Design, construction and operation of water treatment plants

Design, construction and operation of water treatment plants
Dipl.-Ing. Jürgen Schubert, Düsseldorf
Introduction
Since ever, nature is able to provide high quality drinking water. But contamination,
modifications and overexploitation of the natural water resources make clean water to a more
and more scarce and precious treasure. To preserve this treasure for future generations is one
of the most important tasks. Water science, water management and water technology has to
play a dominant role in designing our social and industrial structure for tomorrow. Most of the
knowledge, the experience, the skills and tools that are needed are available.
Suitable concepts and solutions in water technology are based on several scientific and
engineering branches as hydrology, hydrogeology, hydrobiology, water chemistry,
microbiology, fluid mechanics, civil, mechanical, electrical and chemical engineering. Water
and wastewater technologies interfere with natural processes and should be designed,
operated and controlled in a way, which does not stress the hydrological cycle
Only a small, but specialized sector in the field of water technology is the design, construction
and operation of water treatment plants. There are numerous papers and books where the
various procedures of treatment steps, the different types of reactors, the process dynamics
and reactions are described in detail. The purpose of treatment is the provision of save
drinking water. The following approach to the design, implementation and control of
processes to effect or mediate quality transformations in water emphasizes physicochemical
processes rather than operations.
What is save drinking water? The legal definition of drinking water is a negative definition
worldwide: Threshold limit values are limits for substances and micro-organisms found in
water. Values based on toxicological data have been derived to safeguard health on the basis
of lifelong consumption. Regarding carcinogenesis and mutagenesis as non-threshold
phenomena, other principles are applied in addition: Threshold limit values defined by
precautionary aspects for preventing adverse affects of a general nature. Threshold limit
values for aesthetic parameters are provided to prevent distasteful changes, such as in taste
and odour. Any water, which complies with these threshold limit values, can be denominated
and supplied as drinking water.
But the definition of a high quality drinking water is quite different matter. The hydrologic
cycle is an approved method of nature to provide high quality drinking water; the most
important purification step (besides evaporation) is the subsoil passage of water. A positive
definition of a high quality drinking water is therefore based on a pure groundwater without
any contamination with reference to the hydrological cycle. Such a definition can be found in
DIN 2000, a Technical Standard in Germany.
The preference of groundwater for water supply or, if not available, of a natural (riverbank
filtration) or artificial (infiltration, groundwater recharge) subsoil passage of river water is a
result of the conclusions drawn from the outbreak of epidemic cholera in Hamburg, Germany
(1892) and the approved concept of the DIN 2000.
1
Raw water sources
A territorial view on the data of the hydrological cycle shows both, quantitative and
(incorporated) qualitative aspects:
Average annual data in mm
Total land surface
Precipitation
670
Runoff + groundwater
250
Evaporation + transpiration
420
Inflow
0
Specific availability (m3/pers) ca. 6.000
Germany
768
267
501
192
ca. 2.000
Iran
251
78
173
8
ca. 1.800
Greater Tehran
232
ca. 500
Statistical data on a country-by-country basis can be misleading because water problems tend
to be much more localized than that. In order to look at water stress more precisely, the
regional population density has to be related to the regional water availability. A key point is,
that much of water stress is not water supply but exponentially increasing population! One
way out may be to minimize water consumption and to reuse water for e.g. agricultural or
industrial purposes after appropriate wastewater treatment.
To focus the attention on quality aspects behind the data of the hydrologic cycle, it is
expedient to vary the point of raw water extraction. There are two important purification steps
in nature: one step is evaporation which separates H2O from natural substances, chiefly salts,
and all impurities; this step needs too much energy to be employed in urban water supply. A
second more interesting purification step is infiltration and subsoil passage of the water; this
step comprises the physicochemical and biological processes to treat water and to balance out
the physical (e.g. temperature), chemical (e.g. carbonate balance) and biological (e.g. low
AOC- concentrations) properties.
Under quality aspects the most advantageous point to extract raw water for water supply is
after the infiltration step and subsoil passage from suitable aquifers (groundwater). In the
ranking list follows riverbank filtered water and replenished groundwater; both types of raw
water utilise the benefits of the natural purification step. The quality of surface water depends
on several influences, e.g. the contamination by sewage water from industry, agriculture and
cities in the accompanying catchment basin, from traffic on the surface waters, from
modifications of the surface water systems etc. Usually the source water quality decreases
from lakes over dams to the rivers. Due to the high regional demand the water supply of
larger cities is frequently based on surface water with all the disadvantages of poor raw water
quality.
Quality transformations in water
Groundwater
Pure groundwater, including spring water, is free of suspended and colloidal organic or
inorganic impurities. Thus technologies for particle removal as filtration are only employed
when anoxic conditions in the source water require aeration/oxidation to transform dissolved
2
iron (Fe2+) and manganese (Mn2+) into insoluble compounds. In addition aeration or gas
transfer may be applied to adjust the carbonate balance (stabilization). Disinfection with
chlorine, chlorine dioxide or UV-radiation is normally used for safety reasons.
Typical treatment chains for pure groundwater consist of two or three steps:
Aeration – Filtration
or
Aeration – Filtration – Disinfection.
Pure groundwater without any contamination is scarce. Pollution by agriculture (e.g.
fertilizers, pesticides), by industrial production and wastes (e.g. chlorinated hydrocarbons,
aromatic and poly-aromatic hydrocarbons) or even by products for consumption (e.g.
pharmaceutical compounds, complexing agents as EDTA, aromatic sulfonates, gasoline
additives as MTBE) is the price to be paid for insufficient water pollution control in the past.
It is acknowledged in the meantime that the protection of groundwater resources is extremely
important; even expensive remediation measures can need decades to re-establish the original
state in a polluted aquifer.
Riverbank filtered water
In principle several of the above mentioned micro-pollutants are present in river water and
might be present in riverbank-filtered water. In central Europe along the Rivers Rhine, Elbe,
Ruhr and Danube riverbank filtration is employed since 1870 successfully and without
interruption. During the first 80 years of operation along the River Rhine the well water met
the threshold limit values for drinking water and only disinfection was applied. After world
war two the river water quality began to deteriorate due to the “economic miracle” and the
rapid growing population in this area. The problem was an increasing part of mostly unknown
organic compounds and micro-pollutants, which caused taste and odour in drinking water.
The subsoil passage in riverbank filtration compensates for fluctuating concentrations in river
water by hydro-mechanical processes between the infiltration areas and the wells. Riverbank
filtration is a powerful barrier against peaks and shock loads. Biodegradation is a main
purification step of the subsoil passage but is not able to remove persistent organic
compounds. Therefore a new chain of treatment steps had to be generated: oxidation with
ozone, biological filtration, adsorption with activated carbon and final disinfection, This
treatment chain was at first designed, constructed and operated in Düsseldorf waterworks
(1961). To date this concept is applied world wide to remove trace organics from any type of
water.
Typical treatment chains for riverbank-filtered water consist of five steps:
Aeration – Oxidation (ozone) – Filtration – Adsorption (GAC)– Disinfection.
Aeration is applied to enrich the raw water with oxygen and sometimes furthermore to
stabilize the water (carbonate balance). Oxidation with ozone is applied to oxidise traces of
iron and manganese and to crack organic micro-pollutants; oxidised micro-pollutants tend to
be biodegradable in the next step of biological filtration. Activated carbon, preferential
granular activated carbon (GAC), is still the most successful means for the adsorption of nonpolar organic micro-pollutants. Optimised operation of GAC filters is able to remove even
3
remarkable proportions of polar compounds. The purpose of disinfection after such a
treatment chain is not to inactivate any pathogens but to introduce a relatively high redoxpotential (about 900 to 1000 mV) in the finished water; a high redox-potential will prevent the
survival of pathogens, which may be introduced into the distribution system, and will reduce
biofilm formation.
Recharged groundwater
Groundwater recharge is a second method for the extraction of raw water after the beneficial
subsoil passage of surface water. But, dependent on the origin and the quality of the source
water, this technology may need a sophisticated pre-treatment to fit the raw water for
infiltration and an additional final treatment.
Typical treatment chains for the application of recharged groundwater consist of seven (in
some cases up to 12 steps):
Flocculation/Sedimentation – Oxidation – Filtration – Adsorption (GAC)
- Infiltration –
Disinfection – Stabilization.
Lake water
Lakes or dams in the upper, poor populated regions of rivers are desirable raw water sources
for water supply in moderate climate zones due to the satisfactory water quality. In hot and
dry climate zones the evaporation may reach more than 1000 mm/a and raises not only high
losses of water but causes high salt concentrations. Lake water and dam water is
characterized by the cycle of nutrients (P, N) and the seasonal growth of algae. These
biological and chemical processes cause quality fluctuations (e.g. oxygen concentration,
turbidity) in the upper layer of the lake (epilimnion). But these fluctuations are not
continuously in contact with the deep layer (> 40 m below surface) of the lake (hypolimnion),
which therefore is used for the abstraction of raw water. The raw water contains suspended
solids (e.g. debris from algae) and colloidal particles. The removal of these impurities
determines the combination of treatment steps.
