Addressing Groundwater ...

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Addressing Groundwater Contamination

Dear Sivakumar,

The issue is complicated, and goes beyond treatment.

First, as one responder noted, you first have to remove the source(s) for the contamination.  Often, the sources are not all known or easily identified (e.g., leaking underground storage tanks, buried leaking fuel lines, etc.).  Removing the source may also include removing large volumes of soil saturated with the hydrocarbon contamination, which acts as a continuous source of release.  Without removing the source(s), there will be a continuous introduction of contamination into groundwater, which will require an indefinite period for water treatment. 

One must also attempt to delineate the extent of the groundwater contamination, as it will migrate and spread over time, potentially affecting more wells.  Due to hydraulic stresses, drinking water wells can affect groundwater flow patterns, particularly if they pump fairly large volumes of water, for example, a community production well(s) or irrigation well(s).  Thus, they can draw the contamination into their flow path, ultimately contaminating the well(s).

Without proper delineation of the groundwater contamination plume, it will be difficult to prevent it's continued impact without an active form of recovery; for example, "capture wells" that actively pump along the downgradient fringe of the plume (and or in the source areas) to prevent its continued movement.  

Of course you can install treatment on the wells that are being used. 

A few quick points.

One respondent wisely noted that there could be other contaminants.  That is a valid point, and a chemical analysis that includes metals and other potential contaminants should be performed.  And of course if there are multiple sources, each may have different contaminants. 

Fortunately, unlike chlorinated solvents, hydrocarbon contaminants often degrade with time and distance from the source.   However, in your case, it appears that the contamination has reached potable wells, so this "natural remediation" is not a feasible alternative. 

As far as different types of remediation technologies, you might visit the following U.S. EPA website for more information, specific to contaminant types and technologies.

http://www.epa.gov/superfund/remedytech/remed.htm