Semestral Project

Wastewater Treatment in Greece

Makris IoannisPapagiannis Nikolaos

Papadopoulou KonstantinaSaxonis Konstantinos

Souladaki Maria

Czech Technical University in Prague, Faculty of Mechanical EngineeringDepartment of Process Engineering

December 2004

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Index

Wastewater treatment in Greece 1

Historical overview 1

The history of plumbing 6

Major wastewater treatment plants in Greece 10

Thesaloniki 10

Heraklion 24

Psyttalia 35

Small municipal wastewater treatment plants in Greece 38

Ammonia and phosphorus removal in municipal wastewater treatment 48

plants with extended aeration

Application of cost criteria for selection of municipal wastewater 57

treatment systems

Changes in wastewater treatment in regions of Europe between 77

1980s and late 1990s

Treatment and reuse of sewage and sludge in the South Mediterranean 84

and Middle East countries.

Development assistance programme in the field of environment

Computation intelligence in wastewater treatment 85

Freshwater country profile Greece 91

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Wastewater Treatment in Greece

EYDAP (Athens Water Supply and Sewerage Company) is responsible for the monitoring of natural

stream pollution and industrial unit sewage effluent, within its jurisdiction area. Discharging sewage

effluent into the wastewater network is only allowed if the quality characteristics of the effluent are

within the ranges pre-defined by Legislation, in order to ensure the smooth operation of the Wastewater

Network and the Wastewater Treatment Plants.

EYDAP is obligated to monitor the industrial users of the sewerage network adherence to the guidelines

issued in the respective operational licenses they have received. At the present, there are no installations

for the treatment of toxic or radioactive waste.

EYDAP operates two Wastewater Treatment Plants (WWTP). The Wastewater Treatment Plant of

Metamorfosi (WWTP-M), responsible for the treatment of cesspool waste for Attica and sewage from

the northern suburbs and the Wastewater Treatment Plant of Psittalia (WWTP-P), where only phase A

(primary sewage treatment - sludge treatment) operates for the moment, with phase B (secondary

treatment) almost completed.

Historical overview

Antiquity - Ottoman Period

In the ancient times there was no distinct sewerage system in the city of Athens. However, there are

some reports of combined sewerage networks, wastewater and storm water run-off, dating 500 BC,

when Iridanos river together with the Central Sewer, were servicing the areas of Ancient Agora, Areios

Pagos, and Pnyx.

In these open sewerage systems, stagnant water were often sources of serious diseases, like cholera,

plague, etc. This practice continued for almost 15 centuries and was gradually phased out with the

predominance of absorbing septic tanks. When septic tanks reached their saturation point, either a

second tank was added or the waste was collected again and discharged into open streams or the sea.

Naturally this technique did little to allay dangers to public health or to reduce pollution (from the

contamination of the underground aquifer).

1840 - 1930 Period

Circa 1840, for the first time in the modern history of Athens, the first combined flow sewer system for

collection and conveyance of wastewater and storm water runoff was constructed, along Kolokotroni,

Ermou, and Aghios Markos streets, as well as along Hadrian street towards the Thisssion area. These

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sewers flowed to an open torrent in the Kerameikos area. A little later (1860), the existing Stadiou

Street torrent, from Syntagma Square to Omonoia Square was covered.

Between 1880-1890 the first primary sewer network was completed with smaller diameter branches,

mainly for local use, on various streets in the center of the city of Athens, with high population density.

Until 1883 the total constructed combined network length was about 11,5 km while the urban

development at that time required 90 km of sewer lines. The actual needs, in other words, were eight

times more. Athens had only 12% coverage.

During the years 1893-1920, the Greek State successively invited different groups of experts from

France, Germany and the USA to help finalize a strategy for solving the sewerage problem of Athens.

One of the main issues considered was whether to proceed with the construction of a combined

sewerage system or a separate one. The various proposals produced by the above experts, adopting the

one or the other solution, only resulted in having the problem unsolved for many years.

In the meanwhile, due to the influx of refugees caused by the 1922 Minor Asia disaster, the need for the

construction of wastewater projects became imperative. As the water supply distribution networks

expanded, the total quantity of potable water consumption increased, resulting in the subsequent

increase of sewage produced and conveyed to the existing wastewater network.

In 1929, the Italian Professor of Hydraulics Gaudecio Fantoli, was invited by the Greek Government to

study the sewerage problem of Athens. Prof. Fantoli proposed the construction of a combined system

for the Western part of the city (Kifissos River Catchment Basin) and a separate system for the Eastern

part of the City (Ilissos River Catchment Basin), with outlet works of the Main Interceptor Sewer at

Akrokeramos, the tip of the Piraeus Peninsula.

1930 - 1950 Period

twin sewage system

   In 1931, the "Societe Anonyme for the Construction of Sewers in Athens and the Suburbs" was

established, and despite the outbreak of World War II final designs for the construction of the basic

sewerage network infrastructure, based on the preliminary studies by Fandoli, proceeded. One project

was the design study for the Main Interceptor Sewer. Construction for this project began in 1954 and

ended in 1959. Rainwater run-off and raw sewage collected by the combined system, was channeled to

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the Main Interceptor Sewer, running from the end of Patission Avenue to Akrokeramos, where the

wastewater was finally discharge into the sea.  During this period (the 1950s and the beginning of

1960s), the Construction Company called HYDREX undertook a large portion of the design and

construction of the local sewerage network.

1950 - 1980  Period

   In the 1950s, Athens population began to expand exponentially. It was evident that the existing

networks were insufficient. At the same time it became necessary to revise existing design studies

because new areas were continuously being added to the city, and each new area included within the

city zones required adequate network infrastructure.

The severe need for the planning and construction of large wastewater projects resulted in the

establishment of the Athens Sewerage Organization with the enactment of Law 1475/50. The Athens

Sewerage Organization was the first company who undertook the design, construction, maintenance,

operation and exploitation of the City’s wastewater and storm water drainage networks and managed

successfully to set up strong and long-term foundations for the infrastructure of the Athens sewerage

system 

Besides the operation and maintenance of the networks, the Athens Sewerage Organization

established the fundamental standards for the short term and the long term planning of Athens future

needs in wastewater and storm water drainage networks. Thus, in 1950, the preliminary design of the

Athens Sewerage System began covering an area of 20.000 hectares.  This study was finalized in 1963.

The preliminary design was used as a basis for development of the city’s networks during the 1960s’

and 1970s.  In 1977 the Ministry of Public Works commissioned the English firm, "Watson Company",

to investigate an alternative proposal for the disposal of Athens liquid wastes.

In the 1980s, the Supplementary Main Interceptor Sewer, another large diameter main collector, was

added to the existing sewerage network of Athens. This collector main was constructed by the Ministry

of Environment, Urban Planning and Public Works and begins at a junction with the Main Interceptor

Sewage Main, running through the Rendis Area, to discharge at the Akrokeramos location.

1980 - the Present

   In 1980, the responsibilities of Athens Sewerage Organization were transferred to a new company

established for the handling of water supply and sewerage needs of the greater Athens area, called

EYDAP. In the sewage sector, this new organization undertook the collection and discharge of urban

wastewater and industrial waste, as well as the expansion of the existing sewerage networks in co-

operation with the local Municipalities. Its duty was also to monitor the wastewater treatment procedure

and the final disposal of treated effluent into the sea.

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   In the years that followed, EYDAP expanded the primary sewerage collector network of Athens. The

Municipalities, in turn, undertook the construction of the secondary sewer network, consisting of the

smaller diameter pipes. The Municipalities also carried out the construction of the house connections to

the local network (branches).

   The local secondary networks constructed by the Municipalities become part of the network owned

and controlled by EYDAP, after an official asset transfer procedure.

Apart from constructing the primary network, EYDAP also deals with the thorough and efficient

operation of the overall sewerage system, providing regular maintenance and immediate repair in cases

of failures. EYDAP uses state-of-the-art monitoring and control systems, such as CCTV cameras for the

monitoring of the sewage pipes.  With the use of advanced technology, EYDAP administers an

aggressive preventive maintenance program that quickly traces areas of future damage and efficiently

implements repairs.

The Wastewater Treatment Plants in Psyttalia and Metamorphosis constitute the final stage of the

sewerage administration cycle in Athens. For decades, wastewater from the Athens Basin flowed to

Akrokeramos, into Saronikos Gulf, without any treatment, thus polluting the Gulf and degrading its

ecological balance.  Since 1994, the first phase in Psittalia Waste Water Treatment Center has been in

operation. This means that Athens wastewater is initially collected, pretreated in large sedimentation

tanks, where 40% of its polluting load is removed, and then it is conveyed, through three underwater

pipelines, it is discharged into the Gulf of Saronikos.   

Another Wastewater Treatment Plant that has been operating since 1985 is the Metamorphosis Plant.

Biological treatment wastewater is carried out at this facility, producing treated water 90-95% clean.

This water after chlorination is discharged into the Kifissos River.   

The future planning for the sewerage sector encompasses the expansion of the water supply and

sewerage networks in the northern suburbs of the City as well as expansion of the wastewater collectors

in the southern areas of Attica. At the same time, for the environment protection of the coastal areas

surrounding Attica, there is a master plan for the design and construction of new Wastewater Treatment

Plants in different locations around Attica.  Already the construction of the Thriassion Pedion

Wastewater Treatment Plant is in the tender phase.

In the following paragraphs we will shortly describe the history of water treatment and plumbing in

general in some significant periods in greek history, Ancient Greece, the Macedonian and Minoan

Empire.

The History of Plumbing – Greece

Until Philip of Macedon, father of Alexander the Great, rampaged through and destroyed the city in 432

B.C., Olynthus was a rich and flourishing metropolis, its people enjoying the luxury of the latest

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plumbing innovation - bathtubs. Excavations at Olynthus, in northern Greece, attest to tiled bathrooms

and self-draining tubs. Several of the tubs have survived intact, shaped like present-day models though

with one sloping end cut off. It is assumed that underground piping was made of since-deteriorated

clay, as there was no lead piping found.

At this stage the early plumbers were still toying with a new metal -- lead. Indeed one tub uncovered in

a tiled bathroom was repaired with lead clamps. (Archaeologists also found the skeletal remains of a

woman near the tub, her jewelry evidently overlooked by Philip's soldiers as they plundered the town.)

From the shapes of the ancient tubs uncovered, the bathers apparently sat upright and rested their feet

on a depression formed at the bottom. No doubt they were influenced by Hippocrates, the "father of

medicine," who said that sitting in a tub was more healthy than reclining. Hippocrates also advocated

cold water baths as a cure for almost any ills. The Greeks followed his advice very carefully.

The ancient Greeks set a high standard for themselves in promoting bodily and mental fitness. This was

a concept reflected in their approach to exercise and cleanliness - having created the Olympic Games in

776 B.C. In any large city from the 7th Century B.C. onwards, one could find a gymnasium that

featured hot and cold shower baths. As using hot water was considered effeminate, a man's bath

typically was a quick douse of cold water over the head. On average, his "tub" typically was a 30" high,

polished marble bowl. He probably stood beside it.

Private bathrooms, on the other hand, usually contained portable earthenware tubs for milady, whose

taste no doubt demanded warm water for a more relaxing soak.

A Traveler's Treat: More ritual than hygienic, it was considered good manners for a host to offer his

guest the services of his bathroom after a dusty and arduous journey. Ah, the joys of being treated by a

winsome slave girl as she scraped his skin of perspiration and dirt with an iron utensil! Ah, the shock

when she completed her work with a good dousing of cold water from an urn setting on a stand nearby!

(As a rule, the Greeks much preferred sponges, oils, scrapers and rinses over the type of soap available

at that time. Perhaps it was no wonder, for Grecian soap was manufactured from a combination of goat

fat and ashes.)

Many houses in ancient Greece were equipped with closets or latrines that drained into a sewer beneath

the street. They seemed to have been flushed by waste water. Some of the sewers were fitted with

ventilating shafts.

The Greeks gave special protection to their water supplies to ward off severance by enemy attack.

Aqueducts were generally laid underground, sometimes to a depth of 60 feet. Some were broad enough

to accommodate two men waltzing abreast; the deeper ones connected with the surface through large

wells.

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The city of Athens required many aqueducts to bring water from the mountains. The people also

depended upon deep wells which they laboriously had to dig through layers of rock to secure. The water

supplies were directed to storage cisterns which in turn fed a multitude of street fountains, some of

which are still in use today. Water porters carried a supply to homes of the well-to-do.

Heavenly Water: To the people of ancient Greece, everything in nature possessed religious

significance. Water especially played a key role in the development of their culture. For instance,

fountains and springs were held to have certain mystical and medicinal powers which were imbued in a

pantheon of gods and goddesses that the people worshipped.

A free citizen would bathe at three significant times in his life: at birth, marriage and after death. To

assure a long and happy life, for example, a bride would bathe in water taken from a fountain with nine

pipes, called Calirrhoe. In Athens, the Calirrhoe fountain was also the principal source of water supply,

for the most part conveyed by a conduit which brought the water in from the river Illisius.

The Greeks made strong headway in the development of water systems, especially cold water systems.

But it would still remain for others to expand upon their achievements. In 201 B.C., Carthage would fall

to the relentless Roman legions, and then Macedonia four years later. The ancient Greeks would lose

their hold on themselves and soon their Near East conquests, including Assyria, Judea and Egypt.

The History of Plumbing - CRETE

Across the Mediterranean Sea from Mesopotamia, the ancient people of Crete and their Minoan sea-

kings were leaving their mark on the early annals of history. Between 3000-1500 B.C., their early

plumbers had laid elaborate systems of sewage disposal and drainage that resemble one of today. In

fact, archaeologists have discovered underground channels that remained virtually unchanged for

several centuries, except for extensions to include structures built over the original ones. Some vestiges

of the pipes still carry off the heavy rains.

Unlike hot and dry Mesopotamia, Crete suffered from extremes of variable climate and geography.

Some say those forces provided the catalyst to design systems for the inhabitants' comfort. Likewise,

the sharp and jagged slopes of the country provided an early understanding into the principles of

hydraulics.

The Palace: It was originally surmised that the Minoan civilization had been an offshoot of the ancient

civilization of Greece. When the fabled palace of King Minos at Knossos came to light, however, it

proved there was a separate and earlier civilization, and King Minos was no ordinary monarch.

Knossos was the Minoan capital and home to a population of about 100,000, crowded into an area of

about 22 acres. The multi-storied houses of sun-dried brick or dressed stone encircled on different

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levels the king's intricate, four-story palace. There was a public inn too, located near the palace. It

featured a convivial foot-bath with grandiose dimensions of 65' x 4'6" x 18" deep. Surrounding slabs

which formed seats for the foot-bathers jutted over the bath.

The palace of the king had been built up over the centuries, and already experienced one earthquake and

ruin in its history. But by 1500 B.C., it had become four stories high, with endless winding passages,

innumerable halls and corridors and rooms of state and storerooms. The entire floor space comprising

1,500 rooms spanned five acres. Its huge rectangular central court faced north and south.

The palace exemplifies a labyrinth construction; indeed, the word labyrs is derived from the Greek

meaning "double ax". To the Greeks, the Place of Minos was truly a labyrinth, the house of the double

ax, and the double ax design appears on its decoration.

The early plumbing engineers took advantage of the steep grade of the land to devise a drainage system

with lavatories, sinks and manholes. Archaeologists have found pipe laid in depths from just below the

surface in one area, to almost 11 feet deep in others.

They constructed a main sewer of masonry, which linked four large stone shafts emanating from the

upper stories of the palace. Evidently the shafts acted as ventilators and chutes for household refuse.

The shafts and conduit were formed by cement-lined limestone flags, but earthenware or burnt clay

pipes were used in the remainder of the system. These

were laid out under passages, not under the living rooms.

The drainage system consisted of terra cotta pipes, from

4"-6" in diameter. The rain water from the roofs and the

courts and the overflows from the cisterns carried the

water down into buried drains of pottery pipe. The pipes

had perfect socket joints, so tapered that the narrow end of one pipe fixed tightly into the broad end of

the next one. The tapering sections allowed a jetting action to prevent accumulation of sediment.

The queen's bathroom featured decorated walls covered with monochrome frescoes and decorated

friezes, and plaster stands which held ewers and washing basins. At the heart was a five-foot long,

tapered bathtub. The tub was painted terra cotta, and decorated in a bas relief of a watery motif of reeds.

Evidently filled and emptied by hand, the tub had no outlet. The used water was discarded into a cavity

in the floor and connected directly with the main drain. The drain discharged into the river Kairatos.

A terra cotta tub from the Palace of King Minos, circa 1700 B.C.

Not too far away was the world's earliest "flushing" water closet, screened off by gypsum partitions on

either side. It was flushed by rain water or by water held in cisterns. Two conduits were built into the

wall. There were several other closets found in the palace too.

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The Minoan religion is elaborately bound up with the image of the bull. Periodic "roarings" far

underground in the earthquake-prone region were attributed to the bellowing of the huge mythical bull,

the Minotaur, as he thrashed about in the labyrinth caves below. Undoubtedly he portended the future.

In 1400 B.C. the Minoan kingdom at Knossos was leveled, devastated and lost for centuries by a

cataclysmic earthquake.

Major Wastewater Treatment Plants in Greece

Thessaloniki

Study area description

The Thermaikos Gulf forms the north-west Aegean continental shelf and it is a typical deltaic platform.

Four rivers (Axios, Loudias, Aliakmon, Pinios) constitute the major sources of material input into the

marine system of the Thermaikos Gulf. The drainage basin covers an area of ~72,000 km2. Measure-

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Thessaloniki population since 1950 (in thousands)

1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2001 2004

292 329 372 447 542 617 699 724 746 768 789 1000 1500

ments carried out during the METRO-MED project showed a mean annual water discharge of the river

system of about 207 m3 sec-1 or 18x106 m3 d-1 (Karamanos et al . 2000 ).

Thessaloniki Bay, the northern part of the Inner Thermaikos Gulf, receives domestic, agricultural and

industrial effluents not only through the rivers but also in sewage from the city of Thessaloniki. Fishing

activities and extensive aquaculture farming also occurs, along with water recreational activities. This

northern part of the study area is characterized by eutrophic conditions due mostly to the intense nutri-

ent supply through the sewage. The western coast of the Inner Thermaikos Gulf (depth: 0-50 m) is in-

fluenced by the three major river estuaries (Axios, Loudias, Aliakmon) and the prevailing eutrophic

conditions are also related to this freshwater inflow, whereas the eastern coast is influenced by the oli-

gotrophic Aegean Sea. However, depending to the seasonal variability, eutrophic conditions due to the

rivers can be recorded in the whole Inner Gulf area.

Two different water masses have been detected seasonally: the freshwater from the rivers in the surface

layer and the saline Aegean waters in greater depths. Dissolved oxygen and nutrient concentrations are

dependent not only on the water masses circulation and stratification, but also on the freshwater dis-

charge, especially during the rainy period, when there are high levels of dissolved nutrients and oxygen.

On the other hand, low oxygen and high nutrient concentrations were recorded in Thessaloniki Bay, es-

pecially during summer, due to anthropogenic inputs combined with minimal water exchange.

Figure 1. Bathymetry (depth contours in m) and network of sampling stations used to build the budgets

at Inner Thermaikos Gulf (from Karageorgis et al. 2000). The dotted line defines the boundary of the

box.

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The phytoplankton biomass distribution is also affected by water flow and exchange: Thessaloniki Bay

is extremely eutrophic, with very high concentrations of chlorophyll a throughout the year, whereas the

area around the estuary mouths have high to intermediate values of biomass related to the season and

the amount of freshwater entering the sea (Pagou et al. 2000a ).

