title: Comparative human health risk analysis of coastal community water and waste service options.
abstract: As a pilot approach to describe adverse human health effects from alternative decentralized community water systems compared to conventional centralized services (business-as-usual [BAU]), selected chemical and microbial hazards were assessed using disability adjusted life years (DALYs) as the common metric. The alternatives included: (1) composting toilets with septic system, (2) urine-diverting toilets with septic system, (3) low flush toilets with blackwater pressure sewer and on-site greywater collection and treatment for nonpotable reuse, and (4) alternative 3 with on-site rainwater treatment and use. Various pathogens (viral, bacterial, and protozoan) and chemicals (disinfection byproducts [DBPs]) were used as reference hazards. The exposure pathways for BAU included accidental ingestion of contaminated recreational water, ingestion of cross-connected sewage to drinking water, and shower exposures to DBPs. The alternative systems included ingestion of treated greywater from garden irrigation, toilet flushing, and crop consumption; and ingestion of treated rainwater while showering. The pathways with the highest health impact included the ingestion of cross-connected drinking water and ingestion of recreational water contaminated by septic seepage. These were also among the most uncertain when characterizing input parameters, particularly the scale of the cross-connection event, and the removal of pathogens during groundwater transport of septic seepage. A comparison of the health burdens indicated potential health benefits by switching from BAU to decentralized water and wastewater systems.
authors.affiliation: Soller Environmental, Inc. , 3022 King Street, Berkeley, California 94703, United States.
authors.forename: Mary E
authors.initials: ME
authors.lastname: Schoen
authors.forename: Xiaobo
authors.initials: X
authors.lastname: Xue
authors.forename: Troy R
authors.initials: TR
authors.lastname: Hawkins
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Ashbolt
mesh_terms: D004203:Disinfection; D060766:Drinking Water; D004781:Environmental Exposure; D006801:Humans; D011998:Recreation; D018570:Risk Assessment; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater; D014876:Water Pollution
chemical_list: D060766:Drinking Water; D062065:Wastewater