Survey on urban wastewater

Period: Annual
Year: 2016

01. Contact
02. Metadata update
03. Statistical presentation
04. Unit of measure
05. Reference Period
06. Institutional Mandate
07. Confidentiality
08. Release policy
09. Frequency of dissemination
10. Accessibility and clarity
11. Quality management
12. Relevance
13. Accuracy and reliability
14. Timeliness and punctuality
15. Coherence and comparability
16. Cost and Burden
17. Data revision
18. Statistical processing
19. Comment

01. ContactTop
01.1. Contact organisation

Statistical Office of the Republic of Serbia

01.2. Contact organisation unit

Environmental statistics unit

01.3. Contact name

Neda Cukavac

01.4. Contact person function


01.5. Contact mail address

5 Milana Rakica st. Belgrade, Serbia

01.6. Contact email address

01.7. Contact phone number

+381 113290242

01.8. Contact fax number

Not applicable.

02. Metadata updateTop
02.1. Metadata last certified
02.2. Metadata last posted
02.3. Metadata last update

03. Statistical presentationTop
03.1. Data description

Survey on urban wastewater provide the data on:

• Quantities of wastewater discharged in the recipient

• Quantities of discharged treated and untreated wastewater

• Devices for wastewater treatment

• Biological and chemical oxygen demand

   • Sewerage system/ network.

03.2. Classification system

Code list of watercourses

Classification of Activities (CA – 2010, “Official Gazette of RS”, No 54/10)

Regulation on Nomenclature of Statistical territorial Units (“Official Gazette of RS”, No 109/09 and 46/10)

03.3. Coverage - sector

Survey includes according to Classification of Activities (CA 2010) division 37 – Sewerage and division 84 – Public administration and defence, compulsory social security (local communities’ authorities managing water supply systems).

03.4. Statistical concepts and definitions

Public sewerage system (network) is a set of technical – sanitary facilities and measures that provide continuous and systematic collection, drainage, treatment and discharge of wastewaters and atmospheric waters away from settlements and economy into appropriate recipients.

Length of collecting network is the length of the sewerage network system of closed street canals, i.e. pipes for carrying wastewaters and atmospheric waters away from settlements, without household connections and network.

Wastewaters are the quantities of water which, after being used, are carried to the treatment plant or are discharged in underground or surface waters. Atmospheric water is included in the quantities of wastewater. The quantities of wastewater are measured by water meters or are estimated according to defined standards of production.

Wastewater treatment means removal of hazardous and harmful constituents and radio-nuclides from water thus making it harmless for use.

Main collector is the collecting wastewater canal that drains wastewater to the treatment plant or recipient.

One population equivalent (P.E.) means the organic biodegradable load having a five-day biochemical oxygen demand (BOD5) of 60 g of oxygen per a day.

Effluent from wastewater treatment plant is water discharged after wastewater treatment.

03.5. Statistical unit

Statistical units are local units and enteties who in the reference year are classified according to Classification of Activities (CA 2010) in divisions: 37 – Sewerage and 84 – Public administration and defence, compulsory social security (local communities’ authorities managing water supply systems).

03.6. Statistical population

Survey covers observation units which discharge and treat wastewater on the whole territory of the Republic of Serbia. 

03.7. Reference area

The data are representative for the territory of the Republic of Serbia, to level of municipalities. 

Starting from 1999 the Statistical Office of the Republic of Serbia has not at disposal and may not provide available certain data relative to AP Kosovo and Metohija and therefore these data are not included in the coverage for the Republic of Serbia (total).

03.8. Coverage - Time


03.9. Base period

Not applicable.

04. Unit of measureTop
04. Unit of measure

Mil. m3, km, number

05. Reference PeriodTop
05. Reference Period

Calendar year.

06. Institutional MandateTop
06.1. Institutional Mandate - legal acts and other agreements

The survey is conducted on the basis of the Law on Official Statistics ("Official Gazette of the Republic of Serbia" No. 104/09), according to the Plan and Program of Statistical Surveys and according to requirements of „JQ OECD/ Eurostat“(JQ OECD/Eurostat – Inland water), questionnaire for Inland Water and questionnaire UNSD/UNEP – Environmental Statistics (UNSD/UNEP – Environmental statistics

06.2. Institutional Mandate - data sharing

Data are sended to Eurostat every second year, and these data are published in Eurostat´s data base. 

