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►B COUNCIL DIRECTIVE
of 21May 1 991
concerning urban waste water treatment
(91/271/EEC)
(OJ L 135, 30.5.1991, p. 40)
Amended by:
OfficialJournal
No page date
►M1 Commission Directive 98/15/EC of 27 February 1998 L 67 29 7.3.1998
Corrected by:
►C1 Corrigendum, OJ L 139, 2.6.1999, p. 34 (98/15)1991L0271 — EN — 27.03.1998 — 001.001 — 1
1991L0271 — EN — 27.03.1998 — 001.001 — 2
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COUNCIL DIRECTIVE
of 21May 1 991
concerning urban waste water treatment
(91/271/EEC)
THE COUNCIL OF THE EUROPEAN COMMUNITIES,
Having regard to the Treaty establishing the European Economic Com-
munity, and in particular 130s thereof,
Having regard to the proposalfrom the Commission (1),
Having regard to the opinion of the European Parliament (2),
Having regard to the opinion of the Economic and SocialCommittee (3),
Whereas the CouncilResol ution of 28 June 1988 on the protection of
the North Sea and of other waters in the Community (4) invited the
Commission to submit proposals for measures required at Communitylevel for the treatment of urban waste water;
Whereas pollution due to insufficient treatment of waste water in one
Member State often influences other Member States' waters; whereas in
accordance with Article 130r, action at Community level is necessary;
Whereas to prevent the environment from being adversely affected by
the disposalof insufficientl y-treated urban waste water, there is a gen-
eralneed for secondary treatment of urban waste water;
Whereas it is necessary in sensitive areas to require more stringent treat-
ment; whereas in some less sensitive areas a primary treatment could beconsidered appropriate;
Whereas industrial waste water entering collecting systems as well as
the discharge of waste water and disposalof sl udge from urban wastewater treatment plants should be subject to general rules or regulationsand/or specific authorizations;
Whereas discharges from certain industrialsectors of biodegradabl e
industrialwaste water not entering urban waste water treatment pl ants
before discharge to receiving waters should be subject to appropriaterequirements;
Whereas the recycling of sludge arising from waste water treatment
should be encouraged; whereas the disposal of sludge to surface waters
should be phased out;
Whereas it is necessary to monitor treatment plants, receiving waters
and the disposalof sl udge to ensure that the environment is protectedfrom the adverse effects of the discharge of waste waters;
Whereas it is important to ensure that information on the disposalof
waste water and sludge is made available to the public in the form ofperiodic reports;
Whereas Member States should establish and present to the Commission
nationalprogrammes for the impl ementation of this Directive;
Whereas a Committee should be established to assist the Commission
on matters relating to the implementation of this Directive and to itsadaptation to technicalprogress,
(1) OJ No C 1, 4. 1. 1990, p. 20 and
OJ No C 287, 15. 11. 1990, p. 11.
(2) OJ No C 260, 15. 10. 1990, p. 185.
(3) OJ No C 168, 10. 7. 1990, p. 36.
(4) OJ No C 209, 9. 8. 1988, p. 3.
1991L0271 — EN — 27.03.1998 — 001.001 — 3
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HAS ADOPTED THIS DIRECTIVE:
Article 1
This Directive concerns the collection, treatment and discharge of urban
waste water and the treatment and discharge of waste water from certainindustrialsectors.
The objective of the Directive is to protect the environment from the
adverse effects of the abovementioned waste water discharges.
