Water: Stream Quality & Watershed Dynamics

The Missouri River @ Kansas City

After more than a year on the Missouri, Meriwether Lewis found its source, a spring in the Rocky Mountains. “Thus far I had accomplished one of those objects on which my mind has been unalterably fixed for many years,” he wrote, “judge then of the pleasure I felt in allying my

thirst with this pure and ice-cold water.”

Lesson 1

Water Quality Detective

Exploration Phase:

Introduction:

The various sources of fresh water in the Kansas City area such as rivers, lakes, creeks and ponds are affected by human related activities which introduce various pollutants such as fertilizers from golf courses and lawns; industrial effluents; household waste; leakage from underground oil/diesel storage tanks; and various fossil fuel based residues.

In this investigation you are provided with distilled water and water sample from one of the following locations:

1. Missouri River at Parkville2. Brush Creek3. Creek near an industrial site

Your task will be to conduct various tests to determine the water quality for your sample. In the application phase of the lesson, you will use your results to identify the source of your sample.

Objectives:

1. Practice various water quality measurements protocols. 2. Practice precise documentation of observations and measurements.3. Understand the purpose of the tests you perform and their relationship to water quality.

Note: A set of test solutions have been prepared for analyses. Read the following information carefully to ensure you are using the correct solution for the test to be performed. PLEASE READ THROUGH DIRECTIONS FOR WATER QUALITY TESTS - HANDOUT FOR EACH TEST BEFORE YOU START!

Activity 1. Electrical Conductivity (EC) meter in mSEC measures the ability of the water to conduct electricity, caused by dissolved ions. It is closely related to salinity. The higher the conductivity, the more dissolved ions it contains, and the poorer the water quality. Salinity is more of a problem for drinking water supplies than lakes or streams, because salty water doesn’t taste good, and can

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make you sick. Rarely, do lakes and streams contain very high levels of dissolved ions because of the influx of fresh water.

Procedure:

Pour 2-3 cm of sample water into a clean beaker Remove the protective cap on the EC meter and turn the

unit on by sliding the on/off switch. Immerse the sensor-end of the unit into the sample. Make

sure sensors are completely submerged. Wait for the display to stabilize. Multiply the stabilized number by 10 and record. Record your answers on the answer sheet. Rinse off the sensor-end of meter with distilled water. Turn the unit off and replace cap. Return the sample to the correct stock bottle.

Activity 2. 5-in-1 Test Strip: Total Chlorine, Free Chlorine, Total Hardness, Total Alkalinity, and pH

pH: this measures the acidity of water, which is produced by the quantity of hydrogen atoms dissolved in the water. The lower the pH reading, the more hydrogen atoms there are in the solution, and the more acidic the water. Many organisms are sensitive to pH levels.

Total Alkalinity [ppm]: this measures the concentration of calcium carbonate, in parts per million (ppm; also mg/L). The presence of this mineral is related to hardness as well as pH; the higher the value, the harder the water and the higher the pH (it is one of the pH buffers that counteracts the affects of acid rain). The source is usually the soil and bedrock in the watershed.

Total Hardness [ppm]: this measures the concentration of calcium and similar ions in solution, reporting the results as ppm equivalent CaCO3. These ions are of most concern in drinking water, because they can contribute a mineral taste to the water, and their presence can make it difficult for soaps to work correctly.

Total Chlorine and Free Chlorine (Cl) [ppm]: this measures the amount of chlorine in the water. The total measurement includes chlorine that might be combined with other ions, while the free measurement indicates the amount of uncombined chlorine ion in solution. There is some chlorine in natural waters, which may come from minerals in the soil and rocks, or from precipitation. Because

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water treatment plants add chlorine to public water supplies, its presence may also indicate a human source.

Test samples by: Fill a 25 ml beaker with sample water. Dip one strip into the sample water for 1 second. DO NOT

SHAKE OFF EXCESS WATER. Hold strip level for 30 seconds. Compare TOTAL HARDNESS, TOTAL ALKALINITY and pH

pads to color chart on side of bottle. Record measurements on the answer sheet. Dip strip into the sample water again and move back and

forth for 30 seconds. Compare CHLORINE pad to color chart. Record measurements on the answer sheet Dispose of strip, return cap to bottle, and dispose of waste

water into the sink.

