12th EWA Brussels Conference “EU Water Policy and
Sustainable Development”
Storm water overflows Challenges
Bruno rakedjian - European Commission Directorate General for Environment
Unit C.2 - Marine Environment & Water Industry
Main result of UWWTD
implementation in 2012
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Storm water sewage overflows
Compliance results at EU-28, EU-15 and EU-13 level regarding Articles 3 (collection), 4 (secondary treatment) and 5 (more
stringent treatment). Average values are reflected, weighted by pollution load generated by individual Member States.
Study Storm water
sewage overflows
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The Outcome of the study
Synthesis
EU legislation, international conventions (RSCs and river basin commissions)
Member States: regulations and guidance and US approach
Overview of storm water overflows in the Member States
Literature review on potential health risks
• https://circabc.europa.eu/w/browse/e00a649a-7eb4-40b3-9b19-f5ace7a80e08
Main results
Lack of knowledge at local/national/European level
A policy that has still to be achieved in lots of countries
Remaining risks related to these emissions on environment and health
4
Storm water sewage overflows
Main remaining risks
Microbiological contamination of water
Chemical contamination of water and sediments
Oxygen depletion in water bodies
Marine litter/micro plastic contamination
5
Storm water sewage overflows
Uncontrolled Urbanisation
More impervious areas (more emission of pollutants)
Climate change
Change of frequency and intensity of rain events (more emission of pollutants)
Higher seasonal reduction of the flow of rivers (less dilution)
Increase in the temperature of water bodies (acceleration in bacteries development)
Antimicrobial resistance
Three ongoing threats
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Storm water sewage overflows
Why is it so important to reduce storm water sewage overflows?
To implement correctly the European directives to protect environment
and people health
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Storm water sewage overflows
Related to lots of different European or international water regulations:
• Under the Implementation programme of the Urban waste water treatment directive 91/271/EC treated except
under unusually heavy rainfall
• Under the bathing water profiles of the bathing water directive (BWD) 2006/7/EC Good or excellent quality
• Under the programme of measures of the Water framework directive (WFD) 2000/60/EC good ecological and
chemical status, protected areas objectives (shellfish, bathing water, …)
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Implement EU requirements
Storm water sewage overflows
• Under the programme of measures of the Marine Strategy Framework directive (MSFD) 2008/56/EC good environmental
status, shellfish protection, marine litter reduction,…
• under the inventory of the sources of pollution, the quantity of organic pollutants, the circulation of pollutants to protect bivalve molluscs production areas regulation 854/2004 Insure quality for human consumption specifically
to avoid fecal, toxin and chemical contamination
• under the target of the World sustainable development goal 6 Halving the proportion of untreated waste water by 2030
• Natura 2000, groundwater, drinking water, floods, farm animal protection,…
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Implement EU requirements
Storm water sewage overflows
Why is it so important to reduce storm water sewage overflows
The example of E-coli contamination
(e.g. water leisure activities, shellfish consumption, water abstraction for
agriculture) 10
Storm water sewage overflows
E-coli contamination
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107 9 104
90%
10% 100 104
8% UWWTP
92% CSO
107 9.5 104
95%
5%
50 104
16% UWWTP
84% CSO
R99%
R99%
107 9.9 104
99%
1%
104
91% UWWTP
9% CSO
R99%
Rain dilution 106
T 109 104
T 59.5 104
T 10.9 104
UWWTP
CSO
UWWTP
CSO
UWWTP
CSO
Storm water sewage overflows
waterbody
Why is it so important to reduce storm water sewage overflows
More and more a political concern
that has to do with cities attractiveness (bathing water, shellfish, water leisure
activities,…) 12
Storm water sewage overflows
25/08/2015
Political strong reaction of a mayor in France after a beach pollution due to storm water overflows from
another city.
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http://www.20minutes.fr/montpellier/1672575-20150825-montpellier-peut-plus-continuer-comme-ca-alerte-maire-palavas
Storm water sewage overflows
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Storm water sewage overflows
The solutions
Action plans
Implementation of national rain water overflows action plan (article 17 of the UWWTD)
Check that measures related to this topic are implemented if there are the reason of bad quality:
in the bathing water profiles of the BWD
in the programmes of measures of the WFD and MSFD.
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Storm water sewage overflows
Monitoring measures
Building national storm water overflows and storage tank databases
•
establish indicators to follow the actions plans and programme of measures and identify better this pressure
Agglomerations of more than 100 000 p.e.
(4% of the agglomerations ≈ 50% of the total generated waste water load)
•
The solutions
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Storm water sewage overflows
Storm water sewage overflows
The solutions
Information measures
Improve transparency
Implement better alert system
at national/local level
to prevent contact
with contaminated water
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Agglomeration not compliant
Bathing water in poor quality
Natura 2000
Storm water sewage overflows
The solutions
Use INSPIRE services to share the information and
increase knowledge E.g. Urban waste water national website that
includes not only detailed information about urban
waste water but also EEA bathing water, Natura
2000, Soe layers
http://uwwtd.oieau.fr/
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Storm water sewage overflows
At source measures Article 191 of the treaty on the functioning of
the European Union
"preventive action should be taken"
"environmental damage should as a priority be rectified at source"
"the polluter should pay"
The solutions
Top priority NWRMs Natural water retention measures in urban areas
to limit the introduction of rain water in combined sewer collecting systems.
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Storm water sewage overflows
Commission contribution: best practices website
http://www.nwrm.eu/
The solutions
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Storm water sewage overflows
NWRMs to be implemented in priority because they have mid/long term effects but provides multi
benefits…
• Improve water quality and quantity
• Improve air quality
• Improve biodiversity
• Contribute to climate mitigation
• Contribute to flooding prevention
• Increase recreational areas…
Improve quality of life to all citizens
The solutions
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Other solutions have to be implemented
Optimisation of rain storage in collecting systems
storage tank(s) related to the collecting system and/or the treatment plant
Increase in the capacity of pumping station(s)
Increase in the capacity of the treatment plant
Increase in the capacity of the collecting system
The solutions Storm water
sewage overflows
What about building separate collecting systems?
The solutions Storm water
sewage overflows
Advantages No more combine sewage overflows if
correctly built
Disadvantages Double the cost of the collecting system
Generate bad connections (rain in sewage system and sewage in rain drainage system)
If not treated or infiltrated, polluted rain water directly discharged in water bodies (heavy metals, oil, macro and micro waste, PAH…)
Impossibility to avoid malicious acts
Acceleration in floodings
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Excessive costs Storm water overflows
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Use the possibilities offered by the UWWTD directive concerning excessive costs.
Annex I.A of the UWWTD
• Excessive costs have to be justified
• It does not allow to do nothing
• It allows progressive implementation of the projects
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CONCLUSION Storm water
overflows
What MS and local authorities have to do
A better knowledge and transparency
A better management of this policy
Start now implementing Natural water retention measures
Implementation of measures to reduce emissions under the existing regulations
