National Statistical Institute

 Environmental and Energy accounts Department

Alexandra Ivanova

Mariya Zlatkova

Chief expert

Senior expert

2, P. Volov Str.; 1038 Sofia, Bulgaria

[email protected]

[email protected]

+359 2 9857 650

+359 2 9857 182

Not available.

The data provide information on the quantities of water abstraction, water used, wastewater generated and discharged, population with water services, urban water treatment plants, water supply and sewage network. The data are result of four statistical surveys: "Public water supply, sewage and treatment", "Water supply through irrigation systems", "Water use" and "Water used for hydro energy production (HPP/PWPP)".

-        Statistical Classification of Economic Activities (NACE Rev.2)

-        Unified Classifier of Administrative-Territorial and Territorial Units (UCATTU)

-       Classification of Territorial Units for Statistics in Bulgaria (NUTS)

Statistical surveys cover:

-          "Public water supply, sewage and treatment" - all water suppliers - water supply operators and operators of urban drinking and wastewater treatment plants (water supply, municipalities).

-          "Water supply through irrigation systems" - enterprises and local units whose activity is the supply and distribution of water through irrigation/hydromelioration systems to end users.

-          "Water use" - the larger water users - enterprises for whose activities a total of over 36 thousand m³ of water enters or is extracted per year and a total of over 20 thousand cubic meters of water/year for the purposes of irrigation of agricultural areas, animal husbandry, industrial purposes (including cooling). Voluntarily submit data enterprises under this criterion.

-          "Water used for hydro energy production (HPP/PSHP)" - all the electricity producers - HPP/PSHP.

"Water abstraction" is the abstraction/removal of water from any water source, whether permanent or temporary. Abstracted water is divided into two categories - fresh and non-fresh water (marine and transitional).

"Water used" is water that is actually used by end-users for a specific purpose within a within territory, such as for domestic use, irrigation or industrial processing.

"Water losses" are the amount water lost during transport (through leakage and evaporation) between the source and the point of use. Respondents report losses using computational methods, as direct measurements are difficult to apply. The percentage is calculated as a proportion of the volume lost from the water entering the transport network.

"Wastewater discharge" - The amount of water (in m³) or substance (in kg BOD/d or comparable) discharged to a water body from a point or non-point source.

"Urban wastewater treatment plant" - the scope of survey are the treatment plants treating wastewater of settlements on behalf of the state administration (public services). The information contains the main characteristics of the urban wastewater treatment plants (UWTPs) operating in the country - treatment methods, design capacity (water volume and BOD5), input and output load (BOD5), connected settlements. The treatment methods correspond to the definitions in the national legislation.

Definitions are used, according to applicable legislation - Data Collection Manual for the OECD/Eurostat Joint Questionnaire on Inland Waters and Eurostat Regional Water Questionnaire - Concepts, definitions, current practices, evaluations and recommendations, and Joint Questionnaire on Inland Waters (JQ-IW) and Eurostat’s Regional Water Questionnaire (RWQ) - Definitions, notes, relations and schemes.

-          "Public water supply, sewerage and treatment" - a water supplier enterprise and operator of urban drinking water and wastewater treatment plants.

-          "Water supply through irrigation systems" - an enterprise or local units engaged in the supply and distribution of water through irrigation/hydromelioration systems to the end users.

-          "Water use" - enterprise or a local unit, a water user, according to the scope criterion.

-          "Water used for hydro energy production (HPP/PSHP)" - an enterprise producing electricity in HPP/PSHP.

-          "Public water supply, sewerage and treatment" - enterprises, whose economic activity (according to NACE Rev.2) is generally related to water use. For the purpose of statistical monitoring, a list of enterprises that carry out activities under NACE Rev.2 "36.00 Water collection, treatment and supply" – public water supply operators and operators of urban treatment plants for drinking and wastewater (water supply, municipalities) is prepared.

-          "Water supply through irrigation systems" - enterprises and local units, whose economic activity (according to NACE Rev.2 ) is generally related to the water supply and distribution through irrigation/hydromelioration systems to the end users.

-          "Water use" - enterprises and local units, whose economic activity (according to NACE Rev.2) is generally related to the use of water.

-          "Water used for hydro energy production (HPP/PSHP)" - statistical units, whose economic activity (according NACE Rev.2) is related to the use of water for 35.11- Production of electricity. 

