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The discharge of the state administration in water resource management as defined in Act No. 130/1974 of the Law Gazette and the full wording of Act No. 458/1992 of the Law Gazette falls into the purviews of two institutions. One is the Czech Inspectorate of the Environment (CIZP) namely the Water Protection Department of its Prague Office, the other are the Prague City Hall (MHMP), Building Department, Water Resource Management Section. Both institutions are contact points where accidents involving leakage or spillage of substances polluting surface or ground waters are reported and which take subsequent steps (remedial measures, bringing polluters to justice). 
What is being done to fix the problems
with drinking water quality?
In March 1997 an increased content of iron was discovered in three samples. Prazské vodárny immediately took remedial measures. The increased content of iron is attributable mainly to corrosion of metallic water pipes without any inner lining combined with a very low flow rate caused by an ever-decreasing water consumption. To reduce the concentration of iron in drinking water in suburban parts of Prague and to minimize leakage the inside surface of water pipes is lined with cement. The Praha -
Podolí drinking water treatment plant is currently undergoing a second
stage of refurbishment which however, will not require the plant to
be put out of operation. The first stage took place between 1992 and
1995 and included the
following facilities: raw water treatment plant, treated water filtering station,
old filtering plant, boiler room (including conversion to gas), old engine room -
replacement of compressors and blowers. The second stage comprises the
lime handling system, chlorination plant, addition of chemicals
and sludge disposal and should be completed by the end of
1998. The plant draws raw water from the Vltava
River, which has not hitherto been declared a drinking
water source adversely affecting the raw water quality. Owing to this fact, a
project of supplementing additional treatment stages is being considered but the necessary
funding has not yet been arranged. Considerations were also given
to additional water treatment stages - oxidization (using ozone or
chloroxide) and GAC (granulated active carbon) filtering. However, no
model tests were conducted in 1997. At the time when the raw water from
the Švihov reservoir
was difficult to treat, the treatment process
employed by the Zelivka treatment plant was modified to include an
addition of sulphuric acid and ozonization; according to the tests
that have been conducted so far the latter treatment stage has
without any doubt a very positive effect on the drinking water
quality. In particular, there has been a significant reduction of
the content of THM (trihalide methane) in ozonized
water. By definition set forth in Article 22 of Act No. 138/1973 (Waters Act), waste water is “water used by housing projects, municipalities, houses, industrial plants, health care facilities, and other buildings or facilities if the use changes its quality (composition or temperature) as well as other waters discharged by them if they can pose a threat the quality of surface water or groundwater”. There are two drainage systems in the territory of Prague. The so-called separation system keeps sewage and rainwater separate and a universal system which uses a single pipeline to carry both sewage and rainwater. The central sewage and rainwater collection system was started in the beginning of the 20th century as a universal system. The sewer diameter in this system increases as far as so-called separating chambers (more often known as rainwater separators) which subject to achieving a predetermined dilution ratio (sewage: rainwater ratio) allow a part of the mixture to be discharged directly into surface streams and the diameter of sewers to the waste treatment plant to be reduced. According to the initial concept the dilution ratio should have been 1:2. However, as the city grew, its value changed to 1:1 for the Vltava River, and 1:4 for creeks. As water from rainwater separators has not so far been regarded or perceived as waste water there is practically no monitoring of the pollution discharged from the separators into surface streams; water pollution charges are based on an educated guess and paid only for those separators that do not comply with the relevant dilution ratio. The EEC Council Directive of May 21, 1991 on the treatment of municipal waste water (91/271/EEC) explicitly regards the mixture of sewage and rainwater as “municipal waste water”. The Ministry of Agriculture of the Czech Republic is working on a new drainage concept represented by the currently prepared Drainage Master Plan of Prague. It will take into account the target stream water quality be in compliance with pending legislation changes and thus should not pose any problem whatsoever in relation to the accession of the Czech Republic to the European Union. Waste water from the city centre and newly built housing schemes are discharged into a sewage and rainwater collection system which empties into the Central Waste Water Treatment Plant (ÚCOV) in Císarský ostrov, Troja. In addition to the central plant there are 24 small waste water treatment plants (COV) being built or operating in the territory of Prague. As a rule these handle sewage only and serve small townships and villages in Prague’s territory. In 1997 the following small waste water treatment plants were operated on a “permanent” basis: Certouzy, Chvaly, Miškovice, Radotín (till August 1997), Sedlec, Újezd nad Lesy, Prední Kopanina, Nedvezí, Vinor, Zbraslav, and Dolní Chabry. The following small waste water treatment plants were put into operation during 1997: Královice, Klánovice, Kolodeje, Kolovraty, and Kbely. Operational tests were going on in the following small waste water treatment plants: Brezineves (commissioned in September 1997), Ruzyne Airport, Uhríneves, Bechovice, and Nebušice. In Lipence, Sobín, and Holyne the construction of new COVs started. Most of the small waste water treatment plants have been built since 1989 as a result of initiatives of elected members of district authorities who refused to wait until a long-distance trunk sewage collector bringing waste water to the Central Waste Water Treatment Plant reaches their village. Different opinions regarding the drainage system have led to a situation in which the state-owned enterprise PVK (nowadays PVK a.s.) does not operate some of the treatment plants such as Bechovice, Klánovice, Kolodeje, Královice, Nedvezí, Prední Kopanina, and Zbraslav. Selected water quality criteria measured at intakes and discharges of the Central Waste Water Treatment Plant (ÚCOV) and permanently operating Waste Water Treatment Plants (COV) in mg.l -1
Source: PVK a.s., COV The operation of the sewage and rainwater collection system is governed by a set of rules which stipulates especially requirements pertaining to the quality of waste water discharged into the system. As far as the region served by the Central Waste Water Treatment Plant is concerned, waste water producers are divided into two groups: one comprises key producers of industrial waste water to which individual water quality limits are applied, the other all other producers in respect of which general criteria are used. Results of audits focused on compliance with sewage and rainwater collection system operating rules
Source: PVK a.s. Compared to 1996 there was an increased number of audits in 1997. Only chemical enterprises showed worse results than in 1996, other groups have improved. As to the magnitude of failures to meet the applicable limits the numbers of samples exceeding the limit by a hundred or a thousand per cent remain the same. It still holds that producers of waste water pay so-called “contractual fines ” if they do not comply with the limits. The system will have to re-assessed in the framework of a trial operation of the refurbished Central Waste Water Treatment Plant as the fines are often less costly than investments needed to rectify the situation once the existing capacity of the plant is used to the full. The compliance with the limits laid down in the set of rules referred to above also affects the contents of heavy metals in digested sludge which is one of the products of the waste water treatment process. A reduction of the content of heavy metals in the digested sludge would permit it to be re-used for agricultural purposes. In July 1997 Phase Ia of the Central Waste Water Treatment Plant Upgrading project was completed, its purpose being to eliminate the discrepancy between the hitherto different capacities of the mechanical stage (up to 8.4 m3.s-1) and the biological stage (4.6 m3.s-1), and to provide for removing nitrogen and phosphorus from waste water. Although the average waste water inflow in 1997 was lower than the year before, the load of the Central Waste Water Treatment Plant in terms of the dry matter contents continued to increase. As the nature of the waste water processed by the plant is variable, the actual capacity of the upgraded waste water facility can be determined only on the basis of its trial operation which commenced in August 1997 and was initially scheduled to take one year. Because of the variable nature of the waste water it is expected that the trial phase will have to be extended to accumulate enough hard data giving a good idea of the plant’s actual capacity. In the framework of the restructuring of Prazské vodárny, s.p., and Prazská kanalizace a vodní toky, s.p., the infrastructure assets operated by the two companies were transferred to new owners as of December 30, 1997. The new owners are: Prague City Hall and associations of municipalities “Úpravna vody Zelivka” and “Zdroj pitné vody Káraný”. The National Property Fund of the Czech Republic created two joint-stock companies to manage and operate the infrastructure: Prazská vodohospodárská spolecnost, a.s. (PVS a.s.), responsible for a harmonized management, development, and investments into the property of the three new owners, and Prazské vodovody a kanalizace, a.s. (PVK a.s.), responsible for operational matters. Production of pollutants in the territory of Prague in 1997
Source: PVK a.s. Selected water quality criteria at the
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