Contamination of groundwater sources poses serious consequences in the future, especially in light of increasing droughts, which is placing more pressure on dwindling water resources that we direly need to protect at all costs.

A recent report titled 'Alternatives for Managing the Nation's Complex Contaminated Groundwater Sites', commissioned by the National Research Council, revealed that groundwater at more than 126,000 sites around the U.S. is contaminated. These sites are all in need of remediation, with 10% of the contaminated sites being classified as ''complex'', and which were unlikely to be remediated for at least another 50 to 100 years.

The estimated cost of remediating these contaminated sites is over $110 billion, according to the report, and does not take technical problems associated with rehabilitation of ''complex'' sites into account, or the rehabilitation of groundwater at sites that may become contaminated in the future. The U.S. Government has initiated a series of groundwater cleanup programs at both state and national level focusing on reducing the environmental and health risks associated with groundwater contamination. Some of the areas that have been addressed include cleanup of Superfund sites; environmental remediation of sites where hazardous waste is stored, treated, or disposed of; remediation of areas contaminated by leaks from damaged underground storage tanks; as well as remediation of government and military facilities, and industrial operations.

credit: Ryan Griffis - https://www.flickr.com/photos/grifray/3623554655/

It is estimated that about 3.4% of the active cleanup sites are sites that fall under the jurisdiction of the U.S. Department of Defense, who have already spent $30 billion to remediate their sites of hazardous waste. However, many of their sites pose the highest challenges both in terms of technology needed and costs associated with successful cleanup operations and remediation efforts.

"The complete removal of contaminants from groundwater at possibly thousands of complex sites in the U.S. is unlikely, and no technology innovations appear in the near time horizon that could overcome the challenges of restoring contaminated groundwater to drinking water standards," said Michael Kavanaugh, from Geosyntec Consultants, Inc. and chair of the committee that produced the report. "At many of these complex sites, a point of diminishing returns will often occur as contaminants in groundwater remain stalled at levels above drinking water standards despite continued active remedial efforts. We are recommending a formal evaluation be made at the appropriate time in the life cycle of a site to decide whether to transition the sites to active or passive long-term management."

Taxpayers will foot a large portion of the cleanup bill, as many of the sites that are considered ''complex'' are on public land, or fall under the jurisdiction of government agencies. The terminology used in cleanup operations is often misleading, as very often closed sites still have levels of contamination that require monitoring and management well into the future, as well as funding to do so. Half of the Superfund sites that have been removed from the list still require ongoing monitoring, evaluation and management of contaminated groundwater according to the report, which recommends that the different phases in the cleanup process together with progress reports should be clearly defined to increase public and stakeholder awareness. According to Kavanaugh:

"The central theme of this report is how the nation should deal with those sites where residual contamination will remain above levels needed to achieve restoration. In the opinion of the committee, this finding needs to inform decision making at these complex sites, including a more comprehensive use of risk assessment methods, and support for a national research and development program that leads to innovative tools to ensure protectiveness where residual contamination persists. In all cases, the final end state of these sites has to be protective of human health and the environment consistent with the existing legal framework, but a more rapid transition will reduce life-cycle costs. Some residual contamination will persist at these sites and future national strategies need to account for this fact."

In the event of a major storm or natural disaster, this can lead to further problems. For example, in the wake of Hurricane Sandy affected residents were not only exposed to flaking paint from damaged homes, putting them and especially their children at risk of lead poisoning; lead dust from contaminated Superfund sites was washed off site by storm surge or blown off site by strong winds. When disturbed, these highly toxic contaminants pose a risk wherever they settle, both on the soil surface, and to groundwater sources below the soil.

This clearly illustrates the importance of remediating contaminated sites to prevent the contaminants from migrating offsite, where they are far more difficult, if not impossible, to manage. If you know or suspect your are being exposed to such water, a system like a Berkey water filter can filter out contaminants from these affected sources.

Further Reading: National Research Council. Alternatives for Managing the Nation's Complex Contaminated Groundwater Sites. Washington, DC: The National Academies Press, 2013. doi:10.17226/14668.