PURPOSE:

To see wether filtered water has less Ph, phosphates, oil, chlorides, lead, and bacterial pollution in it than water dispensers in front of supermarkets.

HYPOTHESIS:

I think that the water from the dispensers will have more impurities in it then the filtered water.

EQUIPMENT:

¥ 1 Pipet

¥ 1 Sterile Petri Dish

¥ 2 Test Tubes

¥ 1 Forceps

¥ Sodium Chloride Nutrient Agar (.7 grams)

¥ 1 Chloride Test Solution (30 ml. bottle)

¥ Water Sample to be Tested

¥ Lead Test Papaer (1 Strip)

¥ Small Bottle with Cap (at least 30 ml.)

¥ pH Test Paper (3 strips)

¥ Phosphate Test Powder ( 4 pillows)

¥ Access to Sink

¥ 2 Jars with Tops

¥ Test Tube Rack

¥ Scissors

¥ Distilled Water

¥ Blue Cellophane Strip

¥ Oil Test Paper (1 strip)

pH Test: ¥ Pipet ¥2 Test Tubes ¥pH Test Paper

Phosphate Test: ¥Blue Cellophane Strip ¥Scissors ¥Test Tube ¥2 Jars with Tops ¥Water Samples to be Tested ¥Phosphate Test Powder

Chloride Test: ¥2 Test Tubes ¥Scissors ¥Chloride Test Powder ¥Chloride Test Solution¥Water Samples to be Tested

Lead Test: ¥Pipet ¥Test Tube ¥Scissors ¥Lead Test Paper

Oil Test: ¥Oil Test Paper

Bacterial Pollution Test: ¥Pipet ¥Test Tube Nutrient Agar ¥Sterile Petri Dish ¥Supply of Hot Water ¥Small Bottle with Cap (at least 30 ml.)

PROCEDURE:

Testing for pH:

1. Dip a strip of the pH paper into the water to be tested. To assign a pH, match the color in the center indicator box with the color scale on the strip.

Testing for Phosphates:

1. Pipet 5 ml. of water sample into a clean test tube.

2. Cut off end of the phosphate test powder pillow and add to the test tube.

3. Stopper the test tube and shake for 1 minute.

4. A blue or violet color indicates the presence of phosphates.

5. Hold the test tube and color chart side by side against a piece of white paper. Match the colors to determine the phosphate concentration in the sample. A reading over 10 ppm indicates a severe pollution problem.

6. Dispose of the empty powder pillows.

7. Wash test tube and rinse with distilled water.

Testing for Chlorides:

1. Pipet 5 ml. of the water sample into a test tube.

2. Tap one of the chlorides testing powder pillows so that the powder settles to one end. Cut open the end of the powder pillow and add its contents to the water.

3. Gently swirl the test tube to dissolve the contents.

4. Add the chloride testing solution, one drop at a time, swirling gently between each drop. Count the number of drops required to change the color from yellow to orange.

5. To determine the chloride concentration in parts per million (ppm), multiply the number of drops by 50. Chloride concentrations of 250 ppm and greater are considered unsafe.

Testing for Lead:

1. Pipet 2-3 drops of water on a piece of the lead testing paper.

2. A pink to deep purple-red color indicated the presence of lead at a minimum of 5 ppm. (If you have a positive result, report to your local water quality agency.)

3. With the remaining pieces of lead testing paper, test other sources for possible lead contamination, such as bits of paint dissolved in a small amount of water.

Testing for Oil:

1. Using forceps, dip a piece of oil test paper into the water sample.

2. A dark blue of purple color indicates the presence of oil.

Testing for Bacterial Pollution:

1. Place the nutrient agar into the bottle and add 30 ml. of hot water. Cap the bottle tightly and shake to dissolve the agar.

2. Pour the solution into the sterile petri dish. Work quickly and immediately cover the dish when he agar is poured. Set it aside to gel.

3. Thoroughly wash and rinse out the bottle with hot water and wash your hands.

4. Pipet 6 drops of water ample onto the gelled agar.

5. Gently spread the water around on the agar using the tip of the pipet. (try not to poke the tip of the pipet into the surface of the agar).

6. Immediately cover the petri dish and seal the cover by wrapping the edge with tape.

Do Not Open The Lid Of The Dish After This Point

7. Set the dish aside overnight to allow any bacteria present to grow.

8. Examine the plate after a day and again after 2 days.