Human Dimensions of Drinking Water Quality

Transcription

1 Human Dimensions of Drinking Water Quality Developed by Sarah Kiger National Science Foundation Graduate STEM Fellow in K-12 Education Sugar Creek Watershed K-12 Education Program The Ohio State University-Ohio Agricultural Research and Development Center Overview This module contains lessons on water quality and how water pollution can affect humans as well as how humans can create solutions for water pollution problems. These lessons explore water quality from natural and social science perspectives to help students discover methods on how to test for drinking water quality, which human activities contributes to water pollution, and how policy, government, and citizen cooperation can help to alleviate water pollution. All of these lessons can be done in the classroom. While access to a stream or pond source may be useful to help further student engagement, they are not necessary to for this module. Time Frame (based on 40 minute class periods): Day 1: What is Drinking Water Quality (Computer Lab) Day 2-3: Testing for Drinking Water Quality (Science Lab) Day 4 5: Sugar Creek Watershed Case Study (Classroom and Computer Lab) Benchmark and Academic Content Standards for OH (ones that apply to the overarching theme): - Grade 9: Scientific Ways of Knowing: A.1 Comprehend that many scientific investigations require the contributions of women and men from different disciplines in and out of science. These people study different topics, use different techniques and have different standards of evidence but share a common purpose to better understand a portion of our universe. - Grade 11: Earth and Space Scientists: C.13 Explain how human behavior affects the basic processes of natural ecosystems and the quality of the atmosphere, hydrosphere and lithosphere. - Grade 11: Life Sciences: F.11 Investigate issues of environmental quality at local, regional, national and global levels such as population growth, resource use, population distribution, over-consumption, the capacity of technology to solve problems, poverty, the role of economics, politics and different ways humans view the earth. 1

2 - What is Drinking Water Quality? Purpose This lesson will introduce students to two important contaminants in drinking water: nitrate and e. coli. It will also allow them to learn more about the role government and the EPA play in regulating aspects of environmental quality. Finally, the lesson will help them become aware of ways to access information on national and local drinking water quality and inform them of any current drinking water quality problems in their community. Time Frame Students should be able to finish the handout in 1 class period. You may wish to spend part of another class discussing the findings, especially if any interesting local information is found. Objectives 1. To understand the sources or nitrate and e. coli 2. To understand what National Primary Drinking Water Regulations are and what the Maximum Contaminant level of nitrate and e. coli are. 3. To understand the potential health factors if levels are above the MCL. 4. To understand what role the government and EPA plays in drinking water regulation. 5. To understand the difference in regulation between public and private drinking water sources 6. To learn more about local drinking water problems Benchmark and Academic Content Standards for OH: - Grade 10: Earth and Space Sciences: D.5 Explain how the acquisition and use of resources, urban growth and waste disposal can accelerate natural change and impact the quality of life. - Grade 10: Life Sciences: G.10 Illustrate how uses of resources at local, state, regional, national, and global levels have affected the quality of life (e.g., energy production and sustainable vs. nonsustainable agriculture). Instructions for Teacher: Explain to the class that they will be going to the computer lab to look up information on drinking water quality. They will receive a handout with directions on it and they need to follow those and answer the questions. Some things you may want to discuss before having them start this is make sure they know what the EPA is and how it relates to the government and policy. Emphasize that many of the rules the EPA regulates are passed by Congress and that many of the top jobs are political appointments so the organization is government affiliated. Students should be able to work fairly independently. If you have time you can go over the sheet at the end of class or wait until the next period to discuss the results as a class. 2

3 Name: What is Drinking Water Quality? EPA regulations and drinking water contaminants Go to the EPA s ground water and drinking water website: Click drinking water and health basics from the column on the left. Click What contaminants may be found in drinking water in the blue table of contents box. You will navigate through the for more information links and links from the blue box to answer the following questions. Click on the link a list of drinking water contaminants the EPA regulates. 1. What are NPDWRs? 2. What is the difference between MCL and MCLG? 3. Scroll down and find Nitrate a. What is its maximum containment level? b. What are the potential health factors of ingestion? c. What is the main source of the contamination? 4. Scroll to Total Coliform and click on the link a. What is the source of E. coli? b. Are all strains of E. coli harmful? If no, which one(s) is/are? c. How is public drinking water treated for E. coli? d. If you water was contaminated with E. coli what could you do to protect yourself? 3

