By 1995, the existing lagoon system in the Town of Antigonish, Nova Scotia, had become overloaded and was discharging into salmon habitat. The proposed plan to correct the situation was construction of an outfall extension far into the harbour. ABL, together with C. J. MacLellan & Associates, proposed instead that the existing outfall remain and the plant be upgraded to improve effluent quality through process improvements and effluent filtration. This approach resulted in a savings to the Town of nearly $450,000.

The lagoon system capacity was increased by raising the berms to accommodate flows up to 1.8 MGD and to achieve an effluent quality of 5/5 mg/l BOD/SS in the summer, during low river flow periods, and 15/15 mg/l in the winter. The lagoon was retrofitted with a new aeration system, and the effluent passed through continuously cleaned filters and UV disinfection before discharge to Wright's River. A new control building, shown by the lagoon berm, was constructed to house the aeration blowers and other equipment for the upgrade. The project value was approximately $3,000,000; and was completed in the spring of 1996.