Thermaikos Gulf (~39.50°-40.50°N, 22.58°-23.33°E) was sampled seasonally in the framework of the

METRO-MED project. Nutrient data derived during this project were used for the budget estimation

presented hereafter for two seasons, one wet (February 1998) and one dry (September 1998). The

budgetary calculations are focused in the northern inner part of the Gulf (Figure 1). Salinity and nutri-

ent data used are the depth-averaged values of each station which then were separately averaged per

box. The budgetary analysis was performed according to the LOICZ Biogeochemical Budgeting

Guidelines (Gordon et al . 1996 ) and it was also tested using the CABARET software. It was assumed

that the water column was homogeneous during both seasons and the ‘single box single layer’ approach

was followed.

The system has an approximate area of 336 km2 and a volume of 7,235x106 m3 (mean depth of about

21.5 m) and it receives sewage discharges from the city of Thessaloniki (1,000,000 residents), freshwa-

ter inputs discharged mainly from the Axios and Aliakmon rivers. Through its southern open boundary

it communicates with the more saline southern part of Thermaikos Gulf.

Riverine freshwater discharges were intensively monitored during the METRO-MED project and ex-

hibit strong seasonality, being much larger in February than in September (Karamanos and Polyzonis

2000). However, concentrations of dissolved inorganic nutrients do not follow this pattern and in par-

ticular DIP concentrations are almost twice as high in September as in February.

In addition to the riverine supply, a substantial ‘freshwater’ input is contributed by the sewage outfall of

Thessaloniki (1,000,000 residents). Although the water volume of the sewage is small relative to the

other freshwater, inputs of dissolved N and P are highly concentrated in the effluent. Sewage dis-

charges to the sea are evaluated assuming a wastewater production of 250 liters per person per day and

the discharge coefficients proposed by Sogreah (1974), Padilla et al . (1997) and World Bank (1993).

At this stage of the study, due to the absence of any original data from local meteorological stations, the

mean annual values referred for the Aegean Sea by Poulos et al . (1997) will be used for both seasons

(precipitation: 500 mm yr-1; evaporation: 1,280 mm yr-1). These precipitation and evaporation rates are

converted to volume fluxes by multiplying by the area of the system. However since rainfall is minimal

(or does not occur) throughout the summer months, the precipitation value is probably overestimated at

least for September.

Although transport via the atmosphere is recognised as an important route by which nutrients and

particles are delivered to the sea surface, unfortunately there are no data available on atmospheric inputs

for the study area. Most of the available data on atmospheric inputs of nutrients refer to the western

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Mediterranean basin and the only published information on the eastern basin concerns measurements on

the Israeli coasts (Herut and Krom, 1996; Herut et al . 1999 ). The atmospheric inputs of inorganic ni-

trogen and phosphorus were estimated using the calculated values of the fluxes for the SE Mediter-

ranean (Herut et al . 1999 ) extrapolated to the surface area of the system. The estimated wet flux of in-

organic phosphorus and nitrogen over the SE Mediterranean is about 0.018 g P m-2yr-1 or 0.002 mmol P

m-2 d-1 and about 0.24 g N m-2 yr-1 or 0.05 mmol N m-2 d-1, respectively. In the case of phosphorus, the

aforementioned value is the sum of wet and leachable fluxes because it is suggested that they represent

the amount of phosphate that is bioavailable in the surface waters.

Water and salt balance

Figure 2 summarises the steady-state water and salt budgets for the Inner Thermaikos Gulf. During

February the net total freshwater input that drives the whole system is about 22.0x106 m3 d-1, while in

September it is about 6.0x106 m3 d-1. During both seasons freshwater inflows exceed evaporation and

there is seawater outflow to balance this gain of water (VR =-21.6x106 m3d-1 and -5.6x106 m3d-1 for Feb-

ruary and September respectively). Due to the uniform values used for the precipitation-evaporation

and the sewage discharge (VO), this residual water flow exhibits seasonally different values attributed to

the existing difference in the freshwater loads of the two rivers, being much lower in September.

The salt that is exported through the residual flow must be replaced through the mixing volume with the

adjacent ‘ocean’. For February, the higher VR yields to an estimated VX of about 2,010x106 m3d-1 result-

ing to the total exchange time: about 4 days. During September, the mixing volume VX is about

287x106 m3d-1 and the corresponding total exchange time is about 25 days.

Budgets of nonconservative materials

DIP and DIN balance

Nonconservative dissolved inorganic phosphorus (DIP) and nitrogen (DIN) fluxes were calculated

using the estimated volume transports (Figures 3 and 4). Table 1 presents the nonconservative fluxes

and the stoichiometrically-derived rates scaled per unit area for ease of comparison. During February

1998 ∆DIP is positive, indicating that there is a net release of DIP probably related to organic matter re-

generation processes. In contrast, the negative ∆DIP during September 1998 indicates that there is a net

uptake of DIP in order to produce organic matter. For DIN the same pattern was seen during both sea-

sons as for DIP.

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Table 1. Summary of DIP and DIN fluxes and stoichiometric calculations for Inner Thermaikos Gulf

in February and September 1998.

  February ‘98 September ‘98

  System System

Area (106 m2) 336 336

Volume (106 m3) 7,300 7,300

(days) 4 25

     

∆DIP (106 mol d-1) +108 -134

∆DIP (mmol m-2 d-1) +0.3 -0.4

     

∆DIN (106 mol d-1) +112 -751

∆DIN (mmol m-2 d-1) +0.3 -2.2

     

(p-r) (mmol C m-2 d-1) -32 +42

(nfix-denit) (mmol N m-2 d-1) -4.5 +4.2

 

Stoichiometric calculations of aspects of net ecosystem metabolism

The nonconservative ∆DIP flux of each season is then used to calculate the rate of net ecosystem meta-

bolism (p-r). These calculations are based on the assumption that the decomposed organic material is

dominated by plankton having a Redfield composition ([p-r]=-106 ∆DIP). For February the results

suggest that in the Inner Thermaikos Gulf respiration exceeds primary production, whereas during

September the ecosystem is a net producer of organic matter.

The nonconservative ∆DIP and ∆DIN fluxes are used to calculate the difference between nitrogen fixa-

tion and denitrification assuming that the nonconservative DOP and DON fluxes are minor [(nfix-denit)

= ∆DIN – (N/P) ∆DIP]. The estimation of (nfix-denit) was performed using the Redfield N/P ratio (16).

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The results obtained for both seasons using the Redfield ratio probably mean that the system is chan-

ging from net detrification during February to net nitrogen fixing during September.

These results must be regarded as a preliminary approach for the N and P budgets in the Inner Ther-

maikos Gulf. Other models or approaches should also be applied, such as division of the area into more

compartments, since the ‘one box’ selection can hardly explain the complexity of the Thermaikos eco-

system as it is known from research projects to date.

Figure 2. Water and salt budgets for Inner Thermaikos Gulf in February (a) and September (b) 1998.

Water fluxes in 106 m3 d-1 and salt fluxes in 106 psu-m3 d-1.

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Figure 3. DIP budget for Inner Thermaikos Gulf in February (a) and September (b) 1998. Fluxes in 103

mol d-1.

 

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Figure 4. DIN budget for Inner Thermaikos Gulf in February (a) and September (b) 1998. Fluxes in

103 mol d-1.

  Up to the year of 2000, the 75% of the municipal and industrial wastewaters of the city of

Thessaloniki were channeled into the sea without any treatment at all and resulting in the pollution of

Thermaikos Gulf.

With the interventions into the sewerage network,

the operation of the Biological Treatment of the

Summer Resort areas in Michaniona, but mainly due

to the completion of the second phase of the

Biological Treatment of Thessaloniki and its full

operation, the melioration of the sea's quality is

pushed forward.

The combination of the Thermaikos streams with the impetus of Bardaris wind maximizes the potential of self-cleaning of the sea, which quickly renews its waters with clean water from the open sea. An indisputable proof for the considerable purification of the gulf is the presence of dolphins in the

inner part of Thermaikos and the witness of the fishermen regarding the increase of the fish catches.

In parallel, the Oceanographic Institute of the National Center for Marine Research has been assigned

with the task of conducting measurements and general monitoring of the water quality in Thermaikos

Gulf. By this action the degree and the rate of the improvement of the water quality is been recorded

and attended, with specific indicators.

Still, the total purification of the gulf also depends on additional anthropogenic activities, such as the

pollution caused by passing ships and the incoming pollutants through the rivers flowing into the gulf.

Phase A

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During the period 1982-1992 the first phase of wastewater projects had been constructed, with a total

budget of 11.5 billion GRD, which included:

The Main Collector Sewer (MCS) with a length of 16.2 km, of which the 11.8 km have been

constructed in a tunnel.

The total 6.3 km length of the collectors and pressure pipelines, which collect the wastewaters from the

areas downstream the MCS.

The five (5) coastal pump stations that convey the wastewater towards the MCS.

The four (4) pumping stations, the collectors and the pressure pipelines of the lower areas of Western

Thessaloniki.

The 1st stage of the Wastewater Treatment Plant with a 45% degree of treatment during winter and 55%

respectively in the summer.

The twin pipeline between Galikos and Axios River, 12.5 km long, which would convey the treated

effluent to the Axios River.

Concurrently, The Water Supply and Sewerage Company of

Thessaloniki, had arranged to discharge all the city's wastewater to

the Wastewater Treatment Plant, through the MCS. This was

achieved with the construction of new separate sewage networks, the

repair of the already existing combined sewage networks and their

connection to the MCS.

However, due to the strict specifications of the Ramsar Convention

regarding the protection of the greater Axios area wetland, the

reduction of Axios River flows and the concerns of the inhabitants of

the surrounding areas, the 2nd Phase works became necessary.

In a transitional stage until the completion of the works of "Phase B",

supplementary works have been constructed, with a budget of 330

million GRD.Since February 1992, the plant constructed under "Phase A" was treating 40,000 cubic

meters of sewage, daily.

Further, thanks to some improvements of the process, the operating capacity was increased to 55,000

cubic meters per day, which corresponded to the 30 to 40% of the overall Thessaloniki's municipal

sewage, while the degree of treatment was 90%, at least.

18

Phase B

The basic target of the projects of "Phase B", regarding the expansion and completion of the existing

facilities, is the biological treatment of all the municipal wastewaters of the greater Thessaloniki area,

as well as of all the industrial water waste that is compatible to the municipal waste.

The plant has the potential capacity of treating, daily,

296,000 cubic meters of sewage, thus covering not only

the needs of the urban complex of Thessaloniki, but also

those needs anticipated for the next 20 years, including

the 60,000 cubic meters per day of industrial

wastewater.

This modern work is been enhanced to the maximum

possible degree, combined with the parallel construction

and completion of the Twin outfall Pipeline for the

Discharge of the Treated Effluent into the outer Gulf of

Thermaikos, at the distance of 2.6 km from coast.

These projects started in October 1995. During their

construction there has been the effort for the accomplishment of a high quality result. Special emphasis

was given in incorporating advanced technologies, so as to ensure a reliable, continuous, high quality

and economical operation.

In 2000, after the completion of the basic works of the biological treatment and Discharge Pipeline the

testing operation of wastewater was started.

Today, the plant fully processes all the available connected municipal waste of Thessaloniki that reach

160,000 cubic meters per day, while the processed capacity will be increased to 200,000 cubic meters

per day with the addition of the industrial wastewaters.

19

Also, the Water Supply and Sewerage Company of Thessaloniki obtained the permission to install a

unit for electrical energy production form the biogas station, with a capability of 2.5 MW. For the

whole period of the year the plant removes:

1. More than 95% of the organic load.

2. More than 95% of the total nitrogen.

3. The 60 to 70% approx. of the total phosphorous.

Besides, the project for the construction of the facilities for the Reception and Pretreatment of the

septage waste, the testing operation of which is being competed in September 2003, The Thessaloniki

Wastewater Treatment Plants will be able to take in for treatment processing up to 1,200 cubic meters

per day of septage, which uncontrollably polluted the underground aquifers and the surface receiving

water bodies.

The projects of "phase B", having a total budget of 68,860,00 Euro, are included in the Second

European Community Support Framework. The Cohesion Fund finances the projects with 85% of the

cost, while the remainder 15% is covered by national funds.

The allocation of the project expenses is shown in the following pie chart:

 

Wastewater treatment plant 50%

Treated effluent discharge pipe 24%

Septage reception &

pretreatment7%

Other Projects 8%

Research Projects 1%

20

Studies & Technical Consulting 10%

Description of the works

WASTEWATER TREATMENT PLANTS (E.E.L.TH.)

The incoming wastewater is received in the inlet

pumping station. With three screw pumps, the

sewage is raised and after been led through bar

screens, it is collected into two aerated grit removal

tanks, where grit and grease are removed. The

sewage is then subjected to various treatment steps,

as follows:

* Primary sedimentation takes place in five circular

tanks, where a 50% removal of suspended solids and a reduction of 30% at least of the organic load are

attained.

* Through the primary sedimentation effluent channel and then through the booster pumping station,

the sewage is directed to the "activated sludge" process, consisting of eight biological reactors and of

eight final sedimentation tanks.

* The removal of organic load as well as of nitrogen is attained in the biological reactors. The final

sedimentation and clarification of sewage is then carried out in the final sedimentation tanks.

* The clarified sewage is disinfected and then directed to the outlet pumping station, from where it is

discharged into the outlet gulf of Thermaikos through the new Twin Discharge Pipe.

* The produced primary sludge is directed into four thickening tanks and then it is transferred into the

anaerobic digesters through a pumping station.

* Following digestion, the sludge is collected in six storage and post-thickening tanks and then through

a pumping station it is led to the homogenization unit.

* The produced biogas, resulting from the anaerobic digestion, is stored in two gas-holders and is

utilized for energy production.

21

SEPTAGE WASTE RECEPTION & PRE-TREATMENT

The septage waste reception and pre-treatment unit

consists of:

* Equipments for the reception and pre-treatment of

the municipal septage waste, with a capacity of 1200

cubic meters per day.

* Equipments for the reception and treatment of the

high organic load nontoxic industrial waste with a

capacity of 250 cubic meters per day.

* Line for the reception and treatment of the waste with high content of coarse inorganic solids.

* Equipment for the treatment of grid residues.

* Equipment for sampling and quality checking of the incoming septage waste, as well a fully equipped

modern lab for the 24 hour monitoring of the operation of the overall wastewater treatment plant of

Thessaloniki The septage is pre-treated, depending on case, and then directed in the Wastewater

Treatment Plant (E.E.L.Th.), where it is treated.

SUPPLEMENTARY WORKS AND WORKS UPGRATING ENERGY USAGE

The project includes the repairing or the replacement of the electromechanical equipment and also

repairing works in parts of the facilities initially built, with the target of operational safety and step-up,

as well as the target of operational cost reduction. The above works are carried out in the following

units of the plant: inlet pumping station, screening - grit removal, primary sedimentation tanks, primary

sludge and froth pumps, sludge pre-thickening tanks, pump of the excess sludge, sludge dewatering

unit, gas-holders, final sedimentation tanks, outlet pumping station, lightning arrester, automation, area

for the temporary deposition of the final sludge.

The project is under construction and it is expected to finish in the end of 2004.

22

OUTFALL DISCHARGE PIPE (ADEL)

The work of Twin Outfall Discharge Pipeline of the Treated Effluent includes a 7.9 km long land

section and a 2.6 km long sea outfall. It consists of 10 m pipe sections, constructed of reinforced

concrete with 1.6 m internal diameter. The twin sea outfall is constructed for the first 1,000 m of its

length to a depth of 14 m. Two diverging branches each 1,600 m long, are then laid to depths reaching

23 m. Both branches are laid outside the navigation channels.

To achieve better diffusion of treated effluent, the last 400 m consist of diffusers of various diameters,

with 50 risers. For the sake of environmental protection and safety, the sea outfall is protected with

stone armoring and concrete mattresses

23

System sections of the first extension level of the waste water treatment plant Thessaloniki

Characteristics:

- Extension size 1,333,000 PE

- Dry weather influx 16,200 m³/h

- Mixed water influx 24,800 m³/h

Heraklion

24

Heraclion population since 1950 (in thousands)

25

1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2001 2004

86 93 107 125 142 160 174 185 204 222 250 255 265

GENERAL INFORMATION FOR THE WTP OF IRAKLION

Population equivalent, design = 164,000

Served population (today) = 145,000 (88%)

Daily dry flow, design = 30,350 m³

Daily dry flow, today = 20,000 m³In operation since 22-04-1996 (>7 yr)

Construction cost = 9.7 million € (1995)

26

27

28

29

30

31

32

33

34

CONCLUSIONS

According to the experience and data of the 3 last years of operation, the energy production unit gives

an average of 660,905 kwh/yr, i.e. 18.3% of the total energy demand of the installation. To be cost

effective, should be produced 611.000 kwh/yr (17% of the total energy demand). Therefore biogas

reuse at the WTP in Iraklio, is a feasible and cost effective investment. The undertaken analysis

indicates that if NEC does not cause problems with frequent breakdowns to the electricity supply and

voltage variation, there will be 25-30% coverage of the total energy demand, the cost of energy may

then vary from 0.048 to 0.040 €/kwhin contrast to 0.07 €when each kwhis purchased from the NEC.

This price is subsidised and the real economic cost is higher on Crete. Therefore, the benefits are more

than the one given by the economic analysis that was undertaken. Viability and cost effectiveness of

such projects depends not only on available technology and operation efficiency of the wastewater

treatment unit but also on external parameters, such as the cost of locally produced energyand available

resources of energy. Apart from the economic advantages, the recycling of biogas has environmental

benefits because primary material can be saved.

35

Psyttalia

Athens population since 1950 (in thousands)

Athens treatment facilities provided offshore engineering challenges

36

1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2001 2004

1,783 2,001 2,246 2,391 2,521 2,783 2,987 3,047 3,070 3,093 3,116 3,200 3,500

The Athens Olympiad has been hailed as one of the most spectacular in the history of the Olympics

with the stadium providing an elegant site for the athletic performances. While the world was enthralled

by both the opening and closing ceremonies, a major engineering event - a wastewater treatment plant -

played a vital but unheralded role in the Games.

The plant is situated on the island of Psyttalia, 2.2 kilometres south of the Athens suburb of Keratsini,

in the Saronic Gulf.

“The island location was chosen because Athens, a city of almost 4 million people, is so densely

populated that there was simply no room on the mainland,” says Dimitris Adraktas, project manager at

Psyttalia B Consultants, a joint venture between a German and three Greek consultants. Adraktas is

managing the plant’s upgrade on behalf of the Greek Ministry of Public Works.

The Psyttalia plant treats the lion’s share of Athens’wastewater, or about 1 million cubic metres of

wastewater per day, about 12 cubic metres per second. Most of the waste is gravity fed to a huge pump

station on the shore from where nine gigantic Archimedes’ screw pumps pump the waste to the island.

As the Olympics returned to their origins, it was appropriate that modern pumps were installed in the

land where the concept was dreamed up by Archimedes.

Before 1994, when the first phase of the Psyttalia plant was commissioned, most of Athens’ sewage and

industrial effluent was released out to sea without any treatment.

After 1994, the plant provided primary treatment including screening, grit removal, primary

sedimentation, anaerobic digestion, and mechanical dewatering for the sludge. The effluent was then

discharged 2,000 metres out to sea at a depth of 64 metres.

37

The substantial upgrade was necessary in order to comply with stricter effluent limits for nitrogen in

accordance with the European Union (EU) Urban Wastewater Treatment Directive. Prior to the EU-

sponsored upgrade, which cost 200 million euros, the Saronic Gulf off the coast of Athens was

designated as “sensitive” by the EU.

“Upgrading the Psyttalia wastewater treatment plant was used as an argument by Greece in its Olympic

bid,” says John Margiolos, city project manager responsible for the final design and erection of the

upgrade. “While officially we were not an Olympic project (the upgrade was planned before our

Olympic bid), it was clear that we had to be ready for the Olympics,” he says.

So the upgrade included biological treatment of the waste to remove carbon, nitrogen and some

phosphorus, the organic compounds that make wastewater detrimental to the environment. But this was

easier said than done.

