THE QUALITY OF DRINKING WATER IN MIAMI UNIVERSITY DORMS
Austin, Matt, Adam
Introduction and Relevance of Study:
The purpose of our lab is to test the quality of the drinking water of the dorms here at Miami University. In order to get a well rounded sample of the quality of the dorms from all areas of the campus, we will be testing a dorm from each of the north, south, east, west, and central areas of campus. Distilled water will be used as a control in our lab. We will use several testing methods to gain information on the characteristics of the water, including a taste test which will give students the opportunity to rate the taste of the water in each dorm, as well as distilled water. We will then compare the water quality of the dorms, and distilled water to the Environmental Protection Agency's (EPA) standards for drinking water. In addition to our tests, we will further test the quality of water after it has been filtered through a popular water filter (Brita). It is our hypothesis that the composition of the water of each of the dorms will vary, and that distilled water will be far superior in taste, and purity.
We decided to test the quality of the drinking water in the dorms because the quality of the water did not meet EPA standards, and we want to know with absolute certainty that those problems have been corrected. The quality of drinking water can be problematic, with various toxins, bacteria, and organisms causing illness, and sometimes lead to chronic health problems.
Past studies, along with the ever-continuing outbreaks of microbiological diseases in water systems, show us that the quality of drinking water is an issue, which even today has many health-related areas of concern. In the 17 years from 1832 to 1849 the annual death rate in London rose from 10-110 deaths per 10,000 population to over 200 deaths per 10,000 population. This occurred as the plumbing, and flush toilet systems were being introduced to the city (Identifying, 1999). This is perhaps one of the earliest evidences of public drinking water problems. Of course it has gotten much better, but there are still problems with public water systems, and with systems which deliver the water after it has left the distribution and treatment center.
The Committee on Small Water Supply Systems2C of the National Research Council, mentions in their book, Safe Water from Every Tap: Improving Water Service to Small Communities, that nearly 600 waterborne disease outbreaks have been reported in the past two decades (Safe, 1997). The Committee on Drinking Water Contaminants, Water Science and Technology Board, Board on Environmental Studies and Toxicology, of the National Research Council say that chemical and microbiological contaminants still occur in drinking water supplies (Setting, 1999). From statements like these, it is clear that drinking water can have hazardous toxins and elements, which can be detrimental to health.
There are many elements which can deteriorate the quality of drinking water, increasing the health risks. For instance: Radon concentrations of 10,000,000 Bq m-3 or more are known to exist in public water supplies, which are far greater than the typical concentration of 4000 Bq m-3 (Risk, 1999). These amounts of radon in drinking water could potentially produce adverse health effects including lung cancer (Risk, 1999). Copper is also an element which is known to cause health deficiencies from excess consumption in water. The Committee on Copper in Drinking Water, of the National Research Council mentions that, acute ingestion of excess copper in drinking water is associated with adverse health effects, including acute gastrointestinal disturbances, and chronic ingestion of copper can lead to liver toxicity in sensitive populations (Copper, 2000). Another contaminant that can pose a potential threat in drinking water is arsenic, which is associated with an increased risk of hypertension and diabetes (Arsenic, 2001). All of these elements are known to have existed in excess in public water supplies, putting the population at risk.
Although public water is tested regularly, the quality of a public water supply may deteriorate after it leaves the treatment plant where it is tested (Drinking, 1). So when is our water really safe? Ensuring the safety of public drinking water is no small task, and will not be accomplished in any one legislative act. A Committee in Drinking water contaminants of the National Research Council says that, "continuing public health vigilance is necessary to ensure that drinking water contaminants, especially newly identified ones, are appropriately addressed" (Classifying, 2001). Some even feel that our drinking water is getting worse than it has been in the past. Erik Olson, senior attorney at the Natural Resources Defense Council (NRDC) in Washington, D.C., states, "the drinking water supply in this country is definitely getting worse, and we're only beginning to uncover the problem areas" (Kotz, 95). This is why our group has decided to test the water here in the dorms at Miami University, as our expression of vigilance in the name of public health, and in escape of the naiveties of idleness.
Another reason we are conducting this lab is to find out why the water in the dorms tastes "peculiar", and whether or not a water filter can help rid this problem. Some of us feel that our taste buds are being abused, and we want to know why. From the results of the purified water tests we will be able to discern if a filter adequately purifies the water. We are predicting that a filter will improve the taste and purity of the water noticeably. We hope to involve the entire class in the taste testing. Through our lab we hope to find out if students should be concerned with the quality of the drinking water in their dorms. Should students invest in a water filter? Is it needed, and does it really clean the water? These are questions we hope to answer in our lab, which is part water safety testing and part consumer report for water purifiers.
