WATER POLLUTION IN THE HYDROELECTRIC POWER PLANTS AREA Valeriu NISTREANU1, Viorica NISTREANU2, Liana-Ioana VUTA3, Mihaela Amalia Tirniceanu4 University “POLITEHNICA” of Bucharest, Splaiul Independetei 313, Sector 6, Bucharest, Romania E-mail: [email protected], [email protected], [email protected], [email protected]

Abstract: This paper presents the main aspects regarding the impact of hydroelectric power plants on the environment and some aspects on the river pollution. One study case on the River is presented. The negatives effects are not related with hydroelectric power plants. Keywords: hydroelectric power plants, environmental pollution, quality indicators

WASSER-VERUNREINIGUNG IM HYDROELEKTRISCHEN KRAFTWERK-BEREICH

Zusammenfassung: Dieses Papier stellt die Hauptaspekte betreffend sind die Auswirkung der hydroelektrischen Kraftwerke auf das Klima und einige Aspekte auf die Flußverunreinigung dar. Ein Studie Fall auf dem Olt Fluß wird dargestellt. Die Negativeffekte werden nicht mit hydroelektrischen Kraftwerken bezogen. Schlüsselwörter: hydroelektrische Kraftwerke, Klimaverunreinigung, Qualitätsanzeigen

1. Introduction It is well known that hydraulic energy is one of the renewable and unpollutant energy. Water resources arrangement has, in general, positives effects on the environment, but we must mention also some negatives effects, all those effects representing its environmental impact. In most of the cases, the water pollution and environment pollution are due to other kinds of activities, but not to hydroelectric power plants.

2. The aspects of hydroelectric power plants environmental impact The environmental impact produced by hydroelectric power plants consists in effects on the economy, life aspects, water, climate, flora, fauna and so on. If the hydroelectric power plants are not realized, the electric energy must be obtained from thermoelectric power plants or nuclear power plats, but with important negatives effects on the environment. From the positive effects of hydroelectric power plants, we can mention: generating hydroelectricity, creating the big reservoirs for irrigation and water supply, controlling floods, improving the navigation, development of the tourism, sport conditions, hotels, trade, numerous industrial developments, which provides capital for new economic development and more permanent transportation networks. The main negatives effects are: huge numbers of local inhabitants, historical and archaeological monuments may be moved, groundwater effects, landscape destruction (flooding of forests and arable land), destruction of fish habitat and fisheries, changes to climate and changes to the global environment especially in the case of the big reservoirs, disturb of the upstream and downstream ecosystems, disturb of the deltas and wetlands critical to migrating wildlife, changes to coastal ecology. It can easily be observed those negatives effects do not lead to water pollution.

3. Water pollution, pollution sources, quality indicators When we say water pollution, we usually mean its alteration of physical, chemical or biological qualities, produced directly or indirectly by human activities or natural processes. The pollution can be natural when it is produced by the interactions between water and atmosphere or lithosphere, or anthropic, when it is produced by wastewater, meteorically waters, sludge, residuals, navigation, and so on. The sources of natural pollution are: the high level of mineralization, the high content of suspension from the soil erosion, the algae quantity, biological phenomena and water stratification, the sludge from the bad of the rivers and lakes. The main artificial water pollution sources are: sewage waters, waters from the animals farms, industrial waste waters, detergents, radioactive substances, meteorically waste waters, sludge, industrial waters. Usually, for the determination of water quality, we use a small number of physical, chemical and biological characteristics. The world system for environment monitoring established three categories of parameters for water quality monitoring: the basics one, the parameters who indicates the persistent pollution and the optional parameters. For exemplification of the above-mentioned ideas, we present some dates and conclusions regarding the pollution of Olt River, part of the National Hydroelectric System

