Finish earning a CEU toward the renewal of FDACS restricted-use pesticide license with a look at water quality and pesticides.

In our last two blogs, we shared the three fate processes for pesticides and the degradation of pesticides from an article in Citrus Industry that earns “one continuing education unit (CEU) in the Core category toward the renewal of a Florida Department of Agriculture and Consumer Services restricted-use pesticide license when the accompanying test is submitted and approved.” Our last blog looks at water quality and pesticides. See the details below.

Water Quality and Pesticides

From the article, issues where pesticides and water quality are concerned include:

“Groundwater System. Groundwater lies below the soil surface and fills the pore spaces in and around rock, gravel sand and other materials. Contrary to popular belief, groundwater does not move through vast underground rivers and lakes, but through water-saturated zones called aquifers. The upper level of an aquifer is removed from wells or discharged at streams and springs. The water table rises through recharge from rain and melting snow that seeps through soil into the aquifer.

For years, it was believed that the natural filtering of water during its slow movement through the soil, sand, gravel and rock formations was adequate to cleanse it of contaminants before it reached groundwater. Today, many chemicals, including some pesticides, have been detected in groundwater. Studies have shown that recharge can carry pollutants down to aquifers. Furthermore, it seems clear that human activities can lead to contamination of the recharge water.

Surface Water System. Surface water is water stored or flowing at the earth’s surface. It includes natural bodies of water such as rivers, lakes and wetlands, as well as constructed (artificial) water reservoirs such as canals, man-made lakes and drainage ditches. The quantity and quality of surface water is important for many activities: consumption, recreation, transportation, waste assimilation, agricultural production and industrial use.

Surface water is linked to both groundwater and atmospheric water through the hydrologic cycle. Surface water moves into groundwater by infiltrating the soil and percolating downward. It also enters the atmosphere through evaporation and transpiration. Likewise, water from the atmosphere and groundwater can recharge surface waters. Atmospheric water falls as precipitation: rain, sleet, hail and snow. Groundwater that moves to the earth’s surface contributes to the base flow of streams, lakes, wetlands and other waterways.

Precipitation initially infiltrates the top layers of the soil. Continuing precipitation may saturate the upper few inches of the soil, temporarily exceeding its capacity to hold water. Water accumulates on the land surface and moves to lower elevations through surface runoff and may occur across a small or large area.

A surface water system is characterized by its watershed or drainage basin. A watershed is the area of land draining to a specific river; the boundary is defined by the region’s topography. Watersheds vary in size and can be nested within other larger watersheds. Land use within a watershed largely determines the quality of the local surface water.

Protecting Water Sources. It is difficult to clean water once it has become contaminated. Treatment is complicated, time-consuming, expensive and often not feasible. The best solution to water contamination is to prevent it in the first place. The following pest management and pesticide handling practices can reduce the potential for contamination.

Practice Integrated Pest Management. Pesticide application should be timed carefully and combined with other pest management practices. Pests should be identified accurately. Pesticide applications should be made only when necessary, using the least amount needed for adequate pest control. Minimizing pesticide use cuts expenses and reduces potential for environmental problems.

Dispose of Waste Carefully. Follow all label instructions and restrictions when disposing of pesticides. Triple rinse or pressure rinse containers as soon as they are emptied and pour the rinsate into the spray tank.

Never dispose of pesticides or pesticide containers near a water source, over shallow water tables, in sinkholes or in abandoned wells.

Excess pesticide concentrates can be given to another qualified user, safely stored until there is a hazardous waste collection day or disposed of through a hazardous waste transporter.

Prevent Spills. If a spill does occur, it should be contained and cleaned up immediately. Repeated pesticide spills in the same area can exceed the capacity of the soil to adsorb or degrade the chemical and can increase the likelihood of groundwater contamination.

Leave Buffer Zones Around Sensitive Areas. When mixing, applying, storing or disposing (including cleanup) of pesticides, be aware of sensitive areas. These include springs, streams, ponds, wetlands and other surface waters; wells and groundwater recharge areas; and sinkholes. Establishing vegetation and leaving an untreated border are two ways to provide a buffer zone between sensitive areas and pesticide-use or handling sites.

Checklist for Protecting Water From Pesticides

  • Store pesticides in their original containers in a cool, well-ventilated building with a concrete floor.
  • Clean your pesticide application equipment in a way that makes it easy to collect rinsates.
  • Install a check-valve on your water hose to prevent back-siphoning.
  • Grade the area around your well to divert surface runoff.
  • Ensure that any abandoned well near a pesticide handling or application site is properly closed.
  • Build dikes around your bulk tanks to prevent off-site movement of pesticides.
  • Know which pesticides you use have a potential for leaching.
  • Delay pesticide applications if rain is forecast.
  • Always check pesticide labels to learn irrigation practices, rates and application methods.
  • Leave a border of untreated vegetation between treated and sensitive areas.
  • Use pesticides only when necessary and then at the lowest rate needed to control a pest.”

Griffin Fertilizer is committed to helping both growers and ranchers make sound agronomic and economic decisions in order to maximize the health of their grove and pasture. As a full-service custom dry & liquid fertilizer blender and crop protection product distributor, we will continue our mission to further advance Florida agriculture. For questions -or concerns about your farm or pasture, contact us and one of our team will be in touch.