Phytoremediation Helps Clean Contamination in Murdock, Nebraska

In May, 2005, AGEM scientists finished planting more than 2000 trees along a creek tributary as part of an integrated remedial design to remove carbon tetrachloride contamination from the water in Murdock, Nebraska. Residents get clean drinking water from a rural water district, but contamination in the groundwater was moving under the town and into a creek tributary.

	Omaha World-Herald, July 25, 2005: Science lets nature aid in toxin cleanup
	Nebraska Public Radio broadcast with AGEM geologist Lorraine LaFreniere discussing the Murdock project.

The problem: Grain fumigation in the 1950s and 1960s at a former storage facility in Murdock, Nebraska, resulted in carbon tetrachloride contamination of groundwater and surface water at levels exceeding regulatory limits. Subsurface contamination near the former storage facility extends to a depth of approximately 75 feet. The contaminant plume in the aquifer is moving under the town and adjacent fields and into a creek tributary, where it comes to the surface and poses a potential threat to human health.

The solution: Our integrated remediation approach was designed with the aid of computer simulation. The approach protects human health while it cleans up the aquifer through two major strategies:

Groundwater pumping and treatment with a modified spray irrigation system near the source (where the aquifer is deep).

• Treated water is used to irrigate school athletic fields.
• Seasonal operation is anticipated for about 30 years.

Phytoremediation system downstream (where the aquifer is near the surface).

• Includes:
  • More than 2000 planted trees, both shallow-rooted willows and poplars and deeper-rooted species including ash,
  • A surface vegetation cover of native herbaceous plants to capture surface runoff and maximize groundwater uptake by the trees, and
  • Constructed wetlands in the tributary headwaters for additional polishing of contaminated water and to contain and treat flow from major precipitation events.
• Augments natural plant uptake and degradation of carbon tetrachloride.
• Improves surface water quality.

Added benefits: In addition to cleaning up the contaminant plume, the proposed plan will

• Enhance the aesthetics of the area,
• Improve wildlife habitat near the tributary creek, and
• Offer recreational opportunities for property owners and the community.

More Murdock Images...

Our sponsor: This work is supported by the Commodity Credit Corporation of the U.S. Department of Agriculture.