Regulations in UV-C water disinfection
To ensure public health protection and reliable performance, the application of UV systems in water treatment is governed by various national and international regulations and standards. Across the industry, regulations typically focus on several key principles:
- Validated disinfection performance
- Standardized testing procedures
- Operational safety
In Europe, standards such as EN 14897, DVGW W 294, and ÖNORM M 5873 define requirements for UV equipment and performance testing. In the United States, regulatory guidance is largely based on documents from the U.S. Environmental Protection Agency (EPA) and certification standards such as NSF/ANSI 55.
Although the main objective of these regulations is similar worldwide, the regulatory frameworks may differ depending on the application and region.
Drinking water
For drinking water applications, regulations focus on guaranteeing a validated level of pathogen inactivation while ensuring reliable system operation. In Europe, standards such as DVGW Worksheet DIN 19294 (Germany) and ÖNORM M 5873-1 (Austria) define requirements for UV reactors. These include performance testing, validation procedures, and operational monitoring. These standards generally require biodosimetry testing to demonstrate that the reactor delivers the required UV dose under defined operating conditions.
For smaller systems or point-of-use applications in the USA, certification according to NSF/ANSI 55 is commonly required.
Swimming pools
In swimming pool water treatment, UV-C technology is commonly applied to improve water quality and reduce the formation of combined chlorine compounds (chloramines). Regulations generally allow UV systems as a supplementary treatment step alongside chemical disinfectants such as chlorine. In Europe, the use of UV in public pools is addressed in national regulations and guidelines. For example, in France the application of UV treatment technologies is described in ‘Circular DGS/EA4 2008-65’, while the ‘Order of 26 May 2021’ defines sanitary monitoring and water quality control requirements for public swimming facilities.
Low versus medium pressure lamps
Most regulations do not prescribe specific UV technologies such as low-pressure (LP) or medium-pressure (MP) systems, but instead focus on performance criteria. In Europe, where chloramine reduction and indoor air quality are important regulatory drivers, medium-pressure UV systems are commonly used. The broader UV spectrum of MP is effective at breaking down different chloramine compounds. In the United States, UV is often applied as a secondary disinfection barrier, particularly to control chlorine-resistant pathogens such as Cryptosporidium. Here, both LP and MP systems may be used.
Wastewater
In wastewater treatment, UV-C systems are primarily used to disinfect treated effluent before discharge into surface waters or before water reuse. Regulatory frameworks focus on ensuring that treated effluent meets microbiological standards for environmental protection and public health. In Europe, UV technology is typically evaluated based on its ability to meet required microbial limits for discharged or reused water rather than on specific system design criteria.
In the United States, guidance documents such as the ‘EPA Wastewater Technology Fact Sheet: Ultraviolet Disinfection’ describe the design principles, operational requirements, and advantages of UV systems for wastewater treatment plants. For water reuse applications, the National Water Research Institute (NWRI) UV Disinfection Guidelines provide additional recommendations on validation, monitoring, and operational performance.
References
Drinking water
- DVGW W 294-1:2023-12 – UV Devices for Drinking Water – Requirements (Germany).
- DVGW W 294-2:2006-06 – UV Devices – Testing and Disinfection Effectiveness (Germany).
- ÖNORM M 5873-1:2020 – UV Water Disinfection Devices – Requirements and Testing (Austria).
- EN 14897:2006+A1:2007 – Water Conditioning Equipment Using Low-Pressure UV Radiators – Performance, Safety and Testing (Europe).
- U.S. EPA (2006) – Ultraviolet Disinfection Guidance Manual (UVDGM), EPA 815-R-06-007.
- NSF/ANSI 55:2024 – Ultraviolet Microbiological Water Treatment Systems (United States).
Swimming pools
- Order of 26 May 2021 – Sanitary Control and Monitoring of Swimming Pool Water, pursuant to Articles D.1332-1 and D.1332-10 of the French Public Health Code (France).
- Circular DGS/EA4 2008-65 (22 February 2008) – Regulatory Provisions for Public Swimming Pools and the Use of Treatment Products and Processes, including UV Dechloramination Systems (France).
- DIN 19643 1-5 – Treatment of water of swimming pools and baths (Germany)
- M 5890 (preliminary) – UV plants for the photochemical treatment of pool water — Requirements for design, installation and operation (Austria)
Wastewater
- U.S. EPA (1999) – Wastewater Technology Fact Sheet: Ultraviolet Disinfection, EPA 832-F-99-064.
- NWRI (2012) – Ultraviolet Disinfection Guidelines for Drinking Water and Water Reuse, 3rd Edition.
- Directive (EU) 2024/3019 – Urban Wastewater Treatment Directive (recast).
- Regulation (EU) 2020/741 – Minimum Requirements for Water Reuse.