Newswise — David Hand, PhD, whose research focuses on drinking water, explains what causes lead to leach into drinking water:

"Lead release into the water from the pipe depends on pH of the water and much more strongly on alkalinity of the water. Alkalinity is a measure of the ability of water to resists pH changes. At low pH, the dissolved lead ion is in its most stable form, while lead carbonate is favored at neutral pH values and hydroxycarbonate and hydroxide forms of lead are favored at higher pH values. As the pH lowers, the solubility of lead increases dramatically, especially below a pH of 8.

It seems as though the pH of the Flint water may have decreased to a point where the lead scale and lead ion became more soluble, causing the lead contamination of the water.

The alkalinity and pH of the water can be adjusted to prevent this from happening. However, the best fix would be to replace the lead piping with a safer piping material."

Hand can also talk about the health risks of lead in drinking water, how people can know if they are at risk, and what can be done to prevent drinking water contamination by lead.

Hand is chair of the Department of Civil and Environmental Engineering at Michigan Technological University and a board-certified civil engineering member of the American Academy of Environmental Engineers.