When it comes to lead pipes, it is possible for them to safely carry water without the risk of leaching lead into the drinking water, but it relies on the pipes being properly maintained and the water being properly treated. This is where the issue came with Flint.

Prior to 2014, the Flint River was a backup source for drinking water with the primary source being Lake Huron. However, Flint was facing a financial crisis and decided to switch their water supply to the Flint River. When they switched, they also chose to save money by not treating the new water source with the additional anticorrosion materials that would be necessary for the different properties of this water. This caused the existing lead pipes to corrode through the protective layer that had naturally formed previously, allowing lead to leach into the water supply.

Aside from the dangers of lead contamination for the human body, there is another concern when it comes to water treatment. Lead reacts with chlorine, and chlorine is added to drinking water to protect against harmful bacteria. Since there was now a significant amount of lead leaching into the water, a notable portion of the chlorine was now bound to the lead and was not available to kill harmful bacteria. This created the initial problems that were identified by residents in Flint, MI, and it was later discovered that the water supply now had detectable levels of lead.

So Flint exemplifies the issue well. Lead pipes are dangerous and should not be used, but that danger isn’t absolute. Because lead pipes can be safe, we’ve let this problem fester for decades. However, it takes a lot of care and attention to keep using these pipes safely, and, as can be seen in Flint, it is very easy for those precautions to be tossed aside. When that happens, it becomes a major crisis very quickly.