Typical treatment chains for lake water consist of five (up to 7) treatment steps:
Micro strainer – Oxidation (ozone) – Flocculation/Filtration – Adsorption – Disinfection.
River water
In early times rivers were an accepted source of water for most purposes of human activities.
All the water we use is borrowed from nature. If we would return the water in approximately
the same quality, there would be no quality problems with our rivers. But we don’t. Therefore
we have to grapple with the situation. River water is characterized not only by a great variety
of pollutants but also by short-term fluctuations of the physical (e.g. temperature), chemical
(e.g. concentration of specific compounds), and biological (e.g. micro-organisms) properties.
4
This in principle makes it difficult to operate a treatment plant always in a rated range. The
treatment chain has to regard the removal of particles of different size, several kinds of
impurities including organic micro-pollutants. The variability of treatment chains depends on
the characteristics and the agrarian, industrial and social activities in the catchment area. In
some European countries direct intake of river water is not applied for drinking water supply
(only non-potable water) due to the uncertainty of the removal of Giardia and
Cryptosporidium.
Typical treatment chains for direct intake of river water consist of seven steps:
Flocculation/Sedimentation – Oxidation – Flocculation/Filtration –Adsorption – Stabilization
– Disinfection – Backwash water purification.
During the last decade direct intake from rivers and classical surface water treatment came
under pressure because the removal of resistant micro-organisms, particularly cysts and
oocysts from parasites (Giardia, Cryptosporidium), cannot be guaranteed. Most investigations
in this field proved the superiority of natural subsoil passage and slow sand filtration.
The pilot plant method
During preliminary design several alternatives are developed and reviewed to find the best
solution for future demand. It is important to remember the priorities in water supply in this
stage: sustainability in water quality, safety in supply, fair price. Based on knowledge and
experience a preferred suggestion should be checked in detail. But resulting from the
complexity of tailoring a system of unit operations to a specific treatment it is common to use
the pilot plant method in the water quality control field.
Pilot plant investigations are only helpful if the pilot program is based on a thorough
understanding of process concepts, dynamics and interactions. Depending on the source water
the time needed to realise a pilot program may reach 12 month (e.g. to cover seasonal quality
changes in source water). It is advantageous to investigate methods of automatic process
control, suitable measuring instruments and the dynamic properties of the system during the
pilot plant experiments.
From tender to commissioning
The analysis of the pilot plant experiments will confirm the concept or will lead to some
modifications. The conclusion drawn from the pilot plant investigations is the basis for a more
detailed design and to put out to tender. The core of a standard tender is a listing of buildings,
equipments and individual operations. Another idea is to describe the starting situation and
the wanted situation at the end to allow different ways of solution and to include the
knowledge and experience of qualified bidders. A combination of both is recommended.
Proper design, proper material for equipment and professional construction minimize the
future cost for maintenance. Experienced on-site management is very important for a
successful coordination of the works and to enforce the design concept in short time.
Commissioning of a treatment plant is a step-by-step process, which can be carried out in the
style of the pilot experiments. Mechanical and chemical processes in the treatment chain can
5
be started without lag time. But biological processes need a “warm-up” time depending on the
particular process up to several weeks. Therefore the time needed for commissioning and
acceptance depends on the involved processes. The aim of commissioning is not only to
demonstrate proper operation under normal conditions but also to check the limits of the
processes and the plant configuration under extreme conditions, including automatic control
and safety measures.
6
International workshop water and wastewater technology 02.09.2003
Water supply Distribution systems
Design, dimensioning and construction
of urban supply lines
Dipl.-Ing. Jörg Schuchardt
(city works of Munich)
Summary
1.
General
To provide drinking water to the public is one of the most important task of communities.
The Design of Water supply systems has to follow the rules of engineering sciences.
Design and construction needs a lot of technical knowledge and practical experience.
The following lecture will submit an overview about methods , procedures and experiences
concerning water supply systems.
1.1
Design - Technical terms
Design of Pipelines and supply-networks
General
•
trunk mains
-
lines from the water catchment areas
or reservoirs to the supply system
•
main lines
-
pipes of larger diameter without house
connections, e.g. rings in the supply
system
•
distribution network
-
distribution pipes, connected to the
main lines, prepared to connect
consumers with house connection
pipes
•
house connections
-
small pipes connecting the distribution
network to consumers / houses
•
supply pressure
-
minimum pressure in the supply
network, necessary to provide the
consumer with water without any
problems according to the design rules
2
Jörg Schuchardt
1.2
Design - Basic requirements
Basic investigations
design target - consideration of technical and economical aspects, e.g.
•
water supply without interruptions
•
high efficiency of the total water supply facilities
•
extension forecast of the system
•
effective network and distribution control system
•
optimal supply capacity and redundancy in the network
•
high water quality
3
Jörg Schuchardt
2.
Network layout
Network layout
•
easy and economical operation of the system
( e.g. rectilinear and accessible lines)
•
lowest possible construction costs
•
topographic conditions
•
(sub-) soil conditions
•
other public services (e.g. railway, highways, rivers, electricity etc.)
•
other public requirements
(e.g. future development, master planning, traffic, environment protection,
proprietary rights)
4
Jörg Schuchardt
The supply network should be positioned in public areas (streets, footpaths) with easy access for
operation purposes.
Streets have to be crossed in a rectangular manner, and the distribution lines should be positioned on
those roadsides where most house connections are to be expected.
In case of wide streets, highways, it is recommended to provide distribution pipes on both sides of the
road.
In general, dead ends and stagnate water have to be avoid. Before a distribution network will be
planned, the location of other public services has to be identified (electricity, gas, sewer, telephone).
It is recommended to define a regular space for each of the services in the underground of the street.
Once such a rule is officially established, planning will be much easier avoiding difficulties in the
construction period lying ahead.
water gas
sewer
electricity
2.2 distribution zones
water tower
reservoir I
reservoir II
area supplied by water
tower
high zone
high zone
lower zone
typical supply zones
10
Jörg Schuchardt
Elevated reservoirs (storage tanks) are used to equalize the different levels of water demand within
the city and during the day.
If possible, a reservoir should be placed upon an elevated natural topographic point
The operating condition of a reservoir depends on its location as far as the supply network is
concerned.
If you have large supply areas with big topographic differences, you will need more reservoirs to get a
technically efficient standard (see fig. above) .
minimum pressures , measured at house connections
Type of consumer (housing)
Recommended pressure
Recommended pressure
(new areas)
(existing areas)
one-storey buildings
2,0 bar
2,0 bar
two-storey buildings
2,5 bar
2,35 bar
three-storey buildings
3,0 bar
2,70 bar
four-storey buildings
3,5 bar
3,05 bar
five-story buildings
4,0 bar
3,4 bar
A minimum pressure of 1 bar can be ensured at the highest elevated point of the building by applying
this rule.
15
Jörg Schuchardt
3. pipelaying
Main lines and distribution lines are regularly laid in streets covered by an equal distance to the
surface. The air will be evacuated on highpoints of the line through house connections (by operating
the system).
It needs to be considered in any case that the pipes have to be laid in a frost resistant depth
underground.
House connections have to be laid in a rising (ascending) manner from the distribution main to the
building.
If railways, main roads, rivers or the like need to be crossed special arrangements have to be
provided.
minimum cover of distribution pipes
(new method)
Munic water supply
cover of existing old distr. pipes
13
Jörg Schuchardt
51
Jörg Schuchardt
4. contracts – operation and maintenance
contracts
• careful and complete design and planning
• estimation of costs
• tender procedure
• supervision of work
• guaranty of quality
operation of systems
• management
• operation
• cost control
• regular maintenance
69
Jörg Schuchardt
5. remark
•
water is food it is no part of commerce
•
water should be accessible to everybody
•
water supply should ever be a task of the
community
•
the responsibility about water suply has to be the
responsibility of the
community
71
Jörg Schuchardt
Treatment of reservoir water
Abstract for the lecture DW 4 during the Teheran International Workshop on “Water
&Wastewater Technology” from August 30th to September 5th , 2003
Dr.- Ing. Burkhard Wricke
DVGW Technologiezentrum Wasser ,Aussenstelle Dresden,Germany
E-mail: wricke @tzw-dresden.de
Introduction
Reservoir water is an essential source for drinking water supply in Germany. App. 10
% of the drinking water demand is based on reservoir water. In some parts of the
country the portion is greater than 50 %.
The usage of reservoir water for drinking water supply requires an high degree of
protection for the catchment area as well as an effective and safe water treatment.
The requirements on the treatment process are given by the raw water quality and by
the requirements on the drinking water quality.