Activity 3. Test Strip for Nitrate and Nitrite Nitrogen [ppm]

Nitrogen is necessary for plant and animal life. Nitrogen is a nutrient, which can lead to enhanced biological productivity, algal blooms and eventually eutrophication. A eutrophic environment causes more plant growth and decay and is characterized by an abundance of nutrients in the near surface, abundant algae growth and low oxygen conditions below the surface. Water is tested for nitrates/nitrites to monitor and control eutrofication. Nitrate (NO3) and Nitrite (NO2) measure the amount of nitrogen present as each of the two compounds. Nitrification of water results from agricultural or urban runoff through application of fertilizers and sewage discharge.

Test samples by: Fill a 25 ml beaker with sample water. Dip a single strip into sample water for 1 second and

remove. DO NOT SHAKE OFF EXCESS WATER. Hold the strip level, with pad side up, for 30 seconds. Compare the NITRITE test pad to the color chart on side of

bottle. Record your results on the answer sheet. At 60 seconds, compare the NITRATE test pad to the color

chart. Record your results on the answer sheet. Dispose of test strip in waste basket, and replace lid on

test strip bottle. Dispose of used sample water in bottle labeled WASTE

WATER.

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Activity 4. Dissolved Oxygen (DO) [ppm]

This test is the most important of the water quality tests to measure water's ability to support plants and animals. There are many different factors that affect the amount of dissolved oxygen in water, the main one being temperature. As temperature rises, less gas will dissolve.

DO measures the amount of oxygen dissolved in the water. It is affected by biochemical oxygen demand (BOD), and is a good indicator of water quality related to the presence of organic waste. As organic waste is added to the water, bacteria consume oxygen to decompose this waste. Of course, as oxygen is consumed, it is less available to support other life in the water.

Begin by pouring some of the sample from the stock bottle into a clean 25ml beaker.

Obtain the temperature of the sample using the pocket thermometer.

Mark the temperature on the "Determining Percent Saturation" - Handout

From the Dissolved Oxygen kit remove the round bottle with the glass stopper.

Fill bottle with sample. Incline bottle slightly and quickly insert stopper. DO NOT

TRAP ANY AIR BUBBLES IN THE BOTTLE. If you do, your test will fail later and you will have to start over.

Open one Dissolved Oxygen 1 Reagent Powder Pillow and one Dissolved Oxygen 2 Reagent Pillow.

Remove stopper and add both pillows to the sample water. Replace the stopper again by adding a little sample

solution and using the technique in step 4. Gripping the bottle and stopper firmly, carefully shake it

vigorously (do not break the bottle!!) to mix the sample water and the reagents. A flocculent precipitate (floc) should begin to form. If oxygen is present, the precipitate will be a brown-orange color.

o Allow the sample to stand until the floc has settled halfway in the bottle (use the marked line at the bottle), leaving the upper half of the sample clear.

o Shake the sample again, and again let it stand until the upper half of the sample is clear.

o Open one Dissolved Oxygen 3 Reagent Powder Pillow. Remove the stopper from the bottle and add the contents of the pillow. Carefully place the stopper back on the bottle.

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o Shake the sample water and reagent to mix. The floc will dissolve completely and a yellow color will develop if oxygen is present.

Fill the small measuring tube (full) of the prepared sample. Pour the measured sample into the square mixing bottle.

o Add Sodium Thiosulfate Standard Solution. ADD ONE DROP AT A TIME. Swirl the mixture around in the bottle after each drop. Count each drop as it is added. Continue adding drops until the sample changes from yellow to colorless.

o Each drop used is equal to 1 ppm of dissolved oxygen. Mark the amount of drops on the "Determining Percent Saturation" - Handout

o Use information on the attached "Determining Percent Saturation" – Handout to determine the amount of DO in the sample.

Record the value on the %Saturation Graph. Pour used solution into waste water bottle!! Rinse DO bottles and stopper with distilled water and

return to the kit.

Activity 4 Resources:

Dissolved Oxygen Percent Saturation

Percent Saturation is the amount of oxygen dissolved in the water sample compared to the maximum amount that could be present at the same temperature. For example, water is said to be 100% saturated if it contains the maximum amount of oxygen at that temperature. A water sample that is 50% saturated only has half the amount of oxygen that it could potentially hold at that temperature. Sometimes water can become supersaturated with oxygen because of rapidly tumbling water. This usually lasts for a short period of time but can be harmful to fish and other aquatic organisms. DO Percent Saturation values of 80-120% are considered to be excellent and values less than 60% or over 125% are considered to be poor.

Determining % Saturation - The "quick and easy" - Method

For a quick and easy determination of the percent saturation value of dissolved oxygen at a given temperature, use the saturation chart below. Pair up the mg/L of dissolved oxygen you measured and the

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temperature of water in degrees C. Draw a straight line between temperature and mg/L of dissolved oxygen. The percent saturation is the value where the line intercepts the saturation scale. Streams with a saturation value of 90% or above are considered healthy.

