What type of contamination does a high Langelier Index indicate?

A high Langelier Index indicates the potential for scale formation in water. The Langelier Saturation Index (LSI) is a calculation used to assess the chemical balance of water, particularly its saturation with respect to calcium carbonate. When the LSI value is positive, it suggests that the water has a tendency to precipitate calcium carbonate, leading to the formation of scale in pipes, fixtures, and other equipment.

This scale formation can result from supersaturation of calcium carbonate, which is often influenced by factors such as pH, temperature, and alkalinity. Thus, understanding the LSI and its implications for scale formation is essential for water operators to ensure proper treatment and maintenance of the water distribution system.