Swedish action on corrosion control in drinking water distribution systems is evaluated. The extent to which chemicals are used and the costs of different processes are examined and the theoretical calculations of corrosion control effects are made. Improved measuring techniques and process evaluations are recommended with the objective of obtaining a more effective use of the chemicals. The content of copper and iron in water from different Swedish municipalities, before and after water treatment, was calculated using equilibrium models. The actions slightly decrease the iron corrosion in comparison with the drinking water without corrosion control, while the copper content in the water is somewhat increased.