Abstract
The purpose of this experiment was to determine if the depth of the well affects the level of nitrate content found in the water.

My hypothesis was that there was a higher nitrate content in the more shallow wells than in the deeper wells.

To conduct my experiment, I combined a water sample with special powder and mixed them together.  I then combined it with another powder and let it sit until a color developed.

The results indicate that my hypothesis was rejected.  The shallowest wells had the least amount of nitrates.  However the deepest wells had the next lowest amount.  I notice that Group B (101-175 ft) (30.7848-53.34 M) had the highest amount.

From the results, I can conclude that I am not sure if the depth changes the nitrate content.  Even though averages were made, each group had at least one average that was not close to the other averages.

The water softeners could have had an affect on the level.  However to test this theory more affectivity, I would have needed to keep the softener a constant.  Or have certain groups with houses that had a softener and others without.  From my results, I can not draw the conclusion that having a water softener lowers the nitrate content.

If I were to do this again or expand it, I would try a different testing kit.  I would test in different aquifers and in different depths, keeping one constant while the other one was different.  I would also keep the use of a water softener a constant.
 
 

Purpose
The purpose of this experiment was to determine if the depth of the well affects the level of nitrate content found in the water.

I became interested in this topic when I found that a high level of nitrates could affect young infants or people living with health risks.  If the depth did affect the level of nitrate content, then I wanted to know if my well and other wells in my town posed health risks.

Families with small children or any of the families that have a well may be interested in the results.  If the depth does matter, then they can be made aware of the risks and be provided with information.
 
 

Hypothesis
My hypothesis was that there was a higher nitrate content in the more shallow wells than in the deeper wells.  I base my hypothesis on research that said that nitrates are normally found in ground water, which is higher in the ground).  Also there were suggestions in the research to dig a deeper well if a high level of nitrates were found (Washington State Department of Health).
 
 

Experiment Design
The constants in this experiment were:
? Room temperature at testing time
? Method of testing
? All samples were from a kitchen tap
? Volume of water tested
? All samples were from well water
? All wells were for four houses or less
? All samples were stored at the same refrigerator temperature before testing time
 

The manipulated variable was the different depths of the wells.

The responding variable was the nitrate content found in the water.  I measured the responding variable using a HACH Nitrate testing kit. The measurements were recorded in mg/L nitrate.

My control group was distilled water.
 
 

Materials

 
 

Procedures
1. Put on a pair of safety glasses to protect your eyes.
2.   Gather 25 containers to collect the water (sterile).
3. Collect a sample from three houses with domestic wells, in each of the depth categories (all houses are in the Selah area).
4. Get the sample from a kitchen tap.
5. Refrigerate until time to test.
6. Take water out to sit for at least two hours prior to testing to get it to room temperature.
7. To test for nitrates, follow these steps:
    a. Pour water up to the 5ml mark on the test tube from the test kit.
    b. Open one Nitriver6 Nitrates Powder Packet and add the contents to the sample.
    c. Stopper the tube and shake for three minutes.
    d. Let stand still for 30 seconds and unoxidized, cadmium metal particles will settle to the bottom.
    e. Pour the prepared sample into another testing tube carefully leaving the particles in the first tube.
    f. Open one Nitriver3 Nitrate Powder Packet and add the contents to the sample.
    g. Stopper the tube and shake for 30 seconds.
    h. Let stand for 13 minutes.
    i. Insert the tube with the substance into the right hole on the color comparator.
    j. Clean out the tube with the cadmium metal in the bottom with distilled water and dry completely with a paper towel. (the first tube you used)
    k. Fill with the original water sample to the 5ml mark.
    l. Place tube in the left hole of the color comparator.
    m. Hold the comparator to some kind of bright light, such as close to a kitchen light, and look through the openings in front.
    n. Rotate the color wheel to match a color on the tube with the substance.
    o. Record the mg/L nitrogen (N) by the scale.
    p. Change the results to be mg/L nitrate (NO??) multiply the number by 4.4.
    q. Wash both tubes with distilled water.
    r. Dry completely with a clean paper towel each time.
    s. When done with the powder packets, dispose of them properly.
8. Repeat step 7 (a-s) to each water sample twice, checking the first result.
9. Test each sample in the depth categories and record all of the results.
 
 

Research Report
Introduction:
In the next paragraphs there will be information about the items that are related to my project. Information about nitrates, aquifers, and cadmium are in the report.  I learned many interesting new facts that helped me form my conclusion.

