Daily Archives: November 4, 2011

New compact UV disinfection unit introduced

I do not usually cover release of commercial products, but this one seems unique.  A small UV unit is now available that can be used in point-of-use systems….disinfecting up to 4 L/min…..click here.

Ahmed et al 2011: Fecal Indicators and Zoonotic Pathogens in Household Drinking Water Taps Fed from Rainwater Tanks in Southeast Queensland, Australia.

W. Ahmed, L. Hodgers, J.P. Sidhu, and S. Toze. Fecal Indicators and Zoonotic Pathogens in Household Drinking Water Taps Fed from Rainwater Tanks in Southeast Queensland, Australia. Appl Environ Microbiol. 2011 Oct 21. [Epub ahead of print]

Absract: In this study, the microbiological quality of household tap water samples fed from rainwater tanks was assessed by monitoring the numbers of Escherichia coli and enterococci from 24 households in Southeast Queensland (SEQ), Australia. Quantitative PCR (qPCR) was also used for the quantitative detection of zoonotic pathogens in water samples from rainwater tanks and connected household taps. The numbers of zoonotic pathogens were also estimated in fecal samples from possum and various species of birds using qPCR as possums and birds are considered to be the potential sources of fecal contamination in roof-harvested rainwater (RHRW). Among the 24 households, 63% rainwater tank and 58% connected household tap water (CHTW) samples contained E. coli and exceeded Australian Drinking Water Guidelines of < 1CFU E. coli per 100 mL water. Similarly, 92% rainwater tanks and 83% CHTW samples were also contained enterococci. In all, 21%, 4%, and 13% rainwater tank samples contained Campylobacter spp., Salmonella spp., and Giardia lamblia, respectively. Similarly, 21% rainwater tank and 13% CHTW samples contained Campylobacter spp. and G. lamblia, respectively. The number of E. coli (P = 0.78), enterococci (P = 0.64), Campylobacter spp. (P = 0.44), and G. lamblia (P = 0.50), in rainwater tanks did not differ significantly from numbers observed in the CHTW samples. Among the 40 possum fecal samples tested, the Campylobacter spp., Cryptosporidium parvum, and G. lamblia were detected in 60%, 13%, and 30% samples, respectively. Among the 38 bird fecal samples tested, the Campylobacter spp., Salmonella spp., C. parvum, and G. lamblia were detected in 24%, 11%, 5%, and 13% samples, respectively. Household tap waters fed from rainwater tanks tested in the study appear to be highly variable. Regular cleaning of roof and gutter along with pruning of overhanging tree branches might also prove effective in reducing animal fecal contamination to the rainwater tanks.

Click here to obtain the full paper (fee).