A municipal wastewater lagoon was experiencing issues with odour and requested assistance determing the cause. A sludge and lagoon performance assessment was completed. Sludge profiles were measured, and lagoon supernatant was analyzed. Community water supply was also evaluated to estimate the water quantity as well as to determine incoming water quality affecting the lagoon. Influent flow rates were estimated, and overall loading was calculated to determine lagoon performance. Results showed that the sludge had become septic. Additional recommendations beyond the scope of work were provided to help improve performance and plan for expansion.