4 Go back to the original page What contaminants may be found in drinking water 5. Click on Who is responsible for drinking water quality? a. What did the Safe Drinking Water act do? b. When did it begin? c. How many contaminants have safety standards? 6. Click on the for more information link: EPA s local drinking water information web site and then click on Ohio. Scroll down and click on Ohio s drinking water program under State drinking water offices. Click on water advisories near the top and click on Wayne County. a. How many sites currently have drinking water advisories? b. What contaminants are these advisories for? c. What is the major source of lead contamination? d. What is the major source of arsenic contamination? 7. Go to the link Click on Water Department. Click on Current Water Quality Reports and then click on 2007 Water Quality Report. a. Is the city in violation of any of the contaminants? If yes which one(s). b. What was the level of nitrate found? What is the MCL? Is this level in violation? c. Where does Orrville s drinking water come from? 4

5 Testing Drinking Water Quality Purpose: To familiarize students with some of the pollutants in their water and to encourage awareness about what drinking water contains. Students will test their water for nitrate, nitrite, hardness and ph. This lab is more about awareness and encouraging students to question what pollutants their drinking water might contain than to get specific measures of water quality. Time Frame of Water Testing: 1 class period Objectives 1. Familiarize students with drinking water pollutants 2. Explain to students that in most cases water hardness isn t toxic to humans, just inconvenient. 3. Test for ph, nitrate, nitrite, and water hardness 4. Understand that pollutants are measured in ppm (parts per million) and what that means 5. Understand what levels are safe for drinking 6. Understand how public and private water will vary. Materials Needed: Water samples for each student 5 in 1 Water Quality Test Strips (you can find this at pet or aquarium stores, make sure they include nitrate, nitrite, ph, and hardness) Reference strips or sheet to compare the color strip results Benchmark and Academic Content Standards for OH: - Grade 9: Physical Sciences B.8 Demonstrate that the ph scale (0-14) is used to measure acidity and classify substances or solutions as acidic, basic, or neutral. - Grade 11: Scientific Inquiry A.1 Formulate testable hypotheses. Develop and explain the appropriate procedures, controls and variables in scientific experimentation - Grade 12: Scientific Inquiry A.1 Formulate testable hypotheses. Develop and explain the appropriate procedures, controls and variables in scientific experimentation. Instructions for Teacher At the end of class the day before you want to test the water, give students containers with lids to collect a drinking water sample from their house. You want them to collect around 50 ml. Have them bring back the samples the next day. There are many ways to go about testing drinking water in the classroom. This lesson includes one possible ways. This method gives more general results (low medium high) but tests for more categories than more specific tests. On the day of testing, pass out the handout and first go over how ppm works and give examples with fractions. Then go through the information on what the class will be testing for. After you have explained the directions, let students work in groups but still test their own samples. Working in a group is important so that they can compare their samples and also get feedback 5

6 when trying to determine the color/level of contamination. After students have finished, go around the room and have each group share the answer to 1 question that was asked. Discuss how public and private water differed in quality and have them suggest reasons why. 6

