***PLEASE READ THE WHOLE THING / AND ATTACHMENTS***
***ROUGH DRAFT WITH TEACHER FEEDBACK ATTACHED***
Final Lab Report
You are required to write a complete laboratory report that covers the drinking water quality experiment from “Lab 2: Water Quality and Contamination,” using knowledge gained throughout the course. Use the instructor feedback on your Rough Draft from Week Three to guide your writing. Be sure to download the Final Lab Report Template and utilize this form (not the Rough Draft template) to ensure proper formatting and inclusion of all required material. Additionally, view the Sample Final Lab Report before beginning this assignment, which will illustrate what a Final Lab Report should look like. You must use at least two scholarly sources, two other highly credible sources, and your lab manual to support your points. The report must be six to ten pages in length (excluding the title and reference pages) and formatted according to APA style
The Final Lab Report must contain the following eight sections in this order:
- Title Page – This page must include the title of your report, your name, course name, instructor, and date submitted.
- Abstract – This section should provide a brief summary of the methods, results, and conclusions. It should allow the reader to see what was done, how it was done, and the results. It should not exceed 200 words and should be the last part written (although it should still appear right after the title page).
- Introduction – This section should include background information on water quality and an overview of why the experiment was conducted. It should first contain background information of similar studies previously conducted. This is accomplished by citing existing literature from similar experiments. Secondly, it should provide an objective or a reason why the experiment is being done. Why do we want to know the answer to the question we are asking? Finally, it should end the hypothesis from your Week Two experiment, and the reasoning behind your hypothesis. This hypothesis should not be adjusted to reflect the “right” answer. Simply place your previous hypothesis in the report here. You do not lose points for an inaccurate hypothesis; scientists often revise their hypotheses based on scientific evidence following the experiments.
- Materials and Methods – This section should provide a detailed description of the materials used in your experiment and how they were used. A step-by-step rundown of your experiment is necessary; however, it should be done in paragraph form, not in a list format. The description should be exact enough to allow for someone reading the report to replicate the experiment, however, it should be in your own words and not simply copied and pasted from the lab manual.
- Results – This section should include the data and observations from the experiment. All tables and graphs should be present in this section. In addition to the tables, you must describe the data in text; however, there should be no personal opinions or discussion outside of the results located within this area.
- Discussion – This section should interpret your data and provide conclusions. Discuss the meanings of your findings in this area. Was your hypothesis accepted or rejected, and how were you able to determine this? Did the results generate any future questions that might benefit from a new experiment? Were there any outside factors (i.e., temperature, contaminants, time of day) that affected your results? If so, how could you control for these in the future?
- Conclusions – This section should provide a brief summary of your work.
- References – List references used in APA format
Running head: TITLE
SCI 207: Our Dependence Upon the Environment
*This template will provide you with the details necessary to finalize a quality Final Lab Report. Utilize this template to complete the Week 5 Final Lab Report and ensure that you are providing all of the necessary information and proper format for the assignment. Before you begin, please note the following important information:
1. Carefully review the Final Lab Report instructions before you begin this assignment.
2. The Final Lab Report should cover the Drinking Water Quality Experiment from your Week Two Lab.
3. Review instructor feedback from the Week Three outline of the Final Lab Report and make changes as necessary.
4. Review the Sample Final Lab Report for an example of a final product on a different topic. Your format should look like this sample report before submission.
5. Make sure your final report is in proper APA format. Use the Sample Final Lab Report as a guide, or obtain an APA Template from the Writing Center.
6. Run your Final Lab Report through Turnitin using the student folder to ensure protection from accidental plagiarism
The abstract should provide a brief summary of the methods, results, and conclusions. It should very briefly allow the reader to see what was done, how it was done, and the results. It should not exceed 200 words and should be the last part written (although it should still appear right after the title page).
The introduction should describe the background of water quality and related issues using cited examples. You should include scholarly sources in this section to help explain why water quality research is important to society. When writing this section, make sure to cite all resources in APA format.
The introduction should also contain the objective for your study. This objective is the reason why the experiment is being done. Your final report should provide an objective that describes why we want to know the answer to the questions we are asking.
Finally, the introduction should end with your hypothesis. This hypothesis should be the same one posed before you began your experiment. You may reword it following feedback from your instructor to illustrate a proper hypothesis, however, you should not adjust it to reflect the “right” answer. You do not lose points for an inaccurate hypothesis; scientists often revise their hypotheses based on scientific evidence following an experiment. Include an explanation as to why you made the hypothesis that you did.