Raw water quality
The raw water quality is essentially influenced by the hydro geological situation and
the agricultural and forest
activities in the catchment area. Further, if there are
settlements in the catchment area, it may be influenced by waste water. The hydro
geological situation determines mainly the hardness of the water and the
concentration of natural organic matter (NOM). In most cases, the waters only have a
low alkalinity. If there are moors in the catchment area, higher concentration of NOM
can be found.
Very important for the reservoir water quality is the degree of eutrophication. Drinking
water reservoirs should be oligothroph, at least mesothroph. The difficulty of the
treatment process increases with higher degrees of eutrophication. A massive algae
growth in a reservoir is usually connected to higher concentrations of metabolites like
taste and odour substances and toxins. Besides, massive algae bloom may result in
anaerobic conditions in the area between the sediment and the water, which leads to
a release of iron and manganese as well as to higher ammonia concentrations in the
water. The eutrophication is essentially influenced by the input of nutrients by the
agriculture and/or by waste water. If there is a high degree of agricultural exploitation
of the catchment area there may be also an input of nitrate as well as of pesticides. In
most cases washing effects during heavy rains are the reason.
Also important for the drinking water treatment is the concentration of pathogens in
the raw water. In every case it must be aware, that there are bacteria, viruses and
parasites in the water, since it is a surface water, which is not as well protected as a
ground water. However the concentrations may vary considerably, depending on the
protection of the catchment area.
Objectives of the treatment process
The main objective of the treatment process is to guarantee the requirements on the
drinking water quality, which is described in national and international regulations.
However there are further requirements which are determined by the circumstances,
that there are always organic particles in a surface water and that the water is usually
distributed through long distance distribution systems.
To guarantee the final disinfection as well as the removal of parasites, the water
should have a very low turbidity (< 0.1 –0.2 FNU) after the treatment process.
Pathogens, which are included in or adsorbed on organic particles are protected
against the disinfectants and parasites may not be inactivated by using usual
disinfectants.
Further the chlorophyll concentration in the treated water should be below 0.1 µg/l, to
limit the concentration of algae. Higher algae concentration cause an higher
formation of disinfection byproducts as well as an higher risk for bacterial regrowth in
the distribution system. Further dying algae may be the source of taste and odor
problems of the drinking water.
To avoid hydraulic problems in the distribution system as result of manganese
deposition, the manganese concentration in the treated water should be < 0.02 mg/l.
Treatment technologies
The main technologies for the treatment of reservoir water are flocculation and
filtration. The flocculation is necessary to remove smaller particles during filtration
and to reduce the NOM concentration. Further treatment steps are:
-
micro screening for algae removal
-
oxidation by using ozone for the immobilization of algae as well as for manganese
removal and the removal of taste and odor substances
-
oxidation by using potassium permanganate for the algae immobilization and
manganese oxidation
-
the usage of activated carbon as pulverized activated carbon(PAC) or granulated
activated carbon (GAC) for the removal of taste and odor substances and toxins.
Disinfection as the last step of the treatment process may be carried out by using
chlorine, chlorine dioxide and/ or UV irradiation.
The decision on the necessary steps for the treatment of a reservoir water in an
individual case depends at last on the raw water quality and on the efficiency of the
different treatment technologies.
Technologies for particle and NOM removal
Contact filtration, floc filtration and with increasing importance membrane filtration are
the technologies, which are used in Germany for particle removal in the process of
reservoir water treatment.
Using the contact filtration, adding of coagulants during rapid mixing and
destabilisation of suspended solids takes place directly prior to filtration. The
treatment line contains no separate flocculation unit. Usually only single layer filter
are being used. Since only microflocs are being formed, double layer filters do not
have advantages compared to single layer filters. The main disadvantages are the
decreasing running periods at higher algae or turbidity loads and the limitation of the
possibility to use higher PAC dosages while taste and odour problems occur in the
raw water. Contact filtration may be carried out in gravity and pressure filters. In the
case of floc filtration, the flocculation is carried out in separate flocculation basins
prior to filtration. The mixing energy can easily be adjusted by using mechanical
mixers to form flocs which would be suitable for direct filtration. In order to be able to
guarantee longer running periods it is common to use double layer filters in these
systems. Gravity floc filters are well tried and tested. However, it is also possible to
perform floc filtration in pressure filters.
Prerequisite to rich average residual turbidities below 0.1 FNU by using direct or floc
filtration is an optimization of the flocculation process. This can be realized by means
of the following parameters:
-
kind and dosage of the coagulant
-
kind and dosage of the coagulation aid
-
flocculation pH-value
-
point of dosages and mixing times
-
energy input
It is important , that the formed aggregates (flocs) are not being destroyed during the
transport between the flocculation basin and the filter.
Further more the following measures ought to be realized:
-
all control and regulation processes should be carried out slowly and damped
-
no sudden changes of the filtration rate
-
slow increase of the filtration rate
-
equal input for all filters
-
staggered filter running ( that means backwash of the filters after the same
operating time )
-
optimization of the filter backwash
-
backwash of the filter directly after the stop of the filtration process
-
backwash before the start of the filtration process after a longer non operating
period
-
pre run release
-
no recycling of backwash water.
Membrane filtration is a fast developing technology which guarantees the particle
removal only by filtration and without preflocculation, when using UF membranes with
a pore diameter of 0.01 to 0.1 µm. In the beginning the technology was used with
prefiltration to protect the membranes. However new developments show, that it is
possible to work without pretreatment. Nevertheless it is also possible to realize a
preflocculation and/or the dosage of PAC in front of the membrane units. This allows
to combine the particle removal with the removal of organic substances in UF
membrane units, which takes place during floc- and contact filtration, too.
.
Technologies for algae and algal metabolites removal
Using an optimized filtration with pre-coagulation (flocculation) enables to achieve
high removal rates for a lot of algae. However, to remove small, motile algae by
flocculation and filtration, a pre-immobilization by using an oxidant is necessary.
Preozonation is known to yield excellent results for algae removal, but algal cells may
be damaged by ozonation, too. In this case, intracellular metabolites like toxins or
taste and odor substances are released in the water. Using higher ozone doses
allows to oxidize a lot of these substances as well. As a result of the oxidation of
NOM, which are being found in the water too, other by-products may be formed.
PAC- or GAC adsorption are common ways to remove metabolites as well as
oxidation by-products. Another possibility for pre-immobilization is the use of
potassium permanganate as oxidizing agent. In this case the damage of algal cells
as well as the formation of oxidation byproducts are negligible. On the other hand the
possibility to oxidize metabolites, which may be in the water as result of metabolic
activities of algae too, is limited.
Micro screening is only effective if there are higher concentration of algae, which are
filterable using a mesh of 20 to 50 µm. In this case it is possible to use it as a
pretreatment step for the following filtration.
A special problem is the removal of cyanobacteria because of their metabolites, the
cyanotoxins. The removal of intracellular cyanotoxins could be guaranteed by the
removal of the algal cells, however it is necessary to avoid a release of toxins in
consequence to a destruction of the cells during the treatment process. The removal
of extracellular toxins is possible by using PAC or ozonation in combination with GAC
filtration.
Examples for reservoir water treatment
Different treatment technologies for different raw water qualities are presented. It
should be demonstrated how specific problems could be solved by using the
described treatment technologies.
Prof. Dr.-Ing. Peter Cornel
Institut WAR
Wastewater Disposal in Germany
- An Overview Peter Cornel
1. Introduction
Germany is located in the middle of Europe, at 51° N and 9° E. Some general data are
listed in table 1. As can be seen, the population density is much higher compared to Iran.
Table 1:
General data [World Factbook 2002]
Iran
Germany
area [km²]
1,648,000
357,021
population (July 02)
67 Million
83 Million
0-14 years
31.6 %
15.4 %
population growth rate [%/a]
0.77
0.26
population density [Person / km²]
41
232
GDP per capita
7,000 $
26,600 $
(Gross Domestic Product)
The climate is temperate and marine. Cool and cloudy, with wet and freezing winters and
wet summers in general (not in 2003). The annual rainfall equals 600 to 1,000 mm (Iran
250 mm in average). Thus only small amounts (4 %) of the arable land are irrigated (in hot
summers) with almost negligible water amounts.
2.
Wastewater collection
92.2 % of all inhabitants are connected to sewer systems, which feature a total length of
399,201 km, thereof 213,491 km combined sewers, 109,372 km wastewater sewers and
76,339 km stormwater sewers. About 1/3 of the sewer system is older than 50 years. Figure 1 shows the distribution in age.
30.8.03 Tehran
Cornel opening page 1
Prof. Dr.-Ing. Peter Cornel
Institut WAR
75 - 100 years
16%
> 100 years
4%
0 - 25 years
33%
50 - 75 years
11%
25 - 50 years
36%
source: Kanalumfrage 1997, [www.atv.de 1999]
Figure 1
3.
