Operable Unit IV Five-Year Review Released

September 2003


The purpose of a Five-Year Review is to determine whether the remedies agreed upon in a Record of Decision remain protective of human health and the environment. The methods, findings, and conclusions of the review are documented in Five-Year Review Reports. The reports identify issues found during the review and identify recommendations to address them.

Operable Unit IV Five-Year Review

The OU IV Five-Year Review, released on September 18, 2003, was BNL's first Five-Year Review under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA).

The remedy for OU IV included treatment of chemically contaminated soil using soil vapor extraction, an interim remedy of fencing around the radiologically contaminated soil at the Bldg. 650 Sump and Sump Outfall Area with institutional controls and monitoring, treatment of groundwater containing organic compounds at the most contaminated portion of the 1977 oil/solvent spill area using air sparging and soil vapor extraction, and an engineering enhancement option for groundwater as the air sparging and soil vapor extraction system alone did not achieve the desired performance levels.

Construction of the air sparging and soil vapor extraction system began on June 11, 1997. In October 2000, a petition for system shutdown was submitted to the EPA. The system was shutdown in January 2001 and a system closure petition was approved in July 2003. The contaminated soils at the Bldg. 650 Sump and Sump Outfall were fenced in 1995. The contaminated Sump Outfall pipeline was excavated in June 2002.

The Five-Year Review found that the remedies for the soil and groundwater were constructed and implemented in accordance with the OU IV Record of Decision, have functioned as designed, and the threats have been addressed.

Documents / Links

OU IV Five-Year Review