Studying Water Quality in a General Chemistry I Course

Abstract

Water quality is everyone’s concern. We all need water to live healthy lives. Between Flint, MI, and Jackson, MS, it’s important that citizens know how to assess their water quality from chemical and societal perspectives. This project introduces students to water quality, how our water is cleaned for drinking purposes, and how socio-economic influences impact water quality in the US. Students apply general chemistry I concepts to the water quality to understand how the Flint and Jackson Water Crises occurred, experimentally assess a water sample from their home, compare their results it to their local water quality report, draw conclusions based on their findings, and explore if what happened in Flint and Jackson could happen to them. Students conduct literature research as a part of this project and complete a final report on their findings and conclusions.

The slides for the presentation are available at the link below:

Studying Water Quality in a General Chemistry I Course Slides

Objectives

Below is a list of objectives covered while studying water quality in General Chemistry I. This project gives students a better understanding of how chemical concepts apply to real-world research.

I include all applicable objectives on all assignments in my courses to show students how our materials and assignments connect to the concepts they are learning. This demonstrates the value of each assignment and helps reduce the feeling of “busy work.”

  • Apply knowledge of scientific theories to problem-solving applications.
  • Develop a hypothesis for a scientific experiment.
  • Identify the control, independent, and dependent variables for an experiment.
  • Predict the next steps for a scientific study using data that has been collected.
  • Determine if a source is reliable.
  • Evaluate a source for bias.
  • Read primary scientific journal articles.
  • Determine if a data set is valid.
  • Predict products in chemical reactions.
  • Identify acid-base and redox reactions.
  • Write and balance chemical equations.
  • Calculate the concentration of a solution.
  • Predict if a precipitate will form in a reaction.
  • Write the net ionic equation for a reaction.
  • Determine the amount of a compound present in solution by using gravimetric or volumetric analysis.
  • Graphing and analyzing scientific data.
  • Explain sources of human impact on the environment related to a current environmental topic.
  • Suggest an alternative perspective that disputes, explains the issue, solution, or finding from at least two points of view.
  • Explain the implicit assumptions and subsequent decision-making options relative to the report specified in the outcomes referenced above.
  • Explain the process of water treatment.
  • Explain the chemistry behind the cause of the Flint Water Crisis.
  • Identify other instances of drinking water crises in the US.
  • Articulate cultural and socioeconomic impacts from chemical issues.
  • Apply chemical knowledge and scientific thinking to real-world problems.
  • Make predictions and draw conclusions using scientific evidence.
  • Communicating experimental findings in written and oral form.

Case Studies

The Scientific Method

I introduce the class to the concept of the scientific method in lab during the first week of class. Students are provided background information in the lab manual and textbook and participate in an interactive lecture applying these concepts. Once students are familiar with the basic process, the class completes a case study on research done on PCBs identified in the Alaskan Frontier. A link to this case study is provided below. PCBs in the Alaskan Frontier: A Case Study on the Scientific Method, an article about the case study, was also published by the Journal of College Science Teaching in October 2005.

Scientific Method Case StudyPCBs in the Alaskan Frontier (available through the NSTA Case Study Database. A subscription is necessary to access this database.)

Scientific Data, the Media, and Distinguishing Science From Pseudoscience

Other case studies can also be used to present information on reviewing scientific data, science and the media, and the difference between science and pseudoscience. I have not used either of these case studies in my classes, but they both apply to the concepts students learn in this research project. These case studies are available through the NSTA Case Study Database and are linked below:

Eating PCBs from Lake Ontario: A Clicker Case on Science and the Media Case Study

Is the Data Dirty of Clean? The Role of Experimental Design in Human Health Studies Case Study

The lesson I use to address this topic is provided on the Literature Research tab of this post.

The Flint Water Crisis

After students have learned about completing and balancing chemical equations, redox and acid/base reactions, and net ionic equations, I complete The Flint Water Crisis Case study with my students. This case study introduces students to the history and causes of the Flint Water Crisis and applies the chemical reaction concepts they learned in lecture. I have heavily revised this case study to discuss updates in the Flint situation and the water crisis in Jackson, Mississippi. A link to the original case study published in the NSTA Case Study Database is linked below:

The Flint Water Crisis Case Study

Before the Flint Water Crisis Case Study, students are asked to read the article and watch the two videos linked below. They then use this information to complete a short assignment to assess their basic understanding of the information discussed, review EPA allowable lead levels in drinking water, review census information on the population of Flint, and calculate the cost of buying bottled water for a family of 4. The article I provide to students and both videos are linked below:

How Lead Ended Up in Flint’s Tap Water article from C&EN.