Age of sewer system in Germany
Wastewater treatment
3.1. Municipal wastewater treatment
About 88.6 % of the municipal wastewater is treated, 84.4 % in biological wastewater
treatment plants (WWTP). The total amount of WWTP in Germany equals 10,279 varying
in size between some 100 PE to more than 2.5 million PE.
The total amount treated municipal wastewater was 9,861 million m³ in 1995, thereof
3,711 million m³ domestic wastewater, 1,154 million m³ industrial wastewater and
4,996 million m³ stormwater + sewer infiltration water [Stat. Jahrbuch, 2001].
Most of the wastewater treatment includes nitrogen and phosphorus removal to avoid
eutrophication in the receiving water bodies, especially because the North Sea as well as
Baltic Sea and Black Sea have only reduced water exchange with the oceans. Only small
treatment plants are relieved of nutrient removal, as is shown in table 2, where the requirements for municipal wastewater treatment is depict and compared to the average
effluent values in 2001.
30.8.03 Tehran
Cornel opening page 2
Prof. Dr.-Ing. Peter Cornel
Institut WAR
Table 2
German standards for municipal WWTP and average results
(2 h composite samples)
[Abwasserverordnung, Anhang 1
(Fassung vom 15.10.02); 14. ATV-DVWK-Leistungsvergleich, www.atv.de]
Size
COD
BOD5
NH4-N
TNinorganic
TP
PE
mg/l
mg/l
mg/l
mg/l
mg/l
< 1,000
150
40
-
-
-
1,000 to 5,000
110
25
-
-
-
5,000 to 10,000
90
20
10
-
-
10,000 to 100,000
90
20
10
18
2
> 100,000
75
15
10
13
1
Average results in 2001
33
5
3
10
0.8
The municipal wastewater treatment generates 2.96 Mg sewage sludge per year (dry
solids) which is equal to about 25 Mio m³/a. Figure 2 shows the disposal pattern.
incineration
18%
recultivation
13%
others
3%
landfill
10%
agriculture
45%
compost
11%
Figure 2
Disposal of municipal sewage sludge in Germany (1996) [Kanalumfrage 1997]
3.2.
30.8.03 Tehran
Cornel opening page 3
Prof. Dr.-Ing. Peter Cornel
Institut WAR
Industrial wastewater treatment
Out of a total of almost 35,000 million m³/a industrial „wastewater“ almost 90 % is cooling
water. Without cooling water and wastewater of the mining industry, the amount of industrial wastewater accumulates to 1,765 million m³/a, wherefrom 1,073 million m³/a are
treated on site in 3,344 industrial wastewater treatment plants. 718 million m³/a are treated
biologically in 694 biological WWTP`s.
Integrated water management, with less water consumptive processes and water recycling
within the processes led to decreasing specific amounts (m³ / kg product) as shown in
figure 3 exemplarily for the paper industry.
l/kg paper
50
46
40
36
34
30
24
20
20
16.3 14.5
14.1
16.8
13.6
12.3
14.3
10
12
11.7
0
1974 1976 1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000
year
Figure 3
specific water demand in the paper industry [Schmid, PTS-München]
The sewage sludge of industrial waste water treatment is mainly incinerated (498,000 t/a).
The agricultural use is low (63,000 t/a) predominately of food and beverage industries.
Disposal in landfills amounts to 293,000 t/a, but will be banned by law as of 2005.
30.8.03 Tehran
Cornel opening page 4
Prof. Dr.-Ing. Peter Cornel
Institut WAR
4. Water quality management
The aim of wastewater treatment is, to protect surface water bodies and the groundwater
reservoirs to keep a good water quality for all different users today and for future generations. River catchment management is one tool to optimize surface water quality. The aim
is to get all water users of one catchment area focused on the same target, independent of
district or country boarders. Biological, chemical and structural quality of all the rivers are
characterized in 7 (8) categories in each case, with categories started with “unencumbered” (“unstressed”) and end with “ecologically destroyed”, a category which had to be
introduced in 1990 for some river areas in East Germany. Related colors from blue
(= “unstressed”) to dark red (= “ecologically destroyed”) makes it easy, to see at a glance
the situation of water quality (the black and white figure 4 shows the idea of the method).
Summary
More than 92 % of the population in Germany is connected to a sewer system and the
wastewater of about 85 % of the population is treated biologically in nearly 10,000 municipal wastewater treatment plants, nearly all of it with nutrient-removal.
Almost 1,000,000,000 m³/a industrial wastewater is treated on site in more than 3,300
industrial wastewater treatment plants
This measures improved the surface water quality significantly in the last 30 years.
6. Literature
Statistisches Jahrbuch, 2001
Statistisches Jahrbuch für die Bundesrepublik Deutschland 2001, Hrsg.: Statistisches
Bundesamt Wiesbaden, Metzler-Poeschel-Verlag, Stuttgart
Kanalumfrage 1997,
www.atv.de
Verordnung über die Anforderungen an das Einleiten von Abwasser in Gewässer;
(Abwasserverordnung), in der Fassung vom 15.10.02
World Factbook 2002 (internet)
14. ATV-DVWK-Leistungsvergleich, www.atv.de
Schmid, F. 2001
Papiertechnische Stiftung München, personal communication
Gewässergütekarten der Länderarbeitsgemeinschaft Wasser (LAWA),
UMPLIS 1996, Umweltbundesamt Berlin
30.8.03 Tehran
Cornel opening page 5
Prof. Dr.-Ing. Peter Cornel
Institut WAR
Prof. Dr.-Ing. Peter Cornel
Institut WAR
TU Darmstadt
Petersenstraße 13,
D-64287 Darmstadt
Phone
+49 6151 16-21 48
Fax
+49 6151 16-37 58
E-Mail
p.cornel@iwar.tu-darmstadt.de
www.iwar.bauing.tu-darmstadt.de
30.8.03 Tehran
Cornel opening page 6
Measures to minimize water consumption and water losses case study Berlin
Bernd Heinzmann; Berliner Wasserbetriebe
1.
Methods for the reduction of the water consumption
1.1
Sociological aspects
•
•
•
1.2
readiness and attitude of the inhabitants and the carriers of the public management concerning the installation of water meters and water saving in general
optimal approach of the public relation management (selection of the appropriate methods
according to the boundary conditions, such as instruction, publicity etc.)
explaining the costumers the need to introduce tariffs of payment or for increasing these
fees prior to their establishing by the public management
Public campaign
•
•
1.3
stickers
leaflets
Public relation work as a form of active public instruction
•
•
•
•
1.4
customer information about water saving (explaining the reasons – “why”’)
information about the technical possibilities for water saving (equipment, apparatus)
instruction in public institutions (kindergartens and schools)
instructions with the goal to change costumers habits like:
taking showers instead of full-length bathes
running only completely full (not half empty) dishwashers and washing machines
tightening of dropping water taps
washing of the motorcars only in automatic facilities
Economical aspects
•
•
•
2.
tariff system
system for charging the costumers in dependence of the individual water consumption
financial support of water saving measures by the authorities (city, country, water supply
companies)
State of the art for the reduction of the water consumption
The technical rules are described in the regulations of the DVGW (German Association for the Gas
and Water Field) and can be re-read in the corresponding instruction sheets.
2.1
Technical aspects
•
•
•
•
•
2.2
•
•
•
development of water saving devices and apparatus by the industry
availability for the customer
use of water saving tools on the devices and apparatus, like
valves on water taps in hand-basins, showers and in the kitchen
installation of flushing pans with low water filling water quantities
„stop-and-go-push-buttons“ for the water flushing pans in the toilets
flow velocity stabilizers
contact-free armatures
vacuum toilets
installation of domestic water meters
development of suitable strategies for the installation of water meters (e.g. at first in selected areas/districts with great water losses)
Measures in the pipe network
strategy for the detection of leakage losses – analysis of the water losses, preventive
search for leakages
establishing of data banks of the pipe network, especially damage statistics
strategy for the upkeep of the pipe network (maintenance, overhauling, inspection)
1
3.
Public relation work of the Berlin Water Works in the ’80s for water
protection
3.1
Goals
Since 1980 activities were ongoing for the instruction of the Berlin population regarding:
• Protection of the waters and resources and reduction of the water contamination of the
surface water and groundwater to ensure the drinking water supply with respect to both,
quality and quantity.
• to effect a sensible and conscious dealing of the population within the environment and the
water
3.2
Methods
3.2.1 Publicity campaign
• distribution of stickers to the costumers with proclamations like:
„think about water“
„do not transform the toilette into a waste disposal site“
• posters in the public transport system (MRT, bus, tram, city trains)
• distribution of leaflets like „Car washing in Berlin“
3.2.2 Public relation work as a form of active instruction
• development of a culture for a friendly keeping with the user / costumer
• guided tours in the water works = „Accessible Water Works“
• instruction in the kindergartens and schools
• further enhancing education of the teachers (multiplication effect)
4.
