SPECIFIC POLLUTION OF SURFACE WATER AND SEDIMENTS IN THE KLABAVA RIVER BASIN

J. Hydrol. Hydromech., 55, 2007, 2, 122–134

SPECIFIC POLLUTION OF SURFACE WATER AND SEDIMENTS IN THE KLABAVA RIVER BASIN LENKA VOLAUFOVÁ, JAKUB LANGHAMMER Charles University in Prague, Faculty of Science, Department of Physical Geography and Geoecology, Albertov 6, 128 43 Prague 2, Czech Republic; mailto: [email protected]; [email protected]

The paper presents the results of research of surface water and sediment contamination by the specific pollutants in the Klabava River Basin, subcatchment of Vltava River in Central Bohemia, Czech Republic. The analysis of spatial and temporal dynamics of the contamination is based on the water and sediment chemistry data from the long-term monitoring maintained by the Vltava River Authority completed by the own monitoring established in the Klabava River basin. The research revealed that the most important water and sediment contamination loads are mainly concentrated in the industrial area between cities Hrádek and Rokycany situated on downstream of the river basin. The performed analysis identified the cadmium as the most critical parameter as its concentrations in surface water exceeded the references limits up to several hundred times. However, pollution with the specific organic substances was still below the critical limit, except for the AOX indicator. The results of sample-taking in the river basin allowed analyzing the effect of extreme flood in August 2002 on the changes in the sediment load by heavy metals. Contaminated sediments were mostly washed out by the inundation and this resulted in significantly lower values than were observed in the previous seasons. Repeated observations however indicate that the pollution concentrations are gradually reaching their original values. KEY WORDS: Water Quality, Specific Pollution, Sediment, Cadmium, Floods. Lenka Volaufová, Jakub Langhammer: SPECIFICKÉ ZNEČIŠTĚNÍ POVRCHOVÝCH VOD A SEDIMENTŮ V POVODÍ KLABAVY. Vodohosp. Čas., 55, 2007, 2; 24 lit., 5 obr. 5 tab. Článek představuje výsledky výzkumu znečištění povrchových vod a sedimentů specifickým znečištěním v povodí Klabavy. Analýza vychází z dostupných dat o chemismu vody a plavenin ze sledování podniku Povodí Vltavy a z vlastních dat získaných rozbory vzorků odebraných na síti účelově zřízených profilů. Pro hodnocení chemismu sedimentů byly použity standardní metody – porovnání s pozaďovými hodnotami geogenního prostředí podle Turekiana a Wedepohla a zatřídění do tříd jakosti podle Igeo. Z výsledků vyplývá, že zatížení vody i sedimentů je soustředěno zejména do oblasti průmyslového a sídelního uskupení mezi Hrádkem a Rokycany. Varovné jsou zde především koncentrace kadmia ve vodě, které v této oblasti překračují referenční hodnoty i několiksetkrát, silnou zátěž potvrzují i analýzy sedimentu. Znečištění specifickými organickými látkami s výjimkou ukazatele AOX nedosahuje kritických hodnot. Výsledky vlastních odběrů umožnily rovněž zhodnotit vliv povodně v srpnu 2002 na změnu zátěže sedimentů. Kontaminované sedimenty byly povodní vyplaveny a hodnoty, naměřené bezprostředně po povodni, jsou výrazně nižší než v předchozím období. Díky pokračující zátěži se však postupně vrací k původním hodnotám. KLÍČOVÁ SLOVA: kvalita vody, specifické znečištění, sediment, kadmium, povodně.

1. Introduction Currently, more attention is paid to the specific pollution – the pollution of surface waters and sediments by heavy metals and specific organic 122

substances. Due to the short time series of measurements and limited range of sample-taking profiles information on the spatial distribution and dynamics of the loads are still very limited

Specific pollution of surface water and sediments in the Klabava River basin

(Langhammer and Matoušková, 2004; Mohaupt et al., 1998; Thyssen, 2000). The goal of presented research was to analyze the contemporary situation and spatial and temporal dynamics of contamination of surface water and sediments by heavy metals and specific organic substances in traditional industrial region where the current activities as well as the old loads affect seriously the contamination of the water environment. The study area is represented by the Klabava River basin, one of the main tributaries of the Berounka River in Central Bohemia, Czech Republic. In order to assess comprehensively the water environment loads from the specific pollution, both the water component and sediment were analyzed at the same time. The water pollution gives evidence of the actual watercourse pollution levels while the monitoring of sediment pollution allows capturing the long-term pollution trends. The sediment monitoring is increasingly emphasized in the water quality assessment mainly because it is necessary to view the water ecosystem comprehensively, as an integral whole. Unlike the hydrochemical and hydrobiological indicators of water quality the quality of sediments started being monitored systematically as late as in the 1990s in the Czech Republic (Langhammer, 2000; Rudiš, 2004). This is why the available time series are very short, and – furthermore – the number of the profiles monitored is still very limited in contrast to the water quality monitoring network. The performed research was aimed at broadening the information on the spatial distribution of pollution in the assessed river basin by establishing the own sampling network completing information from the long-term monitoring which also helped to identify the main sources of pollution and to assess their impact on the water and sediment contamination. 2. Material and methods 2.1 Data sources The surface water and sediment quality assessment is based on two main sources of data. The basic data source represented the databases of CHMI and the Vltava River Basin Authority containing results of long-term monitoring of surface water and sediment pollution. These data were coupled with the results from own monitoring network established in the river basin to complete the information on contamination of surface water and