7 Name: Water Quality Testing Lab Today we will be testing the quality of tap water from your homes. We will be testing for nitrates, nitrites, hardness, and ph. Measurements We will measure ph in a similar way as we did earlier this year. We will measure nitrates, nitrites, and hardness by parts per million (ppm). Parts per million is a way of expressing how much of a substance is in a sample when it is only found in small amounts. It is similar to saying per cent, but per cent means out of 100 and parts per million means out of 1,000,000. For example: 1 1% = 1 out of 100 = ppm = 1 out of 1,000,000 = 1,000,000 1 ppm also equals 1 milligram of something per liter of water (mg/l). So, usually we use ppm when we are describing things that occur in very small amounts. It is important to remember that just because things occur in small amounts doesn t mean they still aren t harmful or important to consider. Here is some information to read on what we will be testing. Water Hardness: Hard tap water is common when the source is a well. This is because as water moves through soil and rock, it dissolves very small amounts of minerals and holds them in solution. Calcium and magnesium dissolved in water are the two most common minerals that make water hard. Hard water is not a health hazard. In fact, research has shown that hard drinking water can contribute a small amount toward total calcium and magnesium human dietary needs. In some instances, where dissolved calcium and magnesium are very high, water could be a major contributor of calcium and magnesium to the diet. Nitrates (NO3-) and Nitrites (NO2-): Nitrogen is essential for all living things as it is a component of protein. Nitrogen exists in the environment in many forms and changes forms as it moves through the nitrogen cycle. However, excessive concentrations of nitrate-nitrogen or nitrite-nitrogen in drinking water can be hazardous to health, especially for infants and pregnant women. Nitrates can be found in well water as well as treated water. Sources of nitrate include fertilizers, septic systems, industrial waste, and food processing waste. The EPA has set drinking water standards of 45 ppm for nitrates and 1 ppm for nitrites. ph: ph is not as important of an indicator for water quality as the other tests. A ph below 7.0 indicates an acidic solution and a ph above 7.0 indicates a basic solution. The EPA states that ph in drinking water should be from

8 Pre Lab Question Based on what you have read about the different things we will be testing, hypothesize what you think your results will show about your water and why? Directions: For nitrates, nitrites, and hardness 1. Dip strip into the sample to be checked and remove immediately. Be sure to dip all 5 pads into the water. Do not shake excess from the strip. 2. Hold the strip level and at 30 seconds and record a description of the color you observe for hardness (the 3 rd pad down) and nitrite (the 2 nd pad down) on your data sheet. 3. At 60 seconds compare nitrate (1 st pad). 4. Compare the colors you observe to the color chart and record on your data sheet. For ph 1. Take the yellow strip of paper and dip one end in your sample. Make sure to not touch the end of the strip you are putting into the water. 2. Hold the strip level for 30 seconds and record a description of the color you observe on your data sheet. 3. Compare the colors you observe to the color chart and record on your data sheet. 8

9 Sample Name Source (well water, city/treated water if known, city or township) Nitrate ppm Nitrite ppm Total Hardness ppm ph 9

10 Name: Questions on worksheet 1. Write 50ppm as a fraction. 2. Can hard water be beneficial? How? 3. What are 2 sources of nitrate? 4. Is 75ppm a harmful level of nitrate Questions on the lab Use this chart to help you determine levels of nitrate, nitrite, hardness, and ph based on the color you observed. Safe indicates that the water is safe to drink. Nitrate (NO3) None (safe) low (safe) moderate high Clear/white light pink pink bright, dark pink Nitrite (NO2) None (safe) low (safe) moderate high Clear/white beige-pink light pink pink Hardness None (very soft) low (very soft) moderate high (very hard) green greenish brown brown rusty red 10

11 ph orange red-orange red-pink 1. Look back at your hypothesis, was it correct or not? Why? 2. Who in your group had the highest nitrate level? What was the level? Is this water safe for drinking? What was the source? 3. Who in your group with a sample from a house had the highest level of hardness? Was the sample from well water? What was the color? What was the level? 4. What was the lowest ph in your group? Give the color and level. 5. What was the highest ph in your group? Give the color and level. 6. Why is important to test water quality? 7. Hypothesize if you think there is a difference between public and private water and if yes, what kind of difference. 8. Based off the class results was your hypothesis correct or not? 11

