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Presented at the International Conference on New Water Culture of South East European Countries-AQUA 2005,21–23 October 2005, Athens, Greece.

Physicochemical and microbiological characteristics of the potable water supply sources in the area of Kozani,

Western Macedonia

Elisavet Amanatidoua*, Kalliopi Adamidoub, Eleni Trikoilidoub, Foteini Katsioulib, Olga Patrikakib, Lazaros Tsikritzisa

aTechnological Educational Institute of Western Macedonia, Koila Kozanis, Kozani 50100, Greece Tel. +30-2461040161 ext. 300; email: [email protected]

bPurely Prefectional Enterprise of Kozani “Environmental Centre”, 1st Km Ptolemaidas-Kozanis, Ptolemaida 50200, Greece

Received 20 January 2006; revised accepted 3 May 2006

Abstract

In the present study, the physicochemical and microbiological characteristics of the potable water in theprefecture of Kozani are studied, according to the results of the analysis carried out in the Environmental CentreLaboratory, during 2002–2005.

According to the Greek Legislation and the EU Directive for potable water, a water quality monitoringprogram was created for the County of Kozani, and the parameters of the Check and Audit Monitoring wereexamined for a number of samples from selected samples sites at regular intervals.

Conclusions relative to the water adequacy of springs and drills, water tanks and supply network, as well asthe possible reasons for water quality problems are presented in the study. Generally, the water quality depends onits chemical and microbiological condition. In the areas with penetrable formations and agricultural activity, thenitrates presence was observed in relatively stable concentrations in time. The water is easily infected during itstransportation from the source to the internal water supply network and finally to the consumer. The condition ofthe water supply networks is a factor which contributes to the water quality.

Keywords: Potable water; Quality; Monitoring; Kozani

1. Introduction

The ensuring of good quality drinking water isa basic factor in guaranteeing public health, the

protection of the environment and sustainabledevelopment.

The Directive 2000/60/EC [1] for waterresources and its Greek version N. 3199/9-12-2003and Y2/2600/2001 [2,3], impose the organization

*Corresponding author.

doi:10.1016/j.desal.2006.05.053

Desalination 213 (2007) 1–8

0011-9164/06/$– See front matter © 2007 Elsevier B.V. All rights reserved.

2 E. Amanatidou et al. / Desalination 213 (2007) 1–8

of monitoring networks for a variety of qualityand quantity parameters of potable water andaquatic systems.

The objective of the current study is topresent the quality of the drinking water supplysources in the county of Kozani, as well as thecomparative evaluation of the physicochemicaland microbiological analysis results for the lastthree years (2002–2004). The facts resultingfrom the research saw a continuous reduction inthe non-suitable drinking water samples becausespecific protection actions were taken from thelocal administration, the responsible authorityfor preserving the good quality of potable water.

The analysis took place at the laboratory of theEnvironmental Centre (KEPE) of the Prefectureof Kozani, which is responsible, according toagreements with the local municipalities and theMunicipality Union, for analyzing the potablewater of the County.

2. Materials and methods

During the period 2002–2003 the parametersthat belonged to the Routine Analysis wereanalyzed, according to the Ministry of Healthand Social Services legislation [4,5] about thefrequency of the sampling and the quality ofdrinking water [6]. During 2004 the parameters ofthe Check Monitoring and the Audit Monitoringwere analyzed according to the national andEuropean relevant legislation about the qualityof water used for human consumption [3,7].

The testing took place at selected sites withtechniques for sampling and analysis methodsaccording to the Standard Methods, APHA 1998[8], the relevant ISO [9–12], the internationalrecognized manuals [13], and the requirementsof the Quality System according to ISO 17025[14] of the Environmental Center’s laboratory.

Accredited or controlled equipment was usedfor analysis. An accredited photometer HittachiU-2001 for ammonia, nitrite and nitrate analysiswas used. Also for turbidity a Dr. Langer NEPHLA

454 turbidimeter, for conductivity a Mettler ToledoMX300 conductivity meter, for pH a WTWINOLAB pH meter and for residual chlorineanalysis a LaMOTTE 1200 Chlorine residualmeter, were used.

