Lesson Write-Up For Winter Quarter 2013
Your name: Catalina Marambio Jones
Title of Lesson: Kuruvunga Springs Water quality determination
Grade Level: 9-12 grades
Subject(s): Environmental Science AP; Chemistry
Summary:
This lesson seeks to teach about water quality monitoring and the parameters used to
assess the level of pollution in a water body. Teacher and students groups discuss about
the water quality of the Kuruvunga springs, located at University High school and develop
hypothesis about the water quality of two separated locations at the springs. Then,
students visit the spring, make field observations of the 2 selected points and collect water
samples for analysis of pH, T◦, alkalinity, hardness, turbidity, nitrates, phosphates, dissolved
oxygen and coliform bacteria. Based on the data analysis, their observation in the field and
their knowledge on water quality parameters they decide whether their hypothesis were
correct or not and explain why.
Time Required: Three periods of 50 min (in three different days)
Group Size: 30 students (groups of 3-4 students)
Cost to implement:
Chemical materials from LaMotte Science education products
http://lamotte.com/images/pdfs/education/2013_Env_Edu_Refill_Pricelist.pdf
-Reagents: $6/group
-Tubes and containers (can be reused between different classes): $3.75/group
Coliform bacteria
Dissolved oxygen
Nitrate
Phosphate
pH
Turbidity
Alkalinity
Hardness
Extra test tubes
glass vial for DO
Plastic cups
Code
Cost for 100 tests Cost per group
5850
93.75
1.875
5889
30
0.6
5891
25.1
0.502
5892
22
0.44
5890
21
0.42
5887
30
0.6
5893
30.75
0.615
5899
45.9
0.918
Total chemical cost per group($):
5.97
0106
0125
2 for $ 2.95
8 for $2
$.15 per cap
Tubes cost per group($):
2.95
0.5
0.3
3.75
Learning Goals:
After this lesson, students should be able to:
1) Discuss about water pollution
2) Define eutrophication and to list its causes
3) Understand the parameters of coliform bacteria, dissolved oxygen, pH, phosphate,
nitrate, alkalinity, hardness, turbidity and temperature and their relation with the
water quality in the spring.
4) Know how to sample water and follow directions to perform the water quality
analysis.
Level of Inquiry:
Students make hypothesis on the health of the spring based on photos showed during the
introductory presentation. They select two locations of the spring (in a provided map) that
they believe will help to prove or disprove their hypothesis. At the end, based on their
results their decide on the validity of their hypothesis.
Introduction / Motivation:
The activity will be introduced through a power point presentation in which water
pollution issues are discussed and typical water quality monitoring parameters are
explained. The presentation is simple has many big and colorful images to keep the student
engagement. After this part of the presentation is over a short 3-5 min think/pair/share
activity is performed to asses understanding. Following to this, the case study of the
Kuruvunga spring is introduced. Using this case study has for objective to make the topic
relevant to the students since kuruvunga springs are part of the school campus (other
people looking into this activity may want to select a water body relevant for their own
community). After the case study is presented, what include a map of the spring and
picture of different areas, students break in groups to define the hypothesis they will be
investigating.
Lesson Background Concepts for Teachers:
Water pollution affects many water bodies and in special danger are natural springs in
urban areas, such as the kuruvanga springs, were many sources of pollution can be present
such as acid rain, sewage leaks, runoff that wash streets and carry pollutant with it, garden,
fertilizer contamination of ground water, etc. There are several physico-chemical and
biological parameters used to assess the water quality of water body, among these pH,
dissolved oxygen (DO), temperature, alkalinity, hardness, nutrients such as nitrogen and
phosphorus, turbidity, coliform bacteria, the presence or absence of benthic micro
invertebrates, the access to sun light.
pH is of importance not only because controls the water chemistry but because typical fish
and invertebrates are able to live only in narrow pH ranges (check power point), low pH
also cause the dissolution of calcium carbonate, that is one of the main component of the
molluscs and crustaceans. Alkalinity is the capacity of the water to neutralized acid. If the
alkalinity is low the water body will be at higher risk to resist changes on pH caused for
example by acid rain. Dissolved oxygen (DO) is key for the survival of the animals,
typically concentration above 5 mg/L are required for wellbeing, as the concentration of
DO decreases fish becomes more susceptible to sickness and have reproduction problems,
below 2 mg/L they are unable to survive.
