Measuring surplus capacity for multiobjective optimal design of foul sewer systems

ABSTRACT

This paper proposes a new performance index of foul sewer systems, i.e. sewer conveyance capacity (SCC) index, to quantify the surplus capacity for multi-objective optimization design problems. The use of the new SCC index is demonstrated using a hypothetical network and a real-world foul sewer network. Results obtained show clear trade-offs between SCC and the other two objectives considered, i.e., capital and operational costs and greenhouse gas emissions. The results show that the upstream sewers in the system often have a relatively large surplus capacity, while the sewer mains operate close to the design capacity. Moreover, SCC is compared with three common indicators at both individual sewer and system-wide levels. Strong correlations between SCC and other indicators are revealed, implying that SCC is a good representation of system performance and can provide a more comprehensive picture of the foul sewer system performance.

KEYWORDS:

• Foul sewer network
• multi-objective optimization design
• sewer conveyance capacity

Disclosure statement

No potential conflict of interest was reported by the authors.

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Additional information

Funding

This study is financially supported by National Key Research and Development Program (2017YFC0406005) and the National Natural Science Foundation of China (91647201, 91747102, 51708086). The first author is supported by the China Postdoctoral Science Foundation (2016M601309). The fourth and fifth authors are supported from the Building Resilience into Risk Management project (EP/N010329/1) funded by the UK EPSRC; Engineering and Physical Sciences Research Council [EP/N010329/1].