Stream Quality Assessment Program A stream is a combination of
all of its physical, chemical and biological characteristics.
Human activities shape and alter many of these characteristics.
The health of our rivers and streams is closely linked to their
surrounding watersheds. Ecologists measure the extent to which
human activities affect watershed health by gathering and
recording information on physical conditions, water quality and
living communities in streams and in the surrounding
environment. The long-term stream monitoring program meets the
requirements of state and federal regulations and supports the
Board of Supervisors' environmental improvement program by
providing an ongoing evaluation of the streams. The program
maintains a substantial database, which over time will be used
to determine the overall rate of change or trends in the
conditions of our waterways. Based on biological data collected
at 39 randomly selected locations (see map of monitoring site
locations) throughout Fairfax County in 20