Groundwater is an essential natural resource for drinking water, food, industrial processes, and recharging lakes, rivers, and wetlands. Groundwater is found under the Earth’s surface in rocks, soils, cracks and pores. Nearly 99% of the U.S. rural population uses groundwater as a source of drinking water. Contaminated groundwater is nearly always caused by man-made products such as paints, disinfectants, solvents, and gasoline. There are four major ways groundwater is contaminated.
1. Surface Contamination: Surface water such as rivers and ponds slowly infiltrate groundwater through the soil. If the surface water has contaminates, the contaminates will leach into the soil. Eventually hazardous pollutants will reach the aquifer and create a toxic industrial waste plume.
Agriculture: Chemicals such as pesticides and fertilizers can have a lasting effect on crop production, wildlife, and drinking water. The chemicals that are commonly used at golf courses or large farms will stay in the ground for years. Rainfall will dilute the chemicals; However, they will also help the chemicals to penetrate deeper into the ground reaching the aquifer.
Industrial: Surface impoundments and chemical spills/releases are typical at industrial facilities. It is not uncommon for above storage tanks to spill or leak. This is why it is important to have adequate barriers in place to protect against spills running into soil or corroded sewer systems. Surface impoundments at petrochemical facilities often contain hazardous wastes that if they are not lined correctly can leak to surface waters and soil nearby.
Mining: Industrial activities such as mining and metallurgy will lead to metal contamination in waterways such as lead, cadmium, and chromium. There are four types of mining impacts: Acid Rock Drainage, Heavy Metal Contamination & Leaching, Processing Chemicals, and Erosion and Sedimentation.
Natural Sources: Naturally occurring substances such as sulfates, iron, fluorides, and arsenic are found in water. The types and concentrations of natural impurities depends on water temperature, air temperature, pH, dissolved oxygen, flow conditions, and numerous others.
2. Subsurface Contamination: Groundwater contamination can occur from buried sources such as septic systems leaky sewers.
Underground Equipment: Equipment such as underground storage tanks (USTs) and piping can have toxic leaking chemicals and corrosion seep into the ground.
3. Landfill & Waste Disposal: There are municipal and industrial waste landfills that have different regulations on what can be disposed in them. Many times, chemicals that should be disposed of in hazardous waste landfills are not and contaminate municipal landfills.
Landfills: Typically landfills have a barrier (clay liner) between garbage and the ground which the landfill is built into or on. However, this barrier has been known to crack allowing the garbage containing contaminates such as battery acid, paint, and other cleaners to leak into the ground. The leachate from the chemicals are often considered to be hazardous mixtures that will pollute the groundwater.
Waste Disposal: Hazardous waste shall be disposed of by a licensed hazardous waste handler.
4. Atmospheric Contamination: Also known as atmospheric deposition is when water becomes contaminated due to air pollution.
Acid Rain: When nitrogen oxides and sulfur dioxide react in the atmosphere they create acids. These acidic compounds can take the form of rain, sleet, hail, snow, or dust. The effects of acid rain affects forests and plants, wildlife, surface waters, and humans.
Damaging effects of groundwater pollution vary from health issues, economic impact, and devastating changes to our ecosystem. Through proper regulations, filtration systems, management of disposing materials, and maintenance of equipment we can work to reduce negative impact on groundwater contamination.
|Contaminant||Source||Potential Hydrosil Remediation|
|Ammonia||Agriculture, Industrial Activities, Naturally||HS-100|
|Arsenic||Mining, Naturally, Industrial Activities||HS-AS|
|Cadmium||Mining, Industrial Activities||HS-MT|
|Chloride||Drinking Water, Industrial Activities||HS-AC|
|Chromium||Mining, Industrial Activities||HS-MT|
|Color||Industrial Activities, Naturally||HS-AC|
|Copper||Mining, Industrial Activities||HS-MT|
|Cyanide||Agriculture, Industrial Activities||HS-300|
|Fluoride||Naturally, Industrial Activities||HS-F|
|Fats/Oils/Greases (FOG)||Industrial Activities||HS-200|
|Iron||Naturally, Industrial Applications||HS-200|
|Lead||Naturally, Industrial Applications||HS-MT|
|Nickel||Naturally, Industrial Applications||HS-MT|
|Nitrate||Naturally, Agriculture, Industrial Activities||HS-300|
|Sulfate||Naturally, Agriculture, Industrial Activities||HS-300|
|Thallium||Naturally, Industrial Applications||HS-MT|
|Volatile Organic Compounds (VOC)||Industrial Applications, Agriculture||HS-AC , HS-600|
|Zinc||Naturally, Industrial Applications||HS-MT|