sediment and to identify the potential pollution sources. Statistic assessment of the surface water pollution levels by the key hydrochemical parameters was carried out on the basis of the database of the Vltava River Basin Authority, characterizing the main watercourse and its major tributaries in 1965– 2000. The database from 1990–2000 was available for evaluation of the heavy metal water contents. The database from 1997–2000 was used for detail evaluation of the sediment polluting loads. There were variations in analysis methodology in time – in period 1997–2002 the analysis were made on the 25 µm fraction, since 2003 is performed on the 20 µm fraction. The Vltava River Basin Authority is monitoring 9 profiles on the Klabava River and Holoubkovský creek. In 1997–1999 the sediment pollution was observed on six profiles along the Klabava River (Upstream Strašice, Downstream Strašice, Kamenný Újezd, Upstream Rokycany, Downstream Rokycany, and Chrást) and on the Holoubkovský creek. Since 2002, the sediment pollution levels have only been monitored on the Downstream Rokycany profile and this fact is seriously limiting the informational value of the data regarding the pollution distribution over the river basin. The own monitoring was realized on 9 profiles with aim to complete and ameliorate the information on spatial distribution of pollution load (Fig. 1). The sample-taking took place in November 2002 and May 2003, the sample treatment has been made according the National Standard EN 133 46 under the standard conditions as they are given by the manufacturer of the Varian Atomic Absorption Spectrophotometer. The analyses were carried out in the fraction 63 µm. The layers of digital Water Management Base Map (Water Research Institute), CORINE Landcover Database (Czech Ministry of Environment), and the layers of DMÚ-25 (Military Topographical Institute) were used as the cartographic base for GIS analysis and visualization of results. 2.2 Methodology of assessment of surface water quality and sediment pollution The National Standard 75 7221 was used as framework for classification of surface water quality. Using the standard methodology, both the obtained and measured data? are ranked into one of the five water quality classes according the set of thresholds for individual parameters (I – very clean 123

L. Volaufová, J. Langhammer

T a b l e 1. Characteristics of the existing Vltava River Basin Authority profiles for the water and sediment sample-taking in the Klabava River Basin. T a b u l k a 1. Charakteristika stávajících profilů Povodí Vltavy pro odběr vody a sedimentu v povodí Klabavy. Profile

Profile No.

Watercourse

River km

Qr [m3 s-1]

Qd355 [m3 s-1]

Upstream Strašice Downstream Strašice Kamenný Újezd Upstream Rokycany Downstream Rokycany Klabava dam Ejpovice quarry Chrást Rokycany

3513 3501 3502 3503 3504

Klabava River Klabava River Klabava River Klabava River Klabava River

36.2 32.5 22.3 20.5 17.2

0.553 0.66

0.067 0.08

1.3 1.85

0.16 0.21

3505 3507 1091 3510

Klabava River Klabava River Klabava River Holoubkovský creek

14.0 11.4 2.8 1.0

1.98

0.23

2.16 0.42

0.27 0.048

Data source: Vltava River Basin Authority; Abbreviations: Qr – average annual flow rate, Qd355 – 355 daily flow rate. Zdroj: Povodí Vltavy, s.p.; Zkratky: Qr – průměrný roční průtok, Qd355 – 355-denní průtok.

water; II – clean water; III – polluted water; IV – heavily polluted water; V – extremely polluted water). In this study, the contamination by heavy metals was assessed by two methods – by matching the observed values against their background concentrations and by calculating the geo-accumulation index. For the evaluation of the river sediment contamination levels the so-called “natural background heavy metal concentrations” are widely used as a reference value. Turekian and Wedepohl (1965) were dealing with the distribution of the elements in the earth crust basic units, establishing the background heavy metal values in the environment. They determined the globally applicable values for the clay sediments, i.e., the standard clay rocks. Background values have to be taken as a basic indicator only which, however, they should respect the specific conditions of individual geographical regions. This is why in various research projects the background values are more precisely defined for certain regions. For the Elbe River Basin were heavy metal background values defined by Prange et al. (1998) and MKOL (1996). As used in the EU countries the standard sediment pollution load assessment method rests in the classification, i.e. grouping the sediments into the quality classes, depending on the calculated geoaccumulation index (Igeo) which expresses the level of sediment burdening with heavy metals. The index values are calculated by the following formula: 124

Igeo = ln2 (cp (1.5. Bn)-1), where cp – heavy metal concentration in sediment, Bn – clay material background value. Supporting the geo-accumulation index calculation the background values were used according to Turekian and Wedepohl (Tab. 2, hereinafter Turekian and Wedepohl, 1965). 2.3 Study area The Klabava River Basin, the first right-side tributary to the Berounka River downstream Pilsen is diverse in both the very nature of its landscape conditions and the land usage. The water basin has the total of 359 km², with its main watercourse 49 km long and long-term average flow rate at the river mouth reaching to 2.1 m³ s-1 (Volaufová, 2004). The river basin headwaters are located in the Brdy Hills at 630 m a.s.l., the mouth profile of the Klabava River in Chrást is at 285 m a.s.l. In its upper course the water basis stretches itself in the forest-covered area of the Brdy Hills, scarcely populated due to the presence of the Jince Military Training Area. The total share of forested area exceedes 58% of the total river basin area, agricultural areas 34 %, the urban and industrial areas 6% (CORINE landcover). The most intensive anthropogenic pressure is concentrated on the down part of the basin where are located the largest cities and industrial zones with intense manufacturing processes – Pilsen, Hrádek u Rokycan, Kamenný Újezd, and Rokycany (Fig. 1).


