Water samples are collected just below the stream surface to measure water chemistry and determine if toxins are present. Bacteria samples are also collected near the stream bank, where people are likely to be exposed while swimming or fishing. All samples are sent to laboratories for analysis.
How are these data used?
Water samples are used to collect data for four chemical and two human health indicators.
Nitrogen, like phosphorus, is an essential nutrient found in rivers and streams. Excess nitrogen can stimulate overgrowth of algae, cyanobacteria (which can produce toxins), and aquatic plants. These may result in algal blooms, low dissolved oxygen levels, or degraded conditions for macroinvertebrates and other aquatic life.
Where are nitrogen samples collected?
at the midpoint of the
sample reach.
To learn more, see the
NRSA Field Operations Manual.