Water pollution 

    Water pollution in the Czech Republic

Since the profound changes in environmental protection after the political changes in November 1989, water pollution in the Czech Republic is improving . Treated water released into the sewage system increased by 16% from 1990 to 1995. Also, from1990 to 1995, monitored pollutants released into streams decreased: BOD 5 by 59%; insoluble solids by 54%; oil products by 69%; dissolved inorganic salts by 16%; and the apparent acidity/alkalinity by 78%.

There are still, however, many water pollution problems in the Czech Republic. Almost 5000 communities (population 100-10000) are not connected to public sewage networks and waste water treatment plants. Also, most of the waste water treatment plants now in operation have not installed any equipment for the elimination of nitrogen or phosphorus. As a result approximately one-third of the total length of waterways monitored have been catergorised as having "heavily" and "very heavily" polluted water.

The quality of public water supplies is also a problem with over half of the supplies that are monitored ranking in the 3rd and the 4th purity class (unsatisfactory classes). Also, 30% of the wells don't correspond to drinking water standards regulations . Fig 1 shows the Bečva water quality from 1994-1995 measured at Choryně which is after the confluence of the Rožnovská and Vsetínská Bečvas and therefore also downstream of all the towns in Vsetín region. It shows several trends, notably the increase of temperature resulting in a decrease of dissolved oxygen in summer months. There are also many sudden peaks well above the average, maybe caused by discharge from industry or sewage effluents. Discharge of effluents from DEZA Corporation have been under much public scrutiny but they have invested greatly in environmental protection including water pollution control technologies. Fig. 2 shows the water quality parameters of effluents from DEZA Corporation. There is a significant trend of improvement and all effluents are below the standards set by the authorities in Vsetín (see Table 1).

Table1, Water quality standards set by Vsetín District Authority

   Bathing water quality in Vsetín region

In summertime recreation activities on the waters of Vsetín region are very popular. Fig 3 shows water quality for four bathing areas in Vsetín on 10.8.98. Table 2 shows bathing water quality recommendation and limits proposed by the Ministry of Health for the Czech Republic. At Bečva, Choryně, the faecal coliform and coliform bacteria levels are way above the recommended levels. These bacteria's give an indication to the extent of faecal contamination of the water and the likely presence of pathogenic micro-organisms. The position of Choryně downstream of the major towns of Vsetín region probably accounts for these increased levels.

Table 2, Recommended standards for outdoor bathing water in the Czech Republic.

At Chmelník, Kelč, the phytoplankton levels are extremely high and more than twice the limit. The bathing water at Chmelník is a small pool and with the high summer temperatures (water temperature 24. SOC see fig. 3), the phytoplankton are photosynthesising at an increased rate, farther decreasing the dissolved oxygen (see the high COD levels, fig. 3), reducing the quality of the river water. The bathing water quality of the popular beaches at Bystřička and Horní Bečva dams is very good with all parameters below the limits and most below the recommended levels. Both these beaches are at higher altitudes and away from the towns of Vsetín region.

In summertime the Bečva's water quality is usually greater than the recommended standards due to industrial pollution and faecal contamination from people, and with the increased temperature bacteria grows more rapidly. Towards the end of the summer (August) with the faecal contamination, high temperatures with resulting depleted dissolved oxygen, the Bečva is unsuitable for bathing. For the rest of the year the biological water quality is good and very good chemical water quality all year round.

Fig. 4 shows a system for monitoring organic pollution in rivers. It provides a measure of organic pollution over a reasonably long period of time due to invertebrate sensitivity to such pollution. A river is given a score equal to the highest scored family of invertebrates found in the river. According to the system the River Bečva is very clean of organic pollution with iťs great diversity of invertebrates, scoring a maximum 10. The high scoring Heptageniidae, Leptophlebiidae, Ephemeriliidea, Potamanthidae, Ephemeridae, Taeniopterygidae, Leuctridae, Capniidae, Perlo(Iiae, Chloroperlidae, Aphelocheiridae, Phryganeiridae, Molannidae, Beraeidae, Odontoceridae, Leptoceridae, Goeridae, Lepidostomatidae, Brachycentridae, Sericostomatidae families are present.

    Drinking water quality, Vsetín region

In Vsetín region the drinking water quality is of a good standard and very good compared with the rest of the Czech Republic (see Table 3 showing all drinking water quality parameters below the standards) . The water quality in wells, however, varies with most having poor biological water quality.

Tab č.3 Drinking water quality in Jasénka, Vsetín, 20.10.98