Groundwater gets contaminated primarily when human-made pollutants seep into it, rendering it unsafe for use.
Understanding Groundwater Contamination
Groundwater is a vital natural resource, serving as one of our most important sources of water, particularly for irrigation. Despite its significance, groundwater is unfortunately susceptible to various pollutants.
As per the reference, groundwater contamination occurs when man-made products such as gasoline, oil, road salts and chemicals get into the groundwater and cause it to become unsafe and unfit for human use. These contaminants can seep through the soil and rock layers, eventually reaching the underground aquifers that store groundwater.
Key Sources of Groundwater Pollutants
The array of man-made products that can contaminate groundwater is diverse. Understanding these sources is crucial for prevention.
Common contaminants and their origins include:
- Gasoline: Often from leaking underground storage tanks (LUSTs) at gas stations, fuel spills, or improper disposal of petroleum products. Components like benzene and MTBE are particularly problematic.
- Oil: This includes motor oil from vehicle maintenance, industrial lubricants, and spills from transportation or storage facilities. Improper dumping into storm drains or on the ground can lead to infiltration.
- Road Salts: Primarily sodium chloride or calcium chloride used for de-icing roads in colder climates. These salts dissolve in meltwater and runoff, eventually percolating into the groundwater, increasing its salinity.
- Chemicals: This is a broad category encompassing numerous substances, such as:
- Pesticides and Herbicides: Used in agriculture and residential landscaping, these can leach from treated soils into the groundwater.
- Industrial Solvents: Released from manufacturing processes, dry cleaning operations, or improper waste disposal. Examples include trichloroethylene (TCE) and perchloroethylene (PCE).
- Household Hazardous Waste: Items like paints, cleaning agents, batteries, and pharmaceuticals improperly disposed of can leach harmful substances.
- Landfill Leachate: Liquids that seep through waste in landfills can pick up toxic chemicals and heavy metals, carrying them into the groundwater.
- Septic System Effluent: Failing or improperly maintained septic systems can release nitrates, bacteria, and viruses into the ground.
Why Contaminated Groundwater is a Concern
When groundwater becomes contaminated, its quality deteriorates significantly. This renders it unsafe and unfit for human use, impacting its suitability for drinking water supplies, agricultural irrigation, and industrial processes. The presence of pollutants can pose serious health risks to humans and animals, and negatively affect ecosystems dependent on groundwater.
