St. Thomas, ON


Digester Replacement Delivers on Savings & Sustainability



WWTP Rating

7.2 MGD (27,300 m3 / day)

Population Served


Lystek THP Module Size

1 x LY10 (1.0 dry tons / hr)

Lystek THP Processing Footprint

1,600 ft2 (149 m2)


Undigested Municipal Biosolids


The City of St. Thomas is located near of the City of London in southwestern Ontario, surrounded by farmland and in close proximity to Lake Erie. The St. Thomas Water Pollution Control Plant (WPCP) provides full secondary treatment of wastewater prior to discharge into the Kettle Creek. Solids were managed at the WPCP by anaerobic digestion of primary and waste activated sludges. These biosolids were dewatered and then hauled to a nearby landfill by WPCP staff.

Components of the anaerobic digestion process were more than 40 years old and facing increasing requirements for maintenance and replacement. The City in partnership with their engineering consulting firm evaluated all available options, including full replacement of their anaerobic digestion process and several alternative technologies. While all of the options evaluated were able to meet the environmental, technical and social requirements of the analysis, Lystek THP offered significantly lower capital and operating costs compared with the other options.

Lystek THP was implemented at the St. Thomas WPCP in 2018, along with new dewatering and liquid fertilizer storage.


In-Plant Installations