Presence of chlorides raises questions about tap water safety in Missouri

The Missourian reports today that chloride has been detected in water supply wells that supply drinking water to residents of Columbia, Mo.

What does that mean, exactly?

While the chlorides themselves aren't harmful, according to city officials, their presence in the water supply means that treated wastewater is finding its way back into the city's water supplies. That is raising concerns that "other potentially harmful contaminants, such as pharmaceuticals and other household chemicals, could stay circulating in the water supply," according to the newspaper.

It's interesting to note that despite these problems, Columbia's water is "safe" by EPA standards. The city is not currently in violation of any EPA standards for clean water or water quality, though it has been in the past.

The problem could get worse if the city follows through on its plans to place a new well near four others where chloride levels are at their highest