Reliable UV treatment for UV transmittance down to 16%

Denison WWTP installed Enaqua's UV solution for low quality water without the need for extensive pre-treatment systems.



Project Background

Denison received a cease and desist order in 2012. The plant had to overcome its wastewater disinfection issues, and sought after a sustainable solution. The major suppliers of UV disinfection equipment said that it was impossible to go for UV technology – without installing extensive pre-treatment systems. Enaqua in contrast, asked permission to perform a pilot testing and proved that UV truly is an option without the need for pre-treatment.


The Enaqua Solution

Denison’s UV transmittance varies between 16 and 45% and the turbidities up to 70 NTU. The TSS range varies from 11 to 140 mg/l. Uniform UV exposure was therefore essential to ensure a reliable and sufficient disinfection of the wastewater at Denison. Enaqua’s Non-Contact UV system is designed so that water flows through tubes with lamps placed outside of the water surrounding the tube. This design ensures consistent light distribution and hereby increases the overall disinfection quality. Enaqua’s fouling resistant AFPTM (Activated Fluoropolymer) tubes are specifically developed for Enaqua’s UV solutions. The material has a high UV transmittance, a fouling resistant surface, and is proved chemically stable for more than 25 years.


Advantages and Benefits

During the initial pilot study phase, Enaqua’s Non-Contact UV system performed remarkably well and proved effective and reliable in treating effluent with UV transmittance down to 16%. The simple design, and the proven effectiveness of Enaqua’s system made it the ‘best-in-class’ solution for the application. Denison was able to install UV as their preferred disinfection technology without sacrifice investing in additional pre-treatment systems.

UV treatment


System design parameters
Peak Design Flow5 MGD
Average Daily Flow3 MGD
UV Transmittance45%
Disinfection Limit126/100ml E.Coli
Enaqua Product BaseC-Series LT
Upstream TreatmentActivated sludge