T a b l e 2. Classification of the sediment pollution loads with heavy metals and arsenic and background values of the pollutants by Igeo. T a b u l k a 2. Klasifikace zatížení sedimentu těžkými kovy a arsenem podle Igeo. [ug g-1]

1)

Igeo class:

2 Unloaded

3 Unloaded to slightly loaded

4 Slightly loaded

5 Slightly to heavily loaded

6 Heavily loaded

7 Heavily to exceedingly loaded

8 Exceedingly loaded

< 19.5 < 0.45 < 135 < 67.5 < 102 < 30 < 142 < 0.6

< 39 < 0.9 < 270 < 135 < 204 < 60 < 285 < 1.2

< 78 < 1.8 < 540 < 270 < 408 < 120 < 570 < 2.4

< 156 < 3.6 < 1080 < 540 < 816 < 240 < 1140 < 4.8

< 312 < 7.0 < 2160 < 1080 < 1632 < 480 < 2280 < 9.6

< 624 < 14.4 < 4320 < 2160 < 3264 < 960 < 4560 < 19.2

> 624 < 28.8 > 4320 > 2160 > 3264 > 960 > 4560 > 19.2

Background value As Cd Cr Cu Ni Pb Zn Hg

13 0.3 90 45 68 20 95 0.4

1 – Třída Igeo: pozaďová hodnota, 2 – nezatížený, 3 – nezatížený až mírně zatížený, 4 – mírně zatížený, 5 – mírně až silně zatížený, 6 – silně zatížený, 7 – silně až nadměrně zatížený, 8 – nadměrně zatížený.

Fig. 1. Study area: The Klabava River Basin with marked network of sample-taking points. Obr. 1. Zájmové území: Povodí Klabavy s vyznačenou sítí odběrných profilů.

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2.4 Pollution sources in the river basin The pollution sources are distributed very unevenly across the investigated water basin. Majority of the direct pollution sources is concentrated into the area between cities of Hrádek and Rokycany on the medium and lower course of Klabava River (Fig. 1). There are thirty important point pollution sources registered in the Water Balance database in the river basin (VUV, 2005). The largest source of direct pollution in the Klabava River Basin is the VOSS Sokolov Rokycany wastewater treatment plant treating the industrial as well as municipal wastewater. According to the Water Balance database this pollution source discharged in 2002 42.818 t/year of BOD-5, 133.468 t/year of COD-Cr, 45.951 t/year of undissolved solids, 18.798 t/year of N-NH4 and 2.506 t/year of Ptotal. The high volumes of emmissions are caused by spatial concentration of industrial production, dense population and related activities in area with inadequate capacity of recipient. Moreover the wastewater treatment plant was until 2000–2003, when the reconstruction was carried out, insufficient in order to reduce substantially the pollution loads discharged into the watercourse. A significant source of potential threat represents the disperse sources, mainly the old industrial loads

and the waste depositing sites. The inquiries of old loads collected within the Pilsen Region have shown tens of old and active facilities that pose a potential source of surface and ground water contamination (Kodetová, Brzáková, 2005). The pollution loads are mainly concentrated into the backgrounds of the industrial facilities in the areas of Rokycany and Hrádek, some of them being classified as risky. 3. Results 3.1 Long-term trends of water quality The evaluation of the long-term water quality trends in the Klabava Basin mouth profile indicates that the absolute maximum pollution concentration levels tended to appear in the 1960s–1970s for most of assessed indicators. The situation became stabilized in the 1980s and the concentration levels were fluctuating around their long-term averages with only occasional surges to the values much in excess of these long-term averages. A sizeable drop in the concentration levels came around the half-1990s. Since then, both the measurements and 12-month moving averages have solely been below their longterm average limit (Fig. 2).

Fig. 2. Long-term trend of BOD5 concentrations in the Klabava-Chrást profile in 1965–2005. Data source: CHMI. Obr. 2. Dlouhodobý vývoj koncentrací BSK5 na profilu Klabava-Chrást v období 1965–2005. Data: ČHMÚ.