Reduction of the water consumption in Berlin
4.1
The situation of the water supply in Berlin after reunification (1990)
The prognosis given after the reunification predicted an increase of the population from 3.4 Mio. to
5-6 Mio. inhabitants causing a corresponding raise of the drinking water demand. Thus, the necessity occurred:
• to intensify the already since the 80’s ongoing activities for water saving in the western part
of Berlin and
• to extend these activities especially to the eastern part of the city.
• to develop an integrated concept for environmental protection and for sensible water saving
= campaign for water saving and protection of the water bodies
4.2
Measures for the reduction of the water consumption in Berlin
4.2.1 Technical measures
• temporary subsidies of the Country of Berlin for the installation of water saving devices
• promotion of house building: the installation of domestic water meters for fresh water and of
water saving equipment was added into the catalogue for subsidise able measures
4.2.2 Publicity
• distribution of an information leaflet „Berlin saves water“ to 1 Mio. households in the beginning of 1988
• campaigns in the public and private transport systems, like placing the slogan „Berlin saves
water“
4.2.3 Public relation work
• information booth of the Berlin Water Works at exhibitions, fares and technical congresses
• since October 1989 co-operation with the energy provider BEWAG, having their own advisory bureaus in the city area of Berlin, for:
individual advising of the users and customers
exhibiting facts on posters and information boards, like water consumption in
households
presentation and testing of devices for water saving (water saving shower nozzles, flushing pans in the toilets)
announcement of the establishing of the advisory bureaus in a press conference
as a measure of publicity value
2
•
•
4.3
regularly insertion of advertisements for the advisory bureaus in the local press
instruction in the kindergartens and schools
The Berlin population is invited on „Open Days“ to access and go sight-seeing to selected
facilities of the Berlin Water Works, like water works.
Practical experiences
•
•
•
the advisory bureaus should be easily accessible by transport, either public or individual
attractive arrangement of the exhibition area in the advice bureaus necessary
greater advisory demand for areas with single houses compared to areas with rented
homes
• advisory need for water saving measures at crafts, industry and public institutions, e.g. kindergartens
• The advises have to be moved to the customer and user – needs mobility!
• complete advises, i.e. practical and financial transformation (need for co-operation with the
sanitary craft and trade)
→ These practical experiences led to a concept of mobile information busses of the Berlin Water
Works.
4.4
Mobile information busses of the Berlin Water Works
In the ‘90ies mobile information busses of the Berlin Water Works moved around in the supply areas in order to bring the “public relation work” to the customer thus enabling spontaneous contacts.
Special care was taken in the outfit on clearly arranged posters and easily accessible leaflet distribution desks. Thus the effect of water saving equipment like flow limiters in intake armatures or the
flow-through of different shower nozzles can vividly be demonstrated. On the entrance side two
awnings are installed on the roof, serving in fair weather as sun protection and enlargement of the
exhibition area and in rainfalls as a weather protection, respectively.
5.
Measures for the minimization of leakage losses
5.1
Fundamentals
Leakage noises are caused by passing out of water being under pressure and are spreading out
as body and sound waves. The intensity as well as the frequency of these leakage sounds depends on several influencing factors, which are used for the position finding.
5.2
Locating techniques – state of the art in Germany
5.2.1 Correlation measuring techniques
Correlation is the computer aided leakage location in pressure pipe systems laid into the ground.
The noise caused by a leakage spreads out within the pipe system in both directions with a distinct
velocity. It is transformed by converters into electric signals, magnified (radio waves) and transmitted by wireless transmitters to the main correlation unit. There, the exact position of the leakage
may be calculated by means of the difference of the running time of the leakage noises.
5.2.2 Sound-location techniques
• sensitive microphones
• sound locators (bell-shaped, box or pipe)
• bell-shaped soil sound locator with filter depression of disturbing noises
5.2.3 Special techniques (non acoustic position finding techniques)
• measuring the differential pressure (e.g. with a searching go-devil)
• colour test (dyeing of the water)
• use of test gas
• infrared thermograph: measuring in the hot water and heating pipes (to be fairly considered
for countries with high temperatures and drinking water development from surface waters)
• Mini-pipe-camera – not for pipes with incrustations!
• measuring of the moisture
• use of endoscopes for hardly accessible hollow spaces
5.2.4 Combined detection of the pipe and leakage positions
First of all, if yet unknown, a sound frequency analysis should be performed to find the exact positions of the pipes (area exploitation)!
3
5.3
Strategy for the evaluation of the leakage losses in the pipe network in Berlin
5.3.1 Preventive search for leakage losses
Transformation from a prophylactic spontaneous search throughout the whole city area to a strategy, based on a data basis about the pipe network in order to enable a decisive search on leakage
losses, e.g. in areas with high damage rates. The decisive search using a sound level meter is a
preventive strategy, aimed to effect security before the court for the Berlin Water Works. These
sound level meters are installed into hydrants, section gate valves or also into house connections
in order to be able to monitor distinctly selected sections of the pipe system.
5.3.2 Techniques applied
The sound level meters (loggers), which are equipped with antennas and wireless transmission,
are activated in time periods with low consumption (from about 1 a.m. to 4 a.m.), in order to perform sound recordings with a low part of external sounds over a distinct time period. The computeraided evaluation is done in the vehicle or in the pipe operating office.
The pipes identified are then examined by the emergency service or experts from the pipe network
department by means of the correlation measurement technique and thus the exact location of the
leakage identified. For the verification of the results an additional check is made using earth microphones.
5.3.3 Data basis
The data basis comprises among other things:
• damage statistics concerning the nature (classification to pipe and material groups, respectively) as well as the reason of the damage , like natural events, road construction, increasing traffic, increasing truck use due to construction measures, scattering and foreign flows
• age of the pipes
• geometrical, geographical and hydraulic data, like diameter, depth position and flowthrough capacity
• kind of the material
• data of the conditions
• amount of the damage
• hints and statements to leakage losses (especially data from empirical knowledge)
• examination of pipe samples and classification according to:
damages caused by the manufacturing
damages caused by pipe-laying and mounting
technical and biological ageing
natural earth movements
damages due to the management and to the pipe system.
5.3.4 Motives for further additional inspections
• hints from the population
• customers complaints regarding delivery pressure and water quality
• high water losses
• extraordinary pressure drop
• earth movements in pipe areas
• changes in the area surface like gaps and sinking especially regarding traffic roads
5.4.
Results of the measures for reducing the water consumption
Reduction of the leakage losses in the pipe network in the eastern part of the city from about 25 %
to a consistent rate of about von ca. 4-5 % in the whole city area!
6.
Development of the drinking water consumption in Berlin
6.1
Special situation in the eastern part of the city
In the former GDR the attitude of the costumers was determined by a subsidizing policy leading to
a waste of water and energy. Thus, the situation after the drop of the wall in the eastern part of the
city was characterised by:
• extremely high water consumption
• high water losses caused by the obsolete pipe network due to insufficient maintenance
4
•
expensive condition techniques, again caused by insufficient maintenance of the wells and
missing protection of the resources
Briefly, the situation was catastrophic. From that, a special need for advice and education of the
costumers in the eastern part of the city resulted. Furthermore, the pipe breakage rate was with
about 0.2 – 0.25 damages per kilometre and year much higher with an increasing tendency than in
the western part of the city (about 0.05 damages per kilometre and year). The main reasons for
this considerable difference were:
• selection of the materials,
• quality of the pipe-laying and
• maintenance.
6.2
Measures and results to reduce the drinking water consumption
Contrary to many predictions the population and thus the drinking water consumption did not increase! Additionally to the slightly decreasing tendency of the water consumption in the western
part of the city, caused by the measures already described (publicity, public relation work and installation of water saving equipments and apparatus) of the Berlin Water Works for a conscientious
handling with “Foodstuff number one”, came the dramatic reduction of the drinking water consumption in the eastern part of the city especially until 1993:
• breakdowns of the industrial production led to a closing of many industrial firms,
• due to the establishing of higher tariffs, i.e. supply to the costumer in the eastern part of the city
defrayal of costs the attitude of the costumers changed dramatically causing a much more economical use of drinking water.
• publicity campaigns and public relation work for water saving
• availability and installation of water saving apparatus and equipment in the households
• strong efforts of the Berlin Water Works to diminish the leakage losses due to pipe breakages
(from about 25 % to now 4-5 % in the eastern pert, i.e. the level of West Berlin).
These events in East Berlin were followed from 1993 onwards by a dramatic decrease of the water
consumption in the western part of the city caused by the shutting down of the Berlin sponsoring of
the Federal Government:
• shifting of the industry production
• slightly increased fees.