Materials and Methods
The materials and methods section should provide a brief description of the specialized materials used in your experiment and how they were used. This section needs to summarize the instructions with enough detail so that an outsider who does not have a copy of the lab instructions knows what you did. However, this does not mean writing every little step like “dip the chloride test strip in the water, then shake the test strip,” these steps can be simplified to read “we used chloride test strips to measure the chloride levels of each sample in mg/L”, etc. Additionally, this section should be written in the past tense and in your own words and not copied and pasted from the lab manual.
The results section should include all tables used in your experiments. All values within the tables or graphs should be in numerical form and contain units. For instance, if measuring the amount of chloride in water you should report as 2 mg/L or 0 mg/L, not as two or none.
The results section should also highlight the important results in paragraph form, referring to the appropriate tables when mentioned. This section should only state the results as no personal opinions should be included. A description of what the results really mean should be saved for the discussion. For example, you may report, 0mg/L of chlorine were found in the water, but should avoid personal opinions and interpretations of the data (e.g., “No chlorine was found in the water showing it is cleaner than the others samples”).
The discussion section should interpret your data and provide conclusions. Start by discussing whether you accepted or rejected your hypothesis and how you arrived at this decision. In the same section, consider some of the implications of your results. Given the chemical differences you may have noted between the water samples, are any of the differences causes for concern? Why or why not?
The discussion should also relate your results to the bigger water concerns and challenges. For example, based on your experiments you might discuss how various bottled water companies use different filtration systems. Or, you could discuss the billion dollar bottled water industry. For example, do you think it is worth it to buy bottled water? Why or why not? Your final lab report should utilize credible and scholarly resources to put your results into context.
Finally, the results section should also address any possible factors that may have affected your results, such as possible contamination in the experiments or any outside factors (e.g., temperature, contaminants, time of day). If so, how could you control for these in the future? You should also propose some new questions that have arisen from your results and what kind of experiment might be proposed to answer these questions.
The conclusion section should briefly summarize the key findings of your experiment. What main message would you like people to have from this report?
Include at least two scholarly references, two credible references, and your lab manual in APA format.
Running Head: SAMPLE FINAL LAB REPORT 1
Sample Lab Report (The Optimal Foraging Theory)
SCI 207 Dependence of Man on the Environment
SAMPLE FINAL LAB REPORT 2
Sample Lab Report
The theory of optimal foraging and its relation to central foraging was examined by using
the beaver as a model. Beaver food choice was examined by noting the species of woody
vegetation, status (chewed vs. not-chewed), distance from the water, and circumference of trees
near a beaver pond in North Carolina. Beavers avoided certain species of trees and preferred
trees that were close to the water. No preference for tree circumference was noted. These data
suggest that beaver food choice concurs with the optimal foraging theory.
In this lab, we explore the theory of optimal foraging and the theory of central place
foraging using beavers as the model animal. Foraging refers to the mammalian behavior
associated with searching for food. The optimal foraging theory assumes that animals feed in a
way that maximizes their net rate of energy intake per unit time (Pyke et al., 1977). An animal
may either maximize its daily energy intake (energy maximizer) or minimize the time spent
feeding (time minimizer) in order to meet minimum requirements. Herbivores commonly behave
as energy maximizers (Belovsky, 1986) and accomplish this maximizing behavior by choosing
food that is of high quality and has low-search and low-handling time (Pyke et al., 1977).
The central place theory is used to describe animals that collect food and store it in a
fixed location in their home range, the central place (Jenkins, 1980). The factors associated with
the optimal foraging theory also apply to the central place theory. The central place theory
predicts that retrieval costs increase linearly with distance of the resource from the central place
SAMPLE FINAL LAB REPORT 3
(Rockwood and Hubbell, 1987). Central place feeders are very selective when choosing food
that is far from the central place since they have to spend time and energy hauling it back to the
storage site (Schoener, 1979).
The main objective of this lab was to determine beaver (Castor canadensis) food selection
based on tree species, size, and distance. Since beavers are energy maximizers (Jenkins, 1980;
Belovsky, 1984) and central place feeders (McGinley & Whitam, 1985), they make an excellent
test animal for the optimal foraging theory. Beavers eat several kinds of herbaceous plants as
well as the leaves, twigs, and bark of most species of woody plants that grow near water (Jenkins
& Busher, 1979). By examining the trees that are chewed or not-chewed in the beavers’ home
range, an accurate assessment of food preferences among tree species may be gained (Jenkins,
1975). The purpose of this lab was to learn about the optimal foraging theory. We wanted to
know if beavers put the optimal foraging theory into action when selecting food.
