“Groundwater contains naturally existing, dissolved iron,” Ellerhorst said. “When we bring it up and it goes through the pipes in the buildings, (the water) turns red.”

Without oxygen, iron is colorless, assistant professor of plant soil and microbial sciences Wei Zhang said.

“When you pump groundwater, it’s exposed to the air and oxygen, which forms iron oxide,” Zhang said.

“The small iron oxide particles are suspended in the water, making it a yellowish red.”

IPF sends out red water alerts for planned maintenance and emergency repairs, Ellerhorst said.

Examples from previous alerts include water shutdowns in campus buildings, fire-pump testing, fire-hydrant flushing, water-flow testing and equipment repairs.

“This summer we flushed water to try to purge last year’s iron oxide accumulations,” Ellerhorst said.

It’s so routine, Ellerhorst said, that red water can develop any weekend — campus slows down on Saturdays and Sundays, and when the flow picks up again Monday morning, red water always are a possibility.

The alerts reassure students that the discoloration is harmless in terms of sanitation and safety, though it can discolor clothing.

“A lot of students who come to MSU are more accustomed to softened water,” Ellerhorst said. “They’re just not used to the groundwater.”

MSU water is tested annually, as required by the state and the Environmental Protection Agency.

Neuroscience senior Laura Melekian said when she lived on campus she always was curious about what caused the red water alerts.

“Fortunately, my roommates and I never noticed much of a difference in our water,” Melekian said.

“We just wound up deleting the emails.”