Dredging 2.0: now even beaches become sustainable with another Made in Italy technology

Today I will talk again about this high performing technology in relation to another huge environmental issue of our country, which in this particular case is a menace to one of the most important economic items like tourism, since we’re talking about coasts and more specifically of coastal erosion.

An issue with huge environmental, economic and social impact, since Italy has a coastline that spans almost 7500 km. Another chance to take a look, also in practice, at the technology – like last fall in Levane, in the province of Arezzo, where we talked about the de-sliming of dams and inland waters – was the 23rd of may last year in Follonica, one of the sites of the tuscan coast where coastal erosion has the biggest impact, with the seminar titled “Dredging 2.0”, sponsored by the Province of Grosseto and organized by Decomar SpA. Coastlines and port areas, oven more than inland waterbeds, are in need of non-invasive intervention tactics that are highly respectful of the ecosystems, seen as, especially the latter, they are contaminated sites and are often included in the list of polluted sites (SIN, site of national interest, or SIR, site of regional interest).

In the Gulf of Piombino both types discussed in the seminar exist, like the Follonica beach and the nearby Port of Piombino at the centre of the SIN with the same name, which is being remediated in these months. The town at the centre of the Piombino Gulf has been affected for decades by increasingly substantial phenomenons of coastal erosion that were compromising one of the most important items in the local economy, tourism. In response to this the Province of Grosseto has invested a considerable amount of resources, which are making it possible to find concrete solutions to the problem.

After a broad summary of the countermeasures put in place by the Province of Grosseto to rebuild and protect the eroded coastlines, ie using barriers just below the surface of the water (see ggearth image), in synergy with the enlargement works of the Port of Piombino, it was the turn of Dottoressa Gilda Ruberti, director of Regione Toscana, who presented the regional plans for the issue in terms of legislation and of resources on the basis of the preponderance of the receding coastlines over the ones that are growing, with a negative balance of 147.000 m2 of coasts in need of remodeling where it is necessary to carefully assess the origin of the sands that are needed for the restoration.

Also interesting was the speech of Dottor Guerrieri, of the port authority of Piombino, where he presented the adaptation works of the port, that involve bringing its draught to 20 meters, with the possibility of opening up new perspectives for the Piombino docks, from the industry, to commerce as well as tourism, with the possible docking of cruise ships. He also highlighted and emphasized the critical issues that conventional dredging poses in port areas located within SIN (Sites of national interest for remediation) areas with a large concentration of contaminants, and the strong need to have access to adequate technologies for excavation and non-invasive and non-dispersive dredging.

Guerrieri highlighted the dual value of the waterbed, as an “infrastructure” but also more importantly as an “environmental category”. For the scientific part Prof. Enzo Pranzini of the University of Florence, in the guise of technological evaluator, brought the attention to a series of fundamental issues to which a non-invasive dredging technology should be able to respond adequately. Prof. Giuliano Gabbani, also from the University of Florence, and a dear friend, talked about the comforting results of the field audits done with the new technology developed by Decomar, in port areas as well as in the context of de-sliming of inland waters (dams), also underlining the brilliant results of the scientific tests done on the field. The last topic was the technology itself, illustrated by Eng. Davide Benedetti, president and CEO of Decomar, who made a broad and exhaustive presentation of the de-sliming process developed by the company, which is part of the Ecoacciai group. Benedetti, referencing the critical operational issues mentioned by the port authority, highlighted the technical, economical and operational benefits of the technology which is scalable and entirely modular, allowing to operate without external intakes and only with an internal recirculation fluid, never coming in contact with the material, and most of all, in regard to ports, operating as an offshore platform without occupying wharf space.

These advantages give an important response for the sustainable de-sliming of ports, compared to the conventional dredging technologies which have a huge impact on the ecosystems and pose great difficulties for the port operators, drastically mitigating the environmental impact. In fact the conventional dredging techniques that use the traditional grab can have an impact on vast areas even kilometers away from the extraction point, caused by the phenomenon of “resuspension” (not to speak of the questionable operations carried out with disregard for the current environmental legislation).
Decomar’s solution is based on a recirculation technology which allows to operate without contact with the waterbed, reducing the environmental impact by operating the removal of the sediments “on-site”, and their granulometric separation differentiating the bigger materials and eliminating any possible pollutants. Such an operation allows to simultaneously effect a reduction in volume of the fraction that needs to be delivered for a subsequent treatment. Another crucial aspect underlined by Benedetti is that the Decomar system is a controlled selection system, it is selective and customizable depending on the desired granulometry for the site that is being treated, with the extraction and the salvage of foreign materials and by giving the possibility to add processes in cascade, for the treatment of contaminated materials through a predictive setting that can better respond to the treatment necessities.

This new extraordinary methodology falls within the three projects awarded by SOGESID, in house company of the Ministry for Environment, Land and Sea Protection (MATTM) for the technical support for regional/local structures through interventions that aim on one hand to initiate the resolution of environmental issues (remediations, waste management and emergency, hydrogeological instability). It is being currently applied in the major portal areas of Livorno and La Spezia, and the first field results will be know soon.

It is a real technology, that doesn’t just move pollution or a problem from one environmental compartment to another, but gives authentic solutions to fundamental issues that are capable of effecting real change, and opening a new chapter in terms of remediation, redevelopment and environmental remodulation, giving answers hat are not generic but site-specific.


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