In the course of about 10 years the Berlin Water Works succeeded in a considerable reduction of
the water losses due to breakages in the pipe system, but it was also possible to cut in halve the
specific water consumption in the households from about ca. 250 litres per capita and day to about
125 litres per capita and day due to the different measures described above. Thus, the drinking
water consumption was reduced for about 40 %. Similar successes were achieved by:
• Hamburg Water Works with actions to install techniques for water saving in the mid 80’s
leading to a reduction between 10 and 30 % and
• the City Works of Frankfurt am Main, where in the early 90’s a „concept for an economical
water consumption“ led within 5 years to a decrease of the water consumption of about 17
%.
Thus it can be stated, that the Berlin Water Works do not only have a profound knowledge of such
extraordinary situations concerning the water consumption, but have also the competence to draw
the correct strategic conclusions and to transform them into praxis.
5
Abstract
Design and operation of long-distance pipe lines
Prof. Dr.-Ing. H. Mehlhorn, Zweckverband Bodensee-Wasserversorgung, Stuttgart
Although sufficient precipipations are available as a general rule, there are even in
Germany areas with considerable water shortages. The reasons for such shortages
are low water resources available due to geological and meteorological conditions,
built-up areas with several millions of inhabitants on limited areas ( Ruhrgebiet,
Berlin, Munich,Hamburg, Great Stuttgart etc.) .Other reasons such as the lack of
good water quality due to unfavourable geogenic water properties or as a
consequence of water pollution may lead to shortages of drinking water resources
Based on these superimposed influential factors long-distance water supply systems
have been created all over Germany. In particular in the Federal State BadenWürttemberg, due to the fact that all factors for water shortages quoted above are to
be found here large long-distance water supply systems have been built such as the
Bodensee-Wasserversorgung as the biggest long-distance water supply company in
Germany. The BWV produces drinking water from the Lake of Constance situated in
the South of the Federal State and distributes it over a distance of more than 300 km
up to the very North of the Federal State Baden-Württemberg. Over 4 million
inhabitants are supplied directly or indirectily with drinking water from the BWV.
Long-distance water supply systems are in many aspects different from local water
disitributors. Their task is normally not just the compensation of existing water
shortage. But due the fact that local water supply systems are connected to a longdistance pipe line system the water quality is put on „ two supporting legs „ and thus
is much safer. Moreover bad water quality ( such as hardness, pollutants etc) may be
compensated by the long-distance water supply company or it may at least be
minimized. As a general rule the long-distance supply company delivers its drinking
water only to the local water company which is then distributing the drinking water to
the end user. Thus the water demand to be covered by the long distance supplier
very much depends on the conditions encountered by the local water distributor
which makes it rather difficult to plan in advance. In order to reach clearcut planning
parameters the local water distributor has to register with the long-distance supplier
a right for a maximum quantity of water to be delivered which shall not be exceeded
and which is the basis for the calculations of fees the local water distributor has to
pay to the long-distance supplying company.
During the various phases of design, construction, operation and organisation of a
long-distance water supply system the following decisions shall be taken :
- how the extension of the system in case of increased demand may ben taken into
account right from the beginning
- how the long-distance pipelines shall be routed
- how the pipelines may be protected against attacks of third parties
- for which pressures the pipelines shall be designed and which pipe diameters shall
be selected
Seite 2
- whether the pipeline shall be constructed as longitudinally coupled or as open
spigot and socket joint pipeline
- which pipe material shall be selected
- how obstacles ( railways, rivers, roads ) shall be crossed
- which measures may be taken to optimize energy input
- what is to be done to protect the pipeline against pressure fluctuations ( water
hammers)
- how the tanks shall be arranged in the system
- how the water losses occurring in case of pipe breakage may be mastered and
- how the quality of the drinking water may be safeguarded during the long journey it
undertakes from the water catchment point to the end user.
All these questions do certainly also arise in some way or another in local water
distribution systems, however the answers will be different in case of long-distance
supply systems.
As future extensions are very costly in case of rising water demands which can no
longer be met with the existing supply capacities possible future rises in demand
need to be taken care of right from the beginning. For instance the pressure stages
of the pipelines may be designed in such a way that capacity increases are possible
through the installation of pressure rising pumping stations.
Also the routing of the pipeline needs to meet specific requirements. For instance it is
necessary to by-pass built-up areas at adequate distances and to reduce the
number of service points ( drainages, ventilations) to a minimum by ensuring a
continuous routing as to the elevations of the landscape.
As energy input plays an important role for long-distance supply this aspect shall also
be taken care of when fixing the pipe diameter. On the other hand the pipe diameter
chosen should not be too big because of construction cost and flowing times of the
drinking water. Shaft works may lead to a considerable increase in hydraulic
performance of the line depending on local topography..
Pipe materials used in Germany are limited mainly to steel and ductile cast iron
because of the large diameters and the generally high pressure stages. In the past
reinforced and prestressed concrete pipes were also used, but with lower steel
prices, these are no longer used in Germany for new construction.
As great amounts of energy are used for long -distance water transport the
optimization of energy input is of great importance not only by selecting the pipe
diameter. This is in particular true whenever you have to overcome important reief
variations. For instance once a mountain has be overcome part of the energy
consumption may be recoverd by turbines.
In long - distance pipelines big amounts of water are stored as a general rule.
Therefore it is essential to make sure that dynamic pressure fluctuations ( water
hammers) are minimized as far as possible. Otherwise the pipelines would have to
be designed for much too high pressures which is normally very uneconomical .
Arrangement of water reservoirs at not too long distances from each other, sufficient
closing times for valves , flywheels for large pumps or pressure vessels ( compressed
Seite 3
air chambers) are possibilities to achieve that dynamic pressure fluctuations are
reduced to a reasonable measure.
Water reservoirs in long-distance supply systems do not only have the task to master
pressure variations in the system but shall also compensate differences of water
resources available and water demand, to separate supply areas from each other, to
ensure suitable hydraulic conditions ( crown reservoirs) in very elevated points (
overcoming of mountains) and to draw the borderline between the long-distance
supply system and the local distribution system ( transfer tanks). For the
dimensioning of water reservoirs a compromise shall be found between optimum
coverage of water demand fluctuations and minimization of the dwell time of the
water in the pipeline system..
Due to large pipe diameters important water quantities may be released from longdistance pipelines in case of pipe breakage and thus may lead to considerable
damages. Therefore the protection devices against pipe breakage shall be arranged
everywhere in the long-distance supply system where otherwise increased breakage
hazards would exist.
Special attention shall be paid in long-distance supply systems to any alteration of
the drinking water quality during the very long flowing times from water generation to
the end user. Such alterations may be of physical or chemical nature , but also refer
to microbiology. In order to avoid bacterial germinations chemical disinfection will
always be required in long-distance water supply systems.
All these requirements interact in long-distance water supply systems and should
never be considered in isolation. Therefore the design and construction, the
operation and organisation of a long - distance water supply system require
comprehensive and expertise knowledge based on practical experiences. The long
years of experiences we have in Germany with such long-distance supply systems
are the best prerequisite to find solutions to water supply problems also in other
countries worldwide of course in a form adapted to the relevant needs.
2003-08-15
The Regional Centre on Urban Water Management
(RCUWM-Tehran)
1 - Introduction
The process of urbanization and lack of resources is creating acute problems in many
of the countries of the region. At present, there is no regional scientific organization on
urban water management issues that takes into account the climatic and other specificities
of the region. The potential impact of the Centre on international scientific and technical
cooperation in the region is thus significant. Geographically, the Centre is ready to
welcome Central Asian, Middle East and other nearby countries sharing concerns on
urban water management and willing to contribute and benefit from the Centre. Emphasis
would be placed on arid and semi-arid climates.
2 - Inauguration of RCUWM-Tehran
In February 2002, the Regional Centre on Urban Water Management - Tehran was
inaugurated formally at the ceremony by the attendance of about 200 people from
different international organisations, ambassadors of the states in the region, members of
parliament, senior managers and directors from national organisations and ministries,
university professors, senior managers from private sector and NGOs. At this magnificent
ceremony, the agreement between the Government of Islamic Republic of Iran and
United Nations Educational, Scientific and Cultural Organisation was signed by H.E. Mr.
Bitaraf, Minister of Energy on behalf of Government of I.R. Iran and H.E. Mr. Matsuura,
Director General of UNESCO.
3 - RCUWM Mission
Transferring applicable scientific knowledge, and increasing know-how and capacities
in all of the cases and dimensions of urban water management in order to promote
sustainable development, and undertaking activities in this field in order to enhance
human welfare in the region States.
4 - Objectives
1. To generate and provide scientific and technical information on urban water management
issues in the region that will allow the formulation of sound policies leading to
sustainable and integrated urban water management at the local, national and regional
level.
2. To promote research on urban water management issues through regional cooperative
arrangements using and strengthening local capabilities and involving international
institutions and networks, in particular those under UNESCO/IHP auspices.
3. To undertake within the region effective capacity-building activities at institutional and
professional levels, and awareness-raising activities targeted at various audiences,
including the general public.
