Unit of Environmental Engineering – University of Innsbruck, Austria Do we measure the right parameters in the right place(s)? Günther LEONHARDT M. Kleidorfer and W. Rauch Workshop by JCUD Data and Models Working Group Lyon, June 23, 2013

From an integrated case study… … to some more general conclusions or questions Integrated assessment and modelling example Lessons learned – possibilities and limits Monitoring Modelling Attempt to transfer some conclusions to modelling water quality in urban drainage systems

Integrated assessment case study River Schwechat, Lower Austria 4 universities involved (Project IMW3)

Integrated assessment case study River Schwechat, Lower Austria 4 universities involved (Project IMW3) CSO WWTP PE Separate sewer system Combined sewer system Agricultur e Groundwa ter WWTP 6000 PE Uptak e

Integrated assessment case study River Schwechat, Lower Austria 4 universities involved (Project IMW3) Long term online monitoring (11 months) Quality and flow 4 monitoring stations CSO WWT P Separate sewer system Combined sewer system Agricultur e Groundwa ter WWT P Uptak e

Integrated assessment case study River Schwechat, Lower Austria 4 universities involved (Project IMW3) Long term online monitoring Quality and flow 4 monitoring stations  Identification of relevant processes  Modelling CSO WWT P Separate sewer system Combined sewer system Agricultur e Groundwa ter WWT P Uptak e

Results - Monitoring Large unknown inflows (not measured) Groundwater Storm sewers, CSOs, surface runoff Typical but strong dynamics of O 2 Very low concentrations of NH 4 -N Below measurement range of used probes Hardly any impact of CSO observed With respect to “classical” parameters

Results Monitoring Oxygen in mg/l Hour of the day Hourly means of dissolved oxygen in August 2012

Monitoring - CSO event

Results – model identification Low identifiability due to Superposition of effects Low impacts of CSO events and stormwater discharge Data availability Gaps due to failures, … No in-sewer measurements Low spatial resolution (13 km investigated stretch) Only a few dominant processes clearly identified

Model Hydrologic routing scheme (Muskingum) Transport of substances Biochemical reaction processes – conversion model Growth of sessile algae Respiration of sessile algae Nitrification Growth of heterotrophs Lysis of nitrifiers Lysis of heterotrophs

Model Hydrologic routing scheme (Muskingum) Transport of substances Biochemical reaction processes – conversion model Growth of sessile algae good identifiability Respiration of sessile algaegood … Nitrificationlimited … Growth of heterotrophs“indirect …” Lysis of nitrifiers“indirect …” Lysis of heterotrophs“indirect …”

Model results vs. observations downstream

Conclusions case study Satisfactory water quality condition With respect to “classical” parameters Despite large abstraction of water Despite heavy morphological interventions Monitoring requires huge effort …once again proven ;-) …4 sites, 3 pumps, many probes,... Should we focus on other parameters? Ecological indicators, micropollutants, …? How to measure them? Standardisation? How to use these data for models?  More details: Session B3 Tuesday 8:30 a.m.

Conclusions river water quality modelling Comprehensive description of processes available (based on work for WWTP – ASM) Developed for… Steady conditions Heavy impacts Many processes can be proven by measurements, experiments Assumed to work likewise under dynamic conditions But… …measurements of many inputs and states required …dynamic conditions often require even more data  Identification remains challenging

… back to water quality in urban drainage systems

Possible conclusions with regard to UD models Steady state processes (in sewers) Good datasets, descriptions and models for Transport Conversion processes Hvitved-Jacobsen et al. (1998,…), Huisman et al. (2003, 2004,…), …. Sediments? Dynamic conditions (rainfall – catchment and sewer) Measurements of input and some outputs Strong signals observed Limited understanding of catchment processes Poor performance of models

Some questions… Problem/ Aim System dimensions Data/ Measurements MODEL Should we measure other parameters? Where to measure (spatial resolution)? Do we always use the right models for the problems addressed? (  report from INTERURBA III) Are there other ways to interpret our data? (other types of data)

Thank you for your attention! … and discussion! Contact: Günther Leonhardt Unit of Environmental Engineering University of Innsbruck Innsbruck, Austria Acknowledgements to partners and funders of the IMW3 Project

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CSO WWTP Separate sewer system Combined sewer system Agriculture Groundwate r WWTP Uptak e