APES: Water Quality LabObjective: To test surface water for water quality.

Materials: Water testing kit (including tubes, vials, tablets, test strips)

Safety:Eye ProtectionHand SafetyClothing ProtectionChemical SafetyProper Clean Up

Note: All test samples except coliform bacteria, can be disposed down the drain by flushing with excess water.

A. Turbidity (Will Not Test) Turbidity is the measure of the relative clarity of water. Turbid water is caused by suspended and colloidal matter such as clay, silt, organic and inorganic matter, and microscopic organisms. Turbidity should not be confused with color, since darkly colored water can still be clear and not turbid. Turbid water may be the result of soil erosion, urban runoff, algal blooms, and bottom sediment disturbances which can be caused by boat traffic and abundant bottom feeders.

Higher turbidity increases water temperatures because suspended particles absorb more heat. This, in turn, reduces the concentration of dissolved oxygen (DO) because warm water holds less DO than cold. Higher turbidity also reduces the amount of light penetrating the water, which reduces photosynthesis and the production of DO. Suspended materials can clog fish gills, reducing resistance to disease in fish, lowering growth rates, and affecting egg and larval development. As the particles settle, they can blanket the stream bottom, especially in slower waters, and smother fish eggs and benthic macroinvertebrates. Sources of turbidity include:

B. Temperature (Will Not Test) Temperature is very important to water quality. Temperature affects the amount of dissolved oxygen in the water, the rate of photosynthesis by aquatic plants, and the sensitivity of organisms to toxic wastes, parasites and disease. Thermal pollution, the discharge of heated water from industrial operations, for example, can cause temperature changes that threaten the balance of aquatic systems.

C. Dissolved Oxygen Dissolved oxygen (DO) is one of the best indicators of general water quality. As a general rule, the higher the DO, the better the water quality. The solubility of oxygen is affected by temperature and by the partial pressure of oxygen over the water. The solubility of oxygen is greater in colder water than in warm water. Oxygen slips into "pockets" that exist in the loose hydrogen-bonded network of water molecules without forcing them apart. The oxygen is then caged by water molecules, which weakly pin it in place. When organic wastes decompose in water, dissolved oxygen is used up. Because aquatic organisms are “cold-blooded”, their metabolism rises as temperature goes up and the amount of available oxygen goes down. This often results in fish “kills”, especially if the DO drops below 5 ppm. Ideal levels of DO are between 6 and 15 ppm.

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CLASS

D. pH TestpH measurements are made on water because this is a good indication of whether the body of water might be contaminated, especially if the pH is above or below the normal range. A body of water with a pH range of 6.7-8.6 can support a wide variety of fish species. Algae grow best in water with a pH range of 7.5-8.4. Most aquatic organisms are adapted to a specific pH level and may die if the pH of the water changes even slightly. pH can be affected by industrial waste, agricultural runoff, or drainage from improperly run mining operations.

E. ChlorineChlorine in an aqueous solution is an excellent biocide and is used to treat potable waters (drinking water), municipal wastes, and swimming pools. In potable water, it also helps alleviate the adverse effects of iron, manganese, ammonia and sulfide. A chlorine concentration of 0.1-0.4 ppm is considered acceptable for safe drinking water. Over 0.5 ppm is usually evidence of contamination from industrial effluents or processes that use a high concentration of chlorine. Free chlorine is the chlorine that most actively sanitizes contaminants such as bacteria and water-borne diseases. The EPA suggests this level should be at 0.2 ppmTotal chlorine is the sum of free chlorine and combined chlorine (already reacted). Total chlorine levels above 1.0 ppm may give water an unpleasant odor and taste. The EPA has no recommendation for the concentration of total chlorine.

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F. Nitrate/NitriteNitrate is a nutrient needed by all aquatic plants and animals to build protein. The decomposition of dead plants and animals and the excretions of living animals release nitrate into the aquatic system. Excess nutrients like nitrate increase plant growth and decay, promote bacterial decomposition, and therefore, decrease the amount of oxygen available in the water.Sewage is the main source of excess nitrate added to natural waters, while fertilizer and agricultural runoff also contribute to high levels of nitrate.Drinking water containing high nitrate levels can affect the ability of our blood to carry oxygen. This is especially true for infants who drink formula made with water containing high levels of nitrate. The MCLG (maximum contaminant level goals) for nitrate is 10 mg/L or 10 ppm. Nitrates and nitrites are nitrogen-oxygen chemical units which combine with various organic and inorganic compounds. The greatest use of nitrates is as a fertilizer. Once taken into the body, nitrates are converted to nitrites.Infants below six months who drink water containing nitrite in excess of the maximum contaminant level (MCL) could become seriously ill and, if untreated, may die. Symptoms include shortness of breath and blue baby syndrome. The MCLG (maximum contaminant level goals) for nitrite is 1 mg/L or 1 ppm.

G. PhosphatePhosphate is a nutrient needed for plant and animal growth and is also a fundamental element in metabolic reactions. High levels of this nutrient can lead to overgrowth of plants, increased bacterial activity, and decreased dissolved oxygen levels.Phosphate comes from several sources including human and animal waste, industrial pollution, and agricultural runoff.

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H. CopperCopper is a metal found in natural deposits such as ores containing other elements. Copper is widely used in household plumbing materials.Some people who drink water containing copper in excess of the action level may, with short term exposure, experience gastrointestinal distress, and with long-term exposure may experience liver or kidney damage.The MCLG (maximum contaminant level goals) for copper is 1.3 mg/L or 1.3 ppm.