4. To advance cooperation with international institutions in order to advance knowledge in
the field of urban water management.
5 - Functions
1. To promote scientific research on the issues and problems related to urban water
management in the region.
2. To create and reinforce networks for the exchange of scientific, technical and policy
information on urban water issues among the institutions and individuals in the region
and in other countries.
3. To develop and coordinate cooperative research activities on urban water management
issues, taking advantage particularly of the installed scientific and professional capacity
of the region and of the relevant IHP networks and nongovernmental organizations.
4. To organize knowledge and information transfer activities on the subject, including
international training courses, symposia or workshops, and to engage in appropriate
awareness-raising activities.
5. To develop a strong programme of information and communication technology to further
the Centre’s objectives.
6. To provide technical consulting and advisory services in the region and beyond as
required.
7. To produce technical publications and other media items related to the activities of the
Centre.
6 - Cooperation with other countries
After the approval of IHP Resolution XIV-6 in the 14th session of the
Intergovernmental Council of IHP, the Islamic Republic of Iran has made extensive
efforts for bilateral negotiations with the regional States to attract their support for
establishing and maintaining activities of RCUWM-Tehran, and shall continue such
policy in the future. A MOU was signed in Russia between Dr R. Ardakanian, Iranian
Senior Vice- Minister of Energy and Acting Chair of the Iranian National Committee for
IHP, and Mr S.S. Khodkin, the Head of the National Committee of IHP of the Russian
Federation in October 2000. In this MOU, the bilateral cooperation relevant to IHP in
general, and the willingness and readiness of the Russian Federation to cooperate in the
execution of the common projects within the structure of RCUWM, are specifically
emphasized.
The international conference “Integrated Water Resources Management for
Sustainable Development” was held in Roorkee, India, from 12 to 21 December 2000.
Numerous experts from all over the world, especially from the regional States, attended
the conference. Dr R. Ardakanian informed the conference about the establishment of the
RCUWM. The recommendations of this conference emphasized that “… studies on urban
hydrological cooperation and joint efforts by countries of the region are urgently
required”.
In accordance with the action plan set during the December 2000 mission, at the
request of the Government of the Islamic Republic of Iran, UNESCO/IHP convened a
Regional Consultation on 8 and 9 May 2001 in Tehran to discuss cooperation with the
Regional Centre on Urban Water Management in Tehran. The Consultation gathered
representatives of 13 Member States of IHP and 14 international organizations, such as
United Nations system: UNEP, UNCHS-Habitat, WHO, the United Nations Economic
and Social Commissions for Western Asia (ESCWA), and for Asia and the Pacific
(ESCAP); Intergovernmental organizations: Economic Cooperation Organization (ECO);
Development banks: World Bank, Islamic Development Bank (IDB); International
scientific and professional NGOs: International Association of Hydrogeologists (IAH),
International Association of Hydrological Sciences (IAHS), International Commission on
Irrigation and Drainage (ICID), International Water Association (IWA); and
UNESCO/IHP water centres: Regional Humid Topics Centre Kuala Lumpur,
International Research and Training Centre on Urban Drainage (IRTCUD) and Centre on
Urban Water (CUW-UK). In addition to the Islamic Republic of Iran, the following 12
countries were represented: Azerbaijan, Bangladesh, Japan, Jordan, Kuwait, Malaysia,
Oman, Pakistan, Qatar, Saudi Arabia, Turkey and Uzbekistan.
A Memorandum of Agreement with the Japanese National Committee for technical
cooperation with RCUWM was signed immediately thereafter.
At the UNESCO/IHP international symposium “Frontiers in urban water management:
Deadlock or hope?” (Marseille, 18-20 June 2001) that had nearly 200 participants from
46 countries; Dr Ardakanian was invited to make a presentation on the RCUWM. At its
closing the symposium adopted the Marseille Statement, where it recommended to
“Establish and strengthen regional centres of excellence on urban water management,
such as the new UNESCO Regional Centre on Urban Water Management in Tehran,
particularly in countries in transition and developing countries. As part of this measure,
reinforce the UNESCO endorsed network of urban water centres, such as IRTCUD and
work with ongoing initiatives of the United Nations system, such as the cities
programmes of Habitat and action plan on municipal wastewater of UNEP/GPA”.
Following the Consultation a Memorandum of Agreement was signed with IAHS for
cooperation of the Centre and a MOU with IWA, the largest international professional
NGO. Among the specific points, IWA expressed its willingness to provide international
experts to participate in workshops and seminars of the Centre covering their overseas
travel costs, and to serve in the Governing Board of the Centre.
On 22 July 2001, a MOU between the International Institute for Infrastructural,
Hydraulic and Environmental Engineering (IHE) of Delft, Netherlands, and the Ministry
of Energy of the Islamic Republic of Iran on the partnership between UNESCO/IHE
Delft and RCUWM-Tehran, which would strengthen significantly the educational and
training activities of the Centre, while also supporting the regional activities of
UNESCO/IHE.
On 21 November 2002, RCUWM joined to the PoWER programme which is stands
for Partnership for Water Education & Research. Base on the charter of PoWER, 17
water education and research universities and institute from all over the world agreed on
an International partnership of knowledge centres active in education, training and
research in the field of integrated water management.
On January 25 2003, on the occasion of the visit of H.E. Mr. Khatemi, President of I.R.
Iran, to India; a Memorandum of Understanding was signed between the Iranian Ministry
of Energy and Ministry of Water Resources of India, due to this MoU, the role of
RCUWM the mutual cooperation was signified.
As well, RCUWM is introduced at different international water events. Some of them
are:
1. Water & Sanitation in Asian Cities; New Delhi - India; April 2002;
2. International Conference on the Development and Management of Water
Conveyance Systems (Aflaj); Muscat - Oman; May 2002;
3. South–South High-Level Conference on Science and Technology; Dubai - United
Arab Emirate; October 2002;
4. From Conflict to Co-operation in International Water Resources Management:
Challenges and Opportunities (CP→PC); Delft - The Netherlands; November
2002;
5. Presenting a comprehensive report about the activities of Iranian National
Committee of IHP and RCUWM activities at Intergovernmental Council of IHP;
Paris - UNESCO Headquarter; June 2002;
To enhance the cooperation among national entities, in September 2002, three MoUs
were signed with national organisations, which were Power and Water Institute of
Technology (PWIT), National Water Research Centre (WRC) and National Cloud
Seeding Research Centre.
7 - Projects in years 2002 - 03
1. Farsi Edition of “Frontiers in Urban Water Management, Deadlock or Hope”
The book will be the true translation of the original book published by IWA &
UNESCO. The Farsi edition will also include a chapter about Urban Water Management
in Iran. Translation is under operation; the agreement between RCUWM-Tehran & IWA
was signed at the time of the third World Water Forum, Japan, March 2003.
2. Farsi Edition of “Water Conservation: A Guide to Promoting Public Awareness”
The book was prepared by the United Nations Economic and Social Commission for
Asia and the Pacific. The translation of the book was presented to the workshop with the
same subject which was held in May 2003. This book also contains a chapter about the
Water Conservation Issues in Iran. The book is also prepared in digital version.
3. Workshop on “Public Awareness of Water Conservation” with Cooperation of
UNESCAP
The workshop was held on May 7 to 9, 2003 in Tehran with 42 participants from Iran
and 6 Asian countries and three international resource persons from UK, Japan and South
Korea. Representatives from each country prepared a report on Water Conservation and
related activities of their own countries and the reports have been presented in a final
document.
4. Workshop on “Water & Wastewater Technology” with Cooperation of German
Ministry of Higher Education
The workshop will be held in August 30th to September 4th, 2003 in Tehran. The
number of participants will be about 50 from Iran and other region countries. The
lecturers will be both from Iran and Germany. The Workshop will be held in 5 days
which will be followed by a technical tour to Tehran potable water and sewage network
system.
5. Short training course on “Water Demand Management” with Cooperation of
UNESCO
The program in form of the fact finding workshop (up to two days) will be followed
by ten day training course. It will be held in 6 - 19 September, 2003 in Tehran for the
benefit of 25 participants from national and regional entities. The workshop is coorganised by RCUWM-Tehran and one of its internal partner, Power & Water Institute of
Technology (PWIT). Besides running the training course with national teaching staff,
RCUWM will invite three foreign lecturers.
6. Conference on “Policies and Strategies Option for Water Management in the Islamic
Countries” with cooperation of Islamic Development Bank
It will be held at the end of December in Tehran with participation of decision makers
and senior officers of water related organisations from Islamic countries and senior
experts from international and regional organisations. One of the sessions is programmed
to discuss about the long-term plan of RCUWM-Tehran.
