What is the most common and least expensive method of handling sludge?

Lagooning is often considered the most common and least expensive method for handling sludge in wastewater treatment. This process involves storing the sludge in large, shallow ponds, known as lagoons, where natural processes can occur to decompose the organic matter.

The effectiveness of lagooning lies in its simplicity and low operational costs. It requires minimal mechanical intervention and can use natural biological processes facilitated by sunlight, bacterial action, and evaporation, which helps in reducing the volume of the sludge over time. Additionally, lagoons can serve multiple purposes, including serving as storage or even as treatment systems.

While options like centrifugation and filtration are effective in reducing sludge volume and separating solids, they generally involve more complex equipment and operation, leading to higher costs. Composting is also a viable option but typically requires more labor and management than lagooning, making it less commonly adopted for large-scale operations.

Therefore, lagooning stands out as a practical choice for many facilities looking to manage sludge efficiently and cost-effectively.