The process that was followed for taking thefinal measures is given below: (1) Formation of a monitoring program and

determination of the sampling sites at thebeginning of every year.

(2) Realization of the sampling program as it isformatted and laboratory analysis of thesamples for the selected parameters.

(3) Repeat of the sampling program when andwhere a divergence is observed, with newsampling.

(4) Informing the authorities and public andsubmission of proposals for the improvementof the current situation.

(5) Selected parameters analysis and editingof the analysis certifications and Reports/Technical Essays on behalf of the Munici-pality Authorities and observance of elec-tronic files.

The sampling is carried out according to themonitoring program at selected sites, the programis formatted at the beginning of every year, bytaking into account the legislation mentionedabove, with the co-operation of the municipalities.The realization of the sampling program securesthe necessary conditions for prompt and reliablesampling and transportation of samples. If adivergence of the parameters’ limits is observed,the sampling and the analysis are repeated.

For the period 2002–2003, according to therelevant legislation, the sampling sites for everysettlement are the springs and the drills, the exter-nal supply network, the water tanks and theinternal supply network. From the internal net-work, the samples were taken from the top, middleand lower point of each water supply line, aswell as from sites where it is possible to havestagnant water for a long period of time. From

E. Amanatidou et al. / Desalination 213 (2007) 1–8 3

2004 the sampling sites include the water tanks(main point) and the consumers’ tap. The numberof samples and sampling frequency is in proportionto the water consumption.

A sampling report is filled in before thesampling, in which the sanitary recognition of thearea is also included. At the same time the parame-ters that need in situ analysis are realized suchas temperature, pH, residual chlorine includingconductivity. These parameters are recorded onthe in situ analysis report.

3. Results and discussion

3.1. Water analysis

3.1.1. Physical and chemical water parameters

The concentrated results of the physicochem-ical analysis, from water tank and internal supplynetworks samples, for the period 2002–2004 areshown in Table 1. From the observation of theresults it can be seen that the averages do not

exceed the limits indicated by the legislation,although there are divergences, according to therecorded maximum values.

The cases of the lower and the higher con-ductivity measurement (24 μS/cm at 20°C and3110 μS/cm at 20°C) are not estimated in thecalculation of the average value.

Drills and springs water samples from all thecounty ware analyzed for the same period.Around 10% of the drills was exceeding thenominal limits for some parameters while it was0% the springs.

The precision and uncertainty of all thephysicochemical methods was calculated andranged in the relevant standard methods accept-able limits.

The number of samples and their undrinkablepercentage per year and per parameter are shownin Table 2. The undrinkable percentage of nitrite,nitrate and ammonium ions varies mostly due tothe gradual geographical expansion of the samplingin the county of Kozani as well as and to theincreasing number of water samples during 2004.

Table 1Concentrated results of the physicochemical analysis 2002–2004

Number of samples

Parameter Unit Min–max Average Limit Method of analysis

Physicochemicalanalysis

1128 Conductivity μS/cm at 20°C

281–823 480 2500 2510-B 20th Ed. 1998

1134 pH pH units 6.9–8.5 7.45 ≥6.5 και ≤9.5

4500-H + B 20th Ed. 1998

1134 Turbidity mg/L SiO2 0.06–1.2 0.4 No commonalteration

2130 B 20th Ed. 1998

861 Residual chlorine

mg/L 0–0.8 0.3 Min 0.5 tankMin 0.2

network

4500-Cl G 20th Ed. 1998

1179 Ammonium mg/L 0–1.98 0.45 0.5 4500-NH3 F20th Ed. 1998

1164 Nitrite mg/L 0–0.067 0.003 0.5 4500-NO2− B

20th Ed. 1998 1160 Nitrate mg/L 0.29–207 35.7 50 4500-NO3

− B20th Ed. 1998


According to the table, the percentages of2004 are the most representative because theyinclude sampling from almost all around thecounty. A relatively high percentage of nitrateand ammonium concentrations are observedwhich indicates mainly recent and seasonalpollution. In the same period a relatively lowpercentage of increased nitrate concentration isobserved in a few areas. In Fig. 1 an exampleof the nitrate concentration range at a Countyof Kozani settlement, with continuous limitexcess is shown.

