Activity Template Subject Area(s): Chemistry; data analysis and probability; earth and space; measurement, number and operations; problem solving, reasoning and proof; science and technology Associated Unit: None Associated Lesson: None Activity Title : Water Investigation Header Image 1 ADA Description: Graphic of different colored droplets. Caption: Droplets. Source/Rights: Copyright © 2009 Microsoft Corporation, One Microsoft Way, Redmond, WA 98052-6399 USA. All rights reserved. Grade Level: 10 (9 -12) Activity Dependency: None Time Required: 385 minutes (7 periods of 55 minutes) Group Size: 3 Expendable Cost per Group: US $6.00 Summary Students are introduced to the water cycle with an emphasis on the effect of urbanization. Students will learn the fundamentals of water quality monitoring through an inquiry-based lab activity. Armed with an understanding of water quality monitoring, students will devise testable hypotheses related to Ballona Creek, experiment, and analyze results. Students will then communicate their results through in-class presentations and water quality reports. Data will be collected as part of a long-term, longitudinal study of water quality. Engineering Connection Hydrologists are engineers and scientists that study the earth’s water and processes. Specifically, hydrologists study the allocation of water throughout the earth, its circulation, quality, and movement. Hydrology is a highly interdisciplinary field with diverse applications - from ensuring proper water quality for entire cities to developing water slides at the local water parks. Engineering Category 1. Relates science concept to engineering 3. Provides engineering analysis or partial design Level of Inquiry The Water Investigation activity will be open/full inquiry in which students formulate questions and design procedures. Keywords Water, urbanization, pollution, runoff, quality, monitoring Educational Standards State science: California Geology 9. The geology of California underlies the state’s wealth of natural resources as well as its natural hazards. As a basis for understanding this concept: c. Students know the importance of water to society, the origins of California’s fresh water, and the relationship between supply and need. Investigation and Experimentation 1. Scientific progress is made by asking meaningful questions and conducting careful investigations. As a basis for understanding this concept and addressing the content in the other four strands, students should develop their own questions and perform investigations. Students will: a. Select and use appropriate tools and technology (such as computer-linked probes, spreadsheets, and graphing calculators) to perform tests, collect data, analyze relationships, and display data. b. Identify and communicate sources of unavoidable experimental error. c. Identify possible reasons for inconsistent results, such as sources of error or uncontrolled conditions. d. Formulate explanations by using logic and evidence. f. Distinguish between hypothesis and theory as scientific terms. h. Read and interpret topographic and geologic maps. j. Recognize the issues of statistical variability and the need for controlled tests. k. Recognize the cumulative nature of scientific evidence. l. Analyze situations and solve problems that require combining and applying concepts from more than one area of science. m. Investigate a science-based societal issue by researching the literature, analyzing data, and communicating the findings. Examples of issues include irradiation of food, cloning of animals by somatic cell nuclear transfer, choice of energy sources, and land and water use decisions in California. n. Know that when an observation does not agree with an accepted scientific theory, the observation is sometimes mistaken or fraudulent (e.g., the Piltdown Man fossil or unidentified flying objects) and that the theory is sometimes wrong (e.g., the Ptolemaic model of the movement of the Sun, Moon, and planets). Pre-Requisite Knowledge Students should be familiar with proper laboratory safety and techniques. Learning Objectives After this activity, students should be able to: Describe the origins of California’s fresh water, the effect of urbanization, and the source of pollutants. Investigate and identify water pollutants and their source through water quality monitoring techniques. Understand scientific progress through a learning experience that exposes students to the passion and excitement of real world science. Materials List Each group needs: Thermometer pH meter Glassware: beakers, graduated cylinders, test tubes – various sizes To share with the entire class: TDS meter LaMotte Testab® Water investigation kit o Alkalinity Module o Ammonia Module o Chloride Module o Chlorine Module o Chromium Module o Copper Module o Dissolved Oxygen/BOD Module o Hardness Module o Iron Module o Nitrate Module o pH Module o Phosphate Module Additional water investigation kits if available Introduction / Motivation The water cycle describes the circular movement of water from land to atmosphere and back to land, while itself changing through its different phases. The energy from the sun heats the water in the oceans, soil, and that from plants, and converts it into the gaseous state. High in the atmosphere, due to colder temperatures, the gaseous water condenses into