Which treatment technique is most effective in preventing lead contamination?

Corrosion control is the most effective treatment technique for preventing lead contamination in drinking water systems. Lead typically enters drinking water primarily through the corrosion of plumbing materials, particularly in older buildings that may have lead pipes or fixtures. When water is corrosive, it can leach lead from these materials and contaminate the drinking water supply.

The primary goal of corrosion control is to reduce the corrosivity of the water. This can be achieved through methods such as adjusting the pH, alkalinity, or adding corrosion inhibitors like orthophosphate or zinc. By creating a protective layer on the interior surfaces of pipes, corrosion control discourages the dissolution of lead into the water.

In contrast, filtration, while useful for removing particulate matter and some dissolved substances, may not effectively target lead that is already dissolved in the water. Reverse osmosis is a robust method for removing various contaminants, including lead; however, it can be impractical for large-scale water supply systems due to cost and maintenance considerations. Chlorination is primarily used for disinfection purposes and does not have a significant impact on lead leaching.

Therefore, corrosion control directly addresses the source of lead contamination and is the most effective strategy to ensure safe drinking water free from lead.