Bulgaria (country); Statistical region - NUTS2; Statistical zone - NUTS1; District - NUTS3; River Basin Districts.

1990 - 2023

Not applicable.

-          Water abstraction by sources - millions cubic meter;

-          Water distribution by Public Water Supply - millions cubic meter;

-          Water used by economic activity - millions cubic meter;

-          Drinking water used by households from Public water supply - liters per person per day;

-          Generation and discharge of wastewater - millions cubic meter;

-          Operating urban wastewater treatment plants - count;

-          Water supply and sewage network - kilometer;

-          Population and water services - percent.

Calendar year.

Regulatory Documents:

-          Regulation (EC) No 223/2009 on European statistics

-          Regulation (EU) No 2021/690 establishing a programme for the internal market, competitiveness of enterprises, including small and medium-sized enterprises, the area of plants, animals, food and feed, and European statistics (Single Market Programme) defining the work on inland water statistics at UN and EU level (incl. Data Collection Manual for OECD/Eurostat Joint Inland Water Questionnaire)

-          Statistics Act

-          Ordinance on the order and manner of organizing national inventories of emissions of harmful substances and greenhouse gases into the atmosphere (only in Bulgarian)

-          Voluntary provision of national and regional water data to Eurostat/OECD - Gentlemen's Agreement

Аgreements:

Agreements between the National Statistical Institute and the Ministry of Environment and Water for cooperation and exchange of information from 2003 and 2010.

Water statistics data are provided annually to the Executive Agency for the Environment, for preparation and reporting of the National Inventory of Emissions of Harmful Substances, in accordance with the Convention on Long-Range Transboundary Air Pollution (LRTAP) and the United Nations Framework Convention on Climate Change (UNFCCC).

Regulation (EC) No 223/2009 on European statistics provides the necessity to establish common principles and guidelines ensuring the confidentiality of data used for the production of European statistics and access to such confidential data, taking due account of technical developments and the requirements of users in a democratic society.

The Statistics Act (Art. 25, para. 1) stipulates that individual data obtained and collected in statistical surveys are statistical secret and may be used only for statistical purposes.

According to Art. 25 of the Statistics Act, individual data may not disclose or provide. The provision of individual data is possible only according to Art. 26 of the Statistics Act.

The publication date of the statistical information are specified in the Calendar presenting the results of the statistical surveys of the NSI. 

The calendar is available on the NSI website here.

Water statistics data are published on the NSI website in the "Environment" section according to the provisions of the Statistics Act and the principles of the European Statistical Code of Practice, respecting professional independence and aiming at objectivity and transparency, whereby all users are equal.

Annually.

Regular press release on the NSI website.

-        Statistical Reference Book

-        Statistical Yearbook 

-        Electronic publication "Environment" 

-        Brochure "Bulgaria"

Water statistics data are available on the NSI website at:

-        "Environment" section

-        Information System INFOSTAT

According to Rules for Provision of Anonymised Individual Data for Scientific and Research Purposes of the NSI, anonymized individual data may be provided for scientific and research purposes.

Information service on request, according to the Rules for Dissemination of Statistical Products and Services of the NSI.

-        Data Collection Manual for the OECD/Eurostat Joint Questionnaire on Inland Waters;

-        Internal guidelines "Environmental Statistics and Accounts".

-       European Statistics Code of Practice

-       Integrated management system in the NSI

-       Generic Statistical Business Process Model in the NSI (only in Bulgarian)

-       Handbook on internal quality audits of statistical processes and products in the NSI

-       Internal guidelines "Environmental Statistics and Accounts"

Quality report is published annually with the publication of statistical data.

The data quality is ensured by applying the principles of the European Statistics Code of Practice and the NSS Common Framework for Quality Management, including by applying the internal methodology "Statistics and Environmental Accounts", developed by the NSI.

Quality assurance activities ensure compliance with the requirements of the Statistics Act in terms of quality criteria: adequacy, accuracy, timeliness, punctuality, accessibility and clarity, comparability and logical coherence. Through them, the application of the principles of the Code of European Statistical Practice is ensured: stable methodology; appropriate statistical procedures; moderate respondent burden; cost-effectiveness; relevance; accuracy; timeliness and accuracy of presentation; comparability and coherence; accessibility and clarity.

