Memorandum and attached model language documents provide additional guidance on implementing EPA's policy on a potentially responsible party (PRP) performance of the risk assessment component as part of a remedial investigation/feasibility study (RI/FS). OSWER Directive 9835.15a. Issued 7/2/1991.

This supplemental guidance was superseded by the 1/26/1996 revised policy on PRPs performing risk assessments during RI/FS; however, the 1991 model language documents were not attached to the 1996 document and continue to be made publicly available until the model language documents are superseded by new model documents.

Six model language documents were included in the 1991 transmittal package.

• Model RI/FS Administrative Order on Consent (AOC)
• Model Statement of Work (SOW) for RI/FS Conducted by PRPs
• Model SOW for PRP-Conducted RI/FS
• Annotated Model RI/FS AOC
• Annotated Model SOW for RI/FS conducted by PRPs
• Annotated Model SOW for PRP-Conducted RI/FS

The Model AOC for RI/FS (9835.3-1A issued 2/5/1990) - now 9835.3-2A. Model AOC for RI/FS was updated to make changes to sections dealing with risk assessment. Also attached is the Model SOW for RI/FS by PRPs (8335.8 issued 6/2/1989) - now 8335.8a.  The Model SOW/RIFS/PRP was updated to make changes to the sections dealing with risk assessment. 

• Supplemental Guidance on Performing Risk Assessments in Remedial Investigation/Feasibility Studies (RI/FSs) Conducted by Potentially Responsible Parties (PRPs) (PDF)(112 pp, 5 MB)