The divergences are stable for all the periodof the measurements and consistently exceed thelimit given by the legislation, which means thatthe problem is permanent and needs solution.

3.1.2. Water microbiological parameters

The concentrated results and microbiologicalmethods analysis, from water tank and internalsupply networks samples, for the period 2002–2004 are shown in Table 3. We observe that theaverage of total coliforms, E. coli and the totalbacteria at 37°C, exceed the legislation limits.

Drills and springs water samples from all thecounty were analyzed for 2002–2003 period.Total coliforms were detected to around 50% ofthe drills and springs samples.

The number of the samples and theirundrinkable percentage per year and per para-meter are shown in the Table 4. A decrease inthe undrinkable water percentage during themeasurement period is observed. This is due tothe increased information and the conforming ofthe municipalities with the legislation on thesystematic and not occasional water monitoring,the maintenance, frequent cleaning, and installa-tion of disinfection systems in the water tanksand the networks, the adoption of measures forthe protection of the supplying systems, etc. Inmany cases the problem remains and its solutionoften requires replacement of the water tanksand supply networks, which has a high cost.

The above is reinforced also by the fact thatmicrobiological infection is relatively easilyand immediately controlled, in contrast with

Table 2Number of samples and their undrinkable percentage for the period 2002–2004

Parameters 2002 2003 2004

Number ofsamples

Undrinkablepercentage

Number ofsamples


Number ofsamples


Nitrate 121 2.5 255 7.9 784 5.7 Nitrite 141 24.1 238 12.6 785 22.2 Ammonium 141 12.8 236 8.4 802 17.3 Turbidity 121 0.8 230 0.9 783 1.2 Conductivity 121 0 224 0 783 0.4 pH 121 0 230 0 783 0.1

0

10

20

30

40

50

60

70

10/2

003

03/2

004

05/2

004

07/2

004

08/2

004

09/2

004

11/2

004

Month of the Year

Con

cent

ratio

n (m

g/L)

NO3Limit

–

Fig. 1. Range of the nitrate ion during 2003–2004 in asettlement of the County of Kozani.


physicochemical pollution, which requires alot of time and money to be dealt with andoften results in a search of new water supplysources.

3.1.3. Determination of heavy metals, benzolium, pesticides, polycyclic aromatic hydrocarbons and total tri-halogen-methanes

From the beginning of the year 2004 fourteenwater samples were taken and a total numberof 60 parameters like heavy metals, benzolium,pesticides, polycyclic aromatic hydrocarbonsand total tri-halogen-methanes, were examinedfor each sample. In this period no concentrationsof the above parameters were detected.

3.1.4. Water tanks and supply water network situation

In Tables 5 and 6 the percentage of undrinkablesamples for three representative parameters, fromthe water tanks and water supply systems of theKozani settlements are presented.

The observed range of the undrinkable per-centage for these parameters is mostly due to thegradual geographical expansion of sampling inthe county, as well as to the increase in watersamples.

The data from Tables 2–6 show: • The undrinkable percentages, for the nitrate

concentration of the water tanks and the sup-ply networks samples, have no essentiallydifference. In the areas with increased nitrateconcentrations, a relatively stable exceed from

Table 4Number of sample and undrinkable percentage because of the microbiological parameters

Parameter 2002 2003 2004

Number ofsamples


Number of samples


Number ofsamples


Total coliform 100 mL 140 44.3 338 19.2 826 17.5 E. coli 100 mL 826 15.4 Total bacteria at 37°C 1/mL 88 44.3 301 19.3 797 10.3 Total bacteria at 22°C 1/mL 76 23.7 197 9.6 542 16.6 Intestinal enterococci 100 mL 471 24.6 Fecal coliforms 100 mL 140 24.3 302 19.3

