Prove metered areas on the distribution network

Business Sectors (Suites): Leakage Detection and Control
Developed by: Energy & Utility Skills
Approved on: 01 Dec 2018


This Standard is about proving metered areas on the distribution network.  This includes operating network fittings to isolate specified sections of networks, making sure boundary and other required valves are watertight and working and establishing inflow and outflow meters.  It also includes checking all required work has been carried out, recommissioning, flushing and checking that samples have been taken. You must follow safe working and hygiene practices at all times.

This Standard is for anyone who is involved with proving metered areas on the distribution network.

Performance criteria

You must be able to:

1. obtain information from reliable sources about metered areas being proved 2. identify sections of distribution networks which need to be isolated to establish integrity of metered areas 3. confirm that customers who will be affected have been informed, and that service levels will be maintained, in accordance with organisational requirements 4. confirm that specified network fittings are in expected locations, are accessible and are in working condition 5. confirm that there are no obvious sources of potential contamination on network fittings within the area you are working 6. access and operate relevant network fittings in the required sequence to isolate and recommission identified sections of distribution networks 7. deal with network fittings and equipment requiring repair and maintenance in line with organisational processes 8. confirm that known leaks on network fittings have been repaired prior to proving 9. check the water tightness of boundary valves according to organisational procedures 10. confirm that valve operations do not affect system pressures 11. confirm that those meters which provide total inflow and outflow to metered areas are accessible and in working condition 12. check that permanent boundary valves are marked in the correct positions on site and network plans 13. carry out any hygiene procedures required in line with organisational and work requirements 14. carry out flushing operations and discharge water in accordance with organisational procedures 15. confirm that any required mains water sampling is carried out by designated people, according to organisational procedures 16. re-commission sections of networks once all relevant proving activity has been carried out in line with work requirements 17. inform relevant people about progress, problems and actions taken during isolation, proving and recommissioning activities 18. record complete and accurate details of progress, problems and actions taken in line with organisational processes 19. follow safe working and hygiene practices according to relevant regulatory and statutory procedures

Knowledge and Understanding

You need to know and understand:

1. work requirements for isolating, proving and re-commissioning network sections 2. sources of information about metered areas 3. how to interpret network and site plans and network flow information 4. the effect that isolating a section of the network may have on the wider distribution system, the immediate zone, water quality and customers 5. service levels and organisational requirements and processes for informing customers 6. potential sources of contamination of network fittings 7. how to operate network fittings including Isolation valves, air valves and hydrants and the importance of doing it in the required sequence 8. how to check that isolation has been successful, the importance of doing this, and who to inform when it has been completed 9. the importance of checking accessibility and working conditions of boundary valves 10. who to report repair and maintenance details to 11. the importance of checking repair of network fittings 12. procedures for water tightness of boundary valves 13. reasons why valves may not be in the expected status, and the implications of changing them 14. the consequences of making any changes or variations to water quality and supply, with regard to organisational limits 15. the importance of not affecting system pressures 16. air venting methods to avoid bursts or water quality issues 17. when and how to carry out hygiene procedures 18. flushing procedures 19. water disposal procedures and the potential damage which can be caused by incorrect disposal 20. the need for sampling and who should do it 21. recording requirements in relation to progress including date and time of isolation, problems and actions taken 22. who needs to be informed about progress, problems and actions taken and when 23. safety and hygiene practices and related regulatory statutory requirements relating to health and safety and street works


Scope Performance

Scope Knowledge





Links To Other NOS

External Links

Version Number


Indicative Review Date

01 Dec 2021





Originating Organisation

Energy & Utility Skills

Original URN


Relevant Occupations

Engineering, Water Network Technician, Water Leakage Detection Technician

SOC Code



distribution network, water, valves, hygiene practices