Nitrates:
Nitrogen is mostly found in the molecular form N?, which makes up 79% of the air we breathe.

Living plants and animals need nitrogen to build up their protein.  As the plants and animals die, bacteria break down the large protein molecules into ammonia.  The ammonia is then combined with oxygen by specialized bacteria to form nitrates and nitrites.

Ducks and geese contribute a lot of nitrogen from their excretions (waste) in places that they highly populate.

With the decomposition of dead plants and animals and the excretions of living animals, all the nitrogen that is kept secured is now released.  Nitrates when written in scientific form is NO?.

There are bacteria that can transform nitrates into free molecular nitrogen. The cycle begins again when the nitrogen is transformed into nitrates by the bacteria.

There are different kinds of nitrates, such as potassium nitrate (KNO?) and Ammonium nitrate (NH?NO?). They are used as fertilizers to replenish nitrogen in soil.  Nitrates are also used in explosives, fireworks, heart medicine, and photographic films.

Nitrogen in the form of nitrates can act as a nutrient to plants.  It can also cause eutrophication, which promotes more plant growth and decay.  Nitrogen rarely limits plant growth, so plants are not as sensitive to increase in ammonia and nitrate levels.

Sewage is the main source of nitrates, added by humans to rivers.  Sewage enters waterways from improperly treated wastewater in sewage treatment plants, or from poorly functioning septic systems.

Septic systems are common in rural areas and are used to treat the waste from only one household.  Large centralized urban sewer systems usually collect waste from many households.

In septic systems, household wastewater from toilets, sinks, bathtubs, and washing machines flow through a main pipe into a box called a septic tank.  After large waste pieces and floating grease is skimmed off, the rest of the liquid then flows through a grid of pipes with holes.  The holes in the pipes allow the liquid to trickle out on to a layer of stone, gravel, and soil.  This is called a drain field.  In properly functioning septic systems the soil particles reach ground water.

Two factors keep the septic systems from working well.  First they have to be properly located.  If the drain fields are too close to the water table, nutrients and bacteria are able to trickle down into the ground water where they may contaminate drinking water. They also may go to lakes or rivers.  The second factor is that they must be emptied in order to function properly.  If they are full, household wastes go straight to the drain field.  If this happens, the drain field pipes could become plugged and household sewage may start to gather on the ground or enter water through surface runoff.

Two other important sources are fertilizers and runoff from cattle feedlots, dairies, and barnyards.

High levels of nitrates have been found in ground water beneath croplands due to a lot of fertilizer use.  High nitrate levels have also been found in heavily irrigated areas with sandy soils.

Storm water runoff can carry nitrate-containing fertilizers from farms and lawns into waterways.

Places with a lot of animals such as, feedlots and dairies create large quantities of wastes rich in ammonia and nitrates.  If they are not treated right, they can go into the groundwater or be taken somewhere else.  Some nitrates are put into the air by power plants and automobiles.

Once nitrates are formed, it's movement in soil and potential for contamination of groundwater depends on a lot of factors.  Some are the soil characteristics, location, characteristics of the underground water formations (aquifers), and climatic conditions.  Some levels also depend on the depth of the well and how well it is constructed.  When wanting to name the source of nitrates for an individual well, it is hard because nitrates move with the ground water.  The location where the nitrates are could be a great distance from the well.

Water with high nitrate levels can cause methemoglobinemia if it is used for infant milk formula.  It is a serious condition that prevents the babies' blood from carrying oxygen; it is called the "blue baby" syndrome.  A high nitrate level can also affect health-risked people.

If Methemoglobinemia is untreated then it can lead to brain damage and even death.  The first six months of an infant's life is when they are most susceptible to nitrite-induced methemoglobinemia.  Pregnant women with a particular enzyme deficiency and adults with reduced stomach acidity, have a higher risk level than other adults. Fortunately, methemoglobinemia is easy to notice and can be treated readily.

In some rare cases, the nitrites created in the body could develop a cancer.  This happens only if there is an extreme amount of nitrites.

The government has created a Maximum Contaminant Level (MCL) for nitrates in public drinking water supplies.  The level is set at 10 milligrams per liter (mg/L).  It is sometimes written as 10 parts per-million (PPM).  It is often written as "nitrate-nitrogen" or "NO?-N."

