Groundwater is water occurring in the zone of saturation in an aquifer or soil. Water beneath the surface of the earth which saturates the pores and fractures of sand, gravel, and rock formations.
Groundwater begins as precipitation that is absorbed into the ground. Much of the precipitation is taken up by plant roots and evapotranspired. What makes it beyond to root zone is pulled down by gravity until it reaches the water table. Below the water table all the pore space in the soil is filled with water. This is the saturated zone.
There are three basic types of contaminants. They are microorganisms, inorganic chemicals, and organic chemicals.
Microorganism contaminants include bacteria (i.e. E. coli and Salmonella), viruses, protozoa (i.e. Cryptosporidium and Giardia lamblia) and parasites. They are usually just a concern for shallow wells as the soil does a fairly good job of trapping them.
Inorganic chemicals are chemicals such as nitrate, arsenic, and metals. Many of these chemicals are found naturally in the soil and are not in high enough concentrations to cause harm. Public Water Supplies are required to monitor for them. Many land uses can increase their concentrations. For example, applying too much fertilizer can increase the amount of nitrate in the groundwater. Intake of water high in nitrates can cause methemoglobinemia (blue baby syndrome) in infants, which reduces the blood's ability to carry oxygen. If left untreated it can be fatal.
Organic chemicals include pollutants such as fuels, solvents, and pesticides. It only takes a small amount of these chemicals to cause health concerns. These chemicals have a tendency to do one of three things when they come into contact with water. How they react is based on their physical and chemical properties.
As groundwater infiltrates the soil, it can pick up contaminants from the surface of the ground or from the surrounding soil. The water may dissolve the contaminant or just carry it in to the aquifer. Some contaminants can be transported great distances from their source. Groundwater travels very slowly; therefore, little dilution or dispersion of the contaminant usually occurs. The contaminant forms a concentrated plume that follows the groundwater flow path.
A Wellhead Protection Area (WHPA) is a geographically designated surface and subsurface area surrounding a water well or well field, supplying a Public Water System, through which contaminants are reasonably likely to move toward and reach such water well or well field. This is an area where groundwater protection is emphasized. A WHPA includes at least the delineated capture zone area, but could be influenced by other factors such as existing land use and zoning, site and facility identification and location, political boundaries, natural features, and environmentally sensitive areas.
Groundwater protection begins at home. The way you dispose of the products you use can contribute to the contamination of your community's groundwater. Products like motor oil, pesticides, leftover paints or paint cans, weed killers, household cleaners, flea collars, mothballs, and a number of medicines contain materials that can be harmful to groundwater. The average American gets rid of approximately one pound of this type of waste each year. This may seem inconsequential but it is quite large when you multiply it by the number of people in your community. Here are some tips for wisely managing household hazardous waste:
If you think you cannot have a positive influence on the environment, you need to reconsider. The right choices can reduce waste, save money, maximize resources, and protect the environment. The choices you make can and do make a big difference.