Abstract: In the treatment of sewage, fresh, representative samples are continuously collected and analyzed at a number of different points in a sewage treatment reservoir. A submersible grinder pump is connected by a sample supply conduit to a continuous flow through filter, and ground sewage slurry is delivered at high velocity through the filter so that it scours the internal surfaces of the filter. The sewage slurry is continuously returned to the treatment reservoir, and filtrate continuously passes through a rotameter to a transparent sample collection reservoir. Discharge from the sample reservoir is controlled by a solenoid operated valve, and a continuous overflow waste return conduit allows return of the filtrate to the treatment reservoir if the solenoid valve is closed. A computer controls operation of the solenoid valves and one or more analyzers for analyzing filtrate qualities (such as alkalinity). The solenoid controlled valves are connected to the analyzer through a manifold.