W
o
d
o
c
i
ąg
i
i
k
a
n
a
li
z
a
c
j
a
W
o
d
o
c
i
ąg
i
i
k
a
n
a
li
z
a
c
j
a
/W
a
t
e
r s
u
pp
l
y
a
n
d
s
e
w
age
R
ecent change
s
in
E
ur
o
pean Uni
o
n legi
s
lati
o
n imp
o
s
e ne
w
o
bligati
o
n
s
o
n
w
ater utilitie
s
t
o
gather, anal
y
s
e, and rep
o
rt
impartial Ke
y
Perf
o
rmance
I
ndicat
o
r
s
(KP
I
s
)
.
The
s
e include data
o
n
w
ater lea
k
age, entit
y
c
o
nditi
o
n, energ
y
c
o
n
s
umpti
o
n,
and it
s
s
o
urce
s
.
B
enchmar
k
ing ha
s
emerged a
s
a valuable t
oo
l f
o
r c
o
llecting
s
tandardi
z
ed and reliable data, facilitating
impr
o
vement
s
.
Utilitie
s
in P
o
land participate in b
o
th nati
o
nal benchmar
k
ing, led b
y
the Chamber
o
f C
o
mmerce’
s
“
P
o
li
s
h
Water
wo
r
k
s
”
(
I
G
WP), and internati
o
nal benchmar
k
ing thr
o
ugh the
E
ur
o
pean
B
enchmar
k
ing C
oo
perati
o
n (
EB
C)
.
H
ow
ever,
difference
s
in data definiti
o
n
s
affect the c
o
mparabilit
y
o
f indicat
o
r
s
and the accurac
y
o
f ran
k
ing re
s
ult
s
.
A
crucial i
ss
ue i
s
t
o
s
elect the m
o
s
t appr
o
priate and
o
bjective KP
I
f
o
r
w
ater l
o
ss
.
The
D
W
D
mandate
s
the u
s
e
o
f the
I
nfra
s
tructure Lea
k
age
I
nde
x
(
I
L
I
), but thi
s
indicat
o
r i
s
difficult t
o
calculate and verif
y
, pr
o
mpting a
s
earch f
o
r
s
impler,
s
tandardi
z
ed alternative
s
,
s
uch a
s
N
o
n-
R
evenue Water (N
R
W)
.
The auth
o
r
s
c
o
mpare
s
elected KP
I
s
fr
o
m the t
wo
benchmar
k
ing pr
o
ject
s
,
EB
C and
I
G
WP,
s
h
ow
ing that min
o
r definiti
o
nal difference
s
ma
y
ma
k
e the c
o
mpari
s
o
n n
o
n-
o
bjective
o
r imp
o
ss
ible
.
Ke
ywo
rd
s
:
benchmar
k
ing,
D
W
D
, lea
k
age
Os
tatnie
z
mian
y
w
pra
wo
da
w
s
t
w
ie Unii
E
ur
o
pej
s
k
iej na
k
ładają na pr
z
ed
s
iębi
o
r
s
t
w
a
wo
d
o
ciąg
ow
e n
ow
e
o
b
ow
ią
z
k
i
w
z
a
k
re
s
ie gr
o
mad
z
enia, anali
z
ow
ania i rap
o
rt
ow
ania
o
bie
k
t
yw
n
y
ch Kluc
z
owy
ch W
s
k
a
ź
ni
ków
E
fe
k
t
yw
n
o
ś
ci (KP
I
)
.
O
bejmują
o
ne dane d
o
t
y
c
z
ące
wy
cie
ków
wo
d
y
,
s
tanu pr
z
ed
s
iębi
o
r
s
t
w
a,
z
u
ż
y
cia energii i jeg
o
ź
r
ó
deł
.
B
enchmar
k
ing
s
tał
s
ię cenn
y
m nar
z
ęd
z
iem gr
o
mad
z
enia
z
n
o
rmali
z
ow
an
y
ch, r
z
eteln
y
ch dan
y
ch i ułat
w
iania
w
pr
ow
ad
z
ania u
s
pra
w
nień
.
Pr
z
ed
s
iębi
o
r
s
t
w
a
wo
d
o
ciąg
ow
e
w
P
o
l
s
ce uc
z
e
s
tnic
z
ą
z
ar
ów
n
o
w
benchmar
k
ingu
k
raj
owy
m, pr
ow
ad
z
o
n
y
m pr
z
e
z
Iz
bę
G
o
s
p
o
darc
z
ą
„
W
o
d
o
ciągi P
o
l
s
k
ie
”
(
I
G
WP), ja
k
i międ
z
y
nar
o
d
owy
m, pr
ow
ad
z
o
n
y
m pr
z
e
z
E
ur
o
pean
B
enchmar
k
ing
C
o
-
o
perati
o
n (
EB
C)
.
Ró
ż
nice
w
definicjach dan
y
ch
w
pł
yw
ają jedna
k
na p
o
r
ów
n
yw
aln
o
ś
ć
w
s
k
a
ź
ni
ków
i
wy
ni
k
i
ran
k
ing
ow
e
.
Kluc
z
ow
ą
kw
e
s
tią je
s
t
wy
b
ó
r
o
bie
k
t
yw
neg
o
i be
z
s
tr
o
nneg
o
KP
I
dla
s
trat
wo
d
y.
Dy
re
k
t
yw
a 2020/2184
(
D
W
D
), na
k
a
z
uje
s
t
o
s
ow
anie
I
nfra
s
tru
k
turalneg
o
W
s
k
a
ź
ni
k
a W
y
cie
ków
(
I
L
I
), ale
w
s
k
a
ź
ni
k
ten je
s
t trudn
y
d
o
o
blic
z
enia
i
w
er
y
fi
k
acji, c
o
s
k
łania d
o
p
o
s
z
u
k
i
w
ania pr
o
s
t
s
z
y
ch,
z
n
o
rmali
z
ow
an
y
ch alternat
yw
, ta
k
ich ja
k
wo
da niepr
z
y
n
o
s
z
ąca
d
o
ch
o
du (N
R
W)
.
A
ut
o
r
z
y
p
o
r
ów
nują
wy
brane
k
luc
z
ow
e
w
s
k
a
ź
ni
k
i efe
k
t
yw
n
o
ś
ci (KP
I
)
z
d
wó
ch pr
o
je
k
t
ów
bench-
mar
k
ing
owy
ch,
EB
C i
I
G
WP, p
ok
a
z
ując,
ż
e dr
o
bne r
ó
ż
nice definic
y
jne m
o
gą
s
pra
w
ić,
ż
e p
o
r
ów
nanie będ
z
ie nie
o
bie
k
t
y
-
w
ne lub niem
o
ż
li
w
e
.
Sł
ow
a
k
luc
z
ow
e
:
benchmar
k
ing,
Dy
re
k
t
yw
a
wo
dna
D
W
D
,
wy
cie
k
i,
T
o
ma
s
z
Cich
o
ń http
s
:
//
o
rcid
.o
rg/0000- 0002-4114-6220
‒
Kra
kow
Univer
s
it
y
o
f Techn
o
l
o
g
y
,
F
acult
y
o
f
E
nvir
o
nmental
E
ngineering and
E
nerg
y
,
P
o
land, t
o
ma
s
z
.
cich
o
n
@
p
k.
edu
.
pl
Klara
R
amm http
s
:
//
o
rcid
.o
rg/0000-0003-1707-4228
‒
War
s
a
w
Univer
s
it
y
o
f Techn
o
l
o
g
y
, Chamber
o
f C
o
mmerce
“
P
o
li
s
h Water
wo
r
k
s
”
,
P
o
land,
k.
ramm
@
ig
w
p
.o
rg
.
pl
93
T
h
e
i
mpa
ct
of
d
i
ff
e
r
e
n
c
e
s
i
n
de
f
i
n
i
n
g
l
ea
k
age
i
n
d
i
c
a
t
o
r
s
on
t
h
e
c
o
mpa
r
ab
ili
ty
of
da
t
a
r
eq
u
ir
ed
b
y t
h
e
D
ri
n
k
i
n
g
W
a
t
e
r
D
ir
e
ct
i
v
e
W
p
ływ
r
ó
ż
n
i
c w
de
f
i
n
i
c
j
a
c
h
wsk
a
ź
n
i
k
ó
w wyc
i
e
k
ó
w
n
a
p
o
r
ó
w
n
yw
a
l
no
ść
da
n
yc
h
wy
maga
n
yc
h
D
yr
e
ktyw
ą
w s
p
r
a
w
i
e
j
a
k
o
śc
i
w
o
d
y
d
o
s
p
o
ż
yc
i
a
T
OM
A
S
Z
C
I
CH
O
Ń, KL
ARA
RA
MM
DO
I 10
.
