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Water-Quality Trends in the Nation's Rivers
Science (New York, N.Y.)
|March 27, 1987
Summary
Long-term U.S. river water quality analysis reveals significant shifts between 1974-1981. Key findings include decreased fecal bacteria and lead, alongside increased nitrate, chloride, arsenic, and cadmium levels.
Area of Science:
- Environmental Science
- Water Quality Monitoring
- U.S. River Systems
Background:
- Major changes in terrestrial and atmospheric influences occurred between 1974-1981.
- Understanding long-term water quality trends is crucial for environmental management.
- Nationwide water quality data provides a comprehensive view of river health.
Purpose of the Study:
- To analyze long-term water quality trends in major U.S. rivers.
- To correlate observed water quality changes with environmental and industrial factors.
- To provide insight into stream quality dynamics during a period of significant environmental change.
Main Methods:
- Utilized water-quality records from two nationwide sampling networks.
- Analyzed trends in 24 water quality parameters.
- Focused on data from over 300 locations on major U.S. rivers from 1974 to 1981.
Main Results:
- Observed widespread decreases in fecal bacteria and lead concentrations.
- Documented widespread increases in nitrate, chloride, arsenic, and cadmium concentrations.
- Identified correlations between water quality changes and factors like waste treatment, highway salt use, fertilizer application, and gasoline consumption.
Conclusions:
- Water quality changes reflect shifts in human activities and environmental influences.
- Municipal waste treatment improvements likely contributed to reduced bacteria and lead.
- Increased agricultural and industrial activities appear linked to rising nitrate, chloride, arsenic, and cadmium levels.
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