tiny droplets, forming clouds. As the tiny droplets grow larger through collisions with one another, the water precipitates in the form of rain or snow. Water falling on land flows as surface runoff, channel runoff (rivers and streams), or ground water (below ground). The water eventually reaches the ocean where the cycle continues. The water cycle is dramatically influenced by urbanization. With the construction of buildings, roads, and drains, precipitation is quickly diverted away from structures. With less time as puddles and thus less time to evaporate, less water evaporates into the atmosphere. Furthermore, with the clearing of trees to build buildings, less water evaporates from plants into the atmosphere. Water is unable to penetrate through the roads and sidewalk, thus decreasing the amount of ground water. Ultimately, the increase in surface runoff is transported to streams. Urbanization also has an effect on the quality of water through pollution. Pollution that is dumped directly into a body of water is considered point source pollution and includes waste pipes from factories or homes directly into a stream or lake. Pollution that finds it way indirectly into a body of water by means of surface runoff is nonpoint pollution. Runoff from agricultural activities, construction sites, and mines are such examples of nonpoint pollution. The common pollutants of streams are not heavy metals, but rather nitrogen, phosphorus, bacteria, and pesticides predominantly due to agricultural activities, waste treatment plants, and urban runoff. As water is essential for life and all of the earth’s water is tied together by the water cycle, water quality monitoring is extremely important. Water quality monitoring is the process of analyzing the components of water. It allows for not only the identification of pollutants in water, but also the sources of the pollution. Furthermore, monitoring the quality allows for the determination of changes of chemical constituents over time. There are several common water quality measurement parameters (below are parameters from the LaMotte Testab Water Investigation Kit Manual): Alkalinity Alkalinity refers to the ability of water to neutralize acids as they are added to or created in the aquatic ecosystem. This neutralization process is called buffering, and is critical to maintaining proper pH levels. A healthy, productive freshwater lake has a pH of about 8. Natural pH buffers, primarily carbonates and bicarbonates, help to maintain the pH at this level and to prevent drastic pH fluctuations. A temporary loss of buffering capacity can permit the pH to drop to levels that are harmful to aquatic life. For example, an entire season of acidic precipitation can be stored in the form of snow and ice, so areas which receive a lot of snow melt in the spring are especially susceptible to seasonal loss of buffering capacity. Buffering materials in the water are produced by leaching of the rocks and soil through which the water flows. Alkalinity is usually expressed as parts per million (ppm) of calcium carbonate (CaCO 3). Alkalinity levels of 100 to 200 ppm will stabilize the pH level in a body of water. Levels between 20 and 200 are typically found in freshwater, while sea water generally has alkalinity levels from 100 to 125 ppm. Ammonia Ammonia is present in variable amounts in many surface and ground waters. The primary sources of ammonia in water are bacterial decomposition of organic waste and excretions of aquatic animals. Ammonia serves as a source of nitrogen, which is used as a nutrient for the growth of aquatic plants. Ammonia exists in water as two forms, un-ionized (NH3) and ionized (NH4). Un-ionized ammonia is toxic to fish while the ionized form is non-toxic, except at extremely high levels. The relative proportions of each form present are regulated by pH and temperature. Ammonia is usually present in low quantities (less than 1 ppm) in non-polluted, welloxygenated waters, but may reach levels of 5 to 10 ppm in areas with low dissolved oxygen and large amounts of decaying organic materials. Chloride Chloride is one of the major anions found in water and sewage. The presence of chlorides in large amounts may be due to the natural process of water passing through salt formations in the earth, or it may be evidence of the intrusion of sea water or pollution from industrial or domestic wastes. Chloride gives water a salty taste. Drinking water standards recommend a maximum chloride concentration of 250 ppm. Salinity is an important water quality measurement that is related to chloride. It is the total of all salts dissolved in water. The salt content of water affects the distribution of plant and animal life in an aquatic system, based on the amount of salt they can tolerate. Salinity can be calculated from chloride concentrations, and is usually expressed as parts-per-thousand (ppt), ranging from 0 ppt in freshwater, up to 35 ppt in sea water. Chlorine Chlorine is not present in natural waters, and is found only as a result of chlorination of a water supply. It is widely used for sterilization and disinfection in municipal water supplies, swimming pools and spas, food and beverage processing, and in medical facilities such as dialysis units. Swimming pools generally have a chlorine concentration of 1 to 3 ppm, while levels in drinking water are