Psyttalia is a 57-hectare island made up primarily of limestone and clay. In ancient Greek, psytt-allos

means literally “spit out from the sea.” As a proof of this, during extensive civil works on the island to

make room for the biological treatment of Athens’ wastewater, many marine fossils were found in the

limestone.

The island was also involved in vicious sea battles in the Greek and Persian War in 480 BC. The

Persians were defeated, and the empire was prevented from expanding westwards.

In the mid 20th century, Psyttalia was Athens’ Alcatraz, a prison island for the Greek Navy. As a result,

Psyttalia has some historical significance, most of which is preserved. A small archeological site

remains untouched, as well as some graves.

The rest of the island, however, has been totally re-engineered since 1990 to accommodate sewage from

the bustling metropolis of Athens.

First of all, a small bay on the north side of the island was filled in with 2 million cubic metres of

excavated material. A total of 4 million cubic metres of earth was excavated to make room for the

island’s biological treatment. This involved building large 9.4- metre-high bioreactor/aeration tanks on

the island.

When the upgraded Psyttalia wastewater treatment plant is fully operational 800 tonnes of dewatered

sludge a day (with 28 percent dryness) will be produced. This must then be shipped back to the

mainland for disposal.

38

But depositing the sludge in landfill, as was done in the past, is becoming less of an option because of

increased pressure from the EU wastewater and waste directives.

“As far as final disposal options, the most promising solution is to thermally dry the sludge to 90

percent dryness and to use the dry granules as a fuel in the cement industry,” says Adraktas. “This is

our best option. The Greek government has applied for an additional 40 million euros in EU funding for

a sludge-drying plant.”

Olympic upgrade

ITT Flygt played a vital role in upgrading the Psyttalia wastewater

treatment plant in Athens to accommodate the Olympic Games.

The Psyttalia installation of Flygt pumps and mixers was the biggest

order ever for ITT Flygt Hellas, the Greek subsidiary.

A large number of pumps are used to transport the wastewater to the

island and throughout the different treatment processes. Seven

submersible PL 7101 Flygt propeller pumps are used to pump the

wastewater into the bioreactors.

Throughout the bioreactor tanks 36PP 4670 and 13 PL 7081 pumps

are used for recirculation. Forty-eight SR 4410 Banana mixers are

used to mix the bioreactor zones. An additional 24 SR 4650 mixers

are used for degassing at the bioreactor outlet.

Small municipal wastewater treatment plants in Greece

Introduction

In the USA, the projected need for small wastewater treatment plants is far greater than that

for large treatment plants. In the future, construction costs for new and improved small

decentralized systems will run into many millions of dollars (Crites and Tchobanoglous,

1998). Greece as a EU Mediterranean country, is not far from this situation. There is a large

number of small communities and the need for a clean environment has raised concerns for

effective wastewater treatment. The percentage of the population living in small communities

is low but most of them are located in tourist and sensitive areas where a clean environment

is essential both in terms of the environment and income generation. The purpose of

39

this study is to enlighten the municipal wastewater treatment for small communities in

Greece by providing statistical information, discussing problems and suggesting solutions,

on an integrated basis. The output is believed to be useful not only for Greece but for

other countries as well that are planning to implement wastewater management policies.

All data analyzed and presented in this paper are a selective output of a national survey

of all MWTP in the whole of Greece (Tsagarakis et al., 1998a); only small plants are considered,

i.e. those with p.e. less than 10,000. The time the survey visits took place was

between summer 1995 and summer 1997. The collected data stem from: (a) information

given by the personnel and management of plants, (b) available design data, and (c) on-thespot

investigations. Additional data were acquired by post or telephone contact, when

required. It is the first study that was implemented in an integrated way. There where statistical

information is given; this has been done for all plants. Where further analysis is carried

out like land requirements, construction and operation and maintenance (O&M) cost,

only plants that could give reliable data were considered.

Existing conditions

The number of small plants amounts to 147 out of the 241 located during the survey. Their

total potential capacity is equivalent to 7.5% of the population of the country served by

wastewater treatment. Current capacity, referred to as today’s population equivalent

(t.p.e.), is 3.2%. This means that, of the total population of Greece served, only 3.2% is currently

served by small plants. Analysis of the data collected per size is shown in Table 1.

The number of plants providing primary, secondary or advanced treatment is 2, 133 and 12,

respectively. Of these, 117 are suspended growth, 24 natural systems, and 4 attached growth

systems. Further classification of the systems is provided in Table 2. The two primary treatment

plants consist of mechanical pretreatment, sedimentation, chlorination and air drying

for sludge dewatering. From those plants that provide at least the secondary treatment it is

obvious that extended aeration is dominant system, as it provides additional advantages for

Mediterranean climatic conditions. Atypical flow train for the extended aeration type plants

40

is that the liquid line consists of mechanical pretreatment, aeration, sedimentation, and

chlorination. Those with nutrient control also include anoxic and anaerobic tanks (Figure

1a). Sequencing batch reactors (SBR) are not widely practised in Greece. The trend is to

convert SBR to extended aeration plants and most of them are already in the process of

redesign and reconstruction. Attached growth systems are also not popular in Greece.

Advanced wastewater treatment plants are mainly regarded those that include nutrient control

in a separate unit stage.

Natural treatment systems are unusual in the way most of them have been established.

Both waste stabilization ponds (WSP) and hydroponic silviculture were applied at a regional

level, initially by means of a prototype plant. However, instead of monitoring the proto-

41

Fig. 1 a, b, c Dominant wastewater treatment systems in Greece effluent

type to improve design and operation, subsequent plants were mostly a direct copy of the

initial design. This resulted in poorer performances than with the prototype, so engendering

the feeling that such systems are not appropriate for wastewater treatment. There is currently

a shift towards reed beds and it is believed that it is the optimum solution for small communities;

this is also verified by the first reed bed in operation (Avgitidis et al., 1996).

WSP have been implemented only in the Prefectures of Serres and Kavala. Process

design comprises one facultative and one to three maturation ponds, including in some

cases a rock filter prior to the outlet (Figure 1b). Their capacity ranges from 500 to 3,000

p.e. Maintenance is very limited and rooted macrophytes (even trees) occur in almost all the

ponds. Some have also reported mosquito nuisance. Clearly, the existing WSP need to be

upgraded in order to avoid the impression of their inappropriate applicability. Such upgrading

should include anaerobic ponds, as they are extremely efficient in removing BOD5, so

reducing land area requirements considerably (Mara and Pearson, 1998). Hydroponic silviculture

is a natural wastewater treatment process, applied in small communities on the

island of Evia in Central Greece, this consists of a septic tank, a lined multi-layered basin

planted with trees and a seepage well (Figure 1c). Their capacity varies from 600 to 1,500

42

p.e. When this system was established, the tree spacing was so small that their roots blocked

the subsurface flow very fast, so reducing the original bed porosity; as a result the whole

basin had to be replanted. When this problem was first noticed it was too late as many

installations had been constructed and planted in the same way. Further research should be

carried on optimal tree species and their spacing and feasibility of coppicing.

Operational evaluation

It is important to know the status of small MWTP in Greece in order to locate and to evaluate

any construction and/or operation problems. Depending on the status of the plant five

categories have been considered. The first is the category of failure. In this category have

been classified plants which are in operation for less than 10% of their prescribed time or 8

years since their construction was completed and have not operated since (this time is the

average guarantee of the electrical and mechanical equipment given by the construction).

Failure means that almost all of the mechanical equipment needs replacement and some

tanks may need reconstruction. The second category is that of the plants under construction.

The third category is that of the plants that are under construction, but construction works

had paused for more than one year. The construction level in this category is about 50%,

which is more or less equivalent to the construction of the civil works required. The fourth

category is that of the plants in which almost all construction works have finished but the

installations are not in operation due to other reasons. This means that even the mechanical

equipment has been completely installed. The construction level in this category is more

than 90%. The last category refers to the plants in operation. The number of plants per category

and their percentage of the total are summarized in Table 3.

It is pitiful that there are 45 “problematic” plants (i.e. plants which failed, construction

incomplete or completed but not in operation) equivalent to 31% of the total. The main

causes of this are: (a) incomplete sewerage systems, 22 plants; (b) inadequate funds for construction,

operation and maintenance, 15 plants; (c) legal proceedings arising from financial

43

problems and public reactions, 4 plants; (d) absence of discharge structure, 2 plants;

and (e) other causes, 2 plants. The average period not in operation for the plants in categories

3 and 4 (Table 3) is estimated to be 2.5 years. To avoid such problems, a general policy

is needed for improving the management of the allocated funds, in order to avoid

complete mis-investment. Construction of the sewerage, wastewater treatment and disposal

facilities should be planned together in order to optimise project management.

Institutional evaluation

Small villages and towns are subject to central Prefecture administration for technical projects,

as they are not always able to support technical services. Thus, construction of a

MWTPis supervised by Prefecture engineers. Projects are mainly subsidized from national

or EU funds, but O&M is financed from the community’s budget. The weak point here is

that one service is responsible for choosing the system and supervising construction and

another for operating it. The only service that small municipalities and communities can

support with their existing personnel is accounting. What happens most commonly is that a

local technician or unskilled employee is trained for some months to operate the plant, and

experience has shown that this is not adequate if there is no engineering and scientific supervision.

Additional contracts with consulting companies are required, but rarely entered into.

The construction supervision of the 147 plants has been carried out as follows: for 136 by

the technical services of the Prefecture, and for 11 by the technical service of the municipality.

From these only 4 are specialized enterprises for water supply and sewage, while the

other are general technical services. The 71 plants in operation are administrated and supervised

by different enterprises and services. Municipalities are in charge of 17; communities,

39; technical services of municipalities, 5; and specialized enterprises, 10. The performance

of these plants has been classified as poor, moderate, and good according to the responsible

agency (Table 4). Poor performance refers to plants whose effluent is almost always

below quality required; moderate performance, to plants that operate very close to requirements;

44

and good performance, to plants that operate consistently above requirements. This

classification has been made according to effluent data given plant personnel and our onthe-

spot investigation.

Inappropriate fund management is highly related to the public services that delegate

control and supervise transactions for the projects. Their inefficiency can subsequently

influence the wastewater sector. Construction control efficiency (i.e. delay of payments)

may delay the project from its start. In addition, many services are responsible for the same

project and thus mis-coordination exists. A weak point is that the water sector is mainly

governed by the Ministry of Agriculture, the Ministry of Environment and Public Works,

and the Ministry of Development. It is proposed that only one national authority is in charge

of water sector to provide more effective control and promote wastewater treatment.

Changes are needed in the water sector through which: (a) specialized agencies will be promoted,

(b) centralization of administration occurs in cases where there is inadequate individual

viability; and (c) geographical and hydrogeological based agencies are established,

which staffed with specialized personnel. It is then a political issue whether these services

will operate the plant or it will be subcontracted to private companies.

Future perspectives.

At present, a new local administration structure is being implemented,

called Ioannis Kapodistrias. The main innovation is that small local authorities compulsory

merge to form municipalities. Practically this is equivalent to improvement of economic

viability, local administration, and thus the potential of developing specialized agencies for

water supply and sewerage. It is too early to evaluate the output of this structure but is

expected to give a positive contribution to the municipal wastewater sector.

Legislation.

Greek legislation regarding small systems has to comply with the EU Council

plants do not always operate properly. Most of the time, the causes are non-technical and the

majority of them could have alleviated by better administration for construction and operation.

Effluent standards not only have to be established, but plants have to comply with

them. This will require adequate funding for personnel, equipment and consumables.

Johnstone and Horan (1994) provide further advice on this.

Technology choice and decision making.

Aspecific trend in wastewater treatment selection

has become apparent, not surprisingly perhaps as engineers and other decision makers prefer

what is already widely applied and tested: the large number of extended aeration systems

(110 out of 147) is evidence for this. Another critical concept is chosen destination for

the effluent. Although relatively high crop water requirement has been reported for Greece

(Tchobanoglous and Angelakis, 1996), the dominant effluent destination is not for irrigation,

45

but the sea (Tsagarakis et al., 1998b), influenced by northern EU countries.

Lack of training.

It has been widely reported that training of operators of small MWTP

should be carried out in order to secure a proper operation of the plant. This is clearly important

as their everyday responsibilities cover almost everything. In order to operate well,

plants should be designed and constructed properly. Yet at the local administrative level,

where government engineers check plant design, there is inadequate specialization.

Training programmes on environmental projects and pre-feasibility studies should be provided.

Training of engineers, and other technical personnel, is relatively straightforward,

but the training of other decision-makers, including politicians, is less so (and currently

does not exist).

Comparison of different technologies

The different systems used in Greece are compared in terms of land requirements, and construction

and O&M costs. In addition reference is made to the extended aeration (EA)

plants in regard to the sludge treatment they employ and nutrient control.

Plant area

The land required by a MWTP is a primary concern especially in places where the available

land is scarce or high cost. The availability of the land is the first decision making parameter

required to choose between different treatment processes. Land requirements per p.e. used

in 53 MWTP are presented in Table 5. The values given refer to the whole area of the instal-

lation, including any access paths or roads and other such as buildings and laboratory. In

areas where the land cost is high, land-demanding systems cannot be applied.

46

Construction cost

Construction cost is a crucial parameter of prime importance when a MWTP is being

planned. There are many parameters that can influence it. The construction cost data of 54

MWTP are analyzed after subtracting any tax and discounting by the inflation rate at the

beginning of the year 1999 (Anon., 1998) (Figure 2). At the time of analysis the exchange

rate was US$ 1=GDR 285 (Greek Drachma).

Operation and maintenance

O&M costs include personnel salaries, energy costs, chemicals, maintenance, and other.

Annual O&M costs from 23 plants operating at more than 70% of their capacity are given in

Figure 3. Analysis of the costs shows that personnel salaries account for 30% of the total

O&M costs, energy 50, chemicals 11, maintenance 8 and other 1. The personnel employed

can be divided into three main categories: scientific (with a higher education degree), tech-

nical and unskilled. The percentage of personnel per category is 15, 60 and 25%, respectively.

The average ratio of personnel employed per p.e. is 1/5,500.

47

Conclusions and recommendations

The main conclusions and recommendations which can be drawn from this study are as

follows.

Of the 147 MWTP considered, 48.3% are in operation, 17.0% are completed but not in

operation, 4.8% are incomplete, 21.1% are under construction, and 8.8% have failed. 117

plants were suspended growth systems, 4 were attached growth systems and 24 were natural

systems.

Existing natural systems need to be upgraded in order to improve the impression of their

applicability.

Incomplete sewerage system, cessation of the plants’ construction-operation and without

disposal system, due to inappropriate fund management has resulted in failure of 39

plants (i.e. 27% of the total).

Construction of the sewerage, wastewater treatment and disposal facilities should be

planned together in order to optimise project management.

In general, performance of small MWTP can be characterized as moderate. It is believed

that services in charge of construction and O&M are not the optimum ones. Training of state

engineers and operators and centralization of the administration would be beneficial.

48

AMMONIA AND PHOSPHORUS REMOVAL IN MUNICIPAL

WASTEWATER TREATMENT PLANT WITH EXTENDED AERATION

INTRODUCTION

Nitrogen appears in wastewater as ammonia, nitrite, nitrate and organic nitrogen. Organic nitrogenis

decomposed to ammonia, which in turn on one hand is assimilated to bacterial cells, leading thus to net

growth, on the other hand is oxidized to nitrite and nitrate. In a second step, nitrate is converted to

gaseous nitrogen and is removed from the wastewater. Denitrification is known to proceed as

conversion of nitrates to nitrites and subsequent conversion of nitrites to nitric oxide, nitrous oxide and

nitrogen gas. Nitrifying organisms are present in almost all aerobic biological treatment processes, but

usually their numbers are limited, depending on the mean cell residence time (because of the threshold

effect) and on the BOD5/N ratio. In most conventional activated- sludge processes, with a BOD5/N

ratio of 3, the fraction of nitrifying organisms is estimated to be considerably less than 0.083, while for

BOD5/N ratios of 5 to 9, the estimated percentage is between 0.054 and 0.029 (Metcalf and Eddy,

1991). Suspended-growth nitrification and denitri- fication processes are generally adopted to obey

Monod-type kinetics, with the maximum nitrification rate depending on temperature (T, oC), pH and

dissolved oxygen (DO, mg l-1).

Representative kinetic coefficients (ìm in d-1, KS in mg l-1, Y in mgVSS l-1, kd in d-1) are given in the

literature (Metcalf and Eddy, 1991). Phosphorus appears in wastewater as orthophosphate,

polyphosphate and organically bound phosphorus, the last two components accounting usually for up to

70 percent of the influent phosphorus. Microbes utilize phosphorus during cell synthesis and energy

transport. As a result, 10 to 30 percent of the influent phosphorus is removed during traditional

mechanical/biological treatment (Wenzel and Ekama, 1997; Mulder and Rensink, 1987; Metcalf and

Eddy, 1991; Henze, 1996; Sedlak, 1991).

When enhanced phosphorus removal is desired, the process is modified, so that the sludge is exposed to

both anaerobic and aerobic conditions. Then certain microorganisms, capable of storing phosphorus (in

the form of polyphosphates), metabolize it for energy production and cell synthesis, resulting in the

removal of phosphorus from the system through the waste activated sludge. The Metamorphosis/Attica

combined treatment plant was designed for full treatment of 24000 m3 d-1 of raw and highly dilute

septage whose design characteristics were (in mg l-1) : BOD5 = 1200, COD = 4000, SS = 2300, total

Kjeldahl N = 320 of whichNH4 + = 290 (Degremont, 1991) and of 20000 m3 d-1 of municipal

wastewater (65000 p.e.). Estimating one population equivalent (p.e.) at 70 g BOD d-1, with aeration

basin volume at 21000 m3, the design value for BOD/MLSS.d was 0.47. The plant was, thus, designed

to work as a conventional aeration system. It provides grit and grease removal, primary settling,

activated sludge, clarification and chlorination units for wastewater and anaerobic treatment, thickening

and dewatering for the sludge produced.

49

Municipal wastewater and septage follow separate treatment lines until the biological treatment unit.

However today, with the loads treated (i.e. BOD/ MLSS.d is about 0.2), the plant operates at extended

aeration conditions.

Actually the plant treats about 12000 m3 d-1 of municipal wastewater and 8000 m3 d-1 of septage and

unexpectedly introduced industrial wastes. The BOD5/N ratio of septage was found to have roughly a

value of 10 (mean of values throughout a year) (Andreadakis, 1989). A value of about 11 is reported in

literature (Metcalf and Eddy, 1991) while 10 is a typical value proposed by EPA (1984). At the

treatment plant of Kavala municipal wastewater (in Northern Greece) a value of 5 was measured (with a

design value of 6) (Liakos and Stamou, 1991). Based on the estimations mentioned above for the

percentage of the nitrifying microorganisms, the actual fraction is expected to be around 0.04. The

present study was undertaken to evaluate the extent to which ammonia and phosphorus are removed in

the Metamorphosis/Attica combined treatment plant.

MATERIALS AND METHODS

Two-hour composite samples were taken daily from Metamorphosis/Attica combined treatment plant.

These were withdrawn at the inlet of the activated sludge basin (two sampling points, one for municipal

wastewater and one for septage respectively) and at the outlet of the secondary clarifier. Analyses were

performed promptly after sampling.