12 Sugar Creek Watershed Case Study Purpose: This lesson allows students to learn about a real-life pollution issue within their watershed. Using this example, they will role-play as members of society who are directly affected by the water pollution problem. Students will use the PrOACT method to first understand the problem their watershed is facing. Then, while in their roles they will come up with best-case solutions, share them with the class, and then work together with the other students to come up with a compromise that benefits as many as possible. This lesson helps students understand that eliminating pollution can sometimes be costly and not economically feasible and solutions need to be found that can help the environment without denying the polluters the ability to produce goods or provide services. Time Frame: 2-3 class periods depending on the interest of students and discussion generated Objectives: 1. Learn more about the school s watershed (Sugar Creek Watershed) 2. Use of the PrOACT model of decision making to evaluate the issue of land use and pollution in the watershed 3. Apply knowledge learned in other water quality lessons (in and outside of this module) to address the issue 4. Independently find information (mainly on internet) to support proposed objectives and solution Benchmark and Academic Content Standards for OH: - Grade 9: Science and Technology: A.2 Identify a problem or need, propose designs and choose among alternative solutions for the problem - Grade 10: Earth and Space Sciences: D.5 Explain how the acquisition and use of resources, urban growth and waste disposal can accelerate natural change and impact the quality of life. - Grade 10: Life Sciences: G.18 Describe ways that human activities can deliberately or inadvertently alter the equilibrium in ecosystems. Explain how changes in technology/biotechnology can cause significant changes, either positive or negative, in environmental quality and carrying capacity. - Grade 10: Scientific Inquiry: A.4 Draw conclusions from inquiries based on scientific knowledge and principles, the use of logic and evidence (data) from investigations. - Grade 11: Scientific Inquiry: A.3 Design and carry out scientific inquiry (investigation), communicate and critique results through peer review. Instructions for Teacher: While a social science based case study may seem out of place in a science classroom, understanding methods for controlling environmental pollution often fall outside of the scientific realm. In many cases, scientists identify areas or sources of environmental pollution, but it takes the role of legislation, regulation and community awareness to actually put an end to the polluting practices. By having your students examine potential solutions to a specific environmental problem in their watershed they will better understand roles that different members of society will take when they want to benefit the most. By emphasizing the need to 12

13 come to a conclusion that most people can agree on (it is likely that no one will get exactly what they want) students learn how difficult it is to create policy or regulation and that it almost always requires some cost to get the environmental benefits. In this lesson the students will use the PrOACT method which was developed by Hammond, Keeney, and Raiffa (1998) their book Smart Choices: A Practical Guide to Making Better Decisions. Information on how this method can be applied to environmental scenarios can be found at the Ohio Sea Grant Education site An explanation of the PrOACT method can be found in the handout section. For more information on the Alpine Cheese Water Quality Trading Project, the environmental case study presented please see the following sources: Presentation by one of the program creatorshttp:// %20Alpine_ETN_8_24_06_Moore.pdf Plan write-up for the EPA pdf General info with great links Prior to class, highlight or circle one role on each sheet. This is the role the student with that sheet will be assigned to. At some points in the lesson students will have the option to work with their group. Start out the class by going over the introduction, scenario, and PrOACT method with the class. As a class, create a problem statement based on the scenario presented, make sure to emphasize that installing technology is not an option. Have the students read over their role and make sure they understand it. Once the students know their role, they can go to the computer lab to look up more information that they think will aid in creating their objectives and have them fill out the objectives sheet alone and then with their group. Reconvene as a class and have each group present their objectives, each objective should have the goal of benefiting the creator most. Now alternatives must be created, the goal of the alternatives is to try and fulfill some of the objectives. Have the students come up with some alternatives on their own but also have back up alternative available. One backup alternative should be the water quality trading program. Once the 4 alternatives have been discussed, ask students to answer the alternative questions and as a class try to agree on one alternative which is the best. Based on that alternative picked, have the class identify some of the consequences (positive or negative) based on the decision. You can have the class work on these alone or just have a group discussion about them. The same goes for the Tradeoff section, you can have students individually take time to write in answers or just work as a class (while the students still are playing their role). I think it is more fun to have it discussion/debate style with the students in the role. Write the results for the consequences and trade-offs on a board or overhead so the students can see them. If the students are satisfied with the first alternative they picked than the activity can end there. If they think, after further inspection, that there may be another alternative repeat the consequences and tradeoff section until they can agree on a solution. Even if students didn t pick the water quality trading program as the optimal solution, it is still beneficial to show to them 13