maintained below 0.5 ppm. High levels of chlorine can be harmful or fatal to plants and fish. Chromium Chromium compounds may be found in natural waters in trace amounts ranging from 0.003 to 0.040 ppm. It may also be present in water containing waste from industrial processes such as metal plating, or in overflow waters from large air conditioning units, where chromium is frequently added to cooling water to control corrosion. Chromium is one of a class of heavy metals sometimes found in the bottom mud of polluted bodies of water. It is considered to be a toxic chemical. Certain shellfish are capable of concentrating this element, endangering the health of consumer organisms, human or animal. Chromium levels over 0.5 ppm are evidence of pollution from untreated or incompletely treated waste. Copper Copper is usually found only in small amounts (less than 1 ppm) in natural waters. Elevated amounts may be due to industrial effluents or corrosion of pipes and fittings. Copper is also added to swimming pool and aquarium water to control algae and bacteria. Concentrations of 1.0 ppm or higher may give water a bitter taste, and may cause staining and discoloration. The copper content of drinking water is generally below 0.03 ppm, but occasionally ranges up to 0.6 ppm in some areas. Dissolved oxygen/biochemical oxygen demand Fish, invertebrates, plants, and aerobic bacteria all require oxygen for respiration. Oxygen dissolves readily into water from the atmosphere until the water is saturated. Once dissolved in water the oxygen diffuses very slowly, and distribution depends upon the movement of the aerated water. Oxygen is also produced by aquatic plants, algae, and phytoplankton as a by-product of photosynthesis. Aquatic organisms require different amounts of dissolved oxygen. Dissolved oxygen levels below 3 ppm are stressful to most aquatic organisms. Dissolved oxygen levels below 2 or 1 ppm will not support fish. Levels of 5 to 6 ppm are usually required for the growth and activity of aquatic organisms. Biochemical oxygen demand Biochemical Oxygen Demand (BOD) is a measure of the quantity of dissolved oxygen used by bacteria as they break down organic wastes. In slow moving and polluted waters, much of the available dissolved oxygen is consumed by bacteria, robbing other aquatic organisms of the dissolved oxygen needed to live. Hardness Hardness refers primarily to the amount of calcium and magnesium ions in water. Other ions contribute to hardness also, but are usually present in insignificant amounts. Calcium and magnesium enter the water mainly by the leaching of rocks and soil. Calcium is an important component of aquatic plant cell walls and also the shells and bones of many aquatic organisms. Magnesium is an essential nutrient and is a component of chlorophyll. Hardness is usually expressed as parts per million (ppm) of calcium carbonate (CaCO 3). These results can be expressed as calcium or magnesium by multiplying by 0.4 for calcium and 0.24 for magnesium. Waters with calcium levels of 10 ppm or less can support only sparse plant and animal life. Levels of 25 ppm or more are typical of waters having excessive levels of plant nutrients, and may contribute to excessive algae growth. Typical levels of magnesium in freshwater range from 5 to 50 ppm. Sea water contains high levels of both calcium and magnesium. Typical sea water contains 400 ppm calcium and 1350 ppm magnesium, which adds up to a total hardness of above 6625 ppm. Water with a low level of hardness is generally referred to as “soft”, while water with a high level of hardness is described as “hard”. Hard water can cause problems in home and industrial water systems, including scaly deposits in plumbing and appliances, and decreased cleaning action of soaps and detergents. Water with total hardness from 0 to 60 ppm is soft, from 60 to 120 ppm is medium hard, from 120 to 180 ppm is hard, and above 180 ppm is considered very hard. Iron Iron is present in most natural waters, and is an important nutrient for many organisms. Soil and rocks provide the most common sources of iron in water. Industrial waste, such as acid mine drainage, can contribute to elevated levels. Concentrations can vary from trace amounts (0.1 ppm) up to several parts per million. Large amounts of iron in the water will cause problems such as orange stains on porcelain fixtures and laundry, and may cause undesirable taste and color in drinking water and beverages. Iron concentrations should not exceed 0.2 ppm for domestic use, and for some industrial applications, not even trace amounts can be tolerated. Nitrate Nitrogen is a nutrient that acts as a fertilizer for aquatic plants. When nitrogen levels are high, excessive plant and algae growth creates water quality problems. Nitrogen enters the water from human and animal waste, decomposing organic matter, and lawn and crop fertilizer run-off. Nitrogen occurs in water as Nitrate (NO3), Nitrite (NO2), and Ammonia (NH3). Unpolluted waters usually have a nitrate level below 4 ppm. Nitrate levels above 40 ppm are considered unsafe for drinking water. pH The pH test is one of the most common analyses in water testing. pH is a measurement of the activity of hydrogen ions in a water sample. The pH scale ranges from 0 to 14. Water samples with a pH below 7.0 are considered acidic, those above 7.0 are basic, with 7.0 