Science/Strand V/Content Standard 2/High School/Benchmark 2
Benchmark Question: How does water quality change as a
stream flows from its headwaters through its watershed?
Focus Question: How does the water quality at the
source of a stream compare to the water quality at the mouth of the stream?
The teacher will review with
students the standard techniques of water quality sampling and the meaning
of each test. The teacher will choose a local stream that can be easily
sampled in two or more places as far apart as possible.
Students will collect water
samples and analyze them using standard water sampling techniques (water
quality testing kits are commonly available).
Students will compare and
contrast water quality data between sampling sites and develop reasonable
hypotheses to account for their differences.
Note: Students need to know
the difference between point and non point pollution (point pollution is a
discernable source of water pollution like a pipe versus non point
pollution which is a diffuse source of pollution where contaminants enter
water bodies from thousands of different points. Examples of non-point
pollution would be agricultural fields, building sites, and aerial
deposition of contaminants) Environmental clean up efforts have been more
successful with point sources of pollution because these sources are easily
identified. It is more of a challenge to control agricultural runoff or
stop an adjacent state from creating air pollution that will fall as acid
Acid deposition includes
rain as well as snow, sleet, dust, and hail, which are significant sources
of acids in the environment
Extension: Students could also identify the
human activities on the stream located between the sampling sites that
could affect water quality changes.