We hypothesized that the beavers in this study will choose trees that are small in
circumference and closest to the water. Since the energy yield of tree species may vary
significantly, we also hypothesized that beavers will show a preference for some species of trees
over others regardless of circumference size or distance from the central area. The optimal
foraging theory and central place theory lead us to predict that beavers, like most herbivores,
will maximize their net rate of energy intake per unit time. In order to maximize energy, beavers
will choose trees that are closest to their central place (the water) and require the least retrieval
cost. Since beavers are trying to maximize energy, we hypothesized that they will tend to select
some species of trees over others on the basis of nutritional value.
This study was conducted at Yates Mill Pond, a research area owned by the North
SAMPLE FINAL LAB REPORT 4
Carolina State University, on October 25th, 1996. Our research area was located along the edge
of the pond and was approximately 100 m in length and 28 m in width. There was no beaver
activity observed beyond this width. The circumference, the species, status (chewed or not-
chewed), and distance from the water were recorded for each tree in the study area. Due to the
large number of trees sampled, the work was evenly divided among four groups of students
working in quadrants. Each group contributed to the overall data collected.
We conducted a chi-squared test to analyze the data with respect to beaver selection of
certain tree species. We conducted t-tests to determine (1) if avoided trees were significantly
farther from the water than selected trees, and (2) if chewed trees were significantly larger or
smaller than not chewed trees. Mean tree distance from the water and mean tree circumference
were also recorded.
SAMPLE FINAL LAB REPORT 5
Overall, beavers showed a preference for certain species of trees, and their preference
was based on distance from the central place. Measurements taken at the study site show that
SAMPLE FINAL LAB REPORT 6
beavers avoided oaks and musclewood (Fig. 1) and show a significant food preference. No
avoidance or particular preference was observed for the other tree species. The mean distance of
8.42 m away from the water for not-chewed trees was significantly greater than the mean
distance of 6.13 m for chewed trees (Fig. 2). The tree species that were avoided were not
significantly farther from the water than selected trees. For the selected tree species, no
significant difference in circumference was found between trees that were not chewed
(mean=16.03 cm) and chewed (mean=12.80 cm) (Fig. 3).
Although beavers are described as generalized herbivores, the finding in this study
related to species selection suggests that beavers are selective in their food choice. This finding
agrees with our hypothesis that beavers are likely to show a preference for certain tree species.
Although beaver selection of certain species of trees may be related to the nutritional value,
additional information is needed to determine why beavers select some tree species over others.
Other studies suggested that beavers avoid trees that have chemical defenses that make the tree
unpalatable to beavers (Muller-Schawarze et al., 1994). These studies also suggested that
beavers prefer trees with soft wood, which could possibly explain the observed avoidance of
musclewood and oak in our study.
The result that chewed trees were closer to the water accounts for the time and energy
spent gathering and hauling. This is in accordance with the optimal foraging theory and agrees
with our hypothesis that beavers will choose trees that are close to the water. As distance from
the water increases, a tree’s net energy yield decreases because food that is farther away is more
likely to increase search and retrieval time. This finding is similar to Belovskyís finding of an
SAMPLE FINAL LAB REPORT 7
inverse relationship between distance from the water and percentage of plants cut.
The lack of any observed difference in mean circumference between chewed and not
chewed trees does not agree with our hypothesis that beavers will prefer smaller trees to larger
ones. Our hypothesis was based on the idea that branches from smaller trees will require less
energy to cut and haul than those from larger trees. Our finding is in accordance with other
studies (Schoener, 1979), which have suggested that the value of all trees should decrease with
distance from the water but that beavers would benefit from choosing large branches from large
trees at all distances. This would explain why there was no significant difference in
circumference between chewed and not-chewed trees.
This lab gave us the opportunity to observe how a specific mammal selects foods that
maximize energy gains in accordance with the optimal foraging theory. Although beavers adhere
to the optimal foraging theory, without additional information on relative nutritional value of
tree species and the time and energy costs of cutting certain tree species, no optimal diet
predictions may be made. Other information is also needed about predatory risk and its role in
food selection. Also, due to the large number of students taking samples in the field, there may
have been errors which may have affected the accuracy and precision of our measurements. In
order to corroborate our findings, we suggest that this study be repeated by others.
