Corrosion Control in Water Distribution Systems

Distribution water pipes are of smaller diameter than larger transmission pipes and are made of ductile iron, PVC, and copper. Corrosion problems and corrosion control methods for ductile iron and the deterioration of PVC are similar in pipes of both small and large diameters. 

In addition to ductile iron and PVC, copper and lead are used in pipes, and brass in fixtures and connections. Lead is released because of uniform corrosion. Copper is also released because of uniform corrosion, localized-attack cold water pitting, hot water pitting, MIC, corrosion fatigue, and erosion-corrosion. Lead pipes and lead-tin solder exhibit uniform corrosion. Brass corrosion includes erosion-corrosion, impingement corrosion, dezincification, and SCC. The direct health impacts are because of increased copper, lead, and zinc concentrations in the drinking water. Mechanical problems because of corrosion include leaks from perforated pipes, rupture of pipes, and the loss of water pressure because of blockage of pipes by corrosion products. 

1 Corrosion of Lead Pipes and Solders Lead is generally not present in domestic water supplies such as rivers and lakes. The lead content of drinking water is generally below detection limits however, lead can enter water because of the corrosion or wear of brass fixtures, lead pipes, or solders. Stagnant water in pipes can 

TABLE 4.33 Types and Frequency of Failure of Copper Plumbing in the United States in 1983 

Copper has been the most common material for consumer plumbing because of its excellent characteristics such as ease of installation, low cost, and corrosion resistance. Cooper accounts for 50-90% of all tubes installed in drinking water services (52). Corrosion problems, although infrequent, can be severe for the affected consumers and systems. Failure of copper tubing by pitting, blue or green water problems, and failure to meet the US EPA levels for copper in tap water are major problems when they occur. The different causes of copper tubing failure are noted in Table 4.33 (45). 

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Edwards, M (2004). Corrosion Control in Water Distribution Systems, One of the Grand Engineering Challenges for the 21st Century, Edited by Simon Parsons, Richard Stuetz, Bruce Jefferson and Marc Edwards, Water Science and Technology 49(2), pp. 1-8, ISSN 0273-1223. 

M54, Developing Rates for Small Systems, 30054 M55, PE Pipe—Design and Installation, 30055 M56, Nitrification Prevention and Control in Drinking Water, 30056 M57, Algae Source to Treatment, 30057 M58, Internal Corrosion Control in Water Distribution Systems, 30058... 

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