Schreiber’s peripheral drive clarifiers utilize leverage rather than center-drive torque to rotate the scraper and skimming assembly. Equipment for the removal of floatables and settled solids is suspended from a rotating bridge. Rotating skimming equipment removes floatables regardless of wind direction, and helical scrapers transport settled solids to the center of the basin in a single revolution. The scraper design does not require the grouting of the tank bottom in construction.