What type of disinfection system does the hospital lack for its domestic water system?

The correct answer highlights the absence of a supplemental disinfection system in the hospital's domestic water supply. A supplemental disinfection system is critical as it provides an additional layer of protection against pathogens, such as Legionella, which can proliferate in water systems and pose significant health risks.

In a typical plumbing system, regular disinfection methods may not be sufficient to ensure the complete elimination of harmful microorganisms. Supplemental disinfection enhances the effectiveness of primary disinfection methods, addressing gaps that may arise due to water stagnation, inadequate turnover, or dead legs in the piping system.

This option acknowledges the necessity for ongoing monitoring and control measures, often involving the use of chemicals or other methods to maintain water quality and prevent bacterial growth. Proper implementation of a supplemental disinfection system can ultimately help safeguard patient health by reducing the risk of waterborne infections.

The other choices refer to specific methods or systems that may serve different purposes. For instance, a mechanical filtration system focuses on physically removing particulate matter and contaminants from water, while thermal disinfection employs high temperatures to kill bacteria—both of which are valuable but do not address the need for ongoing chemical treatment. UV disinfection is effective in inactivating pathogens using ultraviolet light, yet it may not be enough alone without