Runoff and Agricultural Drains Runoff and Agricultural Drains Agricultural operations can be the source of non-point pollution in surface water. Although soil erosion is a natural process, it can be greatly accelerated by human activities such as farming. Nutrients Nutrients, especially nitrates and phosphates, can create significant water quality problems in both surface and ground water.
Eutrophication can be natural or human-induced.
Agricultural sources of nutrients come from either fertilizer runoff or nutrients attached to eroded sediments. In most instances, the rate of human-induced eutrophication is many times faster than the natural process. The most serious nutrient adversely impacting ground water supplies in the U.S is nitrates. Nitrates are naturally occurring in ground water, but concentrations can be greatly increased by human activities.