MURRIETA -- Students cried out with disdain as rain pelted down on the village, and grimy swirls of oil, pesticides and fertilizer mingled and oozed into the storm drain, through the underground pipes and out into the ocean where the sludge formed a silky slime on the surface of the once blue water.

Sixth-graders at Warm Springs Middle School got a close-up look at how pesticides, fertilizers, oil and soil pollute the water during a presentation from the Mission Resource Conservation District on Tuesday.

"Pollution prevention isn't often taught in the schools," said Jaime Horne, 23, education coordinator for the program funded by Riverside County Flood Control. "So it's important that they learn how to prevent pollution at a young age."

A wall of students gathered around Horne's "enviroscape model" of a small town, and enthusiastic hands shot up when she asked what the farmer uses that could possibly pollute the water.

"Soil and fertilizer, that's right," she said, handing a bottle of "soil" -- or Nestle's Quik powder -- to a student to sprinkle it around. "But, they could use their hay to make walls so their soil won't seep into the storm drain, couldn't they?"

Horne had students pour syrup on the road to simulate leaking car oil, green-dyed water to simulate the toxins from a chemical company, and other household ingredients to simulate fertilizer and pesticides used by the small town. The kids groaned when she pulled out dog "poop" -- which was really baking cocoa mixed with water -- and had a student spread it around on the lawns.

With all the pollutants in place, Horne gave water-filled spray bottles to three students who "rained" on the village. The students moaned in disgust as they saw the pollutants slip into the ocean.

Horne explained that scientists will analyze the ocean's water and try to determine the pollutant's origin.

"We call that a point-source pollution because we can identify the source," she said, pointing to the green dye still coming out of the miniature chemical company.

Horne told the young group they could help keep the water clean by picking up trash.

"A cigarette butt looks like it's made of cotton, but it's actually plastic and takes up to 20 years to decompose," she said. "When you go to the beach, make sure you pick up your plastic bags because it could get into the ocean and a sea turtle could mistake it for a jellyfish and eat it."

Horne said she's made this same presentation more than 150 times this year to schools in the district, specifically targeting kindergarten through eighth-grade students.

"It's important for the kids to know about conserving and saving our natural resources," she said.

The presentation came at the beginning of a six-week environmental unit taught by MaryAnne Jones, sixth-grade science and math teacher.

"This was perfect timing for us," Jones said.

"Water is a precious resource and, personally, I feel the most important thing I could teach is about the environment. This is where I really get excited."

Justin Lowe, 12, said he was going to clean up his baseball park on Juniper Street.

"Whenever I go there, I see lots of trash on the field and people just leaving it," he said. "I've learned that if you don't pick up the trash, it could affect the Earth -- so it's very important."

Justin Hoffman, 12, said he thought the presentation was "really cool."

"I used to have a dog and thought it was important to pick up its 'presents,'" he said, grinning. "Now I know that I was right."