Marian Kwietniewski

Field reliability tests of water distribution system from the point of view of consumer’s needs

The water deficiency, in turn, resulting from system failures is usually expressed by the volume of water that has not been supplied Δ V (m3). Being a random variable in the process of water distribution system (WDS) operation, this parameter has been studied by examining the reliability of a selected WDS based on its field reliability tests. Within the framework of the study reported here, the simultaneous occurrence of water deficiency cases was analysed and the probabilistic model of water deficiency was formulated. It was shown that singular failures of WDS (k=1) have a critical impact on the scale of water deficiency. The developed probabilistic model describes the probability of not exceeding a certain water deficiency level. The model can be helpful in determining the service standards in terms of the quantities of water supplied to the consumers.

Verification of measuring point locations in water quality monitoring used in a selected water distribution system

The verification of water quality measurement point locations in the monitoring of a selected Water Distribution System (WDS) was executed using a so called maximal detection method, described in [6] and widely discussed in [5]. As a result of application of this method, different numbers of measuring points were determined, along with different locations of those points in the examined WDS. Thus the water quality monitoring system, long in use in this WDS, was verified. Moreover, the use of the maximal detection method has led to higher efficiency of water quality monitoring. The resulting probability of water pollution detection in the water supply network was twice as high as for the existing monitoring system.

Results of the vacuum station monitoring in a selected vacuum sewerage system

The vacuum sewerage system is characterised by periodicity of operation, resulting from temporal and spatial non-uniformity of sewage flow to the system, along with short work times and long idle times. In those specific conditions, the operating parameters are kept by the vacuum station, which is a decisive factor in the reliability of operation of the sewerage system. As a result of monitoring of a selected pumping station, it was concluded that the majority of work times of the vacuum pumps is located within the interval between, approximately, 0,5 and 1,5 min., while the total work time of a pump was equal to as little as 37 min.

The reliability assessment of a typical structure fragment of a stormwater collection network including uncertainty

The article presents the reliability assessment of a gravity stormwater collection system. The system components were assumed as having two-state fit/unfit for use characteristics, while the entire system was treated as a multi-state object with many states of partial unfitness. The expected value of the reduced area of the drainage basin connected to the unfit fragments of the system was assumed the basic measure of the system unfitness. The uncertainty of this reliability measure was assessed.

One criterion optimization of location of water quality constant measuring points within monitoring system

The paper presents a method of measuring points location for water quality assessment in water distribution network for monitoring purposes. An algorithm of this method includes two aspects of water quality monitoring i.e. detection possibility and detection rapidity of water pollution in the network. A hydraulic model of water distribution network for simulation of water flow and quality is used within this method. Based on the network hydraulic simulations an optimization task is being solved. Its goal is a selection of water quality measuring points.

A probabilistic model of a stormwater retention tank including the monitoring of hydraulic parameters

Retention tanks are an essential part of stormwater collection systems. This paper considers a probabilistic model which allows to design and plan modernization of retention tanks or conduct risk analysis of already existing ones. The proposal makes use of a submodel of high rainfall sum in a given time period and simple dependences accounting for the stormwater balance in the tank. The parameters used in the model require calibration. Therefore, its practical application necessitates the monitoring of runoff from the drainage area of the tank under analysis as well as of rainfall in that area.

Selected methods of flow measurement for the purposes of wastewater networks monitoring

A system of wastewater flow measurements is a base element of wastewater networks monitoring. A properly designed system of measurements requires suitable selection of methods and measuring devices enable realization of on-line network monitoring. This paper discusses the most serviceable ultrasonic and electromagnetic devices for continues flow measurements. Their application along with requirements and limitation appears in the wastewater network.