By: Dr. Andrej Umek
A lot has already been said about the C0 channel in the media from one point of view or another. The purpose of this column is to look at this construction from the point of view of managing construction and utility projects.
If I follow the professional literature, any planning should start with setting the basic idea of the project by the investor and asking the profession to prepare appropriate projects. In most European countries – for example in Switzerland, Austria, Germany etc. – they require at least three different projects, on the basis of which a final decision is made or the basic idea of the project is corrected and the whole process is repeated until we arrive at a sufficiently high-quality solution to the problem. This basic procedure in the management of the wastewater treatment project in Ljubljana was violated from the very beginning. Mayor Janković, at least in my opinion, did not act as a capable manager and coordinator who is open to different solutions, but at least that is how I see it, like a medieval Turkish sultan who imposes his solution on everyone, be it good or bad, by fear means or foul. This approach ultimately led to a disastrous solution in the construction of the C0 channel.
In the following, I want to argue from a professional point of view why the decision to build the C0 channel is so bad. In my opinion, the basic cause is in what I consider to be a wrong decision, taken many years ago, that MOL solves the waste water problem by itself and only on the territory of the municipality. In my opinion, a much better solution would be for Ljubljana not to close itself within its own municipal borders, but to look for common solutions for the entire Ljubljana basin. Of course, this would require better management and more negotiation, which obviously did not suit the Mayor of Ljubljana, as it would reduce the possibility of his absolute decision-making. The consequence of closing the MOL to itself in solving the problem of wastewater treatment, due to the configuration of the terrain in Ljubljana, led to long connecting channels that connect the southwest and northwest of the city with the treatment plant in Zalog. Unfortunately, the construction of a channel connecting the southwest of the city, e.g., Rakovo with a treatment plant has not attracted much attention, although it has the same disadvantages as C0.
Only the C0 channel received greater attention and opposition from the citizens of Ljubljana, and rightfully so. The main criticism is that, despite all its inefficiency, the channel leads through a water protection area with an important catchment of drinking water for Ljubljana, and this through a seismically active area. MOL representatives’ assurances that the construction of the C0 channel is seismically safe were proved otherwise by the recent earthquake in southeast Turkey.
It is not easy to talk about a seemingly insignificant event, which proves the seismic risk of the C0 channel, in the face of the disaster that hit the southeast of Turkey with many dead, destroyed homes and ruined existences. I am referring to the pipeline explosion. The analysis of this event shows that the pipe broke first and this triggered the explosion. According to the statements of Turkish experts, the gas pipeline should be properly dimensioned for ground shaking during an earthquake. However, they overlooked that the gas pipeline passes through the fault line. Parts of the land on either side of the fault moved about 3 meters during the earthquake, according to preliminary reports (emsc-csem.org). Of course, the gas pipeline could not withstand these movements.
If I now return to the issue of the C0 channel, I must first state that an earthquake of the magnitude that recently occurred in Turkey is not possible in the Ljubljana area. Here, it can reach a maximum of 6.2. Therefore, the size of the movements that occurred in Turkey is not possible here. In my estimation, the maximum possible deviation in the Ljubljana area is about 1.2 meters. However, even if a significantly smaller earthquake occurs with an offset of, say, 0.5 meters, it would collapse the C0 channel. The Turkish experience clearly demonstrates that other loads and not only ground accelerations should be considered when assessing the seismic safety of pipelines. It further proves to us that the C0 channel is not seismically safe. Therefore, the objections against its construction are justified and professionally justified.
I wish, even though this may be too optimistic considering the behaviour of the city administration so far, that based on the Turkish experience, if we can call it that, they would be abandon the construction of the C0 channel and consider expert opinions when looking for an alternative solution.