In which scenario would the production of sludge be maximally reduced?

The scenario that would maximally reduce the production of sludge is linked to improved filtration methods. Enhanced filtration techniques effectively separate solids from liquids, leading to a higher quality effluent and minimal residual solids in the treated water. This not only reduces the volume of sludge generated but also improves the overall efficiency of the treatment process.

Increased chemical treatment can actually lead to more sludge production, as the addition of chemicals is often meant to precipitate out contaminants—this can result in a greater amount of solid waste being created. Keeping chemicals constant would stabilize the process but does not actively reduce sludge production, as it does not address the presence of residual solids. High basin capacity is primarily concerned with the volume of water that can be treated rather than with the mechanisms controlling sludge production. Thus, while maintaining chemical levels or increasing basin capacity may have their benefits, they do not directly reduce sludge as effectively as improved filtration methods.