Pool water quality and prevalence of microbes in filter backwash from metro-Atlanta swimming pools
Murphy, J.L.; Hlavsa, M.C.; Carter, B.C.; Miller, C.; Jothikumar, N.; Gerth, T.R.; Beach, M.J.; Hill, V.R.
Journal of Water and Health 16(1): 87-92
2018
ISSN/ISBN: 1477-8920
PMID: 29424722
DOI: 10.2166/wh.2017.150
Accession: 065415277
During the 2012 summer swim season, aquatic venue data and filter backwash samples were collected from 127 metro-Atlanta pools. Last-recorded water chemistry measures indicated 98% (157/161) of samples were from pools with ≥1 mg/L residual chlorine without stabilized chlorine or ≥2 mg/L with stabilized chlorine and 89% (144/161) had pH readings 7.2-7.8. These water quality parameters are consistent with the 2016 Model Aquatic Health Code (2nd edition) recommendations. We used previously validated real-time polymerase chain reaction assays for detection of seven enteric microbes, including Escherichia coli, and Pseudomonas aeruginosa. E. coli was detected in 58% (93/161) of samples, signifying that swimmers likely introduced fecal material into pool water. P. aeruginosa was detected in 59% (95/161) of samples, indicating contamination from swimmers or biofilm growth on surfaces. Cryptosporidium spp. and Giardia duodenalis were each detected in approximately 1% of samples. These findings indicate the need for aquatics staff, state and local environmental health practitioners, and swimmers to each take steps to minimize the risk of transmission of infectious pathogens.