Investigating the possibility of PCCP mortar coating leaching and the impact on drinking water quality

Abstract

AbstractThe objective of this article was to investigate the potential for the dissolution and leaching of certain chemical elements from the protective mortar coatings of prestressed concrete cylinder pipe (PCCP) into drinking water in the event of leakage and how this might affect the overall quality of the water delivered to consumers. The mortars as linings are also typically used for renovation of old pipes. Samples from three frequently used mortar coating mixtures underwent immersion in water after 28 days of curing and were monitored for 430 days. The water was tested for pH levels and the presence of aluminum, chromium, lead, and iron, in accordance with the standards set for human consumption in Moroccan and other countries such as Australia, Canada, and the United States, as well as organizations such as the European Union and World Health Organization. The results indicate that the highest levels of aluminum, iron, chromium, and lead leaching occurred after the initial contact with water, gradually declining over time. Furthermore, the inclusion of silica fume and fly ash in the coating increases the potential for chemical element leaching. Additionally, preinstallation pipeline washing demonstrates its effectiveness in reducing the leaching of chemical elements into drinking water in the event of leakages. The overall results suggest that the likelihood of contamination of drinking water by leaching of chemical elements from the mortar coating in case of a leakage appears to be negligible under the studied conditions.