COMMISSION STAFF WORKING DOCUMENT EXECUTIVE SUMMARY OF THE IMPACT ASSESSMENT REPORT Accompanying the document Proposal for a Directive of the European Parliament and of the Council concerning urban wastewater treatment (recast)
Date: 2022-10-26
Institutions: Directorate-General for Environment, European Commission
Subjects: industrial pollution, pollution control measures, public health, urban area, wastewater, water pollutant, water pollution, water protection, water treatment

EN 

  EN 

   EUROPEAN COMMISSION  Brussels, 26.10.2022  SWD(2022) 544 final  COMMISSION STAFF WORKING DOCUMENT  EXECUTIVE SUMMARY OF THE IMPACT ASSESSMENT REPORT  Accompanying the document Proposal for a Directive of the European Parliament and of the Council concerning urban wastewater treatment (recast)       {COM(2022) 541 final} - {SEC(2022) 541 final} - {SWD(2022) 541 final}  
 
 
EXECUTIVE SUMMARY  

The  European  Union  adopted  in  1991  the  Urban  Waste  Water  Treatment  Directive 
(UWWTD).  The  objective  of  this  Directive  is  to  “protect  the  environment  from  adverse 
effects of waste water discharges from urban sources and specific industries”. Member States 
(MS) are required to ensure that waste water from all agglomerations above 2.000 inhabitants 
is  collected  and  treated  according  to  EU  minimum  standards.  MS  have  also  to  designate 
‘sensitive areas’ according to criteria included in the Directive where stricter standards apply.   

The  2019  REFIT  Evaluation  confirmed  that  significant  reduction  of  domestic  pollutant 
releases1 into the environment was achieved thanks to the Directive. The effects on the quality 
of  the  EU  lakes,  rivers  and  seas  is  visible  and  tangible.  One  of  the  key  reasons  for  the 
Directive’s  effectiveness  lies  in  the  simplicity  of  its  requirements  which  allows  a 
straightforward enforcement. Its level of implementation is high: 98% of EU waste waters are 
adequately collected and 92% adequately treated, even if  a limited number of MS have still 
difficulties  to  reach  full  compliance.  European  funds  were  also  a  key  driver  to  support 
investments in the required infrastructures (around € 2 billion each year for the water sector).    

Waste  water  operators  are  public  companies  (60%)  or  private  companies  operating  for  a 
public authority or mixed companies. They are operating in a ‘captive’ market: citizens and 
businesses connected to the public network cannot choose their operators. Around 30% of the 
costs related to water supply and sanitation are covered by public budgets and 70% by water 
tariffs with large differences between MS. The sector is mainly reactive to legal requirements.   

PROBLEM DEFINITION  

In the REFIT Evaluation, the following three main sets of problems were identified:  

1. Remaining pollution from urban sources2. The initial Directive was focused on pollution 
from  domestic  sources  collected  and  treated  in  centralised  facilities,  for  which  the 
requirements  are  clear  and  precise.  Less  attention  was  given  to  other  sources  of  urban 
pollution  (smaller  agglomerations,  non-centralised  treatment  facilities  or  heavy  rains)  for 
which  the  requirements  were  kept  more  generic.  The  emissions  from  these  sources  have 
progressively become key remaining sources of urban pollution, as illustrated in Figure 1.   

Part  of  this  pollution  can  be  avoided,  even  if  there  are  limits  to  what  can  be  done  with  the 
current  treatment  techniques.  Depending  on  the  pollutant,  discharges  from  non-compliant 
agglomerations still represent between 1.9% (Nitrogen - N) and 7,78 % (Phosphorus - P) of 
the  remaining  pollution.  Pollution  due  to  heavy  rains  (storm  water  overflows  (SWO)  and 
urban runoff) represent another sizeable remaining source of loads sent to the environment: 
between 7,2% (N) and 29,77% (E. Coli).  Non-centralised treatment systems (Individual or 
other Appropriate Systems  -  IAS),  authorised  under the Directive  as long as  they achieve 

1 Mainly Nitrogen (N), Phosphorus (P), Organic pollution expressed as Biological Oxygen Demand (BOD)  
2 The standard unit to measure pollution is the ‘population equivalent’ (p.e.): 1 p.e. corresponds to the average 
pollution generated by 1 person. For some pollutants (Nitrogen, Phosphorus and organic matters - BOD) it is 
possible to convert p.e. into quantities (grams) of pollutants.      