36119/15
.
2025
.
12
.
16
I
n
t
r
o
d
u
ct
i
on
Change
s
in
E
U legi
s
lati
o
n require the
acqui
s
iti
o
n
o
f m
o
re and m
o
re data, and it i
s
nece
ss
ar
y
t
o
calculate KP
I
s
,
w
hich
s
h
o
uld be
impartial
.
The
D
rin
k
ing Water
D
irective (
E
ur
o
-
pean Uni
o
n, 2020) require
s
rep
o
rting n
o
t
o
nl
y
o
n lea
k
s
but al
s
o
o
n the general c
o
ndi-
ti
o
n
o
f the entit
y.
M
o
re
o
ver, the Ta
x
o
n
o
m
y
R
egulati
o
n (
E
ur
o
pean Uni
o
n, 2020a) and it
s
delegated and implementing act
s
imp
o
s
e,
am
o
ng
o
ther
o
bligati
o
n
s
, the requirement t
o
m
o
nit
o
r energ
y
c
o
n
s
umpti
o
n and it
s
o
rigin
(f
o
ss
il fuel
s
o
r rene
w
able)
.
The e
ss
ence
o
f
s
trengthening
w
ater
s
uppl
y
s
y
s
tem
s
i
s
al
s
o
m
o
nit
o
ring reliabilit
y
(
R
a
k
et al
.
2022)
.
A
helpful t
oo
l f
o
r
o
btaining reliable and
valuable data i
s
benchmar
k
ing (
E
ur
E
au,
2015; Suchace
k
et al
.
, 2018;
G
o
h and See,
2021;
M
arque
s
et al
.
2021)
.
The
o
verarching
g
o
al i
s
t
o
o
bjectivel
y
c
o
mpare participant
s
t
o
indicate area
s
f
o
r
s
tructural and management
change
s
and c
o
rrecti
o
n
s
.
T
o
impr
o
ve their
o
perati
o
n
s
and c
o
mpare efficienc
y
at the na-
ti
o
nal and internati
o
nal level, the P
o
li
s
h fr
o
nt-
runner utilitie
s
participate in t
wo
t
y
pe
s
o
f
benchmar
k
ing
:
internati
o
nal, carried
o
ut b
y
the
E
ur
o
pean
B
enchmar
k
ing C
oo
perati
o
n
(
EB
C), and P
o
li
s
h, implemented b
y
the Cham-
ber
o
f C
o
mmerce
“
P
o
li
s
h Water
wo
r
k
s
.”
B
o
th
pr
o
ject
s
w
ere e
s
tabli
s
hed in the earl
y
2000
s
and are dedicated t
o
c
o
mpanie
s
inv
o
lved in
the drin
k
ing
w
ater
s
uppl
y
and
w
a
s
te
w
ater c
o
l-
lecti
o
n and treatment (
w
ater
s
ervice
s
)
.
Nearl
y
200 P
o
li
s
h
w
ater c
o
mpanie
s
,
member
s
o
f the
o
rgani
z
ati
o
n, are participat-
ing in the
I
G
WP benchmar
k
ing pr
o
ject
.
The
Chamber ha
s
ab
o
ut 500 member
s
,
w
hich
include b
o
th
w
ater and
s
e
w
age c
o
mpanie
s
.
There are a fe
w
ver
y
s
mall entitie
s
am
o
ng
them
.
The benchmar
k
ing participant
s
are
s
plit
int
o
three gr
o
up
s
, ba
s
ed
o
n the number
o
f
inhabitant
s
s
erved
:
–
Small,
s
erving
o
f le
ss
than 20 th
o
u
s
and
inhabitant
s
,
–
M
edium-
s
i
z
ed,
s
erving fr
o
m 20 th
o
u-
s
and t
o
100 th
o
u
s
and inhabitant
s
,
–
B
ig,
s
erving m
o
re than 100 th
o
u
s
and in-
habitant
s
.
The entitie
s
participating in the bench-
mar
k
ing
o
perate m
o
re than 16
%
o
f the t
o
tal
length
o
f the
w
ater net
wo
r
k
and
s
erve ap-
pr
o
x
imatel
y
56
%
o
f h
o
u
s
eh
o
ld
s
in P
o
land
.
Thi
s
benchmar
k
ing pr
o
ject ha
s
been c
o
nducted
9412/2025
www.
inf
o
rmacjain
s
tal
.
c
o
m
.
pl
W
thr
o
ugh a
s
urve
y
meth
o
d,
w
ith the
s
upp
o
rt
o
f
a dedicated
w
eb platf
o
rm
.
The applicati
o
n
w
a
s
created ba
s
ed
o
n the team’
s
e
x
pert e
x
pe-
rience and ha
s
been m
o
dified during
o
pera-
ti
o
n
.
The interface i
s
friendl
y
f
o
r participant
s
and enhance
s
the accurac
y
o
f data
.
The at-
tendant
s
mu
s
t fill in the ba
s
ic data,
w
hich i
s
verified aut
o
maticall
y
up
o
n gathering
.
The
P
o
li
s
h benchmar
k
ing pr
o
ject f
o
cu
s
e
s
o
n f
o
ur
gr
o
up
s
o
f fact
o
r
s
:
o
perati
o
nal, inve
s
tment and
ren
o
vati
o
n, envir
o
nmental, and financial
.
E
C
B
ha
s
s
everal benchmar
k
ing pr
o
p
o
s
-
al
s
but f
o
cu
s
e
s
o
n large
w
ater utilitie
s
.
Thi
s
i
s
due t
o
the c
o
mple
x
it
y
o
f the
s
urve
y
t
o
be
c
o
mpleted
.
I
n 2023, 46 entitie
s
participated
in the e
x
erci
s
e, primaril
y
fr
o
m
E
ur
o
pe, a
s
w
ell
a
s
fr
o
m
A
s
ia and S
o
uth
A
merica
.
The
s
e are
mainl
y
large entitie
s
,
s
uppl
y
ing
o
ver 5 milli
o
n
inhabitant
s
o
f Singap
o
re,
O
man,
o
r
A
n
k
ara
.
H
ow
ever, there are al
s
o
s
maller
o
ne
s
,
s
uch
a
s
th
o
s
e in Nic
o
s
ia (C
y
pru
s
),
w
hich
s
erve
50,000 inhabitant
s
.
A
dditi
o
nall
y
, thi
s
c
o
m-
pan
y
i
s
affected b
y
the e
x
tremel
y
high
s
ea-
s
o
nalit
y
o
f
w
ater demand
.
I
n t
o
tal,
EB
C
benchmar
k
ing participant
s
s
erve 78 milli
o
n
pe
o
ple
.
EB
C indicat
o
r
s
are gr
o
uped int
o
f
o
ur
categ
o
rie
s
:
re
s
o
urce
s
, utilit
y
management,
perf
o
rmance, and
s
o
cietal effect
s
.
Kra
ków
Cit
y
Water
wo
r
k
s
(W
M
K) par-
ticipate
s
in b
o
th e
x
erci
s
e
s
.
Ex
perience
s
h
ow
s
that difference
s
in appr
o
ach t
o
data c
o
llec-
ti
o
n and definiti
o
n
s
are a crucial fact
o
r influ-
encing an entit
y
’
s
p
o
s
iti
o
n in the ran
k
ing and
pr
o
viding valuable in
s
ight
s
.