4. Olt river pollution The Olt River is one of the most important river from Romania which length is 670 km. His hydroelectrically potential is 1867 MW, which mince 4,44 TWh / year, about 17% from inner river potential. This potential is concentrated on the river Olt between Fagaras and Islaz and on his affluents Lotru and -. Olt River arrangements begun in 1971 and in 1998 were finished 30 hydroelectric power plants in the Hoghiz- area, 22 of them in function and 8 in different fazes of execution (see figure 1). Olt River water quality was the object of a great number of studies, studies that lead to the following conclusions regarding the pre-existent situation: • The Olt River waters, with a few exceptions, were first quality waters; • There were a contribution of chemical industrial waters especially in the Fagaras aria; • Contribution of waste waters on Cibin River; • Contribution of wastewaters downstream of Rm. Valcea, from the chemical platform treatment plant. Waterfalls produce a discontinuity of natural hydrographic network and a passing from the lotic flow regime to lentic flow regime, with serious consequences onto biotope and biocoenosis existent. We can expect the following effects: • The intensification of biological processes, with the direct effect of minimization of O2 quantity onto the deep layers and CO2 discharge; • The self-purification process will be slowdown; • The possible appearance of natural pollution and eutrophisation due to great concentration of phosphorus and nitrogen in waters; • The accumulation of different pollutants in sediments; • Modification in thermal regime; • Modification of turbidity. In July and September 1999, were effectuated measurements for establishing the water quality in Olt River, in Hoghiz-Babeni area, and also in some of the Olt affluents. In figure 2 are presented the major pollution sources and the main pollutants, and the quality indicators are presented in table 1. Analysing those results we can easily see that water quality in Olt River is first category, excepting a few zones were the water quality is second category, due to some - pollution sources. We can distinguish a high level of nutrients (NO3 ) along the whole area. The highest values were obtained in storage basins of hydroelectric power plant Racovita

(19-22mg/l) and Gura Lotrului (21,76mg/l), but in the rest of lakes we also obtained high values (13-19mg/l). The values for nutrients concentration indicate that Olt River water is - second category. In comparison, the values of NO2 concentration are smaller, but in the Vistea-Robesti area they are also high (1-2mg/l), and also indicates that Olt River waters are second category. + In Vistea-Caineni area, except Lotrioara dam, the value of ammonium ions (NH4 ) are in the limits of second category of water quality, due to the contribution of water from the

1 11 2 MIERCUREA CIUC

N 3

6 SF ÎNTU GHEORGHE 17 12 15 4 13 5 SIBIU 14 10 BRA ŞOV 9 7 16 S ĂCELE 8

No. Name Pollutants

1 Miercurea Ciuc City BOD5, SS, pH, Petro waste

2 Alcohol factory BOD5, SS, pH, Alcohols

3 Tg.Secuiesc City BOD5, SS, COD 19 RÎMNICU VÎLCEA 4 Sf.Gheorghe City BOD5, SS, COD, Petrol waste

18 5 Covasna City BOD5, SS, COD

6 Pig farm BOD5, SS, NH4, Phenol

7 Braşov Municipality BOD5, Sulphide

8 Chemical factory BOD5, Sulphide, NH4

9 CCH Zărneşti BOD5, SS, Heavy metals, Petro waste

10 Colorom Codlea BOD5, COD, pH, Color, SS, Phenol 11 Mine Fe, SS, Petro waste

12 Pig farm BOD5, COD, SS, NH4

13 Chemical factory BOD5, COD, pH, NH4, NO2 20 14 Chemical factory Chlorine, Sulfur, NH4, Phenol, pH 21 22 15 Sibiu City BOD5, SS, Fe, Heavy metals SLATINA 16 Red Sled enterprise PH, Sulphide, SS, Color

17 Leather factory BOD5, Sulphide, SS

18 Rm. Vâlcea City BOD5, SS, pH, Petrol waste

19 Chemical factory Color, NH4,SO4, Pesticide, pH

24 20 Slatina City BOD5, SS, Petro waste

21 Aluminium factory COD, SS, SO4, Aluminium 23 22 Coal factory SS, Fixed residual

23 Pig farm SS, NH4, BOD5, Phenol

24 Caracal City COD, SS, BOD5, Petrol waste

THE DANUBE RIVER

Figure 2: Major pollution sources and the main pollutants (Olt River basin)

