08. Commitment to the environment

Resource management

Consumo de energía en Valoriza (I) (II Consumo de energía en Valoriza (I) (II

The significant increase in the use of B and C diesel at Valoriza Energía is because in 2010 there was no record of consumption of this fuel at the Biolinares facility, which had only recently come onstream. Furthermore, 2011 consumption figures include Extragol, which had not been calculated to date.

Biomass consumption in 2011 totalled 282,841 tonnes.

In Valoriza Energía, 89.89% of energy consumed in 2011 was generated by the company’s own plants. in line with the figure of 89.57% recorded in 2010.

It is estimated that 38% of the energy consumed by Valoriza in 2011 was generated by the company’s own activities.

Of the total biogas generated in the sludge digestion of the La Reguera waste water treatment plant, a total of 819,349 m3, 339,354 m 3were reused to feed the boiler to heat the digesters and the remaining 479,995 m3 were burnt in a flare.

Sludge generated during the treatment process at the Emmasa WWTP is then digested. Sludge digestion produces gases with a high methane content, which are fully harnessed to generate electricity through a power generator. This energy can be consumed by the plant itself or sold to another company. 139,174 kWh of power were generated in 2011 and consumed at the plant, resulting in a similar reduction in the amount of electricity purchased.

At the Seawater Desalination Station in Santa Cruz de Tenerife (EDAM Tenerife), the programmable automation of the lighting for the frame room and timers were installed in seven rooms at the plant, for an estimated reduction in electricity consumption of approximately 26,000 Kwh in 2011.

At Valoriza Servicios Medioambientales España, 5.72% of energy used in 2011 was generated internally. An increase of 108.7% on 2010.

The electricity produced by Valoriza Servicios Medioambientales was generated at the La Rioja waste treatment plant, through the anaerobic thermophilic biomethanisation processing of organic matter to obtain biogas with an internal heating value which can be used in an electricit/heat cogeneration engine. In 2011 a total of 326,870 kWh of power were produced.

Consumo de energía en Somague Ambiente Consumo de energía en Somague Ambiente

Water

Efficient water management is vital to sustainable development. In awareness of the crucial importance of water, the Sacyr Vallehermoso Group continues to improve its efficiency in water management.

One of the main lines of the SyV Group’s environment policy is to reduce its use of natural resources, including water. In everything we do, therefore, we look for ways of optimising water use, reusing water and using recycled water.

Water consumption in construction is used mainly for temporary facilities, such as concrete and crushing plants, earthmoving, drilling, site cleaning, road irrigation, human use in offices and changing rooms, etc.

Consumo de energía en Sacyr

In line with Group policy, common practice at all sites to minimise water consumption in construction projects is to reuse the water produced by the projects and to harvest water from rainfall run-off. Specifically, water from the following is reused:

• cleaning of concrete tanks. • construction of tunnels after a water treatment process in settling basins. • ground-water level after excavation for cross drainage works. • rain collected at the lowermost points of a construction site by suction through vats. • verification of water-tightness of building coverings. • natural ponds. • location of surface water storage basins at the entrance of cross drainage works and animal transit routes. • washing of concrete plant. • aggregate crushing and washing plant.

Water is mainly reused for road and street irrigation, embankment compaction and site cleaning, so preventing vehicle traffic from bringing up dust. Other uses are reuse in concrete and crushing plants and watering in plantations.

Every construction project is different and has its own distinctive features. This means that the steps taken to reduce water use are different for each project. We research and implement the solutions best suited to each project in accordance with SyV Group policy.

As mentioned in reports in previous years, obtaining data on the total volume of water recycled/reused in a year in construction is difficult given the seasonality of the work and the diversity of the locations, and there are few opportunities for taking water inventory. Every step of the way, all practicable measures are employed to reduce water consumption and use water that would otherwise be wasted. In 2011, the construction division in Spain reused 141,338 m3 water – which would otherwise have to be sourced elsewhere - although this is not necessarily the real volume of recycled water used.

Consumo de energía en Somague

Water consumed at Testa is for human use in offices and changing rooms, and garden and green area maintenance of the buildings.

In each of the businesses carried out by the services division in Spain, the main uses of water are:

- Environment: water is used mainly for street flushing, park and garden watering, and as process water in waste treatment plants. The volume used within the facility itself (sanitary use, car wash facilities, etc.) is negligible by comparison.