Total nonfiltrable solids (TNFS) were determined as the retained material on a Whatman 3 qualitative

filter after filtration of a well-mixed sample. Total suspended solids (TSS) were determined after

centrifugation of a well-mixed sample at 8000 rpm for 15 min. Total volatile suspended solids (VSS)

were determined by igniting the samples at 550±50oC. Chemical oxygen demand (COD) was

determined by the dichromate reflux method. Ammonia nitrogen (N-NH4) was determined by the direct

nesslerization method. Addition of ZnSO4 was not necessary for the outlet samples, as they were clear

and colorless. Nitrate nitrogen (N-NO3) content of the outlet samples was determined by the UV-

spectrophotometric screening method. Orthopho-sphates (ortho-P) were determined by the vana-

domolybdophosphoric acid colorimetric method. Polyphosphates were indirectly determined by the

acid hydrolysisvanadomolybdate method and calculated as the difference between acid-hydrolyzable

(hydr.-P) and orthophosphate phosphorus. All analyses were performed to filtered samples according to

APHA 15th ed. 1980. Total phosphorus (tot.P) was determined according to a digestion method

proposed by Hach.

AMMONIA AND PHOSPHORUS REMOVAL 49Co. (reagents : mixture of sulfuric acid 97%

andhydrogen peroxide 30%, 2,4-dinitrophenol indicator, potassium hydroxide) (Hach Co., 1987),

followed by orthophosphate determination as above. A Perkin-Elmer spectrophotometer model

550Swas used. Sampling was performed over a period of two months during winter. This time interval

50

was estimated to be adequate, as no major unusual events or accidental overflows were observed during

the sampling period.

RESULTS AND DISCUSSION

The daily values of ammonia and nitrate nitrogen, phosphates and total phosphorus (mg l-1) are

presented in Figs. 1-2. A relatively stable pattern can be seen to prevail, except for the total P values,

which, because of the introduction of some industrial loads, known to happen eventually, were

abnormally high. These high values are not considered when calculating typical values and estimating

microbial population characteristics.

Average values as well as the standard deviation

Figure 1. Amounts of NH4-N in the inlet and outlet and of NO3-N in the outlet of the aeration basin at

Metamorphosis / Attica and the range of the measured parameters are reported in Table 1.

51

As can be seen from Table 1, inlet values show a wide variation, which seems to be reduced at the

outlet.

Ammonia is almost completely (98%) eliminated within the plant. Orthophosphates removal

52

varies between 14 and 58% (average 28%), while total phosphorus is removed by 11 to 48% (average

15%). These findings are in good agreement with removals reported in literature: Henze (1991) and

Metcalf and Eddy (1991) report values of 10-25% for phosphorus removal during secondary treatment.

On the other hand, 0.5-1 mg N-NH4 (gMVLSS h)-1 can be assimilated in extended aeration systems

(CEMAGREF, 1990, Eckenfelder and Argaman, 1991). In our case, ammonia assimilation is calculated

to be around 0.7 mg N-NH4 (gMLSS h)-1. Wenzel and Ekama (1997) estimate the phosphorus content

of sludge to 2-4%. In our case, with sludge production estimated at 0.8 times BODinlet, phosphorus

removal is estimated at about 100 kg total-P d-1, with average actual values of 80 kg total-P d-1. The

fact that orthophosphates removal is higher than that of total phosphorus, however strange may it seem,

is probably linked to the poor orthophosphate content of the septage and to the nature of the industrial

wastes, accidentally introduced to the treatment plant.

In Table 2, data for the combined septagewastewater plant at Metamorphosis/Attica are reported.

According to the data of Tables 1 and 2, a mean ratio Peliminated /CODeliminated (mg g-1) value of 8

is calculated. Mulder (1987) attributes a value of 6 to the same ratio for a conventional plug-flow

fullscale plant train operating at 8-16oC, 2.6 h retention time, with 16% P removal, having a capacity of

40000 p.e., where about 75% of the influent is domestic. Ammonia utilization rates [UN, gN-NH+ 4

(gMLSS d)-1] can be calculated by the following equation:

(Q1*N01+Q2*N02) - (Q1+Q2)=UN*X*V

where,

53

Q the volumetric feed rates, (m3 d-1),

X the mixed liquor suspended solids content of the aeration tank (MLSS, g m-3)

N the appropriate ammonia concentrations (g m-3).

Indices 0 are attributed to inlet values, while indices 1 and 2 to municipal wastewater and septage,

respectively. The basin volume V is 21000 m3. Daily values of ammonia utilization rates are presented

in Fig. 3.

AMMONIA AND PHOSPHORUS REMOVAL

Kinetics and kinetic coefficients proposed by Metcalf and Eddy (1991) are assumed. The pertinent

equations are:

UN = k.N/(KN + N) (2)

KN = 10(0.061T-1.158) (3)

k = ´m / Y (4)

m=ìm.[e0.098(T-15)].[DO/(KO2+DO)].[1-0.833(7.2-pH)] (5)

where,

k maximum rate of substrate utilization, time-1

N N-NH4 + concentration, mg l-1

KN half-velocity constant, mg l-1

54

µ΄m specific growth rate, time-1

µm maximum specific growth rate, time-1

KO2 equal to 1.3

Y maximum yield coefficient, equal to 0.2.

From the data of Tables 1 and 2, the effective specific growth rate µ´m (relative to ammonia removal)

of the biomass in the activated sludge basin can be estimated. Comparison of the values obtained with

values predicted from literature for nitrifying biomass (Metcalf and Eddy, 1991), can give an estimation

of the percentage of nitrifiers in the activated sludge population. Following the above mentioned pro-

cedure and based on the data presented in Tables 1 and 2, the percentage of nitrifiers in the activated

sludge population is estimated between 0.4 and 2.4%, with a typical value of 1.1%. Daily estimated val-

ues of the percentage of nitrifiers in the activated sludge population are presented in Fig. 4.

Phosphorus uptake rate (UP, mg P l-1 d-1) can be

calculated from the following equation:

(Q1P01+Q2P02)-(Q1+Q2)P=UP V (6)

with P the appropriate total phosphorus concentrations (mg l-1).

Daily values of phosphorus uptake rates are presented in Fig. 5.

55

Assuming that phosphorus uptake (Up) in the aerated tank is proportional to cell formation (rX, mg

VSS.l-1. d-1) we have:

UP = – aP (rX) = aP a(–rs) (7)

where,

rX is proportional to substrate elimination (-rS, mg BOD5 l-1 d-1) and calculated from a mass balance

equation similar to equation (6), aP is the phosphorus content of the activated sludge [mgP (mgVSS)-1]

a is the maximum yield coefficient [mg VSS (mgBOD5)-1], taking values between 0.4 and 0.8, with a

typical value of 0.6 (Metcalf and Eddy, 1991). Using the data presented in Tables 1 and 2 and following

the procedure described above for the estimation of nitrifiers, a value of aP (the phosphorus content of

the activated sludge) between 0.0082 and 0.066 gP (gVSS)-1, with an average value of 0.031, is estim-

ated.

Daily estimated values of the phosphorus content of the activated sludge are presented in Fig. 6.

56

CONCLUSIONS

Although the Metamorphosis/Attica combined treatment plant for municipal wastewater and septage

was designed as a conventional activated sludge plant, it is actually operating as a treatment plant with

extended aeration. Removal rates are, however, quite high; suspended solids are removed at a rate of

87% that is within the range expected (85 to 90%). COD removal has a value of 92%, a value, which is

considered to be quite satisfactory. Ammonia is almost completely eliminated within the plant, due to

extensive aeration of the wastewater. Orthophosphates and total phosphorus show removal Figure 6.

Daily estimated values of phosphorus content of the sludge in the aeration basin. values of about 28%

and 15%, respectively. Neither during the design nor at the initial stages of plant operation was the fate

of nitrogen and phosphorus taken into consideration. The fact, however, of the successful operation of

the modified plant, as indicated by the measured COD and suspended solids removals, is further sup-

ported by the, well within the expected range, removals of ammonia and phosphorus.

Assuming suspended-growth nitrification and denitrification kinetics proposed in literature, the,percent-

age of nitrifiers in the activated sludge population is estimated between 0.4 and 2.4%. Assuming hat

phosphorus removal in a conventionally aerated tank is proportional to cell formation, which in turn is

proportional to substrate elimination, the phosphorus content of the activated sludge is estimated

between 0.0082 and 0.066 gP (gVSS)-1. Acknowledgments The authors wish to thank EYDAP (the

Water Authority for the Athens greater area) for providing us with permission of entry into the treat-

ment plant. They also thank the staff members of the Metamorphosis / Attica combined treatment plant,

especially Mr H. Thodos, for kindly sharing the technical data of Table 2 and providing liquid samples,

as well as for their pertinent advices during this study.

57

APPLICATION OF COST CRITERIA FOR SELECTION OF

MUNICIPAL WASTEWATER TREATMENT SYSTEMS

1. Introduction

Greece, a typical Mediterranean country, has closely followed the most of the

advances in wastewater technologies. However, many of the technologies which

have been implemented have been largely influenced by northern EU countries

(Tsagarakis et al., 2001a).

Water, Air, and Soil Pollution 142: 187–210, 2003.

© 2003 Kluwer Academic Publishers. Printed in the Netherlands.

188 K. P. TSAGARAKIS ET AL.

This is particularly true for the 1990s, mostly as a

consequence of EU Directive, 91/271/EEC (CEC, 1991), which deals with the

treatment of urban wastewater, and the fact that funds were available from various

EU programmes, such as the cohesion programme, providing economic support for

the construction of MWTP.

All over the world the wastewater technology has been improved substantially

during the last few decades. However, in several parts of the world, decisions on the

more efficient use of the appropriate technology, are often made not on the basis

of the general benefit but are dictated by various ‘factors’, which often result in

wrong directions and decisions and of course high cost installation.

The high cost (for construction, maintenance, and operation) of the most conventional

treatment processes has brought about economic pressures to societies

even in the developed countries, and has forced engineers to search for creative,

cost-effective and environmentally sound ways to control water pollution. At the

present time, it is recognised that even in the developed world complete sewerage

and treatment systems covering 100% of the population may never be possible

to be implemented unless wastewater management is based on selecting the

cost-effective technologies. Therefore, it is clear that cost for construction, operation

and maintenance of a MWTP will play a great importance in wastewater

management strategies in most parts of the world.

Cost functions of the form y = a x b, where a and b are calculated coefficients,

have been used to express land requirements, construction and O&M costs (WRc,

1977; Uluatam, 1991; Okubo, et al., 1994; Balmér and Mattsson, 1994; Xian-wen,

58

1995). Construction cost equations for MWTP of Greece have also been produced

by Aivaliotis et al. (1991) and Stamou et al. (1995). This type of formula has been

also used in this article. The way of data extraction may differ among authors, i.e.

analytically or real values. Moreover, authors may not include the same factors

into the costs. Therefore, cost is regarded as a critical parameter in wastewater

management.

When selecting a system to treat municipal wastewater, initially all processes

are theoretically competitive. To determine the best option three major analyses

should be undertaken (Tsagarakis et al., 2001a). First, the required effluent quality

should be considered. Effluent quality is considered to be of secondary level of

treatment as it is defined by EU legislation. Then a number of aspects which could

restrict the applicability of some processes should be examined. These aspects

are economic, institutional and political, climatic, environmental, land availability

and properties, sociocultural, and others. Finally, a cost-effectiveness analysis

should be carried out to determine the optimum economically viable solution as

the selection criterion.

This article addresses the latter issue and is aimed at helping engineers to evaluate

wastewater projects. It provides real data on the costs of MWTP that has come

out from the field. A cost-effectiveness criterion is presented to enable different

treatment systems to be evaluated.

2. Methods and Materials

Data collected for this article came from a national survey of all MWTP (Tsagarakis

et al., 1998, 1999a COST CRITERIA FOR SELECTION OF MUNICIPAL WASTEWATER

TREATMENT SYSTEMS 189).

Because the data came from fieldwork all the values are

real, and in many cases varied considerably from the analytical pre-estimations.

Obtained data are the most that could be taken out of the MWTP of Greece as one

specialised engineer has visited all the plants and carefully screened data, which is

now analysed to provided all possible experience obtained.

In Greece the dominant wastewater treatment systems are those based on activated

sludge (AS) processes. These were the only systems capable of yielding

adequate data for economic evaluation, apart from a very few natural systems. The

analysis that follows includes these activated systems and the few natural ones.

Although for the latter the data are limited, the available information has been very

carefully evaluated in the absence of any other way of obtaining such information.

In those cases where data have come from only a few plants, this is made clear to

the reader.

59

The dominant activated sludge systems examined were either conventional or

extended aeration (EA) with mechanical dewatering (MD) or air drying (AD). All

of the mathematical formulae presented are derived after analysis of statistical data.

The main treatment units employed for each system are as follows:

(a) For conventional: preliminary treatment, primary sedimentation, aeration, secondary

sedimentation, chlorination, thickening, digestion, and mechanical

dewatering.

(b) For extended aeration with mechanical dewatering: preliminary treatment, aeration,

secondary sedimentation, chlorination, thickening, andmechanical dewatering.

(c) For extended aeration with air drying: preliminary treatment, aeration, secondary

sedimentation, chlorination, thickening, and drying beds.

Data were also sought from all existing systems which could give a similar level

of treatment to activated sludge systems. These included three reed beds and one

waste stabilization pond (WSP). The reed beds typically consist of pre-treatment,

sedimentation, primary and secondary beds, sludge drying beds, and temporary

storage reservoirs. TheWSP consists of anaerobic, facultative and maturation ponds

and filtration.

The cost of land, construction and operation and maintenance are the three major

parameters of the total cost that need to be taken into account in an economic

analysis and are therefore analyzed in detail. Where adequate data are available,

equations have been produced. More detailed analysis of the data can be found in

Tsagarakis (1999).

For the following analyses, MWTP have been categorized into three sizes depending

on the population equivalent (p.e.) that they are servicing: small (500–

10 000 p.e.), medium (10 000–100 000 p.e.) and large (>100 000 p.e.).

3. Land

The amount of land required for oneMWTP is of primary importance, especially in

locations where land is scarce or expensive. The area required for a given system

can be predicted by evaluating data from existing installations. The size of the

area needed for a MWTP mainly depends on the level of treatment, the processes

and systems employed, and the size of the plant. Additionally, the area may vary

60

according to other parameters such as availability and ownership, topography of the

site, spaciousness and layout, specific equipment, and extra system support used.

3.1. LAND REQUIREMENTS

The waste treatment process used may differ according to the liquid and sludge

line. Weighted land requirements per population equivalent for alternative treatments

are summarized in Table I. The values given represent the entire area of the

installation including any access paths or roads and ancillary units such as offices,

store rooms, labs, etc. As would be expected ‘intensive processes’ need less space

than natural ones, at the expense of more mechanical equipment and higher construction

and operation and maintenance costs. In the small systems category, for

example, reed beds require an area ten times larger than that required by extended

aeration systems employing mechanical dewatering. Conventional activated sludge

plants need less land than extended aeration plants. This saving is about 15%

for medium size plants and less for large ones. Small and medium size activated

sludge systems employing mechanical dewatering require 60 and 20% more space

per p.e., respectively, than larger ones. Moreover, a small activated sludge system

employing air drying requires 75% more area per p.e. than a medium size one.

In addition to the average values given in Table I, values for land requirements

for the three dominant systems are shown in graphical form in Figure 1.

3.2. ECONOMIC COST OF LAND

When urban land is considered its economic value may not coincide with its financial

value. For example, the land required for the construction of WSP may be

owned by the government, and the government may decide to give it to the sewerage

authority at no financial cost. However, its economic cost should be calculated

61

on the basis of what it would have been worth had the government sold it to, for

example, a commercial buyer such as a company or a farmer. An idea of this value

can be obtained from recent sales of land in the area (Mara, 1996). The cost of land

may vary considerably depending on its use, its productivity, potential alternative

uses and its availability.

When land is used for agricultural production, its economic cost can be based

on its agricultural production capacity.

62

For this study, data were provided by the internal revenue official quarters by

telephone (Internal Revenue, Telephone conduct with the prefectural revenue of-

fices of Greece). They represent the values of the latest land transactions in the

various areas under consideration. According to this the value of agricultural land

varies between US$0.17 and US$7.00 per m2 (at the beginning of 1999 GRD 500

approx. £1; GRD 300 approx. US$1; GRD 320 approx. 1 euro). Where land is

suitable for building, is close to the sea, or has an additional value, its price may

rise to a maximum of US$170 per m2.

4. Costs of Construction

The costs of construction normally include those for civil works, mechanical works,

buildings, engineering designs and supervision of on-site infrastructure, start-up

costs and working capital. The construction cost (Cc) depends on a number of parameters.

The main ones are the level of wastewater treatment required (the greater

the level of treatment the higher the cost) and the capacity of the installation (cost

per p.e. decreases with increasing capacity due to economy of scale and processes

and systems employed). As well as these, a number of individual local factors may

arise which increase the construction cost. The most common ones are special site

preparations, quality of materials used, tender procedure, housing of unit processes

other than preliminary works, and others; such costs are not included in the values

given.

The construction costs given have had taxes subtracted from them and have been

adjusted to give the equivalent cost as at the beginning of 1999. A full explanation

on how cost is obtained is given later in the article.

Table II shows weighted costs per system and category. Note that the costs

for replacement of major mechanical parts (pumps, blowers, motors, etc.), which

would normally be regarded as capital costs, have been incorporated into the maintenance

cost because it was not possible to separate these costs out (see also next

section).

Statistical data were obtained for the dominant systems. These data were processed

and presented in graphical form to enable construction costs to be predicted

(Figure 2). These systems employ the same typical units as described above for the

liquid and the sludge line.

63

64

5. Operation and Maintenance

The costs of operation and maintenance (O&M) can be divided into four major

categories: personnel, energy, chemicals and maintenance. The costs of sludge

treatment and disposal are included within these. Additional costs may be incurred

which cannot be put into these categories. These costs may include infrastructure,

building, and landscape maintenance, administration, consumables and other

expenses.

Each of the four major categories are discussed below. Emphasis is given to the

personnel and energy costs as these account for most of the cost of operation and

maintenance. Their analysis is needed to ratify the life cycle analysis.

O&M cost may differ also according to the quality of the effluent of the plant.

Those MWTP evaluated in this article has been those that were operating well and

were producing effluent quality within the limits posed by national legislation.

5.1. PERSONNEL

The major parameters that influence the number of personnel employed in MWTP

in Greece are: the degree of automation; the size of the installation (the larger the

installation, the fewer the personnel per p.e.); the treatment processes and systems

(natural processes require fewer personnel); the availability of funds (richer communities

may employ more personnel); productivity efficiency of personnel (this is

closely linked to the country’s institutional and administration system); managerial

efficiency; and other (political, social, etc.).

The quality of the personnel employed in a MWTP play a key role in its proper

operation. Scientific education and special training are essential prerequisites to

achieving high operation proficiency. Plant operators can make a plant of relatively

poor design perform well and, conversely, they can cause the best designed plant

65

to function poorly (Michel et al., 1969).

Data on personnel from 66 activated sludge systems have been evaluated. The population actually

served (today’s population equivalent, t.p.e.) amounts to at least 70% of the p.e. (population equivalent

for which the plants were designed) in all the installations. The data show that 302 people were

employed with the total t.p.e. and p.e. of these plants being 2 483 886 and 1 951 605, respectively.

Personnel working part-time have been ascribed the appropriate percentage (%) of workdays.

5.1.1. Number of Employees

The relationship between p.e. and t.p.e. and the number of personnel employed in MWTP has been

analysed. The numbers of p.e. and t.p.e. per employee in activated sludge systems in relation to the

plant size are shown in Figure 3. This figure shows the number of the p.e. equating to one person

employed in a MWTP. The only conventional activated sludge plant that falls in the small category

gave a figure of 3571 p.e. and t.p.e. per employee. It can be noticed that small installations need more

personnel per p.e. than larger ones. This is a result of economy of scale achieved in larger plants. In

addition, in small and medium size plants, conventional systems seem to be more costly in terms of

personnel in comparison with extended aeration plants.