Materials and Methods
1. Water jugs to collect water
2. Water samples from Peabody, Anderson, Collins, Hepburn, Bell Tower, and distilled water.
3. Paper cups for water sampling
1. Collect water samples from the six sources and label them 1-6 we will collect the water samples around the same time from drinking fountains with in these buildings.
2. We will hold a taste test session in which each person in the class is given the 6 water samples numbered 1-6
3. Before we let the students drink the water we will chill the water to a designated temperature therefore the students are not basing their decision on which sample is cooler or which sample is the hottest.
4. Everyone in the class will be given a data sheet in which they will provide us with the way they think the water ranked 6 being best tasting and 1 being worst tasting.
5. After everyone has completed the taste test and filled out the data sheet we will compile a chart that indicates where the different samples ranked
This testing method will be unbiased because the students do not know where the water is coming from because the samples will be marked with 1-6 and only the proctors of the sampling will know where the water is coming from.
1. Test tube
2. Water samples
3. Electronic pH Detector
1. Fill the test tubes up with water samples from the six different locations and label them.
2. Then place the pH Detector in each of the samples and wait for the reading.
3. When you receive your reading you have the amount of pH in the sample.
1. Water samples
2. Iron reagent #1
3. Iron reagent #2
4. Spoon, 0.05g
5. Test tube
6. Octect Comparator, Iron
1. Fill the test tubes with the water samples and label 1-6 to prevent a bias
2. Add 5 drops of iron reagent #1 then cap and mix
3. Use the spoon and add one level spoon full of iron reagent #2 powder then mix and wait 3 minutes
4. If iron is present in the water, a pink color will develop. Then insert the test tube into the Iron comparator. Match the color to the color standard.
5. Depending upon the amount of iron in the water a pink to deep red color will be present. A trace of iron is apparent if the water that turns a shade of pink. However, a high concentration will produce a dark red color.
TOTAL HARDNESS TEST
1. Water samples labeled 1-6
2. Hardness Reagent # 6 tablet
3. Hardness reagent #5
4. Sodium hydroxide reagent with metal inhibitor
5. Calcium hardness indicator tablets
6. Hardness Dr titration tube
7. Direct Reading Titrator, 0-200
1. Fill the Hardness Dr Titration Tube to the mark with our sampled water
2. Then Proceed to add 5 drops of Hardness reagent #5 and mix. Add one hardness reagent #6 tablet and stir until the tablet is disintegrated. A red color then should develop.
3. Next, proceed to fill the direct reading titration with the hardness titration reagent #7
4. Then add the hardness titration reagent one-drop at a time, stirring to mix after each drop, until red color changes to clear blue.
5. The result is read then directly from the direct reading titrator. Record the Hardness in ppm Calcium Carbonate.
1. Water samples labeled 1-6
2. Copper 1 Reagent
3. Standard color reagent
4. Test tubes A & B
1. First, fill test tube A with the sampled water.
2. Then proceed to drop dive drops of Copper Reagent and mix. If the water turns yellow then copper is present in our water sample.
3. Next, proceed to fill the second test tube to the lower line B with distilled water.
4. Then add the Standard Color Reagent to test tube B 1 drop at a time counting the drops and mixing after each addition. Then proceed to hold the two tubes about one- half inch above a plain white surface and look down through the tubes to compare colors. Continue adding color reagent to the second tube until the colors match the reaction in the first tube.
5. The test is then calculated as:
6. Copper (ppm) =0.025 x No. drops color reagent
1. Water samples labeled 1-6
2. Chloride 2 powder pillow
3. Silver Nitrate Titrant
4. Plastic Measuring tube
5. Mixing bottle
1. Fill the plastic measuring tube level full with the water.
2. Transfer the contents of the tube to a mixing bottle .
3. Add the contents of one Chloride 2 Indicator Powder Pillow to the mixing bottle and then mix.
4. Add the Silver Nitrate Titrant drop by drop to the mixing bottle, count each drop as one is added.
5. Shake the mixing bottle after each drop
6. Continue to add drops until the solution changes from yellow to red-brown
7. If the precipitate is orange but the solution color is yellow, greater agitation is required.
1. Water samples
2. 4 small test tubes
3. Liquid used for finding bacteria
4. Water dropper
1. One test tube is filled with the liquid used for the discovery of bacteria and 1 ml of the sample water is dropped into the test tube.