A
k
e
y
difference
bet
w
een the t
wo
benchmar
k
s
lie
s
in their
definiti
o
n
s
.
I
n b
o
th ca
s
e
s
, the
y
w
ere devel-
o
ped b
y
e
x
pert gr
o
up
s
and accepted b
y
the
participant
s
.
B
enchmar
k
ing can help implement
A
rti-
cle 4
o
f the
D
W
D
; it imp
o
s
e
s
the
o
bligati
o
n
t
o
m
o
nit
o
r lea
k
s
related t
o
w
ater l
o
ss
e
s
in the
w
ater
s
uppl
y
net
wo
r
k.
There i
s
a livel
y
di
s
cu
s
-
s
i
o
n in the
E
U regarding the implementati
o
n
o
f thi
s
practice
.
The
I
nfra
s
tructure Lea
k
age
I
nde
x
(
I
L
I
) i
s
the
o
nl
y
o
ne directl
y
s
pecified in the
D
rin
k
ing Wa-
ter
D
irective
.
I
n the te
x
t
o
f the
D
irective,
w
e can
find
:
“
I
n acc
o
rdance
w
ith
D
irective 2000/60/
E
C,
M
ember State
s
s
hall en
s
ure that an a
ss
e
ss
-
ment
o
f
w
ater lea
k
age level
s
w
ithin their terri-
t
o
r
y
and
o
f the p
o
tential f
o
r impr
o
vement
s
in
w
ater lea
k
age reducti
o
n i
s
perf
o
rmed u
s
ing the
infra
s
tructural lea
k
age inde
x
(
I
L
I
) rating meth
o
d
o
r an
o
ther appr
o
priate meth
o
d
.”
The equati
o
n f
o
r the
I
L
I
i
s
:
(1)
Where
:
Vl
–
v
o
lume
o
f real l
o
ss
e
s
,
U
AR
L
–
Unav
o
idable
A
nnual
R
eal L
o
ss
e
s
.
The m
o
s
t difficult part i
s
calculating the
den
o
minat
o
r
o
f the equati
o
n ab
o
ve
.
The equati
o
n f
o
r the U
AR
L i
s
:
(2)
Where
:
D
–
t
o
tal length
o
f the
w
ater net
wo
r
k
,
Nc
–
number
o
f pipe c
o
nnecti
o
n
s
,
Lc
–
t
o
tal length
o
f pipe c
o
nnecti
o
n
s
,
P
–
pre
ss
ure
o
f
w
ater in the net
wo
r
k.
C
o
n
s
idering the un
s
o
ld
w
ater v
o
lume,
E
C
B
relie
s
o
n the
I
nternati
o
nal Water
A
ss
o
-
ciati
o
n (
I
W
A
) guideline
s
c
o
vering n
o
n-reve-
nue
w
ater (N
R
W) and real l
o
ss
e
s
(
A
bu
E
l-
ta
y
ef et al, 2023)
.
N
R
W i
s
the difference
bet
w
een
w
ater injected int
o
the net
wo
r
k
and
w
ater
s
o
ld in a
s
pecific unit
o
f time
.
Theref
o
re,
it i
s
an ea
s
y
indicat
o
r t
o
calculate (
R
i
zz
o
et
al
.
, 2007; Lea
k
s
Suite Librar
y
, 2025)
.
EB
C pr
o
p
o
s
e
s
s
everal indicat
o
r
s
lin
k
ed
t
o
w
ater l
o
ss
e
s
.
Still, acc
o
rding t
o
the
EB
C,
the be
s
t indicat
o
r
s
f
o
r the
D
W
D
A
rticle 4 re-
p
o
rt are the N
R
W per number
o
f c
o
nnected
pr
o
pertie
s
and the N
R
W a
s
a percentage
o
f
w
ater pumped int
o
the net
wo
r
k.
Water l
o
ss
indicat
o
r
s
are de
s
cribed in the
“D
rin
k
ing
Water
”
area
.
I
n turn,
I
G
WP include
s
w
ater
l
o
ss
e
s
in the gr
o
up
o
f envir
o
nmental indica-
t
o
r
s
.
I
t i
s
n
o
t ba
s
ed
o
n N
R
W, but
o
n the
am
o
unt
o
f
w
ater injected int
o
the net
wo
r
k
,
e
x
cluding the
w
ater u
s
ed f
o
r the entit
y
’
s
ow
n
techn
o
l
o
gical purp
o
s
e
s
(e
.
g
.
, flu
s
hing the
net
wo
r
k
) after being pumped int
o
the net-
wo
r
k
(v
o
lume in m
³
)
.
I
G
WP benchmar
k
ing
include
s
a percentage indicat
o
r and a linear
lea
k
age inde
x
(LL
I
),
w
hich repre
s
ent
s
the
lea
k
age v
o
lume per
k
il
o
meter
o
f the net
wo
r
k.
D
W
D
indicate
s
the
o
bligati
o
n t
o
c
o
llect
value
s
f
o
r the infra
s
tructure lea
k
age inde
x
(
I
L
I
)
o
r
“
an
o
ther appr
o
priate meth
o
d
”.
H
ow
-
ever,
I
G
WP and
E
C
B
empha
s
i
z
e that it i
s
dedicated t
o
entitie
s
that c
o
nduct inten
s
ive
lea
k
age management and have a net
wo
r
k
that i
s
in g
oo
d c
o
nditi
o
n
.
I
L
I
i
s
an indicat
o
r
that depend
s
o
n the technical feature
s
o
f the
net
wo
r
k
,
s
uch a
s
the length
o
f di
s
tributi
o
n
pipe
s
o
r c
o
nnecting pipe
s
(Winarni, 2009)
.
F
o
r man
y
w
ater
o
perat
o
r
s
, it i
s
ver
y
difficult t
o
calculate,
s
o
metime
s
even imp
o
ss
ible
(Palach
o
va and Tuh
o
vca
k
, 2024;
O
cie-
pa-Kubic
k
a et al, 2024)
.
O
n the
o
ther hand,
the
w
a
y
o
f defining and calculating thi
s
KP
I
can be influenced b
y
different a
ss
umpti
o
n
s
(
I
w
ane
k
M
.
, Such
o
rab P
.
2019),
w
hich ma
y
be
s
ubjective and unclear
.
I
t i
s
al
s
o
n
o
t p
o
ss
i-
ble t
o
verif
y
the value
o
f the
I
L
I
fact
o
r thr
o
ugh
e
x
ternal
o
r regulat
o
r
y
agenda
s
.
I
t i
s
nece
s
-
s
ar
y
t
o
identif
y
the fundamental and clear
fact
o
r
s
that
w
ill be
w
idel
y
u
s
ed t
o
evaluate
the efficienc
y
o
f the
w
ater
s
uppl
y
s
y
s
tem and
c
o
mpare the
s
y
s
tem
s
in term
s
o
f lea
k
age
level
.
M
o
re
s
o
, becau
s
e the re
s
ult
s
are t
o
be
rep
o
rted t
o
the C
o
mmi
ss
i
o
n b
y
Januar
y
2026
.
The auth
o
r
s
c
o
nducted a c
o
mparative
anal
y
s
i
s
o
f indicat
o
r
s
related t
o
w
ater l
o
ss
e
s
t
o
determine the
o
ptimal appr
o
ach
.
The
y
u
s
ed
KP
I
s
fr
o
m
EB
C and
I
G
WP and anal
y
s
ed the
re
s
ult
s
o
f the
s
e t
wo
benchmar
k
ing
s
.
Neither
in
s
tituti
o
n
s
publi
s
h rep
o
rt
s
w
ith full re
s
ult
s
.
The
s
e
are available
o
nl
y
t
o
pr
o
ject participant
s
.
H
ow
ever, much data i
s
publi
s
hed in a
s
h
o
rt-
ened, an
o
n
y
mi
z
ed ver
s
i
o
n and pre
s
ented at
c
o
nference
s
and
wo
r
k
s
h
o
p
s
.