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The water quality classification according the national standard (ČSN 757221) reflects well the high level of overall pollution in the industrial area of Rokycany and Hrádek. Most of indicators are classified as satisfactory (class III) with several exceptions. In the parameter of total phosphorus the worst quality class V was identified in 1992–2005. Water quality class IV was identified in multiple cases – at Klabava River in BOD-5 and N-NH4 indicators, at Holoubkovský creek in the BOD-5, COD-Mn, and undissolved solids indicators. The N-NO3 concentrations reached their peaks as late as in the 1980s and in the early 1990s; the second half of the 1990 saw them decreasing again. Hydrobiological indicators are classifying most of the watercourse as beta-mesosaprobitic from the viewpoint of the classification as the watercourse with the quality class II to III. 3.2 Water quality changes in the longitudinal profile In most of treated water quality indicators the highest concentrations in the longitudinal profile

appear in the area of the Kamenný Újezd and Downstream Rokycany profiles. The high level of water pollution revlects the excessive emmissions for the concentrated industrial and municipal point sources in Hrádek and Rokycany region. Absolute maximums are mostly detected on the Downstream Rokycany profiles. The exception represents the nitrates while their concentrations are gradually increasing in the whole longitudinal profile. This trend is caused by the nitrification process and by the absence of the agricultural contaminations on the forested upper part of the river basin. The distribution of concentration of heavy metals in the longitudinal profile proves that the most problematic areas are located in the medium and lower courses where the industrial production is concentrated in the water basin (Fig. 4). The most probable sources of heavy metals are the industrial plants in Hrádek and Rokycany – Rokycany Metalworks and Hrádek Ironworks – which are directly processing the heavy metals. For cadmium and arsenic, higher concentrations were also detected on the upper course in Strašice.

Fig. 3. Annual concentrations of total phosphorus in the longitudinal profile of Klabava River in 1992–2003. Data source: Vltava River Rasin Authority. Obr. 3. Vývoj průměrných ročních koncentrací celkového fosforu v podélném profilu Klabavy v období 1992–2003. Data: Povodí Vltavy s.p.

127


Fig. 4. Median and long-term average concentrations of cadmium in the longitudinal profile of Klabava River in 1992–2003. Data source: Vltava River Basin Authority. Note: The profile Klabava-downstream is not under monitoring in this parameter. Obr. 4. Medián a průměrné koncentrace kadmia v podélném profilu Klabavy za období 1992–2003. Data: Povodí Vltavy. Poznámka: Tento parametr není na profilu Klabava – pod VD sledován.

3.3 Specific pollution of surface water 3.3.1 Heavy metals For the assessment of specific pollution of surface water the following parameters were used: Pb, Hg, Ni, Cd, Mn, Zn and As. The most important problem in the Klabava River Basin rests clearly in the cadmium concentration levels. Over most years, these rank the watercourse on its profiles in Kamenný Újezd and Rokycany into V, i.e. the worst water quality class. The measurements exceed the reference values of the heavy metal water concentration (see Tab. 4) up to four times. In January 1995, for example, the extreme concentrations were detected on the Rokycany profiles – Upstream Rokycany 21 µg l-1 and Downstream Rokycany 19 µg l-1, while the reference values reach only 0.07 µg l-1. High concentration levels were also detected on the profiles in Strašice and downstream the Ejpovice quarry (Tab. 5). Even though lower concentration levels were measured

in the mouth profile, the reference concentrations strongly prevail here (Fig. 5). Except for the profiles in Rokycany an improvement in the pollution by cadmium can be recorded on all the profiles. The reason can rest in the industrial production decline in the water basin and stagnating activities in the Jince Military training area. Because of the unavailability of the direct information on the pollutant emmissions in this indicator the finding have to be deemed indirect. Analogous trends can be noticed in the concentration of zinc, copper, and nickel. Quality Classes V and VI were recorded for these elements in the mid1990s, but their levels now settled at the quality class II. For all the above elements, the top concentrations were appearing on the profiles in Rokycany. Unlike in the case of cadmium, no increased concentration levels were recorded on the upper course. On the profiles in Strašice, the concentration levels do not reach higher than to the quality class II.

T a b l e 3. Reference concentrations of heavy metals in water. T a b u l k a 3. Referenční koncentrace těžkých kovů ve vodě. Parameter Concentration [µg l-1]

Pb 0.20

Cu 1.80

Data source: Rath (1990); Zdroj: Rath (1990)

128

Cd 0.07

Cr 0.50

Cb 0.05

Ni 0.30

Mn 5.00

Zn 0.50


Fig. 5. Trends of Klabava water pollution by heavy metals and specific organic substances in the mouth profile Klabava-Chrást. Data source: CHMI. Obr. 5. Vývoj znečištění toku Klabavy těžkými kovy a specifickými organickými látkami ve výústním profilu Klabava-Chrást. Data: ČHMÚ.

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Throughout the development under study the concentration levels at the Classes II and III could be followed for the lead. The only exception was in 2001 when the contamination with lead aggravated down to the level of the quality class IV on the profiles in Rokycany. The top concentrations in the longitudinal profile can again be followed from Kamenný Újezd to Downstream Rokycany. On the remaining profiles the concentrations fluctuate at the levels of the Quality Classes I and II. The only element which does not match the areas of the medium course in the distribution of its top concentrations is arsenic. Its highest concentrations were determined in Strašice. Throughout the watercourse the concentration levels matching the quality class I were found; the concentration levels of the Class III appeared only on both Strašice profiles. In case of mercury the concentration levels have been followed over longer horizons of time only on the closer profiles of the Klabava River and Holoubkov Stream. Until 1998 the detection limit was at 0.1 µg l-1. On both of these watercourses the value was exceeded in the exceptional cases only. The concentration levels of chromium which matches the quality class I (or II in exceptional cases only) on all the profiles over most years can be denoted as smooth. 3.3.2 Specific organic substances