Activity 5. Turbidity [JTU]

Turbidity measures water clarity, which allows sunlight to penetrate to a greater depth. The main sources of turbidity are erosion, living organisms, and those from human endeavors. Turbidity test gives an indication of the amount of suspended solids in water. It is a visual technique, whereby the scattering effect that suspended particles have on light is measured. Hence it is a visual indicator of water quality. Turbidity is measured in Jackson Turbidity Units (JTU).

Test samples by: Slowly pour sample in the tube until you can no longer

distinguish the black line(s) on the base of the tube. Determine the level of water by the number scale on the

outside of the tube. Record this value and pour sample back into SOL bottle. Return the sample to the stock bottle

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WATER QUALITY INVESTIGATION DATA SHEET BE SURE TO INCLUDE THE UNIT OF FOR EACH TEST (mg/L, %, JTU...)

Sample #:__________

1. Electrical Conductivity

Sample:__________ Distilled H2O:__________

2. Don’t forget the units!

Test Sample Distilled H2O

Total ChlorineFree ChlorineTotal HardnessTotal AlkalinitypH

3. Don't forget the units!

Test Sample Distilled H2O

NitrateNitrite

4. Dissolved Oxygen

Sample:_________ Distilled H2O: __________

5. TurbiditySample: __________ Distilled H2O: __________

Concept Introduction:

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NATIONAL WILDLIFE MAGAZINEApr/May 2004, vol. 42 no. 3

Grasping for SolutionsBy Joby Warrick

While many states are failing to protect rivers and watersheds from polluted runoff, some communities are taking matters into their own hands.

On bright days when the Clinch River in southwestern Virginia runs clear, you can see signs of rebirth strewn along its rocky bottom like so many black pearls. Braven Beaty, an aquatic ecologist in rubber waders, pokes an arm into the mountain stream’s icy swirl and pulls out a hopeful omen.

"Black sandshell," he calls out, rotating a small mussel between fingertips. "A threatened species. I’ve never seen one this far north."

The scientist returns the mussel to its place and scoops up another, and then another, reciting the names of the species as he finds them: fine-rayed pigtoe; kidneyshell; rough rabbitsfoot. In half an hour, he finds 12 different species in a spot no bigger than a carport.

The variety is striking, even for a stream that boasts more varieties of freshwater mussels than any waterway on Earth. But equally striking are the absences: Once there were as many as 60 types of mussels in this Appalachian river before pollution and silt from a century of logging and coal mining wiped out a third of them—forever.

The Clinch’s mussels are slowly coming back, but so far recovery is limited to areas protected by a fragile alliance of conservationists and property owners working to keep sediments out of the water. "It’s hard to get people to

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understand why mussels are important," says Beaty. "It’s even harder to go to landowners and say, ‘You’re part of the problem.’"

Drawing a connection between land and water is crucial, not only for the Clinch but also for hundreds of other waterways around the country. In an era when environmental regulations have stemmed the flow of pollutants from many U.S. factories, rivers are straining under a burden of chemicals and silt from thousands of smaller sources—everything from poorly managed logging projects and animal waste from factory farms to motor oil off parking lots and weed killers from suburban lawns.

Such diffuse, or nonpoint, pollution is now the Number One cause of contamination in American waterways, fouling an estimated 1.3 million miles of streams and rivers. It is the main reason nearly 40 percent of the nation’s lakes, rivers and estuaries still are not clean enough for swimming or fishing, according to a 1997 Environmental Protection Agency (EPA) analysis.

"The magnitude of the problem just hasn’t been recognized," says Michael Murray, an NWF environmental chemist and staff scientist, "and as a result we’re seeing nonpoint pollution getting even worse in a lot of areas of the country." The situation, he adds, is compounded in many areas by air pollution, which contaminates waterways with dioxins and other chemicals emanating from distant sources.

An NWF study released last spring reported that states simply are not enforcing the law when it comes to preventing diffuse pollution from washing into streams (see sidebar). "The failure is inexcusable and the problems are preventable," concludes the report. "The tools for cleaning up polluted runoff and contaminated rain are there, but most states simply aren’t using them aggressively enough."

For states, the primary legal weapon against nonpoint pollution is called the Total Maximum Daily Load (TMDL) restoration program. Created with the passage of the federal Clean Water Act in 1972, the TMDL provision requires regulators to consider all sources of pollution across a river’s watershed, or drainage basin.

