In all waste streams there are both solid and liquid components. To conquer the clog, the first step in the treatment process is to remove as much of the solid components as possible. This is done somewhat in sequence:
1. Headworks screens remove the largest debris. Pumps working at these pumping stations have the toughest duty and exposure to wear and pump malfunction.
2. Grit removal, filtering basins, and sedimentation basins continue the process as liquid goes further into the treatment process.
3. Ultimately, the solids are either screened early and taken to landfills, or they are processed as sludge and treated in large digesters, where they are rendered as fertilizer or send for landfill.