Table 3Concentrating results of the microbiological analysis for 2002–2004

Check monitoring

Parameter Unit Min–max Average Limit Analysis method

Microbiologicalparameters

Total coliform No./100 mL sample 0 to >100 10 0 ISO 9308-1:2000Escherichia coli No./100 mL sample 0–15 3 0 ISO 9308-1:2000 Total bacteria at 22°C No./mL sample 0 to >100 85 100 ISO 6222:1999 Total bacteria at 37°C No./mL sample 0 to >100 25 20 ISO 6222:1999


the limits is observed (Fig. 1). The pollutioncaused from nitrates comes mostly fromagricultural activities.

• A small decrease of ammonium, which ismainly an indication of recent pollution, in thewater tanks’ samples is observed in relation tothe total undrinkable percentage, which may becaused via by their partial oxidation to nitriteand nitrate, during their transportation in theexternal water supply network as well as bytheir transformation in chloramines, due to thechlorination of the water tanks, depending onthe pH value, temperature, initial chorine-to-nitrogen ratio, absolute chlorine demand andreaction time [8,15,16]. A small increase ofammonium cconcentration in the water samplesfrom the internal supply network is observedin comparison to those of the water tanks. Thisoccurs because of the low residual chlorine

concentrations measured, in combination withthe situation of the water supply network.

• An important increase of total coliforms isobserved, especially in the water tanks, incomparison to the total undrinkable percent-age, which indicate that the supply sourcessituation and the water tanks and externalsupply networks bad condition, are usuallyresponsible. It is important to note that thenumber of total coliforms found in samplesfrom the water tanks decreased. In a largenumber of water samples coming from thewater tanks, one or two total coliforms arefound and are estimated as undrinkable sam-ples although they are not heavily infected.

• The internal supply network has lowerundrinkable percentage from the water tanksbecause the chlorination is often applied at thewater tank exit.

Table 6Water quality of the internal supply network

2002 2003 2004

Sum Undrinkable Undrinkablepercentage



Parameters

Nitrate 83 3 4 149 11 7 376 15 4 Ammonium 107 14 13 143 9 6 394 99 25 Total

coliform100 mL

98 39 40 196 89 45 399 125 31

Table 5Water quality of water tanks

2002 2003 2004




Parameters

Nitrate 38 0 0 106 18 17 408 30 7 Ammonium 34 3 9 93 11 12 408 38 9 Total

coliform100 mL

42 23 55 142 106 75 394 264 67


4. Conclusions

(a) The water quality depends on its chemicaland microbiological condition. The alter-ation of the chemical parameters of a watersystem used as potable water, especiallywhen it is underground, depends on manyparameters like the solubility of pollutants,their adsorption and halflife, from the cli-matic and hydrogeological conditions,mainly the percolation factor, the under-ground flow velocity of water, the slope andcomposition of the formations, the aquifer’slevel [17,18]. At the study area the majorityof the drinkable water analyzed samplescome from deep drills passing from cohe-sive formations accordingly to geologicalmaps and studies implemented in the areaand therefore chemical composition rela-tively stable and generally not influencedfrom agricultural activities was observed.

(b) In the areas with penetrable formations andagricultural activity, the nitrates presencewas observed in relatively stable concentra-tions (Fig. 1) in time, because of their highmobility in soil [19]. About 5.7% of testedsamples in the County of Kozani containedNO3-N at concentrations greater than 50mg/L and lower than 210 mg/L. In Europethere are evidences that 87% of the agricul-tural areas have nitrate concentrations ingroundwater above 25 mg/L and 22% above50 mg/L [20]. In USA ground wateraccounts for 86% of their total waterresources and provides 24 and 95% of thedrinking water supply for urban and ruralareas, respectively. About 6.4% of testedwells in the USA contained NO3-N at con-centrations greater than 10 mg/L and 13.2%contained 3.1–10 mg/L. In Greece 70% ofthe total consumed water is used for irritat-ing activities, 10% for drinking and 20% forindustrial use.The nitrate problem ofgroundwater in Greece is not clear [21].