The purpose of this lab was to learn about the optimal foraging theory by measuring tree
selection in beavers. We now know that the optimal foraging theory allows us to predict food-
seeking behavior in beavers with respect to distance from their central place and, to a certain
extent, to variations in tree species. We also learned that foraging behaviors and food selection is
SAMPLE FINAL LAB REPORT 8
not always straightforward. For instance, beavers selected large branches at any distance from
the water even though cutting large branches may increase energy requirements. There seems to
be a fine line between energy intake and energy expenditure in beavers that is not so easily
predicted by any given theory.
SAMPLE FINAL LAB REPORT 9
Belovsky, G.E. (1984). Summer diet optimization by beaver. The American Midland Naturalist.
Belovsky, G.E. (1986). Optimal foraging and community structure: implications for a guild of
generalist grassland herbivores. Oecologia. 70: 35-52.
Jenkins, S.H. (1975). Food selection by beavers:› a multidimensional contingency table analysis.
Oecologia. 21: 157-173.
Jenkins, S.H. (1980). A size-distance relation in food selection by beavers. Ecology. 61: 740-
Jenkins, S.H., & P.E. Busher. (1979). Castor canadensis. Mammalian Species. 120: 1-8.
McGinly, M.A., & T.G. Whitham. (1985). Central place foraging by beavers (Castor
Canadensis): a test of foraging predictions and the impact of selective feeding on the
growth form of cottonwoods (Populus fremontii). Oecologia. 66: 558-562.
Muller-Schwarze, B.A. Schulte, L. Sun, A. Muller-Schhwarze, & C. Muller-Schwarze. (1994).
Red Maple (Acer rubrum) inhibits feeding behavior by beaver (Castor canadensis).
Journal of Chemical Ecology. 20: 2021-2033.
Pyke, G.H., H.R. Pulliman, E.L. Charnov. (1977). Optimal foraging. The Quarterly Review of
Biology. 52: 137-154.
Rockwood, L.L., & S.P. Hubbell. (1987). Host-plant selection, diet diversity, and optimal
foraging in a tropical leaf-cutting ant. Oecologia. 74: 55-61.
Schoener, T.W. (1979). Generality of the size-distance relation in models of optimal feeding.
The American Naturalist. 114: 902-912.
SAMPLE FINAL LAB REPORT 10
*Note: This document was modified from the work of Selena Bauer, Miriam Ferzli, and Vanessa
© eScience Labs, 2016
Lab 2 – Water Quality and Contamination
Experiment 1: Drinking Water Quality
Bottled water is a billion dollar industry in the United States. Still, few people know the health
benefits, if any, that come from drinking bottled water as opposed to tap water. This experiment
will look at the levels of a variety of different chemical compounds in both tap and bottled water
to determine if there are health benefits in drinking bottled water.
1. Develop a hypothesis regarding which water sources you believe will contain the most
and least contaminants, and state why you believe this. Be sure to clearly rank all three
sources from most to least contaminants.
Hypothesis = I believe tap water will have the most contaminants because it is unfiltered
coming a general water treatment facility. I believe Dasani water will have some contaminants
since it is treated (but not a natural source) and has artificial flavoring / sodium. I believe Fiji
will contain the less amount of contaminants based on be filtered and being produce from a
natural untreated source.
Table 1: Ammonia Test Results
Water Sample Test Results (mg/L)
Tap Water 0 mg/L
Dasani® Bottled Water 0 mg/L
Fiji® Bottled Water 0 mg/L
Table 2: Chloride Test Results
Water Sample Test Results (mg/L)
© eScience Labs, 2016
Tap Water 0 mg/L
Dasani® Bottled Water 0 mg/L
Fiji® Bottled Water 0 mg/L
Table 3: 4 in 1 Test Results
Water Sample Total Alkalinity (mg/L)
Tap Water 120 mg/L 1.0 mg/L 0 mg/L
Water 0 mg/L 1.0 mg/L 0 mg/L
Fiji® Bottled Water 0 mg/L 2.0 mg/L 20mg/L
Table 4: Phosphate Test Results
Water Sample Test Results (ppm)
Tap Water 20 ppm
Dasani® Bottled Water 10 ppm
Fiji® Bottled Water 80 ppm
Table 5: Iron Test Results
Water Sample Test Results (ppm)
Tap Water 0.5 ppm
Dasani® Bottled Water 0 ppm
Fiji® Bottled Water 0 ppm
Table 6: pH Results
Water Sample Test Results
Tap Water 7
Dasani® Bottled Water 2
Fiji® Bottled Water 8
2. Based on the results of your experiment, would accept or reject the hypothesis you
produced in question 1? Explain how you determined this.
