Sustainable and cost-effective wastewater systems for rural - wsscc

GlossaryAnnex: Discussion paperAgglomerationAn area where the population and/or economic activities are sufficiently concentratedfor urban waste water to be collected and conducted to an urban waste water treatmentplant or to a final discharge pointBODBiochemical oxygen demand. The measurement is carried out according to standardizedtest after 5 days of oxidation of the organic matter, hence the term BOD 5CODChemical oxygen demandEutrophicationThe enrichment of water by nutrients, especially compounds of nitrogen and/or phosphorus,causing an accelerated growth of algae and higher forms of plant life to producean undesirable disturbance to the balance of organisms present in the water and to thequality of the water concerned.GreywaterDomestic wastewater coming from the house excluding toilet wastewaterIndustrial wastewaterAny waste water which is discharged from premises used for carrying on any trade or industry,other than domestic waste water and run-off rain waterPopulation equivalent (1 PE)The organic biodegradable load by one person (having a five-day biochemical oxygendemand (BOD 5 ) of 60 g of oxygen per day)Primary treatmentTreatment of urban waste water by a physical and/or chemical process involving settlementof suspended solids, or other process in which the BOD 5 of the incoming wastewater is reduced by at least 20% before discharge and the total suspended solids of theincoming waste water are reduced by at least 50%Secondary treatmentTreatment of urban waste water by a process generally involving biological treatmentwith a secondary settlement or other process which meets the requirementsSensitive areas • Freshwater bodies, estuaries and coastal waters which are eutrophic or which maybecome eutrophic if protective action is not taken;• Surface freshwaters intended for the abstraction of drinking water which contain orare likely to contain more than 50 mg/l of nitrates;• Areas where further treatment is necessary to comply with other Council Directivessuch as the Directives on fish waters, on bathing waters, on shellfish waters, on theconservation of wild birds and natural habitats, etc.SludgeResidual sludge, whether treated or untreated, from urban wastewater treatment plants,primary sludge is sludge generated in the pre-treatment step - secondary sludge generatedby biological treatment (in activated sludge processes)Urban wastewaterDomestic waste water or the mixture of domestic waste water with industrial wastewaterand/or run-off rain water30