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the ‘same level of environmental protection’, represent between 4,7% (micro-pollutants) and 
16,1% (E. Coli) of the remaining pollution.   

Micro pollutants

E.Coli

Phosphorus

Nitrogen

BOD

 -

 50.000.000 100.000.000 150.000.000 200.000.000 250.000.000 300.000.000

SWO

Compliant IAS

Remaining compliant treated load

Population equivalent (p.e.) per year 
Urban run off

Non Compliant IAS

Small Agglo

Non compliant load

Figure 1: Remaining loads from urban sources (p.e./year)- Current situation - Source JRC 

Small agglomerations below 2.000 p.e. constitute another significant pressure on EU’s water 
bodies  -  between  9,7%  (micro-pollutants)  and  26,2%  (E.  Coli)  of  the  remaining  pollution. 
Despite  the  emission  reduction  achieved  with  the  existing  Directive,  waste  water  treatment 
plants  remain  a  source  of  N/P  to  the  environment,  respectively  amounting  to  134  and  94 
million p.e. per year. New pollutants such as micro-plastics and micro-pollutants, were also 
identified in the Evaluation as a source of concern. Micro-plastics are relatively well captured 
in  treatment  facilities,  which  is  not  the  case  for  micro-pollutants:  every  year  around  254 
million  p.e.  are  sent  to  water  bodies  in  the  EU  causing  concerns  for  the  environment  and 
public  health.  Treatment  facilities  also  receive  not  well  controlled  non-domestic  waters 
including industrial waste waters (mainly from SME’s) connected to the public network.  

2.  Insufficient  alignment  of  the  Directive  to  EU  Green  Deal  (EGD)  policy  objectives 
(other  than  pollution-reduction):  the  sector  accounts  for  0.8%  of  the  total  energy  use  in  the 
EU  and  was  responsible,  in  2018,  for  0,86%  of  the  total  EU  GHG  emissions.  Almost  one 
third of these emissions could be avoided by improving treatment process, better using sludge 
and  increasing  the  uptake  of  energy  efficiency  and  renewable  technologies  which  is  still 
very  low.  A  better  inclusion  of  the  sector  in  the  Circular  Economy  is  also  needed:  sludge 
management  and  water  reuse  is  not  optimal  as  too  many  valuable  resources  are  still  lost. 
Finally, waste waters are a swift and reliable source of useful information for public health. 
This  was  shown  with  the  surveillance  of  COVID-19  and  its  variants  as  a  complement  to 
manage  the  recent  pandemics.  The  lack  of  coordination  between  public  health  and  waste 
water authorities represents a barrier for an optimal use of this information.    

3.  Insufficient  and  uneven  level  of  governance:  the  Evaluation  and  recent  OECD  studies 
have  highlighted  that  the  level  of  the  operator’s  performance  greatly  varies  from  one  to 
another. This is also the case in relation to transparency and access to key information. As 

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mentioned in a recent Court of Auditor report, and contrary to the principles of the EU Treaty, 
the  ‘polluters  pays’  principle  is  not  sufficiently  applied.  Monitoring  and  reporting 
methods are not adapted to the needs and to the possibilities offered by digitalisation. Access 
to sanitation remains an issue preventing the EU to fully implement SDG 6.  

OBJECTIVES 

The  EU  intervention  has  two  main  general  objectives:  (1)  protect  EU  citizens  and 
ecosystems from the remaining sources of insufficiently treated waste water; (2) improve the 
transparency  and  governance  of  the  sector;  and  two  complementary  objectives:  3)  better 
align  the  sector  to  the  objectives  of  the  Green  Deal  -  in  particular  by  steering  it  towards 
Energy  neutrality  as  a  contribution  to  Climate  Neutrality,  and  by  supporting  its  necessary 
transition  towards  Circular  Economy,  Zero  Pollution  and  enhanced  protection  of 
Biodiversity; (4) make a smarter use of waste water parameters as a support for public health 
action. To do so, it is essential to provide a long term vision as well as legal certainty, since 
investments in this sector take time and must be planned well in advance.  

