Straight from the Tap

Why Cold is Good for Water Quality


After a brief appearance from the sun this past weekend, another stretch of below-freezing temperatures is forecasted. And with it, Lake Erie ice cover is expected to reach over 90% concentration by the end of the week.

Cleveland Water’s Maggie Rodgers appreciates a cold Cleveland winter.

“When it comes to the taste of water, consistency and cold are key,” Maggie said. “Winter brings both.”

Maggie knows. She has more than 20 years of experience making high-quality good tasting water as Cleveland Water’s Manager of Plant Operations.

“Water temperature has a major influence on biological activity and growth of organisms in the water,” Maggie said. “When Lake Erie water temperatures decrease, the growth of everything in the water – from fish to phytoplankton – slows. When ice covers the lake, turbidity also decreases.”   

Turbidity is a measure of the cloudiness of the water. The turbidity of raw water drawn into the treatment plants usually measures at its highest level on stormy days. When ice covers Lake Erie, wind can’t make waves, and waves and currents don’t stir up as much sediment from the lakebed. Instead, the soil settles to the bottom and the water becomes consistent and clear.

“We monitor the raw water drawn into each of our treatment plants around the clock, 365 days a year,” Maggie said. “When the water drawn in is chemically and physically the same from day-to-day, we have to make fewer adjustments in the treatment process in order to deliver the same high-quality product to your tap.”

Fewer adjustments also mean the treatment process is less expensive, saving us – and our customers – money.

To selective taste buds, the colder the winter, the better tasting the water.

“Many people tell us that they prefer the taste of water when the source of raw water is cold,” Maggie said. “Scientifically speaking, colder lake water holds more dissolved oxygen, absorbs fewer minerals and has a slightly higher ph.”

While Maggie and the staff at Cleveland Water’s four treatment plants are enjoying the chill, staff working in distribution and maintenance (i.e. the people who fix pipes) may see things differently.