A simple method to equalize the workload when operating several small wastewater treatment plants: a case study

摘要

The aim of the present study is to define a simple (and easy to use) method to equalize the workload of personnel operating several small wastewater treatment plants (SWWTPs). The approach is illustrated through a case study which is the result of collaboration between researchers and a water and wastewater management company operating in Southern Italy. The topic is important since personnel have a significant impact on the operating costs of SWWTPs, and the approach outlined results in the minimum number of staff being required to assure the management of the service. Four kinds of work units are considered: plant managers, assistant plant managers, laboratory technicians and executives. In order to develop a practical, feasible and easy to use method, the workload was evaluated considering only the population equivalent (PE) and the number of plants managed. The core of the method is the evaluation of the percentage of time that the personnel units devote to the operation of SWWTPs of the municipality considered. The proposed procedure offers a useful tool to equalize the workload, both in terms of PE and the number of plants managed, the procedure being easily modifiable to introduce other evaluation criteria. By using familiar concepts such as PE and number of plants managed, the approach of the method can easily be understood by management. It can also be readily adapted to other similar situations.