Loureiro Engineering

                                                            Ultraviolet Disinfection System for a Wastewater
                                         Treatment Facility Water Pollution Control Authority
                                                   (WPCA) Town of Stafford, Connecticut

About The Project
In 1995, the Town received its new water discharge permit from the DEP, which imposed new effluent limits for residual chlorine. Stafford's method of disinfection was a gas chlorination system that did not satisfy the lower limits in the permit. The Town's WPCA retained LEA to investigate disinfection alternatives in 1997, one year before the new limits went into effect.
We evaluated the disinfection alternatives and determined the most practical solution: installation of a vertical, open-channel ultraviolet (UV) disinfection system. This was one of the first systems of this particular design to be installed in Connecticut. The system kills bacteria consistently and is easy to maintain.

Our design and installation featured:
• a vertical orientation, which maximizes contact efficiency
• a modular configuration, which allows for future expansion
• an air-scrub for self-cleaning, which doubles the time between manual cleanings
• housing in a new concrete channel

Our services
Preliminary design report
Final design drawings and specifications
Contract administration
Construction monitoring

The result
We brought the Town's wastewater treatment facility into compliance with
the limitations of its new water discharge permit. The vertical UV disinfection system lowered the facility's operating costs and also improved safety by eliminating the hazards associated with handling chlorine gas.