title: Rainwater harvesting in American Samoa: current practices and indicative health risks.
abstract: Roof-harvested rainwater (RHRW) is an important alternative source of water that many island communities can use for drinking and other domestic purposes when groundwater and/or surface water sources are contaminated, limited, or simply not available. The aim of this pilot-scale study was to investigate current RHRW practices in American Samoa (AS) and to evaluate and compare the quality of water from common potable water sources including RHRW stored in tanks, untreated stream water, untreated municipal well water, and treated municipal tap water samples. Samples were analyzed using culture-based methods, quantitative polymerase chain reaction (qPCR), and 16S amplicon sequencing-based methods. Based on indicator bacteria (total coliform and Escherichia coli) concentrations, the quality of RHRW was slightly lower than well and chlorinated tap water but exceeded that of untreated stream water. Although no Giardia or Leptospira spp. were detected in any of the RHRW samples, 86% of the samples were positive for Cryptosporidium spp. All stream water samples tested positive for Cryptosporidium spp. Opportunistic pathogens (Pseudomonas aeruginosa and Mycobacterium intracellulare) were also detected in the RHRW samples (71 and 21% positive samples, respectively). Several potentially pathogenic genera of bacteria were also detected in RHRW by amplicon sequencing. Each RHRW system was characterized by distinct microbial communities, 77% of operational taxonomic units (OTUs) were detected only in a single tank, and no OTU was shared by all the tanks. Risk of water-borne illness increased in the following order: chlorinated tap water/well water < RHRW < stream water. Frequent detection of opportunistic pathogens indicates that RHRW should be treated before use. Stakeholder education on RHRW system design options as well as on importance of regular cleaning and proper management techniques could improve the quality of the RHRW in AS.
authors.affiliation: Water Resources Research Center, University of Hawaii, 2540 Dole Street, Holmes Hall 283, Honolulu, HI, 96822, USA. kirs@hawaii.edu.
authors.forename: Marek
authors.identifier: http://orcid.org/0000-0002-7448-8323
authors.initials: M
authors.lastname: Kirs
authors.affiliation: Water Resources Research Center, University of Hawaii, 2540 Dole Street, Holmes Hall 283, Honolulu, HI, 96822, USA.
authors.forename: Philip
authors.initials: P
authors.lastname: Moravcik
authors.affiliation: School of Public Health, The University of Queensland, Herston, QLD, 4006, Australia.
authors.forename: Pradip
authors.initials: P
authors.lastname: Gyawali
authors.affiliation: Drexel University, 3141 Chestnut Street, Philadelphia, PA, 19104, USA.
authors.forename: Kerry
authors.initials: K
authors.lastname: Hamilton
authors.affiliation: Institute of Technology, Tartu University, Nooruse 1, 50411, Tartu, Estonia.
authors.forename: Veljo
authors.initials: V
authors.lastname: Kisand
authors.affiliation: American Samoa Community College, P.O. Box 2609, Pago Pago, 96799, American Samoa.
authors.forename: Ian
authors.initials: I
authors.lastname: Gurr
authors.affiliation: Department of Geology and Geophysics, University of Hawaii, 2540 Dole Street, Holmes Hall 283, Honolulu, HI, 96822, USA.
authors.forename: Christopher
authors.initials: C
authors.lastname: Shuler
authors.affiliation: CSIRO Land and Water, Ecosciences Precinct, 41 Boggo Road, Brisbane, 4102, Australia.
authors.forename: Warish
authors.initials: W
authors.lastname: Ahmed
mesh_terms: D018948:American Samoa; D001419:Bacteria / Q000145:classification; D060766:Drinking Water / Q000382:microbiology*; D006801:Humans; D011891:Rain; D014871:Water Microbiology
chemical_list: D060766:Drinking Water
keywords: Drinking water quality; Fecal indicator bacteria; Microbial communities; Opportunistic pathogens; Roof-harvested rainwater; Water resources