The quality assessment is carried out at each stage of the statistical process (phases/subprocesses), accordingly to the Common Framework for Quality Management in the NSS and the principles of the European Statistics Code of Practice. The assessment of the statistical data quality includes statistical processes and statistical information. The requirements of the current methodological documents are applied for quality assessment, including the instructions in the internal guidelines "Statistics and Environmental Accounts", developed by the NSI.

To assess the quality of the data, their compliance with the data from the Business statistics information system is checked - Income and Expenditure Statement, Tax and Fees Report, PRODENERG Report.

In order to ensure the data quality, work is also being done to continuously improve the online-based information system for collecting primary data, providing an opportunity for arithmetic and logical control of the input data, and additional analyses and checks are being carried out.

The data from the water statistics serve both for reporting to various international institutions (Eurostat, UN Sustainable Development Goals, FAO, etc.) in the relevant formats, according to regulations, directives, signed agreements/contracts, and for carrying out assessments and analyses by various institutions or organizations in the country. The main users of statistical information from the survey are state and municipal organizations, scientific institutes, associations, companies and citizens.

The NSI conducts a regular statistical survey "User Satisfaction with the Provided Statistical Information Products and Services", which covers all statistical areas. The survey aims to assess users’ satisfaction with the statistical information provided by the NSI and to define recommendations for the future development of the statistical system in accordance with user needs.

The data meet the requirements of current legislation in terms of scope and monitored indicators.

Data accuracy is guaranteed through quality assurance activities in the statistical production process, as one of the criteria for the quality of statistical information, according to the Statistics Act.

Not applicable.

Not applicable.

The data are published 14 months after the reporting year.

The data are published according to the Calendar presenting the results of the statistical surveys of the NSI. 

The data are prepared at national and regional level. The data are comparable with other EU countries due to the application of common definitions and classifications.

The data are comparable over time. For the main indicators of water statistics, data are available since 1990. Regional and more detailed information is available since 2008.

Data revisions in the dynamic series is carried out when the methodology changes.

The data are coordinated with data from:

-          Registers of issued permits for water abstraction from surface and groundwater – Basin Directorates;

-          Register of issued guarantees – Sustainable Energy Development Agency(SEDA);

-          Data from energy and business statistics.

Classification is applied according to the Classification of Economic Activities and the Classification of Territorial Units for Statistical Purposes in Bulgaria(NUTS).

The data are of high internal consistency. Within the framework of the quality assessment procedure, the consistency of primary and statistical data by sources, economic activities, national and regional level of aggregated and detailed data is checked.

The costs (budget) for statistical surveys are disclosed in the National Statistical Program, published on the NSI website.

The priority in conducting statistical surveys is to reduce the burden on respondents.

Actions are being taken to alleviate the burden on respondents, such as: collecting and verifying primary data through the online-based information system "Environmental Statistics", containing strict arithmetic and logical control; improving the instructions for filling out questionnaires; providing methodological and technical assistance; continuously exploring the possibilities for using information from administrative and other sources; conducting annual trainings for respondents and NSI experts, etc.

The time required to complete the statistical forms is used as the main measure of the workload of the respondents. For this purpose, a section is included in each form regarding the time needed to fill in the form (including the time for data preparation), which the respondents must complete. Based on this information and considering the specifics of the survey, the respondents' workload can be determined as relatively high. The overall workload of the responsible experts is determined as high, especially in cases of data revisions from previous reporting periods.

According to the principles of the European Statistics Code of Practice and the requirements of the internal rules/integrated management system, statistical processes are regularly monitored and revised, if necessary. Revisions are carried out according to standard, established and transparent procedures. Regular analyses aim to improve data sources, statistical processes and products.

The data is revised upon change in regulatory requirements, the methodology, or when necessary.

-          Statistical survey: "Public water supply, sewage and treatment"; "Water supply through irrigation systems"; "Water use" and "Water used for hydro energy production (HPP/PWPP)"

-          Administrative data (MOEW, EEA, BD, NIMH, SEDA).

Information from other statistical surveys and administrative sources is also used to determine the general population, verify data, and perform estimation

Annually.

