Post on 25-Jun-2015
description
Bathing Water Services Anders Chr. Erichsen
Bathing Water
Services
Operational
Systems
Details of the
approach
Benefits of our
approach
Managing expectations for
Bathing Water Legislative requirements and public perception of bathing waters
have changed. The EU Bathing Water directive has placed
additional requirements on utilities with respect to CSO
discharges.
With the existing pipe networks and increasingly frequent intense
rainfall events, managing CSO discharge in the bathing water
season continues to challenge.
#2
Bathing Water Directive
• ’...The purpose of this [the Bathing Water] Directive is to preserve, protect and improve the quality of the environment and to protect human health ..( article 1, section. 2)’
• ’’…Bathing waters are to be classified as ‘sufficient/good/excellent… if - when subject to short-term pollution - adequate management measures are being taken, including surveillance, early warning systems and monitoring, with a view to preventing bathers’ exposure, by means of a warning or, where necessary, a bathing prohibition (Annex II, sections 2, 3 and 4)
The ongoing problem
Bournemouth, August 2011
Short term pollution (< 72 hours)
• In the UK most short term pollution originates from
direct or indirect (through rivers) outlets from the sewer
system or waste water treatment plants in connection
with rain.
• Problems of diffuse pollution within the catchment are
often longer term
#5
Vibrio
Other
Currents
Waves
Algal
blooms
Indicator
bacteria
safe bathing water 24/7
closing only when necessary
quick information
user-friendly information
Operational Bathing Water Forecasts Copenhagen
© DHI #8
#9
CPH Harbour Copenhagen
Early warning system for Copenhagen harbour
Since year 2002 Copenhagen EPA has used an early warning model for the bathing
water quality in Copenhagen harbour
…but why did Copenhagen introduce an Early warning system before the new directive was agreed
upon? And implemented - 2015?
The traditional monitoring is not sufficient
– Measurement results are received after the incidence is over
– The bathing water maps are based on measurements that are up to one year old
Statistically the traditional monitoring is strong but in practice the beach guests have no guarantees
regarding Today's water quality
Health risk?
Health demands
• Keywords: Secure health
• E.coli and enterococci bacteria
• Heavy metals
• in the water phase
• by re-suspension
• in the sediment
Point Sources (Mapping)
WWTPs
• Two large-scale WWTPs (750.000 and 350.000 PE)
Combined sewer overflows (CSO)
• Both wastewater and urban run-off (“Stormwater”)
Urban run-off
• Separate urban run-off (“Stormwater”)
River with CSO + urban run-off – Sewer installation
Direct industrial discharges to CPH Harbour
#13
Point Sources
#14
Early warning system for Bathing water Quality
Early warning system for bathing water quality
Imagen CSIC 2-8 17:20 Prim Bac de
Roda
Ginebra
Imagen CSIC 2-8 17:20
Resultado simulación 2-8 18:00
Example from Barcelona
10 June, 2014 © DHI #18
Bathing water and the Public
……. And Smart Phones
Auckland Bathing Water Forecast
© DHI
Auckland Bathing Water Forecast
© DHI
Operational Bathing Water Forecasts Example of application
© DHI #23
Extreme Rainfall event in Copenhagen 14. August
Use of Bathing Water forecast – Triathlon 15. August
UTC tid (lokaltid = UTC+2)
Start
kl. 6
Health Risk
1.700 iron men was swimming in sewer
water (Politikken, 20. Aug)
…… a lot of debate, and people getting sick, …
but ……… the Model was spot on
In total 778 (59 %) answered the
questionnaire
send out by the SSI. Out of these
428 (55 %) confirmed symptoms
of gastro-enteritis.
Ref.: SSI
Details of the Approach
10 June, 2014 © DHI #27
Basic Requirements • Local hydrodynamic model (3D) of receiving waters
• Based on wind, air pressure, air temperature provides current, water levels,
water temperature and transport
• Sources of pollution
• Boundary Model (Water forecast)
• Water level, current
• Salinity
• Temperature
• ECO Lab model
• Based on salinity, water temperature and solar radiation (and transparency)
provides bacteria decay
System Components & Functions • Meteorological & model boundary data
• Wind
• Precipitation
• Air temperature
• Clearness
• Humidity
• Water level
• Water temperature
• Salinity
• Current?
• Bacteria (zero?)
• Why?
• Drive the Hydrodynamic model providing
• Circulation,
• Water temperature
• Water levels
• Salinity
System Components & Functions • Direct sources of pollution
• Rain water run-off
• Combined sewer overflows (CSO)
• Waste water treatment plants (WWTP)
• Daily input
• By-pass
• Why
• Important sources for bacteria pollution
(E.coli & Enterococci)
• Origin
• Measurements from WWTP
• Measurements in sewer system
• Sewer modelling/estimations from precipitation
• Estimations from precipitation (modelled, measured, radar)
System Components & Functions • Indirect sources of pollution
• Rivers & estuaries
• Catchment modelling inputs
• Direct sources input to indirect input
• Why?
• Can be equally important
• Origin?
• Estimations from precipitation
(modelled, measured, radar)?
• Additional data
• Direct sources spilling to indirect sources
System Backbone
Internal Surveillance
Internal Surveillance
Internal Surveillance
Internal Surveillance
Handling Flags
QA
Internal QA
10 June, 2014 © DHI #41
Internal QA
Internal QA
Internal QA
Internal QA
Benefits of our Approach
10 June, 2014 © DHI #46
Benefits of our approach
• Warning system for use internally and externally
• Improved public perception of bathing water quality
• Provides added value use of existing telemetered systems
• Can operate outside of traditional bathing water
season for added value
• Extensible and customisable in the future
#47
Thank you for your attention … Anders Chr. Erichsen (aer@dhigroup.com)
© DHI #48