Nonpoint Source Problems
Sedimentation occurs when wind or water runoff carries soil particles from an area, such as a farm field, and transports them to a water body, such as a stream or lake. Excessive sedimentation clouds the water, which reduces the amount sunlight reaching aquatic plants; covers fish spawning areas and food supplies; and clogs the gills of fish. In addition, other pollutants like phosphorus, pathogens, and heavy metals are often attached to the soil particles and wind up in the water bodies with the sediment. Farmers and ranchers can reduce erosion and sedimentation by applying management measures to control the volume and flow rate of runoff water, keep the soil in place and reduce soil transport.
Nutrients such as phosphorus, nitrogen and potassium in the form of fertilizers and manure are applied to enhance production. When they are applied in excess of plant needs, nutrients can wash into aquatic ecosystems where they can cause excessive plant growth, which can reduce water clairity, create a foul taste and odor in drinking water, and impact fish and other aquatic species. Nutrient management plans can help maintain optimum crop yields and save money on the use of fertilizers while reducing NPS pollution.
Improper Animal Waste Management
By confining animals to areas or lots, farmers and ranchers can efficiently feed and maintain livestock. But these confined areas can become major sources of animal waste. Runoff from poorly managed facilities can carry pathogens (bacteria and viruses), and excess nutrients that can create major water quality problems. Ground water can also be contaminated by seepage. Discharges can be limited by storing and managing facility wastewater and runoff with an appropriate waste management system.
Inefficient Irrigation Systems
Irrigation water management is used to match the need of the crop to the amount of water applied..
Pesticides, herbicides, and fungicides are used to kill pests and control the growth of weeds and fungi. These chemicals can enter and contaminate water through direct application, runoff and wind transport. They can kill fish and wildlife, poison food sources, and destroy animal habitat. Integrated Pest Management (IPM) techniques based on the specific soils, climate, pest history, and crop for a particular field can limit pesticide use and manage necessary applications to minimize pesticide movement from the field.
Overgrazing exposes soils, increases erosion, encourages invasion by undesirable plants can destroy fish habitat, stream banks, and floodplains. To reduce the impacts of grazing on water quality, farmers and ranchers can adjust grazing intensity, keep livestock out of sensitive areas, provide alternative sources of water and shade, and re-vegetate pastureland for more plant diversity and health.