considered neutral. A pH range of 6.5 to 8.2 is optimal for most aquatic organisms. Rapidly growing algae and vegetation remove carbon dioxide (CO2) from the water during photosynthesis. This can result in a significant increase in pH. Most natural waters have pH values from 5.0 to 8.5. Acidic, freshly fallen rain water may have a pH of 5.5 to 6.0. Alkaline soils and minerals can raise the pH to 8.0 to 8.5. Sea water usually has a pH value close to 8.0. Phosphate Phosphorus is a nutrient that acts as a fertilizer for aquatic plants. When nutrient levels are high, excessive plant and algae growth creates water quality problems. Phosphorus occurs in natural waters in the form of phosphate (PO4). Over half of the phosphates in lakes, streams, and rivers come from detergents. Phosphate levels higher than 0.03 ppm contribute to increased plant growth. Vocabulary / Definitions Word Definition Water cycle Circular movement of water from land to atmosphere and back to land, while itself changing through its different phases. Surface Flow of water over land before reaching a river or stream. runoff Channel Flow of water in the form of a river or stream. runoff Ground water Flow of water below ground. Urbanization Process of forming a city. Point source Pollution that is dumped directly into a body of water. pollution Nonpoint Pollution that finds it way indirectly into a body of water by means of source surface runoff. pollution Water quality Process of analyzing the components of water. monitoring Alkalinity Refers to the ability of water to neutralize acids. pH Concentration of hydrogen ions. Watershed Area of land draining to an entity of water. Procedure Background Before the Activity Gather materials and make copies of the worksheet. Day 1: Introduction/class discussion o Water cycle o Urbanization o Pollution o City water report o Quality monitoring tests Divide class into groups of three. With the Students Instructions: Day 2: Water forensics inquiry pre-lab A. Refer to memo. Discussion of memo and plan use of chemical tests. Day 3: Water forensics inquiry lab A. Refer to memo. Determine source of unknown sample of water. Using careful chemical analysis, match sample to one of the five known samples. (NOTE: Do NOT taste/drink water). Record all observations and data. May 13, 2009 Re: Burglary/stolen mascot Dear StudentsOn May 12, 2009 at 10:00pm, Culver City High School experienced a burglary to its high school mascot. The Culver City Police Department received calls from concerned citizens reporting they observed two male juveniles removing the high school mascot. The citizens provided detailed descriptions of one of the suspects. The suspect is described as a Male, White, 16-22 yrs, 5’8”, 140 lbs, wearing dark jacket, green t-shirt, grey pants, a ski mask, and carrying a large blue backpack. Police Officers responded to the location within minutes. On police arrival, suspects fled the scene with the mascot in a white van. A photograph of the van was taken by a nearby surveillance camera. Suspects left behind a 1997 red, Ford F150 truck with the license plate and VIN number removed. The truck bed was filled with an inch of water. Investigators have taken a report, but due to other higher priority issues, will allocate minimal resources to this investigation. Culver City High School students are being asked to assist – not by taking the law into their own hands, but to assist in the investigation. Culver City High School is asking the AP Chemistry class to forensically investigate the water found in the truck bed. It is thought that by identifying the source of water in the truck bed, the suspects’ location can be identified. A sample of water from the truck bed, along with a collection of samples for reference, and a test kit has been sent. For Public Distribution Crime Analysis Bulletin Day 4: Brainstorm/plan creek water quality study. A. Refer to excerpt from the City of Culver City Ballona Creek Water Quality Improvement Project Scope of Work: Ballona Creek is a major waterway and open space that winds through the City of Culver City out to Santa Monica Bay. Ballona Creek is on the Environmental Protection Agencies (EPA) 303d list of Impaired Waters. Virtually anything deposited on a street within the 130 square-mile watershed winds up in the ocean via the concrete channel. The area is 65% residential, 13% commercial, 4% industrial, and 12% open space and 4% public space. Ballona Creek ranks the highest among the watershed’s 28 drainage basins in emissions of all nine categories of pollutants (Total Suspended Solids, Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), phosphate, nitrate, lead, copper, zinc, oil and grease). It is estimated that of all the urban runoff entering the Bay, Ballona Creek contributes 69% of the oil and grease, 60% of the BOD, and more than 50% of the lead, copper, zinc, COD and phosphate. High indicator bacterial counts from sources both known (animal waste, sewage overflows) and unknown (illegal sewer connections, leaking sewer lines) have historically been found in Ballona Creek. Sediment deposited by Ballona Creek is contributing to the shoaling problem at the entrance to Marina Del Rey. The shoals, which are a hazard to boating, are heavily contaminated with industrial and urban runoff that flows from upstream. The high levels of heavy metals, especially