Economic aspects Water 4 Management 3 Purification 3 Direct current 2 Distribution 2 Electric currents 2 más ... Electric generators 2 Electric power production 2 Electric power systems 2 Environmental permits 2 Grounding 2 Land use 2 Maintenance and repair 2 Mathematics 2 Planning 2 Protection 2 Water-supply 2 Alternating current 1 Archaeological surveying 1 Archaeology 1 Architectural drawings 1 Benchmarking (Management) 1 Brownfields 1 Building 1 Building laws 1 Building permits 1 Building sites 1 By-products 1 Cogeneration of electric power and heat 1 menos ...