I. IronIron is a harmless, though sometimes annoying, element present in public and private water supplies. High concentrations of dissolved iron can result in poor tasting, unattractive water that stains both plumbing fixtures and clothing. When iron-rich waters mix with tea, coffee, or alcoholic beverages, they assume a black, inky appearance with an unpleasant taste. Vegetables cooked in iron-rich waters will also become dark and unappetizing. Concentrations of iron as low as 0.3 milligrams per liter ( mg/L) will deposit reddish-brown stains on fixtures, utensils, and clothing, all of which can be difficult to remove Ferric iron deposits within corroded pipes can break free and generate rusty tap water. Iron bacteria gives water a disagreeable taste and causes yellow stains on laundry. This bacterium can also clog water systems, plug filters, or envelop pump

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J. HardnessWater hardness is caused almost entirely by calcium and magnesium ions. Other di- and trivalent metals have a similar effect, but usually are not present in high enough concentration in potable waters to cause problems. Hardness increases soap consumption in laundries and causes scale in boilers.

K. Coliform BacteriaEscherichia coli, originally known as Bacterium coli commune, was identified in 1885 by the German pediatrician, Theodor Escherich). E. coli is widely distributed in the intestine of humans and warm-blooded animals and is the predominant facultative anaerobe (can live with or without oxygen) in the bowel helping to maintain the health of the host. In 1892, Shardinger proposed the use of E. coli as an indicator of fecal contamination. This was based on the premise that E. coli is abundant in human and animal feces and not usually found in other niches. Hence, the presence of E. coli in food or water became accepted as indicative of recent fecal contamination. As a result, the term "coliform" was coined to describe this group of enteric (intestinal) bacteria. Coliform is used to describe a group of Gram-negative, facultative anaerobic rod-shaped bacteria that ferments lactose to produce acid and gas within 48 hours at 35°C. In 1914, the U.S. Public Health Service adopted the enumeration of coliform as a more convenient standard of sanitary significance.Fecal coliform bacteria are naturally present in the human digestive tract but are rare or absent in unpolluted waters. Coliform bacteria should not be found in well water or other sources of drinking water. Their presence in water serves as a reliable indication of sewage or fecal contamination. Although coliform bacteria themselves are not pathogenic, they occur with intestinal pathogens that are dangerous to human health. This presence/absence total coliform test detects all coliform bacteria strains and may indicate fecal contamination.The coliform test in this kit will indicate if you have above or below 20 coliform colonies per 100 mL of well or other water sources.

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ANALYSISTest Factors Results Rank

Dissolved Oxygen 91-110% Sat 4 (excellent)71-90 % Sat 3 (good)51-70 % Sat 2 (fair)<50 % Sat 1 (poor)

Coliform Bacteria Negative 3(good)positive 1(poor)

pH 4 1(poor)5 1(poor)6 3(good)7 4(excellent)8 3(good)9 1(poor)10 1(poor)

Nitrate 5ppm 2(fair)10ppm 1.5 (marginal) 20ppm 1(poor)

Phosphate 1ppm 4(excellent)2ppm 3(good)4ppm 2(fair)

Iron 0ppm 4(excellent)1ppm 2(poor)5ppm 1(poor)

Hardness—follow instructions in guide to determineCopper 0ppm 4(excellent)

1ppm 2(fair)3ppm or higher 1(poor)

Chlorine 0ppm 4(excellent)1ppm 2(fair)3ppm or higher 1(poor)

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Rank your water sample on a 1-4 scale for each of the test factors above (chart this) (do not include any tests that were NOT performed).

CLEANUP INSTRUCTIONS Make sure ALL materials go back into your Test Kit. All materials must be cleaned (NO SOAP) and dried. Make sure NO CAPS are on your test tubes, and test tube openings are facing up (this prevents

mold) **EXCEPT FOR BACTERIA** You will have to record observations later Wipe down your lab table Wash your hands Put your goggles back in the designated area Make sure Instruction Packets are returned where you got them from

Any lab stations not cleaned adequately will result in points deducted from lab grade—if you are unsure, ask.

Name_____________________________________ Water Quality Lab Data & Analysis

Data Table—Record your data here- Make sure you include proper units/labels Test Performed Results Rank Notes DO

pH

Chlorine

Nitrate

Phosphate

Copper

Iron

Hardness

Bacteria

Analysis Questions:

FECAL COLIFORM:1. Where is fecal coliform naturally present? 2. What source does fecal coliform come from? 3. What does the coliform test detect? 4. If you have a negative coliform test is your water safe to drink? Why? Why not?

NITRATES:7

1. What are nitrates needed for?2. What releases nitrates into aquatic systems?3. What is the main source of excess nitrate added to waters?4. What are two other sources?5. What can high levels of nitrates do in drinking water?6. What group of people may be particularly susceptible to this?

pH:1. What does pH measure? 2. What is the pH scale?3. What do the extreme ends of the pH scale indicate? (give the number and the word description)4. A pH of 7 is said to be: 5. What is the natural pH of water? 6. pH can be affected by what 3 things?

PHOSPHATES:1. What 2 things are phosphates needed for?2. What 3 things are caused by high levels of phosphates3. What are 3 sources of phosphates?

TURBIDITY:1. What does turbidity measure?2. What is turbid water caused by? (general not examples)3. What are 3 specific examples of things that can be suspended in water to cause turbidity?4. Is turbidity the same thing as color? Explain.5. What are 4 things that may cause turbid water?

HARDNESS1. What is “hard water”? 2. What are some problems with “hard water”? 3. What are strategies to “soften” hard water?

IRON/COPPER1. What are the permissible levels of   trace elements   (such as copper& iron) in water for the water to still be considered safe for exposure by people and aquatic life?2. How can traces of iron and copper be removed/ remediated in water sources?

CHLORINE 1. Why is chlorine added to drinking water?

Based on the above information, what would you say is the overall quality of your water sample? Make sure you reference all tests conducted/information in the above chart. Explain in complete sentences---this should be several paragraphs long.

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