Article 2
For the purpose of this Directive:
1. ‘urban waste water’ means domestic waste water or the mixture of
domestic waste water with industrialwaste water and/or run-offrain water;
2. ‘domestic waste water’ means waste water from residentialsettl e-
ments and services which originates predominantly from the humanmetabolism and from household activities;
3. ‘industrialwaste water’ means any waste water which is discharged
from premises used for carrying on any trade or industry, other than
domestic waste water and run-off rain water;
4. ‘agglomeration’ means an area where the population and/or eco-
nomic activities are sufficiently concentrated for urban waste waterto be collected and conducted to an urban waste water treatmentplant or to a final discharge point;
5. ‘collecting system’ means a system of conduits which collects and
conducts urban waste water;
6. ‘1 p.e. (population equivalent)’ means the organic biodegradable
load having a five-day biochemical oxygen demand (BOD5) of 60g of oxygen per day;
7. ‘primary treatment’ means treatment of urban waste water by a
physical and/or chemical process involving settlement of suspended
solids, or other processes in which the BOD5 of the incoming waste
water is reduced by at least 20 % before discharge and the total sus-pended solids of the incoming waste water are reduced by at least50 %;
8. ‘secondary treatment’ means treatment of urban waste water by a
process generally involving biological treatment with a secondarysettlement or other process in which the requirements established in
Table 1 of Annex I are respected;
9. ‘appropriate treatment’ means treatment of urban waste water by
any process and/or disposal system which after discharge allows the
receiving waters to meet the relevant quality objectives and therelevant provisions of this and other Community Directives;
10. ‘Sludge’ means residual sludge, whether treated or untreated, from
urban waste water treatment plants;
11. ‘eutrophication’ means the enrichment of water by nutrients, espe-
cially compounds of nitrogen and/or phosphorus, causing an accel-erated growth of algae and higher forms of plant life to produce an
undesirable disturbance to the balance of organisms present in the
water and to the quality of the water concerned;
12. ‘estuary’ means the transitionalarea at the mouth of a river between
fresh-water and coastal waters. Member States shall establish theouter (seaward) limits of estuaries for the purposes of this Directiveas part of the programme for implementation in accordance withthe provisions of Article 17 (1) and (2);
13. ‘coastal waters’ means the waters outside the low-water line or the
outer limit of an estuary.
1991L0271 — EN — 27.03.1998 — 001.001 — 4
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Article 3
1. Member States shall ensure that all agglomerations are provided
with collecting systems for urban waste water,
— at the latest by 31 December 2000 for those with a population
equivalent (p.e.) of more than 15 000, and
— at the latest by 31 December 2005 for those with a p.e. of between
2 000 and 15 000.
For urban waste water discharging into receiving waters which are con-
sidered ‘sensitive areas’ as defined under Article 5, Member States shallensure that collection systems are provided at the latest by 31 December1998 for agglomerations of more than 10 000 p.e.
Where the establishment of a collecting system is not justified either
because it would produce no environmental benefit or because it would
involve excessive cost, individual systems or other appropriate systemswhich achieve the same level of environmental protection shall be used.
2. Collecting systems described in paragraph 1 shall satisfy the
requirements of Annex I (A). These requirements may be amended in
accordance with the procedure laid down in Article 18.
Article 4
1. Member States shall ensure that urban waste water entering col-
lecting systems shall before discharge be subject to secondary treatmentor an equivalent treatment as follows:
— at the latest by 31 December 2000 for all discharges from agglom-
erations of more than 15 000 p.e.,
— at the latest by 31 December 2005 for all discharges from agglom-
erations ofbetween 10 000 and 15 000 p.e.,
— at the latest by 31 December 2005 for discharges to fresh-water and
estuaries from agglomerations of between 2 000 and 10 000 p.e.
2. Urban waste water discharges to waters situated in high mountain
regions (over 1 500 m above sea level) where it is difficult to apply aneffective biological treatment due to low temperatures may be subjectedto treatment less stringent than that prescribed in paragraph 1, providedthat detailed studies indicate that such discharges do not adverselyaffect the environment.
3. Discharges from urban waste water treatment plants described in
paragraphs 1 and 2 shall satisfy the relevant requirements of Annex I.B.These requirements may be amended in accordance with the procedurelaid down in Article 18.
4. The load expressed in p.e. shall be calculated on the basis of the
maximum average weekly load entering the treatment plant during theyear, excluding unusual situations such as those due to heavy rain.
