Water Quality Monitoring: Technical Guide Book

Many factors influence the health of aquatic ecosystems and the plant and animal life that depend on them. These factors include physical habitat, riparian function, water quantity, watershed health, and water quality. This guidebook focuses on m ethods for monitoring water quality.

Monitoring involves a series of observations, measurements, or samples collected and analyzed over time. W ater quality varies naturally with location and time. For example: the headwaters of streams at high elevation tend to be cooler than wide streams at lower elevations; solar radiation influences stream temperature fluctuations throughout the day; natural differences in climate and the riparian vegetative cover cause differences in stream temperature. Disturbances such as fires, windthrow or even debris torrents can influence stream temperature, turbidity, and other water quality parameters. Geology, geomorphology, and climate also influence water quality. Pollution can be defined as the fouling or making unclean air or w ater w hich harms beneficial uses. Water pollution is generally characterized as originating from either “ point” or “nonpoint” sources. Point source pollution is associated with a particular site on a stream and typically involves a known quantity and type of pollutant that can be controlled at the site.