Abstract
There has been a recent increase of interest in sewer network water quality, both for pollutants and wastewater epidemiology. Of particular interest is the ability to perform cost-effective small-scale monitoring to understand the sewer network and perform source localization (the process of identifying the sources of materials of interest within the network), enabling prioritization of combined sewer overflow (CSO) interventions and targeted response to the detection of infectious diseases. Rhodamine WT fluorescent dye tracing was carried out in the combined sewer networks of four UK cities, for which network geometries were available. Over 100 dye concentration profiles were recorded, from which discharge, travel time (velocity), and dispersion were quantified. A simplified hydraulic and water quality (conservative solute transport) modeling approach was used to investigate dispersion further. A theoretical method for calculating dispersion over a reach with nonuniform properties was derived and used with the models and recorded data to develop a method for estimating the dispersion coefficient in sewers. Novel simultaneous injections into multiple manholes within one sewer network were conducted. Modeling of these injections validated the modeling approach and explained the measured concentration profiles, demonstrating both the potential of hydraulic and solute transport modeling and the new dispersion coefficient predictor for source localization. Such modeling can be used to develop sewer network "fingerprints"and source location probability plots based on residence time distribution (RTD) theory to maximize information from limited water quality monitoring. This will aid managers and operators in identifying potential intermittent sources of material within the network.
| Original language | English |
|---|---|
| Article number | 04023019 |
| Journal | Journal of Environmental Engineering (United States) |
| Volume | 149 |
| Issue number | 5 |
| DOIs | |
| Publication status | Published - 1 May 2023 |
Bibliographical note
Funding Information:This work was supported by the EPSRC (Grant No. EP/P012027/1) and the UK Health Security Agency. The authors are grateful to Severn Trent Water, United Utilities, Welsh Water, Yorkshire Water, and their staff, for their assistance in accessing and monitoring networks, and to Joseph Milner, Environmental Monitoring Solutions, and others for their assistance in carrying out fieldwork. For the purposes of open access, the authors have applied a Creative Common Attribution (CC BY) license to any Author Accepted Manuscript version arising.
Publisher Copyright:
© 2023 This work is made available under the terms of the Creative Commons Attribution 4.0 International license.
Keywords
- Longitudinal dispersion
- Mixing
- Pollutants
- Sewers
- Solute transport
- Source localization
- Tracing
- Water quality
