1. Purpose and significance of the survey
The purpose of the survey on public water supply and public sewage system (VOD.2) is to collect data on the water supply and the volume of waste water.
The public water supply report gives data on the total volume of abstracted water and water taken over from other water systems by the water source, for the total volume of water distributed and water losses as well as the water treatment water supply network and facilities.
The public sewage system report gives data on the quantity of waste water by the place of generation, for the discharged waste water and the sewage network.
2. Reporting units and method of data collection
Reporting units in the statistical survey are active enterprises classified in the National Classification of Activities - NKD Rev. 2 (harmonised with NACE Rev. 2) in the section: E- Water supply; sewerage, waste management and remediation activities, groups 36, 37. The survey is carried out with annual periodicity.
4. Definitions and other explanations
Water supply from public water supply is the total volume of water abstracted from ground waters,
springs, watercourses, reservoirs and lakes as well as total volume of water abstracted from other water systems.
Abstracted volume of water is the total volume of water abstracted from water springs.
Water springs are all sources that are used in supplying of water mains, such as ground watercourses, springs, watercourses, reservoirs and lakes.
Distributed volume of water is the volume of water sold to consumers.
Water losses are actually found losses in water supply network caused by mechanical troubles or installation defects on water supply network.
Water treatment facilities are facilities used for purification (conditioning). Tanks are divided into
underground and elevated (tower-shaped) ones, used for the accumulation of water and reaching the required pressure.
Length of water mains is the length of pipes used for the supply of water and reaching of the required pressure.
The length of distribution network is the length of the water supply network from a tank to a consumer.
Waste water is water drained to the treatment facility after use, or discharged into the environment (into ground or surface waters). It does not include atmospheric or transitional waters (i.e. waters that power hydro-electric plants).
Treated waste water comprises all amounts of waste water that was treated during the reporting year, either primary (physical and/or chemical processes), secondary (biological and/or other treatment processes) or tertiary (physical and chemical, biological and other treatment processes) treatment of waste water.
Public sewage system is a network of enclosed public drains and sewers used for draining of either waste or atmospheric waters (general water sewage system), or solely waste water, and solely atmospheric waters (separation water sewage system).
Main sewer is a collecting drain, which drains water from one part or the whole city to the recipient or to th? treatment facility.
