Students and others at the University of Iowa may have noticed an unexpected chlorine taste at drinking fountains — but it is not unusual.

“This happens usually,” said UI engineering Professor Richard Valentine. “You’re drinking chlorinated water all year.”

The change in the UI water happens every spring when the winter snow starts to melt, he said. The runoff from the snow adds organic particles to the water supply.

“You get a lot of material that’s been sitting there rotting all winter,” he said. “Organic things in there give it a particularly bad smell and taste.”

The chlorine reacts with these organic particles, giving off a gas, which leads to the noticeable odor and flavor, Valentine said.

UI Water Plant manager Scott Slee said the unusually cold temperatures of the past winter, along with other weather patterns, might have caused this year’s water to be especially pungent.

“It’s more pronounced this year because of the harsh winter we had,” he said. “There were no thaw cycles over the winter, [and] we also have not received any rain.”

Slee said adding chlorine to water is entirely normal and occurs all year. The plant doesn’t increase the amount of chlorine during the spring, he said, and the normal amount of chlorine in UI water is 2.5 parts per million.

Valentine said chlorine, which disinfects the water, is as part of the treatment process.

“They just add it to the water, and then it kills much of the life in there,” He said. “[It kills] bacteria, viruses, that sort of thing.”

Although the university does not increase chlorine use following snow runoff, other water plants may do this to offset the increased organic materials, Valentine said.

“It comes into the system, and usually they have to add a lot more chlorine to oxidize the material,” he said.

Valentine said that the change in water during the spring might be more noticeable in water provided by Iowa City.

Though the flavor of the water may be worsened, the quality and safety are unaffected, Slee said.

“The water is safe to drink,” he said. “It actually doesn’t affect the quality of the water at all.”

While the water may taste different for people drinking directly from water fountains, those using the filtered water bottle fillers may not experience the difference.

UI sophomore Taylor Stucker said she uses the bottle fillers and hasn’t noticed any difference in taste.

Other students don’t use water fountains at all and instead use bottled water.

“I usually just have a bottle,” said UI sophomore Alex Martin.

Valentine said the noticeable difference in the water will not last very long.

“It lasts a relatively short period,” he said. “Personally, I wouldn’t worry about it.”