One common question we receive about using lawn chemicals, both organic and traditional, is how it may or may not affect groundwater when there is an aquifer/well system present. While most chemicals used in modern lawn care have very low leaching properties, there are some properties unique to each lawn that need to be considered when applying any amendment to your soil.
Read The Label!
Prior to mixing and applying any chemical to your lawn, it is paramount that you read and understand the label that is included with any and all EPA registered pesticides. Not doing so is not only important for your safety, it helps prevent contamination of areas outside your lawn, and is legally required.
The label will include information on the product’s chemical properties, specific dangers and warnings, and required personal protective equipment to use while working with the product. There also may be a special “Environmental Hazards” section. In this section you will find any applicable information about the chemical’s soil permeability, which we will discuss next, and it’s risk for groundwater contamination.
For more information on pesticide labeling visit the EPA website here: https://www.epa.gov/pesticide-registration/labeling-requirements
Assess and Understand Your Soil’s Structure & Condition.
In the Northeast we have certain conditions, especially high amounts of slate and limestone layers, that can make our soil uniquely tight structured and acidic. The “permeability” refers to the ability of water and chemicals to move through the soil and leach towards the water table. Several factors affect the permeability of soil. Making smart decisions on protecting your groundwater from contamination, you should understand the properties of your particular soil.
Soils are mostly separated into two classifications of makeup, Sandy soils are loosely structured and allow for easy flow of water, oxygen, and nutrients. Clay soil is tightly compacted and holds water and nutrients much longer than sandy soils. A good mixture of these two styles of soil will offer a good blend of permeability and leaching resistance. Clay that is overly compacted can cause other issues unrelated to water contamination