Sanace bývalé sovětské základny Hradčany

Remedial Action at Former Soviet Air Base Hradcany

The former Hradcany Air Base was used by the Soviet Army as a military airport for 22 years. The Soviets left behind extensive petroleum hydrocarbon contamination in soil and groundwater. The site lies within the Bohemian Cretaceous Basin, an important source of high quality groundwater in the Czech Republic. Groundwater is the only source of drinking water in region. The contaminated area extends over 30 hectares (74 acres). An estimated 400,000 cubic yards of soil was impacted, containing an estimated 8.8 million pounds of jet fuel. The presence of extensive contamination limits the future use of groundwater and the revitalization of the site.

A combination of several cleanup technologies is being used at the site. The first stage employs soil vapor extraction (SVE) and vacuum assisted LNAPL recovery. Some limited groundwater pumping is being conducted to facilitate more efficient LNAPL recovery. The second stage enhances conditions for in-situ aerobic biodegradation. The remedial system is expanded to include air sparging, and nutrient amendment to maximize biodegradation. When the effectiveness of SVE decreases, as the volatile portion of the plume is remediated, the SVE system will be switched to injection mode. The progress and efficiency of the remediation systems will be evaluated continuously.

This site cleanup has evolved into what may be the largest in-situ remediation project in the world. The air sparging system is operated over a 25 hectares (62 acre) area. There are 1,240 SVE wells, 1,350 air sparging wells, 180 dual-phase extraction wells, and 12 groundwater extraction wells. The cleanup is projected to be completed in 2008 with a total anticipated cost of US $9.3 million.

• Remediation design and engineering studies
• Remediation construction
• Remediation system operation, maintenance, and optimization

ZDROJ: www.earthtech.com