Accept/reject = I reject my hypothesis. During my experiment, Fiji ended up having
more contaminates than Tap and Dasani water. The initial hypothesis stated Fiji had the least
amount and Tap had the most contaminants.
© eScience Labs, 2016
3. Based on the results of your experiment, what specific differences do you notice among
the Dasani®, Fiji®, and Tap Water?
Answer = The only differences between the three waters was that the tap and the Fiji both had
the significant higher pH results although some had higher results than others but for the pH
balance, they both were the same. Based on the results of the experiment the major difference
that I see between these is that the Dasani ® is the most impressive of the group. The Dasani®
water is the least contaminated and the Fiji is the most contaminated, which is far from the
original prediction through my hypothesis.
4. Based upon the fact sheets provided (links at the end of this document), do any of these
samples pose a health concern? Use evidence from the lab to support your answer.
Answer = The ammonia levels do not pose a health risk all three tested at 0, chloride also poses
no health risks and the levels within the water samples are within the daily intake suggestions,
Based on all the fact sheets the one that stood out the most with most health risk is phosphate.
Phosphate poses a health concern to humans in high levels and the Fiji water tested at 80 while
the others only tested at below 20 so Fiji water consumed frequently could pose a concern, iron
does not pose a health threat and all three tested at 0, pH does not pose a health risk it just affects
taste tap and Fiji tested at 8 while Dasani tested at a 2 in this so no health risk.
5. Based on your results, do you believe that bottled water is worth the price? Use evidence
from the lab to support your opinion.
© eScience Labs, 2016
Answer = To me I don’t believe bottled water is worth the price. Based on the results not all
bottle water is the same and depending on where you live, tap water will not be the same either.
During my experiments tap water and Fiji bottled water had the most contaminants, while the
other bottle water tested Dasani had the least contaminants. Which made me believe that if you
are going to buy bottled water that is the brand you want to buy. But if unwanted to save money
and drink tap water. I would just buy a special filter that can help filter all the contaminants and
make it the safest water to drink.
**NOTE: Be sure to complete steps 1 – 32 of Lab 3, Experiment 1 (the next lab) before
completing your work for this week. Lab 3 involves growing plants, and if the work is not
started this week, your seeds will not have time to grow and the lab will not be finished on
© eScience Labs, 2016
Any sources utilized should be listed here.
Running head: QUALITY DRINKING WATER 1
QUALITY DRINKING WATER 2
Quality of drinking water
SCI 207: Our Dependence upon the Environment
Instructor John Gomillion
Water is a fundamental resource to human beings. Every person on earth requires safe water for drinking and cooking. Contaminated water is health risk and deadly because it causes serious diseases many of which can be prevented. These diseases affect education and productivity and they may cause death. Contamination of drinking water occurs mostly at their sources which are unprotected. These sources include rivers, streams, lakes and other ground water reservoirs. Appropriate treatment should be done to make water safe for drinking. Access to clean water is essential to human beings because it improves their living standards (Strauss et al., 2001).
Various studies have done research on quality of drinking water. Some studies have done their research in schools while others in household level. They have assessed the quality of water from their source to the point of drinking. One of the studies aimed at identifying the critical points of contamination of drinking water and the treatment measures. This study assessed 347 water sources and 81 households. It used Escherichia coli in measuring quality of water. According to the study, the contamination of water increased from the water point to the drinking vessels. The study contends that the common methods of treatment used were boiling and solar disinfection of water. According to the study, these home-based interventions did not guarantee safe drinking water (Rufener et al., 2010).
Treatment of sewerage water has not been effective in urban areas. This waste water has been deposited in water bodies causing water pollution. Poor rural communities depend mostly on these polluted sources of water. The waste in rural areas is also not managed properly because of lack of improved sewerage systems. Bolivia is one of the poorest countries which 40 percent of people living in extreme poverty. This makes it difficult for rural people to access proper water treatment methods. There is increased number of non-communicable diseases due to use of unsafe drinking water. The objective of this current research is to assess the quality of drinking water in rural communities of Bolivia. It also aims at assessing the effectiveness of the treatment measures of drinking water used in these rural communities. The study will identify the measures for improving access of safe drinking water in these rural communities ((Rufener et al., 2010).
The hypothesis of this current research is that drinking water from bottled water has high quality as compared to tap water because it has more health benefits associated with it. This is because there is pollution of water accessed from the source to the drinking cup. The waste water in urban areas is also thrown in water points which are relied upon by rural communities. The buckets used in carrying water from the source are rarely cleaned inside. Due to these challenges, rural communities suffer from preventable diseases which cost their lives.
