Sewer Performance Reporting: Factors That Influence Blockages

• Published in: Journal of infrastructure systems 2011-03, Vol.17 (1), p.42-51
• Main Authors: Marlow, D. R, Boulaire, F, Beale, D. J, Grundy, C, Moglia, M
• Format: Article
• Language: English
• Subjects: Applied sciences; Blocking; Buildings. Public works; Exact sciences and technology; Infrastructure; Management; Sewerage. Sewer construction; Sewers; Strategy; TECHNICAL PAPERS; Utilities; Water consumption; Water utilities
• ISSN: 1076-0342; 1943-555X
• DOI: 10.1061/(ASCE)IS.1943-555X.0000041

Managing sewer blockages represents a significant operational challenge for water utilities. In Australia, company-level blockage rates are used to compare the effectiveness of the management strategies of different utilities. Anecdotal evidence suggests that this basis may not be a fair one for comparison because blockages are influenced by a range of factors beyond management control and vary from company to company. This issue was investigated as part of a broader research effort on sewer-blockage management undertaken in conjunction with the Water Services Association of Australia (WSAA) and its members. A Web-based survey was used to collate expert opinion on factors that influence blockage rate. The identified factors were then investigated in an exploratory analysis of blockage-related data provided by two participating utilities, supported by literature reviews. The results indicate that blockage rate is influenced by a range of factors, including asset attributes, climatic conditions, water consumption, and soil type. Because these factors vary from utility to utility, this research supports the finding that company-level blockage rate in itself is not an appropriate metric for comparing management effectiveness.