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A watershed is the area of land from which rain or melting snow drains into a river. It can be as small as a few hundred acres—typical of a small stream—or it can encompass thousands of square miles and several states, as in the case of the Mississippi River. In all watersheds, the rainwater that replenishes the river also brings wastes that can damage it. Unless preventive steps are taken, pollutants can be swept up in storm runoff and deposited in the river itself.

A TMDL plan helps states identify these hidden problems. The program starts with careful monitoring of water quality by state regulators, along with an investigation of where the pollutants are coming from. Next, the states set limits for each type of pollution—the "total maximum daily load" a river can safely carry. When a river exceeds the limit for a chemical, the state crafts a pollution-reduction strategy that divides the cuts among both point and nonpoint sources of the chemical. States have discretion in determining how the actual allocations are made, with the only requirement that the reductions result in attainment of water-quality standards.

"This TMDL approach makes a clean-up effort more effective and fairer to all parties," says Murray. It can also yield surprising insights: In the Christina River Basin near Wilmington, Delaware, for example, officials discovered that farming and suburban sprawl had eclipsed the state’s homegrown chemical industry as the leading source of the river’s problems. Runoff from farms, lawns and parking lots alone destroyed or damaged fish habitats in nearly 40 percent of the river’s tributaries, according to a TMDL investigation.

More than two-thirds of the nation’s state governments still lack a workable TMDL program, NWF found. "Not one of the 50 states has done what the law requires," it said. The result: Despite a public perception of steadily cleaner rivers and lakes, progress has stalled in many areas and has actually reversed in others. Some examples:

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Fertilizers and animal waste from factory livestock farms have helped trigger an unprecedented number of algal blooms, destructive growth spurts that clog waterways and suffocate fish. Most notorious were outbreaks of toxic algae, including the organism Pfiesteria piscicida, blamed for killing a billion fish in coastal North Carolina.

Increased monitoring and continued mercury contamination in lakes and rivers has led to a doubling of fish-consumption advisories (warnings against consuming certain fish) from 1993 to 1998. Much of the mercury originates as smokestack emissions and falls to Earth with rain and snow.

Farm chemicals from states in the Midwest have flowed down the Mississippi River, helping feed a growing "dead zone" of barren, oxygen-depleted water in the Gulf of Mexico. The size of the dead zone ballooned in the early 1990s and grew to 7,500 square miles before shrinking last summer due to drought in the plains states.

Even where the problems are not so dramatic, chemicals in polluted runoff have created the equivalent of a low-grade toxic-waste spill that now extends to virtually every river and stream in the country. In a landmark survey completed in 1999, the U.S. Geological Survey (USGS) found at least one pesticide in almost every water and fish sample it collected. In fact, more than half the streams tested in the agency’s National Water Quality Assessment Program contained at least five pesticides. The levels of these individual contaminants were usually within EPA safety limits, but the combinations and ubiquity of the chemicals raised a troubling question: Do chronic, low doses of multiple pesticides add up to a greater risk for wildlife and people? "We simply don’t know the effects of sustained exposure to mixtures of chemicals on an aquatic ecosystem," says USGS scientist Bob Gilliom.

The seesaw fortunes of the Clinch River’s mussels are a case study in how changes on land can impact river species and throw entire ecosystems out of balance. Geology and geography conspired to make the waterway one of the world’s great habitats for mussels. Over time, the creatures became the biological cornerstone for a large and diverse wildlife community in and around the Clinch that includes more than 400 rare plants, animals and insects.

However, for an animal that lives in a rock-hard vault and can survive up to 60 years, the mussel is extraordinarily delicate. "Mussels were once 20 percent of the river’s entire biomass," notes Beaty, who conducts research for The Nature Conservancy.

By the late 1980s, the number of mussel species in the Clinch had dropped from 60 to 40, with 26 of the remaining species now facing a serious threat of extinction, scientists say. "The mussels are the piece of the puzzle that disappears first when things start to go wrong," Beaty says. "The good news is, if it’s early enough, even if you lose some of the species, there’s still a chance you can save the ecosystem."

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Undoing the damage caused by nonpoint pollution is never as easy as closing a factory or turning a faucet. The modest recovery of the Clinch River and its mussels is the result of a decade of work by dozens of groups to neutralize, one by one, the many small problems that caused the river’s water quality to worsen in the first place. Farmers in the area, for instance, with financial assistance from government agencies, have begun fencing in their pastures to keep livestock out of streams. The same sort of slow-but-sure approach is working to help prevent runoff in rivers elsewhere.

In Boston, federal and local leaders have seen a turnaround in the polluted Charles River in the past five years, through the use of TMDL plans and a crackdown on communities with outdated stormwater systems. The Charles is one of the nation’s most heavily used recreational rivers. Yet in 1995, authorities rated it too dirty for swimming 81 percent of the time.

