EWA Workshop – Hennef 2009
Benchmarking of (large municipal) waste watertreatment plants (>100,000 PE) and sewer
systems in Austria
EWA Workshop,Hennef, 4. June 2009
Prof. Helmut Kroiss, Dipl.-Ing. Heidi SchaarVienna University of Technology
Dr. Stefan Lindtnerk2W, Environmental Technology, Development and Consulting, Vienna
Dr. Thomas ErtlUniversity of Natural Resources and Applied Life Sciences, Vienna
25.02.2010 2EWA Workshop – Hennef 2009
Table of content
• Introduction• Terminology & definitions• Benchmarking method• Results• Conclusions
25.02.2010 3EWA Workshop – Hennef 2009
The Austrian BenchmarkingSystem - Introduction
• Developed between 1999 and 2004• > 100 plants from 2,000 to 1 Mio PE were analysed• Process benchmarking – comparable cost elements
are related to clearly defined processes• Performance indicators for the identification of best
practice and benchmarks• Enables the comparison of performance indicators
for different treatment process schemes andoperating modes
25.02.2010 4EWA Workshop – Hennef 2009
Terminology & definitions
• Process indicators are related to one year of operation
• Benchmark plants are defined for yearly total, capital andoperating costs
• Benchmark plants � lowest specific costs
• For yearly total and operating costs benchmark plants have tomeet the following criteria:– Full compliance with the effluent limits (Austrian emission standards)– Compliance with defined data quality criteria (mass balance check, etc.).– Typical characteristics of municipal waste water
(e.g. COD/N ratio, no dominant influence of industrial waste water)
25.02.2010 5EWA Workshop – Hennef 2009
Process model (>100,000 PE)Inf
luent
pump
ing
mech
anica
l pre-
treatm
ent
prima
ry se
dimen
tation
biolog
ical tr
eatm
ent
gas e
ngine
exce
ss sl
udge
thick
ening
stabil
isatio
n
sludg
e dew
aterin
g
sludg
e trea
tmen
t and
disp
osal
labora
tory a
nd m
onito
ring
admi
nistra
tion
opera
tion b
uildin
g and
inf
rastru
cture
works
hops
motor
pool
1.1 1.2 2.1 2.2 2.3 3.1 3.2 4.1 4.2 I.1 I.2 I.3 II.1 II.2Process 2 Process 3 Process 4 Support process I II
Waste water treatmentInfluent pumping
mech.pre-treatmentmechanical-
biological treatmentthickening
stabilisationfurther sludge treatment
and disposalobligatoryprocesses
optionalprocesses
Process 1
Cost AccountAssociated
Mains
AssociatedSpecial
StructuresMains of
Communities
SpecialStructures ofCommunities Administration
AuxiliaryComponents
(Carpark, Workshop)Cost Process P 1 P 2 P 3 P 4 HP I HP II
25.02.2010 6EWA Workshop – Hennef 2009
Terminology & definitions
• Arrangement in groups according to the design capacity (PE)� comparable process indicators
• Process benchmark � lowest specific operating costs for oneof the processes
• No process benchmarks for capital costs - the data basis doesnot allow fair comparison
• Benchmark bands– to take data inaccuracies into account– lowest specific total yearly costs of a benchmark plant increased
by 10 %
25.02.2010 7EWA Workshop – Hennef 2009
Benchmarking method• Following the timeline of a benchmarking year, the
benchmarking process can be sub-divided into three steps:
a) Data acquisitionb) Data processingc) Exchange of experience Ja
nuar
y
September
July
25.02.2010 8EWA Workshop – Hennef 2009
Data acquisition
• Organised via internet platform(www.abwasserbenchmarking.at)
• Data transfer and communication between the stakeholdersare conducted via internet
• Operating data � updated every year by treatment plantmanagers
• Conservative data (master file data) remain stored � updatedin case of changes
• Specific accounting system to process the financial data� automatic update for continuous benchmarking
25.02.2010 9EWA Workshop – Hennef 2009
Data processing• Data quality assessment WWTP
– rough plausibility check � data within a feasible range– operating data: mass balances for COD, nitrogen, phosphorus
and total solids– financial data: variance analysis comparing data input with
previous year value• Data assessment sewer systems
– PTA Value• Computation of performance indicators
– plausibility check• Generation of a draft final report (indicators, interpretation
and conclusions regarding performance improvement)
25.02.2010 10EWA Workshop – Hennef 2009
Data Processing
25.02.2010 11EWA Workshop – Hennef 2009
Performance indicator system
Technical input- and output data, master file data (e.g. volumes, etc.)and data from process oriented cost calculation (accounting)
Processindicators
Financialindicators