DO saturation increases as the water
temperature decreases. Hardness is not typically of great health concern, but corrosion of
pipes are more likely to occur in softer waters than in hard waters. This is of concern
because some pipes such as copper pipes can release toxic heavy metals such as cooper ion
which can affect the water life. Algae provides the food chain base in water bodies as well
as it contributes to the oxygen supply (in addition to the oxygen transferred from the
atmosphere to the water) that is needed to support the life of animals in the water.
Whether algae are important in the water bodies, excess of nutrients such as nitrogen and
phosphorus produced algae to growth uncontrolled producing a phenomenon called
eutrophication. Here, the excess of algae blocks sunlight producing the dead of the algae in
the bottom and posteriori decrease of oxygen concentration in that area. As result the
animals stress and start to die. Coliform bacteria are biological indicators that signal the
presence or absence of fecal matter (from warm blood animals) are an important
indication of the existence of possible pathogenic agents.
Procedure:
First day:
-First part :PowerPoint presentation (15-20 min) introduction to water quality parameters
including a short think--pair share activity on the material presented.
-Second part: PowerPoint (5 min) describing the spring with plan views and pictures.
Explanation on the water flow and my preliminary observation on the spring (from
previous preparation visit).
- Third part: Student group formation and work on worksheet 1, determining hypothesis,
sampling points and distribution of responsibilities among group members (each member
will be in charge of 2 to 3 parameters to test).
Second day:
Class meet at the springs, chemical analysis materials and worksheet 2 (including
instructions) are distributed. Briefly, students make observations on their selected 2
sampling points and starts collecting water samples and analyze them.
Third day:
In first half of the period student complete the missing analysis from the day before and
read their results from coliform bacteria. During the second half of the period student
groups discuss their findings and write a conclusion/discussion paragraph.
Materials List
Each group will need:
Materials
Chemicals:
-at least 3 test tubes
-at least 1 glass vial
-30-40 hardness tablets
-2 nitrate1 and 2 Nitrate2 tablets
-2 clear plastic caps
-2 plastic sponsor stirring bars
-2 phosphate tables
-30-40 alkalinity tables
-1 50 mL graduated cylinder
-2 dissolved oxygen tablets
-globes
-chemical waste container
-2 coliform bacteria tubes/tablets
-color charts for pH wide range,
hardness, alkalinity, phosphate,
nitrate, dissolved,
oxygen,
coliform bacteria
-Worksheet 2
To share with the entire class:
-Turbidity tubes and chart
-Thermometers
Safety Issues:
-Do not ingest any of the chemicals
-No chemical waste to be returned into the springs, pour them in the chemical waste
containers
-Wash your hands thoroughly after the activity, even if you handled the chemicals
with globes
Lesson Closure:
In the third day the students redact a discussion/ conclusion paragraph with their findings.
Additionally, the teacher approaches each group and ask them to explain their conclusions
in person.
After the activity is done the teacher collects worksheets 1 and 2 and analyze the results. A
post activity can be done in the following days, showing the students the collective data set
and analysis. For example plots of each parameters along the water flow. Since is very
likely that several groups sample the same point, a simple statistical analysis can be
performed and averages can be use, standard errors can be included as error bars. These
plots can be used to discuss with the students the experimental variability and possible
testing errors.
Assessment:
Pre-Activity Assessment:
During the Introduction presentation, ask questions to the students about the different
parameters to study and to know what do they know about water pollution.
Activity Embedded Assessment:
Again question to the students. Also a think/pair/share activity is performed half way in
the first day. During water sampling walk around check what students are doing are
question them about the procedures.
Post-Activity Assessment:
Conclusion and Discussion paragraph is reviewed. Also a post activity (in a different day)is
performed summarizing the collective data and discussing it with the students.
References:
The work was not based in any known written material but images used in the power point
were taken from internet and referenced accordingly in it.
Attachments:
-Kuruvunga spring worksheet 1.
-Kuruvunga spring worksheet 2.
-Kuruvunga water quality power point.
-Kuruvunga water quality post activity results.
List CA Science Standards addressed:
The AP environmental Science class is not under CA standards but is guided by College
board. This lesson can be incorporated in the College board curriculum for the water
pollution section in the Pollution Chapter of AP Environmental science.
Chemical class. CA Science standard
Acid and bases: "Students know how to use the pH scale to characterize acid and base
solutions", "Students know buffers stabilize pH in acid–base reactions", "Solution are
homogeneous mixtures of two or more substances".