Wastewater generation & treatment: the questionnaires and water accounting tables

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

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

3. I II III … Country A First Question: What do we want to achieve with harmonisation? Questionnaire I Questionnaire II Other questionnaires Data needed International level: Consistent data for multiple purposes National level: One single set for reporting purposes – developed jointly by all relevant institutions

4. I II III … Country A First Question: What do we want to achieve with harmonisation? Questionnaire I Questionnaire II Other questionnaires Data needed International level: Consistent data for multiple purposes National level: Complementary reporting by the different institutions

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

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

7. UNSD/UNEP: Table W4A Waste Water Generation

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

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?!

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

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

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