This section is composed of three basic subareas: combined sewer overflows (CSOs), sanitary sewer overflows (SSOs), and stormwater discharges. Much of the literature cited came from documents covering noteworthy global conferences (Bathala, 1996; Engineering Foundation, 1996; Hallam et al., 1996; Maxwell et al., 1996; Sieker and Verworn [Eds.], 1996; Society of Environmental Toxicology and Chemistry, 1996; U.S. EPA 1996a; Water Environment Federation, 1996a,b,c). In addition, the U.S. Environmental Protection Agency (U.S. EPA) published guidance documents (U.S. EPA, 1996,c,d,e), which are discussed in more detail in the subsection Regulatory Policies and Financial Aspects.

https://www.jstor.org/stable/pdfplus/29763265.pdf

Urban wet-weather flows

Modelling interactions in urban drainage, water supply and broader integrated urban water systems has been conceptually and logistically challenging as evidenced in a diverse body of literature, found to be confusing and intimidating to new researchers. This review consolidates thirty years of research (initially driven by interest in urban drainage modelling) and critically reflects upon integrated modelling in the scope of urban water systems. We propose a typology to classify integrated urban water system models at one of four 'degrees of integration' (followed by its exemplification). Key considerations (e.g. data issues, model structure, computational and integration-related aspects), common methodology for model development (through a systems approach), calibration/optimisation and uncertainty are discussed, placing importance on pragmatism and parsimony. Integrated urban water models should focus more on addressing interplay between social/economical and biophysical/technical issues, while its encompassing software should become more user-friendly. Possible future directions include exploring uncertainties and broader participatory modelling.

Review: A critical review of integrated urban water modelling - Urban drainage and beyond

Integrated approaches to urban stormwater drainage management are being increasingly advocated as necessary for advancing more sustainable and holistic management of urban water environments. In this paper, the status of integrated approaches in the management of urban stormwater discharges to receiving waterways is summarized. The starting point of the paper is with the recent scientific contributions, revealing that integration is being pursued and implemented predominantly at two conceptual levels. These include 1) integrating the technical system with the receiving waterway environment, and 2) considering the interaction and influence of the human system with the technical system through processes such as stakeholder and public participation. Additionally, it is argued that the evolving shift towards the implementation of water-quality-based strategies advances the need for further development and application of integrated models and approaches. The cases of online physically based models for predictive control and integrated source control and public participation are presented as examples of such ongoing developments in pursuit of integrated urban stormwater management.

Integrated approaches in urban storm drainage: Where do we stand?

This paper develops a decision support framework that assists managers in the urban water industry to analyse a mix of water service options, at the whole-of-city scale. The decision support framework moves decision-making in urban water systems from traditional command and control approaches that tend to focus on an outcome at a point in time to a more sustainable, inclusive and dynamic decision-making process driven by social learning and engagement. While available models and evaluation techniques provide valuable input to decision-making, the complex nature of urban water systems requires more than just social and economic criteria to be considered as part of decision support frameworks. The authors believe that current decision support frameworks need to be presented in a way that incorporates adaptive management and integrated urban water management strengths at the strategic and operational level. The inclusion of social learning and engagement is necessary to achieving this end.

A Sustainable Decision Support Framework for Urban Water Management

The European Union (EU) has implemented effluent (emission) standards since 1991, while North America practices a riskbased, imission approach. Progressing eutrophication and large fees for discharged loads push EU countries toward more stringent effluent concentrations, below total nitrogen (TN) levels of 10 mg/L and total phosphorus (TP) levels of 1 mg/L. In North America, the limit of treatment technology (LOT) concept has been defined as the lowest economically achievable effluent quality, which for TN is <1.5 to 3 mg/L and TP is <0.07 mg/L. These limits are becoming targets in fragile ecoregions in North America and drive the technology solutions towards a combination of advanced biological nutrient removal process trains, followed by chemical polishing and solids separation by granular or cloth filters or membranes. In Western Canada one-biomass biological nutrient removal processes are used, such as Westbank or Step-feed, often followed by filtration to achieve low effluent total phosphorus levels. Eastern Canada has a less stringent approach to nitrogen control and practices chemical phosphorus removal. Requirement for total nitrogen removal and rising costs of phosphorus precipitation drive designers towards advanced one-biomass processes and full utilization of carbon (for denitrification and phosphorus removal) available in raw wastewater and primary sludge. New processes are developed to take advantage of carbon available in waste activated sludge or even in the recycled activated sludge. Sludge treatment return streams have high nutrient loads and novel processes are introduced for their treatment, some utilizing generated nitrifier biomass for bio-augmentation of the main stream nitrification process. The impact of sludge processing on the liquid train and vice versa is now fully embedded in the design process.

/pdf/nutrient-removal-technology-in-north-america-and-the-5fo9pcdcid.pdf

K. Seggelke

Papers

Integrated modelling as an analytical and optimisation tool for urban watershed management.

Integrated operation of sewer system and WWTP by simulation-based control of the WWTP inflow.

Online-simulation of the WWTP to minimise the total emission of WWTP and sewer system

Dynamic simulation of a low loaded trickling filter for nitrification