Fourth grade students in Jen Budick and Sean Killen's classes at Northwestern Elementary celebrated World Water Day with a visit from Eric Andreus, natural resource manager for Nestleé Waters North America.

Andreas began his presentation by asking his audience if they lived in a watershed.

When no one could answer him, Andreus said they would come back to the question at the end of his presentation.

He next asked the students what a water cycle was.

The students responded by stating the water cycle begins with evaporation of water from lakes or oceans.

Condensation occurs when the water vapor in the air cools down and is turned into liquid water, followed by precipitation, which is when the water returns in the form of rain or snow.

The final part of the water cycle is the collection of water that has fallen from the clouds into oceans, rivers, lakes and streams.

Andreus explained it is called the water cycle because water is constantly in motion and the Earth has a limited amount of water that keeps going around and around creating the cycle.

"Do we have more water now on the planet than we did thousands of years ago?" he asked retorically. "The answer to this question is no, which is why it is very important we do not pollute the water we have."

The students were then introduced to the EnviroScape model used by Andreus.

The model depicted a construction site, farm, factory that makes widgets, mountain, golf course, community of homes and roads.

Several students placed pollutants on the EnviroScape.

Andreus said his goal was to show students the different ways each of the communities could pollute the water system.

A construction site could pollute the ground with debris used at the locaton.

Farmers may use fertilizer to protect crops from bugs or spread manure to near a water source.

In this scenario, the factory did not correctly dispose of the oil and grease from its machines, placing it in a ditch behind the factory, and the golf course over-fertilized the course with the runoff going into the ground and water supply.

"Our roads are affected when we throw trash out the car window," Andreus said.

The next group of students were asked to "make it rain" by spraying water on the model.

The water traveled to the bottom of the model into a lake, which used to be blue.

After the storm, the lake became brown and dirty.

As the students worked on the mock-up, they discussed watersheds.

Students learned a watershed is an area of land draining into a lake, river or ocean.

"We all live in a watershed," Andreus said, adding the Ontelaunee and Jordan creeks are part of a watershed.