Article 5
1. For the purposes of paragraph 2, Member States shall by 31
December 1993 identify sensitive areas according to the criteria laid
down in Annex II.
2. Member States shall ensure that urban waste water entering col-
lecting systems shall before discharge into sensitive areas be subject to
more stringent treatment than that described in Article 4, by 31 Decem-
ber 1998 at the latest for all discharges from agglomerations of morethan 10 000p.e.
3. Discharges from urban waste water treatment plants described in
paragraph 2 shall satisfy the relevant requirements of Annex I B. These
requirements may be amended in accordance with the procedure laid
down in Article 18.
4. Alternatively, requirements for individual plants set out in para-
graphs 2 and 3 above need not apply in sensitive areas where it can beshown that the minimum percentage of reduction of the overall load
1991L0271 — EN — 27.03.1998 — 001.001 — 5
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entering all urban waste water treatment plants in that area is at least 75
% for totalphosphorus and at l east 75 % for totalnitrogen.
5. Discharges from urban waste water treatment plants which are
situated in the relevant catchment areas of sensitive areas and which
contribute to the pollution of these areas shall be subject to paragraphs
2, 3 and 4.
In cases where the above catchment areas are situated wholly or partly
in another Member State Article 9 shall apply.
6. Member States shall ensure that the identification of sensitive
areas is reviewed at intervals of no more than four years.
7. Member States shall ensure that areas identified as sensitive fol-
lowing review under paragraph 6 shall within seven years meet theabove requirements.
8. A Member State does not have to identify sensitive areas for the
purpose of this Directive if it implements the treatment establishedunder paragraphs 2, 3 and 4 over all its territory.
Article 6
1. For the purposes of paragraph 2, Member States may by 31
December 1993 identify less sensitive areas according to the criterialaid down in Annex II.
2. Urban waste water discharges from agglomerations of between
10 000 and 150 000 p.e. to coastalwaters and those from aggl omater-ions of between 2 000 and 10 000 p.e. to estuaries situated in areasdescribed in paragraph 1 may be subjected to treatment less stringent
than that prescribed in Article 4 providing that:
— such discharges receive at least primary treatment as defined in Arti-
cle 2 (7) in conformity with the control procedures laid down inAnnex I D,
— comprehensive studies indicate that such discharges will not
adversely affect the environment.
Member States shall provide the Commission with all relevant informa-
tion concerning the abovementioned studies.
3. If the Commission considers that the conditions set out in para-
graph 2 are not met, it shall submit to the Council an appropriate propo-sal.
4. Member States shall ensure that the identification of less sensitive
areas is reviewed at intervals of not more than four years.
5. Member States shall ensure that areas no longer identified as less
sensitive shall within seven years meet the requirements of Articles 4
and 5 as appropriate.
Article 7
Member States shall ensure that, by 31 December 2005, urban waste
water entering collecting systems shall before discharge be subject to
appropriate treatment as defined in Article 2 (9) in the following cases:
— for discharges to fresh-water and estuaries from agglomerations of
less than 2 000 p.e.,
— for discharges to coastal waters from agglomerations of less than
10 000 p.e.
Article 8
1. Member States may, in exceptionalcases due to technicalpro-
blems and for geographically defined population groups, submit a spe-cial request to the Commission for a longer period for complying withArticle 4.
2. This request, for which grounds msut be duly put forward, shall
set out the technicaldifficul ties experienced and must propose an actionprogramme with an appropriate timetable to be undertaken to imple-
1991L0271 — EN — 27.03.1998 — 001.001 — 6
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ment the objective of this Directive. This timetable shall be included in
the programme for implementation referred to in Article 17.
3. Only technical reasons can be accepted and the longer period
referred to in paragraph 1 may not extend beyond 31 December 2005.
4. The Commission shall examine this request and take appropriate
measures in accordance with the procedure laid down in Article 18.
