Ultraviolet Disinfection


Ultraviolet Disinfection

Marshfield, MA


Massachusetts Projects:

About this Project

As part of a Wastewater Treatment Facility (WWTP) upgrade, FST conducted a thorough technical and cost comparison between chlorination/ dechlorination and UV disinfection. A medium-pressure UV pilot plant investigation (Trojan 4000) was conducted to assess the disinfectability of the secondary effluent under various operating conditions. Fecal coliform and enterococci were used as the test microorganisms.
The impacts of various water quality parameters specific to the Marshfield WWTP such as filtered and unfiltered transmissions, suspended solids concentration, and salt water intrusion were evaluated with respect to UV dose requirements. Using the results of the pilot plant investigations, design criteria for the full-scale UV system were developed.
FST designed and oversaw construction of a medium-pressure, high-intensity  SCADA-compatible UV system. The medium-pressure UV system at the Marshfield WWTP consists of 1 reactor, 2 banks, 4 modules per bank, and 16 lamps per bank. The UV system is equipped with a UV intensity probe, an automatic chemical/mechanical UV lamp sleeve wiper system, and an on-line transmission analyzer. 

More Information

Owner: Town of Marshfield

Location: Marshfield, MA

Highlights: The UV system has been operating successfully since 2000. FST also provided services for startup and operator training.