substances, the profiles of Upstream Rokycany, Downstream Rokycany, and Chrást Mouth were selected for the evaluation. The following indicators – the chloroform (trichlormethane), chlorbenzene, AOX, DCBenzenes (expressed as the sum of concentrations of 1,2 – dichlorbenzene and 1,4 – dichlorbenzene), PCB Sum (expressed as the sum of concentrations of the selected PCB 28, PCB 52, PCB 101, PCB 138, PCB 153 and PCB 180 cogeners), and PAU Sum – were selected for depiction of the water pollution with the specific organic substances. It is obvious from the two-year (2002/2003) evaluation of the organic substances water concentration that no critical concentration limits are now appearing in case of most indicators under the evaluation. But the warning concentration levels were found on all three profiles with the summary indicator of the absorbed organically bonded halogens (AOX). Evaluating the pollution load changes in the field of the specific organic substances, one will come across a major obstacle in the form of the short time series of monitoring that do not allow to appreciate the significance of the current values versus the historical ones. Even despite the relatively favorable values in the case of most indicators the pollution load in the form of the specific organic substances, mainly due to their strong capacity to accumulate in sediments and bio mass, has to be understood as a potential risk.

In respect of the data series completeness and the probability of pollution with the above organic T a b l e 4. Assignment of the cadmium concentration levels to the Water Quality Classes according the National Standard 757 221. T a b u l k a 4. Zařazení koncentrací kadmia do tříd jakosti vod podle ČSN 757 221. Profile 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003

Upstream Strašice

IV III II II

Downstream Strašice

IV IV IV III II II II

Kamenný Újezd

Upstream Rokycany

Downstream Rokycany

IV V II

IV V V V V V V IV V V IV II

III IV V V V IV V III IV V V II

V V V V IV IV

Data source: Vltava River Basin Authority; Zdroj: Povodí Vltavy, s.p.

130

Ejpovice

III III IV III IV

Chrást III III III IV III III III III IV II II II


3.4 Specific pollution of sediments It was at the focal point of the sediment heavy metal pollution assessment to localize the spots where the pollution loads have reached critical levels and to identify the indicators that are most problematic for pollution loads on the ecosystem. Furthermore, the results from the analysis conducted after the floods in August 2002 made it possible to assess the influence of flood on the sediment pollution loads in the water basin. According to the data analysis results from the Vltava River Basin Authority and in compliance with the own analysis the most contaminated part of the Klabava River Basin from the sediment specific pollution point of view is the area between Hrádek and Rokycany. The pollution is most probably caused here by the emissions from the concentrated industrial plants that use the heavy metal compounds within their activities – Rokycany Metalworks and Hrádek Ironworks. But the heavy metal traces can also be present in the sediments due to the heavy metal wash-out of the bedrock. This can be supposed from the finding of the contaminated sediment in the Strašice area where none of the anthropogenic pollution sources is present. On the basis of the lower concentration levels found in the sediment from the mouth profile in Chrást it can be anticipated the high level of the sediment contamination with heavy metals on the area of the Ejpovice quarry and the Klabava dam. The analysis of the specific sediment pollution data from the database of the Vltava River Basin Authority is only confirming the fact that the greatest problem in the spectrum of the indicators evaluated rests in the pollution load in the form of cadmium. The cadmium concentration levels in the areas of the Klabava medium course exceed the

background concentrations up to several hundred times. Other elements that are significantly present in the sediments are copper and lead. Pollution with mercury and organic substances fails to show any unambiguous trend, and the pollution loads in these indicators must therefore, in respect of their toxicity, be closely watched further on. As with the data from the Vltava River Basin Authority the own analyses have only confirmed the high pollution levels in the case of cadmium, then copper and zinc, mainly in the urbanized areas and near the industrial plants that work with heavy metals – between Hrádek and Rokycany. Except for cadmium, however, no warning heavy metal concentration levels were found on the Kamenný Újezd profile. Excluding the exceptions, the data from the own analyses of the fall 2002 tend to be lower than their counterparts collected during the spring sampletaking in 2003. In 2002, no classes below the Igeo class 2 were found anywhere and some of the values were even ranging below the relative values established by Turekian and Wedepohl (1965) or Prange (1998). Likely ground behind the substantially low contamination levels is the fact that the sample-taking took place immediately after the floods in August 2002 that have taken the contaminated sediment away or dispersed it throughout the surrounding areas. This likely relationship is confirmed even through the results of the Elbe Project III (Blažková et al., 2002, Rudiš, 2004) that displayed a considerable decrease in the sediment pollution levels by virtue of the catastrophic floods in August 2002 in the case of most indicators.

T a b l e 5. Sediment contamination with cadmium in the Klabava River Basin. Classification according the geoaccumulation index. T a b u l k a 5. Kontaminace sedimentu kadmiem v povodí Klabavy. Zatřídění podle indexu geoakumulace. Cadmium Upstream Strašice Downstream [mg kg-1] Strašice 2.4.1997 below detection 20.10.1997 3 16.4.1998 3 7.4.1999 I 10.5.2000 2 6.6.2001 3 7.5.2002 12.6.2003

3 4 4 2 3 3

Kamenný Újezd

Upstream Rokycany

Downstream Rokycany

Chrást

Rokycany Holoubkovský creek

5 6 5 3 6 6

6 6 5 6 6 6

4 5

4 4 4 4

below detection 3 2 I

5 4 5 6 2

Data source: Vltava River Basin Authority; Zdroj: Povodí Vltavy, s.p.