I
t i
s
al
s
o
wo
rth empha
s
i
z
ing that
I
L
I
o
nl
y
c
o
ncern
s
l
o
ss
e
s
in the
w
ater
s
uppl
y
net
wo
r
k
;
hence, an equivalent meth
o
d
s
h
o
uld al
s
o
f
o
cu
s
o
n l
o
ss
e
s
in the net
wo
r
k
and n
o
t in the
entire
s
uppl
y
s
y
s
tem (fr
o
m
s
o
urce t
o
tap)
.
M
a
t
e
ri
a
l
s
a
n
d
me
t
ho
d
s
the
D
rin
k
ing Water
D
irective require
s
a lea
k
age m
o
nit
o
r f
o
r entitie
s
s
uppl
y
ing at
lea
s
t 10,000 m
3
per da
y
o
r
s
erving at lea
s
t
50,000 pe
o
ple
.
A
cc
o
rding t
o
the Chief
Sanitar
y
I
n
s
pect
o
rate (2024), in P
o
land in
2023, there
w
ere 69
w
ater
wo
r
k
s
that t
ook
in
m
o
re than 10,000 m
³
/da
y
,
s
uppl
y
ing 12
milli
o
n pe
o
ple
.
The
E
ur
o
pean
F
ederati
o
n
o
f Water Ser-
vice
s
(
E
ur
E
au) empha
s
i
z
e
s
that managing
w
ater l
o
ss
e
s
fr
o
m the di
s
tributi
o
n
s
y
s
tem i
s
a crucial a
s
pect
o
f the
w
ater
s
upplier’
s
r
o
le
(
E
ur
E
au, 2021)
.
The rep
o
rting
o
f the lea
k
age
e
s
timate acr
o
ss
E
ur
o
pe i
s
ba
s
ed
o
n
s
everal
indicat
o
r
s
.
The
s
e indicat
o
r
s
are calculated
u
s
ing different f
o
rmula
s
that inc
o
rp
o
rate
c
o
mp
o
nent
s
o
f the
w
ater balance,
w
hich are
al
s
o
calculated in vari
o
u
s
w
a
y
s
.
B
a
s
ed
o
n
the
s
tud
y
,
E
ur
E
au member
s
u
s
e 16 different
indicat
o
r
s
, m
o
s
tl
y
ba
s
ed
o
n v
o
lume, e
.
g
.
, m
3
o
r m
3
/
k
m
o
f
w
ater pipe
.
S
o
me indicat
o
r
s
are
given in percentage
s
.
The
I
nfra
s
tructure Lea
k
-
age
I
nde
x
i
s
o
nl
y
u
s
ed b
y
a ver
y
s
mall num-
ber
o
f large
w
ater pr
o
vider
s
due t
o
the diffi-
cult
y
in data c
o
llecti
o
n and it
s
s
en
s
itivit
y
t
o
average pre
ss
ure in the net
wo
r
k.
F
igure 1 pre
s
ent
s
the di
s
tributi
o
n
o
f an-
s
w
er
s
t
o
the que
s
ti
o
n am
o
ng the member
s
o
f
the Chamber regarding
w
hich
w
ater l
o
ss
in-
dicat
o
r the entit
y
ba
s
e
s
it
s
m
o
nit
o
ring
o
n
.
The
s
urve
y
w
a
s
part
o
f a bigger inve
s
tigati
o
n
c
o
nducted in 2022
.
I
n
I
G
WP benchmar
k
ing (
I
G
WP, 2024),
the
w
ater l
o
ss
fact
o
r
s
are part
o
f three envi-
r
o
nmental KP
I
s
:
The fir
s
t
o
ne i
s
a percentage
o
f
w
ater
l
o
ss
:
(3)
Where
:
A
–
w
ater pumped int
o
the net
wo
r
k
[
th
o
-
u
s
and
s
m
3
]
,
W
o
d
o
c
i
ąg
i
i
k
a
n
a
li
z
a
c
j
a
B
–
w
ater
s
o
ld (
w
h
o
le
s
ale included)
[
th
o
u
s
and
s
m
3
]
,
C
–
w
ater u
s
ed in techn
o
l
o
gical purp
o
-
s
e
s
o
f the
o
perat
o
r
[
th
o
u
s
and
s
m
3
].
F
igure 2 pre
s
ent
s
re
s
ult
s
fr
o
m 2023
.
I
n
ever
y
chart,
w
e can
s
ee the red median
value and the green average value in the
gr
o
up
.
The
s
ec
o
nd indicat
o
r i
s
a linear
w
ater
l
o
ss
inde
x
defined b
y
the equati
o
n
:
(4)
Where
:
A
–
w
ater pumped int
o
the net
wo
r
k
[
th
o
-
u
s
and
s
m
3
]
,
B
–
w
ater
s
o
ld (
w
h
o
le
s
ale included)
[
th
o
u
s
and
s
m
3
]
,
C
–
w
ater u
s
ed in techn
o
l
o
gical purp
o
-
s
e
s
o
f the
o
perat
o
r
[
th
o
u
s
and
s
m
3
]
,
D
–
the t
o
tal length
o
f the
o
perated
w
ater
net
wo
r
k
(
w
ith
o
ut pipe c
o
nnecti
o
n
s
)
[k
m
].
The third indicat
o
r, named the drin
k
ing
w
ater net
wo
r
k
efficienc
y
, i
s
a rati
o
o
f
w
ater
s
o
ld t
o
w
ater pumped int
o
the net
wo
r
k.
I
t i
s
defined a
s
a percentage
.
F
o
r
s
mall entitie
s
,
the median i
s
78,64
%
, f
o
r medium 84,69
%
and f
o
r big 85
.
75
%
[
9
].
E
ur
o
pean
B
enchmar
k
ing C
o
-
o
perati
o
n
al
s
o
mea
s
ure
s
di
s
tributi
o
n l
o
ss
e
s
thr
o
ugh
s
ev-
eralindicat
o
r
s
.
B
ecau
s
ethe
I
W
A
Speciali
s
t
G
r
o
up
o
n Water L
o
ss
e
s
rec
o
m-
mend
s
n
o
t rel
y
ing
o
n the
w
ater l
o
ss
indicat
o
r
e
x
pre
ss
ed a
s
a percentage, the 2024
EB
C
d
o
e
s
n
o
t u
s
e thi
s
indicat
o
r
.
I
t f
o
cu
s
e
s
o
n n
o
n-
revenue
w
ater per main
s
length f
o
r le
ss
urban-
i
z
ed area
s
and
o
n n
o
n-revenue
w
ater per
pr
o
pert
y
f
o
r m
o
re urbani
z
ed area
s
.
F
igure 4
pre
s
ent
s
the re
s
ult
s
pre
s
ented b
y
EB
C f
o
r 2023
in a public rep
o
rt (
E
ur
o
pean
B
enchmar
k
ing
C
o
-
o
perati
o
n, 2024)
.
F
igure 5 pre
s
ent
s
the re
s
ult
s
o
f the
EB
C
benchmar
k
ing
o
n N
R
W per pr
o
pert
y.
F
i
g
u
r
e
1
.
D
i
str
i
b
u
t
i
on
of
r
e
s
p
on
s
e
s t
o
t
h
e
q
u
e
st
i
on
ab
ou
t
t
h
e
m
o
st
f
r
eq
u
e
n
t
l
y
m
on
i
t
o
r
ed
w
a
t
e
r
l
o
ss
i
n
d
i
c
a
-
t
o
r
,
w
h
e
r
e
:
W
n
– w
a
t
e
r
p
u
mped
i
n
t
o
t
h
e
n
e
tw
o
r
k
,
Wt – w
a
t
e
r
t
a
k
e
n
f
r
o
m
t
h
e
e
nv
i
r
on
-
me
n
t
,
Ws – w
a
t
e
r
s
o
l
d
(
i
nvo
i
c
ed
)
F
i
g
u
r
e
1
.