14 what decision was made in reality (to reiterate the point that these types of decisions are being made. 14

15 Name: Sugar Creek Watershed Case Study Introduction: When it rains, do you ever wonder where all the water running off your roof and driveway goes? Usually it runs down the street into a storm sewer or pipe, or maybe a ditch by the road. But where does all this rainwater eventually go? Some rain water soaks into the soil to become groundwater and slowly replenish streams and lakes. The remaining water can take many paths, but it usually ends up in a nearby stream, wetland, river, or lake. A watershed is all of the land that intercepts and drains precipitation through a particular river system or group of river systems. In other words, it is a region of interconnected rivers and streams which functions as a unified system for water transport. Watersheds can be as small as a wetland, stream, or river. A large watershed may be made up of many numerous smaller watersheds. For example, the Sugar Creek is a part of the Sugar Creek Watershed, which is a part of greater watersheds: Tuscarawas then Muskingum, then Ohio River, then the Mississippi watershed. Watersheds come in all shapes and sizes. They can cross county, state, and national boundaries. No matter where you are, you're in a watershed. In this exercise, we are going to work on making a decision for an area of great concern the Sugar Creek Watershed where your school is located and possibly your home as well. Specifically, we will act as citizens, farmers, and employees in Holmes County, Ohio and make a decision on water quality that will impact the Sugar Creek watershed and consequently the rest of the watersheds Sugar Creek contributes to. Through this investigation you should keep the following two activity objectives in mind: 1. Use the PrOACT model of decision making to evaluate the issue of land use in your watershed. 2. Apply the knowledge you have learned about water quality in the stream by your school to address this issue. The Scenario: In 2000 the Ohio Environmental Protection Agency (EPA) labeled the Sugar Creek Watershed the second most impaired watershed in Ohio. The following scenario has come about in an effort by many watershed stakeholders to improve water quality and their watershed s status. As authorized by the Clean Water Act, the National Pollutant Discharge Elimination System (NPDES) permit program controls water pollution by regulating point sources that discharge pollutants into waters of the US. Industrial, municipal, and other facilities must obtain permits if their discharges go directly into surfaces waters. The Alpine Cheese Company in the Sugar Creek Watershed is required to have such a permit and as it stands, their goal for phosphorous levels is 1ppm. Currently, however, the plant has phosphorous levels of 225ppm. Getting down to 3ppm is expensive but the plant decides they can economically do it. However, putting in technology to get from 3ppm to 1ppm will cost the plant the same amount as going from 225ppm 15

16 to 3ppm and is deemed to not be economically feasible. The cheese factory wants to find a solution to get from 3ppm to 1ppm that involves the local community but costs them less than installing the new expensive technology. The PrOACT model of decision making You will be using a structured method of decision making. This method of decision making, abbreviated "PrOACT" follows these steps: 1. Define the Problem. What is the problem we are trying to solve? 2. Identify the Objectives. What are the goals? What should the outcome include? 3. Determine probable Alternatives. In this activity, the main alternatives will be given to you. 4. Identify Consequences of the options. What can happen in each case? Evaluate each method (alternative) for possible consequences. 5. Consider the Tradeoffs. What is negotiable? What parts of the alternatives are you willing to give or take? Are some consequences negotiable? Pr Creating a Problem Statement As a class, we are going to work through the PrOACT process as stakeholders in the Sugar Creek watershed. Before we start our role-play activity, though, we are going to begin the decision-making process together. A good problem statement needs to address two questions: 1. Why are you trying to answer the question? 2. What decision is going to be made? As a class, let's create an initial problem statement for our scenario of land use on the Vermilion River. Consider the history, context of the problem and feelings when writing your statement. Remember, the problem statement is the beginning of the process and will drive everything else in the process. Write the final problem statement on the worksheet. O Developing a List of Objectives Now we begin the role-playing part of this investigation. The committee will consist of 8 individuals 2 farmers, 2 Cheese Company executives, 2 local citizens, 1 Soil and Water Conservation Officer, and 1 Ohio State researcher. Read through the brief description highlighted on your paper this is your assignment. Farmer: You have worried that most of the blame of poor water quality will fall upon you and other farmers. You are interested in conservation practices but are concerned about the amount of money your farm brings in. You know that using conservation practices on your farm can improve water quality and affect your family and local community. However, you are unsure if you can afford the loss in crop yields if you reduce fertilizer level or the loss in income by converting crop or livestock land into conservation land. 16

