Good environmental practices in the production of aggregates

As all extractive activity, aggregates production is conditioned by geological factors, in the territorial framework, and is not therefore comparable with other industrial activities. For aggregates, in addition, its exploitation, not supported, in general terms, long distances to the centers of consumption (the price of transport is doubled every 50 km) implying that often farms aggregates are close to areas with high population density, although located in sparsely populated rural areas.

With regard to the conditions on the natural environment, most notable is the alteration or modification of Habitat in the operational phase, basically due (being areas open) to the visual impact, the loss of the topsoil andto a lesser extent, of the fauna. However, with proper management and implementation of the existing corrective measures, this impact can be controlled during the operation of the exploitation, and corrected during the restoration of the land. The like are great danger of affecting the surface water and groundwater, which leads to the implementation of measures to control such possible damage. Other effects on the environment, of minor importance, are those produced by the noise, dust and vibration.

Other problems stemming from its transport: given that the dry goods is done towards markets located generally within 50 kilometres of the exploitation, by means of trucks (in more than 95% of cases), these heavy vehicular traffic can be a problem for the nearest locationsas well as the effects linked to the emission of CO₂.

Volumes of mining, inert and non-hazardous waste generated in the production of aggregates are completely managed within the process, to the used usually as filler in the refurbishment of the land. Also, they produce and manage waste industrial, own the maintenance of fixed and mobile machinery (batteries, used oils, wood, metal, caucho…).

The recommendations of the National Association of businessmen and manufacturers of aggregate (Anefa) for extractive activity include the following general primary measures:

-Optimization of the control of the process of extraction and processing, with the stabilization of the parameters of the process. It is to reduce the specific consumption of energy and resources, to increase the quality of the treated material and to increase life of the equipment. They have, as a side effect, the reduction in the level of noise and emissions into the atmosphere. Includes measures such as the closing of the tapes and storages, the desempolvamiento of the points of loading and unloading and transfer to the system of transportation, the homogeneity of the material, dosage of untreated material safety and the installation of floor coverings of resistant rubber in equipment, among others.

-Reduction of the consumption of electricity, through a system of energy management and equipment of electric drive of high energy efficiency.

-Reduction of the consumption of resources. This is achieved through the use of waste (RCD) suitable to replace the materials entering the phase of treatment. This reduces the consumption of natural resources, the necessary energy and produced at the stage of mining impacts. But it is convenient to do so with adequate control of substances contained in the process.

Special care should be made in the management of the water in farms of aggregates, as one of the most delicate problems faced with regard to environmental impact. The damage that can generate environmental mismanagement of the water can be: discharges of mud rivers, blinding of the bottom of the channel of the same, the background compaction level of the riverbed (which slows down the possibilities of biological recovery in a long stretch downstream); also, with the increase of the turbidity of the water because of the suspended solids present in them, a continuous sealing by decantation of the channel, is likely which can result in a drastic decrease in the recharge of aquifers and a greater movement of surface water. This favors the torrencialidad of the River, and can cause even detours of the channel.

Exploitation of aggregates will also result in a significant increase in the consumption of water in the area, and can cause erosion by surface water in the most sensitive areas. To avoid these problems must monitor the levels of water, the quantity and quality of the flows of recharge of aquifers, and the variations in the water of the same; they should remove the points of infiltration, and periodically check the tightness of buried deposits.

It must be provided a proper drainage system to remove water from areas of work. You must control the quality of the water, and make rational use of the same in the treatment plant and the car wash.

You can limit erosion transforming more sensitive zones in areas with vegetation. It is advisable to also make use of the rainwater that spend big for exploitation and the stagnant within its boundaries.

Recover and recycle water is highly recommended action. You should retrieve, in particular, the waters of process in cases of treatment in wet, through systems of washing using teams of ciclonado, colanders, decanters-clarifiers, and systems of concentration of pulps such as filters press. The recycled water can also be used to work as cleaning plant, irrigation tracks and vegetation.