An aggressive cleanup effort launched that same year took aim at illegal sewage hookups and storm runoff from more than 30 towns along the river’s banks. A study of the Charles, initiated in 1994 by the Charles River Watershed Association (CRWA), proved conclusively that point-source pollution remained a serious problem in the river. As a result, the EPA ordered local governments to begin a comprehensive search for pollution sources, which discovered hundreds of them. "Over the years, with municipal budgets stretched, it’s been easy to allow funds for sewer and storm-drain maintenance to disappear," says CRWA Executive Director Bob Zimmerman.

The payoff for such efforts came last summer, when the Charles fell short of federal swimming standards only 35 percent of the time and earned an above-average rating from the EPA. "Removal of point sources has made a difference," says Zimmerman. "Getting the river clean the rest of the way, however, is likely to be more difficult."

In northwestern Montana, residents along tiny Elk Creek were moved to action after the stream’s renowned cutthroat trout began disappearing. The

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problem: The fish’s spawning and feeding grounds were seriously damaged by runoff from nearby development and streambed erosion.

The Elk’s fast waters run through mountain gorges and valleys that traditionally were blanketed with a dense covering of evergreens. The trees provided shade, organic matter and shelter for trout, whose size and numbers were legendary. But by the mid-1990s, developers, farmers and loggers had stripped many of the valleys of their trees. The Elk’s denuded banks rapidly eroded, and the creek’s famously clear water turned brown with sediment. As the fish became scarcer, watershed residents began looking for ways to restore the Elk.

Starting with only a few dozen volunteers, the stream’s boosters planted thousands of trees and shored up miles of riverbanks with retention walls made of tree stumps. Today the trout are rebounding, and Elk Creek has become only the third waterway in state history to graduate from Montana’s official list of "impaired" waterways.

"None of us were environmental maniacs, but we all wanted a healthy creek," says local resident Mike Miller. "What we kept hearing was we had to look at the entire watershed. We had to make sure we didn’t have problems upstream that would blow out what we were doing downstream."

For other watersheds, cleanup progress has been maddeningly slow. Neighbors of Lake Tahoe on the California-Nevada border, for example, still have little to cheer about after nearly 40 years of efforts to restore the lake’s famous crystal clarity.

Tahoe is North America’s largest alpine lake and the eighth-deepest freshwater body in the world. A century ago, its waters were so pure a visitor could see objects at depths of more than 100 feet. But runaway development in recent decades brought changes that sullied the lake’s waters. Today the maximum depth for visibility has dropped to 69 feet and is worsening at a rate of a foot a year. A study last year warned the lake’s clarity could be "irreversibly doomed," and many of its fish and wildlife lost, without a dramatic restoration effort.

Attempts to curb runoff at Tahoe are now underway. Local authorities from communities along the lake have adopted some of the nation’s toughest curbs on runoff, requiring landowners to, for example, install water traps and overflow tanks to prevent rainwater from leaving their property. But even with such measures, it may be years before significant improvements are seen.

"There’s no easy fix for these problems," says Murray. "But in a lot of communities, people are coming up with workable solutions. It makes you wonder: What’s holding back the states from doing the same?"

NWF Priority: Safeguarding America’s Watersheds

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The above map shows the results of an NWF assessment conducted last year of state efforts to control nonpoint pollution using the watershed-restoration provision of the Clean Water Act. In the study, NWF assigned a grade of "D" or "F" to 38 states. A dozen others earned a "C" or "B," and no state received an "A." "There are other tools to control runoff," says Kari Dolan, an NWF water resources specialist. "However, because many sources of polluted runoff are industries with political might, some states lack the leadership to confront them. That is why the Clean Water Act restoration provision is essential."

The study is part of NWF’s ongoing Saving Our Watersheds program, designed to provide citizens with an understanding of how watersheds work and what tools are available to help protect local lakes, rivers and estuaries. NWF currently is working with activists and scientists on specific watershed projects throughout the country, including:

In Vermont and New York, NWF is part of a team creating a cleanup plan for a polluted river in the Lake Champlain Basin. NWF also initiated an effort to reduce mercury and polluted runoff in the lake.

In Alaska, NWF is working with Native organizations and other environmental groups to defend the vast Copper River Delta against logging, mining and other water-quality threats.

In Georgia, NWF played a key role in forming a citizen-led coalition addressing problems in the Upper Suwanee River Watershed.

In Minnesota, NWF is part of a unique partnership between industries, municipalities and conservation groups that is developing solutions to stem mercury pollution in the St. Louis River.