According to the respondents' activities, data is collected on:

-        Water abstraction;

-        Water used by activities;

-        Water services by settlements;

-        Active Urban treatment plants and facilities;

-        Wastewater generated and discharged;

-        Water used for hydropower production;

-        Length of the water supply and sewage network;

-        Other.

Data validation is part of the activities to ensure the quality of statistical information. Primary data are validated in terms of completeness, correct classification, units of measurement, comparability with previous years, comparability with data from other statistical areas and/or administrative sources, logical control, etc. According to the quality criteria set out in the Statistics Act, statistical data are validated in terms of their comparability, accuracy, reliability, etc. 

Data processing is carried out by strictly applying the methodology of the survey and data verification methods.

Data processing includes actions to produce statistical data based on primary data, brought into an appropriate form, using specialized software products.

Not applicable.

National Statistical Institute

 Environmental and Energy accounts Department

Alexandra Ivanova

Mariya Zlatkova

Chief expert

Senior expert

2, P. Volov Str.; 1038 Sofia, Bulgaria

[email protected]

[email protected]

+359 2 9857 650

+359 2 9857 182

Not available.

The data provide information on the quantities of water abstraction, water used, wastewater generated and discharged, population with water services, urban water treatment plants, water supply and sewage network. The data are result of four statistical surveys: "Public water supply, sewage and treatment", "Water supply through irrigation systems", "Water use" and "Water used for hydro energy production (HPP/PWPP)".

-        Statistical Classification of Economic Activities (NACE Rev.2)

-        Unified Classifier of Administrative-Territorial and Territorial Units (UCATTU)

-       Classification of Territorial Units for Statistics in Bulgaria (NUTS)

Statistical surveys cover:

-          "Public water supply, sewage and treatment" - all water suppliers - water supply operators and operators of urban drinking and wastewater treatment plants (water supply, municipalities).

-          "Water supply through irrigation systems" - enterprises and local units whose activity is the supply and distribution of water through irrigation/hydromelioration systems to end users.

-          "Water use" - the larger water users - enterprises for whose activities a total of over 36 thousand m³ of water enters or is extracted per year and a total of over 20 thousand cubic meters of water/year for the purposes of irrigation of agricultural areas, animal husbandry, industrial purposes (including cooling). Voluntarily submit data enterprises under this criterion.

-          "Water used for hydro energy production (HPP/PSHP)" - all the electricity producers - HPP/PSHP.

"Water abstraction" is the abstraction/removal of water from any water source, whether permanent or temporary. Abstracted water is divided into two categories - fresh and non-fresh water (marine and transitional).

"Water used" is water that is actually used by end-users for a specific purpose within a within territory, such as for domestic use, irrigation or industrial processing.

"Water losses" are the amount water lost during transport (through leakage and evaporation) between the source and the point of use. Respondents report losses using computational methods, as direct measurements are difficult to apply. The percentage is calculated as a proportion of the volume lost from the water entering the transport network.

"Wastewater discharge" - The amount of water (in m³) or substance (in kg BOD/d or comparable) discharged to a water body from a point or non-point source.

"Urban wastewater treatment plant" - the scope of survey are the treatment plants treating wastewater of settlements on behalf of the state administration (public services). The information contains the main characteristics of the urban wastewater treatment plants (UWTPs) operating in the country - treatment methods, design capacity (water volume and BOD5), input and output load (BOD5), connected settlements. The treatment methods correspond to the definitions in the national legislation.

Definitions are used, according to applicable legislation - Data Collection Manual for the OECD/Eurostat Joint Questionnaire on Inland Waters and Eurostat Regional Water Questionnaire - Concepts, definitions, current practices, evaluations and recommendations, and Joint Questionnaire on Inland Waters (JQ-IW) and Eurostat’s Regional Water Questionnaire (RWQ) - Definitions, notes, relations and schemes.

-          "Public water supply, sewerage and treatment" - a water supplier enterprise and operator of urban drinking water and wastewater treatment plants.

-          "Water supply through irrigation systems" - an enterprise or local units engaged in the supply and distribution of water through irrigation/hydromelioration systems to the end users.

-          "Water use" - enterprise or a local unit, a water user, according to the scope criterion.

-          "Water used for hydro energy production (HPP/PSHP)" - an enterprise producing electricity in HPP/PSHP.

