Filtering Terms

• Water testing terms related to filters and the filtering process include "absolute," which is the micron rating of the filter on the water supply. This rating indicates the specific particle size that will be trapped or filtered out of your water supply. Advanced water treatment or tertiary treatment is the filtering of at least 85 percent of pollutants in a water supply. You may see the term "maximum contaminant level," or MCL, which refers to the highest allowable level of a specific contaminant, most often in a public water supply. These standards are set by the U.S. Environmental Protection Agency.
  
  

Common Pollutant Terms

• Common water testing terms include "organic chemicals" or compounds such as coliform bacteria, nitrates, nitrites, fluoride, chloride, sulfate and lead. If your water testing report lists unsafe levels of any of these compounds, you may need to add an advanced water treatment filter to your water system. You may see the term "VOCs," or volatile organic compounds. These include benzene, styrene, toluene, vinyl chloride, trihalomethanes, MTBE and other toxic chemicals. Finding these compounds in your water should raise a red flag, and you should probably not use the water. You will see the concentration stated as "parts per million," or ppm.
  
  

Trace and Heavy Metals

• Your water testing report may list "trace minerals" or "heavy metals." If your water system is near an industrial area, is downstream from an industrial area or was previously an industrial site, you may find trace metals in your water system. These may also be a result of natural deposits. These water testing terms include carcinogenic metals known to increase the risk of cancer. These metals can also cause damage to human organs and changes in blood chemistry. Some of these metals include arsenic, barium, beryllium, cadmium, chromium, mercury, nickel, selenium and thallium.
  
  

Aquifer

• This term refers to an underground body of water that is less likely to have as many contaminates as surface, ground or standing water. However, an aquifer can still have potentially dangerous contaminants, such as bacteria from animal and human feces, if it is near a farm or septic system. Residential wells often tap underground aquifers, so it is imperative to place your well far from the septic system and any animal holding areas.