(c) The water is easily microbiologicallyinfected in the supply sources because oftheir insufficient sanitary protection and theexternal network bad condition. For thisreason the continuous and systematic chlori-nation and microbiological monitoring ofthe drinking water is essential.

(d) The authorities responsible for the watersupply have to take the proper measures forthe protection of springs and drills, the main-tenance and cleaning of water networks andtanks, as well as informing and training theauthorised personnel in the correct applica-tion of chlorination and in monitoring the con-dition of springs, drills, water tanks, andwater supply networks in their areas.

(e) The condition of the water tanks, which areoften old, not correctly situated, wronglyconstructed, inefficiently maintained andnot systematic chlorinated, contributes con-siderably to the downgrading of the waterquality.

(f) The condition of the water supply networksis a factor which contributes as much as thewater tanks to the downgrading of the waterquality, often due to their age, leaks, wrongplacement near the wastewater network,absorption problems because of watercuts, etc.

References

[1] Directive 2000/60/EK, Establishing a Frameworkfor Community Action in the Field of WaterPolicy.

[2] Law 3199/2003 (ΦEK 280A/9-12-2003), Protec-tion and Management of Water, in accordance tothe Directive 2000/60/EK.

[3] KYA Y2/2600/2001 (ΦEK 892B/11-7-2001),Quality of Water Used for Human Consumption,in accordance to the Directive 98/83/EK of theCouncil of the European Union.

[4] Law Y2/4052/8-11-2000, Systematic Control andMonitoring of Drinking Water for the Protectionof Public Health.


[5] Law A5/288/86, Drinking Water Quality, inaccordance to the Directive 80/778/EOK.

[6] Directive 80/778/EOK, Drinking Water Quality. [7] Directive 98/83/EK, Quality of Fresh Water Used

for Human Consumption. [8] APHA, Standard Methods for the Examination of

Water and Wastewater, 20th edn., APHA, AWWA,WPCF, Washington, DC, 1992.

[9] ISO 5667, Water Quality — Sampling — Part 2Guidance on Sampling Techniques.

[10] ISO 9308-1, Water Quality — Detection andEnumeration of E. coli and coliform bacteria.

[11] ISO 7899.02, Water Quality — Detection andEnumeration of Intestinal Enterococci.

[12] ISO 6222, Water Quality — Enumeration ofCulturable Micro-organisms — Colony Countby Inoculation in a Nutrient Agar CultureMedium.

[13] US Food and Drug Administration, BacteriologicalAnalytical Manual, 2001, www.cfsan.fda.gov.

[14] ISO 17025, General Requirements for the Com-petence of Testing and Calibration Laboratories.

[15] M. Manassis, in: Tziola (Ed.), Quality Character-istics and Treatment of Water, Thessaloniki, 2001.

[16] A.R. Corbitt, Standard Handbook of EnvironmentalEngineering, 2nd edn., McGraw-Hill Handbooks,NY, 1999.

[17] G. Kallergis, Applied-Environmental Hydro-geology I, 2nd edn., Technical Chamber of Greece,Athens, 2001, pp. 33–44.

[18] G. Soulios, General Hydrogeology I, UniversityStudio Press, Thessaloniki, 1986, pp. 41–45.

[19] G.S. Vasilikiotis and K.K. Fytianos, in: Ziti (Ed.),Methods of Environmental Control Pollution,Thessaloniki, 1986, pp. 78–79.

[20] V.Z. Antonopoulos and S.E. Tsiouris, Evaluationof nitrate groundwater pollution using leachingindices and environmental implications, in: Proc.of International Conference of Xanthi, Vol. I,pp. 51–57.

[21] P. Latinopoulos, The problem of groundwater nitratecontamination and its control in the EuropeanUnion, in: Proc. of Helleco 99 Conference, Techni-cal Chamber of Greece, Thessaliniki, 1999, p. 256.

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