Groundwater Remediation Techniques

Protecting our food and water supplies from pollutants is a vital modern concern. In some cases, proper protection means reversing accumulated environmental damage, or taking extra steps to stop damage from occurring. Groundwater remediation is one method employed for this task. It is the process of removing environmental contaminants from drinking water, or preventing them from reaching drinking sources at all. Techniques for remediation are both well-established and effective.

Potential Sources of Contamination

• Groundwater remediation begins with finding any sources of possible contamination. If you are looking to safeguard your water source, identify any landfills, gas stations, fuel storage centers or chemical plants that might be in your area. Learn as much as you can about substances that might be released from these facilities. Different chemicals pose different sorts of risks, and some are more likely than others to affect groundwater. Be aware that certain substances, such as gasoline, are highly complex, and fully assessing your risk may involve doing a considerable amount of self-education. Take advantage of your local library for research and contact any local agencies with responsibility for cataloging and tracking potential contaminants.

  While public water sources are subject to extensive federal regulations, private wells are not. If you use a private well, you are your own best protection against contamination. Make sure to get your water tested regularly by a properly certified testing service.

If Contamination Is Found

• If contamination is found, or if the threat of contamination is imminent, remediation enters its next phase. If at all possible, the source of the problem should be removed. If you own a resource that is leaking into groundwater--whether it's an on-site storage tank or a separate facility--you may have legal responsibility for removal. In addition to removing any leaky tanks or other structures, you may need to remove a significant amount of contaminated soil.

Treatment Techniques

• The next step is dealing with the groundwater itself. You will want to hire professionally trained and certified technicians to handle these operations. Depending on the severity and scale of the contamination, removal operations can be lengthy, extensive and costly. According to local conditions, there are different removal technologies that may be useful. Examples include the following.

  Pump-and-treat methods involve pumping groundwater to an above-ground treatment facility, removing any toxins and releasing the cleansed water at or near the surface. Over time, the water will work its way back down through the soil.

  Hydraulic containment involves pumping water from an aquifer in a way that effectively isolates contaminated water from any wells used for drinking or agriculture.

  Air sparging involves forcing compressed air into groundwater. Once injected, the air rises, forcing contaminants to form a vapor layer above the groundwater. The vapor is then removed.

  Permeable reactive barriers are trenches backfilled with decontaminating materials like activated carbon or iron filings. Groundwater flows through these trenches, where its contaminants are purged.

  Consult federal, state and local authorities to clarify requirements for removing groundwater contaminants in your area.