Technicalindicators
Key
indicators�
Technical input- and output data, master file data (e.g. volumes, etc.)and data from process oriented cost calculation (accounting)
Processindicators
Financialindicators
Technicalindicators
Key
indicators�
25.02.2010 12EWA Workshop – Hennef 2009
Exchange of experience
• Individual consulting on site - discussion of– potential data quality problems– the draft final report
• Workshops– as a platform for the exchange of experience– learn more about the best practice– learn from the best
25.02.2010 13EWA Workshop – Hennef 2009
Costs for participating plants
• Development of internet platform � financed by theFederal Ministry of Agriculture, Forestry, Environmentand Water Management
• Participants pay for running costs (depend on the size ofthe plant)
• The yearly costs for participation (WWTP > 100,000 PE)are calculated as follows:– First year: 7,000 € + 0.01 € * design capacity in PE– Continuous: 3,000 € + 0.005 € * design capacity in PE
25.02.2010 14EWA Workshop – Hennef 2009
Participants• Sewer systems
• 1999: 52 operators with 2914 km public sewers (~4% of A.)1367 ancillary structures incl. 473 pumping stations
• 2004: 6 operators with 244 km public sewers86 ancillary structures incl. 35 pumping stations
• WWTPs:
112 different WWTPs= 42% of total capacity of all WWTPs
>20000 pe of A. (excl. Vienna)
3024212230974116112
2008200720062005200420031999WWTPs
>20000 penot taken part
Untilnow
EWA Workshop – Hennef 2009
Results Sewer Systems (1999):operating costs (€/m)
0
0
0
0
0
0
0
0
0
1
2
3
4
5
€/m
best practice
communities group 1 group 2 group 3
Figure 3: Annual O&M costs per length of sewer (excl. ancillary structures)< 15km > 40 km
EWA Workshop – Hennef 2009
• Group B are associations operating only the associated net (mostlytransport or interurban mains)
• Group C are participants operating also sewage systems of theirmember communities.
Group B
Energy39%
Personnel36%
Others3%
Residualdisposal
0,5% Material1%
ContractedService
21%
Group C
Energy21%
Personnel30%
ContractedService
44%
Others4%Material
1%Residualdisposal
0,3%
Results Sewers (1999)cost categories as
percentage of total operating costs
25.02.2010 17EWA Workshop – Hennef 2009
Results WWTPs (Group 6)–Benchmarking bands
Benchmarking bands
0
5
10
15
20
25
30
35
40
10.000 pe 50.000 pe 100.000 pe
[€/pe-COD 110]
Total yearly costsOperating costs
Oper
ating
costs
Total
yearl
y cos
ts
Group 4 Group 5 Group 6
34,4
27,525,5
10,09,5
13,6
25.02.2010 18EWA Workshop – Hennef 2009
Results WWTP (group 6)- costcategories as % of total operating costs
Personnel costs36%
Energy costs9%
Residue treatment costs20%
Material costs14%
External costs13%
Other costs8%
Personnel costs36%
Energy costs9%
Residue treatment costs20%
Material costs14%
External costs13%
Other costs8%
25.02.2010 19EWA Workshop – Hennef 2009
Results (Group 6)– Box Charts ofprocess related specific operating costs
0,00,51,01,52,02,53,03,54,04,55,0
Oper
ating
cost
[Eur
o/pe-C
OD11
0]
75%-Percentile 0,23,54,91,02,01,1Maximum 0,23,85,01,12,71,3Minimum 0,11,92,80,40,80,6Median 0,13,34,30,71,50,825%-Percentile 0,12,53,70,61,20,7Benchmark 0,11,92,80,72,70,9
optionalsupportprocess
obligatoriysupportprocess
sludgetreatmentdisposal
thickeningstabilisation
mechanical-biologicaltreatment
inf. pumpingmech.pre-treatment
25.02.2010 20EWA Workshop – Hennef 2009
Conclusions regardingperformance indicators
• ≥40% of the total operating costs for sludge treatment anddisposal
• 50 to 65% of the operating costs - independent of the actualCOD-load on the plant � significant impact of the utilisationfactor (actual load/design capacity) on the specific operatingcosts
• No correlation between treatment efficiency and operatingcosts (same treatment efficiency requirements!) �� excellenttreatment efficiency often coincides with low specific costs �quality of the staff is very important
25.02.2010 21EWA Workshop – Hennef 2009
Conclusions regardingmethodology
• Continuous benchmarking - a powerful management tool
• Comparison with the benchmarks and exchange ofexperience help the treatment plant managers toincrease cost-efficiency
• Not only a tool to enhance cost-efficiency, BUT offers theopportunity to prove excellent performance of treatmentplant operation (to public, politicians, board membersetc.)
25.02.2010 22EWA Workshop – Hennef 2009
www.abwasserbenchmarking.atBenchmarkingbereich (LOGIN):Benutzername (username): musterwasserPasswort (password): geanio
Top Related