17 Cheese Company Executive: Your plant was hoping to expand to create new jobs and products, but since you are not in the limits of your permit you are unable to. You want a solution to the problem that would help and involve the local community. You are also concerned about the bottom line that your company makes. You want a solution that is economical but also allows you to meet the requirements of the permit not meeting these would cost you even more in time and money. Ohio State University/Soil and Water Conservation District: You are a facilitator between the farmers and the cheese company. You desire to come up with a solution that involves both the farms and the cheese plant. You value ecosystem function most and would like the solution to have the greatest impact on water quality and the environment. Having a low cost is important, but not as important as the environment. Community Member: You are a father/mother of two and would love to be able take your children fishing and wading in tributary of Sugar Creek which is right down the street. However, you are concerned about the quality of water and if it will hurt your children. Since you live in a rural area, you also have well water and are concerned that pollutants in the watershed are getting into your water supply. You want better water quality, but since poor water quality isn t directly your fault, you don t want your taxes to go up to improve it. An objective is a clearly defined statement that takes into consideration the values of the individual stakeholders. An objective should be measurable, but you may be creative in how you measure (number of times an individual smiles can be a measurement of fun). 1. Brainstorm on your own for a while. Remaining in character, write your 2 or 3 final objectives for the problem on your objectives page. 2. Now get with your twins in the room As a group discuss your objectives and use the computers to help you find information on your objectives. Together create two or three objectives that represent your character s values. Record your group objectives on your worksheet. 3. Now, still staying in character, as a class we need come to a consensus on two or three final objectives for the problem that takes into account all of the stakeholders values. THIS IS NOT EASY! It will also take some time. Stay in your role, but remember that you are creating objectives for a problem that will impact the entire community. These will be your working objectives for the rest of the activity! Record your cooperative group objectives on the worksheet, Links of interest: National Pollution Discharge Elimination System: EPA - Office of Water: Phosphorous Pollution: Ground water: Agricultural best management practices: 17

18 Objectives Worksheet What was the character assigned to you: Individual Objectives: Group Objectives: Class Objectives: What are some potential solutions (alternatives) which your group would advocate to fix this problem? 18

19 A The Alternatives During this step of the process, those involved in the decision would come up with a list of alternative plans that would address the problem. A separate town group, the alternatives committee, has convened and looked at your objectives. They have come up with the following four alternatives for the use of the land. Right now you need to be concerned with just these four alternatives. The four alternatives are listed below. 1. Regulation on farmers (making them reduce their phosphate levels to make up for phosphate released by the plant) 2. Force the cheese plant to suspend operation 3. Student Alternative 4. Water Quality Trading Program If you have any questions about these alternatives, you should speak to the appointed member of the alternatives committee (your instructor). Select one Alternative (control method) that you think best meets the Objectives you listed: Select one Alternative that you think best meets the objectives the class listed: C Consequences Based on the alternative chosen by the class, list 2 or 3 consequences this alternative will have on you (positive or negative): T - Tradeoffs What are the Tradeoffs for using the Alternative? Does the class have to give up one objective in order to meet another? Explain. Which Objectives does the Alternative meet? How do you justify trading some Objectives for others? 19