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4. Discussion It is clear from the evaluation of the related longterm trends that the water quality, when evaluated by means of the chemical and hydrobiological indicators, improved mainly after 1995. The decline in the pollution levels should be seen in the construction and upgrading of the wastewater treatment plants at the industrial and communal sources, but also in the reduced amounts of the pollutant discharges caused by the fading of industrial production in the region. But the contemporary situation cannot yet be perceived as satisfactory. Improvement of water quality can solely be encountered at the profiles on the medium course – they are the profiles in the area of the urbanized and industrial centers from Hrádek to Rokycany – the profiles Kamenný Újezd, Upstream Rokycany and Downstream Rokycany. Maximum pollution loads tend to be observed mainly on the Downstream Rokycany profile. Except for the Ptotal indicator, the worst – quality class V – does not appear with none of the selected indicators in three double-years evaluated after 1990. But the strongly contaminated water – quality class IV – appears with some indicators – BOD-5, TOC, Ptotal, and COD-Mn. It is clear from the evaluation of the point pollution sources that the largest pollutant producer in the Klabava River Basin is the wastewater treatment plant VOSS Sokolov Rokycany. As the capacity of the wastewater treatment plant fails to match on a long-term basis the population density, industrial concentration, and other activities in the area of Rokycany, its intensification has been implemented in 2001–03. Following the reconstruction of the wastewater treatment plant a slight drop in the concentration levels of some indicators can be recorded in the Klabava mouth profile in Chrást. In the urbanized and industrial areas between the Kamenný Újezd and Downstream Rokycany profiles, strong pollution with heavy metals was detected. The greatest problem clearly rests in the cadmium concentrations, followed by the zinc. Due to the cadmium concentration the quality class V and IV can be assigned to the watercourse on both of the Rokycany profiles for most years. Surprisingly, the increased concentration levels, mainly in the case of cadmium and arsenic, appeared on the Upstream Strašice profile, being just below the point where the Klabava River is leaving the forests of the Brdy Hills, on the borderline of the Jince 132

Military Training Area. The sediment pollution data analysis revealed that the levels of the sediment pollution loads of heavy metals remained virtually constant during the studied time period. Like in the case of water quality analysis the pollution with cadmium (followed by zinc and copper) is the greatest problem among those with other heavy metals in the case of sediments as well. Concerning the affected localities, the profiles in the area of the urbanized settlements and industrial plants active in the heavy metal processing prevail among them, mainly there between Hrádek and Rokycany. It is mainly from the data from the Vltava River Basin Authority that the sediment pollution with heavy metals is critical in this area, reaching there the highest sediment quality classes assessed by the geoaccumulation index. The own sediment sample-taking was carried out in November 2002 and May 2003. It means that all samples were taken after the extreme flood in August 2002. The assumption that the contaminated sediment might have been brought away during the flood may help explaining the fact that, except for cadmium on the Kamenný Újezd profile, the own monitoring displayed generally very low level of sediment contamination. The low detected level of contamination was confirmed by analysis performed by the Vltava River Basin Authority in the identical profile after the flood in 2003. On the other hand in some localities there were detected higher concentrations of heavy metals in sediments in 2003. The rise of concentrations was able to be caused by remobilisation contaminated sediment during the flood in August 2002. The sediment contamination as a result of the floods has been here already confirmed by the analysis carried out by SUDOP Pilsen (2003) in the framework of revitalization of the Borecký Fishpond, situated on the Holoubkov Stream. Here, the repeated analysis of the bottom sediments showed a growth of the cadmium, manganese, and nickel concentrations which are connected with the sediment transport by the high water levels during the past floods. It has to be noted that the comparison of heavy metals concentrations in sediments between data from Vltava River Basin Authority monitoring and the data from the own sampling is complicated by the different size of fraction of sediments used for analysis. The 63 µm fraction was used for the analysis during the own data collection while the Vltava River Basin Authority is determining the concentrations of heavy metals from the 25 µm


