RESTON, Va. — Concentrations of dissolved solids — a measure of the salt content in water — are elevated in many of the nation's streams as a result of human activities, according to a press release on a study by U.S. Geological Survey (USGS).

Excessive dissolved-solids concentrations in water can have adverse effects on the environment and on agricultural, domestic, municipal and industrial water-users.

Results from this study provide a nation-wide picture of where dissolved-solids concentrations are likely to be of concern, as well as the sources leading to such conditions, noted the release.

“This study provides the most comprehensive national-scale assessment to date of dissolved solids in our streams,” said William Werkheiser, USGS associate director for water. “For years we have known that activities, such as road de-icing, irrigation and other activities in urban and agricultural lands increase the dissolved solids concentrations above natural levels caused by rock weathering, and now we have improved science-based information on the primary sources of dissolved-solids in the nation’s streams.”

The highest concentrations are found in streams in an area that extends from west Texas to North Dakota. Widespread occurrences of moderate concentrations are found in streams extending in an arc from eastern Texas to northern Minnesota to eastern Ohio. Low concentrations are found in many states along the Atlantic coast and in the Pacific Northwest.