5. In exceptionalcircumstances, when it can be demonstrated that
more advanced treatment will not produce any environmental benefits,discharges into less sensitive areas of waste waters from agglomerations
of more than 150 000 p.e. may be subject to the treatment provided for
in Article 6 for waste water from agglomerations of between 10 000and 150 000 p.e.
In such circumstances, Member States shall submit beforehand the rele-
vant documentation to the Commission. The Commission will examinethe case and take appropriate measures in accordance with the proce-
dure laid down in Article 18.
Article 9
Where waters within the area of jurisdiction of a Member State are
adversely affected by discharges of urban waste water from anotherMember State, the Member State whose waters are affected may notifythe other Member State and the Commission of the relevant facts.
The Member States concerned shall organize, where appropriate with
the Commission, the concertation necessary to identify the discharges in
question and the measures to be taken at source to protect the watersthat are affected in order to ensure conformity with the provisions ofthis Directive.
Article 10
Member States shall ensure that the urban waste water treatment plants
built to comply with the requirements of Articles 4, 5, 6 and 7 are
designed, constructed, operated and maintained to ensure sufficient per-
formance under all normal local climatic conditions. When designingthe plants, seasonal variations of the load shall be taken into account.
Article 11
1. Member States shall ensure that, before 31 December 1993, the
discharge of industrial waste water into collecting systems and urbanwaste water treatment plants is subject to prior regulations and/or speci-
fic authorizations by the competent authority or appropriate body.
2. Regulations and/or specific authorization shall satisfy the require-
ments of Annex I C. These requirements may be amended in accor-dance with the procedure laid down in Article 18.
3. Regulations and specific authorization shall be reviewed and if
necessary adapted at regular intervals.
Article 12
1. Treated waste water shall be reused whenever appropriate. Dispo-
salroutes shal lminimize the adverse effects on the environment.
2. Competent authorities or appropriate bodies shall ensure that the
disposalof waste water from urban waste water treatment pl ants is sub-ject to prior regulations and/or specific authorization.
3. Prior regulations and/or specific authorization of discharges from
urban waste water treatment plants made pursuant to paragraph 2 within
agglomerations of 2 000 to 10 000 p.e. in the case of discharges to freshwaters and estuaries, and of 10 000p.e. or more in respect of all dis-charges, shall contain conditions to satisfy the relevant requirements ofAnnex I B. These requirements may be amended in accordance with theprocedure laid down in Article 18.
1991L0271 — EN — 27.03.1998 — 001.001 — 7
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4. Regulations and/or authorization shall be reviewed and if neces-
sary adapted at regular intervals.
Article 13
1. Member States shall ensure that by 31 December 2000 biodegrad-
able industrial waste water from plants belonging to the industrial sec-tors listed in Annex III which does not enter urban waste water treat-
ment plants before discharge to receiving waters shall before discharge
respect conditions established in prior regulations and/or specificauthorization by the competent authority or appropriate body, in respectof all discharges from plants representing 4 000 p.e. or more.
2. By 31 December 1993 the competent authority or appropriate
body in each Member State shall set requirements appropriate to thenature of the industry concerned for the discharge of such waste water.
3. The Commission shall carry out a comparison of the Member
States' requirements by 31 December 1994. It shall publish the resultsin a report and if necessary make an appropriate proposal.
Article 14
1. Sludge arising from waste water treatment shall be re-used when-
ever appropriate. Disposalroutes shal lminimize the adverse effects onthe environment.
2. Competent authorities or appropriate bodies shall ensure that
before 31 December 1998 the disposalof sl udge from urban wastewater treatment plants is subject to general rules or registration orauthorization.
3. Member States shall ensure that by 31 December 1998 the dispo-
salof sl udge to surface waters by dumping from ships, by dischargefrom pipelines or by other means is phased out.
4. Untilthe el imination of the forms of disposalmentioned in para-
graph 3, Member States shall ensure that the total amount of toxic, per-
sistent or bioaccumulable materials in sludge disposed of to surfacewaters is licensed for disposal and progressively reduced.
