NEWS

Underground the way to go for Athens?

Researchers are looking below the ground for solutions to environmental and other problems of the world above. The aim is not to sweep problems under the carpet, but to free up space above ground. As the urban population grows and with it the need for greenery and recreational spaces, a number of activities could be usefully transferred. Storage complexes, liquid, industrial and hazardous waste processing units, water reservoirs, public transport, car parks and quarries are just a few examples of activities that could be moved below ground. «There is a great shortage of space, due to rapid urbanization over recent decades,» said Dimitris Kaliambakos, associate professor at the National Technical University of Athens (NTUA). «Underground development is much more effective, as it drastically reduces environmental consequences. And it frees up valuable surface space for vital activities, such as recreation and habitation.» The NTUA’s mining technology and environmental mining laboratory is exploring underground solutions for a series of problems, and recently ran a large international conference on the subject. As Kaliambakos explained, underground installations are safer in every respect, even in the case of earthquakes. And, he said, «they are cheaper than those above ground. The rent is lower, operational costs are up to 70 percent lower due to temperatures and the opportunity to make use of mined products.» It is worth remembering that above-ground activities often seem cheaper because the cost does not include the social cost of the plundering and degradation of the environment, of our shared wealth. The following are five proposals from the workshop, as explained to Kathimerini by Kaliambakos and NTUA researchers Thanassis Mavrikos and Andreas Benardos. 1. Metamorphosis Waste Processing Unit. Every day the Metamorphosis Waste Processing Unit receives 8,000 cubic meters of septic tank waste and 13,000 cubic meters of urban waste. The unwanted water is discharged into outdoor tanks covering 9 hectares. Local inhabitants suffer from the unbearable stench, visual pollution and the circulation of hundreds of tanker trucks. «Putting the WPU below ground would deal with the problems of the stench and the visual eyesore, while providing hectares of space for greenery and public use,» explained Mavrikos. All the waste of Helsinki goes to an underground processing unit at Kakolanmaki. In Italy, many cities such as Como use similar methods. 2. Fuel tanks at Perama. Perama is located next to a virtual minefield, as the gasoline distribution center for all of Attica is right inside the city. Crowded into a space of some 30 hectares are 120 surface storage tanks (owned by five companies), which hold some 170,000 cubic meters of petroleum products and different chemicals (around 14 percent of the total in Greece). The tanks sit right next to private homes, which is unacceptable from any point of view. Apart from the multifaceted environmental damage, there is the danger of a massive accident (such as the 1976 industrial disaster in Seveso in northern Italy). Local residents want the tanks moved. The NTUA’s mining technology and environmental mining laboratory considers a more realistic solution would be to shift them to a nearby location and put them underground. «The creation of underground tanks would deal with the environmental damage and neutralize the risk of an accident,» said Benardos. «And it will give the residents 30 hectares of public space.» In the case of underground storage, petrochemicals are enclosed in a hydrodynamic dam. Gasoline floats and does not dissolve in water, as it is lighter than water, so we can trap it, minimizing the risk of an explosion. When the laboratory made its proposal, doubts were raised. Some people claimed that the limestone in the area was not suitable and that the project would be too costly. «Such installations are in use at the Lavera complex in Marseilles, which has a similar geological makeup to ours,» said Kaliambakos. A study submitted by NTUA and the Asprofos engineering firm in 2004 showed that putting the tanks below ground was the best solution on both technical and economic and grounds (in 2003, the cost of shifting to an aboveground site was estimated to be 77,8000 euros, compared to an estimated 55,280 euros to shift to an underground site). The project was included in the Fourth Community Support Framework, but for some reason the funds for it were distributed among smaller projects that would have less electoral fallout than forgotten Perama. 3. Invisible quarries of inert materials. The deep scars in the landscape made by quarries are one of the most serious environmental problems in Attica. «We estimate that some 2-25 million tons of inert material are required every year in Attica. That means demolishing four to five hills. We don’t have any to spare, so what can we do? One solution that could prove effective is to use underground quarries. The technology has become so advanced that the increase in the cost of extraction is minimal,» said Benardos. There are numerous benefits: protection of the land’s contours and of the landscape in general; zero visual pollution and minimization of air pollution; a great deal less noise and reduced vibrations, as there are only small explosions in underground quarrying. In addition, when the quarry is no longer in use, there is no need to restore the contours of the site and the underground areas can be put to use. There are many such places (such as Subtropolis, Kansas, in the USA) which are used for storage, in excellent conditions, which include stable temperatures.