fraction. The difference in resulting concentrations are however surprisingly not too striking – the values from the own analysis in May 2003 are at the concentration levels deduced by the Vltava River Basin Authority on the Downstream Rokycany profile in June 2003. This comparison shows that a different sediment fraction used for the analysis does not always need to affect the results. 5. Conclusions The paper presents results of the analysis of surface water and sediment pollution distribution and dynamics in the Klabava River Basin representing region with strong concentration of traditional heavy industrial facilities and dense settlement. Based on the regular monitoring completed by the data from the own sampling network, the analysis helped to identify the main direct sources of pollution in the water basin. The region between cities Hrádek and Rokycany was identified as the most critical part of the river basin in terms of specific pollution of surface water and sediment. The main sources of contamination by heavy metals are the industrial facilities of Hrádek Ironworks and Rokycany Metalworks that are treating the heavy metals in their manufacturing technology. Most critical is the surface water pollution by cadmium – the concentrations are reaching extreme levels that exceed here the reference values up to several hundred times. The strong pollution of surface water is confirmed by the high levels of heavy metals concentrations detected in the sediment. Despite of the high intensity of the overall pollution the specific organic substances, except for the AOX indicator, have not reached here any important values. The results of the own sample-taking in 2002 and 2003 helped to clear the impacts of the extreme flood in August 2002 on the sediment pollution loads distribution. The contaminated sediments were washed out and moved by the flood in August 2002 in the most of assessed profiles. The values resulted from the analyses of samples taken immediately after the flood are substantially lower that in the previous period. Due to the lasting loads of pollution the concentrations are gradually increased to their original values. Water and sediment contamination with specific pollutants in the Klabava River Basin signals a gradual improvement, mainly thanks to the construction and intensification of the wastewater treatment plants. A part of this drop in contamina-

tion is, however, associated with the decline of the manufacturing activities – should they experience a revival, they would represent a lasting source of potential threat of the environment. Acknowledgement. The above presented research was implemented with the financial aid of the research plan MSM 0021620831: “Geographical Systems and Risk Processes in the Context of Global Changes and European Integration“. The authors would like to express gratitude to their colleagues who had a share in the field sample-taking and laboratory analyses, mainly to the staff of the Laboratory of Environmental Institute of Faculty of Science, Charles University in Prague, and to the staff of the Laboratory of Geological Institutes at the same Faculty where the analyses of surface water and sediments were realized. REFERENCES BARTÁČEK J., 2005: Zpráva o hodnocení jakosti povrchových vod v oblasti povodí Berounky za období 2003–04. (In Czech.) (Report on surface water quality in Berounka River basin in period 2003–04.) Povodí Vltavy, Praha. BLAŽKOVÁ Š. et al., 2002: Elbe Project III – Inventory of Results. VÚV T.G. M., Praha. CHMI, 2005: Water quality database. Czech Hydrometeorological Institute. Prague. (Online.) http://hydro.chmi.cz/ /ojv2/. ČSN 757 221, 1998: Jakost vod – Klasifikace jakosti povrchových vod. (Czech National Standard 75 7221, Classification of surface water quality.) ČSN EN 13346, 2001: Charakterizace kalů – Stanovení stopových prvků a fosforu – metody extrakce. (Czech National Standard 13346: Characterization of sediments.) JURČA V., DAMAŠKA J., DAMAŠKOVÁ H. et al., 1997: Látkový transport z plošných zdrojů v České republice. (In Czech.) (Material transport from nonpoint pollution sources in the Czech Republic.) VÚMOP, Praha. KODETOVÁ J., BRZÁKOVÁ R., 2005: Studie starých ekologických zátěží Plzeňského kraje. (In Czech.) (Inventory of old ecological loads in Plzeň region.) Vodní zdroje, Praha. KOMÍNKOVÁ D., 2001: Pollution of aquatic ecosystems by heavy metals – the Kocába and the Točnický Stream. Faculty of Science, Charles University, Prague. LANGHAMMER J., 2000: Trends of water quality of the Elbe River. Acta Universitatis Carolinae – Geographica, 35, 1, 127–138. LANGHAMMER J., 2005: Classification of the dynamics of water quality changes in the Elbe River basin. J. Hydrol. Hydromech., 53, 4, 205–218. LANGHAMMER J., 2005: Water quality in Berounka River basin. Acta Universitatis Carolinae – Geographica, 36, 2, 111–131. LANGHAMMER J., MATOUŠKOVÁ M, 2004: Kontaminace povrchových vod a sedimentů specifickým znečištěním v povodí Berounky. (In Czech.) (Contamination of surface water and sediment by specific pollution in Berounka river basin.) In: Majerčáková O., Šťastný P., (eds.): Zborník