Article 15
1. Competent authorities or appropriate bodies shall monitor:
— discharges from urba waste water treatment plants to verify compli-
ance with the requirements of Annex I.B in accordance with thecontrolprocedures l aid down in Annex I.D,
— amounts and composition of sludges disposed of to surface waters.
2. Competent authorities or appropriate bodies shall monitor waters
subject to discharges from urban waste water treatment plants and directdischarges as described in Article 13 in cases where it can be expected
that the receiving environment will be significantly affected.
3. In the case of a discharge subject to the provisions of Article 6
and in the case of disposalof sl udge to surface waters, Member Statesshall monitor and carry out any other relevant studies to verify that the
discharge or disposaldoes not adversel y affect the environment.
4. Information collected by competent authorities or appropriate
bodies in complying with paragraphs 1, 2 and 3 shall be retained in theMember State and made available to the Commission within six months
of receipt of a request.
5. Guidelines on the monitoring referred to in paragraphs 1, 2 and 3
may be formulated in accordance with the procedure laid down in Arti-cle 18.
1991L0271 — EN — 27.03.1998 — 001.001 — 8
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Article 16
Without prejudice to the implementation of the provisions of Council
Directive 90/313/EEC of 7 June 1990 on the freedom of access to infor-
mation on the environment (1), Member States shall ensure that every
two years the relevant authorities or bodies publish situation reports onthe disposalof urban waste water and sl udge in their areas. Thesereports shall be transmitted to the Commission by the Member States assoon as they are published.
Article 17
1. Member States shall by 31 December 1993 establish a programme
for the implementation of this Directive.
2. Member States shall by 30 June 1994 provide the Commission
with information on the programme.
3. Member States shall, if necessary, provide the Commission by 30
June every two years with an update of the information described inparagraph 2.
4. The methods and formats to be adopted for reporting on the
nationalprogrammes shal lbe determined in accordance with the proce-dure laid down in Article 18. Any amendments to these methods and
formats shall be adopted in accordance with the same procedure.
5. The Commission shall every two years review and assess the
information received pursuant to paragraphs 2 and 3 above and publisha report thereon.
Article 18
1. The Commission shall be assisted by a Committee composed of
the representatives of the Member States and chaired by the representa-tive of the Commission.
2. The representative of the Commission shall submit to the commit-
tee a draft of the measures to be taken. The committee shall deliver its
opinion on the draft within a time limit which the chairman may lay
down according to the urgency of the matter. The opinion shall bedelivered by the majority laid down in Article 148 (2) of the Treaty inthe case of decisions which the Councilis required to adopt on a propo-salfrom the Commission. The votes of the representatives of the Mem-
ber States within the committee shall be weighted in the manner set out
in that Article. The chairman shall not vote.
3. (a) The Commission shall adopt the measures envisaged if they are
in accordance with the opinion of the committee.
(b) If the measures envisaged are not in accordance with the opinion
of the committee, or if no opinion is delivered, the Commission
shall, without delay, submit to the Council a proposal relating tothe measures to be taken. The Council shall act by a qualifiedmajority.
If, on the expiry of a period of three months from the date of referralto
the Council, the Council has not acted, the proposed measures shall be
adopted by the Commission, save where the Councilhas decided
against the said measures by a simple majority.
Article 19
1. Member States shall bring into force the laws, regulations and
administrative provisions necessary to comply with this Directive nolater than 30 June 1993. They shall forthwith inform the Commissionthereof.
2. When Member States adopt the measures referred to in paragraph
1, they shall contain a reference to this Directive or shall be accompa-
(1) OJ No L 158, 23. 6. 1990, p. 56.
1991L0271 — EN — 27.03.1998 — 001.001 — 9
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nied by such a reference on the occasion of their officialpubl ication.
The methods of making such a reference shall be laid down by theMember States.
3. Member States shall communicate to the Commission the texts of
the main provisions of national law which they adopt in the field gov-erned by this Directive.
Article 20
This Directive is addressed to the Member States.
