Construction waste are two words that have recently been often spoken, read and heard on our Islands. With time, a third word was added, “problem”.

This problem continued growing so much out of hand that the need was finally felt to introduce a regulatory framework for managing such waste. A good percentage of all Malta’s waste is construction and demolition waste, which compounds further the problem due to the limited number of appropriate landfills available on our small country.

Construction waste or debris is any kind of debris from the construction process. These materials are usually heavy materials used in large volumes in modern construction, such as concrete, steel, wood, asphalt and gypsum. That percentage is bound to continue increasing as soon as works are eventually undertaken to build our metro system and the Gozo-Malta tunnel that will generate unprecedented amounts of construction waste.

The boring of tunnels for the proposed metro itself will produce an estimated 10 million tons of construction waste, equivalent to almost 1.5 million truckloads, or 4.9 million cubic metres of waste, five times greater than that estimated for the Malta to Gozo tunnel. Thus, one possible solution scantily referred to in that framework is to resort to land reclamation and, in so doing, put all that waste to good use.

This is where environmental concerns start rearing their head. Take the conceptual metro system, for example, it being such a project presenting a challenge for disposing of the excavated rock and where a number of locations have been allegedly assessed for land reclamation. The term land reclamation can be used in two main ways, to describe actions undertaken by humans to reclaim land from its natural state so that it can be put to some particular use and to describe ways of restoring ecosystems that have been degraded by human actions. The former use normally entails the risk of further negative environmental impact, whereas the latter use includes the concept of ecological restoration, examples of which include the rehabilitation of land that has been degraded by soil erosion, salinization and waterlogging or by chemical contamination. Land reclamation involves a wide range of disciplines from the physical (for example, engineering, pedology, geomorphology and biology) to the social sciences intertwined with economics and politics.

Land reclamation though with its many benefits has certain disadvantages. Land reclamation is associated with some dangers, such as flooding and soil liquefaction and reclaimed lands are expensive and can be damaging to corals and marine life. It also changes the quality of the surrounding areas of water. Material used causes the water to be more acidic and certain organisms are unable to adapt to this environment. Sediments also do not allow sunlight to pass through, causing many aquatic plants to be unable to photosynthesize.

The simplest method of land reclamation involves simply filling the area with large amounts of heavy rock and/or cement, then filling it with clay and soil until the desired height is reached. Such land reclamation might result in the large displacement of the marine sediments and the development of mud-waves beneath the reclamation fill, disrupting the surrounding sea’s ecosystem, leading to soil liquefaction and polluting the water. Land reclamation in coastal areas may further have a significant effect on local groundwater systems, though an unintended advantage of the reclamation might be an increase of fresh groundwater resource because the reclaimed land can be an additional aquifer and rain recharge takes place over a larger area.

The production of waste on a construction, demolition or excavation site is often unavoidable. It should be properly managed and confirmed that it is following the waste management hierarchy, which helps to reduce, reuse and recycle waste before disposing of it. This is crucial in order to help our country minimise its environmental impact and reduce the demands placed on our landfills while proceeding to the land reclamation option. Taking proactive steps is the best way to meet the hierarchy: one should carry out a site waste management audit to determine what amount projects like the metro and the Gozo-Malta tunnel will generate and what the most common materials are on the respective sites that could become waste.

Let us not blindly resort to land reclamation as an easy solution for developing future mega projects. Instead, let us reclaim land in a manner that is economically sustainable – and let us do it with a sense of empathy for the life around us. Take the manner in which Hong Kong, an island region very similar to Malta, has successfully managed to resort to land reclamation when disposing of construction waste in both an economically and environmentally sustainable way. Major reclamation projects included the construction of Hong Kong International Airport, which aided infrastructural development and has proved indispensable for Hong Kong’s quest in becoming a global financial hub. Hong Kong Disneyland was also built on reclaimed land and is today seen as a major tourist attraction. They went about it with the least negative impact on the environment, in particular, marine life surrounding its coast. The amount of inevitable toxic silt generated when reclaiming land was negligible. They went about it with the inverse of the philosophy of a “develop first, preserve later” mentality.

Using waste as fill material within land reclamation projects is more complicated than it seems. Waste needs to undergo major changes before it can be dumped into the open sea without significant environmental consequences. An effective solid waste management system is very important for the use of waste as fill material within land reclamation. Where water is boss, the land must obey. We must be careful not to abuse our coastal waters because we regard them as a commodity belonging to us. When we see our territorial waters as a community to which we belong, we may begin to use them with love and respect.

 

Dr Mark Said is an advocate