EPA Documents

For additional information about the EPA radiological study click here.

EPA Hazard Ranking

EPA Building Survey

2007 EPA Superfund Evaluation of SSFL

On October 10, 2008, DOE recommended to EPA that SSFL be listed on the National Priorities List .

On December 6, 2007, EPA announced its recommendation to list SSFL on the National Priorities List.

In July, 2007, EPA provided additional information on its plans for a Superfund Evaluation of SSFL.

On April 12, 2007 the U.S. Environmental Protection Agency (EPA) announced that is will conduct a third Superfund Evaluation of the Santa Susana Field Laboratory (SSFL), including the site of the DOE operations in Area IV.

The Preliminary Assessment (PA)/Site Inspection (SI) is used by EPA to evaluate the potential for a release of hazardous substances from the site.  During the site assessment process, EOA collects data to identify, evaluate and rank hazardous waste sites based on specific criteria.

The Hazard Ranking System (HRS) is a numerically based screening system that uses information from the initial, limited investigations (PA/SI) to assess the relative potential of sites to pose a threat to human health or the environment.  The HRS score determines the eligibility for placing the site on the National Priorities list (NPL or Superfund).  The PA/SI for SSFL is expected to be completed by the end of 2007.  The results of the investigation will be made available to the public at the Simi Valley Library or upon request from the EPA.

In the past EPA has evaluated different areas of SSFL.  This is the first time that EPA investigated the entire “footprint” of the SSFL. 

2003 EPA Superfund Evaluation of SSFL

In December 2003, EPA issued its Hazard Ranking System (HRS) Assessment of Area IV of SSFL. The EPA's conclusion was that Area IV of SSFL did not rank high enough to be listed on the National Priorities List (NPL) or to be a CERCLA (Superfund) site.

This process determines whether site hazards qualify the site for placement on the National Priorities List (NPL) or the Superfund list and whether federal response is required. EPA determined that "Further remedial site assessment under CERCLA (Superfund) is not required because...the site does not qualify for further remedial site assessment under CERCLA (No further remedial action planned - NFRAP)"

EPA's rationale for these determinations were that:

  1. "Radionuclides associated with historic area IV research are not present at concentrations significantly above background in the soils surrounding residential communities"
  2. "No annual exposures measured are above the Nuclear Regulatory Commission annual dose limit to the general public"
  3. "The outfalls draining Area IV were in full compliance with the regulations established by the National Pollution Discharge Elimination System (NPDES)"
  4. "None of the concentrations of tritium [in groundwater] exceed the USEPA maximum contaminant level"

In order to qualify for listing as a CERCLA (Superfund) site, the HRS has to assign a hazard rank measure of greater than 25. Typical Superfund sites have hazard ranking measures of 50. Area IV of SSFL ranked at 1.08. For more information, read the EPA fact sheet about their assessment.