-          "Public water supply, sewerage and treatment" - enterprises, whose economic activity (according to NACE Rev.2) is generally related to water use. For the purpose of statistical monitoring, a list of enterprises that carry out activities under NACE Rev.2 "36.00 Water collection, treatment and supply" – public water supply operators and operators of urban treatment plants for drinking and wastewater (water supply, municipalities) is prepared.

-          "Water supply through irrigation systems" - enterprises and local units, whose economic activity (according to NACE Rev.2 ) is generally related to the water supply and distribution through irrigation/hydromelioration systems to the end users.

-          "Water use" - enterprises and local units, whose economic activity (according to NACE Rev.2) is generally related to the use of water.

-          "Water used for hydro energy production (HPP/PSHP)" - statistical units, whose economic activity (according NACE Rev.2) is related to the use of water for 35.11- Production of electricity. 

Bulgaria (country); Statistical region - NUTS2; Statistical zone - NUTS1; District - NUTS3; River Basin Districts.

1990 - 2023

Not applicable.

-          Statistical survey: "Public water supply, sewage and treatment"; "Water supply through irrigation systems"; "Water use" and "Water used for hydro energy production (HPP/PWPP)"

-          Administrative data (MOEW, EEA, BD, NIMH, SEDA).

Information from other statistical surveys and administrative sources is also used to determine the general population, verify data, and perform estimation

Annually.

According to the respondents' activities, data is collected on:

-        Water abstraction;

-        Water used by activities;

-        Water services by settlements;

-        Active Urban treatment plants and facilities;

-        Wastewater generated and discharged;

-        Water used for hydropower production;

-        Length of the water supply and sewage network;

-        Other.

Data validation is part of the activities to ensure the quality of statistical information. Primary data are validated in terms of completeness, correct classification, units of measurement, comparability with previous years, comparability with data from other statistical areas and/or administrative sources, logical control, etc. According to the quality criteria set out in the Statistics Act, statistical data are validated in terms of their comparability, accuracy, reliability, etc. 

Data processing is carried out by strictly applying the methodology of the survey and data verification methods.

Data processing includes actions to produce statistical data based on primary data, brought into an appropriate form, using specialized software products.

Not applicable.

The data quality is ensured by applying the principles of the European Statistics Code of Practice and the NSS Common Framework for Quality Management, including by applying the internal methodology "Statistics and Environmental Accounts", developed by the NSI.

Quality assurance activities ensure compliance with the requirements of the Statistics Act in terms of quality criteria: adequacy, accuracy, timeliness, punctuality, accessibility and clarity, comparability and logical coherence. Through them, the application of the principles of the Code of European Statistical Practice is ensured: stable methodology; appropriate statistical procedures; moderate respondent burden; cost-effectiveness; relevance; accuracy; timeliness and accuracy of presentation; comparability and coherence; accessibility and clarity.

The quality assessment is carried out at each stage of the statistical process (phases/subprocesses), accordingly to the Common Framework for Quality Management in the NSS and the principles of the European Statistics Code of Practice. The assessment of the statistical data quality includes statistical processes and statistical information. The requirements of the current methodological documents are applied for quality assessment, including the instructions in the internal guidelines "Statistics and Environmental Accounts", developed by the NSI.

To assess the quality of the data, their compliance with the data from the Business statistics information system is checked - Income and Expenditure Statement, Tax and Fees Report, PRODENERG Report.

In order to ensure the data quality, work is also being done to continuously improve the online-based information system for collecting primary data, providing an opportunity for arithmetic and logical control of the input data, and additional analyses and checks are being carried out.

The data from the water statistics serve both for reporting to various international institutions (Eurostat, UN Sustainable Development Goals, FAO, etc.) in the relevant formats, according to regulations, directives, signed agreements/contracts, and for carrying out assessments and analyses by various institutions or organizations in the country. The main users of statistical information from the survey are state and municipal organizations, scientific institutes, associations, companies and citizens.

The NSI conducts a regular statistical survey "User Satisfaction with the Provided Statistical Information Products and Services", which covers all statistical areas. The survey aims to assess users’ satisfaction with the statistical information provided by the NSI and to define recommendations for the future development of the statistical system in accordance with user needs.

The data meet the requirements of current legislation in terms of scope and monitored indicators.

Not applicable.

Data accuracy is guaranteed through quality assurance activities in the statistical production process, as one of the criteria for the quality of statistical information, according to the Statistics Act.

