Abstract: A monitoring method for wastewater pump station performance and output, which method is capable of detecting an operating malfunction of the wastewater pump station such as a clog or leak within the pump, piping network or valves, or an output reduction due to pump wear. A monitoring apparatus placed at the wastewater pump staion performs continual monitoring of pump output values based on rates of rise of liquid level during pump non-run periods, time periods for the pump to reduce levels and resulting volume changes and at a controlled moment compares the values with measured reference values.