1991L0271 — EN — 27.03.1998 — 001.001 — 10
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ANNEX I
REQUIREMENTS FOR URBAN WASTE WATER
A.Collecting systems (1)
Collecting systems shall take into account waste water treatment require-
ments.
The design, construction and maintenance of collecting systems shall be
undertaken in accordance with the best technical knowledge not entailing
excessive costs, notably regarding:
— volume and characteristics of urban waste water,
— prevention of leaks,
— limitation of pollution of receiving waters due to storm water overflows.
B.Discharge from urban waste water treatment plants to receiving
waters (2)
1. Waste water treatment plants shall be designed or modified so that repre-
sentative samples of the incoming waste water and of treated effluent can
be obtained before discharge to receiving waters.
2. Discharges from urban waste water treatment plants subject to treatment
in accordance with Articles 4 and 5 shall meet the requirements shown in
Table 1.
3. Discharges from urban waste water treatment plants to those sensitive
areas which are subject to eutrophication as identified in Annex II.A (a)
shall in addition meet the requirements shown in Table 2 of this Annex.
4. More stringent requirements than those shown in Table 1 and/or Table 2
shall be applied where required to ensure that the receiving waters satisfy
any other relevant Directives.
5. The points of discharge of urban waste water shall be chosen, as far as
possible, so as to minimize the effects on receiving waters.
C.Industrial waste water
Industrial waste water entering collecting systems and urban waste water
treatment plants shall be subject to such pre-treatment as is required in order
to:
— protect the health of staff working in collecting systems and treatment
plants,
— ensure that collecting systems, waste water treatment plants and asso-
ciated equipment are not damaged,
— ensure that the operation of the waste water treatment plant and the treat-
ment of sludge are not impeded,
— ensure that discharges from the treatment plants do not adversely affect
the environment, or prevent receiving water from complying with other
Community Directives,
— ensure that sludge can be disposed of safety in an environmentally accep-
table manner.
D.Reference methods for monitoring and evaluation of results
1. Member States shall ensure that a monitoring method is applied which
corresponds at least with the level of requirements described below.
(1) Given that it is not possible in practice to construct collecting systems and treatment
plants in a way such that all waste water can be treated during situations such as unu-
sually heavy rainfall, Member States shall decide on measures to limit pollution fromstorm water overflows. Such measures could be based on dilution rates or capacity inrelation to dry weather flow, or could specify a certain acceptable number of overflowsper year.
(
2) Given that it is not possible in practice to construct collecting systems and treatment
plants in a way such that all waste water can be treated during situations such as unu-sually heavy rainfall, Member States shall decide on measures to limit pollution fromstorm water overflows. Such measures could be based on dilution rates or capacity inrelation to dry weather flow, or could specify a certain acceptable number of overflows
per year.
1991L0271 — EN — 27.03.1998 — 001.001 — 11
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Alternative methods to those mentioned in paragraphs 2, 3 and 4 may be
used provided that it can be demonstrated that equivalent results are
obtained.
Member States shall provide the Commission with all relevant information
concerning the applied method. If the Commission considers that the con-
ditions set out in paragraphs 2, 3 and 4 are not met, it will submit an
appropriate proposalto the Council .
2. Flow-proportional or time-based 24-hour samples shall be collected at the
same well-defined point in the outlet and if necessary in the inlet of the
treatment plant in order to monitor compliance with the requirements for
discharged waste water laid down in this Directive.
Good internationall aboratory practices aiming at minimizing the degrada-
tion of samples between collection and analysis shall be applied.
3. The minimum annual number of samples shall be etermined according to
the size of the treatment plant and be collected at regular intervals during
the year:
— 2 000 to 9 999p.e.: 12 samples during the first year.
four samples in subsequent years, if it can be
shown that the water during the first year
complies with the provisions of the Directive;
if one sample of the four fails, 12 samples
must be taken in the year that follows.
— 10 000 to 49 999p. e.: 12 samples.
— 50 000 p.e. or over: 24 samples.