The NSTA Case Study Database also contains a second case study on lead contamination in D.C. that can also be used; however, the Flint case study provides a more recent incident, a set of PowerPoint slides to build from, and a set of chemical reactions that align perfectly General Chemistry I concepts.  The link to this case study is provided below:

What’s in Your Water? Case Study

References

Flowers, P., Neth, E. J., Robinson, W. R., Theopold, K., & Langley, R. (2019). Writing and Balancing Chemical Equations. In Chemistry 2e. OpenStax. https://openstax.org/books/chemistry-2e/pages/4-1-writing-and-balancing-chemical-equations

Flowers, P., Neth, E. J., Robinson, W. R., Theopold, K., & Langley, R. (2019). Classifying Chemical Reactions. In Chemistry 2e. OpenStax. https://openstax.org/books/chemistry-2e/pages/4-2-classifying-chemical-reactions

Gay, G. (2019). Culturally responsive teaching: Theory, research, and practice (3rd ed.). Teachers College Press.

How Lead Ended Up In Flint’s Water. (2016). C&EN Global Enterprise, 94(7), 26–29. https://doi.org/10.1021/cen-09407-scitech1

Reactions. (2016). Chemistry and the Flint Water Crisis – Speaking of Chemistry [Video file]. Retrieved from https://www.youtube.com/watch?v=k18vbGwPxz4

Sci Show. (2018). The Science of Flint’s Water Crisis [Video file]. Retrieved from https://www.youtube.com/watch?v=BAIXmt58iBU&t=2s

Terry, T. (2017). The Flint Water Crisis [Case Study]. Retrieved from

https://sciencecases.lib.buffalo.edu/collection/detail.html?case_id=952&id=952

Literature Review

Students learn how to read scientific literature, evaluate resources to determine if they are reliable, and conduct their own research. Students then complete several discussion boards to apply what they have learned to find sources for their final project. They share their resource with the class so everyone can benefit from each other’s work.

Conducting Literature Research and Determining if a Source is Reliable

Early in the semester. Students complete an assignment on Reliable Sources and How to Read a Scientific Article. They are also introduced to several resources for journals, including:

Students are also provided resources to help them properly cite their sources.

At the end of the lesson, students complete an assignment regarding PFAS in rainwater. They are provided a copy of Outside the Safe Operating Space of a New Planetary Boundary for Per- and Polyfluoroalkyl Substances (PFAS) published in Environmental Science Technology. This article is included in the reference list provided below.

Discussion Boards

Students complete two discussion board assignments during the semester on water quality. In each discussion board, students find a resource on water quality, summarize it, evaluate it for validity, reliability, and bias, and then share their item with the class via a link or document upload.

There are 3 goals to these discussion boards:

  1. Students conduct research using primary scientific literature.
  2. Students evaluate their sources for validity, reliability, and bias.
  3. Students summarize and share their resources with other students.

The first two goals were introduced previously in the class. These discussion boards provide students an opportunity to practice these skills and receive feedback. The third goal allows students to assist each other with the literature research. In graduate school, my colleagues provided me with several research articles that aided my research. I apply the same idea here. Scientists don’t work in a bubble, so science class students shouldn’t either. Collaboration is encouraged but not required.

All discussion boards are set so students must post before seeing what their classmates have shared. Once the due date has passed, the discussion board is opened so all students can access the posts and articles shared whether they completed the assignment or not.

Below, I have shared a screenshot of each discussion board introduction outlining the assignment requirements. Students are also provided a link to the rubric used to grade their discussion board.

Discussion Board #1 – Water Quality

Students can post any resource they find regarding drinking water contamination identified in the U.S.

The image below provides the directions given to students for this assignment.

Discussion Board #2 – Flint Water Crisis

Students can post any resource they find regarding updates to the Flint Water Crisis.

The image below provides the directions given to students for this assignment.


