Anti-biofouling water in fuel sensor, anti-biofouling water sump and reservoir and method of retrofitting water sumps and reservoirs to incorporate anti-biofouling system

An anti-biofouling reservoir for a fuel, hydraulic fluid, or industrial fluid comprises:

• a reservoir space,
• sterilization zone as a lower portion of the reservoir space,
• a drain is coupled to the sterilization zone for periodic draining of the sterilization zone,
• a water sensor coupled to the sterilization zone that is used to periodically activate the drain, and
• at least one UVC light source configured for illuminating the fluid within the sterilization zone, wherein at least one UVC light source is integrated with the water sensor and formed in a sensor body and directed at sensor probes.

A sump of a water coalescing filter configured for separating water from fuel, hydraulic fluid, or industrial fluid comprising:

• a sump space receiving fluid from the water coalescing filter;
• a drain coupled to the sump space for periodic draining of the fluid in the sump space;
• a water sensor coupled to the sump space that is used to periodically activate the drain, wherein the water sensor is a water-in-fuel sensor configured to detect the interface of water and the fuel, hydraulic fluid, or industrial fluid in the fluid within the sump space;
• and
• at least one UVC light source configured for illuminating the water sensor within the sump space.