspects of filtration and energy conservation. Eventually, PWTAG would also like to be in the position to be able to mount empirical research investigations into the effectiveness of the many products and treatments that are promoted with often very flimsy evidence bases.

Asthma
A more recent area of concern to pool operators and particularly to swimmers is the suggested link between swimming and asthma. The implications for young children are particularly difficult to deal with. Although there seems no doubt that the suggested link is by no means proven, there is clearly a need for more work, both experimental and epidemiological. PWTAG has been closely involved in discussions about this difficult area. Various investigations have been followed, so far inconclusively. And there is the possibility of a substantial research project in the UK.