Long-Term Water Quality Trends in Virginia's Waterways

The quality of water in Virginia’s rivers and streams affects the health and welfare of Virginia’s citizens, quality of life in the Commonwealth’s communities, and the state’s economic development potential. Each year, large sums are spent by both the state and the private sector to protect, improve, and monitor the quality of Virginia’s waters. Yet, little information is available on the long-term success of these water-quality-protection expenditures.

The research described in this report was the first-phase of a two-phased, multi-year effort to enhance the Virginia Department of Environmental Quality’s (DEQ) capability to detect and interpret long-term water-quality trends in Virginia’s watersheds (Figure 1).

This report summarizes results of long-term trend analyses of Virginia’s water-quality monitoring data collected over varying periods at individual monitoring stations. Data typically extend from the late 1960s or early-mid 1970s through early 1997. The second phase of this multi-year effort, scheduled to conclude in October 1999, will provide DEQ with the capability to conduct similar trend analyses in-house. The study will also determine relationships between observed water-quality trends and watershed characteristics (Zipper et al., 1997).