DTSC and CEQA Documents ... 75 Hawthorne Street ... (Sodium Reactor Experiment and SNAP). The ... Environmental

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  • VOLUME 3

    Interim Measures Workplan for Soil Cleanup :

    DTSC and CEQA Document s

    Former Sodium Disposal Facility Santa Susana Field Laboratory

    Assembled For :

    Rocketdyne Propulsion and Power Boeing North American, Inc .

    6633 Canoga Avenue Canoga Park, California 9130 9

    IT ,A Memher of The IT Group

    Assembled By :

    IT Corporation 650 Sierra Madre Villa, Suite 204

    Pasadena, California 9110 7

    March 17, 2000



    Appendix L DTSC Approval Letter and Response Comments

    Appendix M CEQA Initial Study

    Appendix N CEQA Notice of Determination and Mitigated Negative Declaratio n

  • 91B-2-99


  • Appendix L

    DTSC Approval Letter and Response to Comments


  • Winston H. Hickox Agency Secreta ry California Environmental

    Protection Agency

    1 1

    Department of Toxic Substances Contro l

    Edwin F . Lowry, Director 10151 Croydon Way, Suite 3

    Sacramento , California 95827-2106

    December 14, 1999

    Mr. David W. Dassler Environmental Remediation Rocketdyne Propulsion & Power 6633 Canoga Avenu e Post Office Box 7922 Canoga Park , California 91309-7922

    D.w Dp st- R

    DEC 161999


    Dear Mr. Dassler :

    Gray Davis Governo r

    The California Environmental Protection Agency, Department of Toxic Substances Control (DTSC) has made a decision to approve the Interim Measures Workplan for the Former Sodium Disposal Facility (FSDF) located in the west end of the Santa Susana Field Laboratory, Simi Hills, California .

    On July 20, 1999, DTSC issued a public notice to request public comments on the Draft Interim Measures Workplan dated July 9, 1999 and the Draft Mitigated Negative Declaration for the FSDF . The public comment period was open throug h August 19 , 1999 . A public hearing was held on July 28 , 1999 , at the Radisson Hotel Simi Valley, to receive oral and wri tten comments for the record. Comments received during the public comment period were considered before DTSC made its approval decision . DTSC has prepared a Response to Comments document which contains DTSC 's responses to the comments received on both the Interim Measures Workplan and the Draft Mitigated Negative Declaration .

    After considering the comments received, DTSC made changes to the Draft Interim Measures Workplan. These changes are outlined in Attachment A, and shall be incorporated into the final Interim Measures Workplan . A copy of the Response to Comments document is enclosed for your records . You may instruct your contractor to begin activities .

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    Printed on Recycled Paper


  • Mr. David W. Dassler December 14, 1999 Page 2

    If excavation activities are to proceed during the upcoming winter season , an HOPE liner cover must be maintained as a contingency. Existing emergency controls in place to remove water which collects on or beneath the HOPE liner during rain events shall be continued until the clay backfill cover is installed and the interim measu res project is complete . During rainfall events , the excavation activities will cease and the impoundments covered with the HDPE liner to minimize possible spread of contaminants . You are required to provide DTSC with a schedule of activities identifying the tasks and the dates of field activities one week prior to commencing with any excavation or removal activities .

    As you are aware, DTSC would like to proceed with completion of characterization for the FSDF as expeditiously as possible . Prior to backfilling the excavation and no later than 60 days from the date of this letter, please submit an Infiltration Monitoring Workplan to DTSC for review. The infiltration monitoring probes should be capable of evaluating moisture infiltration rates through the backfill soils . Please submit an RFI workplan for contaminant characterization (including characterization of the,vadose zone) no later than 120 days from the date of this letter .

    A copy of the final administrative record for the Interim Measures Workplan approval is available for review at our Glendale Office.

    If you have any questions , please feel free to contact Gerard Abrams at (916) 255-3600.


