Energy In the energy economy of steelworks, products which are produced in connection with the various stages of production play a significant role in reducing the amount of energy which needs to be bought in. At Saarstahl AG, for example, the reaction gas (converter gas) produced during the manufacture of steel has been in use in the plant's own facilities since 1986. Instead of being burned off. The gas is used for generating heat in the rolling mill furnaces and for producing steam and electricity. The degree of exploitation is almost 100%. Almost one third of the fuel demand of the Völklingen plant is fulfilled in this way. Emission protection Saarstahl AG has invested large sums of money in the environment in the last few decades in order to reduce dust and noise emissions. Even before new facilities are planned, the demands set by legal requirements for minimizing emissions are taken into consideration so that further investment in the environment can be made to meet the demands of state of the art technology. Water protection At Saarstahl AG, both drinking water and water from the river Saar are used whereby Saarstahl AG makes constant efforts to reduce the amount of water required through water saving measures (e.g. having a cycle flow). The sewage system in the Völklingen plant which disposes of water from sanitary facilities is fed into the public sewage system in Völkingen for purification. Saarstahl AGshares the operating costs for the collection system and water processing system in proportion to the amount of waste water of which Saarstahl AG disposes. The waste water system which discharges straight into the Saar only serves to discharge rainwater. Waste Economics During the production of steel and subsequent further processing, a large number of materials occur which, with regard to the laws on recycling and waste, can all be labelled "waste". The majority of the remaining waste (filter dust, sludge from water purification and others) are either used, due to their high proportion of iron content, for producing pig iron or steel or they are brought to Saarstahl´s own waste dump until they are put to their final use. This waste dump is state of the art, (sealed base) and individual groups of substances such as non-contaminated rubble remain on the dump.   Slag exploitation: some of the slag produced during the manufacture of crude steel is re-used in the construction of roads. Since 1994 ,a central waste collection point has been in operation which is co-ordinated by the Department for Environmental Protection. Here, after obtaining permission, all areas of the plant can deliver their waste so that it can be disposed of in an orderly fashion.