O
dp
o
w
i
ed
z
i
n
a
p
yt
a
n
i
a
o
n
a
j
c
z
ę
śc
i
e
j
u
ż
yw
a
n
y wsk
a
ź
n
i
k st
r
a
t w
o
d
y
,
gd
z
i
e
:
W
n
–
w
o
da
w
p
o
mp
o
w
a
n
a
d
o
s
i
e
c
i
d
ystry
b
u
cy
j
n
e
j,
Wt – w
o
da
p
o
b
r
a
n
a
z
e
śr
o
d
o
w
i
sk
a
,
Ws – w
o
da
s
p
r
z
eda
n
a
(
z
a
f
a
kt
u
r
o
w
a
n
a
)
F
i
g
u
r
e
2
.
W
a
t
e
r
l
o
ss
pe
rc
e
n
t
age
v
a
l
u
e
i
n
t
h
r
ee
c
a
t
eg
o
r
i
e
s
of
w
a
t
e
r s
u
pp
li
e
rs
(
s
ma
ll,
med
i
u
m
,
a
n
d
b
i
g
).
T
h
e
nu
mbe
r
on
t
h
e
l
e
f
t
i
n
d
i
c
a
t
e
s t
h
e
a
v
e
r
age
v
a
l
u
e
,
a
n
d
t
h
e
nu
mbe
r
i
n
t
h
e
m
i
dd
l
e
i
n
d
i
c
a
t
e
s t
h
e
med
i
a
n.
E
a
c
h
ba
r r
ep
r
e
s
e
n
ts
a
n
e
n
t
i
ty
pa
rt
i
c
i
pa
t
i
n
g
i
n
t
h
e
be
n
c
h
ma
rk
i
n
g
F
i
g
u
r
e
2
.
P
r
o
c
e
n
t
o
wy
wsk
a
ź
n
i
k str
a
t
w
o
d
y
w
tr
z
e
c
h
k
a
t
eg
o
r
i
a
c
h
d
o
st
a
w
-
c
ó
w
(
ma
łyc
h
,
śr
ed
n
i
c
h
i
d
u
ż
yc
h).
L
i
c
z-
ba
z
l
e
w
e
j
str
on
y
o
z
n
a
c
z
a
w
a
rt
o
ść
śr
ed
n
i
ą
,
a
li
c
z
ba
w śr
o
d
k
u
med
i
a
n
ę
.
K
a
ż
d
y sł
u
pe
k r
ep
r
e
z
e
n
t
u
j
e
j
ed
no
stk
ę
b
i
o
r
ą
c
ą
u
d
z
i
a
ł w
be
n
c
h
ma
rk
i
n
g
u
F
i
g
u
r
e
3
.
Annu
a
l
w
a
t
e
r
l
o
ss
i
n
m
3
/k
m
of
w
a
t
e
r
ma
i
n
s
i
n
t
h
r
ee
c
a
t
eg
o
r
i
e
s
of
w
a
t
e
r s
u
pp
li
e
rs
(
s
ma
ll,
med
i
u
m
,
b
i
g
).
T
h
e
nu
mbe
r
on
t
h
e
l
e
f
t
i
n
d
i
c
a
t
e
s
t
h
e
a
v
e
r
age
v
a
l
u
e
,
a
n
d
t
h
e
nu
mbe
r
i
n
t
h
e
m
i
dd
l
e
i
n
d
i
c
a
t
e
s t
h
e
med
i
a
n.
E
a
c
h
ba
r r
ep
r
e
s
e
n
ts
a
n
e
n
t
i
ty
pa
rt
i
c
i
-
pa
t
i
n
g
i
n
t
h
e
be
n
c
h
ma
rk
i
n
g
F
i
g
u
r
e
3
.
R
o
c
z
n
a
w
i
e
l
k
o
ść str
a
t
w
o
d
y w
m
3
/
k
m
s
i
e
c
i
w tr
z
e
c
h
k
a
t
e
-
g
o
r
i
a
c
h
d
o
st
a
wc
ó
w
(
ma
łyc
h
,
śr
ed
-
n
i
c
h
i
d
u
ż
yc
h).
L
i
c
z
ba
p
o
l
e
w
e
j
str
o
-
n
i
e
o
z
n
a
c
z
a
w
a
rt
o
ść śr
ed
n
i
ą
,
a
li
c
z-
ba
w śr
o
d
k
u
med
i
a
n
ę
.
K
a
ż
d
y sł
u
pe
k
r
ep
r
e
z
e
n
t
u
j
e
j
ed
no
stk
ę
b
i
o
r
ą
c
ą
u
d
z
i
a
ł w
be
n
c
h
ma
rk
i
n
g
u
a
)
b
)
F
i
g
u
r
e
4
.
D
i
str
i
b
u
t
i
on
of
t
h
e
N
R
W
pe
r
ma
i
n
s
l
e
n
g
t
h
i
n
E
BC
be
n
c
h
ma
rk
i
n
g
[
m
3
/k
m
/
da
y]
a
ss
e
ss
me
n
t r
e
s
u
l
ts
fo
r
2022
,
b
)
5
-
y
ea
r tr
e
n
d
F
i
g
u
r
e
4
.
W
i
e
l
k
o
ść w
o
d
y
n
i
ep
r
z
y
no
s
z
ą
c
e
j
d
o
c
ho
d
u
NRW
n
a
d
ł
u
g
o
ść s
i
e
c
i
w
be
n
c
h
ma
rk
i
n
g
u
E
BC
[
m
3
/k
m
/
da
y
] wy
n
i
k
i
z
a
r
o
k
2022
,
b
)
5
-
l
e
t
n
i
tr
e
n
d
a
)
b
)
F
i
g
u
r
e
5
.
Annu
a
l
N
R
W
d
i
str
i
b
u
t
i
on
i
n
m
3
pe
r
p
r
o
pe
rty [
m
3
/
p
r
o
pe
rty]
;
a
)
a
ss
e
ss
me
n
t r
e
s
u
l
ts
fo
r 2022
,
b
)
5
-
y
ea
r tr
e
n
d
.
F
i
g
u
r
e
5
.
R
o
c
z
n
a
NRW w
m
3
n
a
n
i
e
r
u
c
ho
m
o
ść [
m
3
/
p
r
o
pe
rty]
;
95
9612/2025
www.
inf
o
rmacjain
s
tal
.
c
o
m
.
pl
W
D
i
sc
u
ss
i
on
in the gr
o
up
o
f
s
mall utilitie
s
,
w
here b
o
th the
median and the average value e
x
ceed 14
%
.
D
e
f
i
n
i
t
i
on
s
The be
s
t
s
ituati
o
n i
s
in the gr
o
up
o
f the bigge
s
t
I
t i
s
imp
o
rtant that in paper
s
, la
w
s
, regula-
o
perat
o
r
s
; in thi
s
gr
o
up, the median value
ti
o
n
s
, and directive
s
, the e
x
pre
ss
i
o
n
s
u
s
ed equal
s
9
.
16
%
and the average value i
s
mean the
s
ame thing
.
Ver
y
o
ften, different e
x
-
s
lightl
y
ab
o
ve
1
0
%
.
pre
ss
i
o
n
s
have different meaning
s
and
s
h
ow
The anal
y
s
i
s
o
f the chart
s
w
ith linear
w
ater
different phen
o
mena
.
The
D
W
D
define
s
l
o
ss
inde
x
(
F
ig
.
3),
s
h
ow
s
the
o
pp
o
s
ite
s
itua-
a lea
k
, empha
s
i
z
ing the envir
o
nmental a
s
pect ti
o
n
.
The
s
malle
s
t am
o
unt
o
f
w
ater i
s
l
o
s
t per
related t
o
the pr
o
tecti
o
n
o
f
w
ater re
s
o
urce
s
a
s
main
s
length in the
s
malle
s
t net
wo
r
k
s
,
w
here
the m
o
s
t imp
o
rtant
.
I
n turn,
I
W
A
f
o
cu
s
e
s
o
n the median value i
s
le
ss
than 0
.