lead and petroleum hydrocarbons, have made the dredging and disposal of the material an extremely costly and environmentally hazardous situation. Tremendous quantities of trash and debris are washed into the creek channel and flow into the Bay, particularly after a major storm. The creek often has an oily sheen due to oil-contaminated runoff and the presence of natural oil seeps in the watershed. The City of Culver City in collaboration with Ballona Creek Renaissance and several environmental organizations has been strategizing on methods of rehabilitating and enhancing nine-mile-long Ballona Creek. This project is the first step towards a long-term water quality improvement in Ballona Creek and is looked upon as a prototype that can be duplicated along the creek at various locations, as well as by other cities experiencing many of the same problems. B. Develop a testable hypothesis related to Ballona Creek in groups of 3. a. What evidence or data is necessary? b. What procedures are necessary to obtain evidence or data? c. What equipment is necessary? d. How to sample and collect the water? e. What protocols will be used? f. Will the tests be done at the creek or back in the lab? Day 5: Implement plan and evaluate data A. Collect data. B. Analyze data. Day 6: Implement plan and evaluate data A. Collect data. B. Analyze data. Image Insert Image # or Figure # here, [note position: left justified, centered or right justified] Figure #2 ADA Description: Figure of water cycle in natural setting (top) and developed setting (bottom). Caption: Figure #2. Water cycle influenced by urbanization. Image file name: water_cycle_urbanization Source/Rights: Copyright © Volunteer Stream Monitoring: A Methods Manual. Monitoring Water Quality – United States Environmental Protection Agency (EPA) – Office of Water. 1997. <http://www.epa.gov/volunteer/stream/stream.pdf> Attachments Water_investigation_student_handout.doc Water_investigation_student_handout.pdf Safety Issues Student must not drink water samples nor ingest tablets of the water investigation kit. Care must be taken when collecting samples from creek. o Permission slips for creek necessary. Troubleshooting Tips Students may feel that they cannot think of testable hypotheses using water quality monitoring techniques. Encourage them to be creative and to test for issues important to them and the environment. Assist students in choosing hypotheses that can realistically be tested. Investigating Questions What chemicals or pollutants in water concern you most? Where do they come from? What problem can they cause? Are the chemical or pollutants increasing or decreasing? Assessment Pre-Activity Assessment Pre-lab Questions: Answer all questions prior to the activity. Questions will require research! 1. Where does water to your city come from? 2. Where does the water to your home come from? 3. Where does water go after it goes down the drain? 4. How would you measure how fast water flows in a stream? 5. Is water from the faucet, sprinkler, or bottled water from the supermarket all the same? What could be inside it that makes it different? Activity Embedded Assessment In-Class Presentation: Each team should present their water analysis to the entire class in the form of a PowerPoint presentation. Students should suggest ways to improve their results. Post-Activity Assessment Lab Write-up and Post-lab Questions: Water quality report Write-up: o Objective o Hypothesis o Materials and Methods o Data o Data Analysis o Discussion o Post-lab questions (include in Discussion section of lab-write up): How can the experiments be improved? What can we do to improve the quality of water? What single pollutant do you find to be the most dangerous? o Conclusion Activity Extensions Inquiry-based activity for students to develop methods to clean water – given a glass of dirty water, determine processes to remove dirt. Activity Scaling Additional Multimedia Support References Volunteer Stream Monitoring: A Methods Manual. Monitoring Water Quality – United States Environmental Protection Agency (EPA) – Office of Water. 1997. http://www.epa.gov/volunteer/stream/stream.pdf The Testab® Water Investigation Kit. LaMotte Model AM-12, Code 5849. http://www.lamotte.com/pages/common/pdf/instruct/5849.pdf Wikipedia, the free encyclopedia. 2009. 03 May. 2009 http://en.wikipedia.org/wiki/ 2008 Water Quality Report. Culver City Water System. Golden State Water Company. 12035 Burke Street, Ste #1, Santa Fe Springs, CA 90670 City of Culver City Ballona Creek Water Quality Improvement Project Scope of Work. < www.santamonicabay.org/smbay/LinkClick.aspx?link=Culver+City++Ballona+WQ+CDS.pdf&tabid=81> Figure of water cycle: http://ga.water.usgs.gov/edu/watercycle.html. Water cycle urbanization diagram: Volunteer Stream Monitoring: A Methods Manual. Monitoring Water Quality – United States Environmental Protection Agency (EPA) – Office of Water. 1997. http://www.epa.gov/volunteer/stream/stream.pdf Picture of red pickup truck: http://www.fordf150.net/misc/images/04_1.jpg. Picture of white van: http://inner-west-courierwest.whereilive.com.au/news/story/police-turn-to-cctv-footage-after-attemptedabduction-in-tempe/. Other Redirect URL [For TE submissions only] Owner UCLA SEE-LA GK-12 Program, University of California, Los Angeles. Contributors Azim Laiwalla, Ann McCabe Copyright