References

Cousins, I.T , Johansson, H.A. , Salter, M.E. , Sha, B., and Scheringer, M. (2022). Outside the Safe Operating Space of a New Planetary Boundary for Per- and Polyfluoroalkyl Substances (PFAS). Environmental Science & Technology, 56 (16), 11172-11179 DOI: 10.1021/acs.est.2c02765

Laboratory Research

In the introduction to the lab, students are provided links to EPA impacts from drinking contaminated water, the National Defense Council (NRDC) information on water pollution, including its effects on human health and the environment, and the United States Geological Society (USGS)  information on wastewater treatment use. Students must also review the EPA website regarding Water Quality Standards: Regulations and Resources. I also provide tables outlining the EPAs’s maximum contaminant levels for chlorine, copper, and arsenic drinking water and a second table outlining secondary drinking water standards for chlorine, color, copper, iron, order, ph, and total dissolved solids. Maximum Contamination Levels and Secondary Drinking Water Standards work together to ensure safe drinking water tastes good. Students are instructed to use these values when assessing their water sample results.

Students are provided a clean, unused, plastic 500mL sample bottle to collect a water sample from their home. Students are instructed to follow the EPA Quick Guide To Drinking Water sampling for unpreserved classical chemistry constituents. The sampling instructions provided to students are outlined below:

Water Sampling Instructions

Allow the faucet to run for 2-3 minutes. Rinse the bottle and cap three times with sample water and fill the bottle to within one to two inches from the top.

Students are also instructed to write the time, date, and sample location on the side of their bottle in Sharpe.

Prelab Assignment

Before coming to the lab, students watch a video outlining how City Water Purification works (provided below) and complete a prelab assignment testing their understanding of water quality and treatment and calculate the cost of obtaining drinking water from the tap and when using a Brita Filter. To complete these questions, students need to access and calculate the cost of drinking water from their municipal supplier. These last questions are designed to guide students in understanding how affordable drinking water is from municipal suppliers and the additional financial burden placed on families when the drinking water isn’t safe.

Experimental Procedure

At the start of the lab, students conduct a taste, smell, and appearance test on their sample and record their results. Students then analyze their samples for the following:

  • Total Dissolved Solids (TDS)
  • Chlorine (total and free)
  • Iron
  • Hardness
  • Arsenic
  • pH
  • Temperature
  • Conductivity
  • Copper (total and free)

Experimental Supplies

Below is a list of the equipment used to test the water samples:

HACH Total Hardness and Iron Test Kit

HACH Copper, Free and Total Test Kit

HACH Free and Total Chlorine

HACH Arsenic Test Kit

pH probe (Vernier)

Total Dissolved Solids Meter (I use a COM-100 probe that measured TDS, temperature, and conductivity, available from Amazon).

Students use the directions from the HACH kits to complete the tests.

Above – HACH kits used in this lab.

Below – COM-100 sensor

Student collect all of their data on data tables and use this information to complete a written lab report.

References

Denchak, Melissa. (2022). Water Pollution: Everything You Need to Know. National Resources Defense Council. https://www.nrdc.org/stories/water-pollution-everything-you-need-know

EPA. (2016). Quick Guide to Drinking Water Sample Collection, Second Edition. https://www.epa.gov/sites/default/files/2015-11/documents/drinking_water_sample_collection.pdf

EPA. (2017). Secondary Drinking Water Standards: Guidance for Nuisance Chemicals.  Environmental Protection Agency. www.epa.gov/dwstandardsregulations/secondary-drinking-water-standards-guidance-nuisance-chemicals.

EPA. (2018). National Primary Drinking Water Regulations. Environmental Protection Agency. www.epa.gov/ground-water-and-drinking-water/national-primary-drinking-water-regulations

EPA. (2021). Drinking Water. Environmental Protection Agency. https://www.epa.gov/report-environment/drinking-water

EPA (2022). Drinking Water Mapping Application to Protect Source Waters (DWMAPS). Environmental Protection Agency. https://geopub.epa.gov/dwwidgetapp/Katz, David. “Testing the Waters.” Chymist.com, 2009, www.chymist.com/testing%20the%20waters.pdf

O’Neal, Jacob. (2021). How City Water Purification Works: Drinking and Wastewater [Video]. Animagraffs. https://youtu.be/KsVfshmK0Ak.