66

5.1.2. Level of Education and Expertise

Personnel can be placed in one of three categories according to the education they received before being

employed at a MWTP: scientific (with a higher education degree), technical and unskilled. For all

personnel the percentages per category

are: scientific, 23; technical, 45; unskilled, 32. Two graduates with a Ph.D. degree were found to be

working full time in aMWTP. Figure 4 shows how the proportion of personnel in each category of

education varies with the size of the installation. It can be seen that smaller installations employ fewer

scientific personnel and fewer unskilled labourers, with higher numbers of technical personnel. There

are likely to be two reasons for this. Firstly because small installations have less complicated systems

and secondly small towns find it difficult to employ personnel with a scientific education, relying

instead on local technical personnel. An analysis of the different professions of MWTP personnel was

undertaken and is shown in Table III. Chemical engineers and chemists are the most dominant graduate

employees in MWTP. Chemical, electrical and mechanical engineers

mainly work as control engineers, while technologists are in charge of the technical supervision.

Technologists come from technical colleges which do not have university status. The period of study

for a technologist is 3–4 yr, in contrast to 5 for engineers. Fewer biologists are employed compared

with other countries. Ideally, a MWTP would have an input from all kinds of professionals. However,

67

this is unfeasible for all but the very large installations and for centralized agencies with a number of

plants under their jurisdiction.

5.1.3. Cost of Personnel

The cost of personnel will normally include salaries/wages, pension and insurance costs. A typical

working week consists of five working days per week, with a month’s leave over a year. Depending on

a system’s requirements, there can be

one, two or three eight-hour shifts for specific positions. The cost to the employer of an annual salary,

including insurance, starts from US$17 000 for an unskilled worker and can reach twice that amount for

an engineer.

68

As previously noted, a factor that influences personnel costs is the degree towhich the plant is

automated. Although automation requires considerable capitaloutlay as well as specialized personnel to

operate the plant, there is a concomitant reduction in the number of employees needed (Drake and Page,

1981). Greek MWTP examined in this study were not highly automated, especially those of small and

medium size. Kemper et al. (1994) showed that in developing countries the cost of personnel in the

wastewater treatment sector is proportionately higher than for developed countries. In Greece the cost

of personnel is 48% of the total cost for operation and maintenance of a MWTP. For France the figure

is 24% and for Great Britain 38%.

5.2. ENERGY

Energy consumption is a major contributor to the operational cost of a MWTP. For a meaningful cost

comparison it is clearly important to know the number of kWh consumed per p.e. for different

wastewater treatment technologies (Table IV). Table IV shows that smaller systems require more

energy in terms of kWh per p.e. than larger systems. Medium sized systems operating conventionally

need more energy than extended aeration systems, although the opposite would be expected.

Furthermore, large conventional MWTP are not as economical as expected in comparison to medium

sized installations using extended aeration. The main reason for this is that the process was selected

without adequate consideration of the size of the plant. When considering energy consumption,

conventional systems should be employed for MWTP that are larger than those that currently operate in

69

Greece. There are other reasons that account for the high energy consumption of conventional systems

compared to extended aeration systems. These are as follows: (a) Conventional systems in Greece

operate at low F/M ratios (0.1–0.2). (b) In extended aeration systems denitrification takes place, which

gives back a small part of the energy consumed by utilisation of the oxygen produced. (c) Conventional

systems often require additional energy-consuming processes or infrastructure, such as primary

sedimentation or laboratories.

On the other hand, conventional systems based on anaerobic digestion may enable some energy

reduction by recycling the biogas produced. None of the plants surveyed for this study was producing

energy from biogas, thus data in Table IV do not reflect any savings from energy produced from biogas.

Automation and control is another important factor that influences the overall energy demand. On-line

alterations to the aeration times according to the on-line requirements of the system can save a

substantial amount of energy. During the survey for this study it was reported that after operating an on-

line control system there were considerable savings on energy consumption.

5.3. CHEMICALS

Chemical costs included the purchase costs of one or more of the following: polymers, alum and lime

for sludge conditioning; NaOCl, Cl2, Cl2O, O3, for disinfection; reagents for laboratories where

applicable; and other. The cost of chemicals used is dependent on correct dosing, quantities kept in

stock, and purchasing deals.

5.4. MAINTENANCE

Maintenance costs included one or more of the following: regular repairs (mechanical, electrical,

electronic and civil parts); minor or major replacements (small or large parts for pumps, blowers,

motors, etc.). Quantities of spare parts kept in stock and purchasing deals influence the total

maintenance cost.

5.5. OVERALL OPERATION AND MAINTENANCE COST

The overall annual O&M weighted costs for different systems and sizes were analysed and are shown in

Table V. These costs do not include taxes and are at early 1999 prices. The breakdown of this cost into

the various category of installation is shown in Figure 6. Note that sludge treatment cost is included in

these values. Sludge disposal costs are minor as they normally only include transportation to the landfill

site; because the landfill and the MWTP are usually owned by the

70

.

municipality there is no disposal charge. The cost of sludge treatment and disposal is difficult to

separate from that of the liquid line for two main reasons: firstly, tendering does not usually consider

the processes’ construction separately; secondly, the municipality usually owns the tip used for the solid

waste disposal and permits the disposal of the sludge as well. Thus, the only disposal cost is

transportation.

Therefore sludge treatment and disposal costs are included (Tsagarakis et al., 1999b). Statistical O&M

cost data on the dominant systems are presented in graphical form in Figure 7. The average of annual

operational cost has been considered, which includes short run costs and annuitised long run costs. The

main conclusions which can be drawn from this analysis are as follows: (a) Natural systems require a

much lower O&Mcost per p.e. compared to activated sludge systems. (b) Medium-sized conventional

activated sludge systems require a higher O&M cost per p.e. compared to extended aeration systems.

(c) Medium-sized conventional activated sludge systems require a higher O&M cost per p.e. compared

to extended aeration systems. They need to employ more personnel per p.e. and are more energy

demanding. In addition, more graduates are employed necessitating higher salaries. Existing systems

should be monitored to find out the design range which makes conventional MWTP more economically

sound than extended aeration installations.

6. Methodology for Economic Costing of a Life Cycle Analysis

A LCA will be performed in order to evaluate the different wastewater treatment alternatives. Crites

and Tchobanoglous (1998) define total life costs as the total costs accrued during the project lifetime.

These costs are computed by combining

71

amortized capital costs with annual operation and maintenance costs. WEF and ASCE (1998) also

propose a LCA for the analysis of alternative processes. The steps for the calculation of life costs are

described in detail by Mara (1996). The ultimate decision criterion is the total annual economic cost

(TAEC). LCA has been undertaken for the systems which provide data concerning land requirements,

construction and O&M cost. The methodology of LCA from raw cost data has gone through the

following steps:

6.1. SUBTRACT ANY TAXES FROM THE HISTORICAL COSTS

The cost paid must be adjusted appropriately to reflect the real economic cost, that is the real cost to the

country’s economy. For this reason any taxes must be subtracted as they are merely a transfer of money

within the economy.

6.2. SET APPROPRIATE DISCOUNTING RATES

To correct historical values to the present, the appropriate rate will be the one which equates present

day costs with those of previous years. The relevant rate for adjusting historical costs to the present is

72

regarded the inflation rate. The rate that will be used for opportunity cost of capital (OCC) is one which

subtracts expected inflationrates from long term borrowing rates. Both these rates are subject to change

through time. As OCC is an estimation, a sensitivity analysis is recommended.

6.3. CORRECT HISTORICAL COSTS TO THE PRESENT

To calculate the present value (PV) of a historical cost (HC), Equation (1) is used:

PVt = HCt * (1)

where ft is inflation at different time t . (n = 0 – (t-1) ??)

6.4. MAKE DEFINITE INVESTIGATIONS AND DECISIONS ON COST PARAMETERS

The systems which gave adequate data for the production of equations are conventional activated

sludge, extended aeration with mechanical dewatering and extended aeration with air drying. The

equations produced are summarized in Table VI are shown in graphical form in Figures 1, 2 and 7.

They are all of the form y = axb.

This formula has been widely used to express land requirements, construction and O&M costs. Land

cost is related to the land requirements. Using equations derived from Figure 1 and land values from

recent transactions, the cost of land can be calculated. A typical value of US$17 per m2 has been used

but a sensitivity analysis needs also to be undertaken on the land cost.

6.5. CALCULATE THE CAPITAL RECOVERY FACTOR

Annuitization is simply a way of calculating an annual cost which, when multiplied by the design life in

years, ensures that the capital sum and interest are both fully paid off by the end of the life of the

system. The construction costs are annuitized by multiplying by a capital recovery factor (CRF), which

is calculated by Equation (2):

CRF= (2)

where r is the OCC and t is the design life of the system.

A value of 6% can be regarded as OCC. For the MWTP an economic life of 20 yr is predicted. The

CRF is 8.72% for OCC equal to 6%.

CRF = 0,06*(1+0,06)^20 / ((1+0,06)^20-1) = 0,0872

6.6. CALCULATE THE TOTAL ANNUAL ECONOMIC COST

73

The total annual economic cost (TAEC) of the system is given by the sum of annuitized capital cost

(Cca), which consists of land cost and construction cost (Cc)

6.7. SENSITIVITY ANALYSIS

Sensitivity analysis is undertaken when there are factors which may considerably influence the

economic analysis and which could lead to different conclusions. As stated already, two factors will be

considered for sensitivity analysis. These are the OCC and cost of the land. A sensitivity analysis helps

evaluate the risk from inputs that may vary considerably.

7. Application of LCA for MWTP in Greece

The LCA is first applied to the dominant AS plants. Sensitivity analysis follows for the OCC and cost

of land as discussed before for plants of medium size (10 000– 100 000 p.e.) based on 50 000 p.e.

systems. A sensitivity analysis is also applied to small systems and especially those where capacity is

500–5000 p.e. The analysis has been performed for the size of 3000 p.e., because the majority of the

74

MWTP to be constructed fall into that range. The systems which fall into this size are extended aeration

employing mechanical dewatering, extended aeration employing air drying,WSP and reed beds.

However, due to the very small number of reed beds and WSP currently used in Greece, size analysis

for these could not be applied.

7.1. LCA FOR ACTIVATED SLUDGE SYSTEMS

A LCA for the activated sludge systems is shown in Figure 8. The low effect of the land to the TAEC

and the increased cost per p.e. of smaller systems can clearly be seen. It can be concluded that the most

economic systems are extended aeration with natural air drying, followed by extended aeration with

mechanical dewatering.

The least cost-effective is the conventional activated sludge system. This was a rather unexpected

finding, as conventional systems are regarded to be the cost effective. The reasons for their relatively

poor cost-effectiveness, which were discussed earlier, can be summarized as high energy costs due to

lack of automation and operation at low F/M ratios (see Section 5.2); high personnel cost (see Section

5.1); and inappropriate system selection (Tsagarakis et al., 2001a): it seems that conventional plants

should be selected for flows larger than those currently practised. Thus, the significant issue related to

why high numbers of activated sludge systems have been selected should be further considered

(Tsagarakis, 1999). Engineers and other decision-makers tend to choose tried and tested technologies,

which is not altogether surprising. After a process-system has been established, it is not so easy to

consider different ones. The destination for the effluent is another critical factor in the choice of

technology for wastewater treatment. Although there is a high demand for water for agricultural crops

in Greece, most effluent is not reused for irrigation but is instead disposed of in the sea (Tsagarakis et

al., 2001b), practices influenced mainly by northern EU countries.

7.2. SENSITIVITY ANALYSIS FOR THE OCC

The range of the hypothetical OCC, 0 to 10%, will be examined. This is undertaken for different size of

MWTP and constant land value (Figure 9). It can be noticed that there is no significant change in the

systems’ classification although it seems that reed beds are less favorable as OCC rises. This is due to

their high capital cost compared to the annual O&M.

7.3. SENSITIVITY ANALYSIS FOR THE COST OF LAND

As noted earlier the cost of land can vary considerably. In agricultural areas land is cheap,

costing as little as US$0.17 per m2 in isolated areas close to the borders with Turkey and

Bulgaria. On the other hand in areas near to the urban centers or to the

75

sea that can be used for tourist purposes land can cost US$170 per m2. These two extreme examples,

illustrating that the price of land can vary a thousand-fold, are not just hypothetical limits. There are

MWTP in Greece where the occupied land has cost that little or that much. However, most values

would be less than US$70 per m2. A sensitivity analysis for the cost of land is shown in Figure 10.

WSP is the most cost effective system followed by extended aeration with air drying, then extended

aeration with mechanical dewatering and finally the least economic are the reed beds. Note that

construction cost does not include major site preparation works. For example, site preparation cost will

be higher for WSP at rocky areas.

On the other hand, land value may considerably influence classification of systems. WSP seem to be the

optimum systems where land costs less than about US$30 per m2. For higher land values, EA with air

drying is the preferable system. For land values in excess of US$43 per m2, WSP are less economically

76

attractive, even compared with EA with mechanical dewatering. The latter is the most expensive option

when the cost of land is less than US$7 per m2. For land costing more than that, reed beds are

economically the least cost-effective systems. WSP can be used when land prices are low and the

topography and geology are suitable. This has also been shown by similar studies from Arthur (1983)

and Batchelor et al. (1991). Reed beds are not economically attractive, because they cannot offset their

high construction cost with a low O&M cost. A study mentioned in Batchelor and Loots (1997) also

compares reed beds and activated sludge systems and highlights the high construction cost compared to

the O&M costs. Its should be pointed out however that land for natural processes will hardly need no or

minor earth works. Therefore an additional major cost should be expected in many cases.

8. Concluding Remarks

To undertake a proper economic analysis of wastewater treatment options, data should be sought from

projects constructed in the past. All costs should be included and properly evaluated with a cost-

effectiveness criteria. The analysis presented in this article offers a rational way to select the most cost-

effective technology based on the impact of real-average-cost values. A sensitivity analysis is

undertaken to take account of specific local variables and risk management. The results of such an

analysis should indicate the most preferable technology under normal conditions. However, there is no

universally applicable system for evaluating options in all conditions, and each case should be

considered individually after taking into account all local parameters that might influence the total

annual economic cost.

77

CHANGES IN WASTEWATER TREATMENT IN REGIONS OF

EUROPE BETWEEN 1980s AND LATE 1990s.

Only countries with data from all periods included, the number of countries in parentheses.

Nordic: Norway, Sweden, Finland.

Central Europe: Austria, Denmark, England, Wales, Netherlands, Germany, Switzerland.

Southern: Greece, Spain

AC: Bulgaria, Poland, Estonia, Hungary and Turkey

Over the last twenty years, marked changes have occurred in the proportion of the population connected

to wastewater treatment as well as in the wastewater treatment technology involved. In northern

countries most of the population are today connected to wastewater treatment plants with tertiary

treatment, which efficiently removes nutrients (nitrogen or phosphorus or both) and organic matter from

the wastewater. In the central Europe countries more than half of the wastewater is treated by tertiary

treatment. Southern countries and the Accession countries only have around half of the population

connected to wastewater treatment plants at the moment. 30 to 40 % of the population are connected to

secondary or tertiary treatment. These changes have resulted in improvement of the state of water

bodies with a decrease in concentration of orthophosphates, total ammonium and organic matter over

78

the past ten years. For nitrate however no clear trend can be found at a national level though at the

monitoring station level a decrease in concentration can be found at some stations. In the EU these

decreases are linked with the implementation of European legislation. In the Accession Countries

decreases are due to the general increase in the level and extent of waste water treatment and because of

the recession associated with the transition to market-oriented economies (see WEU2). The increase in

the proportion of the population connected to waste water treatment, as well as in the level of treatment,

leads in turn to an increase in the quantities of sewage sludge produced. This sludge has to be disposed

of, mainly through spreading on soils, to landfills or by incineration: these disposal routes can transfer

pollution from water to soil or air.

79

80

81

82

83

Treatment and reuse of sewage and sludge in the South Mediterranean and Middle East

Countries. Development Assistance Programme in the Field of Environment

(DAC/DAPE)

In the frame of a Five Year Development Assistance Programme in the field of the Environment

(DAPE), the Sanitary Engineering Laboratory was appointed to co-ordinate the project "Treatment and

Reuse of Sewage and Sludge in the South Mediterranean and Middle East Countries". The main

objectives of the project are as follows:

(1) Proposals for wastewater characteristics suitable for a sustainable management of water resources;

(2) Development of socioeconomic criteria for the evaluation of the reuse possibilities according to

the particular characteristics of each country involved;

(3) Identifying appropriate methods for wastewater recovery on the basis of the individual needs,

constrains and objectives;

(4) Setting up an information network among the countries involved, the European Union, etc.

The Sanitary Engineering Laboratory was the co-ordinator of the project and had a major contribution

in all the deliverables of the project which are summarized as follows:

(1) Methods for a rational sustainable water resources management in Mediterranean Countries

involving sewage and sludge reuse;

(2) Proposal for guidelines for the appropriate characteristics of the reclaimed wastewater and sludge,

with respect to the particular needs of Mediterranean Region and specifically Greece;

(3) Adaptation of existing (European, etc) technologies, regulations and practices to the Mediterranean

Countries;

(4) Evaluation of reuse systems appropriate for the Mediterranean Region both in terms of middle and

large scale wastewater plants as well as on site treatment and disposal systems;

(5) Creation of network of experts from the Mediterranean region and construction of a web site in the

Internet containing technical and scientific information on wastewater and sludge reuse.

84

Computational Intelligence in Wastewater Treatment

1. Introduction

The problem of treating wastewater in large urban areas is of major importance today and civic author-

ities are being forced to find solutions in order to meet the ever-increasing demands of urban sprawl.

The control of wastewater treatment plants is a difficult task since plants are subject to varying loads

that are dependent on weather conditions. Thus the performance of most plants often leaves much to be

desired. More efficient control of wastewater treatment plants is a challenging problem whose solution

could potentially lead to significantly increased pollutant removal, reduced use of environmentally un-

friendly chemicals and energy reduction through co-generation using bio-gas by-products. However,

these requirements are often conflicting, which invariably leads to compromises.

Today, wastewater treatment plants are generally operated manually and far from optimally. Continu-

ously increasing loads are making the task of treatment increasingly difficult and many wastewater

plants are no longer able to satisfy the environmental specifications imposed by civic and environ-

mental authorities, thus posing a real hazard to the environment. The consequences of incomplete

knowledge of the treatment process by plant operators, unpredictable fluctuations in the plant inflow

and uncertainty and vagueness in the measurements of the controlled variables and plant operating con-

ditions, are inadequate plant performance, incomplete pollutant removal, high use of chemicals and

high operating costs. Because of the complexity of wastewater treatment plants, conventional control

techniques cannot provide the desired effluent quality and more sophisticated techniques are being

sought that can offer improved plant performance.

All wastewater treatment plants involve subsystems that interact with each other and variables that af-

fect each other. Given this crosscoupling, it is extremely difficult to design a single intelligent controller

85

to handle the entire process [5]. A logical approach to make the control of the process more tractable is

to tear the process into sub-processes each of which is controlled by one or more local controllers. The

physical boundaries specify where to tear the system. When the cross-coupling of the 2 variables of the

various sub-processes is strong, then the local controllers inevitably interact with each other, very often

in undesired ways. This is termed conflict and must be resolved in order to minimise the adverse effects

of cross-coupling, Such coupling can lead to instability, particularly when the variables of any subpro-

cess affect those of earlier stages.

Environmental conditions may alter the relationship among the variables and hence their interactions.

The control problem is compounded by the fact that wastewater treatment plants are often subject to un-

predictable loads due to weather fluctuations and toxic wastes that are cause for significant damage to

the process. In designing supervisory control systems for large scale processes, systems designers make

every attempt to decouple the various subprocesses of the overall process by minimising their interac-

tion. In theory this makes the overall process more manageable, however the task of minimising these

interactions is extremely difficult because of the inherent uncertainty and complexity of the overall sys-

tem, particularly when the available knowledge about the process is incomplete or vague.

