Corrosion Control in Drinking Water Distribution Using Simple Methods – Experiments to Determine the Corrosion Rate and Copper Release

Corrosion of copper or copper alloys affects the durability of drinking water installations and the quality of drinking water in associated pipes. This article presents various methods for investigating this issue from different angles. First, it describes a simplified flow-through method for determining copper loss in flowing water, which allows one to determine the corrosion rate, material removal rate, and rate of protective layer formation. Additionally, a testing procedure using a standardized test rig according to EN 15664-1 is presented for evaluating the suitability of copper pipes and copper alloy fittings for a local drinking water. Though labor-intensive, this procedure yields important information about the suitability of copper and copper alloys in contact with drinking water. The test is intended for corrosion-prone metallic materials within regulatory approval processes and cases of uncertainty regarding materials' suitability for specific local drinking water. A third method, a comparable simplified procedure using a closed-loop system, is presented to evaluate behavior under stagnation conditions. In this method, a copper pipe is supplied with water continuously and tested weekly under stagnation conditions to determine the rate of copper release. Both simplified procedures can be conducted in a laboratory with minimal personnel and cost and provide valuable insights into copper corrosion and the release of copper into drinking water.