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L. Volaufová, J. Langhammer príspevkov 3. konferencie mladých vodohospodárov; SHMÚ, Bratislava, p. 100–117. MKOL, 1996: Výsledky výzkumu v letech 1990–1995: Labe jako pacient – anamnéza, diagnóza, terapie. (In Czech.) (Research results in 1990–1995: Elbe as patient – anamnesis, diagnosis, therapy.) Praha. MOHAUPT V., SIEBER U., ROOVAART VAN DE J., VERSTAPPEN G. G. C., LANGENFELD F., BRAUN M., 1998: Diffuse Sources of Heavy Metals in the German Rhine Catchment, 3rd International IAWQ-Conference on Diffuse Pollution, Edinburgh. MŽP, 2001: CORINE landcover database. Ministry of Environment of the Czech Republic, Praha. PRANGE A., KRÜGER F., JANTZEN F., TREJTNAR K., MIEHLICH G., 1998: Geogene Hintergrundwerte als Bewertungsgrundlage der Schwermetallbelastungen im gesamten Elbeverlauf. In: W. Geller et. al. (Ed.) Gewässerschutz und Gewässernutzung im Einzugsgebiet der Elbe. B.G. Teubner Verlagsgesellschaft Stuttgart, Leipzig. RATH M., 1990: Těžké kovy ve sladkovodních ekosystémech s důrazem na sediment. (In Czech.) [Disertační práce.] (Heavy metals in freshwater ecosystems with focus on sediments. PhD Thesis.) PřF UK, Praha. RUDIŠ M., 2004: Dynamics of pollutants in the main riverbed and floodplain of the Elbe river. Elbe project report. MKOL, VÚV T.G.M., Praha. SALOMONS W., 1993: Sediment pollution in the EEC – Commission of the European comumunities, Luxembourg. SUDOP, 2003: Aktualizace projektové dokumentace k odbahnění Boreckého rybníka. SUDOP, Plzeň. (In Czech.) (Update of project documentation for sludge removal from the Borecky pond.) THYSSEN N., 2000: Rivers in the European Union: Water Quality, Status and Trends. In: Cals M. J. R., Nijland, H. J. (eds.): River Restoration in Europe. Wageningen, p. 63–71. TUREKIAN K. H., WEDEPOHL K. H., 1965: Distributions of the elements in some major units of the earth´s crust. Geol. Soc. Am., p. 175–192. VOLAUFOVÁ L., 2004: Jakost povrchových vod a specifické znečištění sedimentů v povodí Klabavy. Magisterská práce. (In Czech.) (Water quality and specific pollution of sediments in Klabava river basin. Thesis.) PřF UK, Praha. VÚV, 2005: Water Balance database. Water Research Institute TGM, Prague. Received 27. October 2006 Review accepted 20. March 2007

SPECIFICKÉ ZNEČIŠTĚNÍ POVRCHOVÝCH VOD A SEDIMENTŮ V POVODÍ KLABAVY Lenka Volaufová, Jakub Langhammer Příspěvek přináší výsledky výzkumu současného stavu a vývoje zátěže povrchových vod a sedimentů v povodí Klabavy. Klabava představuje jeden z hlavních přítoků Berounky, který výrazně ovlivňujě kvalitu vody v jejím toku díky množství aktivních zdrojů znečištění i starých průmyslových zátěží. Cílem výzkumu bylo vyhodnotit současný stav, dynamiku a prostorové rozložení

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zátěže, identifikovat hlavní zdroje příčinné zátěže vody a sedimentů a určit kritické prvky v procesu kontaminace. Pro komplexní hodnocení zátěže vodního prostředí specifickým znečištěním byla hodnocena současně vodní složka i sediment. Analýza byla založena na kombinaci dostupných dat ze sítě měrných profilů podniku Povodí Vltavy, doplněných vlastním monitoringem. Vzhledem k tomu, že se systematickým sledováním jakosti sedimentů oproti sledování základních hydrochemických a hydrobiologických ukazatelů jakosti vody se v ČR začalo až v 90. letech 20. století, dostupné časové řady hodnot jsou velmi krátké, navíc počet sledovaných profilů je oproti síti monitoringu kvality vody stále omezený. Proto byla studie zaměřena zároveň na doplnění informací zejména o prostorovém rozložení kontaminace vodního prostředí prostřednictvím vlastní sítě odběrů, což umožnilo identifikovat hlavní zdroje znečištění a jejich vliv na kontaminaci vody a sedimentů. Výzkum dále pomohl identifikovat hlavní bodové zdroje znečištění v povodí i vyhodnotit vliv povodně v srpnu 2002 na změnu úrovně kontaminace sedimentů těžkými kovy. Z výsledků můžeme jednoznačně určit jako oblast hlavní emisní zátěže vodního prostředí část toku mezi Hrádkem a Rokycany. Pravděpodobnými původci znečištění těžkými kovy jsou průmyslové podniky Železárny Hrádek a Kovohutě Rokycany, které těžké kovy zpracovávají. Varovné jsou zde především koncentrace kadmia ve vodě, které v této oblasti překračují referenční hodnoty i několiksetkrát, silnou zátěž potvrzují i analýzy sedimentu. Znečištění specifickými organickými látkami, s výjimkou ukazatele AOX, nedosahuje kritických hodnot. Výsledky vlastních odběrů, realizovaných na síti 7 profilů v letech 2002 a 2003 dokumentují vliv povodně v srpnu 2002 na zátěž sedimentů. Kontaminované sedimenty byly povodní v srpnu 2002 vyplaveny a přemístěny, proto hodnoty, zjištěné rozbory na profilech bezprostředně po povodni, jsou výrazně nižší než v předchozím období. Díky pokračující zátěži se však koncentrace těžkých kovů v následném období opět zvyšují. Kontaminace vody a sedimentu specifickým znečištěním v povodí Klabavy ukazuje na postupně se lepšící situaci, zejména díky výstavbě a modernizaci čistíren odpadních vod. Část poklesu znečištění je však spojeno s poklesem průmyslové výroby a v případě jejího znovuoživení představuje přetrvávající zdroj potenciálního ohrožení. Nejvýznamnější problém z hlediska ochrany vod představuje extrémní zátěž vodního prostředí silně toxickým kadmiem. Kontaminované sedimenty sice byly vysokými průtoky při povodni v srpnu 2002 vyplaveny, pokračující znečišťování však působí na opětovný nárůst zátěže.

SPECIFIC POLLUTION OF SURFACE WATER AND SEDIMENTS IN THE KLABAVA RIVER BASIN

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