Theoretically, the performance of large scale processes can be improved significantly by minimising the

conflict caused by plant variable interactions. This can be brought about by determining an acceptable

control policy. The primary objectives of any intelligent control system can thus be summarised as fol-

lows: to minimise the interaction in the plant variables by encouraging existing local controllers to

co-operate. to establish the relationships among the plant variables in qualitative rather than quant-

itative form. The advantage of the proposed scheme is that we now have the tools with which to exploit

human knowledge and expertise in resolving conflict and encouraging co-operation among the local

controllers.

2. Computational Intelligence

A fundamental attribute of advanced control systems using Computational Intelligence [8] is their abil-

ity to operate with symbolic, inexact and vague data, which human operators comprehend best. An in-

herent property of such systems is their ability to deal with incomplete and ill-defined processes and

data, a property which permits implementation of human-like control strategies that have hitherto not

been feasible using any of the conventional control techniques. Computational Intelligence has had a

significant impact in the process industry and hundreds of industrial plants world-wide are being suc-

cessfully controlled using such techniques [3,4,6,9,12,13,15]. The techniques of Computational Intelli-

gence (fuzzy logic, neural networks, neuro-fuzzy and evolutionary computation [2,7]) have migrated

successfully to many fields, e.g. agriculture and fisheries where the controlled processes are too com-

plex and vague to control by conventional techniques. Waste-water treatment is one such field

[1,10,11].

86

Most modern wastewater treatment plants already possess supervisory control and data acquisition sys-

tems through which operators interact with the plant. Invariably the executive or field controllers at the

lowest level of the hierarchy are tuned using one of the well-known techniques assuming no interactions

of the controlled variables [1,14]. Operators specify the desired set-points that yield acceptable operat-

ing conditions for each sub-process and then attempt to compensate for the interactions as best they can

by compromising each subprocess based on their knowledge and experience. It is not unreasonable that

under stress their actions may not always be consistent or optimum. Intelligent centralised controllers

have been implemented and one such controller is operational in Vienna. Hoechst has used fuzzy con-

trol in the aerobic processing step in wastewater recycling plants in Germany. But the need to find

simple, inexpensive solutions to improve wastewater treatment plant performance is urgent and a vari-

ety of techniques are currently under investigation. The proposed approach for improving the perform-

ance of wastewater treatment plants, is to superimpose an intelligent co-ordinator involving a cluster of

agents. These agents can alternatively be embedded in the executive controllers (e.g. PLCs or RTU's) of

the existing control system. The co-ordinator sends corrective actions to the executive controllers when

necessary so as to compensate for conflicts while striving to improve the performance of the plant. A

schematic of the proposed system is shown in Figure 1.

3. Stages of a typical Wastewater Treatment Plant

Wastewater treatment plants typically have two principal stages:

the primary stage (or Grit Removal) which includes the bar racks, grit chamber and primary set-

tling tank whose objective is the removal of the principal organic load and solids in the wastewater to a

degree of 30-50% and

the secondary stage (or Biological Filtration) whose objective is biological treatment of the organic

load. This stage is essential when a higher degree of treatment is required.

87

The removal of organic load (Biochemical Oxygen Demand, Mixed Liquid Suspended Solids) in con-

junction with primary treatment in this stage, leads to an overall treatment level of the order of 80-90%.

Through suitable modification of the biological treatment process, stabilisation of the Nitrogen com-

pounds (nitrates, ammonia) can also be achieved. Biological treatment is classified by the type of mi-

cro-organisms that are used in the removal of the organic load and can be aerobic, anaerobic or both.

Because of the anoxic zone in aerobic treatment it is possible to remove both nitrates and ammonia sim-

ultaneously.

The first stages of wastewater treatment are straightforward and rely on simple mechanical techniques

that do not require complicated control schemes. Interest is focused primarily on secondary biological

treatment and on aerobic treatment in particular. Wastewater treatment plants involve extended aeration

and are variations of the active sludge method.

A schematic of a typical plant is shown in Figure 2. Here the biological reactor possesses a tank with

two zones as well as a secondary settling tank. Wet sludge is fed into the anoxic zone in which low oxy-

gen conditions prevail and denitrification takes place. To operate satisfactorily, this stage requires low

Oxygen concentrations and the presence of nitrates. The sludge is subsequently transferred to a second

aerated zone where organic load is removed and nitrification takes place. A fraction of this sludge is

then returned to the anoxic zone while the remainder is fed to the secondary settling tank.

The quantity of sludge that is returned for further treatment depends on factors that affect nitrification

and de-nitrification and is one of the process variables that must be controlled. Finally, a fraction of the

sludge in the secondary settling tank is returned to the biological reactor while the remainder is re-

moved and fed to the fusion stage. The fraction of sludge fed back to the biological reactor is another

variable that must be controlled. In all wastewater treatment plants it is necessary that the Oxygen con-

tent in the aerated zone of the reactor be subjected to close control.

88

Oxygen content depends on the removal of the organic load and nitrification and for its removal, nitri-

fication and de-nitrification are the three principal quantities in a wastewater treatment plant, which

must be controlled. This is achieved by controlling the following three manipulated variables:

1. the Oxygen supply to the aerated zone,

2. the mixed liquid returns rate from the aerated zone to the anoxic zone of the biological reactor and

3. the sludge returns rate from the secondary settling tank to the biological reactor.

The variables that constitute the controlled variables of the plant are:

1. the ammonia concentration in the reactor,

2. the nitrate concentration in the reactor,

3. the dissolved oxygen in the reactor,

4. the mixed liquid suspended solids concentration in the reactor,

5. the difference in biochemical oxygen demand between the entrance and exit of the secondary settling

tank

4. Intelligent Co-ordination

The proposed intelligent co-ordinator must perform the following two tasks, each of which requires a

separate agent:

the first agent assesses the performance of the plant by continuously evaluating a measure of the

performance of the overall plant using qualitative (i.e. linguistic) rules involving the key variables

whose values are critical to proper operation of the plant. A fuzzy inference engine determines the con-

sequences of discrepancies from the desired specifications, these are then defuzzified to yield a numer-

ical performance index. This performance index will guide the plant operator to strive for improved

plant performance, while

the second agent compensates for the interactions among the controlled variables and advises the

plant operator what corrective actions he must take to attain high plant performance. Human knowledge

about controlling a complex plant can often be expressed in qualitative terms. This knowledge exists in

the form of linguistic rules whose antecedents are related to their consequents. Often, the assessment of

the suitability of a control policy is based on subjective criteria. Thus this agent will use linguistic rules

elicited from expert plant operators and an inference engine to determine the compensatory policy that

must be taken so as to improve overall process performance. The consequences will inevitably be com-

promises that may require a number of iterations to resolve. The two agents can thus be viewed as ele-

ments of a real-time decision support system that suggests the compensatory actions that should be

89

taken by the plant operator in order to enhance overall plant efficiency. Plant operators are thus relieved

of the arduous task of continuously compensating for plant interactions, safe in the knowledge that

these are accounted for in the most appropriate and consistent manner.

5. Conclusions

Intelligent control is diffusing rapidly into areas and processes too complex to control by conventional

control techniques. The control of wastewater treatment plants is no exception and intelligent control of

such plants is eminently feasible. The primary objectives of the joint research program are to: in-

vestigate the efficacy of multi-agent intelligent control of wastewater treatment plants using a network

of executive controllers linked to an intelligent controller whose primary function is to resolve conflicts

and interactions amongst the process variables. develop intelligent co-ordinator algorithms to com-

pensate for the subprocess interactions using techniques of Computational Intelligence.

Acknowledgement

The work described in this paper was funded by the General Secretariat for Research and Technology

of the Greek Ministry of Development, and the Slovene Ministry of Science and Technology in the

framework of a joint research and technology program between Greece and Slovenia, 2001-2002.

90

FRESHWATER COUNTRY PROFILE GREECE

Decision-Making Programmes and Projects

A. Integrated Water Resources Development and Management

B. Water Resources Assessment

C. Protection of Water Resources

D. Drinking Water Supply and Sanitation, Water and Sustainable Urban Development

E. Water for Sustainable Food Production and Rural Development

F. Impacts of Climate Change on Water Resources

Status

Capacity-Building, Education, Training and Awareness -Raising

Information

Research and Technologies

Financing

Cooperation

Decision-Making:

Since December 2003, a new legislative and institutional framework has been put into force in the

country. It consists of Law 3199/9-12-2003 (OJG 280A/2003) on “water protection and the sustainable

management of the water resources” with which the EU Water Framework Directive (WFD)

(2000/60/EC) is transposed into the national legislation. This new framework Law foresees a radical re-

orientation of the respective administrative capacities in Greece and introduces an innovative and hol-

istic approach concerning water management that recognizes explicitly the ecological function of water.

It also lays emphasis on the management of water on the basis of river basins as well as on the water

pricing so that it reflects its full costs. In more detail, the main objectives of the new Law include: the

long-term protection of water resources, the prevention of deterioration and the protection and restora-

tion/remediation of degraded water resources and wetlands, the reduction and, in cases, the phase out of

harmful and polluting discharges, the reduction of groundwater pollution and the prevention of its fur-

ther deterioration as well as the mitigation of the effects of floods and droughts.

The 3199/03 Law also incorporates the ‘polluter pays principle’ and the objective of maintaining or

reaching a ‘good ecological status’ for all water resources through the control of pollution by use of

91

thresholds levels and standards. It also introduces innovative approaches concerning the protection of

water quantity and the transnational cooperation for the protection of transboundary water courses and

lakes. The new legislation for the protection and the sustainable management of the water resources in

Greece, provides a detailed identification of 13 River Basin Districts (RBDs) according to the adminis-

trative units of the country, the competent authorities and their respective responsibilities in water man-

agement in Greece.

In this context, Regional Water Directories and Councils will be established within each River Basin

District / Water Region (RBDs) and they will have the responsibility for organising and coordinating

water policy activities (including water pricing) and specific Water Programmes and Action Plans with

specific measures for each RBD. They will be in charge for implementing the WFD in the RBDs of the

country and they will be supervised by the National Water Agency, a governmental authority with the

overall responsibility for establishing water policy. In the new legislation there is also consideration

about the most effective options for setting up legal coordination mechanisms relating to the designa-

tion and management of the River Basins that cross the Water Region borders. The appointment of the

new authorities will be legally binding once it is integrated into the new legislation. The 3199/03 Law

also integrates the public participation requirements of the WFD.

The active involvement of the interested parties is ensured by their representation at the National and

Regional Water Councils that will be developed as a part of the new administrative framework. In order

to complete the transposition of the WFD, besides this new law, further instruments, Presidential De-

crees and Joint Ministerial Decisions are under preparation, for the incorporation of the technical provi-

sions of the Directive. Before this new law on water was put into force, the legislative framework of the

country on this issue included Law 1739/1987 on Water Resources Management, establishing the insti-

tutional framework for the management of water resources in Greece and the Environmental Protection

Law 1650/1986 for the protection of surface and groundwater quality, including control of effluent dis-

charges.

The 1987 Law also provided for the design and implementation of water resources policies as a pre-

requisite for development that would enhance the results of production processes, balance the various

competitive uses for water and contribute to the renewal-replenishment of water resources as well as to

the protection of the environment through participatory processes. Despite the innovative and integrated

approach introduced by this Law, its complexity made its full implementation in practice quite difficult.

The existing Legal Framework for water resources management in Greece, apart from the above men-

tioned new Law 3199/9-12-2003, also includes Joint Ministerial Decisions (JMD) such as JMD

46399/1352/1986 and JMD A5/288/1986 for the harmonization of the Greek legislation with EU Dir-

ectives 75/440, 76/659, 76/160 and Directives 78/659, 79/869 and 80/778 respectively , as well as JMD

18186/271/1988 for measures and restrictions for the Protection of the Aquatic Environment: Determin-

ation of Limit Values for Dangerous Substances in wastewater. It also includes Council of Ministers’

92

Decisions (CMD) such as CMD 144/1987 for the Protection of the Aquatic Environment from Pollution

caused by Dangerous Substances. Moreover, concerning drinking water quality, the Sanitary Regulat-

ory Decision A5/288/86 (Official Journal of the Government - OJG 53B, 379B) about “Drinking Water

Quality” (which refers to the qualitative characteristics of drinking water, to the frequency of sampling

and the obligations of the responsible persons), in harmonization with Directive 80/778/EEC, was valid

until December 25th 2003,when the new JMD Y2/2600/01 (OJG 892/B/11/11-7-01), in harmonization

with EU Directive 98/83 for the quality of water for human consumption, came into force.

Management of protected areas including wetlands, was defined in 1999 (Law 2742/99) through the es-

tablishment of administrative units (Management Bodies) and the competence of NATURA 2000 Com-

mittee, whereas in 2002, through Law 3044/02, 25 Management Bodies were established, additionally

to the existing two ones. Management of the most important protected wetland sites in Greece, desig-

nated as Ramsar wetlands of international importance, is attained through the establishment of these

Bodies (which are financially supported, for the time being, from the state), that will collaborate with

the respective regional services to be established according to Law 3199/03, with the mandate to de-

velop and implement regional water management plans.

Concerning the protection of the quality of water resources and of vulnerable zones, in years 2001 and

2002 the existing legislative framework was complemented by various JMDs determining protection

measures for vulnerable water resources as well as threshold levels for polluting substances from vari-

ous anthropogenic sources, according to relative EU Directives (described in detail under Chapter ‘Pro-

grammes and Projects’, C. Protection of Water Resources, Water Quality and Aquatic Ecosystems). Fi-

nally, in 2003, a new Forest Act (3208/03) was adopted, concerning the protection and management of

forest resources with emphasis on the protection of forests and their hydrological role.

Programmes and Projects:

The targets of the National Strategy for Sustainable Development (NSSD) (2002), regarding the man-

agement of water resources, are set out in the National Strategy for Water Resources (NSWR) (2002)

and aim at the sustainable use of water resources, the efficient protection of water ecosystems and the

attainment of high quality standards for all surface and ground water bodies by the year 2015. The

NSWR also incorporates the water targets, in line with the Johannesburg Plan of Implementation, for

water supply and sanitation as well as for integrated water management and water efficiency plans.

The basic sectors of action of the NSWR are:

Integrated approach for water management: Development of Management Plans on river basin level in-

cluding transboundary water courses, based on water quality and quantity considerations and the inter-

action between surface and ground waters.

93

Decentralization of water management authorities-bodies: Establishment of Water Managing Bodies the

transposition of competencies to the regional and local levels. These Bodies will also be responsible for

the elaboration of Crises Management Plans, for extreme events e.g. floods and droughts.

Upgrading and expansion of infrastructure: This includes the promotion of specific measures and ac-

tions for meeting the demand for water supply through the expansion of existing networks as well as

through the decrease of losses, the construction of new and the upgrading of existing wastewater treat-

ment plants with emphasis on recycling, the construction of new multi-purpose reservoirs and finally,

the establishment of more effective mechanisms for monitoring water quality and quantity with focus

on creating an updated Data Bank. Incorporation of socio-economic considerations in water manage-

ment: This includes measures to reinforce public participation in water management efforts as well as

adaptation of pricing policies to include ‘the social cost’ in water services’ provision.

Protection from harmful substances: Setting of new maximum permissible levels of harmful substances’

concentrations in water resources as the basis of a sound system for liabilities, water protection and pro-

motion of remedial measures, where required.

More specifically, the NSWR contains a wide series of projects, programmes and actions , according to

the requirements of the WFD that will allow meeting set targets at national, EU and international levels,

by fully implementing the WFD and law 3199/03, such as: Participation in the process of testing the

guiding and supporting documents on key aspects of the WFD (technical Guidance Documents) in sev-

eral pilot river basins across Europe (integrated testing in pilot river basins).

The overall objective of this integrated testing Project is to contribute to the implementation of the

WFD in selected Pilot River Basins, leading in the long-term to the development of River Basin Man-

agement Plans. The specificity of the testing versus the real implementation is that the testing is a front-

runner of the actual implementation. Greece is participating in this Project with Pinios Pilot River Basin

(Thessaly RBD). Update of the National Data Bank of Hydrological and Meteorological Information

and of the National Environmental Information Network. Identification and characterisation of the indi-

vidual river basins and identification of the respective competent authorities.

Development of a new monitoring network for inland surface, transitional, coastal and ground waters,

including the development of monitoring programs for biological quality parameters and the assessment

of their ecological quality. Intercalibration exercise in several water bodies, as a part of the intercalibra-

tion network within the European Union. Designation of heavily modified and artificial water bodies.

Development of water pricing policies that enhance the sustainability of water resources. Continuation

of construction of wastewater treatment plants. Analysis of the role of local authorities and citizens in

securing long-term water resources conservation. Development of Management Plans in Water Districts

for each river basin of the country.

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For the implementation of Law 3199/03 and of the NSWR, in Greece, four (4) Phases have been set

aiming at accomplishing the following intermediate targets (according to the WFD requirements):

1st Intermediate Target (December 2004): Characterization of the RBDs in terms of pressures, impacts

and economics of water uses, including a register of protected areas lying within the river basin dis-

tricts.

2nd Intermediate Target (December 2006): Operation of the monitoring network for inland surface,

transitional, coastal and ground waters and evaluation of the results of the first intercalibration exercise.

3rd Intermediate Target (December 2009): Production and publishing of river basin management plans

for each RBD, including the designation of heavily modified water bodies.

4th Intermediate Target (December 2015): Implementation of the programmes of measures and achieve-

ment of the environmental objectives.

A. Integrated Water Resources Development and Management:

During the first phase of the WFD implementation in Greece, the main problems encountered were re-

lated to compatibility issues with current administrative bodies and lack of information and data, espe-

cially for biological quality elements. This, consequently, has created difficulties in the definition of

reference conditions and the development of classification systems. However, the passing on of Law

3199/03, the establishment of new operational monitoring networks and the testing of the technical

Guidance Documents in Pinios Pilot River Basin (Pinios PRB Project), will be the best way to get

through such problems related to the implementation of WFD at an early stage.

The Pinios Pilot River Basin is part of a 15 Pilot River Basin Network across Europe (integrated pilot

river basins testing network). The overall aim of this PRB Project is to identify the technical and man-

agement problems that may come up in real cases of the WFD implementation in the country and to de-

velop pragmatic solutions to these problems, to test the practicability and efficiency of the technical

Guidance Documents in Greece before they are widely applied, to attain a concrete example of the ap-

plication of the technical Guidance Documents and to inform the interested parties on the implementa-

tion of the WFD, through real circumstances, allowing the stakeholders (including local and regional

author ities) to be involved at an early stage.

Other specific actions and programmes that have been so far promoted include: The elaboration of an

updated “Master Plan of water resources management of the country” (January 2003) by the Ministry of

Development in collaboration with the Technical University of Athens and the Institute of Geological

and Mineral Explorations. This study is a first approach on water supply and demand balance for each

River Basin District and of their inter-dependence. The elaboration of River Basin Management Plans

for each river basin, compatible with the WFD. These management plans are assigned to different Con-

sortium of Companies (2nd semester of 2003), they are funded through the 3rd Community Support

95

Framework (CSF) and will be completed by 2007, with the involvement of the Regional Water Direct-

ories and public participation.

The promotion of these programmes will enable an integrated management of all water resources, com-

bining surface water and groundwater bodies, wetlands and coastal water resources at a river basin

scale. It will also link water quality and water quantity considerations as well as competitive water uses,

functions and values into a common policy framework, with water as a social good. The 3rd Opera-

tional Fisheries Programme 2000-2006 also supports activities contributing to the sustainable develop-

ment and the protection of natural environment.

Other programmes and projects in place on integrated water resource development and management in-

clude : recharging ground water aquifers, restoration of wetlands, torrent control and management of

their watershed, construction of dams and small water storage basins etc. Legislative and administrative

measures are also adopted by local authorities as well as by central services for the protection of people,

properties, agricultural areas and infrastructure, during extreme flood and drought conditions.

