Anaerobic lagoons are a cost-effective, low energy technology for the reduction of organic carbon in meat processing wastewater. They are widely used and are the preferred technology in meat processing wastewater systems for initial biological treatment to reduce organic load.

Anaerobic ponds do however have primary weaknesses of odour and greenhouse gas emissions, especially methane which has a global warming potential 21 times that of carbon dioxide. These weaknesses have driven the need to cover the traditional anaerobic lagoon, the Covered Anaerobic Lagoon (CAL) has been developed as a solution.