In Delaware, NWF and its affiliate, the Delaware Nature Society, are providing information to citizens who are concerned about protecting the Christina River Basin. The program includes training volunteers to conduct periodic water monitoring.

Back to story.

Joby Warrick is a staff writer for The Washington Post.

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Please help us to protect our natural resources, reuse or recycle this paper when you are done.

© 2007 National Wildlife Federation, All rights reserved. - Read more great stories online at www.nwf.org/nationalwildlife

Application Phase:

Review the data that you recorded on page 8 for your water sample and your control (distilled water) to make sure that all your readings were accurately recorded. Collect the data from the other two groups so that your group has measurements for all the three water samples. Review the water quality data for all the three samples, compare and contrast the measurements and write down any differences between the measurements for the three samples below.

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Using your knowledge about the likely types of pollutants from human activities that get washed into urban water bodies and the results of the measurements that you have reviewed above, identify the source of each of the three water samples.

Note: Remember that the samples are from the Missouri River in Parkville, Brush Creek close to the Mission Hills Golf Course, and a creek near an industrial site.

Terms: Water quality, ponds, lakes, rivers, creeks, Salinity, conductivity, dissolved ions, fresh water, pollutant, Total Chlorine, Free Chlorine, Total Hardness, Total Alkalinity, PH, hydrogen atoms, minerals, calcium, minerals, soils, rocks, human activity, biological productivity, eutrofication, dissolved oxygen, biochemical oxygen demand, turbidity, erosion, watershed, point source pollution, non-point source pollution, conservation.

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Lesson 2Seeing the Blues

Safety Note: The solution in the bottle provided during this activity is unknown to you. It is an aqueous solution. DO NOT OPEN THE CONTAINER! All of the components of the solution dilute and relatively harmless in dilute quantities. However, if you get the solution on you wash it off. Do not touch your eyes, face, etc. before washing.

Exploration Phase:

Activities

A. Laboratory Instructions o Obtain a bottle of the unknown solution from the supply table. o DO NOT OPEN THE CONTAINER! o Shake the unknown solution. o List several observations (at least 3).

B. Laboratory Instructionso Shake the unknown solution again. o Measure the length of time the color change remains. Repeat 3

times. o Record the times below.

C. Laboratory Instructionso Place the bottle of unknown solution in an ice bath for 5 minutes. o Shake the unknown solution again. o Measure the length of time the color change remains. Repeat 3

times. (do not re-cool in the ice bath)o Record the times below.o Repeat with a warm water bath. (do not re-warm)

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Record data for B and C here.

Relative temperature

Time in seconds the unknown solution remains blueTime 1 Time 2 Time 2 Average

Room temperatureIce BathWarm Water Bath

Please determine the class averages for each temperature condition.Average Time for Room Temperature

Average Time for Ice Bath

Average Time for Warm Bath

How do your time values compare to the class averages?

Write an explanation for the results of the experiment.

Concept Introduction:

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Exploration Phase: Activity 1--When the solution is shaken it turns blue because oxygen dissolves causing a reversible oxidative-reduction reaction. Methylene blue is a redox reaction indicator. When the oxygen comes out of solution the clear color returns. Sometimes it's possible to see blue color at the surface of the solution. A decrease in temperature cause the solution to stay blue for a longer period of time because gas solubility increases and temperature decreases. 

Based on our observations we can only safely conclude that the air dissolves in solution to cause the color change.  

Chemical Explanations (including important chemical equations):

Essentially, it is an oxidation-reduction reaction. The bottle contains sodium hydroxide, glucose, water, and an indicator called "methylene blue". Glucose is a reducing agent and in an alkaline solution it will reduce methylene blue to a colorless form. Shaking the bottle allows the oxygen in the air to oxidize the methylene blue to the blue form. Upon standing it is reduced by the glucose back to the colorless form. The equations for the reaction are:

  when shaken: O2 + MB (colorless) -> MBox (blue)

  upon standing: RH + OH- -> R- + H2O

    MBox + R- -> MB + oxidation products of glucose

where MB is the reduced (colorless) form of methylene blue, MBox is the oxidized (blue) form of methylene blue, and RH represents glucose.

Methylene blue is an example of a "redox indicator".

 

Main idea: Gases are soluble in aqueous solutions ( or water).

Secondary idea: Solubility of a gas in an aqueous solution is inversely proportional to temperature.

Tertiary idea: The color change results from the reversible oxidation-reduction reaction of the methylene blue indicator

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Other: refraction of light.