8 th
o
u
s
and
l
o
ss
e
s
, empha
s
i
z
ing the ec
o
n
o
mic a
s
pect, m
3
/
k
m/
y
ear, and the average value i
s
1
.
57
s
imilarl
y
t
o
w
ater utilitie
s
, f
o
r
w
hich the m
o
s
t th
o
u
s
and m
3
/
k
m/
y
ear
.
I
n the gr
o
up
o
f the
imp
o
rtant indicat
o
r i
s
N
R
W
.
bigge
s
t
w
ater
o
perat
o
r
s
, b
o
th the median
A
s
s
h
ow
n in the
I
W
A
w
ater balance, value and the average value are ab
o
ut 1
.
7
the
s
e e
x
pre
ss
i
o
n
s
d
o
n
o
t mean the
s
ame KP
I
th
o
u
s
and m
3
/
k
m/
y
ear
.
Thi
s
e
x
ample pr
o
ve
s
(
F
ig
.
6)
.
The lea
k
age
s
are part
o
f the real that the percentage indicat
o
r ma
y
n
o
t reflect
l
o
ss
e
s
.
The n
o
n-revenue
w
ater i
s
a
w
ider realit
y
c
o
rrectl
y.
Es
peciall
y
if it i
s
given
w
ith
o
ut
quantit
y
than the
w
ater l
o
ss
e
s
.
a de
s
cripti
o
n
o
f the technical c
o
nditi
o
n
s
and
F
o
r la
s
t
s
everal
y
ear
s
the
w
ater pr
o
fe
s
-
s
i
z
e
o
f the entit
y.
I
t i
s
inc
o
rrect t
o
c
o
mpare the
s
i
o
nal
s
have publi
s
hed man
y
paper
s
w
ith efficienc
y
o
f different
w
ater
s
uppl
y
s
y
s
tem
s
,
c
o
nclu
s
i
o
n
s
that
w
idel
y
u
s
ed percentage fac-e
s
peciall
y
s
y
s
tem
s
o
f different
s
cale
s
.
t
o
r
o
f
w
ater l
o
ss
e
s
i
s
inaccurate t
o
c
o
mpareC
o
nverting all data int
o
annual l
o
ss
e
s
,
the efficienc
y
o
f the
w
ater
s
uppl
y
s
y
s
tem
s
, the median f
o
r P
o
land range
s
fr
o
m 660 t
o
becau
s
e it d
o
e
s
n
o
t include crucial part
s
o
f 1820 m
3
/
k
m, and f
o
r
EB
C equal
s
3650
the
s
y
s
tem
s
s
uch a
s
a
s
i
z
e
o
f the
s
y
s
tem, length m
3
/
k
m
.
Thi
s
ma
y
be due t
o
s
ignificant differ-
o
f
w
ater net
wo
r
k
, number
o
f c
o
nnecti
o
n
s
, ence
s
in the net
wo
r
k
la
yo
ut and ge
o
graphi-t
o
tal
length
o
f c
o
nnecti
o
n
s
, and pre
ss
ure
o
f cal l
o
cati
o
n
.
A
part fr
o
m
o
ne e
x
cepti
o
nall
y
w
ater in
the net
wo
r
k
, etc (
O
ciepa, 2021;
O
ng high ca
s
e f
o
r
s
mall and
o
ne f
o
r medium utili-et al
.
,
2023)
.
I
W
A
Water L
o
ss
Speciali
s
t tie
s
, in P
o
land, LL
I
o
s
cillate
s
ar
o
und 2000
G
r
o
up
rec
o
mmend
s
n
o
t u
s
ing thi
s
indicat
o
r m
3
/
k
m
.
I
n the
EB
C benchmar
k
, LL
I
annual becau
s
e it
i
s
a p
oo
r meth
o
d
o
f mea
s
uring value
s
range fr
o
m bel
ow
1000 m
3
/
k
m t
o
pr
o
gre
ss
o
r
c
o
mparing
s
imilar utilitie
s
.
H
ow
-
o
ver 20,000 m
3
/
k
m
.
ever, thi
s
indicat
o
r i
s
p
o
pular becau
s
e
o
f it
sEB
C benchmar
k
ing, at the advanced
s
implicit
y
and ea
s
e
o
f calculati
o
n
.
I
n additi
o
n, level
o
f participati
o
n, pr
o
p
o
s
e
s
a calculati
o
n
it i
s
under
s
tandable becau
s
e it
s
impl
y
indi-
o
f
I
L
I
f
o
r a pr
o
fe
ss
i
o
nal anal
y
s
i
s
o
f net
wo
r
k
cate
s
t
o
manager
s
the value
o
f
w
ater that ha
s
lea
k
age
s
.
n
o
t been
s
o
ld (Sant
o
s
, 20
2
4)
.
I
t
s
h
ow
s
the T
o
calculate the U
AR
L, it i
s
nece
ss
ar
y
t
o
value
o
f l
o
s
t revenue b
y
multipl
y
ing the have accurate
k
n
ow
ledge
o
f the net
wo
r
k
am
o
unt
o
f un
s
o
ld
w
ater b
y
the tariff price
.
parameter
s
.
A
l
s
o
, it i
s
n
o
t
o
bvi
o
u
s
h
ow
t
o
E
ven if thi
s
indicat
o
r i
s
n
o
t g
oo
d f
o
r bench- define the average pre
ss
ure
o
f
w
ater in the
mar
k
ing, it can fulfil it
s
ta
s
k
s
in a c
o
mpan
y
net
wo
r
k.
Es
peciall
y
in huge
w
ater
s
uppl
y
c
o
ntr
o
lling (
Y
ilma
z
et al
.
2023)
.
A
cc
o
rding t
o
s
y
s
tem
s
s
upplied fr
o
m m
o
re than
o
ne direc-
F
ig
.
1, thi
s
indicat
o
r i
s
s
till the m
o
s
t p
o
pular in ti
o
n
o
r
s
o
urce
.
I
t can happen that in
o
ne
P
o
land
.
Perhap
s
, in
s
tead
o
f eliminating it fr
o
m
s
pecific
D
M
A
, there are different pre
ss
ure
s
,
benchmar
k
ing, it
s
h
o
uld be c
o
unted f
o
r
s
pe-
o
ne at the inlet and an
o
ther at the cu
s
t
o
mer
cific gr
o
up
s
o
f
w
ater utilitie
s
.
p
o
int
o
f
s
uppl
y.
Sh
ow
ing the average
w
ater
The
o
vervie
w
o
f the chart
s
in
F
ig
.
2
s
ug- pre
ss
ure c
o
uld mi
s
repre
s
ent the
w
h
o
le KP
I
ge
s
t
s
that the
wo
r
s
t efficienc
y
o
f the net
wo
r
k
i
s
and the meth
o
d ba
s
ed
o
n it
.
There are al
s
o
different c
o
nditi
o
n
s
in the
s
y
s
tem
s
o
perated
o
n a flat territ
o
r
y
and different
o
ne
s
in m
o
un-
tain
o
u
s
area
s
.
M
a
y
be due t
o
the
s
h
ow
n i
ss
ue
s
in
s
o
me
s
urve
y
s
, utilitie
s
declare the
y
have in their
s
y
s
tem
s
an
I
L
I
value bel
ow
1
,
w
hich rai
s
e
s
d
o
ubt
s
ab
o
ut the reliable calculati
o
n
o
f
I
L
I
and it
s
credibilit
y
, f
o
r e
x
ample, in the c
o
nte
x
t
o
f the U
AR
L imp
o
s
ed
s
everal
y
ear
s
ag
o.
A
n-
o
ther dra
w
bac
k
o
f the
I
L
I
meth
o
d i
s
that it i
s
n
o
t p
o
ss
ible t
o
calculate directl
y
fr
o
m the
w
ater balance
.