Water Science School. (2018). Wastewater Treatment Waster Use. United States Geological Society. https://www.usgs.gov/special-topics/water-science-school/science/wastewater-treatment-water-use#overview.

Scientific Writing

After the water quality experiment, students report on their findings. Below is the format students follow when writing their report. This is provided to students, along with a rubric for the assignment.

Title Page

A separate and single page that provides the following information:

  • The title of the experiment.

The title says what you did. It should be brief (aim for ten words or less) and describe the main point of the experiment or investigation. An example of a title is “Effects of Ultraviolet Light on Borax Crystal Growth Rate”. If you can, begin your title using a keyword rather than an article like ‘The’ or ‘A’.

  • Your name
  • The date the report was submitted.
  • Please do not use any designs/graphs on your cover page. Only the information listed in a through c should be provided.

Introduction

The introduction explains the concept discussed in the lab.  It should introduce the reader to the chemical concepts being applied in the laboratory.  In other words, if the lab is about chemical changes, then the introduction should contain information about what a chemical change is and how to recognize one.

The introduction should also include a sentence stating the hypothesis (what you expected to happen during the experiment). In the introduction, you also want to outline any applicable EPA drinking water standards and the data from your local drinking water provider. You can do this using a data table. You will compare your results and your water quality report to the EPA standards.

The introduction needs to be in your own words.  Do not copy the introduction from the experimental procedure and paste it into your report.  If you do this, you will receive a zero for the report.

Experimental Procedure

List the equipment used and describe the steps you completed during your investigation. Write it as if you were giving directions for someone else to do the lab, and be detailed enough that anyone could read this section and duplicate your experiment.  You may copy the experimental procedure directly from your laboratory manual if you would like, but all other sections of your report must be in your own words.

This section must be formatted the same as all of the other sections of your report.  Do not scan or otherwise copy the results section and paste it into the report unless it can be formatted the same as the rest of the report.

Results Section

This section should include the numerical data obtained from your procedure, which can be presented as a table.  Data encompasses what you recorded when you conducted the experiment.  It’s just the facts, not any interpretation of what they mean.  Your tables should be

  • Be neatly organized, with all rows and columns appropriately labeled.
  • Have a title and be numbered. For instance, the first table in your report should be numbered “Table 1,” etc.
  • Briefly summarized in your report. DO NOT just provide a data table with your results.  You also need to briefly talk about what your results were.
  • Include information regarding the date and time your water sample was collected and what faucet it was taken from.

If you completed a table during the laboratory activity to document the data collected, this table must be included in the report.  Be sure to title all tables and organize it (complete with labeling any columns or rows) to ensure the data can be easily read and understood.  All tables should be formatted as described at the beginning of this document (Tahoma or Times New Roman 10pt).  Tables must be inserted into your lab report in the appropriate section.

DO NOT INCLUDE A PHOTOGRAPH OF YOUR TABLE FROM THE EXPERIMENTAL PROCEDURE IN YOUR REPORT. These tables should be produced using a word processing program such as MSWord or Excel.

Discussion Section

This section discusses what your results mean and how they tie back to the chemical concept being discussed in the experiment.

  • Compare your results and those obtained from your water quality report to the EPA standards for drinking water and determine if the water is safe to drink.
  • Specifically state if the data collected is valid. Support your answer with evidence from the experiment/results.
  • Research your local water provider. Did you find any evidence of violations or issues with your water provider in the past 5 years? If so, please provide information. If you didn’t identify any issues, state this.
  • Identify sources of error for the experiment (i.e. mistakes you might have made while conducting the investigation or why the experiment didn’t work and what you could have done to improve the outcome.)
  • Discuss if you use any water treatment filters or use a water softener in your home. If you do, this will impact your results and should be noted.
  • Statement that hypothesis was accepted/rejected and why.

Conclusions

The conclusion is a single paragraph summarizing what happened in the experiment, whether your hypothesis was accepted or rejected, and what this means.  This should act as a summary statement for your report.

References

If your research was based on someone else’s work or if you cited facts that require documentation, then you should list these references.  The lab manual should ALWAYS appear in the references section and any other references used to write the report.