4. The treated waste water shall be assumed to conform to the relevant para-
meters if, for each relevant parameter considered individually, samples of
the water show that it complies with the relevant parametric value in the
following way:
(a) for the parameters specified in Table 1 and Article 2 (7), a maximum
number of samples which are allowed to fail the requirements,
expressed in concentrations and/or percentage reductions in Table 1
and Article 2 (7), is specified in Table 3;
(b) for the parameters of Table 1 expressed in concentrations, the failing
samples taken under normal operating conditions must not deviate
from the parametric values by more than 100 %. For the parametric
values in concentration relating to total suspended solids deviations
of up to 150 % may be accepted;
(c) for those parameters specified in Table 2 the annual mean of the sam-
ples for each parameter shall conform to the relevant parametric
values.
5. Extreme values for the water quality in question shall not be taken into
consideration when they are the result of unusual situations such as those
due to heavy rain.
1991L0271 — EN — 27.03.1998 — 001.001 — 12
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Table 1: Requirements for discharges from urban waste water treatment plants subject to Articles 4
and 5 of the Directive. The values for concentration or for the percentage of reduction shall
apply.
Parameters ConcentrationMinimum
percentage of
reduction (1)Reference method of measurement
Biochemicaloxygen demand
(BOD5 at 20 °C) without nitrifi-
cation (2)25 mg/lO270-90
40 under Arti-
cle 4 (2)Homogenized, unfiltered,
undecanted sample. Determi-
nation of dissolved oxygen
before and after five-day incu-
bation at 20 °C ± 1 °C, in
complete darkness. Addition
of a nitrification inhibitor
Chemicaloxygen demand
(COD)125 mg/lO275 Homogenized, unfiltered,
undecanted sample Potassium
dichromate
Totalsuspended sol ids 35 mg/l(3)
35 under Arti-
cle 4 (2) (more
than 10 000
p.e.)
60 under Arti-
cle 4 (2)
(2 000-10 000
p.e.)90 (3)
90 under Arti-
cle 4 (2) (more
than 10 000
p.e.)
70 under Arti-
cle 4 (2)
(2 000-10 000
p.e.)— Filtering of a representa-
tive sample through a 0,45
µm filter membrane. Dry-
ing at 105 °C and weigh-
ing
— Centrifuging of a represen-
tative sample (for at least
five mins with mean accel-
eration of 2 800 to 3 200
g), drying at 105 °C and
weighing
(1) Reduction in relation to the load of the influent.
(2) The parameter can be replaced by another parameter: total organic carbon (TOC) or total oxygen demand (TOD)
if a relationship can be established between BOD5 and the substitute parameter.
(3) This requirement is optional.
Analyses concerning discharges from lagooning shall be carried out on filtered samples; however, the
concentration of total suspended solids in unfiltered water samples shall not exceed 150 mg/l.
1991L0271 — EN — 27.03.1998 — 001.001 — 13
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Table 2: Requirements for discharges from urban waste water treatment plants to sensitive areas
which are subject to eutrophication as identified in Annex II.A(a). One or both parameters
may be applied depending on the local situation. The values for concentration or for the per-
centage of reduction shall apply.
Parameters ConcentrationMinimum
percentage of
reduction (1)Reference method of measure-
ment
Totalphosphorus ►C12 mg/l(10 000 —
100 000 p.e.) ◄80 Molecular absorption spec-
trophotometry
1 mg/l(more than 100 000
p.e.)
Totalnitrogen (2) 15 mg/l(10 000-
100 000p.e.) (3)70-80 Molecular absorption spec-
trophotometry
10 mg/l(more than 100 000
p.e.) (3)
(1) Reduction in relation to the load of the influent.
(2) Totalnitrogen means the sum of totalKjel dahlnitrogen (organic and ammoniacalnitrogen) nitrate-nitrogen and
nitrite-nitrogen.