E
ver
y
utilit
y
mu
s
t calculate it
o
n it
s
ow
n, in c
o
ntra
s
t t
o
o
ther KP
I
s
,
w
hich
are calculated fr
o
m the ba
s
ic data, li
k
e v
o
l-
ume
o
f
w
ater pumped int
o
the net
wo
r
k
and
w
ater
s
o
ld
.
A
dditi
o
nall
y
, in different c
o
un-
trie
s
, there are different definiti
o
n
s
o
f the
s
pecific part
s
o
f the net
wo
r
k.
I
n
s
o
me c
o
un-
trie
s
, pipe c
o
nnecti
o
n
s
are
s
h
o
rt,
w
ith man
y
w
ater meter
s
and client
s
o
n ever
y
c
o
nnec-
ti
o
n
.
I
n
o
ther
s
, pipe c
o
nnecti
o
n
s
are l
o
nger
and
w
ith
o
ne
w
ater meter
o
n each
.
That i
s
w
h
y
, in the auth
o
r
s
’
o
pini
o
n,
I
L
I
i
s
m
o
re academic than practical and n
o
n-
o
b-
jective f
o
r c
o
mparing the efficienc
y
o
f differ-
ent
s
y
s
tem
s
.
S
i
z
e
of
t
h
e
w
a
t
e
r
s
u
pp
l
y syst
em
A
rticle 4
o
f the
D
W
D
s
pecifie
s
the criteri-
o
n
o
f the
s
i
z
e
o
f utilitie
s
,
w
hich mu
s
t pr
o
vide
data
o
n lea
k
s
.
The criteri
o
n i
s
ba
s
ed
o
n the
number
o
f pe
o
ple
s
upplied and the v
o
lume
o
f
w
ater
s
upplied
.
The
o
bligati
o
n applie
s
t
o
s
up-
plier
s
s
uppl
y
ing at lea
s
t
1
0,000 m
3
per da
y
o
r
s
erving at lea
s
t 50,000 pe
o
ple
.
I
t theref
o
re
s
eem
s
rea
s
o
nable f
o
r lea
k
age indicat
o
r
s
t
o
refer t
o
at lea
s
t
o
ne
o
f the
s
e value
s
.
A
ll indica-
t
o
r
s
c
o
n
s
ider the v
o
lume
o
f
w
ater injected int
o
the net
wo
r
k
,
o
r
w
ater
s
o
ld (billed), and thi
s
i
s
n
o
t a value equivalent t
o
the
w
ater
s
upplied
t
o
the c
o
n
s
umer
.
N
o
indicat
o
r refer
s
t
o
the
number
o
f pe
o
ple
s
upplied
.
M
o
s
t c
o
mpanie
s
in
E
ur
o
pe d
o
n
o
t have
s
uch data
.
B
a
s
ed
o
n
billing data, the
y
can determine the number
o
f recipient
s
, but n
o
t the number
o
f pe
o
ple
s
erved
.
I
n additi
o
n, the
D
W
D
refer
s
t
o
the
w
ater
s
upplier
.
Theref
o
re, the data qu
o
ted b
y
the Chief Sanitar
y
I
n
s
pect
o
rate (2024) in P
o
-
land ma
y
be que
s
ti
o
nable
.
I
t can be a
ss
umed
that
s
o
me
s
upplier
s
o
perate
o
n ver
y
s
mall,
rural
w
ater
wo
r
k
s
,
s
erving a t
o
tal
o
f
o
ver
10,000 pe
o
ple
.
The que
s
ti
o
n remain
s
w
heth-
er the
y
w
ill be required t
o
determine lea
k
s
f
o
r
th
o
s
e
s
mall
s
y
s
tem
s
.
W
a
t
e
r
i
n
t
e
n
ded
fo
r
hu
ma
n
c
on
s
u
mp
t
i
on
A
c
o
ntr
o
ver
s
ial i
ss
ue in the c
o
nte
x
t
o
f lea
k
s
i
s
the
s
c
o
pe
o
f their m
o
nit
o
ring
.
B
o
th
E
ur
E
au
and
I
G
WP empha
s
i
z
e that lea
k
s
s
h
o
uld c
o
n-
cern
w
ater l
o
ss
e
s
in the
w
ater
s
uppl
y
net
wo
r
k.
H
ow
ever, the definiti
o
n
o
f
“w
ater intended f
o
r
human c
o
n
s
umpti
o
n
”
i
s
n
o
t equivalent t
o
F
i
g
u
r
e
6
.
W
a
t
e
r
ba
l
a
n
c
e
a
cc
o
r
d
i
n
g
t
o
IW
A
(L
i
embe
r
ge
r
a
n
d
M
a
l
c
o
l
m
,
2004
)
F
i
g
u
r
e
6
.
B
il
a
n
s w
o
d
y w
ed
ł
u
g
IW
A
(L
i
embe
r
ge
r
a
n
d
M
a
l
c
o
l
m
,
2004
)
V
o
lume
R
evenue
Water
N
o
n-
R
evenue
B
illed
B
illed
M
etered C
o
n
s
umpti
o
n
A
uth
o
ri
s
ed
A
uth
o
ri
s
e
d
C
o
n
s
umpti
o
n
B
illed Unmetered C
o
n
s
umpti
o
n
C
o
n
s
umpti
o
n
Unbilled
Unbilled
M
etered C
o
n
s
umpti
o
n
A
uth
o
ri
s
ed
C
o
n
s
umpti
o
n
Unbilled Unmetered C
o
n
s
umpti
o
n
S
y
s
tem
I
nput
Unauth
o
ri
s
ed C
o
n
s
umpti
o
n
A
pparent L
o
ss
e
s
M
etering
I
naccuracie
s
Water (N
R
W)
Water L
o
ss
e
s
Lea
k
age
o
n Tran
s
mi
ss
i
o
n and/
o
r
D
i
s
tributi
o
n
M
ain
s
R
eal L
o
ss
e
s
Lea
k
age and
O
verfl
ow
s
at Utilit
y
’
s
St
o
rage Tan
k
s
Lea
k
age
o
n
s
ervice c
o
nnecti
o
n
s
97
W
o
d
o
c
i
ąg
i
i
k
a
n
a
li
z
a
c
j
a
drin
k
ing
w
ater
.
“
Water intended f
o
r human
c
o
n
s
umpti
o
n
”
mean
s
w
ater bef
o
re and af-
ter treatment
:
“
either in it
s
o
riginal
s
tate
o
r
after treatment
”
a
s
menti
o
ned in
A
rt
.
2
o
f
D
W
D.
Theref
o
re, the limit
s
o
f lea
k
m
o
nit
o
r-
ing in the
w
ater
s
uppl
y
s
y
s
tem
s
h
o
uld be
e
s
tabli
s
hed
.
M
o
re
o
ver,
A
rticle 4
o
f the
D
W
D
adv
o
cate
s
f
o
r maintaining m
o
nit
o
ring
o
nl
y
w
ithin the di
s
tributi
o
n net
wo
r
k
,
w
hich
require
s
m
o
nit
o
ring
o
f
I
L
I
o
r the u
s
e
o
f an-
o
ther, but equivalent, meth
o
d
.
I
n thi
s
c
o
n-
te
x
t, m
o
nit
o
ring l
o
ss
e
s
at the inta
k
e and
treatment
s
tage
s
s
eem
s
ab
s
urd
.
Lo
c
a
l
c
on
d
i
t
i
on
s
Water l
o
ss
indicat
o
r
s
s
h
ow
a large varia-
ti
o
n due t
o
the different
o
perating envir
o
n-
ment
s
o
f the participating utilitie
s
.
The gr
o
up
trend
s
s
h
ow
a clear decline
o
ver the pa
s
t five
y
ear
s
.
R
a
w
lea
k
age data al
o
ne are n
o
t
s
ufficient
t
o
meet the requirement
s
o
f
A
rticle 4
o
f the
D
rin
k
ing Water
D
irective
.
I
t i
s
empha
s
i
z
ed
that
“
a
ss
e
ss
ment
s
hall ta
k
e int
o
acc
o
unt rele-
vant public health, envir
o
nmental, technical
and ec
o
n
o
mic a
s
pect
s
”.