If a nitrate level is more than the maximum concentration level, the water should not be consumed.  The residents need to drink from bottled water until the problem is fixed. They need to contact their health officials around their town for information on how to get the problem fixed.

Public health officials have said that they may change the rules so that if a level of nitrates in a private water system exceeds 5 mg/L the residents need to be put on public water systems.  No changes have been made, but they may in the future.

Cadmium:
Cadmium metal is silver-white and is bright and shiny.  Friedrich Stromeyer of Germany discovered it in 1817.  For every 10 million parts of the earth's crust, only about 5 parts are cadmium.  Japan is the leading producer of Cadmium.  Cadmium is sometimes found in vegetables, such as mushrooms, and offal.

It is similar to zinc and is sometimes obtained as a byproduct of zinc refining.  It is also often used instead of zinc for galvanizing iron and steel.  Cadmium provides poorer long-term protection than zinc, but keeps a brighter color for longer periods of time.  It is used in the making of batteries (nickel-Cadmium batteries), and in the creation of protective coatings or electroplating metal parts.

The symbol is Cd. The atomic number is 48 and the atomic weight is 112.41.The density is 8.65g/cm?.  It melts at 320.9?C and boils at 765?C.

Cadmium is poisonous and people have become ill or died from breathing cadmium dust or fumes of cadmium oxide.  Small amounts entering the body over time may cause damage to the kidneys and deform bones.  Cadmium salts are highly damaging to water and become environmentally toxic at very low concentrations.

Aquifers:
Aquifers are the areas of rock that are in the earth that ground water flows through.  Many different kinds of rocks can be in the aquifers.  Ground water is the largest single supply of fresh water available for use by communities.  The water table is the top of the zone below where the openings in rocks are saturated.

When a well is put into saturated rocks it will fill with water to the level of the water table.  When the water is pumped from the well gravity will make the water from the saturated rocks move to the well.  Clay and Granite have very few cracks for which water can move through, so they make poor aquifers.  Sandstone and cavernous limestone have rather large openings, which allow water to flow through nicely, and they make good aquifers.

The range of how much water an aquifer can carry is a few hundred gallons a day to several million gallons a day.

The principal aquifers by rock type are unconsolidated sand and gravel, semi-consolidated sand, sandstone, carbonate-rock, sandstone and carbonate-rock, and basalt and volcanic rock.

Volcanic rocks have a large variety of chemical, mineralogical, structural and hydraulic properties.  Basaltic lava tend to be fluid and they also tend to have large pore space at the top and bottoms of the flows.  Basaltic rocks are the most useful aquifers in volcanic rocks.

Summary:
Nitrates are found in ground water and are from feedlots, dairies, fertilizers, and sewage.  Nitrates are not that dangerous unless you have an exceedingly high level.  When this happens it can lead to methemoglobinemia in young infants.  The MCL is 10mg/L.  Cadmium metal can be poisonous and/or damaging towards the kidneys.  It is similar to zinc and is sometimes used in place of zinc.  Aquifers are rocks in the earth that ground water flow through.  There are many different kinds and they are found in different places.
 
 

Results
The purpose of this experiment was to determine if the depth of a well changes the level of nitrates found in the water.  I became interested in this topic when I found that a high level of nitrates could affect young infants or health-risked people.  If the depth did affect the level of nitrate content, then I wanted to know if my well was too deep or shallow and about the wells around my town.

The results of my experiment were Group A had an average content of .975mg/L.  A-1 had an average of 2.618mg/L, A-2's was .176mg/L, and A-3's was .132mg/L.  Group B had an average of 4.385mg/L.  B-1's average was 4.4mg/L, B-2's was 4.356mg/L, and B-3's was 4.4mg/L.  Group C had an average of 3.886mg/L.  C-1's average was 4.4mg/L, C-2's was 4.4mg/L, and C-3's was 2.86mg/L.  Group D had an average of 2.998mg/L.  D-1's average was 3.113mg/L, D-2's was 4.092mg/L, and D-3's was 1.76mg/L.  Group E had an average of 1.42mg/L.  E-1's average was 2.134mg/L, E-2's was .586mg/L, and E-3's was 1.54mg/L.

For Group B-1 the first trial had a different result than trials two and three.  I decided to do another trial and since two, three, and four were all the same, I didn't count the first result in B-1's average.

For Group C-1 between the first trial and second trial there was such a wide difference I decided to test it two more times.  When the result came out the same as the second trial, I decided not to count trial one in the average for C-1.

