In solids contact basins, what is the maximum weir loading that should not be exceeded?

In solids contact basins, the maximum weir loading is crucial to ensure effective treatment and operational efficiency. A maximum weir loading of 10 gallons per minute per foot (gpm/ft) is generally considered optimal because it balances the need for effective settling of solids while preventing excessive turbulence that could re-suspend settled solids.

When weir loading exceeds this level, it increases the risk of not allowing adequate time for sedimentation, potentially leading to poor effluent quality. The design considerations for these treatment processes require maintaining a controlled flow rate to facilitate the removal of solids effectively while also ensuring that the operational characteristics of the basin are kept within favorable limits.

Therefore, maintaining a maximum of 10 gpm/ft promotes both stability in the treatment process and compliance with regulatory requirements for effluent quality. The higher weir loading rates are not ideal, as they can compromise the performance and efficiency of the solids contact basins.