Effective removal of microbial contamination from harvested rainwater using a simple point of use filtration and UV-disinfection device

There is a growing interest in the utilisation of harvested rainwater as an alternative water source. This study summarises an evaluation of the water quality obtained for privately-owned cisterns sampled in Tucson, AZ and the feasibility to obtain high-quality water from harvested rainwater by fitting cisterns with Point of Use (POU) filtration and UV disinfection devices. Of the 11 cisterns sampled, 30–50% tested positive for E. coli, 100% contained Enterococci and a few tested positive for lead at concentrations above the MCL. All physicochemical and microbiological constituents analysed were present at higher numbers in the summer than in the winter. The POU devices sufficiently cleared the harvested rainwater of total coliforms, E. coli, and Enterococci but performed marginally with respects to improving turbidity and heterotrophic bacteria.

[1]  Awwa,et al.  Standard Methods for the examination of water and wastewater , 1999 .

[2]  Charles P. Gerba,et al.  The disinfection efficacy of a point-of-use water treatment system against bacterial, viral and protozoan waterborne pathogens , 1997 .

[3]  G. Lewis,et al.  Contamination of potable roof-collected rainwater in Auckland, New Zealand. , 2001, Water research.

[4]  C. Gerba,et al.  Oligotrophic bacteria in ultra-pure water systems: Media selection and process component evaluations , 1991, Journal of Industrial Microbiology.

[5]  P. M. Berthouex,et al.  Acidic deposition and cistern drinking water supplies , 1989 .

[6]  Mark D Sobsey,et al.  UV disinfection of Giardia lamblia cysts in water. , 2002, Environmental science & technology.

[7]  Dennis J. Lye,et al.  Microbiology of rainwater cistern systems: A review , 1992 .

[8]  A. E. Greenberg,et al.  Standard methods for the examination of water and wastewater. 14th edition. , 1976 .

[9]  A. Fewkes.  Modelling the performance of rainwater collection systems: towards a generalised approach , 2000 .

[10]  Ramon G. Lee,et al.  Inactivation of biofilm bacteria , 1988, Applied and environmental microbiology.

[11]  N B Munro,et al.  Drinking-water standards. , 1986, Environmental science & technology.

[12]  J. Namieśnik,et al.  Quality of roof runoff waters from an urban region (Gdańsk, Poland). , 2002, Chemosphere.

[13]  S. Wuertz,et al.  UV disinfection in a model distribution system:; biofilm growth and microbial community. , 2004, Water research.

[14]  J. Siemiatycki,et al.  Gastrointestinal health effects associated with the consumption of drinking water produced by point-of-use domestic reverse-osmosis filtration units , 1991, Applied and environmental microbiology.

[15]  Joan B. Rose,et al.  The detection of Cryptosporidium oocysts and Giardia cysts in cistern water in the U.S. Virgin Islands , 1996 .

[16]  J. C. Goldman,et al.  Colonization and disinfection of biofilms hosting coliform-colonized carbon fines , 1996, Applied and environmental microbiology.

[17]  A. Appan.  Roof water collection systems in some Southeast Asian countries: status and water quality levels , 1997, Journal of the Royal Society of Health.

[18]  Theo A. Dillaha,et al.  Rainwater catchment water quality in micronesia , 1985 .

[19]  V. Adams,et al.  Ultraviolet inactivation of selected bacteria and viruses with photoreactivation of the bacteria , 1987 .

[20]  A. E. Greenberg,et al.  Standard methods for the examination of water and wastewater : supplement to the sixteenth edition , 1988 .

[21]  Dennis J. Lye,et al.  HEALTH RISKS ASSOCIATED WITH CONSUMPTION OF UNTREATED WATER FROM HOUSEHOLD ROOF CATCHMENT SYSTEMS 1 , 2002 .

[22]  Roy L. Wolfe,et al.  Ultraviolet disinfection of potable water. , 1990 .

[23]  R. E. Anderson,et al.  Effect of point-of-use, activated carbon filters on the bacteriological quality of rural groundwater supplies , 1995, Applied and environmental microbiology.

[24]  K. Linden,et al.  Comparative effectiveness of UV wavelengths for the inactivation of Cryptosporidium parvum oocysts in water. , 2001, Water science and technology : a journal of the International Association on Water Pollution Research.

[25]  D. Reasoner.  Heterotrophic plate count methodology in the United States. , 2004, International journal of food microbiology.