Group D-1 trial kept coming out different, so I kept testing.  Since they were all close, I decided to put them all in the average.

Group E-2 trials one and two were very different so a third trial was attempted.  When trial three was even more different, trials four and five were completed.  Since trial three, four, and five were all fairly close, those are the ones that were counted in E-2's average.

The shallowest well has the lowest nitrate count (.975mg/L).  Then it jumps to a high count for the next depth category (4.385mg/L).  After that it slowly declines for the next three groups, C (3.886mg/L), D (2.998mg/L), and E (1.42mg/L).

I did a test with distilled water and it showed no nitrates.  I also tested river water and the result was .88mg/L.
 
 

Tables/Graphs

Conclusion and Analysis
My hypothesis was that there was a higher nitrate content in the more shallow wells than in the deeper wells.  I base my hypothesis on research that said that nitrates are normally found in ground water, which is higher in the ground.  Also there were suggestions to dig a deeper well if a high level of nitrates were found.

The results indicate that my hypothesis was rejected.  The shallowest wells had the least amount of nitrates.  However the deepest wells had the next lowest amount.  I notice that Group B (101-175 ft) (30.7848-53.34 M) had the highest amount.  From the results, I can conclude that I am not sure if the depth changes the nitrate content.  Even though averages were made, each group had at least one average that was not close to the other averages.

The water softeners could have had an affect on the level.  However to test this theory more affectivity, I would have needed to keep the softener a constant.  Or have certain groups with houses that had a softener and others without.  From my results, I can not draw the conclusion that having a water softener lowers the nitrate content.

After I found out that the experiment did not draw an accurate consistent conclusion if the depth changes the level of nitrates, I did more literary research on the ground water.  I found out about aquifers and that there are many different kinds and levels.  The conclusion that I can draw is that the nitrate content may depend on a number of things. For instance, the depth in one location could have a different nitrate content level than another location of the same depth.  All of the other factors such as location of sewage systems, feedlots, fertilizers, etc, as well as the sort of rock must be taken into account.

Another project could be to test wells at the same depth but in different aquifers.  Or flip it around and have wells in the same aquifers but at different depths.

There are some things that could have gone wrong or been inconsistent.  Something that was brought up was how accurate the testing kit was.  The distilled water result was a good sign the testing kit was accurate.  However the powder packets may not be consistent.

The river water result was not what I had expected. There is not any irrigation water or snow melt running into the river yet.  Those two contributors pick up many things along the way and nitrates are probably in some of it.  Considering that fact, it may explain why the river nitrate count was so low.

If I were to do this again or expand it, I would try a different testing kit.  I would test in different aquifers and in different depths, keeping one constant while the other one was different.  I would also keep the use of a water softener a constant.  I would suggest learning about the rock layers beneath Selah.  Specifically how many different kinds of aquifers are in Selah and how deep they are.  Also how they would affect the water flow and nitrate content.  I would also try to find out about all the different aquifers, where they are located, if they change the ground water flow, and if they affect the nitrate content.
 
 

Bibliography
Cadmium, Online, http://www.umweltbundesamt.de/uba-info-daten-e/daten-e/cadmium.htm, 2-6-01

Culligan International Company, Culligan Household Problem Water Reference Manual, North Brook IL

David B. Guralnik, Webster's New World Dictionary, Second College Edition, 1970

Emily Jane Rose, Nitrate, World Book Encyclopedia, 1999

Hach Company, Analytical Procedures, Online,
http://www.hach.com/cs/knowledge_pdfs/L8151.pdf, 1-18-01

Leo Harsh, Water Specialist, Culligan, 12-5-00 and 12-13-00

Michigan State University, Nitrate - a Drinking Water Concern, Online, http://www.gem.msu.edu/pubs/msue/wq19p1.html, 12-24-00

Mitchell, Mark, and Stapp, William, Field Manual for Water Quality Monitoring, Dexter, Michigan, Thomson-Shore Printers, 1994

Raymond E. Davis, Cadmium, World Book Encyclopedia, 1999

USGS, Aquifers Basics, Online, http://sr6capp.er.usgs.gov/aquiferBasics/, February 7, 2001

Washington Sate Department of Health, Nitrates in Drinking Water, Online, http://www.doh.wa.gov/ehp/dw/fact_sheet/npp.htm, 2-6-01

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