1. Lester J. Rosario
Workshop: Water sampling, testing, and statistical application
By Dr. Javier Arce
Water plays an important role in a human’s metabolism. Since humans have to
drink water, it is very important to keep it free from microorganisms and other substances
that may have adverse effects on health. This workshop offered good information about the
process that water has to pass through in order to make it suitable for drinking in our
homes. I learned that water quality depends on the country, and that there are some
environmental and human variables that affect water quality. Environmental variables
include: animals, soil composition, forests, and climate. Examples of human variables are:
agriculture (fertilizers containing toxics), urban areas, and the management of residuals. To
analyze water samples, a especial procedure is needed. It begins with the technique for
obtaining water samples from tap water in different areas, then, the samples are examined
for the presence of E. coli and total coli forms. Later, Excel is used to arrive at statistical
calculations such as averages, standard deviations, and lineal regression, and to plot graphs
of the results of the different water samples. In conclusion, I learned that water sources
found in densely populated areas have more presence of E. coli (fecal coli forms) than
water sources found in unpopulated areas.