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Comparison of Physical-chemical Properties of San
Salvadors and Yunques Soil and Contamination
Impact on Its Fertility Cruz Bonilla, Jennifer
Franco Diaz, Eframir GEO Explorer School of
Science and Technology, Universidad del Turabo
Introduction In the present, we are customary
to consider the soil like something dead, where
we can dispose any solid or liquid waste. When we
dispose any items like paper, glass, plastic,
organic material, organic waste, solvents,
excrements, toxic waste or radioactive
substances, etc., the physical-chemical
properties are affected. This situation also
affects human, animal and plant species. Maybe,
we are tired of hearing the same topic, but we
have to take a minute and think that this is a
catastrophic problem that needs to be solved
today. Day by day, we are limiting our time in
this planet. Are we going to make a landfill of
the earth that saw us be born? When we accumulate
waste in a specific place, it stays there for a
long time. A big part of the wastes are organic
(food residues like fruit and vegetable rinds,
tortilla pieces, etc.), when its fermented it
produces bad scents and toxic gases. In this
investigation we are going to talk about the
contamination of septic wells. A septic well is a
container used to deposit grey and dirty water of
a house. When the soil absorbs this contaminants,
it attracts bacteria, fungus, and other pathogen
microorganisms (ill producers), contaminating the
superficial and subterranean waters that are in
contact with the soil, interrupting the
bio-chemical cycle. For that reason, it is
fundamental to not destroy or contaminate the
soil. Although, its important to protect the
soil because it can be destroyed by natural
phenomena (erosion produced by the wind or water,
storms, and the forestall fires). In addition,
today a great part of the destruction and
contamination of the soil is a product of human
kind and his ideal of technologic revolutions.

Problem Will the contamination of a septic well
affect the physical-chemical properties and
fertility of the soil around it?

• Results
• Physical properties and water holding capacity
• San Salvador and Yunque Soil Composition
• Chemical properties of San Salvadors
  contaminated and unaffected soil

Hypothesis The contamination in the soil will
affect the physical-chemical properties of the
soil and its fertility.

• Materials
• Hanna instruments - Soil Quality Education Test
  Kit
• Soil Samples
• Gloves
• Lab Coat
• Safety Glasses
• Beakers
• Spoons
• Beans
• Containers
• GPS

Methodology The soil samples were taken from
three different places The Yunque National
Rainforest, San Salvador Community, and from
ground around a septic well. Samples are taken to
the lab for physical-chemical tests. The
instruments used for this investigation were from
the Hanna Instruments-Soil Quality Education Test
Kit. To test Nitrogen and Phosphoruous in the
soil a colorimetric method is used. A reaction
tube is filled with 7.5mL of the extraction
solution. With a small spoon, nine measures of
soil samples are added to the reaction tube. The
cap is placed on the tube and its shaken gently
for one minute. The tube is allowed to stand for
five minutes. The pipette is used to extract
2.5mL of the clear water with no soil content.
The content of one packet of reactive solution is
added to the reaction tubes. The cap is replaced
and shaken vigorously for 30 seconds. Then, the
resultant colors in the tube are matched with the
respective color-cards to know the results of the
tests. DiST meter is used in this test. First of
all, a soil sample was taken and 200mL of water
is added. Then, the sample is filtrated. The
measurements were taken submerging the probe in
the solution. Finally, the pH and Temperature
tests are made. A pHep 4 meter is used for these
tests. A soil sample was taken and 200mL of water
is added. Then, the sample is filtrated. The
measurements and temperature were taken
submerging the electrode in the solution. Other
soil samples were used to plant a bean to see how
the soil variation affected their growth. At
last, the results are compared to observe
changes.
Photos Sample Extractions
Sample testing
Yunque bean
plant San Salvadors bean plant
Septic well bean plant
Conclusion The results of the investigation show
great differences between the compositions and
properties of the different soils. San Salvadors
soil is more fertile than the Yunques because
the soil is composed greatly in sand and clay
making it a better water retainer. The bean
plants were bigger in the San Salvadors
community unaffected soil. The Yunque soil was
good for the plants but not better than the
communitys soil. In the soil around the septic
well nothing grew. In conclusion our hypothesis
was true because the ground around the septic
well doesnt have the properties making it an
unfertile soil.
Investigation site San Salvador
Caguas, P.R.
Yunque National Rainforest  

 The investigation was
made in San Salvador Community in Caguas and in
the Yunque National Rainforest.
References 1) Composición del Suelo -
www.agro.misiones.gov.ar/biblioteca
2) Tema5 Principales ecosistemas gtgt Suelo -
Libro electrónico Ciencias de la tierra y del
medio ambiente Luis Echarri Prim -
www.esi.unav.es   3) Contamination of soil EPA
- http//www.epa.gov/superfund/students/wastsite/s
oilspil.htm