07. Confidentiality Top
07.1. Confidentiality - policy

Law on Official Statistics („Official Gazette of RS“, No 104/2009), chapter IX

07.2. Confidentiality - data treatment

Data are published at the aggregated level.

08. Release policyTop
08.1. Release calendar

Notification about dissemination of statistical data are published in Publication calendar which is available on web site.

08.2. Release calendar access

08.3. Release policy - user access

All users have been granted an equal access to official statistics: this means that the dissemination dates of official statistics have to be announced in advance and no user can have access to the official statistics (results of official statistical surveys) before other users. Statistical information is first published in Statistical Release. Official statistics are available on the website on the date announced in the release calendar.

09. Frequency of disseminationTop
09. Frequency of dissemination


10. Accessibility and clarityTop
10.1. Dissemination format - News release

Not applicable.

10.2. Dissemination format - Publications
  • Statistics Yearbook
  • Statistical Pocket-book
  • Eco-bulletin
  • Statistical Release Urban wastewater
  • Municipalities and regions of the Republic of Serbia 
  • Website:
10.3. Dissemination format - online database

The data are available in the database of the Statistical Office of the Republic of Serbia, Division Environment, the subdivision Water.

10.4. Dissemination format - microdata access

Not applicable.

10.5. Dissemination format - other

Not applicable.

10.6. Documentation on methodology

On the web site of the Statistical Office of the Republic of Seriba short methodology is available for  Survey on urban wastewater. 

10.7. Quality management - documentation

SORS describe the sources and methods in the quality report and metadata. A summary of the quality information аt the country level is available on SORS web page (QMC- quality management system).

11. Quality managementTop
11.1. Quality assurance

The Quality Policy document is available on the SORS website:

11.2. Quality management - assessment


12. Relevance Top
12.1. User needs

The main users of the statistical surveys on Urban wastewater are:

- National users: Ministry of Agriculture and environmental protection, industrial and business associations, environmental associations, NGO's, local municipalities.

- International users: Eurostat, UN, European Agency for environmental protection.

12.2. User satisfaction

User satisfaction is not conducted yet.

12.3. Completeness

Not applicable.

13. Accuracy and reliabilityTop
13.1. Overall accuracy

The overall accuracy is good. Response rate of the survey on urban wastewater is 99%.

13.2. Sampling error

Not applicable.

13.3. Non-sampling error and

Not applicable.

14. Timeliness and punctualityTop
14.1. Timeliness

The data are available in the fifth month of the end of the reporting year.

14.2. Punctuality

Preliminary data are published in accordance with the deadline given in the Regulation on the Plan of official statistics. Final data are published in accordance with the terms announced in the Regulation on the Plan of official statistics and the Release Calendar.

15. Coherence and comparabilityTop
15.1. Comparability - geographical

The application of concepts and definitions from the methodology enables geographical comparability with the data of EU countries.

15.2. Comparability - over time

The time series has been available since 2000 without time brake.

15.3. Coherence - cross domain

Not applicable.

15.4. Coherence - internal

Not applicable.

16. Cost and BurdenTop
16. Cost and Burden

Not applicable.

17. Data revisionTop
17.1. Data revision - policy

The audit policy is carried out in accordance with the General Policy of the Audit of the Statistical Office of the Republic of Serbia (Chapter 3 - Audit Policy).

17.2. Data revision - practice

The published data should be regarded as final, unless otherwise stated. Corrections and revisions might occur.

18. Statistical processingTop
18.1. Source data

Тhe source of data are a statistical survey on urban wastewater.

A methodological instrument which are used for carrying out the survey - Questionnaire Annual survey оn Urban wastewater (VOD-2k). 

18.2. Frequency of data collection

Data are collected annualy. 

18.3. Data collection

Data collection is done by the reporting method, meaning that the reporting unit uses its available documentation and records to fill in the paper or web questionnaires. The competent person enters the requested data in the first quarter of the current year for the previous year. If related records are non-existent for certain data, competent persons will make an evaluation. The reporting unit forwards the questionnaire to the relevant statistical authority on which territory its head office is located within the deadline set up in the annual plan.

18.4. Data validation

Validation of data is done during the entire data processing from input to final results.

18.5. Data compilation

Not applicable.

18.6. Adjustment

Not applicable.

19. CommentTop