References

The chemical explanation came from School of Chemistry at the University of Tasmania, http://www.scieng.utas.edu.au/chem/

Application Phase:

Relate these basic physical concepts that you explored above to explain why thermal pollution of water bodies is an environmental problem.

What are the sources of thermal pollution that you are familiar with?

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Why are Trout raised in cold water?

What happens to carbonated soda when left out unsealed?

Why do fish tanks have bubble making devises?

Careers where knowledge of gas solubility is required.

US Nave Experimental Diving Unit

Consolidated Divers Unit US Navy

 

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@

Concept Mapping Terms: Aqueous Solution, solubility, chemical reaction, oxidation, reduction, concentration, solutes, solvents, matter, energy, Methylene blue, temperature, oxidation-reduction reaction, sodium hydroxide, glucose, water, redox indicator, gases, trout, thermal pollution, bubbles. Add five or more terms of your own.

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Teacher Notes Topic

Gas solubility in an aqueous solution

   National Standards Addressed

Chemical Reactions: A large number of important reactions involve the transfer of either electrons (oxidation/reduction reactions) or hydrogen ions (acid/base reactions) between reacting ions, molecules, or atoms.

Geochemical Cycles: Carbon, for example, occurs in carbonate rocks such as limestone, in the atmosphere as carbon dioxide gas, in water as dissolved carbon dioxide, and in all organisms as complex molecules that control the chemistry of life.

ABILITIES NECESSARY TO DO SCIENTIFIC INQUIRY: FORMULATE AND REVISE SCIENTIFIC EXPLANATIONS AND MODELS USING LOGIC AND EVIDENCE.

    DESE Science Curriculum Frameworks Addressed

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Matter and Energy A. Properties, Characteristics and Structures of Matter: Solution properties depend upon the concentrations, properties, and interactions of the solutes and solvents.

Scientific Inquiry B. Investigations: The testing of a hypothesis requires a structured and rigorous investigative process.

Grade Level

High School Science (grade 9-12)

Process Skills

Observing, collecting data, explaining

Materials

Exploration Activity Solution

1.   To a 1000 ml beaker add 40 grams of glucose and approximately 700 ml of water.

2.      Add 100 ml of 95% ethanol to glucose solution and add water to the 1000 ml mark.

3.      To a 1000 ml beaker add 40 grams of NaOH and add water to the 1000 ml mark.

4.      Mix 0.5 grams of methylene blue to 100 ml of 50% ethanol.

5.   Mix the following together:

500 ml of glucose solution 500 ml of NaOH solution 5 ml of methylene blue solution

Let blue color clear and place in observation bottle (100 ml bottles with lids). This solution will remain reactive for about 6 hours).

Ice water and warm water bath. 

 Application Activity Solution

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1. In many places in the KC metro area tap water is basic enough to turn Phenolphthalein pink. (or just add a very small amount of dilute NaOH to water. You may have to play with it to get the amount right). Prepare about 1 liter (you can chose to add or not add the Phenolphthalein here).

2.  30 straws.

Estimated Time to Complete Lesson        60-75 minutes  

Lesson 3GLOBE Data Entry & Visualization

(www.globe.gov)The GLOBE Program: GLOBE is a worldwide hands-on, primary and

secondary school-based education and science program developed as an interagency program of the US Government with funding from NASA, NSF and the State Department. Students in GLOBE affiliated schools have the opportunity to learn by taking teacher-directed scientifically valid measurements in the fields of biology, earth science, and environmental science; reporting their data through the Internet; and creating graphs or maps on the GLOBE interactive Web site to analyze data.

All GEOPATHS participants will receive training and be certified on several GLOBE exploration and science investigation protocols. Each school represented in GEOPATHS has been assigned a unique site ID, which allows teachers and students from those schools to report student generated data on the GLOBE website. The data reported by students from thousands of schools worldwide will also be available to GEOPATHS teachers and their students for data exploration or math-science integration activities.

This computer-based lesson will enable GEOPATHS participants to become familiar with the GLOBE website and the procedures for uploading and visualizing data using the GLOBE web portal.

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Step 1: Log on to the GLOBE Data Input Training website http://training.globe.gov

Step 2: Practice Data Entry After successfully logging on to the training site (http://training.globe.gov), you are now ready to practice entering data. Please hold your mouse over the heading “For Students” and select “Data Entry”.

Once you are on the main page for Data Entry, you can see several colored boxes such as “Site Definition”, “Atmosphere/Climate”, “Hydrology”, etc… You will notice that as you roll your mouse over each title, the options for that particular investigation will appear. For now, please roll your mouse over “Site Definition” and select “Define, Edit, or Update a Site”.