To this end, the Operational Programme for Rural Development of the Ministry of Agriculture incor-

porates actions on integrated programmes for the reclamation of areas undergone natural disasters. Such

projects also contribute to combating desertification. The large multi-purpose reservoirs constructed by

the Public Power Corporation (PPC S.A.) are contributing to the development and management of wa-

ter resources. PPC S.A. operates seventeen large hydroelectric plants that serve a variety of purposes

apart from power production, i.e. drinking water supply (to approximately 20% of the population), irrig-

ation water supply, flood protection as well as preservation of existing ecosystems and creation of new

ones. The reservoirs of these large hydroelectric projects have a useful storage capacity of 6.5 billion

m3 at the end of the wet period. The effective management of these large reservoirs by PPC SA contrib-

utes highly to meeting the freshwater demands of the country without any impact to the groundwater

bodies.

B. Water Resources Assessment:

YPEHODE supervises the existing national monitoring network for water quality. This network that

measures water quality systematically since 1995, relies on existing sampling stations, such as those set

up since the 70s by the Ministry of Agriculture for monthly monitoring of irrigation water quality (90

sampling points in rivers, 30 sampling points in lakes plus seasonal sampling in 100 irrigation projects

and 250 drillings). The network encompasses upgraded Laboratories of the General Chemical State

Laboratory (GCSL), under the authority of the Ministry of Finance, as well as Municipal and Research

Laboratories.

Monitoring is based on 200 sampling points in lakes and rivers and samples are being analyzed for

around 69 parameters (physicochemical parameters, nutrients, heavy metals and microbiological) on a

trimester basis. This Monitoring Network includes sampling points where water is analyzed for toxic

96

substances contained in Lists I and II of the EU Directive 76/464/EC. More specifically, samples are

monitored for 156 substances of Lists I (7 substances) and II (116 substances) as well as 33 priority

substances, at 50 sampling points through out the country. For the transboundary rivers, 5 sampling

points have been established at the entry points from the upstream neighboring countries, where 5 auto-

matic monitoring stations have been situated at Axios, Strymonas, Nestos and Evros (2 stations) rivers.

Groundwater monitoring is carried out at approximately 400 sampling points covering the whole coun-

try except the Aegean islands. Sample analyses focus on nitrates of agricultural origin. The Institute of

Geology and Mineral Exploration (IGME) has also established a national network for monitoring qual-

itative and quantitative properties of groundwater, collecting systematically hydrological, hydrochem-

ical and other data (heavy metals, pollutants). Data are then incorporated in a GIS database for compil-

ing adequate timeseries and determining evolutionary trends of groundwater according to the WFD.

Pesticide residue monitoring is carried out in cooperation with the Benakion Phytopathological Insti-

tute. A water quality monitoring programme of rivers, lakes and groundwater, including the determina-

tion of all heavy metals and pesticide residues has been executed and will be continued in cooperation

with the Aristotle University of Thessaloniki in the Regions of Macedonia and Thrace, in Northern

Greece.

Drinking water is analyzed for 66 sampling points in rivers and lakes, using the laboratory infrastruc-

ture of the GCSL. Further 14 sampling points for surface waters are located in specific areas, such as

water supply areas. Therefore monitoring programmes for drinking water quality, specify, inter alia, the

water sampling points. These programmes are submitted to the Directorate for Health of the corres-

ponding Prefecture for approval, together with a graphical illustration of the points of water intake,

which are also notified to the competent Regional Authorities.

PPC S.A. runs a hydrologic monitoring network, the hydrometric part of which is very advanced in its

capacities and most valuable for data collection in the context of relevant studies. However this network

is restricted in the mountainous part of Greece, where the PPC’s interests are primarily focused. In the

frame of the obligations derived from Directive 91/676/EC, YPEHODE assigned to the University of

Patras the elaboration of a study and the organization and operation of a Groundwater Quality Monitor-

ing Network in the country (monitoring parameters: NO3, NO2, NH4, Cl, SO4, ions, conductivity and

pH).

From the conclusions of this study and according to the criteria of the Directive , vulnerable zones have

been designated as regards nitrate pollution of agricultural origin and “Codes for a Good Agricultural

Practice” along with Action Programs for the promotion and implementation of such Codes, have been

developed in these zones. A project for “Collection and evaluation of ecological data for rivers and

lakes” of the country, according to the requirements of the WFD has been also assigned to the National

Center of Marine Research.

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The aim of this project is to estimate the sufficiency and adequacy of existing data for the typology, the

classification of ecological status, the definition of reference conditions and the inter-calibration. In ad-

dition, it will formulate proposals concerning the future steps on research to be accomplished and the

monitoring systems.

Monitoring results from the above mentioned Networks are made available to the public and are also

forwarded to EUROWATERNET, managed by the European Environment Agency (EEA). The Na-

tional Surface and Groundwater Quality Monitoring Networks are currently under revision and read-

justment, according to the requirements of the WFD and Law 3199/03. In this context, the Operational

Environmental Programme (OEP) 2000-2006 of Greece includes the development of a new, expanded

and complemented National Monitoring Network (Priority Axis 1, Measure 1.1) for the quality of sur-

face waters and groundwater, transboundary rivers, drinking water, and bathing waters including a cent-

ral laboratory for the calibration and coordination of regional laboratories involved in the monitoring

networks. Moreover, though Measure 8.1 of Priority Axis 8 of OEP 2000-2006, monitoring parameters

(biotic, abiotic) will be evaluated and selected at national level and a unique database will be compiled,

together with the formulation of monitoring plans for the areas under the responsibility of the Manage-

ment Bodies.

Through these activities, a coherent and comprehensive overview of the chemical and ecological status

within each River Basin District will be provided. This overview will enable, after assessment of the

reference conditions, the classification of the surface waters into five classes, on the basis of specific

quality elements and the development of national classification schemes. The establishment of this new

legally binding monitoring network (under the competencies of the Regional Water Directories and the

overall supervision of the National Water Directorate) for inland surface, transitional and coastal waters

is part of an overall project to be implemented in the country by 2006.

B. Protection of Water Resources, Water Quality and Aquatic Ecosystems:

Measures aiming at the protection of water resources and aquatic ecosystems in Greece encompass a

special ‘concessions and permitting’ system. Permits for building water infrastructure are issued by the

relevant Ministry following an application accompanied by an assessment of the quantitative and qualit-

ative situation of water resources before and after the execution of the project. Concessions (water use

permits) are granted for 10 years by the Ministry of Development or the relevant prefect following a

valid license. Permits for the discharge of effluents into rivers are granted to industries after the effluent

discharge thresholds have been set and a discharge and water use permit have been issued.

The Ministry of Health carries out sampling of discharged wastewater to control compliance with per-

missible levels and impose sanctions if required. Other measures for protecting environmental integra-

tion and ecosystems include Environmental Impact Assessments (EIA) as a prerequisite for any water

related project or infrastructure. According to the requirements of the EU Directive 91/676/EEC (trans-

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posed into national legislation with JMD 195652/1906/1999, OJG 1575B), four (4) “vulnerable zones”

towards nitrogen pollution from agricultural run-offs have been established and respective special Ac-

tion Programmes have been planned and adopted, according to art.5 of the Directive, focusing on the

minimization of the adverse impacts on the environment of Greece. The implementation of these pro-

grammes is obligatory for all farmers of these vulnerable zones.

These Action Programmes include: Action programme for Thessaly plain (JMD 25638/2905/2001, OJG

1422B) Action programme for Kopaida plain (JMD 20417/2520, OJG 1195B) Action programme for

Argolida plain (JMD 20416/2519, OJG 1196B) Action programme for Pinios basin, Prefecture of Ilia

(JMD 20418/2521, OJG 1197B) In 2001 three more areas were identified as sensitive areas (with JMD

20419/2522, OJG 1212B), completing the list with the sensitive areas, namely: Thessaloniki plain, Stri-

monas basin, Preveza-Arta plain. The respective Actions Plans are under publication procedures.

Moreover, under the National Programme (OJG 1866/B/12.1.03) for the reduction of toxic substances

of List II of Directive 76/464/EC, a special Action Programme for the protection of Lake Vegoritida-

Petron and Soulos stream has been established through JMD 15782/1849/2001 (OJG 797B) and is

already being implemented. In the above mentioned context, national legislation has been complemen-

ted in recent years with the following enactments:

i. Transposition of Article 7 of Directive 76/464/EU regarding the determination of National Pro-

gramme for reducing the disposal of hazardous substances to waters: CMD 2/2001 regarding the de-

termination of guidelines of water quality from disposals JMD 4859/726/2001 regarding the determina-

tion of measures and limits for water protection

ii. Implementation of Article 5 of Directive 91/676/EU (pollution from nitrates)

iii. Implementation of Article 5 of Directive 91/271/EU (disposal of urban waste water): JMD

48392/939/2002 (OJG 405B/3-4-2002), regarding the completion of the list with sensitive areas for the

disposal of waste water.

Under Priority Axis 8 (total budget of around 193 million €), of the OEP 2000-2006, significant

amounts are being invested for the protection of natural sites and wetlands. These Programmes will sup-

port the organization of a National System of Protected Areas, which are part of the NATURA 2000 list

and include, inter alia, all important Ramsar wetlands, coastal and sea areas, the integrated protection

and management of ecosystems, species and landscapes and the restoration of Lake Karla.

By the national legislation, 27 Management Bodies have been established in important Greek ecosys-

tems, which include all Ramsar wetlands and important coastal and sea areas. These administrative

units are formulating respective Management Plans and Action Plans, which are in line and specify the

management priorities described in their respective Specific Environmental Studies. Management Bod-

ies are entitled with opinion giving prior to EIA procedures, assisting public authorities in the imple-

mentation of environmental legislation, elaboration of projects and specific studies, information and

99

public awareness actions as well as implementation of eco-tourist projects. In the past, through the 2nd

CSF, Programme Agreements had been signed for these areas, with the aim to put forward projects and

activities that would prepare the future function of the Management Bodies. Additionally, the Greek Bi-

otope/Wetland Centre (EKBY), founded by the Greek Government and the European Commission in

1991, constitutes an autonomous non-governmental scientific institute that assists in many cases com-

petent authorities in the planning and implementation of conservation and sustainable development

measures.

C. Drinking Water Supply and Sanitation, Water and Sustainable Urban Development:

In Greece, the supply of clean and sanitarily appropriate water, from underground and surface waters, to

every citizen in the country, consists one of the main responsibilities of Public Administration. The

state is responsible for providing water and wastewater services to Athens and Thessaloniki and has ef-

fectively entrusted water services to two large companies: to EYDAP in Athens, which legally has

private status but is supervised by YPEHODE and to DEYATH in Thessaloniki, a public sector com-

pany. In cities, over 10000 municipal companies manage water and wastewater services.

In smaller towns and rural areas, communities are directly responsible. Aside from some small

wastewater treatment plants installed in private properties, there is no further private sector involve-

ment. In 1998 more than 90% of Greek population was connected to drinking water networks and the

percentage is rising. Currently, drinking water supply for the 20% of the population derives from large

reservoirs managed by the PPC S.A. The most serious shortages occur in the Aegean islands , particu-

larly during the tourist season. In some areas rain water retention works are being built.

Drinking water is good for 82% of the population, satisfactory for 8% and not satisfactory for 2% due

to marine water intrusion in coastal aquifers. Monitoring of drinking water quality is carried out by the

Ministry of Health and its Regional Laboratories for Public Health. Water supply prices vary consider-

ably throughout the country and are set by municipalities, whereas in Athens are approved by YPE-

HODE.

Water charges are based on volumetric rates and are progressive, with the price per cubic meter increas-

ing with the level of consumption; however, a ceiling exists for large families. The areas of Athens and

Thessaloniki have a combined water billing system covering both water supply and wastewater collec-

tion & treatment charges. Volumetric rates for industry are generally higher than for households with

charges including also flat rate pollution charges and wastewater charges.

Four protection areas have been designated for vulnerable drinking water sources, in the framework of a

programme to protect drinking water resources. Within these areas polluting activities are restricted and

environmentally friendly farming is encouraged for abating nitrate pollution. In 1998, the percentage of

settlements served by sewerage systems (with population equivalent – p.e.>15.000) was 45%, and in

2000 increased to 64%. This percentage has increased even more, during the last 3 years, after the con-

100

struction of additional collecting systems. Regarding the operation of the urban wastewater treatment

plants in Greece, the percentage of served population of settlements with p.e.> 10.000, with plants dis-

charging in sensitive areas has increased from 16% in 1998 to 42% in 2000. For settlements with p.e.>

15.000 that discharge into normal areas, the percentage has increased from 27% to 43% in 2000.

This percentage has further increased in 2001, with the total number of municipal wastewater treatment

plants amounting to 290, whereas projections show that in 2005 the number will reach 475, covering

94,8% of Greek population, giving emphasis to secondary and tertiary treatment. The operation of a sig-

nificant number of existing treatment plants is a responsibility of the Municipal Services for Water Sup-

ply and of EYDAP and DEYATH for Athens (where the secondary treatment plant of Psytalia is in op-

eration since some years) and Thessaloniki respectively. OEP 2000-2006 is promoting, under Measures

1.1, 1.2, 1.3 and 6.2, the development of a National Management Scheme for urban and industrial

wastewater, the construction of tertiary treatment facilities in sensitive regions and the implementation

of innovative and adjusted technologies for the treatment of urban and industrial wastewater in selected

areas.

D. Water for Sustainable Food Production and Rural Development:

The agricultural sector consumes around 75% of water withdrawals in Greece with the surface of irrig-

ated areas rising in recent years. Farmers are not charged for irrigation water supplied by individual

projects but they pay only a small fee per hectare of cultivated area served by collective irrigation pro-

jects to the Local Land Reclamation Board (TOEV). Water provided by the Public Power Corporation

(PPC S.A.) to farmers from large dams to cover irrigational needs is not charged. The programmes pro-

moted in line with the Amended Common Agricultural Policy (CAP) since the mid 90s focus, inter alia,

on streamlining economic, ecological, social and alimentary needs, increasing the ‘multi-functionality’

of the agricultural sector as well as promoting an integrated and sustainable development of rural areas.

In the context of the NSSD, a Scheme for the Agricultural Development has been promoted. The

Scheme includes specific programmes and actions such as: promotion of best agricultural practices and

more sustainable production patterns, rational use of water aiming at resources’ conservation and deser-

tification abatement, promotion of an integrated approach for the development of agricultural land,

gradual reform of state support to the sector and of market distorting mechanisms, promotion of ad-

equate economic instruments for internalizing external costs, promotion of programmes for biological

agriculture, fallow and biodiversity protection in hot spot areas of increased ecological value, promo-

tion of information and awareness raising campaigns among farmers, upgrade farmers’ social status and

development of an integrated fisheries policy.

These actions are also included in the Operational Programme of the Ministry of Agriculture ‘Opera-

tional Programme for Rural Development 2000-2006’. In this context, the programmes promoted by the

Ministry of Agriculture have resulted in the development of more sustainable irrigation systems, the

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promotion of ecological products (without chemicals and pesticides), the decrease in per hectare con-

sumption of fertilizers by discontinuing subsidies as well as the decrease of total agrochemicals’ use

through awareness raising. For this purpose, the Ministry of Agriculture has established and published

“Codes of Good Agricultural Practices” for the management of agricultural areas, of grazing lands, of

water resources and of biodiversity. The Ministry of Agriculture is also promoting the implementation

of a Programme for the Integrated Pest Management (IPM) that is aiming at “Application of Alternative

methods of Integrated Pest Management and Disease Control” in different crops at the country level.

E. Impacts of Climate Change on Water Resources:

The recent National Action Plans to Combat Climate Change (2002) and Desertification (2002) include

projects, programmes and actions on water resources, as a priority area for protection. The Ministry of

Agriculture has promoted the implementation of an Action Plan, of approximately 450 million € total

budget, through: construction of small dams, reservoirs for rain water in threatened areas and artificial

water recharging, torrents’ watershed management, control and reduction of irrational use of irrigation

water and of water losses by modernizing irrigation networks, reduction of nitrogen pollution of agri-

cultural origin in groundwater, protection of mountainous watersheds with terraces, and development of

coastal and inland karstic water resources.

Water recycling and re-usage is implemented through the projects promoted by the Land Reclamation

Directorate of Ministry of Agriculture and by the TOEVs. Other ongoing land reclamation projects for

facing drought also include promotion of new drillings where the groundwater table permits it , and har-

vesting of spring water. YPEHODE and the Ministry of Development have contributed to the above

mentioned Action Plan by taking measures in the same direction, for protecting water systems from sa-

linization and erosion. These activities, complemented by a reinforced component on research, ex-

change of information and training, as well as establishment of appropriate monitoring mechanisms, are

intensified in 2000-2006.

The refilling of artificially drained lakes planned under OEP 2000-2006 and the pla nned diversion of

the Acheloos River will also contribute to address desertification problems in the threatened plains of

Central Greece. By now almost 10% of power production is coming from renewable sources, a large

proportion of which, in terms of installed capacity, are large hydroelectric plants. Greece has been com-

mitted to meeting the target of 20.1% power generated by renewable sources. Hydroelectric power gen-

eration contributes substantially to meeting the target of reduction of greenhouse gas emissions and hy-

dropower development is one of the measures included in the National Action Plan for the abatement of

Climate Change.

Status: Freshwater resources- water quantity :

Greece is generously endowed with freshwater resources. Mean annual precipitation in Greece is about

700 mm, nearly half of which is lost to evapotranspiration. However, freshwater resources are unevenly

102

distributed throughout the country, due to the climatic conditions and the rugged geographic relief of

Greece. Precipitation ranges from around 400 mm in the Aegean islands and Athens to more than 900

mm in the North West and the Ionian islands with the island of Kerkyra presenting maximum precipita-

tion levels. On the contrary, parts of the southern and central mainland, the Aegean islands and Crete

are in danger of desertification.

Water distribution is also uneven in time. Peak periods for water demand and consumption are reported

during the summer dry period when the population in certain areas (mainly coastal) is multiple due to

tourist arrivals. During the dry period, water demand is also maximized for irrigational purposes. There-

fore water is not always available where and when it is mostly demanded. Water redistribution, storage

and saving and a sound demand side management are therefore indispensable priorities for water policy

in Greece. The mean annual surface run-off of Greece’s mainland rivers is 35 billion cubic meters.

More than 80% of the surface flows originates in eight major river basins: the Acheloos (Central

Greece), Axios, Strimonas and Aliakmonas (Macedonia), Evros and Nestos (Thrace) and Arachtos and

Kalamas (Epirus). Nine rivers flow over 100 kilometers within Greece: the Aliakmonas, Acheloos,

Pinios, Evros, Nestos, Srimonas, Kalamas, Alfios and Arachtos. Four major rivers originate in neigh-

boring countries: Evros (Turkey), Nestos and Strymonas (Bulgaria) and Axios (FYROM); total inflow

from upstream neighboring countries amounts to 12 billion cubic meters.

Some 41 natural lakes (19 with an area over five km2) occupy more than 600000 hectares or 0.5% of

the countries total area. The largest are lakes Trichonida, Volvi and Vegoritida. Lake Prespa is on the

borders with Albania and FYROM. The number of Greek wetlands according to the inventory of

EKBY, rises to about 400 with 10 of them designated as Ramsar wetlands of international importance.

The 14 artificial lakes (ten with an area over five km2) occupy 26000 hectares. Some 80-85% of fresh-

water resources are in the form of surface water and the rest are groundwater. Per capita consumption of

water is around 830 m3 with peaks of over 1000 m3 recorded during heat wave days and days of intens-

ive snow fall. Around 75% of total freshwater withdrawals are for agriculture with irrigated areas rep-

resenting a third of total cultivated areas.