Materials and methods
Materials used in this current study are Dasani bottled water, Fiji bottled water, Jiffy Juice, 4 in 1 test strip, 250 mL Beakers, Tap water and stopwatch. This current study selected the households from rural communities by use of random sampling method. Every fourth household was enrolled in the study. In the initial meeting with community groups, the purpose of study was explained to them.60 households were enrolled for the study and they all participated in the study. Water samples were taken from 120 water sources and also from their drinking vessels. 4 in 1 test strip was used to measure the quality of water. This test strip was used to measure the total chlorine, total hardness and total alkalinity. The PH was measured using Jiffy Juice. The PH key is used to determine the PH of the tap water, Fiji bottled water and the Dasani bottled water.
The sources of water in these rural communities were mostly from dug wells which had hand-pumps. There was also tapped and piped water systems. The household visited showed that 48 percent used plastic cups, 28 percent used cups made of metals and 16 percent used cups made of glass. 96 percent of the households washed their drinking cups. 80 percent of the households treated water using boiling method.
From the study, the quality of drinking water deteriorated gradually from the source points to the drinking cups. The 4 in 1 test strip showed that in the water points the PH of 8.5, total alkalinity of 50mg/l, and total chloride of 140mg/l. The rural people rarely access bottled water.
From the study, it is clear that rural communities do not access quality drinking water. The tests results from the water sources showed that the quality of water was poor. The quality continued to deteriorate up to the drinking cups. This is because the buckets and barrels used to carry water were not washed thoroughly. Although they treated water through boiling, the quality improved for a while and then it deteriorated again in the drinking cups. This showed that there was recontamination before drinking. This showed that quality of drinking water is higher in bottled water than in tap water.
The previous studies are in agreement with our study that the quality of drinking water deteriorates after collection and also to the point of drinking. Inadequate cleanliness of storage is the source of contamination of drinking water in the households. This problem is applicable to all households in rural communities in the world. The stains in the inner surface of the container are the cause of the contamination.
The findings of the study showed that many households used uncovered buckets for transportation of water from water source to home place. Some also stored water while uncovered and this caused contamination of water. The use of narrow-mouthed containers could prevent contamination of water during transportation and storage. Cleaning of the inner surface of the buckets and also cleaning drinking cups could also reduce contamination of water. Hygiene practices will ensure safe drinking water (Fewtrell et al., 2005).
Rufener, S., Mäusezahl, D., Mosler, H. J., &Weingartner, R. (2010). Quality of drinking-water at source and point-of-consumption—drinking cup as a high potential recontamination risk: a field study in Bolivia. Journal of health, population, and nutrition, 28(1), 34.
Fewtrell, L., Kaufmann, R. B., Kay, D., Enanoria, W., Haller, L., &Colford, J. M. (2005). Water, sanitation, and hygiene interventions to reduce diarrhoea in less developed countries: a systematic review and meta-analysis. The Lancet infectious diseases, 5(1), 42-52.
Strauss, B., King, W., Ley, A., &Hoey, J. R. (2001). A prospective study of rural drinking water quality and acute gastrointestinal illness. BMC Public Health, 1(1), 8.
Water Quality and Contamina on
Ground water contaminates
Drinking water quality
Figure 1: At any given moment, 97% of the planet’s water is in oceans. Only a small fraction of
the remaining freshwater is usable by humans, underscoring the importance of treating our wa-
ter supply with care.
It is no secret that water is one of the most valuable resources on Earth. Every plant and animal requires wa-
ter to survive, not only for drinking, but also for food production, shelter creation, and many other necessities.
Water has also played a major role in transforming the earth’s surface into the varied topography we see to-
While more than 70% of our planet is covered in water, only a small percentage of this water is usable fresh-
water. The other 99% of water is composed primarily of salt water, with a small percentage being composed
of glaciers. Due to the high costs involved in transforming salt water into freshwater, the earth’s population
survives off the less than 1% of freshwater available. Humans obtain freshwater from either surface water or
Surface water is the water that collects on the ground as a result of precipitation. The water that does not
evaporate back into the atmosphere or infiltrate into the ground is typically collected in rivers, lakes, reser-
voirs, and other bodies of water, making it easily accessible.
Groundwater, on the other hand, is located underneath the ground. This water is stored in pores, fractures,
and other spaces within the soil and rock underneath the surface. Precipitation, along with snowmelt, infil-
trates through the ground and accumulates in available underground spaces.
