Sources of Potential Groundwater Contamination

In comparison with rivers or streams, groundwater tends to move very slowly and with very little turbulence. Therefore, once a contaminant reaches the groundwater, little dilution or dispersion normally occurs. Instead, the contaminant forms a concentrated plume that can flow along the same path as the groundwater. Among the factors that determine the size, form, and rate of movement of the contaminant plume are the amount and type of contaminant and the speed of groundwater movement. Because groundwater is hidden from view, contamination can go undetected for years until it is detected in a water supply well. The table below list examples of sources of potential groundwater contamination.

Ground Surface

  • Infiltration of polluted surface water
  • Land disposal of wastes
  • Stockpiles
  • Dumps
  • Sewage sludge disposal
  • Animal feedlots
  • Fertilizers & pesticides
  • Accidental spills
  • Wastewater discharges
  • Chemical storage areas
  • Above ground storage tanks

Above Water Table

  • Septic tanks, cesspools & privies
  • Holding ponds & lagoons
  • Sanitary landfills
  • Land Application of Wastes
  • Underground storage tank leaks
  • Underground pipeline leaks
  • Artificial recharge
  • Sumps and dry wells
  • Graveyards

Below Water Table

  • Underground storage tank leaks
  • Improperly abandoned wells
  • Improperly constructed wells