The Urban Streams Monitoring Program
was developed to obtain baseline water quality data for streams in the city
of Bellingham. Data is used to detect changes in these streams. The program
is conducted by the Public Works Operations Division. The city has carried
out monthly water quality monitoring of streams since 1990. Currently
monitoring takes place at 18 sites, on 11 streams: Whatcom, Hanna, Cemetery,
Lincoln, Fever, Padden, Connelly, Chuckanut, Squalicum, Baker, and Silver
Water Quality Parameters Measured
Fecal coliform bacteria—inhabitants of the digestive
tracts of warm-blooded animals. While fecal coliforms generally do not cause
illnesses themselves, they can indicate that other illness–causing bacteria
or viruses from fecal sources such as septic systems, sewer lines, pets,
birds, and other wildlife may be present in the water.
Temperature—many fish species need cooler temperatures
to survive. Sockeye salmon eggs will not survive above about 13oC (64oF).
Human activities, including removal of streamside trees and other
vegetation, can lead to higher temperatures in streams.
Dissolved oxygen—living things in streams need oxygen to
survive. Dissolved oxygen is the amount of oxygen dissolved in water. If
dissolved oxygen becomes too low there may not enough oxygen to sustain
aquatic life. Salmon need a minimum of 7.5 mg/L dissolved oxygen to survive.
Decreases in dissolved oxygen can be caused by increases in temperature
(warm water will not hold as much dissolved oxygen as cool water), and
inputs of pollutants that rob the water of oxygen.
pH—most living things in water need a pH that is close
to neutral (around 7.0). Natural water usually has a pH between 6.5 and 8.0.
Changes in pH, often an indication of pollutants, can seriously affect the
health and diversity of aquatic life in streams. Fish species such as salmon
are very sensitive to pH, especially in the early life stages. For example,
when pH gets below 6.5 salmon eggs and newly hatched salmon begin to die;
below 5.5, few survive.
Turbidity—used to estimate the amount of suspended
materials in water. High turbidities, usually caused by streamside or bank
erosion, can clog gills, smother living things, cover spawning beds, and
destroy habitat. Salmon growth is reduced and gill tissue damaged after only
5 to 10 days of exposure to a turbidity level of 25 NTU (Nephelometric
Turbidity Unit). Removal of streamside trees and other vegetation can
Conductivity—measures the ability of water to conduct an
electric current and is directly related to the total dissolved ions in the
water. Conductivity can be used as an overall indication of water quality.
Higher conductivities may be a sign of contamination in the water.
City of Bellingham laboratory staff follow strict protocols for
collecting and processing samples. Field instruments are calibrated and
maintained also following strict protocols. Some of the quality
control/quality assurance guidelines include duplicate samples and
measurements and quality control standards. Data are carefully examined and
anomalous values investigated before publication.