Aquifers are areas in which water collects in sand, gravel, or permeable rock from which it can be extracted
for usable freshwater. The depth of aquifers varies from less than 50 feet to over 1,500 feet below the sur-
face. The water within an aquifer typically does not flow through, as it would through a river or stream, but in-
stead soaks into the underground material, similar to a sponge. As aquifers are depleted by human use, they
are also recharged from precipitation seeping into the ground and restoring the water level. However, many
times the recharge of the aquifers does not equal the amount of water that has been extracted. If that cycle
continues, the aquifer will eventually dry up and will no longer be a viable source of groundwater.
Cloud forma on
Figure 2: Water is a renewable source, purified and
delivered across the planet by the hydrological cycle.
While the water that precipitates in the form of rain is relatively pure, it does not take long for it to pick up con-
taminants. There are natural, animal, and human-made sources of water pollutants. They can travel freely
from one location to another via streams, rivers, and even groundwater. Pollutants can also travel from land
or air into the water. Groundwater contamination most often occurs when human-made products, such as mo-
tor oil, gasoline, acidic chemicals, and other substances, leak into aquifers and other groundwater storage
areas. The most common source of contaminants come from leaking storage tanks, poorly maintained land-
fills, septic tanks, hazardous waste sites, and the common use of chemicals, such as pesticides and road
The dangers of consuming contaminated water are
high. Many deadly diseases, poisons, and toxins can
reside in contaminated water supplies, severely affect-
ing the health of those who drink the water. It is also
believed that an increased risk of cancer may result
from ingesting contaminated groundwater.
With the many contaminants that can infiltrate our wa-
ter supply, it is crucial that there be a thorough water
treatment plan in place to purify the water and make it
drinkable. While each municipality has its own water
treatment facility, the process is much the same at
The process begins with aeration, in which air is added
to the water to let trapped gases escape while increasing the amount of oxygen within the water. The next
step is called coagulation or flocculation, in which chemicals, such as filter alum, are added to the incoming
Water is the only substance
that is found naturally in
three forms: solid, liquid,
If the entire world’s supply
of water could fit into a one-
gallon jug, the fresh water
available to use would equal
less than one tablespoon
Approximately 66% of the
human body consists of wa-
ter – it exists within every
organ and is essential for its
Figure 3: Sedimentation tanks, such as those shown
above, are used to settle the sludge and remove oils
and fats in sewage. This step can remove a good por-
tion of the biological oxygen demand from the sew-
age, a key step before progressing with the treat-
ments and eventually releasing into the ground or
body of water.
water and then stirred vigorously in a powerful mixer. The alum causes
compounds, such as carbonates and hydroxides, to form tiny, sticky clumps
called floc that attract dirt and other small particles. When the sticky clumps
combine with the dirt, they become heavy and sink to the bottom. In the next
step, known as sedimentation, the heavy particles that sank to the bottom
during coagulation are separated out and the remaining water is sent on to
filtration. During filtration, the water passes through filters made of layers of
sand, charcoal, gravel and pebbles that help filter out the smaller particles
that have passed through until this point. The last step is called disinfection,
in which chlorine and/or other disinfectants are added to kill any bacteria
that may still be in the water. At this point, the water is stored until it is dis-
tributed through various pipes to city residents and businesses.
After the water goes through the treatment process, it must also pass the
guidelines stated in the Safe Drinking Water Act, in which various compo-
nents are tested to ensure that the quality of the water is sufficient for drink-
ing. There are currently over 65 contaminants that must be monitored and maintained on a regular basis to
keep local drinking water safe for the public. Some of these chemical regulations include lead, chromium,
selenium, and arsenic. Other components, such as smell, color, pH, and metals, are also monitored to ensure
residents are provided clean and safe drinking water.
Figure 4: Fresh water is essen-
tial to humans and other land-
based life. Contaminated water
must be treated before it can be
released into the water supply.
Bottled water is a billion dollar industry in the United States. Still, few people know the health benefits, if any,
that come from drinking bottled water as opposed to tap water. This experiment will look at the levels of vari-
ous different chemical compounds in both tap and bottled water to determine if there are health benefits in
drinking bottled water.
1. Before beginning, record your hypothesis in post-lab question 1 at the end of this procedure. Be sure to
indicate which water source you believe will be the dirtiest and which water source will be the cleanest.