Here you will see headings for your school location as well as sites for Atmospheric Measurements, Hydrology, etc…Please select “Edit your School Location”.

You will notice that your Latitude and Longitude coordinates have been automatically generated based on the school address you provided. Please fill out all fields marked with an asterisk. “Measurement date” will be the only required field if you do not have more accurate GPS coordinates. You may also submit any additional comments such as “We are surrounded by high rise buildings and our school is in the shade.” or any other pertinent information in the “metadata” section found at the bottom of the page. If you have a GPS unit, it is recommended that you edit your coordinates in order to be as accurate as possible. Please follow the directions in the GPS protocol found here: http://www.globe.gov/tctg/gps_prot.pdf?sectionId=46 . You may choose to “average your coordinates” by selecting the link and entering your GPS data. Please make sure to select the button “GPS” if that is how you obtained your coordinates.

At the bottom of the page, select “send data” to submit your changes. You should see smiley faces when your data has been accepted.

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Your input has passed system checks! Step 3. Define your Atmospheric Site:

After logging on to the GLOBE Web site, select “Data Entry” from the left hand column. Holding your mouse over the section “Site Definition”, selecting “Define, Edit, or Update a Site” will bring up the page you need. From here, under the heading “Sites for Atmospheric Observations” select “Define a New Site”.

Please fill out all required fields marked with an asterisk. (Date, Name, Coordinates, and Thermometer Type are the only required fields.) You will notice that you can use the same coordinates as your school location, or you may enter new coordinates if your site will be away from the building. Please remember, the more accurate you can be, the better. You may refer to the protocol for defining your atmospheric site for help in determining the best location for your site. Be sure to look at the frequently asked questions at the end. You will find this to be very useful:http://www.globe.gov/tctg/atinst.pdf?sectionId=7 . (Scroll down to the section about defining your site.)

You can always come back to edit or update any of the fields, so if you do not have an instrument shelter, rain gauge, or thermometer yet, you can skip this for now. Please choose “no thermometer” if this is the case (required field).

At the bottom of the page, select “send data” to submit your changes. You should see smiley faces when your data has been accepted.

Your input has passed system checks!

You may wish to add additional sites at this point if you are using protocols from other investigation areas.

You are now ready to submit your data!!!

How to Submit Data

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Now that you have defined your School Location and Atmospheric Study Site, you are ready to enter data.

Please follow the steps above to log on to the GLOBE Web site. Select “Data Entry” from the left hand navigation panel.

Holding your mouse over the section “Atmosphere/ Climate”, choose the appropriate data sheet. You will notice there are choices for 1 or 7 day forms. This allows you to enter multiple days on the same form. All measurements that are reported on the 7 day form must be taken within one hour of local solar noon. If any of your measurements were taken outside of this window, you must use the 1 day form. See below for more details about local solar noon.

Again, you can refer to the teacher’s guide for additional information about the specific protocol you are participating in. The atmosphere chapter can be found here:http://www.globe.gov/tctg/tgchapter.jsp?sectionId=1 .

A note about Universal Time:

You will notice that all measurements must be entered in Universal Time (UT). To determine the conversion between your local time and Universal Time you may want to look at the current time displayed in UT on the GLOBE homepage (found just above the left hand navigation panel mentioned above) or on any data entry page and compare that time with your local time. Once you have calculated the difference, you can apply this correction to the times of your observations. Be sure to pay attention though, when daylight savings time begins or ends. You will need to adjust your conversion again when that occurs. Always be sure to enter the time you made the observation, and not the time that you are entering it into the computer.

A note about local solar noon:

You are encouraged to make all atmospheric measurements within one hour (plus or minus) of local solar noon. To determine the time of solar noon in your location, you can use the link in the lower right hand corner of the data entry page “Solar Noon Calculator”. For instance, if your local solar noon is determined to be 19:22 UT, you are encouraged to make your observations between 18:22 and 20:22. If your measurements were taken within this window, you may use the 7 day data entry form. However, if any of your measurements were taken outside of this window, please use the 1 day data entry form,

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and select the box to acknowledge your measurements were taken outside of this window. This is how it appears on the 1 day data entry page:

Check here if your measurements were not taken within one hour of Local Solar Noon.

The only measurement that is mandatory to be taken within this window is precipitation. All other atmospheric observations can be made outside the solar noon restriction as long as the box has been checked.

Of course, if you have any questions at all, feel free to contact the GLOBE help desk by e-mailing to help@globe.gov or you may call us toll free 8:00 AM to 4:00 PM MST Monday through Friday at 1-800-858-9947.

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