Loudonville Reservoir Disinfection Improvements

What Was the Challenge?

The Albany Water Department sought to replace outdated ultraviolet (UV) disinfection reactors at the Loudonville Reservoir storage facility. The existing reactors, over 20 years old, were inefficient, and technologically obsolete.  The original system was installed prior to the finalized guidance published in EPA’s UV Disinfection Guidance Manual.  The system had never received final approval under the Long Term 2 Enhanced Surface Water Treatment Rule (LT2-ESWTR) for disinfection of uncovered finished water storage. This presented compliance challenges for achieving disinfection targets for giardia, cryptosporidium, and viruses without extensive modifications to the facility’s infrastructure.

How Did Barton & Loguidice Provide a Solution?

B&L assessed the facility’s water quality, peak and average demands, and disinfection strategy to size a new UV disinfection system. The design provided 3-log giardia inactivation and 2-log cryptosporidium inactivation via UV, while 4-log virus inactivation continued with sodium hypochlorite. B&L specified a cost-effective T1 challenge organism for the UV reactor design, achieving protection comparable to MS2 phage while reducing costs.

Pre-purchase documents allowed the City to procure the replacement equipment directly as owner-furnished, using a net present value analysis for cost-effective selection. To address the existing reactors’ noncompliance with the EPA’s UV Disinfection Guidance Manual (UVDGM), B&L developed a computational fluid dynamics (CFD) model. This model verified that the hydrodynamic effects of the existing piping layout would not compromise the validated UV dose, eliminating the need for costly piping or building modifications.

Why Was This Project a Success?

B&L’s innovative approach resulted in the new system’s approval from the New York State Department of Health for the first time under LT2-ESWTR. The CFD modeling effort allowed the City to retain its existing piping configuration while implementing a modern, efficient UV disinfection system. This saved significant costs and ensured compliance with stringent disinfection regulations. The new system provides improved water quality and public health protection, marking a critical milestone for the Loudonville Reservoir facility and the Albany Water Department.