2. Shake up this sample thoroughly.
4. Then use the eye dropper to fill up the other three test tubes with 1 ml from the full bottle.
5. Then let the tubes sit for 24-36 hours.
6. Depending on the amount of bottles that have become cloudy and filled with bacteria, it will be clear how much bacteria is in each of the sample.
pH Copper Hardness Iron Bacteria
Water Samples Tested: Before Brita After Brita
Water Samples (Ranked 6-1 Based on Taste): Before Brita After Brita
Week 9 (10/16-10/18) Ph Tests
Week 10 (10/23-10/25) Iron and Hardness tests
Week 11 (10/30-11/1) Bacteria and Taste Tests
Week 12 (11/6-11/80) Copper and Further Taste Tests
Week 13 (11/13-11/15) Research Review and Analysis
In the taste test, we had the tests takers rank the water from 1-6, 1 tasting the worst and 6 tasting the best. We did this test before using the Brita water filter and after using the Brita. All of our results were added up and then averaged to find the final results. The test participants ranked Anderson 4, Belltower 3.5, Collins 1.7, Hepburn 2.9, Peabody 3.3, and Distilled water 1.5. These results show us that before the Brita our sample audience of 30 people thought Anderson’s water tasted the best and that distilled water tasted the worst. After we ran the water through the Brita filter we found that out audience Anderson 2.9, Belltower 2.5, Collins 1.5, Hepburn 2.7, Peabody 3.0, distilled water 1.3. These results show us that Anderson still has the best tasting water and the Distilled ranked the lowest.
If the water contains more alkaline than a pH level of 8.5-9.0 and more acid than a pH of 5.0, you should exam the water for possible contamination. The secondary level for pH is 6.5-8.5. The tests found that Anderson was 7.073, Belltower was 7.028, Collins was 6.818, Hepburn was 6.851, Peabody was 6.844, and Distilled water was 6.814. On the pH scale that ranges from 1-14 we found that Belltower has the best pH with a level of 7.028 because it is the closest to 7.0, which is neutral. When using the Brita water filter we found that the results were inconclusive. Some of the pH values went up and some went down showing the Brita had little to no effect on the pH value.
Iron is known to be found in water samples that have been contaminated by acid mine wastes. The secondary level for iron is .3 mg/l. Our results found that Anderson had .09 mg/l, Belltower had .031 mg/l, Collins had .017 mg/l, Hepburn had .02 mg/l, Peabody had .001 mg/l, and the distilled water had 0 mg/l. After finding the results, the Brita test was used which completely eliminated any iron in all of the water sources. All of the dorms had 0 mg/l after the Brita test.
The higher level of copper found in water will cause a more bitter taste. The normal level of copper is 1.3 mg/l and the secondary level is 1.0 mg/l. The results showed that Anderson had 1.0 mg/l, Belltower had 1.0 mg/l, Collins had 2.0 mg/l, Hepburn had 1.0 mg/l, Peabody had 1.0 mg/l, and the distilled water had 0 mg/l.
The Brita removed any copper found in the water giving all six water samples 0 mg/l.
Total hardness is highly valued when studying water quality due to the high content of calcium and magnesium ions. Most natural water is known to have a high level of hardness. Our results proved this and also that hardness has an effect on the taste of the water. The normal level of hardness is 25 grains/gallon. Anderson had 19 grains/gallon, Belltower had 26 grains/gallon, Collins had 2 grains/gallon, Hepburn had 28 grains/gallon, Peabody had 26 grains/gallon, and the distilled water had 1 grain/gallon. After the Brita test was completed it lowered the hardness amount significantly in all the samples. Anderson had 6 grains/gallon, Belltower had 8 grains/gallon, Collins had 1 grain/gallon, Hepburn had 9 grains/gallon, Peabody had 7 grains/gallon, and the distilled water had 1 grain/gallon.
The secondary level of contamination for chloride is 250 mg/l. This is not an official law that needs to be followed but should be taken into consideration. Our results showed that Anderson had 1,500 mg/l, Belltower had 2,000 mg/l, Collins had 2,000 mg/l, Hepburn had 1,500 mg/l, Peabody had 2,000 mg/l, and the distilled water had 500 mg/l. The Brita test did not completely erase the chloride but lowered it considerably. All of the samples after the Brita test had 500 mg/l.
