The construction process begins with the formulation of an idea for the project and finishes with the final commissioning. This consists of many stages, the most important of which is the construction of the buildings for the facility. This results from the specific features of the construction project, such as its long duration, its uniqueness, the seasonality of the work, dependence on weather con-ditions, and the necessity of interfering with the environment. There are many more factors, and when we consider the construction of a treatment works plus the sewerage system itself, we must also take into account any special requirements connected with their function in the local water and sewage management system. All these factors generate the risk exposure. Such risks should be included in the initial project-costing, schedule planning, and establishing the duration of the work. Events which can occur during the building of the sewage treatment works and the sewerage system have been detailed in this paper. Such events can lead to cost overruns and the prolonging of the construction phase. The method known as expert interview was used to establish whether the pre-prepared list contained the most important sources of risk. The specialists, all with long ...