(3) These values for concentration are annual means as referred to in Annex I, paragraph D.4(c). However, the
requirements for nitrogen may be checked using daily averages when it is proved, in accordance with Annex I,
paragraph D.1, that the same level of protection is obtained. In this case, the daily average must not exceed 20
mg/l of total nitrogen for all the samples when the temperature from the effluent in the biological reactor issuperior or equal to 12 °C. The conditions concerning temperature could be replaced by a limitation on the timeof operation to take account of regionalcl imatic conditions.
1991L0271 — EN — 27.03.1998 — 001.001 — 14
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Table 3
Series of samples taken in any yearMaximum permitted number of
samples which fail to conform
4-7 1
8-16 2
17-28 329-40 441-53 554-67 668-81 782-95 8
96-110 9
111-125 10
126-140 11141-155 12156-171 13172-187 14188-203 15204-219 16220-235 17236-251 18252-268 19
269-284 20
285-300 21301-317 22318-334 23335-350 24351-365 25
1991L0271 — EN — 27.03.1998 — 001.001 — 15
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ANNEX II
CRITERIA FOR IDENTIFICATION OF SENSITIVE AND LESS SENSI-
TIVE AREAS
A.Sensitive areas
A water body must be identified as a sensitive area if it falls into one of the
following groups:
(a) naturalfreshwater l akes, other freshwater bodies, estuaries and coastal
waters which are found to be eutrophic or which in the near future may
become eutrophic if protective action is not taken.
The following elements might be taken into account when considering
which nutrient should be reduced by further treatment:
(i) lakes and streams reaching lakes/reservoirs/closed bays which are
found to have a poor water exchange, whereby accumulation may
take place. In these areas, the removal of phosphorus should be
included unless it can be demonstrated that the removal will have
no effect on the level of eutrophication. Where discharges from
large agglomerations are made, the removal of nitrogen may also be
considered;
(ii) estuaries, bays and other coastalwaters which are found to have a
poor water exchange, or which receive large quantities of nutrients.
Discharges from small agglomerations are usually of minor impor-
tance in those areas, but for large agglomerations, the removal of
phosphorus and/or nitrogen should be included unless it can be
demonstrated that the removal will have no effect on the level of
eutrophication;
(b) surface freshwaters intended for the abstraction of drinking water which
could contain more than the concentration of nitrate laid down under the
relevant provisions of Council Directive 75/440/EEC of 16 June 1975
concerning the quality required of surface water intended for the abstrac-
tion of drinking water in the Member States (1) if action is not taken;
(c) areas where further treatment than that prescribed in Article 4 of this
Directive is necessary to fulfil Council Directives.
B.Less sensitive areas
A marine water body or area can be identified as a less sensitive area if the
discharge of waste water does not adversely affect the environment as a result
of morphology, hydrology or specific hydraulic conditions which exist in that
area.
When identifying less sensitive areas, Member States shall take into account
the risk that the discharged load may be transferred to adjacent areas where it
can cause detrimentalenvironmentaleffects. Member States shal lrecognize
the presence of sensitive areas outside their nationaljurisdiction.
The following elements shall be taken into consideration when identifying
less sensitive areas:
open bays, estuaries and other coastalwaters with a good water exchange and
not subject to eutrophication or oxygen depletion or which are considered
uhlikely to become eutrophic or to develop oxygen depletion due to the dis-
charge of urban waste water.
(1) OJ No L 194, 25. 7. 1975, p. 26 as amended by Directive 79/869/EEC (OJ No L 271,
29. 10. 1979, p. 44).
1991L0271 — EN — 27.03.1998 — 001.001 — 16
▼B
ANNEX III
INDUSTRIALSECTORS
1. Milk-processing
2. Manufacture of fruit and vegetable products
3. Manufacture and bottling of soft drinks
4. Potato-processing5. Meat industry
6. Breweries
7. Production of alcohol and alcoholic beverages8. Manufacture of animalfeed from pl ant products
9. Manufacture of gelatine and of glue from hides, skin and bones
10. Malt-houses11. Fish-processing industry