JUSTIFICATION TO ACT AT EU LEVEL 

EU action remains  essential to ensure that  all EU citizens can draw  benefits from improved 
water quality of rivers, lakes, ground-waters and seas. As 60% of the EU water bodies are 
transboundary, it is necessary to ensure the same level of protection  everywhere and at the 
same rhythm, to avoid the risk that efforts made by some MS are jeopardised by the lack of 
progress of others. The Evaluation has shown that in most MS the Directive was the unique 
driver for investing in the required infrastructures.   

POLICY OPTIONS  

For each of the problem, several options were defined based on the best practices in place in 
the MS as well as on an in depth consultation of the stakeholders. Options lacking support 
from the stakeholders or too complex to implement were discarded at an early stage. Different 
options were developed starting from low ambition (measures applied only to larger facilities) 
to high ambition (same measures but  applied also to smaller facilities).3 For some problems 
options  were  limited  –  this  is  the  case  for  instance  for  non-centralised  facilities  (IAS), 
improving  transparency  or  monitoring  health  parameters.  For  other  problems  (heavy  rain 
waters, IAS or energy use), in line with the subsidiarity principle, enough flexibility was left 
to allow for the most cost effective solutions at local level.    

PREFERRED OPTION  

The  impacts  of  the  options  were  assessed  using  a  model  developed  by  the  Joint  Research 
Centre and used in the REFIT Evaluation. A baseline scenario (assuming full compliance) and 
a  maximum  feasible  scenario  were  developed  as  comparison  points.  For  each  problem,  the 
several  criteria:  costs/benefits, 
choice  of 

the  preferred  option  was  based  on 

3 The threshold for ‘Larger’ facilities was fixed to 100.000 p.e. taking into account that 46% of the generated 
load is treated in a relatively low number of ‘larger’ facilities (974). Another threshold of 10.000 p.e. was fixed 
as 81% of the load is treated in 7.527 facilities above 10.000 p.e.   

3 

 
 
                                                           
costs/effectiveness,  level  of  contribution  to  the  EU  Green  Deal  objectives  and  to  water 
pollution reduction, enforceability and administrative burden.   

In the preferred option, in order to tackle the key remaining pollution sources, it is proposed 
to (1) expand the scope of the Directive to cover all urban agglomerations above 1.000 p.e.; 
(2)   develop  new EU standards  for  IAS  and require MS to  put  in  place effective inspection 
strategies;  (3)  establish  and  implement  integrated  water  management  plans  in  all  large 
agglomerations and in those above 10.000 p.e. where there is a risk for the environment, and, 
when  required,  limit  the  pollution  from  heavy  rain  waters  with  a  priority  for  preventive 
(including green) measures. To further limit nutrient releases, more stringent limit values to 
treat Nitrogen and Phosphorus will be progressively applied to all larger facilities but also in 
all  facilities above 10.000 p.e.  located in  areas  where  eutrophication  remains  an issue.  New 
limit values on micro-pollutants will progressively be imposed first for all large facilities and 
then for facilities above 10.000 p.e. where there is a risk to the environment on the basis of 
clear and simple criteria. In line with the suggestions of several stakeholders, the feasibility of 
a system of producer responsibility for the additional treatment needed for micro-pollutants 
was assessed and is included in the preferred option.4 New monitoring requirements will be 
put in place notably on GHG emissions, pollution from rain waters and health parameters.  

Energy audits will be progressively imposed to all facilities above 10.000 p.e. so that energy 
neutrality could be met by 2040 at the level of the sector, in line with best practices already in 
place in some MS for 2025/2030. To increase the possibilities of re-using sludge and re-use 
water after treatment, MS will be required to better monitor and track at source non domestic 
pollution. Finally, in order to secure an overall better governance of the sector, reporting will 
be  simplified  and  further  digitalised.  The  effects  of  additional  measures  to  improve 
transparency, the operator’s performances as well as access to sanitation are presented in 
the IA. All measures included in the preferred option will be progressively applied by 2040.  

