Environmental Science Lab

Environmental Science

Table of Contents

Lab 2
Water Quality and Contamination


Water Quality and Contamination
Concepts to Explore
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Usable water Ground water Surface water

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Ground water contaminates Water treatment Drinking water quality

Figure 1: At any given moment, 97% of the planet’s water is in the oceans. Only a small fraction of the remaining freshwater is usable by humans, underscoring the importance of treating our water supplies with care.

It is no secret that water is one of the most valuable resources on planet Earth. Every plant and animal requires water to survive, not only for drinking, but also for food production, shelter creation and many other necessities. Water has also played a major role in transforming the earth’s surface into the varied topography we see today.

While more than 70% of our planet is covered in water, only a small percent of this water is usable freshwater. The other 99% of the water is composed primarily of salt water, with a small percentage being composed of


Water Quality and Contamination
glaciers. Due to the high costs involved in transforming salt water into freshwater, the Earth’s population survives off the less than 1% of freshwater available. Humans obtain freshwater from either surface water or groundwater.

Surface water is the water that collects on the ground as a result of precipitation. The water that does not evaporate back into the atmosphere or infiltrate into the ground is typically collected in rivers, lakes, reservoirs, and other bodies of water and is easily accessible.

Precipitation Precipitation Transpiration Cloud formation Evaporation Evaporation Groundwater Precipitation

Figure 2: Water is a renewable source, purified and delivered across the planet by the hydrological cycle.

Groundwater, on the other hand, is precisely as the name suggests; water located underneath the ground. This water is stored in pores, fractures...