Meanwhile, the Austrian Development Cooperation and Cooperation with Eastern Europe (OEZA), or rather the Austrian Development Agency/ADA, has spent approximately € 4.26 million on the rehabilitation of the water supply of the North-Albanian city of Shkodra. Initially, measures were taken at the pumping stations and the mains, which have already mitigated the situation considerably. As Hans Sailer reports, the next target could soon be the rehabilitation of an elevated tank for drinking water (8,000 m3). The head of the Vienna Waterworks (Municipal Department 31) and president of the Austrian Gas and Water Association (ÖVGW) had only recently been consulted in this regard by the project partners involved: ADA, the Albanian Ministry of Territory Adjustment and Tourism /MoTAT, the Shkodra Waterworks, and the Austrian consulter GWCC.
Rehabilitation of drinking water tanks – a difficult task? It is actually like Hans Sailer knows from his long activities within the European standardisation system for water tanks and in the framework of his ten-year work for the department for construction and studies of the MD 31 (now Department 5)! Sealing of the tank walls and bottom, ventilation, heat insulation, stirring of the stored water, and microbiology are the main factors to be accomplished.
In the case of Shkodra’s elevated tank, the decision had to be made as to whether the five-year old tank – built on an elevation in the city and lowered into the ground – could be rehabilitated at all or had to be replaced by a new one. The elevated tank should be used as reserve in the case of pipe bursts and for offsetting peak demands. However, severe deficiencies in construction causing among other defects considerable water losses did not allow a start-up. Claims for compensation against the construction firm should be irrecoverable.
After a thorough inspection of the facilities and examination of the extensive documentation compiled by GWCC, Hans Sailer was soon convinced that rehabilitation should be preferred over demolition. Thus, the external walls could be used as lost casings for new walls, the abutments were intact to an extent that they could be used after the renewal of the corrosion protection. In detail this means:
- Improvement of the bearing capacity of the ceiling by applying gunite
- Careful humidity and heat insulation
- Ventilation via a gate-valve chamber with pressure-tight stainless-steel doors (to be newly built)
- Reinforcement of inner walls and bottom plate
- Water inlet at the base for a better stirring of the tank content
- Compilation of operation instructions
- Installation of electronic remote monitoring, which can be used for emergency control.
All measures mentioned are state-of-the-art. Altogether, Shkodra could thus receive an "as-good-as-new" elevated tank for approx. € 700,000 (GWCC will provide an exact cost assessment)! Particularly remarkable about this project is the transfer of know-how offered on the part of the City of Vienna, which is an advantage not only for the "Albanian side", but also for Austrian companies to be integrated in the project. After all, Hans Sailer considers his department as a kind of university providing for basic research, but which would be overstrained with the practical execution of such a project. In addition, the well-proven technology "Made in Austria" could again be employed for this Shkodra Project.
After all, the gate valve by Hawle was already used in the rehabilitation of the mains. The supply of fittings, water meters, stainless steel doors, but also of innovative technologies for finding pipe burst could be possible (keyword: network-independent "Easy Data Transfer"/EDT on solar energy basis).
The Austrian commitment in Shkodra will soon enter into Phase IV. Since the necessary treaty between ADA and MoTAT has not been signed yet, the projected tank rehabilitation still has chances to be fully considered in the contract. By the way: in a number of top-level talks, Hans Sailer was able to offer Austrian know-how also for possible further OEZA projects in Albania.
(Source: aqua press Int. 3/2004, Mag. Christof Hahn)