Not applicable.

Not applicable.

Not applicable.

Not applicable.

Not applicable.

Not applicable.

Not applicable.

Not applicable.

Not applicable.

Not applicable.

Not applicable.

Not applicable.

Not applicable.

Not applicable.

According to the principles of the European Statistics Code of Practice and the requirements of the internal rules/integrated management system, statistical processes are regularly monitored and revised, if necessary. Revisions are carried out according to standard, established and transparent procedures. Regular analyses aim to improve data sources, statistical processes and products.

The data is revised upon change in regulatory requirements, the methodology, or when necessary.

Not applicable.

The data are published 14 months after the reporting year.

Not applicable.

Not applicable.

The data are published according to the Calendar presenting the results of the statistical surveys of the NSI. 

The data are published according to the Calendar presenting the results of the statistical surveys of the NSI.

The data are prepared at national and regional level. The data are comparable with other EU countries due to the application of common definitions and classifications.

Not applicable.

The data are comparable over time. For the main indicators of water statistics, data are available since 1990. Regional and more detailed information is available since 2008.

Data revisions in the dynamic series is carried out when the methodology changes.

For the main indicators of water statistics, data are available since 1990. Regional and more detailed information is available since 2008.

The data are coordinated with data from:

-          Registers of issued permits for water abstraction from surface and groundwater – Basin Directorates;

-          Register of issued guarantees – Sustainable Energy Development Agency(SEDA);

-          Data from energy and business statistics.

Classification is applied according to the Classification of Economic Activities and the Classification of Territorial Units for Statistical Purposes in Bulgaria(NUTS).

Not applicaple.

Not applicable.

The data are of high internal consistency. Within the framework of the quality assessment procedure, the consistency of primary and statistical data by sources, economic activities, national and regional level of aggregated and detailed data is checked.

Regular press release on the NSI website.

-        Statistical Reference Book

-        Statistical Yearbook 

-        Electronic publication "Environment" 

-        Brochure "Bulgaria"

Water statistics data are available on the NSI website at:

-        "Environment" section

-        Information System INFOSTAT

Not applicable.

According to Rules for Provision of Anonymised Individual Data for Scientific and Research Purposes of the NSI, anonymized individual data may be provided for scientific and research purposes.

Information service on request, according to the Rules for Dissemination of Statistical Products and Services of the NSI.

Not applicable.

-        Data Collection Manual for the OECD/Eurostat Joint Questionnaire on Inland Waters;

-        Internal guidelines "Environmental Statistics and Accounts".

High

-       European Statistics Code of Practice

-       Integrated management system in the NSI

-       Generic Statistical Business Process Model in the NSI (only in Bulgarian)

-       Handbook on internal quality audits of statistical processes and products in the NSI

-       Internal guidelines "Environmental Statistics and Accounts"

Quality report is published annually with the publication of statistical data.

The costs (budget) for statistical surveys are disclosed in the National Statistical Program, published on the NSI website.

The priority in conducting statistical surveys is to reduce the burden on respondents.

Actions are being taken to alleviate the burden on respondents, such as: collecting and verifying primary data through the online-based information system "Environmental Statistics", containing strict arithmetic and logical control; improving the instructions for filling out questionnaires; providing methodological and technical assistance; continuously exploring the possibilities for using information from administrative and other sources; conducting annual trainings for respondents and NSI experts, etc.

The time required to complete the statistical forms is used as the main measure of the workload of the respondents. For this purpose, a section is included in each form regarding the time needed to fill in the form (including the time for data preparation), which the respondents must complete. Based on this information and considering the specifics of the survey, the respondents' workload can be determined as relatively high. The overall workload of the responsible experts is determined as high, especially in cases of data revisions from previous reporting periods.

Regulation (EC) No 223/2009 on European statistics provides the necessity to establish common principles and guidelines ensuring the confidentiality of data used for the production of European statistics and access to such confidential data, taking due account of technical developments and the requirements of users in a democratic society.

The Statistics Act (Art. 25, para. 1) stipulates that individual data obtained and collected in statistical surveys are statistical secret and may be used only for statistical purposes.

According to Art. 25 of the Statistics Act, individual data may not disclose or provide. The provision of individual data is possible only according to Art. 26 of the Statistics Act.