As Mason County makes comprehensive plans for the future, we must consider data on risks from current activities.
In the United States, agricultural pollution is the top source of contamination in rivers and streams, the second-biggest source in wetlands, and the third main source in lakes. It’s also a major contributor of contamination to estuaries and groundwater. Every time it rains, fertilizers, pesticides, and animal waste from farms and livestock operations wash nutrients and pathogens—such bacteria and viruses—into our waterways. Nutrient pollution, caused by excess nitrogen and phosphorus in water or air, is the number-one threat to water quality worldwide and can cause algal blooms, a toxic soup of blue-green algae that can be harmful to people and wildlife. Read complete article
Pesticides are used to increase crop production, lower maintenance costs, and control public health hazards. The majority of pesticide use is in agriculture, accounting for 70 to 80 percent of total pesticide usage yearly. The Ohio River Valley Water Sanitation Commission (ORSANCO) estimated that in 1994, 70 million pounds of five herbicides (atrazine, metolachlor, alachlor, cyanazine, and simazine) were applied to corn and soybean acreage in the lower Ohio River basin (ORSANCO, 1997).

List the top 15 pesticides (excluding growth regulators) applied to Kentucky croplands in 1996 and 1997. Atrazine, metolachlor, glyphosate, acetochlor, and pendimethalin were the five most heavily applied pesticides in both years. As a group, they represent 4.72 million pounds of applied product in 1996 and 4.54 million pounds of applied product in 1997. Acephate was the leading insecticide in both years. It is estimated that 9.3 million pounds of pesticides were sold in Kentucky in 1996, and 8.9 million pounds of pesticides were sold in 1997 (Kentucky Department of Agriculture, Division of Pesticides, 1997, 1998).
Nitrogen is a primary building block for plants, and healthy soil uses nitrogen efficiently. But under monocropping, the soil becomes depleted of nutrients, requiring farmers to try to regenerate the soil through practices like planting cover crops or, failing that, to move on to more arable land. The invention of synthetic nitrogen in the 20th century (and then, quickly, its skyrocketing use) removed this limiting factor and allowed for a boom in chemical-intensive, industrial farming practices. A big boom, indeed: In 1964, U.S. farmers applied about 4.3 million tons of nitrogen to their crops each year. By 2018, it had doubled to about 8 million tons of nitrogen, not including potash or phosphate fertilizers, being used across the country’s major agricultural regions.
A Growing Dead Zone in the Gulf of Mexico
Because many conventional farms in the Midwest are reliant on nitrogen-based fertilizers, this also has repercussions on ecosystems beyond the farm boundaries. Heavy rains cause run off so these fertilizers make their way to the Mississippi River and eventually pour into the Gulf of Mexico, where they contribute to a growing “dead zone.” This dead zone is a 6,300 square mile patch caused by fertilizers triggering algae blooms which chokes off oxygen in water and makes it impossible for any marine life to live.
Phosphorus is a natural part of an aquatic ecosystem. It helps support the growth of algae and aquatic plants that provide food and habitat for fish and other organisms to thrive in. However, too much phosphorus can cause the water to become polluted over time. This excess of nutrients may even develop into harmful algal blooms (HABs).
