method of sewer net segmentation and equivalenting

Summary

The design procedure of evaluating a most important index of the municipal sewer net reliability, i.e. relative amount of raw sewage spills resulting from the failure of separate sewer sections is suggested. The design procedure is using a typical characteristic of the system, i.e. its tree-type structure, and lies in the formal substitution of the sewer net for one dummy equivalent pipeline with the reliability parameters that are evaluated with the use of the known rates of failure and rehabilitation of the original (existing) sewer elements. The design procedure is simple and can be used directly by the companies that are operating municipal sewers.

reliability , failure , sewerage network , rehabilitation , state graph , raw sewage discharge amount

Specificity and methodological features of evaluating the reliability of sewer networks in large cities

Summary

The paper draws attention to the structural differences of two equivalent subsystems of a single infrastructure of a water supply and wastewater disposal system in a large city: a water supply subsystem and a wastewater disposal subsystem. It is stated that by now there is no unified established concept regarding the quantitative measure of the reliability of the sewer network. Based on the results of a review of modern domestic scientific and technical literature, three approaches to evaluating the reliability of municipal wastewater disposal systems are singled out and critically analyzed. The capabilities determined by the accepted assumptions are identified, and the areas of practical use of each of them are specified.

Key words

reliability , sewerage network , state graph , method of segmentation and equivalenting , Kolmogorov equations , «destruction and replication» scheme