Uneven rainfall distribution results in scarcity of water resources during peak period for irrigation, a

period similarly crucial for other uses such as tourism. Therefore, about half of irrigation water is

pumped from aquifers. A considerable portion of irrigation water comes from large multi-purpose reser-

voirs owned by PPC S.A. Households account for about 10-15% of total freshwater withdrawals. Water

supply to the Metropolitan area of Athens is provided mainly from surface water stored in dams several

hundred kilometres away and transferred to the city. Other big coastal cities usually extract groundwa-

ter, even though salinization problems have caused other solutions to be sought such as spring and sur-

face water collection in reservoirs.

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Water quality:The national water quality standards for various uses (drinking, aquatic life etc) have

been harmonized with the relevant legislation (Directives) of the European Union (EU). Human eco-

nomic and industrial activity in Greece is concentrated in river basins where additional pressures occur

due to agricultural activity. Surface run-offs and wastewater discharges create intense point pressures

on the quality of water resources. However, the situation has been enhanced over recent years due to the

massive construction of municipal wastewater treatment plants for most of the country’s human settle-

ments.

Greek rivers are generally of very good quality. They host some 78 indigenous fish species half of

which are endemic. Mean annual nutrient concentration as well as the heavy metals’ concentrations low

and in most cases below maximum permissible limits for drinking water. Only in some cases in down-

stream river locations, in urban areas or in areas of intensive agricultural and industrial activity, the

levels of phosphorus, nitrites, ammonium and dissolved solids might be rather higher than the stand-

ards. High nutrient concentrations , phosphorus concentrations slightly exceeding thresholds , as well as

heavy metals are found in certain lakes, mainly in the northern part of the country, indicating human in-

fluence (from agricultural run-off, municipal and industrial wastewater discharges) leading, in certain

cases, to eutrophication.

Groundwater quality, even though generally good, is threatened by uncontrolled wastewater disposal

and salinization caused from over-extraction due to seawater intrusion at coastal areas. High concentra-

tions of nitrates, deriving from nitrogenous fertilizers and the use of livestock manure, as well as pesti-

cide residues have been detected in northern and western parts of the country but do not always exceed

maximum permissible values. The implementation of recent Law 3199/2003 for the protection and

management of water resources (see Chapter ‘Decision Making’) will give new impetus to sustainable

and integrated water management in Greece, by giving emphasis on the ecological function of water

and by introducing an integrated water resources management (IWRM) approach on river basin level as

well as a pricing policy so that it reflects water’s full costs.

Capacity-Building, Education, Training and Awareness-Raising:

The Ministry of National Education and Religious Affairs organizes, funds and supports a big variety of

environmental projects every year in all classes of primary and secondary schools. During the school

period 2002-2003, around 5700 projects were executed by 11000 teachers and 157000 pupils, a consid-

erable number of which was related to freshwater issues. Greek Schools’ curricula include various pro-

grammes and projects related either to “management of natural resources” or to critical environmental

issues, such as water pollution and water management. Moreover, Greek Schools participate in many

regional, national and international thematic networks such as “The River” aiming at awareness raising

from an early age, the “Water fountains”, the “Lakes”, etc.

104

The importance of freshwater in environmental education is also highlighted by the fact that 14 of the

17 official “Centres of Environmental Education” established by the Ministry of Education throughout

the country execute freshwater related programs, in which hundreds of pupils and teachers participate

every year. Training on the sustainable use of soil and water resources is also provided by related Uni-

versity Departments. Greek Universities (e.g. the National Technical University of Athens, National

and Kapodistrian University of Athens, Aristotle University of Thessaloniki, University of Thessaly,

Democritus University of Thrace) participate actively in a number of initiatives related to the impacts’

assessment of climate change, floods and droughts on water resources management throughout the EU

and other critical water issues, via workshops and research programmes.

On 5 June 2002, YPEHODE started an extended ‘do your bit’ campaign that covered the whole coun-

try, focusing on awareness raising of all ages, with emphasis on providing school children with prac-

tical information for protecting the environment, the natural and water resources, in everyday life,

through dissemination of leaflets and educational material, questionnaires, interactive dialogues etc.

This campaign is repeated on a yearly basis. Moreover, in the framework of OEP 2000-2006, funds

have been bound for environmental awareness raising programmes, with a total budget of 2.8 million €.

In the Athens area, information campaigns, during peak consumption periods, combined with economic

incentives succeeded to curb the wasteful use of water and to severe reductions in drinking water re-

serves. For the optimum operation of the existing Urban Wastewater Treatment Plants and the person-

nel training, the Union of Municipal Services for Water Supply and Sewerage has undertaken signific-

ant initiatives, such as the implementation of a project called ‘Equal’ , promoted by the Ministry of La-

bour. The objective of this project is the development of educational mechanisms on environmental

practises, particularly on the operation of the treatment plants.

In the agricultural sector, programmes have been promoted for the awareness raising of farmers (e.g.

publication of ‘Codes of good Agricultural Practices’) to adopt well balanced agricultural and fishery

practices which decrease the adverse effects on the natural environment and to support organic farming

and fallow. The WFD aspects and other general information concerning its implementation have been

shared among interested parties and stakeholders. Information has been disseminated also to the general

public.

Activities at regional level, e.g. in the Pinios Pilot River Basin have established the basis for the public

involvement. On the long-run, there will be public involvement in formulating the content of the River

Basin Management Plans, whereas at present, a series of public seminars and workshops are organised,

in order to raise awareness and to foster discussions on social considerations. The publication of in-

formation leaflets for activities related to the implementation of the WFD (e.g. for Pinios Pilot River

Basin Project) and the use of the internet as an information platform will ensure transparency and

provide the framework for an applied and fruitful public participation.

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Awareness raising and education has also been the key objective of type II initiatives that are being im-

plemented, with emphasis on water resources. MEDIES, a partnership initiative on Education for Envir-

onment and Sustainability, launched at the WSSD, for the implementation of Agenda 21 and the

MDGs, has already produced an Educational Package for school children ‘Water in the Mediterranean’

in several languages. Two widely attended training seminars have also been organised in Athens

(15.12.02 and 25- 26.10.03) on the methodologies and teaching methods of education for environment

and sustainability, and an interactive webpage (www.medies.net) has been set up.

Information:

The access to Internet, the world wide web and other websites about sustainable development and state

of the environment helps Greek citizens to acquire knowledge on policies, programmes and legislation

on freshwater management. Data on the quality of surface water can be found at www.thisavros.gr

whereas information on the WFD and the Pinios River Basin Pilot Project can be found at www.minen-

v.gr/pinios_river.html. On YPEHODE’s website (www.minenv.gr) the national annual report on sur-

face water quality is also posted as well as other related national reports.

The National Data Bank of Hydrological and Meteorological Information (NDBHMI) provides the re-

quired hydrological and environmental information for the development of the Master Plan and specific

regional management plans for the inland waters in Greece. The Programme is based on a major envir-

onmental network and data base consisting of hydrological and meteorological information at the na-

tional scale.

The Ministry of Health and Welfare collects relevant data and cooperates with the Ministry of Internal

Affairs and Decentralization for its evaluation and the measures to be taken for the protection of Public

Health. The Ministry for Health and Welfare sends required data to the Commission of the European

Union, by drawing up a Report, every three years. The elaboration of data under the NDBHMI contrib-

utes considerably to integrated water management and addressing adverse impacts of droughts, floods

and forest fires.

Currently, the update of the National Data Bank of Hydrological and Meteorological Information is un-

derway, to include new data, and thus, adapting to the new extended National Network of Environ-

mental Information in order to improve the information exchange and information management mech-

anisms on water resources in Greece. Publication and diffusion of information material as well as in-

formation exchange through related activities, including websites’ keeping, is also carried out by the

National Centre for Environment and Sustainable Development (EKPAA) and several NGOs and Insti-

tutes throughout the country.

Research and Technologies:

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In the framework of the 3rd CSF, OEP 2000-2006 encompasses several research projects that will com-

plement activities for the implementation of WFD in Greece, inter alia:

The EVALUWET project aiming at an harmonized approach and functional evaluation methodology, at

catchment scale, amongst European environment agencies and stakeholders;

The IT Framework-HarmoniT project for the development and implementation of a European Open

Modeling Interface and Environment for strategic planning;

The SHYLOC project for the development of adequate software for monitoring surface water storage

and wet width of natural and man-made ditches;

and The WWI project for the assessment of existing water management policies and river basin man-

agement measures, according to the WFD model and the integrated river basin management principles,

aiming at measuring progress and effectiveness of their implementation.

Other related research projects such as the Harmoni-CA, a tool for sustainable management and quality

of water, have been supported under the 5th Framework Programme of the Directorate-General for Re-

search of the European Commission. The 8th Priority of the 6th Framework Programme of the

European Commission promotes activities in support of the development and implementation of EU

policies.

Among the main objectives of this Priority, the section 3.1.5 is dealing with “environmental assessment

(soil, water, air, noise, including the effects of chemical substances)”. In this frame, the proposed re-

search intends to contribute, inter alia, to the implementation of the CIS of the WFD. One of the topics

relevant to water policies deals with the identification of groundwater pollutant’s threshold values for

the evaluation of the chemical status of groundwater bodies.

The main objective of the BRIDGE (Background cRiteria for the IDentification of Groundwater

thresholds) research programme, in which Greece is actively participating, is to set out criteria for the

assessment of the chemical status of groundwater, which is based on existing Community quality stand-

ards (nitrates, pesticides and biocides) and on the requirement for Member States to identify pollutants

(substances that may occur from both natural and anthropogenic sources, and synthetic pollutants) and

threshold values that are representative of groundwater bodies found as being at risk, in accordance

with the analysis of pressures and impacts carried out under the WFD.

The Operational Programme ‘Competitiveness’ (OPCOM) 2000-2006 of the Ministry of Development

has also included an applied research programme for the development of systems, tools and methodolo-

gical approaches for addressing hydrological, hydrogeological and environmental issues in order to

draw up Integrated Water Resources Management (IWRM) Plans for 4 major RBDs. In the same con-

text, the implementation of various research projects through public -private partnerships has been ap-

proved by the Ministry of Development for 2000-2006, aiming at exploring innovative approaches to

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water management, through advanced technological methods. Such projects include the development of

optimized irrigation systems, the protection of aquifers through recharge with treated industrial

wastewater, the innovative use of telematics and GIS for mapping water resources etc.

Greece is an active member of the EURAQUA Forum of Governmental Institutions on water resources,

an organization involved with the implementation and promotion of research programmes regarding cli-

mate change, integration of information technology in water resources and management, etc. In addi-

tion, several University Departments together with the Department of Forest Hydrology of the Forest

Research Institute of Athens carry out research on hydrological aspects of natural ecosystems and on

mountainous hydronomics.

Financing:

A number of economic instruments are used in Greece, among them Municipal, Industrial and Irrigation

water supply charges (see also Chapter ‘Programmes and Projects’, D). The Environmental Protection

Law 1650/86 includes the “polluter pays principle” (Article 29) and provides for the levying of waste

and water user charges. The development of water pricing policies that enhance the sustainability of

water resources is also foreseen by Law 3199/03 (see also Chapters ‘Decision Making’ and ‘Pro-

grammes and Projects’). OEP 2000-2006 includes several Measures and respective budget lines for the

promotion of integrate water management, protection of water resources and water supply and sanita-

tion.

For the implementation of the WFD and Law 3199/03 in Greece, the funds that will be disbursed by the

Greek Government up to 2006 will be about 19.3 million € and additional funds will be allocated, if

needed. Other Operational Programmes (e.g. Competitiveness, Rural Development, Fisheries etc) also

include Measures (see Chapters ‘Programmes and Projects’ and ‘Research and Technology’) with re-

spective budget lines related to water resources. At the Regional level, financial support for the protec-

tion and management of natural resources, with emphasis on water resources, and of significant ecosys-

tems is provided by the Regional Operational Programmes, for each Administrative Region of Greece,

under the framework of the CSF. Additional activities concerning development of infrastructure in

Greece are also partially financed by the EU Cohesion Fund.

Cooperation:

Major rivers (Evros, Nestos, Axios, Strimonas) in Greece originate in upstream countries. Lakes Doir-

ani and Prespa are also transboundary. Therefore, international cooperation concerning the management

of shared natural resources is an important issue for Greece. Greece ratified the Helsinki Convention

(1992) on the protection and use of transboundary watercourses and international lakes (Law

2425/1996, OJG 148/4.07.1996), the Barcelona Convention (law 855/1978, OJG 235/A/23-12-78) in-

cluding its latest amendments of 1995 (law 3022/2002, OJG 144/A/19.06.2002), and the Ramsar Con-

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vention (1971) on wetlands of international importance as the waterfowl habitat (Decree 191/1974, OJG

350/20.11.74), among others.

Furthermore, Greece has signed all – and ratified most of - the Protocols of the Barcelona Convention.

In May 2003, during the 5th Ministerial Conference ‘Environment for Europe’ in Kiev, Greece signed

the Protocol on ‘Civil liability and compensation for damage caused by the transboundary effects of in-

dustrial accidents on transboundary waters’ to the 1992 Helsinki Conventions on the ‘Protection and

Use of Transboundary Watercourses and International Lakes’ and on the ‘Transboundary Effects of In-

dustrial Accidents’.

Bilateral Agreements have been signed between Greece and Bulgaria, for the river Nestos in 1996, re-

garding issues of water sharing and for the river Ardas, regarding the amount of water used annually by

the Greek side for irrigation purposes. Greece has also signed an Agreement of Understanding with

Bulgaria covering, inter alia, issues of possible bilateral cooperation on integrated monitor ing of water

quality and application of the necessary measures for water protection. Agreements and initiatives have

also been launched between Greece and FYROM for the protection of Lakes Megali Prespa and Doirani

and between Greece, Albania and FYROM for the establishment of a transboundary National Park and

of a Permanent Tri-lateral Committee on Transboundary Freshwater issues, aiming at protecting the

Prespa Lakes shared among these three countries, following a Joint Declaration by the 3 Prime Minis-

ters in February 2001.

Greece has also signed and ratified (Law 2902/2001, OJG 77/A/2001) a MoU with Turkey that has

already entered into force (30.6.01) that covers issues of possible bilateral cooperation on transbound-

ary water resources (Evros river) and a MoU with Cyprus (Law 2424/1996, OJG 147/A/1996), cover-

ing, inter alia, issues of possible bilateral cooperation related to the protection of waters and soils, as

well as to the protection of the marine environment. Furthermore, Greece has signed (but not yet rati-

fied) MoU’s with Georgia, FYROM and Albania, covering issues related to, inter alia, the sustainable

management of transboundary waters, the monitoring of water pollution and the protection of the mar-

ine environment. Greece and Albania have also signed an agreement on the Establishment of a Perman-

ent Greek-Albanian Commission on Transboundary Freshwater Issues. Regarding monitoring of the

quality of shared waters, control stations have been established at the entry points of transboundary

rivers from other countries (see Chapter ‘Programmes and Projects’, B. Water Resources Assessment).

Since 1999 and in the framework of OECD’s Development Assistance Committee (DAC), Greece has

funded the implementation of several projects on water resources management and protection, in part-

ner countries. Through the Bilateral Programme of Development Assistance and Cooperation in the

field of Environment and Sustainable Development of YPEHODE, the water resources related projects

funded in 1999 were 9, with a total budget of around 77164 € whereas in 2000 they were 12 of total

budget of around 2.8 million €. These projects were implemented through Universities, Research Insti-

tutes and NGOs in Greece and recipient countries of South East Europe, the Mediterranean and East

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Europe, Caucasus and Central Asia (EECCA). Projects laid emphasis on transboundary water quality

and capacity building issues as well as protection of wetlands.

In 2001, the implementation of a project for the construction of a wastewater treatment plant in the city

of Strumica in FYROM for the protection of water resources was initiated. In the context of the Na-

tional Bilateral Programme of Development assistance and Cooperation “Hellenic Aid” for the years

2000-2001, the total budget allocated to the implementation of water related projects in partner coun-

tries was around 0.56 million USD, whereas for year 2002 the allocated budget was around 0.665 mil-

lion USD. The implementation of these aid projects contribute to the MDGs/WSSD targets for sustain-

able development and poverty reduction.

A representative example of a project to this direction is the construction of a dam as well as a water

reservoir in the Damte region in Ethyopia aiming at drinking and irrigational water supply in the area.

The sums already allocated are 130000 € whereas the overall estimated budget rises to 500000 €. At

WSSD in 2002, the Greek Government participated together with other partners (e.g GWP-Med, Medi-

terranean Information Office for Environment, Culture and Sustainable Development, UNESCO,

UNEP/MAP, Governments of other Mediterranean and SE European countries, Research Institutes,

Local Authorities etc) in the launching of 3 type II partnership initiatives focusing on water resources

protection and management: the ‘MEDIES initiative’ (see also Chapter ‘Capacity-Building, Education,

Training and Awareness-Raising’), the ‘Euro-Mediterranean Water-Poverty Facility’ and the ‘Sustain-

able water management in the Balkan and SE Mediterranean area’.

Greek Government has provided a start up budget of around 160000 € in support of these partnerships.

Since WSSD, the Greek Government has also taken up the responsibility of leading the Mediterranean

Component of the EU Water Initiative (MED EUWI) that was launched in Johannesburg. The MED

EUWI gives particular emphasis to Mediterranean priorities, according to needs and strategies defined

in partnership with governments, the European Commission and stakeholders. The Components' Secre-

tariat is served by GWP-Med. The MED EUWI aims to assist design of better, demand-driven and out-

put-oriented water programmes in the region, to facilitate better coordination of water programmes and

projects, targeting more effective use of existing funds, through identification of gaps and mobilization,

where required, of new financial resources and to enhanced cooperation for their proper implementa-

tion, based on peer review and strategic assessment. The focus themes of MED EUWI are:

(i) water supply and sanitation, with emphasis on the poorest part of the societies,

(ii) integrated water resources management, with emphasis on management of transboundary water

bodies,

(iii) water, food and environment interaction, with emphasis on fragile ecosystems,

(iv) non-conventional water resources as well as

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(v) horizontal issues such as transfer of technology, transfer of know how, capacity building, training

and education.

The Component is currently running its Preparatory Phase: its Operation Plan was produced in July

2003 and its detailed Activity Plan will be elaborated by end of March 2004. On EU level, the Hellenic

Presidency of the EU (1st semester of 2003) in its political agenda gave particular emphasis and priorit-

ised water issues especially in the Mediterranean Region and South East Europe, in a number of inter-

national events; inter alia :

3rd World Water Forum (Kyoto, 16-23.3.03): The EUWI with all its Components was extensively

presented, whereas EU’s key positions on the water-related WSSD targets and MDGs were reflected in

the adopted Ministerial Declaration.

EU Informal Council of Environment Ministers (Lagonissi, 3-4.5.03): Effective water resources man-

agement in SE Europe and common work on transboundary waters, as a catalyst for peace and conflict

prevention in the Region were some of the main issues discussed. The Meeting was attended by Minis-

ters of Environment of the enlarged EU (25 countries) and SE European countries.

International Conference on “Sustainable Development for Lasting Peace: Shared Water, Shared Fu-

ture, Shared Knowledge” (Vouliagmeni, 6-7.5.03), organised by Greece and the World Bank (WB): Co-

operation for the management of transboundary water bodie s and aquifers in the SE Europe and the

Mediterranean was the priority theme of the Conference, aiming to assess opportunities and constraints

and formulate recommendations for regional sustainable development, peace and stability. The

‘Vouliagmeni process’ has been systematically pursued since the Conference by both Greece and the

WB. Hellenic Water Week (Athens, 17-20.6.03), organised by Greece and the EU Commission: The

event focused on the implementation of the WFD especially in the Mediterranean, as well as the elabor-

ation of the different themes of the MED EUWI, through the suggestion of concrete actions (building

blocks, demonstrations projects) and development of synergies by different players.

* * *

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MAP OF GREECE

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