In agriculture, pesticides and plant nutrients can enter the groundwater and contaminate it. These chemicals may reach large enough levels to become harmful to animals and people. So we must understand how contamination may occur and how it can be avoided. With good management practices, we can keep the groundwater from becoming contaminated by agricultural chemicals. Fuels and solvents.
Animal wastes from confinement areas can potentially be a serious contaminant to well water.
Plant nutrient contaminants are predominantly nitrates and, to a lesser degree, phosphates. Animal waste contaminants can enter groundwater through poorly constructed wells, or by percolating through soil layers. Spills or leaks of fuels, solvents and pesticides are often the most reasonable explanations of well water contamination. The most common source of well contamination is inadequate well construction and maintenance. They combine to literally pour contaminants down the well into the groundwater.