# 8.3.9 Corrosion inhibition The mechanisms of corrosion in a water distribution system are complex, and involve an interrelated combination of physical, chemical and biological processes. These depend greatly on the materials used within the distribution system and the chemical properties of the water, particularly its buffering capacity. Water corrosivity can be minimised by adjusting pH and increasing calcium carbonate hardness (resulting in a positive Langelier index). Corrosion can also be reduced by maintaining disinfection residual throughout the distribution system. Corrosion inhibition chemicals (such as sequestering agents) are used to reduce corrosion of pipes and household services. They also control the build-up of scale deposits from the dissolved mineral content of drinking water. This is achieved through the addition of chemicals that form a protective film on the surface of pipes. While corrosion inhibitors reduce corrosion, limit metal solubility or convert one form of corrosion to another (e.g. alleviating tuberculation and replacing it with more uniform corrosion), they do not totally prevent corrosion. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://guidelines.nhmrc.gov.au/australian-drinking-water-guidelines/part-2/chapter-8/8.3-overview-of-chemical-treatment-processes/8.3.9-corrosion-inhibition.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.