The heterotrophic plate count measures a range of bacteria that are naturally present in the environment which have no health effects. It is likely that any bacteria measured falls into this range. However the lower the bacteria count, the better maintained the water system. When testing four tubes were used for each sample and the amount of bacteria present was shown by the amount of bottles with bacteria in them. Our results showed that Anderson had 3 bottles or 100-1,000 bacteria/ml, Belltower had 1 bottle or 1-10 bacteria/ml, Collins had 3 bottles or 100-1,000 bacteria/ml, Hepburn had 1 bottle or 1-10 bacteria/ml, Peabody had 2 bottles or 10-100 bacteria/ml, and the distilled water had 4 bottles or 1,000 + bacteria/ml. The Brita test had no effect on the results because it is not designed to remove bacteria from water.
When we were finished with our tests we faced the problem of forming a conclusion from all of the data we collected. At the beginning of our project we thought that the distilled water would taste the best because it was the purest water from all are water samples. We assumed the water with the most components would taste the worst because the components in the water would decrease the taste quality of the water.
As we proceeded with our test we expected to see a relationship develop between the taste of water and the purity of the water. After completing our taste test and our experiments we noticed that the pure water (distilled) was the worst tasting while the water with the most components (Anderson) was the best tasting.
We organized our results using statistics and stat view software. Once we entered our raw data into the computer we ran paired t-tests on every possible pair of variables. Regretfully we did not find any correlations between the data. All of the p-values were below .05, and thus we had to reject the null hypothesis that there is a statistic correlation between the variables. After doing some research we discovered that the proper test for this situation to find correlation was the Spearman Rank Correlation (SRC) test. The SRC test first takes the raw data and ranks the values on an ordinal scale, then uses the same equation used in the Pearson Correlation test analyze the correlation. This equation is simply r = sum (zXzY) / N (Statistica, 2002). The correlation coefficient, r, ranges from -1 to +1. The nonparametric Spearman correlation coefficient, Rho, has the same range and works as follows:
Value of Rho: Interpretation:
r = 0 The two variables do not vary together at all.
r = 1.0 Perfect correlation.
r = -1.0 Perfect negative or inverse correlation. (Analyzing,2002)
In the SRC test, if the P value is smaller than .05, you can reject the idea that the correlation is a coincidence, and accept the null hypothesis that there is a statistical correlation (Analyzing, 2002). However, a p-value larger than .05 does not necessarily mean that there is no correlation between the variables, but that the chance of random numbers from similar data sets having the same correlation as these variables is high. When we ran the SRC test on iron and pH we ended up with a p-value of .0350, and a rho value of .943. This means that there is a positive scientific correlation between these two variables, and this is not by chance; thus we accept the null hypothesis. The next SRC test we ran was between taste and pH. We found that there is a very strong positive correlation between the two variables because there was a rho value of .943 and had a p-value of .0350. Again we accept the null hypothesis that this correlation is not by chance. After running these two SRC tests, we noticed a close relationship forming between iron, pH, and taste. When we ran a SRC test for taste and iron there was a rho value of .829 but it had a p-value of .0639. The p-value was greater than .05 so we had to reject the null hypothesis that this correlation was not by chance, but the rho of .829 shows that there is a strong positive correlation between the two variables. The other correlation we found is between bacteria and hardness. They formed a negative correlation because the rho value was -.857 and the p-value was .0355. Once again we accept the null hypothesis that the variables scientifically correlate.
Although correlation does not necessarily mean causation, we can make the logical interpretation that higher levels of Iron relates to higher levels of pH, which in turn increases the quality of the taste of the water. This correlation tells us that it was not by chance that the water which had the highest pH, and iron values ranked best in the taste test. Our results also showed that bacteria and hardness had a negative correlation we can assume water with high hardness levels result in lower bacteria levels.
After reviewing all of our data, we have concluded that part of our hypothesis was true, and that part was incorrect. The first part of our hypothesis was that the composition of the water of each of the dorms would vary -- this is true. We also hypothesized that distilled water would be “far superior” in taste -- this is not the case. On the contrary, distilled water was ranked worst in the taste test.
