In order to prevent the generation of dust and particles during the implementation of a project, it is essential that the machinery transit zone, loading and unloading zones, stock zones, etc. are maintained in conditions that prevent the emission of dust.

Therefore the following measures are taken:

• Watering of areas to keep them moist, but without forming pools.
• Laying of granular material (reusing suitably sized rejected or excess material) along the most transited zones.
• Control the movements of machinery on site (principally during excavation work) and at access points, limiting speeds especially on dry windy days.

It is important:

• To draw up an irrigation plan for transit zones with heavy traffic, with more frequent irrigation in the dry season.
• To provide systems for washing machinery and vehicle wheels at the points where vehicles join existing communication paths.
• To locate dust creating activities (for example: powdery supplies, cutting of ceramic elements, carpenter’s workshop, etc.) in an area protected from the air and draught-free wherever possible.
• To use machinery for cutting ceramic and radial saws with built-in watering systems to favour the precipitation of the dust created.
• To install screens to retain the dust (fixed or mobile) in areas near to homes where the environment may be affected, in order to prevent damage as a result of the spreading of dust to other areas.
• To always ensure that the concentration of particles does not suppose a risk for the operators.
• To always use pipes for lowering debris from different levels, protecting the container or area where the debris is dumped with dust sheets.

Noise is another environmental impact produced in the vicinity of construction works due to the use of machinery including rollers, generators, cranes, dumpers, excavators and lorries when moving earth.

It is essential to ensure the implementation of good environmental practices to reduce noise as much as possible:

• Check the EC certification concerning noise emissions in order to comply with the established in the regulation.
• To carry out regular general service checks to catch any breaches of regulations that could lead to increased noise emissions.
• To install silencers on particularly noisy machines (rollers, generators, etc.)
• To use the minimum possible power on the machinery compatible with the work to be carried out (the less powerful are usually the quieter, similarly for silencer devices).
• To switch off engines when not required, provided that a machinery traffic flow diagram can be drafted, indicating noise-sensitive areas in the vicinity of the site (schools, hospitals, homes...), setting speed limits and selecting paths that avoid traffic in the more sensitive areas.
• To provide machinery operators with a copy of the recommended routes and post a copy in an easily visible area for the information of all site personnel.
• To locate stock in areas which are easily accessed with machinery.
• To locate site installations in sheltered areas don’t amplify the noise.
• To install barriers to muffle sound.
• To use plastic pipes to remove waste, preferably covered with noise insulation and muffling material.
• To reduce the free-fall distance of materials and the removal of waste with, for example, the installation of nets placed at mid-height to catch elements that become detached in order to prevent damage to structures.

Reducing potential waste, dumping and spillage:

ACCIONA Infrastructure places special emphasis on the prevention of possible dumping during the implementation of its projects. Some examples of good practices are:

• To carry out maintenance work and other work with hazardous products in specially designated areas on site, ensuring these areas are away from waterways and the drainage network, carrying out repairs to machinery or other work on a concrete platform with a point below the platform for the collection of possible spills, or with a small perimeter barrier to capture spills.
• To prevent the discharge of slurry and concrete and mortar waste to the drains and waterways. To not wash chutes or buckets in areas close to waterways.
• To build a low brick or breezeblock wall in the mortar silo zone to serve as a clarification basin for material resulting from accidental spillage, to be removed on a regular basis to authorised tanks or dumps and thus prevent it reaching the drains or waterways in the area.
• To prepare areas for the cleaning of elements used in concreting on site (sealed ditches, sealed containers...) such that discharges are concentrated at these points and are more easily treated. To clearly mark the areas so that all site personnel wishing to use the areas may do so.
• To protect nearby drain outlets to prevent uncontrolled discharge with:
  • the placement of sediment barriers made of concrete bricks.
  • the formation of drainage channels before the outlets or waterways to encourage the collection of discharge at a localised point.
  • To cover nearby outlets, taking care not to stop the drainage of rainwater.
• To keep slopes in good condition during earth movements to encourage the concentration of water in one area from where it can easily be drained, or, where it is prone to evaporation.
• When working near a waterway, special care should be taken to prevent material spilling into the waterway. To construct perimeter ditches to encourage the flow of fine silt from runoff into a clarification tank or zone.
• To keep the site clean to reduce runoff in the area to the gutters and nearby waterways.

The execution of a project will, inevitably, produce waste, some of which is hazardous and some which is not. In order to minimise waste, ACCIONA Infrastructure adopts the following measures:

• Piling of topsoil for reuse in the environmental rehabilitation on completion of the project.
• To reuse excess earth in the regeneration of depressed areas or in filling in former borrow pits.
• To prevent poorly executed demolitions.
• Avoid the purchase of excess material.
• To require adequate protection during the transport of materials to prevent breakage.
• To require returnable, reusable or recyclable containers when purchasing materials.
• To request materials in more appropriate sizes to avoid unnecessary cuts.
• To allocate and prepare areas for cleaning tools used in concreting and the treatment of inert waste.
• To inform all site personnel involved in waste generation of the waste selection system, indicating the areas that can be used for storing the waste until its removal.

With respect to hazardous waste:

• To study alternatives products for use that do not generate hazardous waste.
• To have absorbent material (sawdust, sand, hydrocarbon polymers...) available on site to contain and collect spillages of waste or hazardous liquid products.
• Prepare an area for the maintenance /change of oil in machinery. The area should be clearly marked and accessible to vehicles. The ground in this area should be sealed and located at a distance from any sources of fire, waterways or stormwater drains. The used oil is treated as a hazardous waste.
• In the event of accidental spillage of waste or hazardous liquid products, the spillage is contained with absorbent products: sawdust, sand, polymers..., the mixture should be piled in the hazardous waste container and marked as 'oil-drenched material' or 'contaminated earth’.

ACCIONA Infrastructure is currently involved in development work on the optimisation of process water.

Based on a number of pilot projects for water recycling on specific sites, a manual is being prepared to generalise these practises for use on all projects undertaken by the division.

This is a significant initiative as water consumption is one of the most important areas of the Infrastructures Division, covering 985,364 m³ in 2007.