Wastewater Treatment Plant Lagoon Maintenance

The City of Lethbridge Wastewater Treatment Plant (WWTP) biosolids storage lagoons were constructed in 1970. The lagoons are 15 feet deep total with 3 feet of freeboard in the original design. The lagoons are located northwest of the WWTP and receive digested sludge for thickening, storage, and further stabilization. Biosolids from the lagoons are seasonally dredged and land applied to agricultural fields. The land application program typically begins to ramp up March through to May, and September through October, depending on weather conditions and land availability. The lagoons are now in a state that maintenance and select upgrades are required in order for continued efficient operation (i.e. accumulation of various items requiring labour for removal, poor road and berm condition, failed digester lagoon feed valves and cross-connect, etc.).