In a past study done on drinking water, chemicals were shown to have an effect on the taste of the drinking water. Our findings bring us to the same conclusion. In the lab we made some striking discoveries. From our tests we found the water that contained the most inorganic material tasted the best. This was evident when people voted distilled water the worst tasting and Anderson the best tasting. Distilled water contained the least amount of inorganic material, and Anderson which contained high levels of iron, and pH, and moderate levels of chloride, copper, and hardness tasted the best. Although there were no scientific correlations between the taste and hardness of the water, it does appear that very low levels of hardness decrease quality of the taste of the water because the two samples with the lowest hardness were the least favorite.
Another part of our study was to compare our results to the EPA’s MCL’s (maximum contaminant level). We didn’t hypothesize that the drinking water in the dorms would, or would not meet the EPA’s standards for drinking water, but we did come up with some interesting findings. We were pleased to find that all of our samples tested below the EPA’s primary and secondary MCL’s for iron and pH. The EPA does not list a primary MCL for chloride, so we can assume that the chloride levels are safe. The secondary MCL for chloride were not meet, except for the distilled. Because the secondary level for chloride is below the minimum level that we can test at, potentially all of the samples could be below this level after being filtered through the Brita. Our results for copper showed all of the samples to be at or below the primary MCL except for Collins. Collins’ level was 2 mg/L, which was above the MCL of 1 mg/L. We do not take this to be a danger due to the fact that the measuring system is not exact, and because it is very close to 1 mg/L. When testing for hardness, all of the samples were near the normal range of 25 grains/ gallon, with the exception of the Collin’s and distilled samples, which had levels of 2 and 1 grains/ gallon.
The biggest scare in our results came from the bacteria tests. Three of the six samples tested showed bacteria levels of 100-1000 bacteria/mL or greater, with distilled water showing a level of over 1000 bacteria/ mL. We were somewhat relieved to find that there were no available MCL levels for a range of bacteria, which are common in drinking water, and have no adverse health effects. It is likely that the bacteria discovered in our results fell inside this range; however, the drinking water systems with fewer bacteria are usually better maintained.
Ultimately, higher levels of inorganic material in water lead to a better taste. Although the levels of inorganic material in the water here at Miami University does not appear to have adverse health affects, the make up of the water often does not meet the EPA’s Secondary standards, and may have cosmetic affects such as skin and tooth discoloration. It has also been speculated that hard water is better for your heart, but the scientific evidence is not strong enough to prove that hard water causes your heart to be healthier (Kotz, 1995).
We also discovered that the “Brita” water filter didn’t make the water taste better. Perhaps it is just the coldness that makes the water taste better after it has been stored in the refrigerator. The “Brita” does lower hardness, copper, and iron, thus reducing adverse cosmetic affects that the water may have on the individuals who consume it.
Analyzing Data with GraphPad Prism: The Prism Guide to Interpreting Statistical Results http://www.graphpad.com/articles/interpret/corl_n_linear_reg/correlation.htm (2002)
Arsenic in Drinking Water: 2001 Update (2001, 244 pp.) Subcommittee to Update the 1999 Arsenic in Drinking Water Report, Committee on Toxicology, Board on Environmental Studies and Toxicology, National Research Council
Branstrator, –Final Report: The Effects of Inorganic Components of Water on Taste” Natural Systems Study, fall 1998.
Classifying Drinking Water Contaminants for Regulatory Consideration (2001, 255 pp.) Committee on Drinking Water Contaminants, Water Science and Technology Board, Board on Environmental Studies and Toxicology, National Research Council
Copper in Drinking Water Committee on Copper in Drinking Water, National Research Council, 2000.
Drinking Water and Health, Volume 4, Safe Drinking Water Committee; Board on Toxicology and Environmental Health Hazards; National Research Council, 1982.
Identifying Future Drinking Water Contaminants (1999, 276 pp.) 1998 Workshop on Emerging Drinking Water Contaminants, National Research Council
Kotz, Deborah "How Safe is Your Water?" (1995) WCP 121 articles.
Risk Assessment of Radon in Drinking Water (1999, 296 pp.) Committee on Risk Assessment of Exposure to Radon in Drinking Water, National Research Council
Safe Water from Every Tap: Improving Water Service to Small Communities (1997, 230 pp.) Committee on Small Water Supply Systems, National Research Council
Setting Priorities for Drinking Water Contaminants (1999, 128 pp.) Committee on Drinking Water Contaminants, National Research Council
Statistica Online: Statsoft (2002) U.S. Environmental Protection Agency’s Ground Water and Drinking Water Homepage (2002)
For Further Info on this Topic, Check out this WWW Site: www.epa.gov/safewater/ .
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