7. Project on “Data bank of Urban Water Management Literature, Organizations and
Human Resources” in the Region
The main objective of the project is preparing an informative platform to enable access
to the most relevant sources data about existing literature, institutions concerned, and
professionals involved in the region. A database will be developed based on web media
for users ease of access and provides ease of use for end services, so there will be two
releases of this project (i) Intranet version, which each client utilizes locally to provide
services for local users and (ii) Extranet version that can be placed on Internet for remote
and local users.
This project is a fully IT-based project which requires all levels of software
engineering. The steps for producing the system will be: (1) Analysing the requirements
(2) Designing (3) Development of forms and classification of data (4) Test and validation
(5) complete live data (6) Final validation and verification. The geographical area will
cover the states in Middle East and CIS countries. The executive body in Amirkabir
University of Technology in Tehran is designated and the contract is signed and the
project is under progress.
8. Project on “Urban Water Management in the region” (Inventory, Problem
Assessments and Scenarios for development)
This project is under study by UNESCO-IHE. In the first stage an inventory of the
potential such as human resources, literature and organisation in contradiction of
challenges will be prepared. The survey through regional states will be executed by
means of face-to-face interviews with resource experts, tours to states, preparing
questionnaires, workshops and even new technologies like video conferences. On the
basis of a problem assessment the study would enable the elaboration of the potential
application of the methodological guidelines for inventories of other major cities and
their sub-urban compounds in the region. The final outcome of this project will be a
proposed overall strategy in consideration socio-economical, environmental, and regional
aspects.
9. Participation in Rehabilitation of Afghanistan:
The project is divided into four sub-projects which will be financed by the
Government of Islamic Republic of Iran and other international sponsors such as
UNESCO, and RCUWM-Tehran will coordinate the project. The subprojects are:
o Reconstruction and establishment of meteorological stations
hydrometrical network;
o Establishing a branch of Water Research Centre;
o Comprehensive study on Water Management in Kabul River Basin;
o Supplying potable water to Zeranj City in Nimrouz Province.
and
Remote Monitoring for Water Supply Networks
Guenter Ruecker, p2m Berlin GmbH, Fasanenstr. 7-8, D-10623 Berlin, Germany
Tel.: +49-30-74735 101, Fax: +49-30-74735 105, email: guenter.ruecker@bwb.de
Introduction
Due to the fact that proprietary automation systems will be replaced step by step by modern open automation
systems, also in the field of Water Supply Networks of big cities, the existing systems will be renewed. The
focus is not only on the reproduction of the former functionalities with the new system but also to add new,
more comfortable functionalities. Besides that one of the main intentions is the reduction of staff personnel
for the operation of the whole network and the optimization of the operational regime.
In a brief overview the differences between proprietary telecontrol systems and open control systems is
stated. Based on requirements for data transfer rate and the availability sufficient bandwidth online- and
switched line concepts will be defined.
Basis of all Remote Monitoring Systems are telecommunication services which provide the necessary data
transmission lines. Starting with public wire line and wireless services, fiber optics and radio data links will
be characterized.
An example for an online monitoring system is the SCADA and Management System of the BERLINER
WASSERBETRIEBE, which will be set into operation during this year. The single water works has own
automation systems which have partly been renewed and are now connected to the overall SCADA system
for the water supply network. The SCADA and automation system is organized due to administrative and
hydraulic correlations in groups. The administrative groups are bound to main water works, the hydraulic
correlated groups will be arranged due to current consumption situation and geodetic height. Project goals
are the implementation of central supervision and monitoring, a rise in cost efficiency, secure operation of
supply network and a standardized appearance of automation systems in all levels of the system. The
ManageMent Execution System (MMS) will provide a consumption forecast and on-/offline simulation
functionality as well as a cost optimization program which will make available input data for elaboration of
net schedules for water works.
As GIS (Geographic Information Systems) data are also important input data for water supply networks to
generate the hydraulic model the possibilities of integration of GIS data in a SCADA system will be
described.
State of the art
The proprietary standards in remote monitoring systems are nowadays replaced with open control systems
also for RTUs (Remote Terminal Unit). The RTUs also provide PLC (Programmable Logic Controller)
functionality according to IEC-standards. Standardized protocols provides connectivity to standard
automation products, an OPC-server (Open Process Control) enables the connection to various SCADAsystems.
The delta-event-principle guarantees a reduction in data amount and allows the use of switched data transfer
lines.
If company-own communication network is available and the data amount and the control functionality is
more complex online monitoring systems will be implemented.
Telecommunications
Public telecommunication services will be only used for low data transfer rates, especially when switched
lines have to be used. For locations without wire line connections to telecommunication services, wireless
services will be used.
Especially when new water supply lines should be constructed, parallel ducts for fiber optics can be
installed. The bandwidth will support the own WAN services and offers the capacity for additional
telecommunication use.
If company-own wire line services does not exist or public telecommunication services are too expensive an
radio data link can provide sufficient bandwidth also for high data transfer demands. For pipeline control
systems point to point connections will be used, for network supervision point to multipoint will be
applicated.
BERLIN water supply network
The area of the city of Berlin measures 890 square kilometers. The daily water consumption is about
600.000 m³, in one year about 217.000.000 m³ water is be consummated. About 8.000 km supply lines with
diameters from 40 mm to 1400 mm make the water available for the consumer.
Starting in the year 1999 first preparations for the implementation of a SCADA and ManageMent System
(MMS) has been made. The WAN (Wide Area Network) was already built and can be transferred from a
previous Data Acquisition System. For the object oriented data base the object definitions have been created.
The implementation of whole systems was been carried out in several steps.
1. Implementation of standardized local automation:
To provide standardized automation functionality the automation systems were changed for most of the
water works. The pure water pumps get redundant automation systems. Water works without renewed
automations systems were connected with interfaces.
2. Automatic control of water works groups:
Due to administrative and hydraulic correlations the central supervision and monitoring center is able to
define groups of water works. For each water works a net schedule can be composed, which consists of data
for every hour and every resource. For each processing step (ground water pumping, processing of ground
water, pure water storage, pure water pumping) all necessary parameters are defined in the net schedule,
valid for every hour of a whole day. The net schedule will be created separately for each group. In the
implementation step of the project the net schedule have to be elaborated manual.
3. Implementation of Management Execution System:
With the third implementation step the MMS will be set into operation. It consists of three parts.
-
Consumption forecast program: A neural network calculates a consumption forecast for the next
seven days based on historical consumption and weather data from the last ten years, the actual
consumption, weather data and the weather forecast.
-
On-/offline simulation: simulation of flow and pressure for the water supply network, based on
online data or on data from optimization system or manual manipulated net schedule data.
-
Optimization: The optimization program calculates the flow and pressure for each water works for
groundwater pumping, pure water pumping as basis data for the manual elaboration of the net
schedule. The complex mathematical problem was divided in the sub problems optimization of
ground water pumping, optimization of pure water pumping and optimization of supply network.
The program calculates the best pumping configurations according to charge for ground water,
energy costs, costs for resources.
The project goals are:
-
central supervision and monitoring
-
remote monitoring and control by main water works
-
standardized and ergonomic automation
-
reduction of staff for monitoring and control
-
optimization of ground water charge
-
optimization of energy costs
-
optimization of use of technical resources
-
secure operation of water supply network
In the present state of the project step two of implementation is reached. The group wise automatic control is
on trial operation. The whole functionality of the MMS will be completed in 2004.
GIS interfaces
GIS data are integrated in the network description file or are manually typed in an input table of the SCADA
visualization in the present project.
For automatically integration of static GIS network data with realtime SCADA data Distribution
Management Systems (DMS) can be established. The DMS can be integrated either in the GIS or in the
SCADA application. Preferred solution is an independent platform. The SCADA visualization is in most
cases not able to display the graphic information of the GIS systems with e.g. zoom functionality. The GIS
system is often not able to provide the necessary reliability.
The independent platform DMS can provide visualization function for both applications and can
communicate with both data bases.
Conclusion
Remote monitoring systems can provide besides their original monitoring and control functionality a various
diversity of features. In the mentioned project the Management Execution System is dedicated to gather
expert knowledge as a self learning system from the daily operation. The operator can use the management
tools as support, the results have to be proofed by the operational experience. The next years of operation
will improve the data base and the mathematical models.
The integration of additional features as GIS applications, online integrated weather data or online blocking
valve data can be realized on an independent platform.
References
-
Grundlagenermittlung zum Modul Optimierung innerhalb des LSW-Managementsystems, BWB
IN-VT, Dr. Burgschweiger, Berlin 2002
-
Presentation: Introduction of an Integrated Water Supply Control and Management-System in the
City of Berlin, BWB WW Wiesener, Klinger, Berlin 2002
-
Presentation: LSW-Optimierung Grundlagenermittlung, BWB IN-VT, Dr. Burgschweiger, Berlin
2002
-
Presentation: Neuronale Netze für die Wasserbedarfsprognose, BWB IN-VT, Dr. Broll, Berlin 2002
-
Project documentation of Project LSW, ABB UTD/PA, Berlin 2003