Table 1: Quality indicators for Olt River water Quality Hoghiz Voila Viştea Arpaş Scorei Avrig Racoviţa Lotrioara Câineni Robeşti Cornetu Gura Căciulata Rm. Govora Băbeni indicators Lotru Vâlcea Temp. 0C 19,2 21 19 20 22 20,9 22 23,8 20,7 23 23,2 20,4 20,2 20 20 21 pH 7,5 7,5 7,7 7,5 7,4 8,6 7,3 7,7 7,9 8,6 8,3 8,6 7,2 8,6 7,6 8,2 DO mg/l 7,24 8,12 7,09 6,17 6,21 9,10 9,26 9,49 9,56 8,88 8,33 9,1 9,1 6,7 BOD5 mg/l 4,57 2,47 4,99 3,04 4,17 7,14 8,02 7,43 3,62 6,25 3,50 9,33 54,1 3,1 COD mg/l 9,5 140,3 43,6 7,0 13,4 21,3 185,5 Hardness 0G 8,41 4,7 9,09 10,52 8,19 9,98 9,98 9,76 9,65 8,75 9,65 8,07 9,54 8,7 Fixed residue 240 134,4 336 364 252 370 368 382 397 347 351 264 356 298 528 mg/l SS, mg/l 4,0 110 44 39 43 125 52,3 25,4 Ca2+ mg/l 48,09 32,1 52,10 60,12 46,49 57,51 55,31 56,11 54,50 48,90 55,31 46,49 52,90 54 83,4 Mg2+ mg/l 7,29 1,2 7,78 8,27 7,29 8,27 9,73 8,26 8,75 8,26 8,26 6,81 9 9,4 10,9 + NH4 mg/l 0,52 0,151 2,17 3,40 1,11 1,68 0,36 4,6 0,18 0,09 0,10 2,20 0,62 0,26 0,26 + HCO3 mg/l 54,9 134,0 115,9 128,1 98,5 2- SO4 mg/l 32,25 13,9 36,00 39,00 39,10 37,50 35,10 37,30 34,70 30,75 34,30 36,20 33,9 37 50,9 Cl- mg/l 17,04 5,3 29,11 42,60 27,69 46,29 48,85 56,80 61,91 48,28 41,75 30,53 44,59 27,14 209,96 - NO2 mg/l 0,36 0,012 0,650 1,725 1,380 1,240 0,92 0,86 1,03 0,54 0,05 1,260 1,040 0,810 - NO3 mg/l 3,94 4,90 11,57 19,21 13,60 19,55 19,55 19,21 18,02 17,85 21,76 10,20 17,17 16,28 4,53 3- PO4 mg/l 0,151 2,17 3,40 1,11 1,68 0,36 0,25 0,18 0,09 0,10 0,053 0,62 0,15 0,094 0,127 Alkalinity 2,44 2,60 2,96 2,12 1,72 2,68 2,68 2,56 2,40 2,64 2,12 2,64 Mval/l Organic 33,03 28,63 31,52 30,83 28,14 26,44 26,44 22,71 25,76 27,80 54,5 28,47 44,8 substances mg/l

Fagaras area. Downstream of Caineni, the values are not so big, except Caciulata Lake, due to auto purifying process. The concentration of dissolved oxygen reveal a good oxygenation in the study area, and it is in the first category limits. As we know, the dissolved oxygen is one of the important parameters in water quality analysis; it can be due to biological sources (photosynthesis) or physical sources (dissolved from the atmosphere). In August and September the temperature and the reduced water flow influenced the values recorded. The content of solid organic substances is in the highest limits for first quality water. The dynamics of BOD5 concentration values indicates a growth in august due to high temperature, so the water is first and second category of quality. Knowing all this we can appreciate that in downstream of Caineni it is tacking place an auto purifying process. The phosphors concentrations are relatively low, and the mineralization level is moderate. From all the Olt River affluents only the Cibin River have very polluted water, with a high value of organic substances, ammonium and phosphorus, the ammonium concentration being in the third category limits.

5. CONCLUSIONS Hydroelectric power plants have in general in general no negatives effects onto the river water quality. In the above mentioned cases we can easily see that water pollution is due to a numerous sources but not due to hydroelectric sources. We must mention that the number of treatment plant is very small and their efficiency is low so it is necessary to improve the existing treatment plants and to build new ones, and, also, to improve the water quality monitoring.

6. References V. Nistreanu, V. Nistreanu - „The environmental impact of hydroelectric power plants”, Ed. BREN, Bucharest, 1999 V. Nistreanu, V. Nistreanu, L. Vuta, G. Dumitran - „ Water pollution in Olt River and Buzau River”, The 1st Conference of Hydroelectric Engineers, Bucharest, Romania, 2000