2. Label three 250 mL beakers Tap Water, Dasani®, and Fiji®. Pour 100 mL of each type of water into the
3. Locate the ammonia test strips. Begin by placing a test strip into the Tap Water sample and vigorously
moving the strip up and down in the water for 30 seconds, making sure that the pads on the test strip are
Dasani® bottled water
Fiji® bottled water
Ammonia test strips
Chloride test strips
4 in 1 test strips
Phosphate test strips
Iron test strips
(3) 250 mL Beakers
(3) 100 mL Beakers
(1) 100 mL Graduated Cylinder
(3) Foil packets of reducing powder
*You must provide
4. Remove the test strip from the water and shake off the excess water.
5. Hold the test strip level with the pad side up for 30 seconds.
6. Read the results by turning the test strip so the pads are facing away from you. Compare the color of the
small pad to the color chart at the end of the lab. Record your results in Table 1.
7. Repeat the procedure for both Dasani® and Fiji|® bottled water. Record your results for both in Table 1.
8. Locate the chloride test strips. Begin by immersing all the reaction zones (“the pads”) of a test strip in the
Tap Water sample for 1 second.
9. Shake off the excess liquid from the test strip. After 1 minute, determine which color row the test strip
most noticeably coincides with on the color chart at the end of the lab. Record your results in Table 2.
10. Repeat the procedure for both Dasani® and Fiji® bottled water. Record your results for both in Table 2.
11. Locate the 4 in 1 test strips. Begin by dipping a test strip in the Tap Water for 5 seconds with a gentle
back and forth motion.
12. Remove the test strip from the water and shake once, briskly, to remove the excess water.
13. Wait 20 seconds and use the color chart at the end of this lab to match the test strip to the Total Alkalini-
ty, Total Chlorine, and Total Hardness on the color chart. Be sure to do all of the readings within seconds
of each other. Record your results in Table 3.
Note: You will not be using the pH reading obtained from the 4 in 1 test strips. The pH will be
determined at the end of this experiment using a different method.
14. Repeat the procedure for both Dasani® and Fiji® bottled water. Record your results for both in Table 3.
15. Locate the phosphate test strips. Begin by dipping a test strip into the Tap Water for 5 seconds.
16. Remove the test strip from the water and hold it horizontally with the pad side up for 45 seconds. Do not
shake the excess water from the test strip.
17. Compare the results on the pad of the test strip to the color chart at the end of this lab. Record your re-
sults in Table 4.
18. Repeat the procedure for both Dasani® and Fiji® bottled water. Record your results for both in Table 4.
19. Now, label the three 100 mL beakers Tap Water, Dasani®, and Fiji®. Use the 100 mL graduated cylinder
to measure 30 mL of the Tap Water from the 250 mL beaker. Pour the Tap Water into the 100 mL beaker.
Repeat these steps for the Dasani® and Fiji® bottled water.
20. Beginning with the Tap Water, open one foil packet of reducing powder and add it to the 100 mL beaker.
Cover the beaker with a piece of Parafilm® and shake the beaker vigorously for 15 seconds.
21. Locate the iron test strips. Remove the Parafilm® and dip the test pad of an iron test strip into the Tap Wa-
ter sample, rapidly moving it back and forth under the water for 5 seconds.
22. Remove the strip and shake the excess water off. After 10 seconds, compare the test pad to the color
chart at the end of this lab. If the color falls between two colors on the color chart, estimate your result.
Record your results in Table 5.
23. Repeat the procedure for both Dasani® and Fiji® bottled water. Record your results for both in Table 5.
24. Use your 100 mL graduated cylinder to measure and remove 45 mL of the Tap Water from the 250 mL
beaker. Discard this water. Your 250 mL beaker should now contain 25 mL of Tap Water. Repeat these
step with the Dasani® and Fiji® bottled water.
25. Use a pipette to add 5 mL of Jiffy Juice to the Tap Water. Mix gently with the pipette or by swirling the liq-
26. Compare the color of the Tap Water to the pH chart in the key. Record the pH in Table 6.
27. Repeat the procedure with both the Dasani® and Fiji® bottled water and record your results in Table 6
0 10 30 60 100 200 400
4-in-1 Test Strip:
*Note there are 4 pads on this test strip. From top to bottom (with the bottom of the strip being the handle),
the pads are: pH, Chlorine, Alkalinity, and Hardness. Remember that the pH is not to be measured using the
pH Chlor. Alk. Hard.
0 0.2 1.0 4.0 10.0
0 40 80 120 180 240 500
0 50 120 250 425 1000
Soft Hard Very Hard
Total Chlorine (mg/L)
Total Alkalinity (mg/L)
Total Hardness (mg/L)
0 0.15 0.3 0.6 1 2 5
0 10 25 50 100
Total Iron (ppm)
1-2 3 4 5 6 7 8 9 10 11-12