    James M. Pappas , P.E., Chief Land Disposal Branch Hazardous Waste Management Progra m

    Enclosure s

    cc: Mr. Joe Lyou (w 3 copies) Executive Director Rocketdyne Cleanup Coalition do Committee to Bridge the Gap 1637 Butler Avenue , Suite 203 Los Angeles, California 90025

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  • • Mr. David W . DasslerDecember 14, 1999 Page 3


    cc: Ms . Kim Rener (w 1 copy) The Boeing Company, Rocketdyne 6633 Canoga Avenue Post Office Box 7922 Canoga Park, California 91309-7922

    Mr. Tom Kelly, Project Manager (w 1 copy) U.S. Environmental Protection Agency Waste Management Division 75 Hawthorne Stree t San Francisco, California 94105

    Mr. Roger Lupo (w 1 copy) Radiologic Health Branch 601 N. 7th Street (MS 178) Sacramento , California 9581 4

    Mr. Mike Lopez (w 1 copy) Oakland Operations Office 1301 Clay Street, N825 Oakland , California 9461 2

    Mr. Steve Cain (w 1 copy) Public Participatio n Department of Toxic Substances Control 1011 N. Grandview Avenu e Glendale, California 9120 1

    Mr. T.R. Hathaway (w 1 copy) Human & Ecologic Risk Division Department of Toxic Substances Control 301 Capital Mall, 3rd Floo r Sacramento , California 9581 3

    Mr. Gerard Abrams (w 1 copy ) Senior Hazardous Substances Engineering Geologist Land Disposal Branc h Department .of Toxic Substances Control 10151 Croydon Way, Suite 3 Sacramento, California 95827-2106

  • • Mr. David W. DasslerDecember 14, 1999 Page 4

    cc: Glendale File Room (w 2 copies) do Mr. Stephen Baxter Senior Hazardous Substances Engineer Department of Toxic Substances Control 1011 North Grandview Avenue Glendale, California 9120 1



    1 . Section 1 . 1 .4 will be modified as follows :

    CEQA compliance has been reviewed by DTSC and a Mitigated Negative Declaration finding made for this Interim Measure

    2. Section 4.1 .3.3 . 2 (paragraph 4) will be modified as follows :

    One randomly located documentation sample will be collected on each sample grid (established in the FSDF Characterization Report, refer to Section 2.1.3 and Figure 3-1 of this workplan ) from the scarified bedrock of the excavation bo ttom. If field conditions warrant or if directed by a DT geologist biased sample will be collected at locations of staining or obse rvable signs of contamination Bedrock samples will be taken using a clean steel hammer to extract chips from the bedrock surface . The bedrock samples will be placed in clean containers provided by the laboratory.

    3. Section 4.1 .3.3.3 Sampling and Analysis Procedures - Waste Characterization, Paragraph 1, will be modified as follows :

    Soils will be collected from the excavator bucket during bin loading by driving the stainless steel sampling sleeve directly into the soil. The sampling sleeve will then be retrieved, capped, and labeled. A scoop must not be used to transfer the soil from the excavator bucket into the sampling sleeve .

    4.. Section 4 .3.3.1 .2 Identification and Testing of Backfill Sources, will be modified to include the following statement :

    If it becomes necessa ry to import backfill soil, the imported soil must be of similar soil type to the onsite borrow source soils , and meet or exceed the permeability specifications of 4 x 10~ cm /s when compacted to 90 percent.

    5. Section .4 Backfi ll Placement and Grading , Paragraph 2, will be modified as follows:

    Soil will be placed and compacted within 2 percent of optimum moisture content, to meet 4x10-0 cm/s permeability.

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    6. Section .3 Backfill Placement Inspection and Testing , Paragraph 2, will be modified as follows:

    At a minimum . 3 density and moisture content tests will be performed per 6-inch lift in the lower ball materials .

    The compacted backfill will be tested to assess in-situ permeability, following installation and compaction of the low permeability backfill .

    7. During excavation and backfilling activities , the following dust control measures shall be observed, as requested by the Ventura County Air Pollution Control Board in a le tter dated August 24, 1999:

    (a) All clearing, grading , earth moving , or excavation activities shall cease during periods of high winds ( i .e ., greater than 15 miles per hour averaged over one hour) to prevent excessive amounts of fugitive dust.

    (b) All trucks that will haul excavated or graded material off-site shall comply with State Vehicle Code Section 23114 regarding the prevention of such material spilling onto public streets and roads.

    (c) All unpaved on-site roads shall be periodically watered or treated with environmentally-safe dust suppressants to prevent excessive