Cite the water quality report you obtained from your water provider. If the report was accessed online, be sure to include a link to the report. If it is not accessible online, please upload a copy of it with your lab report.

Cite the EPA water quality guidelines.

NOTE:  If references have not been properly cited, this will be considered plagiarism and can result in a zero for the assignment.

You are expected to properly cite your sources in APA format. Information on how to cite sources in this format and additional information regarding plagiarism can be found at the Purdue Online Writing Lab (OWL) website.

Final Project

By the time the students get to their final project, they have had ample time for feedback from previous assignments. They should also have almost all the necessary information to complete this assignment. This should be a matter of organizing their data into a presentation and filling in the gaps.

Students can complete the final project as a blog or vlog. This allows students to work from their strengths (writing or speaking). It also allows students creative flexibility.

The final project has three components:

Part 1: Flint Water Crisis Summary

Students need to outline the cause of the Flint Water Crisis and explain the chemistry behind this issue. They also need to conduct demographic research for Flint using US Census data. Students need to discuss the impact on human health and any economic hardships suffered by the residents of Flint, provide an update on what has happened in Flint since 2016, research other historical issues regarding water quality in the US and summarize their findings, and state their informed opinion on the Flint Water Crisis by answering the following questions:

  • Do you think the racial, cultural, and economic demographics of Flint played a role in the time it took to address this issue?
  • Do you think this issue has been adequately addressed?

Part 2: Assessing Water Quality at Your Home

Students summarize the data they collected on the drinking water at their home. They summarize their results and compare them to the water quality report they obtained from their municipal supplier and EPA standards. Student also conduct demographic research for their community using Census Data. Students are then asked if they have concerns that what happened in Flint will happen where they live. They must support their opinion with what they have learned from their research.

Part 3: Citing and Assessing Sources

Students need to cite at least seven sources for this project using either MLA or APA format. None of these sources can be Wikipedia. Their sources need to include at least one primary journal article source and one other non-internet source (i.e. newspaper, secondary source in a scientific publication, etc). This prevents students from relying solely on websites for their information. Students then need to analyze each of their sources using the following guidelines:

  • Analyze each source’s underlying assumptions or bias on the part of the source. If bias is found, suggest an alternative perspective that disputes it or explain the issue, solutions, or findings from at least two points of view.  If no bias was identified, then state this.
  • Explain any areas of uncertainty (questions that were raised) identified in the research. If no areas of uncertainty were raised, then state this.
  • Is this sources reliable? Explain the reasoning using the information discussed earlier in this course regarding identifying reliable sources.

This information should be summarized below the citation for each source.

Students submit a link to their vlog/blog for Parts 1 and 2 and a separate MSWord (or similar) document for Part 3.

Students are also provided the rubric used to assess their submission.

Future Directions

This project is under regular revision. Below are a list of future directions for this research:

Student Portfolio

The students will create a portfolio of their work using EduBlogs, a free educational blog site. This allows students to take their work with them after the class is complete.

Reflective Writing Assignments

Create a few reflective writing assignments throughout the semester to help students process what they are learning during their research and consider additional socioeconomic and racial considerations.

One of these writing assignments is a reflection on the following Tedx Talk. A second will be the financial impact of purchasing bottled water for a family rather than drinking the water provided by the municipality.

Expand the Water Quality Lab

Include an analysis for lead and other ions in the water quality lab.

Expand Applicable Labs

Expand/update labs, such as titration and gravimetric analysis labs, to simulate water quality applications. This will better demonstrate how these processes are used in water quality analysis.

Evaluation of Water Infrastructure

Students will determine the age of their home, conduct a visual inspection of their home for lead pipes, and research when the service pipes in their neighborhood were last replaced to determine if the pipes contain lead.

References

TED. (2020, January 14). Why lakes and rivers should have the same rights as humans. [Video]. YouTube. https://youtu.be/opdCfb8cCFw?si=kJXbu1pAqcaPkr2F

This webpage was designed to supplement a presentation given at the National Science Teacher Association Conference in Kansas City, MO on October 2023.

The information here will be updated as I develop this curriculum for my general chemistry I course. Please check back periodically for updates.

This blog is also listed on my Projects page for easy access.

Originally posted: October 27, 2023

Last Updated: October 27, 2023

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