Small Islands

Why Sewage Matters

Municipal wastewater is a mixture of domestic wastewater, effluents from commercial establishments and industry, urban runoff, and infiltration. The impact of wastewater on aquatic ecosystem depends on the type of contaminants present in the wastewater.

Suspended solids increase turbidity of water thus reducing the light available for light-depending organisms.
Biodegradable organics increase Biochemical Oxygen Demand (BOD) resulting in anaerobic conditions, that cause fish kills and bad smell.
Nutrients, when in excess, cause eutrophication. Eutrophication stimulates the growth of (toxic) algae and nuisance. The former increase the oxygen production during the day, while during the night the respiration and degradation of algae will lead to anaerobic conditions, causing fish kills.
Toxic compounds not only accumulate in consumable water organisms (fish, shellfish), but also interfere with microbiological process in sewage treatment.
Pathogens affect humans directly by causing illness and possible death, which places them among the main health concerns in the world.

It may seem at first sight, contaminants in municipal wastewater mainly affect aquatic organisms, and are therefore not a direct threat to a human life. Wrong! Not only is deterioration of aquatic ecosystem unacceptable, through loss of biodiversity the human race is faced with loss of fresh water. One of the challenges to be faced is ensuring environmental sustainability as stated in Goal 7 of the UN-Millennium Development Goals from the Millennium Declaration. Targets under this Goal are clearly expressing the need for a proper wastewater management, because sewage does matter!



Guidelines Municipal Wastewater Management Full Text (PDF) Executive Summary Ten Keys Checklists Resources Strategic Approach Enabling Policy Small Islands Institutional Arrangements participation, partnerships reform, capacity building advocacy, awareness Technologies technology selection pollution prevention on-site treatment sewerage and drainage reuse, ecosan conventional treatment Financing cost recovery willingness-to-pay investment options, PPP Best Practices	Why Sewage Matters Municipal wastewater is a mixture of domestic wastewater, effluents from commercial establishments and industry, urban runoff, and infiltration. The impact of wastewater on aquatic ecosystem depends on the type of contaminants present in the wastewater. Suspended solids increase turbidity of water thus reducing the light available for light-depending organisms. Biodegradable organics increase Biochemical Oxygen Demand (BOD) resulting in anaerobic conditions, that cause fish kills and bad smell. Nutrients, when in excess, cause eutrophication. Eutrophication stimulates the growth of (toxic) algae and nuisance. The former increase the oxygen production during the day, while during the night the respiration and degradation of algae will lead to anaerobic conditions, causing fish kills. Toxic compounds not only accumulate in consumable water organisms (fish, shellfish), but also interfere with microbiological process in sewage treatment. Pathogens affect humans directly by causing illness and possible death, which places them among the main health concerns in the world. It may seem at first sight, contaminants in municipal wastewater mainly affect aquatic organisms, and are therefore not a direct threat to a human life. Wrong! Not only is deterioration of aquatic ecosystem unacceptable, through loss of biodiversity the human race is faced with loss of fresh water. One of the challenges to be faced is ensuring environmental sustainability as stated in Goal 7 of the UN-Millennium Development Goals from the Millennium Declaration. Targets under this Goal are clearly expressing the need for a proper wastewater management, because sewage does matter!	Contact Search News Events CSD-12 2004 UNEP Korea H2O Partnership Partner sites UNESCO-IHE UCC-Water IRC FAQs Technology selection Financing mechanisms more Themes O&M Small Islands more

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Why Sewage Matters