Theref
o
re, the l
o
ss
rep
o
rt
s
h
o
uld include data
o
n l
o
cal c
o
ndi-
ti
o
n
s
.
B
enchmar
k
ing can be u
s
eful here, a
s
it
include
s
certain indicat
o
r
s
fr
o
m the
s
e f
o
ur
gr
o
up
s
.
Theref
o
re, there i
s
a need f
o
r an
o
b-
jective a
ss
e
ss
ment
o
f l
o
cal c
o
nditi
o
n
s
o
f hu-
man health
.
Neither
I
G
WP n
o
r
EB
C f
o
cu
s
e
s
o
n data
o
n the health c
o
nditi
o
n
o
f recipient
s
,
but
EB
C c
o
llect
s
data
o
n
w
ater qualit
y.
I
t
wo
uld be nece
ss
ar
y
t
o
define the relati
o
n
s
hip
bet
w
een public health and lea
k
s
.
Perhap
s
the
UWWT
D
requirement
s
regarding m
o
nit
o
ring
di
s
ea
s
e
s
in
s
e
w
age
wo
uld help here
.
EB
C
c
o
llect
s
m
o
re relevant indicat
o
r
s
.
Thi
s
bench-
mar
k
ing f
o
cu
s
e
s
m
o
re
o
n the c
o
n
s
umer
.
KP
I
s
are theref
o
re related t
o
acce
ss
t
o
drin
k
ing
w
ater
s
ervice
s
,
w
ater qualit
y
, and c
o
mpli-
ance,
w
hich can be c
o
n
s
idered directl
y
re-
lated t
o
public health
.
R
egarding envir
o
nmental a
s
pect
s
in the
benchmar
k
ing, the
s
e primaril
y
include indi-
cat
o
r
s
related t
o
energ
y
c
o
n
s
umpti
o
n
.
I
n thi
s
c
o
nte
x
t, it
s
eem
s
rea
s
o
nable t
o
a
ss
e
ss
the
qualit
y
o
f the envir
o
nment u
s
ed b
y
the
w
ater
s
upplier
.
Thi
s
data can be
s
o
urced fr
o
m
s
tate
envir
o
nmental m
o
nit
o
ring
.
Technical data
u
s
eful f
o
r characteri
z
ing l
o
cal c
o
nditi
o
n
s
in
the
I
G
WP benchmar
k
ing include net
wo
r
k
failure rate (
o
perati
o
n inde
x
),
s
hare
o
f re-
m
o
te
w
ater meter
s
(
o
perati
o
n inde
x
), and
the degree
o
f net
wo
r
k
replacement (inve
s
t-
ment and ren
o
vati
o
n inde
x
)
.
The
EB
C ha
s
s
imilar indicat
o
r
s
related t
o
a
ss
et manage-
ment
.
The
I
G
WP’
s
ec
o
n
o
mic indicat
o
r
s
can
al
s
o
be u
s
ed t
o
a
ss
e
ss
w
ater
s
uppl
y
pr
o
fit-
abilit
y
and
w
ater price
s
.
The
E
C
B
can lever-
age reliabilit
y
and aff
o
rdabilit
y.
C
on
c
l
u
s
i
on
s
The
w
ater
s
ect
o
r p
o
ss
e
ss
e
s
s
pecific char-
acteri
s
tic
s
that require tail
o
red benchmar
k
ing
appr
o
ache
s
t
o
enable meaningful c
o
mpari-
s
o
n
s
am
o
ng utilitie
s
.
The current c
o
nditi
o
n
o
f
a
w
ater
s
uppl
y
s
y
s
tem can be effectivel
y
de-
s
cribed u
s
ing KP
I
s
and fact
o
r
s
calculated and
balanced
o
n the ba
s
i
s
o
f reliable input data
.
I
t
i
s
e
ss
ential that the calculati
o
n pr
o
ce
ss
be tran
s
-
parent,
o
bjective, and c
o
n
s
i
s
tent acr
o
ss
all
w
ater
s
upplier
s
.
I
n the c
o
nte
x
t
o
f
w
ater l
o
ss
e
s
, the LL
I
repre
s
ent
s
the m
o
s
t
o
bjective and c
o
mpara-
ble indicat
o
r
.
The reducti
o
n
o
f lea
k
age
s
in the
w
ater
s
ect
o
r i
s
increa
s
ingl
y
s
upp
o
rted b
y
ne
w
techn
o
l
o
gie
s
and inn
o
vative
s
o
luti
o
n
s
,
w
hich
s
h
o
uld be activel
y
pr
o
m
o
ted
.
A
par-
ticular empha
s
i
s
s
h
o
uld be placed
o
n the
accurac
y
and reliabilit
y
o
f fl
ow
mea
s
urement
data
w
ithin
w
ater di
s
tributi
o
n net
wo
r
k
s
, a
s
thi
s
f
o
rm
s
the f
o
undati
o
n f
o
r credible perf
o
r-
mance a
ss
e
ss
ment
.
The pr
o
ce
ss
s
h
o
uld begin
w
ith the devel-
o
pment
o
f clear and impartial definiti
o
n
s
,
en
s
uring that the termin
o
l
o
g
y
and meth
o
d
o
l-
o
g
y
u
s
ed are harm
o
ni
z
ed
.
F
urtherm
o
re,
lea
k
age data
s
h
o
uld be
s
y
nchr
o
ni
z
ed
w
ith
l
o
cal c
o
nte
x
tual inf
o
rmati
o
n t
o
all
ow
f
o
r ac-
curate interpretati
o
n,
w
hile al
s
o
en
s
uring that
s
uch data remain
s
c
o
mparable acr
o
ss
E
U
M
ember State
s
.
I
t
s
h
o
uld al
s
o
be empha
s
i
z
ed that c
o
mpli-
ance
w
ith
A
rticle 4
o
f the
D
rin
k
ing Water
D
i-
rective i
s
inherentl
y
lin
k
ed t
o
the m
o
nit
o
ring
o
f
w
ater l
o
ss
e
s
w
ithin di
s
tributi
o
n net
wo
r
k
s
, in
c
o
njuncti
o
n
w
ith
o
ther indicat
o
r
s
de
s
cribing
the perf
o
rmance
o
f
w
ater utilitie
s
.
Theref
o
re,
the
E
ur
o
pean C
o
mmi
ss
i
o
n’
s
pr
o
p
o
s
al t
o
m
o
ni-
t
o
r lea
k
age acr
o
ss
the entire
w
ater
s
uppl
y
s
y
s
tem appear
s
unju
s
tified
.
R
E
F
E
R
E
N C
E
S
[
1
]
A
bu
E
lta
y
ef, H
.
T
.
,
A
bu
A
lhin, K
.
S
.
,
A
la
s
tal K
.
M
.
(2023)
.
A
ddre
ss
ing n
o
n-revenue
w
ater a
s
a gl
o
bal pr
o
blem and it
s
interlin
k
age
s
w
ith
s
u
s
tainable devel
o
pment g
o
al
s
.
Water Practice
and Techn
o
l
o
g
y
1 18 (12)
:
3175
–
3202
.
http
s
:
//d
o
i
.o
rg/10
.
2166/
w
pt
.
2023
.
157
.
[
2
]
Chief Sanitar
y
I
n
s
pect
o
rate, (2024)
.
Stan Sani-
tarn
y
Kraju 2023
.
G
ł
ów
n
y
I
n
s
pe
k
t
o
rat Sanitar-
n
y
, War
s
z
a
w
a
.
[
3
]
E
ur
E
au (2015)
.
H
ow
benchmar
k
ing i
s
u
s
ed in
the
w
ater
s
ect
o
r,
(
A
cce
ss
ed 15
.
05
.
2025)
.
[
4
]
E
ur
E
au (2021)
.
D
rin
k
ing Water Suppl
y
and
Lea
k
age
M
anagement
.
B
riefing n
o
te
(
A
cce
ss
ed
15
.
05
.
2025)
.
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