| Slide 1 Wastewater generation & treatment: the questionnaires and water accounting tables Michael Nagy

| Slide 2 Reporting of waste water data Country type A Eurostat / OECD JQ Eurostat Water Accounting Eurostat / DG REGIO Reg. Quest. DG ENV UWWTD DG ENV / EEA EPER Other quest. …. Country type B FAO Water Accounting UNSD Env. Quest. Purpose for data collection? Reporting frequency? Coverage? Reporting threshold? Aggregation level? Definitions and terminology? Reporting authorities? …

| Slide 3 First Question: What do we want to achieve with harmonisation? Data needed Country A IIIIII… Questionnaire IOther questionnairesQuestionnaire II International level: Consistent data for multiple purposes National level: One single set for reporting purposes – developed jointly by all relevant institutions

| Slide 4 Data needed Country A IIIIII… Questionnaire IOther questionnairesQuestionnaire II International level: Consistent data for multiple purposes National level: Complementary reporting by the different institutions First Question: What do we want to achieve with harmonisation?

| Slide 5 Country A IIIIII… Questionnaire IOther questionnairesQuestionnaire II International level: different data flows, but harmonised definitions National level: One single set for reporting purposes – developed jointly by all relevant institutions First Question: What do we want to achieve with harmonisation?

| Slide 6 Second question: Do we need complementary data collection? Eurostat / OECD JQ UNSD Env. Quest. + = FAO UNESCO … Overlaps? Gaps?

| Slide 7 UNSD/UNEP: Table W4A Waste Water Generation

| Slide 8 Eurostat/OECD-JQ: Table 7: Generation and discharge of waste water Other units: BOD, SS, N tot, P tot, heavy metals

| Slide 9 Comparison of WW Generation Tables W4A and 7 Breakdown to branches comparable UNSD/UNEP-Quest: volumes of WW only Open question: Is the definition of waste water comparable? Eurostat/OECD-JQ: Water which is of no further immediate value to the purpose for which it was used or in the pursuit of which it was produced because of its quality, quantity or time of occurrence. However, waste water from one user can be a potential supply to a user elsewhere. Cooling water is not considered to be waste water for purposes of this questionnaire. UNSD/UNEP (2004-Quest):The quantity of water in cubic meters (m3) that is discharged due to being of no further immediate value to the purpose for which it was used or in the pursuit of which it was produced because of its quality, quantity or time of occurrence. This definition of UNSD/UNEP covers also cooling water?!

| Slide 10 Other observations Definition of Urban Waste Water is comparable, Eurostat-OECD-JQ more precise (e.g. WW transported with trucks Types of urban waste water treatment are not comparable: Eurostat /OECD: primary / secondary / tertiary UNSD/UNEP: mechanical / biological / advanced Sludge production: Both Questionnaires: DS Eurostat / OECD: Splitted into urban / other / independent UNSD/UNEP:Total sludge production

| Slide 11 Conclusion Some of the definitions of UNSD/UNEP-Questionnaire are to be improved Be careful with comparisons: WW treatment types Cooling water? There is a high potential for developing one single information system available for world-wide comparison Questionnaires are mainly from the environmental point of view – variables for humanitarian aspects (to be checked critically)? If data is in bad quality – this may indicate need for improving of water management

| Slide 12 Cyclic Procedure of Data Management Water management and nat. statistics Information needs Data manag. strategy Monitoring points / areas Sample collection (Laboratory) analyses Data handling Data analysis Reporting Information utilization Cyclic procedure Intern. Quest. Int. Quest.