The tidings of the skills of Austrian experts – Viennese in particular – have spread around the globe in the past few years. The successful model project "Clean-up of the Old Danube" has resulted in a new export success of domestic know-how: the clean-up of the West Lake (Hô Tây) in the Vietnamese capital Ha Noi.

Thorough preparation

This wonderful success was already prepared two years ago, when the head of the Municipal Department 30 - Sewerage, Helmut Kadrnoska, created the external department headed by Gerald Loew. At the same time the City of Vienna has for years striven to conclude Memoranda of Understanding (MoU) with capitals abroad. The aim of this policy is to attract lucrative contracts in the environmental field, at first for Viennese companies and later naturally also for the Austrian Economy as a whole. The focus of these activities in the water and sewage sector is city technology, i.e. that domain where the Austrian capital holds a leading position among most of the other capitals world-wide.

Gerald Loew describes the landmarks on this way that finally led to the conclusion of the commercial contract with the City of Ha Noi worth € 31.7 million: "In principle, business contracts of this size need to be prepared for quite some time. Similar to other projects, the case of Ha Noi had to be clarified first, particularly with regard to the problems that would have to be solved. Then the city managers of Ha Noi came to Vienna to see for themselves how we solve our problem. Equally, our experts had the possibility to get a picture of the situation in Vietnam. Although the contacts at that time remained exclusively on the administrative level, we already involved possible suppliers and civil engineers as supporting engineering consultants."

In the case of Ha Noi a "core" consisting of the companies VA-Tech WABAG and the enterprises Bilfinger & Berger and Mahr Maschinenbau Ges.m.b.H. were commissioned to execute the construction. Although the City of Vienna sees its function mainly as a door-opener, the municipality of Ha Noi insisted on including the City of Vienna. The company Wien Kanal Abwassertechnologiengesellschaft m.b.H. (WKA), a 100-percent subsidiary of the Municipal Department 30, took over this task as a member of the group. The contract was finally concluded – with strong Japanese competition – between the City of Ha Noi and a consortium of the above-mentioned Viennese partners. The funds for the necessary feasibility study were provided by the Wiener Wirtschaftsförderungsfonds. The project shall be managed with the support of the Austrian export promotion (Österreichische Exportförderung).

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The tasks

Ha Noi, the capital of the People’s Republic of Vietnam, is traversed by a vast network of lakes and channels that were connected to the Red River before the construction of flood protection measures. As in the old times, the waters still have to swallow all kinds of wastewaters. In the course of time – particularly by the booming population of the capital (from 700,000 in 1970 to the present figure of 2.5 million inhabitants) the lakes turned into cloaca; sewage treatment plants are still unknown in Vietnam. At the same time the water bodies in Vietnam – in spite of Uncle Ho’s activities – are still considered "sacred", i.e. closely connected to religious ideas. The clean-up is therefore only possibly in consideration of these circumstances and by optically inconspicuous construction measures.

The largest lake of the city with a surface of 9 square kilometres is the Hô Tây (West Lake). In former times it was far outside of the city, today, however, it is situated right in the middle of the pulsating centre. After the completion of the Austrian clean-up measures in 2004 the lake shall have bathing quality and thus be re-included in social, or rather tourist activities.

In order to reach this goal, Helmut Kadrnoska and the domestic company group can rely on the experience made in the successful clean-up of the Old Danube, since the starting condition and the solutions are quite similar.

The following procedure is planned:

• Discontinuation of discharge of pollutants into the Hô Tây. For this purpose a ring sewerage system with a total length of 13 km will be built, which will conduct the collected wastewater via three pumping stations into a purification plant that will also be built (sewage sludge shall be used in agriculture). Due to the expected reverse dissolution of the sludge that had been bound for a long time at the bottom of the lake, a complete clean-up will not be possible.
  
• The Viennese consortium is therefore planning a permanent water exchange with the nearby Red River. Since this river is transporting a lot of sediments, the waters fed into the West Lake have to be adequately treated before (1 cubic metre per second). The sediments filtered off which are rich in phosphate are redirected downstream into the Red River.
• Training of the engineering staff as to the operation of the purification plant.
• A monitoring programme is going to analyse the effects of the measures taken over a period of several years.

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Turtles as "door openers"?

The measures taken for the West Lake are only the beginning for the city fathers of Ha Noi, but, at the same time, the most important part of a comprehensive water clean-up project. In this context, Gerald Loew points to the still existing network of the lakes and channels, "which will – over the years – automatically result in an improvement of the situation in other parts of the network."

On the other hand, Helmut Kadrnoska has already another trump in his hand, with which the City of Vienna could become famous in Ha Noi: the clean-up of a particularly mystical lake, the little Sword Lake. As the story goes, there was once a king who lost his sword in a decisive battle in the lake. "The turtles of the lake (which really live there) are said to have brought back the sword – and became therefore almost sacred. And there still is a saying in Ha Noi: ’If you see one of these turtles you will be very lucky in the year to come.’

Unfortunately this story did not save the water animals from increasing water pollution and thus from the dramatic reduction of their population. I am sure that Vienna will gain a lot of prestige by cleaning-up this lake in particular – and this could open many other doors ..." (Source: aqua press 01/2001)
Mag. Christof Hahn

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Information & Contact:
Municipal Department 30 - Vienna Sewerage
Modecenterstraße 14
A–1030 Vienna
Tel. +43 1 79 514–93 043
Fax +43 1 79 514–79 30