UV systems in reuse applications Figure 4. Flow capacity for reuse plants UV has been used for reuse disinfection since 1987. Presently, UV systems treat more than 500 MGD produced by 80 reuse sites in 12 states. The majority of the UV installations are based on conventional low-pressure lamp technology. The lamps are arranged horizontally in open channels.
Larger plants have medium-pressure UV lamp systems.
These high intensity lamps can supply the required high UV doses using 90 percent fewer lamps than a low-pressure system. Many of the reuse sites process comparatively lower flows. As suggested by the variation in disinfection targets, these sites represent a variety of restricted and non-restricted applications, ranging from deep well injection to irrigation of landscapes, golf courses and crops. For many plants, these allowed TSS levels are inconsistent with the requirement to meet the low turbidity levels. Filtration, often required for reuse effluents, decreases the solids, particle size and number and ensures a consistent effluent quality.