Santa Susana

Groundwater and Soil

RCRA Facility Investigation

A RCRA Facility Investigation (RFI) is a detailed investigation to determine the nature, extent, and migration rate of a release of hazardous waste or hazardous constituents, and to provide the information necessary to develop a strategy for cleanup.

The 135 Solid Waste Management Units (SWMUs)/Areas of Concern (AOCs) have been grouped by location into 57 RFI "Sites" as shown on the map. RFI Site configurations and boundaries have changed over time based on in-depth review of historical documents and/or sampling data. The 57 RFI Sites have been grouped into 11 RFI reporting groups (see map).

Surficial Media Operable Unit Investigation

As of April 2008, 3 RFI Group reports for the Surficial Media Operable Unit (SMOU) have been submitted to the Department of Toxic Substances Control (DTSC) for review and public comment:

These reports discuss, in detail, the Group's physical setting, site history and chemical use, the nature and extent of the chemicals found, the fate and transport of these chemicals in the environment, an assessment of risk to humans and ecological receptors (e.g., plants, reptiles, birds, mammals, etc.), and recommendations for cleanup, as necessary and appropriate. An RFI must determine if No Further Action is justified or if a Corrective Measures Study (CMS) is required. This determination can be made for the entire Group or by individual area, SWMU, or AOC within the Group. The remaining RFI reports for surficial media will continue to be submitted to DTSC for review and public comment with the anticipated completion date of 2011 (see schedule).

Chatsworth Formation Operable Unit Investigation

The Santa Susana Field Laboratory (SSFL) is concurrently conducting a Chatsworth formation Operable Unit (CFOU) RFI under the direction of a panel of three of the world's leading experts in contaminant hydrogeology of fractured sedimentary rock -- Dr. John Cherry, Dr. David McWhorter and Dr. Beth Parker. Under their direction, the groundwater characterization program applies both conventional and advanced investigation methods, some of which are being pioneered at Santa Susana. The data being collected for groundwater characterization, which include groundwater sampling, seep and spring sampling, and extensive chemical and geotechnical analysis of bedrock core samples, are believed to be the most comprehensive dataset for any site anywhere in the world. The CFOU RFI report is scheduled to be submitted to DTSC for review and public comment in September 2009 (see schedule).