Study: Urban streams contaminated by road salt

A new government study says many urban streams have become salty enough to harm aquatic life. And the study puts much of the blame on salt used for deicing roads in the winter.

The U.S. Geological Survey studied urban streams and groundwater in 20 states across the northern U.S. for levels of chloride, a component of salt. It found chloride levels above federal recommendations designed to protect aquatic life in more than 40 percent of the streams it tested.

Among the states included in the study are Minnesota, Wisconsin, Iowa and North Dakota.

High chloride levels can slow plant growth, impair reproduction and reduce the diversity of organisms in affected waters.

The study released Wednesday says road salt is a major source of the chloride. Other sources include wastewater treatment plants, septic systems, water softeners and farms.