MAIN IMPACTS 

By 2040, the impacts on water pollution of the preferred options are summarised in Figure 2 
below. Compared to the baseline, the total pollution would be reduced by 4,8 million p.e. (or 
105.014 tons) for BOD, 56,4 million p.e. for N (or 229.999 tons),  49,6 million p.e. (or 29.678 
tons)  for  P,  77,4  million  p.e.  for  toxic  load  of  micro-pollutants  and  24,8  million  p.e.  for  E. 
coli.  These reductions represent 27% of what is ‘technically feasible’ for BOD, 62% for N, 
61%  for  P,  63%  for  the  toxic  load  of  micro-pollutants  and  50%  for  E.  coli.  Micro-plastics 
emissions would be reduced by 9% mainly though actions on SWO and urban runoff.  

With the planned measures to reach energy neutrality, GHG emissions would be reduced by 
4,86 million tons (37,32 % of the avoidable emissions from the sector which represents 0.86% 
of the total EU emissions). Compared to 1990, and together with the expected effects of the 
baseline this would represent a reduction of 62.51% of the GHG emissions - in line with the 
objectives of  the EU Climate Law and the ‘Fit for 55’ climate package.  

4  The  envisaged  system  would  be  similar  to  systems  in  place  for  solid  waste  management:  importers  and 
producers would be financially responsible for the treatment of the pollution generated by their products. In this 
case, pharmaceuticals and personal care products (PCP’s) represent the main sources of micro-pollutants.   

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Preferred option - impacts on Emissions 
(million p.e.) 

300

250

200

150

100

50

0

BOD

N

P

E. Coli

Micro
pollutants

Baseline

Preferred Option (2040)

Maximum feasible

Figure 2: Preferred option – impacts on emissions (million p.e. per year in 2040) 

The  expected  monetised  benefits  of  the  preferred  option  by  2040  at  EU  level  (€  6,643   
bn/year) are above the costs (€ 3,793 bn per year). In all MS the benefits are higher than the 
costs - knowing that, for micro pollutants (representing 27% of the total costs of the preferred 
option), no methodology is available to monetise the benefits linked to their reduction.     

The  costs  of  the  initiative  would  represent  an  increase  of  3,79%  compared  to  the  current 
expenditures  for  water  supply  and  sanitation.5  These  additional  expenses  would  be  partly 
covered  by  the  producer  responsibility  system  (around  €  1,2  billion/year  needed  to  treat 
micro-pollutants)  with  limited  impacts  expected  on  final  product  prices  or  on  the  benefit 
margins of the sector (0.6% on average). Based on current MS financing strategies, it can be 
assumed that around 30% (or € 0,774 billion/year) of the remaining costs would be covered 
by public budgets and 70% (or € 1,806 billion/year) by water tariffs. This would represent a 
2,26% increase of the average EU water tariffs. Affordability of water prices would not be 
in danger, though in a limited number of MS accompanying social measures would be useful. 
EU funds (around € 2 bn/year for the water sector) would remain indispensable to cover part 
of  the  investments  needed  to  reach  full  compliance  with  the  revised  Directive.  Even  if 
digitalisation  can  help  to  improve  and  simplify  monitoring  and  reporting,  additional  efforts 
would  be  needed  to  better  track  remaining  sources  of  pollution.  EU  water  industry  is 
expected to benefit from new business opportunities while innovation and research will be 
promoted contributing to maintain and improve the competitive position of the water industry.     

With the preferred option, the Directive would be fully aligned with all other key Green Deal 
objectives, including the overarching climate-neutrality goal, while being fully consistent with 
several  ongoing/planned  legislative  proposals  such  as  the  reviews  of  the  Environmental 
Quality  Standard  Directive,  the  Bathing  Water  Directive,  the  Marine  Strategy  Framework 
Directive and the Evaluation of the Sewage Sludge Directive. It will also directly contribute to 
a better implementation of the SDG 6 on access to adequate and equitable sanitation.  

5 around 100 billion/year according to the OECD 

5