- Water: public supply, human use in offices, office building facilities (sanitary use, maintenance, deodorisation towers etc.) preparation of polyelectrolyte, flushes and watering of garden areas.

- Multi-services: human use in offices and conservation centres, and cleaning of these centres.

Consumo de agua en Testa Consumo de agua en Valoriza

As in the construction division, the services division researches and implements water saving measures and prioritises the reuse of water deriving from internal processes and the use of recycled water in preference to water from other sources. In the services area, the following actions were carried out in 2011:

• The wastewater treatment plant (WWTP) in Emmasa (Spain): treatment of 9,546,483 m3 of water from the sewage network, of which 8,760,773 m3 went to agricultural use and 519,156 m3 to park sprinkling and street cleaning.

• Biomasas de Puente Genil, S.L., belonging to the Sedebisa Complex (Spain): the reuse of approximately 1,586 m3 of water from boiler blowdown. The difference compared to the volume reused in 2010, 2,261.36 m³, is because in summer months it is not feasible to reuse water due to the high temperature at which it enters the facilities, which when mixed with the blowdown, results in temperatures of over 25º C, which is damaging for the osmosis membranes in the gross water treatment plant.

• 6,748 m3 of seawater undergoes the osmosis process and, instead of being carried directly to the header tank for subsequent supply to the public, is sent back into the plant to clean the membrane frames. Lastly, the water again undergoes desalination and ends up in the header tank. This is an instance of water reuse in so far as the same volume of water is used for two distinct purposes, supply and cleaning.

• The wastewater treatment plant (WWTP) in La Reguera (Spain): of the total water treated in 2011, 8,03*106 m³, 479,010 m³ was subjected to tertiary treatment for internal use. Specifically, filtering, chloration and disinfection by UV (tertiary treatment) and, subsequently, used in the industrial water network: cooling of equipment, flushes, irrigation, and, with the object of reducing the consumption of drinking water, for preparing polyelectrolite. As a result, a comparison of the amount of drinking water consumed in the first quarter of 2011 with water consumed monthly after that date, shows a significant reduction in the volume of water used from the water supply network (of around 90%).

• In the environment business, 45,140 m3 of water consumed was recycled and reused water, accounting for 4.32% of total water used in this division. Recycled water is sourced externally from wastewater treatment plants operated by the Autononomous Region of Madrid and used for street flushing and watering garden areas. Reused water is sourced internally from leaching and runoffs from wastewater treatment plant processes. Whether directly or after a process of purification by settling and physical/chemical/ biological treatment, the water is reincorporated to waste treatment processes to provide the necessary humidity conditions.

• In the the construction area of the environment business, specifically in the project to expand the Mataró incinerator, 6,400 m³ of non-drinking water were used to carry out hydraulic tests of digestor tanks. Approximately 3,000 m³ of this amount was reused to carry out the same tests in the different tanks on the site, for which purpose the relevant metres of piping were laid in order to empty some tanks at the same times as others were being filled.

Detalle baldeo de calles

At Somague Ambiente, the wastewater treatment plants and drinking water purification plants managed by AGS use water sourced from the network for the company’s own use – i.e., for human consumption, washing of equipment and irrigating green spaces.

In the waste management division, water is used mainly for street cleaning and container washing.

Consumo de agua en Somague Ambiente

Some of the drinking water purification plants have treated water reuse systems in place for internal use (irrigating green areas and cleaning equipment) preventing water being taken from the water supply. In 2011, 28,639 m³ of treated water were reused, accounting for 30% of total water consumption.

Proyecto de control de flujo inadecuado en las EDAR Proyecto de control de pérdidas de agua

In 2011, the engineering department of AGS took part in a nationwide initiative to develop operating indicators for drinking water plants and purification plants. This initiative is called Past21.

The project has the following objectives:

• To establish benchmarks for evaluating performance measures;

• Identify sub-groups of performance indicators with specific objectives such as benchmarking, strategic management, operational management, for example - minimising energy and reagent usage.

• Reinforce the applicability of the current performance assessment system and the respective calculation tool for different types of purification plants and drinking water plants.

More information at: http://past21.lnec.pt